JPS6036415Y2 - Mold for molding rubber products - Google Patents

Description

[Detailed description of the invention] Scope of application The present invention relates to a mold for molding rubber products, particularly a mold for molding rubber products that allows obtaining test pieces that are vulcanized under exactly the same conditions as the molded product. It is.

Conventional technology/problems Conventionally, the test method for vulcanized comb products has been standardized, for example, based on JIS standards, and test specimens for this purpose have been collected either directly from the product or vulcanized under the same conditions as the product. There is a method in which a rubber plate is manufactured separately from the product and a test piece is taken from the rubber plate, but in the former case, the product would be destroyed to collect the test piece, so the latter method is generally preferred. method has been adopted.

Even if the product has small dimensions such as backing or valves, it is impossible to take a test piece of standard size from the product.
A method has been adopted in which rubber plates are prepared separately and vulcanized under the same conditions, and test pieces are taken from these.

However, the method of preparing test pieces separately from the product does not necessarily mean that the test pieces are blended or vulcanized under exactly the same conditions as the product, and accurate test results may not be obtained.

Purpose of the invention The object of the invention is to provide a mold for molding rubber products that allows obtaining a test piece produced under exactly the same conditions as the product without destroying the product.

Specific Structure/Function The mold for molding rubber products according to the present invention is characterized by having a cavity for molding a test piece in the vicinity of the cavity for molding the product, separate from the protrusion groove.

Note that the above-mentioned 1 protrusion groove refers to a concave groove (for example, , Com Industry Handbook, Japan Rubber Association
Published on November 15, 1972, page 502 (see section 1.Flash type), and is commonly referred to as ``bori-groove'' or ``spiyu-groove.''

In the mold of the present invention, as described above, the cavity for molding the test piece is formed near the cavity for molding the product, so that at the same time the product is molded, it is vulcanized using the same material and under the same conditions as the product. The mechanical and chemical properties of the product can therefore be precisely determined.

EXAMPLE Hereinafter, an example will be described in which the present invention is applied to a mold for compression molding a rubber pressure-operated membrane body.

FIG. 1 is a partial plan view of the lower die 1 of the mold for forming the pressure-operated membrane body, and shows the required shape for the rubber pressure-operated membrane body having the cross-sectional shape as shown in FIG. It is formed as one section of four lower mold cavities 2 engraved with a concavo-convex pattern.

As shown in FIG. 2, the upper mold 3 paired with the lower mold 1 has an upper mold cavity 4 engraved with an uneven pattern corresponding to the upper surface shape of the rubber pressure-operated membrane body. Corresponding to the lower mold 1, it is pressed against the lower mold 1 by a known pressure device (not shown), and compresses the rubber material previously installed between the two molds 1 and 3 to form the cross-sectional shape shown in FIG. Compression molding of rubber pressure membrane bodies is well known.

In Fig. 1, reference numeral 5 denotes a spout carved in a grid pattern around each section of the lower mold cavity 2 in order to adjust the volume of the rubber material for molding. The grooves 5 do not necessarily need to be carved around the four circumferences of the lower mold cavity in one section, but depending on the dimensions such as the diameter and depth of the cavity 2 and the number, the left and right, upper and lower spill grooves 5 may be formed.
Either can be omitted.

Ring-shaped "protrusion grooves" (protrusion grooves) 2a and 4a are formed adjacent to the periphery of a rubber product molding cavity defined by the lower mold cavity 2 and the upper mold cavity 4.

In this example mold, a circular (or rectangular, etc.) test piece molding cavity 6 is provided near the engraved portion of the lower mold cavity 2 (or upper mold cavity 4) of the lower mold 1 (or upper mold 3). is engraved.

The cavity 6 has four product molding cavities 2.
Those 2... so that they are located equidistant from...
It is engraved in the center of...

In addition, as mentioned above, there are four product molding cavities 2.
In addition to providing a cavity 6 for molding the test piece at the center equidistant from ......, as shown by the dotted line in Fig.
An annular test piece molding cavity 6a can also be provided on the outer periphery of the R'' 2a, 4a.

This example mold having the above structure was used to perform vulcanization molding of a rubber pressure membrane body using the lower mold cavity 2 and upper mold cavity 4, and at the same time, a test was performed in which molding was performed using exactly the same material and under the same conditions as the product mold. A test piece T can be produced, and the test piece T is used, for example, for testing tensile strength, elongation, aging resistance, etc., and obtains extremely reliable test results that can be regarded as the physical properties of the product itself. be able to.

Effects of the Invention As detailed above, the present invention provides a mold for molding rubber products that allows obtaining test pieces produced under exactly the same conditions as the product without destroying the product.

[Brief explanation of the drawing]

Fig. 1 is a partial plan view of the lower die of a mold for molding rubber products according to an embodiment of the present invention, and Fig. 2 is a partial sectional view taken along the line A-A in Fig. 1, in which the upper die is combined. This shows the state in which the product and test piece are being molded between the lower part of the mold shown in FIG. The meanings of the symbols in each figure are as follows. 1...Lower mold, 2...Lower mold cavity, 3...Upper mold, 4...Upper mold cavity 2a, 4a... ...Burr groove, 5...Spew groove, 6, 6a...Cavity for molding test piece, D...Pressure actuated membrane, T... Test pieces.

Claims (1)

[Scope of utility model registration request] A mold for molding a rubber product, characterized in that a cavity for molding a test piece is provided in the vicinity of a cavity for molding a product, and a cavity for molding a test piece is provided separately from a protrusion groove.