JPH09207136A - Mold for resin molding and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively improve the cooling efficiency by effectively bringing a cooling tube into contact with the inner surface of the molding surface side of a mold body. SOLUTION: The resin mold comprises a groove 18 of the shape copying the shape of the cavity 14 side of a mold body 12 corresponding to the site for embedding a tube 16 in the body 12, and a rib-like radiating part 22 formed by protruding outward of the groove 18 and inserting the tube 16 made of metal material having higher thermal conductivity than that of the body 12 with lower melting point than that of the tube 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molding die for casting a cooling pipe in a die body and a method for manufacturing the same.

[0002]

2. Description of the Related Art In general, various molding methods such as injection molding, compression molding, blow molding and the like are employed to obtain a resin molded product using a synthetic resin material. The mold used in this type of molding method is to supply cooling water into the mold in order to rapidly cool and solidify the molten resin material poured into the cavity to improve productivity. Cooling pipes are provided.

At this time, it is desired that even a mold having a cavity of a complicated shape can effectively and accurately cool a necessary portion without causing a lack of cooling capacity or a non-uniform state. .

Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. 3-99767, a groove for accommodating a pipe for a cooling water passage is formed in a main body of a casting mold so as to follow the shape of a cavity. After forming and arranging the pipe for the cooling water passage in this groove, the molten metal of a material having a lower melting point and higher thermal conductivity than the main body of the casting mold and the pipe is poured into the groove to form the pipe. Casting technology is known.

[0005]

However, in the above conventional technique, the pipe is bent along the shape of the cavity, and then the pipe is inserted into the groove in a loosely fitted state. For this reason, the piping portion that is not temporarily fixed by the fixing means is bent downward by its own weight, and particularly in the concave portion having R, the piping is separated from the back surface (molding surface side inner surface portion) of the cavity forming portion of the mold. There are cases. As a result, even if the pipe is cast from a material having a high thermal conductivity, there will be a portion where the cooling efficiency is lower than the portion in contact with the back surface of the cavity forming portion of the mold. Therefore, it has been pointed out that there is a problem that an efficient and highly accurate molding process cannot be performed.

The present invention solves this kind of problem, and the cooling pipe can be surely brought into contact with the inner surface of the mold body on the molding surface side, whereby the cooling efficiency can be effectively improved. Another object of the present invention is to provide a resin molding die and a method for producing the same.

[0007]

In order to solve the above-mentioned problems, the present invention is characterized in that a cooling pipe is provided in a groove formed in the mold body following the shape of the molding surface, and The pipe is in contact with the molding surface side inner surface portion forming the groove portion. Then, when the molten metal material is poured into the groove, the molten metal pressure causes the pipe to come into contact with the inner surface of the molding surface more reliably, and the contact area between the pipe and the inner surface of the molding surface increases. As a result, the molding surface side can be cooled uniformly, and the cooling efficiency is effectively improved.

Further, since the pipe is formed into a deformable bellows shape, particularly when the molding surface has a complicated shape,
This pipe can be surely deformed following the shape of the groove corresponding to the shape of the molding surface. Therefore, the pipe can surely contact the inner surface of the groove on the molding surface side to further improve the cooling efficiency. Further, from the shape following property of the pipe itself, the distance (thickness) between the molding surface and the groove can be reduced. The thickness can be reduced, and the cooling efficiency can be easily promoted.

Furthermore, since the heat radiating portion is formed in the shape of a rib protruding to the outside of the groove portion, the heat radiating portion formed of a metal material having high thermal conductivity contributes to the cooling effect as a heat radiating fin. Further, since the heat radiating portion is cast in the mold body, it also has a function of reinforcing the mold body.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective explanatory view of a resin molding die 10 according to an embodiment of the present invention. This mold 10
Includes a mold body 12 made of cast iron, and a cavity surface (molding surface) 14 for resin molding is formed on the surface side of the mold body 12. Inside the mold body 12, a cooling pipe 16 is provided.
A plurality of groove portions 18 having a shape corresponding to the portion to be embedded and having a shape following the shape of the cavity surface 14 side are provided.

The pipe 16 is made of a metal material, for example, copper or an iron-based material, and as shown in FIGS. 2 and 3,
It is configured in a bellows shape that is deformable so as to surely contact the inner surface portion 20 on the side of the cavity surface 14 that constitutes the groove portion 18.

The mold body 12 is made of a metal material having a lower melting point than the pipe 16 and a higher thermal conductivity than the mold body 12, for example, an aluminum alloy.
A plurality of rib-shaped heat radiating portions 22 are provided which are cast around and project outside the groove portion 18.

A method of manufacturing the mold 10 having the above structure will be described below.

First, as shown in FIGS. 4 and 5, an extinguishable model 30 for forming the mold body 12 by the full molding method is formed. The fusible model 30 has a plurality of piping grooves 32 corresponding to the groove portions 18 of the mold body 12, and each piping groove 32 is a cavity surface 34 corresponding to the cavity surface 14 of the mold body 12. The shape is set according to the shape.

Next, as shown in FIG. 6, the vanishing model 3
0 is placed in the iron frame 40, and the iron frame 40 is filled with sand 42 to form a sand mold 44. The sand mold 44 is provided with a pair of gates 46, and as shown in FIG. 7, molten cast iron 50 is supplied from the gates 46 toward the runner 48. As a result, the fugitive model 30 is burned and disappears and is replaced with the molten metal, and the cast iron mold body 12 is manufactured.

In the mold body 12 taken out from the sand mold 44, as shown in FIG.
Is arranged. Here, the pipe 16 is formed in a deformable bellows shape, and the groove portion 1 corresponds to the cavity surface 14.
Even if 8 has a complicated shape, the pipe 16 can be easily and surely deformed following the inner surface 20 of the groove 18 on the side of the cavity surface 14.

If necessary, by using a fixing member (not shown) for holding the pipe 16, the pipe 16 can be more surely contacted along the inner surface portion 20.

Further, as shown in FIG. 9, the mold body 12
Inside the frame 6 is formed a rib-shaped cavity 60 that communicates with each groove 18 and projects outward from the groove 18.
2 is placed. Then, the molten aluminum alloy 64 is poured into the cavity 60 formed by the frame 62, the molten aluminum alloy 64 is solidified, and then the frame 62 is taken out from the mold body 12, whereby the resin molding die 10 is obtained. It is manufactured (see FIGS. 1 to 3).

In this case, in this embodiment, the pipe 16 is
Molten aluminum alloy 64 is poured into the groove 18 from the cavity 60 via the frame 62 while being in contact with the inner surface 20 on the cavity surface 14 side that constitutes the groove 18.
Therefore, the pipe 16 is pressed against the inner surface portion 20 by the molten metal pressure of the molten aluminum alloy 64, and the contact area between the pipe 16 and the inner surface portion 20 increases. This allows the pipe 1
6 can be reliably prevented from separating from the inner surface portion 20, and the cooling efficiency of the cavity surface 14 can be effectively improved.

Further, in this embodiment, the pipe 16 is formed in a deformable bellows shape. Therefore, even if the cavity surface 14 has a complicated shape, the pipe 16 can be reliably deformed following the shape of the groove portion 18 corresponding to the cavity surface 14. Therefore, the pipe 16
Can be reliably brought into contact with the inner surface portion 20 of the groove portion 18, and the cooling efficiency is further improved. Moreover, due to the shape following property of the pipe 16 itself, it is possible to reduce the distance (thickness) between the cavity surface 14 and the groove portion 18, and there is an advantage that the cooling efficiency is easily promoted.

Furthermore, the heat radiating portion 22 is formed in the shape of a rib projecting to the outside of the groove portion 18 (FIGS. 2 and 3).
reference). As a result, the heat dissipation portion 22 formed of a metal material (aluminum alloy) having a high thermal conductivity contributes to the cooling effect as a heat dissipation fin, and the heat dissipation portion 22 is cast in the mold body 12, It also has a reinforcing function of the mold body 12.

[0022]

In the resin molding die and the manufacturing method thereof according to the present invention, the cooling pipe is arranged in the groove formed in the mold body along the shape of the molding surface, and the pipe is The molten metal material is poured into the groove portion in a state of being in contact with the molding surface-side inner surface portion that constitutes the groove portion, so that the pipe is reliably contacted with the molding surface-side inner surface portion by the molten metal pressure. As a result, the contact area between the pipe and the inner surface of the molding surface is increased, the molding surface can be cooled uniformly, and the cooling efficiency is effectively improved.

[Brief description of drawings]

FIG. 1 is a perspective explanatory view of a mold according to an embodiment of the present invention.

FIG. 2 is a partial vertical cross-sectional explanatory view of the mold.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a perspective explanatory view of a model corresponding to a mold shape.

5 is a sectional view taken along line VV in FIG.

FIG. 6 is a vertical cross-sectional explanatory view of a sand mold in which the model is placed.

FIG. 7 is an explanatory diagram when manufacturing a mold body with the sand mold.

FIG. 8 is an explanatory diagram showing a state in which piping is arranged on the mold body.

FIG. 9 is an explanatory diagram for manufacturing a heat radiating section by casting a pipe around the mold body.

[Explanation of symbols]

10 ... Mold 12 ... Mold body 14 ... Cavity surface 16 ... Piping 18 ... Groove 20 ... Inner surface 22 ... Heat dissipation part 30 ... Model 32 ... Piping groove 34 ... Cavity surface 44 ... Sand mold 60 ... Cavity 62 ... Frame

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B22C 9/06 B22C 9/06 F

Claims (4)

[Claims] 1. A resin molding die manufactured by casting a cooling pipe in a mold body, which is provided in the mold body and corresponds to a portion where the pipe is embedded. A groove having a shape following the shape of the molding surface of the mold body, made of a metal material having a lower melting point than the pipe and a higher thermal conductivity than the mold body, and is poured into the groove in which the pipe is arranged. And a rib-shaped heat dissipation portion formed so as to be cast around the pipe by being melted and to project to the outside of the groove portion, and the pipe is in contact with the molding surface-side inner surface portion forming the groove portion. Therefore, the resin molding die is formed in a deformable bellows shape. 2. A method of manufacturing a resin molding die in which a cooling pipe is cast in a mold body, the method corresponding to a portion in which the pipe is embedded in the mold body, and A step of forming a groove portion having a shape following the molding surface side shape; a step of arranging the pipe in the groove portion in a state of being brought into contact with the molding surface side inner surface portion forming the groove portion; A step of pouring a molten metal material having a lower melting point than the pipe and having a higher thermal conductivity than the mold body in the groove, and providing a heat radiating portion projecting outside the groove along with casting the pipe; A method for producing a resin-molding die, comprising: 3. The method for manufacturing a resin molding die according to claim 2, wherein the pipe is formed in a deformable bellows shape. 4. The method of manufacturing a resin molding die according to claim 2, wherein the heat dissipation portion is formed in a rib shape.