JPH05319009A - Assembly of tire and rim for two wheeler - Google Patents

Abstract

PURPOSE:To prevent generation of puncture without reducing maneuvering stability and riding quality. CONSTITUTION:An assembly is provided with a tire 2, a rim 3, a tube 5 arranged in a pit 4 surrounded with an inside circumferential face which is formed by the tire 2 and rim 3, a cushioning body 6 arranged between the inside circumferential face and tube 5, and the cushioning body 6 is provided with a pair of wing parts 6B, 6B extending to the tire shoulder part 13A on both ends of the base part 6A along a rim well 18 and the thickness T1 of the wing parts 6B at the height of 1/2 of the tire sectional height H is set thicker compared with the thickness T3 of the base part 6A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire / rim assembly for a two-wheeled vehicle capable of preventing punctures without impairing running performance.

[0002]

2. Description of the Related Art A motorcycle that travels off-road has a higher frequency of punctures than one that travels only on-road because the condition of the road surface and the traveling conditions differ from those when traveling on-road. . Especially when running on gravel, rubble, or bedrock, the tire skin, especially the sidewall part, is locally deformed, so that the skin is sandwiched between the obstacle and the rim and the tube is cut. Punctures often occur. Further, during a motocross race, the sidewall is often locally deformed at the time of landing after jumping, so that the tube is often compressed and damaged.

[0003]

In a tire for a motorcycle that travels on such an uneven terrain, it is necessary to increase the internal pressure of the tube, use a thick tube, and apply for example in Japanese Unexamined Patent Publication No. Hei 3-231008. As suggested by others, use a tube protective layer with a cross-sectional shape that is the thickest in the tread portion of the tire and gradually becomes thinner from the equatorial plane to both sides in the meridian direction and terminates near the bead portion, double tube, mousse tube Although punctures are prevented by using a special material such as, the puncture is not extinct even with such specifications. Further, in the case of the above specifications, the distance between the inner peripheral surface of the tread portion and the air chamber tends to be long, so the air capacity is reduced and the performance is inferior. That is, steering stability and riding comfort are significantly reduced.

Therefore, there has been a demand for a tire which is less likely to cause banking and which maintains driving stability and riding comfort among drivers traveling on rough terrain.

The inventor intervenes a cushioning material between the side wall portion of the tire and the tube, excluding the tread portion, to prevent the shock force from propagating to the tube by the cushioning material and prevent puncture. It was found that steering stability and riding comfort can be maintained by bringing the tread portion closer to the air chamber.

The present invention is based on the fact that a cushioning material is interposed between the tire and the tube and along the rim well and the side wall portion, and it is possible to prevent tire puncture while maintaining steering stability and riding comfort. It is intended to provide a tire and rim assembly for a motorcycle.

[0007]

DISCLOSURE OF THE INVENTION The present invention is directed to a tire, a rim for assembling the tire, a tube disposed in an inner cavity surrounded by an inner peripheral surface formed by the tire and the rim, and the inner peripheral surface and the tube. In a tire meridian section by integrally providing a pair of wings extending along the inner peripheral surface of the tire to the tire shoulders at both ends of the base portion arranged along the rim well of the rim in a transverse section including the tire shaft. A cushioning body having a letter-like shape and made of a sponge material is provided, and the thickness of the wing portion at the 1/2 cross-section height position, which is ½ the height of the tire cross-section height, is the thickness of the base portion. It is an assembly of a tire and a rim for a motorcycle, which is thicker than the above.

Further, it is preferable that the buffer has closed cells and the expansion ratio thereof is 4 or more and 15 or less.

[0009]

Since the wing portion of the shock absorber extends from both ends of the base portion along the tire inner peripheral surface to the tire shoulder portion, the shock absorber protects the bead portion and the sidewall portion of the tire from impact and reduces the risk of puncture. On the other hand, the tread portion is close to the inner cavity, and the high-pressure air filled in the inner cavity can maintain steering stability and riding comfort substantially equivalent to the normal one.

