JPH04101726A - Wire electric discharge machining device - Google Patents

Abstract

PURPOSE:To minimize wear of a guide part or the like by making one of two guide parts into a cylindrical shape which rotates, synchronizing with the feed speed of a wire electrode, and forming a V-shaped groove in it to hold the wire electrode. CONSTITUTION:A wire guide 1 consists of an approximately cylindrical rotating guide 2 and a fixing guide 3, and a V-shaped groove 4 is engraved over its Mole periphery in the approximately central position of the cylindrical surface in the rotating guide 2. The fixing guide 3 is arranged, facing the rotating guide 2, and a cylindrical surface 3a of the approximately same radius as the rotating guide 2 is formed on the side which faces the rotating guide 2 of the fixing guide 3. A driving pulley 8 is fixed firmly at the shaft end of a wire feed pulley 7, and a driven pulley 9 fixed firmly on the rotating guide 2 is rotated through a belt 10. It is thus possible to prevent, chips or the like from adhering to the wire guide, reduce the wear to the surface of the guide part, and lengthen the service life of the wire guide remarkably.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wire electrical discharge machining device, and more particularly to a wire electrical discharge machining device equipped with a wire guide that reduces contact friction with a feeding wire electrode and has a long life. .

[Conventional technology]

In general, in a wire electric discharge machining apparatus, in order to improve the machining accuracy of a workpiece, it is important to accurately move the applied wire electrode and to make it travel at a uniform speed. For this reason, various wire feeding mechanisms for stable feeding of the wire electrode are incorporated in the wire electrical discharge machining apparatus.

Among these, the wire guides provided above and below the workpiece play an important role in holding the wire electrode at a predetermined position on the workpiece.

FIGS. 12 and 13 show a conventional wire guide of this type. Wire guide 2 shown in FIG.
1 consists of a single rectangular parallelepiped-shaped guide holder, and a pin-shaped guide portion 21a is formed approximately in the center of the rectangular parallelepiped. And at the center position there is a diameter of 0.2nn.
A circular hole is bored therein so that the wire electrode 23 can be guided (see Japanese Patent Publication No. Sho 62-18348).

Further, FIGS. 13(a) and 13(b) show a wire guide in which the guide holder is composed of two guide parts 24.25, and the opposing surfaces 26 and 26 of the guide parts 24.25 are shown in FIGS.
A V-shaped or semicircular groove 27 is formed in the groove 27 so that the wire electrode 23 can be guided. The opposing surfaces of these two guide parts 24 and 25 are in a state where they are almost in contact during electrical discharge machining, so as to minimize the lateral vibration of the wire electrode. In addition, these two guide parts 24
．． 25 allows a slight gap to be left when the wire electrode 23 is inserted into the guide groove 27;
This facilitates insertion into the guide groove 27 of No. 3.

[Problem to be solved by the invention]

However, in the above-described wire guide, the wire electrode vibrates in an arcuate manner in a constant vibration mode during feeding, so the wire electrode to which this voltage is applied is fed while always being in contact with the surface of the guide hole (groove).

For this reason, the wire guide becomes electrically charged, and cutting debris or the like adheres or welds to the wire guide, thereby blocking the guide hole (groove) and causing the wire to break. Another problem is that the surface of the wire guide wears out quickly. When the surface of the wire guide is worn, the constraint conditions for the wire electrode in the wire guide change, and there is a risk that the processing accuracy of the workpiece will be significantly reduced.

To solve these problems, wire guides made of materials with high insulation properties and excellent wear resistance, such as sapphire, diamond, and ceramics, are generally used.

However, in this case as well, the wire guide itself is expensive, and
Since the wire electrode is moved in contact with the same location for a long period of time, wear of the wire guide surface is unavoidable.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a wire electrical discharge machining device in which a rotating body is incorporated into a part of a wire guide, which eliminates the problems of the above-mentioned conventional technology and enables feeding equal to the feeding speed of the wire electrode. It's about doing.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a wire electrical discharge machining apparatus equipped with a wire guide that guides the feeding of the wire electrode by sandwiching the wire electrode between the two guide parts, at least one of the two guide parts. has a cylindrical shape that rotates in synchronization with the feeding speed of the wire electrode, and the wire electrode has a V formed on the guide component.
It is characterized by being held in place by a shape groove.

[For production]

According to the present invention, at least one of the two guide parts provided in the wire electrical discharge machining apparatus is formed into a cylindrical shape that rotates in synchronization with the feeding speed of the wire electrode, and a part of the guide part has a V-shape. Since a groove is formed and the wire electrode to be fed is held in this V-shaped groove, charging of the guide component due to contact with the wire electrode can be suppressed, and the wire electrode can be fed in a stable state. This reduces the frictional resistance with the guide parts and minimizes wear of the guide parts.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a wire guide for a wire electrical discharge machining apparatus according to the present invention will be described below with reference to FIGS. 1 to 3.

In FIG. 1, reference numeral 1 indicates a wire guide, and this wire guide 1 is composed of a substantially cylindrical rotating guide 2 and a fixed guide 3. As shown in FIG.

A 7-shaped groove 4 is cut approximately at the center of the cylindrical surface of the rotation guide 2 over the entire circumference. The dimensions of this 7-shaped groove 4 must be such that the wire electrode 5 does not oscillate laterally within the groove, and the depth of the groove depends on the diameter of the wire electrode 5 used, but is approximately 0.3 fin. It is preferable to finish it.

On the other hand, the fixed guide 3 is fixed to a part of the main body of the processing apparatus so as to face the rotary guide 2. A cylindrical surface 3a having a radius substantially equal to that of the rotation guide 2 is formed on a surface 6 of the fixed guide 3 facing the rotation guide 2. In addition, the rotating guide 2 and the fixed guide 3 are
As shown in the figure, they are arranged slightly apart from each other, and the amount of separation is set to such an extent that the wire electrode 5 held in the 7-shaped groove 4 does not come off from the wire guide 1 due to lateral vibration during feeding. has been done.

Next, an example of a device for rotating this rotation guide 2 at a predetermined rotation speed will be described.

The wire electrode 5 shown in FIGS. 4 and 5 after processing the workpiece is
As shown in the figure, the wire is wound around a wire winding bobbin (not shown) via a lower wire feeding pulley 7, and can be recovered. At this time, the wire feed pulley 7 is rotated at a predetermined rotational speed by a drive system (not shown), and a drive pulley 8 that can rotate coaxially is attached to the shaft end of the wire feed pulley 7. It is fixed.

On the other hand, a driven pulley 9 is disposed substantially vertically above the driving pulley 8 and is coaxially fixed to the rotation guide 2 . This driven pulley 9 and the driving pulley 8
A belt 10 is hooked between and rotated, and the driven pulley 9 can be rotated at a predetermined number of rotations by belt transmission.

Further, the rotation speed ratio between the driving pulley 8 and the driven pulley 9 is set so that the wire feeding speed of the wire feeding pulley 7 and the circumferential speed of the rotating guide 2 are equal.

Therefore, the diameter of the drive pulley 8 and the diameter of the driven pulley 9 are determined by the diameters of the rotation guide 2 and the wire feeding pulley 7.

Next, as a modification of the above embodiment, a wire guide in which a V-shaped groove is formed on the fixed guide side will be described with reference to FIGS. 6 to 8.

In FIG. 6, reference numeral 3 indicates a fixed guide in which a V-shaped groove 4 is formed, and this V-shaped groove 4 is located approximately at the center of the cylindrical surface 3a of the fixed guide 3, as shown in FIGS. 7 and 8. It is formed in an arc shape at the position. At this time, the cylindrical rotating guide 2 is rotating in synchronization with the feeding speed of the wire electrode 5, and the V-shaped groove 4 of the fixed guide 3 is rotating in synchronization with the feeding speed of the wire electrode 5.
serves to hold the wire electrode 5 so that it does not move laterally.

Further, in order to prevent the wire electrode 5 from coming into contact with the rotation guide 2 at only one point on the circumferential surface thereof, it is preferable that the rotation guide 2 is translated and reciprocated with a small amplitude in the direction of the rotation axis. This can prevent the surface of the rotation guide 2 from being locally worn.

Further, as another embodiment, as shown in FIGS. 9 to 11, a rotation guide 11 having the same shape as the rotation guide 2 described above may be provided in place of the fixed guide 3 described above.

In this embodiment, the rotating guide 2 can be rotated in conjunction with the drive system of the wire feed pulley 7, and the other rotating guide 11 can be rotated smoothly by slight contact with the wire electrode 5. It is pivoted on.

It is also possible to drive both rotational guides 2.11 in opposite directions.

At this time, the V-shaped groove 4 for guiding the wire may be formed in either one of the rotary guides 2.11 as in the above embodiment. Also in this case, it is desirable that the rotation guide in which the V-shaped groove 4 is not formed is translated and reciprocated with a small amplitude in the direction of the rotation axis.

According to the wire guide described above, the wear loss of the rotating guide and the fixed guide can be considerably reduced, so instead of expensive sapphire or diamond, ceramics such as alumina or carbide such as tungsten carbide can be used as the material. It is also possible to use metal.

Furthermore, in the above embodiments, the structure was explained using the lower wire guide provided on the lower side of the workpiece as an example, but it is clear that the same shape can be set for the upper wire guide on the upper side of the workpiece. be.

Further, the wire guide can be incorporated into a two-axis UV-axis drive system for tapering the cut surface of a workpiece. In this case, it is necessary to provide a drive system that can control the position so that the rotation axis of the rotation guide always intersects at right angles to the wire electrode 5, which is fed while changing the inclination angle. Thereby, even if the wire electrode 5 is fed at an arbitrary inclination angle, the frictional resistance with the wire guide can always be minimized.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, at least one of the two guide components included in the wire guide is formed into a cylindrical shape that rotates in synchronization with the feeding speed of the wire electrode. By providing a V-shaped groove in the guide component to hold the wire electrode within the wire guide, it is possible to prevent chips and the like from adhering to the wire guide, and to reduce wear on the surface of the guide component. This has the effect of significantly extending the life of the wire guide.

6 and 9 are perspective views showing other embodiments of the wire guide of the wire electric discharge machining apparatus according to the present invention, and FIGS. 7 and 10 are plan views thereof, 8th
Figures 11 and 11 are cross-sectional views of the same, Figures 12 and 13 (
Figures a) and (b) are perspective views showing a conventional wire guide.

1... Wire guide, 2.11... Rotating guide, 3
...Fixed guide, 4...V-shaped groove, 5...Wire electrode.

Claims (1)

[Claims] In a wire electrical discharge machining apparatus equipped with a wire guide that guides the feeding of the wire electrode by sandwiching the wire electrode between two guide parts, at least one of the two guide parts is synchronized with the feeding speed of the wire electrode. A wire electrical discharge machining apparatus characterized in that the wire electrode has a cylindrical shape that rotates at the same time, and the wire electrode is held in a V-shaped groove formed in the guide component.