JP2000158239A - Manufacture of electrode for electric discharge machining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an electrode for electric discharge machining in a precisely desired shape without the necessity of an expensive working machine or high skill. SOLUTION: In a method of manufacturing an electrode for electric discharge machining, the electric discharge machining is carried out with reversed polarity in such a condition that a prototype member 1 previously formed therein with a caliber for forming a workpiece is connected to a negative pole while an electrode 3 to be formed is connected to a positive pole so as to melt the electrode 3 to be formed following the caliver 2 in the prototype member 1 so as to produce an electrode. Further, a die prototype member or a stripper prototype member is used as the prototype member 1 in order to manufacture different electrodes for electric discharge machining.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing an electrode for electric discharge machining.

[0002]

2. Description of the Related Art For example, a die apparatus produces a product by punching a workpiece by moving a punch into and out of a die hole, and the die is provided with a die hole and a pilot hole. Also, at the time of punching, the workpiece is pressed against the die by a stripper and punched by the punch, and the stripper is provided with a punch guide hole for guiding the punch to the die hole.

In punching with a die apparatus, for example, in order to prevent twisting or slipping to the punching side when punching an inner lead or an outer lead of a multi-pin lead frame having a fine punching width and a relatively long punching length, The side to be punched by the lead holding piece may be strongly pressed over the entire length. The lead holding piece is detachably provided along one side of the punch guide hole of the stripper, and a hole for installing the lead holding piece is formed.

[0004] Each hole of the die and the stripper is precisely formed by electric discharge machining into a predetermined shape in order to punch a workpiece in a good shape.

In the electric discharge machining, an electrode for electric discharge machining and a material to be molded which are previously formed in a tank of the electric discharge machine are opposed to each other, and the electrode for electric discharge machining is connected to a negative electrode of a power supply for electric discharge machining and a positive electrode to the material to be molded. The material to be molded is melted by a minute amount by discharging, and a predetermined punch guide hole or a lead holding piece installation hole is formed in a stripper, for example.

The forming of a material to be formed, for example, a stripper, by electric discharge machining is performed according to the shape of the electrode for electric discharge machining.
Therefore, the electrode for electric discharge machining is formed of a material to be formed, such as a stripper.
It must be formed in a shape similar to the shape of the punch guide hole with high accuracy.

[0007]

Conventionally, the forming of an electrode for electric discharge machining is performed by an expensive machining machine such as an end mill, and requires a high level of skill. In addition, there is a problem that it is difficult to form a fine portion by molding with the processing machine. An object of the present invention is to accurately form an electrode for electric discharge machining into a desired shape without using an expensive machining machine or high skill.

[0008]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a method of manufacturing an electric discharge machining electrode for electric discharge machining, comprising the steps of:
A method for producing an electrode for electric discharge machining, comprising: performing electric discharge machining with a reverse polarity in which a positive electrode and a molded electrode are connected to a positive electrode; melting the molded electrode according to a mold of a prototype member; and molding the electrode. It is in.

Another feature is that the prototype member is a die prototype member having a die hole, or a stripper prototype member having a punch guide hole and further a lead holding piece installation hole. The method for producing an electrode for electric discharge machining described above.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a prototype member in which a die for processing a workpiece is formed in advance, for example, a die prototype member having a die hole 2 for punching a lead frame material. Note that the size of the opening of the die hole 2 of the die prototype member 1 is changed corresponding to the punch. Although not shown, a pilot hole is formed.

Reference numeral 3 denotes an electrode to be molded. The surface to be molded has a flat plate shape and is set in the electric discharge machining tank 4 so as to face the die prototype member 1. The electrode to be molded 3 is an insulating liquid 5 in an electric discharge machining tank 4.
It is immersed inside and is electrically connected to the positive electrode of the electric discharge machining power supply 6 via a wire.

The die prototype member 1 is provided with a
It is electrically connected to the poles through wires, and if necessary, a capacitor or the like is provided between the circuits, and the molded electrode 3 is connected to +
Electric discharge is performed by supplying electricity with the opposite polarity as the polarity. The die prototype member 1 and the molded electrode 3 are movably installed so that the distance between them can be changed.

When the electric discharge machining is started, the portion of the electrode 3 connected to the positive electrode facing the non-die hole 2 of the die prototype 1 is gradually melted and dented, while the portion facing the die hole 2 is dented. Does not melt, and protrusions 7 are formed along the contour of the die hole 2.
Shape. Thus, the molded electrode 3 is a die prototype member 1.
Is transferred and molded according to the inverted shape of the mold. At the time of the electric discharge machining, it is desirable to adjust the distance between the die prototype member 1 and the electrode 3 to be molded according to the size and shape of the die hole to be transferred, or the elapse of molding time.

As described above, the electrode 6 to be molded is the die prototype member 1.
Is formed in a specularly reflective manner, so that the mold can be accurately formed even if it has a complicated shape or is fine.

In this embodiment, an electrode for electric discharge machining for manufacturing a die has been described. However, a prototype member of a stripper 9 having a punch guide hole 8 as shown in FIG.
Similarly, when the electrode is subjected to electric discharge machining, the electrode to be formed is formed into an electrode for electric discharge machining for manufacturing a stripper. Similarly, when the electric discharge machining is similarly performed using the stripper prototype member further provided with the lead holding piece installation hole as the negative electrode, an electrode for electric discharge machining by the stripper manufacturing operation is formed.

[0016]

As described above, according to the present invention, the electrode to be formed is subjected to electric discharge machining with the opposite polarity, in which the positive electrode of the electric discharge machining power supply is used, and the mold member for punching the workpiece is formed in advance as the negative electrode. Since the electrode to be molded is molded, the electrode to be molded is molded into a shape precisely similar to the mold of the prototype member. In addition, the electrode for electric discharge machining can be formed without the need for expensive machining machines or advanced skills, and there is an operational effect that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing the formation of an electric discharge machining electrode according to one embodiment of the present invention.

FIG. 2 is a plan view of a stripper prototype member according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Prototype member 2 Die hole 3 Electrode to be molded 4 EDM tank 5 Insulating liquid 6 EDM power supply 7 Projection 8 Punch guide hole 9 Stripper

Claims (4)

[Claims] In a method of manufacturing an electric discharge machining electrode for electric discharge machining, a negative electrode is connected to a negative electrode of a prototype member in which a mold for molding a workpiece is formed in advance, and an electric discharge is performed with a reverse polarity of connecting the positive electrode to a positive electrode. A method for producing an electrode for electric discharge machining, wherein the electrode is molded by performing machining and transferring a mold of the prototype member to the electrode to be molded. 2. The method for producing an electrode for electric discharge machining according to claim 1, wherein the prototype member in which a mold for molding the workpiece is formed in advance is a die prototype member having a die hole. 3. A stripper having a punch guide hole formed therein, wherein a prototype member in which a mold for molding the workpiece is formed in advance.
The method for producing an electrode for electrical discharge machining according to claim 1, wherein the electrode is a prototype member. 4. A prototype member in which a mold for molding a workpiece is formed in advance is a stripper prototype member in which a punch guide hole and a lead presser frame setting hole are formed. A method for producing the electrode for electric discharge machining according to the above.