JPWO2018189806A1 - Wire electrical discharge machine and wire electrical discharge method - Google Patents

Abstract

  A drive control device (20) for generating a discharge between a workpiece and a wire electrode to machine the workpiece and controlling a relative distance between the wire electrode and the workpiece; An inter-electrode average machining voltage detection unit (40) for detecting an inter-electrode average machining voltage between the wire electrode and the workpiece, and a drive control device based on the inter-electrode average machining voltage and a predetermined target voltage Average between poles so that the side gap between the wire electrode and the workpiece becomes constant regardless of the processing direction based on the processing speed control unit (43) and the processing information and processing direction during processing And a voltage correction unit that corrects either the processing voltage or the target voltage.

Description

  The present invention relates to a wire electric discharge machine and a wire electric discharge machining method for machining a workpiece by wire electric discharge.

  As a method of improving machining accuracy in wire electric discharge machining, as in the technique disclosed in Patent Document 1, the machining state during machining is detected, and between the wire electrode and the workpiece according to the machining state It has been proposed to correct at least one of the set voltage and the average machining voltage between poles so that the side gap is constant. Thereby, the improvement of the processing accuracy based on the processing state is achieved.

  By the way, in the wire electric discharge machine, in order to improve the power supply to the wire electrode, the feeder which is electrically connected to the processing power supply is pressed against the wire electrode for processing. In wire electric discharge machining, discharge occurs on the side of the wire electrode facing the workpiece, but the wire electrode is consumed along with the electric discharge. Will occur. If the finishing process is performed in the state where the displacement of the center of the electrode occurs, the finished dimensions will vary, so the finished dimensions will vary depending on the processing direction.

Patent No. 5794401

  In recent years, high processing accuracy is required for the wire electric discharge machine, and measures against variation in finished dimensions due to the processing direction described above are required. However, in the technology disclosed in Patent Document 1, The correction depending on the processing direction was not performed.

  This invention is made in view of the above, Comprising: It aims at obtaining the wire electric discharge machine which can suppress the dispersion | variation in the process dimension error depending on the process direction.

  In order to solve the problems described above and to achieve the object, the present invention is a wire electric discharge machine that generates an electric discharge between a workpiece and a wire electrode to machine the workpiece, and A drive control device for controlling a relative distance to a workpiece and an inter-electrode average machining voltage detection unit for detecting an average machining voltage between the wire electrode and the workpiece. The present invention controls the drive control device based on the inter-electrode average machining voltage and the predetermined target voltage, regardless of the machining direction based on the machining information and the machining direction during machining. And a voltage correction unit that corrects either the average machining voltage between the electrodes or the target voltage so that the side gap between the wire electrode and the workpiece becomes constant.

  The wire electric discharge machine according to the present invention has an effect that it is possible to suppress the variation of the processing dimension error depending on the processing direction.

The block diagram of the wire electric discharge machine concerning Embodiment 1 to 4 of this invention A diagram for explaining the non-processed shape of the wire electrode in a plane perpendicular to the stretching direction according to the first embodiment The figure explaining the shape at the time of finish processing of the wire electrode in the plane perpendicular | vertical to the stretching direction concerning Embodiment 1. The figure explaining another shape at the time of finish processing of the wire electrode in a plane perpendicular to the stretching direction concerning Embodiment 1. The figure which shows the relationship between the wire electrode at the time of finish processing concerning Embodiment 1, and a to-be-processed object The figure which showed the process dimension error depending on the process direction concerning Embodiment 1. The figure which showed the detailed structure of the process control apparatus concerning Embodiment 1. Block diagram showing a more detailed configuration of the processing control device according to the first embodiment The figure which shows the hardware constitutions of the computer numerical control apparatus concerning Embodiment 1. FIG. 6 is a graph showing the relationship between the side gap correction value and the amount of change in machining dimension in the wire electric discharge machine according to the first embodiment The figure which showed the detailed structure of the processing control apparatus concerning Embodiment 2 of this invention. Block diagram showing a more detailed configuration of the processing control device according to the second embodiment

