JPS62157726A - Wire-cut electric discharge machining method - Google Patents

Abstract

PURPOSE:To prevent an unsatisfactory discharge or an impossible discharge due to residual chips and an open wire or unsatisfactory machining accuracy caused by biased dissipation of an electrode by melting a traveling wire electrode while rotating it centering its axis. CONSTITUTION:A wire electrode 1 is extracted from a feed reel 2 and travels at a fixed speed and passes a work 7 while being rotated in the positive direction and negative direction centering its axis by a rotary driving device 9 made of rollers 10 reciprocating in opposite directions to each other after passing a die guide 8. A machining liquid is sprayed through a nozzle 11, the voltage is applied across an electrode 1 and the work 7 serving as both poles, an electric discharge is generated, and the molten portion is scattered as chips. The work 7 is moved by a table 6, and chips scattered at the gap section between the electrode 1 and machining section 12 are exhausted and removed so as to be gradually extracted to a wide space section on the opposite side to the machining side because the electrode 1 is being rotated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a wire-cut electrical discharge machining method for cutting a workpiece into a desired shape while causing electrical discharge between a traveling wire electrode and the workpiece. .

(Prior art and its problems) Generally, in wire-cut electrical discharge machining, while a wire electrode is running at a constant speed, the electric discharge between the wire electrode and the workpiece heats the machined part of the workpiece to a high temperature of several thousand degrees. The cutting process is carried out while the molten material is scattered from the workpiece by the processing fluid and discharged and removed from the processing section. However, in this case,
Most of the fine chips that are separated from the workpiece and scattered by the machining fluid are discharged outside the workpiece, but some of the chips remain in the narrow gap between the wire electrode and the machining part. The chips tend to remain attached to the machined part without being discharged to the outside, and the remaining chips on the machined part may undesirably narrow the gap between the wire electrode and the machined part, causing discharge defects, and even cause damage to both electrodes. There was a problem in that a short circuit occurred between the two, making it impossible to discharge. In addition, the workpiece side is melted and removed by the electric discharge as described above, and the wire electric discharge! ! ii
The side also melts and is consumed, although to a lesser extent than the workpiece side. However, since the wire electrode itself does not rotate, wear and tear on the wire electrode is concentrated on the side facing the machining part, and as a result, one side of the wire electrode, which normally has a circular cross section, is deeply gouged. This caused wire breakage and poor machining accuracy.

(Technical means for solving the problems) In view of the above, the present invention has been made to solve the problems in conventional wire-cut electrical discharge machining. It is characterized in that the wire electrode is fused and cut while being rotated by applying rotation.

(Example) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a wire-cut electric discharge machining apparatus for implementing the present invention. In this figure, 1 is a wire electrode,
The wire is supplied from a supply reel 2 at the top of the device, guided vertically downward by upper and lower guide rollers 3.4, and then wound onto a winding reel 5 at the bottom. The winding reel 5 is driven by a motor (not shown), and the supply reel 2 is driven by a motor (not shown).
This is done via an intermediate drive roller (not shown) provided between the take-up reel 5 and the take-up reel 5. Reference numeral 6 denotes an XY table for processing, which is movable on a horizontal plane in the X-axis and Y-axis directions, and a workpiece 7 is supported on this table 6. 8 is a die guide provided on the rear side of the workpiece 7 with respect to the feeding direction of the wire electrode 1, that is, between the upper guide roller 3 and the workpiece 7; It has a guide hole (number omitted) with a slightly smaller diameter.

Reference numeral 9 denotes a wire electrode rotation drive device provided on the front side of the workpiece 7 with respect to the feeding direction of the wire electrode 1, and as shown in FIG. 2, it is arranged horizontally so as to sandwich the wire electrode 1 from both sides. / consists of a pair of drive rollers 10°10, and this /
By reciprocating the pair of drive rollers 10.10 in opposite directions, the wire electrode l passes through the workpiece 7.
is rotated forward and backward around its axis every rotation or multiple rotations. The wire electrode 1 is rotated by the rotation drive device 9 in a range from the die guide 8 to the front side of the lower guide roller 4.
Reference numeral 11 denotes a machining fluid supply nozzle, which jets machining fluid from the upper part of the workpiece 7 toward the machining section 12, as shown in FIG.

In wire-cut electrical discharge machining using a device having the above configuration, the wire electrode l is unwound from the supply reel 2 and runs at a constant speed, while the die guide 8
When it leaves the workpiece 7, it is rotated by the rotary drive device 9 and passes through the workpiece 7 while rotating about its axis.

