JPH0349859Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a vulcanization molding apparatus for solid tires.

Solid tires are currently widely used in low-speed, heavy vehicles such as forklifts, and usually have a steel base ring integrally attached to their inner diameter. In other words, this base ring consists of a cylindrical body with a width that is approximately the same as the cross-sectional width of the tire, and after unvulcanized rubber is wound around it to a predetermined thickness, it is vulcanized together with the unvulcanized rubber. By being placed in a sulfur mold, it is integrally attached to the rubber material. However, during vulcanization molding, the rubber base ring may be deformed due to thermal expansion pressure. This becomes more noticeable as the cross-sectional width of the tire increases, and the incidence of defective products increases. To deal with this, it would be possible to increase the thickness of the base ring, but there are restrictions on this in terms of standards, and the difficulty of processing such as bending increases accordingly.

Therefore, the purpose of this invention is to provide a solid tire vulcanization molding apparatus that is equipped with a support frame that can firmly support the inner surface of the base ring in order to prevent the base ring from being deformed during vulcanization molding. It is in.

Hereinafter, this invention will be described in detail with reference to embodiments shown in the accompanying drawings.

As shown in Fig. 1, this vulcanization molding apparatus consists of a base ring 1 made of a steel cylindrical body with a predetermined width, and an unvulcanized rubber made by winding unvulcanized rubber and laminating it to a predetermined thickness. It is intended for solid tires 3, and includes a molding mold consisting of an upper mold 4 and a lower mold 5 formed in a half-split shape, and a support frame 6 removably disposed within the molding mold. There is. In this embodiment, the upper mold 4 and the lower mold 5 have the same structure, and each has an annular groove that forms a cavity that cooperates with each other to receive the above-mentioned portions of the unvulcanized rubber 2. 7, 7, and concave walls 8, 8 for forming a space communicating with the above-mentioned cavity are provided in the center of the mold. The support frame 6 is arranged in a space formed by the concave walls 8, and its structure is illustrated in detail in FIG. That is, this support frame 6
The main shaft 10 has a handle 9 (see Fig. 1) at the upper end, and is formed in a corrugated shape so as to be bent in opposite directions at two points, and one end is pivoted to the main shaft 10, and from there an equiangular section is formed. A plurality of arms 12, four in this embodiment, are arranged radially at intervals, and a holder is arranged concentrically around the main shaft 10 and pivots the intermediate portion of each arm 12 closer to the main shaft 10. ring 11 and each arm 12
4 backing plates (frame members) pivoted to the other end
It is equipped with 13. Note that each arm 12 has a slit hole 14 bored along its longitudinal direction, and the retaining ring 1 is inserted through this slit hole 14.
1 pin 26. Therefore, when the handle 9 is operated to rotate the main shaft 10, for example, in the counterclockwise direction in FIG.
As the arms 13 move, each arm 13 expands radially from the position indicated by the chain line in the figure and comes into contact with the inner wall surface of the base ring 1. In order to apply a uniform pressing force to the inner wall surface of the base ring 1, each contact plate 13 is preferably formed to have approximately the same curvature as the inner wall surface of the base ring 1.

In the above configuration, the unvulcanized solid tire 3 having the base ring 1 is placed in a cavity formed by the grooves 7, 7 of the upper mold 4 and the lower mold 5, while the holding frame 6 has a concave wall. 8, 8 in the space formed in its central part. Then, by operating the handle 9, the diameter of each backing plate 13 is expanded as described above to firmly press the inner wall surface of the base ring 1, and then both molds 4 and 5 are closed, and vulcanization molding is started. Ru. Therefore. According to this invention, there is almost no possibility that the base ring 1 is deformed inward by the expansion pressure from the unvulcanized rubber 2 that expands thermally during vulcanization molding.

FIG. 3 shows a modification of the support frame 6 that is applicable to this invention. That is, in this modification, a cam shaft 16 having a cam surface 15 on the shaft portion is used in place of the main shaft 10 described above, and the cam surface 15 and the above-mentioned backing plate 13 are connected to the cam surface 1.
5 is operatively connected via a stem 18 having a follower 17. In addition, reference numeral 19
is a guide pin for regulating the sliding direction of the stem 18 in cooperation with the slit 20 formed in the stem 18. Therefore, the camshaft 16
By rotating the back plate 13 in the left and right direction,
corresponds to the diameter expansion or contraction, and acts selectively in contact with the base ring 1 as in the above embodiment. Furthermore, the support frame 6 may be of the pantograph type shown in FIG. 4. That is, in this support frame 6, a driving screw shaft 22 having a left-handed screw 22a and a right-handed screw 22b, and a drive screw shaft 22 having a left-handed screw 22a and a right-handed screw 22b, and
A pair of movable sleeves 23 and 24 are provided, and each of the abutting plates 13 has two connecting rods 25 and 2, respectively.
5 to the sleeves 23 and 24. Therefore, by rotating the drive screw shaft 22 in the left-right direction via the operating handle 21,
The sleeves 23 and 24 are moved toward or away from each other, and each contact plate 13 expands or contracts in diameter accordingly, and selectively abuts against the base ring 1 as in the embodiment described above. become. In this embodiment, four backing plates 13 are used as frame members, but the number may be arbitrary.

As is clear from the description of the above embodiments, this invention provides a solid tire that can be vulcanized and molded without deforming the base ring when vulcanizing an unvulcanized solid tire having a base ring. It is possible to provide a vulcanization molding apparatus.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the vulcanization molding apparatus according to this invention, Fig. 2 is a plan view of the support frame in Fig. 1, and Figs. 3 and 4 are schematic illustrations of modified examples of the support frame. It is a diagram. In the figure, 1 is a base ring, 2 is unvulcanized rubber, and 3
1 is an unvulcanized solid, 4 is an upper mold, 5 is a lower mold, 6 is a holding frame, 7 is a groove, 8 is a concave wall, 9 is a handle, 10
is the main shaft, 11 is the retaining ring, 12 is the arm, 13
is the backing plate (frame member).

Claims (1)

[Claims for Utility Model Registration] An apparatus for vulcanizing and molding an unvulcanized solid tire made by winding and laminating unvulcanized rubber around a base ring by placing it in a mold together with the base ring, A molding die consisting of a half-split upper mold and a lower mold that cooperate with each other to form an annular cavity into which a vulcanized solid tire is fitted and a central space connected to the cavity; a support frame including a plurality of frame members whose diameter can be expanded and contracted and which is removably disposed in the central space of the mold, and when the unvulcanized solid tire is vulcanized and molded, the inner wall surface of the base ring A solid tire vulcanization molding apparatus characterized in that the solid tire is abutted and supported by the frame member having an enlarged diameter frame.