JP2003094911A - Pneumatic radial tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an annular shade caused by a rim protector in a pneumatic radial tire having the rim protector. SOLUTION: The cross sectional shape of the rim protector 14 provided on the bead part 1 side of a side wall 3 is formed generally triangular.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic radial tire, and more particularly to a pneumatic radial tire having a rim protector raised.

[0002]

2. Description of the Related Art An outline of a conventional pneumatic radial tire will be described with reference to FIG. 6, "A tire having a protrusion B protruding on an outer surface of a bead portion A along a tire circumferential direction,
The sectional shape of the protrusion B is divided by a straight contour B1 having a length of 4.0 to 8.0 mm and two concave curved contours B2 and B3 on the outer side and the inner side in the tire radial direction with the straight contour B1 interposed therebetween. It has a trapezoidal shape and has a loss tangent (ta) between the protrusion B and the outermost carcass layer C or the bead reinforcing layer D.
nδ) is 0.35 to 0.50 and the dynamic elastic modulus (E ′) is 1
An area in which a rubber layer E having a maximum thickness of 4.0 to 7.0 mm made of a compound of 0.0 to 40.0 Kg / cm ² is arranged, and the maximum thickness portion corresponds to the linear contour B1 portion of the protrusion B. Pneumatic radial tires located at. (See Japanese Patent Laid-Open No. 4-212605).

In FIG. 6, F is a bead core and G is
Indicates a bead filler. The pneumatic radial tire shown in FIG. 6 has "a protrusion B having a trapezoidal cross-section that is raised along the tire circumferential direction is provided on the outer surface of the bead portion A, so that a large amount of rubber in the bead portion A is secured. The durability of the bead portion can be improved by suppressing the deformation of the bead portion A when a load or a lateral force is applied to the tire, and a dynamic property having a large damping characteristic and a large rigidity is provided inside the protrusion B. Since the rubber layer E having characteristics is arranged,
Road noise performance and steering stability can be improved at the same time without lowering the durability of the bead portion. It was that.

[0004]

The conventional example shown in FIG. 6 has the following problems due to the sectional shape of the protrusion (rim protector). a: The cross-sectional area is large and the weight is increased, resulting in higher fuel consumption.
There is a problem in that the formation of protrusions is costly due to the inclusion of air during extrusion molding or the like, and the layer thickness is not uniform. b: Since the thickness of the side wall and the protector are extremely different from each other, a stress difference (rigidity difference) is likely to occur at the boundary between the side wall and the protector, resulting in poor sense of power.

C; The outer curved contour is a curved concave portion, which is continuous in the tire circumferential direction. Therefore, when the tire is mounted on the rim, the curved concave portion becomes a so-called shadow (annular shadow) and the tire pressure is normal pressure. However, it was easy to feel weak in appearance due to the illusion of lack of air, and foreign matter was likely to adhere to the curved concave portion, and removal of the foreign matter was troublesome. In particular, in a flat pneumatic radial tire having an oblateness of 55 or less, a sense of competence is insufficient even if the oblateness and the annular shadow are combined and the internal pressure is normal.
This was unsuitable for application to high performance radial tires and high performance radial tires.

An object of the present invention is to provide a pneumatic radial tire which solves the above-mentioned problems a to c by improving the cross-sectional shape of the rim protector.

[0007]

The present invention relates to a pneumatic radial tire T having a rim protector 14 protruding along the tire circumferential direction on the outer surface of the sidewall 3 near the bead portion 1 as described above. The following technical measures are taken to achieve the purpose. That is, claim 1
In the pneumatic radial tire according to, the cross-sectional shape of the rim protector 14 is such that the ridge protector 14A, the first oblique side 14B of the concave curved contour located inside the tire radial direction with the top 14A sandwiched therebetween, and the tire radial outside. The first oblique side 14B is mounted on the rim flange 11B, and the top 14A is along the tire circumferential direction. And the second hypotenuse portion 14C forms a band surface 14C-1 that extends along the tire circumferential direction.

