JPH07136855A - Wire electric discharge machining device - Google Patents

Abstract

PURPOSE:To carry out the dimension measurement before the cutting-out work for a workpiece in the wire electric discharge machining. CONSTITUTION:A workpiece 8 is installed on a working table 4 which is fixedly installed on an X-axis-Y-axis cross table 5 which is shifted by an X-axis driving motor 6 and a Y-axis driving motor 7. The dimension measurement for the workpiece 8 is carried out by using a wire positioning means 11 which is constituted so that a wire electrode 1 is shifted to a measurement position which is previously designated by a measurement instruction position input means 10 through the working passage of a shape working program which is necessary for the wire electric discharge machining by a control means 9, and the wire electrode 1 and the workpiece 8 are brought into contact, and positioning is carried out. Since the dimension measurement is completed before the cutting-out of the workpiece 8, the additional work such as correction work can be executed in this state, and the manhour for the dimension measurement after the cutting- out work can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire electric discharge machine, and more particularly to a wire electric discharge machine which can measure the dimensions of a workpiece.

[0002]

2. Description of the Related Art FIG. 6 is a perspective view showing a schematic structure of a conventional wire electric discharge machine. In FIG. 6, 1 is a wire electrode, 2 is an upper wire guide that supports the wire electrode 1, 3
Is a lower wire guide, 4 is a processing table, 5 is an X-axis-Y
Axis cross table, 6 is an X axis drive motor, 7 is a Y axis drive motor, 8 is a workpiece mounted on the machining table 4, 9 is control means, 12 is CRT display means, and 13 is a keyboard. The control means 9 mainly includes the CPU 9a,
ROM 9b for storing control programs, RAM 9c for storing various data, X-axis drive motor driver 9d, Y
The axis drive motor driver 9e and the interface 9f are included. The control means 9 then drives the driver 9 based on a predetermined shape program for wire electric discharge machining.
The X-axis drive motor 6 and the Y-axis drive motor 7 are driven via d and the driver 9e to move the X-axis-Y-axis cross table 5 in an arbitrary direction.

Next, in order to form a product shape, as an example, the processing conditions and offset values are changed in the same path, and
Wire electric discharge machining and dimension measurement in the case where st machining, 2nd machining, 3rd machining and shape machining are performed three times will be described. As a shape program required for wire electric discharge machining, at least two kinds of programs, a shape machining program and a cut-off machining program, are required. These programs are stored in advance in the ROM 9b in the control means 9.

A procedure in the conventional wire electric discharge machining will be described with reference to the flowchart of FIG. First, in step S301, shape processing is executed. R in the control means 9
The X-axis drive motor 6 and the Y-axis drive motor 7 are driven according to the shape machining program stored in the OM 9b, and the machining table 4 is moved in the X-axis-Y-axis direction. Then, electric discharge is generated between the wire electrode 1 whose upper and lower portions are supported by the wire guides 2 and 3 and the workpiece 8 attached to the machining table 4, and wire electric discharge machining is performed. In the shape processing, the processing conditions and offset values are changed in the same route, and 1st processing, 2nd processing, 3rd processing and 3 times processing are performed. Next, in step S302, cut-off processing is executed. After the shape processing in step S301 is completed, the cut-off processing is performed according to the cut-off processing program stored in the ROM 9b in the control means 9, and the shape of the product 8a is cut off and separated from the workpiece 8. . Then, in step S303, dimension measurement is executed. The cut-off product 8a is measured using a micrometer, a coordinate measuring machine, or the like.

[0005]

As described above, conventionally, the finished dimension of the product 8a is measured by cutting it off from the workpiece 8 and then manually using a micrometer or a three-dimensional measuring machine. Since it is done, it is a separate process from the shape processing and takes time. Also, as a result of the dimension measurement, the product 8
Even when it is determined that the dimension a does not reach the target value, the product 8a has already been cut off from the workpiece 8, and it is not possible to perform additional machining such as correction machining by the wire electric discharge machine. It was impossible.

Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide a wire electric discharge machining apparatus capable of measuring dimensions after finishing the shaping of a workpiece and before cutting off.

[0007]

According to a first aspect of the present invention, there is provided a wire electric discharge machining apparatus, wherein an electric discharge is generated between a wire electrode and a work piece, and the work piece mounted on a machining table is attached to the wire electrode. The wire electrode is moved with respect to the workpiece according to the shape program for wire electric discharge machining, and the workpiece is positioned by bringing the workpiece into contact with the wire electrode. Is to measure the dimensions of.

