JPH031231Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a mold, and more specifically, a mold in which a plurality of ring-shaped molded products having different diameters are formed with a plurality of concentric cavities. The present invention relates to a mold that can be efficiently molded using a single mold, and that improves the yield of molding material by attaching a dummy ring to the cavity with a diameter that is unnecessary during molding.

[Conventional technology]

The conventionally known mold a is as shown in FIG.
Its dimensions are determined according to the size of the processing surface of the vulcanization press, and a plurality of annular recesses b are formed on the parting surface to form a plurality of cavities.
When the diameter of the ring-shaped molded product to be molded is large, the number of molded products that can be molded at one time with one mold is extremely limited, and there is a demand for improved productivity. Further, even if the molded products are made of the same material but have different dimensions, a mold with a cavity corresponding to the dimension is required for each molded product, and vulcanization must be performed separately.

[The problem that the idea attempts to solve]

In response to this, a mold in which a plurality of cavities are formed concentrically in one mold has been devised, as shown in U.S. Patent No. 3,524,538, in an attempt to improve productivity. According to the above, during molding, cavities with unnecessary dimensions are also filled with molding material, resulting in a portion of the material being wasted.

[Means to solve the problem]

In view of the above points, the purpose of the present invention is to use molding materials efficiently and provide a molding die with excellent productivity. In a mold for forming a ring-shaped molded product by forming a concave portion forming a concave portion and filling a molding material into a cavity formed by a combination of the concave portions to form a ring-shaped molded product, there is a split mold in which a plurality of cavities with different diameter dimensions are provided concentrically. and a plurality of dummy rings attached to each of the recesses, and the molding material is configured to flow between the pair of dummy rings attached to the pair of recesses.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the figure, 1 is a lower die of a forming mold that is divided into upper and lower parts, and on the parting surface 1a of the lower die 1, there are 3 pieces having different diameters. Six sets of molded parts 3 each having annular recesses 2, 2a, and 2b are formed in two rows. In addition, between these six sets of molded parts 3, 3..., there are two separate annular recesses 4, which have different diameter dimensions.
Two sets of small-diameter molded parts 5 are formed, one set being 4a. As shown in FIG. 4, each of the annular recesses 2, 4 provided in the molded parts 3, 5 has a semicircular cross-sectional shape, and a padding 6, 6, etc. is provided on each peripheral edge thereof. Further, the mold has an upper mold 7 corresponding to the lower mold 1, and molding parts corresponding to the molding parts 3, 5, etc. are also formed on the parting surface of the upper mold 7, The molding parts 3, 5, . . . of the lower mold 1 and the molding part of the upper mold 7 overlap to form a plurality of cavities for molding an O-ring having a circular cross-sectional shape. In the figure, 8 is a dummy ring made of Teflon containing a magnet, and has a semicircular cross section and a diameter corresponding to each of the recesses 2, 4, and so on. The number is the same as the number of the recesses 2, 4, etc. (44 in this embodiment).

In the mold constructed as described above, as in the conventional method, a rubber dough is appropriately placed between the lower mold 1 and the upper mold 7, this is vulcanized, and the rubber dough is placed in each cavity 2, 4... During this process, dummy rings 8 are attached in advance to the recesses 2, 4, whose dimensions do not require molding, and the recesses 2, 4, etc. are closed. . Since the dummy ring 8 is molded from Teflon containing magnets, it is extremely easy to attach it into the recesses 2, 4 due to the magnetic force, and the dummy ring 8 can be taken out from the recesses 2, 4... It can be easily removed by using a strong magnet (not shown). The dummy ring 8 is made of Teflon in consideration of adhesion to the vulcanized rubber fabric, but it may of course be made of other metals. Furthermore, the dummy ring 8 has a semicircular cross-sectional shape and is formed to have the same inner and outer diameters as the corresponding recesses 2, 4, so that the inner surface of the recesses 2, 4... There is no risk of damaging the In addition, since the vulcanized rubber fabric flows between the pair of dummy rings 8 attached to the pair of recesses 2, 4... of the lower mold 1 and the upper mold 7, the recesses 2, 4... 1 attached to...
The pair of dummy rings 8 prevents the flow of the rubber dough from causing the inconvenience of the rubber dough not being able to reach the cavity to be filled.

[Effect of idea]

The present invention has the above-mentioned structure, that is, a ring-shaped molded product is formed by forming paired recesses on the parting surface of a split mold, and filling a molding material into the cavity formed by the combination of the recesses. The mold includes a split mold in which a plurality of cavities with different diameter dimensions are provided concentrically, and a plurality of dummy rings installed in each of the recesses. Because the molding material is configured to flow between the dummy rings, it is possible to mold a large amount of molded products with multiple different diameters at the same time using one mold, as well as molded products with unnecessary diameters due to production planning. Molding can be stopped at will, and the yield of molding material can be improved. When molding an O-ring, if a dummy ring with a circular cross section is inserted into a cavity that is a combination of recesses with a semicircular cross section, the flow of the molding material will be hindered by the dummy ring. Accordingly, such inconvenience will not occur. In addition, the mold of the present invention can also be used to mold rings with various cross-sectional shapes such as square rings, U-packs, V-packs, etc. in addition to O-rings by changing the cross-sectional shape of the cavity. ,
Furthermore, in addition to the above-mentioned compression molding method, it can also be used in the case of transfer molding method and injection molding method, and the range of application thereof is wide, and the practical effects of the present invention are extremely large.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of the main parts of a conventional mold, FIG. 2 is a perspective view of the main parts of a mold according to the present invention, and FIG. FIG. 4 is an enlarged sectional view of the same essential part. 1... Lower mold, 2, 2a, 2b, 4, 4a... Annular recess, 3, 5... Molding part, 6... Overlay, 7...
...Upper mold, 8...Dummy ring.

Claims (1)

[Claims for Utility Model Registration] 1. In a mold for forming a ring-shaped molded product by forming paired recesses on the parting surface of a split mold and filling a molding material into a cavity formed by a combination of the recesses, A split type with multiple cavities of different dimensions arranged concentrically,
a plurality of dummy rings installed in each of the recesses, and one ring installed in the recesses forming a pair with each other.
A molding die characterized in that a molding material is allowed to flow between a pair of dummy rings. 2. The mold according to item 1, wherein the dummy ring is made of Teflon containing a magnet.