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

Abstract

To provide a control device etc. allowed to suppress the lowering in machining accuracy while reducing the time required for machining a work-piece.SOLUTION: A control device reads out a plurality of commands in order and controls the movement of a movable main shaft attached with a tool and a movable hold unit holding a work-piece. The hold unit requires a previous cancellation of brake for movement. The control device comprises a movement determining section that, if reading out a first command which is a command indicative of a movement of the main shaft from the work-piece in an axial direction, determines whether or not a second command read out following the first command is of a command indicative of a movement of the hold unit, a start-position determining section that, if the movement determining section has determined the second command to be a command indicative of a movement of the hold unit, determines whether or not a movement-start position of the main shaft in the first command is of a position distant a first distance or more from the work-piece, and a first executing section that, if the start-position determining section has determined the movement-start position to be of a position distant the first distance or more from the work-piece, executes a cancellation of brake from the hold unit in execution of the first command.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present technology relates to a control device, a machine tool, a control method, and a computer program for controlling a spindle for mounting a tool and a holding unit for holding a workpiece.

Background Art

[0002] A machine tool reads a machining program and executes machining of a workpiece. The machining program includes, for example, a preceding command indicating the movement of a spindle for mounting a tool and a reference command that is read after the preceding command and indicates the movement of a holding unit for holding a workpiece. The control device of the machine tool releases the braking of the holding unit when executing the preceding command. Since the braking of the holding unit is released before executing the reference command, the time required for machining the workpiece can be shortened (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] The movement of the spindle indicated by the preceding command includes the movement of the spindle during workpiece machining, for example, during drilling. If the braking of the holding unit is released during workpiece machining, the workpiece may move unnecessarily and the machining accuracy may decrease.

[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 can shorten the time required for machining a workpiece while suppressing a decrease in machining accuracy.

Means for Solving the Problems

[0006] A control device according to an embodiment of the present disclosure is a control device that sequentially reads a plurality of commands and controls the movement of a movable spindle that mounts a tool and a movable holding unit that holds a workpiece. In the control device, the holding unit requires pre-release of braking for movement. When a first command, which is a command indicating the movement of the spindle away from the workpiece in the axial direction, is read, a movement determination unit determines whether a second command read after the first command is a command indicating the movement of the holding unit. When the movement determination unit determines that the second command is a command indicating the movement of the holding unit, a start position determination unit determines whether the movement start position of the spindle in the first command is a position separated from the workpiece by a first distance or more. When the start position determination unit determines that the movement start position is a position separated from the workpiece by a first distance or more, the control device includes a first execution unit that executes release of braking of the holding unit during execution of the first command.

[0007] In the present disclosure, when the movement start position of the spindle is a position separated from the workpiece by a first distance or more, release of braking of the holding unit is executed during execution of the first command. Even if the workpiece moves during execution of the first command, the movement of the workpiece does not affect the machining of the workpiece.

[0008] The control device according to an embodiment of the present disclosure includes a first writing unit that writes a braking release command for releasing the braking of the holding unit in association with the first command to a storage unit when the start position determination unit determines that the movement start position is a position separated from the workpiece by a first distance or more. The first execution unit executes the braking release command written by the first writing unit when the first command is executed.

[0009] In the present disclosure, a braking release command is written to the storage unit in association with the first command, and parallel execution of the braking release of the holding unit for the first command is realized.

[0010] When the start position determination unit determines that the movement start position is not a position that is at least a first distance away from the workpiece, a end position determination unit determines whether the movement end position of the main shaft is a position that is at least a first distance away from the workpiece. When the end position determination unit determines that the movement end position is a position that is at least a first distance away from the workpiece, a second execution unit executes braking release of the holding unit when the main shaft reaches a position that is at least a first distance away from the workpiece during execution of the first command.

[0011] In the present disclosure, when the movement start position of the main shaft is not at least a first distance away from the workpiece and the movement end position of the main shaft is at least a first distance away from the workpiece, braking release of the holding unit is executed when the main shaft reaches a position that is at least a first distance away from the workpiece during execution of the first command. When the braking of the holding unit is released, the tool is in a position where it does not interfere with the workpiece.

[0012] When the end position determination unit determines that the movement end position is a position that is at least a first distance away from the workpiece, a second writing unit writes a braking release command for releasing the braking of the holding unit when the main shaft reaches a position that is at least a first distance away from the workpiece, which is associated with the first command, into a storage unit. The second execution unit executes the braking release command written by the second writing unit during execution of the first command.

[0013] In the present disclosure, a command for releasing the braking of the holding unit when the main shaft reaches a position that is at least a first distance away from the workpiece, which is associated with the first command, is written into the storage unit, and non-interference between the tool and the workpiece is realized.

[0014] A control device according to an embodiment of the present disclosure is a control device that sequentially reads a plurality of commands and controls the movement of a movable spindle for mounting a tool and a movable holding unit for holding a workpiece. In the control device, the holding unit requires pre-braking release for movement. A first repetitive determination unit that determines whether or not a first repetitive command in which the spindle repeatedly moves between a first position that is a first distance away from the workpiece and a second position that contacts the workpiece is read; an axial movement determination unit that determines whether or not a first command that indicates movement of the spindle away from the workpiece in the axial direction is read when the first repetitive determination unit determines that the first repetitive command has been read; a holding unit movement determination unit that determines whether or not a second command read after the first command indicates movement of the holding unit; and a third execution unit that executes braking release of the holding unit when the first command is executed when the holding unit movement determination unit determines that the second command indicates movement of the holding unit.

[0015] In the present disclosure, when the first command is executed after the first repetitive command and the movement of the holding unit is executed after the first command, the braking release of the holding unit is executed during the execution of the first command.

[0016] A control device according to an embodiment of the present disclosure includes a third writing unit that writes a braking release command for releasing the braking of the holding unit in association with the first command into a storage unit when the holding unit movement determination unit determines that the second command indicates movement of the holding unit, and the third execution unit executes the braking release command written by the third writing unit when the first command is executed.

[0017] In the present disclosure, a braking release command is written into the storage unit in association with the first command executed after the first repetitive command, and parallel execution of the first command and the braking release of the holding unit is realized.