  Hereinafter, a wire electric discharge machine and a wire electric discharge machining method 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 1
FIG. 1 is a block diagram of a wire electric discharge machine 100 according to a first embodiment of the present invention. The wire electric discharge machine 100 includes a wire electrode 30, an upper power supply 31 and a lower power supply 32 in contact with the wire electrode 30, a processing power supply 35, and a table 9 on which the workpiece 13 is mounted. The upper power supply 31 and the lower power supply 32 are pressed against the upper pressing block 33 and the lower pressing block 34 with the wire electrode 30 interposed therebetween in order to keep the power supply to the wire electrode 30 good.

  The wire electric discharge machine 100 further includes a drive control device 20 composed of an X-axis drive device 7 and a Y-axis drive device 8, and an upper die 1 and a lower die 2 which each allow the wire electrode 30 to penetrate. The X-axis drive 7 moves the table 9 in the X-axis direction, and the Y-axis drive 8 moves the table 9 in the Y-axis direction. Here, the X-axis direction and the Y-axis direction are two directions perpendicular to each other in the vertical direction of FIG. 1, that is, in a plane perpendicular to the stretching direction of the wire electrode 30. In the following description, although the processing direction is described as an in-plane direction including the X-axis direction and the Y-axis direction as an example, the processing direction is limited to the in-plane direction perpendicular to the tension direction of the wire electrode 30 It does not mean that

  The upper die 1 has a hole for guiding the wire electrode 30 and positions the wire electrode 30 above the workpiece 13. The lower die 2 has a hole for guiding the wire electrode 30 and positions the wire electrode 30 below the workpiece 13. When the wire electrode 30 is inclined, the upper die 1 and the lower die 2 serve as upper and lower fulcrums of the wire electrode 30.

  The drive control device 20 moves any or all of the table 9 on which the workpiece 13 is mounted, the upper die 1 and the lower die 2. The drive control device 20 may be a drive system that controls the relative distance between the wire electrode 30 and the workpiece 13. Here, as an example, the X-axis drive 7 and the Y-axis drive 8 are described as moving the table 9. When the X-axis drive 7 and the Y-axis drive 8 drive the table 9, the positions of the upper die 1 and the lower die 2 move relative to the workpiece 13 in the XY plane.

  Further, the wire electric discharge machine 100 converts the traveling direction of the wire electrode 30, the feeding roller 4 which changes the traveling direction of the wire electrode 30 and holds the wire electrode 30, and converts the traveling direction of the wire electrode 30. And a recovery roller 6 for recovering the wire electrode 30 whose direction has been changed by the lower roller 5.

  The wire electric discharge machine 100 further includes a processing power supply 35, a processing control device 111 for controlling the drive control device 20, and a data input / output device 120 serving as an input / output means of the operator. The upper power supply 31 and the lower power supply 32 and the workpiece 13 are connected to the processing power supply 35 respectively. The processing power supply 35 applies a voltage between the upper power supply 31 and the lower power supply 32 and the workpiece 13. The wire electrical discharge machine 100 discharges the workpiece 13 by generating a discharge between the workpiece 13 mounted on the table 9 and the wire electrode 30.

  The operator inputs processing conditions, processing programs and control parameters to the data input / output device 120. The processing control device 111 controls the drive control device 20 based on the processing conditions, the processing program, and the control parameters input by the operator via the data input / output device 120. That is, the processing control device 111 and the data input / output device 120 constitute a computerized numerical control (CNC) device.

  In the wire electric discharge machine 100 configured as described above, the wire electrode 30 is fed from the wire bobbin 3 and is changed in direction by the feed roller 4. Thereafter, the wire electrode 30 passes through the hole of the upper die 1 and the hole of the lower die 2 and performs electric discharge machining on the workpiece 13 while passing between the upper die 1 and the lower die 2. After passing through the lower die 2, the wire electrode 30 is changed in direction by the lower roller 5, and is recovered by the recovery roller 6 into a recovery box (not shown).

