JPH0446727B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a mold for forming a cushion body of different hardness, which is used to manufacture a cushion body of different hardness that partially has different hardness.

(Prior art) Cushion bodies are often used in furniture, seats in vehicles, etc., but cushion bodies with partially different hardness are required for seats in vehicles to improve the ability to hold occupants. It became like that.

Conventionally, to manufacture such cushion bodies of different hardness, a mold is used in which the inside of the cavity is divided by a partition into a cavity for molding the hard part and a cavity for molding the soft part. Different liquid foaming raw materials are injected into a cavity for molding a cavity and a soft part, and are foamed without mixing to produce a cushion body with different hardness having a hard part and a soft part.

In addition, in order to prevent the hard and soft parts of the cushion body of different hardness from separating during the manufacturing process, a partition is provided protruding from the lower mold cavity surface, and an uneven partition that partitions the lower mold cavity is provided on the upper mold cavity. A mold is used which is perpendicular to a surface and has a structure in which cavities are separated by partitions of the upper and lower molds, and the separated cavities are communicated with each other by the uneven shape of the partitions provided on the upper mold cavity surface. It has been proposed that
-19734 Publication).

(Problem to be Solved by the Invention) However, with the above-mentioned molding mold, two types of liquid foaming raw materials with different compositions must be injected into the cavity of the molding mold, and the injection work, blending work, etc. are troublesome. There is also the problem that raw materials cannot be rationalized.

SUMMARY OF THE INVENTION In view of the above-mentioned points, the present invention aims to provide a molding die capable of manufacturing a cushion body of different hardness from a single liquid foaming raw material.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a cavity with different hardness, in which the inside of the cavity is divided by a partition into a cavity for molding a soft part and a cavity for molding a hard part. In the mold for forming the cushion body, the partition is made of a knitted material or a lattice-like material.

(Function) In the molding die of the present invention, a predetermined liquid foaming raw material is injected into the cavity in which the soft portion is to be molded when manufacturing a cushion body of different hardness. The liquid foaming material injected into the cavity for molding the soft part fills the cavity for molding the soft part by expansion due to the foaming reaction, and further passes through the mesh or lattice-like material partitioning the cavity of the mold. and flows into the cavity that molds the adjacent hard part. At this time, the flow of the liquid foaming raw material is disturbed by the mesh of the net or the lattice part of the lattice, restricting the growth of bubbles, and forming a hard part in the cavity where the bubbles are made uneven. flows into. Therefore, the cushion body obtained by completing the foaming of the liquid foaming material is composed of normal cells that have been foamed normally in the cavity that molds the soft part.
The foam-molded part in the cavity that molds the hard part is hard and consists of non-uniform bubbles with limited bubble growth, creating a cushion body with different hardness.

(Example) Examples of the present invention will be described below.

Fig. 1 is a partially cutaway perspective view showing a mold for forming a cushion body of different hardness (hereinafter referred to as the mold) according to an embodiment of the present invention, and Fig. 2 shows a partition made of a net-like material attached. FIG. 3 is a perspective view of the previous mold.

The mold 100 is used for manufacturing a seat cushion body, and includes an upper lid 110 and a lower mold 120.
and a partition 130. The lower mold 120 includes
A locking part 131 for locking the partition 130 made of a net-like material such as cheesecloth, and a support part 132 on the top lid 110 that supports the locked partition 130 when the mold is closed.
is molded. Further, the partition 130 is locked to a locking part 131 of the lower mold via an adhesive, and divides the inside of the cavity into a cavity _a1 for molding a soft part and a cavity _a2 for molding a hard part. Incidentally, 150 indicates a vent hole, which is used to release the air in the mold during the production of the cushion body and to prevent the formation of under-walled portions in the cushion body. The hole diameter, position, and number of vent holes are determined depending on the product shape, but it is best to place them at the edges of the product so that the liquid foaming material can spread easily and can be placed in every corner of the cavity. This is desirable for distributing the liquid foaming raw material until the end.