According to a second aspect of the present invention, in addition to the first aspect, the wire electric discharge machining apparatus further includes the wire electrode for the workpiece to be machined after the wire electric discharge machining according to the shape program and before the cut-off machining. The coordinate value difference between the coordinate value on the machining path of the shape program corresponding to the predetermined measurement position and the coordinate value measured by the dimension measuring means after the completion of the positioning operation by the wire positioning means is calculated. It is a thing.

According to a third aspect of the present invention, in addition to the first and second aspects, the wire electric discharge machining apparatus compares the coordinate value difference with a preset allowable value, and the coordinate value difference is the allowable value. When the value exceeds the value, the electric discharge machining by the wire electrode is performed again on the workpiece.

[0010]

According to the first aspect of the present invention, the wire electrode is moved with respect to the work piece in accordance with the shape program for wire electric discharge machining of the work piece, so that the wire electrode is not subjected to the shape work when the dimension of the work piece is measured. It can enter the narrow slit-shaped part without touching. Therefore, the size of the workpiece (product) can be measured before cutting off.

According to the wire electric discharge machining apparatus of claim 2, in addition to the operation of claim 1, the wire electrode is preliminarily designated on the workpiece after the wire electric discharge machining and before the cut-off machining. Are moved according to the shape program. The coordinate value difference is calculated from the coordinate value on the machining path of the shape program at the measurement position and the coordinate value measured by contacting the workpiece, and the required dimension of the workpiece (product) is measured before cutting off. To be done.

According to the wire electric discharge machining apparatus of claim 3, in addition to the functions of claims 1 and 2, the calculated coordinate value difference is compared with a preset allowable value and is larger than the allowable value. At times, the workpiece (product) is again subjected to wire electric discharge machining. That is, the workpiece (product) is subjected to correction processing before cutting off.

[0013]

EXAMPLES The present invention will be described below based on specific examples. FIG. 1 is a perspective view showing a schematic configuration of a wire electric discharge machine according to an embodiment of the present invention. In the figure, the same reference numerals and symbols as those of the conventional example show the same or corresponding components as those of the conventional example. In FIG. 1, 1 is a wire electrode, 2 is an upper wire guide that supports the wire electrode 1, 3 is a lower wire guide, 4 is a working table, and 5 is X.
Axis-Y axis cross table, 6 and 7 are an X-axis drive motor and a Y-axis drive motor that move the X-axis-Y-axis cross table 5 in an arbitrary direction, 8 is a workpiece mounted on the processing table 4, Reference numeral 9 is a control means, 10 is a measurement command position input means for designating a measurement location, and 11 is a wire positioning means. Further, 12 is a CRT display means, and 13 is a keyboard. The control means 9 is mainly composed of a CPU 9a, a ROM 9b for storing a control program, a RAM 9c for storing various data, an X-axis drive motor 6 driver 9d, a Y-axis drive motor 7 driver 9e, an interface 9f and the like.

FIG. 4 is an enlarged inclination view showing an example of dimension measurement in the wire electric discharge machining apparatus of this embodiment. The designation of the measurement point is to designate the dimension measurement position in advance before starting the processing. As shown in FIG. 4, when it is desired to perform wire positioning with respect to the workpiece 8 so that the coordinate value of the wire electrode 1 in the Y-axis direction becomes Y1, the measurement command position input means 10 for designating a measurement location. At Y =
It may be specified as Y1.

The wire positioning means 11 is a wire electrode 1.
The X-axis drive motor 6 and the Y-axis drive motor 7 are driven from the state where the workpiece 8 and the workpiece 8 are not in contact with each other, and the machining table 4 is automatically moved to a position where the gap between the wire electrode 1 and the workpiece 8 becomes zero.
Is moved, and when it reaches that position, it is temporarily stopped and the coordinate value of each axis is read and stored by the control means 9. Then, after that, the X-axis drive motor 6 and the Y-axis drive motor 7 are driven again, and the machining table 4 is automatically moved to the first position where the wire electrode 1 and the workpiece 8 were in the non-contact state. is there.

