JPH03292206A - Assembly member of tire and rim for two-wheel vehicle - Google Patents

Abstract

PURPOSE:To maintain operation stability and comfortableness of riding, while prevent puncture of tire by providing a buffer member, which consists of an outer layer made of soft sponge material and an inner layer made of the mate rial harder than the outer layer, between a tire and a tube. CONSTITUTION:An assembly member 1 comprises a tire 2, a rim 3 for rimming the tire 2, a tube 5 arranged in an inner hollow 4 surrounded by the tire 2 and the rim 3, and a buffer member 6 which consists of an inner layer 6a arranged in contact with the tube 5 and an outer layer 6b made of the material softer than the inner layer 6a and arranged in contact with the tire 2. The outer layer 6b and the inner layer 6a of the buffer member 6 are made of the closed cell type sponge material, and the outer layer 6a has a degree of hardness at 35 - 45HS, and the inner layer 6a has a degree of hardness at 45 - 55HS. A ratio of a gage GT of the buffer member 6 in the equatorial surface of the tire 2 and a gage Gb of the outer layer 6b Gb/GT is set at a value more than 0.4 and less than 0.7. Furthermore, a ratio of a cross section S6 of the buffer member 6 and a tube cross section S5 in the cross section S6/S5 is set at a value more than 3/7 and less than 1.5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tire and rim assembly for a two-wheeled vehicle that can prevent the occurrence of banking without impairing running performance.

[Conventional technology]

For off-road motorcycles that travel on rough terrain, the condition of the road surface and driving conditions are harsh, so banking occurs more frequently than for motorcycles that only travel on-road. When driving over gravel, rubble, or rock, the outer skin of the tire is locally deformed and the tube is repeatedly deformed locally, increasing the risk of bank. When a tire lands on the ground, it often deforms locally, compressing the tube and damaging it.

For tires for motorcycles that travel on such uneven terrain, it is recommended to use thicker gauge tires, thicker tubes, double tubes, and tubes made of special materials such as mousse. Banking is prevented by using .

[Invention tries to solve! However, when driving off-road, even with such improvements, banking often occurs, and handling stability and riding comfort are significantly reduced.

As a result of conducting various studies to solve this problem, we found that by interposing a two-layer buffer between the tire and the tube, the soft sponge layer improves handling.
We have discovered a scale that improves stability, cushion absorption, and riding comfort, while at the same time preventing the impact force from propagating to the tube with a two-layer cushioning material, thereby preventing banks.
The invention has been completed.

Therefore, the present invention provides a two-wheeled vehicle tire that prevents tire banking while maintaining handling stability and ride comfort, based on the interposition of a hard and soft two-layer cushioning material between the tire and the tube. The purpose is to provide rim assemblies.

[Means for Solving the Problems] The present invention provides a tire, a rim for assembling the tire, a tube disposed in a bore surrounded by the tire and the rim, and a buffer disposed between the tire and the tube. In addition, the shock absorber has an annular shape that extends from the tire equator in a cross section including the tire axis, terminates near the tire bead, and has a thinner end portion than the tire equator, and is made of sponge material. This is a tire and rim assembly for a two-wheeled vehicle, which is composed of two layers: an inner layer that is formed by the tube and is in contact with the tube, and an outer layer that is in contact with the tire and is softer than the inner layer.

[Function] A buffer body consisting of two layers, an outer layer made of a soft sponge material and an inner layer that is harder than the outer layer, is provided between the tire and the tube, so the soft outer layer provides steering stability close to pneumatic performance. In addition, the hard inner layer protects the tube and greatly improves banking performance.

In addition, the shock absorber has a thin wall at the end near the bead compared to the equator, so near the equator, where a large shock is applied to the tube, the shock absorber efficiently absorbs the shock and prevents bank formation. In the bead portion, which deforms in a curved direction when an impact force is applied and relieves the impact force, the bending deformation of the bead portion is maintained due to the thin cushioning body, which improves steering stability and riding comfort. Deterioration can be prevented.

Further, when the ratio of the cross-sectional area S6 of the shock absorber in the cross-sectional area including the tire shaft to the cross-sectional area S5 of the tube is regulated, the steering stability and riding comfort are further stabilized, and the bank resistance is also improved.

Furthermore, the circumferential length ratio R of the buffer body and tire in a natural state
6/R3, and the transverse length ratio of the buffer body and tire L6/L
When each of 2 is regulated, the shape of the buffer and the amount of bubbles are stabilized when the tire is pressurized, and it becomes easy to ensure steering stability and ride comfort.

〔Example〕

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

In the figure, a tire and rim assembly 1 for a two-wheeled vehicle according to the present invention
a tire 2, a rim 3 on which the tire 2 is assembled, a tube 5 disposed in a bore 4 surrounded by the tire 2 and the rim 3;
and a buffer body 6 consisting of two layers: an inner layer 6a disposed between the tire 2 and the tube 5 and in contact with the tube 5, and an outer layer 6b that is softer than the inner layer 6a and in contact with the tire 2. .

