Machine tool control devices and control methods

Abstract

This invention provides a control device and method for a machine tool that can further reduce instruction wait time. The control device for a machine tool that controls the synchronous operation of the spindle and feed axis includes: a numerical control unit that generates spindle and feed axis instructions based on a tapping program; a spindle control unit that controls the rotational movement of the spindle according to the spindle instructions; a rotation detection unit that detects the rotational position of the spindle; and a feed axis control unit that controls the feed movement of the feed axis based on the rotational position and the feed axis instructions. The numerical control unit includes: a spindle instruction output unit that, when performing an infeed and pull-out action an arbitrary number of times from the machining start position to the target position, obtains the spindle rotation amount and maximum speed during the infeed and pull-out actions from the tapping program, and sends the spindle rotation amount and maximum speed as the spindle instruction to the spindle control unit.

Description

Technical Field

[0001] This invention relates to a control device and control method for machine tools. Background Technology

[0002] In the past, various technologies have been proposed in machine tools that perform tapping operations by synchronously rotating the spindle and feed axis to improve machining accuracy or shorten cycle time (for example, see Patent Document 1). Patent Document 1 discloses a control device that can shorten cycle time by maximizing the spindle's acceleration capability with a simple structure.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-78223 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the control device of such a machine tool, in order to further shorten the cycle time, it is desirable to further reduce the instruction waiting time from the end of the action of the path to the start of the action of the next path.

[0008] Methods for solving problems

[0009] The control device disclosed herein is a machine tool control device for controlling the synchronous operation of the spindle and feed axis, comprising: a numerical control unit that generates spindle commands and feed axis commands based on a tapping program; a spindle control unit that controls the rotational movement of the spindle according to the spindle commands; a rotation detection unit that detects the rotational position of the spindle; and a feed axis control unit that controls the feed movement of the feed axis based on the rotational position and according to the feed axis commands. The numerical control unit includes: a spindle command output unit that, when performing an infeed and pull-out operation an arbitrary number of times from the machining start position to the target position, obtains the spindle rotation amount and maximum speed during the infeed and pull-out operations from the tapping program, and sends the spindle rotation amount and maximum speed as the spindle commands to the spindle control unit. The spindle control unit includes: an initial motion control unit that uses the maximum rotational speed as a target value to accelerate the spindle from the machining start position to the target position by maximizing the allowable current capacity of the drive source; a maximum acceleration detection unit that detects the maximum acceleration based on the rotational position during accelerated rotation at the maximum capacity; a remaining rotation detection unit that detects the remaining rotation of the spindle from the current position to the target position based on the rotation amount and the rotational position; a current speed detection unit that detects the current speed of the spindle based on the rotational position; and a positioning motion control unit that, after accelerating rotation at the maximum capacity, decelerates the spindle by rotating at a maximum deceleration corresponding to the maximum acceleration and reaches the target position based on the maximum acceleration, the remaining rotation amount, and the current speed.

[0010] The control method disclosed herein is a machine tool control method for controlling the synchronous operation of the spindle and the feed axis, comprising the following steps: when performing an infeed and a pull-out action an arbitrary number of times from the machining start position to the target position, obtaining from the tapping program the spindle rotation amount and the maximum speed during the infeed and pull-out actions; using the maximum speed as a target value, accelerating the spindle from the machining start position to the target position to the maximum capacity of the allowable current of the drive source; detecting the maximum acceleration based on the spindle rotational position feedback value during the accelerated rotation at the maximum capacity; detecting the remaining rotation amount of the spindle from the current position to the target position based on the rotation amount and the rotational position feedback value; detecting the current speed of the spindle based on the rotational position feedback value; and after the accelerated rotation at the maximum capacity, decelerating the spindle at a maximum deceleration corresponding to the maximum acceleration and reaching the target position based on the maximum acceleration, the remaining rotation amount, and the current speed.

[0011] Invention Effects

[0012] According to the present invention, instruction waiting time can be further reduced. Attached Figure Description

[0013] Figure 1 It is a diagram showing the outline of the control device.

[0014] Figure 2 This diagram illustrates the tapping process of the control device according to the first embodiment.

[0015] Figure 3 This is a flowchart illustrating the tapping process of the control device in the first embodiment.

[0016] Figure 4 This diagram illustrates the tapping process of the control device according to the second embodiment.

