JP6494874B1 - Numerical control device - Google Patents

Abstract

The numerical controller (1) moves the actual feed shaft based on the amount of movement of the actual feed shaft per unit time including the information indicating the direction in which the actual feed shaft of the machine tool (10) moves. Whether or not to execute the lost motion correction based on the movement amount calculated by the calculation unit (4) that calculates the actual movement amount of the feed shaft after the direction of the direction reverses is determined And a control unit (8) which does not execute the lost motion correction when the judgment unit (5) determines that the lost motion correction is not performed.

Description

  The present invention relates to a numerical controller for controlling a machine tool.

  There is a lost motion correction function to improve the accuracy of the machined surface of a workpiece being a workpiece. The lost motion is a response delay that occurs when the direction of movement of the feed axis that the machine tool has reverses. The response delay is caused, for example, by the friction between the tool and the work. The lost motion correction function, when the direction of movement of the feed axis is reversed, gives a pre-calculated lost motion correction amount to the direction of movement of the feed axis after the reversal, so that it is left as it is due to lost motion or It is a function to reduce overcutting.

  In the case where a machining program is generated by a computer-aided manufacturing apparatus in order to machine complex shapes on a workpiece, there may be a description in the machining program to cause a minute inversion operation of, for example, 1 μm. Conventional numerical control devices perform lost motion correction for all reversing operations of the feed axis. Therefore, when using a conventional numerical control device, when a minute reverse operation is performed, the amount of lost motion correction becomes larger than the amount of movement designated by the processing program, so that the uncut or over-cut becomes relatively large. There is a problem that the accuracy of the work surface of the workpiece is reduced.

  To solve the above-mentioned problems, a technology has been proposed in which a machining program is read ahead and a reversed portion where it is not necessary to execute lost motion correction is identified based on the machining program, and lost motion correction is not executed at the identified reversed portion. (See, for example, Patent Document 1).

Patent No. 6147456

  However, in the technique of Patent Document 1, when the command axis of the machining program which is the axis designated by the machining program is different from the actual feed axis, the lost motion correction can not be properly controlled. If the command axis of the machining program and the actual feed axis are different, for example, the machining program includes rotation of coordinates.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a numerical control device that appropriately controls lost motion correction when the command axis of the processing program and the actual feed axis are different.

In order to solve the problems described above and to achieve the object, the present invention relates to the feed speed of the actual feed axis obtained by analyzing the machining program with respect to the actual feed axis possessed by the machine tool and the actual feed. Storing a plurality of files including information indicating an amount of movement of the actual feed axis per unit time including the information indicating the direction of movement of the actual feed axis calculated based on the direction of movement of the axis; The movement of the actual feed axis based on the direction in which the actual feed axis moves indicated by the first storage portion and the information contained in each of the plurality of files stored in the first storage portion detects the direction of reversal, the plurality of orientations of the movement of the previous SL actual feed axis based on the movement amount per unit time of the actual feed axis indicated by the information contained in each file Said actual after flipping A calculation unit for calculating the movement amount of the tilt axis, a judgment unit for judging whether or not to execute the lost motion correction based on the movement amount calculated by the calculation unit, and the lost motion correction by the judgment unit And a controller which does not execute the lost motion correction when it is determined that the controller does not execute.

  The numerical control apparatus according to the present invention can appropriately control the lost motion correction when the command axis of the machining program and the actual feed axis are different.

A diagram showing a configuration of a numerical control device according to an embodiment Diagram for explaining lost motion and lost motion correction Diagram to explain the problem of lost motion correction The flowchart which shows the procedure of operation of the calculation section which the numerical control control equipment which depends on the form possesses The flowchart which shows the procedure of operation of the decision section which the numerical control control equipment which depends on the form possesses The figure which shows an example to which the position of the actual feed axis which the machine tool used as the control object of the numerical control apparatus concerning embodiment changes with progress of time The figure which shows the case where the moving amount | distance of the actual feed axis after the direction of movement of the actual feed axis which the machine tool used as the control object of the numerical control apparatus concerning embodiment reverses is smaller than a threshold value. A flowchart showing the procedure of the operation of the control unit of the numerical control device according to the embodiment The figure which shows a processor in the case where a processor implement | achieves at least one part function of the interpolation part which the numerical control device concerning embodiment has, a calculation part, a judgment part, a control part, and a drive unit. The figure which shows the processing circuit in the case where the at least one component which comprises the interpolation part, calculation part, judgment part, control part, and drive unit which the numerical control device concerning an embodiment is realized by a processing circuit

  Hereinafter, a numerical control apparatus according to an embodiment of the present invention will be described in detail based on the drawings. The present invention is not limited by the embodiment.

