JPH03216320A - Manufacture for injection mold - Google Patents

Abstract

PURPOSE:To take out easily a model without destroying the same and reduce the post-manufacturing processes, by a method wherein at the time of casting of a core, an ejector pin is buried beforehand into the core. CONSTITUTION:A parting surface forming plate 3 and model 4 are provided within a casting frame 2 on a bottom plate 1. Resin 5a is cast, an opening part is covered with an upper plate 6, which is reversed after temporary cure of the same, the parting surface forming plate 3 and bottom plate 1 are removed, a fitting plate 10 having an ejector pin 9 to an outer circumference of which a mold release material 9a is applied is set up to the casting frame 2, into which resin 5b is cast and cured secondarily. Then an upper part is removed from the casting frame 2 and the model 4 is separated easily from the casting frame 2 without destroying the model 4. Then since the ejector pin hole 9a is formed already into a core 5B to be obtained by performing finish processing of the outer circumferential parts of the cured resin 5a, 5b and post-processing is unnecessary, a sprue 13 is formed in a cavity 5A, those of which are incorporated into a mold base and made into an injection mold.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing an injection mold made of resin, which is suitable as an injection mold for molded products produced in small quantities in a wide variety of products.

(Conventional technology) In the past, injection molds were generally made of metal, but when the molded product is produced in small quantities, the manufacturing period of the injection mold is short and it is easy to handle. Due to these advantages, resins are increasingly being used as injection molds.

25 to 31 show conventional examples of this type. In the conventional method, first, as shown in FIG. 25, a parting surface is formed in a casting frame 50 provided on a bottom plate 51. A plate 52 is set, a model 53 is placed on it, and then, as shown in FIG. 26, resin 54a is injected and the upper opening is covered with an upper plate 55.

Then, as shown in FIG. 27, after curing, the parting surface forming plate 52 and the bottom plate 51 are removed, and the casting frame 5 is removed.
0 was inverted, and as shown in FIG. 28, resin 54b was injected and a mounting plate 56 was provided.

As shown in FIG. 29, after curing, it is turned over and
In addition, the casting frame 50, top plate 55, mounting plate 56, model 53, etc. were removed. In this case, when the model 53 was demolded from plastic, it was heated to soften it.

Thereafter, as shown in FIG. 30, an ejector pin hole 57 and a cooling water pipe 58 were formed in the core 54B made of resin 54b, and a spool 59 and a cooling water pipe 58 were formed in the cavity 54A by machining. FIG. 31 shows core 54B,
This shows the state in which the cavity 54A etc. are assembled into the mold head.
3 is a mounting plate, 64 is a spacer block, 65 is an upper ejector plate, and 66 is a lower ejector plate. Further, 67 is an ejector bin, and a mounting plate 63
One side is the fixed side and the opposite side is the movable side.

(Problem to be Solved by the Invention) However, in the conventional example described above, when manufacturing an injection mold, the model 53 is demolded as shown in FIG. 29, but this operation includes a heating process. Furthermore, as shown in FIG. 30, the ejector bin hole 57 must be formed by machining, and the manufacturing process as a whole is complicated.

The present invention has been proposed in view of the above circumstances, and its purpose is to be able to easily demold the model, that is, to remove it from the model, and to make it possible to remove the ejector one by one through post-processing after the resin has hardened. It is an object of the present invention to provide a method for manufacturing an injection mold that does not require the formation of pin holes 57, thereby shortening manufacturing time and facilitating manufacturing.

(Means for Solving the Problems) The present invention achieves the above object by embedding an erectabine in advance during core casting in a method for manufacturing an injection mold using resin.

Furthermore, the above object is achieved by embedding the ejector bin and the sleeve positioned around its outer periphery in advance when casting the core.

(Function) The present invention is configured as described above, and the ejector bin embedded during casting is used to remove the model, and when the resin is hardened and the core is formed, post-processing is performed. This eliminates the need for machining the ejector pin hole.

(Embodiment 1) Figures 1 to 12 show a first embodiment of the present invention. In this example, an injection mold is manufactured through 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 part, the upper opening is covered with the upper plate 6, and the resin 5a is placed at room temperature or in a drying oven to be temporarily hardened. Incidentally, the upper plate 6 is provided with a screw member 8 for obtaining a mounting hole 7 when the upper plate 6 is assembled into a mold base after the resin hardens.

Next, as shown in FIG. 3, after the resin 5a is cured, it is turned over and the parting surface forming plate 3 and the bottom Fi1 are
, and before casting the core, a mounting plate 10 having an ejector pin 9 is placed on the upper part of the casting frame 2, and then, as shown in FIG. , secondary curing is performed. In this case, resin 5
A mold release agent 9a is applied to the outer periphery of the ejector pin 9 embedded in the
is applied (see Figure 3). Further, the mounting plate 10 is provided with a screw member 11 similar to the screw member 8.

Thereafter, as shown in FIG. 5, the model 4, the cured resin 5b, the ejector pin 9 embedded in the resin 5b, the mounting plate 10 through which the ejector bin 9 is inserted, etc. are removed from the casting frame 2. .

