WO2008050503A1

WO2008050503A1 - Non-pneumatic tire

Info

Publication number: WO2008050503A1
Application number: PCT/JP2007/058557
Authority: WO
Inventors: Yoshiaki Hashimura; Jun Matsuda; Tsuyoshi Kitazaki; Ryoji Hanada; Hideki Seto; Izumi Kuramochi; Kenichiro Endo
Original assignee: The Yokohama Rubber Co., Ltd.
Priority date: 2006-10-27
Filing date: 2007-04-19
Publication date: 2008-05-02
Also published as: JP2008105644A; JP3923073B1

Abstract

A non-pneumatic tire having a structure in which an outer ring and an inner ring are connected by spokes and having improved steerability during braking achieved without sacrificing durability. The non-pneumatic tire has a structure body in which an outer ring (3) and an inner ring (4) that are coaxially disposed and made of an elastic material are connected to each other by a large number of circumferentially intermittently disposed spokes (5, 5') made of an elastic material. Each adjacent two spokes (5, 5') forming a pair in the circumferential direction are bent so that their projecting surfaces circumferentially face each other, and theprojecting surfaces are connected to each other by at least one circumferentially extending connection part (6) made of at least a single elastic material.

Description

Specification

Non-pneumatic tire

Technical field

TECHNICAL FIELD [0001] The present invention relates to a non-pneumatic tire, and more specifically, to improve the maneuverability during braking in a non-pneumatic tire having a structure in which an outer ring and an inner ring are connected by a spoke. Related to non-pneumatic tires.

Background art

Conventionally, solid tires such as solid tires and cushion tires are mainly used for industrial vehicles as non-pneumatic tires. However, conventional non-pneumatic tires have not been adopted for passenger cars where ride comfort is important because they are heavy and lack shock absorption.

[0003] In order to improve the riding comfort performance of such a non-pneumatic tire and make it applicable to passenger cars as well, as shown in Fig. 5, a concentricity is established between the tread ring 1 and the wheel 10. The spoke structure 2 connected by a large number of spokes 5 made of an elastic material between the outer peripheral ring 3 and the inner peripheral ring 4 that are arranged in the shape of a ring so as to achieve light weight and shock absorption A non-pneumatic tire is proposed (for example, see Patent Document 1).

[0004] As described above, the non-pneumatic tire having a structure in which the spokes of elastic material are connected between the outer ring and the inner ring is good because the spoke supports the radial load with an appropriate sag. Ride comfort is obtained. However, when braking is applied from the time of running, the outer peripheral wheel receives a tensile force rearward due to friction with the road surface, whereas the inner peripheral wheel moves forward due to inertia. The outer ring and inner ring undergo shear deformation until a circumferential shear force is applied between them and the spokes tilt in the circumferential direction and generate tension, resulting in unstable maneuverability during braking. There was a drawback.

[0005] As described in Patent Document 1 as one of the embodiments, such controllability at the time of braking can be achieved by adopting a structure in which two spokes are slanted and crossed in an X shape. Since the circumferential rigidity of the spoke is improved, a certain degree of improvement can be achieved. However, the spokes with the X-shaped cross are extremely excessively stiff at the intersection. For this reason, there is a disadvantage that the stress is concentrated at the place where the radial end of the spoke is connected to the outer ring or the inner ring, and the breakage easily occurs and the durability is lowered.

Patent Document 1: Japanese Special Table 2005-500932

Disclosure of the invention

Problems to be solved by the invention

[0006] An object of the present invention is to improve the maneuverability during braking without reducing durability in a non-pneumatic tire having a structure in which the outer ring and the inner ring are connected by spokes. The object is to provide a non-pneumatic tire.

Means for solving the problem

[0007] The non-pneumatic tire of the present invention for achieving the above object is intermittently arranged in a large number of circumferential directions between the outer peripheral ring and the inner peripheral ring made of concentric elastic material force. In the non-pneumatic tire composed of a structure connected by the elastic material force and the spokes, the two spokes that make a pair in the circumferential direction are bent so that the convex surfaces face each other in the circumferential direction, The convex surfaces are connected by a connecting portion made of at least one elastic material extending in the circumferential direction.

