Control device, machine tool, control method, and computer program

Abstract

To provide a control device, a machine tool, a control method, and a computer program that enable workpiece setup in a non-processing area after a brake test.SOLUTION: A control device for a machine tool comprises: a moving part capable of moving between a processing area for processing a workpiece and a non-processing area separated from the processing area; a first holding part and a second holding part which are movably provided in the moving part and hold the workpiece. The first holding part and the second holding part each have a brake. The brakes of the first holding part and the second holding part include: a first brake which is a brake possessed by one of the first holding part and the second holding part conveyed to the processing area; and a second brake which is a brake possessed by the other of the first holding part and the second holding part conveyed to the non-processing area. The control device comprises a test execution unit that performs a brake test, which is a brake operation test, on the first brake and the second brake.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present technology relates to a control device, a machine tool, a control method, and a computer program for processing a workpiece.

Background Art

[0002] Conventionally, there is a machine tool including a rotary table and two workpiece holding devices. The workpiece holding devices are provided on the rotary table. By the rotation of the rotary table, the workpiece holding devices move between a processing area close to the spindle, that is, a processing chamber, and a non-processing area away from the spindle, that is, a setup chamber. When one workpiece holding device is located in the processing chamber, the other workpiece holding device is located in the setup chamber. The machine tool can execute the processing in the processing chamber and the setup of the workpiece in the setup chamber in parallel (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Some machine tools have a drive mechanism, and the drive mechanism may include a brake mechanism. For a drive mechanism equipped with a brake mechanism, the machine tool needs to confirm whether the brake mechanism operates normally. For this reason, the machine tool appropriately conducts a brake test. The brake test was performed on the brake mechanism located in the processing chamber. The workpiece holding device has a brake mechanism. For this reason, the machine tool conducts a brake test on the workpiece holding device located in the processing chamber and does not conduct a brake test on the workpiece holding device located outside the processing chamber. For the safety of the operator, when the brake test has not been performed, the door of the setup chamber cannot be opened. Therefore, the workpiece may not be set up in the setup chamber.

[0005] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a control device, a machine tool, a control method, and a computer program that enable setup of a workpiece in a non-processing region after a brake test.

Means for Solving the Problems

[0006] A control device according to an embodiment of the present disclosure is a control device for a machine tool including a moving unit movable between a processing region for processing a workpiece and a non-processing region separated from the processing region, and a first holding unit and a second holding unit movably provided on the moving unit for holding the workpiece. The first holding unit and the second holding unit each have a brake, and the brakes of the first holding unit and the second holding unit include a first brake which is a brake of one of the first holding unit and the second holding unit conveyed to the processing region, and a second brake which is a brake of the other of the first holding unit and the second holding unit conveyed to the non-processing region. The control device includes a test execution unit that performs a brake test which is an operation test of the brakes on the first brake and the second brake.

[0007] In the present disclosure, a brake test is performed on both the first brake and the second brake.

[0008] A control device according to an embodiment of the present disclosure includes a completion determination unit that determines whether or not setup of the workpiece in the non-processing region has been completed. When the completion determination unit determines that the setup has been completed, the test execution unit performs a brake test on the first brake and the second brake.

[0009] In the present disclosure, when the setup of the workpiece is completed, a brake test is performed on both the first brake and the second brake.

[0010] A control device according to an embodiment of the present disclosure, the machine tool includes a machining chamber located in the machining area and a setup chamber located in the non-machining area. A first switch for notifying the completion of workpiece setup in the setup chamber is provided in the setup chamber, and a second switch for notifying the start of machining in the machining chamber is provided in the machining chamber. The completion determination unit determines that the workpiece setup in the non-machining area is completed when the first switch is operated.

[0011] In the present disclosure, a brake test is performed on both the first brake and the second brake when the first switch is operated. The first switch and the second switch are provided at different positions. When the first switch is operated, a brake test is performed on both the first brake and the second brake. When the second switch is operated, a brake test is performed only on the first brake. That is, by selecting the first switch or the second switch, the operator can easily distinguish and execute the two brake tests.

[0012] A control device according to an embodiment of the present disclosure, the moving part is a rotary table.

[0013] In the present disclosure, the rotary table moves between the machining area and the non-machining area.

[0014] A machine tool according to an embodiment of the present disclosure includes a moving part movable between a machining area for machining a workpiece and a non-machining area separated from the machining area, and a first holding part and a second holding part movably provided on the moving part for holding the workpiece. In the machine tool, the first holding part and the second holding part each have a brake, and the brakes of the first holding part and the second holding part include a first brake which is the brake of one of the first holding part and the second holding part conveyed to the machining area, and a second brake which is the brake of the other of the first holding part and the second holding part conveyed to the non-machining area. A test execution unit for performing a brake test which is an operation test of the brakes is provided for the first brake and the second brake.

[0015] In the present disclosure, a brake test is performed on both the first brake and the second brake.

[0016] A control method according to an embodiment of the present disclosure is a control method for a machine tool including a moving unit movable between a machining area for machining a workpiece and a non-machining area separated from the machining area, and a first holding unit and a second holding unit movably provided on the moving unit for holding the workpiece. The first holding unit and the second holding unit each have a brake. The brakes of the first holding unit and the second holding unit include a first brake which is a brake of one of the first holding unit and the second holding unit conveyed to the machining area, and a second brake which is a brake of the other of the first holding unit and the second holding unit conveyed to the non-machining area. A brake test which is an operation test of the brakes is performed on the first brake and the second brake.

[0017] In the present disclosure, a brake test is performed on both the first brake and the second brake.

[0018] A computer program according to an embodiment of the present disclosure is a computer program executable by a control device of a machine tool including a moving unit movable between a machining area for machining a workpiece and a non-machining area separated from the machining area, and a first holding unit and a second holding unit movably provided on the moving unit for holding the workpiece. The first holding unit and the second holding unit each have a brake. The brakes of the first holding unit and the second holding unit include a first brake which is a brake of one of the first holding unit and the second holding unit conveyed to the machining area, and a second brake which is a brake of the other of the first holding unit and the second holding unit conveyed to the non-machining area. The control device is caused to execute a process of performing a brake test which is an operation test of the brakes on the first brake and the second brake.

[0019] In the present disclosure, a brake test is performed on both the first brake and the second brake.

Advantages of the Invention

[0020] In a control device, a machine tool, a control method, and a computer program according to an embodiment of the present disclosure, a brake test is performed on both a first brake and a second brake. Therefore, after the brake test, workpiece setup in a non-machining area becomes possible.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0022] Hereinafter, the present invention will be described based on the drawings showing a machine tool according to an embodiment. In the following description, up / down, front / rear, left / right in the drawings are used. FIG. 1 is a perspective view schematically showing a machine tool. In FIG. 1, illustration of a tool magazine for accommodating exchange tools, a machining chamber, a setup chamber, a partition wall, etc. (see FIG. 2) described later is omitted. The tool magazine is driven by the rotation of a magazine motor 82 (see FIG. 3). The magazine motor 82 has an electromagnetic brake 82e.

[0023] The machine tool includes a base 1 that is rectangular in plan view. A column 2 is provided on the base 1. The column 2 moves in the X-axis direction (left-right direction) and the Y-axis direction (front-back direction). A spindle head 4 is provided along the front surface of the column 2 so as to be movable up and down. The spindle head 4 includes a spindle (not shown). A tool is attached to the lower end of the spindle. A Z-axis motor 81 (see FIG. 3) is provided on the column 2. The Z-axis motor 81 has an electromagnetic brake 81e (see FIG. 3). By the rotation of the Z-axis motor 81, the spindle head 4 moves in the Z-axis direction (up-down direction). The spindle moves between an upper exchange position and a lower machining position by the up-and-down movement of the spindle head 4.

[0024] A spindle motor 6 for rotating the spindle is provided above the spindle head 4. By the rotation of the spindle motor 6, the spindle and the tool rotate.

[0025] A rotary table 8 is provided on the base 1 and below the spindle head 4. The rotary table 8 constitutes a moving part. The rotary table 8 rotates about a vertical axis (up-down axis) by the rotation of a table motor 83 (see FIG. 3). The table motor 83 has an encoder 83e. A first holding device 11 and a second holding device 12 for holding a workpiece are arranged side by side in the front-back direction on the rotary table 8. The first holding device 11 and the second holding device 12 constitute a first holding part and a second holding part.

[0026] FIG. 2 is a schematic plan perspective view of the rotary table 8, the machining chamber 51, and the setup chamber 52. The rotary table 8 rotates about a center 8a. L in FIG. 2 is a boundary line extending left and right passing through the center 8a when the rotary table 8 is stopped. The region on the rear side (upper side in FIG. 2) of the boundary line L is a machining region for machining the workpiece, and the region on the front side (lower side in FIG. 2) is a non-machining region separated from the machining region.

