Patent Publication Number: US-2023134626-A1

Title: Machining method for workpiece

Description:
TECHNICAL FIELD 
     The present invention relates to a method for machining a workpiece (machining method for workpiece). 
     BACKGROUND ART 
     Conventionally, there is a machine tool capable of performing both a cutting process by rotating a cutting tool in which the tool is attached to a spindle and the tool is rotated to machine a workpiece and a cutting process by rotating a workpiece in which a lathe machining tool is attached to the spindle and the workpiece is rotated to machine the workpiece (for example, JP 2013-202713 A). 
     SUMMARY OF THE INVENTION 
     In the above-described technique, since the workpiece is machined by the lathe machining tool attached to the spindle, there is a problem that it is necessary to modify the machine tool. 
     The present invention has been made to solve the above problems, and an object of the present invention is to provide a workpiece machining method that does not require modification of a machine tool when machining a rotating workpiece in the machine tool having a spindle. 
     According to an aspect of the present invention, there is provided a method for machining a workpiece, the method including: a first attachment step of attaching a workpiece holder holding a workpiece to a spindle of a machine tool; and a first machining step of machining the workpiece with a tool installed on a table of the machine tool, while rotating the spindle. 
     According to the present invention, when machining a rotated workpiece in a machine tool having a spindle, it is not necessary to modify the machine tool. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a schematic view of a cutting machine; 
         FIG.  2    is a schematic view of a workpiece and a workpiece holder that holds the workpiece; 
         FIG.  3    is a schematic view showing how a first machining of the workpiece is performed; 
         FIG.  4    is a schematic view showing how the workpiece holder is attached to a spindle and detached from the spindle; 
         FIG.  5    is a schematic view showing how a second machining of the workpiece is performed; 
         FIG.  6    is a flowchart showing a flow of a machining process of the workpiece; 
         FIG.  7    is a schematic view showing how a workpiece holder is loaded into a turret and how the workpiece holder is removed from the turret; 
         FIG.  8    is a flowchart showing a flow of a machining process of the workpiece; 
         FIG.  9    is a flowchart showing a flow of a machining process of the workpiece; 
         FIG.  10    is a schematic view showing how the first machining of the workpiece is performed; and 
         FIG.  11    is a schematic view showing how the second machining of the workpiece is performed. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     First Embodiment 
       FIG.  1    is a schematic view of a cutting machine  10 , The cutting machine  10  performs a first machining and a second machining. The first machining refers to machining that is performed with a workpiece  12  being attached to a spindle  16  side of the cutting machine  10 . The second machining refers to machining that is performed with the workpiece  12  being attached to a table  18  side of the cutting machine  10 . The cutting machine  10  corresponds to a machine tool of the present invention. 
       FIG.  2    is a schematic view of the workpiece  12  and a workpiece holder  14  that holds the workpiece  12 . The workpiece holder  14  holding the workpiece  12  is mounted on the spindle  16  of the cutting machine  10 . As shown in  FIG.  2   , the workpiece holder  14  has a tapered surface  14   a  and a pull bolt  14   b , similar to those of a collet holder. 
     A first tool  20  is attached to a collet chuck  24  installed on a table  18  of the cutting machine  10 . The collet chuck  24  is formed with a tapered hole having the same shape as the tapered hole of the spindle  16 . The collet chuck  24  can rotate the attached first tool  20  or the like by a motor (not shown), but can also fix the first tool  20  or the like so as not to rotate. The first tool  20  is, for example, a cutting tool, a drill, or the like, and is a roughing tool. The first tool  20  is held by a collet holder (not shown). The collet chuck  24  corresponds to a jig of the present invention. 
     A second tool  21  is installed on the table  18  of the cutting machine  10 . Unlike the first tool  20 , the second tool  21  is fixed directly to the table  18 . The second tool  21  is, for example, a cutting tool, a drill, or the like, and is a finishing tool. 
       FIG.  3    is a schematic view showing how the first machining of the workpiece  12  is performed. Rough machining or roughing is performed by the first tool  20  installed on the table  18  by rotating the workpiece  12 . At this time, the collet chuck  24  non-rotatably fixes the first tool  20 . Thereafter, while the workpiece  12  is being rotated, finish machining or finishing is performed by the second tool  21  installed on the table  18 . After the roughing, finishing is performed by the second tool  21  installed on the table  18  while the workpiece  12  is being rotated. In the first machining, for example, lathing, boring, threading, drilling, or the like is performed. 
