JPH0446765B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention can prevent the tire from disengaging from the rim even if the internal pressure decreases due to a puncture or the like while driving.
This invention relates to a motorcycle tire and rim assembly with improved running safety.

Conventionally, in the assembly of a motorcycle tire and rim, the tire bead is pressed by the air pressure inside the tire to press the bottom and outer surfaces of the tire bead against the rim bead seat and rim flange. It is fixed to the rim.

Therefore, when the internal pressure of a tire decreases, its holding power decreases, and especially if the internal pressure decreases rapidly due to a puncture, etc., lateral force from steering wheel operation during cornering may cause the bead of the tire to move away from the rim. The rim may come off and come off, impairing driving safety.

Particularly in motorcycle tires, when cornering, the wheel tilts significantly, and the camber thrust that works to recover this tilt causes a pressing force to act on the bead inward of the tire, or on rocks, sand, mud, etc. When running on rough roads with relatively low internal pressure, the tire undergoes severe deformation in the vertical and lateral directions, and as a result of pressure acting on the bead inward of the tire, the bead becomes detached from the rim. It becomes easier.

The applicant has also filed a patent application No. 58-93185 (Japanese Unexamined Patent Publication No.
59-220406), a protruding toe portion and a rib are formed on the bead portion of the tire, and a fitting groove on the axially inner end of the bead seat and a recess on the lower side of the rim flange are formed on the rim. The present invention proposes an assembly of a two-wheeled vehicle tire and rim in which grooves are formed respectively.

As a result of consideration when implementing such a two-wheeled vehicle tire and rim assembly, the present applicant has determined that the concave groove and the fitting groove are formed by an inclined surface that slopes obliquely inward in the radial direction from the concave groove to the bottom of the fitting groove. It has been found that by making the rim more smoothly continuous, the tire can be easily mounted while increasing the effect of preventing the rim from coming off.

SUMMARY OF THE INVENTION An object of the present invention is to provide a two-wheeled vehicle tire and rim assembly that allows safe driving even when a sudden drop in internal pressure occurs and also facilitates tire installation.

The present invention provides a two-wheeled vehicle tire, and a rim having a bead seat and a rim flange. In a two-wheeled vehicle tire and rim assembly in which the tire is mounted on the rim, a projection is provided on the axially inner toe portion of the bead portion of the tire, and a protrusion is provided on the lower side of the axially outer surface of the bead portion in the circumferential direction. A rib extending in the circumferential direction is formed, and a fitting groove extending in the circumferential direction and into which the projection is fitted is provided in the bead seat of the rim, and a fitting groove extending in the circumferential direction and into which the projection is fitted is provided in the lower side of the rim flange. A concave groove is formed by recessing the rim outward in the axial direction, and the concave groove and the bottom of the fitting groove are smoothly connected to each other by an inclined surface that faces in the axial direction of the tire and tilts inward in the radial direction. This is a two-wheeled vehicle tire and rim assembly characterized by:

[Effect]

By filling with air, the bottom of the bead is pressed against the bead seat and the outer surface of the bead is pressed against the rim flange. Further, the protrusion is pushed into the fitting groove, so that even when an axially inward force is applied, the protrusion is fitted in the fitting groove, thereby preventing displacement. Furthermore, since the protrusion protrudes from the toe portion, it cooperates with the bead core to prevent the bead portion from rising due to rotation around the tip of the protrusion. Also, since the rib fits into the groove of the rim flange,
In addition to improving airtightness and increasing the fitting force with the rim, the fitting of the rib into the concave groove prevents the bead from rising due to rotation around the tip of the protrusion, and also directs the bead outward in the axial direction of the tire. Even when a force is applied, the close contact between the rib and the groove can resist the inclination of the vehicle body and prevent the rim from coming off. Furthermore, by smoothly connecting the concave groove and the fitting groove with an inclined surface that slopes inward in the radial direction from the concave groove to the bottom of the fitting groove, the transmission of force at the bead part is smooth, and the above-mentioned effects in each part are made smooth. To make it easy to install tires without interfering with the process.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

Also, the width W of the groove 16 is 3 to 10 mm, and the depth D is 0.5 to 10 mm.
The depth D is 1.5 mm, and accordingly, the protrusion margin of the rib 10 is determined in accordance with this depth D so that the rib 10 fits into the groove 16. Further, when the depth D approaches 0.5 mm, the protrusion of the rib 10 becomes relatively small as shown in FIG. Moreover, if the width W is too wide, the internal pressure air retention property will be reduced when used as a tubeless tire, and if it is too small, the effect of preventing rim detachment will be reduced.