  FIG. 2 is a view for explaining the non-processed shape of the wire electrode 30 in a plane perpendicular to the stretching direction according to the first embodiment. FIG. 3 is a diagram for explaining the shape of the wire electrode 30 at the time of finish processing in a plane perpendicular to the stretching direction according to the first embodiment. FIG. 4 is a view for explaining another shape at the time of finish processing of the wire electrode 30 in a plane perpendicular to the stretching direction according to the first embodiment. FIG. 5 is a view showing the relationship between the wire electrode 30 and the workpiece 13 at the time of finish processing according to the first embodiment.

  2 to 4 are diagrams showing the arrangement relationship of the wire electrode 30, the lower die 2, the lower power supply 32 and the lower pressing block 34 as viewed from the table 9 in the stretching direction of the wire electrode 30. FIG. FIG. 2 shows a state at the time of non-machining, FIG. 3 shows a state at the time of electric discharge finishing on the surface of the wire electrode 30 in contact with the lower pressing block 34, and FIG. Shows the state when the electric discharge finish processing is performed. FIG. 5 shows the front gap and the side gap between the wire electrode 30 and the workpiece 13. The side gap is the distance between the wire electrode 30 and the workpiece 13 in the direction perpendicular to the processing direction.

  As shown in FIG. 2, the non-processed shape of the wire electrode 30 is substantially circular, and the center of the wire electrode 30 is at a position controlled by the processing control device 111 as the central position of the wire electrode 30. On the other hand, in FIGS. 3 and 4, due to the consumption of the wire electrode 30 during the finishing process, the actual center of the wire electrode 30 corresponds to the wire electrode 30 depending on the processing direction in which the finishing process is performed during one shaping process. As a center position of the position control unit 111 deviates from the position controlled by the processing control device 111. As a result, the control of the side gap occurs, which causes a problem that the shape and the dimension vary depending on the processing direction.

  FIG. 6 is a diagram showing a processing dimension error depending on the processing direction according to the first embodiment. When the positive direction of the X axis is 0 degrees and the positive direction of the Y axis is 90 degrees, the distance 51 from the origin of the point 50 indicating the processing dimensional error with respect to the processing direction θ indicates the value of the processing dimensional error There is. Taking the case of the processing direction θ = 45 degrees as an example, when the processing direction in FIG. 5 is 45 degrees in FIG. 6, the distance 51 is derived from the design value of the processing dimension in the direction perpendicular to the processing direction. A processing dimension error which is an error of is indicated by a distance 51. If the value of the distance 51 indicating the case where the processing dimension error is zero is determined, it indicates that the larger the size of the distance 51 is, the more processing remaining than the design value with respect to the workpiece 13, and the distance As the size of 51 is smaller than the value, it indicates that the workpiece 13 is cut more deeply than the design value.

  Therefore, as shown in FIG. 6, it can be seen that the processing dimensional error is not constant regardless of the processing direction. Thus, one of the causes that the processing dimensional error in finishing is changed depending on the processing direction is the centering of the wire electrode 30 in the processing direction due to the consumption of the wire electrode 30 during the finishing described with reference to FIGS. Is considered to be changed by Here, it is desirable from the viewpoint of processing control that the processing dimensional error is a constant value regardless of the processing direction. That is, it is ideal that the points 50 in FIG. 6 are arranged concentrically.

  FIG. 7 is a diagram showing a detailed configuration of the processing control device 111 according to the first embodiment. In FIG. 7, in order to explain the configuration of the processing control device 111 in detail, other configurations such as the wire electrode 30, the workpiece 13 and the processing power supply 35 are simplified and shown.

  The processing control device 111 controls the processing speed via the drive control device 20 based on the processing program and the inter-electrode average processing voltage between the wire electrode 30 and the workpiece 13. The processing speed is the relative speed between the wire electrode 30 and the workpiece 13.

  The processing control device 111 detects an inter-electrode average processing voltage detection unit 40 that detects an inter-electrode average processing voltage, a side surface gap estimator 45 that estimates a side surface gap during processing and outputs it as a side surface gap estimated value And a side gap controller 47 for generating and outputting a correction value of an inter-electrode average machining voltage so that the side gap estimated value follows the side gap command value. And.

