JPH0334807A - Radiator for forming mold - Google Patents

Abstract

PURPOSE:To lower dispersion in temp. distribution of molding material at a time of molding and to obtain the moldings excellent in precision by inserting an intense heat conductive material such as graphite as a core into the inside of a cylindrical jacket part made of metal and packing thermal transfer paste between the outer surface of the core and the inner surface of the jacket part. CONSTITUTION:The core 12 of a radiator for a forming mold is inserted into the inside of a jacket part 10. Material high in thermal conductivity is utilized as the core 12. For example, graphite formed into a slender round bar shape is utilized. Copper material excellent in thermal conductivity is utilized for the jacket part 10. Mixed paste of silver and copper is utilized as thermal transfer paste 14. This thermal transfer paste 14 is interposed between the core 12 and the jacket part 10 and thermal conductivity between the core 12 and the jacket part 10 is made excellent. Since the jacket part 10 and the core 12 are made superior in thermal conductivity, the radiator can be utilized as the radiator for cooling by providing this radiator to a forming mold. Especially the radiator is provided to the core and a cavity part of the forming mold and fitted to the part thick in wall thickness of a product. Thereby dispersion in temp. of molding material is made small and molding precision of the product is raised and quality of the moldings is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application) The present invention No. 11JJ relates to a heat sink used for cooling a mold.

(Prior art and problems to be solved) In molds used in thermoplastic synthetic resin molding, the molding material filled in the mold is cooled and solidified, so cooling water or λ! A through hole is provided in the mold through which the molding material passes through to remove heat from the molding material and assimilate it.

The cooling method of the molding die affects the cooling rate of the molding material and has a large impact on production efficiency.
From the point of view of product accuracy, it is desirable to uniformly cool the molded forest material so that there are no temperature differences in each part. This is because by uniformizing the temperature of the molding material and cooling it, it is possible to reduce sink marks and warpage when the molding material solidifies.

However, actual products vary in shape and the thickness is not always constant, so there are problems such as variations in temperature distribution in the molding material during cooling, resulting in reduced product accuracy.

In addition, conventionally, in addition to flowing cooling water, the mold temperature was
Although heat pipes and the like for cooling are provided for molds with mold temperatures of about 100° C. or lower, there are no suitable ones for molds with mold temperatures as high as 100° C. or higher.

Therefore, the present invention has been made to solve the problems described in (1), and its purpose is to be able to use the mold properly even when the temperature of the mold rises to about 100°C or more. Another object of the present invention is to provide a heat radiator for a molding die that can reduce variations in temperature distribution of a molding material during molding to obtain a molded product with high precision.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention has the following configuration.

That is, it is a heat dissipation body for a molding die that is inserted into the molding die close to the molding part of the molding die for resin molding, and includes graphite or the like as a core material inside a metal cylindrical outer mantle. A highly thermally conductive material is inserted, and a heat transfer paste is filled between the outer surface of the core material and the inner surface of the mantle.

(Function) A heat radiator is installed in the parts of the mold where the product becomes thick,
Heat dissipation by the heat radiator suppresses variations in the temperature of the molding material due to differences in the wall thickness of each part of the product, and suppresses sink marks and warpage of the molding material during molding. − [Improve accuracy.

(Embodiments) Preferred embodiments of the present invention will be described in detail below with reference to the attached four pages.

FIG. 1 is a sectional view showing an embodiment of a heat sink for a molding die according to the present invention. In the figure, reference numeral 10 denotes a mantle portion formed into an elongated cylindrical shape, and reference numeral 12 denotes a core material formed into an elongated round bar shape and attached inside the mantle portion 10. As the core material 12, a material with high thermal conductivity was used, and in the example, graph eye 1~ formed into an elongated round bar shape was used. 14 is the core material 12 and the outer mantle 1
The heat transfer pastes 1 to 1 are filled between the

A steel material with good thermal conductivity +' (thermal conductivity of about 0.04 cal/cm, 5 ec) was used for the jacket portion 10, and a mixed paste 1- of silver and copper was used as the heat transfer pastes 1 to 14.

The heat transfer pastes 1 to 14 are interposed between the core material 12 and the mantle portion 1o to improve thermal conductivity between the core material 12 and the mantle portion 10.

