JPH07256433A - Metallic mold for forming - Google Patents

Abstract

PURPOSE:To drastically improve the heating and cooling functions of a metallic mold by executing corrugate-working to the outer surface of a pipe and applying electroplating of the same material as the metallic mold, at the time of inserting the copper alloy pipe as cast-in into the inner part of the metallic mold of an aluminum alloy. CONSTITUTION:Pure copper, copper alloy or stainless steel-made pipe 1 is inserted as cast-in over the whole body in the inner part of the aluminum alloy casting-made metallic mold 18 for forming synthetic resin. At this time, the corrugate-working is executed to the outer surface of the pipe 1 to make the outer surface area of the metallic pipe 1 large. Further, the electroplating or thermal spraying of the same material as the metallic mold is applied on the corrugated outer surface to form a coated material 5. Then, the molten aluminum alloy melts the coated material 5 on the outer surface of the pipe 1 and integrated to obtain a heating and cooling medium passage sufficiently welded between the product metallic mold 18 base material and the pipe 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for molding synthetic resin or the like.

[0002]

2. Description of the Related Art Compared to injection-molded products, resin blow-molded products do not have a high air-blowing pressure that is equivalent to the injection pressure, resulting in poor surface quality. Due to its shortcomings, it is one of the factors limiting the applications of blow molded products. However,
Since the air blowing pressure is low, the mold clamping force can be reduced, so there are advantages such as low mold cost or low molding machine, and if the surface texture and molding cycle are improved at the same time, the application will be greatly improved. Expanding.

Conventionally, as shown in FIGS. 6 and 7, a normal metal pipe 1 whose outer surface is not processed at all has been used as a cast-in pipe.

Further, in FIG. 8, a heating or cooling medium hole 3 is formed at a desired position in a die 2 manufactured by a mechanical working or a casting method using a drilling tool such as a drill.

[0005]

However, in the case of manufacturing the above-mentioned molding die, when the metal pipe 1 having a smooth outer surface as in the former case is used as a cast-in pipe, the metal pipe 1 and the die are Since the material for the die base material 2a is different, the molten metal for the die base material 2a is difficult to be fused to the metal pipe 1, and poor fusion occurs to cause poor thermal conductivity, which depends on the heating / cooling medium flowing in the metal pipe 1. There is a problem that it is difficult to heat and cool the mold 2 smoothly.

Further, when the latter is drilled,
Since the heating or cooling medium hole 3 can be processed only linearly, unevenness of heating and cooling occurs on the cavity surface of the mold 2 having irregularities, and therefore, molding defects such as poor surface quality, deformation, and baking of the molded product occur. There was a problem that it occurred.

The present invention has been made in view of the above problems, and an object thereof is to provide a molding die having a significantly improved heating / cooling function.

[0008]

In order to achieve the above object, in the present invention, in a mold for molding synthetic resin, the mold is an aluminum alloy casting, and pure copper is entirely provided inside the casting. When casting a copper alloy or stainless steel pipe, the outer surface of the pipe is corrugated, and the outer surface of the corrugated pipe is electroplated or sprayed with the same material as the mold. did.

[0009]

In most cases, steel such as die steel is used as the metal of the mold, but in the case of blow molding, since the air blowing pressure cannot be increased as described above, the surface quality is poor, but this is solved. There is a method of heating and cooling the mold as one of the means for achieving this. In other words, it is a method of sandwiching the parison and heating the mold being blown to promote transfer, then cooling and taking out the product, but in order to efficiently perform the heating and cooling cycle, the thermal conductivity as described above is used. A mold that takes heat capacity into consideration is required. An aluminum alloy that can shorten the heating / cooling cycle time of the mold in consideration of thermal conductivity and heat capacity is used. On the other hand, in the case of cast metal, the outer surface of the pipe is corrugated, and copper or SUS (stainless steel) plated with the same material as the die base material is bent into a predetermined shape and placed in the mold. It is possible to provide a heating / cooling medium passage in which the die base material and the metal pipe are sufficiently fused by arranging them along the cavity surface and casting them with an aluminum alloy.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the molding die according to the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view of a metal pipe for cast doll according to the present invention, FIG. 2 is an enlarged sectional view of a portion A of FIG. 1 in which the outer surface of the metal pipe is corrugated and plated, and FIG. FIG. 4 is an explanatory view showing the manufacturing method of the working die, FIG. 4 is an explanatory view showing the continuation of FIG. 3, and FIG. 5 is an explanatory view showing the continuation of FIG.