[0017] Figure 5 This is a flowchart illustrating the tapping process of the control device in the second embodiment. Detailed Implementation

[0018] Hereinafter, an example of an embodiment of the present invention will be described. Figure 1 This is a diagram showing the outline of the control device 200. (For example...) Figure 1 As shown, the control device 200 is a device in which tapping is performed by the synchronous operation of the spindle 101 and the feed axis 105, and the feed axis 105 is controlled to operate synchronously in a manner that follows the rotation of the spindle 101 (so-called master-slave synchronization mode) while taking into account the pitch specified by the tapping program 500.

[0019] The control device 200 includes a numerical control unit 210, a spindle control unit 220, a rotation detection unit 230, and a feed axis control unit 240.

[0020] The numerical control unit 210 includes a spindle command output unit 211, a program interpretation unit 212, and a feed axis command output unit 213. The numerical control unit 210 can have the hardware structure of a known CNC (computerized numerical control) device.

[0021] Before the tapping process begins, the spindle command output unit 211 obtains the total rotation amount S and maximum speed V of the spindle 101 from the machining start position (rotation position) to the target thread depth (rotation position) based on the command value of the tapping program 500 interpreted by the program interpretation unit 212, and sends these total rotation amount S and maximum speed V as spindle command CS to the spindle control unit 220.

[0022] For example, if the tapping program 500 includes an instruction to set the maximum rotational speed (in this example, the maximum speed per minute) V of the spindle 101 to 3000 rev / min and to machine an internal thread with a thread pitch of 1.25 mm and a thread depth of 30 mm, the total rotational amount S of the spindle 101 from the machining start position to the target thread depth is 30 ÷ 1.25 = 24 (rev). Therefore, the spindle instruction output unit 211 notifies the spindle control unit 220 of the maximum rotational speed V = 3000 (rev / min) and the total rotational amount S = 24 (rev). In this way, the spindle instruction CS does not include position instructions or acceleration / deceleration instructions for rotating the spindle 101 to the target thread depth.

[0023] Furthermore, when the spindle command output unit 211 performs any number of cutting and pulling actions from the machining start position to the target position, it obtains the rotational amount S and maximum speed V of the spindle 101 during the cutting and pulling actions from the tapping program 500. Then, the spindle command output unit 211 sends the rotational amount S and maximum speed V of the spindle 101 as spindle commands to the spindle control unit 220.

[0024] Specifically, before the spindle control unit 220 starts moving the spindle 101, the spindle command output unit 211 obtains the spindle rotation amount S and maximum speed V during the cutting and pulling actions from the tapping program 500, and sends the spindle rotation amount S and maximum speed V of the spindle 101 as spindle commands to the spindle control unit 220.

[0025] In addition, the spindle control unit 220 starts the movement of the spindle 101 before the command from the numerical control unit 210, based on the spindle command sent from the spindle command output unit 211, which is the rotation amount S and the maximum speed V.

[0026] The program interpretation section 212 interprets the tapping process program 500.

[0027] The feed axis command output unit 213 generates a feed axis command CF according to the interpretation of the program interpretation unit 212, and sends the feed axis command CF to the feed axis control unit 240.

[0028] The spindle control unit 220 includes an initial motion control unit 221, a maximum acceleration detection unit 222, a remaining rotation detection unit 223, a current speed detection unit 224, and a positioning motion control unit 225.

[0029] The initial motion control unit 221 controls the spindle 101 to accelerate from the machining start position by using the maximum allowable current of the drive source to the maximum value of the spindle 101 as the target value of the maximum rotational speed V sent from the spindle command output unit 211.

[0030] The maximum acceleration detection unit 222 detects the maximum acceleration A0 (min) based on the rotational position FBS during accelerated rotation at maximum capacity. -1 / s).

[0031] The remaining rotation detection unit 223 detects the remaining rotation Sr (rev) of the spindle 101 from the current position (rotation position) to the target thread depth based on the total rotation S sent from the spindle command output unit 211 and the rotation position FBS output from the rotation detection unit 230.

[0032] The current speed detection unit 224 detects the current speed Vc(min) of the spindle 101 based on the rotational position FBS output from the rotation detection unit 230. -1 When the current speed Vc reaches the maximum speed V, the rotation of the spindle 101 is changed from accelerated rotation to rotation at the maximum speed V.

