Patent Publication Number: US-11045922-B2

Title: Surface treatment processing method and surface treatment processing device

Description:
TECHNICAL FIELD 
     An aspect of the invention relates to a surface treatment processing method and a surface treatment processing device. 
     BACKGROUND ART 
     As surface treatment processing, processing by shot processing (hereinafter, simply referred to as “shot processing”) such as shot peening processing (see FIG. 4 in Patent Literature 1 below) and shot blasting processing is known. The shot processing is to process a treatment target by shooting shot media at the treatment target. When the treatment target is processed in this way, a device operation management of monitoring an operation state of a shot processing device or a product management of measuring a surface side state and the like of a treatment target subjected to shot processing is performed order to manage quality. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: Japanese Unexamined Patent Publication No. H5-279816 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, there is also a case in which a desired effect is not given to the treatment target subjected to shot processing due to, for example, an inappropriate treatment target state before shot processing even when the device operation management is appropriately performed. That is, it is not possible to directly manage an actual surface side state and the like of the treatment target subjected to shot processing in the device operation management. In the product management, for example, when a destructive inspection should be performed, a partial inspection is performed instead of a total inspection. Accordingly, it is impossible to manage the processing degree for all products. It can be said that the same applies to the case of inspecting a specimen such as a test sample (see, for example, Patent Literature 1). 
     Also in the case of inspecting the treatment target subjected to shot processing based on an appropriate device operation management, unnecessary shot processing is caused, for example, when a desired effect is not given to the treatment target subjected to shot processing due to the treatment target state before shot processing. 
     In consideration of the above-described circumstances, an aspect of the invention is to obtain a surface treatment processing method and a surface treatment processing device capable of managing a processing degree of all treatment targets subjected to shot processing while suppressing unnecessary shot processing. 
     Solution to Problem 
     A surface treatment processing method according to an aspect of the invention includes: a first inspection step of nondestructively inspecting at least one of a surface side state and an external dimension of a treatment target to be subjected to shot processing of shooting shot media at the treatment target and evaluating that the treatment target is failed when an inspection result is out of a first allowable range predetermined; a condition setting step of setting a shot processing condition in response to the inspection result of the first inspection step for the treatment target evaluated as not failed in the first inspection step after the first inspection step; a shot processing step of performing shot processing of shooting shot media at the treatment target evaluated as not failed in the first inspection step in the shot processing condition set in the condition setting step after the condition setting step; and a second inspection step of nondestructively inspecting at least one of a surface side state and an external dimension of the treatment target after the shot processing step. 
     According to the above-described configuration, in the first inspection step, at least one of the surface side state and the external dimension of the treatment target to be subjected to shot processing of shooting shot media at the treatment target is nondestructively inspected and evaluated that the treatment target is failed when the inspection result deviates from the first allowable range predetermined. In the condition setting step after the first inspection step, the shot processing condition is set in response to the inspection result of the first inspection step for the treatment target evaluated as not failed in the first inspection step. In the shot processing step after the condition setting step, the shot processing of shooting shot media at the treatment target is performed in the processing condition which is set in response to the inspection result of the first inspection step for the treatment target evaluated as not failed in the first inspection step. Thus, it is possible to perform the shot processing in response to the treatment target while suppressing unnecessary shot processing. In the second inspection step after the shot processing step, at least one of the surface side state and the external dimension of the treatment target is nondestructively inspected. That is, it is possible to know the processing state of all treatment targets subjected to the shot processing. 
     In the second inspection step, it is evaluated that the treatment target is passed when an inspection result of the second inspection step is within a normal range predetermined. The surface treatment processing method according to an aspect of the invention may further include a reference value resetting step of resetting a reference value of the shot processing condition to suppress a ratio in which the inspection result of the second inspection step is out of the normal range based on a tendency of a temporal change in inspection result of the second inspection step. 
     According to the above-described configuration, in the second inspection step, it is evaluated that the treatment target is passed when the inspection result of the second inspection step is within a normal range predetermined. In the reference value resetting step, the reference value of the shot processing condition is reset to suppress a ratio in which the inspection result of the second inspection step is out of the normal range based on the tendency of a temporal change in inspection result in the second inspection step. Thus, it is possible to suppress a ratio in which the treatment target is not evaluated as passed in the second inspection step after the resetting and to suppress unnecessary shot processing. 
     In the reference value resetting step, the reference value of the shot processing condition may be reset to a time before which an average value of the inspection result of the second inspection step for each predetermined period is predicted to deviate from the normal range based on the tendency of a temporal change in the average value. 
     According to the above-described configuration, in the reference value resetting step, the reference value of the shot processing condition is reset to a time before which the average value of the inspection result of the second inspection step for each predetermined period is predicted to deviate from the normal range based on the tendency of a temporal change of the average value. For this reason, it is possible to effectively suppress a ratio in which the inspection result of the second inspection step is out of the normal range after the reference value resetting step. 
     In the reference value resetting step, at least one of a shot media projection volume per unit time, a shot media projection speed, a projection pressure for projecting shot media, a rotation speed of an impeller per unit time for accelerating and shooting shot media by a centrifugal force with a rotation of the impeller, a processing time, and each reference value of a relative shooting position with respect to the treatment target is reset. 
     According to the above-described configuration, in the reference value resetting step, the resettable reference value is reset to suppress a ratio in which the inspection result of the second inspection step is out of the normal range based on the tendency of a temporal change in inspection result of the second inspection step. 
     The first inspection step and the second inspection step may include at least one of a step of measuring a residual stress on a surface side of the treatment target, a step of magnetically evaluating the surface side of the treatment target by an eddy current, a step of measuring a color tone on the surface side of the treatment target, and a step of measuring a surface roughness of the treatment target in order to inspect the surface side state of the treatment target each corresponding to an inspection target. 
     According to the above-described configuration, in the first inspection step and the second inspection step, at least one of the step of measuring the residual stress on the surface side of the treatment target, the step of magnetically evaluating the surface side of the treatment target by an eddy current, the step of measuring the color tone of the surface side of the treatment target, and the step of measuring the surface roughness of the treatment target is performed. 
     In the first inspection step and the second inspection step, the residual stress on the surface side of the treatment target each corresponding to the inspection target may be measured. A measurement method may be a method of measuring the residual stress of the treatment target by using a stress measurement device including an X-ray generation source, a first detection element detecting intensities of diffracted X-rays of the treatment target at a first detection position, a second detection element detecting the intensities of the diffracted X-rays of the treatment target at a second detection position different from the first detection position, and a movement mechanism moving each of the first detection element and the second detection element in a direction orthogonal to an X-ray incident direction, including: an X-ray irradiation step of irradiating X-rays to the treatment target; a movement control step of moving the first detection element and the second detection element by driving the movement mechanism; and a stress calculation step of calculating the residual stress of the treatment target based on intensity peaks of the diffracted X-rays of the treatment target respectively detected by the first detection element and the second detection element during the movement control step. 
     According to the above-described configuration, in the first inspection step and the second inspection step, at least the residual stress on the surface side of the treatment target each corresponding to the inspection target is measured. The measurement method is a method of using the stress measurement device including the X-ray generation source, the first detection element, the second detection element, and the movement mechanism. Here, the first detection element detects the intensities of the diffracted X-rays of the treatment target at the first detection position and the second detection element detects the intensities of the diffracted X-rays of the treatment target at the second detection position different from the first detection position. The movement mechanism moves each of the first detection element and the second detection element in a direction orthogonal to the X-ray incident direction. 
     In this measurement method, X-rays are first irradiated to the treatment target in the X-ray irradiation step. Then, in the movement control step, the movement mechanism is driven to move the first detection element and the second detection element. Further, in the stress calculation step, the residual stress of the treatment target is calculated based on the intensity peaks of the diffracted X-rays of the treatment target respectively detected by the first detection element and the second detection element during the movement control step. Accordingly, it is possible to shorten the residual stress measurement time compared to the residual stress measurement device acquiring all data of the diffraction ring by rotating the imaging plate as disclosed in, for example, Japanese Unexamined Patent Publication No. 2013-113734. Thus, even when there are many treatment targets, it is possible to inspect all treatment targets in the first inspection step and to inspect all treatment targets subjected to shot processing in the second inspection step. 
     In the movement control step, movement of the first detection element and movement of the second detection element may be synchronized with each other. 
     According to the above-described configuration, in the movement control step, the movement of the first detection element and the movement of the second detection element are synchronized with each other. For this reason, it is possible to shorten the residual stress measurement time compared to a case in which the first detection element and the second detection element are individually controlled. 
     The surface treatment processing method may further include a storage step of storing at least one of the inspection result of the first inspection step and the inspection result of the second inspection step. 
     According to the above-described configuration, in the storage step, at least one of the inspection result of the first inspection step and the inspection result of the second inspection step is stored. For this reason, utilization of these inspection results is enhanced. 
     The surface treatment processing method may further include a storage step of storing at least one of the inspection result of the first inspection step, the inspection result of the second inspection step, and the shot processing condition in a server. In the storage step, at least one of the inspection result of the first inspection step, the inspection result of the second inspection step, and the shot processing condition may be stored in an internal storage unit and then at least one of the inspection result of the first inspection step, the inspection result of the second inspection step, and the shot processing condition stored in the internal storage unit may be stored in the server. 
     According to the above-described configuration, in the storage step, at least one of the inspection result of the first inspection step, the inspection result of the second inspection step, and the shot processing condition is stored in the internal storage unit and then at least one of the inspection result of the first inspection step, the inspection result of the second inspection step, and the shot processing condition stored in the internal storage unit is stored in the server. For this reason, for example, these data can be temporarily stored in the internal storage unit and then be stored in the server at an arbitrary timing. 
     In the condition setting step, the shot processing condition may be set in response to information input from the server. 
     According to the above-described configuration, in the condition setting step, the shot processing condition is set in response to the information input from the server. For this reason, the shot processing condition can be optimized. 
     A surface treatment processing device according to an aspect of the invention includes: a first inspection unit configured to nondestructively inspect at least one of a surface side state and an external dimension of a treatment target; a control unit configured to evaluate that the treatment target is failed when an inspection result of the first inspection unit deviates from a first allowable range predetermined and set a shot processing condition for shooting shot media at the treatment target corresponding to an inspection target evaluated as not failed in response to the inspection result of the first inspection unit; a shooting unit configured to perform shot processing of shooting shot media at the treatment target evaluated as not failed by the control unit in the treatment targets in the shot processing condition set by the control unit; and a second inspection unit which nondestructively inspects at least one of a surface side state and an external dimension of the treatment target subjected to the shot processing by the shooting unit. 
     According to the above-described configuration, at least one of the surface side state and the external dimension of the treatment target is nondestructively inspected by the first inspection unit. When the inspection result of the first inspection unit deviates from the first allowable range predetermined, the control unit evaluates that the treatment target is failed. When the control unit evaluates that the treatment target is not failed, the shot processing condition for shooting shot media at the treatment target of the inspection target is set in response to the inspection result of the first inspection unit. Then, the shooting unit performs the shot processing of shooting shot media at the treatment target evaluated as not failed by the control unit in the treatment targets in the shot processing condition set by the control unit. Thus, it is possible to perform shot processing in response to the treatment target while suppressing unnecessary shot processing. Then, at least one of the surface side state and the external dimension of the treatment target subjected to the shot processing by the shooting unit is nondestructively inspected by the second inspection unit. That is, it is possible to know the processing state of all treatment targets subjected to the shot processing. 
     The control unit may evaluate that the treatment target is passed when an inspection result of the second inspection unit is within a normal range predetermined and reset a reference value of the shot processing condition to suppress a ratio in which the inspection result of the second inspection unit is out of the normal range based on a tendency of a temporal change in the inspection result of the second inspection unit. 
     According to the above-described configuration, the control unit evaluates that the treatment target is passed when the inspection result of the second inspection unit is within the normal range predetermined. The control unit resets the reference value of the shot processing condition to suppress a ratio in which the inspection result of the second inspection unit is out of the normal range based on the tendency of a temporal change in inspection result of the second inspection unit. Thus, it is possible to suppress a ratio in which the inspection result of the second inspection unit is out of the normal range after the resetting and to suppress unnecessary shot processing. 
     At least one of the first inspection unit and the second inspection unit may include a stress measurement device. The stress measurement device may include an X-ray generation source configured to irradiate an X-ray to the treatment target, a first detection element configured to detect intensities of diffracted X-rays of the treatment target at a first detection position, a second detection element configured to detect the intensities of the diffracted X-rays of the treatment target at a second detection position different from the first detection position, a movement mechanism configured to move each of the first detection element and the second detection element in a direction orthogonal to an X-ray incident direction, a movement control unit configured to control the detection positions of the first detection element and the second detection element by driving the movement mechanism, and a stress calculation unit configured to calculate a residual stress of the treatment target based on intensity peaks of the diffracted X-rays respectively detected when the first detection element and the second detection element are respectively moved by the movement mechanism. 
     According to the above-described configuration, at least one of the first inspection unit and the second inspection unit includes the stress measurement device. In the stress measurement device, X-rays are irradiated from the X-ray generation source to the treatment target and the intensities of the diffracted X-rays of the treatment target are detected by the first detection element at the first detection position and are detected by the second detection element at the second detection position different from the first detection position. Each of the first detection element and the second detection element is moved by the movement mechanism in a direction orthogonal to the X-ray incident direction. The movement control unit controls the detection positions of the first detection element and the second detection element by driving the movement mechanism. Then, the stress calculation unit calculates the residual stress of the treatment target based on the intensity peaks of the diffracted X-rays respectively detected by the first detection element and the second detection element respectively moved by the movement mechanism. 
