JP2011084143A - Tire/rim assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce rolling resistance and tire mass while preventing the leakage of air. <P>SOLUTION: An inner ring 12 suppressing the leakage of air in a tire cavity S and made from resinous material which can deform is inserted in the tire cavity S surrounded by a tire 2 and a rim 3. The inner ring 12 includes: a body portion 13 continuously extending in a tire circumferential direction along a tire cavity surface 2i between a pair of bead portions 2c, 2c of the tire 2; and a locking portion 14 continuous to both end portions 13A in a tire axial direction of the body portion 13, extending to the outside in the tire axial direction between a rim base 4 and a bead bottom surface 2ce, and locked to a rim flange 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a tire / rim assembly that is lightweight and excellent in productivity.

  Conventionally, a pneumatic tire having a tubeless structure is known. In this type of tire, in order to prevent air leakage, an inner liner using butyl rubber having a high air impermeability is disposed almost all over the inside of the carcass. However, the thickness of the inner liner is increased in order to prevent air leakage. Such an inner liner becomes an obstacle when reducing the mass of the tire.

  On the other hand, Patent Documents 1 and 2 below describe a pneumatic tire in which an inner liner formed of a nylon film is bonded to a tire lumen. Nylon film has a lower specific gravity and higher air impermeability than butyl rubber. Therefore, the tires of Patent Documents 1 and 2 below can be lighter than a tire having an inner liner of butyl rubber while preventing air leakage.

Japanese Patent Laid-Open No. 7-40702 JP-A-9-165469

  However, when manufacturing the pneumatic tires of Patent Documents 1 and 2, a special process of attaching a nylon film to the tire lumen is added. Therefore, such a pneumatic tire has a problem that productivity is poor.

  The present invention has been devised in view of the above problems, and an inner ring made of a deformable resin material, which is formed separately from a tire, is provided across the tire lumen surface and between the rim flanges. Based on this, the main object is to provide a tire / rim assembly capable of preventing the deterioration of productivity while reducing the weight.

  The invention described in claim 1 is a tire / rim assembly including a pneumatic tire and a rim to which the tire is assembled, wherein the rim receives a bottom surface of a bead portion of the tire. A rim base, and a pair of rim flanges that support the outer surface in the tire axial direction of the bead portion by extending outward in the tire radial direction and continuing to an outer end in the tire axial direction of the rim base, and the tire and the rim surround the rim base An inner ring made of a deformable resin material that suppresses air leakage from the tire lumen is inserted into the tire lumen, and the inner ring extends between the pair of bead portions of the tire along the tire lumen surface. A body portion extending continuously in the tire circumferential direction, and a tie that is connected to both ends of the body portion in the tire axial direction and passes between the rim base and the bottom surface of the bead. Characterized in that it comprises a locking portion to be locked axially outwardly extending Moreover the rim flange.

  The invention according to claim 2 is the tire / rim assembly according to claim 1, wherein the inner ring is made of nylon resin.

  The invention according to claim 3 is the tire / rim assembly according to claim 1 or 2, wherein the inner ring has a thickness of 0.5 to 1.0 mm.

  According to a fourth aspect of the present invention, at least a part of the main body portion of the inner ring is provided with a heat shielding portion coated with a metal material. A rim assembly.

  According to a fifth aspect of the present invention, the pneumatic tire includes a carcass extending in a toroidal shape between a pair of bead portions, and the inside of the carcass is exposed to a tire cavity surface. The tire / rim assembly according to any one of the above.

  In the rim / tire assembly according to the first aspect, an inner ring made of a deformable resin material is provided in a tire lumen surrounded by the tire and the rim, while suppressing air leakage from the tire lumen. Such inner ring can prevent leakage of air that permeates from the tire. Further, since the inner ring is manufactured separately from the tire, it is possible to prevent the tire manufacturing process from being complicated and the productivity from being deteriorated. Further, since the inner ring is made of a resin material, it can be made lighter than an inner liner made of butyl rubber. Furthermore, the inner ring passes between the rim base and the bead bottom surface, improves the airtightness between the bead and the rim, and can effectively prevent air leakage from the gap between the rim and the tire (bead bottom surface). In particular, as in the invention described in claim 5, the inner side of the carcass extending in a toroidal shape between the pair of bead portions is exposed to the tire cavity surface, in other words, the conventional inner liner made of rubber on the inner side of the carcass. Further weight reduction can be achieved by omitting.

  Further, as in the invention of claim 4, when a heat shielding part in which a metal material is vapor-deposited is provided on at least a part of the main body part of the inner ring, the heat of the tire is absorbed in the tire by the heat reflecting action of the metal material. Prevent release to the cavity side. Thereby, since the fall of tire temperature is suppressed, rolling resistance can be made small.

1 is a cross-sectional view of a tire / rim assembly according to an embodiment of the present invention. It is a perspective view of one embodiment of an inner ring. (A) thru | or (C) is sectional drawing explaining an example which attaches an inner ring to a rim | limb. 10 is a cross-sectional view illustrating Comparative Example 1. FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, a tire / rim assembly 1 includes a pneumatic tire (hereinafter simply referred to as “tire”) 2, a rim 3 on which the tire 2 is assembled, an inner ring 12, and the like. In this embodiment, an assembly for a motorcycle is illustrated.

  The tire 2 is formed at a tread portion 2a that contacts the road surface, a pair of sidewall portions 2b and 2b extending inward in the tire radial direction from both sides of the tread portion 2a, and an inner end of each sidewall portion 2b. And a toroid having a bead portion 2c. Further, the tire 2 includes a carcass 2e composed of a single carcass ply extending between the bead cores 2d and 2d embedded in each of the pair of bead portions 2c.

  In the tire 2 of the present embodiment, an inner liner made of butyl rubber is not disposed inside the carcass 2e. Accordingly, the carcass 2e is disposed so as to be exposed on the tire lumen surface 2i. Since such a tire 2 does not include a relatively heavy inner liner made of butyl rubber, the tire mass and rolling resistance can be reduced.

  The rim 3 includes a pair of rim bases 4 and 4 that receive the bottom surface 2ce of the bead portion 2c of the tire 2, and extends outward in the tire radial direction along the tire axial direction outer end of the rim base 4 to thereby extend the bead portion 2c. It has a pair of rim flanges 5 and 5 that support the outer surface in the tire axial direction, and an annular well 6 that is provided between the pair of rim bases 4 and 4 and that is recessed inward in the radial direction. The rim 3 is formed of various metal materials such as iron, aluminum alloy, or magnesium alloy.

  The well 6 includes, for example, a pair of side portions 7 and 7 extending inwardly in the radial direction at the tire axial direction inner end of the rim base 4 and inwardly in a direction of decreasing the well width, It is comprised from the bottom part 8 which extends the inner end of the side parts 7 and 7 in the tire axial direction. A through hole 22 is provided in the bottom 8 of the well 6. An air valve 21 capable of injecting air into a tire lumen S surrounded by the tire and the rim 3 is fixed to the through hole 22.

  Further, in the assembly 1 of the present embodiment, an inner ring 12 made of a deformable resin material is provided in the tire lumen S, which suppresses air leakage from the tire lumen S and is deformable.

  The inner ring 12 includes a main body 13 extending continuously between the pair of bead portions 2c and 2c of the tire 2 along the tire cavity surface 2i in the tire circumferential direction, and both end portions of the main body 13 in the tire axial direction. 13A, and a pair of locking portions 14 extending between the rim base 4 and the bottom surface 2ce of the bead portion 2c and extending outward in the tire axial direction and locked by the rim flange 5.

  Such an inner ring 12 can prevent the air in the tire lumen S from leaking through the rubber by covering almost the entire area of the tire lumen surface 2i. Further, since the inner ring 12 is made of an elastically deformable resin material, it does not hinder the deformation of the running tire. Further, as a result of the inner ring 12 being made of a resin material, the specific gravity can be made smaller than that of the butyl rubber, and the total mass with the tire 2 can be made smaller than the tire mass including the conventional inner liner of the butyl rubber. .

  Further, the locking portion 14 of the inner ring 12 is sandwiched between the bead portion 2c of the tire 2 and the rim 3 in the tire axial direction and the tire radial direction when the tire 2 is assembled to the rim 3. Thereby, the position shift etc. of the inner ring 12 by the vibration at the time of driving | running | working, etc. are prevented.

  Further, the engaging portion 14 of the inner ring 12 can be observed with the naked eye from the outside by protruding onto the rim flange 5 even after the tire 2 is assembled to the rim 3. Therefore, even after the rim of the tire 2 is assembled, it is possible to easily confirm the attachment state of the inner ring 12 and the presence / absence of positional deviation. This helps to prevent use with the inner ring 12 being misaligned. Furthermore, since the tire 2 can be assembled to the rim 3 while checking the attached state of the inner ring 12 with the naked eye, the assembly workability is improved.

  As the resin material constituting the inner ring 12, various materials having air impermeability, low specific gravity and flexibility can be used, for example, acrylic resin, polyethylene resin or nylon resin is preferable, Among the nylon resins, 6 nylon is preferable from the viewpoint of low elastic modulus and corrosion resistance.

  Further, the resin material of the inner ring 12 may be one obtained by blending, for example, short fibers with the resin polymer. As the short fiber, for example, high elasticity such as aramid is suitable. Thereby, the strength of the inner ring 12 is improved, and damage due to friction during traveling, pressure during rim assembly, and the like is effectively prevented.

  As shown in FIG. 2, the inner ring 12 of the present embodiment is integrally formed as a ring body in which a main body portion 13 and a pair of locking portions 14 on both sides thereof are continuous in the circumferential direction. Such an inner ring 12 can be easily and inexpensively mass-produced by an injection molding method in which a molten resin is injected into a mold and cured.

  The thickness t (shown in FIG. 2) of the inner ring 12 is not particularly limited, but if it is too large, the rim assembly workability deteriorates due to an increase in the fitting pressure between the rim 3 and the tire 2, and the inner ring 12 There is a tendency for damage due to the decrease in stretchability of the ring 12 and an increase in mass of the tire / rim assembly 1 due to the inner ring 12. Conversely, if the thickness t is too small, there is a tendency that damage due to friction with the rim flange 5 or the like or contact with the tire during rim assembly tends to occur. From such a viewpoint, the thickness t is preferably about 0.5 to 1.0 mm.

  Further, it is preferable that the locking portion 14 of the inner ring 12 includes a folded portion 14 </ b> A that extends outward in the tire axial direction along the outer surface in the tire radial direction of the rim flange 5 and is folded back on the inner surface of the rim flange 5. As a result, the engagement force between the inner ring 12 and the rim 3 is improved, and positional displacement during rim assembly or traveling can be prevented. The locking portion 14 of the inner ring 12 may be joined to the rim base 4 and the rim flange 5 by adhesion or the like.

  Further, as shown in FIG. 2, at least a part of the surface of the main body portion 13 of the inner ring 12 may be provided with a heat shielding portion M coated with a metal material. Generally, the rolling resistance of the tire 2 tends to decrease as the tire temperature increases. Therefore, in order to reduce tire rolling resistance and improve fuel efficiency, it is necessary to prevent a decrease in tire temperature during traveling. The above-described heat shield part M reflects the heat of each rubber part of the tire to the tire side and prevents it from being released into the tire lumen S. As a result, the temperature during running of the tire is maintained at a moderately high level, which helps to reduce the rolling resistance.

  For the coating, for example, a surface modification technique using a vapor phase method such as a vapor deposition method such as CVD (Chemical Vapor Deposition), PVD (Physical Vapor Deposition), or a diffusion method is used. it can. Further, as the metal material to be coated, for example, aluminum, chromium, gold, silver, copper, and the like are preferable, but aluminum is particularly preferable from the viewpoint of cost.

FIG. 3 shows an assembling process of the tire / rim assembly 1 of the present embodiment.
In this embodiment, as shown in FIG. 3A, the inner ring 12 is attached to the rim 3. Since the inner ring 12 has flexibility and can extend greatly, it can be easily mounted on the rim 3 while being deformed. As described above, the locking portion 14 of the inner ring 12 may be bonded on the rim 3 in advance.

  Further, when the inner ring 12 is mounted, it is desirable that the air valve 21 of the rim 3 is freely communicated with the atmosphere in advance. Thereby, the main-body part of the inner ring 12 can be compactly folded and arrange | positioned on the rim | limb 3. FIG.

  Next, as shown in FIG. 3B, the tire 2 is mounted on the rim 3 on which the inner ring 12 is mounted. As in the normal rim set, a part of one bead portion 2c of the tire 2 is dropped into the well 6 of the rim 3, and the remaining portion of the bead portion 2c can get over the rim flange 5 in this state. The same operation is performed for the bead portion 2c on the other side. As a result, as shown in FIG. 3C, both the bead portions 2 c and 2 c can be arranged in the well 6. Since the inner ring 12 can be folded compactly, the rim assembly process of the tire 2 is not hindered.

