JPS6218290B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire cut electrical processing apparatus, in particular, a wire electrode is stretched through a workpiece along guides provided on both upper and lower sides of the workpiece, and the workpiece and the wire electrode are connected to each other. The present invention relates to a wire cut electrical processing apparatus that processes a wire cut by generating electric discharge or electrolysis between the two while moving the two relatively.

In wire cut electrical current machining, the factors that determine the machining accuracy are the installation accuracy (parallelism) of the workpiece, the perpendicularity of the wire electrode, and the setting position of the wire electrode guide (between the wire electrode guides installed on both the top and bottom of the workpiece). distance) etc. Among these factors, the mounting accuracy of the workpiece can be adjusted relatively easily;
The perpendicularity of the wire electrode is extremely difficult to manually set in micron order due to the fact that the wire is a non-rigid body. This requires the most skill among wire cutting electrical processing, making automation and labor saving difficult. This was a contributing factor.

In particular, if the perpendicularity of the wire electrode is inaccurate, the cut surface of the workpiece 10 becomes an inclined surface with a difference ε between the upper and lower surfaces, as shown in FIG. When the mounting surface is used as a punch, the inclined surface 14 comes into contact with the cutting edge of the die, causing problems such as a reduction in the life of the mold and occurrence of mold cracking.

Therefore, in the conventional wire cutting electrical processing apparatus, a method as shown in FIG. 2 was used to set the verticality of the wire electrode. That is, the workpiece 1
The verticality of the wire electrode 24 to be held and guided is set by the upper guide 20 and the fixed lower guide 22, which have the moving axes 16 and 18 in the same direction as the moving axes (X and Y axes) of 0. For this purpose, contact detectors 26 and 28 are provided on a workpiece mounting table (not shown). In this case, the verticality of the wire electrode can be maintained with high precision by making the correlation distance D between the contact detectors 26 and 28 as large as possible.

The verticality of the wire electrode was set as follows. First, the workpiece mounting table is moved in the +X-axis direction along the movement axis 16,
The wire is fed until the wire electrode 24 contacts one of the contact detectors 26 and 28. Here, if the contact detector 26 is contacted first, the wire electrode 2
4 is tilted in the +X-axis direction, so first return the workpiece mounting table to the -X-axis direction,
After breaking the contact between the wire electrode 24 and the contact detector 26, the upper guide 20 is moved along the moving axis 16.
Feed the workpiece by several microns in the X-axis direction, and then feed the workpiece mounting table again in the +X-axis direction. Thereafter, the above operation is repeated until the wire electrodes 24 come into contact with the contact detectors 26 and 28 at the same time on the order of several microns.

This series of operations sets the perpendicularity of the wire electrode 24, but since it is necessary to set the position with extremely high precision on the order of microns, the operator requires skill and it takes a lot of time. This has been a major hindrance to automating and saving labor in wire cutting electrical processing.

The present invention has been made in view of the above-mentioned conventional problems, and its object is to provide a wire cut electrical processing apparatus that can automatically set the verticality of a wire electrode with high precision.

In order to achieve the above object, the present invention provides a wire electrode guide provided on both upper and lower sides of a workpiece mounting table, a wire electrode stretched along the guide, and one or both of the guides. a guide driving means for moving the workpiece in a horizontal direction parallel to the surface of the workpiece mounting table; a control means for moving the workpiece and the wire electrode relative to each other; and a conductive conductor having a circular hole through which the wire electrode passes. a contact detection circuit for detecting contact between the wire electrode and the measurement jig, and a control circuit for supplying a control signal to the guide drive means and the control means, the guide drive means While changing the inclination of the wire electrode, measure the length of the circular hole in a range where the wire electrode does not touch, and position the wire electrode so that the length of the wire electrode is minimized;
It is characterized by automatically setting the verticality of the wire electrode.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings. FIG. 3 is a schematic diagram showing an embodiment of the wire cut electrical processing apparatus of the present invention, in which the same parts as in FIG. 2 are denoted by the same reference numerals. In Figure 3,
The workpiece mounting table 30 is provided with feed nuts (not shown) on its orthogonal sides, and feed screws 32 and 34 are screwed into each of the feed nuts.
Drive forces are transmitted to the feed screw 32 from an X-axis drive motor 36 and from a Y-axis drive motor 38 to the feed screw 34, respectively, to move the workpiece mounting table 30 relative to the wire electrode 24. Upper guide 2
0 is provided with feed nuts (not shown) on its orthogonal sides, and a feed screw 4 is attached to each feed nut.
0,42 are screwed together. And the feed screw 4
0 is driven by an X-axis drive motor 44, the feed screw 42 is driven by a Y-axis drive motor 46, and the upper guide 20
By displacing the position of the wire electrode 24, the inclination of the wire electrode 24 is changed. In the present invention, one measuring jig 48 is used to measure the verticality of the wire electrode 24.
As shown in FIG. 4, the measuring jig 48 has a circular hole (hereinafter referred to as a round hole) 50 in the center, and a slit for fitting the wire electrode 24 into the circular hole 50 from the side. 52 are provided. This measuring jig 48 is made of a conductive material, and is directly attached to the workpiece mounting table 30 as shown in FIG.
In addition to placing the workpiece 10 directly on a table, the workpiece 10 may be placed on a table. Further, in the present invention, in order to electrically detect contact between the wire electrode 24 and the measurement jig 48, a contact detection circuit 54 is provided.
The contact detection circuit 54 is composed of a power source E, resistors R1, R2, R3, a capacitor C, and an amplifier A. This contact detection circuit 54 is connected to the
Numerical control device 5 that controls the amount of movement in the axis and Y-axis directions
6. This numerical control device 56 is connected to a servo amplifier 58, and the output side of the servo amplifier 58 is connected to the drive motors 36, 38, 44, 46.
It is connected to the.

