JPH0354045B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold for molding and a method for manufacturing the same, and particularly to a mold for molding in which a curved surface and/or a flat surface and a projection protruding from the curved surface and/or the flat surface are integrally formed. , a protrusion mold member in which the protrusion and an embedded part extending from the protrusion are integrally formed, and a mold in which the curved surface and/or flat surface is preformed in the embedded part of the member. The present invention relates to a molding die manufactured by being embedded and fixed in a base material, and a method for manufacturing the same.

As is generally known, electric discharge machining equipment is
It is used in a wide range of machining fields, taking advantage of the excellent characteristics of electrical discharge machining. In other words, electrical discharge machining allows efficient machining regardless of the mechanical properties of the workpiece, such as hardness, tensile strength, work hardening properties, etc., and even when machining complex shapes, it is possible to machine the workpiece efficiently. Electrical discharge machining equipment is widely used in the field of mold machining, particularly in the field of mold machining, because high-precision machining is possible by using an electrode tool with a corresponding shape. however,
For example, in a molding die consisting of a curved surface and a protrusion formed on the curved surface, such as the tire molding die shown in FIGS. 1 to 3, the protrusion is formed by electrical discharge machining. If you try to process it, there is a problem that the machining allowance is large and therefore a lot of machining time is required. That is, FIG. 1 is a side sectional view of an embodiment of a tire molding die, and FIG. 2 is an enlarged view of the cross-sectional portion shown in FIG.
A sectional view at B', Figure 3 is arrow A shown in Figure 2.
- Shows the developed plan view at A′, and the reference numeral 1 in the figure
is the upper mold, 2 is the lower mold, 3 is the contour surface and is a curved surface corresponding to the contact surface of the tire, 4 is the shoulder surface, 5 is the protrusion, PL is the parting line, and is the upper mold 1. and the joint surface with the lower mold 2,
CL is a center line and represents the center line of the contour surface 3, respectively.

Generally, a tire molding mold is composed of an upper mold 1 and a lower mold 2, as shown in FIG. Projections 5, 5, . . . shown in FIGS. 2 and 3 are formed on the inner peripheral surface, that is, the contour surface 3 and shoulder surface 4 of each of the molds. In order to form the upper mold 1 and the lower mold 2 by electric discharge machining, as already proposed in Patent Application No. 26919 of 1971, the upper mold 1 or the lower mold 2 is formed in the opposite manner. This is carried out using a processing electrode (not shown) having an uneven shape. The portions machined by the electric discharge machining are the projections of the machining electrode (not shown), that is, the portions corresponding to the contour surface 3 and shoulder surface 4 shown in FIGS. 2 and 3. Therefore, the larger the ratio of the area of the contour surface 3 and the shoulder surface 4 in the mold processing surface, that is, the larger the ratio of the area of the curved surface and/or flat surface in the mold processing surface in a general molding die. The larger the size, the longer the processing time will be. In other words, especially when small protrusions are present roughly, the machining allowance for electrical discharge machining becomes large, the machining time becomes long, and the mold machining cost increases.

The present invention aims to solve the above-mentioned drawbacks, and provides a molding die in which a curved surface and/or a plane and a protrusion protruding from the curved surface and/or the plane are integrally formed. The mold includes a protruding mold member in which an embedded part of the protruding part and an embedded part extending from the protruding part are integrally formed, and a mold base material in which the curved surface and/or the flat surface are preformed. By providing an embedding recess having a shape in which the shape of the embedding part is transferred to a curved surface and/or a plane of the base material, and inserting and fixing the embedding part of the protrusion mold member into the embedding recess. The object of the present invention is to provide a molding die and a method for manufacturing the same, which can reduce the number of man-hours required for manufacturing the mold and thereby reduce the manufacturing cost. This will be explained below with reference to the drawings.

4A to 4D are side views and cross-sectional views of one embodiment of the protrusion mold member of the present invention, and FIG. 5 is an embodiment of the process of embedding the protrusion mold member in the mold base material of the present invention. Explanatory diagram for explanation, Figure 6A
and B respectively show a partial plan view and a sectional view of another embodiment of the molding die of the present invention.

Reference numerals 3 and 4 in the figure correspond to FIGS. 2 and 3, 6 is a protrusion mold member, 7 is a protrusion,
8 is an embedded part, 9 is an electric discharge machining head, 10 is an electrode mounting jig, 11 is a mold base material, 12 and 13 are protrusions, 14 is an embedded part, and 15 is a plate-like protrusion. .

A molding die and a method for manufacturing the same according to the present invention will be explained with reference to FIGS. 4 and 5 in relation to the tire molding die shown in FIGS. 2 and 3 above. That is, when manufacturing the molds shown in FIGS. 2 and 3 using the manufacturing method of the present invention,
First, the protruding mold member 6 shown in FIG. 4 is formed. The protrusion mold member 6 is integrally formed with a protrusion 7 having the same shape as the protrusion 5 shown in FIGS. 2 and 3, and an embedded portion 8. FIGS. 4A and 4 show side views of the protrusion mold member 6.
The one-dot chain line a in FIGS. 4B, C, and D showing cross-sectional views taken along b-b', c-c', and d-d' in FIG. It represents. In addition, the projection mold member 6 shown in FIG.
shows an embodiment in which a plate-shaped material is formed by processing means such as press working.