Next, the control in the apparatus of this embodiment will be described with reference to the flow chart of the wire electric discharge machining control of FIG. 2 and the flow chart of the dimension measurement processing of FIG. << Wire EDM Control: See FIG. 2 >> Step S1 in FIG.
In 01, the measurement command position input means 10 for designating the measurement location designates the measurement location in advance before the start of the shape machining. Next, in step S102, the X-axis drive motor 6 and the Y-axis drive motor 7 are driven according to the shape machining program stored in the ROM 9b in the control means 9.
Is driven to move the machining table 4 in the X-axis and Y-axis directions. Then, electric discharge is generated between the wire electrode 1 whose upper and lower portions are supported by the wire guides 2 and 3 and the workpiece 8 mounted on the machining table 4, and wire electric discharge machining is performed. The shape processing is performed three times by changing the processing conditions and offset values in the same route, 1st processing, 2nd processing, 3rd processing.

Next, in step S103, the dimensions of the product 8a integral with the workpiece 8 are measured at this point. After finishing the shape processing, the ROM 9 in the control means 9
After the wire electrode 1 reaches the measurement position according to the shape machining program stored in b, the wire electrode 1 and the workpiece 8 are brought into contact with each other by the wire positioning means 11 to position them, and the dimension of the product 8a is measured. To do. Then, the process proceeds to step S104, and as will be described later, when the measured dimension value is within the allowable value, the ROM 9 in the control means 9
According to the cut-off processing program stored in b, the cut-off processing is performed, and the shape of the product 8a is cut off and separated from the workpiece 8.

<< Dimension Measurement Processing: See FIG. 3 >> Details of step S103 in FIG. 2 will be described with reference to the flowchart in FIG. In step S201, the ROM 9 in the control means 9
The X-axis drive motor 6 and the Y-axis drive motor 7 are driven in accordance with the shape machining program stored in b.
The processing table 4 mounted on the axis cross table 5 is moved. At this time, in order to move the wire electrode 1 and the workpiece 8 in a non-contact state, for example, the offset value H1 used during the 1st machining is set.

Next, the process proceeds to step S202, and the measurement command position, that is, the position where Y = Y1 is reached, is stopped. Before the positioning operation by the wire positioning means 11 is started, the coordinate value of each axis is once read and the current position X1 is read.
Is stored in the RAM 9c in the control means 9. The processing table 4 is moved in step S203. The movement at this time is a direction in which the wire electrode 1 approaches the product 8a integrated with the workpiece 8 in the direction opposite to the offset direction. In step S204, the wire electrode 1 and the product 8a are in contact with each other (the gap is 0), and the workpiece 8 is stopped with respect to the wire electrode 1 when the position reaches the position where the gap is 0.
Then, the coordinate value of each axis is once read and stored in the RAM 9c in the control means 9 as the current position X2.

Next, in step S205, the machining table 4 is moved to the coordinate position stored in the RAM 9c of the control means 9 before the positioning operation of step S202 is started. In step S206, the machining table 4 is stopped at the coordinate position before the start of the positioning operation in step S202. At this point, the positioning operation by the wire positioning means 11 is completed. Also, | X1-X2 | is calculated from the two stored coordinate values, and the coordinate value difference which is the calculation result is stored and displayed on the CRT display screen. When there is the next measurement command position in step S207, the processing from step S201 to step S207 is repeated. The next coordinate value read as the measurement command position is X
3 and X4. If there is no measurement command position, the X-axis drive motor 6 and the Y-axis drive motor 7 are used until the end of the shape machining program stored in the ROM 9b in the control means 9.
Is driven to move the processing table 4. The dimensions of the product 8a integrated with the workpiece 8 are calculated from the coordinate values stored in the RAM 9c in the control means 9 in step S204,
It is displayed on the CRT display screen.

Next, in step S209, the measurement result and the target value are compared. That is, using the radius D of the wire electrode, K1 = | H1-D |-| X1-X2
|, K2 = | H1-D |-| X3-X4 | is calculated,
K1 and K2 are compared with the allowable value, respectively. K1, K
When either of the two is smaller than the allowable value, the measurement is ended. When both K1 and K2 are larger than the allowable values in step S209, the process proceeds to step S210, and additional machining such as correction machining is executed. Using the same shape processing program as that used for shape processing, the offset value is corrected and additional processing is performed. However, in order to prevent overworking, the smaller correction amount of K1 and K2 is used. After the additional machining, the dimension is measured again, and if either K1 or K2 is within the allowable value, the measurement is finished.

FIG. 5 shows an example of a screen for designating a measurement point. Based on this screen, each measurement position in the machining shape corresponding to the shape machining program and step S209
The allowable value to be used in the comparison of is specified and input in advance. For example, if you want to perform measurement at the position of Y = Y1 in the first shape, enter "1" in the shape item, enter "Y1" in the measurement point Y item, and set any allowable value ""A" is set. Further, on the same screen, the coordinate value difference calculated in step S206 as the measurement result and the step S
The measured dimension of the product 8a in the workpiece 8 calculated in 208 is displayed.

