JPS59129630A - Die guide of wire cut electric discharge machine - Google Patents

Abstract

PURPOSE:To reduce the deflection of a wire, by making a die holder of a die guide for guiding a wire electrode up of an insulating material thereby allowing the die guide positioned near a work. CONSTITUTION:The die holder DH of the die guide 24 for guiding the wire electrode 1 is made up of an insulator. As a result, the die guide is not given an electric potential, so that even if the die guide is positioned near a work, an electrolysis current would not flow out via an electro-discharge machining liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a die guide, and more particularly to a die guide for guiding a wire electrode of a wire-cut electrical discharge machine.

A wire-cut electric discharge machine applies a pulse voltage to a gear knob formed between a wire electrode running in the longitudinal direction and the workpiece, generates sparks between the wire electrode and the workpiece, and uses the discharge energy to cut the workpiece little by little. Along with taking the
Based on the command data, the workpiece and the wire electrode are moved relatively to process the workpiece into a desired shape. The wire electrode in such an electric discharge machine is wound around a supply reel, and then the wire electrode is guided by several guide rollers and pulled out to the bottom of the workpiece. The die guide is guided to the lower die guide provided in the lower die guide, passes through this, penetrates the workpiece, and is led out to the upper side of the workpiece. Then, it passes through another upper die guide provided above the workpiece, is further guided by several guide rollers, and then is wound onto a take-up reel. When the wire electrode traveling along such a path penetrates the workpiece, the wire electrode is deflected by the repulsive force caused by the discharge energy. This deflection does not pose much of a problem when machining a straight line, but when machining a curved portion, the dimensional accuracy of the machining deteriorates because the deflected portion protrudes from the machining line. It is known that in order to improve this inconvenience, it is possible to bring the die guides provided above and below the workpiece as close to the workpiece as possible, and to shorten the length of the bent portion of the wire electrode as much as possible. .

By the way, during machining with a wire-cut electrical discharge machine, electrical discharge machining fluid is injected into the electrical discharge machined portion of the workpiece from the tips of the two die guides. However, the die guide consists of a die that guides the wire and a die holder.The die is usually made of diamond or sapphire, but the conventional die holder is made of metal, so when the die guide is brought close to the workpiece as described above, the wire electrode A leakage current flows between the die holder and the workpiece, which are at the same potential. For this reason, there is a drawback that the surface of the workpiece to which the electrical discharge machining fluid is sprayed is corroded by electrolytic corrosion.

The present invention aims to improve these conventional drawbacks, and its purpose is to prevent electrolytic corrosion from occurring on the workpiece surface even if the die guide is brought as close as possible to the workpiece during machining in a wire-cut electrical discharge machine. The purpose of the present invention is to provide a die guide which is free from corrosion caused by corrosion.

Next, one embodiment of the present invention will be described in detail using the drawings.

FIG. 1 is a side view showing a wire-cut electrical discharge machine.

In the figure, reference numeral 5 denotes a column erected on a base 6, which has an inverted letter shape, and a capacitor box 7 for power supply is placed on top of the column. A workpiece mount 22 is disposed on the base 6, and the workpiece mount 22 is two-dimensionally movable on the base 6 by an X-direction drive motor and a Y-direction drive motor. A p-workpiece 2 is mounted on the workpiece mounting base 22 by a clamp 26. 1 is a wire electrode, which runs in the direction of the arrow during electrical discharge machining. 8 is a feed-out reel on which an unused wire electrode is wound; 9 is a brake roller that applies a brake to feed the wire electrode, especially in the pulling direction 9, and applies tension T; the wire electrode is wound; be done. 10 is a roller, 11
12 is a lower roller, 12 is an upper roller, 16 is a roller, and 14 is a feed roller, which are rotated in reverse by a drive motor that drives a wire electrode. A pinch roller 15 is pressed against the feed roller 14 by a spring 16. Note that the wire electrode 1 is sandwiched between a feed roller 14 and a pinch roller 15. 17 is a take-up reel for winding up the used wire electrode. A moving member 1B is arranged at the tip of the column 5. A slider 19 movable in two directions is disposed on the moving member 18, and a machining start drilling member 20 is attached to the slider 19, and a drilling tool 21 is provided at the tip thereof.

24 and 25 are die guides, each of which is a substantially identical imitation, and the wire electrode 1 is passed through the center thereof.

The upper die guide 24 is provided at the tip of the moving member 18, and during processing, it descends as shown by the dotted line and approaches the workpiece 2. On the other hand, the lower die guide 25 is attached to the workpiece mounting base 220.
It is fixed at a position close to the lower surface of the workpiece 2.