Then, as shown in FIG. 6, the rond 12 provided on the head side of the ejector pin 9 is extended, and the
Take out the model 4 provided at the tip. In this way, the model 4 can be easily removed from the resin 5 without being destroyed.
It can be separated from the resin mold in b. Then, as shown in FIG. 7, the casting frame 2, the upper plate 6 having the screw members 8, 9, etc., the mounting plate 10, etc. are removed, and the cured resins 5a, 5b are inverted and placed in proper positions. do.

Then, as shown in FIG. 8, the cured resin 5a is
Finish processing the outer peripheral portion of 5b to obtain the cavity 5A and core 5B. That is, the dashed dotted line on the outer periphery in the figure is this finishing margin.

In this case, the ejector pin hole 9a is already formed in the core 5B, so there is no need for post-processing as in the past, and this processing step is unnecessary.

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

Figure 9 shows the state in which the cavity 5A and core 5B are assembled into the mold heath. In the figure, reference numeral 14 denotes a base, and on the upper outer part of this base, a base plate 15 is erected, and a receiving film 6 is provided above it. A core 5B is provided on the receiving plate 16 via a screw member 17, and a template 18 is provided on the outside of the core 5B. Further, a template 19 on the cavity 5A side is provided opposite to the template 18, and a mounting plate 21 to which the cavity 5A is attached via a fixing member 20 is provided on the upper part of the template 19. In addition, the temporary mounting 21 has a spool 1 that communicates with the spool 13 of the cavity 5A.
3a is formed. Further, the core 5B is provided with an ejector pin 9, and the base end side of the ejector pin 9 extends below the receiving plate 16, and the ejector pin 9 on the upper side
It is supported by 2. Also, this ejector plate 2
A lower ejector plate 23 is provided below the base 14 and is configured to drive the ejector bin 9 in a known manner.

Figure 10 shows the spool 13 and spool 1 installed on the molding machine.
This figure shows a state in which resin is injected from 3a and molding is completed. In the figure, 24 is the molded product, 25 is the fixed side of the molding machine, and 26 is the movable side.

FIG. 11 shows a state in which the movable side is moved and the mold is opened. Furthermore, FIG. 12 shows a state in which the ejector pin 9 is pushed up via the rod 27 and the molded product 24 is swept away 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. 9A, and as shown in FIG. 24, the sleeve 9A prevents wear and damage of the core 5A when the ejector pin 9 is driven.

Note that other configurations, manufacturing processes, effects, etc. are the same as those of the first embodiment, so the same members are designated by the same reference numerals and explanations will be omitted.

(Effects of the Invention) As described above, according to the present invention, in the method for manufacturing a mold using resin, since the ejector pin is embedded in advance during core casting, a. The embedded ejector bin allows for easy removal of the model without destroying it.

b. Post-processing of the ejector bin hole from which the molded product is taken out is no longer necessary, so damage to the core can be prevented, post-processing steps can be reduced, and time can be shortened.

In addition, since the ejector bin and the sleeve positioned around its outer periphery are embedded in advance when the core is cast, C. The sleeve prevents wear and damage to the core. It has the following effects.

[Brief explanation of drawings]

Figures 1 to 12 show the first embodiment of the present invention, with Figure 1 showing the set state of the model, Figure 2 showing the resin injection and primary curing process, and Figure 3 showing the core manufacturing process and casting. An explanatory diagram of the ejector bottle with a release agent applied to it,
Fig. 4 is an explanatory diagram of the state of primary curing and secondary curing of the injected resin, Fig. 5 is an explanatory diagram of the division of the mold part, Fig. 6 is the process of demolding the model, Fig. 7 is the removal of the mold part, The removal process of the screw member, Figure 8 is the machining and finishing process, Figure 9 is an explanatory diagram of the state in which it is assembled into the mold head, and Figure 10 is the state in which the core, cavity, etc. are attached to the molding machine and molding is completed. Fig. 11 is an explanatory drawing showing the mold opening state, Fig. 12 is an explanatory drawing showing the state in which the molded product is taken out, Fig. 13 to 2
Figure 4 shows the second embodiment of the present invention, Figure 13 shows the seven-note state of the model, Figure 14 shows the resin injection and primary curing process, and Figure 15 shows the core manufacturing process. Fig. 16 is an explanatory diagram of the state of primary curing and secondary curing of the injected resin, Fig. 17 is an explanatory diagram of the division of the mold part, Fig. 18 is the demolding process of the model, 1
Figure 9 shows the removal process of the mold part and screw member, Figure 20 shows the machining and finishing process, Figure 21 is an explanatory diagram of the assembled state in the mold head, and Figure 22 shows the core, cavity, etc. in the molding machine. Figure 23 is an explanatory diagram showing the state in which the mold is opened, Figure 24 is an explanatory diagram showing the molded product being taken out, and Figures 25 to 31 are the conventional manufacturing process. FIG. 4...Model,
5a, 5b...Resin, 5A...Cavity, 5B.
...Core, 9...Ejector bin, 9A...Sleeve. (1 other person) Figure 1 Figure 2 Figure 5 Figure 6 Figure 9 Figure 22 23 Figure 12 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 2223 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28

Claims (2)

[Claims] (1) In a method of manufacturing an injection mold using resin,
A method for manufacturing an injection mold, characterized by embedding an ejector pin in advance during core casting. (2) In a method of manufacturing an injection mold using resin,
A method for producing an injection mold, characterized in that an ejector pin and a sleeve positioned around the outer periphery of the ejector pin are embedded in advance when the core is cast.