Abstract:
A tool shape measurement apparatus for imaging a tool is provided with: a camera for imaging the tool disposed at a previously determined imaging position; a shutter disposed on the opposite side of the tool from the camera; an illuminating device for shining light toward the shutter; and a control device for calculating the shape of the tool from an image of the tool. The illuminating device is disposed so that an image in which the tool is darker than the background of the tool is captured due to light reflected at the reflecting surface of the shutter.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. National Stage Patent Application of International Application No. PCT/JP2015/053974, filed Feb. 13, 2015, which is hereby incorporated by reference in the present disclosure in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a tool shape measurement device and a machine tool. 
       BACKGROUND OF THE INVENTION 
       [0003]    When workpieces are machined with a machine tool, several types of tools may be used for machining one workpiece. When the several types of tools are used for machining, a machine tool provided with a tool exchange device configured to exchange tools is used. The tool exchange device can exchange tools automatically, for example, according to a machining program. 
         [0004]    The tools may be broken while machining workpieces. It is known that the machine tool is provided with a tool shape measurement device in order to confirm soundness of tools. The tool shape measurement device can determine whether or not tools are damaged by measuring shapes of the tools. The shape of the tool includes, for example, a tool length and a tool diameter. Items for inspection of the tool shape include partial damages or breakages of surfaces of the tools. 
         [0005]    The contact type device that measures shapes of tools by bringing a probe or the like into contact with the surfaces of the tools is known as an example of tool shape measurement devices. The image pickup type device that captures an image of the shape of the tool with a camera and calculates the shape of the tool by analyzing the captured image is known as an example of tool shape measurement devices. 
         [0006]    Japanese Unexamined Patent Publication No. 6-134638A discloses a pattern collation and recognition apparatus for tools that includes a photographing device such as a CCD camera disposed so as to face a measurement position in a magazine and an illumination device disposed so as to oppose the photographing device. In addition, it is disclosed that illumination device illuminates the tool from behind by using a diffuser panel. Furthermore, it is disclosed that the photographing device captures a tool pattern image formed by backlight of the tools. 
       CITATION LIST 
       [0007]    Patent Literature 1: Japanese Unexamined Patent Publication No. 6-134638A 
       SUMMARY OF THE INVENTION 
       [0008]    The tool shape measurement device of image pickup type has less number of movable parts and thus is more reliable than the tool shape measurement device of contact type. The tool shape measurement device of image pickup type has a feature that a shape of the tool can be measured at a higher speed than the tool shape measurement device of contact type. For example, the machine tool provided with the tool exchange device measures the shape of the tool after machining by the predetermined tool. 
         [0009]    In the device disclosed in the above-described Japanese Unexamined Patent Publication No. 6-134638A, an illumination device such as fluorescent light or the like irradiates a diffuser panel disposed on a back side of the tool with light. It is disclosed that a frosted glass, an acrylic panel, or the like are used as the diffuser panel. Light passes through the diffuser panel. In a picked up image of the tool, a background of the tool becomes bright and the tool becomes dark. The shapes of the tools are measured by analyzing the dark part of the image. 
         [0010]    In the method disclosed in this publication, chips or the like may be adhered to the diffuser panel. The image pickup device for tools is disposed in a tool storage chamber in which a tool magazine, for example, is disposed. The tool storage chamber is isolated by a partition wall from a machining chamber in which workpieces are machined. However, the partition wall is provided with an opening for loading and unloading the tools. Foreign substances such as chips and coolant may enter the storage chamber through the opening and may be adhered to the diffuser panel. Alternatively, chips may be adhered to the tool and thus may enter the tool storage chamber. The foreign substances may be adhered to the diffuser panel as a result of operation of the tool magazine. When the foreign substances are adhered to the diffuser panel, there was a problem that the shadow of the foreign substances may reflect in a bright area in the background of the tool. Consequently, there was a problem that an adverse effect on the measurement of the tools may occur. 
         [0011]    A tool shape measurement device of the present invention is the tool shape measurement device mounted on a machine tool and configured to measure a shape of a tool by picking up an image of the tool, including: an image pickup device that picks up an image of the tool disposed at an image pickup position determined in advance; a reflector disposed on a side opposite to the image pickup device with respect to the tool in a direction from the image pickup device toward the tool disposed at the image pickup position; a light source that irradiates a reflective surface of the reflector with light; and a control device that calculates the shape of the tool from the image of the tool picked up by the image pickup device. The light source is disposed at a position at which the image of the tool being darker than a background is captured by light reflected from the reflective surface of the reflector. 