     In the stress measurement device, since the first detection element and the second detection element are provided, it is possible to obtain the diffracted X-rays at two angles with one X-ray irradiation. Since the first detection element and the second detection element respectively move in a direction orthogonal to the X-ray incident direction, it is possible to obtain the X-ray intensity distribution (the diffraction peak) for each element. It is possible to calculate the residual stress of the measurement target by acquiring at least two diffraction peaks. For this reason, there is no need to acquire all data of the diffraction ring by rotating the imaging plate as disclosed in, for example, Japanese Unexamined Patent Publication No. 2013-113734. Thus, it is possible to shorten the residual stress measurement time compared to the residual stress measurement device acquiring all data of the diffraction ring by rotating the imaging plate. 
     The surface treatment processing device according to an aspect of the invention may further include a storage unit configured to store at least one of the inspection result of the first inspection unit, the inspection result of the second inspection unit, and the shot processing condition and the storage unit may include a server. 
     According to the above-described configuration, the storage unit stores at least one of the inspection result of the first inspection step, the inspection result of the second inspection step, and the shot processing condition. The storage unit includes the server. For this reason, utilization of these data is enhanced. 
     A surface treatment processing method according to an aspect of the invention includes: a first inspection step of nondestructively inspecting at least one of a surface side state and an external dimension of a treatment target to be subjected to shot processing of shooting shot media at the treatment target and evaluating that the treatment target is failed when an inspection result is out of a first allowable range predetermined; a shot processing step of performing shot processing of shooting shot media at the treatment target evaluated as not failed in the first inspection step after the first inspection step; and a second inspection step of nondestructively inspecting at least one of a surface side state and an external dimension of the treatment target after the shot processing step. 
     According to the above-described configuration, in the first inspection step, at least one of the surface side state and the external dimension of the treatment target to be subjected to the shot processing of shooting shot media at the treatment target is nondestructively inspected. Then, when the inspection result deviates from the first allowable range predetermined, it is evaluated that the treatment target is failed. In the shot processing step after the first inspection step, the shot processing of shooting shot media at the treatment target is performed on the treatment target evaluated as not failed in the first inspection step. Thus, unnecessary shot processing is suppressed. In the second inspection step after the shot processing step, at least one of the surface side state and the external dimension of the treatment target is nondestructively inspected. That is, it is possible to know the processing state of all treatment targets subjected to the shot processing. 
     The surface treatment processing method may further include a storage step of storing at least one of the inspection result of the first inspection step and an inspection result of the second inspection step in a server. 
     According to the above-described configuration, in the storage step, at least one of the inspection result of the first inspection step and the inspection result of the second inspection step is stored in the server. For this reason, utilization of these inspection results is enhanced. 
     In the storage step, at least one of the inspection result of the first inspection step and the inspection result of the second inspection step may be stored in the internal storage unit and then may be stored in the server. 
     According to the above-described configuration, in the storage step, at least one of the inspection result of the first inspection step and the inspection result of the second inspection step is stored in the internal storage unit and then is stored in the server. For this reason, for example, these inspection results can be stored in the internal storage unit and then be stored in the server at an arbitrary timing. 
     Advantageous Effects of Invention 
     According to the surface treatment processing method and the surface treatment processing device of an aspect of the invention, it is possible to manage the processing degree of all treatment targets subjected to shot processing while suppressing unnecessary shot processing. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1(A)  is a flowchart showing a flow of a series of processes and  FIG. 1(B)  is a flowchart showing a flow of a process performed when a control unit is activated before daily processing starts. 
         FIG. 2  is a perspective view showing a surface treatment processing device used in a surface treatment processing method according to a first embodiment. 
         FIG. 3(A)  is a schematic diagram showing a part of a control system of the surface treatment processing device of  FIG. 2  in the form of a block and  FIG. 3(B)  is a schematic diagram showing a main part of a shot peening processing device in a simplified state. 
         FIG. 4(A)  is a circuit configuration diagram of a magnetic evaluation device and  FIG. 4(B)  is a perspective view showing a configuration of an inspection detector in a see-through state. 
         FIG. 5  is a schematic configuration diagram showing a part of a stress measurement device of  FIG. 2  as a schematic perspective view. 
         FIG. 6  is a schematic configuration diagram showing a part of the stress measurement device of  FIG. 2  as a side view in a simplified state. 
         FIG. 7  is a schematic diagram illustrating a detection position of the stress measurement device of  FIG. 2 . 
         FIG. 8  is a diagram illustrating a diffraction ring depicted by diffracted X-rays. 
         FIG. 9(A)  is a flowchart showing an adjustment process before a residual stress is measured and  FIG. 9(B)  is a flowchart showing a method of measuring a residual stress on a surface side of an inspection target. 
         FIG. 10  is a schematic diagram showing a part of a control system of a surface treatment processing device according to a modified example in the form of a block. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
     A surface treatment processing method according to a first embodiment of the invention will be described with reference to  FIGS. 1(A) to 9(B) .  FIG. 2  shows a perspective view of a surface treatment processing device  10  used in the surface treatment processing method according to this embodiment. First, the surface treatment processing device  10  will be described. As a treatment target W which is processed by the surface treatment processing device  10  of this embodiment, for example, a metallic product or the like can be used. In this embodiment, as an example, a gear for a transmission of an automobile is applied. Heat treatment processing is performed on a treatment target (a product) which is formed in a product shape by plastic processing and mechanical processing and is an example of the treatment target W to be subjected to shot peening processing (surface treats lent processing) using the surface treatment processing device  10 . A treatment target having a compressive residual stress on a surface side at the step of being carried into the surface treatment processing device  10  is applied as the treatment target W. 
     (Overall Configuration of Surface Treatment Processing Device  10 ) 
     As shown in  FIG. 2 , the surface treatment processing device  10  includes a carry-in conveyor  12 , a first inspection zone  14 , two inspection tables  16 A and  16 B, a six-axis robot  18 , a magnetic evaluation device  20 , and a stress measurement device  22 . The carry-in conveyor  12  carries the treatment target W loaded on the carry-in conveyor  12  in a conveying direction (see the arrow X 1 ) which is predetermined. The first inspection zone  14  is provided at the center of the carry-in conveyor  12  in the conveying direction. In the first inspection zone  14 , two inspection tables  16 A and  16 B are provided to straddle the carry-in conveyor  12 . The six-axis robot  18  is disposed at the lateral side of the carry-in conveyor  12  in the first inspection zone  14 . 
     The six-axis robot  18  is a robot capable of lifting and moving the treatment target W. The six-axis robot  18  is able to move the treatment target W so that the treatment target is disposed on the inspection tables  16 A and  16 B (that is, inspection positions). That is, the six-axis robot  18  is able to move the treatment target W disposed on the carry-in conveyor  12  so that the treatment target is disposed on the inspection table  16 A and is able to move the treatment target W disposed on the inspection table  16 A so that the treatment target is disposed on the inspection table  16 B. The six-axis robot  18  is able to move the treatment target W disposed on the inspection table  16 B so that the treatment target is disposed on the carry-in conveyor  12  (the downstream side) and is able to extract the treatment target W disposed on the inspection table  16 B to the outside of the line of the surface treatment process. 
     One inspection table  16 A is provided with the magnetic evaluation device  20  as an inspection device. In the other inspection table  16 B, the stress measurement device  22  is adjacently disposed as an inspection device. The magnetic evaluation device  20  and the stress measurement device  22  constitute a first inspection unit  14 E. In this embodiment, the magnetic evaluation device  20  is disposed closer to the upstream side in the conveying direction (see the arrow X 1 ) than the stress measurement device  22 , but the stress measurement device  22  may be disposed closer to the upstream side in the conveying direction (see the arrow X 1 ) than the magnetic evaluation device  20 . 
     The magnetic evaluation device  20  inspects an entire surface layer state of a processing target portion of the treatment target W disposed on the inspection table  16 A. For example, the magnetic evaluation device  20  evaluates an unevenness presence/absence state and a metal structure state in the treatment target W by eddy currents. The magnetic evaluation device  20  may output a signal representing a voltage value as a result of an inspection performed by the magnetic evaluation device  20 . The magnetic evaluation device  20  of this embodiment evaluates (determines) whether the result of the inspection performed by the magnetic evaluation device  20  is within a first normal range set in advance. The magnetic evaluation device  20  outputs a signal representing the evaluation result to a control unit  26  (see  FIG. 3(A) ) to be described later. The stress measurement device  22  measures a residual stress of the treatment target W disposed on the inspection table  16 B by using an X-ray diffraction method. The stress measurement device  22  of this embodiment measures a residual stress only for a specified measurement point while not measuring a stress state for the entire treatment target W. The stress measurement device  22  outputs a signal representing a stress value as a measurement result (an inspection result) thereof to the control unit  26  (see  FIG. 3(A) ) to be described later. 
     As described above, in order to appropriately determine whether the treatment target W is suitable for shot peening processing, the homogeneity of the entire processing target surface of the treatment target W is evaluated by the magnetic evaluation device  20  and a specific residual stress for a part of the processing target range is measured by the stress measurement device  22 . The magnetic evaluation device  20  and the stress measurement device  22  will be described later in detail. 
       FIG. 3(A)  is a schematic diagram showing a part of a control system of the surface treatment processing device  10  of  FIG. 2  in the form of a block. As shown in  FIG. 3(A) , the surface treatment processing device  10  further includes the control unit  26 . The magnetic evaluation device  20 , the stress measurement device  22 , and the six-axis robot  18  are connected to the control unit  26  (the control unit). The control unit  26  includes, for example, a storage device, an arithmetic process device, and the like. Although not specifically shown, the arithmetic process device includes, for example, a CPU, a memory, a storage unit, and a communication interface (I/F) unit and these components are connected to each other via a bus. The storage unit stores an arithmetic processing program. The storage device and the arithmetic process device can communicate with each other by the communication interface (I/F) unit thereof. 
     The control unit  26  inputs the evaluation result of the magnetic evaluation device  20  from the magnetic evaluation device  20  and inputs the inspection result of the stress measurement device  22  from the stress measurement device  22 . The evaluation result of the magnetic evaluation device  20  is information representing whether the inspection result of the magnetic evaluation device  20  is within a first normal magnetic range (a first normal range for magnetism) set in advance. The evaluation on whether the inspection result of the magnetic evaluation device  20  is within the first normal magnetic range is performed by a determination means  96  to be described later. The control unit  26  determines (evaluates) whether the inspection result obtained by the stress measurement device  22  is within a first allowable stress range (a first allowable range for stress) set in advance and whether the inspection result obtained by the stress measurement device  22  is within a first normal stress range (a first normal range for stress) set in advance. In the present specification, the “allowable range” is set in advance to be wider than the “normal range” and to include the “normal range”. The control unit  26  evaluates (determines) that the result is “passed”, that is, processing can performed in a standard shot processing condition (a shot peening processing condition) when both inspection results of the magnetic evaluation device  20  and the stress measurement device  22  are within the first normal range. The control unit  26  determines (evaluates) that the treatment target is “conditionally passed” for which the magnetic evaluation device  20  obtained an evaluation of normal (the surface is homogeneous), and for which the inspection result obtained by the stress measurement device  22  can be considered normal by changing the standard shot processing condition, despite being slightly lower or slightly higher than the standard value (the first normal stress range). The “conditionally passed” state means that processing can be performed while the shot processing condition is changed. The control unit  26  evaluates (determines) that the result is “failed” (in this embodiment, an object to be discarded) when the result is neither “passed” nor “conditionally passed” (when the inspection result of the first inspection unit  14 E is out of the first allowable range which is predetermined, that is, in this embodiment, the inspection result of the stress measurement device  22  is out of the first allowable stress range). 
     That is, the control unit  26  evaluates that the treatment target W is “passed” when the inspection result of the magnetic evaluation device  20  the first normal magnetic range set in advance and the inspection result of the stress measurement device  22  is within the first normal stress range set in advance. The control unit  26  evaluates that the treatment target W is “conditionally passed” when the inspection result of the magnetic evaluation device  20  is within the first normal magnetic range set in advance and the inspection result of the stress measurement device  22  is out of the first normal stress range set in advance, but is within the first allowable stress range set in advance. The control unit  26  evaluates that the treatment target W is “failed” when the inspection result of the magnetic evaluation device  20  is out of the first normal magnetic range set in advance or the inspection result of the stress measurement device  22  is out of the first allowable stress range set in advance. 
     In the case of “failed”, the control unit  26  controls the six-axis robot  18  so that the treatment target W is extracted to the outside of the line of the surface treatment process. In the case other than “failed”, that is, in the case of “passed” and “conditionally passed”, the control unit  26  controls the six-axis robot  18  so that the treatment target W is returned to the carry-in conveyor  12  (see  FIG. 2 ). 
     As shown in  FIG. 2 , the surface treatment processing device  10  further includes a carry-in/carry-out loader  28  and a shot peening processing device  30  (a shot processing device). An upstream side of a carry-out conveyor  66  to be described later is disposed at one lateral side (the front side of the drawing) of the downstream side of the carry-in conveyor  12 . A cabinet  32  of the shot peening processing device  30  (the shot processing device) which is a shooting unit is disposed at the other lateral side (the rear side of the drawing) of the downstream side of the carry-in conveyor  12 . The conveying direction (see the arrow X 2 ) of the carry-out conveyor  66  is set to the same direction as the conveying direction (see the arrow X 1 ) of the carry-in conveyor  12 . The cabinet  32  is formed in a box shape. A side wall on the side of the carry-in conveyor  12  of the cabinet  32  is provided with a carry-in/carry-out opening  32 A. Further, the carry-in/carry-out loader  28  (the carry-in/carry-out device) is provided at the upper side of the downstream side of the carry-in conveyor  12 . The carry-in/carry-out loader  28  carries the treatment target W on the carry-in conveyor  12  into the cabinet  32  from the opening  32 A of the cabinet  32  and carries the treatment target W in the cabinet  32  onto the carry-out conveyor  66  from the opening  32 A of the cabinet  32 . 
