JPH09240212A - Assembly of tire and rim - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an assembly, which is excellent in a built-in property to the rim, cornering performance, and a cushioning property and causes no deflection in the lateral direction during driving, of a tire and a rim. SOLUTION: In an assembly, in which an elastic ring body 30 is arranged in an internal space between a tire 10 and a rim 20, of a tire and a rim, a supporting member 40 for the elastic ring body 30 is arranged between the elastic ring body 30 and a rim groove bottom 24, and when the elastic ring body 30 is installed and the rim 20 and a bead part 14 are matched with each other, the rim radius directional position of a contact face between the elastic ring body 30 and the supporting member 40 is positioned between the outermost edge of the rim 20 and the intermediate position between a bead core body 13 and the rim groove bottom 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembly of a tire and a rim in which an elastic ring body is mounted in a tire used for a bicycle, a wheelchair and the like.

[0002]

2. Description of the Related Art Usually, a tire is provided with a tube filled with air or a tube filled with air to provide a cushioning property. Therefore, there is a drawback that a flat tire will be punctured if nails, broken glass, or the like is stabbed, and a tire in which a ring body made of foam or the like is mounted in the tire has been proposed as a non-puncture tire.

For example, as shown in Japanese Utility Model Laid-Open No. 55-8027, a foamed plastic having a circular cross section is used as an elastic ring body, Japanese Utility Model Laid-Open No. 58-1154.
As disclosed in JP-A No. 04, JP-A-57-186503 and JP-A No. 1-144101, there are those which use an elastic ring body having a projecting portion fitted to a rim groove on the inner peripheral surface. .

[0004]

[Problems to be Solved by the Invention]
When an elastic ring body having a circular cross section is used as disclosed in Japanese Patent Publication, the elastic ring body falls into the space between the elastic ring body and the bottom of the rim groove due to the pressure from the road surface, and the elasticity of the rear side of the tread portion of the tire Since there is a gap between the ring bodies, the tires do not have a clean circular shape even in appearance, and there are problems in that the tire feels blurring in the left and right directions while driving, and cornering performance deteriorates. It is possible to increase the hardness of the elastic ring body so that it does not fall into the bottom of the rim groove, but if the hardness is too high, the cushioning property is poor and it is not possible to absorb the unevenness of the road surface and the riding comfort is impaired.

Protrusions are provided on the inner peripheral surface of the elastic ring body as described in JP-A-57-186503 and Japanese Utility Model Laid-Open No. 1-144101 so that no gap is formed between the elastic ring body and the bottom of the rim groove. With this structure, the elastic ring body does not fall into the bottom of the rim groove, and it is not necessary to make the elastic ring body hard.Therefore, the left-right blurring and cornering performance are deteriorated, and the cushioning property is poor and the riding comfort is poor. Although the problem of badness is solved, the minimum inner diameter of the elastic ring body becomes small, so that there is a problem that the mountability on the rim becomes poor.

If the mountability to the rim is poor, it is inevitable that somewhere will be forced upon mounting, which may damage the elastic ring body or damage the rim. Also, in some cases, it will not be possible to install without using a dedicated machine. Therefore, an object of the present invention is to provide an assembly of a tire and a rim which is free from blurring in the left-right direction during traveling without impairing the assembling property to the rim, has good cornering performance, and has excellent cushioning properties.

[0007]

In order to achieve such an object, the present invention provides a tread portion, a pair of sidewall portions supporting the tread portion, and at least one bead core body located at the innermost edges of the sidewall portions. In a tire consisting of a pair of bead portions reinforced by the above, in a tire-rim assembly in which an elastic ring body is mounted in an internal space in which the bead portion is fitted to a rim, the elastic ring body and the rim groove bottom are Between, the support member of the elastic ring body is interposed,
The position of the contact surface between the elastic ring body and the supporting member in the rim radial direction when the elastic ring body is fitted and the rim and the bead portion are matched is the middle between the outermost edge of the rim and the bead core body and the rim groove bottom. It is characterized in that it exists between the position and the position.