         [0012]    In the invention described above, the reflective surface can be formed so as to scatter light, and the reflector can be disposed so that at least part of the light scattered from the reflective surface proceeds toward the image pickup device. 
         [0013]    A machine tool of the present invention is the machine tool that is configured to machine a workpiece by relatively moving a spindle on which a tool is attached and a table on which the workpiece is placed, and includes: an image pickup device that captures an image of the tool disposed at an image pickup position determined in advance; a reflector disposed on a side opposite to the image pickup device with respect to the tool in a direction from the image pickup device toward the tool disposed at the image pickup position; a light source that irradiates a reflective surface of the reflector with light; and a control device that calculates a shape of the tool from the image of the tool picked up by the image pickup device. 
         [0014]    Preferably, in the invention described above, a partition wall that partitions between a machining chamber in which the workpiece is machined and a tool storage chamber in which the tool is stored is provided, and the reflector is formed by a shutter supported by the partition wall, and the shutter is formed movably with respect to the partition wall. 
         [0015]    Preferably, in the invention described above, a removal member that comes into contact with a reflective surface of the shutter so as to remove foreign substances adhered to the reflective surface is provided, and the removal member extends in a direction perpendicular to movement direction of the shutter and slides along the reflective surface when the shutter moves. 
         [0016]    In the invention described above, the reflector is preferably formed by an oil pan that is disposed in bottom portion of the tool storage chamber where the tool is stored. 
         [0017]    In the invention described above, the reflective surface can be formed so as to scatter light, and the reflector can be disposed so that at least part of the light scattered from the reflective surface proceeds toward the image pickup device. 
         [0018]    According to the present invention, the tool shape measurement device of image pickup type and the machine tool that reduce effects of foreign substances such as chips and coolant can be provided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a schematic cross-sectional view of first machine tool according to an embodiment. 
           [0020]      FIG. 2  is a schematic cross-sectional view of first tool shape measurement device according to the embodiment. 
           [0021]      FIG. 3  is a schematic front view of the first tool shape measurement device according to the embodiment. 
           [0022]      FIG. 4  is an example of an image picked up by an image pickup device according to the embodiment. 
           [0023]      FIG. 5  is a schematic cross-sectional view of a portion of a tool storage chamber of second machine tool according to the embodiment. 
           [0024]      FIG. 6  is a schematic cross-sectional view of a third machine tool according to the embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    With reference to  FIG. 1  to  FIG. 6 , a tool shape measurement device and a machine tool according to an embodiment will be described. The machine tool of the present embodiment is the tool of a numerically controlled type that performs machining by automatically moving a tool and a workpiece relatively in accordance with a machining program. 
         [0026]      FIG. 1  is a schematic cross-sectional view of first machine tool according to the present embodiment. The first machine tool  1  is a lateral type machining center. The machine tool  1  includes a movement device that moves the tool and the workpiece relatively to each other. The movement device moves an object to be driven in a plurality of directions of movement axes. The movement axes include an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other as linear feed axes. 
         [0027]    The machine tool  1  is provided with a bed  12  which serves as a base table. X-axis guide rails  19  are fixed to an upper surface of the bed  12 . A column  16  is disposed on upper surfaces of the X-axis guide rails  19 . The column  16  is formed so as to be movable along the X-axis guide rails  19  as indicated by an arrow  86 . Y-axis guide rails  20  are fixed to a front surface of the column  16 . A spindle head  3  is supported by the Y-axis guide rails  20 . The spindle head  3  is configured to be movable along the Y-axis guide rails  20  as indicated by an arrow  85 . 
         [0028]    Z-axis guide rails  18  are fixed to the upper surface of the bed  12 . A table  14  is disposed on upper surfaces of the Z-axis guide rails  18 . A workpiece is fixed to the table  14  via a palette  15 . The table  14  is formed so as to be movable in a Z-axis direction along the Z-axis guide rails  18 . 
         [0029]    The spindle head  3  includes a spindle  4 . A tool  5  for machining the workpiece is fixed to the spindle  4 . A motor for rotating the tool  5  is integrated in the spindle head  3 . By the motor being driven, the tool  5  rotates about an axial line of the spindle  4  as a rotational axis. 