     The carry-in/carry-out loader  28  includes a pair of rails  28 A and a carriage  28 B. The pair of rails  28 A extends in a direction orthogonal to the conveying direction of each of the carry-in conveyor  12  and the carry-out conveyor  66 . The carriage  28 B can travel along the pair of rails  28 A. The carriage  28 B is connected to the control unit  26  shown in  FIG. 3(A) . A mechanism for driving the carriage  28 B is not shown in the drawings. The driving of the carriage  28 B is controlled by the control unit  26 . Although not described in detail, a lower surface side of the carriage  28 B shown in  FIG. 2  is provided with a hanging mechanism (not shown) for hanging the treatment target W. A lower portion for receiving and delivering the treatment target W in the hanging mechanism is movable up and down. 
       FIG. 3(B)  is a schematic diagram showing a main part of the shot peening processing device  30  in a simplified state. A basic configuration of the shot peening processing device  30  is substantially the same as the configuration disclosed in Japanese Unexamined Patent Publication No. 2012-101304. As shown in  FIG. 3(B) , the shot peening processing device  30  includes a shot processing chamber  34 , a product placement portion  36 , and a projection device  40 . The shot processing chamber  34  is formed inside the cabinet  32 . In the shot processing chamber  34 , shot peening processing (broadly speaking, surface processing) of the treatment target W is performed by allowing shot media (shots of steel balls or the like) to collide with the treatment target W. A product placement portion  36  on which the treatment target W is placed is provided at the lower portion inside the shot processing chamber  34 . 
     A nozzle  64  of the projection device (the air nozzle type shot peening processing device)  40  is provided at the side portion inside the cabinet  32 . The projection device  40  projects compressed air including shot media from the nozzle  64  so that the shot media collide with the treatment target W of the shot processing chamber  34 . Hereinafter, the projection device  40  will be briefly described. 
     As shown in  FIG. 3(B) , the projection device  40  includes a shot media tank  42 , a quantitative supply device  44 , and a pressurizing tank  46 . The shot media tank  42  is connected to the pressurizing tank  46  via the quantitative supply device  44 . The quantitative supply device  44  includes a poppet valve  44 I which is provided between the pressurizing tank  46  and the quantitative supply device. The poppet valve  44 I is connected to the control unit  26  (see  FIG. 3(A) ). The pressurizing tank  46  is provided with a level meter (not shown) which detects the amount of the shot media inside the pressurizing tank  46 . The level meter is connected to the control unit  26  (see  FIG. 3(A) ). The control unit  26  (see  FIG. 3(A) ) controls the poppet valve  44 I of the quantitative supply device  44  to be opened when the level meter detects that the amount of the shot media inside the pressurizing tank  46  is smaller than a predetermined value. The poppet valve  44 I is driven by a driving cylinder (not shown). Opening and closing of the poppet valve  44 I is controlled by the control unit  26  (see  FIG. 3(A) ) in response to the detection state of the level meter. In a state in which the poppet valve  44 I is opened, an appropriate amount of the shot media is sent from the shot media tank  42  to the pressurizing tank  46  via the quantitative supply device  44 . 
     An air inlet  46 A is formed at the upper portion of the pressurizing tank  46 . One end portion of the connection pipe  48  is connected to the air inlet  46 A. The other end portion of the connection pipe  48  is connected to an intermediate portion of the passage of the connection pipe  50 . One end portion of the upstream side (the right side of the drawing) of the passage of the connection pipe  50  is connected to a compressor  52  (a compressed air supply device) for supplying compressed air. That is, the pressurizing tank  46  is connected to the compressor  52  via connection pipes  48  and  50 . The compressor  52  is connected to the control unit  26  (see  FIG. 3(A) ). An air flow control valve  54  (an electropneumatic proportional valve) is provided at an intermediate portion of the passage of the connection pipe  48 . When the air flow control valve  54  is opened, compressed air is supplied from the compressor  52  into the pressurizing tank  46 . Accordingly, the inside of the pressurizing tank  46  can be pressurized. 
     A shot outlet  46 B provided with a cut gate  56  is formed at the lower portion of the pressurizing tank  46 . One end portion of the connection pipe  58  is connected to the shot outlet  46 B. The other end portion of the connection pipe  58  is connected to an intermediate portion of the passage of the connection pipe  50 . A shot flow control valve  60  is provided at an intermediate portion of the passage of the connection pipe  58 . As the shot flow control valve  60 , for example, a magnet valve and a mixing valve are applied. A joint portion with the connection pipe  58  in the connection pipe  50  is formed as a mixing portion  50 A. An air flow control valve  62  (an electropneumatic proportional valve) is provided at the passage downstream side (the left side of the drawing) of the connection portion with the connection pipe  48  and at the passage upstream side (the right side of the drawing) of the mixing portion  50 A in the connection pipe  50 . 
     That is, when the cut gate  56  and the shot flow control valve  60  are opened and the air flow control valve  62  is opened while the inside of the pressurizing tank  46  is pressurized, the shot media supplied from the pressurizing tank  46  and the compressed air supplied from the compressor  52  are mixed at the mixing portion  50 A and flow to the passage downstream side (the left side of the drawing) of the connection pipe  50 . 
     The projection (shot peening) nozzle  64  is connected to the passage downstream end portion of the connection pipe  50 . Accordingly, the shot media flowing to the mixing portion  50 A is projected from the tip of the nozzle  64  while being mixed with the compressed air. The air flow control valves  54  and  62 , the cut gate  56 , and the shot flow control valve  60  are connected to the control unit  26  shown in  FIG. 3(A) . 
     The control unit  26  shown in  FIG. 3(A)  stores a program for performing shot peening processing (shot processing) on the treatment target W by the projection device  40 . The surface treatment processing device  10  further includes an operation unit  24  which is connected to the control unit  26 . With the use of the operation unit  24 , it is possible to input a reference value (a standard setting reference value) of a shot processing condition when performing shot peening processing on the treatment target W (see  FIG. 2 ). The operation unit  24  outputs a signal in response to an input operation to the control unit  26 . Then, the control unit  26  controls the compressor  52 , the air flow control valves  54  and  62 , the cut gate  56 , the shot flow control valve  60 , and the like shown in  FIG. 3(B)  on the basis of a signal output from the operation unit  24  and inspection results output from the magnetic evaluation device  20  and the stress measurement device  22 . That is, the control unit  26  shown in  FIG. 3(A)  controls the shot processing condition of the projection device  40 , more specifically, a shot media projection volume (a shot media flow amount) per unit time, a shot media projection pressure, a shot media projection timing, or a processing time. 
     In this embodiment, the control unit  26  sets the shot processing condition for shooting the shot media at the treatment target W of the inspection target in response to the inspection result of the first inspection unit  14 E when the evaluation (determination) result is not “failed”. Specifically, the control unit  26  sets the standard shot processing condition (the reference value) as the shot processing condition for the treatment target W of the inspection target determined as “passed”. The control unit  26  sets the shot processing condition obtained by correcting the standard shot processing condition (the reference value) for the treatment target W of the inspection target determined as “conditionally passed”. 
     That is, the control unit  26  controls the projection device  40  so that the shot media are projected (shot) at the treatment target W of the inspection target determined as “passed” in the standard shot processing condition. The control unit  26  controls the projection device  40  so that the shot media are projected (shot) at the treatment target W of the inspection target determined as “conditionally passed” in the shot processing condition obtained by correcting the standard shot processing condition. More specifically, the shot media are projected at the treatment target W, in which the inspection result of the stress measurement device  22  is slightly smaller than the standard value (the first normal stress range), of the treatment target W of the inspection target determined as “conditionally passed”, for example, in the shot processing condition obtained by correcting the standard shot processing condition so that the projection pressure (the shooting pressure) increases in order to compensate for a compressive residual stress. In contrast, the shot media are projected at the treatment target W in which the inspection result of the stress measurement device  22  is slightly larger than the standard value (the first normal stress range) in the treatment target W of the inspection target determined as “conditionally passed”, for example, in the shot processing condition obtained by correcting the standard shot processing condition so that the projection pressure (the shooting pressure) decreases in order to avoid excessive accumulation of the compressive residual stress. The projection pressure for projecting the shot media can be increased and decreased by controlling the input values (the opening degrees of the air flow control valves  54  and  62 ) of the air flow control valves  54  and  62  which are electropneumatic proportional valves shown in  FIG. 3(B) . 
     Although not described in detail, in this embodiment, as an example, the product placement portion  36  has a so-called multi-table structure. That is, a revolving table  36 A is disposed in the product placement portion  36  and a plurality of spinning tables  36 B are disposed on the revolving table  36 A so as to be located at a plurality of positions on the concentric circle of the revolving table  36 A. The revolving table  36 A includes a rotation shaft  35 X which is formed in the vertical direction of the device. The revolving table  36 A is able to rotate (revolve) about the rotation shaft  35 X. The revolving table  36 A is disposed at a position including a projection range in which the shot media are projected by the projection device  40  and a non-projection range other than the projection range. The diameter of the spinning table  36 B is shorter than the diameter of the revolving table  36 A. The spinning table  36 B includes a rotation shaft  35 Z which is parallel to the rotation shaft  35 X of the revolving table  36 A. The spinning table  36 B is able to rotate (spin) about the rotation shaft  35 Z. 
     The treatment target W is disposed on the spinning table  36 B. A pressing mechanism (not shown) is provided at the upper side of the projection range in the revolving table  36 A. A pressing portion of the pressing mechanism is rotatable along with the treatment target W while pressing the treatment target W on the spinning table  36 B from above. A revolving driving mechanism (not shown) rotating (revolving) the revolving table  36 A and a spinning driving mechanism (not shown) rotating (spinning) the spinning table  36 B are respectively connected to the control unit  26  (see  FIG. 3(A) ). The operations of the revolving driving mechanism and the spinning driving mechanism are respectively controlled by the control unit  26  (see  FIG. 3(A) ). Since these components are controlled, the relative shot position for the treatment target W is controlled. The relative shot position is one of the shot processing conditions. 
     As shown in  FIG. 2 , the surface treatment processing device  10  includes the carry-out conveyor  66 , a second inspection zone  68 , two inspection tables  70 A and  70 B, a six-axis robot  72 , a magnetic evaluation device  74 , and a stress measurement device  76 . The carry-out conveyor  66  conveys the treatment target W loaded on the carry-out conveyor  66  in a conveying direction (see the arrow X 2 ) which is predetermined. The conveying direction of the carry-out conveyor  66  is set to be the same as the conveying direction (see the arrow X 1 ) of the carry-in conveyor  12 . The second inspection zone  68  is provided at the center of the carry-out conveyor  66  in the conveying direction. In the second inspection zone  68 , two inspection tables  70 A and  70 B are provided to straddle the carry-out conveyor  66 . The six-axis robot  72  is disposed at the lateral side of the carry-out conveyor  66  in the second inspection zone  68 . 
     The six-axis robot  72  is a robot capable of lifting and moving the treatment target W. The six-axis robot  72  is able to move the treatment target W so that the treatment target is disposed on the inspection tables  70 A and  70 B (that is, inspection positions). That is, the six-axis robot  72  is able to move the treatment target W disposed on the carry-out conveyor  66  so that the treatment target is disposed on the inspection table  70 A and is able to move the treatment target W disposed on the inspection table  70 A so that the treatment target is disposed on the inspection table  70 B. The six-axis robot  72  is able to move the treatment target W disposed on the inspection table  70 B so that the treatment target is disposed on the carry-out conveyor  66  (the downstream side) and is able to extract the treatment target W disposed on the inspection table  70 B to the outside of the line of the surface treatment process. 
     In one inspection table  70 A, the magnetic evaluation device  74  is disposed as an inspection device. In the other inspection table  70 B, the stress measurement device  76  is adjacently disposed as an inspection device. The magnetic evaluation device  74  and the stress measurement device  76  constitute a second inspection unit  68 E. In this embodiment, the magnetic evaluation device  74  is disposed closer to the upstream side in the conveying direction (see the arrow X 2 ) than the stress measurement device  76 , but the stress measurement device  76  may be disposed closer to the upstream side in the conveying direction (see the arrow X 2 ) than the magnetic evaluation device  74 . 
     The magnetic evaluation device  74  inspects an entire surface layer state of a processing target portion of the treatment target W disposed on the inspection table  70 A. For example, the magnetic evaluation device  74  evaluates an unevenness presence/absence state and a metal structure state in the treatment target W by eddy currents. The magnetic evaluation device  74  may output a signal representing a voltage value as a result of an inspection performed by the magnetic evaluation device  74 . The magnetic evaluation device  74  of this embodiment evaluates (determines) whether the result of the inspection performed by the magnetic evaluation device  74  is within a second normal magnetic range (a second normal range for magnetism) set in advance. The magnetic evaluation device  74  outputs a signal representing the evaluation result to the control unit  26  (see  FIG. 3(A) ). The second normal magnetic range may be the same as or different from the first normal magnetic range. 