     The second tool  21  of the finishing tool may be attached to the collet chuck  24 , and the first tool  20  of the roughing tool may be directly fixed to the table  18 . 
       FIG.  4    is a schematic view showing how the workpiece holder  14  is attached to the spindle  16  and how the workpiece holder  14  is detached from the spindle  16 . As shown in  FIG.  4   , the workpiece holder  14  is attached to the spindle  16  and detached from the spindle  16  by a robot  22  provided outside the cutting machine  10 . Attachment of the workpiece holder  14  to the spindle  16  and detachment of the workpiece holder  14  from the spindle  16  may be performed by an operator. 
     Installation of the collet chuck  24  on the table  18  and removal of the collet chuck  24  from the table  18  may be performed by the robot  22  or may be performed by an operator. Attachment of the first tool  20  to the collet chuck  24  and detachment of the first tool  20  from the collet chuck  24  may be performed by the robot  22  or may be performed by an operator. Installation of the second tool  21  on the table  18  and removal of the second tool  21  from the table  18  may also be performed by the robot  22  or may be performed by an operator. The robot  22  corresponds to a changing apparatus of the present invention. 
     The robot  22  according to the present embodiment is an articulated robot, but is not limited to such an articulated robot, and may be a SCARA robot, etc. Instead of the robot  22 , a dedicated device for attaching the workpiece holder  14  or the like to the spindle  16  and detaching the workpiece holder  14  or the like from the spindle  16  may be used. 
       FIG.  5    is a schematic view showing how the second machining of the workpiece  12  is performed. In the second machining, a third tool  23  is attached to the spindle  16  of the cutting machine  10 . The third tool  23  is, for example, a milling cutter, an end mill, or the like. The third tool  23  is held by a collet holder (not shown). 
     The workpiece holder  14  holding the workpiece  12  is attached to the collet chuck  24  installed on the table  18  of the cutting machine  10 . 
     In  FIG.  5   , the second tool  21  is installed on the table  18  of the cutting machine  10 , but the second tool  21  may be removed. 
     In the second machining, the third tool  23  is rotated to machine the workpiece  12  placed on the table  18 . At this time, the collet chuck  24  non-rotatably fixes the workpiece holder  14 . In the second machining, for example, milling, end milling, or the like is performed. 
     In the second machining, a fourth tool (not shown) may be installed on the table  18 , and the workpiece  12  may be machined by the fourth tool with the workpiece  12  being rotated. In this case, in the second machining, for example, lathing, boring, threading, drilling, or the like is performed. 
     The attachment of the third tool  23  to the spindle  16  and the detachment of the third tool  23  from the spindle  16  may be performed by the robot  22  provided outside the cutting machine  10  or may be performed by an operator. The attachment of the workpiece holder  14  to the collet chuck  24  and the detachment of the workpiece holder  14  from the collet chuck  24  may be performed by the robot  22  or may be performed by an operator. 
       FIG.  6    is a flowchart showing a flow of a machining process of the workpiece  12 . The flow of the machining process shown in this flowchart is an example, and the machining process does not necessarily have to be performed in this flow. 
     In step S 1 , the robot  22  places the collet chuck  24  on the table  18 , and the process proceeds to step S 2 . 
     In step S 2 , the robot  22  attaches the first tool  20  to the collet chuck  24 , and the process proceeds to step S 3 . 
     In step S 3 , the robot  22  places the second tool  21  on the table  18 , and the process proceeds to step S 4 . 
     In step S 4 , the robot  22  attaches the workpiece holder  14  to the spindle  16 , and the process proceeds to step S 5 . The workpiece  12  is held by the workpiece holder  14 . 
     In step S 5 , the cutting machine  10  performs the first machining, and the process proceeds to step S 6 . 
     In step S 6 , the robot  22  removes the workpiece holder  14  from the spindle  16 , and the process proceeds to step S 7 . 
     In step S 7 , when there is another workpiece  12  to be subjected to the first machining, the process returns to step S 4 , and when there is no more workpiece  12  to be subjected to the first machining, the process proceeds to step S 8 . 