Embodiment.
FIG. 1 is a diagram showing a configuration of a numerical control device 1 according to the embodiment. The numerical control device 1 is a device that controls the machine tool 10. The machine tool 10 is also shown in FIG. The machine tool 10 has a feed axis that moves a specific component in a specific direction. An example of a specific component is a table which the machine tool 10 has, and a work is placed on the table. The feed shaft, the table and the work are not shown in FIG. The numerical control device 1 has a function of controlling lost motion correction when the direction of movement of the feed axis is reversed.

  The numerical control device 1 interpolates the movement amount per unit time of the actual feed axis based on the feed speed 21 of the actual feed axis of the machine tool 10 and the movement direction 22 of the actual feed axis. It has part 2. The actual feed axis is not the command axis of the machining program, but is literally the actual feed axis. Each of the feed speed 21 and the movement direction 22 is obtained based on a processing program. Furthermore, each of the feed speed 21 and the direction of movement 22 is obtained by analyzing the processing program.

  The movement amount per unit time of the actual feed axis is the movement amount per unit time of a specific part of the actual feed axis. In the present application, the movement amount per unit time of a specific part of the actual feed axis is defined as the movement amount per unit time of the actual feed axis. An example of the specific part is the center of gravity of the feed axis. The specific part may be one end of the feed shaft. The movement amount per unit time includes information indicating the direction in which the actual feed axis moves. That is, the amount of movement per unit time includes information indicating the direction in which the specific part of the actual feed axis moves. The direction in which the actual feed axis moves is indicated by a sign indicating either positive or negative. That is, the interpolation unit 2 calculates the movement amount per unit time with a sign of the actual feed axis.

  The numerical control device 1 further includes a first storage unit 3 that stores information indicating the movement amount per unit time calculated by the interpolation unit 2. Specifically, the first storage unit 3 stores a plurality of files 23 including information indicating the movement amount per unit time. An example of the first storage unit 3 is a flash memory.

  The numerical control device 1 reverses the actual direction of movement of the feed axis based on the information indicating the movement amount per unit time included in each of the plurality of files 23 stored in the first storage unit 3. It further has a calculation unit 4 that detects and calculates the actual amount of movement of the feed shaft after the direction of movement of the actual feed shaft is reversed. Since the movement amount per unit time includes information indicating the direction in which the actual feed axis moves, the calculation unit 4 moves the actual feed axis based on the information indicating the direction in which the actual feed axis moves. Inversion of the direction of can be detected. The calculation unit 4 calculates the actual movement amount of the feed axis after the direction of movement of the actual feed axis is reversed, based on the information indicating the movement amount per unit time included in each of the plurality of files 23 can do.

  The calculation unit 4 also has a function of specifying a position at which the actual movement direction of the movement of the feed axis is reversed, based on the information indicating the movement amount per unit time possessed by each of the plurality of files 23. In FIG. 1, the position where the direction of movement of the actual feed axis is reversed is described as "axis movement reversal position 24", and the actual amount of movement of the feed axis after the direction of movement of the actual feed axis is reversed. Is described as "the movement amount 25 after axis movement reversal". The calculation unit 4 also has a function of storing information.

  The numerical control device 1 further includes a determination unit 5 that determines whether or not to execute the lost motion correction based on the movement amount calculated by the calculation unit 4. The movement amount calculated by the calculation unit 4 is an actual movement amount of the feed axis after the direction of movement of the actual feed axis is reversed. The numerical control device 1 further includes a second storage unit 6 that stores information indicating a threshold value 26 for determining whether or not to execute the lost motion correction. An example of the second storage unit 6 is a flash memory. The threshold 26 is a preset value.

  Depending on the material of the workpiece or the environment around the machine tool 10, a difference occurs between the actual movement of the actual feed axis and the movement determined in the machining program, and it is determined whether or not to execute lost motion correction. It may be misjudged. The threshold value 26 is set by the user in order to suppress false determination as to whether or not to execute the lost motion correction. When the user sets the threshold 26 in consideration of the material of the work or the environment around the machine tool 10, the determination unit 5 can appropriately determine whether or not to execute the lost motion correction. However, the threshold 26 may be a fixed value.