[0018] A control device according to an embodiment of the present disclosure is a control device that sequentially reads a plurality of commands and controls the movement of a movable spindle that mounts a tool and a movable holding unit that holds a workpiece. In the control device, the holding unit requires pre-braking release for movement. A command for executing a repetitive operation in which the spindle repeatedly moves between a first position that is a first distance away from the workpiece and a second position that contacts the workpiece, and the end position of the repetitive operation is a third position that is a second distance away from the workpiece and different from the first position. A second repetition determination unit that determines whether a second repetition command is read; when the second repetition determination unit determines that the second repetition command is read, an axial movement determination unit that determines whether a first command that is a command indicating the movement of the spindle away from the workpiece in the axial direction is read; when the axial movement determination unit determines that the first command is read, a holding unit movement determination unit that determines whether a second command read after the first command is a command indicating the movement of the holding unit; and when the holding unit movement determination unit determines that the second command is a command indicating the movement of the holding unit, a fourth execution unit that executes braking release of the holding unit when the spindle reaches a position that is a first distance or more away from the workpiece during execution of the first command.

[0019] In the present disclosure, when a second repetition command is read, braking release of the holding unit is executed when the spindle reaches a position that is a first distance or more away from the workpiece during execution of the first command.

[0020] A control device according to an embodiment of the present disclosure includes a fourth writing unit that writes a braking release command for releasing braking of the holding unit when the spindle reaches a position that is a first distance or more away from the workpiece, associated with the first command, into a storage unit when the holding unit movement determination unit determines that the second command is a command indicating the movement of the holding unit. The fourth execution unit executes the braking release command written by the fourth writing unit during execution of the first command.

[0021] In the present disclosure, when reading a second repetition command, a command for releasing braking when the spindle reaches a position at a distance of at least a first distance from the workpiece is written to a storage unit in association with the first command, thereby realizing non-interference between the tool and the workpiece.

[0022] A machine tool according to an embodiment of the present disclosure includes a movable spindle on which a tool is mounted, a movable holding unit that holds a workpiece, and a control device that sequentially reads a plurality of commands and controls the movement of the spindle and the holding unit. In the machine tool, the holding unit requires pre-release of braking for movement, and the control device, when reading a first command that is a command indicating movement of the spindle away from the workpiece in the axial direction, a movement determination unit that determines whether a second command read after the first command is a command indicating movement of the holding unit, and when the movement determination unit determines that the second command is a command indicating movement of the holding unit, a start position determination unit that determines whether a movement start position of the spindle in the first command is a position at a distance of at least a first distance from the workpiece, and when the start position determination unit determines that the movement start position is a position at a distance of at least a first distance from the workpiece, a first execution unit that executes release of braking of the holding unit during execution of the first command.

[0023] In the present disclosure, when the movement start position of the spindle is a position at a distance of at least a first distance from the workpiece, release of braking of the holding unit is executed during execution of the first command. Even if the workpiece moves during execution of the first command, the movement of the workpiece does not affect the machining of the workpiece.

[0024] A control method according to an embodiment of the present disclosure is a control method for sequentially reading a plurality of commands and controlling the movement of a movable spindle that mounts a tool and a movable holding unit that holds a workpiece. The holding unit requires pre-release of braking for movement. When a first command, which is a command indicating the movement of the spindle away from the workpiece in the axial direction, is read, it is determined whether a second command read after the first command is a command indicating the movement of the holding unit. When it is determined that the second command is a command indicating the movement of the holding unit, it is determined whether the movement start position of the spindle in the first command is a position that is separated from the workpiece by a first distance or more. When it is determined that the movement start position is a position that is separated from the workpiece by a first distance or more, the braking of the holding unit is released during the execution of the first command.

[0025] In the present disclosure, when the movement start position of the spindle is a position that is separated from the workpiece by a first distance or more, the braking of the holding unit is released during the execution of the first command. Even if the workpiece moves during the execution of the first command, the movement of the workpiece does not affect the machining of the workpiece.

[0026] A control method according to an embodiment of the present disclosure is a control method for sequentially reading a plurality of commands and controlling the movement of a movable spindle that mounts a tool and a movable holding unit that holds a workpiece. The holding unit requires pre-release of braking for movement. When, after a first command, which is a command indicating the movement of the spindle away from the workpiece in the axial direction, a second command indicating the movement of the holding unit is executed, if the movement start position of the spindle in the first command is a position that is separated from the workpiece by a first distance or more, the braking of the holding unit is released during the execution of the first command; if the movement start position of the spindle in the first command is not a position that is separated from the workpiece by a first distance or more, the braking of the holding unit is released after the execution of the first command.

[0027] In the present disclosure, when the movement start position of the spindle is a position that is separated from the workpiece by a first distance or more, the braking of the holding unit is released during the execution of the first command. Even if the workpiece moves during the execution of the first command, the movement of the workpiece does not affect the machining of the workpiece.

[0028] A computer program according to an embodiment of the present disclosure is a computer program executable by a control device that sequentially reads a plurality of commands and controls the movement of a movable spindle for mounting a tool and a movable holding unit for holding a workpiece. In the computer program, the holding unit requires pre-release of braking for movement. When the control device reads a first command that is a command indicating the movement of the spindle away from the workpiece in the axial direction, it determines whether a second command read after the first command is a command indicating the movement of the holding unit. When it is determined that the second command is a command indicating the movement of the holding unit, it determines whether the movement start position of the spindle in the first command is a position separated from the workpiece by a first distance or more. When it is determined that the movement start position is a position separated from the workpiece by a first distance or more, a process of releasing the braking of the holding unit during the execution of the first command is executed.

[0029] In the present disclosure, when the movement start position of the spindle is a position separated from the workpiece by a first distance or more, the braking of the holding unit is released during the execution of the first command. Even if the workpiece moves during the execution of the first command, the movement of the workpiece does not affect the processing of the workpiece.

Effect of the Invention

[0030] In a control device, a machine tool, a control method, and a computer program according to an embodiment of the present disclosure, when the movement start position of the spindle is a position separated from the workpiece by a first distance or more, the braking of the holding unit is released when the first command is executed. Even if the workpiece moves during the execution of the first command, the movement of the workpiece does not affect the processing of the workpiece, and it is possible to suppress a decrease in processing accuracy while shortening the processing time.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Embodiments for Carrying Out the Invention

[0032] (Embodiment 1) The following description will be based on the drawings showing the machine tool according to Embodiment 1 of the present invention. In the following description, the up-down, left-right, and front-back directions indicated by arrows in the drawings are used. The operator operates the machine tool in the front and attaches and detaches the workpiece W (see FIG. 6). FIG. 1 is a perspective view of the machine tool, and FIG. 2 is a perspective view of the machine tool with the tool changer and the cover covering the track omitted.

[0033] The machine tool 100 includes a base 20, a Y-axis direction moving device 22, an X-axis direction moving device 26, a column 28, a Z-axis direction moving device 30, a spindle head 32, a tool changer 10, etc. The X-axis direction corresponds to the left-right direction, the Y-axis direction corresponds to the front-back direction, and the Z-axis direction corresponds to the up-down direction. The base 20 is fixed on the floor surface. The base 20 supports the column 28 so as to be movable in the front-back direction and the left-right direction via the Y-axis direction moving device 22 and the X-axis direction moving device 26. The base 20 supports the workpiece holding device 120. The workpiece holding device 120 corresponds to the holding portion. The Z-axis direction moving device 30 is provided on the column 28. The Z-axis direction moving device 30 moves the spindle head 32 in the up-down direction. The tool changer 10 exchanges the tools mounted on the spindle head 32.

[0034] The Y-axis direction moving device 22 includes two mutually parallel tracks 22a, a plurality of moving bodies 22b, a Y-axis direction moving table 22c, and a Y-axis motor 22d (see FIG. 4). The track 22a extends in the front-back direction on the upper surface of the base 20. The moving body 22b is fitted to each of the two tracks 22a so as to be movable in the front-back direction. The Y-axis direction moving table 22c is fixed on the moving body 22b straddling the two tracks 22a. By driving the Y-axis motor 22d, the Y-axis direction moving table 22c moves in the front-back direction.

[0035] The X-axis direction moving device 26 includes two tracks 26a parallel to each other, a plurality of moving bodies 26b, a column base 26c, and an X-axis motor 26d (see FIG. 4). The tracks 26a extend in the left-right direction on the upper surface of the Y-axis direction moving table 22c. The moving bodies 26b are respectively fitted to the two tracks 26a so as to be movable in the left-right direction. The column base 26c is fixed on the moving bodies 26b straddling the two tracks 26a. The column 28 is fixed on the column base 26c. By driving the X-axis motor 26d, the column base 26c moves in the left-right direction. The column 28 moves in the front-rear direction and the left-right direction by the Y-axis direction moving device 22 and the X-axis direction moving device 26.

[0036] The Z-axis direction moving device 30 includes two tracks 30a parallel to each other, a plurality of moving bodies 30b, a spindle head base 30c, and a Z-axis motor 30d (see FIG. 4). The tracks 30a extend in the up-down direction on the front surface of the column 28. The plurality of moving bodies 30b are respectively fitted to the two tracks 30a so as to be movable in the up-down direction. The spindle head base 30c is fixed on the front surface of the moving bodies 30b straddling the two tracks 30a. By driving the Z-axis motor 30d, the spindle head base 30c moves in the up-down direction.

[0037] The spindle head 32 is fixed to the spindle head base 30c. The spindle head 32 rotatably holds a spindle 34 extending in the up-down direction inside the front side. The spindle 34 has a hollow cylindrical shape. By driving and controlling the X-axis motor 26d, the Y-axis motor 22d, and the Z-axis motor 30d, the spindle head 32 moves forward and backward, left and right, and up and down.

[0038] The tool changing device 10 includes an oval track (not shown) and a plurality of moving tables (not shown) that move on the track. The track surrounds the spindle head 32 and the column 28, extends from the lower front side to the upper rear side, and is inclined at a predetermined angle from the horizontal plane. The plurality of moving tables are connected in a chain-like manner by links. As shown in FIG. 1, a gear 51 and a drive motor 52 are arranged inside the track. The gear 51 is connected to the drive motor 52 and rotates by driving the drive motor 52. The plurality of moving tables mesh with the gear 51 and rotate on the track by driving the drive motor 52. Each moving table supports a gripping arm 53.

[0039] An empty gripping arm 53 is disposed at the front end of the orbit of the tool changer 10. When the spindle 34 with the tool 11 mounted thereon rises, the gripping arm 53 removes the tool 11 from the spindle 34 and grips it. The gripping arm 53 that grips the tool 11 is disposed at the front end of the orbit of the tool changer 10. When the spindle 34 that does not grip the tool 11 descends, the spindle 34 mounts the tool 11.

[0040] Figure 3 is a front-side perspective view of the workpiece holding device 120. The workpiece holding device 120 includes a support base 121. Shaft portions 122 having the left-right direction as the axial direction are provided on the left and right portions of the support base 121, respectively. Hereinafter, the central axis of the shaft portion 122 is also referred to as the A axis. The left shaft portion 122 is rotatably supported about the A axis by a support portion 124. The support portion 124 is connected to the base 20. A turntable 127 that is rotatable about the C axis is provided on the upper surface of the support base 121. The C axis is orthogonal to the upper surface of the support base 121.

[0041] The right shaft portion 122 is rotatably supported about the A axis by a support portion 123. An A-axis motor 125 is provided on the support portion 123. Transmission members (not shown) such as gears, cams, and cam followers are accommodated in the support portion 123. The rotation of the A-axis motor 125 is transmitted to the shaft portion 122 via the transmission members, and the support base 121 rotates about the A axis. A turntable 127 is provided on the upper portion of the support base 121, and a C-axis drive portion 126 is provided on the lower portion of the support base 121. The C-axis drive portion 126 has a C-axis motor 79 (see FIG. 4), and the turntable 127 rotates about the C axis by the rotation of the C-axis motor 79. The workpiece holding device 120 includes an A-axis brake B1 (see FIG. 4) that brakes or releases the braking of the A-axis motor 125, and a C-axis brake B2 (see FIG. 4) that brakes or releases the braking of the C-axis motor 79.