As described above, the wire electric discharge machining apparatus according to the embodiment of the present invention generates the electric discharge between the wire electrode 1 and the work piece 8 to remove the work piece 8 mounted on the machining table 4. By storing the storage means which is the ROM 9b in the control means 9 which stores the shape program for the wire electric discharge machining with the wire electrode 1 and the workpiece 8 with respect to the wire electrode 1, the workpiece 8 with respect to the wire electrode 1 is brought into contact. The wire electrode 1 is moved with respect to the workpiece 8 according to the wire positioning means 11 for positioning and the shape program stored in the storage means, and the dimensions of the workpiece 8 are measured using the wire positioning means 11. The control means 9 is provided with a dimension measuring means composed of a CPU 9a, which can be the embodiment of claim 1. Therefore, the dimensional measurement of the product integrated with the workpiece 8 can be performed without performing the cutting off processing after the shape processing of the workpiece 8.

Further, the wire electrode 1 is moved with respect to the workpiece 8 which has been subjected to the wire electric discharge machining and has not been cut-off, according to the shape program stored in the storage means, so as to correspond to a predetermined measurement position. The CPU in the control means 9 for calculating the coordinate value difference between the coordinate value on the machining path of the shape program and the coordinate value measured by the dimension measuring means after the completion of the positioning operation by the wire positioning means 11.
9a is provided with coordinate value difference calculating means,
This can be the embodiment of claim 2. Therefore, the coordinate value difference between the coordinate value on the machining path of the shape program corresponding to the position and the coordinate value measured after the completion of the positioning operation by the wire positioning means 11 is calculated by simply designating the measurement position in advance, and the coordinate value is calculated. The dimension measurement for the specified position of the product in which the workpiece 8 is wire-discharge machined is completed.

Furthermore, the coordinate value difference calculated by the coordinate value difference calculating means is compared with a preset allowable value, and when the coordinate value difference exceeds the allowable value, the workpiece 8 is processed.
On the other hand, again, it is provided with an additional machining means composed of the CPU 9a in the control means 9 for carrying out the wire electric discharge machining by the wire electrode 1, and this can be the embodiment of claim 3. Therefore, the product in which the workpiece 8 is subjected to the wire electric discharge machining is subjected to additional machining such as correction machining as necessary before the cut-off machining so that the dimensional accuracy at the designated position is guaranteed.

As described above, the workpiece 8 which has been subjected to the electric discharge machining with the wire electrode 1 based on the shape program has a shape corresponding to the designated measurement position in a state where it is mounted on the processing table 4 before the cut-off processing. The coordinate value difference between the coordinate value on the machining path of the program and the coordinate value of the dimensionally measured end surface of the workpiece 8 is calculated. When the difference in the coordinate values exceeds the allowable value, it is possible to perform additional machining by the wire electrode 1 again on the workpiece 8 before the cut-off processing. Therefore, in the product 8a cut off from the workpiece 8 by the wire electric discharge machining by the apparatus of the present embodiment, it is not necessary to perform dimension measurement after this, and the dimension of the designated measurement position is within the predetermined dimension tolerance. Therefore, no additional work is required.

By the way, the storage means of the above-mentioned embodiment generates an electric discharge between the wire electrode 1 and the work piece 8 to wire the work piece 8 mounted on the working table 4 with the wire electrode 1. Although the shape program for electric discharge machining is stored, other programs such as a machining condition program can be added when the present invention is carried out.

The wire positioning means 1 of the above embodiment
1 is for positioning the workpiece 8 with respect to the wire electrode 1 by bringing the workpiece 8 into contact with the wire electrode 1. In the case of practicing the present invention, the wire electrode 1 and the workpiece are It suffices if the relative position of 8 can be determined.

Then, the dimension measuring means of the above-mentioned embodiment uses the shape program stored in the storage means according to the shape program 8
The wire electrode 1 is moved relative to the wire electrode 1, and the dimension of the workpiece 8 is measured by using the wire positioning means 11. In the case of practicing the present invention, the wire electrode 1 and the workpiece 8 are moved relative to each other. The size of the workpiece 8 can be measured by the position.

Furthermore, the coordinate value difference calculating means of the above embodiment is
On the machining path of the shape program corresponding to the pre-specified measurement position, the wire electrode 1 is moved with respect to the workpiece 8 before being cut off after the wire electric discharge machining is performed according to the shape program stored in the storage means. The CPU 9a in the control means 9 calculates the coordinate value difference between the coordinate value of 1 and the coordinate value measured by the dimension measuring means after the wire positioning means 11 completes the positioning operation. Is to calculate the difference in coordinate value between the coordinate value on the machining path of the shape program corresponding to the previously designated measurement position and the coordinate value measured by the dimension measuring means after the completion of the positioning operation by the wire positioning means 11. Good.

[0031]

As described above, in the wire electric discharge machining apparatus according to the first aspect of the present invention, the electric discharge is generated between the wire electrode and the workpiece, and the workpiece mounted on the machining table is treated by the wire electrode. Storage means for storing a shape program for wire electric discharge machining, wire positioning means for positioning the work piece by bringing the work piece into contact with a wire electrode, and a wire for the work piece according to the stored shape program Equipped with a dimension measuring unit that moves the electrode and measures the dimension of the workpiece using the wire positioning unit, and is integrated with the workpiece without cutting off after shape processing of the workpiece. It is possible to measure the dimensions of various products.

In addition to the effect of the first aspect, the wire electric discharge apparatus of the second aspect moves the wire electrode with respect to the workpiece before the cut-off machining after the wire electrical discharge machining is performed according to the stored shape program. Then, the coordinate value difference calculation for calculating the coordinate value difference between the coordinate value on the machining path of the shape program corresponding to the prespecified measurement position and the coordinate value measured by the dimension measuring means after the positioning operation by the wire positioning means is completed. It is equipped with means, and the coordinate value difference between the coordinate value on the machining path of the shape program corresponding to the position and the coordinate value measured after the completion of the positioning operation by the wire positioning means There is an effect that the dimension measurement is completed for the specified position of the product calculated and subjected to wire electric discharge machining of the workpiece.

In addition to the effects of claim 1 and claim 2, the wire electric discharge machining apparatus of claim 3 compares the calculated coordinate value difference with a preset allowable value, and the coordinate value difference is the allowable value. When it exceeds the limit, the work piece is equipped with additional machining means to perform wire electric discharge machining with the wire electrode again. As a result, additional processing such as correction processing is performed to ensure the dimensional accuracy at the designated position.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a wire electric discharge machine according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a wire electric discharge machining control procedure of the wire electric discharge machine according to the embodiment of the present invention.

FIG. 3 is a flowchart showing a dimension measurement processing procedure of the wire electric discharge machining apparatus according to the embodiment of the present invention.

FIG. 4 is an enlarged perspective view showing a dimension measurement situation before cutting off a product of a workpiece in a wire electric discharge machining apparatus according to an embodiment of the present invention.

FIG. 5 is a diagram showing a screen in the dimension measurement of the wire electric discharge machine according to the embodiment of the present invention.

FIG. 6 is a perspective view showing a schematic configuration of a conventional wire electric discharge machine.

FIG. 7 is a flowchart showing a procedure of conventional wire electric discharge machining.

[Explanation of symbols]

 1 Wire Electrode 4 Processing Table 5 X Axis-Y Axis Cross Table 6 X Axis Drive Motor 7 Y Axis Drive Motor 8 Workpiece 9 Control Means 9a CPU 9b ROM 9c RAM 10 Measurement Command Position Input Means 11 Wire Positioning Means

Claims (3)

[Claims] 1. Storage means for generating an electric discharge between a wire electrode and a workpiece, and storing a shape program for wire-discharge machining the workpiece mounted on a machining table with the wire electrode. A wire positioning unit that positions the workpiece by bringing the workpiece into contact with the wire electrode; and moving the wire electrode with respect to the workpiece according to the shape program stored in the storage unit. And a dimension measuring unit that measures the dimension of the workpiece using the wire positioning unit. 2. The wire electrode is moved with respect to the work piece before being cut off after being subjected to wire electric discharge machining according to the shape program stored in the storage means, to a predetermined measurement position. Coordinate value difference calculating means for calculating a coordinate value difference between the coordinate value on the machining path of the corresponding shape program and the coordinate value measured by the dimension measuring means after the positioning operation by the wire positioning means is completed. The wire electric discharge machine according to claim 1, wherein 3. The coordinate value difference calculated by the coordinate value difference calculating means is compared with a preset allowable value, and when the coordinate value difference exceeds the allowable value, the workpiece is processed. And an additional machining means for performing wire electric discharge machining with the wire electrode again.
Alternatively, the wire electric discharge machine according to claim 2.