[0033] After accelerating rotation at maximum capacity, the positioning motion control unit 225 performs position control based on the maximum acceleration A0, the remaining rotation amount Sr, and the current speed Vc to decelerate the spindle 101 to rotate at the maximum deceleration corresponding to the maximum acceleration and reach the target thread depth.

[0034] In one embodiment, the positioning motion control unit 225 can be configured to decelerate the spindle 101 at a maximum deceleration corresponding to the maximum acceleration and stop it at the target thread depth. Alternatively, in another embodiment, the positioning motion control unit 225 can also be configured to not stop the spindle 101 at the target thread depth (i.e., not make the acceleration zero), but to accelerate the spindle 101 to a predetermined rotational position by a reverse rotational acceleration A0 (negative value) that is the same as the maximum deceleration A0 (negative value) during deceleration.

[0035] In addition, the spindle control unit 220 uses the rotational position FBS (i.e., feedback value) of the spindle 101 detected by the rotation detection unit 230 to send the torque command value to the spindle 101 through general feedback control, thereby controlling the rotational action of the spindle 101.

[0036] The rotation detection unit 230 can obtain the rotational position FBS based on the output of the position detector 102, such as the encoder that detects the operating position of the spindle 101.

[0037] The feed axis control unit 240 controls the feed movement of the feed axis 105, which follows the movement of the spindle 101, according to the feed axis command CF sent from the feed axis command output unit 213. This control utilizes feedback values ​​from the position detector 102 (such as an encoder that detects the operating position of the feed axis 105) and the rotational position FBS of the spindle 101. Furthermore, the feed axis control unit 240 causes the feed axis 105 to feed linearly relative to the workpiece in the Z direction. However, it is also possible to have two feed axis control units that control two feed axes that feed the workpiece or tool relative to the X and Y axes.

[0038] During the period when the spindle control unit 220 controls the rotational movement of the spindle from the machining start position to the target thread depth, the feed axis control unit 22 uses the rotational position FBS of the spindle 101 to control the feed axis 105 to follow the movement of the spindle 12 and perform the feed operation. During the tapping process performed by the spindle control unit 220, the numerical control unit 210 monitors the remaining rotation amount Sr notified by the spindle control unit 220, and determines that the tapping has reached the target thread depth when the remaining rotation amount Sr becomes below a first predetermined value (a minimum value close to zero).

[0039] <First Implementation>

[0040] Figure 2 This figure illustrates the tapping process of the control device 200 according to the first embodiment.

[0041] The control device 200 performs tapping by performing an infeed and a pull-out action an arbitrary number of times from the starting position to the target position (bottom of the hole).

[0042] like Figure 2 As shown, the spindle control unit 220 performs a cutting motion from the tapping start position to the first target position by controlling the rotation amount S0 and the maximum speed V0 of the spindle 101.

[0043] Next, the spindle control unit 220 performs a pulling action from the first target position after the cutting action ends to the second target position by the rotation amount S1 of the spindle 101 and the maximum speed V1.

[0044] Next, the spindle control unit 220 performs a cutting motion from the second target position after the pulling action ends to the third target position by controlling the rotation amount S3 of the spindle 101 and the maximum speed V0.

[0045] In this way, tapping is performed through repeated cutting and pulling actions, until the spindle 101 finally reaches the target position (bottom of the hole). Furthermore, in Figure 2 In the example shown, the highest rotational speed during the cutting-in action is V0, and the highest rotational speed during the pulling-out action is V1.

[0046] Figure 3 This is a flowchart illustrating the tapping process of the control device 200 in the first embodiment.

[0047] In step S1, before the spindle control unit 220 performs rotation control on the spindle 101, the spindle command output unit 211 obtains the rotational amounts S0, S1, S2... and the maximum speeds V0, V1 of the spindle 101 during the cutting and pulling actions from the tapping program 500. Then, the spindle command output unit 211 sends the rotational amounts S0, S1, S2... and the maximum speeds V0, V1 of the spindle 101 during the cutting and pulling actions as spindle commands to the spindle control unit 220.

[0048] In step S2, the spindle control unit 220 uses the rotation amount S0 of the spindle 101 and the maximum speed V0 as spindle commands to start the movement of the spindle 101.