  Furthermore, the machining control device 111 uses an inter-electrode average machining voltage correction unit 41 that corrects the inter-electrode average machining voltage detected by the inter-electrode average machining voltage detection unit 40 using a correction value, and a target inter-electrode average machining voltage. A target voltage storage unit 44 for storing a target voltage predetermined for processing, a voltage calculation unit 42 for calculating a voltage difference between the corrected average machining voltage between poles and the target voltage, and a voltage calculation unit 42 And a processing speed control unit 43 that controls the processing speed via the drive control device 20 so that the absolute value of the voltage difference decreases. The inter-electrode average processing voltage correction unit 41, the side surface gap estimator 45, the side surface gap command device 46, and the side surface gap controller 47 constitute a voltage correction portion that corrects the inter-electrode average processing voltage.

  The side surface gap estimator 45 estimates a side surface gap under processing from processing information during finish processing, and outputs it as a side surface gap estimated value. The processing information includes information such as an inter-electrode average processing voltage, a processing speed, a plate thickness, and an offset amount. A method of estimating the side gap is known, and it is described in, for example, FIG. 6 of Patent Document 1 that the side gap is determined based on the average machining voltage between electrodes and the machining speed. In the first embodiment, as an example, the side surface gap estimator 45 includes the inter-electrode average processing voltage detected by the inter-electrode average processing voltage detection unit 40 and the processing speed obtained from the processing speed control unit 43. Based on the configuration, the side gap estimated value is obtained and output.

  The side gap commander 46 has a side gap correction value corresponding to the processing direction. The side gap correction value corresponding to the processing direction is a correction value for the side gap determined for each processing direction so that the processing dimension error obtained by the experimental data shown in FIG. 6 becomes a constant value regardless of the processing direction. It is. Specifically, the side surface gap correction value is a correction value obtained such that the side surface gap is constant regardless of the processing direction. The side gap correction value corresponding to the processing direction may be calculated in advance and may be given to the side gap commander 46 by the operator via the data input / output device 120. Further, the operator gives data of machining dimension error depending on the machining direction as shown in FIG. 6 to the side gap commander 46 through the data input / output device 120, and the side gap commander 46 depends on the machining direction The side gap correction value corresponding to the processing direction may be calculated and held based on the processing dimension error. The side gap correction value corresponding to the processing direction is a finite number of data corresponding to the finite number of processing directions. The side gap commander 46 further has a side gap command value before correction, which is a fixed value that does not depend on the processing direction. The side gap commander 46 acquires the processing direction from the drive control device 20, adds the side gap correction value corresponding to the processing direction to the side gap command value before correction to obtain the side gap command value after correction, and outputs Do. Therefore, the side gap command value is corrected in the above-described finite number of machining directions.

  The side gap controller 47 obtains and outputs a correction value of the machining gap average machining voltage so that the side gap estimated value follows the side gap command value output by the side gap command device 46. Here, the side surface gap controller 47 is a controller having proportional characteristics as an input / output characteristic using the deviation between the side surface gap command value and the side surface gap estimated value as an input and using the correction value of the inter-electrode average processing voltage as an output. It may have integral characteristics or differential characteristics like a general servo system. Further, the side gap controller 47 may have non-linear input / output characteristics. The side gap controller 47 is not limited in its configuration as long as it outputs a correction value of the inter-electrode average machining voltage so as to make the side gap estimated value follow the side gap command value.

  FIG. 8 is a block diagram showing a more detailed configuration of the processing control device 111 according to the first embodiment.