Since the cross-sectional shape of the rim protector 14 is substantially triangular as described above, the rim protector 1 is concerned.
4 can be molded to have a substantially uniform thickness, and therefore productivity is improved, and the thickness is not increased by a considerable amount, the amount of rubber is reduced, the weight is reduced, and fuel consumption can be suppressed. Further, since there is no extreme change in the thickness (gauge) between the sidewall 3 and the bead portion 1, it is possible to improve the durability of the bead portion and also improve the road noise performance and the steering stability.

Further, the second oblique side portion 1 of the rim protector 14
The belt surface 14C-1 formed by 4C does not become a curved concave portion, and the tire maximum width portion 10 of the sidewall 3 is not formed.
Therefore, it becomes a divergent flat surface or a gentle curved surface, and it is possible to prevent the illusion that the regular internal pressure is insufficient, and to prevent the illusion that the regular internal pressure is insufficient, since the ring-shaped shadow is not expressed here. Therefore, it can be applied to a high-performance radial tire having a flatness of 55 or less and a high-performance radial tire.

Further, in the above-mentioned claim 1, the cross-sectional shape of the rim protector 14 has a first hypotenuse part 14B and a second hypotenuse part 14B.
It is recommended that the side length of the hypotenuse portion 14C is substantially an isosceles triangular shape in which the former is short and the latter is long (claim 2). The rim protector 14 may have a substantially isosceles triangular cross-sectional shape, but has a longer side length than the first oblique side 14B attached (fitted) to the rim flange 11B with the radially outward second oblique side 14C. By doing so, the sense of force can be increased in combination with the rib effect of the top portion 14A that is raised at the radially outer end of the rim flange 11B.

Further, in the above-mentioned claim 1 or 2,
The top portion 14A of the rim protector 14 forms a first strip surface 14A-1 with a linear contour, and the second hypotenuse portion 14C forms the second strip surface 14A-1.
C-1 is formed, and the first strip surface 14A-1 and the second strip surface 1 are formed.
4C-1 has a narrow first band surface 14A-1 and a second band surface 14C-1.
-1 is wide, and the first strip surface 14A-1 and the second strip surface 14A
The boundary portion with C-1 is formed on the concave curved surface 14D, and the first and second band surfaces 14A-1, 14 are formed through this concave curved surface 14D.
It is recommended that C-1 be connected (Claim 3).

The top portion 14A of the rim protector 14 can be formed by raising this cross-sectional shape as a curved contour, but as described above, it is raised as a straight contour so that the first band surface 14A-
By forming No. 1, it is possible to enhance the sense of power of the tire side portion, and the second band surface 14C-1 connected to the first band surface 14A-1 on the radially outer side is connected to the first band surface 14A-1.
By making the width wider than that, it is less likely that shadows will remain on the tire side portion, and in addition, the first belt surface 14A
It is also possible to directly connect the boundary portion between -1 and the second strip surface 14C-1. However, by connecting the boundary portion via the concave curved surface 14D, stress relaxation at the boundary portion can be expected. Of.

In addition, in claims 1 to 3, the first band surface 14A-1 formed on the top portion 14A of the rim protector 14 is described.
Is recommended to be an inclined surface in which the first band surface 14A-1 is in contact with the tire radial direction by positioning the radial outer edge on the tire axial inner side and the radial inner edge on the tire axial outer side ( Claim 4). As described above, the first belt surface 14A-1 is in contact with the tire radial direction by the slope (the first belt surface 14A-1 is positioned radially outward), so that the first belt surface is positioned radially inward. Compared with the above (refer to the straight line contour B1 in FIG. 6), it is possible to surely elevate the top portion 14A from the radially outer end of the rim flange 11B, and the first band surface 14A-1 and the second band surface 14C- It is possible to prevent the joint portion with 1 from becoming a sharp edge.