Machining fluid is jetted from the nozzle 11 toward the machining section 12, and a voltage is intermittently applied between the wire electrode 1 and the workpiece 7 as polar poles, causing an electric discharge. As a result, the workpiece 12 is melted at a high temperature of several thousand degrees or more, and the melted portion becomes chips and scatters due to impact pressure caused by vaporization of the processing fluid. In addition, workpiece 7
is X so that the wire electrode l moves relatively along the fusion line.
It is moved by the Y table 6. Most of the chips scattered in this way are absorbed by the flowing machining fluid and the running wire electrode l.
However, in the case of the conventional method, the chips scattered in the narrow gap between the wire electrode 1 and the processing section 12 tend to stay in the narrow gap and remain attached to the processing section 12. However, in the present invention, since the wire electrode 1 rotates around its axis, the chips scattered in the narrow gap described above are destroyed by the rotating action of the wire electrode 1.
11 where processing is currently being performed by the wire electrode 1;
Then, it is gradually dragged out to a wide space on the opposite side, and is effectively discharged and removed.

In the electrical discharge machining apparatus shown in FIG. 1 described above, rotation is applied to a part of the wire electrode 1 by twisting it and returning it in the opposite direction using the rotary drive device 9, but in FIG. This figure shows an electric discharge machining apparatus equipped with a rotation drive device 13 for rotating the wire electrode 1 as a whole. Note that this electric discharge machining apparatus is almost the same as the apparatus shown in FIG. 1 except for the rotary drive device 2Z 13, so corresponding members are indicated by the same numbers. That is, the rotation drive device 13 shown in FIG. 3 includes a pedestal 14 that supports the supply reel 2, the upper guide roller 3, the die guide 8, etc., the take-up reel 5, the lower guide roller 4, the intermediate guide roller 15, etc. The frame 16 supporting the axis i
A rotary drive shaft 17 is provided parallel to this axis l, and fixed sprockets 8 and 19 and a frame 14 are supported on the rotary drive shaft 17 in parallel to the axis l.
The sprockets 20 and 21 provided on the wire electrodes 1 and 16 are connected by chains 22 and 23, respectively, and the rotational drive shaft 17 is driven to rotate the frames 14 and 16 about the axis l, respectively.
Similarly, it is made to rotate around the axis l. The wire cut electric discharge machining method using this electric discharge machining apparatus is almost the same as that using the apparatus shown in FIG. 1 described above.

In wire-cut electrical discharge machining using the electrical discharge machining apparatus shown in FIGS. 1 and 3, the wire electrode 1 rotates around its axis during machining. It wears out uniformly along the circumferential direction without deviation, and even if the cross section is, for example, a square, it is removed from the four corners of the cross section, so it wears out substantially uniformly.

In the present invention, since it is sufficient that the wire electrode substantially rotates within the workpiece, for example, only the lower pedestal 16 in FIG. 3 may rotate or rotate;
The wire electrode may be fed in either an up or down direction.

(Operations and Effects of the Invention) According to the method of the present invention, since the wire electrode itself rotates, chips that stay in the narrow gap between the wire electrode and the processing part of the workpiece during processing are removed from the wire electrode. Due to the rotational action, the electrode is successively dragged out into a wide space on the opposite side to the side where processing is currently being performed, and the workpiece is effectively discharged and removed without adhering to the processing area. The gap between the electrode and the wire electrode can be maintained almost constant, so that no discharge failure occurs, and there is no risk of short circuit between the two electrodes. In addition, unlike conventional methods, the wire electrode does not wear out intensively on one side, but wears out evenly around the entire circumference, so there is less risk of wire breakage, extending its life. Even if there is distortion in the wire (for example, when there are variations in cross-sectional size, shape, etc. in the longitudinal direction of the electrode), the effects caused by the distortion (for example, discharge defects) will be reduced. , thereby also improving machining accuracy.

[Brief explanation of drawings]

FIG. 1 is an overall schematic explanatory diagram showing an example of a wire-cut electric discharge machining apparatus for implementing the present invention, and FIG. 2 is a perspective view showing a wire electrode rotation drive device used in the electric discharge machining apparatus of FIG. 1. FIG. 3 is an overall schematic explanatory diagram showing a wire-cut electrical discharge machining apparatus equipped with a rotational drive device having a different configuration from the rotational drive device shown in FIG. 2. DESCRIPTION OF SYMBOLS 1... Wire electrode, 7... Workpiece, 9... Wire electrode rotation drive device, 12... Processing part. Applicant Osaka Fuji Kogyo Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] In a wire-cut electrical discharge machining method in which a workpiece is cut into a desired shape while a wire electrode is running while electric discharge is generated between the wire electrode and the workpiece, the cutting is carried out while rotating the running wire electrode. A wire cut electrical discharge machining method characterized by: