JPH0440128B2 - - Google Patents

Abstract

PURPOSE:To correctly work a workpiece to a correct form by replacing a tool and calculating the posture of the tool mounted onto a working machine and correcting the posture through the comparison with the correct posture, in an electric-discharge machine. CONSTITUTION:Replacement of electrode 124 by an electrode replacing device 66 is carried out for the electrode holder 50 of an electric-discharge machine. Then, the X and Y-direction slide tables 102 and 104 and Z-direction slide means 54 are shifted by a driving circuit 56, and the coordinate of a touch sensor 52 on the contact with the shaped surface of the electrode 124 is memorized into a CPU 60, and the coordinates of a plurality of electrode surfaces are input into a posture calculation circuit 62. Then, the posture quantity is calculated by the comparison with the correct posture data, and a posture controller 42 is driven by a posture correction driving circuit 64, and control is performed to obtain the posture quantity close to the that with the correct posture. Thus, tool replacement is carried out correctly, and plural kinds of unmanned working can be carried out continuously and with high precision.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a machining method using an electrical discharge machine. [Prior art and its problems] Electrical discharge machining is generally used as one of the precision machining methods. Electrical discharge machining uses a tool as an electrode to generate an arc discharge in a minute gap between the workpiece and the workpiece, thereby removing a small amount of the workpiece surface and machining the workpiece into a shape that corresponds to the shape of the tool. It is something to do. According to electrical discharge machining, it is possible to machine tough materials and highly hard materials that are difficult to machine into accurate shapes, and the surface can also be made relatively fine.Furthermore, as long as electrodes are made, it is possible to machine any shape. Since surfaces can also be machined, electric discharge machining is used, for example, to manufacture molds for press working. A conventional example of an electrical discharge machine used for such electrical discharge machining is shown in FIG. In the figure, 102 is an X-direction slide table, and 104 is the X-direction slide table 10.
2, and a machining liquid storage tank 106 is fixed on the Y-direction slide table 104. 108 is a workbench provided in the tank 106, and a workpiece 110 is fixed on the workbench 108. Note that during machining, a machining fluid such as water or oil is stored in the tank 106. 112 is a column, 114 is a processing head, 116 is an insulating plate, 118 is a chuck, 120
is a rotating head, 122 is an electrode holder, and 124 is an electrode or tool. Rotating head 120 is rotatable relative to chuck 118 about the Z direction. That is, the rotary head 120 has a protrusion 120 facing in the horizontal direction.
a is fixedly installed, and the chuck 118 has a rotation adjustment screw 118a that abuts from both sides in the rotation direction of the protrusion 120a around the Z direction.
118b is attached. Therefore, the rotary head 120 can be rotated relative to the tick 118 by operating the two adjustment screws 118a, 118b. Further, the electrode holder 122 is provided with adjustment screws 122a and 122b that are brought into contact with the electrode 124 from the X direction and the Y direction, and by operating the adjustment screws 122a and 122b, the electrode 124 can be adjusted in the Z direction. It is possible to correct the collapse. That is, by operating the adjustment screw 122a, the electrode 124 is rotated by an appropriate angle around the Y direction, and by operating the adjustment screw 122b, the electrode 124 is rotated by an appropriate angle around the X direction. During electrical discharge machining, the electrode 124 is moved downward along the Z direction with respect to the column 112, and electrical discharge is started at a position where the gap between the electrode 124 and the workpiece 110 becomes minute. Thereafter, discharge is performed while moving the electrode 124 downward little by little,
The discharge is stopped at a predetermined position, and the electrode 124 is moved upward. As a result, a machined surface corresponding to the shape of the lower surface and side surface of the electrode 124 is formed on the workpiece 110. Therefore, in order to perform highly accurate machining on a workpiece by electric discharge machining, it is necessary not only that the shape of the electrode 124 is accurate, but also that the electrode 124 be attached to the electrode holder 122 in an accurate posture. be. However, in the conventional electric discharge machine as described above, the electrode 12 attached to the electrode holder 122
4 is not necessarily accurate, so after attaching the electrode 124, move the electrode up and down and bring the dial gauge into contact with the electrode surface or the reference surfaces 124a and 124b formed on the side surface of the electrode. Measure the inclination of the electrode, and operate the adjustment screws 122a and 122b based on the measurement result to adjust the electrode 1.