         [0030]    In the machine tool  1 , the tool  5  is moved in the X-axis direction and the Y-axis direction, and the workpiece is moved in the Z-axis direction. The movement device is not limited to this embodiment, and the tool can be moved relative to the workpiece by an arbitrary device. The machine tool may have a rotary feed axis that rotates about a predetermined axial line in addition to the linear feed axes. 
         [0031]    The machine tool  1  includes a tool exchange device  40  that automatically exchanges the tool. The machine tool  1  is provided with a machining chamber  61  in which the workpiece is machined and a tool storage chamber  62  in which the tools are stored. The machining chamber  61  and the tool storage chamber  62  are surrounded by a splash guard  54 . The machining chamber  61  and the tool storage chamber  62  are isolated by a partition wall  51 . The bed  12 , the column  16 , the spindle head  3  and the like are disposed inside the machining chamber  61 . The tool exchange device  40  is disposed inside the tool storage chamber  62 . The partition wall  51  is provided with an opening  51   a  which allows the tools to be moved between the machining chamber  61  and the tool storage chamber  62 . A shutter  52  that opens and closes the opening  51   a  is disposed on the partition wall  51 . The shutter  52  is supported by the partition wall  51 . 
         [0032]    The machine tool  1  includes a motor that drives the shutter  52 . The shutter  52  is formed so as to be movable with respect to the partition wall  51 . The shutter  52  of the present embodiment is formed so as to be movable in the Z-axis direction. The shutter  52  is moved so as to form opening, whereby the tools  5  can be moved through the opening  51   a.    
         [0033]    The tool exchange device  40  includes a tool magazine  41  that holds the tools  5 , and a carrier device that carries the tools between the tool magazine  41  and the spindle  4 . The tool magazine  41  of the present embodiment is formed so as to hold the tools  5  around a base material formed into a disk shape via a tool holder  45 . The tool exchange device  40  includes a motor that rotates the tool magazine  41 . The tool magazine  41  rotates as indicated by an arrow  87 . The carrier device includes a tool shifter  44  and a tool exchange arm  43 . The tool shifter  44  moves the tools between the tool magazine  41  and a standby position of the tool. The standby position is a position where the tool can be held by the tool exchange arm  43 . The tool shifter  44  moves in a direction indicated by an arrow  88  so as to detach the tools  5  from the tool magazine  41  or attach the tools  5  to the tool magazine  41 . 
         [0034]    The tool exchange arm  43  is formed into a rod shape. The tool exchange arm  43  includes a retaining part  43   a  that retains the tools  5  at both end portions thereof. The tool exchange device  40  includes a motor that rotates the tool exchange arm  43 . The tool exchange arm  43  is formed so as to be rotatable about the rotation axis that extends in the Z-axis direction as indicated by an arrow  89 . 
         [0035]    When the tool  5  is exchanged, the spindle head  3  moves to a predetermined position for exchanging the tool  5  in the machining chamber  61 . The spindle head  3  moves to a position where the retaining part  43   a  is capable of retaining the tool  5  attached to the spindle  4  when the tool exchange arm  43  rotates. The tool  5  after machining has completed is attached to the spindle  4 . In the tool storage chamber  62 , the tool magazine  41  rotates to a position where a tool  5  to be used next is retained by the tool shifter  44 . The tool shifter  44  shifts the tool  5  to be used next from the tool magazine  41  to the standby position. 
         [0036]    Next, the shutter  52  opens and the tool exchange arm  43  rotates. The tool exchange arm  43  retains the tool  5  retained by the tool shifter  44  and the tool  5  attached to the spindle  4 . By a further rotation of the tool exchange arm  43 , a tool  5  to be used next is attached to the spindle  4 , and the machined tool  5  is attached to the tool shifter  44 . The tool shifter  44  returns the tool  5  after machining has completed to the tool magazine  41 . 
         [0037]    In this manner, the tool exchange device  40  can move the tool  5  attached to the spindle  4  to the tool magazine  41 . The tool exchange device  40  is also capable of transferring the tool  5  held by the tool magazine  41  to the spindle  4 . After the tool  5  has been exchanged, the tool exchange arm  43  rotates to an initial state. After the shutter  52  has been closed, next process starts in the machining chamber  61 . 
         [0038]    The tool exchange device is not limited to the embodiment described above, and may be formed in any mode as long as the tool attached to the spindle may be exchanged with the tool held by the tool magazine. 