[0042] The machine tool is provided with a control device 80. FIG. 4 is a block diagram schematically showing the configuration of the control device 80. The control device 80 includes a CPU 80a, a RAM 80b that temporarily stores information, a rewritable non-volatile memory 80c that stores a machining program, an input / output interface (input / output I / F) 80d, etc., which are interconnected via a bus. The CPU 80a is an example of a control unit, and an MPU or a logic circuit (e.g., FPGA) etc. may be used instead of the CPU 80a. The non-volatile memory 80c is, for example, an EEPROM or an EPROM. The non-volatile memory 80c stores the machining program. Instead of the non-volatile memory 80c, a rewritable recording medium such as a hard disk or a flash memory may be used. The RAM 80b and the non-volatile memory 80c correspond to a storage unit.

[0043] The CPU 80a reads the machining program from the non-volatile memory 80c into the RAM 80b and controls the machine tool. The machining program may be recorded on a recording medium 81 such as an optical disk and downloaded from the recording medium 81 to the non-volatile memory 80c. The machining program may be recorded on a server, the server and the control device 80 may be connected via a network, and the machining program may be downloaded from the server to the non-volatile memory 80c.

[0044] The CPU 80a outputs drive signals to the X-axis motor 26d, the Y-axis motor 22d, the Z-axis motor 30d, the A-axis motor 125, and the C-axis motor 79. The X-axis motor 26d, the Y-axis motor 22d, the Z-axis motor 30d, the A-axis motor 125, and the C-axis motor 79 are each provided with an encoder (not shown), and rotate to a target position using the detection value of the encoder as a feedback signal. The CPU 80a outputs a braking signal or a brake release signal to the A-axis brake B1 and the C-axis brake B2.

[0045] FIG. 5 is a conceptual diagram showing an example of a machining program stored in the non-volatile memory 80c. FIG. 6 is a schematic diagram showing the operations of the instructions of each block in FIG. 5. The machining program includes a plurality of blocks, and each block has a block number and an instruction. In FIG. 5, "number" indicates the block number, and "instruction" indicates the content of the instruction. The CPU 80a executes the instructions in the order of the numbers. In FIG. 6, E(n - 2) to E(n + 1) indicate the operations of the (n - 2)th to (n + 1)th blocks in FIG. 5.

[0046] "G90" in the (n - 2)th block is an instruction for specifying the coordinate axes within the block in absolute coordinates, and "G1" is an instruction indicating linear movement of the main axis. That is, "G90G1Z50" is an instruction indicating linear movement of the main axis 34 to the Z coordinate 50 (see E(n - 2) in FIG. 6). "G0" in the (n - 1)th block is an instruction indicating positioning at the maximum speed. That is, "G0Z110" indicates movement of the main axis 34 to the Z coordinate 110 at the maximum speed (see E(n - 1) in FIG. 6). The same applies to "G0Z130" in the nth block and "G0Z150" in the (n + 1)th block (see E(n) and E(n + 1) in FIG. 6). "G0Z100", "G0Z130", and "G0Z150" are all instructions indicating movement in the axial direction of the main axis 34, that is, axial movement instructions.

[0047] "G0A_" in the (n + 2)th block indicates an instruction for positioning around the A axis at the maximum speed. For example, a target angle or position is described after A. That is, "G0A_" indicates an instruction for rotating around the A axis to the target angle or position at the maximum speed, and indicates an additional axis movement instruction. Note that the additional axis movement instruction indicates an instruction for performing movement other than movement in the X, Y, and Z axis directions, and includes, for example, an instruction for rotating around the B or C axis.

[0048] In FIG. 6, I indicates the initial position of the tool 11 in the Z-axis direction. In this embodiment, the initial position I is greater than 150. P indicates the Z coordinate, and indicates a coordinate at least a first distance above the upper end coordinate of the workpiece W. That is, P is a threshold value indicating a position at least a first distance away from the workpiece. In this embodiment, P = 100, and the workpiece W is arranged between Z coordinates 50 and 95. The difference between the upper surface of the workpiece W and the threshold value P is a distance greater than or equal to the first distance. In this embodiment, the first distance is 5 or less. FIG. 7 is a conceptual diagram showing an example of a machining program and a brake release command written in the RAM 80b. The CPU 80a writes a command to release the brake in association with each block of the machining program as necessary. For example, as shown in FIG. 7, in association with the (n + 1)-th block, "A" is written as a command to release the brake of the A-axis.

[0049] FIG. 8 is a flowchart for explaining the machining process by the control device 80. In the initial state, the operator inputs the threshold value P into the control device 80 in advance, and the CPU 80a writes the threshold value P (100 in this embodiment) into the RAM 80b. The CPU 80a reads the k-th block from the non-volatile memory 80c (S1). Note that the initial value of k is 1. The CPU 80a determines whether the k-th block is an axial movement command (S2). As described above, the axial movement command is, for example, "G0Z_" (the Z coordinate is described after Z). When the k-th block is an axial movement command (S2: YES), the CPU 80a reads the (k + 1)-th block (S3) and determines whether the (k + 1)-th block is an additional axis movement command (S4).

[0050] When the (k + 1)-th block is an additional axis movement command (S4: YES), the CPU 80a determines whether the movement start position in the axis direction movement command of the k-th block, that is, the coordinate Z1 of the start position in the Z-axis direction, is equal to or greater than the threshold value P (S5). When the coordinate Z1 is equal to or greater than the threshold value P (S5: YES), the CPU 80a associates a first braking release command, for example, a first braking release command for the A-axis brake B1, with the axis direction movement command of the k-th block (S6), and writes the k-th block into the RAM 80b (S7, see FIG. 7). The first braking release command is a command to release the braking of, for example, the A-axis brake B1 during the execution of the axis direction movement command of the k-th block. The CPU 80a increments k by one (S8), and returns the process to step S1.

[0051] For example, when the (n + 1)-th block, that is, the axis direction movement command, is read (S1, S2, see FIG. 5), the CPU 80a determines whether the (n + 2)-th block is an additional axis movement command (S3, S4). Since the (n + 2)-th block is a rotation command around the A-axis, that is, an additional axis movement command (S4: YES), the CPU 80a determines whether the movement start position of the (n + 1)-th block is equal to or greater than the threshold value P, that is, 100 (S5). Since the movement start position of the (n + 1)-th block is 130 and is equal to or greater than 100 (S5: YES, see FIGS. 5 and 6), the CPU 80a associates a first braking release command with the (n + 1)-th block (S6), and writes the (n + 1)-th block into the RAM 80b (S7).