  The specific determination by the determination unit 5 is performed as follows. The determination unit 5 determines whether the movement amount calculated by the calculation unit 4 is smaller than the threshold 26 and executes the lost motion correction when it is determined that the calculated movement amount is smaller than the threshold 26. I decide not to do it. If the determination unit 5 determines that the movement amount calculated by the calculation unit 4 is equal to or larger than the threshold 26, the lost motion correction is determined to be performed.

  The numerical control device 1 further includes a third storage unit 7 that stores information. An example of the third storage unit 7 is a flash memory. The determination unit 5 reads the plurality of files 23 from the first storage unit 3 and writes the plurality of files 23 in the third storage unit 7. The third storage unit 7 stores the plurality of files 27 written by the determination unit 5. The plurality of files 27 correspond to the plurality of files 23 stored in the first storage unit 3, and the number of the plurality of files 27 is the same as the number of the plurality of files 23.

  Each of the plurality of files 27 includes information on the amount of movement per unit time and a lost motion correction control signal. The lost motion correction control signal is a signal indicating whether or not to execute lost motion correction. If it is determined that the lost motion correction is not to be performed, the determining unit 5 writes the lost motion correction control signal indicating that the lost motion correction is not to be performed in the file 27 and determines that the lost motion correction is to be performed. Write a lost motion correction control signal to the file 27 indicating that the. For example, if it is determined that the lost motion correction is not to be performed, the determining unit 5 turns the lost motion correction control signal to the OFF state, and if it determines that the lost motion correction is to be performed, the lost motion correction control signal to the ON state. .

  The numerical control device 1 further includes a control unit 8 that controls lost motion correction. Specifically, when the determination unit 5 determines that the lost motion correction is not to be performed, the control unit 8 does not execute the lost motion correction. When the determination unit 5 determines that the lost motion correction is to be performed, the control unit 8 causes the lost motion correction to be performed. The numerical control device 1 further includes a drive unit 9 that drives a motor that moves an actual feed shaft under control of the control unit 8. The motor is included in the machine tool 10.

  Specifically, the determination unit 5 determines whether to cause the drive unit 9 to execute the lost motion correction based on the movement amount calculated by the calculation unit 4. If the determination unit 5 determines that the movement amount calculated by the calculation unit 4 is smaller than the threshold 26, the determination unit 5 determines that the drive unit 9 does not execute the lost motion correction, and the movement amount calculated by the calculation unit 4 If it is determined that the threshold value is 26 or more, it is determined that the drive unit 9 is to execute the lost motion correction. The control unit 8 does not cause the drive unit 9 to execute the lost motion correction when the determination unit 5 determines that the lost motion correction is not to be performed, and the drive unit 9 when the determination unit 5 determines that the lost motion correction is to be performed. To perform lost motion correction.

  More specifically, the control unit 8 sequentially reads the plurality of files 27 from the third storage unit 7, and information 28 indicating the movement amount per unit time of each of the plurality of files 27 and the lost motion correction control signal 29. And the drive unit 9 in order. The drive unit 9 receives the information 28 indicating the movement amount per unit time from the control unit 8 and the lost motion correction control signal 29, and the information 28 indicating the movement amount per unit time received and the lost motion correction control signal 29 Drive the motor of the machine tool 10.

  If the lost motion correction control signal 29 received by the drive unit 9 is a signal indicating that the lost motion correction is not to be performed, the drive unit 9 executes the lost motion correction even if the actual movement direction of the feed axis is reversed. Instead, the actual feed axis is moved by the movement amount indicated by the information 28 indicating the movement amount per unit time. When the lost motion correction control signal 29 received by the drive unit 9 is a signal indicating that the lost motion correction is to be performed, the drive unit 9 executes the lost motion correction and also performs the information 28 indicating the movement amount per unit time. And move the actual feed axis.

  FIG. 2 is a diagram for explaining the lost motion and the lost motion correction. Lost motion is a response delay that occurs when the direction of movement of the actual feed axis that the machine tool has reverses. The response delay is caused, for example, by the friction between the tool and the work. The solid line in FIG. 2 shows an example of how the position of the feed shaft indicated by the machining program changes with the passage of time. The position of the feed axis indicated by the solid line in FIG. 2 is defined as a command position. The broken line in FIG. 2 shows an example of how the position of the ideal feed shaft sequentially generated by the drive unit 9 in accordance with the control system in the drive unit 9 changes with the passage of time. The ideal feed axis position indicated by the broken line in FIG. 2 is defined as the model position, and is described as “the drive unit model position” in FIG.