         [0039]      FIG. 2  illustrates a schematic cross-sectional view of first tool shape measurement device according to the present embodiment.  FIG. 3  illustrates a schematic front view of the first tool shape measurement device according to the present embodiment. In  FIG. 1  to  FIG. 3 , a state in which the tool  5  held by the tool shifter  44  is located at the standby position is illustrated. With reference to  FIG. 1  to  FIG. 3 , the machine tool  1  is provided with first tool shape measurement device  24  configured to measure the shape of the tool by picking up an image of the tool  5 . The tool shape measurement device  24  is an image pickup type device. The tool shape measurement device  24  employs a back light system in which a background of the tool  5  becomes bright while the tool  5  appears dark in the captured image of the tool  5 . 
         [0040]    The machine tool  1  of the present embodiment includes a control device  27  that controls the machine tool  1 . The control device  27  is provided with an arithmetic processing device which includes, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory) connected to one another via a bus. The control device  27  functions as a control device of the tool shape measurement device  24  that analyzes the image that is picked up by the image pickup device. The control device  27  controls the image pickup device that picks up the image of the tool  5  and the tool exchange device  40 . The image pickup device includes a camera  25 . Any camera that can perform image processing of the captured image such as a CCD (Charge Coupled Device) camera and the like can be employed as the camera  25 . 
         [0041]    The control device  27  calculates the shape of the tool from the image of the tool  5 . Images picked up by the camera  25  are input to the control device  27 . The control device  27 , for example, binarizes the input image. The control device  27  measures the number of pixels of a portion corresponding to the tool and a portion corresponding to a portion other than the tool. The control device  27  then calculates the shape of the tool based on the number of pixels of the portion corresponding to the tool. The shape of the tool includes a tool length and a tool diameter. The control device  27  determines the soundness of the tool based on the calculated shape of the tool. For example, it is determined whether or not the tool  5  is damaged. 
         [0042]    The image pickup device picks up an image of a tool  5  disposed at the predetermined image pickup position inside the tool storage chamber  62 . The camera  25  of the present embodiment is disposed so as to capture the image of the tool  5  when the tool  5  is disposed at the standby position. The image pickup position is not limited to the standby position, and may be set to any position. The image pickup device is capable, for example, of photographing the tool immediately after machining has completed. Alternatively, the image pickup device may pick up the image of the tool to be used next. 
         [0043]    The shutter  52  of the present embodiment functions as a reflector disposed on a side opposite to the camera  25  with respect to the tool in a direction from the camera  25  toward the tool  5  disposed at the standby position. The shutter  52  is disposed behind the tool  5  when viewed from the camera  25 . The camera  25  is disposed at a position so that the substantially entire part of the background of the tool  5  in the image is filled with the shutter  52  when the image of the tool  5  is picked up at the standby position. The shutter  52  is disposed at the position that intersects a line connecting the camera  25  and the tool  5  disposed at the standby position. The tool  5  is disposed between the shutter  52  and the camera  25 . 
         [0044]    The shutter  52  includes a reflective surface  52   a  that reflects light. The reflective surface  52   a  is formed so as to scatter the light. In the present embodiment, a surface facing inside the tool storage chamber  62  among the area maximum surfaces in which areas are largest in the shutter  52 , corresponds to the reflective surface  52   a . The reflective surface  52   a  of the shutter  52  in the present embodiment is coated. 
         [0045]    The reflector is not limited to the mode described above, and may be configured so as to scatter at least part of the incident light. In other words, any member can be used as the reflector as long as the member does not have mirror surface characteristic in which the almost the entire incident light is reflected in the one direction. For example, the reflector may not be coated on a surface thereof, and may have an exposed metallic surface. The reflector may be formed of any material. Any color may be employed when the surface of the reflector is coated. In particular, bright mat coatings such as a bright gray that is used in an inner wall surface of a sheet-metal cover in the machine tool were effective among various coatings. 
         [0046]    The tool shape measurement device  24  is provided with an illumination device  26  as a light source that irradiates light toward the shutter  52 . The illumination device  26  of the present embodiment is an LED (Light Emitting Diode) illumination. The shutter  52  scatters light on the reflective surface  52   a , and thus part of the light irradiated by the illumination device  26  proceeds to the camera  25 . In this manner, the tool shape measurement device  24  of the present embodiment employs an indirect illumination system which illuminates the tool  5  with the reflected diffused reflection light instead of a direct illumination system which directly illuminates the tool  5 . The illumination device  26  is disposed so as to capture the image in which the tool becomes darker than the background of the tool with the diffused reflection light that is reflected from the reflective surface  52   a  of the shutter  52 . 