[0052] In step S5, when the coordinate Z1 is not equal to or greater than the threshold value P (S5: NO), the CPU 80a determines whether the movement end position in the axis direction movement command of the k-th block, that is, the coordinate Z2 of the end position in the Z-axis direction, is equal to or greater than the threshold value P (S9). When the coordinate Z2 is equal to or greater than the threshold value P (S9: YES), the CPU 80a associates a second braking release command for the A-axis brake B1 with the axis direction movement command of the k-th block (S10, see FIG. 7), and writes the k-th block into the RAM 80b (S7). The second braking release command is a command to release the braking of the A-axis brake B1 during the movement in the axis direction when the Z coordinate of the main shaft 34 reaches equal to or greater than the threshold value P after the start of execution of the axis direction movement command of the k-th block. The CPU 80a increments k by one (S8), and returns the process to step S1.

[0053] FIG. 9 is a conceptual diagram showing another example of a machining program, and FIG. 10 is a schematic diagram showing the operation of commands for each block of FIG. 9. FIG. 9 is obtained by replacing the (n + 2)-th block, the n-th block, and the (n + 1)-th block of FIG. 5 with the n-th block, the (n + 1)-th block, and the (n + 2)-th block, respectively. FIG. 11 is a conceptual diagram showing another example of a machining program and a brake release command written in the RAM 80b. The CPU 80a writes a command to release the brake in association with each block of the machining program as necessary. For example, as shown in FIG. 11, in association with the (n - 1)-th block, when the Z coordinate of the spindle 34 reaches a threshold value P or more, a command to release the brake of the A axis, that is, "A" is written as a second brake release command.

[0054] For example, when the (n - 1)-th block, that is, an axial movement command is read (see S1 and S2 in FIG. 9), the CPU 80a determines whether the n-th block is an additional axis movement command (S3 and S4). Since the n-th block is a rotation command around the A axis, that is, an additional axis movement command (S4: YES), the CPU 80a determines whether the movement start position of the (n - 1)-th block is a threshold value P, that is, 100 or more (S5). Since the movement start position of the (n - 1)-th block is 50 and is not 100 or more (S5: NO, see FIGS. 9 and 10), the CPU 80a determines whether the movement end position of the (n - 1)-th block is 100 or more (S9). Since the coordinate Z2 is 110 and is 100 or more (S9: YES), the CPU 80a associates a second brake release command for the A-axis brake B1 with the axial movement command of the (n - 1)-th block (see S10 in FIG. 11) and writes the (n - 1)-th block to the RAM 80b (S7). The A-axis brake B1 releases the brake of the A axis when the Z coordinate of the spindle 34 reaches 100, that is, when the Z coordinate of the spindle 34 becomes 100 or more. When the brake of the A axis is released, the tool 11 is in a position where it does not interfere with the workpiece W.

[0055] In step S2, when the k-th block is not an axial movement command (S2: NO), for example, when the k-th block is an additional axis movement command, the CPU 80a determines whether the k-th block is an end command (S11). When the k-th block is not an end command (S11: NO), the CPU 80a stores the k-th block in the RAM 80b (S7), increments k by one (S8), and returns the process to step S1.

[0056] In step S11, when the k-th block is an end command (S11: YES), the CPU 80a stores the k-th block in the RAM 80b (S12), executes all the blocks stored in the RAM 80b (S13), and ends the process.

[0057] In the machine tool according to the first embodiment, when the movement start position of the main shaft 34 is at least a first distance away from the workpiece W, the braking release of the workpiece holding device 120 is executed during the execution of the axial movement command (first command). Even when the workpiece W moves during the execution of the axial movement command, the tool 11 and the workpiece W do not interfere with each other, and it is possible to suppress a decrease in machining accuracy while shortening the machining time.

[0058] Also, a braking release command is written to the RAM 80b in association with the axial movement command (first command) to realize parallel execution of the axial movement command and the braking release of the workpiece holding device 120.

[0059] Also, when the movement start position of the main shaft 34 is not at least a first distance away from the workpiece W and the movement end position of the main shaft 34 is at least a first distance away from the workpiece W, after the main shaft 34 reaches a position at least a first distance away from the workpiece W during the execution of the axial movement command (first command), the braking release of the workpiece holding device 120 is executed. When the braking of the workpiece holding device 120 is released, the tool 11 is in a position where it does not interfere with the workpiece W.

[0060] Also, in association with the axial movement command, a command to release the braking of the axial movement command when the main shaft 34 reaches a position at least a first distance away from the workpiece is written to the RAM 80b to realize non-interference between the tool 11 and the workpiece W.

[0061] (Embodiment 2) The present invention will be described below based on the drawings showing a machine tool according to Embodiment 2. Among the configurations of the machine tool according to Embodiment 2, the same configurations as those in Embodiment 1 are denoted by the same reference numerals, and detailed descriptions thereof are omitted. FIG. 12 is a conceptual diagram showing an example of a machining program, and FIG. 13 is a schematic diagram showing the operations of the commands of each block in FIG. 12.

[0062] In FIG. 13, the Z coordinate R (R = 50 in this embodiment) indicates a coordinate separated at least by a first distance above the upper end coordinate of the workpiece W. The difference between the upper surface of the workpiece W and R is a distance equal to or greater than the first distance. The workpiece W is disposed, for example, between Z coordinates 0 and 45. In this embodiment, the first distance is 5 or less.