  In FIG. 8, the side gap commander 46 determines the side gap command value corrected by the side gap correction value as described above based on the processing direction given by the drive control device 20 which is not described in FIG. Output. The side gap estimator 45 is a side surface based on the inter-electrode average machining voltage detected by the inter-electrode average machining voltage detection unit 40 and the machining speed obtained from the machining speed control unit 43, which are not described in FIG. Calculate and output the gap estimation value. In FIG. 8, part of the function of the side gap controller 47 of FIG. 7 is shown outside the side gap controller 47 as a subtractor 49. The subtractor 49 obtains the deviation between the side gap command value and the side gap estimated value, and inputs it to the side gap controller 47. The side gap controller 47 obtains and outputs a correction value of the inter-electrode average machining voltage based on the deviation obtained by the subtractor 49. The side gap controller 47 may have the function of the subtractor 49 as shown in FIG. The inter-electrode average processing voltage correction unit 41 is an adder, and the correction value of the inter-electrode average processing voltage output by the side gap controller 47 is added to the inter-electrode average processing voltage detected by the inter-electrode average processing voltage detection unit 40 It adds and outputs the average machining voltage between poles after correction. The voltage calculation unit 42 is a subtractor, and calculates the voltage difference between the target voltage obtained from the target voltage storage unit 44 (not shown in FIG. 8) and the average machining voltage between the poles after correction to the machining speed control unit 43. input. The processing speed control unit 43 obtains a processing speed at which the absolute value of the input voltage difference decreases, and supplies the processing speed to the drive control device 20. The drive control device 20 controls the relative distance between the wire electrode 30 and the workpiece 13 so as to achieve the processing speed. Therefore, the voltage correction unit including the inter-electrode average processing voltage correction unit 41 corrects the inter-electrode average processing voltage so that the side gap becomes constant regardless of the processing direction. That is, according to the wire electric discharge machine 100 according to the first embodiment, the side gap in the case of processing in a certain linear direction and the side gap in the case of processing in another linear direction by changing the angle of the processing direction It becomes possible to control to become the same value.

  FIG. 9 is a diagram illustrating a hardware configuration of the computer numerical control device according to the first embodiment. When the functions of the processing control device 111 and the data input / output device 120 are realized by a computer, the functions of the processing control device 111 and the data input / output device 120 are CPU (central processing unit) 201, memory 202, as shown in FIG. It is realized by the storage device 203, the display device 204, and the input device 205.

  The functions of the processing control device 111 are realized by software, firmware, or a combination of software and firmware. Software, firmware, or a combination of software and firmware is written as a program and stored in the storage device 203. The CPU 201 implements the function of the processing control device 111 by reading the program stored in the storage device 203 into the memory 202 and executing the program. That is, the computer numerical control device stores the program that results in the step of performing the function of the processing control device 111 being executed when the function of the processing control device 111 is executed by the computer. A storage device 203 is provided. Further, it can be said that the above program causes a computer to execute a wire electric discharge machining method that realizes the function of the machining control device 111. Therefore, the above-mentioned program includes the above-mentioned machining program. The data input / output device 120 is realized by the input device 205 and the display device 204. Specific examples of the input device 205 are a keyboard, a mouse, a touch panel, and the like. Specific examples of the display device 204 are a monitor, a display, and the like. The target voltage storage unit 44 is realized by the memory 202 or the storage device 203. A specific example of the memory 202 corresponds to a volatile storage area such as a random access memory (RAM). Specific examples of the storage device 203 correspond to nonvolatile or volatile semiconductor memory and magnetic disk.

  FIG. 10 is a view showing the relationship between the side gap correction value and the amount of change in the processing dimension in the wire electric discharge machine 100 according to the first embodiment. FIG. 10 shows the amount of change in the processing dimension relative to the side gap correction value used when a steel material having a thickness of 60 mm is processed by the wire electric discharge machine 100. The amount of change in the processing dimension changes linearly with respect to the side gap correction value. Therefore, the effectiveness by controlling the side surface gap to the side surface gap command value corrected by the side surface gap correction value is shown by the wire electric discharge machine 100.

  That is, according to the wire electric discharge machine 100 according to the first embodiment, the machining dimension can be controlled by changing the side gap in finish machining using the side gap correction value according to the machining direction. As a result, it is possible to obtain an effect that it is possible to suppress the variation of the processing dimension error depending on the processing direction and the processing shape and the material of the workpiece 13. As a result, adjustment of processing conditions becomes easy.