Further, the elastic ring body has a substantially circular cross-section, or the elastic ring body and the supporting member are fitted together, and the elastic ring body is made of foam and the supporting member is ring-shaped. Those that are provided over the entire circumference of the rim are also included in the scope of the present invention.

[0009]

In the present invention, in the tire-rim assembly,
Since the elastic ring body support member is interposed between the elastic ring body and the rim groove bottom, the elastic ring body does not fall into the rim groove bottom due to the pressure from the road surface, and the ride comfort and running Even if the hardness of the elastic ring body is adjusted only in consideration of the balance of performance, it is possible to prevent the appearance of the tire from being disturbed, the lateral blurring during running, and the deterioration of cornering performance due to the fall of the elastic ring body. Further, since it is not necessary to form the elastic ring body into a shape having a protruding portion that fits into the bottom of the rim groove in order to prevent the elastic ring body from falling, the elastic ring body can be easily incorporated into the rim.

[0010]

1 is a sectional view showing an example in which a tire and rim assembly 1 of the present invention is applied to a bicycle. The tire and rim assembly 1 of the present invention includes a tire 10 and a rim 20.
And an elastic ring body 30 mounted in the internal space formed by the tire 10 and the rim 20, and a support member 40 for the elastic ring body 30 interposed between the elastic ring body 30 and the bottom of the rim groove.

The tire 10 is a tire which is usually used, and includes a tread portion 11, a pair of sidewall portions 12 and 12 for supporting the tread portion, and sidewall portions 12 and 12.
The bead portion 14 is located at the innermost edge of the and has at least a pair of bead cores 13 embedded therein, and the bead portion 14 is fitted to the rim 20. On the other hand, on the rim 20, rim flanges 21 and 22, a rim groove 23 into which a tire is fitted, a bead seat 24 with which the tip of the bead portion 14 contacts, and a support member 40 of an elastic ring body 30 described later are arranged. There is a groove bottom 25.

The elastic ring body 30 is a ring having a substantially circular cross section to be mounted in the internal space formed between the tire and the rim, and is made of an elastomer material. Examples are styrene-butadiene, ethylene-propylene-
Terpolymer, silicone polymer, chloroprene rubber,
A foamed or non-foamed material of rubber such as butadiene rubber, natural rubber, acrylonitrile-butadiene rubber, butyl rubber or the like, which is a simple substance or a blend thereof, or a resin such as polyurethane is used. It is more advantageous to use a foam in order to improve the cushioning property.

Regardless of which material is used, the hardness of 15 to 65 ° JIS A is suitable. If it is less than 15 ° JIS A, the flexure becomes too large, causing bottom bumps (inside the rim) due to unevenness on the road surface.
If it exceeds 5 ° JIS A, the cushioning property is deteriorated, the unevenness of the road surface cannot be absorbed, and the riding comfort is deteriorated, which is not preferable.

Further, the cross-sectional shape of the elastic ring body 30 is a substantially circular shape, which is a shape that is unlikely to be damaged even when pressure is applied from the rim flange 21, and a preferable shape from the viewpoint of easy mounting on the rim 20. However, as shown in FIG. 3 and FIG. 4, the inner peripheral surface 31 may have a flat surface in which the support member 40 is combined or a convex portion or a concave groove may be provided, if necessary.
It may be fitted to the support member 40, and by fitting the support member 40, it is possible to obtain the effect of further preventing the appearance of the tire from being disturbed and the tire being shaken during running. The outer peripheral surface has a shape along the inner surface of the tire 10.

The support member 40 shown in FIG. 2 is also made of an elastomer, specifically, styrene-butadiene, ethylene-propylene-terpolymer, silicon polymer, chloroprene rubber, butadiene rubber, natural rubber, acrylonitrile-butadiene rubber, butyl rubber, etc. A foamed body or a non-foamed body made of a resin such as rubber or polyurethane, which is composed of a single substance or a blended product, is used.