Furthermore, by fitting the rib 10 and the concave groove 16, when the tire rim is dislocated, the bead part rotates around the tip of the toe part 7, and the heel part lifts up. As a result, the rim can be prevented from slipping.

Note that the tire 1 can be attached to the rim 2 in the same way as a normal tire and rim. For example, in FIG. 1, after the bead portion 9 is fitted into the rim well 11 beyond the rim flange 13, the bead portion 9 is filled with air from the air valve 17.
is pressed toward the bead seat 12 and the rim flange 13 by internal pressure, the protruding toe portion 7 is pushed into the fitting groove 15, the bead portion 9 is firmly held on the rim 2, and the rib 10 is pushed into the groove 16. Fits in.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

In the figure, a two-wheeled vehicle tire 1 includes a carcass 4 having a folded part 4a that extends from a tread part 5 whose tread surface is an arc, passes through a sidewall part 6, and is folded back at a bead part 9 and a bead core 3, and the tread part 4.
and a belt layer 6 disposed inside the carcass 4 and radially outside the carcass 4. Further, a protrusion 7 smoothly protruding from the toe portion of the bead portion 9 in the axial direction of the tire and having an arcuate cross section is provided.
As a result, the length of the toe portion becomes longer than that of a normal tire.

The protrusion 7 extends radially inward and axially inward from the bead core 3, and has a predetermined flexibility in the direction perpendicular to the length direction to facilitate fitting with the rim 2. On the other hand, it is preferable to have rigidity in the length direction, that is, to have low elongation and high bending flexibility.

As a result, when the axially inward force acting on the tread portion 5 is transmitted to the bead portion, the bead core 3 and the protrusion 7 of the toe portion rotate around the toe tip of the bead portion. To prevent the part from lifting up and to make the fitting between the bead part 9 and the rim 2 strong. Note that an elastomer material with a JISA hardness of 65° to 95°, which is harder than ordinary bead rubber, is used as the projection 7, and it is particularly preferable that the inner side of the bead portion 9 be formed along the outer contour of the projection 7, as shown in FIG. It is reinforced with a fiber layer 8 extending from the outside. As the fiber layer 8, preferably a relatively highly elastic organic fiber cord such as polyester or aromatic polyamide fiber is used.

As shown in FIG. 1, the protrusion 7 is made of a single elastomer material, and in order to have high bending flexibility and low elongation, as shown in FIG.
An annular core 7a made of hard rubber, plastic, or a bundle of fibers, which is harder than the surrounding elastomeric material, may be provided, in which case the fit with the rim 2 will be even stronger.

Further, on the outer side of the bead portion where the bead portion 9 abuts the rim flange 13, a rib 10 that gently protrudes outward in the tire axial direction with a circular arc cross section is formed over the entire circumference inwardly in the radial direction. .

The carcass 4 is a so-called cross made of at least two plies of organic fiber cords such as nylon, polyester, rayon, aromatic polyamide fibers, etc., arranged in parallel so that the cords between the plies intersect with each other. Ply structure or one or more of the plies to the tire equatorial plane
It can also be formed into a radial structure arranged at an angle of up to 80°. Note that FIG. 1 shows a radial structure.

Next, the belt layer 6 is usually composed of a steel cord, and the cord is oriented at an angle of 10° to the tire equatorial plane.
It is inclined at an angle of ~30° and its width spans the entire width of the tread. The arrangement of this belt layer 6 improves the rigidity of the tire contact patch,
Safety is ensured when driving straight. Note that this belt layer 6 is not necessarily required in a tire with a cross-ply structure.

As shown in FIG. 3, the rim 2 includes a rim well 11 recessed in the center of the rim 2, a pair of bead seats 12 connected to both ends of the rim well 11, and a pair of bead seats 12 connected to both ends of the bead seats 12. and a rim flange 13 disposed on the axially and radially outer shoulder of the bead seat 12, and the bead seat 12 has a fitting groove 15 extending circumferentially adjacent to the axially inner end a of the bead seat 12.
It is equipped with

The protrusion 7 of the toe portion contacts the bottom of the fitting groove 15 and can fit into each other, so that the bead seat 12
The length WB of the bottom of the fitting groove 15 must approximately match the distance from the center of the fitting groove 15 to the axially outer end of the bead seat 12.