  As shown in FIG. 2, in the model position, a delay in response to the gain set in the drive unit 9 occurs with respect to the command position. In general, lost motion correction is performed at the model position indicated by the white arrow in FIG. That is, generally, lost motion correction is performed when the direction of movement of the model position is reversed.

  FIG. 3 is a diagram for explaining the problem of lost motion correction. FIG. 3 shows that the movement path 30 of the actual feed axis, which changes with the passage of time, includes the first inversion position 31 and the second inversion position 32. The actual feed axis movement path 30 is a locus of the actual feed axis position that changes with the passage of time. Each of the first reversing position 31 and the second reversing position 32 is a position at which the direction of movement of the actual feed axis is reversed. The direction in which the actual feed shaft moves is reversed at the second reversing position 32 after being reversed at the first reversing position 31.

  In addition, FIG. 3 shows that the movement amount 25 after axis movement reversal which is the actual movement amount of the feed axis after the direction in which the actual feed axis moves is reversed is smaller than the lost motion correction amount 33 set in advance. It shows. The post-axis movement reverse movement amount 25 is an actual movement amount of the feed shaft from the first inversion position 31 to the second inversion position 32. The outlined arrows in FIG. 3 generally indicate where lost motion correction is to be performed. The triangular marks in FIG. 3 indicate the actual position of the feed shaft when the direction is reversed.

  As shown in FIG. 3, when the movement amount 25 after the axis movement reversal is smaller than the lost motion correction amount 33, when the lost motion correction is performed when processing the work, unnecessary correction will be performed, and the work of the work The precision of the machined surface is reduced. For example, when the movement amount 25 after the axis movement reversal is smaller than the lost motion correction amount 33, when the lost motion correction is performed, the work is unnecessarily scraped, and the accuracy of the work surface of the work is lowered.

  However, in the embodiment, if the movement amount calculated by the calculation unit 4 is smaller than the threshold 26, even if the actual movement direction of the movement of the feed axis is reversed, the lost motion correction is not performed. That is, in the embodiment, the decrease in the accuracy of the processing surface of the workpiece is suppressed.

  FIG. 4 is a flowchart showing the procedure of the operation of the calculation unit 4 of the numerical control device 1 according to the embodiment. That is, in the flowchart of FIG. 4, the calculation unit 4 detects the reversal of the direction of movement of the actual feed axis and calculates the actual amount of movement of the feed axis after the direction of movement of the actual feed axis is reversed. Shows the procedure of The operation of the calculation unit 4 will be described based on the flowchart of FIG.

  The calculation unit 4 sets the actual number of inversions of the feed axis to "0" (S1). That is, the calculation unit 4 stores information indicating that the actual number of inversions of the feed axis is "0" (S1). The calculation unit 4 reads the file 23 having information indicating the movement amount per unit time from the first storage unit 3 (S2). That is, the calculation unit 4 reads information indicating the movement amount per unit time from the first storage unit 3 (S2).

  As described above, the amount of movement per unit time is assigned a code that is information indicating the direction in which the actual feed axis moves. Based on the code attached to the movement amount per unit time indicated by the information read in step S2, the calculation unit 4 indicates the movement per unit time indicated by the information included in the file 23 read in step S2. It is determined whether or not the direction in which the actual feed axis moves is reversed at the time corresponding to the amount (S3).

  When the calculation unit 4 determines that the direction in which the actual feed axis moves is reversed (Yes in S3), that is, when the reverse of the direction in which the actual feed axis is moved is detected (Yes in S3), the actual feed axis The number of inversions of is increased by one (S4). In step S4 of the flowchart of FIG. 4, increasing the actual number of inversions of the feed axis by one is described as "counting up the number of inversions". The calculation unit 4 stores the actual number of inversions of the feed axis increased by one. The calculation unit 4 determines whether the actual number of inversions of the feed axis is "1" (S5). When it is determined that the actual number of inversions of the feed axis is “1” (Yes in S5), the calculation unit 4 specifies and stores the position at which the movement direction of the actual feed axis is inverted (S6). The calculation unit 4 starts accumulation of the actual movement amount of the feed axis after the direction of movement of the actual feed axis is reversed (S7).

