The present invention relates to a non-pneumatic tire and a method of manufacturing the same, and, more specifically, to a non-pneumatic tire excellent in the assemblability to a wheel and a method of manufacturing the same.
Although pneumatic tires are excellent in riding comfort, in order to maintain the performance, constant check of air pressure is necessary. Patent Document 1 proposes a product in which a non-pneumatic tire (non-air pressure tire) is constituted by joining a spoke structure including an annular outer peripheral member and an inner peripheral member connected to each other by a plurality of spokes to the inside of a tread ring and the non-pneumatic tire is integrally fixed to a wheel, as a tire that does not require the check of the air pressure and gives good riding comfort.
However, since the non-pneumatic tire is attached and fixed to a wheel as an assembly with the wheel, there was such a problem that, when the tire is worn or damaged, the operation of separating the tire from the wheel and assembling a new tire is very difficult.
Patent Document 1: Japanese patent application Tokuhyou No. 2005-500932
An object of the present invention is to provide a non-pneumatic tire easily assemblable to and dismountable from a wheel, and a method of manufacturing the same.
A non-pneumatic tire of the present invention that achieves above object is one in which a spoke structure including an annular outer peripheral member and an inner peripheral member connected to each other by a plurality of spokes is joined to the inner peripheral side of a tread ring, characterized in that the inner peripheral member is divided into independent members in the circumferential direction of the tire.
Further, a method of manufacturing a non-pneumatic tire of the present invention is characterized by comprising the steps of joining a spoke structure to one side of a belt-shaped unvulcanized rubber, the spoke structure including a belt-shaped outer peripheral member and an inner peripheral member connected to each other by a plurality of spokes wherein the inner peripheral member is divided into independent members in the longitudinal direction, and turning the belt-shaped unvulcanized rubber into a ring and connecting both end portions with each other to form a tread ring to be vulcanized and molded.
In the non-pneumatic tire of the present invention, the inner peripheral member constituting the spoke structure is divided into independent members in the circumferential direction of the tire, and, therefore, assembling to and dismounting from a wheel can easily be performed because, when it is assembled to a wheel and dismounted from the wheel, each of independent members constituting the inner peripheral member easily changes the position in the tire radial direction caused by the flexure of the spoke.
According to the method of manufacturing a non-pneumatic tire of the present invention, since it is sufficient to join the spoke structure to the belt-shaped unvulcanized rubber and then to turn the product into a ring shape to be vulcanized and molded, it is possible to manufacture the non-pneumatic tire easily at low cost without requiring particular facilities.
1 non-pneumatic tire
2 tread ring
3 outer peripheral member
4 spoke
5 inner peripheral member
51 independent member
6 fastening face
6′ through-hole (for fastening)
7 connecting means
8 reinforcing cord layer
9 rubber layer
10 spoke structure
As shown in
In the assembling of the non-pneumatic tire 1 of the present invention to a wheel, since the inner peripheral member 5 is divided into independent members 51 in the circumferential direction, when assembling it to the wheel 31, external force toward the outside in the radial direction is added to respective independent members 51 to bend and displace respective spokes 4 in the tire radial direction. Therefore, it is possible to allow the protrusion 51b to climb easily over a rim 32 and seat onto the rim seat. Further, the dismounting work can also be operated easily in the same way. Furthermore, preferably, after the rim assembling, by winding a connection means 7 around a fastening face 6 at the outer periphery of both end portions of the inner peripheral member 5 and performing the fastening, further strong mounting is possible.
As a wheel to which the non-pneumatic tire of the present invention is assembled, an exclusive wheel may newly be designed, or existing standard wheels for a pneumatic tire can directly be used.
In the present invention, in the inner peripheral member 5, a space is preferably provided between independent members 51 mutually adjacent to each other. This allows each of the independent members 51 to easily displace independently in the radial direction, and can increase the degree of freedom relative to the difference in diameters of wheels. Further, the length of the independent members 51 in the circumferential direction of the tire may be the same with each other, but, preferably, the lengths are made different periodically. By making the lengths in the circumferential direction of the tire different periodically, the vibration at driving due to the tire rotation can be dispersed to improve the ride comfort.