The tire 1 also includes a tread portion 12 having a tread pattern formed on its outer peripheral surface, a sidewall portion 13.13 extending radially inward from both ends of the tread portion 12, and a radially inner end of the sidewall portion 13.13. It has a hollow toroidal shape with a pair of bead portions 15 and 15 located on each side.

The rim 3 has a ring shape connecting a pair of bead seat parts 17.17 on which bead bottom surfaces 16.16 formed at the radially inner ends of the bead parts 15.15 are respectively seated,
The inner cavity 4 is formed by the tire 2 and the rim 3, and the tube 5 that can apply internal pressure to the tire 2 is arranged in the inner cavity 4.

The outer layer 6b and inner layer 6a of the buffer body 6 are both made of closed cell sponge material, and the sponge material of the outer layer 6b has a JISC hardness lower than that of the inner layer 6a, and the outer layer 6b has a JISC hardness of 35 to 45.
HS, the inner layer 6a has a hardness of 45 to 55 HS, and is selected from sponge materials having compositions A to D as shown in Table 1, for example.

Furthermore, a gauge GT on the tire equatorial plane of the buffer body 6,
The ratio Gb/GT of the outer layer 6b to the gauge Gb is set to be 0.4 or more and 0.7 or less. If it is less than 0.4, the elasticity will be insufficient and the steering stability and shock absorption will decrease, while if it is 0.7
If the temperature exceeds that level, the protection of the tube 5 will be insufficient and banks will easily occur.

In this example, the foaming ratio of the sponge material with each of the above compositions is set to be 4 or more and 15 or less. If it is less than 4, the cushioning property is lowered and the impact force is weaker, so that the impact acting on the tire is propagated to the tube 5 without being attenuated, resulting in a decrease in the bank resistance of the tube 5. On the contrary, 15
In this case, the buffer body 6 becomes excessively flexible and becomes thin due to the lumen force applied to the tube 5, resulting in a decrease in shock absorption ability.

The buffer body 6 has a surface facing the inner circumferential surface 21 of the tire 2, that is, an outer surface 2.
2 extends from the tire equator C to both sides and the bead part 1 of the tire 2
It terminates in the 5 neighborhood.

Further, in this embodiment, the buffer body 6 has a cross-sectional area S6 in a cross section including the tire axis, that is, a cross-sectional area of the buffer body 6 in a pressurized state in which a pressure equal to the normal internal pressure of the tire 2 is applied inside the tube 5. The ratio S6/S5 of the tube cross-sectional area S5 surrounded by the outer circumferential surface 19 of the tube in the cross section is set to be 3/7 or more and 1.5 or less.

If the ratio 36/S5 is less than 3/7, the shock absorbing power of the shock absorber 6 will be reduced and the bank prevention effect will be small, and if it exceeds 1.5, the steering stability will be reduced.

Furthermore, the thickness of the buffer body 6 is thinner at the end F portion than at the tire equator C portion. Note that the thickness of the buffer body 6 may be formed so as to gradually decrease from the tire equator C toward the end portion F, or may be made uniform in the range of the tread portion 12 including the tire equator C, and the thickness of the tread portion 12
The thickness may be gradually reduced from the end toward the sidewall portion 13 and bead portion 15.

In addition, in the natural state where the buffer body 6 is not pressurized, the circumference R6 (not shown) of the outer peripheral surface of the buffer body S passing through the tire equator C8 and the tire circumference R6 (not shown) of the tire inner circumferential surface 21 passing through the tire equator. JiR6/R2 with 0.6 (not shown)
It is preferable that the value is greater than or equal to 1.0.

If the ratio R6/R2 is less than 0.6, even when the tube is pressurized, the inner peripheral surface 21 of the tire 2 and the outer peripheral surface 23 of the buffer body 6 will not come into contact near the tire equator C. However, there may be cases where no internal pressure acts on the tire 2. Conversely, if the ratio R6/R2 exceeds 1.0, the buffer 6
Even when the tire is fitted into the tire 2, there will be a shimmy between the two, and the buffer 6 will be compressed near the tire equator C and the gap will be reduced, making it impossible for the buffer 6 to achieve the expected performance. Sometimes. Furthermore, when inserting the buffer body 6 into the inner cavity 4 of the tire 2, there is a possibility that the buffer body 6 may not be inserted into the tire 2 in a homogeneous state, such as wrinkles occurring in the buffer body 6.

