JPS61297028A - Wire electric discharge machine - Google Patents

Abstract

PURPOSE:To reduce useless consumption of wire electrode by automatically controlling the feeding speed of wire electrode when resetting the wire electrode having recovered starting position to the original disconnecting position while passing through the gap of machined locus. CONSTITUTION:When executing cutting through wire electrode, the wire electrode is recovered at the starting position of machining and reset to the disconnecting position. Here, a program previously inputted through HC tape 27 into NC unit 26 will function to provide a signal to a current control circuit 25. The feeding speed of wire electrode under normal cutting is neglected to flow micro current through a wire electrode hoist motor 4. Consequently, useless consumption of wire electrode under non-machining condition can be prevented resulting in efficient usage of expensive wire electrode.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a wire electrical discharge machining device that, when a wire electrode is broken, returns the wire electrode repaired at the machining start position to the original broken position. This is related to controlling the feeding speed of the wire electrode during the process.

[Conventional technology]

FIG. 2 is a schematic configuration diagram showing a conventional wire electric discharge machining apparatus. In the figure, 1 is a wire electrode, 2 is a workpiece, and 3
is the machining start position on workpiece 2.

4 is a wire electrode winding motor, 5 is a main tension brake, 6 is a tensioning motor, 7 is a rotation detector, 8 is a collection roller, 9 is a pinch roller, 10 is a lower roller, 11 is a wire electrode supply motor, 12 is a upper roller,
13.14 is a pinch roller, 15, 16.17, 18.
19 is a pulley.

20 is a wire electrode supply bobbin, 21 is a pipe guide clamp, 22 is a pipe guide, and 23 is a collection box.

24 is a disconnection position of the wire electrode 1 on the workpiece 2.

In the wire electric discharge machining apparatus as described above, a pulsed electric discharge is repeatedly generated between the workpiece 2 and the wire electrode 1, and the workpiece 2 is cut by the discharge energy. By the way, since the wire electrode 1 is usually composed of a thin metal wire, the wire electrode 1 is often broken due to an abnormal situation occurring during electrical discharge machining. In such a case, the X-axis and Y-axis table drive motors (not shown) are automatically started, and the wire electrode 1 is automatically repaired at the processing start position 3 on the workpiece 2. . after that,
The repaired wire electrode 1 is returned to the original broken position 24 while passing through the gap in the low machining trajectory of the workpiece 2. In that case, the feed speed of the wire electrode 1 is controlled at the same speed as the speed during cutting. The feeding speed of the wire electrode 1 is determined by controlling the rotational speed of the wire electrode winding motor 4. The rotational speed of the wire electrode winding motor 4 is varied depending on the magnitude of the current flowing through the wire electrode winding motor 4, and the control range can usually be varied manually within a range of 1 to 16 notches. It's like that.

[Problem that the invention seeks to solve]

Since the conventional wire electric discharge machining apparatus described above is configured as described above, when the wire electrode 1 is cut during machining, the wire electrode 1 is moved to the machining start position 3 on the workpiece 2.
When the wire electrode 1 is returned from the machining start position 3 to the original disconnection position 24 after being repaired at , the wire electrode 1 passes through the gap in the low machining trajectory of the workpiece 2. Since the shape to be machined on the workpiece 2 is usually very complex, the distance between the wire breakage position 24 of the wire electrode 1 on the workpiece 2 and the machining start position 23 is long. However, since the feeding speed of the wire electrode 1 during that time is controlled at the same speed as the speed during machining, there is a problem that the wire electrode 1 is wasted.

This invention was made to solve this problem, and automatically controls the feeding speed of the wire electrode when restoring the repaired wire electrode to its original broken position, thereby reducing the waste of the wire electrode. The purpose of the present invention is to provide a wire electrical discharge machining device that can suppress wear and tear.

[Means for solving problems]

The wire electrical discharge machining apparatus according to the present invention is used when the wire electrode is cut during cutting of a workpiece.

To automatically control the feed speed of a wire electrode when repairing the wire electrode at a machining start position and returning the repaired wire electrode to the original broken position through a gap in a low machining trajectory. Accordingly, the feeding speed of the wire electrode is made slower than the speed during cutting.

[Effect]

In the wire electric discharge machining if of this invention, by providing a means for automatically controlling the feed rate of the wire electrode, the feed rate of the wire electrode is automatically controlled in unmanned operation, thereby eliminating wasteful consumption of the wire electrode. can be prevented.

〔Example〕 .

FIG. 1 is a block diagram showing a feed speed control circuit for a wire electrode hoisting motor connected to a wire electrical discharge machining apparatus which is an embodiment of the present invention. In the figure, 4 is a wire electrode winding motor, 25 is a current control circuit, 26 is an NO (numerical control) device, and 27 is an NC tape.

The structure of the wire electric discharge machining apparatus which is an embodiment of the present invention described above is almost the same as the conventional apparatus shown in FIG. Return the broken wire electrode 1 to the original disconnection position 2
4 and continue the electric discharge machining before the wire breakage again using the wire electrode 1, a description of the series of operations will be omitted.

Now, the feeding speed of the wire electrode 1 is determined by the rotational speed of the collection roller 8. The collection roller 8 is connected to the wire electrode winding motor 4, and the rotational speed of the wire electrode winding motor 4 is controlled by a feed speed control circuit for the wire electrode winding motor 4 shown in FIG. Therefore, when the wire electrode 1 is cut, after repairing the wire electrode 1 at the processing start position 3, when returning the repaired wire electrode 1 to the disconnection position 24, the N
The program in the NC device 26 inputted by the C tape 27 operates, a signal is given to the current control circuit 25, the feeding speed of the wire electrode 1 during normal cutting processing is ignored, and a minute current is passed to the wire electrode winding motor 4. Set the above program so that it runs as follows. If the program in the NC device 26 is stored so as to perform the above-described operation, the wire electric discharge machining machine can be operated in an unmanned manner.

Prevents unnecessary wear and tear on the wire electrode 1 when the workpiece 2 is not being subjected to electrical discharge machining, such as when the wire electrode 1 passes through a gap in the machining trajectory and returns to the original disconnection position 24. can do.

Furthermore, after returning the wire electrode 1 to the disconnection position 24, the wire electrode 1 will be fed at the same speed as during electrical discharge machining.
The processing before the wire breakage will be continued using the wire electrode 1 again.

In the above embodiment, when the wire electrode 1 is cut, after the wire electrode 1 is repaired at the processing start position 3, when the repaired wire electrode 1 is returned to the disconnection position 24, the wire Although automatic speed control of the electrode winding motor 4 has been described, there are other cases where feeding of the wire electrode 1 is required in addition to cutting the workpiece 2 (1) For example, end face positioning in setup work, wire electrode This method can be similarly applied to the case of performing the vertical alignment of item 1.

〔Effect of the invention〕

As explained above, the present invention is applicable to a wire electrical discharge machining device in which, when cutting a wire electrode, the wire electrode, which has been repaired at the machining start position, passes through the gap in the machining trajectory and returns to the original broken position. In addition, since it is configured to automatically control the feed speed of the wire electrode, unnecessary consumption of the wire electrode is minimized and expensive wire electrodes can be used efficiently. be.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a feed speed control circuit for a wire electrode hoisting motor used in a wire electrical discharge machining device which is an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram showing a conventional wire electrical discharge machining device. . In the figure, 1... wire electrode, 2... workpiece. 3... Processing start position, 4... Wire electrode winding motor. 5...Main tension brake, 6...Bri tension motor, 7...Rotation detector, 8...Recovery roller. 9.13.14... Pinch roller, 10... Lower roller, 11... Wire electrode supply motor, 12... Upper roller, 15, 16, 17, 18. 19... Pulley. 20... Wire electrode supply bobbin, 21... Pipe guide clamp, 22... Pipe guide, 23... Collection box. 24... Disconnection position, 25... Current control circuit, 26.
...NC device, 27...NO tape. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In a wire electrical discharge machining device that opposes a workpiece through a small gap and cuts the workpiece using electrical discharge energy, when the wire electrode breaks, the wire electrode is moved to the machining start position. The wire electrode is repaired by a wire electrode, and when the repaired wire electrode is returned to the original broken position by passing through a gap in a pre-processed trajectory, the wire electrode is characterized by comprising means for automatically controlling the feeding speed of the wire electrode. Wire electrical discharge machining equipment.