         [0047]    The control device  27 , for example, causes the illumination device  26  to irradiate for a short time and picks up the image of the tool  5 . In the present embodiment, a time length of irradiation with light by the illumination device  26  is around 15 ms. The LED illumination that provides a brightness of 1300 lux at a position 1 m apart from the illumination device  26 , for example, may be used as the illumination device  26 . 
         [0048]    With reference to  FIG. 2 , a projection area PR may be determined when the tool  5  disposed at the standby position is projected to the shutter  52  from the camera  25 . The irradiation area LR that is mainly irradiated with light when the shutter  52  is illuminated by the illumination device  26  may be determined. The irradiation area LR is preferably large enough to include the projection area PR therein. 
         [0049]      FIG. 4  illustrates an example of the image of the tool picked up by the image pickup device of the present embodiment. In the example illustrated in  FIG. 4 , a probe  6  corresponding to the tool is used. When an image of the tool is picked up, a portion corresponding to the tool appears in black as a whole. In contrast, the background of the tool is brighter due to the diffused reflection light from the reflector. In this manner, the image pickup device picks up the image in which the tool is darker than the background of the tool. For example, when the color of light emitted by the illumination device is white, the background of the tool becomes white and the tool appears in black. The control device has an ability to calculate the shape of the tool by using the image as described above. 
         [0050]    In the method of directly illuminating the tool, an image of the tool is picked up in a state in which the entire part of the tool is bright. However, when the tool is illuminated directly, light may reflect significantly at a part of the tool. Consequently, the part of the tool becomes bright, and the shape of the tool as a whole may be blurred. In contrast, in the backlight system of the present embodiment, the portion corresponds to the tool appears dark. Since a part of the tool does not become bright, the shape of the tool may be measured with high degree of accuracy. 
         [0051]    With reference to  FIG. 1  to  FIG. 3 , the illumination device  26  preferably includes brightness that makes the image of the entire part of the tool picked up by the camera  25  to be black. In other words, the illumination device  26  is preferably a bright light source generating the brightness which makes the entire part of the tool to be black. By adoption this configuration, an image having a clear shape of the tool appears therein may be obtained and the shape of the tool may be measured more accurately. 
         [0052]    In addition, the tool shape measurement device  24  performs image pickup with the diffused reflection light reflected by the shutter  52 . When the machine tool  1  is driven, foreign substances such as fine chips, lubricant supplied to the sliding part, or coolant may be adhered to the reflective surface  52   a  of the shutter  52 . However, the foreign substances such as the fine chips reflect light on the surfaces, and accordingly serve as part of the reflector. Therefore, there is the feature that the foreign substances are hardly captured in the background of the tool. In other words, the tool shape measurement device  24  may reduce the probability that chips or the like create shadows and black substances come out in the background of the tool. Consequently, accurate measurement of the shape of the tool can be achieved. 
         [0053]    In the tool shape measurement device  24 , the reflector which reflects light is formed by the shutter  52 . The shutter  52  is moved in the direction indicated by an arrow  90  (see  FIG. 3 ) when the tool is exchanged. Even when large-sized foreign substances are adhered to the reflective surface  52   a  of the shutter  52 , the large-sized foreign substances drop off as the shutter  52  moves. Therefore, it is possible to restrain the foreign substances from being picked up in the background of the tool in the picked up image. 
         [0054]    The shutter  52  of the present embodiment extends in a direction that is perpendicular to the reflective surface  52   a . In other words, the shutter  52  is supported by the partition wall  51  in an upright state. Therefore, the shutter  52  has a feature that the foreign substances easily drop off due to an action of gravitational force even when the foreign substances are adhered to the reflective surface  52   a  of the shutter  52 . In this manner, the reflector is preferably disposed so that the reflective surface stands upright. 
         [0055]    Furthermore, the tool shape measurement device  24  includes a brush  28  serving as a removal member that comes into contact with the reflective surface  52   a  of the shutter  52  so as to remove the foreign substances adhered to the reflective surface  52   a . The brush  28  is formed into a rod shape. The brush  28  extends in a direction perpendicular to the movement direction of the shutter  52  indicated by the arrow  90 . The brush  28  extends in the Y-axis direction. A length of the brush  28  is longer than the length of the shutter  52  in the Y-axis direction. The brush  28  has a length that comes into contact with the shutter  52  from one end to the other end thereof in the direction perpendicular to the movement direction of the shutter  52 . 
