JPS6321383Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in a mold used for molding styrofoam and the like.

When packaging products in carton boxes, etc.
A so-called core made of styrofoam or the like is used to protect the product. When this core is used, for example, in electronic equipment, it is provided with a hole through which a knob or the like can be passed.

Conventionally, as shown in FIG. 1, such a core combines a first mold 1 and a second mold 2 that can be attached and detached, and the first mold 1 and the second mold 2 are connected to each other. A molding material was injected from the outside so that a gap of the desired shape was formed between the molding material and the molding material, and the molding material was then heated and molded. The molded product 3 is taken out by separating the first and second molds 1 and 2.

In order to provide the above-mentioned holes in the molded product in such a molding method, a hole 4 is provided in a part of the first mold 1, and a protrusion 5 that closes the hole is provided in the second mold 2. , except for this protrusion 5, which is filled with the molding material.

However, in this case, if there is even a slight gap between the hole 4 and the protrusion 5, a so-called burr 6A will occur in the hole 6 of the molded product 3, as shown in FIG. 2a. When this burr 6A is packed, it will break when it comes into contact with the carton box, and will fall and scatter. Furthermore, this burr 6A was attached to the product and became a factor detracting from its aesthetic appearance. For this reason, in the past, it was necessary to remove the burrs before packaging.

This flash can generally be prevented by improving the precision of the mold. However, aluminum molds are mainly used for foamed polystyrene, and there is a limit to how much accuracy can be increased, and even if the accuracy is increased, the accuracy decreases due to wear during use.
For this reason, the occurrence of burrs was considered unavoidable in this type of mold.

The present invention improves these drawbacks and provides a molding die that can make holes without causing burrs to appear on the surface of the molded product.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 3, 11 is a first mold having a concave portion 11A, 12 is a second mold having a protrusion 12A corresponding to the concave portion 11A of the first mold 11, and the first mold has a concave portion 11A. The second molds 11 and 12 are detachable, and when combined, a predetermined gap is formed between the concave portion 11A and the protruding portion 12A. A hole 11B passing through to the outside is provided at the center of the bottom surface of the recessed portion 11A, and an annular projection 11c is formed around the periphery of this hole 11B. On the other hand, the protruding portion 12A has the hole 11B.
A protrusion 12B that is slightly inserted into the hole of the annular protrusion 11c is provided at a position facing the annular protrusion 11c.

When the first mold 11 and the second mold 12 are combined, a gap is formed between them as described above, and the hole 11B is closed by the protrusion 12B. In this state, a molding material such as foamed polystyrene is injected from an injection port (not shown) provided in the first mold 11, and processing such as heating is performed to perform molding.

In this case, since the protrusion 11c and the protrusion 12B are provided, the molded product 13 has a hole 14 having a stepped portion 14A as shown in FIG.
is formed.

By the way, when injecting the molding material, if there is even a slight gap between the protrusion 11c and the protrusion 12B, the molding material will enter from there in the direction of the hole 11B. Therefore, a burr 15 will be formed, but this burr 15
As shown in FIG. 4a, this occurs at the stepped portion 14A of the hole 14 of the molded product 13, so it does not protrude to the outside of the hole 14. Therefore, even if the molded product 13 is used for packaging, the burrs may touch the carton box and break.
It will no longer fall, and therefore it will no longer adhere to the product and spoil its aesthetic appearance. Furthermore, even if there is a burr, there is no need to remove it, reducing man-hours. Furthermore, there is no need to increase the precision of the mold to prevent burrs, and the cost of the mold can be reduced.

The present invention is not limited to aluminum molds, and can of course be applied to molds other than styrofoam molding.

As described above, according to the present invention, even if warping occurs, it can be prevented from protruding from the surface of the molded product, so that it is possible to provide a molding die suitable for use in molding packaging cores, etc. I can do it.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing a conventional molding die, Figure 2 is a sectional view showing a conventional molding die.
The figures show a molded product made with the mold shown in Fig. 1, in which a is a sectional view and b is a plan view. FIG. 3 is a sectional view showing a molding die according to an embodiment of the present invention;
The figure shows a molded product made with the mold shown in FIG. 3, with a being a sectional view and b being a plan view. 11...First mold, 11A...Concave portion, 11
B...hole, 11C...protrusion, 12...second mold, 12A...protrusion, 12B...protrusion, 13...
... Molded product, 14... Hole, 14B... Step part, 15...
...Burr.

Claims (1)

[Scope of utility model registration request] A desired shape is formed between a first mold having a hole on the surface for receiving the molding material and an annular protrusion formed around the periphery of the hole, and the first mold that is coupled to the first mold. and a second mold having a protrusion that is provided at a position facing the hole and closes the hole, and a molding material is injected between the first and second molds to form the mold. 1. A molding die, characterized in that a molded product is provided with a hole having a step formed by the hole, protrusion, and protrusion.