Assembly for airless tire and airless tire

Abstract

To realize an airless tire with excellent load-bearing performance, cushioning performance, vibration-damping performance and quietness. [Solution] The assembly for an airless tire disclosed herein includes a support part and a buffer part. The support part is formed in an annular shape, has a first edge part and a second edge part along the circumferential direction of the annular shape, is non-contractile and flexible, and is arranged so as to closely contact the inner surface of the tread part of the tire cover. The buffer part includes a first buffer part extending from the first edge part to a first end part and a second buffer part extending from the second edge part to a second end part over the entire circumference of the annular shape. The first buffer part has a third end part located radially outward of the wheel from the first end part and displaceable. The second buffer part has a fourth end part located radially outward of the wheel from the second end part and displaceable.

Description

[Technical field]

[0001] The present disclosure relates to an airless tire. [Background technology]

[0002] The airless tire described in Patent Document 1 has a wheel portion, an outer peripheral ring portion, and an elastic connecting body that connects the wheel portion and the outer peripheral ring portion. In order to simultaneously improve ride comfort and maintain vehicle posture, the airless tire adjusts the relationship of the amount of tire deflection relative to the load acting on the wheel portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-171113 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the airless tire, since the outer circumferential ring portion and the wheel portion are connected, when the vehicle runs on an uneven road surface, vibrations and noise are transmitted to the vehicle body via the tire, and therefore there is room for improvement in the quietness performance of the airless tire.

[0005] The present disclosure provides a technique that makes it possible to realize an airless tire that has load-bearing performance, cushioning performance, vibration-damping performance, and quietness. [Means for solving the problem]

[0006] One aspect of the present disclosure is an assembly for an airless tire configured to be disposed around the entire circumference of a tire cover inside the tire cover having a first end and a second end that are attached to a rim of a wheel of the tire and non-extensible. The assembly includes a support part and a buffer part. The support part is formed in an annular shape, has a first edge part and a second edge part along the circumferential direction of the annular shape, is non-contractible and flexible, and is disposed so as to closely contact the inner surface of the tread part of the tire cover. The buffer part is elastic and flexible, and is disposed so as to closely contact the inner surface of the side part of the tire cover. The support part and the buffer part are integral members or separate members. The buffer part includes a first buffer part and a second buffer part. The first buffer part extends from the first edge part to the first end part around the entire circumference of the annular shape. The second buffer part extends from the second edge part to the second end part. The first buffer portion has a third end portion located radially outward of the wheel and displaceable from the first end portion, and the second buffer portion has a fourth end portion located radially outward of the wheel and displaceable from the second end portion.

[0007] In the above assembly, the support part is disposed so as to be in close contact with the inner surface of the tread part of the tire cover, so that the arch structure of the tire is maintained. As a result, even if there is no support pillar connecting the support part to the wheel and the tire cover is not filled with compressed air, the support part can efficiently support the static and dynamic loads applied to the tire. Furthermore, since there is no support pillar, it is possible to reduce vibration and noise transmitted to the vehicle body via the tire.

[0008] In the above assembly, the first and second cushioning parts, which have elasticity and flexibility, push the side parts of the tire cover in the width direction of the tire, so that the first and second ends are pressed against the rim, preventing the tire cover from coming off the rim. Furthermore, when a load is applied to the tire and the support member is bent, the elastic force of the first and second cushioning parts helps the support part to return to its original shape, and the tire returns to its original shape.

[0009] Therefore, it is possible to realize an airless tire that has excellent load-bearing performance, cushioning performance, vibration-damping performance, and quietness.

[0010] Another aspect of the present disclosure is an airless tire comprising a tire cover having a first end and a second end attached to a wheel rim and being inextensible, and an assembly for an airless tire configured to be disposed around the entire circumference of the tire cover in the circumferential direction. The assembly comprises a support part and a buffer part. The support part is formed in an annular shape, has a first edge part and a second edge part along the circumferential direction of the annular shape, is non-contractible and flexible, and is disposed so as to closely contact the inner surface of the tread part of the tire cover. The buffer part is elastic and flexible, and is disposed so as to closely contact the inner surface of the side part of the tire cover. The support part and the buffer part are integral members or separate members. The buffer part includes a first buffer part and a second buffer part. The first buffer part extends from the first edge part to the first end part over the entire circumference of the annular shape. The second buffer part extends from the second edge part to the second end part. The first buffer portion has a third end portion located radially outward of the wheel and displaceable from the first end portion, and the second buffer portion has a fourth end portion located radially outward of the wheel and displaceable from the second end portion.