Further, since a buffer is provided between the rim well and the tube, the risk of the tube being rubbed by the rim and being punctured by abrasion can be eliminated.

Further, since the shock absorber has a large thickness in the vicinity of the 1/2 cross section height at which a large impact is exerted on the tube during traveling, the impact is efficiently absorbed and puncture is prevented, while the impact force is increased. Since the bending deformation of the sidewall portion due to the addition is greatly relaxed, the phenomenon of being sandwiched between the rim and the obstacle is significantly reduced. Further, since the cushioning body is formed thin at the base portion, the cushioning body can be easily assembled when the rim is assembled, and in addition, even if the rim is made of steel, the tube is protected from rust generated on the rim.

When the bubble magnification of the buffer is regulated,
It becomes easy to maintain the steering stability and the riding comfort, and the puncture resistance is further improved.

As described above, according to the present invention, the above-mentioned components are organically combined and integrated to enhance the puncture resistance without impairing the riding comfort and the steering stability.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the figure, a tire and rim assembly 1 for a motorcycle is
The tire 2 and a rim 3 that rims the tire 2, a tube 5 disposed in an inner cavity 4 surrounded by the tire 2 and an inner peripheral surface 8 of the rim 3, and a tube 5 disposed between the tire 2 and the tube 5. And a shock absorber 6.

The tire 1 includes a tread portion 12 having a tread pattern formed on the outer peripheral surface thereof, and sidewall portions 13 and 13 extending from both ends thereof inward in the tire radial direction.
It has a hollow toroidal shape having a pair of bead portions 15 and 15 respectively located on the radially inner end sides of the sidewall portions 13 and 13.

The rim 3 has a ring shape in which a pair of bead seat portions 17, 17 on which the bead bottom surfaces 15a, 15a formed at the radially inner ends of the bead portions 15, 15 are seated are connected by a rim well 18. The inner cavity 4 is formed by the tire 2 and the rim 3, and the inner cavity 4 is provided with the tube 5 capable of applying an inner pressure to the tire 2.

The shock absorber 6 has a base portion 6A along the rim well 18 of the rim 3 and inner peripheral surfaces 2A of the tire 2 at both ends of the base portion.
A pair of wing portions 6B and 6B extending along the tire shoulder portion 13A of the shoulder portion 13 along with the base portion 6A and the wing portions 6B and 6B are integrally provided so that the cushioning body 6 is U-shaped in the tire meridional section. Make a state.

The buffer body 6 is made of a sponge material having closed cells, and is reinforced by blending carbon black with a raw material rubber selected from natural rubber, SBR, BR or butyl rubber, for example, as shown in Table 1. Each of the sponge materials of compositions A to E can be formed by blending and producing

[0019]

[Table 1]

In this embodiment, the expansion ratio of the sponge material is shown in Table 1.
In each composition A to E shown in (4), it is 4 or more and 15 or less. If it is 4 or less, the cushioning property is deteriorated and the impact absorbing power is weakened, so that the shock acting on the tire is propagated to the tube 5 without being attenuated, and as a result, the puncture resistance of the tube 5 is deteriorated. On the contrary, when the number is 15 or more, the shock absorber 6 becomes flexible and becomes thin due to the inner cavity pressure applied to the tube 5, and as a result, the shock absorbing ability also decreases.

Further, the shock absorber 6 has a pointed end P which is an outer end in the tire radial direction of the wing 6A, and has a tread width TW which is a distance L from the tire equator C to the point P in the tire meridian section. Is set to 0.2 to 0.3 times. Therefore, on the inner peripheral surface of the tread portion 12, the tread width T
Discontinuity 20 over the length 2L of 0.4 to 0.6 times W
Is formed. At this discontinuity 20, the inner peripheral surface of the tread portion 12 comes into direct contact with the tube 5.

The blade portion 6B has a half of the tire section height H which is the distance from the bead bottom surface 15 to the outermost end of the tire.
The thickness T1 in the tire axial direction at the ½ cross-section height ½H that separates the double distance from the bead bottom surface 15a in the tire radial direction is the thickness of the sidewall portion 13 of the tire 2 at that height in this embodiment. It is 1.5 to 2.5 times T2.