The hardness of the support member 40 is 30 to 90 ° JIS.
The range of A is suitable, and if it is less than 30 ° JIS A, the support member 40 is largely deformed by the pressure from the road surface, and the elastic ring body falls, resulting in 90 ° JIS.
When A is exceeded, the elasticity of the support member 40 is lost and the ease with which the support member 40 follows the rim groove bottom 25 is impaired, causing unevenness in the elasticity of the tire, or fitting to the rim when the support member has an endless ring shape. Is difficult to do, which is not preferable.

Further, the support member 40 is the elastic ring body 30.
It is an endless ring-shaped object having a substantially rectangular parallelepiped cross section which is interposed between the elastic ring body 30 and the rim 20. However, a discontinuous ring shape or a plurality of fragments are formed in the rim groove. It may be arranged at a required place on the bottom 25 or fixedly arranged by adhesion or the like. It can be said that the endless ring-shaped product is preferable because there is no unevenness over the entire circumference in cushioning properties and appearance.

The thickness of the support member 40 in the radial direction of the rim is such that the support member 40, the elastic ring member 30, and the tire 10 are mounted on the rim 20 and the inner peripheral surface 41 of the support member 40 is brought into contact with the rim groove bottom 25. In this state, the outer peripheral surface 42, which is the contact surface with the elastic ring body 30, has the outer peripheral portion 2 of the rim flanges 21 and 22.
A position (H) at the same height as 6, 27 and a position (L) at a height exactly in the middle between the height of the bead core 13 and the rim groove bottom 25.
And the outer peripheral surface 42 of the support member 40 is located in the range. When the thickness of the support member 40 is maximum, as shown in FIG. 5, the support member 40 bites into the elastic ring body 30 and deforms, and the bead portion 14 is between the elastic ring body 30 and the rim flanges 21 and 22. Is sandwiched between.

However, when the outer peripheral surface 42 of the support member 40 is located outside the above-mentioned position (H), the force pushing the tire 10 outward through the elastic ring body 30 becomes too large and the bead portion 14 comes off. And the bead portion 14 does not receive pressure from the elastic ring body 30, so the rim flange 2
There is a problem that they are worn by rubbing with each other. In addition, the outer peripheral surface 42 is at the above-mentioned position (L).
When the inner side of the elastic ring body 30 is inside,
When the tire is in the interior, the appearance of the tire is disturbed, the tire during running is shaken, cornering performance is deteriorated, shock absorption is poor, and durability of the elastic ring body 30 is adversely affected.

The width of the support member 40 in the rim axial direction is set to be narrower than the width of the rim groove bottom 25. This is because a gap is created in the rim groove 23 and the bead portion 14 can be dropped to the rim groove bottom 25 when the tire 10 is assembled, so that the tire 10 can be easily assembled. However, the rim groove bottom 25 is not limited to this form.
When the support member 40 is strongly fixed to the rim 20 in the same manner as or more than the above, it is combined with the structure of fitting the support member 40 and the elastic ring body 30 to prevent the appearance of the tire from being disturbed and the tire being shaken during running. It is also possible.

[0021]

EXAMPLES Next, specific examples for confirming the effects of the present invention will be described. The same tire, rim, and elastic ring body are used, the distance from the rim groove bottom of the outer peripheral surface of the support member is changed, the detachability of the tire from the rim, the appearance of the tire,
A sharp turning rim disengagement test, shock absorption over bumps, rolling resistance, cornering force, and durability were evaluated.

Tires are rubber tires for bicycles Brand: Mitsusei Belt Co., Ltd. MW-258 Size 37-590
(26 × 13/8 WO) and stainless steel rim for the rim Brand: WO-2 type size 26 manufactured by Araya
X13 / 8 WO), and the elastic ring body is a circular ring-shaped ring made of foamed EPT (ethylene propylene terpolymer) rubber. Cross sectional diameter: φ31 mm, outer peripheral length: 2075 mm, hardness: 25 ° JIS A was used.