Second Embodiment
The block diagram of the wire electric discharge machine 100 concerning Embodiment 2 of this invention is the same as FIG. 1 except the point by which the process control apparatus 111 is changed into the process control apparatus 112 demonstrated below. In the wire electric discharge machine 100 according to the second embodiment, the target voltage, not the inter-electrode average machining voltage, is corrected. The hardware configuration of the computer numerical control device configured by the processing control device 112 and the data input / output device 120 is the same as that shown in FIG.

  FIG. 11 is a diagram showing a detailed configuration of the processing control device 112 according to the second embodiment of the present invention. In FIG. 11, in order to explain the configuration of the processing control device 112 in detail, other configurations such as the wire electrode 30, the workpiece 13 and the processing power supply 35 are simplified and shown. In the following, the description of the same points as the processing control device 111 according to the first embodiment will be omitted, and different points will be described.

  The side gap controller 47 obtains and outputs a correction value of the target voltage such that the side gap estimated value follows the side gap command value output by the side gap command device 46. A specific example of the correction value of the target voltage is a value obtained by inverting the sign of the correction value of the inter-electrode average machining voltage in the first embodiment. Here, the side gap controller 47 may be a controller having a proportional characteristic as an input / output characteristic using the deviation between the side surface gap command value and the side surface gap estimated value as the input and using the correction value of the target voltage as the output. And may have integral characteristics or differential characteristics like a general servo system. Further, the side gap controller 47 may have non-linear input / output characteristics. The configuration of the side gap controller 47 is not limited as long as the side gap controller 47 outputs a correction value of the target voltage so as to make the side gap estimated value follow the side gap command value.

  The target voltage correction unit 48 corrects the target voltage output from the target voltage storage unit 44 using the correction value of the target voltage obtained from the side surface gap controller 47. The voltage calculation unit 42 calculates a voltage difference between the inter-electrode average machining voltage detected by the inter-electrode average machining voltage detection unit 40 and the corrected target voltage obtained from the target voltage correction unit 48. The target voltage correction unit 48, the side surface gap estimator 45, the side surface gap commander 46, and the side surface gap controller 47 constitute a voltage correction portion that corrects the target voltage.

  FIG. 12 is a block diagram showing a more detailed configuration of the processing control device 112 according to the second embodiment. Also in the following, the description of the same points as the processing control device 111 according to the first embodiment will be omitted, and different points will be described.

  Also in FIG. 12, a part of the function of the side gap controller 47 of FIG. 11 is shown outside the side gap controller 47 as a subtractor 49. The side gap controller 47 obtains and outputs a correction value of the target voltage based on the deviation obtained by the subtractor 49. The side gap controller 47 may have the function of the subtractor 49 as shown in FIG. The target voltage correction unit 48 is an adder, and the correction value of the target voltage output from the side gap controller 47 is added to the target voltage obtained from the target voltage storage unit 44 (not shown in FIG. 12) to make corrections. Output the target voltage. The voltage calculation unit 42 is a subtractor, and calculates the voltage difference between the corrected target voltage and the inter-electrode average processing voltage detected by the inter-electrode average processing voltage detection unit 40 (not shown in FIG. 12) to process the processing speed Input to the control unit 43. The processing speed control unit 43 obtains a processing speed at which the absolute value of the input voltage difference decreases, and supplies the processing speed to the drive control device 20. The drive control device 20 controls the relative distance between the wire electrode 30 and the workpiece 13 so as to achieve the processing speed. Therefore, the voltage correction unit including the target voltage correction unit 48 corrects the target voltage so that the side gap becomes constant regardless of the processing direction. That is, also in the wire electric discharge machine 100 according to the second embodiment, the side surface gap in the case of processing in a certain linear direction and the side gap in the case of processing in another linear direction by changing the angle of the processing direction are the same. It becomes possible to control to become a value.

  According to the wire electric discharge machine 100 of the second embodiment, the same effect as that of the first embodiment can be obtained by correcting the target voltage instead of the inter-electrode average machining voltage.

Third Embodiment
In the first and second embodiments, as shown in FIG. 6, the side gap command value is corrected in the finite number of machining directions based on data of machining dimension errors corresponding to the finite number of machining directions. In some cases, the actual processing direction may be different from the processing direction in which the data of the processing dimension error is obtained. In order to cope with such a case, in the wire electric discharge machine 100 according to the third embodiment of the present invention, the side gap correction value is obtained in an arbitrary processing direction, and the side gap command value is corrected.

  Specifically, the operator inputs data of machining dimension error depending on the machining direction as shown in FIG. 6 obtained from the past machining result to the side gap command device 46 through the data input / output device 120 Do. The side surface gap commander 46 can perform interpolation calculation to obtain a side surface gap correction value of an arbitrary processing direction based on the data of the processing dimension error depending on the given processing direction.

  The following variations can be considered as a method of the side surface gap command device 46 performing interpolation calculation to obtain the side surface gap correction value in an arbitrary processing direction. First, the side gap command device 46 executes interpolation calculation based on the given data of machining dimension errors depending on a finite number of machining directions to obtain data of machining dimension errors in any machining direction, The side gap correction value in any processing direction may be calculated from the data of the processing dimension error. Further, the side gap command device 46 obtains side gap correction values of the finite number of processing directions based on the given data of the processing dimension error depending on the finite number of processing directions, and obtains the side gaps of the finite number of processing directions. Interpolation calculation may be performed on the correction value to calculate the side gap correction value in any processing direction. The method of interpolation calculation may be linear interpolation or curve interpolation between data, and is not limited as long as side gap correction values can be obtained in the continuous processing direction.

  According to the wire electrical discharge machine 100 according to the third embodiment, it is possible to suppress the variation of the processing dimension error depending on the processing direction even in any processing direction other than the processing direction in which the data of the processing dimension error is acquired. The effect of being able to

Fourth Embodiment
In the first to third embodiments, the processing control device 111 or 112 needs to store the processing dimension error or the side gap correction value corresponding to the finite number of processing directions in the memory 202 or the storage device 203. Therefore, in the wire electric discharge machine 100 according to the fourth embodiment of the present invention, it is necessary to store data of machining dimension errors corresponding to a finite number of machining directions by approximating them by a function using a plurality of parameters. Reduce the amount of data. The case where an error with respect to the processing direction is approximated by an ellipse will be described below as an example. Specifically, using four parameters a (> 0), b (> 0), c (> 0), α (−π <α ≦ π), the approximate value e of the processing dimensional error with respect to the processing direction θ θ) is defined as the following equations (1) and (2).

ここで、数式（１）のｘおよびｙは、上記の数式（２）を用いて求められる。

Here, x and y in equation (1) can be obtained using equation (2) above.

  A plurality of parameters for approximation may be calculated by applying the least squares method to data of machining dimension errors respectively corresponding to a finite number of machining directions, or determined by an operator and used as a data input / output device You may input directly via 120. The processing control device 111 or 112 may execute the calculation for approximating with the function using a plurality of parameters using the method of least squares method to the data of the processing dimension error corresponding to the finite number of processing directions. , And may be performed outside the wire electric discharge machine 100. Specifically, the side gap commander 46 which receives the data of the processing dimension error through the data input / output device 120 may perform parameter fitting using a method such as the least squares method to determine a plurality of parameters. Alternatively, the side gap commander 46 may receive a plurality of parameters determined by an external computer via the data input / output device 120.

  The side gap commander 46 obtains a side gap correction value corresponding to the processing direction θ based on the plurality of determined parameters and the processing dimension error with respect to the processing direction θ such as the above e (θ) obtained by the approximation function. And correct the side gap command value. The side gap correction value may be calculated based on a plurality of parameters and the approximation value of the machining dimension error obtained from the function to be approximated, so that the machining dimension error becomes a constant value regardless of the machining direction. The machining dimensional error may be set to 0 using a value obtained by inverting the sign of θ).