Next, the process of embedding the protruding mold member 6 into the mold base material 11 by electric discharge machining will be explained with reference to FIG. That is, first, the protrusion mold member 6 is attached to the electrode attachment jig 10 of the electric discharge machining head 9 at the protrusion 7 by appropriate means. Although not shown, the mounting means includes, for example, a plurality of screws that pass through the mounting portion of the projection 7 of the electrode mounting jig 10, and the projection mold member 6 is secured to the projection mold member 6 by the plurality of screws.
All you have to do is set it. Then, electrical discharge machining is performed on the mold base material 11 on which the predetermined contour surface 3 and shoulder surface 4 are formed, using the protrusion mold member 6 as a machining electrode. It goes without saying that prior to the electrical discharge machining, the electrode feeding direction (direction of the arrow in the figure) of the electrical discharge machining head 9 is set and the relative positioning of the protruding mold member 6 and the mold base material 11 is performed. The method for setting the direction, positioning, etc. has already been proposed by the inventors of the present invention in Patent Application No. 77654 of 1982, so the explanation thereof will be omitted. After the above-mentioned direction setting and positioning are performed, the protruding mold member 6 is fed in the direction of the arrow shown in the figure by the electrical discharge machining head 9 to perform electrical discharge machining. The virtual boundary line a with the portion 8 is the contour surface 3 and the shoulder surface 4.
Repeat until it matches. After that, the protruding mold member 6 is separated from the electrode mounting jig 10, and the embedded part 8 and the mold base material 11 are connected by caulking or a fixing means using an adhesive. Fix it to the material 11. In this way, the protruding mold members 6 are successively embedded and fixed in the predetermined positions of the mold base material 11, thereby completing the tire molding mold shown in FIGS. 1 to 3. I can do it. The reason why it is necessary to use the fixing means is that a minute gap exists between the embedded portion 8 and the mold base material 11 due to the discharge gap.
Furthermore, the machining allowance in the electrical discharge machining described above can be kept to a minimum because the volume corresponding to the plate-shaped embedded portion 8 is sufficient as shown in FIG.

In the embodiment of the present invention shown in FIGS. 4 and 5, the protruding mold member 6 is shown to be formed from a plate-shaped material, but it may also be formed by cutting a block material or by casting. It's okay to have something like that. In this case, the machining allowance increases slightly, but the machining allowance is much smaller than the conventional method described at the beginning of this specification.

Another embodiment of the invention is illustrated in FIG. That is, the illustrated embodiment in FIG. 6 shows a part of a mold for molding a tire partially having slit grooves. FIG. 6A is a plan view of the part, and FIG. 6B is a sectional view taken along line a-a' in FIG. A mold for molding a tire having the above-mentioned slit grooves must have a plate-like protrusion 15 corresponding to the slit grooves. 6th
It is relatively difficult to form the thin plate-like protrusion 15 as shown in the figure using conventional machining means such as cutting or electric discharge machining, which directly machines the mold base material 11. In particular, the smaller the thickness of the plate-like protrusion 15 and the longer the length, the more difficult it is. In such a case, the projection mold member 6 having the cross-sectional shape shown in FIG. By embedding the embedding portion 14 into the contour surface 3 through processing and then fixing the embedding portion 14 to the mold base material 11, a desired molding die can be obtained relatively easily.

Above, the molding die and the manufacturing method thereof of the present invention have been explained mainly in relation to tire molding molds, but the present invention is not limited to the above tire molding molds, but can be applied to other general molding molds. Needless to say, it is also applied to molds.

As explained above, according to the present invention, the embedded part of the projecting mold member, in which the projecting part of the mold to be molded and the embedded part extending from the projecting part are integrally formed, is curved in advance. and/or by manufacturing a mold by embedding and fixing it in a mold base material that has a flat surface, it is possible to shorten mold manufacturing man-hours and reduce manufacturing costs. A mold and a method for manufacturing the same can be provided.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of a tire molding die and one embodiment, Fig. 2 is an enlarged view of the cross-sectional portion shown in Fig. 1, and Fig. 3 is a developed plan view taken along arrow A-A' in Fig. 2. 4A to 4D are side views and cross-sectional views of one embodiment of the protruding mold member of the present invention, FIG. 5 is an explanatory view for explaining the method of manufacturing a molding die of the present invention, and FIG. 6 A and B show a partial plan view and a sectional view, respectively, of another embodiment of the molding die of the present invention. In the figure, 3 is a contour surface, 4 is a shoulder surface, 6 is a projection mold member, 7 is a projection, 8 and 14 are embedded parts, 9 is an electric discharge machining head, 10 is an electrode mounting jig,
Reference numeral 11 represents a mold base material, and reference numeral 15 represents a plate-like protrusion.

Claims (1)

[Scope of Claims] 1. A molding die configured by integrally forming a curved surface and/or a plane and a protrusion protruding from the curved surface and/or plane, a protrusion corresponding to the above-mentioned protrusion. a protruding mold member having an embedded part extending from the protruding part and having an internal recess therein, and in which both the protruding part and the embedded part are integrally formed; A mold base material is provided with a curved surface and/or a flat surface formed in advance, and the mold base material has the curved surface and/or the flat surface of the mold base material.
Or, a recessed part having a convex part corresponding to the internal recess of the embedded part is formed on a plane from the surface, and the shape of the embedded part of the projection mold member is transferred to the shape of the embedded part. A molding die characterized in that an embedding recess is formed with a shape that allows proper engagement, and the embedding part of the protrusion mold member is inserted into the embedding recess and is fixed therein. 2. In a method for manufacturing a mold that is configured by integrally forming a curved surface and/or a plane and a protrusion protruding from the curved surface and/or plane, the protrusion and the embedded part extending from the protrusion are A protruding mold member molded so that an embedded part having an internal recess therein is integrally formed, and a mold base material on which the curved surface and/or flat surface are formed are prepared in advance. The curved surface and/or flat surface of the mold base material is subjected to electric discharge machining using the embedded part of the protruding mold member as a machining electrode until the embedded part is embedded in the metal base material. A method for manufacturing a molding die, characterized in that, after proceeding with electrical discharge machining, the protruding die member is fixed to the die base material at the embedded portion.