The supporting member is an endless ring having a rectangular parallelepiped cross section, which is made of a blend of NR (natural rubber) and SBR (styrene-butadiene rubber) and has a cross sectional width of 8 mm.
(2 mm shorter than the width of the rim groove bottom), inner circumference length: 1550 m
m, hardness: 57 ° JIS A is used, and the distance from the rim groove bottom of the outer peripheral surface of the support member is 4 to 11 as an example.
The distance was varied within a range of mm, and as comparative examples, those without a supporting member and those with a distance of 1 mm, 2 mm, and 12 mm from the rim groove bottom of the outer peripheral surface of the supporting member were used. When the tire, the rim, the elastic ring body and the support member are combined, the minimum position (L) of the outer peripheral surface of the support member is about 2.5 mm from the rim groove bottom, and the maximum position (H) is the rim. The position is about 11.5 mm from the groove bottom.

[0024]

[Table 1]

From the results shown in Table 1, if the thickness of the supporting member is too small, the elastic ring body falls into the bottom of the rim groove, so that the tire can be easily attached to and detached from the rim, but its appearance and rim during a sharp turn. It can be seen that it is inferior in shock absorption at the time of slipping off and over a step, rolling resistance is large, cornering force value is also small, and cornering performance is also inferior. Regarding the durability, the elastic ring body has fallen into the bottom of the rim groove, and the tire is greatly deformed.

On the other hand, when the thickness of the supporting member is too large, the value of rolling resistance is small, but problems occur in other evaluations. As for the detachability of the tire from the rim, if the support member is too thick, it is pushed by the support member and the outer circumference of the elastic ring body becomes large, making it difficult to incorporate the tire into the rim. Further, it is understood that the outer appearance of the tire is deteriorated because the elastic ring body is excessively compressed.

[0027]

As described above, in the tire-rim assembly of the present invention, the elastic ring body is mounted in the inner space of the tire and the rim, and the support member is interposed between the rim groove bottom and the elastic ring body. Since it has a configuration, there is no need to worry about puncture as with a normal pneumatic tire, and the elastic ring body and the rim of the tire can be easily incorporated into the tire. It is possible to provide a tire-rim assembly that solves the problem of detachment and has excellent cushioning properties, rolling resistance, cornering performance, and durability.

[Brief description of drawings]

FIG. 1 is a perspective sectional view of a main part of an assembly of a tire and a rim.

FIG. 2 is a perspective view of a support member.

FIG. 3 is a cross-sectional view showing a boundary between an elastic ring body and a support member in another embodiment.

FIG. 4 is a cross-sectional view showing a boundary between an elastic ring body and a support member in yet another embodiment.

5 is a perspective cross-sectional view of a main part corresponding to FIG. 1 when the thickness of the support member is maximum.

[Explanation of symbols]

 Reference Signs List 1 tire-rim assembly 10 tire 11 tread portion 12 sidewall portion 13 bead core body 14 bead portion 20 rim 21 rim flange 22 rim flange 23 rim groove 24 bead seat 25 rim groove bottom 26 outer peripheral portion 27 outer peripheral portion 30 elastic ring Body 31 Inner peripheral surface 40 Support member 41 Inner peripheral surface 42 Outer peripheral surface

Claims (5)

[Claims] 1. A tire comprising a tread portion, a pair of sidewall portions supporting the tread portion, and a pair of bead portions positioned at the innermost edges of the sidewall portions and reinforced with at least one bead core, wherein the bead portion is provided. In a tire-rim assembly in which an elastic ring body is mounted in an inner space adapted to the rim, a supporting member of the elastic ring body is interposed between the elastic ring body and the rim groove bottom, and the elastic ring body is also provided. The rim radial position of the contact surface between the elastic ring body and the support member in a state where the
The tire-rim assembly according to claim 1, wherein the tire-rim assembly is located between the outermost edge of the rim and an intermediate position between the bead core and the rim groove bottom. 2. The tire-rim assembly according to claim 1, wherein the elastic ring body has a substantially circular cross-sectional shape. 3. The tire / rim assembly according to claim 1, wherein the elastic ring body and the support member are fitted together. 4. The elastic ring body is made of foam.
The tire-rim assembly according to any one of claims 1 to 3. 5. The tire-rim assembly according to claim 1, wherein the support member is ring-shaped and is provided over the entire circumference of the elastic ring body and the rim.