JP2001212830A - Method for producing mold for vulcanization molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a mold for vulcanization molding which can produce a rubber article having a good appearance and a high dimensional precision by forming a gap capable of securing necessary exhaust performance at an optional position of the mold and improve productivity and working properties by omitting work to cut off an overflowing spue. SOLUTION: A mold crude material 11 in which the processing margin of a pattern 14 and a recessed groove 12 are formed by the first shot casting by die-casting or mechanical processing is formed, and a casting metal 13 is cast/laminated in/on the recessed groove 12 of the material 11 by the second shot by die-casting to complete the material 11. After that, the pattern 14 is processed in the processing margin of the profile surface 11a of the material 11 by mechanical processing or electric discharge machining, and an exhaust hole 15 communicating with the air in the slope line direction the mold back side is formed on the line of the cast joint part X of the material 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a vulcanization mold, and more particularly, to a vent hole or an exhaust groove which is small enough to prevent molten rubber material from flowing out during vulcanization molding of a rubber product. By using a mold (Spyless mold) equipped with a mold, required exhaust performance can be secured at any position of the mold, and a rubber product with good appearance and high dimensional accuracy can be manufactured. The present invention relates to a method for producing a sulfur molding die.

[0002]

2. Description of the Related Art Conventionally, a mold W for vulcanizing and molding rubber products such as a track belt is called a ring mold as shown in FIG. 2, and a pattern segment 1 divided into 24 parts is generally used. ing.

When vulcanizing using such a vulcanizing mold for a track belt, air traps and gas are generated between the molding surface of the rubber product and the molding surface of the mold. The gas forms minute depressions on the surface of the rubber product, causing product defects. For this reason, in the related art, an overflow groove is provided between the pattern segments 1 or air or gas is extracted from the parting surface 2.

[0004] In the drawing, reference numeral 4 denotes a pattern formed in the pattern segment 1.

[0005]

However, in the case of a conventional vulcanization molding die, as shown in FIGS. 3 and 4, a rubber material for vulcanization molding is formed from an overflow groove 3 and a parting surface 2. Flow into the surface of the product to form Spyu Q (burrs, beard-like rubber projections). For this reason, there is a problem that a finishing operation for removing the spew Q after the molding is necessary, and after removing the spew Q, there is a problem that the appearance is impaired by leaving a trace thereof.

SUMMARY OF THE INVENTION It is an object of the present invention to form a gap at any position of a mold to ensure necessary exhaust performance so that a rubber product having a good appearance and high dimensional accuracy can be manufactured, and an overflow spew can be manufactured. An object of the present invention is to provide a method of manufacturing a vulcanization molding die which can improve productivity and workability by omitting the operation of removing the above.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention forms a mold blank having a pattern machining allowance and a concave groove by a first shot casting by die casting or machining. A second shot by die casting is performed in the concave groove of the rough material, and a cast metal is cast and laminated to complete a mold rough material, and a pattern is formed by machining or electric discharge machining in the machining allowance of the profile surface of the mold rough material. It is intended to be processed.

According to the present invention, a mold blank having a pattern machining allowance and a concave groove is formed by a first shot casting or machining by die casting. A second shot by die casting in the groove is cast and laminated with a cast metal to complete a mold rough, and a pattern is processed by machining or electric discharge machining in place of a processing allowance for a profile surface of the mold rough. By forming exhaust holes communicating with the atmosphere in the normal direction from the back side of the mold, on the line of the joint portion of the material, a gap that can secure the required exhaust performance at any position of the mold is formed, It is possible to manufacture rubber products with good appearance and high dimensional accuracy, and improve productivity and workability by eliminating the work of removing overflowed spews. It is what can be.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 (1) to 1 (4) show a manufacturing process of a mold for vulcanization molding of a rubber product according to the present invention.

FIG. 1A and FIG. 1A in a first manufacturing process of the present invention are plan views of a rough mold material 11, and FIG.
FIG. 3A is a side view taken along the line AA of FIG. 3A, and FIG. 3C is a side view of FIG. 3A. In this first manufacturing process, a first mold blank 11 provided with a pattern processing allowance is die-cast by a first method. It is manufactured by shot casting or a mold blank 11 provided with a pattern processing allowance in advance is prepared, and a concave portion is formed on the profile surface side 11a of such a mold blank 11 at the time of die casting or by machining. The groove 12 is formed.

Next, FIG. 1 (2), (a), (b),
In the second manufacturing step (c), a second shot is made by die casting in the concave groove 12 of the molded rough material 11 in which the concave groove 12 has been formed, and a cast metal 13 is cast and laminated to complete the molded coarse material.

In the third manufacturing process shown in FIGS. 1 (3), 1 (a) and 1 (b), a pattern 14 is mechanically formed on the profile surface side 11a of the mold blank 11 so as to intersect with the casting metal 13. It is formed by machining or electric discharge machining.

