JP7384641B2 - tire vulcanization mold - Google Patents

Description

The present invention relates to a tire vulcanization mold.

Markers such as letters, symbols, or figures are provided on the outer surface of the side portion of a pneumatic tire to facilitate identification of the tire manufacturer, type, size, year and week of manufacture, etc. In order to form such a sign, it is known that a stencil plate made of a metal plate such as aluminum or iron is replaceably attached to the side forming surface of a tire vulcanization mold with screws (see Patent Document 1 below). .

JP2017-154282

To change the side markings on a pneumatic tire, the stencil plate must be removed and replaced with another stencil plate. The stencil plate and the screws that fix it are small parts, and the screw holes are hidden by the stencil plate, making it difficult to screw the screws into the screw holes provided in the tire vulcanization mold. Fixation workability is poor.

It is also known to attach a stencil plate to a tire vulcanization mold using an adhesive, but when using this adhesive, it is difficult to set the stencil plate in a specified position, and it is difficult to remove the stencil plate. It becomes.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tire vulcanization mold in which a stencil plate can be easily attached to and removed from a desired position of the tire vulcanization mold.

A tire vulcanization mold according to an embodiment of the present invention includes a tire molding surface for molding a tire, a mounting recess formed in a concave shape with respect to the tire molding surface, and a mark disposed in the mounting recess on the outer surface of the tire. In a tire vulcanization mold comprising a stencil plate to be formed, the tire vulcanization mold protrudes from the bottom surface of the mounting recess, is inserted into an insertion hole provided in the stencil plate, and has a tip portion that protrudes further inside the mold than the stencil plate. The present invention includes a bolt, and a fixing part that is fastened to the tip of the bolt and fixes the stencil plate to the mounting recess.

In the pneumatic tire vulcanization mold described above, the stencil plate can be easily attached to and removed from a desired position of the tire vulcanization mold.

Cross-sectional view of a tire vulcanization mold according to an embodiment A view of the side plate of the embodiment seen from inside the mold An exploded perspective view of the mounting recess, spacer, and stencil plate. AA sectional view in Figure 2 An exploded view of the mounting recess, spacer, and stencil plate in Figure 4. Partial side view of a pneumatic tire molded with a tire vulcanization mold according to an embodiment

FIG. 1 is a diagram showing a tire vulcanization mold (hereinafter simply referred to as a vulcanization mold) 10 according to an embodiment. This vulcanization mold 10 is used to vulcanize and mold a pneumatic tire T.

Here, the pneumatic tire T includes a tread portion T1 forming a ground contact surface, and a pair of sidewall portions T2, T2 and bead portions T3, T3 extending inward in the tire radial direction from both widthwise ends of the tread portion T1. A general tire structure can be adopted except for the mark provided on the sidewall portion T2.

The vulcanization mold 10 is a mold in which an unvulcanized green tire is set and vulcanized and molded, and a cavity, which is a molding space for the tire T, is formed inside. This vulcanization mold 10 includes a tread mold 12, a pair of upper and lower sidewall molds 14, 14, and a pair of upper and lower bead molds 16, 16. The tread mold 12 has a tire molding surface (tread molding surface) 12A that molds the outer surface of the tread portion T1. The pair of upper and lower sidewall molds 14, 14 have tire molding surfaces (sidewall molding surfaces) 14A, 14A that mold the outer surface of the sidewall portion T2. The pair of upper and lower bead molds 16, 16 have a tire molding surface (bead molding surface) 16A that molds the outer surface of the bead portion T3.

As shown in FIGS. 1 to 5, the sidewall mold 14 is provided with a mounting recess 20 that is recessed into the sidewall molding surface 14A. A stencil plate 30 for forming a marker and a spacer 40 are provided in the mounting recess 20 with bolts 22 inserted therein.

The mounting recess 20 is a narrow recess that extends in a curved manner along the tire circumferential direction, and the length in the tire circumferential direction is larger than the width in the tire radial direction. It is set slightly larger.
Bolts 22 protruding from the bottom surface 21 of the mounting recess 20 toward the cavity are provided at both ends of the mounting recess 20 in the longitudinal direction (tire circumferential direction).

As shown in FIG. 2, the stencil plate 30 is a narrow plate-shaped body that extends in a curved manner along the circumferential direction of the tire, the length of which is greater in the circumferential direction of the tire than the width thereof in the radial direction of the tire. The material of the stencil plate 30 is, but not limited to, aluminum or aluminum alloy, for example. The thickness t1 (see FIG. 5) of the stencil plate 30 is not particularly limited, and is, for example, 0.4 to 0.6 mm.

The stencil plate 30 includes a flat plate-like portion 33 and insertion holes 35 provided at both ends in the longitudinal direction.

The flat portion 33 includes a front surface 33 a that forms the surface of the tire, and a back surface 33 b that faces the bottom surface of the mounting recess 20 and 21 . On the surface 33a of the flat portion 33, label forming portions 31 are formed side by side. The marker forming portion 31 is provided in a concave shape when viewed from the surface 33a side, and forms a convex marker M on the side portion of the tire T as shown in FIG. The sign M is formed by arranging letters, symbols, figures, etc., and collectively represents part or all of the manufacturer's name, manufacturing plant, size, manufacturing week, manufacturing year, etc. When the stencil plate 30 is viewed from the front side, the mark forming portion 31 has the shape of an inverted mark M as a whole.

The mark forming portion 31 is formed by depression of the flat portion 33 from the front surface 33a to the back surface 33b by press working. Therefore, a bulging portion 32 corresponding to the marker forming portion 31 appears on the back surface 33b side of the flat portion 33. The depth t2 (see FIG. 5) of the marker forming portion 31 is, for example, 0.2 to 0.8 mm, and the height of the bulging portion 32 is equivalent to the depth of the marker forming portion 31.

Insertion holes 35 passing through the stencil plate 30 are formed at both ends of the flat portion 33 in the longitudinal direction. The insertion hole 35 is a cut-out hole that opens at the outer end of the flat portion 33 in the longitudinal direction.

The spacer 40 is a frame-shaped member having substantially the same shape as the stencil plate 30, which is slightly smaller than the stencil plate 30 when viewed from the stencil plate 30 side. As shown in FIG. 4, the spacer 40 is stored in the mounting recess 20 overlapping the back side of the stencil plate 30, avoiding the bulge 32 corresponding to the sign forming part 31, and facing the back side of the peripheral edge of the stencil plate 30. comes into contact with. Thereby, the spacer 40 supports the stencil plate 30 so that the surface 33a of the flat portion 33 and the sidewall molding surface 14A are connected without any difference in level.

Moreover, when the stencil plate 30 and the spacer 40 stored in the mounting recess 20 are stacked and stored in the mounting recess 20, the insertion hole 35 and the insertion hole 42 communicate with each other, and the bolt 22 protruding from the bottom surface 21 of the mounting recess 20 passes through the insertion hole. 35 and the insertion hole 42.

The fixing portion 23 includes a female screw portion, such as a nut or a bra bolt, that screws into the male screw portion of the bolt 22 . The fixing part 23 clamps the stencil plate 30 and the spacer 40 between the fixing part 23 and the bottom surface 21 of the mounting recess 20 by screwing into the male threaded part of the bolt 22 inserted through the insertion hole 35 and the insertion hole 42. do. At that time, as shown in FIGS. 2 and 4, the fixing part 23 is arranged so as to straddle the stencil plate 30 and the sidewall molding surface 14A, which is the tire molding surface, and It is desirable that the bolt 22 be fastened to the bolt 22 so as to come into contact with the bolt 14A.

Further, as shown in FIG. 4, it is preferable that the edge 23a of the fixing portion 23 is chamfered with a C surface, an R surface, or the like. By chamfering the edge 23a of the fixed part 23, no sharp edge is formed in the recess formed in the tire T corresponding to the fixed part 23, and cracks originating from the edge of the recess can be suppressed. Can be done.

