JPS6114824A - Method of manufacturing mold with extremely small odd-shaped hole - Google Patents

Abstract

PURPOSE:To manufacture a high precision mold with an odd-shaped hole such as a mold for forming a wire guide, etc., by manufacturing a precision electrode without bending and eccentricity and thereafter employing said electrode. CONSTITUTION:In a method of manufacturing a mold for forming a molded article with an extremely small odd-shaped hole less than 1mm., a steel block for primary electrode is cut into two blocks 11a, 11b both having the same width and combined into a block with holes 12-14, 15a, 15b analogous or partly equal to a final shape thereof. The resulting block is employed as a primary electrode 4. Then, a secondary electrode material mounted on the main shaft of an electrical discharge machine is forced to pass through, in order, the holes 12-14, 15a, 15b of the electrode 11 with a pitch measured previously and subjected to opposite electrical discharge machining for preparing an odd-shaped secondary electrode. Employing the secondary electrode so prepared, a mold with an odd-shaped hole of 1mm. or less, particularly 0.5mm. or less can be manufactured with high precision.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a mold for molding a molded product having extremely small irregularly shaped holes with high precision.

[Prior art]

Conventionally, electrical discharge machining has been used to manufacture molds with irregularly shaped holes. Electric discharge machining requires electrodes, and the electrodes can be manufactured using copper, copper/tungsten, silver/
A round bar made of tungsten or the like was machined to a predetermined diameter using a lathe, and then the surface was milled by grinding.

However, if the electrode tip has a diameter of 1 mm or less,
Since the electrode is cut out into a long piece of about 200 mm and then processed one side at a time by grinding, bending occurs, and eccentricity with the rear part of the electrode occurs easily, making it difficult to process the tip of the electrode with high precision.

[Purpose of the invention]

Therefore, the purpose of the present invention is to provide a highly accurate electrode without bending or eccentricity, and to use this electrode to manufacture high-precision molds with irregularly shaped holes such as molds for wire guide molding. be.

[Structure of the invention]

The present invention is a method for manufacturing a mold using electrical discharge machining for molding a molded product having an extremely small irregularly shaped hole of 111 II or less, in which an electrode rod for forming an irregularly shaped hole in the mold is manufactured by electrical discharge machining using reverse electrical discharge. The present invention relates to a method for manufacturing a mold characterized by:

Hereinafter, an example of the present invention will be explained with reference to the drawings.

As shown in Fig. 1, a plurality of grooves (2), (3) each having an approximate or similar shape, the same shape, or partially the same shape as the final shape divided into two are formed in the steel block (1). ), (41,
(5a) and (5b) from larger to final shape, such as "rough finishing", "medium rough finishing", "semi finishing", and "finishing", to the final shape or a shape that is partially the same as the final shape. It is formed by polishing.

This is cut into two blocks (11a) and (11b) of the same width along line A-A in Fig. 1, and assembled as shown in Fig. 2, so that the final shape is similar or partially the same. holes (12), (13), (14), (15a), (15b
), and this is a -molded pole (11).

- The holes in the molded electrode material (11) are shaped according to the cross-sectional shape of the secondary electrode material before processing and the final secondary electrode (20) shown in FIG. 3 (it).
Considering the cross-sectional shape of
3), (14), Straight line part (21) of the final secondary electrode cross-sectional shape
) have the same shape as a trapezoid (15aL) and a circular shape (15b) in which the curved part (22) of the final secondary electrode cross-sectional shape has the same shape.
). In FIG. 2, the dotted lines each indicate the cross-sectional shape of the secondary electrode material before passing it through the hole of the primary electrode material (11).

Next, the holes (12), (13L (14), (15a) of the primary electrode (11) in Fig. 2 are inserted into the holes (12), (13L (14), (15a)) of the secondary electrode material attached to the main shaft of the electrical discharge machine at the pitch measured in advance. , (15b
) Through K reverse discharge machining, a secondary electrode (20) having an irregular shape as shown in FIG. 3 is created.

In the present invention, in reverse electrical discharge machining and electrical discharge machining, -
This refers to the production of secondary electrodes using molded electrodes.

Using this secondary electrode (20), the mold can be subjected to normal electric discharge machining to obtain a mold having irregularly shaped holes of the desired final shape.

〔Effect of the invention〕

As described above, according to the present invention, a mold having irregularly shaped holes of IW or less, particularly Q, of 5 m or less can be manufactured with much higher precision than conventional methods.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a steel block for primary electrodes with grooves;
FIG. 2 is a plan view of the primary electrode, FIG. 3(a) is a side view of the secondary electrode, and FIG. 3(b) is a sectional view taken along line BB in FIG. 3(a). 1: Steel block] Secondary electrode. 12.13.14.15a, 15b: Hole 20: Secondary electrode

Claims (1)

[Claims] A method for manufacturing a mold by electrical discharge machining for a mold used for a molded product having a very small irregularly shaped hole of 1 mm or less, characterized in that an electrode rod for forming the irregularly shaped hole in the mold is manufactured by electrical discharge machining by reverse discharge. manufacturing method.