     In step S 8 , when there is a workpiece  12  to be subjected to the second machining, the process proceeds to step S 9 , and when there is no workpiece  12  to be subjected to the second machining, the machining process is ended. 
     In step S 9 , the robot  22  attaches the third tool  23  to the spindle  16 , and the process proceeds to step S 10 . 
     In step S 10 , the robot  22  attaches the workpiece holder  14  to the collet chuck  24 , and the process proceeds to step S 11 . 
     In step S 11 , the cutting machine  10  performs the second machining, and the process proceeds to step S 12 . 
     In step S 12 , the robot  22  removes the workpiece holder  14  from the collet chuck  24 , and returns to step S 8 . 
     Operational Effect 
     In general, in the cutting machine  10 , a tool is attached on the spindle  16  and a cutting process is performed on the workpiece  12  while the tool is being rotated. When machining is performed by pressing the tool against the rotating workpiece  12  as in lathe machining or the like by the cutting machine  10 , it is necessary to modify the cutting machine  10  in order to non-rotatably fix the tool attached to the spindle  16 , and there is a problem that the cost increases. 
     In order to address the above problem, in the present embodiment, the workpiece holder  14  holding the workpiece  12  is attached to the spindle  16  of the cutting machine  10 , the spindle  16  is rotated, and the workpiece  12  is machined by the first tool  20  or the second tool  21  attached to the table  18  side. Thus, when machining the rotated workpiece  12 , it is not necessary to modify the cutting machine  10 , and the cost can be suppressed. 
     In the present embodiment, after completion of the first machining, the workpiece holder  14  is removed from the spindle  16  by the robot  22  installed outside the cutting machine  10 . Thus, detaching of the workpiece holder  14  from the spindle  16  is automatically performed. 
     In the present embodiment, after the first machining is completed, the workpiece holder  14  is detached from the spindle  16 , and then the workpiece holder  14  is attached to the collet chuck  24  installed on the table  18 , and the workpiece  12  is machined by the third tool  23  attached to the spindle  16 . As a result, it is possible to increase the types of machining that can be performed by one cutting machine  10 . 
     In the present embodiment, the workpiece holder  14  is attached to the spindle  16  by the robot  22  installed outside the cutting machine  10 . Thus, attaching of the workpiece holder  14  to the spindle  16  is automatically performed. 
     In the present embodiment, the first tool  20  is attached to the collet chuck  24  installed on the table  18 . In order for the collet chuck  24  to non-rotatably fix the first tool  20 , it is necessary to modify the collet chuck  24 . However, the cost of modifying the collet chuck  24  is lower than the cost of modifying the cutting machine  10  to non-rotatably fix the first tool  20  attached to the spindle  16  of the cutting machine  10 . 
     Further, the common collet chuck  24  can be used in the first machining and the second machining. Therefore, when changing from the first machining to the second machining, the time for installing the collet chuck  24  can be saved. Further, when changing from the first machining to the second machining, the setup of the workpiece  12  is completed just by attaching the workpiece holder  14  initially attached to the spindle  16 , to the collet chuck  24 , so that the setup time can be shortened. 
     Second Embodiment 
       FIG.  7    is a schematic view showing how the workpiece holder  14  is loaded into a turret  26  and how the workpiece holder  14  is removed from the turret  26 . The workpiece holder  14  is attached to the spindle  16  and detached from the spindle  16  by the turret  26  of the cutting machine  10 . The workpiece holder  14  is loaded into the turret  26  and removed from the turret  26  by a robot  22  provided outside the cutting machine  10 . Loading of the workpiece holder  14  into the turret  26  and removing of the workpiece holder  14  from the turret  26  may be performed by an operator. The turret  26  corresponds to a changer of the present invention. 
     The robot  22  according to the present embodiment is an articulated robot, but is not limited to such an articulated robot, and may be a SCARA robot, etc. Instead of the robot  22 , a dedicated device for loading the workpiece holder  14  into the turret  26  and removing the workpiece holder  14  from the turret  26  may be used. 
       FIGS.  8  and  9    are flowcharts showing the flow of a machining process of the workpiece  12 . The flow of the machining process shown in the flowcharts is an example, and the machining process does not necessarily have to be performed in this flow. 
     In step S 21 , the robot  22  loads the turret  26  with the workpiece holder  14 , and the process proceeds to step S 22 . 
     In step S 22 , the robot  22  places the collet chuck  24  on the table  18 , and the process proceeds to step S 23 . 
     In step S 23 , the robot  22  attaches the first tool  20  to the collet chuck  24 , and the process proceeds to step S 24 . 
     In step S 24 , the robot  22  places the second tool  21  on the table  18 , and the process proceeds to step S 25 . 
     In step S 25 , the turret  26  attaches the workpiece holder  14  to the spindle  16 , and the process proceeds to step S 26 . 
     In step S 26 , the cutting machine  10  performs the first machining, and the process proceeds to step S 27 . 
     In step S 27 , the turret  26  removes the workpiece holder  14  from the spindle  16 , and the process proceeds to step S 28 . 
     In step S 28 , when there is another workpiece  12  to be subjected to the first machining, the process returns to step S 25 , and when there is no more workpiece  12  to be subjected to the first machining, the process proceeds to step S 29 . 
     In step S 29 , the robot  22  removes the workpiece holder  14  from the turret  26 , and the process proceeds to step S 30 . 
     In step S 30 , when there is a workpiece  12  to be subjected to the second machining, the process proceeds to step S 31 , and when there is no workpiece  12  to be subjected to the second machining, the machining process is ended. 
     In step S 31 , the robot  22  loads the turret  26  with the third tool  23 , and the process proceeds to step S 32 . 
     In step S 32 , the turret  26  attaches the third tool  23  to the spindle  16 , and the process proceeds to step S 33 . 
     In step S 33 , the robot  22  attaches the workpiece holder  14  to the collet chuck  24 , and the process proceeds to step S 34 . 
     In step S 34 , the cutting machine  10  performs the second machining, and the process proceeds to step S 35 . 
     In step S 35 , the robot  22  removes the workpiece holder  14  from the collet chuck  24 , and the process proceeds to step S 36 . 
     In step S 36 , when there is another workpiece  12  to be subjected to the second machining, the processing returns to step S 33 , and when there is no more workpiece  12  to be subjected to the second machining, the machining processing is ended. 
     Operational Effect 
     In the present embodiment, the workpiece holder  14  is loaded into the turret  26  of the cutting machine  10  by the robot  22  provided outside the cutting machine  10 , and the turret  26  attaches the workpiece holder  14  to the spindle  16 . Thus, attaching of the workpiece holder  14  to the spindle  16  is automatically performed. 
     Third Embodiment 
       FIG.  10    is a schematic view showing how the first machining of the workpiece  12  is performed.  FIG.  11    is a schematic view showing how the second machining of the workpiece  12  is performed. 
     In the present embodiment, the collet chuck  24  is provided on an additional axis  28  installed on the table  18 . The additional axis  28  is capable of rotating the collet chuck  24  about a plurality of different axes. 
     This embodiment is the same as the first embodiment or the second embodiment except that the collet chuck  24  is provided on the additional axis  28 . 
     Operational Effect 
     The collet chuck  24  can be inclined by the additional axis  28 , and wide variety of machining can be performed on the workpiece  12 . 
     Technical Concepts Obtainable from the Embodiments 
     The following is a description of technical concepts that can be understood from the embodiments described above. 
     The method for machining the workpiece ( 12 ) includes: a first attachment step of attaching a workpiece holder ( 14 ) holding a workpiece to a spindle ( 16 ) of a machine tool ( 10 ); and a first machining step of machining the workpiece with a tool ( 20 ) installed on a table ( 18 ) of the machine tool, while rotating the spindle. 
     The above-described workpiece machining method may further include a detachment step of detaching the workpiece holder from the spindle with a changing apparatus ( 22 ) installed outside the machine tool, after completion of the first machining step. 
     The above-described workpiece machining method may further include a second attachment step of attaching the workpiece holder to a jig ( 24 ) installed on the table, after completion of the detachment step; and a second machining step of machining the workpiece with the tool attached to the spindle or the tool installed on the table. 
     In the above-described workpiece machining method, in the first attachment step, the workpiece holder may be attached to the spindle by a changing apparatus provided outside the machine tool. 
     The above-described workpiece machining method may further include a loading step of loading the workpiece holder into a changer ( 26 ) of the machine tool with a changing apparatus provided outside the machine tool, before the first attachment step, and, in the first attachment step, the workpiece holder may be attached to the spindle by the changer.