[0063] "G81" in the (n - 3)th block is a command for repeating a predetermined operation. "G99" is a command for setting the Z coordinate return position of the predetermined operation of G81 to the Z coordinate R. Details of the predetermined operation are described in later blocks, and the predetermined operation is a drilling operation of moving between a first position and a second position after moving to the initial position. "G90Z100" in the (n - 2)th block is a command for linearly moving to the initial position I, that is, the Z coordinate 100 (see E(n - 2) in FIG. 13). "G81R50.Z0.F1000" in the (n - 1)th block is a command for the main shaft 34 to reciprocate between the initial position I and the first position, that is, the Z coordinate R, and the second position, that is, the Z coordinate 0, at a feed rate of 1000 mm / min to perform drilling (see E(n - 1)2 and E(n - 1)3 in FIG. 13). E(n - 1)1 to E(n - 1)3 in FIG. 13 show the execution operations of the commands in the (n - 1)th block in detail. "X_Y_" in the nth block is a command for linearly moving in the X-axis direction and the Y-axis direction at the Z coordinate R (see E(n) in FIG. 13). For example, a target coordinate or a moving distance is described after X and Y. That is, after executing the operation E(n - 1)3 in FIG. 13, the CPU 80a executes the operation E(n), and then executes the operation E(n - 1)3.

[0064] After the execution of the nth block, until a command to invalidate "G81", for example, an axial movement command, is executed, the operations of the (n - 1)th block excluding E(n - 1)1, that is, operations E(n - 1)2 and E(n - 1)3, and the operation E(n) of the nth block are repeatedly executed. "G0Z100" of the (n + s)th block is a movement command for the main shaft 34 to the Z coordinate 100 at the maximum speed (refer to E(n + s) in Fig. 13). The (n + s)th block is an axial movement command and a command to invalidate "G81". The repeated command ends by the execution of the (n + s)th block. The (n - 3)th block, the (n - 1)th block, and the nth block correspond to the first repeated command. Hereinafter, after the reading of "G81" in the G99 state, the state until "G81" is invalidated is referred to as the first repeated state.

[0065] Fig. 14 is a conceptual diagram showing an example of a machining program and a braking release command written in the RAM 80b. The CPU 80a writes a command to release the braking in association with each block of the machining program as necessary. For example, as shown in Fig. 14, in association with the (n + s)th block, "A" is written as a command to release the braking of the A axis when the Z coordinate of the main shaft 34 reaches a position of R or more.

[0066] Fig. 15 is a flowchart for explaining the machining process by the control device 80. The CPU 80a reads the kth block (S21). Note that the initial value of k is 1. The CPU 80a determines whether it is in the first repeated state (S22). If it is in the first repeated state (S22: YES, refer to the (n - 3)th to nth blocks in Fig. 12), the CPU 80a determines whether the kth block is an axial movement command (S23). If the kth block is an axial movement command (S23: YES, refer to the (n + s)th block in Fig. 12), the CPU 80a reads the (k + 1)th block (S24).

[0067] The CPU 80a determines whether the (k + 1)-th block is an additional axis movement (S25). When the (k + 1)-th block is an additional axis movement (S25: YES, refer to the (n + s + 1)-th block in Fig. 12), the CPU 80a associates a braking release command, for example, a braking release command for the A-axis brake B1, with the axis direction movement command of the k-th block (S26, refer to Fig. 14), and writes the k-th block into the RAM 80b (S27). The braking release command in step S26 is a command to release the braking of, for example, the A-axis brake B1 when, during the execution of the operation E(n + s) in Fig. 13, that is, when the main shaft 34 moves in the direction away from the workpiece W and reaches a position above the first position. The CPU 80a increments k by one (S28) and returns the process to step S21.

[0068] In step S25, when the (k + 1)-th block is not an additional axis movement (S25: NO), the CPU 80a proceeds to the process of step S27.

[0069] In step S22, when it is not in the first repetition state (S22: NO), the CPU 80a determines whether the k-th block is an end command (S29). When the k-th block is not an end command (S29: NO), the CPU 80a proceeds to the process of step S27. When the k-th block is an end command (S29: YES), the CPU 80a stores the k-th block in the RAM 80b (S30), executes all the blocks (S31), and ends the process.

[0070] In the machine tool according to the second embodiment, when an axis direction movement command (first command) is executed after the first repetition command and an additional axis movement command (second command) of the workpiece holding device 120 is executed after the axis direction movement command, the braking release of the workpiece holding device 120 is executed during the execution of the axis direction movement command. Also, a braking release command is written into the RAM 80b in association with the axis direction movement command executed after the first repetition command, realizing the parallel execution of the axis direction movement command and the braking release of the workpiece holding device 120.

[0071] (Embodiment 3) The following will be described based on the drawings showing the machine tool according to Embodiment 3 of the present invention. Among the configurations of the machine tool according to Embodiment 3, the same configurations as those in Embodiment 1 or 2 are denoted by the same reference numerals, and detailed descriptions thereof are omitted. FIG. 16 is a conceptual diagram showing an example of a machining program, and FIG. 17 is a schematic diagram showing the operations of the commands of each block in FIG. 16.

[0072] "G81" in the (n - 2)-th block is a command for repeating a predetermined operation. "G98" is a command for setting the Z-axis return position of the predetermined operation of G81 to the initial position. The details of the predetermined operation are described in a later block. The predetermined operation is a drilling operation in which, after moving to the initial position I, it reciprocates between the first position and the second position and then returns to the initial position I. The initial position I corresponds to the third position. "G90Z100" in the (n - 1)-th block is a command for linearly moving to the initial position I, that is, up to the Z coordinate 100 (see E(n - 1) in FIG. 17). "G81R50.Z0.F1000" in the n-th block is a command for moving from the initial position I to the first position, that is, up to the Z coordinate R (R = 50 in this embodiment) at a feed rate of 1000 mm / min (see E(n)1 in FIG. 17), and further moving to the second position, that is, up to the Z coordinate 0 (see E(n)2 in FIG. 17). "X_Y_" in the (n + 1)-th block is a command for moving from the second position to the first position (see E(n + 1)1 in FIG. 17), further moving from the first position to the initial position I (see E(n + 1)2 in FIG. 17), and linearly moving in the X-axis direction and the Y-axis direction at the initial position I (see E(n + 1)3 in FIG. 17). E(n)1 and E(n)2 in FIG. 17 show the execution operations of the n-th block command in detail, and E(n + 1)1 to E(n + 1)3 show the execution operations of the (n + 1)-th block command in detail.

[0073] Operation E(n + 1) includes operations E(n + 1)1 and E(n + 1)2 which are movements in the Z-axis direction. That is, the (n + 1)-th block which is the command for operation E(n + 1) can be regarded as an axial movement command.

