JPH0788028B2 - Injection mold manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an injection molding die made of resin, which is suitable as an injection molding die for a molded product of high-mix low-volume production.

(Prior Art) Conventionally, a metal injection mold has been generally used, but when a molded product is manufactured in a small amount, the injection mold has a short production period and is easy to handle. Due to the advantages described above, it has become popular to use a resin as an injection molding die.

7 to 13 show a conventional technique in a method of manufacturing a resin injection mold.

In the conventional technique shown in these figures, first, as shown in FIG. 7, a parting surface forming plate 52 is set in a casting frame 50 provided on a bottom plate 51, and a model 53 is installed thereon. Then, as shown in FIG. 8, resin 54a is injected,
Moreover, the upper opening is covered with the upper plate 55.

Then, as shown in FIG. 9, after curing, the parting surface forming plate 52 and the bottom plate 51 are removed, the casting frame 50 is inverted, and the resin 54b is injected as shown in FIG. There were 56.

Then, as shown in FIG. 11, after curing, it was inverted and the casting frame 50, the upper plate 55, the mounting plate 56, the model 53, etc. were removed. In this case, the model 53 was demolded by heating and softening it when the model material was plastic. Then, as shown in FIG. 12, the ejector pin hole 57 and the cooling water pipe 58 are machined in the resin mold 54B on the core side made of the resin 54b, and the sprue 59 and the cooling water pipe 58 are machined in the resin mold 54A on the cavity side. Was formed by.

FIG. 13 shows a resin mold 54B on the core side and a resin mold 54A on the cavity side.
In the figure, 60 and 61 are mold plates, 62 is a receiving plate, 63 is a mounting plate, 64 is a spacer block, 65 is an upper ejector plate, and 66 is a lower ejector plate. is there. 67 is an ejecta pin,
Moreover, the mounting plate 63 side is the fixed side, and the opposite side is the movable side.

Further, as another conventional technique, for example, Japanese Patent Publication No. Sho 58-2426.
There is a technology described in Japanese Patent Publication No. 2.

In the prior art described in the above-mentioned publication, a rod-shaped member made of a better thermal conductor than the mold is embedded at a position facing the gate in the movable mold.

(Problems to be Solved by the Invention) However, in the prior art shown in FIGS. 7 to 13, when manufacturing the injection mold, as can be seen from FIG. Although it is formed, there has been a problem that a device for obtaining an excellent cooling effect is required and the formation of the cooling circuit is complicated.

Further, the conventional technique described in the above-mentioned publication has a problem that a special man-hour such as machining is required to form the gate sprue leading to the cavity.

The present invention has been proposed in view of the above, and an object thereof is to form a cavity and a sprue communicating with the cavity in a single step, and to cool the molded product in a mold. An object of the present invention is to provide a method of manufacturing an injection mold that can easily form a circuit.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention is to preliminarily arrange an integrated body of a cavity forming model and a sprue forming member on a cavity forming side of an injection mold and inject a resin to cure the same. Then, a heat conductive member is previously arranged on the back surface side of the model, and resin is injected from the core forming side of the injection molding die to cure the resin, and then an integrated product of the model and the sprue forming member is formed on the injection molding die. It was taken out from the.

(Operation) In the present invention, since the integrated body of the cavity forming model and the sprue forming member is arranged in advance on the cavity forming side of the injection mold and the resin is injected and cured, the cavity is formed by the model. At the same time, the sprue forming member can form a sprue that communicates with the gate, so that the cavity and the sprue can be formed with a single man-hour.

Further, in the present invention, the heat conducting member is arranged in advance on the back surface side of the model, and the resin is injected from the core forming side of the injection mold to be cured. The cooling circuit for the product can be easily formed.

(Example) Hereinafter, the Example of this invention is described based on drawing.

1 to 6 are explanatory views showing an embodiment of the present invention in the order of steps.

In the embodiment shown in these figures, first, as shown in FIG. 1, the casting frame 2 is installed on the bottom plate 1, and the parting surface forming plate 3 is placed on the lower half side of the casting frame 2. . Also,
On the parting surface forming plate 3, an integrated product of the cavity forming model 4 and the sprue forming member 4a is installed in advance. Further, a heat conducting member A for forming a cooling circuit is previously arranged on the back surface side of the model 4.

Then, as shown in FIG. 2, the resin 5a is injected into the upper portion, the upper opening is covered with the upper plate 6, and the upper opening is placed in a normal temperature or drying oven to be primarily cured. It should be noted that the upper plate 6 is provided with a screw member 8 for obtaining a hole 7 for mounting the upper plate 6 when the resin is hardened and then incorporated into a mold base.

Next, as shown in FIG. 3, after the resin 5a is cured, it is inverted. Also, the parting surface forming plate 3 and the bottom plate 1
To remove. Further, an ejector pin 9 for ejecting an integrated product of the model 4 and the sprue forming member 4a is provided.

Then, the resin 5b serving as the resin mold on the core side is injected upward, and the mounting plate 10 having the screw member 11 similar to the screw member 8 is placed above the casting frame 2 and secondarily cured. .

Then, as shown in FIG. 4, turn the casting frame 2 over,
From the casting frame 2, the integrated product of the model 4 and the sprue forming member 4a, the cured resin 5a, the ejector pin 9 provided on the resin 5a, the mounting plate 10 through which the ejector pin 9 is provided, and the like are removed.