24 around the X direction and around the Y direction, and further move the workbench in the X or Y direction while bringing the dial gauge supported on the workbench into contact with the electrode surface or reference surface. Let the Z of the electrode
The rotation around the Z direction is measured, and the adjustment screws 118a, 118b are operated based on the measurement results to rotate the electrode 124 around the Z direction, thereby adjusting the desired electrode posture. There is. On the other hand, in electrical discharge machining, only one shape of a workpiece can be machined with one electrode. For this reason,
When performing complex machining, multiple electrodes are required, and electrodes are replaced in the electrical discharge machine. In addition, in electric discharge machining, even when machining the same shape, in order to maintain good finishing accuracy, machining may be performed first with a rough machining electrode and then with a finish machining electrode, and in this case, electric discharge machining Electrode exchange is performed at the machine. Depending on the type of workpiece, more than 100 electrodes may be used to complete the process. Therefore, in conventional electrical discharge machining, each time the electrode is attached to the electrical discharge machine, the attitude of the electrode is manually measured as described above, and based on this, the attitude of the electrode is adjusted to within the desired tolerance range. is being done. For this reason, there was a problem in that the setup process required for electrical discharge machining took a long time, and it was difficult to expect an improvement in work efficiency. In addition, attempts have been made to automatically exchange electrodes using automatic electrode exchange equipment to reduce the setup process time and manual labor, but current automatic electrode exchange equipment suffers from exchange errors and cannot be used as is. There is a problem in that sufficient machining accuracy cannot be obtained if machining is performed in this posture. For this reason, it has conventionally been thought that it is impossible to automatically perform highly accurate machining in electric discharge machining. [Means for Solving the Problems] According to the present invention, the above objects are provided in a machining method for automatically machining a plurality of machining parts of a workpiece by attaching an additional electrode to an electric discharge machine. (a) At least one of the machining parts is processed for another machining part, and such related machining parts are treated as a common block, and all the machining parts are divided into blocks, (b) Corresponding to each electrode, a code indicating the type of workpiece to be machined by the electrode, the type of machining part block, and the machining order of the machining part within the machining part block is attached, (c) each machining part (d) However, if the attitude control of the electrode is defective in (c) above, (e) For the machining part to be machined from now on, the machining part block type is the same as that of the code and the machining order is stored as passing the machining related to the later code. It is checked based on the memory whether the code passed is the one passed, and if it is passed, electrode replacement, electrode posture control and processing are not performed, and if it is not passed, the code is not passed. A machining method using an electric discharge machine, characterized in that the above (c) and subsequent steps are performed only when
This is achieved by [Example] Hereinafter, specific examples of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an electric discharge machine used in the machining method of the present invention. In this figure, the same members as in FIG. 10 are denoted by the same reference numerals, and explanations thereof will be omitted. In the figure, 42 is an attitude control device. 44
is an insulating plate, 46 is an electrode mounting face plate, and 4
8 is a pull stud chuck, and 50 is an electrode holder. Further, 52 is a touch sensor. The attitude control device 42 rotates the electrode 124 side (i.e., the lower side) around the X direction, around the Y direction, and around the Z direction.
Each direction can be rotated independently, and this rotation is performed by an appropriate drive circuit (described later).
This is done based on instructions from. Further, FIG. 2 is a block diagram showing the configuration of a control system of the electrical discharge machine shown in FIG. 1 above. In the figure, an X-direction slide table 102,
The Y-direction slide table 104 and the electrode Z-direction slide means 54 of the electrical discharge machine main body are connected to the drive circuit 5.
6, and is caused to move in the X direction, Y direction, and Z direction, respectively, by the circuit according to a command from the CPU 60. Here, the measurement ball 201 attached to the processing head and the top of the touch sensor 52 are brought into contact as shown in FIG.
2. Set a coordinate system whose origin is the position of the Y-direction slide table 104 and the Z-direction slide means 54. That is, at this origin position, X in the drive circuit 56,
Clear the Y and Z axis feed counters and count the amount of movement of the machine as a coordinate value using this point as a reference. The following explanation will be based on this coordinate system. The value of the position counter of the drive circuit 56 when the touch sensor 52 contacts the shaped surface of the electrode 124 moved in the X direction, Y direction, and Z direction is
It can be stored in the CPU 60 as Y and Z coordinate values. Then, touch sensor 52 is connected to electrode 1.