[0049] In step S3, the spindle control unit 220 performs a cutting action from the tapping start position to the first target position by controlling the rotation amount S0 of the spindle 101 and the maximum speed V0.

[0050] In step S4, the spindle control unit 220 determines whether the spindle 101 has completed the rotational movement S0. If the spindle 101 has completed the rotational movement S0 (yes), the process proceeds to step S5. If the spindle 101 has not completed the rotational movement S0 (no), the process returns to step S3.

[0051] In step S5, after the cutting action in step 3 is completed, that is, after the movement of rotation amount S0 is completed, the spindle control unit 220 uses the rotation amount S1 and the maximum speed V1 sent from the spindle command output unit 211 as the spindle command, and starts the movement of the spindle 101 before the command from the numerical control unit 210.

[0052] In step S6, the spindle control unit 220 performs a pulling action from the first target position after the cutting action ends to the second target position by controlling the rotation amount S1 of the spindle 101 and the maximum speed V1.

[0053] In step S7, the spindle control unit 220 determines whether the spindle 101 has completed the rotational movement S1. If the spindle 101 has completed the rotational movement S1 (yes), the process proceeds to step S8. If the spindle 101 has not completed the rotational movement S1 (no), the process returns to step S6.

[0054] In step S8, after the pulling action in step 6 is completed, that is, after the movement of rotation amount S1 is completed, the spindle control unit 220 uses the rotation amount S2 and the maximum speed V0 sent from the spindle command output unit 211 as spindle commands, and starts the movement of the spindle 101 before the commands from the numerical control unit 210.

[0055] In step S9, the spindle control unit 220 performs a cutting action from the second target position after the pulling action ends to the third target position by controlling the rotation amount S2 of the spindle 101 and the maximum speed V0.

[0056] Furthermore, for the process, the same process as steps S3 to S9 is repeated until the spindle 101 reaches the bottom of the hole, and then the process is transferred to step S10.

[0057] In step S10, after the spindle 101 reaches the bottom of the hole, the spindle control unit 220 uses the rotation amount Sn and the maximum speed V1 sent from the spindle command output unit 211 as spindle commands to start the movement of the spindle 101 toward the tapping start position.

[0058] In step S11, the spindle control unit 220 performs a pulling action from the bottom of the hole to the starting position of tapping by controlling the rotation amount Sn of the spindle 101 and the maximum speed V1.

[0059] Furthermore, the spindle control unit 220 determines whether the spindle 101 has completed moving towards the tapping start position. If the spindle 101 has completed moving towards the tapping start position (yes), the process ends. If the spindle 101 has not completed moving towards the tapping start position (no), step S11 is repeated.

[0060] <Second Implementation>

[0061] Next, the tapping process of the control device 200 in the second embodiment will be described.

[0062] The second embodiment differs from the first embodiment in that it changes the amount of rotation and the maximum speed during the cutting or pulling action.

[0063] Specifically, the rotation amount and maximum speed of the spindle 101 are changed at predetermined positions during the cutting or pulling action.

[0064] Then, the spindle command output unit 211 obtains the first rotation amount before the change, the second rotation amount after the change, the first maximum speed before the change, and the second maximum speed after the change of the spindle 101 from the tapping program 500. Then, the spindle command output unit 211 sends the first rotation amount, the second rotation amount, the first maximum speed, and the second maximum speed as spindle commands to the spindle control unit 220.

[0065] More specifically, the rotational amount and maximum speed of the spindle 101 are changed to predetermined positions in the cutting-in action after the drawing action. The predetermined position can also be the target position in the previous drawing action. Here, in the cutting-in action after the drawing action, the control device 200 starts the cutting-in action from the target position (reached position) of the drawing action.

[0066] Since the part undergoing the drawing motion has already been machined, the tool traces the machined portion, and the cutting motion becomes a no-load machining process. Therefore, the maximum speed of the spindle 101 in the machined portion can be set to a speed faster than the cutting speed, further shortening the cycle time.

[0067] In addition, the rotation amount and maximum speed of the spindle 101 can be changed at a predetermined position during the pulling action after the cutting action.

[0068] Figure 4 This diagram illustrates the tapping process of the control device 200 according to the second embodiment. (See diagram for example.) Figure 4 As shown, the spindle control unit 220 performs a cutting action from the tapping start position to the first target position by controlling the rotation amount S0 and the maximum speed V0 of the spindle 101.

