JP2678672B2 - Injection mold manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a method for producing an injection molding die made of a resin, which is suitable as an injection molding die for a molded product of high-mix low-volume production according to the present invention.

(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.

11 to 17 show a conventional example of this kind. In the conventional case, as shown in FIG.
The parting surface forming plate 52 is set in the casting frame 50 provided on the 51, the model 53 is installed on the plate 52, and then, as shown in FIG. 12, the resin 54a is injected and the upper opening is formed. The part is covered with the upper plate 55.

Then, as shown in FIG. 13, after curing, the parting surface forming plate 52 and the bottom plate 51 are removed, the casting frame 50 is inverted, and as shown in FIG. 14, the resin 54b is injected and the mounting plate is attached. There were 56.

Then, as shown in FIG. 15, after curing, turn it over,
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. 16, an ejector pin hole 57 and a pipe 53 for cooling water pipe, for example, are formed in the core 54B made of resin 54b, and a spool 59 and a similar pipe 58 are formed in the cavity 54A by machining. Was there.

FIG. 17 shows a state in which the core 54B, the cavity 54A, etc. are assembled in the mold base. In the figure, 60 and 61 are template plates and 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-described conventional example, as shown in FIG. 16, when manufacturing an injection mold, as a cooling water pipe to form a heating circuit or a cooling circuit by post-processing by machining. The functioning pipe 58 is formed, but in this case, it becomes difficult to machine a hole along the model shape, and the cooling performance deteriorates.
In addition, there is a problem in that it is difficult to process a complicated shape with many holes, and in addition, there is a possibility that the strength of the mold may be reduced and the mold may be damaged by post-processing.

The present invention has been proposed in view of the above, and an object thereof is to eliminate the step of forming a pipe by post-processing, reduce the strength of the mold portion, prevent damage, and have an excellent cooling effect. It is an object of the present invention to provide a method for manufacturing an injection molding die that can obtain the above.

(Means for Solving the Problems) The present invention provides a method for producing an injection mold from a resin, in which a pipe is provided in advance in a casting frame at the time of casting and the pipe is embedded. Has been achieved.

Similarly, at the time of casting, a pipe is previously provided in the casting frame via a nut screwed to the end of the pipe, and the pipe is embedded so as to achieve the above object.

(Function) Since the pipe is embedded in the resin in advance with the above-described configuration, a desired cooling circuit can be easily obtained, and an excellent cooling effect can be obtained when the pipe is used for cooling. I am allowed to do so.

Further, since the post-processing after the resin is cured is unnecessary, the strength and the damage of the mold portion made of the resin are eliminated.

(Embodiment 1) FIGS. 1 to 6 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.

In addition, the pipe P bent according to the shape of the model 4
Is provided in the casting frame 2. In this case, fixing holes 2a for fixing the pipes P are formed in the inner wall of the casting frame 2 at desired intervals in the height direction, and the ends of the pipes P are easily inserted into the fixing holes 2a. The pipe P can be set in the. The fixing hole 2a may be a groove instead of a hole. Then, as shown in FIG. 2, a resin 5a to be a cavity is injected into the upper portion, and the resin is cured at room temperature or in a drying oven for primary curing.

Next, as shown in FIG. 3, after the resin 5a is hardened, the parting surface forming plate 3 and the bottom plate 1 are removed and inverted to provide the mounting plate 6 on the bottom of the casting frame 2, and Formwork 2
A pipe 5'having a predetermined shape is fixed inside, and a resin 5b serving as a core is formed.
Is injected for secondary curing.

Then, as shown in FIG. 4, the mounting plate 6, the casting frame 2
And remove the model 4 from the mold.

Then, as shown in FIG. 5, the outer peripheral portions of the cured resins 5a and 5b are finish-processed to obtain a cavity 5A and a core 5B as an injection mold. That is, the one-dot chain line in the outer peripheral portion in the figure is the finishing margin.

The core 5B is machined to ejector pin holes 7
However, the spool B is formed in the cavity 5A.

FIG. 6 shows a state in which the cavity 5A and the core 5B are incorporated in the mold base. In the figure, 9 is a base, on the upper outer part of which a spacer block 10 is erected and a receiving plate 11 is provided above it. A core 5B is provided on the receiving plate 11 via a screw member 12, and a template 13 is provided outside the core 5B. Further, a mold plate 14 facing the mold plate 13 is provided on the side of the cavity 5A, and a mounting plate 16 to which the cavity 5A is mounted is provided on the mold plate 14 via a screw member 15.
The mounting plate 16 is provided with a spool 8a which communicates with the spool 8 of the cavity 5A.

Further, the core 5B is provided with an ejector pin 16, and the base end side of the ejector pin 16 extends below the receiving plate 11 and is supported by the upper ejector plate 17. Also,
A lower ejector plate 18 is provided below the ejector plate 17, and these are provided above the base 9. The ejector pin 16 is driven and injected through the spools 8a, 8 as is well known. The molded product 19 made of resin can be taken out when the mold is opened.

In this case, the positions of the end faces of the pipes P'and P are set so that the fixing holes 2a of the casting frame 2 (see FIG. 1) at the time of casting have the same pitch as the external hose connecting portions of the mold plates 13 and 14 of the mold base. Therefore, standardization (module) of the cooling circuit is possible, such as easy connection with an external hose.

Then, in forming the molded product 19 in the above, since a desired cooling circuit constituted by the pipe P′P is formed in the cavity 5A and the core 5B, cooling water is passed through the pipe P′P. In this case, a sufficient cooling effect can be obtained.

Of course, the pipes P'and P can also be used for heating.

(Embodiment 2) FIGS. 7 to 10 show a second embodiment of the present invention. In this embodiment, the inner wall of the casting frame 2 is not provided with a special pipe fixing portion, and the end portions of the pipes P and P'are screwed into a pipe fixing nut N, and the pipe N is poured through the nut N. It is characterized in that the pipes P and P'are properly fixed in the mold 2.

Other configurations, manufacturing processes, operational effects, and the like are the same as those in the first embodiment described above, and therefore, the same members are denoted by the same reference numerals and the description thereof will be omitted.

(Effect of the Invention) As described above, according to the present invention, in a method of manufacturing an injection molding die using a resin, a pipe is previously provided in a casting frame at the time of casting, and the pipe is embedded. , At the time of casting, a pipe is installed in the casting frame in advance through a nut screwed to the end of the pipe, and this pipe is embedded. Thus, the pipe is desired to be embedded in the casting frame at the time of casting. Since the cooling circuit can be easily formed in advance, the cooling performance is improved when it is used for cooling, and since it is not necessary to form holes for pipes by post-processing, the strength and damage of the mold part due to post-processing is reduced. It is effective in preventing such problems.

[Brief description of the drawings]

1 to 6 show a first embodiment of the present invention, and FIG. 1 shows a cavity manufacturing process in which a pipe is set,
The figure shows the resin injection that becomes the cavity, explanatory diagram of the primary curing process,
Fig. 3 shows a state in which a pipe is set as in the cavity in the core manufacturing process, Fig. 4 is a model demolding process, Fig. 5 is a machining and finishing process, and Fig. 6 is a state of being incorporated in a mold base. FIGS. 7 to 10 show a second embodiment of the present invention, FIG. 7 is a cavity manufacturing process, FIG. 8 is a resin injection and primary curing process, FIG. 9 is a core manufacturing process, and FIG. FIG. 11 is an explanatory view of a state of being incorporated in a mold base, and FIGS. 11 to 17 are explanatory views of a conventional manufacturing process. 2 …… Casting mold 2a …… Fixing hole 4 …… Model P, P ′ …… Pipe N …… Nut 5a, 5b …… Resin 5A …… Cavity 5B …… Core

Claims (2)

(57) [Claims] 1. A method for manufacturing an injection mold, which is characterized in that in the method of manufacturing an injection mold made of resin, a pipe is previously provided in a casting frame at the time of casting and the pipe is embedded. 2. A method for producing an injection mold from a resin, wherein at the time of casting, a pipe is previously provided in a casting frame via a nut screwed to the end of the pipe, and the pipe is embedded. Method of manufacturing injection mold.