Further, on the inner surface of the rim flange 13 facing the bead portion 9, a groove 16 is provided on the lower side, which is radially inward, for recessing the rim flange 13 outward in the tire axial direction and engaging with the rib 10. Provided all around. In the present invention for mounting a two-wheeled vehicle tire, the radial width W is 3 to 10 mm and the depth D is 0.5 to 1.5 mm. If the width W is too large, the internal pressure air retention property will be reduced when used as a tubeless tire, and if it is too small, the effect of preventing rim detachment will be reduced.

Furthermore, the bead seat 12 is smoothly continuous from the concave groove 16 to the bottom of the fitting groove 15 by a gentle inclined surface that faces inward in the tire axial direction and tilts obliquely inward in the radial direction.

Furthermore, the area from the bottom of the fitting groove 15 to the axially inner end a of the bead seat 12 is continuous by an inclined surface that faces inward in the tire axial direction and steeply slopes outward in the radial direction.

The two-wheeled vehicle tire 1 can be mounted on the rim 2 in the same way as a normal tire and rim.

For example, in FIG. 1, after the bead portion 9 is inserted into the rim well 11 over the rim flange 13, by filling air from the air valve 17, the bead portion 9 is pressed toward the bead seat 12 and the rim flange 13 by internal pressure. . Also, the protrusion 7 has a fitting groove 15.
Since the protrusion 7 is fitted into the fitting groove 15, even when the protrusion 7 is pushed in and an inward force is applied in the axial direction, the protrusion 7 is prevented from shifting and the protrusion 7 protrudes from the toe. Because of this, bead core 3
This prevents the bead portion from rising due to rotation around the tip of the protrusion 7, and effectively suppresses the rim from coming off.

Further, the rib 10 is connected to the concave groove 16 of the rim flange 13.
Since the ribs 10 and the concave grooves 16 are fitted, the airtightness and the fitting force with the rim are increased, and even when a force directed outward in the tire axial direction is applied, the ribs 10 and the grooves 16 are in close contact with each other. Further, by fitting the rib 10 into the groove 16, the bead portion is prevented from rising due to rotation about the tip of the projection, and the rim can be prevented from coming off against the inclination of the vehicle body. Furthermore, by smoothly connecting the concave groove and the fitting groove with an inclined surface that slopes inward in the radial direction from the concave groove to the bottom of the fitting groove, the transmission of force at the bead part is smooth, and the above-mentioned effects in each part are made smooth. To make it easy to install tires without interfering with the process.

[Effects of the Invention] As described above, the motorcycle tire and rim assembly of the present invention has a fitting groove and a concave groove in the rim, a projection on the toe of the tire bead, and a projection on the outer surface of the bead. Since ribs are provided to fit into each groove, the fit between the two is further strengthened, causing a sudden drop in internal pressure, and also effectively preventing the rim from coming off when the wheel is driven at a large incline. In addition, since the fitting groove and the concave groove are smoothly continuous on an inclined surface, the transmission of force at the bead part is smooth, the above-mentioned action in each part is not hindered, and the tire installation is easy. do.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the assembly of the present invention, FIG. 2 is a partial sectional view of the bead portion, and FIG. 3 is a partial perspective view of the rim. 1...Two-wheeled vehicle tire, 2...Rim, 3...Bead core, 4...Carcass, 5...Tread section,
6...Belt layer, 7...Protrusion, 9...Bead portion,
10... Rib, 12... Bead seat, 13... Rim flange, 15... Fitting groove, 16... Concave groove.

Claims (1)

[Scope of Claims] 1. A motorcycle tire, comprising a rim having a bead seat and a rim flange, the bead seat receiving the bottom surface of the bead portion of the tire, and the rim flange supporting the axial outer surface of the bead portion. In the two-wheeled vehicle tire and rim assembly in which the tire is mounted on the rim, a projection is provided on the axially inner toe portion of the bead portion of the tire, and the lower side of the axially outer surface of the bead portion is provided. A rib extending in the circumferential direction is formed on the rim, and a fitting groove extending in the circumferential direction and into which the projection is fitted is provided in the bead seat of the rim, and a rib extending in the circumferential direction is formed on the lower side of the rim flange. A groove into which the rim is fitted is formed by recessing the rim outward in the axial direction, and the groove and the bottom of the fitting groove are smoothed by an inclined surface that faces in the axial direction of the tire and tilts inward in the radial direction. A two-wheeled vehicle tire and rim assembly characterized in that they are continuous.