JPH03284919A - Stamper mounting device in disc mold - Google Patents

Abstract

PURPOSE:To absorb the elongation which is caused by the expansion of a stamper by a method wherein suction ports, by which the stamper is suckingly held and which are open at the mirror-finished part locating near the inner edge of an outer peripheral ring, are provided. CONSTITUTION:The suction ports 11, which are open at the mirror-finished part 5 of a movable mold 2, face to the inner peripheral edge 8b of an outer peripheral ring 8. The open positions of the suction ports are ones, at which a space B formed by deformation and the suction ports 11 communicate with each other under the condition that a stamper 6 comes into contact with the inner peripheral edge 8b of the outer peripheral ring 8 due to the deformation. Accordingly, the preferable open positions lie within the domain ranging from slightly outward from the inner peripheral edge 8b of the outer peripheral ring 8 to slightly inward from the inner peripheral edge 8b. Further, a plurality of the suction ports 11 are arranged concyclic along the outer peripheral part of the stamper. Even when the stamper 6 expands, since the suction ports 11 suck the stamper 6 at this part, the stamper 6 expands outwards and is held flat, resulting in preventing a non-conforming product from developing.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a stamper attachment device used in a mold of an injection molding machine for manufacturing disks.

(Prior art) As shown in FIG. 3, a mold in a conventional injection molding machine for manufacturing disks consists of a fixed mold 1 and a movable mold 2, and a cavity 3 is formed on the abutting surface of the two. It is formed.

A sprue bush 4 is attached to the center of the fixed mold 1, and a perforated disc-shaped stamper 6 is located on the mirror surface 5 facing the cavity 3 of the movable mold 2, and the stamper 6 has a hole in the inner peripheral part 6a. was held by a stamper holder 7, and its outer circumferential portion 6b was covered with an outer circumferential ring 8 to be held.

However, in this conventional example, undulations (flapping) occur due to resin pressure, heat, etc. during molding, and gas enters between the outermost periphery of the stamper 6 and the mirror surface 5.
It was thought that deforming the stamper 6 or rubbing the mirror surface part with the stamper would shorten the life of the stamper 6 or the mirror surface part 5.

Therefore, an improved device as shown in FIG. 4 has been proposed in which the suction port 10 of the vacuum circuit is opened at the outermost periphery of the mirror surface 5.

(Problem to be Solved by the Invention) In the second improved device, the outermost peripheral part 6b of the stamper 6 and the mirror surface part 5
Although we were able to solve the problem of gas entering between the two, a new problem arose. The new problem is that the stamper expands radially outward due to the influence of resin pressure, heat, etc. during molding, so if the outermost periphery 6b of the stamper 6 is fixed by suction, the pressing surface of the outer ring 8 Since the gap X between the stamper 8a and the surface of the stamper 6 is very narrow, 5 to lOμ, the elongated stamper 6 has nowhere to go, as shown in FIG. It may also cause product defects.
Moreover, if such deformation occurs, the stamper 6 will hit the part A of the mirror surface part 5 with each shot of injection molding, and it will come into contact with the inner edge of the outer circumferential ring, so that the mirror surface part 5i
3 and the stamper 6, resulting in their deterioration.

The present invention aims to solve the above-mentioned conventional problems, and is capable of holding down the outer periphery of the stamper, and even when the stamper expands and expands due to the influence of resin pressure, heat, etc. during molding. It is an object of the present invention to provide a stand bar holding device that can absorb this.

(Means for Solving the Problems) In order to achieve the above object, the present invention abuts a stamper on the mirror surface of a movable mold, holds the inner peripheral part of the stamper with a stamper holder, and In the stamper mounting device, the stamper is covered with an outer ring and held by suction on a mirror surface part, and a suction port is provided in the mirror part located near the inner edge of the outer ring for sucking and holding the stamper. It is characterized by:

(Function) Since the present invention has the above configuration, when the molten resin is injected into the cavity, the resin is filled in the radial direction from the center of the cavity.

As this injection is repeated, the stamper increases the resin pressure.
6 The outer periphery of the stamper, which expands due to heat and extends outward in the radial direction, is suctioned and fixed near the inner periphery of the outer ring, so when the stamper tries to deform so as to bulge, there is a space created by the deformation. Since this area communicates with the suction port of the vacuum circuit, suction is applied to this area, and the amount of deformation of the stamper is released to the outside before deformation occurs, and the stamper is kept smooth without being deformed such that it bulges. Do not hit the mirror surface with a sagging or expanded stamper.

(Example) An example of the present invention will be described based on FIGS. 1 and 2. 1 and 2 are longitudinal cross-sectional views of the vicinity of the outer ring 8,
The other structure is the conventional mold and track as shown in Figure 3.
It is.

Vacuum circuit 1 opened in mirror surface 5 of movable mold 2
The second suction port 11 corresponds to the inner peripheral edge 8b of the outer peripheral ring 8. This opening position is a position where, when the stamper 6 is deformed and in contact with the inner peripheral edge 8b of the outer peripheral ring 8, the space B formed by the deformation and the suction port 11 are in communication.

Therefore, it is desirable that the opening position range from slightly outward from the inner circumferential edge 8b of the outer circumferential ring 8 to slightly inward from the inner circumferential edge 8b. are arranged.

Although the shape of the inner circumferential edge 8b of the outer circumferential ring 8 is inwardly pointed in the embodiment, it is not limited by the shape, and the edge of the outer circumferential ring that covers the outer circumference of the stamper and the opening position of the suction port are is important.

(Effects) Since the present invention has the above configuration, even if gas etc. enters from the outermost periphery of the stamper, the stamper is suctioned and fixed near the inner periphery of the outer ring, so there is no effect on molding. Further, even if the stamper expands, the suction port sucks this part of the stamper, so that the stamper extends outward and is kept smooth, thereby preventing product defects. In addition, since deformation due to expansion of the stamper does not occur, the expanded stamper does not hit the mirror surface part during injection molding, and therefore, there is no damage to the back surface of the stamper and the mirror surface part caused by hitting the mirror surface part as in the conventional case. In addition to improving the quality of the product, the lifespan of the stamper and mirror surface can be maintained for a long time, so costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of the main part of the mold of the present invention, and FIG.
FIG. 3 is a partial vertical cross-sectional view of a conventional mold, FIG. 4 is a partial vertical cross-sectional view of yet another conventional mold, and FIG.
The figure is an explanatory view of the operation of FIG. 4. 1-Fixed mold 2-Movable mold 3-Cavity 5-Mirror part 6-Stamper 8-Outer ring 11-Suction port

Claims (1)

[Claims] (1) The stamper is brought into contact with the mirror surface of the movable mold, the inner periphery of the stamper is held by a stamper holder, the outer periphery of the stamper is covered with an outer ring, and the stamper is held by suction on the mirror surface. A stamper mounting device for a disk mold, characterized in that a suction port for sucking and holding a stamper is provided, the suction port opening in the mirror surface portion located near the inner edge of the outer circumferential ring.