Further, the cushioning body 6 has a cross-sectional length L6 of the cushioning body 6 extending from its terminal end F through the tire equator C to the other terminal end F′ at the outside 11i123 of the cross section in the natural state where no pressure is applied as described above; The ratio L6/L2 of the cross-sectional inner circumference of the tire 2 from one bead end E to the other bead end E'' via the tire equator C is set to 0.8.
It is desirable that it be above and 0.9 or less! 3@The compressor 6 is compressed by applying internal pressure to the tube 5, but if the ratio L6/L2 exceeds 0.9,
When pressurized, said channel @F extends beyond the bead end E, with the result that the buffer 6 becomes non-uniform due to compression in the transverse length direction. There is also a risk that the tube 5 will be locally deformed due to wrinkles forming on the inner surface facing the tube 5. Moreover, when the ratio L 6 /L 2 becomes 0.8 or less, the tire 2 and the tube 5 come into direct contact from the bead portion 15 to a part of the sidewall portion 13.
The buffer body 6 is not present near the connection between the bead portion 15 and the sidewall portion 13, which undergoes the greatest bending deformation during running. Therefore, there is a risk that the tube 5 will be pinched by the tire 2 due to repeated deformation of the tire 2, resulting in local deformation that may cause a bank.

[Example] Tire size 80/100-21 for the front wheel of a motorcycle
tires, and tire size 110/90 for the rear wheels.
-19 tires each having the configuration shown in Figure 1 and having the configuration shown in Figure 1.2.
We manufactured a prototype with the specifications shown in the table and tested its performance. For comparison, we also prototyped a tire with a conventional structure without a buffer and tested its performance.

The test was conducted and judged under the following conditions.

The front and rear wheels of a motocross motorcycle were equipped with tires of the same specifications, and the vehicle was run on a motocross course with a lot of gravel and rock.

B) Driving Performance Handling performance, straight-line stability, turning stability, shock absorption, and ride comfort were each judged based on the driver's feeling and evaluated using a 5-step method. The larger the numerical value, the better, and 2°5 or more is a pass.

(Example) Durability The above course was continuously run for 2 hours and the presence or absence of banks was investigated. The test was repeated three times under the same conditions.

As a result of the test, banking could be prevented in the example, and no significant deterioration in running performance was observed in the example.

〔Effect of the invention〕

Like Soft Earth, the motorcycle tire and rim assembly of the present invention is characterized by providing a shock absorber made of sponge material between the tire and the tube, so it can be used without impairing handling stability or riding comfort. Banking can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention. 2.-Tire, 3.--Rim, 4-.Inner cavity, 5
...-tube, 6...buffer, 6a...outer layer,
6b--Inner layer, 15--Bead portion 2, S6-Buffer cross-sectional area, R6--Perimeter of buffer, L6--Transverse length of buffer, 85--Cross-sectional area of tube, R2- ... Tire circumference, L2 - Tire transverse length, E, E
'...Bead end, F, F'-end of buffer. GT...total thickness of the buffer, cb--thickness of the outer layer.

Claims (1)

[Scope of Claims] 1. Consisting of a tire, a rim on which the tire is assembled, a tube disposed in an inner cavity surrounded by the tire and the rim, and a buffer disposed between the tire and the tube, and furthermore, the buffer is ,
In a cross section including the tire axis, the tube extends from the tire equator to both sides, terminates near the tire bead, and is annular with a thinner end portion than the tire equator, and is both formed using a sponge material and is in contact with the tube. An inner layer and an outer layer that is in contact with the tire and is softer than the inner layer.
A motorcycle tire and rim assembly consisting of layers. 2. The tire and rim assembly for a two-wheeled vehicle according to claim 1, wherein the outer layer has a JISC hardness of 35 to 45 HS, and the inner layer has a JISC hardness of 45 to 55 HS. 3. The tire and rim assembly for a two-wheeled vehicle according to claim 1, wherein the outer layer has a thickness Gb in the tire equatorial plane of 40 to 70% of the total thickness GT of the buffer body. 4 The buffer has a cross-sectional area (S6
) and a tube cross-sectional area (S5) surrounded by the outer peripheral surface of the tube in the cross section S6/S5 is 3/7 or more and 1.5 or less, for a two-wheeled vehicle according to claim 1. tire and rim assembly. 5 The buffer body, in its natural state without being pressurized, has an outer circumferential length (R
6) and the ratio R6/R2 of the inner circumferential length of the tire passing through the tire equator of the inner circumferential surface of the tire is 0.6 or more and 1.0
The cross-sectional length (L6) of the buffer body from the terminal end to the tire equator to the other terminal end on the outer circumferential surface of the cross section of the buffer body, and from one bead end of the inner circumferential surface of the tire to the tire The motorcycle according to claim 1 or 2, characterized in that the ratio L6/L2 of the cross-sectional length (L2) of the tire extending from the equator to the other bead end is 0.8 or more and 0.9 or less. tire and rim assembly.