A plurality of electrode surface coordinates obtained by contacting a plurality of measurement points of 24 are inputted into the attitude calculation circuit 62, and the data stored in the CPU 60 as the electrode surface coordinates in the correct attitude are also inputted to the above-mentioned data. The data is input to the arithmetic circuit 62, where the attitude amount is calculated by comparing these data, and the result is stored in the CPU. and,
The attitude control device 42 is driven by the attitude correction drive circuit 64 based on this attitude amount. As a result, the attitude control device is driven to bring the attitude amount closer to the correct attitude. Note that an electrode exchange device 66 is also connected to the CPU 60. The electric discharge machining apparatus used in the machining method of the present invention processes a workpiece into a predetermined shape while sequentially replacing a plurality of machining electrodes. The apparatus is equipped with a posture control device that automatically measures the inclination of the electrodes when they are attached to the processing head and then corrects the posture. In order to automatically measure this electrode inclination, it is necessary to select measurement points for each electrode used in processing and to set a measurement start point for electrode measurement as preparatory work. Below, based on FIG. 4, (i) selection of measurement points and (ii) setting of measurement start points will be explained. (i) Selection of measurement point Since the electrode moves parallel to the workpiece during machining, when measuring the orientation of the electrode,
What is necessary is to find the rotation angle around the X direction, ie, the Y rotation, the rotation angle, ie the X rotation, around the Y direction, and the rotation angle, ie, the Z rotation, around the Z direction from the reference posture. (a) Case of square electrode Figure 4a shows a square electrode. In order to obtain the X-axis, coordinates of a plurality of points on the electrode surface intersecting the Z-X plane are measured. As measurement points, for example, two points (x ₁ , x ₂ ) from the side surface of the electrode or two points (x ₃ , x ₄ ) from the bottom surface of the electrode are selected. Similarly, Y
In order to obtain the surface area, the coordinates of a plurality of points on the electrode surface intersecting the Y-Z plane are measured. As measurement points, for example, two points (y ₁ , y ₂ ) from the side surface of the electrode or two points (y ³ , y ₄ ) from the bottom surface of the electrode are selected. Further, in order to obtain the Z rotation, the coordinates of a plurality of points on the electrode surface intersecting the X-Y plane are measured. For example, the measurement points are two locations (z ₁ , z ₂ ) on the side of the electrode.
Or select (z ₃ , z ₄ ). (b) In the case of a round electrode Figure 4b shows a round electrode. In the case of a round electrode, there is no need to take Z rotation into account, so the X and Y rolls can be measured in the same manner as in the case of a square electrode. Furthermore, in the case of a round electrode, two sets of measurement points w with different Z coordinates on a plane parallel to the X-Z plane and a plane parallel to the Y-Z plane, as shown in FIG. ₁ to _w4 and _w5 to _w8 can also be selected. Then, the coordinates of the center point W1 are calculated from the coordinates of the measurement points _w1 to _w4 , and the coordinates of the center point _W1 are calculated from the coordinates of the measurement points _w5 to _w8.
Calculate the coordinates of their center point W ₂ from the coordinates of
The direction of the line connecting W ₁ and W ₂ is determined by calculation, and from this it is possible to determine the X direction and the Y direction. (ii) Setting the measurement start point The measurement opening point is the start point of the feed to bring the touch sensor into contact with each measurement point selected in (i). Set a measurement start point for each measurement point. The electrode coordinate measurement as described above can be performed, for example, as follows. (a) For square electrodes First, set the coordinate system so that the origin is inside the tool shape. In FIG. 4a, when measuring the X direction, for the measurement points x ₁ and x ₂ , positions x ₁ ',
The touch sensor 52 is positioned at x ₂ ', and these points are used as starting points for coordinate measurement of the measurement point. Furthermore, for the measurement points x ₃ and x ₄ , touch sensors 52 are positioned at positions x ₃ ′ and x ₄ ′ that are separated by an appropriate distance from the measurement points in the Z direction, and these are used to measure the coordinates of the measurement points. as the starting point. These starting points are set by teaching in advance according to the type of electrode. That is,
Before starting the electrode posture measurement for actual processing, the measurement start point for the electrode is stored as data in the CPU 60, and the X-direction slide table 102, Y-direction slide table 104, and Z-direction slide means 54 are manually moved. The touch sensors 52 are operated to be positioned at the respective starting points, and the relative positions of the touch sensors 52 and the electrodes at that time are stored in the CPU 60 as coordinate values. (b) In _the case of a round electrode In the case of a round electrode as shown in Fig _{. 4b} , the measurement start point is determined by manual teaching for all measurement _points For example, instead of setting the measurement starting points for measurements x ₁ , x ₂ , x ₃ manually, you can teach only the measurement start points for the other measurement points x ₄ , y ₁
I would like to automatically set the measurement start point for ~ _y4 from the three measurement start point coordinates set above based on the axial symmetry of the electrode. This kind of automatic setting is done in advance.