[0027] A processing chamber 51 is provided on the processing area side. A side door 51a is provided on the left side of the processing chamber 51. A setup chamber 52 is provided on the non-processing area side. A front door 52a is provided on the front side of the setup chamber 52, and a side door 52b is provided on the left side. The side doors 51a and 52b may be provided on the right side. Lock mechanisms (not shown) are provided on each of the two side doors 51a and 52b and the front door 52a. The processing chamber 51 and the setup chamber 52 are adjacent via a partition 53. The partition 53 is provided along the boundary line L, and the partition 53 is movable up and down. The rotary table 8 is located inside the processing chamber 51 and the setup chamber 52. When the partition 53 rises, the rotary table 8 rotates. After the rotation is completed, the partition 53 descends.

[0028] In FIGS. 1 and 2, the first holding device 11 is located at the rear part of the rotary table 8 and is positioned in the processing area. The second holding device 12 is located at the front part of the rotary table 8 and is positioned in the non-processing area. By the rotation of the rotary table 8, one of the first holding device 11 and the second holding device 12 moves from the processing chamber 51 to the setup chamber 52, and the other moves from the setup chamber 52 to the processing chamber 51. A first switch 54 for notifying the completion of workpiece setup in the setup chamber 52 is provided in the setup chamber 52. A second switch 55 for notifying the start of processing in the processing chamber 51 is provided in the processing chamber 51. When using the setup chamber 52, rotating the rotary table 8, and processing the workpiece held by the first holding device 11 and the second holding device 12, the operator operates the first switch 54. When processing the workpiece held by the first holding device 11 or the second holding device 12 located in the processing chamber 51 without using the setup chamber 52 and without rotating the rotary table 8, the operator operates the second switch 55.

[0029] The first holding device 11 includes an A-axis motor 11a, a support portion 11b, a rotary support base 11c, and a clamp portion 11d. The A-axis motor 11a and the support portion 11b are spaced apart left and right. The rotary support base 11c is in the shape of a plate that is long left and right. The A-axis motor 11a and the support portion 11b rotatably support the left and right end portions of the rotary support base 11c about the A-axis (an axis having the left-right direction as the axial direction). The rotary support base 11c rotates by the rotation of the A-axis motor 11a. The clamp portion 11d fixes the workpiece by compressed air sent from a compressor (not shown). The clamp portion 11d is provided on the upper surface of the rotary support base 11c. The clamp portion 11d fixes and releases the fixing of the workpiece manually or automatically. The A-axis motor 11a has an electromagnetic brake 11e (see FIG. 3).

[0030] The second holding device 12 includes an A-axis motor 12a, a support portion 12b, a rotary support base 12c, and a clamp portion 12d. The A-axis motor 12a and the support portion 12b are spaced apart left and right. The rotary support base 12c is in the shape of a plate that is long left and right. The A-axis motor 12a and the support portion 12b rotatably support the left and right end portions of the rotary support base 12c about the A-axis. The rotary support base 12c rotates by the rotation of the A-axis motor 12a. The clamp portion 12d fixes the workpiece by compressed air sent from a compressor (not shown). The clamp portion 12d is provided on the upper surface of the rotary support base 12c. The clamp portion 12d fixes and releases the fixing of the workpiece manually or automatically. The A-axis motor 12a has an electromagnetic brake 12e (see FIG. 3).

[0031] A control device 60 is provided on the back surface of the column 2. FIG. 3 is a block diagram schematically showing the configuration near the control device 60. The control device 60 includes a control unit 61, a RAM 62, a storage unit 63, an input interface 64, an output interface 65, etc. The control unit 61 has a CPU, an MPU, or a logic circuit, etc. The control unit 61 has a timer (not shown). The storage unit 63 has a rewritable storage medium, such as an EPROM, an EEPROM, a hard disk, etc.

[0032] The memory unit 63 stores a control program, a first processing program for processing the workpiece, a second processing program (program product), etc. The control program is a program for controlling the entire machine tool. The first processing program is a program for processing the workpiece held by the first holding device 11. The second processing program is a program for processing the workpiece held by the second holding device 12.

[0033] The control program and each processing program may be stored in a recording medium 66 such as an optical disk or a USB memory, and downloaded from the recording medium to the memory unit 63. Alternatively, the control device may be connected to a network, and the control program and each processing program may be downloaded from a server on the network to the memory unit 63.

