JP7694438B2 - Control device, machine tool, control method, and computer program - Google Patents

Description

This technology relates to a control device, a machine tool, a control method, and a computer program that controls a spindle on which a tool is attached and a holding unit that holds a workpiece.

The machine tool reads out a machining program to machine a workpiece. The machining program includes, for example, a preceding command that indicates the movement of a spindle on which a tool is attached, and a reference command that is read out after the preceding command and indicates the movement of a holding part that holds the workpiece. The control device of the machine tool releases the brake on the holding part when the preceding command is executed. Since the brake on the holding part is released before the reference command is executed, the time required to machine the workpiece can be shortened (see Patent Document 1).

JP 2018-173912 A

The spindle movement indicated by the preceding command includes the movement of the spindle when machining the workpiece, for example when drilling a hole. If the brake on the holding part is released while machining the workpiece, the workpiece may move unnecessarily, which may result in reduced machining accuracy.

This disclosure has been made in consideration of these circumstances, and aims to provide a control device, machine tool, control method, and computer program that can reduce the time required to machine a workpiece while suppressing a decrease in machining accuracy.

A control device according to one embodiment of the present disclosure reads out a plurality of commands in sequence to control the movement of a movable spindle on which a tool is attached and a movable holding unit that holds a workpiece, the holding unit needs to be braked beforehand in order to move, and includes a movement determination unit that, when a first command is read out that is a command indicating the movement of the spindle away from the workpiece in the axial direction, determines whether a second command read out after the first command is a command indicating the movement of the holding unit, a start position determination unit that, when the movement determination unit determines that the second command is a command indicating the movement of the holding unit, determines whether the movement start position of the spindle in the first command is a position that is a first distance or more away from the workpiece, and a first execution unit that executes brake release of the holding unit during execution of the first command when the start position determination unit determines that the movement start position is a position that is the first distance or more away from the workpiece.

In the present disclosure, when the spindle movement start position is a position that is a first distance or more away from the workpiece, the brake of the holding unit is released while the first command is being executed. Even if the workpiece moves while the first command is being executed, the movement of the workpiece does not affect the machining of the workpiece.

A control device according to an embodiment of the present disclosure includes a first writing unit that writes a brake release command to release the brake of the holding unit in a memory unit in association with the first command when the start position determination unit determines that the movement start position is a position that is a first distance or more away from the workpiece, and the first execution unit executes the brake release command written by the first writing unit when the first command is executed.

In this disclosure, the brake release command is written to the memory unit in association with the first command, and the first command is executed in parallel with the brake release of the holding unit.

The control device according to one embodiment of the present disclosure includes an end position determination unit that determines whether the end position of the movement of the spindle is a position that is a first distance or more away from the workpiece when the start position determination unit determines that the movement start position is not a position that is a first distance or more away from the workpiece, and a second execution unit that releases the brake of the holding unit when the spindle reaches a position that is the first distance or more away from the workpiece during execution of the first command when the end position determination unit determines that the movement end position is a position that is the first distance or more away from the workpiece.

In the present disclosure, when the start position of the spindle movement is not more than a first distance away from the workpiece and the end position of the spindle movement is more than the first distance away from the workpiece, the brake of the holding unit is released when the spindle reaches a position more than the first distance away from the workpiece upon execution of a first command. When the brake of the holding unit is released, the tool is in a position that does not interfere with the workpiece.

A control device according to an embodiment of the present disclosure includes a second writing unit that, when the end position determination unit determines that the movement end position is a position that is a first distance or more away from the workpiece, writes a brake release command to a memory unit that is linked to the first command and releases the brake of the holding unit when the spindle reaches a position that is the first distance or more away from the workpiece, and the second execution unit executes the brake release command written by the second writing unit when the first command is executed.

In this disclosure, a command is written to the memory unit in response to the first command to release the brake on the holding unit when the spindle reaches a position that is a first distance or more away from the workpiece, thereby preventing interference between the tool and the workpiece.

A control device according to one embodiment of the present disclosure reads out a plurality of commands in sequence to control the movement of a movable spindle on which a tool is attached and a movable holding unit that holds a workpiece, and includes a first repetition determination unit that determines whether a first repetition command has been read out, in which the holding unit needs to be released from the brake beforehand in order to move, and the spindle repeatedly moves between a first position a first distance away from the workpiece and a second position in contact with the workpiece; an axial movement determination unit that determines whether a first command has been read out, which is a command indicating the movement of the spindle away from the workpiece in the axial direction, when the first repetition determination unit determines that the first command has been read out; a holding unit movement determination unit that determines whether a second command read out 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; and a third execution unit that executes release of the brake of the holding unit when the first command is executed, when the holding unit movement determination unit determines that the second command is a command indicating the movement of the holding unit.

In the present disclosure, when the first command is executed after the first repeat command, and the movement of the holding part is executed after the first command, the brake of the holding part is released during the execution of the first command.

The control device according to one embodiment of the present disclosure includes a third writing unit that writes a brake release command to release the brake of the holding unit in a memory unit in association with the first command when the holding unit movement determination unit determines that the second command is a command indicating movement of the holding unit, and the third execution unit executes the brake release command written by the third writing unit when the first command is executed.

In this disclosure, the brake release command is written to the memory unit in association with the first command executed after the first repeat command, and the first command and the brake release of the holding unit are executed in parallel.

