JPH06226550A - Electric discharge machining method - Google Patents

Abstract

PURPOSE:To make it possible to form a metal mold directly without using any intermediate metal mold by extracting contour line data of inner and outer surface of a final workpiece from design data of the final workpiece formed by injection molding make female and male metal mold design data based on such data and control electric discharge machining on the basis of both data. CONSTITUTION:An injection molded final product, for example, a truncated cone parts is designed by CAD and the data obtained therefrom is incorporated into a CPU on the electric discharge machine side. From such data, contour line data, for example, slice data of each section in the mold opening direction is extracted. In designing a female metal mold 12, the contour line on the outer side of the slice data is made the nominal and data with its inside made solid is prepared and, in designing a male metal mold 13, the contour line on the inner side of the slice data is made the nominal and data with its outer side made solid is prepared. Respective metal molds 12, 13 are built by drive controlling a moving member and a reel of the electric discharge machine, discharging electrode material at each position against the mold material and performing electric discharge machining by every respective slices.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric discharge machining method for male and female dies for injection molding.

[0002]

2. Description of the Related Art In a conventional die-sinking electric discharge machine, a shape to be machined is molded into a soft material such as copper or carbon,
Using this as a male mold, the female mold shape is transferred to a hard material to mold one of the molds for injection molding. In this method, in molding a pair of male and female molds for injection molding, two male and female molds are required for each mold, which is time consuming and increases manufacturing cost. There was a problem.

[0003]

SUMMARY OF THE INVENTION According to the present invention, a final-purpose injection molding die is formed by electric discharge machining without using an intermediate die for producing the same, thereby reducing the production time and the production cost. The purpose is to

[0004]

In order to solve the above-mentioned problems, the present invention extracts contour line data of inner and outer surfaces from design data of a final processed product by injection molding and uses the contour line data of the outer surface to extract the contour data. Create the female mold design data with the inside of the contour line solid and the male mold design data with the outside of the contour line solid using the contour data of the inner surface, and based on these both design data The position of the machining head for electric discharge machining with respect to the mold material and the amount of discharge are controlled to mold both male and female dies from the mold material.

[0005]

Function: Both the male and female dies are directly formed by electric discharge machining by using the data when designing the final injection mold, so that the production time and the production cost can be shortened.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electric discharge machining method according to the present invention will be described in detail below with reference to the drawings.

First, FIG. 2 is a schematic perspective view of an electric discharge machine for carrying out the method of the present invention. In the figure, 1a, 1
b is a pair of guide members fixed to a base (not shown), 2
Is a horizontal movement member held so as to be movable in the X and Y directions with respect to the guide members 1a and 1b.
An XY table is constructed according to b and 2.

Reference numeral 3 denotes a pulley 6a for holding an electric reel 5 for paying out and winding up the electrode lead 4 on the upper portion thereof, and for guiding the lead 4 while adjusting the deviation of the lead 4 on the front surface,
6b is a Z-direction movement driving member that rotatably holds 6b,
A control drive unit that controls the rotation of the reel 5 and a power supply unit (both not shown) that supplies a discharge current to the lead 4 are housed inside. A wire-like electrode material 7 as an electric discharge machining head electrically connected to the lead 4 is housed in the lower part of the Z-direction movement driving member 3 and is interlocked with the movement of the lead 4 in the Z direction. The electrode support 8 that moves up and down in the Z direction is movably held by a holder 9.

Reference numeral 10 denotes a mold material that is a base material for forming male and female dies for injection molding by electric discharge machining, and for example, SKD60, NAK55, S55C and the like are used as the material.
And this mold material 10 is normally processed in a state of being placed in an oil tank, and 11 shows its oil level.

In the electric discharge machine having the structure shown in FIG. 2, the electrode material 7 moves the moving member 2 in the XY plane with respect to the guide members 1a and 1b, and winds the reel 5.
It is possible to move freely in the oil tank by the movement in the Z direction due to the feeding. Then, the mold material 10 can be continuously carved into a desired shape by the energy of the spark discharge emitted from the electrode material 7 at the tip of the support material 8. The wire-shaped electrode material 7 is used for easy replacement and maintenance of the discharge electrode and maintenance-free.

Next, the electric discharge machining method will be described with reference to the flow chart of FIG. 1 and the process chart of FIG. First step S
In 1, the final injection-molded product, for example, the truncated cone-shaped part of FIG. 3A is designed by CAD, and the design data is loaded into the CPU (not shown) on the electric discharge machine side. Then step S
2 from the above design data to contour line data, for example, FIG.
Slice data at each cross section in the mold opening direction as shown in (b) is extracted.

When processing the female die 12, step S
In step 3, the outer contour line of the slice data is used as a reference, and the inside of the slice data is solid (data is filled), that is, the data shown in FIG. 3C is created for each slice data. This data is data such as the position of the machining point and the amount of electric discharge, and indicates the portion where the electric discharge machining is actually performed on the mold 10.

Further, when the male die 13 is machined, in step S4, the inside contour line of the slice data is taken as a reference and the outside thereof is solid, that is, the data shown in FIG. Create for each slice data as in the case of the mold.

After that, the moving member 2 and the reel 5 are driven based on the solid data obtained in steps S3 and S4 (step S5), the electrode material 7 is spark-discharged at each position with respect to the mold material 10, and each slice is sliced. Electrical discharge machining is performed for each (step S6).

Male and female molds 12 thus obtained,
13 is combined as shown in FIG. 3 (e) to form an injection molding die, in which a thermoplastic resin is poured into a gap portion formed by each die to be solidified, and the molded product shown in FIG. 3 (a) is obtained. To get

FIG. 4A shows an external perspective view of the female die 12, and FIG. 4B shows an external perspective view of the male die 13. In this embodiment, since the number of slices is small, the processing surface is stepwise in both molds, but the number of slices is increased,
If the amount of data is increased, the processed surface can be made smooth.

5 (a) and 5 (b) show the molds 12 and 13 respectively.
The relationship between the support tool 8 and the processed portion at the time of processing is shown. Since the supporting member 8 is provided so as to project below the Z-direction movement driving member 3 as described above, the driving member 3 is
Processing can be performed smoothly without interfering with 0.

[0018]

As described above, according to the present invention, the mold material can be directly processed from the shape data of the final molded product without using the intermediate mold, so that the manufacturing time can be shortened and the manufacturing cost can be largely reduced. Have an effect.

[Brief description of drawings]

FIG. 1 is a flowchart illustrating an electric discharge machining method of the present invention.

FIG. 2 is an external perspective view of a processing machine for carrying out the electric discharge machining method of the present invention.

FIG. 3 is a process drawing based on the flowchart of FIG.

FIG. 4 is an external perspective view of a female mold (a) and a male mold (b).

FIG. 5: Wire-shaped electrode material and female mold (a) and male mold (b)
It is a figure which shows the interference relationship with.

[Explanation of symbols]

 1a, 1b Guide member 2 Moving member 3 Z direction movement driving member 4 Lead 5 Pulley 7 Wire-like electrode material 10 Mold material

Claims (1)

[Claims] 1. The outline data of the inner and outer surfaces is extracted from the design data of the final processed product by injection molding, and the inside die of the outline is made solid by using the outline data of the outer surface. In addition, using the contour line data of the inner surface to create male mold design data in which the outside of the contour line is solid, the position of the machining head for the electrical discharge machining and the amount of discharge on the die material are determined based on these both design data. An electric discharge machining method of controlling and molding both male and female dies from the mold material.