[0011] The airless tire described above has the same effects as an airless tire in which the assembly described above is attached to a tire cover. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram showing the outline of a first airless tire according to a first example of a first embodiment. FIG. [Diagram 2] Fig. 2A is a diagram showing an assembly before being attached to a tire cover according to a first example of the first embodiment. Fig. 2B is a diagram showing an assembly attached to a tire cover according to the first example of the first embodiment. Fig. 2C is a diagram showing a tire cover according to the first example of the first embodiment mounted on a wheel, and is a view taken along the line IIC-IIC in Fig. 1. [Figure 3A]FIG. 2 is a diagram illustrating a state in which a load is applied to a first airless tire according to a first example of the first embodiment. [Figure 3B] FIG. 3B is a view taken along the line IIIB-IIIB of FIG. 3A. [Figure 3C] FIG. 3C is a view taken along the line IIIC-IIIC in FIG. 3A. [Figure 3D] FIG. 3D is a view taken along the line IIID-IIID in FIG. 3A. [Figure 4] Fig. 4A is a diagram showing an assembly attached to a tire cover according to a second example of the first embodiment, and Fig. 4B is an enlarged view of a portion of Fig. 4A. [Diagram 5] 4A and 4B in the direction of arrows VV. [Figure 6] Fig. 6A is a plan view of an assembly according to a second example of the first embodiment, and Fig. 6B is a view taken along the line VIB-VIB of Fig. 6A. [Figure 7] FIG. 7 is a view taken along the line VII-VII of FIG. 6A. [Figure 8] FIG. 11 is a diagram showing an assembly attached to a tire cover according to a third example of the first embodiment. [Figure 9] Fig. 9A is an enlarged view of a part of Fig. 8. Fig. 9B is a view taken along the line IXB-IXB in Fig. 8 and Fig. 9A. Fig. 9C is a view showing a compression coil spring before and after being attached to a tire cover according to a third example of the first embodiment. [Figure 10] Fig. 10A is an enlarged view of another part of Fig. 8. Fig. 10B is a view taken along the line XB-XB in Fig. 8 and Fig. 10A. Fig. 10C is a view showing the continuous crank leaf spring before and after it is attached to a tire cover according to a third example of the first embodiment. [Figure 11] FIG. 11 is a diagram showing an assembly attached to a tire cover according to a fourth example of the first embodiment. [Figure 12] Fig. 12A is an enlarged view of a portion of Fig. 11. Fig. 12B is a view taken along the line XIIB-XIIB of Fig. 11 and Fig. 12A. Fig. 12C is a view showing a portion of a first compression coil spring according to a fourth example of the first embodiment in third angle projection. [Figure 13]Fig. 13A is an enlarged view of another part of Fig. 11. Fig. 13B is a view taken along the line XIIIB-XIIIB of Fig. 11 and Fig. 13A. Fig. 13C is a view showing a part of a second compression coil spring according to a fourth example of the first embodiment in third angle projection. [Figure 14] Fig. 14A is a diagram showing the appearance of a pneumatic tire according to a first reference example, Fig. 14B is a view taken along the line XIVB-XIVB in Fig. 14A, and Fig. 14C is an enlarged view of a portion surrounded by a dashed line in Fig. 14B. [Figure 15] FIG. 13 is a diagram showing an assembly attached to a tire cover of a second airless tire according to a first example of the second embodiment. [Figure 16] 13A is a diagram showing a state in which an assembly is attached to a tire cover of a second airless tire according to a first example of the second embodiment, and the tire cover is attached to a wheel. FIG. [Figure 17A] FIG. 13 is a diagram illustrating a state in which a load is applied to a second airless tire according to a first example of the second embodiment. [Figure 17B] FIG. 17B is a view taken along the arrows XVIIB-XVIIB in FIG. 17A. [Figure 17C] 17B is a view taken along the line XVIIC-XVIIC of FIG. 17A. [Figure 17D] 17B is a view taken along the arrows XVIID-XVIID in FIG. 17A. [Figure 18] 13A is a diagram showing a state in which an assembly is attached to a tire cover of a second airless tire according to a second example of the second embodiment, and the tire cover is attached to a wheel. FIG. [Figure 19] 13A is a diagram showing a state in which an assembly is attached to a tire cover of a second airless tire according to a third example of the second embodiment, and the tire cover is attached to a wheel. FIG. [Figure 20] FIG. 4 is a diagram showing the appearance of a pneumatic tire according to a second reference example. [Figure 21] FIG. 21 is a view taken along the line XXI-XXI of FIG. 20. [Figure 22] FIG. 13 is a diagram showing an assembly attached to a tire cover of a third airless tire according to a first example of the third embodiment. [Diagram 23]Fig. 23A is a view taken along the line XXIIIA-XXIIIA in Fig. 22. Fig. 23B is a diagram showing a buffer portion and a connecting portion of a third airless tire according to a first example of the third embodiment. Fig. 23C is a diagram showing a spacer of the third airless tire according to the first example of the third embodiment. [Figure 24A] 13A to 13C are diagrams illustrating a buffer section and a connecting section attached to a tire cover of a third airless tire according to a first example of the third embodiment, and a spacer before being attached to the tire cover. [Figure 24B] FIG. 13 is a diagram showing an assembly attached to a tire cover of a third airless tire according to a first example of the third embodiment. [Figure 24C] FIG. 13 is a diagram showing a tire cover of a third airless tire according to a first example of the third embodiment attached to a wheel. [Figure 25A] FIG. 13 is a diagram illustrating a state in which a load is applied to a third airless tire according to a first example of the third embodiment. [Figure 25B] This is a view taken along the arrows XXVB-XXVB in Figure 25A. [Figure 25C] 25B is a view taken along the line XXVC-XXVC of FIG. 25A. [Figure 25D] This is a view taken along the arrows XXVD-XXVD in Figure 25A. [Figure 26] FIG. 26A is a cross-sectional view of a third airless tire according to a first example of the third embodiment, showing the third airless tire in a state where the vehicle body is tilted. FIG. 26B is a cross-sectional view of a third airless tire according to a first example of the third embodiment, showing the third airless tire passing over an inclined road surface. FIG. 26C is a cross-sectional view of a third airless tire according to a first example of the third embodiment, showing the third airless tire passing over a fallen object on the road surface. FIG. 26D is a cross-sectional view of a third airless tire according to a first example of the third embodiment, showing the third airless tire running over a curb. FIG. 26E is a cross-sectional view of a third airless tire according to a first example of the third embodiment, showing the third airless tire passing over a step. FIG. 26F is a view taken along the arrows XXVIF-XXVIF in FIG. 26E. [Figure 27]FIG. 13 is a diagram showing a casing, a compression coil spring, and a continuous crank leaf spring attached to a tire cover of a third airless tire according to a second example of the third embodiment. [Figure 28] FIG. 13 is a diagram showing a procedure for mounting a compression coil spring and a continuous crank leaf spring to a casing, mounting the casing to a connecting part, and mounting the connecting part and the buffer part to a tire cover in a third airless tire according to a second example of the third embodiment. [Figure 29A] FIG. 11 is a diagram showing the appearance of a pneumatic tire according to a third reference example. [Figure 29B] This is a view taken along the arrows XXIXB-XXIXB in Figure 29A. [Diagram 30] FIG. 13 is a diagram illustrating the direction of a force applied to a third airless tire according to a first example of the third embodiment. [Explanation of symbols]