[0069] Next, the spindle control unit 220 performs a pulling action from the first target position to the second target position after the cutting action ends by controlling the rotation amount S1 of the spindle 101 and the maximum speed V1.

[0070] Next, the spindle control unit 220 performs a cutting action from the second target position after the pull-out action ends to the first target position after the cutting action ends, using the rotation amount S2 of the spindle 101 and the maximum speed V1.

[0071] Furthermore, the spindle control unit 220 performs a cutting action from the first target position to the third target position by controlling the rotation amount S3 of the spindle 101 and the maximum speed V0.

[0072] In this way, by using the rotation amount S2 and the maximum speed V1 to perform the cutting action from the second target position that has already been cut to the first target position, the spindle 101 can be moved at a speed faster than the maximum speed V0 in the actual cutting action.

[0073] This tapping process is performed by repeatedly performing cutting and pulling actions until the spindle 101 reaches the target thread depth (bottom of the hole).

[0074] Figure 5 This is a flowchart illustrating the tapping process of the control device 200 in the second embodiment.

[0075] In step S21, before the spindle control unit 220 begins rotating control of the spindle 101, the spindle command output unit 211 obtains the rotational amounts S0, S1, S2, S3... and the maximum speeds V0, V1 of the spindle 101 during the cutting and pulling actions from the tapping program 500. Then, the spindle command output unit 211 sends the rotational amounts S0, S1, S2, S3... and the maximum speeds V0, V1 of the spindle 101 during the cutting and pulling actions as spindle commands to the spindle control unit 220.

[0076] In step S22, the spindle control unit 220 uses the rotation amount S0 of the spindle 101 and the maximum speed V0 as spindle commands to start the movement of the spindle 101.

[0077] In step S23, the spindle control unit 220 performs a cutting action from the tapping start position to the first target position by controlling the rotation amount S0 and the maximum speed V0 of the spindle 101.

[0078] In step S24, the spindle control unit 220 determines whether the spindle 101 has completed the rotational movement S0. If the spindle 101 has completed the rotational movement S0 (yes), the process proceeds to step S25. If the spindle 101 has not completed the rotational movement S0 (no), the process returns to step S23.

[0079] In step S25, after the cutting action in step 13 is completed, that is, after the movement of rotation amount S0 is completed, the spindle control unit 220 uses the rotation amount S1 and the maximum speed V1 sent from the spindle command output unit 211 as the spindle command, and starts the movement of the spindle 101 before the command from the numerical control unit 210.

[0080] In step S26, the spindle control unit 220 performs a pulling action from the first target position after the cutting action ends to the second target position by controlling the rotation amount S1 of the spindle 101 and the maximum speed V1.

[0081] In step S27, the spindle control unit 220 determines whether the spindle 101 has completed the rotational movement S1. If the spindle 101 has completed the rotational movement S1 (yes), the process proceeds to step S28. If the spindle 101 has not completed the rotational movement S1 (no), the process returns to step S26.

[0082] In step S28, after the pulling action in step 16 is completed, that is, after the rotation amount S1 is completed, the spindle control unit 220 uses the rotation amount S2 and maximum speed V1, and the rotation amount S3 and maximum speed V0 sent from the spindle command output unit 211 as spindle commands, and starts the movement of the spindle 101 before the command from the numerical control unit 210.

[0083] In step S29, the spindle control unit 220 performs a cutting action from the second target position after the pull-out action ends to the first target position after the cutting action ends by controlling the rotation amount S2 of the spindle 101 and the maximum speed V1.

[0084] Furthermore, the spindle control unit 220 performs a cutting action from the first target position to the third target position by controlling the rotation amount S3 of the spindle 101 and the maximum speed V0.

[0085] Furthermore, for the process, the same process as steps S23 to S29 is repeated until the spindle 101 reaches the bottom of the hole, and then the process is transferred to step S30.

[0086] In step S30, after the spindle 101 reaches the bottom of the hole, the spindle control unit 220 uses the rotation amount Sn and the maximum speed V1 sent from the spindle command output unit 211 as spindle commands to start the movement of the spindle 101 toward the tapping start position.