Further, when the tire T is assembled to the rim, the rim protector 14 is made substantially vertical to avoid the tire from appearing to be bent in a round shape, thereby providing a sense of power. Furthermore, in Claims 1-4, the 2nd of the rim protector 14 is used.
It is recommended that the radial outer edge of the second hypotenuse portion 14C forming the band surface 14C-1 be joined and integrated with the tire outer surface at the maximum width portion 10 of the tire or at a position slightly radial outside thereof (claim) Item 5). Further, in claims 1 to 5, the rim protector 14 includes the rising portion 12A of the abrasion rubber 12 and the sidewall 3 in the bead portion 1.
It is recommended that the inner surface 3A is covered with the wedge-shaped joint 13 and is integrally bonded to the outer surface of the sidewall 3 (claim 6).

By adopting such a configuration,
It is possible to suppress a large variation in the wall thickness (rubber gauge) from the sidewall 3 to the bead portion 1, and improve the road noise performance and the steering stability while improving the durability of the bead portion 1. In addition, the abrasion rubber 1
By covering the rising portion 12A of No. 2 with the side wall 3 and the rim protector 14, the abrasion rubber 12 is disengaged since the light resistance is improved with less protection.
Further, in the above-mentioned claims 1 to 6, the first band surface 14A
-1, the inclination angles θ1 and θ2 of the second belt surface 14C-1 and the amount of protrusion of the top portion 14A can be set with a certain degree of freedom, but the first belt surface from the reference line parallel to the equatorial line OO of the tire When the angle of 14A-1 is θ1 and the angle of the second band surface 14C-1 is θ2, θ1 is around 10 °, and θ2 is
Is set to 0 ° to 20 °, and the first band surface 14A is
It is recommended that the amount of protrusion of the top portion 14A forming -1 from the rim flange 11B be 2 to 5 mm (claim 7).

Further, it is recommended that the pneumatic tire T according to any one of claims 1 to 7 is applied to a flat tire having an aspect ratio of 55 or less (claim 8). Here, the oblateness of 55 or less means that the oblateness is 55, 45, 40, 35,
It says 30 mag. However, it goes without saying that the present invention can be applied to pneumatic radial tires other than flat tires.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings. 1 (1) and 1 (2) show a pneumatic tire T having an aspect ratio of 30 according to the first embodiment. 2 (1) and 2 (2) are the second embodiment and show a pneumatic tire T having an oblateness of 40. 3 (1) and 3 (2) are the third embodiment, and a pneumatic tire T having an oblateness of 45 is shown.
Indicates. 4 (1) and 4 (2) are the fourth embodiment and show a pneumatic tire T having an aspect ratio of 50.

In each of the embodiments shown in FIGS. 1 to 4, the left half of the equator line OO of the tire T and its main part are shown, and the right half is omitted, but the equator line OO is the axis of symmetry (center). ), And the parts common to FIGS. 1 to 4 are described below with reference to common reference numerals. The pneumatic radial tire T has a left and right bead portion 1 and a tread portion 2 that connects the bead portion 1 via a sidewall 3 and a shoulder 4 and is formed in a toroidal cross section.

The bead portion 1 has a ring-shaped (link-shaped) bead core 5 embedded therein, and is provided with a radial carcass 6 which surrounds the bead core 5 and is folded back from the inside of the tire toward the outside of the tire. The left and right bead cores 5 are connected to each other. A belt layer (breaker layer) 7 is provided so as to cover the carcass crown of the tread portion 2, and the tread portion 2 is configured to include the base tread rubber 8 that covers the belt layer 7.

The bead portion 1 is provided with a bead filler rubber 9 having a wedge-shaped cross section on a bead core 5. Both end portions of a carcass 6 including the filler rubber 9 are folded back from the tire inner side to the tire outer side. Terminal 6B
It is located near the tire maximum width portion 10 in FIGS. 1, 3 and 4, and is located on the shoulder 4 in FIG.
The bead portion 1 is to be fitted to the rim 11, and includes the rim base 11A and the abrasion rubber 12 having an L-shaped cross section along the rim flange 11B. The tip of the abrasion rubber 12 at the rising portion 12A and the inside diameter 3A of the sidewall 3 are provided. Are joined and integrated via a wedge-shaped fitting portion 13, and the leading end of the rising portion 12A constitutes the wedge-shaped joining portion 13 with the tip inside the tire and the diameter inside 3A outside the tire.