Further, in the fourth manufacturing process shown in FIGS. 1 (4), 1 (a) and 1 (b), the atmosphere is formed on the line of the joint portion X of the mold blank 11 in the normal direction from the back side of the mold. The communicating exhaust holes 15 are formed by machining.

As a method of processing the pattern 14 by machining, for example, the pattern 14 is processed by using NC data (numerical control data) for simultaneous 5-axis processing created from three-dimensional modeling data. In the electric discharge machining, an electrode of the pattern 14 is prepared in advance and the pattern 14 is automatically processed.

The spliced portion X of the cast and laminated mold coarse material 11 is 0.005 mm due to the solidification shrinkage of the cast metal material 13.
It is a fine gap of about 0.06 mm, and only air and gas generated during vulcanization are discharged from the joint portion X and the exhaust hole 15.

As described above, in the embodiment of the present invention,
A first shot casting by die casting or machining is used to form a processing allowance for the pattern 14 and a mold coarse material 11 provided with a concave groove 12, and a second shot by die casting to the concave groove 12 of the mold rough material 11. By casting and laminating the cast metal 13
To complete.

Thereafter, the pattern 14 is processed by machining or electric discharge machining in place of the processing allowance for the profile surface 11a of the mold rough material 11, and the normal line is formed on the line of the joint X of the rough material from the back side of the mold. By forming the exhaust hole 15 communicating with the atmosphere in the direction, a gap that can secure the required exhaust performance at any position of the mold can be formed, so that a rubber product with good appearance and high dimensional accuracy can be manufactured. In addition, productivity and workability can be improved by omitting the operation of deleting the overflowed spew.

Further, in the above-described embodiment, the first shot and the second shot of die casting use the same kind of aluminum alloy for die casting. However, the die casting may be performed by using zinc alloy die casting or magnesium alloy die casting. Is possible.

[0020]

According to the present invention, as described above, the first shot casting by die casting or the machining is used to form a mold blank having a pattern machining allowance and a concave groove.
A second shot by die-casting is performed in the concave groove of the mold coarse material, and a cast metal is cast and laminated to complete the mold coarse material, and a machining allowance for the profile surface of the mold rough material is formed by machining or electric discharge machining. Since the pattern is processed and the exhaust hole communicating with the atmosphere in the normal direction from the back side of the mold is formed on the line of the joint portion of the mold rough material, the following excellent effects can be obtained. . By forming a gap at any position in the mold to ensure the required exhaust performance, a rubber product having good appearance and high dimensional accuracy can be manufactured. . The productivity and workability can be improved by omitting the work of deleting the overflowed spew. . Since the entire pattern surface can be easily machined by machining or electric discharge machining, the pattern can be manufactured in a short time and at low cost. In particular, the time required for manufacturing a purees mold by the conventional method can be reduced to 1/3 to 1/4. Can be done. . The gap amount (slit amount) of the mold coarse material alone can be confirmed at room temperature, and required exhaust performance can be guaranteed. . The gap can be set at any desired position, and the amount of the gap can be controlled by the casting conditions for the second shot.

[Brief description of the drawings]

1 (a), (b), (c) to (4), (a) and (b) of (1) are first to first molds for vulcanization molding of a rubber product according to the present invention. FIG. 4 is an explanatory view of a fourth manufacturing process, and FIG.
(A) and (a) are plan views of a rough mold material, (b) is a side view taken along the line AA of (a), (c) is a side view of (a),
FIGS. 1 (2) and 1 (a) are finished plan views of the second shot of the molded material, FIG. 1 (b) is a side view taken along the line BB of FIG. 1 (a), and FIG. 1 (c) is a side view of FIG. (A) of (3) is a plan view of the rough mold material at the time of pattern processing, (b) is a side view of (a), and (a) of (4) is a plane in which exhaust holes are formed in the rough mold material. FIG. 2B is a side view of FIG.

FIG. 2 is a plan view of a conventional mold (ring mold) for vulcanizing a rubber product.

3A is a partially enlarged view of FIG. 2, and FIG.
It is an enlarged view of the P section of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pattern segment 2 Parting surface 3 Groove Q spew 11 Mold rough material 11a Profile surface 12 Concave groove 13 Cast metal 14 Pattern 15 Exhaust hole X Cast joint

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B29K 105: 24 B29K 105: 24

Claims (3)

[Claims] 1. A first shot casting by die casting or a machining process to form a mold rough material having a pattern machining allowance and a concave groove, and a second shot by die casting in the concave groove of the mold rough material. A method for producing a mold for vulcanization molding, in which a mold rough is completed by casting and laminating a cast metal, and a pattern is formed by machining or electric discharge machining in place of a processing margin of the profile surface of the mold rough. 2. The method for manufacturing a vulcanization molding die according to claim 1, wherein an exhaust hole communicating with the atmosphere in a normal direction from the back side of the mold is formed on a line of the joint portion of the mold crude material. . 3. The vulcanization mold according to claim 1, wherein the joint portion of the cast and laminated mold coarse material has a fine gap of 0.005 to 0.06 mm due to solidification shrinkage of the cast metal material. Production method.