  Further, by ensuring the thickness t of the inner ring 12, damage to the inner ring 12 can be prevented even if the tire 2 is in contact with the bead portion 2c when the rim is assembled. Further, the locking portion 14 can prevent the inner ring 12 from being displaced. Even when a positional deviation occurs, the positional deviation can be easily corrected by pulling the locking portion 14 or the like.

  Next, as shown in FIG. 3C, high-pressure air is injected from the air valve 21. The injected high-pressure air expands the inner ring 12 in the tire lumen S and gradually spreads the bead portions 2c and 2c. As the inner ring 12 expands, the air between the tire lumen surface 2i and the inner ring 12 is also sequentially released from between the bottom surface 2ce of the bead portion 2c and the inner ring 12 to the outside. In particular, when the heat shield M coated with a metal material is provided on the outer surface of the inner ring 12, the frictional resistance between the tire lumen surface 2i and the inner ring 12 becomes smaller, so that the remaining air is discharged more efficiently. it can.

  The inner ring 12 pushes up the bead portions 2c and 2c onto the rim base by further increasing the air pressure in the tire lumen S to complete the rim assembly (FIG. 1).

  As mentioned above, although the especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect. Further, the tire / rim assembly of the present invention can be used not only for motorcycles but also for passenger cars and the like.

  The following test was conducted on an assembly of a tubeless tire for a motorcycle of size 110 / 70-16, which was prototyped based on the specifications in Table 1, and an MT16 × 2.50 rim. Each of the tires was provided with two cross-ply carcasses in which nylon cords were inclined at 30 degrees with respect to the tire circumferential direction.

  In addition, the inner ring of the tire / rim assembly of the example was made of 6 nylon, and only the inner ring of the example 5 was provided with a heat shielding part in which aluminum was deposited on the entire outer surface of the main body part.

Further, as shown in FIG. 4, the tire of Comparative Example 1 was a conventional tubeless type having an inner liner made of butyl rubber having a thickness of 1.5 mm.
The test method is as follows.

<Air leakage resistance>
The initial internal pressure of each assembly was 250 kPa, and the air leak performance was measured by measuring the tire internal pressure after 90 days. The result is displayed as a percentage value obtained by dividing the leakage pressure by the initial internal pressure. The smaller the value, the better.

<Tire mass>
The mass per tire was measured and displayed as an index with the value of Comparative Example 1 being 100. A smaller index indicates a lighter weight.

<Rolling resistance>
Using a rolling resistance tester, rolling resistance was measured at an internal pressure of 250 kPa, a speed of 72 km / h, and a load of 1.44 kPa. A result is an index | exponent which sets the value of the comparative example 1 to 100, and shows that rolling resistance is so small that a numerical value is small.
The test results are shown in Table 1.

  As a result of the test, it was confirmed that the examples had reduced rolling resistance and tire mass while preventing air leakage.

DESCRIPTION OF SYMBOLS 1 Tire and rim assembly 2 Tire 2c Bead part 2ce Bead bottom face 2i Tire lumen surface 3 Rim 4 Rim base 5 Rim flange 6 Well 8 Tube 12 Inner ring 13 Main body part 14 Locking part

Claims (5)

A tire / rim assembly including a pneumatic tire and a rim to which the tire is assembled,
The rim includes a pair of rim bases that receive the bottom surface of the bead portion of the tire, and a pair of rim bases that support the outer surface in the tire axial direction of the bead portion by extending outward in the tire radial direction along the tire axial outer end. A rim flange,
An inner ring made of a deformable resin material is inserted into the tire lumen that is surrounded by the tire and the rim, while suppressing air leakage in the tire lumen,
The inner ring has a main body portion extending continuously in the tire circumferential direction along a tire lumen surface between a pair of bead portions of the tire;
A locking portion that is provided at both ends in the tire axial direction of the main body and extends between the rim base and the bead bottom surface and extends outward in the tire axial direction and is locked by the rim flange. Characteristic tire / rim assembly.   The tire / rim assembly according to claim 1, wherein the inner ring is made of nylon resin.   The tire / rim assembly according to claim 1 or 2, wherein the inner ring has a thickness of 0.5 to 1.0 mm.   The tire / rim assembly according to any one of claims 1 to 3, wherein at least a part of the main body portion of the inner ring is provided with a heat shielding portion coated with a metal material.   5. The tire rim according to claim 1, wherein the pneumatic tire includes a carcass extending in a toroidal shape between a pair of bead portions, and the inside of the carcass is exposed to a tire inner surface. Assembly.

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