[0013] 10,110,210...wheel, 12,112,212...rim, 20,70,120,220...tire cover, 25,125,225...carcass, 30,30A,130,130A,230...buffer part, 31,31A,131,131A,231...first buffer part, 32,32A,132,132A,232...second buffer part, 40,40A,140,140A,140B,240,240A...support part, 43,143,143C,243...spacer, 43A,243A...first spacer, 43B,243B...second spacer, 44,144,144A,244...connecting part, 1 00, 100A, 100B, 100C...first airless tire, 131c, 231c...first contact portion, 132b, 232b...second wing portion, 132c, 232c...second contact portion, 141, 141A, 141B...first straight portion, 142, 142A, 142B...second straight portion, 143A, 143B, 243a to 243g...split spacer, 145, 145A, 145B...center portion, 200, 200A, 200B...second airless tire, 300, 300A...third airless tire, 400, 400A, 400B, 400C, 410, 410A, 410B, 420, 420A...assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0015] (First embodiment) <1-1. First example of the first airless tire> A first airless tire 100 according to a first example of the first embodiment will be described with reference to Figures 1 to 3D. Hereinafter, the direction perpendicular to the ground is referred to as the up-down direction, the width direction of the first airless tire 100 is referred to as the left-right direction, and the direction perpendicular to the up-down direction and the left-right direction is referred to as the front-rear direction. The first airless tire 100 and first airless tires 100A, 100B, and 100C described below are relatively narrow tires and are applied to relatively lightweight moving bodies such as bicycles, assisted bicycles, and wheelchairs.