This can be easily done by incorporating a program into the CPU 60. In addition, in the case of measurement as shown in Fig. 4c, for example, only the measurement start points for measurement points w ₁ , w ₂ , and w ₅ are manually taught, and other measurement points are taught manually.
The measurement starting point for w ₃ , w ₄ , w ₆ to w ₈ is set at the fourth point above.
It may be set automatically in the same manner as in the case of FIG. b. When setting the measurement start point, instead of performing the above-described teaching, the data of the start point coordinates may be directly input to the CPU 60 and stored. The above description has been made regarding the measurement of the X direction, but the same applies to the measurement of the Y direction and the Z rotation. After setting the measurement start point as described above and positioning the touch sensor 52 at the measurement start point for electrode coordinate measurement, the touch sensor 52 may be moved in a predetermined direction in a direction in which the absolute value of the coordinates becomes smaller. In addition, the movement of the touch sensor between each measurement point is, for example,
Alternatively, it is performed so as not to collide with the electrode 124 along the Z direction. (iii) Processing method FIG. 3 shows the flow of the processing method of the present invention. The processing method will be explained based on the figure. First, the electrode holder 50 of the electrical discharge machine is replaced by the electrode replacement device 66 (step 3-1). In this electrode exchange, if the electrode used in the previous machining is attached to the electrode holder 50 of the electric discharge machine, it will be replaced with a new electrode, and if the electrode is glued to the pull stud chuck. If not, only a new electrode needs to be installed. After the new electrode is thus installed in the electrical discharge machine, control is performed to correct the orientation of the electrode (step 3-2). This electrode posture control measures the posture of the attached electrode, then determines whether the posture is within a desired tolerance range, and if it is not within the desired range, corrects the electrode posture. This is done by measuring the posture and repeating this to obtain the posture within the desired accuracy. After the newly attached electrode is in the desired posture, the electric discharge machine is operated to move the electrode close to the workpiece and perform electric discharge machining (step 3-3). In this electric discharge machining, the final target shape is not machined all at once, but after a certain amount of machining, the shape of the machined part is measured by a measuring means, and the machining target is corrected based on the measurement results before machining is performed. This correction process is repeated as necessary to obtain a desired processed part. Through the above steps, accurate electrical discharge machining regarding the electrode is completed. Next, to perform accurate electrical discharge machining using another electrode, follow steps 3-1 to 3-3 above.
You can do this repeatedly. Next, details of the electrode attitude control step 3-2 will be explained. (-1) Electrode posture control process The electrode posture control process includes: ● a measurement process that measures the electrode posture; ● a posture amount calculation process that calculates the amount of towel roll from the difference between the measured value and the correct posture; A comparison process with a reference value to determine whether the inclination is within the allowable value, and a posture correction process to correct the electrode posture to the correct posture if the electrode tilt is outside the allowable value. Each of these processes is automatically performed sequentially by the CPU. be processed. A flow sheet of the attitude control process as described above is shown in FIG. That is, first, the touch sensor 52 is moved to the first measurement starting point, and then the coordinates of the first measurement point are measured, and the coordinates of the second and subsequent measurement points are similarly measured, and the coordinates related to the X-direction towel are measured. The coordinate measurement is completed, and then the coordinate measurement regarding the Y direction orientation and Z rotation is similarly completed (step 5-1). Posture amount calculation is performed based on the coordinates thus measured (step 5-2). Next, the attitude state quantity obtained by the calculation is compared with the correct attitude state quantity which is stored in advance in the CPU 60 as a reference (step 5-3).