[0087] In step S31, the spindle control unit 220 performs a pulling action from the bottom of the hole to the starting position of tapping by controlling the rotation amount Sn of the spindle 101 and the maximum speed V1.

[0088] Then, the spindle control unit 220 determines whether the spindle 101 has completed its movement towards the tapping start position. If the movement of the spindle 101 towards the tapping start position is completed (yes), the process ends. If the movement of the spindle 101 towards the tapping start position is not completed (no), step S31 is repeated.

[0089] As described above, according to the embodiment, the machine tool control device 200 includes: a numerical control unit 210 that generates spindle commands and feed axis commands based on the tapping program 500; a spindle control unit 220 that controls the rotational movement of the spindle 101 according to the spindle commands; a rotation detection unit 230 that detects the rotational position of the spindle 101; and a feed axis control unit 240 that controls the feed movement of the feed axis according to the feed axis commands based on the rotational position. The numerical control unit 210 includes: a spindle command output unit 211 that, when performing an infeed and pull-out operation an arbitrary number of times from the machining start position to the target position, obtains the rotational amount and maximum speed of the spindle 101 during the infeed and pull-out operations from the tapping program 500, and sends the rotational amount and maximum speed of the spindle 101 as spindle commands to the spindle control unit 220.

[0090] Therefore, by using the pre-transmitted rotation amount and maximum speed of the spindle 101, the spindle control unit 220 can begin the movement of the spindle 101 in the subsequent pulling or cutting action after the cutting or pulling action has ended. Thus, the control device 200 can further reduce the command waiting time in the spindle control unit 220. Therefore, the control device 200 can shorten the tapping cycle time.

[0091] In addition, before the spindle control unit 220 starts moving the spindle 101, the spindle command output unit 211 obtains the rotation amount and maximum speed of the spindle 101 during the cutting and pulling actions from the tapping program 500, and sends the rotation amount and maximum speed of the spindle 101 as spindle commands to the spindle control unit 220.

[0092] Therefore, before the spindle 101 begins to move, the spindle control unit 220 obtains the rotational amount and maximum speed of the spindle 101, and can start the movement of the spindle 101 in the next pulling or pulling action after the cutting or pulling action has ended. Therefore, the control device 200 can further reduce the command waiting time in the spindle control unit 220.

[0093] Furthermore, the spindle control unit 220 uses the rotation amount and maximum speed sent from the spindle command output unit 211 as spindle commands, and starts the movement of the spindle 101 before the commands from the numerical control unit 210. As a result, the control device 200 can further reduce the command waiting time in the spindle control unit 220.

[0094] Furthermore, the rotational amount and maximum speed of the spindle 101 are changed at predetermined positions during the cutting or pulling action. The spindle command output unit 211 obtains the first rotational amount of the spindle 101 before the change, the second rotational amount after the change, the first maximum speed before the change, and the second maximum speed after the change from the tapping program 500. Then, the spindle command output unit 211 sends the first rotational amount, the second rotational amount, the first maximum speed, and the second maximum speed as spindle commands to the spindle control unit 220.

[0095] Therefore, by changing the rotation amount and maximum speed of the spindle 101 during the cutting or pulling action, the control device 200 can further shorten the tapping cycle time.

[0096] Furthermore, the rotational amount and maximum speed of the spindle 101 are changed at predetermined positions during the cutting-in action after the drawing action. These predetermined positions are the target positions from the previous drawing action. Therefore, by changing the rotational amount and maximum speed of the spindle 101 during the cutting-in action after the drawing action, the control device 200 can further shorten the tapping cycle time.

[0097] The embodiments of the present invention have been described above, but the control device 200 can be implemented by hardware, software, or a combination thereof. Furthermore, the control method performed by the control device 200 can also be implemented by hardware, software, or a combination thereof. Here, implementation by software means implementing it by loading a program into a computer and executing it.

[0098] Programs can be stored and provided to a computer using various types of non-transitory computer-readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (e.g., hard disk drives), optical-magnetic recording media (e.g., optical discs), CD-ROMs (Read Only Memory), CD-Rs, CD-R / Ws, semiconductor memories (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash memory ROMs, and RAMs (Random Access Memory)).

[0099] Furthermore, the above-described embodiments are preferred embodiments of the present invention, but are not intended to limit the scope of the invention to these embodiments alone. Various modifications can be made without departing from the spirit of the invention.