A control device according to one embodiment of the present disclosure sequentially reads out a plurality of commands to control the movement of a movable spindle on which a tool is attached and a movable holding unit which holds a workpiece, the holding unit needs to be braked beforehand in order to move, the spindle is to repeatedly move between a first position a first distance away from the workpiece and a second position in contact with the workpiece, and a second repetition determination unit determines whether a second repetition command has been read out, the second repetition command being a command for executing a repetitive operation in which the spindle repeatedly moves between a first position a first distance away from the workpiece and a second position in contact with the workpiece, the end position of the repetitive operation being a third position a second distance away from the workpiece different from the first position, and a second repetition determination unit determines whether the second repetition command has been read out, The device includes an axial movement determination unit that, when it is determined that a repeat command has been read, determines whether a first command has been read, which is a command indicating movement of the spindle away from the workpiece in the axial direction; a holding unit movement determination unit that, when it is determined that the first command has been read by the axial movement determination unit, determines whether a second command read after the first command is a command indicating movement of the holding unit; and a fourth execution unit that, when the first command is executed and the holding unit movement determination unit determines that the second command is a command indicating movement of the holding unit, releases the brake of the holding unit when the spindle reaches a position that is a first distance or more away from the workpiece.

In this disclosure, when the second repeat command is read, the brake of the holding unit is released when the spindle reaches a position that is at least the first distance away from the workpiece during execution of the first command.

The control device according to one embodiment of the present disclosure includes a fourth writing unit that, when the holding unit movement determination unit determines that the second command is a command indicating movement of the holding unit, writes into a memory unit a brake release command that is linked to the first command and that releases the brake of the holding unit when the spindle reaches a position that is a first distance or more away from the workpiece, and the fourth execution unit executes the brake release command written by the fourth writing unit when the first command is executed.

In this disclosure, when the second repeat command is read, a command is written to the memory unit that is linked to the first command and that releases the brake when the spindle reaches a position that is a first distance or more away from the workpiece, thereby realizing non-interference between the tool and the workpiece.

A machine tool according to an embodiment of the present disclosure includes a movable spindle on which a tool is attached, a movable holding unit that holds a workpiece, and a control device that reads out a plurality of commands in sequence to control the movement of the spindle and the holding unit. The holding unit needs to be released from the brake before it can move. The control device includes a movement determination unit that, when a first command is read out, which is a command indicating the movement of the spindle away from the workpiece in the axial direction, determines whether a second command read out after the first command is a command indicating the movement of the holding unit, and, when the movement determination unit determines that the second command is a command indicating the movement of the holding unit, determines whether the movement start position of the spindle in the first command is a position that is a first distance or more away from the workpiece. And, when the start position determination unit determines that the movement start position is a position that is the first distance or more away from the workpiece, a first execution unit that executes release of the brake of the holding unit during execution of the first command.

In the present disclosure, when the spindle movement start position is a position that is a first distance or more away from the workpiece, the brake of the holding unit is released while the first command is being executed. Even if the workpiece moves while the first command is being executed, the movement of the workpiece does not affect the machining of the workpiece.

A control method according to an embodiment of the present disclosure reads out a plurality of commands in sequence to control the movement of a movable spindle on which a tool is attached and a movable holder that holds a workpiece, the holder requires a brake release in advance to move, and when a first command is read out 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 out after the first command is a command indicating the movement of the holder, and when it is determined that the second command is a command indicating the movement of the holder, it is determined whether the movement start position of the spindle in the first command is a position that is a first distance or more away from the workpiece, and when it is determined that the movement start position is a position that is the first distance or more away from the workpiece, the brake of the holder is released during the execution of the first command.

In the present disclosure, when the spindle movement start position is a position that is a first distance or more away from the workpiece, the brake of the holding unit is released while the first command is being executed. Even if the workpiece moves while the first command is being executed, the movement of the workpiece does not affect the machining of the workpiece.

A control method according to one embodiment of the present disclosure reads out a plurality of commands in sequence to control the movement of a movable spindle on which a tool is attached and a movable holding unit that holds a workpiece, the holding unit needs to be braked before it can move, and when a second command indicating the movement of the holding unit is executed after a first command which is a command indicating the movement of the spindle away from the workpiece in the axial direction, if the movement start position of the spindle in the first command is a position that is a first distance or more away from the workpiece, the brake of the holding unit is released during the execution of the first command, and if the movement start position of the spindle in the first command is not a position that is the first distance or more away from the workpiece, the brake of the holding unit is released after the execution of the first command.

In the present disclosure, when the spindle movement start position is a position that is a first distance or more away from the workpiece, the brake of the holding unit is released while the first command is being executed. Even if the workpiece moves while the first command is being executed, the movement of the workpiece does not affect the machining of the workpiece.

A computer program according to an embodiment of the present disclosure is a computer program executable by a control device that sequentially reads out a plurality of commands to control the movement of a movable spindle on which a tool is attached and a movable holding unit that holds a workpiece, the holding unit needs to be braked before it can move, and the control device executes a process to read out a first command that is a command indicating the movement of the spindle away from the workpiece in the axial direction, determine whether a second command read out after the first command is a command indicating the movement of the holding unit, determine whether the movement start position of the spindle in the first command is a position that is a first distance or more away from the workpiece, and execute a process to release the brake of the holding unit while the first command is being executed if it is determined that the movement start position is a position that is the first distance or more away from the workpiece.

