JP2002166429A - Molding method and molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide both a molding method and a molding die for obtaining thin-wall moldings with good dimensional precision without causing a crack and deformation. SOLUTION: In the die for molding thin-wall moldings by using a thermosetting resin material, protrusion pins are installed in the outside periphery of a cavity and a bridging recessed part reaching the protrusion pins from the cavity is formed in the mold opening part of the die. When moldings are separated from the die, a resin part formed in the recessed part is protruded by the protrusion pins.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a thermosetting resin material, and more particularly, to a molding method and a molding die for obtaining a thin molded product without causing cracks or deformation in a product.

[0002]

2. Description of the Related Art Conventionally, when a resin product is molded by using a mold, as a method of taking out the product from the mold, a lot of take-out methods using protruding pins are generally used. Generally, a method of providing one or a plurality of protruding pins on the movable side of the cavity and taking out the product is used. However, in this case, the shape of the protruding pin is left on the surface of the molded product, and it is difficult to use the product in which appearance is regarded as important. In addition, since burrs are generated at the protruding pin portions during molding, burrs may need to be removed. Further, in a thin-walled molded product, there is a possibility that a deformation or a crack may occur due to a load applied to the molded product by the protruding pin. Further, in the case of molding in which minute holes are formed in a thin-walled molded product, deformation near the minute holes of the molded product due to protrusion may occur, and there is a possibility that a core pin of a mold for forming the minute holes may be bent or damaged. When pursuing the improvement of the moldability of a thin-walled molded product, these methods have limitations, and in particular, a thin-walled molded product having a large number of minute holes as shown in FIG. Was. In FIG. 1, reference numerals 21 and 22 are minute holes.

[0003]

SUMMARY OF THE INVENTION The present invention has been made as a result of various studies to solve such problems in conventional molding, and the object of the present invention is to crack or deform a thin molded product. The object of the present invention is to provide a molding method for realizing a thin-walled molded product having excellent dimensional accuracy.

[0004]

According to the present invention, there is provided (1) a mold for molding a thin molded product using a thermosetting resin material, wherein a protruding pin is provided around the outside of the cavity, and the protruding pin is provided from the cavity to the protruding pin. A molding method, wherein a bridging concave portion is formed on a mold opening surface of a mold, and when a molded product is separated from the mold, a resin portion formed in the concave portion is protruded by a protruding pin. The molding method according to (1), wherein the thin-walled molded product has one or more minute holes, and (3) a die for molding a thin-walled molded product using a thermosetting resin material, wherein the protrusion pin has a cavity. A molding die, which is installed around the outside of the mold, and a bridging recess from the cavity to the protruding pin is formed on the mold opening surface of the die,
It is.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The thermosetting resin material in the present invention is not particularly limited, and examples thereof include a phenol resin, a melamine resin, an epoxy resin, and an unsaturated polyester resin. Among these, phenol resins and epoxy resins are preferred for applications requiring heat resistance. Generally, fillers such as silica, alumina, and clay are added.

[0006] The thin molded article in the present invention is, for example,
The thickness is 1 mm or less. Further, the molding method and the molding die of the present invention are preferably used for a thin-walled molded product requiring a thickness of 1 mm or less and a thickness dimensional accuracy of 0.02 mm or less. This is because when a molded product having such a thickness is molded by a conventional mold, the product may be deformed when the molded product is released.

The present invention is characterized in that the protruding pin is installed around the outside of the cavity, and a bridging recess extending from the cavity to the protruding pin is formed on the mold opening surface of the mold. By placing the protruding pin around the outside of the cavity, the molded product is not directly protruded by the protruding pin, so that the appearance of the molded product is not impaired and deformation of the thin molded product due to the protruding is prevented. Can be. Further, the molded product can be protruded from an unnecessary resin portion formed around the molded product and released from the mold. That is, the resin portion formed in the bridging recess is used as a protruding portion, and the resin in the bridging recess is cut and separated after molding. Therefore, according to the present invention, it is possible to obtain a thin-walled molded product that satisfies the required quality such as dimensional accuracy without cracking or deformation.

The position of the protruding pin provided around the outside of the cavity is, for example, when the thickness of a thin molded product is 0.5 m.
In the case of m, it is preferable to install at intervals of 15 to 30 mm in the width direction of the molded product. For example, when the thickness of the thin molded product is 0.5 mm, the bridging recess preferably has a depth of 0.20 to 40 mm and a width of 3 to 7 mm.

The present invention is particularly preferably used when the thin molded article has one or more micro holes. Since the product itself is not deformed by the protruding pin, the molded product can be released smoothly from the core pin that forms the minute hole, there is no damage or deformation by the core pin, and bending and damage of the mold core pin are reduced. It will come out. Here, the minute hole means, for example, a hole having a diameter of 2 mm or less.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 2 shows a conventional molding die,
(A) is a plan view, (b) is a side sectional view. (1) is a cavity, (2) is a gate, (3) is a protrusion,
(4) is a protruding pin. 3A and 3B show an example of a molding die of the present invention, wherein FIG. 3A is a plan view, and FIG.
Is a side sectional view. (1) is a cavity, (2) is a gate, (5) is a bridging recess for protrusion, and (6) is a protrusion pin. In FIG. 2, a protruding pin (4) is installed in the cavity (1), whereas in FIG. 3, a protruding pin (6) is installed around the outside of the cavity (1), and a mold is provided on the mold opening surface. A bridging recess (5) from the tee to the protruding pin is formed. In the present invention,
According to the thermosetting resin material used for the thin molded product and the shape of the molded product, determine the position, size and number of the protruding pins, and project to the outside of the cavity to prevent deformation of the thin molded product due to protrusion. Install the pins.

Further, as shown in an example in FIG. 4, the mold structure according to the present invention is extremely effective for molding a thin-walled molded product having minute holes as shown in FIG. In FIG. 4, 11 is a cavity, and 12 is a gate (side gate). Reference numerals 13 and 14 denote micro holes provided in the molded product, which are formed by core pins (not shown) provided to be able to advance and retreat in the mold in the cavity portion. On the outside of the cavity (11), bridging recesses (15, 16) for projecting a molded product are formed. Since the molded product itself is not deformed by the protrusion pins (not shown) when the molded product is protruded, the product is smoothly released from the core pins forming the minute holes (13, 14) of the molded product,
Accordingly, there is no damage or deformation of the molded product due to the core pin, and bending and breakage of the mold core pin are reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments according to the present invention will be described in detail with reference to the drawings. The shape of the molded product is as shown in FIG. 1, but has a plane outer diameter of 110 × 17 mm and a thickness of 0.6 mm. Molding was performed with a mold configuration as shown in FIG. In this method, a total of ten protruding pins are provided on the outer side of the product, of which four protruding pins exist on the gate side and six protruding pins exist on the side opposite to the gate. The gate is 5
A side gate having a width of 0 mm is adopted, and a thermosetting resin is poured from the longitudinal direction of the product. Two types of through holes of 25 × 2 rows are formed on the product surface. Hole diameter is φ0.12 ± 0.02m for hole (13)
m (front), φ0.2 ~ 0.3mm (back), and holes (1
In 4), it is φ0.5 ± 0.02 mm. As compared with the conventional method in which the protruding pins are provided in the cavity, it was possible to form an extremely high-precision thin-walled product without partial warpage or deformation. Also, the core pin forming the hole of φ0.12 mm could be formed without breaking.

[0013]

According to the method of the present invention, cracks and deformation of a molded product due to a protruding pin which occur in a conventional mold structure are reduced, and a thin molded product excellent in dimensional accuracy can be efficiently molded. Becomes possible. Moreover, in the case of a molded article having minute holes, it is possible to prevent the core pin forming the minute holes from being damaged by reducing the deformation of the molded article when projecting. As described above, the present invention is most suitable as a method for forming a thin-walled molded product.

[Brief description of the drawings]

FIG. 1 is a plan view of an example of a thin molded product having a large number of minute holes.

FIGS. 2A and 2B are views showing positions of protruding pins in a conventional mold, wherein FIG. 2A is a plan view and FIG. 2B is a side sectional view.

FIGS. 3A and 3B show the positions of protrusion pins in a mold used in the present invention, wherein FIG. 3A is a plan view and FIG. 3B is a side sectional view.

FIG. 4 is an example of another mold used in the present invention, and FIG.
For molding molded products (molded products and their surroundings)
It is a perspective view of.

[Explanation of symbols]

 1, 11 Cavity 2, 12 Gate 3 Projection 4, 6 Projection pin 5, 15, 16 Bridge recess 13, 14 Micro hole

Claims (3)

[Claims] In a mold for molding a thin molded product using a thermosetting resin material, a protruding pin is provided around the outside of a cavity, and a bridging recess extending from the cavity to the protruding pin is formed on a mold opening surface of the mold. A molding method, characterized in that when a molded product is separated from a mold, a resin portion formed in the concave portion is protruded by a protruding pin. 2. The molding method according to claim 1, wherein the thin molded article has one or more minute holes. 3. A mold for molding a thin molded product using a resin material, wherein a protruding pin is provided around the outside of a cavity, and a bridging recess extending from the cavity to the protruding pin is formed on a mold opening surface of the mold. Molding mold.