If the difference is within the allowable value, the process proceeds to the processing step. On the other hand, if it is outside the allowable value, the attitude control device 4
2 is driven to rotate the electrode 124 at an appropriate angle in the X direction, Y direction and/or Z direction (step 5-4), and then in step 5
Return to -1. (-2) Processing Step Next, details of processing step 3-3, which corresponds to the corrective processing method of the present invention, will be explained. Before proceeding to actual machining, the positional relationship between the electrode and the workpiece is determined, and the electrode feed dimension is calculated. FIGS. 6a and 6b are diagrams for explaining a method of calculating the electrode feed dimension. In the attitude control step 3-2, the results of electrode coordinate measurement are used to calculate the electrode feed dimension. That is, after measuring the electrode coordinates, if the posture amount is calculated based on the measured value and it is found to be within the allowable range when compared with a reference value, the measured value represents the coordinate of the electrode. Therefore, the feed dimension can be calculated from these coordinates and the position coordinates of the workpiece 110 fixed on the workbench 108. Referring to FIG. 6a, a specific example of calculating the feed dimension for the tapered electrode 124 will be described. First, the angle θ is calculated from the difference in the X and Z coordinates of the measurement points x ₁ and x ₂ . Then, from the angle θ, the X coordinate of measurement point x ₂ , and the Z coordinate of measurement point x ₃ , point P is calculated.
Calculate the X coordinate of The Y coordinate of point P is the measurement point x ₁ ,
The Y coordinates of x ₂ and x ₃ are the same, and the Z coordinate of point P is the same as the Z coordinate of measurement point x ₃ . As a result, the coordinates of point P can be determined. On the other hand, the coordinates of the point Q of the workpiece 110 in the coordinate system based on the touch sensor 52 are actually measured in advance (that is, at the time the workpiece 110 is fixed to the workbench 108). This actual measurement is carried out, for example, by attaching a measuring ball to the electrode holder 50,
The X-direction slide table 102, the Y-direction slide table 104, and the Z-direction slide means 54 are moved so that the measuring ball comes into contact with the point Q of the workpiece 110.
is driven, and the coordinates of point Q on the workpiece 110 are determined. Note that the coordinates of point Q may be measured by directly bringing the measuring ball into contact with point Q as described above, but as _shown in FIG _{. 3} , the coordinates of these points can be measured, and the coordinates can be calculated from the coordinates. Further, R is a point on the final target processing surface to be formed on the workpiece, corresponding to the point P of the electrode 124.
The relationship between point Q and point R is determined by design dimensions. Therefore, the coordinates of point P, the touch sensor and point Q
The coordinates of point Q are determined from the relative positional relationship with . Based on this, the coordinates of point R are determined from the relative positional relationship between point Q and point R. From the above, the feed dimensions in the X direction, Y direction, and Z direction for machining feed from point P to point R are calculated. The feed dimensions for this machining are calculated by the CPU.
60. In this manner, after the calculation of the machining feed dimension is completed, the electrode is moved and electrical discharge machining is performed. In this example, if there are n or more cases in which the attitude amount obtained in the attitude amount calculation process for the same electrode is outside the allowable value, no further attitude correction is performed for the electrode, and the electrode Move on to the replacement process. As a result, it is possible to move on to processing using the next electrode without attempting long-term posture control for an electrode whose posture cannot be controlled satisfactorily for some reason. Furthermore, in this embodiment, when moving to the electrode replacement process due to a posture correction failure, a related electrode pass command is issued. The related electrode paths will be explained below. FIG. 9 is a diagram showing a plurality of works 110, 111 fixed on the workbench 108. Work 11
0 has machining parts A, B, C, D, and E, and workpiece 1
11 has processed parts E and F. These processing parts A~
F is processed by electrodes 124a to 124f, respectively. Processing of the processing portion B by the electrode 124b is performed after processing of the processing portion A by the electrode 124a, and processing of the processing portion C by the electrode 124c is performed after processing of the processing portion B by the electrode 124b. Therefore, if the machining part A is not machined due to a defective posture correction of the electrode 124a,
After that, machining of the machining parts B and C cannot be performed. In such a case, it is desirable that the electrodes 124b and 124c that are to be used to process the machining parts B and C are not attached to the electrical discharge machine. Therefore, when the electrodes related to the related machining parts belonging to the same block are passed, the electrodes related to the machining parts belonging to the same block are also passed thereafter. By attaching a code to each electrode, the paths of these related electrodes can be easily accessed by the CPU.