In the present disclosure, when the spindle movement start position is a position that is a first distance or more away from the workpiece, the brake of the holding unit is released while the first command is being executed. Even if the workpiece moves while the first command is being executed, the movement of the workpiece does not affect the machining of the workpiece.

In the control device, machine tool, control method, and computer program according to an embodiment of the present disclosure, if the movement start position of the spindle is a position that is a first distance or more away from the workpiece, the brake 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 machining of the workpiece, and it is possible to reduce the machining time while suppressing a decrease in machining accuracy.

1 is a perspective view of a machine tool according to a first embodiment; FIG. 2 is a perspective view of the machine tool omitting the tool changer and the cover that covers the track. FIG. 2 is a front perspective view of the work holding device. FIG. 2 is a block diagram illustrating a simplified configuration of a control device. FIG. 4 is a conceptual diagram showing an example of a machining program stored in a non-volatile memory. 6 is a schematic diagram showing the operation of commands in each block in FIG. 5 . 11 is a conceptual diagram showing an example of a machining program and a brake release command written in a RAM. FIG. 4 is a flowchart illustrating a processing process performed by a control device. FIG. 11 is a conceptual diagram showing another example of a machining program stored in the nonvolatile memory. FIG. 10 is a schematic diagram showing the command operations of each block in FIG. 9 . 11 is a conceptual diagram showing an example of a machining program and a brake release command written in a RAM. FIG. FIG. 11 is a conceptual diagram showing an example of a machining program stored in a non-volatile memory according to the second embodiment. FIG. 13 is a schematic diagram showing the command operation of each block in FIG. 12 . 11 is a conceptual diagram showing an example of a machining program and a brake release command written in a RAM. FIG. 4 is a flowchart illustrating a processing process performed by a control device. FIG. 13 is a conceptual diagram showing an example of a machining program stored in a non-volatile memory according to the third embodiment. FIG. 17 is a schematic diagram showing the command operation of each block in FIG. 16 . 11 is a conceptual diagram showing an example of a machining program and a brake release command written in a RAM. FIG. 4 is a flowchart illustrating a processing process performed by a control device.

(Embodiment 1)
The present invention will be described below based on the drawings showing a machine tool according to a first embodiment. In the following description, up/down, left/right, and front/rear directions will be used as indicated by arrows in the drawings. An operator operates the machine tool from the front and loads/unloads a 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, etc., omitted.

The machine tool 100 includes a base 20, a Y-axis direction moving device 22, an X-axis direction moving device 26, a vertical column 28, a Z-axis direction moving device 30, a spindle head 32, a tool changer 10, and the like. The X-axis direction corresponds to the left-right direction, the Y-axis direction corresponds to the front-rear direction, and the Z-axis direction corresponds to the up-down direction. The base 20 is fixed on the floor. The base 20 supports the vertical column 28 so that it can move in the front-rear 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 a workpiece holding device 120. The workpiece holding device 120 corresponds to a holding section. The Z-axis direction moving device 30 is provided on the vertical column 28. The Z-axis direction moving device 30 moves the spindle head 32 in the up-down direction. The tool changer 10 changes the tool attached to the spindle head 32.

The Y-axis direction moving device 22 comprises two parallel tracks 22a, multiple 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-rear direction on the top surface of the base 20. The moving bodies 22b are fitted into each of the two tracks 22a so as to be movable in the front-rear direction. The Y-axis direction moving table 22c is fixed onto the moving bodies 22b, straddling the two tracks 22a. The Y-axis direction moving table 22c moves in the front-rear direction when driven by the Y-axis motor 22d.

The X-axis direction moving device 26 includes two parallel tracks 26a, multiple moving bodies 26b, a pillar base 26c, and an X-axis motor 26d (see FIG. 4). The track 26a extends in the left-right direction on the upper surface of the Y-axis direction moving base 22c. The moving bodies 26b are fitted into each of the two tracks 26a so as to be movable in the left-right direction. The pillar base 26c is fixed onto the moving bodies 26b, straddling the two tracks 26a. The pillar 28 is fixed onto the pillar base 26c. The pillar base 26c moves in the left-right direction when driven by the X-axis motor 26d. The pillar 28 moves in the front-rear and left-right directions by the Y-axis direction moving device 22 and the X-axis direction moving device 26.

The Z-axis direction moving device 30 comprises two parallel tracks 30a, multiple moving bodies 30b, a spindle head table 30c, and a Z-axis motor 30d (see FIG. 4). The track 30a extends vertically on the front surface of the upright column 28. The multiple moving bodies 30b are fitted to each of the two tracks 30a so as to be vertically movable. The spindle head table 30c is fixed to the front surface of the moving body 30b, straddling the two tracks 30a. The spindle head table 30c moves vertically when driven by the Z-axis motor 30d.

The spindle head 32 is fixed to the spindle head base 30c. The spindle head 32 rotatably holds the spindle 34, which extends vertically inside the front side. The spindle 34 has a hollow cylindrical shape. By controlling the drive of the X-axis motor 26d, the Y-axis motor 22d, and the Z-axis motor 30d, the spindle head 32 moves forward/backward, left/right, and up/down.

The tool changer 10 is equipped with an elliptical track (not shown) and multiple movable carriages (not shown) that move on the track. The track surrounds the spindle head 32 and the upright column 28, extends from the lower front to the upper rear, and is inclined at a predetermined angle from the horizontal plane. The multiple movable carriages are connected in a chain shape by links. As shown in FIG. 1, a gear 51 and a drive motor 52 are disposed inside the track. The gear 51 is connected to the drive motor 52 and rotates when driven by the drive motor 52. The multiple movable carriages mesh with the gear 51 and rotate on the track when driven by the drive motor 52. Each movable carriage supports a gripping arm 53.

