JPS6224946A - Modified processing method with processing machine - Google Patents

Abstract

PURPOSE:To enhance the accuracy of modificational processings by providing practicability to measure the figure of processed parts without requiring demounting of tool from the processing machine and by sending the dislocation of the tool with respect to the processed part of the work. CONSTITUTION:Coordinates over an electrode surface obtained by touching a touch sensor 52 to a plurality of measuring points on an electrode 124 are entered in an attitude amount calculating circuit 62, while the data stored in a CPU 60 as coordinates over the electrode surface to represent correct attitudes are also put in the same circuit 62, which calculates the attitude amount through comparison of these data, the result wherefrom shall be stored in the CPU 60. An attitude modifying circuit 64 drives an attitude control device 42 on the basis of the attitude amount thus obtained, and control shall be conducted so that the current attitude amount will approach the correct one. In such a manner the processing figure is measured removal of the tool from the processing machine, to allow precision sensing of dislocation of the tool with respect to the processed part, and on the basis thereof the accuracy of modificational processings can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of directly measuring the shape of a machined part of a workpiece during processing and correcting the shape based on the measurement results. Such a method is suitably applied in electrical discharge machining, etc., where the shape of the tool/tool is directly transferred to the shape of the machined part.

[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. Of course.

According to electric discharge machining, it is possible to process tough materials and high hardness materials that are difficult to machine into accurate shapes, and the surface can also be made relatively fine. Since it is possible to machine the surface of a shape, 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,
104 is a Y-direction slide table provided on the X-direction slide table 102, and a machining liquid storage tank 106 is fixed on the Y-direction slide table 104. 1-08 is a workbench provided in the tank 106, and a workpiece 110 is fixed on the workbench 10g. 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 tile, 116 is an insulating board, 118
is a chuck, 120 is a rotating head, 122
is an electrode holder, and 124 is an electrode or tool.

The rotary paddle 120 can rotate relative to the chuck 118 around the Z direction. That is, a protrusion 120a facing in the horizontal direction is fixed to the rotating head 120.
On the other hand, 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, two Go 4 screws 11
Senyaaku 118 by operating Fla, 118b
The electrode holder 122 also has adjustment tips 122a and 1 that are brought into contact with the electrode 124 from the X and Y directions.
22b is attached and No. 8l Akasa Seimushi 122PL, 1
2? By making b temperature-sensitive, the inclination of the electrode 124 in the Z direction can be corrected. That is, the adjustment screw 122
By operating a, the electrode 124 is rotated by an appropriate angle around the Y direction, and the -force adjustment screw 122b is operated. This allows the electrode 124 to be rotated by an appropriate angle around the X direction.

During electrical discharge machining, the electrode 124 is connected to the column 112.
is moved downward along the Z direction, and 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.

However, in the conventional electric discharge machine as described above, the posture of the electrode 124 attached to the electrode holder 122 is not necessarily accurate, so after the electrode 124 is attached, the electrode is moved up and down to adjust the electrode surface. Alternatively, a dial gauge is brought into contact with the reference surfaces 124a, 124b formed on the side surfaces of the electrode to measure the inclination of the electrode, and based on the measurement results, the adjusting screws 122a, 122b are operated to adjust the electrode 12.
Rotate around the X direction and around the Y direction in step 4, and then move the work bench in the X or Y direction while bringing the dial gauge supported on the work bench into contact with the electrode surface or reference surface. The rotation of the electrode around the Z direction is measured, and the adjustment screws 118a and 118b are adjusted based on the measurement results.
is operated to rotate the electrode 124 around the Z direction, thereby adjusting the desired electrode posture.

On the other hand, in electrical discharge machining, one electrode is used to
Only one shape can be processed. Therefore, when performing complicated machining, a plurality of electrodes are required, and electrodes are replaced in the electric discharge machine. In addition, in electrical 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. Electrodes are replaced in the processing machine.

Depending on the type of workpiece, it may take up to 100 hours to finish machining.
More than one electrode may be used.

Therefore, in conventional electrical discharge machining, each time an electrode is attached to an electrical discharge machine, the attitude of the electrode is manually measured as shown in L, and based on this, the attitude of the electrode is adjusted within the desired tolerance range. Things are being done.

For this reason, the setup process required for electrical discharge machining takes a long time.
No improvement in work efficiency can be expected.