  After performing the operation of step S7, the calculation unit 4 reads the file 23 of the next order including the information indicating the movement amount per unit time from the first storage unit 3 (S2), that is, the next order Information indicating the movement amount per unit time is read (S2), and the operation of step S3 is performed. When it is determined that the direction in which the actual feed axis moves does not reverse (No in S3), the calculation unit 4 determines whether the direction in which the actual feed axis moves in the past has reversed (S8). That is, in step S8, the calculation unit 4 determines whether the actual number of inversions of the feed axis is "1". If the calculation unit 4 determines that the direction in which the actual feed axis has moved in the past has been reversed (Yes in S8), that is, if it is determined that the actual number of reversals of the feed axis is "1" (S8) Yes), the actual movement amount of the feed axis after the direction of movement of the actual feed axis is reversed is accumulated (S7).

  If the calculation unit 4 determines that the actual number of inversions of the feed axis is not “1” (No in S8), the file of the next order including the information indicating the movement amount per unit time from the first storage unit 3 23 is read (S2), and the operation of step S3 is performed. When the calculation unit 4 determines that the actual number of inversions of the feed axis is not "1" (No in S8), the calculation unit 4 determines that the direction in which the actual feed axis moves in the past has not been inverted It is. When the calculation unit 4 determines that the actual number of inversions of the feed axis is not “1” in step S5 (No in S5), the operation ends. In the case where the actual number of inversions of the feed shaft is not "1", this is a case where the actual inversion of the feed shaft is performed twice or more. The calculation unit 4 repeatedly executes the operations from step S2 to step S7 described above until the second reversal of the actual feed shaft occurs, and the direction of movement of the actual feed shaft is reversed from the plurality of operations in step S7. Calculate the actual feed axis movement amount after

  FIG. 5 is a flowchart showing the procedure of the operation of the determination unit 5 of the numerical control device 1 according to the embodiment. That is, the flowchart of FIG. 5 shows the procedure of the operation | movement which the judgment part 5 judges whether a lost motion correction | amendment is performed. The operation of the determination unit 5 will be described based on the flowchart of FIG.

  The determination unit 5 reads information indicating the movement amount per unit time included in each of the plurality of files 23 from the first storage unit 3 and writes the information in the third storage unit 7 (S11). When the information indicating the movement amount per unit time is written in the third storage unit 7, the plurality of files 27 including the information indicating the movement amount per unit time is stored in the third storage unit 7. The determination unit 5 acquires, from the calculation unit 4, information for specifying the position at which the movement direction of the actual feed axis is reversed (S12).

  The determination unit 5 determines whether the information indicating the movement amount per unit time included in the file 23 being processed includes information indicating the position where the direction in which the actual feed axis moves is reversed (S13). Specifically, since the movement amount per unit time has a code indicating the direction in which the feed axis actually moves, the determination unit 5 includes the file 23 being processed based on the code. It is determined whether the information indicating the movement amount per unit time includes information indicating the position where the direction in which the actual feed axis moves is reversed (S13).

  FIG. 6 is a diagram showing an example in which the actual position of the feed shaft of the machine tool 10 to be controlled by the numerical control device 1 according to the embodiment changes with the passage of time. Specifically, FIG. 6 shows an example of the actual position of the feed shaft, which changes with the passage of time, as a curve. FIG. 6 shows that the maximum value of the curve is the first reversal position where the direction of movement of the actual feed axis is reversed, and the minimum value of the curve is the case where the direction of movement of the actual feed axis is reversed. It shows that it is a reversal position of 2. After the time corresponding to the second reverse position, the actual feed axis moves in the direction in which the actual feed axis has moved before the time corresponding to the first reverse position.

  When the determination unit 5 determines that the information indicating the movement amount per unit time included in the file 23 being processed includes information indicating the position where the direction in which the actual feed axis moves is reversed (Yes in S13), Information indicating the threshold value 26 is read from the second storage unit 6 (S14). The determination unit 5 acquires, from the calculation unit 4, information indicating the actual movement amount of the feed shaft after the direction of movement of the actual feed shaft is reversed (S15). The determination unit 5 determines whether the actual amount of movement of the feed shaft after the direction of movement of the actual feed shaft is reversed is smaller than the threshold 26 (S16).

  FIG. 7 shows the case where the actual amount of movement of the feed shaft after reversal of the direction of movement of the actual feed shaft possessed by the machine tool 10 to be controlled by the numerical control device 1 according to the embodiment is smaller than the threshold FIG. FIG. 7 also shows the first inversion position and the second inversion position shown in FIG. The actual amount of movement of the feed shaft after the direction of movement of the actual feed shaft is reversed is the distance from the first reverse position to the second reverse position. If the determination unit 5 determines that the actual amount of movement of the feed shaft after reversing the direction of movement of the actual feed shaft is smaller than the threshold 26 (Yes in S16), the determination unit 5 corresponds to the file 23 being processed. The lost motion correction control signal 29 of the file 27 is turned off (S17).

  When the operation of step S17 is performed, the operation of the determination unit 5 for the file 23 being processed ends. For the file 23 being processed, the determination unit 5 determines that the information indicating the movement amount per unit time included in the file 23 being processed does not include the information indicating the position at which the direction in which the actual feed axis moves is reversed. Also when it is (No in S13), the operation is ended. In the case where it is determined that the actual movement amount of the feed axis after the direction of movement of the actual feed axis is reversed for the file 23 being processed is the threshold value 26 or more (No in S16) End the operation.

  FIG. 8 is a flowchart showing the procedure of the operation of the control unit 8 of the numerical control device 1 according to the embodiment. Further, the flowchart of FIG. 8 shows the procedure of the operation of transmitting the lost motion correction control signal 29 to the drive unit 9 which indicates whether the control unit 8 executes the lost motion correction. The operation of the control unit 8 will be described based on the flowchart of FIG.

  The control unit 8 reads information 28 indicating the movement amount per unit time included in the file 27 from the third storage unit 7 (S21). The control unit 8 reads the lost motion correction control signal 29 from the third storage unit 7 (S22). The lost motion correction control signal 29 read by the control unit 8 in step S22 is a signal contained in the file 27 including the information 28 indicating the movement amount per unit time read by the control unit 8 in step S21. .

  The control unit 8 transmits the information 28 indicating the read movement amount per unit time and the lost motion correction control signal 29 to the drive unit 9 (S23). The lost motion correction control signal 29 is a signal indicating whether or not to execute lost motion correction. If it is determined by the determination unit 5 that the lost motion correction is not to be performed, the lost motion correction control signal 29 indicates that the lost motion correction is not to be performed. When it is determined by the determination unit 5 that the lost motion correction is to be performed, the lost motion correction control signal 29 indicates that the lost motion correction is to be performed. The control unit 8 performs the operations from step S21 to step S23 for each of the plurality of files 27 stored in the third storage unit 7.

  As described above, the numerical control device 1 according to the embodiment is an actual feed after the direction of movement of the actual feed axis is reversed based on the amount of movement of the machine tool 10 per unit time of the actual feed axis. Calculate the movement amount of the axis. Since the movement amount per unit time described above includes information indicating the direction in which the actual feed axis moves, the numerical control device 1 calculates the actual move amount of the feed axis after the direction of movement of the actual feed axis is reversed. Can be calculated. The numerical control device 1 determines whether or not to execute the lost motion correction based on the calculated movement amount. Specifically, the numerical control device 1 determines that the lost motion correction is not to be performed when the calculated movement amount is smaller than a preset threshold value. The numerical control device 1 does not execute the lost motion correction when it is determined that the lost motion correction is not performed.

  For example, when the machining program includes rotation of coordinates, the command axis of the machining program, which is the axis specified by the machining program, may differ from the actual feed axis. If the command axis of the machining program and the actual feed axis are different, the conventional numerical control device can not appropriately control the lost motion correction. However, since the numerical control device 1 calculates the actual movement amount of the feed axis after the direction of movement of the actual feed axis is reversed based on the movement amount per unit time of the actual feed axis, the machining program In the case where the commanded axis of and the actual feed axis are different, the lost motion correction can be appropriately controlled.

  In addition, since the numerical control device 1 does not execute the lost motion correction when the calculated movement amount is smaller than the preset threshold value, it is possible to suppress the decrease in the accuracy of the processing surface of the workpiece.

  FIG. 9 shows the processor 51 when at least a part of the functions of the interpolation unit 2, calculation unit 4, determination unit 5, control unit 8 and drive unit 9 included in the numerical controller 1 according to the embodiment is realized by the processor 51. FIG. That is, at least a part of the functions of the interpolation unit 2, the calculation unit 4, the determination unit 5, the control unit 8 and the drive unit 9 may be realized by the processor 51 that executes a program stored in the memory 52. The processor 51 is a central processing unit (CPU), a processing device, an arithmetic device, a microprocessor, a microcomputer, or a digital signal processor (DSP). A memory 52 is also shown in FIG.