The empty gripping arm 53 is placed at the front end of the orbit of the tool changer 10, and the spindle 34 with the tool 11 attached thereto rises, causing the gripping arm 53 to remove the tool 11 from the spindle 34 and grip it. The gripping arm 53 gripping the tool 11 is placed at the front end of the orbit of the tool changer 10, and the spindle 34 not gripping the tool 11 is lowered, causing the spindle 34 to attach the tool 11.

Figure 3 is a front perspective view of the workpiece holding device 120. The workpiece holding device 120 includes a support table 121. A shaft portion 122 with its axial direction extending in the left-right direction is provided on each of the left and right portions of the support table 121. Hereinafter, the central axis of the shaft portion 122 is also referred to as the A-axis. The left-side shaft portion 122 is supported by a support portion 124 so as to be rotatable around the A-axis. The support portion 124 is connected to the base 20. A rotating table 127 rotatable around the C-axis is provided on the upper surface of the support table 121. The C-axis is perpendicular to the upper surface of the support table 121.

The right-side shaft portion 122 is supported by a support portion 123 so that it can rotate around the A-axis. An A-axis motor 125 is provided in the support portion 123. Transmission members (not shown) such as gears, cams, and cam followers are housed within 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 around the A-axis. A rotating table 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 Figure 4), and the rotation of the C-axis motor 79 rotates the rotating table 127 around the C-axis. The workpiece holding device 120 is equipped with an A-axis brake B1 (see FIG. 4) that brakes or releases the A-axis motor 125, and a C-axis brake B2 (see FIG. 4) that brakes or releases the C-axis motor 79.

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

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, and 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.

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 each have an encoder (not shown), and rotate to a target position using the detected value of the encoder as a feedback signal. The CPU 80a outputs a brake signal or a brake release signal to the A-axis brake B1 and the C-axis brake B2.

Figure 5 is a conceptual diagram showing an example of a machining program stored in non-volatile memory 80c. Figure 6 is a schematic diagram showing the operation of the commands of each block in Figure 5. The machining program has multiple blocks, and each block has a block number and a command. In Figure 5, "number" indicates the block number, and "command" indicates the content of the command. The CPU 80a executes the commands in numerical order. In Figure 6, E(n-2) to E(n+1) indicate the operation of blocks n-2 to n+1 in Figure 5.

"G90" in the n-2th block is a command that gives the coordinate axis in the block in absolute coordinates, and "G1" is a command that indicates linear movement of the spindle. That is, "G90G1Z50" is a command that indicates linear movement of the spindle 34 to Z coordinate 50 (see E(n-2) in Figure 6). "G0" in the n-1th block is a command that indicates positioning at maximum speed. That is, "G0Z110" indicates movement of the spindle 34 to Z coordinate 110 at maximum speed (see E(n-1) in Figure 6). The same is true for "G0Z130" in the nth block and "G0Z150" in the n+1th block (see E(n) and E(n-1) in Figure 6). "G0Z100", "G0Z130", and "G0Z150" are all commands that indicate axial movement of the spindle 34, that is, axial movement commands.

"G0A_" in the n+2th block indicates a command to perform positioning around the A axis at maximum speed. After the A, for example, a target angle or position is written. In other words, "G0A_" indicates a command to rotate around the A axis at maximum speed to the target angle or position, and indicates an additional axis movement command. Note that additional axis movement commands indicate commands to perform movements other than movements in the X-axis, Y-axis, and Z-axis directions, and include commands to rotate around the B or C axis, for example.

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, which indicates a coordinate at least the first distance above the top end coordinate of the workpiece W. That is, P is a threshold value indicating a position at least the first distance away from the workpiece. In this embodiment, P=100, and the workpiece W is placed between Z coordinates 50 and 95. The difference between the top surface of the workpiece W and the threshold value P is a distance equal to or greater than 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 by linking it to each block of the machining program as necessary. For example, as shown in FIG. 7, "A" is written as a command to release the brake of the A-axis by linking it to the n+1th block.

Figure 8 is a flow chart explaining the processing by the control device 80. In the initial state, the operator inputs the threshold value P to the control device 80 in advance, and the CPU 80a writes the threshold value P (100 in this embodiment) to the RAM 80b. The CPU 80a reads the kth block from the non-volatile memory 80c (S1). The initial value of k is 1. The CPU 80a judges whether the kth block is an axial movement command (S2). As described above, the axial movement command is, for example, "G0Z_" (Z is followed by the Z coordinate). If the kth block is an axial movement command (S2: YES), the CPU 80a reads the kth+1th block (S3) and judges whether the kth+1th block is an additional axis movement command (S4).

If the k+1th block is an additional axis movement command (S4: YES), the CPU 80a determines whether the movement start position in the axial movement command of the kth block, i.e., the coordinate Z1 of the start position in the Z-axis direction, is equal to or greater than the threshold value P (S5). If the coordinate Z1 is equal to or greater than the threshold value P (S5: YES), the CPU 80a links the axial movement command of the kth block to a first brake release command, for example, a first brake release command for the A-axis brake B1 (S6), and writes the kth block to the RAM 80b (S7, see FIG. 7). The first brake release command is, for example, a command to release the brake of the A-axis brake B1 while the axial movement command of the kth block is being executed. The CPU 80a increments k by one (S8) and returns the process to step S1.