For this reason, 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 Conventionally, the feed dimension of the tool during machining is often set graphically depending on the tool and the machining section, so if machining is performed in the same position, sufficient machining accuracy cannot be obtained.

In addition, in electrical discharge machining, a machined part with a shape corresponding to the electrode shape is formed as described above, but in reality, the machining time elapses due to the heat generated from the motor in the processing machine and the heat generated by electric discharge. At the same time, a shift occurs in the relative position between the workpiece and the electrode, which causes the shape of the machined part (in the present invention, this term is used to include the position of the machined part with respect to a reference point or surface of the workpiece). changes. That is,
When attaching an electrode to a processing machine, even if the posture remains unchanged, the shape of the machined part formed will not always be the same, and when high processing accuracy is required, such minute changes in shape should be avoided. In order to make corrections, the shape of the machined part is measured after a certain amount of processing, and based on the measurement results, correction processing is sometimes performed by removing a small amount by precision feeding in order to finally achieve the desired shape.

However, to measure the shape of the machined part for such correction machining, a measuring ball is attached to the electrode holder instead of the conventional electrode.
This was carried out by bringing the measuring ball into contact with the processed part.

However, in such conventional measurement methods, it is necessary to repeatedly attach and detach the electrodes and the measurement bulb each time a measurement is made, making the setup complicated and causing the above-mentioned attachment and detachment errors each time the electrodes are attached. However, if machining is performed as is, high precision machining cannot be expected, and in order to achieve high precision machining, it is necessary to perform the posture control as described above each time the electrode is attached.

For this reason, it has conventionally been thought that it is virtually impossible to automatically perform mass production machining with high precision in electrical discharge machining.

The above-mentioned problems may exist not only in electrical discharge machining, but also in general machining machines that change tools.

[Means for Solving the Problems] According to the present invention, as a solution to the problems of the prior art as described above, the relative position with respect to a tool can be detected, and the mounting means for the tool is A correction machining method for a machining machine is provided, which is characterized in that the shape of a machining part is measured using a measuring stylus attached to the machining machine by a separate attachment means.

[Example] Hereinafter, specific examples of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a specific example of an electric discharge machine used in a cutting system to which the modified machining method of the present invention is applied. In this figure, the same members as in FIG. The description of these items will be omitted.

゛ In the figure, 42 is an attitude control device. 44 is an insulating plate, 46 is an electrode mounting face plate, 48 is a pull stud chuck, and 50 is an electrode holder. Further, 52 is a touch sensor.

The attitude control device 42 has the electrode 124 side (that is, the lower side)
It can be rotated independently around this direction, around the Y direction, and around the Z direction, and this rotation is performed by a command from an appropriate drive circuit (described later).

In addition, in FIG. 1, the column 112 includes support arms 2 and 3.
, 4.5 is provided with a hydraulic cylinder 6.7. piston rod 8 of said hydraulic cylinder 6.7;
9 faces the Z direction.

The upper ends of rod-shaped bodies 12 and 13 are connected to the upper ends of the piston rods 8 and 9 via connecting members 10 and 11. The rod-shaped body 12.13 is oriented in the Z direction and is connected to the supporting arms 2, 3,
Guide members 14, 15, 16.17 attached to 4.5
It can be guided by and reciprocated in the Z direction. A touch sensor 30.
31 and probes 18 and 19 are formed. In addition, a rod-shaped body 12.1 is attached to the guide members 14, 15, 16.17.
Means 20, 21, 22, 23 for locking 3 are provided.

Therefore, by operating the hydraulic cylinder 6.7, the probe 18.19 can be positioned at a desired height in the Z direction.

Note that it is not necessarily necessary to provide two measuring means attached to the column 112 as described above, and depending on the range of the workpiece 110 to be measured, only one measuring means may be provided as long as the slide table has a sufficient stroke.

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, the 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 a drive circuit 56.
These circuits allow movement in the X, Y, and Z directions, respectively. Furthermore, the coordinates of the touch sensor 52 when it touches the shaped surface of the electrode 124 moved in the X, Y, and Z directions can be stored in the CPU 60. Then, a plurality of electrode surface coordinates obtained by bringing the touch sensor 52 into contact with a plurality of measurement points of the electrode 124 are inputted into the posture amount calculation circuit 62, and are further stored in the CPU 60 as the coordinates of the electrode surface in the correct posture. The data stored in
In this case, the attitude amount is calculated by comparing these data, and the result is stored in the CPU. Then, based on this attitude amount, the attitude correction drive circuit 64 controls the attitude control bag.
i! 142 is driven. As a result, the attitude control device is driven to bring the attitude amount closer to the correct attitude.