Through the above steps, as can be seen from FIG. 4, the resin 5b forming the resin mold on the core side is provided with the heat conducting member A, and the resin 5a forming the resin mold on the cavity side is formed with the model 4 and the sprue. With the member 4a, the cavity and the sprue communicating with the cavity can be formed in a single process.

Then, as shown in FIG. 5, the rod B provided on the head side of the ejector pin 9 is extended to move the ejector pin 9
Then, the integrated product of the model 4 and the sprue forming member 4a is taken out. As a result, the integrated product of the model 4 and the sprue forming member 4a can be easily separated from the resin mold in which the resin 5a has been cured without breaking the resin mold. Next, the casting frame 2, the upper plate 6 having the screw member 8, the ejector pin 9, etc., the mounting plate 10, etc. are removed.

Then, as shown in FIG. 6, the outer peripheral portions of the cured resins 5a and 5b are subjected to finish processing to obtain a cavity side resin mold 5A and a core side resin mold 5B.

Further, on the resin mold 5B on the core side, directly below the heat conducting member A,
The cooling water pipe 12 is formed by machining. This cooling water pipe 12
Cooling water is inserted into the mold during molding, and the cooling effect of the cooling water is efficiently transmitted to the molded product in the mold through the good heat conducting member A.

Next, the cavity side resin mold 5A and the core side resin mold
5B is positioned and incorporated into the mold base as shown in FIG. The mold base in this embodiment is
A base 14 is provided, a spacer block 15 is erected on an upper outer portion of the base 14, and a receiving plate 16 is provided above the spacer block 15. A resin mold 5B on the core side is provided on the receiving plate 16 via a screw member 17, and a mold plate 18 is provided outside the resin mold 5B. A mold plate 19 is provided outside the cavity side resin mold 5B.
A mounting plate 21 is provided on top of 19. This mounting plate 21
A resin mold 5A on the cavity side is attached to this via a screw member 20. Further, the mounting plate 21 is formed with a sprue 13a communicating with the sprue 13 formed in the resin mold 5A on the cavity side.

An ejector pin 9 is provided on the resin mold 5B on the core side, and the base end side of the ejector pin 9 extends below the receiving plate 16 and is supported by the upper ejector plate 22. A lower ejector plate 23 is provided below the ejector plate 22, and these are provided above the base 14 so that the ejector pin 9 is driven, as is well known.

Reference numeral 24 in FIG. 6 denotes a molded product, which can be molded by injecting resin into the cavity through the sprues 13a, 13.
You can get 24.

As described above, in this embodiment, the integrated body of the cavity forming model 4 and the sprue forming member 4a is arranged in advance on the cavity forming side of the casting frame 2, and the resin is injected and cured. Since the cavity and the sprue 13 can be formed in a single step and there is no need to machine the sprue in a subsequent step, the number of steps can be reduced accordingly.

Further, since the heat conducting member A is arranged in advance on the back surface side of the model 4 for forming the cavity and the resin is injected from the core forming side of the injection molding die to be cured, the molded article is molded in the die. A cooling circuit for cooling 24 can be easily formed, and a cooling water pipe 12 is formed at a position close to the heat conducting member A, and cooling water is poured into the cooling water pipe 12, so that heat Through the guide member A, the molded product 24 in the mold can be efficiently cooled.

(Effects of the Invention) As described above, according to the present invention, the integrated body of the cavity forming model and the sprue forming member is previously arranged on the cavity forming side of the injection mold, and the resin is injected and cured. Since the cavity and the sprue can be formed in a single step and the sprue does not need to be machined in a subsequent step, the number of steps can be reduced accordingly.

Further, according to the present invention, the heat conducting member is arranged in advance on the back surface side of the model, and the resin is injected from the core forming side of the injection mold to be cured. There is an effect that a cooling circuit for a product can be easily formed and an effect that cooling efficiency can be improved.

[Brief description of drawings]

1 to 6 show an embodiment of the present invention.
FIG. 1 is a view showing a set state of a model, a sprue forming member, and a heat conducting member, FIG. 2 is an explanatory view showing a process of forming a resin mold on a cavity side, and FIG. 3 is a resin mold forming on a core side. Fig. 4 is an explanatory view showing the steps, Fig. 4 is an explanatory view of a step of separating the cavity side resin mold from the core side resin mold, and Fig. 5 is a step of removing the model and the sprue forming member from the cavity side resin mold. Explanatory drawing, FIG. 6 is explanatory drawing of the process of incorporating the resin mold of a core side, and the resin mold of a cavity side into a mold base. 7 to 13 are process explanatory diagrams showing a conventional technique. 2 ... Casting frame, 4 ... Cavity forming model, 4a ...
... Sprue forming member, A ... Heat conducting member, 5a ... Resin for forming resin mold on the cavity side, 5b ... Resin for forming resin mold on the core side, 5A ... Resin for cavity side Mold, 5B ... Resin mold on the core side.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tadao Sakata 1048 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (56) References JP, B2)

Claims (1)

[Claims] 1. A method of manufacturing an injection molding die using a resin, wherein an integrated product of a cavity forming model and a sprue forming member is previously arranged on the cavity forming side of the injection molding die, and the resin is injected and cured. Placing a heat conducting member on the back side of the model in advance, injecting resin from the core forming side of the injection mold to cure it, and then taking out the integrated product of the model and the sprue forming member from the injection mold. A method for manufacturing an injection mold, comprising: