JPH03216314A - Manufacture of injection mold - Google Patents

Abstract

PURPOSE:To easily form an excellent cooling circuit by improving cooling performance, by a method wherein a good conductive member of heat is buried beforehand into a core side of the rear of a model, which corresponds to and buried into a gate position of a cavity side, and a core is cast. CONSTITUTION:A parting surface forming plate 3 and model 4 are provided within a casting frame 2 on a bottom plate 1, underneath of which a good conductive member A of heat is arranged. Resin 5a is cast, which is reversed after an opening part is covered with an upper plate 6 and cured primarily and an ejector pin 9 is provided. Then resin 5b is cast, a fitting plate 10 having a screw member 11 similar to a screw member 8 is provided on the upper part of the casting frame 2. The same is reversed after secondary cure of the same and an upper part is removed from the casting frame 2. Then, the mold 4 is separated easily from the casting frame 2 by an ejector pin 9 without destroying the model 4. Then, a cooling water pipe 12 is formed on the lower side of the good conductive member A in a core 5B to be obtained with finish processing of outer circumferential part of the cured resin 5a, 5b, a sprue 13 is formed in a cavity 5A and they are made into an injection mold by incorporating them into a mold base.

Description

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

(Prior art) Conventionally, injection molds have generally been made of metal, but when the molded product is produced in small quantities, the manufacturing period of the injection mold is short, the mold is easy to handle, etc. Because of these advantages, resins are increasingly being used as injection molds.

15 to 21 show conventional examples of this type. In the conventional method, first, as shown in FIG. 15, a parting surface is formed in a casting frame 50 provided on a bottom plate 51. The plate 52 is set, the model 53 is placed on it, and then, as shown in FIG. 16, the tree! N54a is injected and the upper opening is covered with an upper plate 55.

Then, as shown in FIG. 17, 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, resin 54b was injected, and a mounting plate 56 was provided, as shown in FIG. However, the 19th
As shown in the figure, after curing, the casting frame 50,
Upper temporary 55, mounting plate 5G, 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. 20, 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. 21 shows the state in which the core 54B1 cavity 54A, etc. are assembled into the mold head, and in the figure, 60, 61
62 is a template plate, 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. Further, 67 is an ejector bin, and the mounting plate 63 side is a fixed side, and the opposite side is a movable side.

(Intelligence to be Solved by the Invention 8) However, in the above conventional example, when manufacturing the injection mold, the cooling water pipes 58, etc. are formed later by machining, as shown in FIG. In order to obtain the cooling effect, some ingenuity is required, and the formation of the cooling circuit is complicated.
There was a tlB. The present invention was proposed in view of the above, and its purpose is to
The purpose of this invention is to provide a method for manufacturing an injection mold, which improves cooling performance by embedding a heat-conducting member during molding to prevent sink marks (gate opening), and in which a cooling circuit can be easily formed. In addition to the above, it also eliminates the need for post-processing to form the spool.
The purpose of this invention is to provide a method for manufacturing an injection mold that can shorten the manufacturing time accordingly. (Means for Solving the Problems) The present invention provides (1) a method for manufacturing an injection mold using a resin, in which a thermal conductor is placed on the back side of the model to be embedded, corresponding to the gate position on the cavity side, and on the core side. The above object is achieved by embedding the conductive member in advance and casting the core.

(2) In the method of manufacturing an injection molding mold using resin, a gate/spool member is embedded in advance with the model on the cavity side, and a gate/spool member is placed on the core side corresponding to the gate position on the cavity side and on the back side of the model. The above objective is achieved by pre-embedding a thermally conductive material on the core side and casting the core. (Function) First, with the configuration described in (1) above, the thermal conductivity member is provided above the cooling water pipe facing the gate and formed on the core side, so that the cooling effect of the cooling water pipe is improved. It is transmitted to the resin injected from the gate via the conductive member, improving cooling performance.

Further, by adopting the configuration described in (2) above, in addition to the above-mentioned effect, the process of forming the subur by post-processing is reduced. (Embodiment 1) Figures 1 to 6 show one embodiment of the present invention. In this example, an injection mold is manufactured through the following steps.

That is, as shown in FIG. 1, first, 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. In this case, model 4
A thermally conductive member A is disposed at the bottom of the 20 thermally conductive member A.
corresponds to the gate position.

Next, 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 primarily cured.

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 plate are removed. Also, ejector pin 9 for model 4 ejection
will be established.

Then, the resin 5b serving as the core is injected upward, and a mounting plate 10 having a threaded member 11 of the same rod as the threaded member 8 is provided above the casting frame 2, and secondary hardening is performed.

After that, as shown in Fig. 4, it is reversed and model 4,
The cured resin 5a, the ejector pin 9 provided on the resin 5a, the mounting plate 10 through which the ejector pin 9 is inserted, and the like are removed from the casting frame 2.

Then, as shown in FIG. 5, the rod B provided on the head side of the ejector bin 9 is extended, and the model 4 provided at the tip thereof is taken out by the ejector pin 9. In this way, Model 4 can be transferred to Yongchang with resin 5a without being destroyed.
It can be separated from the resin mold.

As shown in FIG.
, 9, etc., remove the upper plate 6, mounting plate IO, etc.

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

In this case, the cooling water pipe 12 is formed in the core 5B by machining. Further, a spool 13 and the like are formed in the cavity 5A.

Thus, the cooling water pipe l2 on the core 5B side is located below the heat conducting member A, so that the cooling effect of the cooling water is efficiently transmitted to the heat conducting member A.

Figure 8 shows the cavity 5A and core 5 as an injection mold.
B is shown assembled into the mold hese. 14 in the diagram
is the base, and the upper outer part of this is the spacer block 15.
is erected, and a receiving plate 16 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 mold plate 19 is provided on the side of the cavity 5A facing the mold plate 18, and a mounting plate 21 to which the cavity 5A is attached via screw members 20 is provided on the upper part of the mold plate 19.
Note that a spool 13a is formed on the mounting plate 21 and communicates with the spool 13 of the cavity 5A.

Further, the core 5B is provided with an ejector bin 9, and the base end side of the ejector bin 9 extends below the receiving plate 16 and is supported by the upper ejector plate 22. Further, a lower ejector plate 23 is provided below this ejector plate 22, and these are provided above the base 14, and are configured so that the ejector pin 9 is driven, as in the well-known configuration. There is.

In addition, 24 in the figure is a molded product, and the molded product 24 is obtained by injecting resin into the mold through the Subur 13. In this case, cooling water is supplied to the cooling water pipe 12 in order to quickly harden the resin. is passed. In this embodiment, the heat conductive member A is embedded above the cooling water pipe l2 in correspondence with the gate position of the spool 13, so that the cooling effect is quickly transmitted to the resin to promote its hardening. be able to.

(Embodiment 2) FIGS. 9 to 14 show a second embodiment of the present invention. In this embodiment, a model 4 in which a spool forming portion 4a is integrally protruded is used, and as shown in FIG. 7 in the first embodiment, the process of forming the spool l3 by post-processing is unnecessary. In particular, it has some special features.

Other configurations, manufacturing processes, and effects are similar to those of the first embodiment described above, so the same members are designated by the same reference numerals and description thereof will be omitted. (Effects of the Invention) As described above, according to the present invention, in the method of manufacturing an injection mold using resin, a portion of the mold that corresponds to the gate position on the cavity side and on the back side of the model to be embedded and that has good thermal conductivity on the core side. Since the member is embedded in advance and the core is cast, cooling performance is improved by the heat conductive member, and an excellent cooling circuit can be easily formed.

In addition, in a method of manufacturing an injection mold using resin,
A gate/subur member is pre-embedded with the model on the cavity side, and a thermally conductive material is pre-embedded on the core side, corresponding to the gate position on the cavity side, and on the back side of the model, and the core is cast. In addition to the above-mentioned effects, this method eliminates the need for the process of later forming a spool in the cavity by machining, prevents damage to the cavity by post-processing, and shortens manufacturing time.
There is an effect like this.

[Brief explanation of drawings]

Figures 1 to 8 show the first embodiment of the present invention, in which Figure 1 shows the model in its seven-point state, Figure 2 shows the resin injection and primary curing process that will become the cavity, and Figure 3 shows the core manufacturing process. , 4th
The figure is an explanatory diagram of the division of the mold part, Figure 5 is the model demolding process, Figure 6 is the mold part removal process and screw member removal process, Figure 7 is the machining and finishing process, and Figure 8 is the mold head. Figures 9 to 14 are explanatory diagrams of the assembled state, and Figures 9 to 14 are the second embodiment of the present invention, Figure 9 is the cent state of the model with the Subur forming part, Figure IO is the resin injection that will become the cavity, Primary hardening process explanatory diagram, Figure 11 is the core manufacturing process, 1st
Figure 2 shows the process of dividing the mold part, Figure 13 shows the process of demolding the model,
Fig. 14 is an explanatory diagram of the installation state in the mold base, Fig. 15
21 to 21 are explanatory diagrams of conventional manufacturing steps. A ・ ・ 4 ・ 4 a ・ 5a, 5A ・ 5 B ・ Good thermal conductivity member model Spool forming member Resin cavity core

Claims (2)

[Claims] (1) In a method of manufacturing an injection mold using resin,
A method for manufacturing an injection mold, characterized by embedding a thermally conductive material in advance on the core side, which corresponds to the gate position on the cavity side and on the back side of the model to be embedded, and then casting the core. (2) In a method of manufacturing an injection mold using resin,
A gate spool member is embedded in advance with the model on the cavity side, and a thermally conductive material is embedded in advance on the core side, corresponding to the gate position on the cavity side, and on the back side of the model and on the core side, and the core is cast. A method for manufacturing an injection mold, characterized by: