JPH0957758A - Mold structure for release-ejecting molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To release and eject moldings with a relatively extensible plane such as a box-shaped molding and, dish-shaped molding from the mold without causing any deformation of moldings. SOLUTION: The mold structure for release-ejecting a molding 3 is such that the ejector pin 5 against the plane part 4 of a molding 3 has a tip end 6 with a larger diameter than that of its lower part, and the diameter becomes large as approaching the tip end surface 7, and further, in the part except the tip end part 6 of ejector pin 5, an air circulation path 8 is provided between it and the mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold structure in which a molded product having a relatively wide flat surface such as a box-shaped molded product or a dish-shaped molded product is released from a mold and projected.

[0002]

2. Description of the Related Art Conventionally, when a molded product as described above is projected from a mold by a flat portion thereof with a pin, the protruding pin has a structure as shown in FIG.
The shape is usually an elongated cylindrical shape or a prismatic shape. In this case, particularly in the case of a large-sized molded product, when the mold opens and the protruding pin 13 is advanced to project the molded product 12, when the molded product tries to separate from the mold 11, a gap between the molded product and the mold is generated. A vacuum is applied, and a force acts in the direction that prevents release. Forcibly advancing the protruding pin against this force has a problem that deformation of the molded product, breakage of the protruding pin and the like often occur, and a solution thereof has been desired. For example, it was considered to provide a groove that communicates from the surface of the molded product to the outside on the surface of the mold that is in contact with the protruding pin. A new problem will arise.

[0003]

The problem of mold release due to the protruding pin of a molded article having such a flat surface portion cannot be said to be sufficiently solved. The present invention has been completed as a result of various studies to solve this problem, and is intended to release the molded product mainly by changing the shape of the protruding pin.

[0004]

SUMMARY OF THE INVENTION The present invention is a box-formed article,
In a mold structure in which a molded product having a plane parallel to the mold opening surface, such as a dish-shaped molded product, is released from the mold and projected, the protruding pin that abuts against the flat surface of the molded product has its tip end portion,
It has a larger diameter than the lower part, and the diameter increases as it goes to the tip surface, and there is an air flow path between the die and the die except the tip of the protruding pin. It is the mold release projecting mold structure of the molded product.

2 to 5 are sectional views showing an example of the mold structure of the present invention. 1 is a fixed mold, 2 is a movable mold, 3
Is a molded product, and 5 is a protruding pin in the present invention. Reference numeral 9 is a conventional protruding pin, and 10 is a protruding plate. The flat surface portion 4 of the molded product 3 is perpendicular to the mold opening direction of the mold, that is, parallel to the mold opening surface. It is molded in a state where the tip end surface 7 of the pin 5 is abutted against the flat surface portion 4. Protruding pin 5
Has a columnar shape or a prismatic shape, and its tip portion 6 has a diameter larger than that of the columnar portion, and also has a diameter increasing toward the tip surface 7. An air passage 8 communicating with the outside is provided between the projecting pin 5 and the mold 2 except for the tip portion 6. The air flow path is protruding pin 5
It may be the entire outer circumference or a part of the outer circumference.

FIG. 2 is a schematic sectional view showing the entire die,
The projecting pin 5 includes the projecting pin 5 which is a feature of the present invention and the conventional projecting pin 9 as the projecting pin.
Release is performed. 3 to 5 are parts of the mold structure of FIG. 3A is a state in which the molded product 3 is molded and the mold is opened, and FIG. 3B is a sectional view taken along line AA of FIG. In FIG. 3B, the projecting pin has a square cross section, and an air flow path is provided between the projecting pin and a void having a circular cross section of the die. FIG. 4 shows a state in which the protrusion of the molded product is started by the protrusion pin 5, but when the protrusion pin moves forward,
The diameter of the protruding pin tip 6 is larger than that of the other portions, and further, the diameter increases toward the tip surface 7, so that the air in the air flow passage 8 smoothly projects and passes through the pin tip 6 and the flat portion of the molded product. Reach 4. As a result, a vacuum is not created between the molded product 3 and the mold 2, and the molded product is released from the mold and ejected without any problem. FIG. 5 shows a state where the protrusion of the molded product is completed.

Although the diameter of the protruding pin 5 may be continuously changed between the tip portion 6 and the other columnar portion, it is better to provide a step at this portion in manufacturing the protruding pin. . Further, the air flow path 8 does not need to be provided at the tip portion 6 of the protruding pin 5, but may be provided at the tip portion (or part thereof) except the tip surface 7.

[0008]

As is apparent from the above description, the mold structure of the present invention has the same structure as the conventional mold when a molded product having a relatively wide flat surface is projected and released from the mold by a pin. The protrusion can be performed without any trouble such as deformation of the molded product and breakage of the protrusion pin.

[Brief description of drawings]

FIG. 1 is a sectional view of a mold using a conventional protruding pin.

FIG. 2 is a schematic sectional view of an example of a mold structure of the present invention.

3A is a sectional view of a mold of the present invention, and FIG. 3B is a sectional view taken along the line AA of FIG. 3A, in which a molded product is molded and the mold is opened.

FIG. 4 is a cross-sectional view of the mold of the present invention, showing a state where the protrusion of the molded product is started by the protrusion pin.

[Fig. 5] A state where ejection of a molded product is completed.

[Explanation of symbols]

 1 Fixed Side Mold 2 Movable Side Mold 3 Molded Product 4 Flat Surface of Molded Product 3 Projecting Pin 6 in the Present Invention 6 Tip Part of Projecting Pin 5 7 Tip Surface of Projecting Pin 5 8 Air Flow Path 9 Conventional Projecting Pin 10 Overhang plate 11 Mold 12 Molded product 13 Conventional overhang pin

Claims (1)

[Claims] 1. A mold structure in which a molded product, such as a box-shaped molded product or a dish-shaped molded product, having a flat surface parallel to the mold opening surface is released from the mold and protrudes from the mold. The tip of the projecting pin is larger in diameter than the lower part, and the diameter of the projecting pin increases as it goes to the tip surface. A mold release projecting mold structure for a molded product, characterized in that it has an air flow path in its interior.