Next, to briefly explain the operation of the configuration shown in FIG. 1, the workpiece 2 is attached to the workpiece mounting table 22 with the clamp 23, a machining start hole is drilled in the workpiece 2 with the drilling tool 21, and then the movable member 12 is lowered. and point the upper die guide 24!
from the feed reel 8 to the rollers 9 and 10.
, 11, the wire electrode 1 is fed through the lower die guide 25, passed through the machining start hole of the workpiece 2, passed through the upper die guide 24, the rollers 12, 13, 14, and then wound onto the winding series 17.
sent to.

Next, while energizing the wire electrode 1, the workpiece mounting base 2
2 is two-dimensionally controlled by X-axis and Y-axis motors (not shown). The wire electrode 1 is wound up from the feed-out rule 8,
? 1.1-The electric discharge machining fluid is supplied to the workpiece 2 from the upper die guide 24, an electric discharge is generated between the wire electrode 1 and the workpiece 2, and the workpiece 2 is transferred to the workpiece mounting base 2.
2, it is cut and processed into a desired shape.

FIG. 2 is a cross-sectional view of one embodiment of the present invention, showing the upper die guide 24. FIG. NZ is a nozzle, made of synthetic resin such as plastic, and has an opening PM at the bottom.
The upper part has an inlet LI into which electrical discharge machining fluid is injected, and the inside is hollow.

DH is a die holder, which in this embodiment is made of an insulator such as ceramic, is provided in the hollow part of the nozzle NZ, and is screwed to the upper part of the nozzle NZ. DS is a die and is provided at the tip of the nozzle NZ to restrict the lateral movement of the wire electrode 1, has a circular hole, and is made of a super wear-resistant material such as diamond. Note that the lower die guide 25 is similarly configured.

To explain the operation of this embodiment, the wire electrode 1 moves upward in the die holder DH from the opening of the nozzle NZ through the die DS. On the other hand, the electrical discharge machining fluid is injected from the inlet Li, passes between the hollow part of the nozzle NZ and the die holder DH, and is supplied from the inlet PM of the nozzle NZ toward the workpiece 2 located directly below. This promotes electric discharge between the wire electrode 1 and the workpiece 2. On the other hand, since the die holder DH is made of an insulator, the wire electrode 1-
Since the potential is not applied to the dice holder DH, no voltage is applied between the dice holder DH and the workpiece 2. Therefore, no electrolytic current flows through the electrical discharge machining fluid, and the workpiece 2
The surface will not rust during processing.

FIG. 3 is a sectional view of another embodiment of the present invention, showing the lower die guide 25, but the upper die guide is similarly constructed.

In FIG. 3, NZ is a nozzle made of synthetic resin or the like, DH is a die holder made of a conductor, DS is a die, and Is is an insulating layer provided on the surface of the die DS.

In this embodiment, since the die DS is covered with the insulating layer Is, the potential of the wire electrode 1 is not applied to the die DS1, so that no electrolytic current flows.

The insulating layer Is can be easily applied to the dice DS by coating with an insulating paint, dipping with enamel, or baking ceramic.

As explained above, according to the present invention, the die guide that guides the wire electrode energized near the workpiece is insulated from the wire electrode, so even if the wire electrode is energized,
Since no potential is applied to the die guide and no voltage is applied between the die guide and the workpiece, the electrolytic current flows through the electrical discharge machining fluid more easily.
Therefore, the surface of the workpiece does not rust during processing, and the quality of the processed product can be improved. In addition, since the electrolytic current flows rapidly, the die guide can be placed close to the workpiece, which reduces the amount of deflection of the wire electrode.
This also has the effect of improving machining accuracy for the workpiece. Furthermore, since this can be achieved simply by insulating the die guide, it can be realized easily and at low cost.

Although the present invention has been described with reference to Examples, the present invention is not limited to the above-mentioned Examples, and various modifications can be made in accordance with the spirit of the present invention, and these are not excluded from the scope of the present invention. do not have.

[Brief explanation of the drawing]

FIG. 1 is a side view of a wire-cut electric discharge machine, FIG. 2 is a cross-sectional view of one embodiment of the present invention, and FIG. 3 is a cross-sectional view of another embodiment of the present invention. In the figure, 1... wire electrode, 2... workpiece, 24.2
5...Dice guide, DS...Dice, DH...
dice holder. Patent applicant: Fananoku Co., Ltd. Patent attorney Sangai Tsuji (1 person) Figure 1 Figure 2 Figure 3

Claims (3)

[Claims] (1) Applying a voltage between the wire electrode and the workpiece, causing electrical discharge between the wire electrode and the workpiece, and guiding the wire electrode of a wire cut electrical discharge machine that performs electrical discharge machining on the workpiece near the workpiece. A die guide for a wire-cut electrical discharge machine, characterized in that a die holder of the die guide is insulated. (2) The die guide for a wire-cut electric discharge machine according to claim (1), wherein the die holder itself is made of an insulator. (3) The die guide for a wire-cut electric discharge machine according to claim (1), wherein an insulating layer is provided on the surface of the die holder.