JPH07205608A - Non-pneumatic tire - Google Patents

Abstract

PURPOSE:To improve comfortable feeling and the driving stability of a non- pneumatic tire used as a sparetire. CONSTITUTION:A circular part 3 is provided at the external peripheral edge of a disc 2 attached to a tire shaft and a tire base body formed in one body by use of plastics is provided. The circular part 3 is attached at both sides of tire shaft and opend at radially different positions respectively. And further it is provided with circumferential side grooves 7A, 7B extending in the peripheral direction and circular supports 9 of an elastic material which contact both inner peripheral face F1 and outer peripheral face F2 in the radial direction of the circumferential side grooves 7A, 7B are arranged inside the circumferential side grooves 7A, 7B and further, a tread rubber 5 is stuck at the outer peripheral face of the circular part 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-pneumatic tire used as a so-called spare tire for emergency use.

[0002]

2. Description of the Related Art A spare tire is mounted on a vehicle for replacement in an emergency such as flat tire of a ground tire. As such spare tires, in order to effectively use the luggage compartment, high-pressure tires with the same tire outer diameter and reduced width, and foldable tires that are filled with internal pressure during use are used. The above-mentioned high-pressure tire is mainly used as a spare tire because it is inconvenient to fill the internal pressure of the tire.

However, such a high pressure tire is
If it is stored for a long period of time, the internal pressure tends to drop if it is a little, and it is necessary to perform regular inspections for emergency use.

Therefore, the spare tire can be easily used in an emergency without the trouble of replenishing the internal pressure and periodical inspection at the time of use.
Moreover, in order to improve the fuel economy of vehicles in recent years, it is desired to reduce the weight of such spare tires.

As one that satisfies one of these requirements, for example, Japanese Patent Publication No. 41-22201 (hereinafter referred to as Conventional Example 1), Japanese Patent Laid-Open No. 50-21401 (hereinafter referred to as Conventional Example 2), and Japanese Patent Laid-Open No. Sho. No. 62-295704 (hereinafter referred to as Conventional Example 3) has been proposed as a non-pneumatic tire.

As shown in FIG. 3, the prior art example 1 includes an annular rim portion a, a central hub portion b and a plurality of radially extending spoke portions c ... And the spoke portions c.
Discloses an elastic wheel t which receives a load to flatten the outer surface of the rim portion a like a cantilever so as to adapt to the shape of the surface on which the wheel rotates.

The conventional example 2 is an automobile in which a disc is provided with a rim having webs each having a half-sine wave shape and webs each having a half-sine wave bent in the opposite direction alternately provided in the circumferential direction. Wheels have been proposed.

Further, Conventional Example 3 discloses a non-pneumatic tire in which a tread rubber is arranged on the outer surface of an annular portion which is joined by ribs which are provided between a cylindrical outer member and an inner member and which are circumferentially separated from each other. .

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Since the spoke portions c are circumferentially separated from each other, a rugged feeling corresponding to the bending of each spoke portion c during traveling cannot be avoided, and riding comfort and steering stability are not necessarily good.

Also in the conventional example 2, since the webs having different directions are discontinuously formed in the circumferential direction, vibration during running is easily induced, and the riding comfort and the steering stability tend to be poor.

Further, the conventional example 3 has the same problems as those of the conventional example 1 because the ribs are spaced in the circumferential direction.

The present invention is based on the provision of circumferential side grooves that are open at different positions in the radial direction and on both sides of the annular portion in the axial direction of the tire, and that extend in the circumferential direction. The purpose of the present invention is to provide a non-pneumatic tire that can be flexed by bending and can improve riding comfort and steering stability.

[0013]

SUMMARY OF THE INVENTION The present invention is a non-pneumatic tire having a tire base integrally formed with a synthetic resin by providing an annular portion on the outer peripheral edge of a disk portion attached to a tire shaft. The annular portion is provided with circumferential side grooves that are open at different positions in the radial direction and at different positions in the radial direction and extend in the circumferential direction, and the annular portion is made of an elastic material in the circumferential side groove of the tire base. An annular support material is arranged in contact with both the radially inner peripheral surface and the outer peripheral surface of the circumferential groove, and a tread rubber is adhered to the outer peripheral surface of the annular portion.

The opening of the circumferential groove is preferably smaller in radial length than the central portion of the circumferential groove in the tire axial direction.

[0015]

In the non-pneumatic tire, the tread rubber is affixed to the tire base integrally formed with the synthetic resin by providing the annular portion on the outer peripheral edge of the disc portion.
There is no need for rim assembly, and there is no need to worry about flat tires.
The safety can be improved, the weight can be reduced, and the cost can be reduced.

Further, the annular portion is provided with circumferential side grooves which are open at different positions in the radial direction and on both side surfaces in the tire axial direction and which extend in the circumferential direction. Since the annular supporting member is arranged, the annular portion can be continuously and smoothly bent in the circumferential direction, so that the rugged feeling during traveling can be reduced, the riding comfort can be improved, and the steering stability can be improved.

Further, the radial length of the opening of the circumferential groove is made smaller than the radial length of the central portion of the circumferential groove in the axial direction of the tire, so that the supporting member is prevented from falling off due to displacement. It is possible to maintain riding comfort and steering stability, and further enhance safety.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, the non-pneumatic tire 1 of the present invention
Has a tire base body 4 composed of a disk portion 2 and an annular portion 3 provided on an outer peripheral edge thereof integrally formed of synthetic resin, and the tread rubber 5 is provided on the outer peripheral surface of the annular portion 3 over the entire circumference thereof. It is pasted on.

The disk portion 2 has a flat disk shape having a hole portion 14 for mounting a tire shaft as a center, and the hole portion 1
Bolt holes 15 through which a plurality of tire shaft mounting bolts pass are separated from each other.

The annular portion 3 extends from the outer peripheral edge of the disc portion 2 to the outer side in the tire axial direction and the outer side in the radial direction. A ring-shaped inner ring 19 whose one end is continuous and extends in the tire axial direction and whose central portion is located on an extension line of the disc portion 2, and a middle connecting piece 20 which extends radially outward from the other end of the inner ring 19. A ring-shaped intermediate ring 21 that has one end connected to the radially outer end of the middle connecting piece 20 and extends radially outward of the inner ring 19 in the tire axial direction, and radially outward from the other end of the intermediate ring 21. Outer connecting piece 22 extending
From the outer end in the radial direction of the outer connecting piece 22 to the intermediate ring 2
1. An outer ring 23 that extends radially outward of 1 and extends in the tire axial direction to form the outer peripheral surface of the annular portion 3 to which the tread rubber 5 is attached.
The cross section is composed of and and has a substantially inverted S shape.

Thus, the inner ring 19 and the inner ring 1
The intermediate ring 21 having a diameter larger than 9 and the outer ring 23 having a diameter larger than the intermediate ring 21 include the middle connecting piece 20 and the outer connecting piece 22.
While being concentrically coupled by the inner ring 19, the middle connecting piece 20, and the intermediate ring 21, a circumferential side groove 7A that continuously extends in the circumferential direction in which the opening 6A is provided on one side surface in the tire axial direction, Further, the intermediate ring 21, the outer connecting piece 22, and the outer ring 23 form the opening 6 on the other side surface in the tire axial direction.
Circumferential side grooves 7B, which are different in position from A in the radial direction and which continuously extend in the circumferential direction and are provided with openings 6B, are formed.

The openings 6A and 6B are formed in the inner ring 1.
The radial length LA of the intermediate ring 21, the intermediate ring 21, and the outer ring 23 are provided by the projections 25 provided at the tire axial ends.
LB is set to be smaller than the radial lengths LC and LD of the tire axial center portions of the circumferential grooves 7A and 7B. Further, it is preferable that the lengths LC and LD be the same in order to bend the annular portion 3 in the tire axial direction in a well-balanced manner by the ground pressure. If the ratio LC / LD is less than 0.95 or greater than 1.05, the bending of the annular portion 3 becomes unevenly large in one side in the tire axial direction, and the steering stability tends to be impaired. Therefore, the ratio LC / LD is 0.95 or more and 1.
05 or less, more preferably 0.98 or more and 1.02 or less.

The ratio D19 / D23 of the diameter D19 of the inner ring 19 and the diameter D23 of the outer ring 23 is 0.75 or more and 0.85 or less, preferably 0.78 or more and 0.
It is set to 82 or less. As a result, the grounding force transmitted from the annular portion 3 can be appropriately reduced and transmitted to the disc portion 2,
It is possible to absorb the deformation of the outer ring 23 at the time of contact with the ground or unevenness by the circumferential side grooves 7A and 7B. When the ratio D19 / D23 is larger than 0.85, the tendency of transmitting the deformation to the disc portion 2 through the inner ring 19 becomes remarkable, while the ratio D19 / D23 is 0.75.
When it is smaller than the above value, the bending of the annular portion 3 increases, and it becomes easy to promote the eccentricity of the outer ring 23 due to the ground contact rotation, which lowers the steering stability.

As described above, the annular groove 3 has the circumferential groove 7A,
By providing 7B, the annular portion 3 can be flexed smoothly over the entire length in the circumferential direction of the tire, the riding comfort can be improved, and the steering stability can be improved.

The tire base 4 comprising the disc portion 2 and the annular portion 3 is made of polyurethane resin, polyester resin, nylon, polycarbonate resin or the like, has strength, impact resistance,
It is integrally formed using a synthetic resin having excellent fatigue resistance.

Further, the circumferential groove 7A of the tire base body 4,
A support material 9 is arranged in 7B. The support member 9 is made of an annular elastic material in which, for example, three support member pieces 9A having a mountain-shaped cross section and extending over the entire length in the circumferential direction are aligned in the tire axial direction and integrated. The radially inner surface is brought into contact with the radially inner circumferential surface F1 of the circumferential grooves 7A and 7B, and the radially outer surface is brought into contact with the radially outer circumferential surface F2 of the circumferential grooves 7A and 7B, respectively, and is fixed by using an adhesive or the like. As a result, they are arranged in the circumferential grooves 7A and 7B so that they cannot be laterally displaced.

As the elastic material forming the support material 9, JI
A compounded rubber having an SA hardness of 45 to 55 degrees is used. When it is less than 45 degrees, the impact relaxation performance of the support member 9 tends to be impaired, and steering stability is deteriorated. On the other hand, when it is more than 55 degrees, the bending of the annular portion 3 becomes too small and the riding comfort deteriorates.

The radial length L of the openings 6A and 6B
Since A and LB are smaller than the lengths LC and LD,
It is possible to prevent the support member 9 from falling off the openings 6A and 6B.

The tread rubber 5 adhered to the outer peripheral surface of the annular portion 3 can have improved wear resistance by having a JISA hardness of 50 degrees or more.
Even if it is formed directly on the outer peripheral surface of the tire base body 4 by injection molding, it may be originally formed into a band shape using a press and then attached by adhesion or the like.

[0030]

As described above, in the non-pneumatic tire of the present invention, the annular portion is provided with circumferential side grooves that are open at different positions in the tire axial direction and at different positions in the radial direction, and that extend in the circumferential direction. Since an annular support member made of an elastic material is arranged in the circumferential groove, the annular portion can be continuously flexed by the ground pressure by an appropriate amount over the entire length in the circumferential direction. It is possible to reduce the ruggedness of the vehicle, improve the riding comfort, and improve the steering stability.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view thereof.

FIG. 3 is a front view for explaining a conventional technique.

[Explanation of symbols]

 2 disk part 3 annular part 4 tire base 5 tread rubber 6A, 6B opening 7A, 7B circumferential groove 9 support material

Claims (2)

[Claims] 1. A non-pneumatic tire having a tire base body which is integrally formed by using a synthetic resin and which is provided with an annular portion on an outer peripheral edge of a disc portion attached to a tire shaft. A circumferential groove that is open on both sides in the axial direction and at different positions in the radial direction and that extends in the circumferential direction is provided, and in the circumferential groove of the tire base body, an inner circumference of the circumferential groove made of an elastic material is formed. The non-pneumatic tire is characterized in that an annular support material is provided in contact with both the outer surface and the outer surface, and a tread rubber is attached to the outer surface of the annular portion. 2. The non-pneumatic tire according to claim 1, wherein the opening of the circumferential groove has a radial length smaller than that of the central portion of the circumferential groove in the tire axial direction.