60 software. When machining the workpieces 110, 111 as shown in FIG. 9, the following code is attached to each electrode, and the machining system is controlled by this code. Electrode code 124a 110-A-1 124b 110-A-2 124c 110-A-3 124d 110-D-1 124e 110-E1 124e 111-E-1 124f 111-F-1 Here, the first The number indicates the type of work to be processed by the electrode, the next code indicates the type of the processing section block, and the last number indicates the processing order of the processing sections within the processing section block. As shown in the above-mentioned electrode 124e with two cords, the electrode may have two or more cords if two or more locations are to be processed using the same electrode. Therefore, due to poor posture correction, for example, the electrode 12
When 4a is passed, a command is issued and stored so that the electrodes 124b and 124c having the code A of the same processing section block type will pass from now on. Then, in the electrode replacement step 3-1, before executing the electrode replacement, it is confirmed whether or not the electrode to be newly installed is the one for which the pass command has been given, and if it is the one for which the pass command has been given, it is immediately Move on to the next electrode in the processing order. A detailed flow sheet of the overall configuration of the embodiment as described above is shown in FIG. In the above embodiments, a touch sensor is used as the electrode coordinate measuring means.
Instead, it is also possible to use a method that utilizes electrical continuity or a means that eliminates contact. [Effects of the Invention] According to the present invention as described above, the posture of the tool is corrected after the tool is replaced, and the tool is mounted on the processing machine in an accurate posture, so that the workpiece can be machined into an accurate shape. can. Further, according to the present invention, tools can be automatically exchanged and a plurality of types of machining can be performed continuously and with high precision unmanned. Furthermore, in the present invention, the feed dimension of the tool during machining can be calculated using the tool coordinates measured for posture control, so setup can be performed efficiently and machining can be completed in a short time. can. Furthermore, according to the present invention, since the contact surface of the tool with the workpiece is directly measured and the posture is corrected, the mounting accuracy of the tool on the processing machine can be rough, and therefore, the tool holder of the processing machine and the processing of the tool can be easily adjusted. Since the machine mounting part does not require much precision, costs can be reduced. In addition, according to the invention, corresponding to each electrode,
By attaching a code indicating the type of workpiece to be machined by the electrode, the type of machining part block, and the machining order of the machining part within the machining part block, if a posture control failure occurs, the code can be identified. Based on this, it is possible to immediately pass the subsequent processing of the processing section block, and therefore there is no need to provide an avoidance program for electrodes that should be passed in the event of posture control failure.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an electric discharge machine. FIG. 2 is a block diagram of the control system of the electrical discharge machine. FIG. 3 is a flow sheet of the processing method of the present invention. Figures 4a, b, and c are partial perspective views of the electrodes. FIG. 5 is a flow sheet of the attitude control process. Figure 6a,
b is a diagram for explaining processing feed size calculation. FIG. 7 is a diagram showing the state when setting the coordinate system. FIG. 8 is a flow sheet of the processing method of the present invention. FIG. 9 is a diagram showing a processing section of a workpiece. FIG. 10 is a schematic diagram of a conventional electric discharge machine. 42... Posture control device, 50... Electrode holder, 52... Touch sensor, 102... X direction slide table, 104... Y direction slide table, 108... Work table, 110, 111...
Work, 124...electrode.

Claims (1)

[Scope of Claims] 1. A machining method for automatically machining a plurality of machining parts of a workpiece by attaching an electrode to an electric discharge machine, wherein: (a) at least one of the machining parts is connected to another machining part; (b) Corresponding to each electrode, the workpiece to be machined by the electrode is (c) For each machined part, replace it with an electrode for that process, and check the orientation of this electrode. (d) However, if the attitude control of the electrode is defective in the above (c), the machining of the relevant machining part is stopped and the machining part block type is the same as the machining part block type of the code and the machining is not performed. (e) For a processing part to be processed from now on, the code attached to the electrode used therein is stored as a code that has been passed. If the discharge is confirmed based on the above, and the discharge is passed, electrode replacement, electrode posture control, and processing are not performed, and if the discharge is not passed, the above (c) and subsequent steps are performed only. Processing method using a processing machine.