         [0056]    When the tool  5  attached to the spindle  4  is exchanged with the tool  5  held by the tool magazine  41 , the shutter  52  moves in a direction indicated by the arrow  90 , and the brush  28  slides on the reflective surface  52   a  of the shutter  52  so as to remove the foreign substances. In this manner, by the provision of the brush  28 , the foreign substances adhered to the reflective surface  52   a  of the shutter  52  can be removed even when a specific brush drive mechanism for removing the foreign substances is not provided. In particular, the brush  28  can remove large-sized foreign substances. 
         [0057]    The removal member for removing the foreign substances is not limited to the brush, and any member that removes the foreign substances adhered to the reflective surface may be employed. For example, a lip seal formed of rubber can be employed as the removal member. The lip seal includes a rubber plate extending in a rod shape. The foreign substances adhered to the reflective surface of the shutter may be removed by the rubber plate sliding on the reflective surface as the shutter moves. In the present embodiment, the reflector moves while the removal member is fixed. However, the mode is not limited thereto, and any mode is applicable as long as the removal member is formed so as to be movable relative to the reflector. For example, the removal member may be formed so as to be movable. 
         [0058]    Any illuminations may be employed as the illumination device  26  in addition to the LED illumination. By adopting the LED illumination such as the illumination device  26 , brightness may be increased in a short time. Therefore, time that is needed for picking up the image may be shortened. In addition, the LED illumination allows the illumination device to be downsized in comparison with other illumination devices. 
         [0059]    The illumination device  26  is preferably disposed at a position where chips or the like are hardly adhered. For example, the illumination device  26  is preferably disposed so that a back surface faces the tool magazine  41 . Alternatively, the illumination device  26  preferably includes a device that removes the foreign substances adhered to the surface that emits light. For example, a device that ejects cleaning liquid onto the surface of the illumination device  26  can be employed as the device that removes the foreign substances. The camera  25  is preferably disposed at a position higher than the image pickup position of the tool  5  when performing image pickup. Although there is a probability that the foreign substances adhered to the tool  5  in the machining chamber drop off from the tool  5  in the vicinity of the image pickup position, with the configuration described above, adhesion of the foreign substances onto a surface of a lens of the camera  25  is restricted. The reflector is disposed at a position lower than the image pickup position of the tool  5 , so that the image pickup device can pick up the image of the tool  5  desirably as described above even when the foreign substances dropped off from the tool  5  are adhered thereto. 
         [0060]      FIG. 5  illustrates a schematic view of second machine tool according to the embodiment.  FIG. 5  is a schematic cross-sectional view of a portion including the tool storage chamber  62 . The second machine tool  7  includes second tool shape measurement device  31 . A reflector of the tool shape measurement device  31  is formed by an oil pan  53  disposed on a bottom portion of the tool storage chamber  62 . The oil pan  53  is formed into a plate shape. The oil pan  53  has a function of receiving foreign substances such as chips, lubricant, coolant, or the like that drops off from the device disposed in the tool storage chamber  62  on the surface thereof and flowing the foreign substances to a predetermined position. In the tool shape measurement device  31 , the camera  25  is disposed so as to pick up the image of the tool  5  disposed at the standby position from an upper side in a vertical direction. In the tool shape measurement device  31 , the upper surface of the oil pan  53  corresponds to the reflective surface  53   a  that reflects light. The illumination device  26  irradiates part of the reflective surface  53   a  of the oil pan  53  with light so that the background of the tool  5  becomes bright. 
         [0061]    Liquid such as the coolant flows on the reflective surface  53   a  of the oil pan  53 . The liquid has a property of scattering light from a surface thereof. Therefore, even though liquid exists in the irradiation area LR illuminated with light, the liquid has a property of hardly coming out in the background of the tool. Consequently, even when the liquid flows on the surface of the oil pan  53 , the image of the tool may be picked up desirably. Since the reflective light is used for picking up the image as described above in the present embodiment, the effects of the small-sized foreign substances can also be restricted. 
         [0062]    The machine tool  7  is provided with a cleaning liquid supply device that flows the cleaning liquid on the reflective surface  53   a  of the oil pan  53 . The cleaning liquid supply device includes a cleaning liquid nozzle  29 . The cleaning liquid supplied from the cleaning liquid nozzle  29  is caused to flow by an inclination of the oil pan  53  as indicated by an arrow  92 . The cleaning liquid cleans the reflective surface  53   a . Accordingly, large-sized foreign substances remaining on the reflective surface  53   a  of the oil pan  53  can also be removed. When the cleaning liquid supply device is disposed, the removal member that removes the foreign substances adhered to the reflective surface  53   a  of the oil pan  53  does not need to be disposed. 
         [0063]    The tool shape measurement device  31  includes a plurality of the illumination devices  26 . The light source includes first light source and second light source that are disposed at positions different from each other. By arranging a plurality of the illumination devices  26 , the reflector can be irradiated from the multiple directions. Consequently, creation of shadows of the large-sized foreign substances can be restricted. Appearance of black substances in the background of the tool in the image is restricted. Alternatively, by arranging a plurality of the illumination devices  26 , the background of the tool in the image may be brightened, and color unevenness or the like generated in the background of the tool in the image can be restricted. Consequently, the shape of the tool can be measured accurately. Other configurations, actions, and advantageous effects are the same as those of the first machine tool, and thus explanations are not repeatedly described here. 
         [0064]      FIG. 6  illustrates a schematic cross-sectional view of a third machine tool provided with a third tool shape measurement device according to the present embodiment. The machine tool described above is a horizontal-type machine tool that has the spindle  4  extending in a horizontal direction. A third machine tool  8  is a vertical-type machine tool. The machine tool  8  is provided with the column  16  which stands upright on a surface of the bed  12 . The column  16  supports the spindle head  3  via a saddle  17 . In the example illustrated in  FIG. 6 , the saddle  17  is formed so as to move in a vertical direction. The spindle  4  disposed in the interior of the spindle head  3  is formed so as to extend in the vertical direction. 
         [0065]    The machine tool  8  is provided with second tool exchange device  55 . The tool exchange device  55  is provided with a disk-shaped tool magazine  41 . The tool  5  is held in the tool magazine  41  via the tool holder  45 . The tool exchange device  55  includes a tool transfer member that transfers the tool between the tool magazine  41  and the tool exchange arm  43 . In the tool exchange device  55 , the tool exchange arm  43  extends in the horizontal direction. The tool exchange arm  43  rotates in a horizontal plane. The tool exchange arm  43  removes the tool  5  from the spindle  4  and attaches the tool  5  to the spindle  4 . The tool exchange arm  43  removes the tool  5  from the tool transfer member and attaches the tool  5  to the tool transfer member. 
         [0066]    A machining chamber  61  surrounded by a splash guard  54  is formed in the machine tool  8 . The partition wall  51  is formed above the table  14 . The tool storage chamber  62  is defined by a space partitioned by the partition wall  51 . The shutter  52  for opening and closing the opening  51   a  is disposed on the partition wall  51 . The shutter  52  is disposed so as to extend in the horizontal direction. In the machine tool  8 , the shutter  52  moves in the horizontal direction. 
         [0067]    The machine tool  8  is provided with a third tool shape measurement device  32 . The illumination device  26  is disposed on a lateral side of the shutter  52 . The camera  25  picks up the images of the tools  5  attached to the tool magazine  41 . The camera  25  is disposed so as to pick up the image of the tool  5  disposed at the predetermined image pickup position. The tool shape measurement device  32  is capable of picking up the image of the tool  5  that is returned to the tool magazine  41 , for example, after machining has completed. 
         [0068]    In this manner, the tool shape measurement device of the present invention may be applied to a vertical-type machine tool. The shutter serving as the reflector may be disposed so as to extend in the horizontal direction. The image pickup device may pick up an image in a state in which the tool is held in the tool magazine. Other configurations, actions, and advantageous effects are the same as those of the first machine tool or the second machine tool, and thus explanations are not repeatedly described here. 
         [0069]    The embodiments described above may be combined as needed. In the respective drawings described above, the same or equivalent portions are denoted by the same reference numerals. The above-described embodiments are examples only, and are not intended to limit the invention. In the embodiments, modification of the modes described in claims are included. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1 ,  7 ,  8  machine tool 
           5  tool 
           24 ,  31 ,  32  tool shape measurement device 
           25  camera 
           26  illumination device 
           27  control device 
           28  brush 
           51  partition wall 
           52  shutter 
           52   a  reflective surface 
           53  oil pan 
           53   a  reflective surface 
           61  machining chamber 
           62  tool storage chamber