     The stress measurement device  76  measures a residual stress of the treatment target W disposed on the inspection table  70 B by using an X-ray diffraction method. The stress measurement device  76  of this embodiment measures a residual stress only for a specified point while not measuring a stress state for the entire treatment target W. The stress measurement device  76  outputs a signal representing a stress value as a measurement result (an inspection result) thereof to the control unit  26  (see  FIG. 3(A) ). In this embodiment, the magnetic evaluation device  74  of the second inspection zone  68  has the same configuration as the magnetic evaluation device  20  of the first inspection zone  14 . The stress measurement device  76  of the second inspection zone  68  has the same configuration as the stress measurement device  22  of the first inspection zone  14 . 
     As shown in  FIG. 3(A) , the magnetic evaluation device  74 , the stress measurement device  76 , and the six-axis robot  72  are connected to the control unit  26 . The control unit  26  inputs an evaluation result of the magnetic evaluation device  74  from the magnetic evaluation device  74  and inputs an inspection result of the stress measurement device  76  from the stress measurement device  76 . The evaluation result of the magnetic evaluation device  74  is information on whether the inspection result of the magnetic evaluation device  74  is within a second normal magnetic range (a second normal range for magnetism) set in advance. An evaluation on whether the inspection result of the magnetic evaluation device  74  is within the second normal magnetic range is performed by the determination means  96  to be described later. The control unit  26  determines (evaluates) whether the inspection result obtained by the stress measurement device  76  is within a second normal stress range (a second normal range for stress) set in advance. The second normal stress range may be the same as or different from the first normal stress range. The control unit  26  evaluates (determines) that the result is “passed” when both inspection results of the magnetic evaluation device  74  and the stress measurement device  76  are within the second normal range (the inspection result of the second inspection unit  68 E is within the second normal range set in advance). In other cases, the control unit  26  evaluates (determines) that the result is “failed” (in this embodiment, an object to be discarded). 
     That is, the control unit  26  evaluates that the treatment target W is “passed” when the inspection result of the magnetic evaluation device  74  is within the second normal magnetic range set in advance and the inspection result of the stress measurement device  76  is within the second normal stress range set in advance. The control unit  26  evaluates that the treatment target W is “failed” when the inspection result of the magnetic evaluation device  74  is out of the second normal magnetic range set in advance or the inspection result of the stress measurement device  76  is out of the second normal stress range set in advance. 
     In the case of “passed”, the control unit  26  controls the six-axis robot  72  so that the treatment target W is returned to the carry-out conveyor  66  (see  FIG. 2 ). In the case of “failed”, the control unit  26  controls the six-axis robot  72  so that the treatment target W is extracted to the outside of the line of the surface treatment process. The treatment target W returned to the carry-out conveyor  66  (see  FIG. 2 ) flows to the next process. 
     The control unit  26  stores the inspection results of the magnetic evaluation device  74  and the stress measurement device  76  in the storage device. The control unit  26  allows the arithmetic process device to calculate an average daily value (in a broad sense, an average value for every predetermined period) of the inspection result (data) obtained by the stress measurement device  76  of the second inspection unit  68 E (see  FIG. 2 , a second inspection step to be described later) stored in the storage device, for example, for a period of many days or weeks (in this embodiment, twenty days). Hereinafter, the average value will be simply referred to as an “average stress value”. The control unit  26  further allows the arithmetic process device to calculate a difference between the average stress value and the stress standard median value (the median value of the second normal stress range) as a deviation amount. The control unit  26  allows the arithmetic process device to calculate the gradient and the intercept of the linear equation showing the tendency of the deviation amount to rise and fall (the tendency of a daily change) from day (horizontal axis) and the daily divergence amount (vertical axis) by the least squares method. The control unit  26  determines whether the inspection result of the stress measurement device  76  tends to deviate from the second normal stress range (the second normal range for stress) as a mid/long-term trend. The control unit  26  calculates a day (in a broad sense, “time”) when the average stress value is predicted to deviate from the second normal stress range (the second normal range for stress) set in advance. Then, the control unit  26  resets the reference value (the standard setting reference value) of the shot processing condition so as to suppress a ratio in which the inspection result of the second inspection unit  68 E (the stress measurement device  76 ) is out of the second normal stress range on the basis of a tendency of a temporal change in inspection result obtained by the second inspection unit  68 E (the stress measurement device  76 ) at a predetermined timing to be described later. The second normal stress range may be the same as or different from the first normal stress range. 
     (Magnetic Evaluation Devices  20  and  74 ) 
     Next, the magnetic evaluation devices  20  and  74  will be described with reference to  FIGS. 4(A) and 4(B) .  FIG. 4(A)  shows a circuit configuration of the magnetic evaluation device  20  (the surface characteristic inspection device).  FIG. 4(B)  is a perspective view showing a configuration of an inspection detector  86  of the magnetic evaluation device  20  in a see-through state. Since the magnetic evaluation device  20  and the magnetic evaluation device  74  shown in  FIG. 2  have the same device configuration, the magnetic evaluation device of  FIG. 4(A)  is represented by the reference numeral  20 . 
     As shown in  FIG. 4(A) , the magnetic evaluation device  20  includes an AC power source  78 , an AC bridge circuit  80 , and an evaluation device  90 . The AC power source  78  is able to supply AC power with variable frequency to the AC bridge circuit  80 . 
     The AC bridge circuit  80  includes a variable resistor  82 , the inspection detector  86 , and a reference detector  84  which detects a reference state corresponding to a reference for comparison with the output from the inspection detector  86 . In the inspection detector  86 , a coil is disposed to excite an eddy current in the treatment target W (hereinafter, appropriately referred to as a “subject W”) which is a subject (an inspection target). The variable resistor  82  can distribute a resistor R A  into a resistor R 1  and a resistor R 2  according to a distribution ratio γ. The distribution ratio γ is variable. The resistor R 1  and the resistor R 2  constitute a bridge circuit along with the reference detector  84  and the inspection detector  86 . In this embodiment, a point A and a point B are connected to the AC power source  78  of the magnetic evaluation device  20 . A point C and a point D are connected to an amplifier  91 . The point A is a distributing point between the resistor R 1  and the resistor R 2 . The point B is located between the reference detector  84  and the inspection detector  86 . The point C is located between the resistor R 1  and the reference detector  84 . The point D is located between the resistor R 2  and the inspection detector  86 . The reference detector  84  and the inspection detector  86  are grounded to reduce noise. The variable resistor  82  and the reference detector  84  are disposed on a circuit board  88  as an example. 
     The evaluation device  90  includes an amplifier  91 , an absolute value circuit  92 , a low pass filter (LPF)  93 , a phase comparator  94 , a frequency adjuster  95 , a determination means  96 , a display means  97 , and a temperature measurement means  98 . The amplifier  91  amplifies a voltage signal output from the AC bridge circuit  80 . The absolute value circuit  92  performs full-wave rectification. The LPF  93  performs DC conversion. The phase comparator  94  compares the phases of the AC power supplied from the AC power source  78  and the power supplied from the amplifier  91 . The frequency adjuster  95  adjusts the frequency of the AC power supplied from the AC power source  78 . The determination means  96  performs a non-equilibrium adjustment for optimizing the distribution of the resistor R 1  and the resistor R 2 . Furthermore, the determination means  96  inputs an output from the LPF  93  as the inspection results of the magnetic evaluation devices  20  and  74 . The determination means  96  determines whether the surface state of the treatment target W is acceptable on the basis of the inspection result. Specifically, the determination means  96  evaluates (determines) whether the inspection result is within the first normal magnetic range or the second normal magnetic range set in advance. When the surface state of the treatment target W is homogeneous, the inspection results of the magnetic evaluation devices  20  and  74  are within the first normal magnetic range or the second normal magnetic range. The display means  97  displays and warns the evaluation result obtained by the determination means  96 . The temperature measurement means  98  detects a temperature of an evaluation position. 
     The amplifier  91  is connected to the point C and the point D. A potential difference between the point C and the point D is input to the amplifier  91 . An output of the amplifier  91  is connected to the absolute value circuit  92 . An output of the absolute value circuit  92  is connected to the LPF  93 . An output of the LPF  93  is connected to the determination means  96 . The phase comparator  94  is connected to the AC power source  78 , the amplifier  91 , and the determination means  96 . The frequency adjuster  95  is connected to the AC power source  78  and the amplifier  91 . The determination means  96  is able to change the position of the point A of the AC bridge circuit  80 , that is, the distribution ratio γ between the resistor R 1  and the resistor R 2  by outputting a control signal. 
     The temperature measurement means  98  is formed as a non-contact type infrared sensor or a thermocouple and outputs a surface temperature signal of the subject W to the determination means  96 . The determination means  96  determines whether the surface treatment state of the subject W is acceptable when a temperature of the subject W detected by the temperature measurement means  98  is within a predetermined range. The determination means  96  does not determine whether the surface treatment state of the subject (the treatment target) W is acceptable when the temperature detected by the temperature measurement means  98  is out of the predetermined range. 
     The inspection detector  86  and the reference detector  84  have the same configuration. As the inspection detector  86  and the reference detector  84 , a detector which is formed by winding a coil on an outer periphery of a core through which an evaluation unit of the subject W is insertable is used. The detector is able to excite an eddy current in the subject W by moving the coil toward the surface of the subject W. That is, the coil is wound to surround the surface characteristic inspection region of the subject W and faces the surface characteristic inspection region of the subject W. Here, a state in which the surface characteristic inspection region of the subject W is surrounded means that an eddy current is excited in the surface characteristic inspection region while the coil surrounds (encloses) at least a part of the surface characteristic inspection region. 
     As shown in  FIG. 4(B) , the inspection detector  86  includes a core  86 A and a coil  86 B. The core  86 A has a cylindrical shape and is disposed to cover the subject W (which is depicted as a cylindrical body in the drawing). The coil  86 B includes an enameled copper wire wound on the outer peripheral surface of the core  86 A. In this embodiment, a cylindrical magnetic shield  86 C is provided to surround the core  86 A on which the coil  86 B is wound. The core  86 A is formed of a non-magnetic material, for example, resin. The shape of the core  86 A may not be a cylindrical shape as long as the subject W can be disposed therein. The inspection detector  86  may not include the core  86 A as long as the coil  86 B can maintain the shape. 
     The inspection detector  86  is disposed so that the coil  86 B surrounds the inspection target surface (the surface characteristic inspection region) of the subject W and the coil  86 B opposes the inspection target surface of the subject W. When AC power with a predetermined frequency is supplied to the coil  86 B by the AC power source  78  (see  FIG. 4(A) ) in this state, an AC magnetic field is generated. As a result, an eddy current flowing in a direction intersecting the AC magnetic field in the surface of the subject W is excited. The eddy current changes in response to the electromagnetic characteristics of the residual stress layer. For this reason, the phase and the amplitude (impedance) of the output waveform (voltage waveform) output from the amplifier  91  (see  FIG. 4(A) ) change in response to the characteristics (the surface treatment state) of the residual stress layer. According to a change in output waveform, the electromagnetic characteristics of the surface treatment layer can be detected and the inspection can be performed. 
     That is, the evaluation device  90  shown in  FIG. 4(A)  evaluates the surface characteristics of the subject W on the basis of the output signal from the AC bridge circuit  80 . At this time, since AC power is supplied to the AC bridge circuit  80 , the AC bridge circuit  80  is in a state in which the inspection detector  86  detects electromagnetic characteristics of the subject W and the reference detector  84  detects a reference state. The determination means  96  of the evaluation device  90  is connected to the control unit  26 . The determination means  96  outputs a signal according to the evaluation result to the control unit  26 . The determination means  96  outputs a signal representing “unavailable inspection” to the control unit  26  when the temperature detected by the temperature measurement means  98  is out of a predetermined range and a determination is avoided. Accordingly, the determination means  96  notifies the control unit  26  that the determination result cannot be output. 
     The determination means  96  outputs a signal representing the “unavailable inspection” to the display means  97 . The display means  97  inputs this signal and displays and warns a state of “unavailable inspection” as the evaluation result of the determination means  96 . Accordingly, for example, an operator may inspect the magnetic evaluation devices  20  and  74 , improve the operation environment if necessary, and may operate the magnetic evaluation devices  20  and  74  again. For example, the operator may invalidate the inspection result obtained by the evaluation device  90  and operate the magnetic evaluation devices  20  and  74  again. Accordingly, it is possible to evaluate the surface characteristics of the subject W again. 
     &lt;Inspection Method by Magnetic Evaluation Device  20 &gt; 
     Next, an inspection method by the magnetic evaluation device  20  will be described. First, the inspection detector  86  is disposed in the subject W or the subject W is disposed for the inspection detector  86  so that an eddy current is excited in the subject W while AC power is supplied from the AC power source  78  to the AC bridge circuit  80  (an arrangement step). That is, the inspection detector  86  is disposed to surround the subject W disposed in advance or the subject W is disposed to be inserted into the inspection detector  86  disposed in advance. Next, the evaluation device  90  evaluates the surface characteristics of the subject W on the basis of an output signal output from the AC bridge circuit  80  (an evaluation step). Then, the evaluation result is output from the evaluation device  90  to the control unit  26 . 
     As for the magnetic evaluation by an eddy current, the magnetic evaluation can be performed by using a device disclosed in, for example, Japanese Unexamined Patent Publication No. 2013-529286, Japanese Unexamined Patent Publication No. 2015-525336, or International Publication No. 2015/107725. 
