JP2711923B2 - Injection mold manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an injection mold made of resin, which is suitable as an injection mold for a molded product manufactured in a large variety of small quantities.

(Prior Art) Conventionally, metallic injection molding dies have been generally used. However, when a molded product is produced in a small quantity, the production period of the injection molding die is short and handling is easy. Due to the advantages such as the above, the use of resin as an injection mold has been increasingly performed.

FIGS. 25 to 31 show this type of conventional example. Conventionally, first, as shown in FIG.
A parting surface forming plate 52 is set in a casting frame 50 provided on 51, a model 53 is set thereon, and thereafter, as shown in FIG. 26, a resin 54a is injected, and the upper opening is opened. The part is covered with an upper plate 55.

Then, after curing, as shown in FIG. 27, the parting surface forming plate 52 and the bottom plate 51 are removed, the casting frame 50 is inverted, and as shown in FIG. There were 56.

Then, as shown in FIG. 29, after curing, invert,
In addition, the casting frame 50, the upper plate 55, the mounting plate 56, the model 53 and the like have been removed. In this case, when the model material was plastic, the model 53 was heated and softened.

Thereafter, as shown in FIG. 30, a core 5 made of resin 54b is formed.
An ejector pin hole 57 and a cooling water pipe 58 are formed in 4B, and a spool 59 and a cooling water pipe 58 are formed in the cavity 54A by machining.

FIG. 31 shows a state in which the core 54B, the cavity 54A, etc. are incorporated in the mold base, in which 60, 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. Reference numeral 67 denotes an ejector pin, and the mounting plate 63 side is a fixed side, and the opposite side is a movable side.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional example, the model 53 is removed from the mold as shown in FIG. 29 when the injection mold is manufactured. As shown in FIG. 30, the ejector pin hole 57 must be formed by machining, which is complicated, and the overall production is complicated.

The present invention has been proposed in view of the above, and it is an object of the present invention to easily remove a model, that is, to remove a model, and to set an ejector pin by post-processing after resin curing. It is an object of the present invention to provide a method of manufacturing an injection mold in which the hole 57 does not need to be formed and the manufacturing time is shortened and the manufacturing is facilitated.

(Means for Solving the Problems) The present invention relates to a method of manufacturing an injection mold using a resin, wherein a first screw member for obtaining a mounting hole at the time of injecting a resin to be a cavity is provided in the casting frame. A second portion is provided at a portion where the resin to be a cavity is injected, and is used to obtain an ejector pin and a mounting hole when the resin to be a core is injected.
The screw member is placed in the casting frame at a position where the resin to be the core is injected, and after the resin is cured, the outer peripheral portion of the resin is finish-processed to obtain a cavity and a core. Form a spool in the cavity,
Disposing a first template outside the core, attaching the core to the receiving plate via a mounting hole formed by the second screw member with a screw, and disposing the second template outside the cavity;
The above object is attained by attaching the cavity to the mounting plate with a screw through the mounting hole formed by the first screw member.

Further, the above object is achieved by embedding a sleeve in advance in the outer periphery of the ejector pin when casting the core.

(Operation) In the present invention, the model is configured as described above, and the model is released using the ejector pin embedded at the time of casting.
In addition, when the resin is cured to form the core, a step of processing the ejector pin holes by post-processing is not required.

Embodiment 1 FIGS. 1 to 12 show a first embodiment of the present invention. In this embodiment, an injection mold is manufactured by the following steps.

That is, first, as shown in FIG. 1, a parting surface forming plate 3 is provided in a casting frame 2 provided on a bottom plate 1, and a model 4 is provided thereon.

Then, as shown in FIG. 2, a resin 5a is injected into the upper portion, and the upper opening is covered with the upper plate 6, and the upper portion is placed in a room temperature or a drying furnace to be temporarily cured. Note that the upper plate 6 is provided with a screw member 8 as a first screw member for obtaining a mounting hole 7 when the resin is cured and then incorporated into a mold base.

Next, as shown in FIG. 3, after the resin 5a is cured, the resin 5a is turned over, and the parting surface forming plate 3 and the bottom plate 1 are removed. A mounting plate 10 having ejector pins 9 is set in advance, and a resin 5b serving as a core is injected as shown in FIG.
Secondary curing is used. In this case, a release agent 9a is applied to the outer periphery of the ejector pin 9 embedded in the resin 5b (see FIG. 3). A screw member 11 as a second screw member similar to the screw member 8 is provided on the mounting plate 10.

Thereafter, as shown in FIG. 5, the model 4, the cured resin 5b, the ejector pins 9 embedded in the resin 5b, the mounting plate 10 through which the ejector pins 9 are penetrated, and the like are removed from the casting frame 2. Remove.

Then, as shown in FIG. 6, the rod 12 provided on the head side of the ejector pin 9 is extended, and the ejector pin 9 is extended.
Take out the model 4 provided at the tip. In this way, the model 4 can be easily broken without the resin 5b.
Can be separated from the resin mold.

Then, as shown in FIG. 7, the casting frame 2, the screw member
The upper plate 6 having 8, 9 and the like, the mounting plate 10 and the like are removed, and the cured resin 5a, 5b is turned over and set at an appropriate position.

Next, as shown in FIG. 8, the outer peripheral portions of the cured resins 5a and 5b are finished to obtain a cavity 5A and a core 5B. That is, the one-dot chain line in the outer peripheral portion in the figure is the finishing margin.

In this case, the ejector pin hole 9a is already formed in the core 5B, and it is not necessary to perform post-processing as before, and the processing step is unnecessary.

 Note that a spool 13 is formed in the cavity 5A.