A rim protector 14 is provided on the outer surface of the sidewall 3 so as to be raised along the tire circumferential direction. The rim protector 14 includes a tire maximum width portion 10
And the outer surface of the sidewall 3 on the radially inner side and the wedge-shaped joint portion 13 are covered.
Is integrally joined to the outer surface of the rim protector 14 and the rim protector 14 is provided on the outer surface of the sidewall 3 near the bead portion 1. A cross-sectional shape of the rim protector 14 is a top portion 14A, and a first oblique side portion 14B having a concave curved contour located inside the tire radial direction with the top portion 14A interposed therebetween.
And a second hypotenuse portion 14C having a linear contour located on the outer side in the radial direction of the tire, and has a substantially triangular shape.

Since the cross-sectional shape of the rim protector 14 is substantially triangular as described above, the rim protector 1
4 can be molded to have a substantially uniform thickness, and therefore, the productivity by a rubber extrusion molding machine or the like is improved, and the amount of rubber is reduced and the weight is reduced without increasing the thickness to a comparable extent, thereby suppressing fuel consumption. Can be done. Further, since there is no extreme change in the thickness (gauge) between the sidewall 3 and the bead portion 1, it is possible to improve the durability of the bead portion and also improve the road noise performance and the steering stability.

Further, the first hypotenuse part 1 of the protector 14
4B is attached to the rim flange 11B, and the top 14A
Are arranged along the tire circumferential direction and are raised from the radially outer end of the rim flange 11B, and the second hypotenuse part 1
4C forms a band surface 14C-1 along the tire circumferential direction. Here, the band surface 14C-1 formed by the second oblique side portion 14C of the rim protector 14 does not become a curved concave portion but becomes a divergent flat surface or a gentle curved surface from the tire maximum width portion 10 of the sidewall 3, It is possible to prevent the illusion that the regular internal pressure is insufficient, and to prevent the adhesion of foreign matter.

Therefore, it can be applied to high-performance radial tires having a flatness of 55 or less and high-performance radial tires. Further, since the band surface 14B-1 formed by the first hypotenuse part 14B is along the tire circumferential direction as a concave curved contour, it is continuously provided flush with the outer surface of the rising portion 12A of the abrasion rubber 12. The rim is adapted to the rim flange 11B to facilitate the rim assembly and prevent air leakage and the like. Further, the rim protector 14 may have a substantially isosceles triangular cross section, but is longer than the first oblique side 14B attached (fitted) to the rim flange 11B with the radially outward second oblique side 14C. The sides are long, and the shape is almost an isosceles triangle.

As a result, the sense of force can be increased in combination with the rib effect of the top portion 14A which is raised at the radially outer end of the rim flange 11B. Further, the top portion 14A of the rim protector 14 forms the first band surface 14A-1 with a linear contour,
The hypotenuse part 14C forms the second band surface 14C-1, and
The band surface 14A-1 and the second band surface 14C-1 are the first band surface 14A.
-1 is narrow and the second strip surface 14C-1 is wide, and the boundary portion between the first strip surface 14A-1 and the second strip surface 14C-1 is formed on the concave curved surface 14D. The first and second band surfaces 14A-1 and 14C-1 are connected to each other through.

That is, the top portion 14 of the rim protector 14
A can also bulge this cross-sectional shape as a curved contour, but as described above, by bulging it as a linear contour to form the first band surface 14A-1, it is possible to enhance the sense of power of the tire side portion. This first strip surface 14A-
By making the second band surface 14C-1 that is connected to the outer diameter side 1 to be wider than the first band surface 14A-1, it is less likely that shadows will remain on the tire side portion.
Although it is possible to directly connect the boundary portion between the band surface 14A-1 and the second band surface 14C-1, it is possible to relax the stress at the boundary portion by connecting the boundary portion via the concave curved surface 14D. Can be expected.

Further, the first band surface 14A-1 formed on the top portion 14A of the rim protector 14 has its outer radial edge located on the inner side in the tire axial direction and its inner radial edge located on the outer side in the axial direction of the tire. -1 is a slope that is in contact with the tire radial direction, and the radial outer edge of the second hypotenuse portion 14C that forms the second band surface 14C-1 of the rim protector 14 is the maximum width portion 10 of the tire or more. It is joined and integrated with the outer surface of the tire at a position slightly outside the radius. In this way, the first belt surface 14A-1 is in contact with the outer radial direction of the tire (the first belt surface 14A-1 is located in the outer radial direction)
As a result, it becomes possible to surely elevate the top portion 14A from the radially outer end of the rim flange 11B, as compared with the case where the first band surface is positioned in the radially inward direction (see the linear contour B1 in FIG. 6). It is possible to prevent the joining portion between the first band surface 14A-1 and the second band surface 14C-1 from becoming a sharp edge.

The second band surface 14 of the rim protector 14
The radial outer edge of the second hypotenuse portion 14C forming C-1 is
By being integrally joined to the outer surface of the tire at the maximum width portion 10 of the tire or at a position slightly outside of this, a large variation in the wall thickness (rubber gauge) from the sidewall 3 to the bead portion 1 is suppressed, and the bead is suppressed. It is possible to improve road noise performance and steering stability while improving the durability of the part 1. Furthermore, FIG. 1 (2), FIG. 2 (2),
As shown in FIGS. 3 (2) and 4 (2), the first band surface 14A-1 from the reference line L-L parallel to the equatorial line O-O of the tire.
Is θ1 and the angle of the second band surface 14C-1 is θ2, θ1 is about 10 °, θ2 is set to 0 ° to 20 °, and the first band surface 14A-1 is The amount of protrusion S of the top 14A to be formed from the rim flange 11B is 2 to 5
It is set to mm.

In the above-described first to fourth embodiments, for example, as shown in FIG. 5, the band surface 14-B and the band surface 14C-1.
Ridges (striped irregularities) 14C-2, 14B-2
Can be formed to improve the decoration function, but of course, this ridge need not be formed. As described above, by providing the ridge 14C-2, the region of the sidewall 3 is narrowed, and the section height looks low.
This makes the tire T feel thin.

Further, by providing the ridges 14C-2 and 14B-2 separately above and below the top 14A, the top 14
Since the position of A is raised, even if a clearance is formed between the rim flange 11B and the rim flange 11B, a ridge 14B-2 is formed in a portion corresponding to the clearance so that the rim protector 14 is shaded and the rim protector 14 is conspicuous. It is improving. 2 except for the first embodiment shown in FIG.
In the second to fourth embodiments shown in (2) to FIG. 4 (2), the rigidity of the bead portion 1 is improved by interposing the steel reinforcement 16 between the carcass folded-back portion 6A and the bead filler rubber 9. You may let me.

Further, as shown in FIG.
In the embodiment, the rim protector 14 is integrally joined with the outer surface of the sidewall 3, and the bottom surface 14E is formed into a curved recess along the surface. I am doing it.

[0032]

As described in detail above, according to the present invention, in a pneumatic radial tire provided with a rim protector, the tire side portion is ensured while ensuring bead portion durability, road noise performance, and steering stability. A ring-shaped shadow did not appear on the tire, and it was possible to provide a tire with a strong sense of power.

[Brief description of drawings]

FIG. 1 shows a first embodiment of a tire according to the present invention,
(1) is a left half sectional view, and (2) is an enlarged sectional view of a main part.