  According to the wire electric discharge machine 100 of the fourth embodiment, the same effect as that of the third embodiment can be obtained, and the number of plural parameters for approximation can be calculated as the data of the processing dimension error corresponding to the processing direction. If the number is smaller than the number, an effect of saving a storage area for storing in the memory 202 or the storage device 203 can be obtained.

  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. Parts can be omitted or changed.

  1 upper die, 2 lower die, 3 wire bobbin, 4 feed roller, 5 lower roller, 6 recovery roller, 7 X axis drive, 8 Y axis drive, 9 table, 13 workpieces, 20 drive controller, 30 Wire electrode, 31 upper power supply, 32 lower power supply, 33 upper pressing block, 34 lower pressing block, 35 processing power, 40 inter-electrode average processing voltage detection unit, 41 inter-electrode average processing voltage correction unit, 42 voltage calculation unit, 43 machining speed control unit, 44 target voltage storage unit, 45 side gap estimator, 46 side gap commander, 47 side gap controller, 48 target voltage correction unit, 49 subtractor, 50 points, 51 distance, 100 wire electrical discharge machining , 111, 112 processing control device, 120 data input / output device, 201 CPU, 202 memory, 203 Storage device, 204 display device, 205 input device.

Claims (7)

A wire electric discharge machine which generates an electric discharge between a workpiece and a wire electrode to machine the workpiece.
A drive control device for controlling a relative distance between the wire electrode and the workpiece;
An inter-electrode average processing voltage detection unit that detects an inter-electrode average processing voltage between the wire electrode and the workpiece;
A processing speed control unit that controls the drive control device based on the inter-electrode average processing voltage and a predetermined target voltage;
Based on the processing information during processing and the processing direction, the average processing voltage between the electrodes or the target voltage is set so that the side gap between the wire electrode and the workpiece is constant regardless of the processing direction. A voltage correction unit that corrects either
A wire electric discharge machine characterized by comprising: The voltage correction unit is
A side gap estimator that calculates an estimated value of the side gap based on the processing information;
A side gap commander for obtaining a side gap command value corresponding to the processing direction,
A side gap controller for obtaining a correction value so that the estimated value follows the side gap command value;
Have
The processing speed control unit controls the drive control device such that a processing speed at which an absolute value of a voltage difference between the inter-electrode average processing voltage corrected by the correction value and a predetermined target voltage decreases. Alternatively, the drive control device is controlled such that a processing speed at which an absolute value of a voltage difference between the target voltage corrected by the correction value and the inter-electrode average processing voltage decreases is obtained. Wire electric discharge machine as described. The side gap commander obtains the side gap command value corresponding to the processing direction by correcting the side gap command value before correction with the side gap correction value based on the data of the processing dimension error depending on the processing direction. The wire electric discharge machine according to claim 2, characterized in that. The wire electric discharge machine according to claim 3, wherein the side surface gap commander performs interpolation calculation on data of the processing dimension error to obtain the side surface gap correction value. The side gap commander approximates the data of the processing dimension error with a function using a plurality of parameters, and the side gap correction is performed based on the plurality of parameters and the approximation value of the processing dimension error obtained from the function. The wire electric discharge machine according to claim 3, wherein the value is determined. The wire processing machine according to any one of claims 1 to 5, wherein the machining information is the inter-electrode average machining voltage and the machining speed. Wire discharge of a wire electric discharge machine having a drive control device for controlling a relative distance between a wire electrode and a workpiece and generating electric discharge between the workpiece and the wire electrode to machine the workpiece Processing method,
Detecting an inter-electrode average machining voltage between the wire electrode and the workpiece;
Controlling the drive control device based on the inter-electrode average machining voltage and a predetermined target voltage;
Based on the processing information during processing and the processing direction, the average processing voltage between the electrodes or the target voltage is set so that the side gap between the wire electrode and the workpiece is constant regardless of the processing direction. Correcting any of the
A wire electric discharge machining method comprising:

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