[0034] The memory unit 63 stores the position of the table motor 83, i.e., the first position, in association with the first processing program, and stores the position of the table motor 83, i.e., the second position, in association with the second processing program. When the position of the table motor 83 is the first position, the first holding device 11 is located within the processing chamber 51, and the second holding device 12 is located in the setup chamber 52. When the position of the table motor 83 is the second position, the second holding device 12 is located within the processing chamber 51, and the first holding device 11 is located in the setup chamber 52. The control unit 61 executes the first processing program when the position of the table motor 83 is the first position or when the table motor 83 moves toward the first position, and executes the second processing program when the position of the table motor 83 is the second position or when the table motor 83 moves toward the second position.

[0035] The control unit 61 reads out the control program and each processing program stored in the memory unit 63 to the RAM 62 and executes them. The RAM 62 temporarily stores the control program, each processing program, and various data generated during the processing process, etc., read out from the memory unit 63.

[0036] The input device 71 outputs a signal to the input interface 64. The input device 71 includes a keyboard or a touch panel, etc., and accepts the operator's operations. The operator operates the input device 71 to input, for example, the execution time of the brake test. The storage unit 63 stores the execution time of the brake test. Note that the processing program may have the execution time of the brake test. When the first switch 54 is turned on, the objects of the brake test are the electromagnetic brakes for testing for safety during processing, that is, the electromagnetic brakes within the processing area during processing (hereinafter referred to as the in-processing-area electromagnetic brakes), and the electromagnetic brakes transported to the setup chamber 52, that is, the electromagnetic brakes in the non-processing area during processing (hereinafter referred to as the setup-use electromagnetic brakes).

[0037] For example, when the first holding device 11 is in the setup chamber 52 and the second holding device 12 is in the processing chamber 51, and when the first switch 54 is turned on, the in-processing-area electromagnetic brakes are the three electromagnetic brakes 81e, 82e, 11e. The electromagnetic brake 11e corresponds to the first brake. The setup-use electromagnetic brake is the electromagnetic brake 12e. The electromagnetic brake 12e corresponds to the second brake.

[0038] When the second holding device 12 is in the setup chamber 52 and the first holding device 11 is in the processing chamber 51, and when the first switch 54 is turned on, the in-processing-area electromagnetic brakes are the three electromagnetic brakes 81e, 82e, 12e. The electromagnetic brake 12e corresponds to the first brake. The setup-use electromagnetic brake is the electromagnetic brake 11e. The electromagnetic brake 11e corresponds to the second brake. That is, when the first switch 54 is turned on, both the electromagnetic brakes 11e and 12e are the objects of the brake test.

[0039] On the one hand, when the second switch 55 is turned on, the object of the brake test is only the electromagnetic brake within the processing area. The electromagnetic brake for setup is not the object of the brake test. Incidentally, when the second switch 55 is turned on, the rotary table 8 does not rotate. The operator opens the side door 51a of the processing chamber 51 to exchange the workpiece. That is, the operator does not use the first holding device 11 or the second holding device 12 located in the setup chamber 52. For example, when a malfunction occurs in the first holding device 11 or the second holding device 12, the operator can continue the processing by installing the malfunctioning holding device in the setup chamber 52 and the non-malfunctioning holding device in the processing chamber 51.

[0040] Since the first switch 54 is provided in the setup chamber 52, the operator can quickly operate the first switch 54 after setup. Since the second switch 55 is provided in the processing chamber 51, the operator can quickly operate the second switch 55 after installing the workpiece in the processing chamber 51. Whether the setup chamber 52 is used or not, the operator can perform the work smoothly.

[0041] When the memory unit 63 conducts a brake test on the electromagnetic brakes 81e, 82e, 11e, and 12e, it stores an executed flag in association with the electromagnetic brakes 81e, 82e, 11e, and 12e on which the brake test has been conducted. After the brake test is completed, when a predetermined time has elapsed, the control unit 61 deletes the executed flag from the memory unit 63. The executed flag may be deleted when the preset brake test execution time is reached. An electromagnetic brake for which the executed flag is not stored is an electromagnetic brake on which the brake test has not been conducted. The presence or absence of the executed flag corresponds to the execution / non-execution of the brake test.

[0042] The control unit 61 outputs drive or stop signals to the Z-axis motor 81, the magazine motor 82, the A-axis motor 11a, the A-axis motor 12a, the table motor 83, and the spindle motor 6 via the output interface 65. The control unit 61 outputs drive or stop signals to each of the electromagnetic brakes 81e, 82e, 11e, and 12e via the output interface 65. The encoder 83e outputs a detection signal to the input interface 64. The control unit 61 acquires the position of the table motor 83 based on the detection signal of the encoder 83e.