FIG. 2 shows a second embodiment of a tire according to the present invention,
(1) is a left half sectional view, and (2) is an enlarged sectional view of a main part.

FIG. 3 shows a third embodiment of the tire according to the present invention,
(1) is a left half sectional view, and (2) is an enlarged sectional view of a main part.

FIG. 4 shows a fourth embodiment of the tire according to the present invention,
(1) is a left half sectional view, and (2) is an enlarged sectional view of a main part.

FIG. 5 is a cross-sectional perspective view of a main part including a bead part.

FIG. 6 is a sectional view of a conventional example.

[Explanation of symbols]

T tire 1 bead part 2 tread section 11 rims 14 Rim protector 14A top 14B First hypotenuse part 14C 2nd hypotenuse

Claims (8)

[Claims] 1. A pneumatic radial tire (T) comprising a rim protector (14) protruding along a tire circumferential direction on an outer surface of a sidewall (3) near a bead portion (1), wherein the rim is The cross-sectional shape of the protector (14) is the top (14
A), with the first hypotenuse portion (14B) of the concave curved contour located inside the tire radial direction with the top portion (14A) sandwiched therebetween, and the second hypotenuse portion (14C) of the linear contour located outside of the tire radial direction. The first oblique side portion (14B) is attached to the rim flange (11B), and the top portion (14A) extends along the tire circumferential direction and is outside the diameter of the rim flange (11B). A pneumatic radial tire characterized in that it is raised from the end and the second hypotenuse portion (14C) forms a belt surface (14C-1) along the tire circumferential direction. 2. The cross-sectional shape of the rim protector (14) is substantially an isosceles triangular shape in which the side lengths of the first hypotenuse portion (14B) and the second hypotenuse portion (14C) are short in the former and long in the latter. The pneumatic radial tire according to claim 1. 3. The top (14) of the rim protector (14).
A) forms a first strip surface (14A-1) with a linear contour, a second hypotenuse portion (14C) forms a second strip surface (14C-1), and the first strip surface (14A-1) And the second strip (14C-
In 1), the first strip surface (14A-1) is narrow and the second strip surface (14A-1) is narrow.
C-1) is wide, and the first band (14A-1) and the second
The boundary portion with the band surface (14C-1) is formed into a concave curved surface (14D), and the first and second surfaces are formed through this concave curved surface (14D).
The pneumatic radial tire according to claim 1 or 2, wherein the belt surfaces (14A-1) (14C-1) are connected to each other. 4. The top (14) of the rim protector (14).
The first band surface (14A-1) formed in (A) has a radially outer edge located on the inner side in the tire axial direction and an inner radial edge located on the outer side in the tire axial direction. The pneumatic radial tire according to any one of claims 1 to 3, which has an inclined surface that is in contact with the outside. 5. The second band surface (1) of the rim protector (14).
4C-1), the outer radial edge of the second hypotenuse portion (14C) is integrally joined to the outer surface of the tire at the maximum width portion (10) of the tire or at a portion slightly outside the radial portion. The pneumatic radial tire according to any one of claims 1 to 4. 6. The rim protector (14) has a wedge-shaped joint (13) between the rising portion (12A) of the abrasion rubber (12) in the bead portion (1) and the inside diameter (3A) of the sidewall (3). The pneumatic radial tire according to any one of claims 1 to 5, which is covered with and is integrally bonded to the outer surface of the sidewall (3). 7. When the angle of the first belt surface (14A-1) from the reference line parallel to the equatorial line OO of the tire is θ1 and the angle of the second belt surface (14C-1) is θ2, θ1 is 10 °
Before and after, θ2 is set to 0 ° to 20 °, and the amount of protrusion from the rim flange (11B) of the top portion (14A) forming the first band surface (14A-1) is set to 2 to 5 mm. The pneumatic radial tire according to any one of claims 1 to 6, characterized in that. 8. A pneumatic radial tire according to claim 1, wherein the pneumatic tire (T) is applied to a flat tire having an aspect ratio of 55 or less.