  When at least a part of the functions of the interpolation unit 2, the calculation unit 4, the determination unit 5, the control unit 8 and the drive unit 9 is realized by the processor 51, the part of the functions is the processor 51, software, firmware or It is realized by a combination of software and firmware. The software or firmware is written as a program and stored in the memory 52. The processor 51 reads out and executes the program stored in the memory 52 to realize at least a part of the functions of the interpolation unit 2, the calculation unit 4, the determination unit 5, the control unit 8, and the drive unit 9.

  That is, when at least a part of the functions of the interpolation unit 2, the calculation unit 4, the determination unit 5, the control unit 8 and the drive unit 9 is realized by the processor 51, the numerical control device 1 determines the interpolation unit 2, the calculation unit 4, the determination It has a memory 52 for storing a program that results in the steps executed by the unit 5, the control unit 8 and part of the drive unit 9. The program stored in the memory 52 can be said to cause the computer to execute a procedure or method executed by the interpolation unit 2, the calculation unit 4, the determination unit 5, the control unit 8, and part of the drive unit 9.

  The memory 52 is, for example, nonvolatile such as random access memory (RAM), read only memory (ROM), flash memory, erasable programmable read only memory (EPROM), EEPROM (registered trademark) (electrically erasable programmable read only memory), etc. Alternatively, it is volatile semiconductor memory, magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD (Digital Versatile Disk), or the like.

  In FIG. 10, the processing circuit 53 realizes at least a part of constituent elements of the interpolation unit 2, calculation unit 4, determination unit 5, control unit 8, and drive unit 9 included in the numerical control device 1 according to the embodiment. It is a figure showing processing circuit 53 in a case. That is, at least a part of the functions of the interpolation unit 2, the calculation unit 4, the determination unit 5, the control unit 8 and the drive unit 9 may be realized by the processing circuit 53.

  The processing circuit 53 is dedicated hardware. The processing circuit 53 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a combination thereof. It is. The interpolation unit 2, the calculation unit 4, the determination unit 5, the control unit 8 and a part of the drive unit 9 may be dedicated hardware separate from the rest.

  With regard to the plurality of functions of the interpolation unit 2, the calculation unit 4, the determination unit 5, the control unit 8 and the drive unit 9, a part of the plurality of functions is realized by software or firmware, and the remaining part of the plurality of functions is dedicated hardware. May be realized by As described above, the plurality of functions of the interpolation unit 2, the calculation unit 4, the determination unit 5, the control unit 8, and the drive unit 9 can be realized by hardware, software, firmware, or a combination thereof.

  The configuration shown in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and one of the configurations is possible within the scope of the present invention. It is also possible to omit or change parts.

  1 Numerical Control Device, 2 Interpolation Unit, 3 First Storage Unit, 4 Calculation Unit, 5 Determination Unit, 6 Second Storage Unit, 7 Third Storage Unit, 8 Control Unit, 9 Drive Units, 10 Machine Tools, 21 Feeding Speed, 22 Direction of movement, 23, 27 files, 24 axis movement reversal position, movement amount after 25 axis movement reversal, 26 threshold values, 28 information indicating movement amount per unit time, 29 lost motion correction control signal, 51 processor, 52 memory, 53 processing circuits.

Claims (2)

The actual feed axis calculated based on the actual feed axis feed speed obtained by analyzing the machining program with respect to the actual feed axis possessed by the machine tool and the direction of movement of the actual feed axis A first storage unit for storing a plurality of files including information indicating an amount of movement per unit time of the actual feed axis including information indicating a direction in which the object moves ;
The reversal of the direction of movement of the actual feed axis is detected based on the direction of movement of the actual feed axis indicated by the information contained in each of the plurality of files stored in the first storage unit while the after the plurality of orientations of the movement of the previous SL actual feed axis based on the movement amount per unit time of the actual feed axis indicated by the information contained in each file is inverted in fact A calculation unit that calculates the amount of movement of the feed shaft of
A determination unit that determines whether or not to execute lost motion correction based on the movement amount calculated by the calculation unit;
A control unit which does not execute the lost motion correction if the judgment unit judges that the lost motion correction is not executed. The numerical control according to claim 1, wherein the determination unit determines not to execute the lost motion correction when the movement amount calculated by the calculation unit is smaller than a preset threshold. apparatus.

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