For example, when the n+1th block, i.e., an axial movement command, is read (S1, S2, see FIG. 5), the CPU 80a judges whether the n+2th block is an additional axis movement command (S3, S4). Since the n+2th block is a rotation command about the A axis, i.e., an additional axis movement command (S4: YES), the CPU 80a judges whether the movement start position of the n+1th block is equal to or greater than the threshold value P, i.e., 100 (S5). Since the movement start position of the n+1th block is 130, which is equal to or greater than 100 (S5: YES, see FIG. 5, FIG. 6), the CPU 80a links the first brake release command to the n+1th block (S6) and writes the n+1th block to the RAM 80b (S7).

In step S5, if the coordinate Z1 is not equal to or greater than the threshold P (S5: NO), the CPU 80a determines whether the coordinate Z2 of the end position in the axial movement command of the kth block, i.e., the end position in the Z-axis direction, is equal to or greater than the threshold P (S9). If the coordinate Z2 is equal to or greater than the threshold P (S9: YES), the CPU 80a links the axial movement command of the kth block to a second brake release command for the A-axis brake B1 (S10, see FIG. 7) and writes the kth block to the RAM 80b (S7). The second brake release command is a command to release the A-axis brake B1 during axial movement when the Z coordinate of the spindle 34 reaches or exceeds the threshold P after the execution of the axial movement command of the kth block is started. The CPU 80a increments k by one (S8) and returns to step S1.

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 in each block in Fig. 9. Fig. 9 shows the n+2th block, nth block, and n+1th block in Fig. 5 replaced with the nth block, n+1th block, and n+2th block, respectively.
11 is a conceptual diagram showing another example of the machining program and the brake release command written in the RAM 80b. The CPU 80a writes the command to release the brake in association with each block of the machining program as necessary. For example, as shown in FIG. 11, the CPU 80a writes "A" as a command to release the brake of the A-axis when the Z coordinate of the spindle 34 reaches or exceeds the threshold value P in association with the n-1th block, that is, as a second brake release command.

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

If the kth block is not an axial movement command in step S2 (S2: NO), for example if the kth block is an additional axis movement command, the CPU 80a determines whether the kth block is an end command (S11). If the kth block is not an end command (S11: NO), the CPU 80a stores the kth block in the RAM 80b (S7), increments k by one (S8), and returns to step S1.

In step S11, if the kth block is an end command (S11: YES), the CPU 80a stores the kth block in the RAM 80b (S12), executes all blocks stored in the RAM 80b (S13), and ends the process.

In the machine tool according to the first embodiment, when the movement start position of the spindle 34 is at least a first distance away from the workpiece W, the brake of the workpiece holding device 120 is released during execution of an axial movement command (first command). Even if the workpiece W moves when the axial movement command is executed, the tool 11 and the workpiece W do not interfere with each other, and it is possible to reduce the machining time while suppressing a decrease in machining accuracy.

In addition, a brake release command is written to RAM 80b in association with the axial movement command (first command), realizing parallel execution of the axial movement command and brake release of the work holding device 120.

In addition, if the movement start position of the spindle 34 is not at least the first distance away from the workpiece W, and the movement end position of the spindle 34 is at least the first distance away from the workpiece W, during execution of the axial movement command (first command), the brake of the workpiece holding device 120 is released after the spindle 34 reaches a position that is the first distance away from the workpiece W. When the brake of the workpiece holding device 120 is released, the tool 11 is in a position that does not interfere with the workpiece W.

In addition, a command is written to RAM 80b that is linked to the axial movement command and that releases the brake on the axial movement command when the spindle 34 reaches a position a first distance away from the workpiece, thereby realizing non-interference between the tool 11 and the workpiece W.

(Embodiment 2)
The present invention will be described below with reference to 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 given the same reference numerals, and detailed description thereof will be omitted. Fig. 12 is a conceptual diagram showing an example of a machining program, and Fig. 13 is a schematic diagram showing the operation of commands in each block in Fig. 12.

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

"G81" in the n-3th block is a command to repeat a specified operation. "G99" is a command to set the Z coordinate return position of the specified operation of G81 to Z coordinate R. Details of the specified operation are described in the following blocks, and the specified operation is a hole-drilling operation in which the machine moves to the initial position and then moves between the first and second positions. "G90Z100" in the n-2th block is a command to move in a straight line to the initial position I, i.e., Z coordinate 100 (see E(n-2) in Figure 13). "G81R50.Z0.F1000" in the n-1th block is a command to perform hole-drilling by moving the spindle 34 back and forth at a feed rate of 1000 mm/min from the initial position I to the first position, i.e., Z coordinate R, and the second position, i.e., Z coordinate 0 (see E(n-1)2 and E(n-1)3 in Figure 13). E(n-1)1 to E(n-1)3 in FIG. 13 show in detail the execution operations of the command in the n-1th block. "X_Y_" in the nth block is a linear movement command in the X-axis direction and Y-axis direction at the Z coordinate R (see E(n) in FIG. 13). After X and Y, for example, the target coordinates or movement distance are written. That is, after executing operation E(n-1)3 in FIG. 13, the CPU 80a executes operation E(n), and then executes operation E(n-1)3.