[0043] Figure 4 is a flowchart for explaining the brake test execution process when the first switch 54 is turned on, and it starts when there is an operation from the input device 71. The operator attaches the workpiece to the first holding device 11 or the second holding device 12 located in the setup chamber 52. That is, the setup of the workpiece is performed. When the setup of the workpiece is completed, the operator operates the first switch 54 to turn it on.

[0044] The control unit 61 determines whether the first switch 54 is on, that is, whether the setup of the workpiece in the setup chamber 52 is completed (S1). If the first switch 54 is not on (S1: NO), the control unit 61 returns the process to step S1. If the first switch 54 is on (S1: YES), the control unit 61 refers to the timer and determines whether it is the execution time of the brake test (S2). Note that instead of determining by the execution time, it may be determined whether the number of times the first switch is pressed has reached a predetermined number of times. The control unit 61 that executes S1 corresponds to the completion determination unit. The process of S2 may not be provided.

[0045] If it is the execution time of the brake test (S2: YES), the control unit 61 refers to the presence or absence of the executed flag and determines whether there is an electromagnetic brake in the processing area for which the test has not been performed (S3). If there is an electromagnetic brake in the processing area for which the test has not been performed (S3: YES), the control unit 61 performs a brake test on the electromagnetic brake in the processing area for which the brake test has not been performed (S4), and stores the executed flag in the storage unit 63 in association with the electromagnetic brake in the processing area for which the brake test has been performed (S5).

[0046] The control unit 61 determines whether or not a brake test has been performed for all the electromagnetic brakes within the machining area (S6). If the brake test has not been performed for all the electromagnetic brakes within the machining area (S6: NO), the control unit 61 returns the process to step S4. If the brake test has been performed for all the electromagnetic brakes within the machining area (S6: YES), the control unit 61 determines whether or not a test has not been performed for the setup electromagnetic brake (S7).

[0047] If a test has not been performed for the setup electromagnetic brake (S7: YES), the control unit 61 performs a brake test on the setup brake (S8), stores and sets the executed flag associated with the setup brake, rotates the rotary table 8 (S10), and after the rotation is completed, the control unit 61 starts machining in the machining chamber 51 (S11). The operator can open the front door 52a or the side door 52b of the setup chamber 52 during machining to perform workpiece setup.

[0048] In step S3, if there is no electromagnetic brake within the machining area for which the test has not been performed (S3: NO), the control unit 61 proceeds to step S7 with the process. In step S2, if it is not the time to perform the brake test (S2: NO), and in step S7, if a test has been performed for the setup electromagnetic brake (S7: NO), the control unit 61 proceeds to step S10 with the process.

[0049] In the machine tool according to the first embodiment, a brake test is performed on both the electromagnetic brake 11e and the electromagnetic brake 12e, that is, the first brake and the second brake. Therefore, after the brake test, the door of the setup chamber 52 opens, and workpiece setup in the non-machining area becomes possible.

[0050] Also, when the workpiece setup is completed, a brake test is performed on both the first brake and the second brake.

[0051] Also, when the first switch 54 is operated, a brake test is performed on both the first brake and the second brake. The first switch 54 and the second switch 55 are provided at different positions. When the first switch 54 is operated, a brake test is performed on both the first brake and the second brake. When the second switch 55 is operated, a brake test is performed only on the first brake. That is, by selecting the first switch 54 or the second switch 55, the operator can easily distinguish and execute the two brake tests.

[0052] Also, since the rotary table 8 moves between the processing area and the non-processing area, parallel execution of processing and setup can be realized.

[0053] In the above-described embodiment, the brake test performed when the first switch 54 is operated is different from the brake test performed when the second switch 55 is operated. However, when either the first switch 54 or the second switch 55 is operated, a brake test may be performed on both the first brake and the second brake.

[0054] The rotary table 8 is an example of the moving part. Instead of the rotary table 8, a first slide table and a second slide table that linearly move between the processing area and the non-processing area may be provided, and the first holding device 11 and the second holding device 12 may be provided on the two slide tables, respectively. When the first slide table is in the processing area, the second slide table is in the non-processing area. When the first slide table is in the non-processing area, the second slide table is in the processing area. When the first slide table moves from the processing area to the non-processing area, the second slide table moves from the non-processing area to the processing area. When the first slide table moves from the non-processing area to the processing area, the second slide table moves from the processing area to the non-processing area.