The invention's effect

[0008] According to the present invention, two spokes adjacent to each other in the circumferential direction between the outer ring and the inner ring are paired so that the convex surfaces of the pair of spokes face each other in the circumferential direction. Since the bent surfaces are bent and connected by a connecting portion extending in the circumferential direction, when the vehicle is controlled from the running state, one of the paired spokes is connected to the outer ring side and the other spoke is connected to the inner side. A brake is applied to the portion that is connected to the peripheral ring side and the connecting portion that connects these spokes at the same time to generate tensile resistance and prevent relative rotation between the outer ring and the inner ring. Stabilize the maneuverability of the time. That is, since the rigidity in the circumferential direction between the outer ring and the inner ring increases, the maneuverability during braking is improved. The pair of spokes can maintain durability because the stresses are not dispersed and concentrated almost entirely by the structure in which the convex surfaces are connected by the connecting portions.

Brief Description of Drawings FIG. 1 is a perspective view showing an example of an embodiment of a non-pneumatic tire according to the present invention.

FIG. 2 is an explanatory view for explaining the operation of the non-pneumatic tire of the present invention.

FIG. 3 is an explanatory view showing the dimensional relationship of the non-pneumatic tire of the present invention.

FIG. 4 is a partial cross-sectional view showing another embodiment of the present invention.

FIG. 5 is a perspective view illustrating a conventional non-pneumatic tire.

Explanation of symbols

[0010] 1 tread ring

2 Spoke structure

3 Outer ring

4 Inner ring

5, 5 'spoke

50 spokes vs

6 Connecting part

BEST MODE FOR CARRYING OUT THE INVENTION

As shown in FIG. 1, the non-pneumatic tire of the present invention is configured to join a tread ring 1 made of rubber or resin to the outer periphery of a spoke structure 2. The spoke structure 2 is configured by connecting a plurality of pairs of spokes 50 between an outer peripheral ring 3 and an inner peripheral ring 4 made of an elastic material arranged concentrically. Spoke pair 50 is composed of two spokes 5 and 5 'force adjacent to each other in the circumferential direction, and spokes 5 and 5' are connected to outer ring 3 and inner ring 4 with both ends connected to each other. The convex surfaces are bent so as to face each other in the circumferential direction. The shape of the convex surface may be curved as shown in FIG. 1 as long as it is bent, or may be refracted into a V shape as shown in FIG. Further, the convex surfaces are connected by a connecting portion 6 extending in the circumferential direction. The connecting portion 6 is made of an elastic material and may be one for a pair of spokes 50, but at least one may be arranged as shown in FIG. 4 (B).

[0012] When the non-pneumatic tire configured as described above starts to rotate in the direction of the arrow R as shown in FIG. 2, the outer ring 3 and the inner ring 4 are opposite to each other as indicated by broken arrows. Directional arrows ^, F 'act, and the broken arrows on the spokes 5 and 5' and the connecting part 6 where the convex surfaces face each other As shown in Fig. 1, the tensile resistance is generated, and the rigidity that prevents the relative rotation between the outer ring 3 and the inner ring 4 is generated. When braking from this running state, forces F and F indicated by solid arrows in opposite directions opposite to the above act on the outer ring 3 and the inner ring 4, and one spoke 5 moves toward the outer ring 3 side. a portion portion connecting the other of the spokes 5 'is connected to the inner circumferential wheel 4 side, these spokes 5, 5 and a connecting part 6 for connecting the ^r tensile nervous simultaneously anti mosquito T (solid line illustrated ) To prevent relative rotation between the outer ring and the inner ring. That is, since the rigidity in the circumferential direction between the outer peripheral wheel and the inner peripheral wheel is increased, the maneuverability during braking is stabilized.

[0013] Further, since the spokes constituting the pair of spokes are configured such that the convex surfaces are connected to each other by a connecting portion, the stress generated during braking is distributed to almost the whole of the connecting portion and each of the spokes on both sides. Since it is not concentrated on the outer ring or the joint between the inner ring and the spoke, durability can be maintained.

