JPH07205155A - Mold processing method - Google Patents

Abstract

PURPOSE:To provide a method for processing a mold usable for a long period by largely deleting processing man-hour, eliminating shape malfunction, splash of a molded form, and obviating a malfunction such as sagging, scuffing of a processed part. CONSTITUTION:A method for processing a mold comprises the steps of solely discharging protrusions 1 when an extruded surface or a contact surface having the protrusions 1, recesses 2, a through hole or a groove, solely discharging the recesses 2, the hole or the groove, and inserting or bringing the discharged protrusions 1 into or into contact with the discharged recesses 2, the holes or the grooves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die machining method for machining a push-cut surface or a contact surface of a die used for injection molding or the like by electric discharge machining.

[0002]

2. Description of the Related Art A conventional method for processing a stamped surface or a contact surface by a mold processing method will be described with reference to the drawings. FIG. 6 is a cross-sectional view showing an example of a push-cut surface of an injection molding die. In FIG. 6, reference numeral 10 denotes a convex portion of the mold E. The convex portion 10 is provided in three rows in parallel, and a tip end of the convex portion 10 has a contact surface 10a with a mating member. Reference numeral 20 denotes a concave portion of the mold F, and the bottom surface of the concave portion 20 has the convex portion 10
The contact surface 20a with the contact surface 10a is processed.

FIG. 7 is a sectional view showing another example of a push-cut surface of an injection molding die. In FIG. 7, 30 is a convex portion of the mold G, and the convex portion 30 is composed of two triangular sides,
The inclined portions on the two sides of the convex portion 30 come into contact with the other party, and the contact surfaces 30a and 30b are processed. Reference numeral 40 denotes a recess of the mold H, and slopes 40 are provided on both sides above the recess 40.
a and 40b are processed, and the contact surface 3 of the convex portion 30 is formed.
It comes into contact with 0a and 30b.

FIG. 8 is a sectional view showing another example of the push-cut surface of the injection molding die. In FIG. 8, reference numeral 50 denotes a convex portion of the mold I, and the convex portion 50 has an arc-shaped contact surface 50a.
Is being processed. Reference numeral 60 denotes a circular arc-shaped concave portion of the mold J, and a convex portion 60a protrudes in the center of the concave portion 60, and the upper surface of the convex portion 60a contacts the contact surface 50a of the counterpart convex portion 50. 60b is processed.

The above-mentioned push-cut surface and contact surface are processed and finished by repeating manual sliding work by skilled hands.

[0006]

However, there are the following problems in the above-mentioned manual processing and finishing of the push-cut surface and the contact surface. 1) Depending on the complicated shape of the contact surface, it is difficult to adjust the contact surface of the blade processing or hand processing, or the contact surface, which requires a large number of man-hours. 2) Since the surfaces are in contact with each other, the contact surfaces may be displaced depending on the molding method and the raw material used, and the product may have abnormal shapes or burrs. 3) When the contact accuracy between the surfaces is 0.0025 mm or more, when the raw material used has a low melt viscosity such as nylon 66, burrs are generated in the product due to the gap between the contact surfaces. 4) In the case of push-cutting by surface contact, if the mold is used for a long period of time, surface sagging or hit damage is likely to occur, and there is a problem that the mold needs to be corrected.

The present invention has been made by paying attention to the above-mentioned problems, and these problems are solved, the man-hours for processing are significantly reduced, and the abnormal shape and burrs of molded products are prevented. The present invention also provides a method for working a molding die that can be used for a long period of time without any problems such as chamfering or galling of the processed portion.

[0008]

In the die machining method of the present invention, when machining a press-cut surface or a contact surface composed of a convex portion and a concave portion, a through hole, or a groove, the convex portion is a convex portion and is independently electric discharge machined. However, the recesses, the through holes, or the grooves are individually subjected to electrical discharge machining, and the electrical discharge machined convex portions are inserted into or contact with the electrical discharge machined recesses, through holes, or grooves. And

In the above-described die machining method, the shape of the concave portion is machined by die-sinking electric discharge machining using an electric discharge machine, and the convex portion which comes into contact with or is inserted into the concave portion is machined to form the concave portion and the convex portion. To complete the combination of. The recess is also applied to the case of a through hole and the case of a groove.

[0010]

In the die machining method of the present invention, when processing the pressing surface and the contact surface of the convex portion and the concave portion, the through hole, or the groove, the convex portion is subjected to the electric discharge machining independently at the convex portion, and the concave portion and the through hole are formed. Alternatively, each groove is individually subjected to electrical discharge machining, and the above-mentioned electrical discharge machined convex portion is inserted into or brought into contact with the electrical discharge machined recessed portion, through hole, or groove, thereby significantly reducing the number of machining steps. However, it is possible to obtain a molding die that can be used for a long period of time by eliminating the abnormal shape of the molded product and the occurrence of burrs, and by eliminating the problems such as surface warping and galling of the processed part. Further, it is possible to prevent the displacement of the contact surface even under an unreasonable molding condition or a heterogeneous composite molding material.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. [Embodiment 1] FIG. 1 is a sectional view of a die showing an example of the die working method of the present invention. In FIG. 1, 1, 1, and 1 are convex portions of the mold A portion, and 2, 2, and 2 are concave portions.
The convex portions 1, 1, and 1 are inserted while being in contact with the concave portions 2, 2, and 2, respectively.

The recesses 2, 2 and 2 are machined by die-sinking electric discharge machining, and the protrusions 1, 1 and 1 are machined by whole surface electric discharge machining. This convex portion 1,
When 1 and 1 are quenching parts such as quenching pins, only the tip 1a is tapered so that the tip is sharpened in order to prevent galling etc. at the time of contact with the recesses 2, 2 and 2 of the mating part. Preferably. Also, the recess 2,
When 2 and 2 have no problem in the structure or strength of the die, the through hole is preferable without providing the bottom surface 2a in terms of processing difficulty and accuracy.

[Embodiment 2] FIG. 2 is a sectional view of a die showing another example of the die working method of the present invention. In FIG.
Reference numerals 3, 3, and 4 are convex portions of the protruding mold C portion having different symmetrical shapes, and reference numerals 5, 5, and 6 are concave portions. The convex portions 3, 3, and 4 are inserted while contacting the concave portions 5, 5, and 6, respectively.

The sloped surfaces 5a, 5a of the concave portion 5 and the sloped surfaces 6a, 6a of the concave portion 6 are machined by stamping electric discharge machining, and the convex portions 3, 3, and 4 are machined by full surface electric discharge machining. It is produced by being broken. Also in the present embodiment, the recess 6 is preferably a through hole from the viewpoint of the degree of processing difficulty and accuracy when there is no problem in the structure of the mold or the strength. Further, in order to prevent the convex portion 4 from contacting and galling at the time of insertion, it is preferable that the distal end portions 4a and 4a are tapered so that the distal end is sharpened.

Even in the case of convex portions such as a triangular shape having a sharp tip or an arc shape other than the present embodiment, these convex portions are machined by full-surface electrical discharge machining, and the concave portions which come into contact with or are inserted into them are not formed. It is preferable to perform die-sinking electric discharge machining.

[Embodiment 3] FIG. 3 is a sectional view of a die showing another embodiment of the die working method of the present invention, and FIG. 4 is a top view of FIG. FIG. 5 is a front view of a push-cut pin used in the mold of FIG. 3 and 4,
Reference numeral 7 is a mold, 7a is a lower hexagonal tubular portion, and the upper portion thereof is constituted by a cylindrical portion 7b. 7
c and 7c are pin holes provided penetrating the side surface of the rectangular tube portion 7a at symmetrical positions, and the push-cut pin 8 shown in FIG. 5 is inserted into the pin hole 7c.

A pin hole 7 provided in the square tube portion 7a of the die 7.
c is machined by die-sinking electrical discharge machining, and push-cut pin 8
The tip portion 8a of the is finished by machining by electric discharge machining and is inserted into the pin hole 7c.

In the conventional machining method, the cutting surface of the tip of the push-cut pin is applied to a hexagonal slope, and the tip shape along the hexagonal slope is manually machined while cutting with a cutting tool. Was being processed. Therefore, although there is a problem that the angle of the tip of the push-cut pin does not match the length or the length of the hexagonal slope, the problem can be solved by the die machining method of the present invention.

[0019]

According to the die machining method of the present invention, in the processing of the push-cut surface and the contact surface formed by the convex portion and the concave portion, the through hole, or the groove, the convex portion is subjected to the electric discharge machining independently on the convex portion, and the concave portion,
Each of the through holes or the grooves is subjected to electric discharge machining independently, and the electric discharge machined convex portion is replaced with the electric discharge machined concave portion, the through hole,
Alternatively, by inserting it into the groove or making contact with it, the number of processing steps can be greatly reduced, the abnormal shape of the molded product and the occurrence of burrs can be eliminated, and the defects such as chamfering and galling of the processed part can be eliminated for a long time. It can be a molding die that can be used across. Further, it is possible to prevent the displacement of the contact surface even under an unreasonable molding condition or a heterogeneous composite molding material. Therefore, it is suitable as a die processing method.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a mold showing an example of a mold processing method according to the present invention.

FIG. 2 is a sectional view of a mold showing another example of the mold processing method of the present invention.

FIG. 3 is a sectional view of a mold showing another embodiment of the mold processing method of the present invention.

FIG. 4 is a top view of FIG.

5 is a front view of a push-cut pin used in the mold of FIG.

FIG. 6 is a cross-sectional view showing an example of a push-cut surface of an injection molding die.

FIG. 7 is a cross-sectional view showing another example of the push-cut surface of the injection molding die.

FIG. 8 is a cross-sectional view showing another example of the push-cut surface of the injection molding die.

[Explanation of symbols]

 1, 3 and 4 Convex part 1a Tip part 2, 5 and 6 Recessed part 2a Bottom surface 5a and 6a Slope surface 7 Mold 7a Square tube part 7b Cylindrical part 7c Pin hole 8 Push-cut pin 8a Tip part

Claims (1)

[Claims] 1. A method of machining a die used for injection molding, wherein a die-cutting surface and a contact surface of the die are processed by electrical discharge machining. The die-cutting surface comprises a convex portion and a concave portion, a through hole, or a groove. In the machining of, the convex portion is subjected to the electric discharge machining independently in the convex portion, the concave portion, the through hole, or the groove is subjected to the electric discharge machining independently, the electric discharge machined convex portion, the electric discharge machined concave portion, the through hole, Alternatively, a die machining method characterized in that the die is inserted into or brought into contact with the groove.