JPH10656A - Resin molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable molding in which no gate cutting trace is left on the cavity side and appearance is not damaged even when a gate is installed in a slide core part by using a mold having a means which passes through the under part of the slide core and injects a resin from the core side into a cavity. SOLUTION: By installing a pin gate 9 in a slide core 5 and a runner 8 and a gate 7 in the under part of the core 5, when mold opening is started after the completion of the injection of a resin into a cavity core and the solidification of the resin, the end part of the pin gate 9 is cut by a runner lock pin 11 fixed to a fixed side mold plate 3, and the core 5 is moved backward by an angular block 6 fixed to the mold plate 3. Next, by protruding an ejector pin 10, by taking out a molding 12 in the mold, the gate 7 of the under part of the core 5, and a runner 8, the installation of the gate 7 on the core 2 side of the mold is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plastic molding die, and more particularly, to a gate structure of a plastic molding die having a slide core.

[0002]

2. Description of the Related Art FIGS. 3A and 3B are schematic sectional views showing a gate structure of a conventional plastic molding die. FIG. 3A shows a state in which upper and lower dies are closed, and FIG. It is a figure which shows the state which opened.

In FIG. 3, reference numeral 29 denotes a slide core;
Is a gate, and 19 is a molded product.

In a conventional plastic molding die, when a slide structure is provided, the slide structure portion and the gate portion are buffered, and the gate cannot be arranged on the slide core portion from the core side, resulting in a cabinet having the appearance of a product. There is a gate on the side.

[0005] Japanese Patent Application Laid-Open No. 6-55579 discloses that
"Injection molding method and injection mold" for reducing the remaining gate height of a molded product formed by the injection mold.
Discloses a structure in which a gate is provided on a fixed mold.

[0006]

In the above-mentioned conventional example, the first problem is that in a plastic molding die having a slide core, the gate cannot be set on the slide portion on the core side, so that the gate is mounted on the cabinet side. It is a point that has been installed.

For this reason, there is a problem to be solved in that a gate cut mark remains on the mold side of a molded product having an appearance as a product.

FIG. 3 is a cross-sectional view of a conventional plastic mold gate structure.

A conventional molded article 19 having an undercut
In the example, the gate portion 39 is installed on the upper portion of the slide core 29, and the gate portion 39 is cut from the molded product 19 after molding. For this reason, there is a problem that a gate cut mark is left on the surface of the appearance of the molded article 19 and the appearance of the molded article 19 is impaired.

[0010] That is, the gate cut mark on the mold side of the molded product seen from the appearance of the product is flawed and impairs the aesthetic appearance of the product.

[Object of the Invention] An object of the present invention is to provide a plastic molding die having a slide core, in which a gate is provided on a slide core portion and molding can be performed without leaving a gate cut mark on a mold side. The object of the present invention is to prevent the appearance of a molded article from being damaged by traces.

[0012]

According to the plastic molding die under slide gate structure of the present invention, in a plastic molding die having a slide core, a gate is provided at an under part of the slide core.

Specifically, there are provided a means for installing a pin gate in the slide core, a means for installing a runner and a gate on the core side which is an under part of the slide core, and injecting resin into the cavity core.

[Operation] According to the present invention, a gate can be installed on the core side. For this reason, the mark of the gate cut is located on the core side, not on the mold side where the appearance of the product is, so that the appearance of the molded product can be prevented from being impaired.

The structure and operation of the plastic molding die under slide gate of the present invention will be described with reference to schematic diagrams.

FIG. 4 is a sectional view of the under slide gate structure of the present invention. According to the under slide gate structure of the present invention, a pin gate 9 is provided on the slide core portion 5, passes through the runner 8 at the under portion of the slide core 5 and passes through the core surface 2.
The gate 7 is installed in. For this reason, a gate cut mark does not remain on the appearance of the molded product 12, and the appearance of the molded product 12 is not spoiled.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] Next, a plastic molding die under slide gate structure of the present invention will be described with reference to the drawings.

1 and 2 show an under slide gate structure of a plastic molding die according to the present invention.

FIG. 1 is a cross-sectional view of an underslide gate structure of a plastic molding die when the mold is clamped.
Is a cross-sectional view when the mold is opened.

The under-slide gate structure of the plastic molding die of the present invention comprises a cavity 1, a core 2, a fixed mold plate 3, a movable mold plate 4, a slide core 5, an angular block 6, a gate 7, a runner 8, Pin gate 9, ejector pin 10, runner lock pin 11, molded product 1
2. It includes a runner stripper plate 13.

According to the structure of the present invention, the pin gate 9 is provided on the slide core 5 and the runner 8 and the gate 7 are provided on the under part of the slide core 5 so that the injection of the resin into the cavity core and the solidification of the resin are completed. After that, when the mold opening is started, the tip of the pin gate 9 is cut off by the runner lock pin 11 fixed to the fixed side template 3 and the angular block 6 fixed to the fixed side template 3. The slide core 5 retreats.

Next, by ejecting the ejector pin 10, the molded product 12 in the mold and the gate 7 and the runner 8 in the under part of the slide core 5 are taken out, so that the slide surface of the plastic mold having the slide core 5 is removed. The gate 7 can be installed on the side of the core 2.

[0023]

As described in detail above, the first effect of the present invention is that even if a gate is installed on a slide portion of a mold having a slide core, the gate is formed on a mold surface which is an external surface of a product. It is possible to form a molded product that does not leave a cut mark and does not impair the aesthetic appearance of a product.

The reason for this is that the gate is installed on the core surface instead of the mold surface, which is the external surface of the product, so that even if there is a gate cut mark, if the product is assembled, it will not be visible from the external appearance. .

In the plastic under slide gate structure of the present invention, a pin gate is provided inside a slide core, and a runner and a gate are provided at an under part of the slide core.
By injecting the resin into the mold core from the core side of the under part of the slide core, the gate can be arranged on the core side. This leaves the gate trace on the core side,
It can be molded without impairing the appearance of the molded product.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a plastic molding die under slide gate structure according to the present invention at the time of mold clamping.

FIG. 2 is a schematic cross-sectional view of the plastic molding die under slide gate structure of the present invention when the mold is opened.

FIG. 3 is a schematic sectional view for explaining the structure of a conventional example.

FIG. 4 is a schematic cross-sectional view for explaining a plastic molding die under slide gate structure of the present invention.

[Explanation of symbols]

 Reference Signs List 1 cabinet 2 core 3 fixed mold plate 4 movable mold plate 5 slide core 6 angular block 7 gate 8 runner 9 pin gate 10 ejector pin 11 runner lock pin 12 molded product 13 runner stripper plate

Claims (3)

[Claims] 1. A plastic molding die having a slide core, wherein a resin having means for injecting resin from the core side into the cavity core through an under part of the slide core is used. Molding equipment. 2. The resin molding apparatus according to claim 1, wherein a pin gate is provided on the slide core portion, and a gate is provided on a core surface through a runner at an under portion of the slide core. 3. The resin molding apparatus according to claim 2, further comprising means for cutting a tip end of said pin gate portion when the mold is opened.