JPH047106A - Resin molding die - Google Patents

Abstract

PURPOSE:To make it possible to obtain even a wall of a resin molded item when no draft can be provided, without a scratch by a method wherein a core insert, which has a clearance to a retainer plate at mold opening and mold releasing, a locking block, which restrains the core insert at mold closing, and a spring, which acts in the direction to let the core insert off its restrained position, are provided. CONSTITUTION:Clearance of 0.1 - 0.2 mm is present between a core insert 7 and a retainer plate 8. In addition, a spring 10, which exerts force in the direction to part the core insert 7 from the wall 9 of a resin molded item, is assembled in the core insert 7. A sleeve 12 is assembled onto a bolt 11, which holds down the insert 7. The clearance in vertical direction between the insert 7 and the sleeve 12 is 0.02 mm at their parting surfaces and the clearance in parallel direction between them is 0.1 - 0.2 mm. At mold closing, the insert 7 is restrained by a locking block 13 so as to constitute the surface of the wall 9 and the spring 10 is compressed. At mold opening, the locking block 13 is separated from the insert 7, resulting in moving the insert 7 with the spring 10 by the clearance between the retainer plate 8 and the insert 7. Due to the clearance developed at this time, the wall 9 of the molded item does not come into contact with the core insert 7 and is released from a mold by means of an ejector pin 15.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a resin molding die for molding a resin molded product having a wall without draft and a shape that results in an undercut when the wall is constructed with a slide core. be.

Conventional technology Conventionally, resin molded products with walls that could not be constructed with a draft angle or with a slide core were molded.
In order to release the mold without damaging the wall, conventional resin molding molds had a two-stage protruding structure as shown in FIGS. 3 and 4.

That is, the vertical wall 1 is constituted by the oblique surface of the stripper 2, and in the process of releasing the molded product, the spring 3 is first
The force causes the stripper 2 to eject the resin molded product 4 while holding the wall 1. The stripper 2 is stopped by the action of the stopper 5 at the point where the wall 1 is pulled out from the core body.

Thereafter, the ejection piston 6 ejects the molded product 4 and releases it from the mold.

At this time, wall 1 comes off from stripper 2 with one side free, so wall 1 is not damaged.

Problems to be Solved by the Invention However, with the above structure, the mold is complicated and expensive due to the stripper protrusion structure and the two-stage protrusion structure, and the ejection stroke is also A<B (
A + 8) < C, which means that the mold is unnecessarily thick compared to the size of the molded product, and a large molding machine must be used, leading to problems such as poor molding quality and molding costs. be.

Accordingly, the present invention provides a resin molding die that is configured to release the molded product without damaging the wall without a draft without using a two-stage protruding structure.

Means for Solving the Problems In order to solve the above problems, the present invention includes a locking block that restrains a core insert that is attached to a mold plate with a gap during mold opening and mold release during mold clamping; It consists of a spring attached in a direction that releases the core insert from the restrained position.

Effect According to the above configuration, since a force is acting on the wall of the resin molded product in the direction of escape, the part of the resin molded product contained in the top surface of the core insert and the wall portion of the resin molded product undergo elastic deformation. Deformation occurs within the region, and a minute space is generated between the core insert and the wall of the resin molded product. Thereby, the core insert and the wall portion of the resin molded product can be released from the mold without contacting each other, and a resin molded product without any scratches can be obtained.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

In FIG. 1, there is a gap of 0.1 to 0.2 between the core insert 7 and the template 8, and there is a spring 1 that exerts a force in the direction of releasing the core insert 7 from the wall 9 of the resin molded product.
0 is included. A sleeve 12 is incorporated into the bolt 11 that holds down the core insert 7, and the core insert 7 and sleeve 12 are aligned vertically to the part surface.
．． There is a space of 02, and in the direction parallel to the part surface, 0°1 ~
There is a space of 0.2.

When the mold is clamped, the core insert 7 is restrained by the locking block 13 and forms the surface of the wall 9 of the resin molded product, and the spring 10 is in a compressed state.

When opening the mold, locking block 1 is pressed as shown in Figure 2.
3 is removed, the core insert 7 is moved by the force of the spring 10 into a space of 0.1 to 0 between the template 8 and the template 8 shown in FIG.
．． Move by 2. At this time, the shape 14 of the resin molded product formed on the top surface of the core insert 7 and the wall 9 of the resin molded product are deformed, but a moment acts between the shape 14 and the spring 10, and the core insert 7 resists rotational displacement. In order to do
The amount of deformation between the shape 14 and the wall 9 of the resin molded product is small and falls within the elastic deformation region.

Due to the space created by the movement of the core insert 7, the wall 9 of the resin molded product is released from the mold by the ejecting pin 15 without contacting the core insert 7.

Effects of the Invention As described above, the present invention has a core insert that is attached to a mold plate with play, allowing a space between the resin molded product and the core insert to be released from the mold, resulting in a resin molded product that does not have a draft angle. It can be obtained without damaging the wall of goods.

In addition, since the mold structure becomes simpler, it is possible to reduce mold costs and shorten the mold delivery time.Furthermore, since the mold is smaller, molding can be performed using a smaller molding machine, which reduces molding costs. You can also aim for

7... Core insert, 8... Template,
9...Resin molded wall, 10...Spring.

Name of agent: Patent attorney Shigetaka Awano and 1 other person'1-E isosuichitodo-1tsuto5 9...

Claims (2)

[Claims] (1) A resin characterized by comprising a locking block that restrains the core insert mounted with a gap between the mold plate and the mold plate when the mold is clamped, and a spring that is mounted in a direction that releases the core insert from the restrained position when the mold is opened. Molding mold. (2) The resin molding die according to claim 1, wherein a resin molded product shape is formed on the top surface of the core insert.