According to the above embodiment, the bolt 22 protruding from the bottom surface of the mounting recess 20 is inserted into the insertion hole 35 of the stencil plate 30, and then the fixing part 23 is screwed onto the bolt 22 to attach the stencil plate 30. Therefore, the fixing part 23 can be attached and detached while the stencil plate 30 is held in a predetermined position by the bolts 22, and the stencil plate 30 can be easily replaced. Further, since the screwing position between the bolt 22 and the fixing portion 23 can be visually observed, the stencil plate 30 can be easily attached to the mounting recess 20.

Furthermore, in the present embodiment, if the spacer 40 is disposed between the stencil plate 30 and the bottom surface 21 of the mounting recess 20, even if the bulge portion 32 is formed on the back surface 33b side of the flat portion 33, However, the stencil plate 30 can be attached to the mounting recess 20 so that the surface 33a of the flat portion 33 and the sidewall molding surface 14A are connected without any difference in level.

Furthermore, when the spacer 40 contacts the back side of the periphery of the stencil plate 30 as in the present embodiment, it is possible to suppress the formation of a gap between the stencil plate 30 and the mounting recess 20 due to deformation of the stencil plate 30. This makes it possible to suppress poor appearance of product tires.

Further, in this embodiment, when the fixing part 23 is fastened to the bolt 22 so as to come into contact with the stencil plate 30 and the sidewall molding surface 14A, the area where the fixing part 23 comes into contact with the stencil plate 30 can be reduced. Therefore, it is possible to expand the area occupied by the mark forming portion 31 on the stencil plate 30, and it is possible to form more marks M in a limited space.

In addition, in this embodiment, when the insertion hole 35 provided in the stencil plate opens at the periphery of the stencil plate 30, the area of the mark forming part 31 occupied in the stencil plate 30 can be expanded, and the limited space can be expanded. More labels M can be formed. Furthermore, since the position of the bolt 22 within the insertion hole 35 can be finely adjusted, unnecessary force is less likely to act on the stencil plate 30 when fastening the fixing portion 23, and deformation of the stencil plate 30 can be suppressed.

(Example of change)
The embodiments described above are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention.

For example, in the embodiment described above, a notch-shaped hole that opens at the outer end in the longitudinal direction of the stencil plate 30 is provided as the insertion hole 35 through which the bolt 22 is inserted, but it may be a hole that is closed in the circumferential direction. .

Further, in the above-described embodiment, a case has been described in which the fixing part 23 is fastened to the bolt 22 so as to come into contact with the stencil plate 30 and the sidewall molding surface 14A. It may be fastened to the bolt 22 as shown in FIG.

Further, in the above-described embodiment, the stencil plate 30 and the mounting recess 20 are provided on the sidewall molding surface 14A, but they may be provided on the bead molding surface 16A. may be provided on both sides.

DESCRIPTION OF SYMBOLS 10...Tire vulcanization mold, 12...Tread mold, 14...Side wall mold, 16...Bead mold, 18...Side mold, 20...Mounting recess, 21...Bottom surface, 22...Bolt, 23...Fixing part, 30...Stencil Plate, 31... Marker forming part, 32... Swelling part, 33... Flat part, 33a... Surface, 33b... Back surface, 35... Insertion hole, 40... Spacer, 42... Insertion hole

Claims (4)

A tire vulcanization mold comprising a tire molding surface for molding a tire, a mounting recess formed in a concave shape with respect to the tire molding surface, and a stencil plate disposed in the mounting recess and forming a mark on the outer surface of the tire,
a bolt that protrudes from the bottom surface of the mounting recess, is inserted into an insertion hole provided in the stencil plate, and has a tip portion that protrudes further inside the mold than the stencil plate;
a fixing part fastened to the tip of the bolt to fix the stencil plate to the mounting recess;
Tire vulcanization mold equipped with. The tire vulcanization mold according to claim 1, further comprising a spacer disposed between the bottom surface of the mounting recess and the stencil plate. The tire vulcanization mold according to claim 1 or 2, wherein the fixing part is fastened to the bolt so as to come into contact with the stencil plate and the tire molding surface. The stencil plate includes an insertion hole through which the bolt is inserted,
The tire vulcanization mold according to any one of claims 1 to 3, wherein the insertion hole is opened at a peripheral edge of the stencil plate.

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