After execution of the nth block, the operations other than E(n-1)1 in the n-1th block, i.e., operations E(n-1)2 and E(n-1)3, and operation E(n) in the nth block are repeatedly executed until a command that invalidates "G81", for example an axial movement command, is executed. "G0Z100" in the n+sth block is a command to move the spindle 34 at the maximum speed to the Z coordinate 100 (see E(n+s) in Figure 13). The n+sth block is an axial movement command, and is a command that invalidates "G81". The repeat command ends with execution of the n+sth block. The n-3th block, the n-1th block, and the nth block correspond to the first repeat command. Hereinafter, the state from when "G81" is read in the G99 state until "G81" is invalidated is referred to as the first repeat state.

Figure 14 is a conceptual diagram showing an example of a machining program and brake release command written to RAM 80b. CPU 80a writes a command to release the brake, linked to each block of the machining program as necessary. For example, as shown in Figure 14, it writes "A" as a command to release the brake of the A axis when the Z coordinate of the spindle 34 reaches a position equal to or greater than R, linked to the n+sth block.

Figure 15 is a flow chart explaining the processing by the control device 80. The CPU 80a reads out the kth block (S21). The initial value of k is 1. The CPU 80a judges whether or not it is in the first repetition state (S22). If it is in the first repetition state (S22: YES, see blocks n-3 to n in Figure 12), the CPU 80a judges whether or not the kth block is an axial movement command (S23). If the kth block is an axial movement command (S23: YES, see block n+s in Figure 12), the CPU 80a reads out the k+1th block (S24).

The CPU 80a determines whether the k+1th block is an additional axis movement (S25). If the k+1th block is an additional axis movement (S25: YES, see the n+s+1th block in FIG. 12), the CPU 80a links the axial movement command of the kth block to a brake release command, for example, a brake release command for the A-axis brake B1 (S26, see FIG. 14), and writes the kth block to the RAM 80b (S27). The brake release command in step S26 is, for example, a command to release the brake of the A-axis brake B1 during the execution of the operation E(n+s) in FIG. 13, that is, when the spindle 34 moves in a 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 (S28) and returns the process to step S21.

In step S25, if the k+1th block is not an additional axis movement (S25: NO), the CPU 80a proceeds to step S27.

If it is not the first repetition state in step S22 (S22: NO), the CPU 80a determines whether the kth block is an end command (S29). If the kth block is not an end command (S29: NO), the CPU 80a proceeds to step S27. If the kth block is an end command (S29: YES), the CPU 80a stores the kth block in the RAM 80b (S30), executes all blocks (S31), and ends the process.

In the machine tool according to the second embodiment, when an axial movement command (first command) is executed after the first repeat command, and an additional axis movement command (second command) of the work holding device 120 is executed after the axial movement command, the brake release of the work holding device 120 is executed during the execution of the axial movement command. In addition, a brake release command is written to RAM 80b in association with the axial movement command executed after the first repeat command, thereby realizing the parallel execution of the axial movement command and the brake release of the work holding device 120.

(Embodiment 3)
The present invention will be described below with reference to the drawings showing a machine tool according to embodiment 3. Among the configurations of the machine tool according to embodiment 3, the same configurations as those of embodiment 1 or 2 are given the same reference numerals, and detailed description thereof will be omitted. Fig. 16 is a conceptual diagram showing an example of a machining program, and Fig. 17 is a schematic diagram showing the operation of commands in each block in Fig. 16.

"G81" in the n-2th block is a command to repeat a specified operation. "G98" is a command to set the Z coordinate return position of the specified operation of G81 to the initial position. Details of the specified operation are described in the following blocks, and the specified operation is a hole-drilling operation in which the tool moves to the initial position I, then moves back and forth between the first and second positions, and returns to the initial position I. The initial position I corresponds to the third position. "G90Z100" in the n-1th block is a command to move in a straight line to the initial position I, i.e., Z coordinate 100 (see E(n-1) in Figure 17). "G81R50.Z0.F1000" in the nth block is a command to move from the initial position I to the first position, i.e., Z coordinate R (R = 50 in this embodiment) at a feed rate of 1000 mm/min (see E(n)1 in Figure 17), and then further to the second position, i.e., Z coordinate 0 (see E(n)2 in Figure 17). "X_Y_" in the n+1th block is a command to move from the second position to the first position (see E(n+1)1 in FIG. 17), then move from the first position to the initial position I (see E(n+1)2 in FIG. 17), and move linearly in the X-axis and Y-axis directions 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 operation of the nth block command in detail, and E(n+1)1 to E(n+1)3 show the execution operation of the n+1th block command in detail.

Motion E(n+1) includes motions E(n+1)1 and E(n+1)2, which are movements in the Z-axis direction. In other words, the n+1th block, which is the command for motion E(n+1), can be considered an axial movement command.

Blocks n to n+2 are executed repeatedly. Blocks n-2 and n to n+2 correspond to the second repeat command. Hereinafter, the state after reading "G81" in the "G98" state will be referred to as the second repeat state.

Figure 18 is a conceptual diagram showing an example of a machining program and brake release command written to RAM 80b. CPU 80a writes a command to release the brake, linked to each block of the machining program as necessary. For example, as shown in Figure 18, it writes "A" as a command to release the brake of the A axis when the Z coordinate of the spindle 34 reaches R or higher, linked to the n+1th block.

