JPS6325134Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a molding die that improves the adhesion between the upper and lower molds.

Traditionally, molds used for molding foams such as urethane foam have poor adhesion between the upper and lower molds.
When the stock solution is injected into the mold, the solution oozes out from the mating areas during the foaming process, forming protruding areas commonly called burrs.

Therefore, in this type of molding field, finishing work is required to remove burrs with scissors, cutters, etc.
Improvement measures were desired in terms of workability and raw material loss.

In response to such demands, this invention provides a molding die with improved adhesion between the upper and lower molds.

To explain this in detail based on the drawings, the first
The figure shows a molding die according to an embodiment of this invention, which is composed of an upper die 1 and a lower die 2. At the joint part A of the upper die 1 and lower die 2, there is a mold. 2, a convex protrusion 3 is integrally formed on the mating surface of the upper die 1, and an elastic member 4 selected from rubber or elastic resin is formed on the mating surface of the lower die 2 to receive the convex protrusion 3.
is buried. Although the shape of the convex projection 3 is not strictly limited, it is not preferable to have a too acute angle because the elastic member 4 will be seriously damaged.

Furthermore, in order to embed the elastic member 4, a groove 5 having a rectangular cross section may be formed on the mating surface of the lower die 2, and a known elastic material such as silicone resin, natural rubber, synthetic rubber, or urethane elastomer may be embedded in this groove. When embedding it, it is not necessarily necessary to embed it completely in the groove as in A, but it can be embedded in a shape that fits into the convex protrusion 3, as shown in B, for example.
The width and depth of the groove 5 can be appropriately determined depending on the type and shape of the mold, but generally a width of about 2 to 10 mm and a depth of about 1 to 5 mm are appropriate.
Furthermore, the shape is not limited to that shown in FIG.
As shown in the figure, the shape can be made to match the convex projection 3. Figure A shows an example in which the elastic member 4 is buried completely within the groove, and Figure B shows an example in which the elastic member 4 is buried in such a way that the convex protrusion 3 fits into it.

According to the mold forming die of this invention, the upper mold 1
When the lower mold 2 and the lower mold 2 are matched, the elastic member 4 is elastically deformed by the tip of the convex protrusion 3 and the adhesion between the two becomes more perfect, so that leakage of the urethane stock solution is prevented during the foaming process. , the formation of burrs can be prevented.

Therefore, according to this invention, there is no need for finishing work to remove burrs, and raw materials are saved accordingly, making it possible to carry out economically advantageous molding.

Note that this invention is not limited to the above-described embodiment; for example, an elastic member 4 is provided on the mating surface of the upper mold 1.
The convex protrusion 3 may be provided on the mating surface of the lower die 2, or the convex protrusion 3 may be detachably attached.

Furthermore, in terms of application, it is not limited to molding foams such as urethane foam, but can be applied to molding synthetic resins in general.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a molding die showing one embodiment of this invention, and FIGS. 2 and 3 are enlarged longitudinal sectional views of essential parts of different embodiments. 1...Upper mold, 2...Lower mold, 3...Convex projection, 4
...Elastic member, A...A joint between the upper mold and the lower mold.

Claims (1)

[Scope of utility model registration request] A molding die characterized in that a convex protrusion is formed on one mating surface of the mating portion of an upper mold and a lower mold, and an elastic resin or rubber is embedded in the other mating surface that receives the convex projection.