The drive circuit 56 also includes a hydraulic cylinder 6.7 for driving the probe.
are connected to each other, and the drive circuit 56 drives the rod-shaped body 12 .
13 is moved in the Z direction. Further, the drive circuit 56 inputs the amount of movement of the measuring stylus 18.19 in the Z direction to the CPU 60, which allows the measuring stylus 18.1 to move at a desired time.
9 coordinates can be stored in the CPU 60.

Note that an electrode exchange device 66 is also connected to the CPU 60.

FIG. 3 is a schematic flow sheet showing one embodiment of the above-mentioned Kanji system.

First, the electrode exchange device 66 performs electrode exchange on the electrode holder 50 of the electrical discharge machine (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 attached to the pull-stat chuck, it will be replaced with a new electrode. If not, only a new electrode needs to be installed. At this time, in order to correct the tilted position due to attitude control, an attitude control orientation command signal is sent from the CPU 60 to the attitude correction drive circuit before the first electrode exchange. After orientation, the end signal is received from the attitude control bag and the electrode exchange operation begins.

After a new electrode is installed in the electric discharge machine, control is performed to correct the orientation of the electrode (step 3-2).This electrode orientation control involves measuring the orientation of the installed electrode. After that, it is determined whether the posture is within the desired tolerance range, and if it is not within the desired range, the electrode posture is corrected and the posture is measured again, and this is repeated until the desired accuracy is within the desired range. This is done by holding one's posture.

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). Rather than machining to the final target shape all at once, the shape of the machined part is measured after a certain amount of machining, and the machining target is corrected based on the measurement results before machining. Repeat the machining to obtain a machined part with the desired precision.

Through the above steps, accurate electrical discharge machining regarding the electrode is completed. Subsequently, in order to perform accurate electrical discharge machining using another electrode, steps 3-1 to 3-3 may be repeated.

Next, details of the electrode attitude control step 3-2 will be explained.

The electrode moves parallel to the workpiece during machining, so when measuring the posture of the electrode, the rotation angle around the What is necessary is to find the rotation angle around the rotation angle and the Z direction, that is, the Z rotation.

Therefore, a rectangular electrode 124 as shown in FIG.
In this case, the coordinates of the electrode plane on a plane parallel to the Z-X plane are measured in order to obtain the X-axis. As measurement points, for example, two points (Xl, X2) from the side surface of the electrode or two points (X3, X4) from the bottom surface of the electrode are selected. Similarly, the coordinates of the electrode plane on a plane parallel to the Y-X plane are measured in order to obtain the Y axis. For example, select two measurement points from the side surface of the electrode (yx, y2) or two points from the bottom surface of the electrode (73174). Also, to obtain the Z rotation, select the coordinates of the electrode surface on a plane parallel to the X-Y plane. Measure. For example, the measurement points are 2 on the side of the electrode.
Part (zl.

Select Z2) or (Z3+24).

In the case of a round electrode as shown in Figure 4(b), 2
Since there is no need to take rotation into consideration, it is sufficient to measure the X direction and the Y direction in the same manner as in the case of the square electrode.

Furthermore, in the case of a round axle, as shown in Fig. 4(C), two sets of Z coordinates with different Z coordinates on a plane parallel to the Δ constant point w1~
It is also possible to select w4 and w5 to w8. and,
? ! From the coordinates of Ill fixed points W1 to W4, their center point W
1, then calculate the coordinates of the center point W2 from the coordinates of the measurement points W5 to W8, calculate the direction of the line connecting w, and w2, and calculate the X Taore and Y Taore from this. be able to.

The electrode coordinate measurement as described above can be performed, for example, as follows.

First, the coordinate system is set so that the origin is located inside the tool shape section. In FIG. 4(a), when measuring the X-proportion, the measurement point X1. For X2, a position 2txt'' separated from the measurement point by an appropriate distance in the X direction,
The touch sensor 52 is positioned at ', and these are used as starting points for coordinate measurement of the measurement point. In addition, measurement point X 3
*For X4, the touch sensor 52 is positioned at positions x3' and x4' separated by an appropriate distance from the measurement point in the Z direction, and these are used as starting points for coordinate measurement of the measurement point.