[0016] 1, the first airless tire 100 includes a tire cover 20 and an assembly 400, and can be attached to a wheel 10. The wheel 10 may be a wheel for a conventional pneumatic tire, for example, a wheel conforming to the ISO standard. Unlike conventional pneumatic tires, the first airless tires 100, 100A, 100B, and 100C do not have compressed air filled in the tire cover 20. The first airless tires 100, 100A, 100B, and 100C include the assembly 400 instead of compressed air.

[0017] In this embodiment, the wheel 10 is a conventional wheel for a pneumatic tire. For example, as shown in FIG. 1, the wheel 10 includes a rim 12, a hub 11, and a plurality of spokes 13. The rim 12 is configured in a circular ring shape and has a first rim 12a and a second rim 12b. The hub 11 is a disk-shaped member and is disposed at the center of the ring of the rim 12. Each of the plurality of spokes 13 is a rod-shaped member and connects the hub 11 and the rim 12. In another embodiment, the wheel 10 may be a wheel other than a wheel for a pneumatic tire as long as it has a function equivalent to that of the wheel 10 of this embodiment.

[0018] 2A to 2C, the assembly 400 is attached to the tire cover 20, and the tire cover 20 is assembled to the wheel 10. The tire cover 20 is a non-stretchable and flexible member, and includes an outer layer made of a thick rubber layer, resin, or the like, and an inner layer such as the carcass 25. The carcass 25 is a cord layer that forms the tire framework, and is made of fibers or metal fibers coated with rubber or the like.

[0019] The tire cover 20 also has a tread portion 21, two sidewall portions 22, two bead portions 23, a first end portion 23a, and a second end portion 23b.

[0020] The tread portion 21 is a portion that comes into direct contact with the road surface, and has a tread pattern engraved thereon. The two sidewall portions 22 are disposed on both sides of the tread portion 21 and form two side surfaces of the tire cover 20. The two sidewall portions 22 are deflected when a load is applied to the first airless tire 100.

[0021] The bead portion 23 is formed by bundling wires into a ring shape and covering them with rubber or the like. One of the two bead portions 23, a first end portion 23a, is fitted and fixed to the first rim 12a, and the other, a second end portion 23b, is fitted and fixed to the second rim 12b. The tire cover 20 can be used with a conventional pneumatic tire, and can also be filled with air.

[0022] The assembly 400 is disposed inside the tire cover 20, over the entire circumferential direction of the tire cover 20 so as to be in contact with the carcass 25. The assembly 400 is attached to the tire cover 20 in place of the filled air of a conventional pneumatic tire, and has a load supporting function and a cushioning function similar to the filled air.

[0023] As shown in Figures 2A to 2C, the assembly 400 includes a buffer section 30 and a support section 40. The buffer section 30 and the support section 40 may be an integral member or may be separate members. The buffer section 30 and the support section 40 shown in Figures 2A to 2C are an integral member.

[0024] The support portion 40 is a non-shrinkable and flexible member, and is made of, for example, hard rubber, thermoplastic resin (or special resin), carbon fiber, spring steel, steel, etc. The support portion 40 has an annular shape, and is disposed so as to be in close contact with the inner surface of the tread portion 21. Here, "in close contact" means that the surface of one member is in contact with the surface of another member without any gaps.