[0100] Explanation of reference numerals in the attached figures

[0101] 200 control device

[0102] 210 Numerical Control Department

[0103] 211 Spindle Command Output Unit

[0104] 212 Program Interpreter Department

[0105] 213 feed axis command output unit

[0106] 220 Spindle Control Unit

[0107] 221 Initial Motion Control Unit

[0108] 222 Rotation Measurement Unit

[0109] 223 Remaining Rotation Detection Unit

[0110] 224 Current Speed ​​Detection Department

[0111] 225 Positioning Motion Control Unit

[0112] 230 Rotary Inspection Unit

[0113] 240 feed axis control unit.

Claims

1. A control device for a machine tool that controls the synchronous operation of the spindle and the feed axis, characterized in that, The control device has the following features: The numerical control unit generates spindle commands and feed axis commands based on the tapping program; The spindle control unit controls the rotation of the spindle according to the spindle commands; A rotation detection unit detects the rotational position of the main shaft; The feed axis control unit controls the feed action of the feed axis according to the feed axis command based on the rotational position. The numerical control unit includes a spindle command output unit, which, when performing an infeed and pull-out action an arbitrary number of times from the machining start position to the target position, obtains the spindle rotation amount and the maximum speed during the infeed and pull-out actions from the tapping program, and sends the spindle rotation amount and the maximum speed as the spindle command to the spindle control unit. The spindle control unit includes: The initial motion control unit uses the maximum rotational speed as the target value to accelerate the spindle from the machining start position to the target position by maximizing the utilization of the maximum allowable current of the drive source. A maximum acceleration detection unit detects the maximum acceleration based on the rotational position during accelerated rotation at the maximum capacity. The remaining rotation detection unit detects the remaining rotation of the spindle from the current position to the target position based on the rotation amount and the rotation position. The current speed detection unit detects the current speed of the spindle based on the rotational position; The positioning motion control unit, after accelerating rotation at the maximum capacity, causes the main shaft to decelerate and rotate at a maximum deceleration corresponding to the maximum acceleration, based on the maximum acceleration, the remaining rotation amount, and the current speed, and to reach the target position.

2. The control device according to claim 1, characterized in that, Before the spindle movement based on the spindle control unit begins, the spindle command output unit obtains the spindle rotation amount and the maximum speed of the spindle in the tapping operation and the pulling operation from the tapping program, and sends the spindle rotation amount and the maximum speed of the spindle as the spindle command to the spindle control unit.

3. The control device according to claim 1 or 2, characterized in that, The spindle control unit takes the rotation amount and the maximum speed sent from the spindle command output unit as the spindle command and starts the movement of the spindle before the command from the numerical control unit.

4. The control device according to claim 1 or 2, characterized in that, The amount of rotation and the maximum speed of the spindle are changed at predetermined positions during the cutting or pulling action. The spindle command output unit obtains from the tapping program the first rotational amount of the spindle before the change, the second rotational amount after the change, the first maximum speed before the change, and the second maximum speed after the change. The spindle command output unit sends the first rotation amount, the second rotation amount, the first maximum speed, and the second maximum speed as spindle commands to the spindle control unit.

5. The control device according to claim 4, characterized in that, The predetermined positions of the spindle's rotation amount and maximum rotation speed during the cutting action after the drawing action are changed. The predetermined position is the target position in the previous pulling action.

6. A control method for a machine tool that controls the synchronous operation of the spindle and feed axis, characterized in that, This method includes the following steps: The step of obtaining the spindle rotation amount and maximum speed during the tapping process when performing cutting and pulling actions an arbitrary number of times from the machining start position to the target position; The step of accelerating the spindle from the machining start position to the target position by using the maximum rotational speed as the target value, thereby maximizing the utilization of the maximum allowable current of the drive source. The step of detecting the maximum acceleration based on the rotational position feedback value of the spindle during accelerated rotation at the maximum capacity; The step of detecting the remaining rotation of the spindle from the current position to the target position based on the rotation amount and the rotation position feedback value; The step of detecting the current speed of the spindle based on the rotational position feedback value; After accelerating rotation at the maximum capacity, the spindle decelerates and rotates at a maximum deceleration corresponding to the maximum acceleration, based on the maximum acceleration, the remaining rotation amount, and the current speed, to reach the target position.

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