[0055] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The technical features described in each embodiment can be combined with each other, and the scope of the present invention is intended to include all modifications within the scope of the claims and the scope equivalent to the claims.

Explanation of Signs

[0056] 8 Rotary table 11 First holding device (holding part) 12 Second holding device (holding part) 51 Processing chamber 52 Setup chamber 54 First switch 55 Second switch 60 Control device 61 Control unit 62 RAM 63 Storage unit 81e Electromagnetic brake (first brake, second brake) 82e Electromagnetic brake (first brake, second brake)

Claims

1. In a control device for a machine tool including a moving part movable between a machining area for machining a workpiece and a non-machining area separated from the machining area, and a first holding part and a second holding part movably provided on the moving part for holding the workpiece, each of the first holding part and the second holding part has a motor for rotating the held workpiece and a brake for braking the rotation of the motor, the brakes of the first holding part and the second holding part include a first brake which is a brake of one of the first holding part and the second holding part conveyed to the machining area, and a second brake which is a brake of the other of the first holding part and the second holding part conveyed to the non-machining area, a test execution part for performing a brake test which is an operation test of the brake on the first brake and the second brake is provided, a completion determination part for determining whether or not the setup of the workpiece in the non-machining area is completed is provided, when the completion determination part determines that the setup is completed, the test execution part performs a brake test on the first brake and the second brake Control device.

2. The machine tool includes a machining chamber located in the machining area and a setup chamber located in the non-machining area, a first switch for notifying the completion of the setup of the workpiece in the setup chamber is provided in the setup chamber, a second switch for notifying the start of machining in the machining chamber is provided in the machining chamber, the completion determination part determines that the setup of the workpiece in the non-machining area is completed when the first switch is operated The control device according to claim 1.

3. The moving part is a rotary table The control device according to claim 1 or 2.

4. In a machine tool including a moving part movable between a machining area for machining a workpiece and a non-machining area separated from the machining area, and a first holding part and a second holding part movably provided on the moving part for holding the workpiece, each of the first holding part and the second holding part has a motor for rotating the held workpiece and a brake for braking the rotation of the motor, the brakes of the first holding part and the second holding part include a first brake which is a brake of one of the first holding part and the second holding part conveyed to the machining area, and a second brake which is a brake of the other of the first holding part and the second holding part conveyed to the non-machining area, A test execution unit that performs a brake test, which is an operation test of the brakes, on the first brake and the second brake is provided. A completion determination unit that determines whether or not the setup of the workpiece in the non-processing area has been completed is provided. When the completion determination unit determines that the setup has been completed, the test execution unit performs a brake test on the first brake and the second brake. Machine tool.

5. In a control method for a machine tool including a moving unit capable of moving between a processing area for processing a workpiece and a non-processing area separated from the processing area, and a first holding unit and a second holding unit movably provided on the moving unit for holding the workpiece, Each of the first holding unit and the second holding unit has a motor for rotating the held workpiece and a brake for braking the rotation of the motor. The brakes of the first holding unit and the second holding unit include a first brake that is a brake of one of the first holding unit and the second holding unit conveyed to the processing area, and a second brake that is a brake of the other of the first holding unit and the second holding unit conveyed to the non-processing area. A brake test, which is an operation test of the brakes, is performed on the first brake and the second brake. It is determined whether or not the setup of the workpiece in the non-processing area has been completed. When it is determined that the setup has been completed, a brake test is performed on the first brake and the second brake. Control method.

6. In a computer program executable by a control device of a machine tool including a moving unit capable of moving between a processing area for processing a workpiece and a non-processing area separated from the processing area, and a first holding unit and a second holding unit movably provided on the moving unit for holding the workpiece, Each of the first holding unit and the second holding unit has a motor for rotating the held workpiece and a brake for braking the rotation of the motor. The brakes of the first holding unit and the second holding unit include a first brake that is a brake of one of the first holding unit and the second holding unit conveyed to the processing area, and a second brake that is a brake of the other of the first holding unit and the second holding unit conveyed to the non-processing area. In the control device, A brake test, which is an operation test of the brakes, is performed on the first brake and the second brake. It is determined whether or not the setup of the workpiece in the non-processing area has been completed. When it is determined that the setup is completed, a braking test is performed on the first brake and the second brake. A computer program that executes the process.

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