These starting points are set by prior teaching according to the type of electrode. That is, before starting the electrode posture measurement for actual machining, the measurement starting point for the electrode is stored as data in the CPU 60. For example, the X-direction slide table 102, the Y-direction slide table 104, and Operate the Z-direction slide means 54 to position the touch sensors 52 at the respective starting points, and move the touch sensors 52 at that time.
There is a method of storing the coordinates of in the CPU 60. Furthermore, the fourth
In the case of a round electrode as shown in Figure (b), the measurement point
Instead of setting the measurement start point by manual teaching for l#X4 and all of y1 to y4, for example, the measurement point x1.

Only the measurement start point for X 2 + x3 is taught manually, and the measurement start points for other measurement points x+, yt to y4 are automatically taught from the coordinates of the three measurement start points set above based on the axial symmetry of the electrode. It can also be set.

Such automatic setting can be easily performed by incorporating a program into the CPU 60 in advance. Furthermore, instead of performing such manual teaching,
The data of the starting point coordinates may be directly input to the CPU 60 and stored.

The above description has been made regarding the measurement of X-proportion, but the same applies to the measurement of Y-shape and Z-rotation.

Incidentally, in the case of measurement as shown in FIG. 4(C), for example, the measurement point W1. Manually teach only the measurement start point for W21WS, and teach other measurement points "3 * "4,
The measurement starting points for W6 to W8 can also be automatically set in the same manner as in the case of FIG. 4(b).

If the measurement starting point is set to the north, ``When measuring the electrode coordinates, it is sufficient to move the touch sensor 52 in the predetermined direction in the direction in which the absolute value of the coordinates becomes smaller. Movement control is facilitated, and the movement of the touch sensor between each measurement point is carried out without colliding with the electrode 124, for example along the x, Y or Z direction.

A flow sheet of the attitude control process as described above is shown in FIG. Then, the coordinate measurements of the second and subsequent measurement points are performed, and the coordinate measurements regarding the X-direction orientation are completed, and then the coordinate measurements regarding the Y-direction orientation and Z rotation are 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), and if the difference is within the tolerance value, Next, the process moves on to the processing process.

On the other hand, if it is outside the allowable value, the posture control device 42 is driven to rotate the electrode 124 at an appropriate angle around the X direction, Y direction and/or Z direction (step 5-4), and then Then return to step 5-1.

Next, details of processing step 3-3 corresponding to the correction 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. Figure 6(a), (
b) is a diagram for explaining the method for calculating the electrode feed dimension.The results of the electrode coordinate measurement performed after the posture correction is completed in the above posture control step 3-2 are used to calculate the electrode feed dimension. That is, after measuring the electrode coordinates, the posture amount is calculated based on the measured value, and if 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 lOa.

In FIG. 6(a), a specific example of calculating the feed dimension regarding the tapered electrode 124 will be described.

First, measurement point X1. Angle 0 is calculated from the difference in the X coordinate of X2 and the difference in the X coordinate. Then, the X coordinate of point P is calculated from the angle θ, the X coordinate of measurement point x2, and the X coordinate of measurement point x3. The Y coordinate of point P is the measurement point Xl, X2, X3
is the same as the Y coordinate of point P, and the X coordinate of point P is the same as the X coordinate of measurement point x3.
Same as coordinates.

This allows the coordinates of point P to be determined.

On the other hand, the coordinates of the point Q on the workpiece 110 with respect to the touch sensor 52 are measured in advance (that is, when the workpiece 110 is fixed to the workbench 108). Then, attach the measuring ball so as to bring the measuring ball into contact with point Q of the workpiece 110.
X-direction slide table 102. Drive the Y-direction slide table 104 and the Z-direction slide means 54, and then drive the measuring ball to contact the touch sensor 52,
The coordinates of the point Q on the workpiece 110 with respect to the touch sensor 52 are determined from the amount of movement at this time. 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. 6(b),
It is also possible to measure the coordinates of these points by contacting them with l, q2° and q3, and calculate the coordinates 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 set based on the designed dimensions.

Therefore, the coordinates of point Q are determined from the coordinates of point P, the coordinates of touch sensor 52, and the relative positional relationship between the touch sensor and point Q. Based on this, the coordinates of point H 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 calculation of the feed size for this processing is performed 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.

Machining is not carried out all at once, but once the discharge is stopped midway, the shape of the machined part is measured, and based on the results, the relative positional relationship between the electrode 124 and the workpiece 110 is corrected as necessary, and then further processing is performed. Apply pressure.

FIG. 7 is a diagram for explaining a method for measuring the shape of such a processed part.

After the discharge is stopped F, without removing the electrode 124, the X-direction slide table and the Y-direction slide table of the electrical discharge machine are driven, and the hydraulic cylinder 6 is operated, thereby moving the probe 18 to the reference point Q' of the workpiece 11O. contact with. In this way, the coordinates of point Q' can be determined from the amount of movement of the X-direction slide table and the Y-direction slide table and the amount of movement of the tracing stylus 18 in the Z direction. The coordinate measurement of this point Q' can also be carried out in the same manner as the coordinate measurement of point Q explained with reference to FIG. 6(b). Further, the coordinates of the point Q can also be measured using the measuring tip 18.

Next, move the slide table in the X direction and the probe 18 further to bring the probe 18 into contact with points a1 to a6 on the surface of the workpiece 110 in sequence, and determine the coordinates of each of these points (the Y coordinate is constant). . The coordinates of points M and N are calculated from the X and Z coordinates of each point thus determined.

On the other hand, the relative positions of points M' and N' on the target final machined surface corresponding to points M and N of the machined part with respect to point Q' are determined by the design dimensions as described above. Therefore, point M'
The coordinates of and N' can be calculated from the coordinates of point Q' and the designed dimensions.

Therefore, the difference ΔM in the X coordinates of points M and M′ and the difference ΔM between points N and N
The difference ΔN in the X coordinate from be able to. If the center deviation is large and (Δ/2) exceeds the allowable value, the amount is stored in the CPU 60.

Although the explanation has been made regarding the plane parallel to the X-Z plane, the shape of the machined part is similarly measured on the plane parallel to the Y-Z plane.

Next, the hydraulic cylinder 6 is operated to move the probe 18 upward in the Z direction. Then, further processing is performed using the electrode 124 that is still attached to the electrode holder 50.
During this machining, if the center deviation of the current machined part shape surface from the target machined surface exceeds an allowable value in the shape measurement, the target value is corrected in a direction to eliminate the center deviation. . This target value can be corrected by, for example, correcting the feed dimensions in the X direction and Y direction set in the calculation of the feed dimension, and thus a new machining target is set.

Note that FIG. 7 shows a case where processing is performed by using a tapered electrode and swinging the electrode around the Z direction. The target can be corrected by moving in the X direction by (Δ/2) and moving in the Y direction by a similarly calculated amount.

In addition, when measuring the shape of the machined part for this correction process,
The measurement start point for each measurement point can be set in association with the measurement start point set in the electrode coordinate measurement. FIG. 8 is a schematic explanatory diagram showing a method of setting a measurement starting point in such measurement of the shape of a machined part. In the figure, Xi' to x6' are measurement starting points set for measurement of measurement points XI-X (l) in the coordinate measurement of the electrode 124. On the other hand, xl to x6'' are measurement starting points set for measurement of measurement points x1 to , is the measurement start point for measuring the shape of the machined part of the workpiece 110, which is set on the opposite side to the measurement start points Xi' to x6'.In electrode coordinate measurement, the touch sensor 52 starts from the measurement start points Xi' to X6'. The probe 18 moves in the direction where the absolute value of the coordinates becomes smaller (that is, toward the electrode 124), but when measuring the shape of the machined part, the probe 18 moves in the opposite direction to the electrode coordinate measurement. What should be noted is that when measuring the shape of the machined part, it is convenient to use a different coordinate system than when measuring the shape of the electrode.In other words, when measuring the shape of the electrode, Although the origin of the coordinate system was set within the shape part of 124,
When measuring the shape of a machined part, the origin of the coordinate system is set within the machined part. This coordinate origin can be easily determined from the set position of the workpiece 110 and the designed shape of the machined part. Conversion between these two types of coordinates is easy because it is a f-row movement. By using such a coordinate system, during measurement, it is sufficient to move the probe 18 from the starting point in the direction in which the absolute value of the coordinates Iil+ increases.

Since the shape measurement of the machined part is performed before the final target machined surface is formed, the measurement starting points x1" to x6" should be set with a reasonable margin (i.e., so that they are inside the measurement point of the workpiece machined part). Set.

By repeating the machining and shape measurement a predetermined number of times, a more accurate machined surface can be obtained.

A detailed flow sheet of the overall configuration of the embodiment including the modified processing method of the present invention as explained above is shown in FIG. It looks like you'll get it.

FIG. 10 shows a flow sheet of another embodiment of the above-mentioned Kanji system.

In this example, if there are eight 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 attitude control for an electrode whose attitude cannot be controlled satisfactorily for some reason.

Furthermore, in this embodiment, when moving to the electrode replacement step due to a posture correction failure, a related electrode pass command is issued.

The related electrode paths will be explained below.

FIG. 11 shows a plurality of workpieces 1 fixed on a workbench 10a.
10 and 111. FIG. Workpiece 110 is processing section A
, B, C, D, and E, and the workpiece 111 has machining parts E and F.
has. These processed parts A to F are each provided with an electrode 124a.
Processed by -124f. 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 machining of machining part A is not performed due to a defective posture correction of the electrode 124a, machining of machining parts B and C cannot be performed subsequently. It is desirable that the electrodes 124b and 124c are also 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. Such a path of related electrodes can be performed by the software of the CPU 60 by attaching a code to each electrode. When machining the workpieces 110, 111 as shown in FIG. 11, each electrode is assigned a code such as the following, for example, and the machining system is controlled by this code.

Electrode code 124
a 110-A-1 124b 110-A-2 124c 11O-A-3 124d 110-D-1 124e 110-E-1 124e 111-E-1 124f 111-F-1 Here, the first of the codes The number indicates the type of workpiece to be processed by the electrode, the next code indicates the type of processing section block, and the last number indicates the processing order of the processing section within the processing section block. The electrode may have two or more codes, as shown in the example with two codes, if two or more locations are to be processed using the same electrode.

Therefore, when, for example, the electrode 124a is passed due to a defective posture correction, 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 attached is the one for which the pass command was given, and if it is the one for which the pass command was given, - Immediately move on to the next electrode in the processing order.

In the above embodiments, the coordinate measurement was explained while ignoring the size of the measuring element and the touch sensor. In reality, the measuring head and touch sensor have different sizes, so
When performing coordinate measurements, it is necessary to perform corrections based on this point, but such correction calculations can be easily performed using conventional methods.

Although the above embodiments have been described with respect to electric discharge machining, the corrective machining method of the present invention can be similarly applied to general machining in which tools or workpieces are replaced other than electric discharge machining.

[Effects of the Invention] According to the corrective machining method of the present invention, since the shape of the machined part is measured without removing the tool from the processing machine, the positional deviation between the tool and the machined part of the workpiece can be detected extremely accurately. Based on this, it is possible to improve the accuracy of correction processing.

Further, according to the corrective machining method of the present invention, it is possible to construct a machining system that automatically exchanges tools and performs a plurality of types of machining continuously and extremely accurately unattended.

[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 shows a 70-sheet sheet of a Canadian stem to which the modified processing method of the present invention is applied. FIGS. 4(a), (b), and (C) are partial side views of the electrode. FIG. 5 is a flow sheet of the attitude control process. FIGS. 6(a) and 6(b) are diagrams for explaining calculation of machining feed size. FIG. 7 is a diagram for explaining the measurement of the shape of the processed part. FIG. 8 is a diagram showing a method of setting a measurement starting point in measuring the shape of a processed part. FIG. 9 and FIG. 1O are flow sheets of the Kanji system including the method for measuring the shape of a machined part according to the present invention. FIG. 11 is a diagram showing a processing section of a workpiece. FIG. 12 is a schematic diagram of a conventional electric discharge machine. 18.19: Measuring element 42: Posture control device 50: Electrode holder 52: Touch sensor 102: X direction slide table 104: Y direction slide table 108: Workbench 110.111: Work 124: Electrode agent Patent attorney Tsuki Yamashita Figure 2 Figure 4 (0) Figure 4 (b) Figure 5 Figure 6 (b) Figure 7 Figure 8 Figure 9 Figure 10 Prisoner

Claims (2)

[Claims] (1) In a method of measuring the shape of the machined part of a workpiece machined by a tool, calculating the deviation between the shape and the final target shape of the workpiece machining, and performing correction machining based on the calculation result, A processing machine characterized in that the shape of a machined part is measured using a measuring element that can detect a relative position and that is attached to the processing machine by a mounting means different from that of the tool. Correction processing method. (2) Only when the amount of deviation between the measured shape of the machined part and the final target shape exceeds a tolerance value, the machining target set value is changed in the machining subsequent to the measurement.
Corrective machining method on the processing machine described in Section 1.