Next, a method for manufacturing a cushion body of different hardness using this mold 100 will be explained.

(A) First, a liquid foaming raw material, such as a polyurethane foam raw material, which is a raw material for manufacturing a cushion body, is injected into the cavity _a1 for molding the soft portion of the lower mold 120.

(b) After injecting the liquid foaming raw material, the upper lid 110 is closed.

(c) The liquid foaming raw material injected into the mold begins to foam, forming a cavity that molds the soft parts.
It fills inside a ₁ and forms the soft part of the cushion body, and begins to flow through the mesh of the net-like material forming the partition 130 into the adjacent cavity, that is, the cavity a ₂ forming the hard part.

At this time, the reaction of the liquid foaming raw material has already progressed considerably, so the bubbles grow to some extent and pass through the narrow mesh with increased viscosity.
When passing through the mesh, the liquid foaming material encounters great resistance, disrupting the flow and restricting the growth of bubbles.
The shape of the bubbles becomes uneven. Then, the liquid foaming raw material with non-uniform bubbles flows into the cavity _A2 where the hard part is formed.

(d) Molding the hard part The liquid foaming raw material that has flowed into the cavity _a2 completes foaming and molds the hard part of the cushion body. In the hard part of the cushion body, the growth of the bubbles is restricted as described above, the shape of the bubbles becomes non-uniform, the thickness of the bubbles becomes thicker, and the hardness is higher than that of the other parts.

(E) After the foaming reaction is completed, the cushion body is demolded,
A cushion body with different hardness is obtained.

Note that the partition 130 is locked by a locking part 131 on the side of the cavity that molds the soft part, and is supported by the locking part 131 and the support part 132 from the side of the cavity that molds the hard part when the liquid foaming raw material is foamed. . For this locking, auxiliary locking using a pin or the like is added as necessary.

In addition to cheesecloth, various materials are used for the partitions, such as lattice-like materials made of synthetic resin or wire mesh, but since they are embedded inside the product, the hardness of the partition, mesh or lattice is used depending on the product. It is necessary to determine the size of

FIGS. 3 and 4 are perspective views showing a mold 200 according to another embodiment of the invention. As shown in FIG.
It is divided into 22 parts, and there is a cheesecloth partition 2 in the divided part.
30 is inserted, the divided parts are brought together as shown in Figure 4, and the cavity molding the soft part is formed.
It is divided into A ₁ and cavity A ₂ which molds the hard part. The portion of the partition 230 that protrudes from the cushion body of different hardness is removed after the cushion body of different hardness is molded.

In addition to the molds shown in the above examples, there are also molds in which a mesh or lattice-like material is fixed to the opening of a plate-like body in which an opening such as a hole is formed in a part of the product. It is used depending on the shape etc.

Further, the net-like or lattice-like partitions may be constructed by providing grooves or the like in the mold and fitting the partitions into the mold, and allowing the partitions to be freely removed.

Further, in the above embodiment, there was one partition, but two partitions were provided to divide the inside of the cavity into three sections, the center of which was the cavity in which the soft part was molded, and the hard parts on both sides of the cavity. It can also be used as a cavity.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a molding die according to an embodiment of the present invention, FIG. 2 is a perspective view before a partition is attached to the molding die, and FIGS. The figure is a perspective view of a molding die according to another embodiment of the invention. 100,200...Molding mold, 110...Upper lid, 120,220...Lower mold, 130,230...
...Partition, 150...Vent hole, _a1 ...Cavity for molding soft parts, _a2 ...Cavity for molding hard parts.

Claims (1)

[Claims] 1. In a mold for forming a cushion body of different hardness, the inside of the cavity is separated by a partition into a cavity for molding a soft part and a cavity for molding a hard part, where the partition is made of a knitted material or a lattice-like material. A mold for forming a cushion body of different hardness.