FIG. 9 shows a state in which the cavity 5A and the core 5B are assembled in a mold base. In the figure, reference numeral 14 denotes a base on which a spacer block 15 is erected on an upper outer portion, and a receiving plate 16 is provided above the spacer block. A core 5B is provided on the receiving plate 16 via a screw member 17, and a template 18 is provided outside the core B. Also, the mold plate facing the mold plate 18 and facing the cavity 5A
19 is provided, and a mounting plate 21 to which the cavity 5A is mounted via a screw member 20 is provided above the template 19. The mounting plate 21 has a spool 13a communicating with the spool 13 of the cavity 5A.

An ejector pin 9 is provided on the core 5B, and the base end of the ejector pin 9 extends below the receiving plate 16 and is supported by the upper ejector plate 22. Also,
Below the ejector plate 22, a lower ejector plate 23 is provided. These are provided above the base 14, and the ejector pins 9 are configured to be driven as in a well-known configuration.

Fig. 10 shows mounting on the molding machine, spool 13, spool 13a
The figure shows a state in which the resin is injected from the mold to complete the molding, in which 24 is a molded product, 25 is a fixed side of the molding machine, and 26 is a movable side.

FIG. 11 shows a state where the movable side is moved and the mold is opened. Further, FIG. 12 shows a state in which the ejector pin 9 is pushed up via the rod 27 and the molded product 24 is removed from the core 5B.

(Embodiment 2) Figs. 13 to 24 show a second embodiment of the present invention. In this embodiment, as shown in Fig. 15, when the ejector pin 9 is set, a sleeve is provided around the outer periphery thereof. 9A is also set, and as shown in FIG. 24, the feature is that wear and damage of the core 5A are prevented by the sleeve 9A when the ejector pin 9 is driven.

Since other configurations, manufacturing steps, operational effects, and the like are the same as those of the above-described first embodiment, the same members are denoted by the same reference numerals, and description thereof will be omitted.

(Effects of the Invention) As described above, according to the present invention, in a method of manufacturing a molding die using a resin, the ejector pins are embedded in advance at the time of casting the core. Take out the model,
It can be done easily without destroying the model.

b. No post-processing of the ejector pin holes for removing the molded product is required, damage to the core can be prevented, post-processing steps can be reduced, and time can be shortened.

Also, since the ejector pin and the sleeve located on the outer periphery thereof are embedded in advance when the core is cast, c. The core can be prevented from being worn or damaged by the sleeve. Further, in the present invention, the first template is disposed outside the core, and the core is mounted on the receiving plate via a mounting hole formed by the second screw member with a screw, and the second die is mounted outside the cavity. Since the plate is arranged and the cavity is mounted on the mounting plate by screws via the mounting holes formed by the first screw member, d. The high pressure molding can be sufficiently endured.

In addition, the injection molding die manufactured according to the present invention finishes the outer peripheral portion of the cured resin, and improves the accuracy of the die, so that e. And the dimensional accuracy of the molded article is improved.

It has such an effect.

[Brief description of the drawings]

FIGS. 1 to 12 show a first embodiment of the present invention. FIG. 1 is a view showing a set state of a model, FIG. 2 is an explanatory view of a resin injection and a primary curing step, and FIG. FIG. 4 is an explanatory view showing a state in which an ejector pin to which a release agent is sometimes applied is set, FIG. 4 is an explanatory view showing a primary curing and a secondary curing of an injected resin, FIG. Fig. 7 is a model removal process, Fig. 7 is a mold portion removal and screw member removal process, Fig. 8 is a machining and finishing process, Fig. 9 is an explanatory view of a state of being assembled into a mold base, Fig. 10 FIG. 11 is an explanatory view showing a state in which a core, a cavity and the like are attached to a molding machine and molding is completed, FIG. 11 is an explanatory view showing a mold open state, FIG. 12 is an explanatory view showing a state in which a molded product is taken out, and FIG. FIGS. 24 to 24 show a second embodiment of the present invention. FIG. 13 shows a model set state, and FIG. 14 shows a resin injection and primary curing step. Explanatory drawing, FIG. 15 shows a core manufacturing process, a state explanatory diagram in which a soub and an ejector pin are set at the time of casting, FIG. 16 is a state explanatory diagram of primary curing and secondary curing of injected resin, FIG. Illustration of the division of the mold part, FIG. 18 shows the removal process of the model, FIG. 19 shows the removal process of the mold portion and the removal of the screw member, FIG.
FIG. 21 is an explanatory view showing a state where the mold and the core are mounted on a molding machine, and FIG. 22 is an explanatory view showing a state in which molding is completed.
FIG. 24 is an explanatory view showing a state in which a molded product is taken out, and FIGS. 25 to 31 are explanatory views showing a conventional manufacturing process. 4… Model, 5a, 5b …… Resin, 5A …… Cavity, 5B
... core, 9 ... ejector pin, 9A ... sleeve.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tadao Sakata 1048 Odomo Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Works, Ltd. (56) References JP-A-51-20950 (JP, A)

Claims (2)

(57) [Claims] In a method of manufacturing an injection mold using a resin, a resin for forming a cavity in a casting frame is injected into a first screw member for obtaining a mounting hole when the resin for forming a cavity is injected. A second part for arranging an ejector pin and a mounting hole at the time of injecting a resin serving as a core.
The screw member is placed in the casting frame at a position where the resin to be the core is injected, and after the resin is cured, the outer peripheral portion of the resin is finish-processed to obtain a cavity and a core. Form a spool in the cavity,
Disposing a first template outside the core, attaching the core to the receiving plate via a mounting hole formed by the second screw member with a screw, and disposing the second template outside the cavity;
A method for manufacturing an injection mold, wherein a cavity is attached to a mounting plate with a screw through a mounting hole formed by the first screw member. 2. The method of manufacturing an injection mold according to claim 1, wherein a sleeve is embedded in the outer periphery of the ejector pin before casting the core.