Note that the contact detection circuit 54 applies a voltage between the workpiece mounting table 30 and the wire electrode 24 from the power source E, and the contact detection circuit 54 applies a voltage between the workpiece mounting table 30 and the wire electrode 24, and
8 makes contact, a current flows from the workpiece mounting table 30 in the path of the measurement jig 48 and the wire electrode 24 (therefore, the workpiece mounting table 30 and the upper and lower guides 20 and 22 are electrically conductive. made of)
This is a device that performs contact detection, and is completely equivalent to a device conventionally used as a contact positioning device or a short circuit detection device in electrical processing equipment.

The embodiment of the present invention has the above configuration, and the procedure for vertically extending the wire electrode 24 will be explained below with reference to the flowchart of FIG. First, at the beginning, it is not known what state the wire electrode 24, which has passed through the workpiece 10 and the measuring jig and is stretched along the upper guide 20 and the lower guide 22, is in state. Therefore, the control signal from the numerical control device 56 is supplied to the X-axis drive motor 36 via the servo amplifier 58 in this state, and the wire electrode 24 moves the workpiece mounting table 30 in the +X-axis direction to the measuring jig 48. Send until it comes into contact with. Subsequently, the wire electrode 24 and the measurement jig 48 are fed in the -X-axis direction until they come into contact with each other, and at this time, the length φ of the round hole 50 in the X-axis direction is adjusted so that the wire electrode 24 does not come into contact with the measuring jig 48.
Measure ₀ .

Then, a control signal is supplied to the X-axis drive motor 44 to displace the upper guide 20 by +△ Measure the length _φ1 . Here, the amount of displacement of the upper guide 20 +△
× is a minute amount that can be compared with the accuracy of the perpendicularity to be set.

Next, the above-measured difference lengths φ ₀ and φ ₁ are compared, and when φ ₀ >φ ₁ , the search direction K is set to −1, and when φ ₀ <φ ₁ , the search direction K is set to K=1. φ ₀ =φ
When it is ₁ , it is determined that the vertical position is already vertical, and the vertical alignment work is completed. When φ ₀ ≠ φ ₁ , φi=φ ₁
Then, the upper guide 20 is further displaced by KΔx, and the length across the round hole 50 in the range where the wire electrode 24 does not come in contact is measured again and is set as φ _i+1 . Here, φi and φi ₊₁ are compared, and if φi= _φi+1 , the wire electrode 24 is considered to be vertical and the work is completed.
If φi>φi ₊₁ , it is considered to be a little too far, and −K△×
The work is completed by displacing the upper guide 20 in the return direction. Also, if φi<φ _i+1 , φi=φ _i+
1 , the upper guide 20 is further displaced by KΔx, and the intersecting length of the round hole 50 in the range where the wire electrode 24 does not come into contact is measured in the same manner as above. In this way, if the above operation is repeated and the work is completed when φi≧φi ₊₁ , the wire electrode 24 becomes perpendicular to the X-axis.

Here, the position of the wire electrode 24 within the round hole 50 may be any position. The wire electrode 24 does not necessarily need to be located at the center of the round hole 50, as long as it is set so that the length across the round hole 50 is maximized within a range where the wire electrode 24 does not come into contact with the wire electrode 24 at this position.

FIG. 6 shows the relationship between the wire electrode 24 and the round hole 50 of the measuring jig 48, which changes according to the operating procedure. When I became
It can be seen that the measured length of the round hole 50 (range where the wire electrode does not contact) is the maximum. That is, φ ₁ <φ ₂ <φ ₃ >φ ₄ .

Therefore, by changing the inclination of the wire little by little according to the procedure described above, measure the length across the round hole 50 in the area where the wire electrode 24 does not come in contact with it, and end the work when the length reaches the maximum. By doing so, the wire electrode 24 can be stretched perpendicularly to the workpiece mounting table 30.

In the above description, the vertical alignment between the X-axis and the axis has been described, but it goes without saying that the verticality in the Y-axis direction can also be set using the same procedure as above.

In the above, it is preferable for the measuring jig 48 to have a certain degree of thickness in terms of accuracy in setting the verticality.
Further, the inner circumferential surface of the round hole 50 needs to be sufficiently polished, and the perpendicularity between the lower surface of the measuring jig 48 and the inner circumferential surface of the round hole 50 needs to be finished with sufficient precision. By measuring the diameter of the round hole 50 in advance and positioning the wire on the center line of the round hole 50 when starting the verticality setting operation in the present invention, it is possible to The measured value of the diameter of the round hole 50 is supposed to be the diameter of the round hole - the diameter of the wire electrode, so if the measured value is more than a certain value away from this calculated value, it means that no tension is being applied to the wire electrode 24. , it is possible to detect the occurrence of some inconvenience, such as damage to the measuring jig 48, and to prevent erroneous operations.

In the embodiment shown in FIG. 3, only the upper guide 20 is configured to be movable in the X-axis and Y-axis directions, but the lower guide or both the upper and lower guides are configured to be movable in the X-axis and Y-axis directions. Also, the same effects as above can be obtained.

As described above, according to the present invention, one conductive measuring jig having a round hole is used, whereas conventionally it was required to position at least two upper and lower contact detectors in an accurate relative positional relationship. With an extremely simple configuration, it is possible to automatically set the perpendicularity of the wire electrode, which requires the most skill and time among the preparatory work in wire cutting electrical processing, and which has been a factor in preventing automation and labor saving. It has become possible to perform this process with high precision, making it extremely effective for wire cutting electrical processing equipment. Furthermore, while the conventional wire cutting electrical processing apparatus shown in FIG. 2 requires two contact detection circuits (connected to contact detectors 26 and 28) to set the perpendicularity of the wire electrode, The wire cut electrical processing apparatus of the present invention having the illustrated configuration requires only one contact detection circuit 54, which has the effect of simplifying the configuration. Furthermore, if a slit is provided in a part of the measuring jig to fit the wire electrode into the round hole from the side as shown in the example shown in the figure, only the measuring jig can be removed once the wire electrode has been drawn out vertically. This has the advantage that machining work can be started immediately.

[Brief explanation of the drawing]

FIG. 1 is a front view of a machining state using an inclined wire electrode, FIG. 2 is a perspective view of a verticality setting mechanism of a wire electrode in a conventional wire cut electric current processing apparatus, and FIG. 3 is a front view of a wire cut electric current processing apparatus of the present invention. Schematic diagram, Figures 4a and 4b are plan and front views of the measuring jig, Figure 5 is a flowchart showing the procedure for setting the verticality of the wire electrode using the Kaiyakatsu electrical processing apparatus of the present invention, and Figure 6 is the wire electrode. FIG. 3 is a front view showing the relationship between the measurement jig and the round hole of the measurement jig. In each figure, the same members are given the same symbols, 10 is the workpiece, 20 is the upper guide, 22 is the lower guide, 24 is the wire electrode, 30 is the workpiece mounting table, 48 is the measurement jig, 54 is a contact detection circuit, 5
6 is a numerical control device, and 58 is a servo amplifier.

Claims (1)

[Claims] 1. A wire electrode guide provided on both the upper and lower sides of the workpiece mounting table, a wire electrode stretched along this guide, and one or both of the guides parallel to the surface of the workpiece mounting table. a guide drive means for moving the workpiece in a horizontal direction; a control means for moving the workpiece and the wire electrode relatively;
A conductivity measuring jig having a circular hole through which the wire electrode passes, a contact detection circuit for detecting contact between the wire electrode and the measuring jig, and supplying a control signal to the guide driving means and control means. and a control circuit that measures the length of the circular hole in a range where the wire electrode does not touch while changing the inclination of the wire electrode by the guide driving means so that the length of the wire electrode is minimized. A wire cutting electrical current processing device characterized in that a wire electrode is positioned at a position and the perpendicularity of the wire electrode is automatically set.