[0074] The n-th block to the (n + 2)-th block are repeatedly executed. The (n - 2)-th block, the n-th to the (n + 2)-th blocks correspond to the second repetition command. Hereinafter, the state after reading "G81" in the "G98" state is referred to as the second repetition state.

[0075] FIG. 18 is a conceptual diagram showing an example of a machining program and a brake release command written in the RAM 80b. The CPU 80a writes a command to release the brake in association with each block of the machining program as necessary. For example, as shown in FIG. 18, in association with the (n + 1)-th block, “A” is written as a command to release the brake of the A-axis when the Z coordinate of the main shaft 34 reaches R or more.

[0076] FIG. 19 is a flowchart for explaining the machining process by the control device 80. The CPU 80a reads the k-th block (S41). Note that the initial value of k is 1. The CPU 80a determines whether it is in the second repetition state (S42). When it is in the second repetition state (S42: YES, refer to the (n - 1)-th to (n + 2)-th blocks in FIG. 13), the CPU 80a determines whether the k-th block is an axis movement command (S43). When the k-th block is an axis movement command (S43: YES, refer to the (n + 1)-th block in FIG. 16), the CPU 80a reads the (k + 1)-th block (S44).

[0077] The CPU 80a determines whether the (k + 1)-th block is an additional axis movement (S45). When the (k + 1)-th block is an additional axis movement (S45: YES, refer to the (n + 2)-th block in FIG. 16), the CPU 80a associates a brake release command, for example, a brake release command for the A-axis brake B1, with the command of the k-th block (S46, refer to FIG. 18), and writes the k-th block to the RAM 80b (S47). The brake release command in step S46 is, for example, a command to release the brake of the A-axis brake B1 when, after the start of execution of the (n + 1)-th block, during the execution of the operation E(n + 1)2 in FIG. 17, that is, when the main shaft 34 moves in the direction away from the workpiece W and reaches a position equal to or higher than the first position. The CPU 80a increments k by one (S48), and returns the process to step S41.

[0078] In step S45, when the (k + 1)-th block is not an additional axis movement (S45: NO), the CPU 80a proceeds to the process of step S47.

[0079] In step S42, when it is not in the second repetition state (S42: NO), the CPU 80a determines whether the k-th block is an end command (S49). When the k-th block is not an end command (S49: NO), the CPU 80a proceeds to the process of step S47. When the k-th block is an end command (S49: YES), the CPU 80a writes the k-th block to the RAM 80b (S50), executes all the blocks (S51), and ends the process.

[0080] In the machine tool according to the third embodiment, when a second repetition command is read, during the execution of the axial movement command (first command), after the main shaft 34 reaches a position that is a first distance away from the workpiece W, the braking release of the workpiece holding device 120 is executed. Also, when the second repetition command is read, a command to release the braking when the main shaft 34 reaches a position that is a first distance away from the workpiece is written to the RAM 80b in association with the axial movement command, thereby realizing non-interference between the tool 11 and the workpiece W. W from which realizes non-interference between the tool 11 and the workpiece W when the main shaft 34 reaches a position that is a first distance away from the workpiece.

[0081] In the first to third embodiments, although the axial direction of the main shaft 34 is the vertical direction, the axial direction of the main shaft 34 may be the front-rear direction or the left-right direction. Since the tool change includes the movement in the axial direction of the main shaft 34, the axial movement command includes the tool change command. The additional axis movement command includes the rotation command around the B axis or the C axis. In the first to third embodiments, when the CPU 80a reads the additional axis movement command (second command) for the first time after reading the axial movement command (first command), a command to release the braking of the additional axis movement command during the execution of the first command may be written to the RAM 80b. For example, after reading the first command, when reading a command other than the first command and the second command, for example, a parameter calculation command, and then reading the second command, a command to release the braking of the additional axis movement command during the execution of the first command may be written to the RAM 80b.

[0082] In Embodiments 1 to 3, after the end command is read, all blocks are executed. However, each time the k-th block is written to the RAM 80b, the k-th block may be executed. For example, between steps S7 and S8 shown in FIG. 8, and after step S12, the k-th block may be executed. For example, between steps S26 and S27 shown in FIG. 19, and after step S29, the k-th block may be executed. For example, between steps S46 and S47 shown in FIG. 19, and after step S49, the k-th block may be executed.

[0083] 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 Reference Numerals

[0084] 11 Tool 34 Spindle 80 Control device 80a CPU 80b RAM 120 Workholding device B1 A-axis brake B2 C-axis brake W Workpiece

Claims

1. In a control device that sequentially reads a plurality of commands and controls the movement of a movable spindle for mounting a tool and a movable holding part for holding a workpiece, the holding part requires pre-release of braking for movement, a movement determination unit that determines whether a second command read after the first command, which is a command indicating the movement of the spindle away from the workpiece in the axial direction, is a command indicating the movement of the holding part; an start position determination unit that, when the movement determination unit determines that the second command is a command indicating the movement of the holding part, determines whether the first command is a command in which the movement start position of the spindle is a position separated from the workpiece by a first distance or more, or a command in which the movement start position of the spindle is not a position separated from the workpiece by a first distance or more; a first writing unit that writes a braking release command for releasing the braking of the holding part in association with the first command to a storage unit when the start position determination unit determines that the first command is a command in which the movement start position is a position separated from the workpiece by a first distance or more; a first execution unit that executes the braking release command written by the first writing unit during the execution of the first command and comprising a control device.

2. an end position determination unit that determines whether the movement end position of the spindle in the first command is a position separated from the workpiece by a first distance or more when the start position determination unit determines that the first command is a command in which the movement start position is not a position separated from the workpiece by a first distance or more; a second execution unit that executes the release of the braking of the holding part when the spindle reaches a position separated from the workpiece by a first distance or more during the execution of the first command when the end position determination unit determines that the movement end position is a position separated from the workpiece by a first distance or more; The control device according to claim 1, comprising.

3. When the end position determination unit determines that the movement end position in the first command is a position separated from the workpiece by a first distance or more, a second writing unit that writes a braking release command for releasing the braking of the holding unit when the spindle reaches a position separated from the workpiece by a first distance or more is associated with the first command is provided in the storage unit. The second execution unit executes the braking release command written by the second writing unit when executing the first command. The control device according to claim 2.

4. In a control device that sequentially reads a plurality of commands and controls the movement of a movable spindle that mounts a tool and a movable holding unit that holds a workpiece. The holding unit requires pre-release of braking for movement. A first repetition determination unit that determines whether or not a first repetition command in which the spindle repeatedly moves between a first position separated from the workpiece by a first distance and a second position inside the workpiece is read. When the first repetition determination unit determines that the first repetition command is read. An axial movement determination unit that determines whether or not a first command that indicates the movement of the spindle away from the workpiece in the axial direction is read. When the axial movement determination unit determines that the first command is read, a holding unit movement determination unit that determines whether or not a second command read after the first command is a command that indicates the movement of the holding unit. When the holding unit movement determination unit determines that the second command is a command that indicates the movement of the holding unit, a third execution unit that executes the release of the braking of the holding unit when the first command is executed with the spindle being arranged at the first position by the execution of the first repetition command. It is provided with Control device.

5. When the holding unit movement determination unit determines that the second command is a command that indicates the movement of the holding unit, a third writing unit that writes a braking release command for releasing the braking of the holding unit in association with the first command is provided in the storage unit. When the third execution unit executes the first command, it executes the braking release command written by the third writing unit. The control device according to claim 4.

6. In a control device that sequentially reads a plurality of commands and controls the movement of a movable spindle for mounting a tool and a movable holding unit for holding a workpiece, The holding unit requires pre-braking release for movement, A second repetition determination unit that determines whether or not a second repetition command is read, which is a command for executing a repetition operation in which the spindle repeatedly moves between a first position separated from the workpiece by a first distance and a second position in contact with the workpiece, and the end position of the repetition operation is a third position separated from the workpiece by a second distance different from the first position; When the second repetition determination unit determines that the second repetition command has been read, an axial movement determination unit that determines whether or not a first command, which is a command indicating the movement of the spindle away from the workpiece in the axial direction, has been read; When the axial movement determination unit determines that the first command has been read, a holding unit movement determination unit that determines whether or not a second command read after the first command is a command indicating the movement of the holding unit; When the holding unit movement determination unit determines that the second command is a command indicating the movement of the holding unit, a fourth execution unit that executes braking release of the holding unit when the spindle reaches a position separated from the workpiece by a first distance or more during the execution of the first command; Control device.

7. When the holding unit movement determination unit determines that the second command is a command indicating the movement of the holding unit, a fourth writing unit that writes a braking release command for releasing the braking of the holding unit when the spindle reaches a position separated from the workpiece by a first distance or more, associated with the first command, into a storage unit; When the first command is executed, the fourth execution unit executes the braking release command written by the fourth writing unit. The control device according to claim 6.

8. In a machine tool including a movable spindle for mounting a tool, a movable holding part for holding a workpiece, and a control device that sequentially reads a plurality of commands and controls the movement of the spindle and the holding part, the holding part requires pre-release of braking for movement, the control device when reading a first command which is a command indicating the movement of the spindle away from the workpiece in the axial direction, a movement determination unit that determines whether a second command read after the first command is a command indicating the movement of the holding part; when the movement determination unit determines that the second command is a command indicating the movement of the holding part, a start position determination unit that determines whether the first command is a command in which the movement start position of the spindle is a position separated from the workpiece by a first distance or more, or a command in which the movement start position of the spindle is not a position separated from the workpiece by a first distance or more; when the start position determination unit determines that the first command is a command in which the movement start position is a position separated from the workpiece by a first distance or more, a first execution unit that executes release of braking of the holding part during execution of the first command; when the start position determination unit determines that the first command is a command in which the movement start position is a position separated from the workpiece by a first distance or more, a first writing unit that writes a braking release command for releasing the braking of the holding part in association with the first command to a storage unit; a first execution unit that executes the braking release command written by the first writing unit during execution of the first command and includes a machine tool.

9. In a control method that sequentially reads a plurality of commands and controls the movement of a movable spindle for mounting a tool and a movable holding part for holding a workpiece, the holding part requires pre-release of braking for movement, when reading a first command which is a command indicating the movement of the spindle away from the workpiece in the axial direction, it is determined whether a second command read after the first command is a command indicating the movement of the holding part, When it is determined that the second command indicates the movement of the holding unit, it is determined whether the first command is a command in which the movement start position of the main shaft is a position separated from the workpiece by a first distance or more, or whether the first command is not a command in which the movement start position of the main shaft is a position separated from the workpiece by a first distance or more. When it is determined that the first command is a command in which the movement start position is a position separated from the workpiece by a first distance or more, a braking release command for releasing the braking of the holding unit is written to the storage unit in association with the first command. During the execution of the first command, the written braking release command is executed. Control method.

10. In a control method for sequentially reading a plurality of commands and controlling the movement of a movable main shaft for mounting a tool and a movable holding unit for holding a workpiece, The holding unit needs to be pre-released from braking for movement. When a second command indicating the movement of the holding unit is executed after a first command indicating the movement of the main shaft away from the workpiece in the axial direction, if the movement start position of the main shaft in the first command is a position separated from the workpiece by a first distance or more, the braking of the holding unit is released during the execution of the first command. If the movement start position of the main shaft in the first command is not a position separated from the workpiece by a first distance or more, the braking of the holding unit is released after the execution of the first command. Control method.

11. In a computer program executable by a control device that sequentially reads a plurality of commands and controls the movement of a movable main shaft for mounting a tool and a movable holding unit for holding a workpiece, The holding unit needs to be pre-released from braking for movement. To the control device, When a first command indicating the movement of the main shaft away from the workpiece in the axial direction is read, it is determined whether the second command read after the first command indicates the movement of the holding unit. When it is determined that the second command indicates the movement of the holding unit, it is determined whether the first command is a command in which the movement start position of the main shaft is a position separated from the workpiece by a first distance or more, or a command in which the movement start position of the main shaft is not a position separated from the workpiece by a first distance or more. When it is determined that the first command is a command in which the movement start position is a position separated from the workpiece by a first distance or more, a braking release command for releasing the braking of the holding unit is written to the storage unit in association with the first command. During the execution of the first command, the written braking release command is executed. A computer program for executing processing.

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