[0014] In the non-pneumatic tire described above, it is preferable that the spoke and the connecting portion have the following length relationship.

[0015] In the cross section orthogonal to the tire axis shown in Fig. 3, the intersection of the center line passing through the center of thickness of the spokes 5 and 5 'and the extension line of the inner peripheral surface of the outer ring 3 is a. , 5 'is the intersection of the inner ring 4 and the extension line of the outer peripheral surface of the inner ring 4, b is the intersection of the center line of the spoke 5, 5' and the center line passing through the thickness center of the connecting part 6, c Let d be the point of intersection with the perpendicular drawn from intersection c with respect to the straight line connecting a and b. Where L is the distance between intersections a and d, and L is the distance between intersections b and d.

1 2, the larger of the distances L and L is L, and the distance between the intersections c and d.

1 2

[0016] The ratio t / L between the distance t and the distance L when defined in this way is preferably set to 0.0.08-1.73, more preferably set to 0 · 08-1.0. If the ratio t / L is less than 0.08, the amount of bending of the spoke is small, so the spoke may bend in the direction opposite to the direction bent in advance due to deformation during tire rotation. Decreases. On the other hand, if it exceeds 1.73, the amount of bending is too large to sufficiently support the load in the tire radial direction.

[0017] When the distance between the intersections c, c at both ends of the connecting portion 6 is k, the ratio kZL of the distance k to the distance L is preferably 0.08 to: 1.73, more preferably 0. 08 ~: 1. 0 If itk / L force S is less than 0.08, the length of the connecting part is small and the overall shape of the spoke pair is nearly X-shaped, so the rigidity of the connecting part becomes excessive, and the spoke, outer ring and inner ring Each joining Stress tends to concentrate on the part and durability is reduced. If the ratio k / L exceeds 1.73, the force that restrains the spoke pair in the tire circumferential direction becomes weak, and the shear rigidity in the circumferential direction becomes insufficient.

[0018] The thickness of the connecting portion 6 is preferably 0.03L to 0.23L, more preferably 0.09L to 0.20L with respect to the distance L described above. If the thickness of the connecting portion is less than 0.03L, it will be insufficient to maintain the shear rigidity in the circumferential direction between the outer ring and the inner ring, and if it exceeds 0.23L, The rigidity becomes excessive, stress concentrates on the spokes 5 and 5 ', and the durability decreases.

[0019] It should be noted that the dimensions L, t, and k are measured in a cross section orthogonal to the rotational axis direction when no load is applied to the non-pneumatic tire.

[0020] The structure of the spokes and the connecting portion constituting the non-pneumatic tire of the present invention is not limited to the form of FIG. 1, and examples of such modifications as FIGS. 4 (A) to (C) are shown. Can

In the example of FIG. 4 (A), the spokes 5 and 5 ′ are convex surfaces that are refracted in a “<” shape so as to face each other. In the example shown in the figure, the spokes ^ and 5 that belong to the adjacent spoke pair 50 and face 5 form a hexagon including the outer ring 3 and the inner ring 4, and the shape formed by them is It is not limited to diamonds, pentagons, or polygons that are more than hexagons.

In the example of FIG. 4 (B), two connecting portions 6 are provided, and the spokes 5 and 5 ′ are connected substantially in parallel. Thus, the shear rigidity in the circumferential direction can be more effectively increased by changing the position in the radial direction and arranging the plurality of connecting portions. The number of connecting parts may be three or more, and the number of connecting parts need not be the same in all spoke pairs, but the number of connecting parts may be different.

In the example of FIG. 4 (C), an inclined reinforcing portion 7 is additionally connected between the convex surfaces of the spokes 5 and 5 ′ and the inner peripheral surface of the outer ring 3, and the convex surfaces of the spokes 5, 5 ^; An inclined reinforcing portion 8 is additionally connected to the outer peripheral surface of the inner peripheral ring 4. Only one of these inclined reinforcing portions 7 and 8 may be provided. By disposing the inclined reinforcing section 7 and / or inclined reinforcing portion 8 can be any time so high spokes 5, 5 Contact Keru circumferential shear stiffness to ^r. Inclined reinforcements 7, 8 are tire widths The shape may be continuous in the direction (axial direction), or may be a cylinder or prism arranged intermittently in the width direction. Also, it may be bent in a side view in the tire axial direction.

