JPS62164517A - Molding mold - Google Patents

Abstract

PURPOSE:To simplify the assembly and constitution of a mold by a method wherein a part, related to the part of the under cut of a molded form only, among fixed molds is replaced with a slidable mold. CONSTITUTION:A slidable slide piece 12 is provided so as to be replaced with one part of a core plate 11. Injection molding is effected by closing a mold in a condition that the slide piece 12 is advanced toward the core plate 11. When the mold is opened after the injection and the cooling of resin, the slide piece 12 is retreated by the effect of a spring 22 and mold releasing is effected from the under cut part 15 of the molded form 16. The molded form 16 is projected by a projecting pin 18, a runner part 17 is projected by the projecting pin 19 and the core plate 11 is projected by the projecting pin 20 with the same timing. The dimensional accuracy in the profile of an obtained molded form 16 is achieved only in the worked part of the core plate 11 except the under cut part 15.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a molded product having an undercut on its outer periphery.
This relates to the molds used to make the molds.

BACKGROUND OF THE INVENTION In recent years, efforts have been made to reduce the cost of high-precision molds as product cycles have shortened.

An example of the conventional mold mentioned above will be described below with reference to the drawings.

Conventionally, this type of mold has had a structure as shown in FIGS. 9 and 10, for example. In other words, undercut 2 on the outer periphery
is removed from the main body of the υ molded product by moving a plurality of slide cores 1 outward, and then the molded product is taken out of the mold using an ejector pin 3.

Problems to be Solved by the Invention However, in such a configuration, the outer shape of the molded product is
Since it is formed by the slide core 1, positional accuracy and two-dimensional accuracy of the plurality of slide cores are required, which poses a problem in mold manufacturing.

Therefore, the present invention makes it possible to manufacture high-precision molds with a simple structure by processing the outer periphery of the molded product, which requires precision, into a single core plate, and forming only the undercut part with a slide piece. It is something to do.

Means for solving the problem and the means of the present invention for solving the above problem are to form the outer peripheral part of the molded product requiring precision with a single core plate,
The slide piece is actuated only at the undercut portion, and after the core plate and the core plate are projected out of the mold, the molded product is removed.

action The effect of this technical means is as follows.

That is, since the outer periphery can be achieved with the machining accuracy of a single core plate, the number of places to pursue precision in mold processing 9 assembly is greatly reduced, and the configuration of a high-precision mold can be simplified.

EXAMPLE An example of the present invention will be described below with reference to the attached FIGS. 1 to 8. In the figure, 11 is a core plate, and this core plate 11 is provided with a plurality of grooves 111L as shown in FIGS. 4 to 8. A plurality of slide pieces 12 are slidably installed in the groove portion 11a.

Reference numeral 13 denotes a guide pin, which also prevents the core plate 11 from falling when it is protruded. Reference numeral 14 denotes a presser ring of the slide piece 12, which is fixed to the core plate 11.

18 is a protruding pin of the molded product 16, 19 is a protruding pin of the sprue 17, and 2o is a protruding pin of the core plate 11.

The operation of the molding die configured as described above will be described below with reference to FIGS. 1 to 8.

First, FIG. 1 shows a sectional view of the molding die of the present invention when the mold is closed, and the slide piece 12 is installed on the core plate 11 and moved forward. and core plate 11
is inserted into the template 21 with regular positional accuracy under the guidance of the guide pin 13.

FIG. 2 shows the mold opened after injection and cooling, the slide piece 12 being retracted by the action of the spring 22, and the undercut portion 15 coming out from the molded product 16.

In FIG. 3, the molded product 16 is projected by the projecting pin 18, the runner part 17 is projected by the projecting pin 19, and the core plate 11 is projected by the projecting pin 20 at the same timing.

Figure 7 shows molded product 16. This is the core plate taken out of the mold while holding the slide piece 12, and the molded product 16
is taken out in the direction of arrow C. FIG. 8 shows the molded product 16 taken out.

As described above, according to this embodiment, since the slide piece is installed on the core plate and the molded product is protruded while being held by the core plate, the dimensional accuracy of the outer shape of the molded product is equivalent to the processing accuracy of the core plate as a single unit. It can be achieved only by

Effects of the Invention As described above, the present invention allows the slide piece to be slidably installed in the groove provided in the core piece, and the molded product and the core plate are simultaneously ejected. This can be achieved by simplifying the structure of a high-precision mold.

[Brief explanation of drawings]

Figures 1 to 3 are cross-sectional views showing each process of a molding die in an embodiment of the present invention, Figure 4 is a plan view of the main parts of the present invention, and Figure 5 is a cross-section of the same as in Figure 4. 6 is a sectional view taken along line B-B in FIG. 4, FIG. 7 is a partially sectional front view of the main parts of the present invention, and FIG. 8 is a sectional view of a molded product formed by the mold of the present invention. FIG. 9 is a front view of a conventional mold, and FIG. 10 is a sectional view of the conventional mold. 11... Core plate, 12... Slide piece, 13... Guide pin, 14...
...Pressure ring, 1B, 19.20...Eject pin. Name of agent: Patent attorney Toshio Nakao and 1 other person rt
-m-core plate/Z-m-slide and one-piece t3-11 diagonal pin broom 2 Figure 17 Figure 4 II mountain Figure 7 Figure 9 West figure 10

Claims (1)

[Claims] A mold for molding a molded product having an undercut on the outer periphery, the mold comprising a plurality of slide pieces that slide outward, and a core plate on which the slide pieces are slidably installed.