     (Stress Measurement Devices  22  and  76 ) 
     Next, the stress measurement devices  22  and  76  will be described with reference to  FIGS. 5 to 9 (B). Since the stress measurement device  22  and the stress measurement device  76  shown in  FIG. 2  have the same device configuration, the stress measurement device of  FIG. 5  is represented by the reference numeral  22 . 
       FIG. 5  is a schematic perspective view showing a part of the stress measurement device  22 .  FIG. 6  is a side view simply showing a part of the stress measurement device  22 . As shown in  FIG. 5 , the stress measurement device  22  includes a device body  100  and a control device  150 . 
     The device body  100  is a box-shaped casing. In this embodiment, an X-ray generation source  102  is accommodated inside the device body  100 . The X-ray generation source  102  is a device including an X-ray tube and generating X-rays of a predetermined wavelength. In this embodiment, the X-ray generation source  102  is fixed to the device body  100 . In the stress measurement device  22 , X-rays having an appropriate wavelength are used in accordance with the treatment target W of the inspection target (hereinafter, appropriately referred to as the “inspection target W”). A front surface  100 F of the device body  100  is provided with an X-ray irradiation window (not shown). The X-rays which are generated by the X-ray generation source  102  are irradiated to the inspection target W through the window. In  FIGS. 5 and 6 , a path and an irradiation direction (an incident direction) of the X-ray from the X-ray generation source  102  to the inspection target W are indicated by a line Xa with an arrow. 
     The device body  100  includes a first detection element  106  and a second detection element  108 . Here, the first detection element  106  and the second detection element  108  are disposed on the front surface  100 F of the device body  100 . Each of the first detection element  106  and the second detection element  108  detects the intensities of the diffracted X-rays of the inspection target W. The first detection element  106  is a zero-dimensional X-ray intensity measurement element. The zero-dimension means the measurement of the intensity of the X-ray at the element arrangement position. That is, the first detection element  106  is different from a one-dimensional line sensor in which a plurality of elements are arranged along a straight line and a two-dimensional imaging plate in which a plurality of elements are arranged in a plane. The second detection element  108  is also a zero-dimensional X-ray intensity measurement element. As the first detection element  106  and the second detection element  108 , for example, a scintillation counter is used. 
     The device body  100  includes a movement mechanism  120  which moves each of the first detection element  106  and the second detection element  108  in a direction (see the direction of the arrow X 3 ) orthogonal to the X-ray incident direction. As shown in  FIG. 6 , the movement mechanism  120  includes an electric motor  122  for driving a displacement and a ball screw mechanism  124 . 
     The electric motor  122  is fixed to the device body  100 . The ball screw mechanism  124  includes a linear screw  126  which extends in a direction (see the direction of the arrow X 3 ) orthogonal to the X-ray incident direction and first and second nuts  128  and  130  threaded into the screw  126 . The screw  126  is supported to be rotatable about its axis. When the electric motor  122  is driven, a driving force is transmitted to the screw  126  through a driving force transmission mechanism (not shown) so that the screw rotates about its axis. The screw  126  is disposed at a position offset in the lateral direction (a direction perpendicular to the sheet of  FIG. 6 ) with respect to the X-rays incident from the X-ray generation source  102 . A first slider  132  is fixed to the first nut  128 . A second slider  134  is fixed to the second nut  130 . The first slider  132  and the second slider  134  are supported to be slidable in the extension direction by a pair of rails  136  (see  FIG. 5 ). The pair of rails  136  is provided on the front surface  100 F of the device body  100  and extends in a direction parallel to the screw  126  (a direction orthogonal to the X-ray incident direction). The pair of rails  136  is schematically shown in  FIG. 5 , but a pair of known guide rails can be used as the pair of rails  136 . 
     As shown in  FIG. 6 , the first detection element  106  is fixed to the first slider  132 . The second detection element  108  is fixed to the second slider  134 . When the electric motor  122  is driven, the first nut  128  and the first slider  132  are relatively moved in the axial direction with respect to the screw  126 , and the second nut  130  and the second slider  134  are relatively moved in the axial direction with respect to the screw  126 . Accordingly, the first detection element  106  and the second detection element  108  are respectively moved in synchronization in a direction (see the direction of the arrow X 3 ) orthogonal to the X-ray incident direction. That is, the first detection element  106  and the second detection element  108  are able to change the X-ray intensity detection position by the movement mechanism  120 . 
     The first detection element  106  detects the intensities of the diffracted X-rays of the inspection target W at a first detection position. The second detection element  108  detects the intensities of the diffracted X-rays of the inspection target W at a second detection position different from the first detection position. The first detection position and the second detection position can be changed in response to, for example, the material of the inspection target W and the focal distance. In this embodiment, the first detection element  106  and the second detection element  108  move in synchronization by the same distance set in advance. The preset distance is a distance in a range in which a necessary diffraction intensity distribution can be obtained. 
     The movement mechanism  120  is connected to the control device  150  shown in  FIG. 5 . The control device  150  is configured as, for example, a general-purpose computer including a CPU, a ROM, a RAM, and a HDD. The control device  150  includes a processing device  152 , an input device  154  (for example, a keyboard and a mouse), and an output device  156  (for example, a display). As shown in  FIG. 6 , the processing device  152  includes an input/output unit  160 , a movement control unit  162 , a stress calculation unit  164 , and a storage unit  166 . 
     The input/output unit  160  is a communication device such as a network card and an input/output device such as a graphic card. For example, the input/output unit  160  is communicably connected to the electric motor  122 . The input/output unit  160  is communicably connected to, for example, the input device  154  and the output device  156  shown in  FIG. 5 . The input/output unit  160  shown in  FIG. 6  is connected to the X-ray generation source  102 , the first detection element  106 , and the second detection element  108 . The movement control unit  162  and the stress calculation unit  164  to be described later exchange information with components via the input/output unit  160 . 
     The movement control unit  162  controls the detection positions of the first detection element  106  and the second detection element  108  by driving the movement mechanism  120  (controlling the driving of the movement mechanism  120 ). The movement control unit  162  acquires a peak appearance angle determined based on the material forming the inspection target W and controls the detection positions of the first detection element  106  and the second detection element  108  to include the peak appearance angle. The peak appearance position determined based on the material forming the inspection target W is stored in the storage unit  166 . The stress calculation unit  164  calculates the residual stress of the inspection target W on the basis of the intensity peak of the diffracted X-rays detected when the first detection element  106  and the second detection element  108  are moved by the movement mechanism  120 . Hereinafter, the calculation of the residual stress will be described in detail. 
       FIG. 7  is an outline diagram for illustrating a detection position of the stress measurement device  22  according to this embodiment.  FIG. 7  shows a case in which incident X-rays XIN are irradiated to the inspection target W and diffracted X-rays are output at a diffraction angle of 2θ. In this case, a diffraction ring R is depicted on a predetermined plane PL by the diffracted X-rays. Here, in this embodiment, for example, an intensity peak appears at each of the detection position corresponding to 0° of the diffraction ring of the diffracted X-rays and the detection position corresponding to 180° of the diffraction ring of the diffracted X-rays. The diffraction intensities of these positions (that is, symmetric points) are acquired. 
       FIG. 8  is an outline diagram for illustrating the diffraction ring. As shown in  FIGS. 7 and 8 , diffracted X-rays X R1  are detected at a first detection position P 1  corresponding to 0° of the diffraction ring R. Diffracted X-rays X R2  are detected at a second detection position P 2  corresponding to 180° of the diffraction ring R. In this case, the movement control unit  162  (see  FIG. 6 ) sets a range including the first detection position P 1  corresponding to 0° of the diffraction ring R so that the first detection element  106  (see  FIG. 6 ) moves in the range. Similarly, the movement control unit  162  (see  FIG. 6 ) sets a range including the second detection position P 2  corresponding to 180° of the diffraction ring R so that the second detection element  108  (see  FIG. 6 ) moves in the range. Accordingly, it is possible to obtain two the X-ray diffraction intensity distributions by obtaining two angle diffracted X-rays with one X-ray irradiation. 
     The stress calculation unit  164  (see  FIG. 6 ) acquires the diffraction peak on the basis of the X-ray diffraction intensity distribution (a relationship between the angle and the intensity) detected at each of the first detection position P 1  and the second detection position P 2 . Here, it is possible to obtain two intensity peaks including the intensity peak corresponding to 0° of the diffraction ring R and the intensity peak corresponding to 180° of the diffraction ring R. The diffraction ring R R  of the two-dot chain line shown in  FIG. 8  is a diffraction ring when no residual stress exists in the inspection target W. In the diffraction ring R with the residual stress, the center position deviates in response to the residual stress compared to the diffraction ring R R  without the residual stress. 
     The stress calculation unit  164  (see  FIG. 6 ) calculates a residual stress value by using this difference. For example, the stress calculation unit  164  (see  FIG. 6 ) calculates the residual stress value using a cos α method. In the cos α method, the residual stress can be obtained from the gradient of the ε-cos α diagram. The ε-cos α diagram shows a relationship between cos α (α: diffraction center angle) and distortion ε expressed by using the distortion (ε α , ε π+α , ε −α , ε π−α ) at four positions (α, π+α, −α, π−α) on the diffraction ring. 
     The stress calculation unit  164  (see  FIG. 6 ) calculates the gradient of the ε-cos α diagram (the gradient of linear function) using two points of α=0° and 180°. Then, the stress calculation unit  164  (see  FIG. 6 ) obtains the residual stress by multiplying the gradient of the linear function by the X-ray stress measurement multiplier. The X-ray stress measurement multiplier is a constant determined by Young&#39;s modulus, Poisson&#39;s ratio, complementary angle of Bragg angle, and X-ray incident angle and is stored in advance in the storage unit  166  shown in  FIG. 6 . The stress calculation unit  164  outputs a calculated residual stress value to the control unit  26  via the input/output unit  160 . The residual stress value calculated by the stress calculation unit  164  may be output to the control unit  26  and stored in the storage unit  166  or may be output to the output device  156  (see  FIG. 5 ). 
     &lt;Residual Stress Measurement Method by Stress Measurement Device  22 &gt; 
     Next, a residual stress measurement method using the stress measurement device  22  will be described.  FIGS. 9(A) and 9(B)  are flowcharts showing a residual stress measurement method according to this embodiment. 
     First, an adjustment process before residual stress measurement is performed.  FIG. 9(A)  is a flowchart showing the adjustment process before residual stress measurement. As shown in  FIG. 9(A) , an angle adjustment process (step S 240 ) is first performed. In this process, the angle of the X-rays incident to the inspection target W is adjusted. For example, as shown in  FIG. 6 , when the device body  100  is tilted to adjust a tilting angle θ 1 , the angle of the incident X-ray is adjusted. A process of tilting the device body  100  is performed by a separate device (a control unit and an actuator) as an example. An incident angle during measurement is fixed to a predetermined angle (a single angle) by the angle adjustment process (step S 240 ) shown in  FIG. 9(A) . 
     Next, a focus adjustment process (step S 242 ) is performed. In this process, a focus of the X-rays incident to the inspection target W is adjusted. For example, when the position of the device body  100  (see  FIG. 6 ) is changed, the focus of the X-rays is adjusted. A process of changing the height and the position is performed by a separate device (a control unit and an actuator) as an example. 
     When the flowchart shown in  FIG. 9(A)  ends, the stress measurement device  22  can measure the residual stress on the surface side of the inspection target W.  FIG. 9(B)  is a flowchart showing a method of measuring the residual stress on the surface side of the inspection target W. 
     As shown in  FIG. 9(B) , an X-ray irradiation process (step S 250 : an X-ray irradiation step) is first performed. In the X-ray irradiation process (step S 250 ), X-rays are irradiated from the X-ray generation source  102  to the inspection target W. Next, a measurement process (step S 252 : a movement control step) is performed during the X-ray irradiation process (step S 250 ). In the measurement process (step S 252 ), the movement mechanism  120  is driven by the control of the movement control unit  162  to move the first detection element  106  and the second detection element  108  (the movement control step) and two X-ray diffraction intensity distributions are obtained on the basis of the detection results of the first detection element  106  and the second detection element  108  in the moving state. In this step, the movement of the first detection element  106  is synchronized with the movement of the second detection element  108 . When the measurement process (step S 252 ) ends, the X-ray irradiation may end. 
     Next, a residual stress calculation process (step S 254 : a stress calculation step) is performed. In the residual stress calculation process (step S 254 ), the residual stress of the inspection target W is calculated on the basis of the intensity peaks of the diffracted X-rays respectively detected by the first detection element  106  and the second detection element  108  during the measurement process (step S 252 : the movement control step). That is, in the residual stress calculation process (step S 254 ), two intensity peaks are acquired on the basis of two X-ray diffraction intensity distributions obtained during the movement by the stress calculation unit  164 . Then, the gradient of the ε-cos α diagram is calculated by the stress calculation unit  164  and is multiplied by the X-ray stress measurement multiplier to calculate the residual stress. Finally, the residual stress calculated by the stress calculation unit  164  is output to the control unit  26  (see  FIG. 3(A) ) (step S 256 ). 
     The flowchart shown in  FIG. 9(B)  ends as described above. When the control process shown in  FIG. 9(B)  is performed, the residual stress can be calculated by using the data obtained by moving the first detection element  106  and the second detection element  108 . Then, the calculated residual stress can be output to the control unit  26  (see  FIG. 3(A) ). 
     As described above, since the stress measurement device  22  shown in  FIG. 6  includes the first detection element  106  which detects the intensities of the diffracted X-rays at the first detection position P 1  (see  FIG. 7 ) and the second detection element  108  which detects the intensities of the diffracted X-rays at the second detection position P 2  (see  FIG. 7 ) different from the first detection position P 1  (see  FIG. 7 ), it is possible to obtain the diffracted X-rays at two angles by one X-ray irradiation (an irradiation at a single angle). Each of the first detection element  106  and the second detection element  108  can acquire the X-ray intensity distribution (the diffraction peak) for each element while moving in a direction orthogonal to the X-ray incident direction. It is possible to calculate the residual stress of the inspection target W by acquiring at least two diffraction peaks. For this reason, it is not necessary to acquire all data of the diffraction ring by rotating the imaging plate. Thus, it is possible to shorten the residual stress measurement time compared to the conventional residual stress measurement device. 
     The stress measurement device  22  according to this embodiment does not need to include an imaging plate rotating mechanism and a reading mechanism. For this reason, since the stress measurement device  22  is simplified and decreased in weight compared to the residual stress measurement device with such a mechanism, the stress measurement device can be easily provided and assembled to other devices. Since the device configuration of the stress measurement device  22  is simplified, it is possible to decrease the manufacturing cost of the device compared to the known residual stress measurement device. 
     Since the movement control unit  162  synchronizes the movement of the first detection element  106  and the movement of the second detection element  108 , it is possible to shorten the residual stress measurement time compared to a case in which the first detection element  106  and the second detection element  108  are individually controlled. 
     (Surface Treatment Processing Method by Surface Treatment Processing Device  10 ) 
     Next, a surface treatment processing method using the surface treatment processing device  10  shown in  FIG. 2  will be described with reference to the flowcharts shown in  FIGS. 1(A), 1(B) , and  2 . The surface treatment processing device  10  includes the magnetic evaluation device  20  shown in  FIG. 4(A)  and the like, the stress measurement device  22  shown in  FIG. 5  and the like, and the shot peening processing device  30  shown in  FIG. 3(B)  and the like. Heat treatment processing is performed on a treatment target (a product) having a product shape by plastic processing and mechanical processing as an example of the treatment target W to be carried into the surface treatment processing device  10  shown in  FIG. 2 . 
     The treatment target W which is carried to the surface treatment processing device  10  shown in  FIG. 2  is carried on the carry-in conveyor  12 . When the treatment target W reaches the first inspection zone  14 , the treatment target W is disposed on the inspection table  16 A by the six-axis robot  18  and is inspected by the magnetic evaluation device  20 . Then, the treatment target W is disposed on the inspection table  16 B by the six-axis robot  18  and is inspected by the stress measurement device  22 . 
     That is, an inspection before the shot processing shown in step S 200  of  FIG. 1(A) , that is, a first inspection step is performed on the inspection tables  16 A and  16 B. In the first inspection step, the surface side state of the treatment target W to be subjected to the shot processing for shooting the shot media at the treatment target W is nondestructively inspected. When the inspection result deviates from the first allowable range which is predetermined, it is evaluated that the result is “failed”. 
     First, on the inspection table  16 A shown in  FIG. 2 , the magnetic evaluation device  20  inspects the surface side of the treatment target W by an eddy current. A detailed inspection method is as described above. In the magnetic evaluation device  20 , the determination means  96  determines the surface state on the basis of the inspection result. The magnetic evaluation device  20  outputs the inspection result (that is, the evaluation result of the determination means  96 ) to the control unit  26  (see  FIG. 3(A) ). Next, on the inspection table  16 B, the stress measurement device  22  measures the residual stress on the surface side of the treatment target W by using an X-ray diffraction method. A detailed measurement method is as described above. The stress measurement device  22  outputs the measurement result to the control unit  26  (see  FIG. 3(A) ). The control unit  26  performs an evaluation of any one of “passed”, “conditionally passed”, and “failed” on the basis of the inspection results of the magnetic evaluation device  20  and the stress measurement device  22 . 
     In step S 202  shown in  FIG. 1(A) , the control unit  26  determines whether the treatment target W is “failed”. A process of the control unit  26  proceeds to step S 206  when the determination of step S 202  is negative. The process of the control unit  26  proceeds to step S 204  when the determination of step S 202  is positive. In step S 206 , the control unit  26  controls the six-axis robot  18  shown in  FIG. 2  so that the treatment target W is extracted to the outside of the line of the surface treatment process. The treatment target W which is extracted to the outside of the line is discarded. That is, the treatment target W which is evaluated as “failed” in the first inspection step is excluded from the shot processing target in advance. Accordingly, unnecessary shot peening processing (defective product processing) is suppressed. 
     In step S 204  shown in  FIG. 1(A) , the control unit  26  determines whether the treatment target W is “passed”. A process of the control unit  26  proceeds to step S 210  when the determination of step S 204  is negative. The process of the control unit  26  proceeds to step S 208  when the determination of step S 204  is positive. In step S 208  and step S 210 , the condition setting step is performed. In the condition setting step performed after the first inspection step, the control unit  26  sets the shot processing condition for the treatment target W which is evaluated as “failed” in the first inspection step in response to the inspection result of the first inspection step. 
     In step S 210 , the control unit  26  sets (feeds forward) a condition (an adjusted condition) obtained by correcting the standard shot processing condition as the shot processing condition for the treatment target W determined as “conditionally passed”. That is, the shot processing condition is individually adjusted (for each product) in accordance with the property of the treatment target W (the product) before the individual shot peening processing. Accordingly, the treatment target W which can be a defective product due to the processing in the standard shot processing condition can be manufactured as a good product. Accordingly, it is possible to decrease the treatment target W to be discarded. Accordingly, productivity can be improved. 
     A correction (adjustment) of the shot processing condition for the treatment target W determined as “conditionally passed” will be described in detail. In this embodiment, a condition obtained by correcting the projection pressure for projecting the shot media is set as an example in the shot processing condition. A correction condition (a correction value) of the shot processing condition is calculated as below. First, the arithmetic process device of the control unit  26  reads a program including a calculation equation stored in the storage unit in advance and develops the program in the memory. Next, the program which is developed in the memory is executed by the CPU. Accordingly, the correction condition is calculated. The calculation equation is an equation including the reference value of the shot processing condition. In a modified example, a program including a condition determination may be stored in the arithmetic process device of the control unit  26  in advance and the program may be executed to determine the correction condition for the shot processing condition. 
     Meanwhile, in step S 208 , the control unit  26  directly sets the standard shot processing condition as the shot processing condition for the treatment target W determined as “passed”. It is possible to perform shot processing in response to the treatment target W by step S 210  and step S 208 . 
     The treatment target W which is determined as “passed” or “conditionally passed” is moved onto the carry-in conveyor  12  from the inspection table  16 B by the six-axis robot  18  shown in  FIG. 2 . Then, the treatment target W is carried into the cabinet  32  of the shot peening processing device  30  by the carry-in/carry-out loader  28  at the downstream side of the carry-in conveyor  12 . 
     In the cabinet  32  of the shot peening processing device  30 , step S 212  shown in  FIG. 1(A) , that is, the shot processing step is performed. In the shot processing step performed after the condition setting step, the projection device  40  of the shot peening processing device  30  shown in  FIG. 3(B)  performs the shot processing of shooting the shot media at the treatment target W. The shot processing condition in the shot processing step is set by the control unit  26  in the condition setting step for the treatment target W which is evaluated as “not failed” by the control unit  26  in the first inspection step. 
     Here, the shot processing will be described. As the shot processing, for example, shot peening (processing) and shot blasting (processing) are known. In such shot processing, for example, roughly spherical shot media (including shots (including abrasive grains)) of several tens of μm to several mm is made to collide with the treatment target W at a high speed. Accordingly, an effect of improving the part surface layer of the treatment target W can be obtained. Shot peening processing is used for the purpose of improving the fatigue strength (durability) of parts subjected to repeated load. Examples of parts subjected to repeated load include automobiles, aircraft, ships, construction machines, processing devices, steel structures, and the like. If the shot peening processing is not properly performed, the surface hardness, the hardness distribution, the compressive residual stress, and the like which need to be obtained are not applied to the parts and the parts may be destroyed at an early stage. Thus, it is necessary to carry out shot peening processing with adequate control in order to maintain proper processing. The shot blasting process is used to secure, for example, removal of deposits on a surface such as rust and scale, adjustment of a surface shape such as surface roughness, improvement of adhesion such as coating and coating film, or an appropriate wear coefficient in a frictional coupling part for the same processed product. Thus, it is necessary to perform shot blasting processing after adequate control similarly to shot peening processing. The shot processing of this embodiment is shot peening processing. 
     The treatment target W subjected to the shot processing is carried to the upstream side of the carry-out conveyor  66  from the inside of the cabinet  32  of the shot peening processing device  30  by the carry-in/carry-out loader  28  shown in  FIG. 2 . The treatment target W is carried by the carry-out conveyor  66 . When the treatment target W reaches the second inspection zone  68 , the treatment target W is disposed on the inspection table  70 A by the six-axis robot  72  and is inspected by the magnetic evaluation device  74 . Then, the treatment target W is disposed on the inspection table  70 B by the six-axis robot  72  and is inspected by the stress measurement device  76 . 
     In other words, an inspection after the shot processing shown in step S 214  of  FIG. 1(A) , that is, the second inspection step is performed on the inspection tables  70 A and  70 B. In the second inspection step after the shot processing step, the surface side state of the treatment target W is nondestructively inspected. When the inspection result is within the second normal range set in advance, it is evaluated that the result is “passed”. Then, when the inspection result is out of the second normal range, it is evaluated that the result is “failed”. 
     The magnetic evaluation device  74  performs an inspection of performing a magnetic evaluation on the surface side of the treatment target W by an eddy current on the inspection table  70 A shown in  FIG. 2 . A detailed inspection method is as described above. In the magnetic evaluation device  74 , the determination means  96  determines whether the surface state is acceptable on the basis of the inspection result. The magnetic evaluation device  74  outputs the inspection result (that is, the evaluation result of the determination means  96 ) to the control unit  26  (see  FIG. 3(A) ). Next, the stress measurement device  76  measures the residual stress on the surface side of the treatment target W on the inspection table  70 B by using the X-ray diffraction method. A detailed measurement method is as described above. The stress measurement device  76  outputs a measurement result to the control unit  26  (see  FIG. 3(A) ). As described above, the control unit  26  performs an evaluation of any one of “passed” and “failed” on the basis of the inspection results of the magnetic evaluation device  74  and the stress measurement device  76 . 
     In step S 216  after step S 214  shown in  FIG. 1(A) , the control unit  26  stores the inspection result (the measurement value) of the stress measurement device  76  in the storage device. In step S 218  after step S 216 , the control unit  26  determines whether the treatment target W is “passed”. A process of the control unit  26  proceeds to step S 222  when the determination of step S 218  is negative and proceeds to step S 220  when the determination of step S 218  is positive. 
     In step S 222 , the control unit  26  controls the six-axis robot  72  shown in  FIG. 2  so that the treatment target W is extracted to the outside of the line of the surface treatment step. The treatment target W which is extracted to the outside of the line is discarded. The treatment target W which is determined as “passed” is moved onto the carry-out conveyor  66  from the inspection table  70 B by the six-axis robot  72 . Then, the treatment target W is carried by the carry-out conveyor  66  to be sent to the subsequent step. That is, step S 220  shown in  FIG. 1(A)  is performed. 
     In this way, according to this embodiment, the actual treatment target W is inspected instead of the test sample in the second inspection step performed after the shot processing step. Accordingly, it is possible to directly determine whether a shot peening effect (an effect of shot processing) is given to the treatment target W. Then, it is possible to prevent the incomplete treatment target W from flowing to the step after the step performed in the surface treatment processing device  10 . In this embodiment, the first inspection step is provided before the shot processing step. For this reason, it is possible to selectively remove the treatment target W which is not suitable for shot peening processing (that is, the treatment target which cannot have the shot peening effect even after shot peening processing) before the shot processing step. Accordingly, it is possible to prevent a defective product from occurring or to suppress a defective product effectively in the shot processing step. 
     Next, a process of resetting the reference value (the standard setting reference value) of the shot processing condition, that is, a reference value resetting step will be described with reference to  FIG. 1(B) . As an example, this process is performed when the control unit  26  is activated before processing starts everyday. 
     First, in step S 230  shown in  FIG. 1(B) , the control unit  26  determines whether the reference value of the shot processing condition needs to be reset. In this embodiment, as an example, the control unit  26  first predicts a date (in a broad sense, “time”) when the average stress value deviates from the second normal stress range (the second normal range for stress) set in advance on the basis of the tendency of a daily change (in a broad sense, a “temporal change”) of the above-described stress average value. Next, the control unit  26  determines whether or not the execution time of step S 230  is later than the date set in advance by a predetermined number of days (for example, three days ago) with respect to the predicted date. Next, the control unit  26  determines whether the execution time of step S 230  is later than a date set in advance by a predetermined number (for example, three days ago). Since a method of calculating a date in which the average stress value is predicted to deviate from the second normal stress range (the second normal range for stress) set in advance has been described above, a description thereof will be omitted. A process of the control unit  26  ends when the determination of step S 230  shown in  FIG. 1(B)  is negative and proceeds to step S 232  when the determination of step S 230  is positive. 
     In the reference value resetting step of step S 232  shown in  FIG. 1(B) , the control unit  26  resets the reference value of the shot processing condition so as to suppress a ratio in which the treatment target W is not evaluated as “passed” in the second inspection step (a ratio in which the inspection result of the second inspection unit  68 E is out of the second normal range) on the basis of the tendency of a temporal change in inspection result obtained by the stress measurement device  76  in the second inspection step. That is, in the reference value resetting step, the inspection result of the second inspection step is fed back to the reference value of the shot processing condition. The reference value resetting step is performed before a date in which the average stress value is predicted to deviate from the standard stress range (the second normal stress range) on the basis of the tendency of a daily change in the average stress value. Since a method of calculating a date in which the average stress value is predicted to deviate from the standard stress range (the second normal stress range) has been described, a description thereof will be omitted. In the reference value resetting step of this embodiment, the control unit  26  resets the reference value of the projection pressure for projecting the shot media as an example in the shot processing condition. 
     Accordingly, it is possible to perform a correction in response to a mid/long-term change of the shot peening processing device  30  including the projection device  40  shown in  FIG. 3(B)  and the like, that is, a change in particle diameters of the shot media, a change in shape of a mechanism (a nozzle or the like) for accelerating the shot media, and a change in property of the compressed air supplied from the compressor. Accordingly, it is possible to effectively suppress the ratio of “failed” in the second inspection step at the next time. Thus, it is possible to suppress unnecessary shot peening processing. 
     As described above, according to the surface treatment processing method and the surface treatment processing device  10  (see  FIG. 2 ) of this embodiment, it is possible to manage the processing degree of all treatment targets W subjected to shot processing while suppressing unnecessary shot processing. 
     Here, the functions and effects of the above-described embodiment will be further described. As a method of quality control in shot peening processing, a device operation management and a product management are known. In the device operation management, the operation state of the processing device is monitored. In the device operation management, parameters (specifically, the projection pressure of the air nozzle type shot peening processing device and a rotation speed of a shooting impeller of the centrifugal shooting device) relating to the speed of the shot media, the flow rate of the shot media, the processing time, and the rotation speed and the rotation state of the treatment target W (the product) on the rotation table are monitored. In the device operation management, the shot peening processing step is guaranteed by operating the processing device while these parameters are within a specified value. In contrast, in the product management, the compressive residual stress, the hardness, and the surface roughness which are shot peening effect indexes are measured for the actually processed product. There is known a method of measuring the processing degree by the shot peening processing device according to an Almen method as an intermediate role between the device operation management and the product management. The method according to the Almen method is a method of measuring a bent state using a test sample and can measure the reproducibility of the processing degree of the device. However, in the method according to the Almen method, it is impossible to control the processing degree to the actual product. 
     Incidentally, in the device operation management, only the operation state of the device is monitored. For this reason, it is not possible to determine whether a shot peening effect is given to the processed product. Most of the treatment targets W (products) to be brought into the shot peening step are subjected to a heat treatment or the like to be in a state that a sufficient effect can be obtained by shot peening processing. However, since a metal structure is not suitable due to the trouble of the heat treatment state, there is a possibility that the treatment target W (the product) which is not proper due to unsatisfactory surface hardness or hardness distribution may be input. Also the product subjected to satisfactory processing in the device operation management may not be suitable as a passed product. Meanwhile, in the product management, the shot peening effect is given to the surface and a range of several tens of μm to several hundreds of μm from the surface. For this reason, the product management often involves a destructive inspection that scratches and measures the inside of a product. Further, since it takes a measurement time, only a part of a processing lot is generally inspected. 
     In contrast, in the surface treatment processing method according to this embodiment, all treatment targets W are inspected. Accordingly, it is possible to manage the processing degree of all treatment targets W subjected to the shot processing. 
     Second Embodiment 
     Next, a surface treatment processing method according to a second embodiment will be described with reference to  FIG. 2 . A treatment target W according to this embodiment is a thin product such as a leaf spring and a disc spring. A configuration of a surface treatment processing device according to this embodiment is substantially the same as the surface treatment processing device  10  of the first embodiment shown in  FIG. 2 , but is different from the configuration of the surface treatment processing device  10  of the first embodiment in that a non-contact laser displacement meter (not shown) is disposed instead of the magnetic evaluation devices  20  and  74  and the stress measurement device  22  of the first inspection unit  14 E is not disposed. The difference is substantially the same as that of the first embodiment. 
     The laser displacement meter nondestructively inspects the external dimension of the treatment target W. The thin product is easily deformed by shot peening processing. For this reason, the laser displacement meter is disposed. The laser displacement meter of the first inspection zone  14  constitutes the first inspection unit. The laser displacement meter and the stress measurement device  76  of the second inspection zone  68  constitute the second inspection unit. 
     In the first inspection step, the laser displacement meter nondestructively inspects the external dimension of the treatment target W to be subjected to shot processing (measures initial distortion). In the shot processing, the shot media are shot at the treatment target W. The control unit  26  inputs the inspection result of the laser displacement meter and evaluates that the treatment target is “failed” when the inspection result deviates from the first allowable range (the first allowable displacement range) set in advance. In the condition setting step after the first inspection step, the control unit  26  sets the shot processing condition in response to the inspection result in the first inspection step for the treatment target W which is evaluated as “not failed” in the first inspection step. Specifically, the control unit  26  controls the deformation amount by increasing and decreasing the processing time in the shot processing condition on the basis of a difference between a target shape and an initial distortion amount. The control unit  26  sets the shot processing condition so that the shape of the treatment target W subjected to shot peening processing becomes similar to the target shape. In the shot processing step after the first inspection step, similarly to the first embodiment, the shot processing of shooting the shot media at the treatment target W is performed in the shot processing condition set for the treatment target W, which is evaluated as “not failed” in the first inspection step, in the condition setting step. 
     In the second inspection step after the shot processing step, the laser displacement meter and the stress measurement device  76  nondestructively inspect the surface side state and the external dimension of the treatment target W. The control unit  26  inputs the inspection result and evaluates that the treatment target W is “passed” when the inspection result is within a second normal range (a second normal displacement range for displacement and a second normal stress range for stress) set in advance. That is, in the second inspection step, the distortion after processing is measured by the laser displacement meter in order to determine whether the shape subjected to shot peening processing is appropriate. At the same time, the stress measurement device  76  measures the residual stress on the surface side of the treatment target W by using the X-ray diffraction method. The control unit  26  (see  FIG. 3(A) ) performs an evaluation of any of “passed” and “failed” on the basis of the inspection results of the laser displacement meter and the stress measurement device  76 . More specifically, the control unit  26  (see  FIG. 3(A) ) evaluates (determines) that the treatment target W is “passed” when any one of the inspection results of the laser displacement meter and the stress measurement device  76  is within the second normal range set in advance and evaluates (determines) that the result is “failed” (discarded) in other cases. 
     In the reference value resetting step, similarly to the first embodiment, the reference value of the shot processing condition is reset so as to suppress a ratio in which the treatment target is not evaluated as “passed” in the second inspection step (a ratio in which the inspection result in the second inspection step is out of the second normal range) on the basis of a temporal change in inspection result of the second inspection step. Thus, it is possible to increase the number of the treatment targets W evaluated as “passed” in the second inspection step. In this embodiment, the reference value (the standard setting reference value) of the shot processing condition reset in the reference value resetting step is a reference value for processing time. 
     Also in this embodiment, it is possible to obtain the same functions and effects as that of the above-described first embodiment. 
     The outer diameter dimension of the treatment target W may be measured by a contact distance meter such as a micrometer as long as the control dimension for each treatment target W can be measured. In a modified example of this embodiment, the control unit  26  may evaluate that the treatment target W is “failed” when the surface side state and the external dimension of the treatment target W are nondestructively inspected in the first inspection step and the inspection result is out of the first allowable range which is predetermined. That is, in the first inspection step, the nondestructive inspection may be performed by, for example, the magnetic evaluation device  20  or the stress measurement device  22  in addition to the laser displacement meter. In another modified example of this embodiment, only the external dimension of the treatment target W is nondestructively inspected in the second inspection step and the treatment target W may be evaluated as “passed” when the inspection result is within the second normal range set in advance. 
     In this embodiment, the stress measurement device  22  of the first inspection unit  14 E shown in  FIG. 2  is not disposed and the stress measurement device  76  of the second inspection unit  68 E is disposed. The stress measurement device  76  of the second inspection unit  68 E shown in  FIG. 2  may not be disposed and the stress measurement device  22  of the first inspection unit  14 E may be disposed. 
     [Additional Description of Embodiments] 
     In the above-described embodiments, the shot peening processing device  30  including the projection device  40  (the air nozzle type shot peening processing device) is used as a shooting unit. As the shooting unit, for example, another shooting unit such as a shot blasting device including a centrifugal shooting device for accelerating and shooting shot media by a centrifugal force generated as an impeller rotates may be used. Since the centrifugal shooting device is a known technology, a detailed description will be omitted. As an example, a device which includes a control gauge, an impeller including a plurality of blades, and a drive motor rotationally driving the impeller corresponds to the centrifugal shooting device. The control gauge is formed in a cylindrical shape and supplies shot media thereinto. An outer peripheral wall of the control gauge is provided with an opening window which is shot media discharge portion. The plurality of blades are disposed on the outer peripheral side of the control gauge and rotate in the circumferential direction of the control gauge. In the case of such a centrifugal shooting device, for example, when the rotation speed of the drive motor per unit time is controlled, the rotation speed of the impeller per unit time is controlled. 
     As a modified example of the above-described embodiments, at least one of the first inspection step and the second inspection step may include at least one of an inspection of measuring a color tone of a surface side of the treatment target W corresponding to the inspection target and an inspection of measuring surface roughness of the treatment target W corresponding to the inspection target. 
     When the inspection of measuring the surface roughness of the treatment target W is performed in at least one of the first inspection step and the second inspection step, a non-contact laser displacement meter using an optical system or the like may be applied in addition to a stylus type surface roughness meter. 
     When the inspection of measuring the color tone of the surface side of the treatment target W is performed in at least one of the first inspection step and the second inspection step, for example, color of the treatment target W (the product) may be distinguished. A color measurement method disclosed in JIS Z8722 may be applied. In addition, since the treatment target W (the target product) is formed of metal in many cases, an image sensor or a gloss meter measuring the degree of gloss by a measurement method disclosed in JIS Z8741 may be applied. 
     The inspection device used in the first inspection step and the second inspection step may output a measurement result to an external calculation device and a control device in order to store and calculate the measurement result. 
     The same inspection item is inspected in the first inspection step and the second inspection step of the first embodiment, but a different inspection item may be inspected as in the first inspection step and the second inspection step of the second embodiment. An inspection item according to the treatment target W (the target product), preceding steps, and the shot processing effect (the shot peening effect) to be obtained may be inspected. In the first inspection step and the second inspection step, a plurality of inspection items may be inspected or one inspection item may be inspected. Various patterns can be applied to a combination of the inspection items. In other words, each of the first inspection unit and the second inspection unit may be provided with a single inspection device or a plurality of inspection devices. Various patterns can be applied to a combination of the inspection devices. 
     As the control unit  26 , a control unit including a calculator such as a PC, a sequencer, and a microcomputer can be applied. The calculator or the like may be provided at the shooting unit (the shot peening processing device  30 ) or the first inspection unit  14 E. 
     In the first embodiment, the determination means  96  of the magnetic evaluation devices  20  and  74  determines whether the inspection results of the magnetic evaluation devices  20  and  74  are within the first normal magnetic range or the second normal magnetic range set in advance and outputs the evaluation results to the control unit  26 . The invention is not limited thereto. For example, the magnetic evaluation devices  20  and  74  may output the inspection results (the voltage values) of the magnetic evaluation devices  20  and  74  to the control unit  26  and the control unit  26  may evaluate (determine) whether the inspection results are within the first normal magnetic range or the second normal magnetic range set in advance. 
     The stress measurement devices  22  and  76  may include the determination means. In this case, the determination means of the stress measurement devices  22  and  76  may evaluate (determine) the inspection results of the stress measurement devices  22  and  76  and may output the evaluation results to the control unit  26 . 
     The control unit  26  can evaluate (determine) that the treatment target W is “conditionally passed”, that is, whether the processing is available by changing the shot processing condition on the basis of the inspection result of the stress measurement device  22 . Similarly, the control unit  26  can evaluate (determine) that the treatment target W is “conditionally passed” on the basis of the inspection result of the magnetic evaluation device  20 . In this case, the control unit  26  evaluates that the treatment target W is “passed” when the inspection result of the magnetic evaluation device  20  is within the first normal magnetic range and the inspection result of the stress measurement device  22  is within the first normal stress range. The control unit  26  evaluates (determines) that the treatment target W is “conditionally passed” when the inspection result of the magnetic evaluation device  20  is within the first allowable magnetic range deviating from the first normal magnetic range and the inspection result of the stress measurement device  22  is within the first normal stress range. The control unit  26  evaluates (determines) whether the inspection result is “failed” when the inspection result of the magnetic evaluation device  20  is out of the first allowable magnetic range or the inspection result of the stress measurement device  22  is out of the first normal magnetic range. 
     The control unit  26  can evaluate (determine) that the treatment target W is “conditionally passed” on the basis of both inspection results of the magnetic evaluation device  20  and the stress measurement device  22 . In this case, the control unit  26  evaluates that the treatment target W is “passed” when the inspection result of the magnetic evaluation device  20  is within the first normal magnetic range and the inspection result of the stress measurement device  22  is within the first normal stress range. The control unit  26  evaluates that the treatment target W is “conditionally passed” when the inspection result of the magnetic evaluation device  20  is within the first normal magnetic range and the inspection result of the stress measurement device  22  is out of the first normal stress range, but is within the first allowable stress range. The control unit  26  evaluates that the treatment target W is “conditionally passed” when the inspection result of the magnetic evaluation device  20  is out of the first normal magnetic range, but is within the first allowable magnetic range and the inspection result of the stress measurement device  22  is within the first normal stress range. The control unit  26  evaluates that the treatment target W is “conditionally passed” when the inspection result of the magnetic evaluation device  20  is out of the first normal magnetic range, but is within the first allowable magnetic range and the inspection result of the stress measurement device  22  is out of the first normal stress range, but is within the first allowable stress range. The control unit  26  evaluates that the treatment target W is “failed” when the inspection result of the magnetic evaluation device  20  is out of the first allowable magnetic range or the inspection result of the stress measurement device  22  is out of the first allowable stress range. 
     The control unit  26  sets (feeds forward) a condition (an adjusted condition) obtained by correcting the standard shot processing condition as the shot processing condition for the treatment target W determined as “conditionally passed”. Accordingly, it is possible to decrease the number of the treatment targets W to be discarded. More specifically, shot media are projected in the shot processing condition obtained by correcting the standard shot processing condition so that, for example, the projection pressure (the shooting pressure) increases for the treatment target W of which the inspection result in the magnetic evaluation device  20  is slightly smaller than the first normal magnetic range in the treatment targets W of the inspection targets determined as “conditionally passed”. In contrast, shot media are projected in the shot processing condition obtained by correcting the standard shot processing condition so that, for example, the projection pressure (the shooting pressure) decreases for the treatment target W of which the inspection result of the magnetic evaluation device  20  is slightly larger than the first normal magnetic range in the treatment targets W of the inspection targets determined as “conditionally passed”. 
     For example, at least one of a shot media projection volume per unit time, a shot media projection speed, and a relative shooting position for the treatment target W may be corrected other than the projection pressure for projecting the shot media and the processing time in the shot processing condition for the treatment target W determined as “conditionally passed” in the first inspection step. In the case of the centrifugal shooting device which accelerates and shoots shot media with a rotation of the impeller, the rotation speed of the impeller per unit time may be corrected and set. When the shot media projection speed cannot be directly changed, it is possible to change a parameter closely relating to the projection speed instead of changing the projection speed. As such a parameter, the projection pressure of the air nozzle type shot peening processing device and the rotation speed of the impeller per unit time of the centrifugal shooting device are exemplified. The relative shooting position for the treatment target W can be changed depending on the movement range of the air nozzle, the movement amount of the treatment target W (the processing product), or the rotation amount of the rotation table (the revolving table, the spinning table) on which the treatment target W is disposed. 
     As a modified example of the above-described embodiments, the treatment target W (the product) evaluated as “failed” may be discarded by evaluating the treatment target in two stages of “passed” and “failed” on the basis of the inspection result of the first inspection step. That is, the control unit  26  does not distinguish the states of “conditionally passed” and “passed”. The control unit  26  determines that the treatment target W is “passed” when the inspection result of the first inspection step is within the first allowable range and determines that the inspection result is “failed” when the inspection result is out of the first allowable range. In this case, in the condition setting step, the shot processing condition is set in response to the inspection result of the first inspection step instead of uniformly setting the reference value of the shot processing condition for the treatment target W evaluated as “passed”. 
     In the above-described embodiments, the treatment target W evaluated as “failed” in the first inspection step is discarded, but the treatment target W evaluated as “failed” in the first inspection step may be reused or may not be discarded as long as it does not flow to the shot processing step. In the case of reusing the treatment target W, the treatment target W evaluated as “failed” may be reused as a treatment target for another purpose, or may be carried into the same surface treatment processing device  10  again to be processed after a process to correct the treatment target W in a separate step and. 
     In the above-described embodiments, the treatment target W evaluated as “failed” in the first inspection step is discarded immediately after the determination as “failed” and only the treatment target W evaluated as “passed” or “conditionally passed” flows to the next step. For example, the treatment target W evaluated as “passed” and the treatment target W evaluated as “failed” may be carried in a mixed state for the convenience of the configuration of the production line. In this case, the treatment target W evaluated as “failed” may be separately removed and only the treatment target W evaluated as “passed” may be extracted to be subjected to the shot processing. 
     The reference value of the shot processing condition which is resettable in the reference value resetting step may include at least one of the shot media projection volume per unit time, the shot media projection speed, the projection pressure for projecting the shot media, the rotation speed of the impeller per unit time for accelerating and shooting shot media by the centrifugal force generated by the rotation of the impeller, the processing time, and each reference value of the relative shooting position for the treatment target W. In the reference value resetting step, the reference value can be reset to a higher value or a lower value. 
     As a modified example of the above-described embodiments, the control unit  26  shown in  FIG. 3(A)  may calculate an average value per half day instead of the average value per day. In that case, the control unit calculates a date in which the average stress value deviates from the standard stress range (the second normal range for stress, that is, the second normal stress range) on the basis of the tendency of a temporal change of the average stress value which is an average value per half day. Then, in the reference value resetting step, the control unit  26  resets the reference value of the shot processing condition before the predicted date. That is, the “average value for each predetermined period” may be an “average value per day” as in the above-described embodiments, an “average value per half day” as in a modified example of the above-described embodiment, or an average value for every other predetermined period (for example, an average value per week). 
     As a modified example of the above-described embodiments, the control unit  26  may reset the reference value of the shot processing condition to suppress a ratio in which treatment target W is not evaluated as not “passed” in the second inspection step (a ratio in which the inspection result of the second inspection unit  68 E is out of the second normal range) on the basis of the tendency of a temporal change in inspection result of the magnetic evaluation device  74  in the second inspection step instead of the tendency of a temporal change in inspection result of the stress measurement device  76  in the second inspection step. That is, the inspection result of the magnetic evaluation device  74  may be fed back to the reference value of the shot processing condition. Both of the magnetic evaluation device  74  and the inspection result of the stress measurement device  76  may be fed back to the reference value of the shot processing condition. 
     In the above-described embodiments, the stress measurement devices  22  and  76  include the first detection element  106  and the second detection element  108  shown in  FIG. 6  and the like, but the stress measurement devices  22  and  76  may include three or more detection elements. 
     In the stress measurement devices  22  and  76  (see  FIG. 2 ) according to the above-described embodiment, the movement mechanism  120  shown in  FIG. 6  includes the single electric motor  122  and the single ball screw mechanism  124  operated by the single electric motor  122  in order to respectively move the first detection element  106  and the second detection element  108 , but may include electric motors and ball screw mechanisms respectively corresponding to the first detection element  106  and the second detection element  108 . In this case, the control device  150  can control the movements of the first detection element  106  and the second detection element  108  by controlling the electric motors respectively corresponding to the first detection element  106  and the second detection element  108 . The control device  150  can synchronize the movements of the first detection element  106  and the second detection element  108  or cannot synchronize the movements by controlling two electric motors. 
     In the above-described embodiments, the treatment target W to be inspected by the first inspection step is subjected to a heat treatment, but the treatment target W which is inspected by the first inspection step may be the treatment target W not subjected to the shot processing or the heat treatment, for example, the treatment target subjected to a nitriding treatment. As a modified example of the above-described embodiments, compressive residual stress may be applied to the surface side of the treatment target W, which has a tensile residual stress at the first inspection step, due to processing the shot peening in the shot processing step. 
     As a modified example of the above-described embodiments, as shown in  FIG. 10 , the surface treatment processing device  10  may further include a storage unit  170 . The storage unit  170  includes at least one of the inspection result of the first inspection unit  14 E, the inspection result of the second inspection unit  68 E, and the shot processing condition as data acquired by the surface treatment processing device  10 . The storage unit  170  may store at least one of the inspection result of the first inspection unit  14 E and the inspection result of the second inspection unit  68 E. Here, the storage unit  170  stores, for example, all of the inspection result of the first inspection unit  14 E, the inspection result of the second inspection unit  68 E, and the shot processing condition. 
     The storage unit  170  includes an internal storage unit  172  and an external storage unit  174 . The internal storage unit  172  is a storage unit dedicated for the surface treatment processing device  10  and is not shared by other surface treatment processing devices  10 . The internal storage unit  172  is, for example, an HDD or a flash memory such as an SD card directly connected to the control unit  26 . The external storage unit  174  is a storage unit shared by other surface treatment processing devices  10 . The external storage unit  174  may have a configuration which can be shared by other surface treatment processing devices  10  and may not be actually shared by other surface treatment processing devices  10 . The external storage unit  174  is a server connected to the control unit  26  via an intranet or an internet line (within a facility such as a factory) or outside (out of a facility such as a factory). The external storage unit  174  can be a server within the surface treatment processing device  10  as long as a configuration which can be shared by other surface treatment processing devices  10  is provided. The server may be a cloud server. The external storage unit  174  can store, for example, data acquired by the surface treatment processing devices  10 . 
     In the surface treatment processing method using the surface treatment processing device  10  shown in  FIG. 10 , the storage unit  170  stores at least one of the inspection result of the first inspection step, the inspection result of the second inspection step, and the shot processing condition as the data acquired by the surface treatment processing device  10  (the storage step). In the storage step, the storage unit  170  may store at least one of the inspection result of the first inspection step and the inspection result of the second inspection step. By the storage unit  170  and the storage step, utilization of these data is enhanced. For example, it is possible to analyze the data of the tendency of the operation state of the surface treatment processing device  10  or the surface treatment processing devices  10  later. 
     The data acquired by the surface treatment processing device  10  is temporarily stored in, for example, the internal storage unit  172 . Then, the data stored in the internal storage unit  172  is sent to the external storage unit  174  to be stored in the external storage unit  174  every predetermined period (every shot processing or everyday). For this reason, for example, these data can be temporarily stored in the internal storage unit  172  and can be stored in the external storage unit  174  at an arbitrary timing. For example, when the data acquired by the surface treatment processing device  10  is stored for each shot processing as described above, the storage step may be performed as step S 217  instead of, for example, step S 216  of  FIG. 1(A) . The inspection result of the first inspection unit  14 E may be stored in the internal storage unit  172  by the first inspection step of step S 200 , the inspection result of the second inspection unit  68 E may be stored in the internal storage unit  172  by the second inspection step of step S 214 , and the shot processing condition may be stored in the internal storage unit  172  by the condition setting step of step S 208  or step S 210 . When these data is stored the server, the data may be stored in the server through a transmission step of transmitting the data to the server. That is, the surface treatment processing method may include a first transmission step of transmitting the inspection result of the first inspection unit  14 E to the server, a second transmission step of transmitting the inspection result of the second inspection unit  68 E to the server, and a shot processing condition transmission step of transmitting the shot processing condition to the server. 
     In the condition setting step, the control unit  26  may set the shot processing condition in response to the information input from the server. In the reference value setting step, the control unit  26  may set the reference value in response to the information input from the server. Specifically, when a program read from the storage unit of the arithmetic process device of the control unit  26  is executed, the correction condition for the shot processing condition or the reference value of the shot processing condition is calculated. The control unit  26  can transmit and receive (input and output) information to and from the server by a communication interface unit. The information input from the server may be, for example, the tendency of the operation state of the surface treatment processing device  10  or the surface treatment processing devices  10  obtained by the data analysis. According to these information, the shot processing condition can be optimized. 
     In addition to the configurations of the above-described embodiments, marking (embossing) for product identification may be performed on the treatment target W by a laser marker before the first inspection step or before the shot processing step after the first inspection step. In this case, the control unit  26  may store identification information corresponding to the marking, information of the inspection result of the first inspection step, and information of the inspection result of the second inspection step in the external storage device (the storage unit). Accordingly, it is possible to provide a traceability system that can confirm history information of a finished product using a reader for mark reading. In the surface treatment processing device  10  according to the above-described modified example shown in  FIG. 10 , the storage unit  170  may store these information (the storage step). 
     A method of assigning identification information such as an additional number (a back number) to the processing target W is not particularly limited as long as the processing target W can be specified by the identification information. As the assigning method, for example, in addition to the above-described marking, a method of directly writing characters, a method of writing a shape having code information such as a bar code and a two-dimensional code, a method of writing color tone by paint or the like, and a method of attaching and embedding an IC chip or the like having information can be exemplified. As the data stored in the external storage device or the storage unit  170 , the operation data of the surface treatment processing device  10  can be exemplified other than the identification information of the treatment target W and the workpiece information data including the inspection result. The workpiece information data may further include, for example, an inspection time, a name (identification information) of the surface treatment processing device  10 , or a processing start time. The operation data of the surface treatment processing device  10  includes, for example, a projection pressure (an air pressure), a processing start time, a shot media projection volume (shot projection volume) per unit time, an air flow rate, or a workpiece rotation speed. That is, the operation data of the surface treatment processing device  10  includes the shot processing condition. When the surface treatment processing device  10  includes a plurality of air nozzles, the operation data of the surface treatment processing device  10  includes the operation data for each air nozzle. The storage unit  170  may store these data in another database at, for example, a measurement timing. 
     The above-described embodiments and modified examples can be appropriately combined with each other. 
     An example of the invention has been described above. The invention is not limited to the description above. In addition to the description above, various modifications can be, of course, made within the scope not departing from the gist of the invention. 
     REFERENCE SIGNS LIST 
       10 : surface treatment processing device,  14 E: first inspection unit,  20 : magnetic evaluation device,  22 : stress measurement device,  26 : control unit,  30 : shot peening processing device (shooting unit),  68 E: second inspection unit,  74 : magnetic evaluation device,  76 : stress measurement device,  102 : X-ray generation source,  106 : first detection element,  108 : second detection element,  120 : movement mechanism,  162 : movement control unit,  164 : stress calculation unit,  170 : storage unit, W: treatment target.