If the thickness T1 of the wing portion 6B is less than 1.5 times the thickness T2 of the sidewall portion 13, the wing portion 6B is likely to be locally deformed, which causes puncture. On the contrary, if the thickness exceeds 2.5 times and the thickness is increased, the volume in the tube 5 is reduced, and there is a risk that driving performance such as steering stability and riding comfort may be deteriorated.

Further, the thickness T1 of the wing portion 6B at the above position
Is formed thicker than the thickness T3 of the base portion 6A, and the thickness T3 of the base portion 6A in this embodiment is substantially uniform over the entire area and in the range of 3 to 5 mm. This is because if the thickness of the base portion 6A is less than 3 mm, there is a risk of breakage when the rim 3 is rusted, and if it exceeds 5 mm, the rigidity of the buffer body 6 becomes large and the rim assembly work becomes difficult.

[0025]

[Specific example] Tire size 80/1 for front wheels of motorcycles
00-21 tires and tire size 1 for rear wheels
Tires of 10 / 90-19 were manufactured as prototypes (Examples 1 to 5) having the configurations shown in FIG. 1 and the specifications shown in Tables 1 and 2, and their performances were tested. For comparison, tire comparative example 1 having a conventional structure in which a cushioning body is not provided and tire comparative examples 2 and 3 having a configuration other than the configuration of the present invention were prototyped and their performances were also tested.

The test was conducted and judged under the following conditions. Tires of the same specifications were attached to the front and rear wheels of the motorcycle for motocross, and the motocross course was dominated by gravel and rock.

(A) Running performance The handling, straight running stability, curving stability, shock absorption and riding comfort were each judged by the driver's feeling and evaluated by the 5-step method. The larger the value, the better, and the value of 2.5 or more is acceptable.

B) Durability The above course was continuously run for 2 hours, and the presence or absence of puncture was investigated. The test was repeated 3 times under the same conditions. The test results are shown in Table 2.

As a result of the test, in the examples, punctures could be prevented, and in the examples, the running performance was not significantly deteriorated.

[0030]

[Table 2]

[0031]

As described above, the tire and rim assembly for a motorcycle according to the present invention is a wing made of a sponge material between a tire and a tube and extending from an inner peripheral surface to a tire shoulder on a base body along the rim well. Since the gist of the present invention is to provide a cushioning body provided with a portion, it is possible to prevent punctures without impairing steering stability and riding comfort.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 2 Tire 3 Rim 4 Lumen 5 Tube 6 Buffer 6A Base 6B Wing 8 Inner Surface 13A Tire Shoulder 18 Rimwell H Tire Cross Section Height T1 Wing Thickness T2 Sidewall Thickness T3 Base Thickness

Claims (3)

[Claims] 1. A tire, a rim for assembling the tire, a tube arranged in an inner cavity surrounded by an inner peripheral surface formed between the tire and the rim, and a tire shaft arranged between the inner peripheral surface and the tube. In a cross section including the rim, a pair of wings extending along the inner peripheral surface of the tire and extending to the tire shoulder are integrally provided at both ends of the base portion along the rim well of the rim to form a U-shape in the tire meridian section and from the sponge material. A two-wheeled vehicle having a cushioning body and a thickness of the wing portion at a ½ cross-section height position that is ½ times the tire cross-section height as compared with the base thickness. Tire and rim assembly for car. 2. In the meridian section of the cushion in the pressurized state of the tube, the thickness of the cushion at the half section height is the sidewall portion of the tire at the half section height. 1.5 to 2.5 times the thickness of
The tire-rim assembly for a motorcycle according to claim 1, wherein the base has a thickness of 3 to 5 mm. 3. The tire-rim assembly for a motorcycle according to claim 1, wherein the cushioning body has closed cells and a foaming ratio thereof is 4 or more and 15 or less.