- Although the size calculation of the heating body is not particularly limited, in the embodiment shown in FIG.
0 mm, outer f (%) 5 mm, inner diameter 3 mm, and outer diameter of the core material 12 is 2.5 mm.

FIG. 2 is a sectional view showing another embodiment of the heat radiating body. In this embodiment, a screw 16 is provided on the outer periphery of the jacket portion 1o in order to screw the heat radiating body into the mold and fix it. In this example as well, a core material 1 made of graphite 1 is placed inside the mantle 1o.
2 is buried, and a heat transfer paste 1-14 is filled between the core material 12 and the mantle 10.

Since the above-mentioned heat dissipation body has excellent thermal conductivity in both the jacket part], O, and the core material 12, it can be effectively used as a heat dissipation body for cooling by installing it in a molding die. In particular, it is installed in the core and cavity of the mold,
By applying 4117
This makes it possible to improve the molding precision of the product and improve the quality of the molded product.

FIG. 3 shows an example in which the heat radiator described in "2" is actually installed in a molding die.

In the figure, 20 is a second mold, 22 is a lower mold, 24 is a split mold, and (5) 26 is a diagonal pin that guides the split mold 24. 28 is a molded product.

Reference numeral 30 denotes the heat dissipating body, which is embedded in a hole bored from the outer surface of the split mold 24 toward the molding cavity of the molded product 28. 32 is a water hole provided in the split mold 24. water hole 3
2 through which cooling water flows.

The above-mentioned molding die passes cooling water, and the heat sink 30
By installing this, it is possible to equalize the temperature distribution of the molding material during molding.

The molding precision of the molded metal can be improved.

The heat radiator can be installed at an appropriate position depending on the shape of the product, and the heat radiator can of course be provided as a molding die in which the heat radiator is pre-installed.

This makes it possible to easily manufacture products with higher molding precision than when using conventional molding dies.

FIG. 4 shows another example in which the heat sink 30 is disposed in the molding die. In this example, a heat sink 30 is installed along the side surface of the molded product 28, and the water hole 32 is installed so as to pass through the heat sink 30 portion. That is, in this molding die (6), molding is carried out while cooling water is flowing through the water holes 32, and since the heat sink 3o is in contact with the cooling water at 115 o'clock, it is effectively cooled, and the molding die is Since the cooling effect on the sides of the molded product 28 is enhanced and the sides of the molded product 28 are cooled uniformly as a whole, variations in the temperature distribution of the molding material during cooling are reduced.

Furthermore, since the heat dissipation body described above has a shape in which the core material 12 is covered with a 1° outer mantle, the temperature of the molding die is 100°C or higher.
It can be used without any problem even when the temperature is high, and there are no restrictions on operating temperature. Moreover, by using a heat radiator, when a deliverable resin is used, it can be effectively used to adjust the deliverability of the resin.

Furthermore, by arranging heat radiators at required locations, it is possible to improve the cooling rate of the molding material, making it possible to achieve high cycles during molding, thereby increasing production efficiency.
can be raised.

Although the present invention has been explained above with reference to preferred fire examples, the present invention is limited to these examples.

Needless to say, many modifications can be made without departing from the spirit of the invention.

(Effects of the Invention) According to the present invention, by installing a heat dissipation body for a molding die at a required part of the molding die, it is possible to easily reduce variations in the temperature distribution of the molding material during molding, and Product accuracy can be improved. In addition, this heat dissipation body for molding molds is thermally stable, works effectively even when the molding mold reaches high temperatures, and has remarkable effects such as being able to function as a cooling tool for the molding mold. .

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the heat dissipation body for a molding die according to the present invention, FIG. 2 is a cross-sectional view showing another embodiment, and FIG.
FIG. 4 and FIG. 4 are explanatory diagrams each showing an example in which a heat sink for a molding die is used in a molding die. DESCRIPTION OF SYMBOLS 10... Mantle part, 12... Core material, 14... Heat transfer paste, 20... Upper mold, 22... Lower mold,
24...split mold, 28...戊(8) Fig. 1

Claims (1)

[Scope of Claims] 1. A heat dissipation body for a molding die inserted into the molding die in close proximity to the molding part of a molding die for resin molding, the inside of a metal cylindrical outer mantle. 1. A heat dissipating body for a molding die, characterized in that a high heat conductive material such as graphite is inserted as a core material, and a heat transfer paste is filled between the outer surface of the core material and the inner surface of the mantle.