Figure 19 is a flow chart explaining the processing by the control device 80. The CPU 80a reads out the kth block (S41). The initial value of k is 1. The CPU 80a judges whether or not it is in the second repetition state (S42). If it is in the second repetition state (S42: YES, see blocks n-1 to n+2 in Figure 13), the CPU 80a judges whether or not the kth block is an axial movement command (S43). If the kth block is an axial movement command (S43: YES, see block n+1 in Figure 16), the CPU 80a reads out the kth block (S44).

The CPU 80a determines whether the k+1th block is an additional axis movement (S45). If the k+1th block is an additional axis movement (S45: YES, see the n+2th block in FIG. 16), the CPU 80a links the command of the kth block to a brake release command, for example, a brake release command for the A-axis brake B1 (S46, see FIG. 18), and writes the kth 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 during the execution of the operation E(n+1)2 in FIG. 17 after the execution of the n+1th block starts, that is, when the spindle 34 moves in a 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.

In step S45, if the k+1th block is not an additional axis movement (S45: NO), the CPU 80a proceeds to step S47.

If it is not the second repeat state in step S42 (S42: NO), the CPU 80a determines whether the kth block is an end command (S49). If the kth block is not an end command (S49: NO), the CPU 80a proceeds to step S47. If the kth block is an end command (S49: YES), the CPU 80a writes the kth block to the RAM 80b (S50), executes all blocks (S51), and ends the process.

In the machine tool according to the third embodiment, when the second repeat command is read out, during execution of the axial movement command (first command), the brake of the work holding device 120 is released after the spindle 34 reaches a position separated by the first distance from the workpiece W. Furthermore, when the second repeat command is read out, a command to release the brake when the spindle 34 reaches a position separated by the first distance from the workpiece W is written in the RAM 80b in association with the axial movement command, thereby realizing non-interference between the tool 11 and the workpiece W.

In the first to third embodiments, the axial direction of the spindle 34 is the up-down direction, but the axial direction of the spindle 34 may be the front-rear direction or the left-right direction. Tool change includes axial movement of the spindle 34, so the axial movement command includes a tool change command. The additional axis movement command includes a rotation command about the B axis or the C axis. In the first to third embodiments, when the CPU 80a reads an additional axis movement command (second command) for the first time after reading an axial movement command (first command), the CPU 80a may write a command to release the brake on the additional axis movement command during execution of the first command to the RAM 80b. For example, when the CPU 80a reads a command other than the first command and the second command, such as a parameter calculation command, after reading the first command, and then reads the second command, the CPU 80a may write a command to release the brake on the additional axis movement command during execution of the first command to the RAM 80b.

In the first to third embodiments, all blocks are executed after the end command is read, but the kth block may be executed each time the kth block is written to RAM 80b. For example, the kth block may be executed between steps S7 and S8 shown in FIG. 8 and after step S12. For example, the kth block may be executed between steps S26 and S27 shown in FIG. 19 and after step S29. For example, the kth block may be executed between steps S46 and S47 shown in FIG. 19 and after step S49.

The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. 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 equivalents to the scope of the claims.

11 Tool 34 Spindle 80 Control device 80a CPU
80b RAM
120 Work holding device B1 A-axis brake B2 C-axis brake W Work

Claims (11)

A control device that sequentially reads out a plurality of commands to control movement of a movable spindle that mounts a tool and a movable holder that holds a workpiece,
The holding part needs to be released from the brake before it can move.
a movement determination unit that, when a first command is read out, which is a command indicating a movement of the spindle away from the workpiece in an axial direction, determines whether a second command read out after the first command is a command indicating a movement of the holding unit;
a start position determination unit that, when it is determined by the movement determination unit that the second command is a command indicating movement of the holding unit , determines whether the first command is a command for starting the movement of the spindle at a position that is a first distance or more away from the workpiece, or a command for starting the movement of the spindle at a position that is not the first distance or more away from the workpiece;
a first writing unit that writes a brake release command to release the brake of the holding unit in a memory unit in association with the first command when the start position determination unit determines that the first command is a command for the movement start position to be a position that is a first distance or more away from the workpiece; and
a first execution unit that executes the brake release command written by the first writing unit while the first command is being executed. an end position determination unit that, when it is determined by the start position determination unit that the first command is a command in which the movement start position is not a position that is a first distance or more away from the workpiece, determines whether or not the movement end position of the spindle in the first command is a position that is a first distance or more away from the workpiece;
and a second execution unit that, when the end position determination unit determines that the movement end position is a position that is a first distance or more away from the workpiece, releases the brake of the holding unit when the spindle reaches a position that is the first distance or more away from the workpiece during execution of the first command. a second writing unit that writes a brake release command to a memory unit when the end position determination unit determines that the movement end position in the first command is a position that is a first distance or more away from the workpiece, the brake release command being associated with the first command and causing the spindle to release the brake of the holding unit when the spindle reaches a position that is a first distance or more away from the workpiece;
The control device according to claim 2 , wherein the second execution unit executes the brake release command written by the second writing unit when the first command is executed. A control device that sequentially reads out a plurality of commands to control movement of a movable spindle that mounts a tool and a movable holder that holds a workpiece,
The holding part needs to be released from the brake before it can move.
a first repetition determination unit that determines whether a first repetition command for repeatedly moving the spindle between a first position that is a first distance away from the workpiece and a second position inside the workpiece has been read out;
When it is determined that the first repeat command has been read out by the first repeat determination unit,
an axial movement determination unit that determines whether a first command, which is a command indicating a movement of the spindle away from the workpiece in the axial direction, has been read;
a holder movement determination unit that, when it is determined that the first command has been read out by the axial movement determination unit, determines whether a second command read out after the first command is a command indicating movement of the holder; and
a third execution unit that, when the holding unit movement determination unit determines that the second command is a command indicating movement of the holding unit, causes the spindle to be positioned at the first position by executing the first repeat command, and releases the brake of the holding unit when the first command is executed . a third writing unit that writes a brake release command to release the brake of the holding unit in a storage unit in association with the first command when the holding unit movement determination unit determines that the second command is a command indicating the movement of the holding unit,
The control device according to claim 4 , wherein the third execution unit executes the brake release command written by the third writing unit when the first command is executed. A control device that sequentially reads out a plurality of commands to control movement of a movable spindle that mounts a tool and a movable holder that holds a workpiece,
The holding part needs to be released from the brake before it can move.
a second repetition determination unit that determines whether a second repetition command has been read out, the second repetition command being 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 an 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;
an axial movement determination unit that, when it is determined that the second repeat command has been read out by the second repeat determination unit, determines whether or not a first command has been read out, the first command being a command indicating a movement of the spindle away from the workpiece in the axial direction;
a holder movement determination unit that, when it is determined that the first command has been read out by the axial movement determination unit, determines whether a second command read out after the first command is a command indicating movement of the holder; and
the holding unit movement determination unit determines that the second command is a command to move the holding unit, and during execution of the first command, the control device further comprises a fourth execution unit that executes release of the brake of the holding unit when the spindle reaches a position that is a first distance or more away from the workpiece. a fourth writing unit that, when it is determined by the holding unit movement determination unit that the second command is a command indicating movement of the holding unit, writes a brake release command to a memory unit in association with the first command, for releasing the brake of the holding unit when the spindle reaches a position that is a first distance or more away from the workpiece;
The control device according to claim 6 , wherein the fourth execution unit executes the brake release command written by the fourth writing unit when the first command is executed. A machine tool including a movable spindle on which a tool is attached, a movable holder that holds a workpiece, and a control device that sequentially reads out a plurality of commands to control movement of the spindle and the holder,
The holding part needs to be released from the brake before it can move.
The control device includes:
a movement determination unit that, when a first command is read out, which is a command indicating a movement of the spindle away from the workpiece in an axial direction, determines whether a second command read out after the first command is a command indicating a movement of the holding unit;
a start position determination unit that, when it is determined by the movement determination unit that the second command is a command indicating movement of the holding unit , determines whether the first command is a command for starting the movement of the spindle at a position that is a first distance or more away from the workpiece, or a command for starting the movement of the spindle at a position that is not the first distance or more away from the workpiece;
a first execution unit that executes brake release of the holding unit during execution of the first command when the start position determination unit determines that the first command is a command for the movement start position to be a position that is a first distance or more away from the workpiece ; and
a first writing unit that writes a brake release command to release the brake of the holding unit in a memory unit in association with the first command when the start position determination unit determines that the first command is a command for the movement start position to be a position that is a first distance or more away from the workpiece; and
a first execution unit that executes the brake release command written by the first writing unit during execution of the first command;
A machine tool equipped with: A control method for controlling movement of a movable spindle for mounting a tool and a movable holder for holding a workpiece by sequentially reading out a plurality of commands, comprising:
The holding part needs to be released from the brake before it can move.
When a first command is read out, the first command being a command indicating a movement of the spindle away from the workpiece in an axial direction, a second command read out after the first command is determined to be a command indicating a movement of the holding unit;
When it is determined that the second command is a command indicating movement of the holding unit, it is determined whether the first command is a command for causing the movement start position of the spindle to be at a position away from the workpiece by a first distance or more, or a command for causing the movement start position of the spindle to be at a position not away from the workpiece by a first distance or more;
When it is determined that the first command is a command for the movement start position to be a position that is a first distance or more away from the workpiece, a brake release command is written in a storage unit in association with the first command to release the brake of the holding unit;
Executing the written brake release command during execution of the first command.
Control methods. A control method for controlling movement of a movable spindle for mounting a tool and a movable holder for holding a workpiece by sequentially reading out a plurality of commands, comprising:
The holding part needs to be released from the brake before it can move.
When a second command indicating a movement of the holding unit is executed after a first command which is a command indicating a movement of the spindle away from the workpiece in an axial direction, if a movement start position of the spindle in the first command is a position away from the workpiece by a first distance or more, the brake of the holding unit is released during the execution of the first command,
when the movement start position of the spindle in the first command is not a position that is a first distance or more away from the workpiece, releasing the brake of the holding unit after execution of the first command. A computer program executable by a control device for sequentially reading out a plurality of commands and controlling movement of a movable spindle on which a tool is mounted and a movable holder for holding a workpiece, comprising:
The holding part needs to be released from the brake before it can move.
The control device includes:
When a first command is read out, the first command being a command indicating a movement of the spindle away from the workpiece in an axial direction, a second command read out after the first command is determined to be a command indicating a movement of the holding unit;
When it is determined that the second command is a command indicating movement of the holding unit, it is determined whether the first command is a command for causing the movement start position of the spindle to be at a position away from the workpiece by a first distance or more, or a command for causing the movement start position of the spindle to be at a position not away from the workpiece by a first distance or more;
When it is determined that the first command is a command for the movement start position to be a position that is a first distance or more away from the workpiece, a brake release command is written in a storage unit in association with the first command to release the brake of the holding unit;
Executing the written brake release command during execution of the first command.
A computer program that executes a process.

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