Although no particular limitation is imposed on the shape of the spoke 4, but it may be preferable to form the spoke in a blade shape as shown in
The spokes 4 formed in a blade shape is arranged so as to be elongated in the width direction of the tire as shown in
For the tread ring 2, rubber is used because it is excellent in frictional force and wear resistance in ground-contacting. Further, in order to reinforce the rubber layer, a reinforcing cord layer 8 is preferably buried. As the reinforcing cord layer 8, one made of a steel cord and one made of an organic fiber cord may be employed. In the case of the organic fiber cord, an aramid fiber, polyketone fiber and the like having a high strength and elastic modulus are preferably used.
In the spoke structure 10, the outer peripheral member and the inner peripheral member 5 are favorably constituted of rubber, resin and the like. Further, the spoke 4 can be constituted of at least one kind selected from resin, rubber and metal. For the purpose of enabling the spoke to perform action substitutable for the air pressure in pneumatic tires, the material selected from the resin, rubber, and metal favorably has an excellent toughness and a suitable degree of elasticity. The resin, rubber and metal may be used separately, and a complex material containing plural kinds of them may also be used. In particular, when it is constituted of resin and/or rubber, it is also possible to insert a reinforcing cord layer or to mix a short fiber for reinforcement. Furthermore, when inserting the reinforcing cord layer, a surface treatment is preferably applied in order to improve the adhesiveness with resin or rubber to be the matrix.
In the present invention, the connecting means 7 used as an auxiliary means for fixing the non-pneumatic tire 1 to the wheel 31 maybe a belt-shaped band, and a rope-shaped one. As the material, resin and metal are usable. As a means for connecting both end portions of the connecting means 7 with each other, publicly known metal parts are usable for any material.
The connecting means 7 is preferably hung over the inner peripheral member 5 of the spoke structure 10. The connecting face 6 to be hung over may be the outer circumferential face of the shoulder portion of the inner circumferential portion 5, as exemplified in
Although no particular limitation is imposed on the method of manufacturing the non-pneumatic tire of the present invention, the method exemplified in
As a material for the tread ring, an unvulcanized rubber 22 continuously molded in a belt shape is previously prepared. Further, as a material for the spoke structure, a structure is prepared, which is formed by connecting an independent member 251 to an outer peripheral member 23 continuously molded in a belt shape by a plurality of blade-shaped spoke members 24 and intermittently arranging a plurality of the structural portions of the independent member 251 in the longitudinal direction of the outer peripheral member 23. The material for the spoke structure may be a molded body of unvulcanized rubber, or a molded body of vulcanized rubber or resin. Further, as the spoke member 24, a metal material may be used.
Each of the material for the tread ring and the material for the spoke structure prepared as described above is cut in a length corresponding to one circuit of the tire, and then the outer peripheral member 23 of the material for spoke structure is stuck together to the unvulcanized rubber 22 of the material for tread ring, as shown in
Next, by winding a forming member of tread patterns (not shown) around the outer periphery of the unvulcanized rubber 22 wound in a cylindrical shape, and inserting the product in an oven and the like to vulcanize, it is possible to manufacture a non-pneumatic tire. As the forming member, one formed from a resin excellent in mold releasability in a belt shape as a flexible member, or one made of metal and constituted as an annular mold divided into a plurality of pieces can be used.
According to the method of manufacturing a non-pneumatic tire of the present invention, since it is sufficient to join the spoke structure to the belt-shaped unvulcanized rubber, and then to turn the product into a ring shape to be vulcanized and molded, the manufacturing can be carried out without particular facilities, simply at low cost.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2007/058884 | 4/24/2007 | WO | 00 | 10/19/2009 |