[0024] In the present invention, the elastic material constituting the outer ring and the inner ring is preferably rubber, a thermoplastic resin, a thermosetting resin, and a composition containing these. The elastic material is more preferably reinforced by a reinforcing material such as a metal cord such as a steel cord or an organic fiber cord such as nylon, polyester, or rayon. By configuring the outer ring and the inner ring with such an elastic material force, a load support mechanism and a buffer mechanism equivalent to a pneumatic tire can be provided. The elastic materials constituting the outer ring and the inner ring may be the same as or different from each other.

[0025] The spoke and the connecting portion may be made of an elastic material similar to that of the outer ring and the inner ring, but preferably made of a thermosetting resin typified by urethane. Furthermore, it is preferable that the thermosetting resin has a crosslinked structure from the viewpoint of tensile resistance during braking and heat resistance. The tensile elastic modulus of such a thermosetting resin is preferably 10 to 70 MPa, more preferably 20 to 50 MPa. By setting the tensile elastic modulus within such a range, the effect of increasing the circumferential shear rigidity between the outer peripheral ring and the inner peripheral ring is highly effective, and the controllability during braking can be improved. it can.

[0026] It is preferable that the inclined reinforcing portion is made of an elastic material similar to that of the spoke and the connecting portion.

Claims

The scope of the claims

[1] In a non-pneumatic tire comprising a structure in which concentrically arranged elastic material forces are connected by spokes made of elastic material, which are intermittently arranged in the circumferential direction, between an outer peripheral ring and an inner peripheral ring.

The two spokes that make a pair in the circumferential direction are bent so that the convex surfaces are opposed to each other in the circumferential direction, and are connected by a connecting portion made of at least one elastic material extending in the circumferential direction between the convex surfaces. Non-pneumatic tire.

[2] In a cross section perpendicular to the tire axis, a and b are intersection points of a center line passing through the center of thickness of the spoke and an extension line of the inner peripheral surface of the outer peripheral ring and an extension line of the outer peripheral surface of the inner peripheral ring, The intersection point of the spoke center line and the center line passing through the thickness center of the connecting portion is c, the intersection point of the perpendicular line drawn from the intersection point c with respect to the straight line connecting the intersection points a and b is d, and the intersection point a , d and the distance between b and d is L, and the distance between the intersections c and d is t, then the ratio t / L between the distance t and the distance L is 0.08 ~: 1. The non-pneumatic tire according to claim 1, which is 73.

[3] In a cross section orthogonal to the tire axis, a and b are intersection points of a center line passing through the center of thickness of the spoke and an extension line of the inner peripheral surface of the outer peripheral ring and an extension line of the outer peripheral surface of the inner peripheral ring, The intersection point of the spoke center line and the center line passing through the thickness center of the connecting portion is c, the intersection point of the perpendicular line drawn from the intersection point c with respect to the straight line connecting the intersection points a and b is d, and the intersection point a , d and the distance between b and d is L, and the distance between the intersections c and c at both ends of the connecting part is k, the ratio k / L between the distance k and the distance L is 0 08-: 1. The non-pneumatic tire according to claim 1 or 2 according to claim 73.

4. The non-pneumatic tire according to any one of claims 1 to 3, wherein the elastic material constituting the outer peripheral ring and the inner peripheral ring is rubber, a thermoplastic resin, or a thermosetting resin.

5. The non-pneumatic tire according to claim 4, wherein the elastic material is reinforced with a metal cord or an organic fiber cord.

[6] The non-pneumatic tire according to any one of [1] to [5], wherein the elastic material constituting the spoke and the connecting portion is a thermosetting resin.

[7] The thermosetting resin has a crosslinked structure, and has a tensile modulus of 10 to 70 MPa.

6. The non-pneumatic tire according to 6.