1 and 2, the metal pipe 1 is cast at a desired position in the mold 2 in order to heat and cool the mold 2 by flowing a heating / cooling medium.

As shown in FIG. 2, the outer surface of the cast metal metal pipe 1 is processed into a wavy shape (or a screw shape) so that the outer surface area of the metal pipe 1 is increased.

The surface of the corrugated metal pipe 1 is coated with a coating material 5 of the same material as the aluminum alloy used for the die base material 2a by electrolytic plating or thermal spraying. As the material of the metal pipe 1, pure copper, copper alloy, stainless steel (SUS), or the like is used.

In the present embodiment, of the molding dies 2, particularly blow molding dies will be described. The blow molding dies 2 are aluminum alloy castings, and the sprue 6 and the runner are selected according to the casting plan. 7 and feeder 8 are attached, covering material 5
The metal pipe 1 made of a copper alloy coated with is bent along a predetermined mold cavity surface 10 and then arranged at a desired position of the mold 9.

The mold 9 comprises an upper mold 11, a lower mold 12, an upper mold flask 13 and a lower mold flask 14.

The blow molding die 2 is manufactured as follows.

First, as described above, the covering material 5 is formed into a corrugated shape 4.
The copper alloy metal pipe 1 electrolytically plated or sprayed on the outer surface of the metal pipe 1 is bent into a similar shape along the mold cavity surface 10. In some cases, electrolytic plating or thermal spraying may be performed on the outer surface of the bent mold pipe 1.

The coated metal pipe 1 is attached to the lower mold flask 14
After arranging so as to have a predetermined pitch, for example, 25 mm on the top, molding sand is filled to form the lower mold 12.

At this time, the depth from the outer surface of the metal pipe 1 to the mold cavity surface 10 is set to, for example, 10 to 30 mm.

Subsequently, after placing the upper mold 11 which has been previously filled with molding sand and molded into the upper mold flask 13, for example, 700
~ 740 ℃ aluminum alloy (AC4C) molten metal 16
Pour it into the ladle 15 and pour it through the sprue 6 as shown in FIG.

When the molten aluminum alloy 16 is poured in this way, the coated metal pipe 1 reaches the melting temperature and is fused to the molten aluminum alloy 16.

At this time, the surface of the coated metal pipe 1, that is, the coating material 5 is melted in the molten aluminum alloy 16 and is surrounded by casting, and is integrated with this (FIG. 4).

By cooling the poured aluminum alloy melt 16 for a predetermined time in this way, the aluminum alloy melt 16 is solidified to form a product mold 18.

After that, the feeder 20 is cut into a product mold 18 in FIG.

[0026]

As is apparent from the above description, in the present invention, in the mold for molding synthetic resin, the mold is an aluminum alloy casting, and pure copper and When casting a copper alloy or stainless steel pipe, the outer surface of the pipe was corrugated, and the outer surface of the corrugated pipe was electroplated or sprayed with the same material as the mold. As a result, since the mold base material and the metal pipe are completely fused, the heating and cooling function of the mold is improved, the surface quality of the molded product can be improved and the molding cycle time can be shortened at the same time, and the productivity is also improved. .

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a cast metal pipe according to the present invention.

FIG. 2 is an enlarged sectional view of a portion A of the coated metal pipe shown in FIG.

FIG. 3 is an explanatory view showing a method for manufacturing a molding die.

FIG. 4 is an explanatory diagram showing a sequel to FIG. 3;

FIG. 5 is an explanatory diagram showing a sequel to FIG. 4;

FIG. 6 is a vertical cross-sectional view of a conventional metal pipe.

7 is an enlarged sectional view of a B part in FIG.

FIG. 8 is a cross-sectional view of a conventional mold.

[Explanation of symbols]

 1 Metal Pipe 2 Mold 2a Mold Base Material 3 Heating or Cooling Medium Hole 4 Rippled (Screwed) 5 Cover Material 6 Gate 7 Runner 9 Mold 10 Mold Cavity Surface 11 Upper Mold 12 Lower Mold 13 Upper Mold Casting Frame 14 Lower mold flask 15 Handle ladle 16 Aluminum alloy melt 18 Product mold 20 Riser part

Claims (1)

[Claims] 1. A synthetic resin molding die, wherein the die is a casting of an aluminum alloy, and when casting a pipe of pure copper and a copper alloy or a stainless steel throughout the casting, the die of the pipe is A molding die, wherein the outer surface is corrugated, and the outer surface of the corrugated pipe is electroplated or sprayed with the same material as the die.