[0025] The support portion 40 is a band-shaped member rolled into a circular ring shape, having a width along the width direction of the tire cover 20, i.e., a width along the width direction of the tread portion 21, and a thickness along the radial direction of the tire cover 20. The support portion 40 has a first edge portion 41 and a second edge portion 42. The first edge portion 41 is one of two ends along the circumferential direction of the band-shaped member, and the second edge portion 42 is the other of the two ends.

[0026] Specifically, the support part 40 includes a belt-shaped spacer 43 rolled into a ring shape, and a belt-shaped connecting part 44 rolled into a ring shape. The connecting part 44 connects the first buffer part 31 and the second buffer part 32 described later. The connecting part 44, the first buffer part 31, and the second buffer part 32 may be composed of a single sheet-like member. The diameter of the spacer 43 and the diameter of the connecting part 44 are approximately the same. The spacer 43 is joined to the connecting part 44, and is integrated with the connecting part 44 to form a belt-shaped member rolled into a ring shape. The support part 40 is attached to the tire cover 20 so that the spacer 43 or the connecting part 44 is in close contact with the inner surface of the tread part 21.

[0027] The buffer section 30 is a member having elasticity and flexibility, and is made of, for example, hard rubber, thermoplastic resin (or special resin), carbon fiber, spring steel, steel material, etc. The buffer section 30 includes a first buffer section 31 and a second buffer section 32. The first buffer section 31 extends from a first edge section 41 of the support section 40 toward a first end section 23a of the tire cover 20 over the entire circumference of the support section 40. The second buffer section 32 extends from a second edge section 42 toward a second end section 23b of the tire cover 20 over the entire circumference of the support section 40. The first buffer section 31 has a third end section 31a, and the second buffer section 32 has a fourth end section 32a.

[0028] 2A , the assembly 400 is inserted into the inside of the tire cover 20 with the first buffer portion 31 and the second buffer portion 32 in a deflected state, and is attached to the tire cover 20. The first buffer portion 31 and the second buffer portion 32 are disposed so as to be in close contact with the inner surface of the sidewall portion 22. The support portion 40 is disposed so as to be in close contact with the inner surface of the tread portion 21.

[0029] Then, as shown in Fig. 2B, the first end 23a and the second end 23b are attached to the first rim 12a and the second rim 12b with the assembly 400 attached to the tire cover 20. As a result, the tire cover 20 and the assembly 400 are assembled to the wheel 10 as shown in Fig. 2C.

[0030] When the tire cover 20 and the assembly 400 are attached to the wheel 10, the third end 31a of the first buffer portion 31 is positioned radially outward of the wheel 10 relative to the first end 23a of the tire cover 20 and displaceably positioned. Also, the fourth end 32a of the second buffer portion 32 is positioned radially outward of the wheel 10 relative to the second end 23b of the tire cover 20 and displaceably positioned. In other words, the assembly 400 is not physically connected to the wheel 10.

[0031] In the first airless tire 100, the assembly 400 and the wheel 10 are not in contact with each other, are not provided with a connecting support, and are not physically connected (i.e., are not physically connected). This suppresses the transmission of vibrations and noises during traveling from the assembly 400 to the wheel 10. As a result, the vibrations and noises transmitted from the first airless tire 100 to the vehicle body are reduced.

[0032] Since the first and second buffer parts 31 and 32 have elasticity, they tend to expand outward in repulsion to the inward bending. As a result, the first and second buffer parts 31 and 32 apply an outward force to the tire cover 20. That is, the first and second buffer parts 31 and 32 push and expand the tire cover 20 in the width direction.

[0033] The first buffer portion 31 and the second buffer portion 32 push and spread the tire cover 20 in the width direction, so that the tire cover 20 is pressurized outward and pressed against the rim 12. This prevents the tire cover 20 from coming off the rim 12.

[0034] The support part 40 has a non-contractible annular shape, and the circumference does not change even when an external force is applied. The tire cover 20 has non-stretchability and flexibility. When the elasticity of the buffer part 30 pushes the sidewall part 22 in the width direction, the tread part 21 moves radially inward, and the circumference of the tire cover 20 becomes shorter. Therefore, the non-stretchable tire cover 20 presses the non-contractable assembly 400, and the two layers of the tire cover 20 and the assembly 400 are in close contact with each other. Then, the arch structure of the two layers is maintained by continuous pressure due to the elasticity of the buffer part 30. In addition, the bead part 23 of the tire cover 20 fits into the rim 12 of the wheel 10, which is in a perfect circular shape, so that the perfect circular shape of the tire cover 20 is maintained when no load is applied. In this embodiment, the annular shape of the tire cover 20 and the assembly 400 as viewed from the side of the first airless tire 100 is referred to as a vertical arch structure.

[0035] In addition, the first buffer portion 31 and the second buffer portion 32 push and spread the tire cover 20 outward, thereby maintaining the shape of the sidewall portion 22 that bulges outward (specifically, a convex shape that protrudes to the left and right). In this embodiment, the fan shape of the tire cover 20 and the assembly 400 in a cross section along the radial direction is referred to as a lateral arch structure.

[0036] In the first airless tire 100, even if compressed air is not filled inside the tire cover 20, the support portion 40 maintains the vertical arch structure to support a load applied to the first airless tire 100. Furthermore, the first buffer portion 31 and the second buffer portion 32 maintain the horizontal arch structure to absorb impacts applied to the first airless tire 100 and assist the deflected support portion 40 in restoring its shape.

[0037] The action of forces applied to the first airless tire 100 will be described with reference to Figs. 3A to 3D. An "external force" corresponds to a load applied to the first airless tire 100 at the ground contact point. The load applied to the first airless tire 100 includes a static load and a dynamic load. A static load is a continuous load such as the weight of the vehicle body. A dynamic load is a repeated load during driving, or a temporary load such as an impact. The static load is adjusted so that the strength of the assembly 400 in which stress is generated is balanced with the weight of the vehicle body, and the assembly 400 is maintained in a substantially perfect circular shape by supporting the load. Of the loads, the dynamic load is supported by the elastic reaction force (restoring force) after the assembly 400 is deformed.

[0038] "Stress" is an elastic force generated in the arch-structured assembly 400 when an external force, which is a load, is applied. The support part 40 of the assembly 400 deforms due to its non-contractibility and flexibility to support the dynamic load, and the buffer part 30 of the assembly 400 absorbs shock due to its elasticity and flexibility, and assists in the restoration of the support part 40 that has been deformed due to the application of the dynamic load.

[0039] The reaction force is a movable reaction force generated in the tire cover 20, which is a ring-shaped tire cover having inextensibility and flexibility and covers the assembly 400 in which stress is generated. The reaction force restricts the deformation of the assembly 400 due to the dynamic load load to within the movable range of the tire cover 20, and supports the restoring force due to the elasticity of the assembly 400 and converts it into a reaction force. In other words, the tire cover 20 has both a load supporting function and a shock-absorbing function, similar to conventional tire covers.

[0040] The first airless tire 100 efficiently functions by continuously and closely contacting two layers, the non-stretchable tire cover 20 and the non-contractable assembly 400. The close contact of the two layers, the tire cover 20 and the assembly 400, is realized by the elasticity of the buffer section 30 of the assembly 400. More specifically, in the first airless tire 100, the non-contractable support section 40 is disposed so as to be in close contact with the inner surface of the non-stretchable tread section 21, so that the load (i.e., external force) received on the ground contact surface is distributed to the entire circumference of the support section 40, reducing the surface pressure and increasing the efficiency of load support. This allows the assembly 400 to be made compact and lightweight. In addition, the elasticity of the buffer section 30 pushes the sidewall section 22 outward in the width direction to form a convex shape, creating a movable range for the support section 40 to bend, which is necessary for the buffer function. Furthermore, the elasticity of the cushioning portion 30 pressurizes the flexible sidewall portion 22, maintaining the two layers of the tire cover 20 and the assembly 400 in a tight contact state, making it possible to achieve both the load support function and the cushioning function, which are contradictory functions of rigidity and flexibility.

[0041] 3A and 3D, a load (i.e., an upward external force) is applied to the first airless tire 100 at the ground contact portion of the first airless tire 100. When a dynamic load is applied to the first airless tire 100, the flexible support portion 40 is bent so as to bend upward at the ground contact portion, and a gap is formed between the support portion 40 and the carcass 25. Furthermore, when a dynamic load is applied to the first airless tire 100, the elasticity of the first buffer portion 31 and the second buffer portion 32 pushes the inextensible carcass 25 apart in the left-right direction. Since the bead portion 23 is restrained by the rim 12, when the carcass 25 is pushed apart in the left-right direction, the two layers of the tire cover 20 and the assembly 400 are brought into close contact with each other due to the reaction force generated in the rim 12 and the movable reaction force generated in the carcass 25, and the horizontal arch and the vertical arch of the support portion 40 receive the dynamic load. At this time, the assembly 400 supports the load without coming into contact with the wheel 10, so that the transmission of vibrations and noise generated at the contact surface to the vehicle body is suppressed.

[0042] As shown in Figures 3A and 3B, the assembly 400 is tightly held inside the carcass 25 by the movable reaction force of the carcass 25, and when the load load at the ground contact point is only a static load, the tire cover 20 and the assembly 400 maintain a shape close to a perfect circle. When an upward dynamic load load is applied to the ground contact point, the flexible support part 40 bends so as to bulge forward, and the non-stretchable and flexible carcass 25 is pushed forward, narrowing the left and right directions inward. At the same time, the first buffer part 31 and the second buffer part 32, which are horizontal arches restrained by the reaction force of the carcass 25, are also squeezed like a bow and pushed inward, and the recoil force due to elasticity gradually increases. When the load load of the external force that is deflected forward and released through the support part 40, which is a vertical arch, and the recoil force due to the elasticity of the buffer part 30 are balanced, the dynamic load is supported. When the dynamic load at the contact point is removed, the forward pushing force of the support part 40, which is a vertical arch, decreases, and the recoil force due to the elasticity of the first buffer part 31 and the second buffer part 32, which are horizontal arches, becomes stronger, the carcass 25 is pushed open in the left and right directions, and the support part 40, which has been bent into an oval shape, is pushed back and restored to a substantially perfect circular shape. As described above, in the first airless tire 100, the elasticity of the first buffer part 31 and the second buffer part 32 controls the amount of bending of the support part 40, thereby achieving both the conflicting functions of load support function and buffer function.

[0043] As shown in FIGS. 3A and 3C, the operations performed on the rear side of the first airless tire 100 are symmetrical to those performed on the front side of the first airless tire 100 shown in FIG. 3B.

[0044] Furthermore, as shown in Fig. 3D, when the dynamic load applied to the first airless tire 100 is removed at the ground contact point of the first airless tire 100, the elastic forces of the first buffer section 31 and the second buffer section 32 restore the shape of the support section 40 via the carcass 25. As shown in Fig. 3B and Fig. 3C, the elliptically bulging deflection of the support section 40 is pushed back toward the wheel 10, so that the upward deflection of the support section 40 due to buffering at the ground contact point is pushed back downward, and the shape of the support section 40 is restored to a substantially perfect circular shape, thereby supporting the static load.

[0045] As the assembly 400 is displaced, the annular shape of the tire cover 20 is deformed so as to shrink in the up-down direction and swell in the front-rear direction. That is, the shape of the tire cover 20 is deformed from a perfect circle to an ellipse. Furthermore, the tire cover 20 is deformed so as to widen in the left-right direction at the ground contact portion and to narrow in the left-right direction at the front and rear sides. Then, the assembly 400 returns to its original position (i.e., the position when no dynamic load is applied to the first airless tire 100) due to the elastic force of the first buffer section 31 and the second buffer section 32 and the reaction force of the carcass 25. That is, the tire cover 20 is deformed by the application of a dynamic load, and is restored to a substantially perfect circle shape when the dynamic load is removed.

[0046] That is, the support portion 40 receives the reaction force of the carcass 25, maintains the vertical arch structure, and supports the load applied to the first airless tire 100. The first buffer portion 31 and the second buffer portion 32 maintain the two-layer close contact structure between the assembly 400 and the tire cover 20, and further maintain the lateral arch structure, and absorb the impact applied to the first airless tire 100 while assisting the support portion 40 in restoring its shape when bent.

[0047] 14A to 14C show a bicycle pneumatic tire 150 according to a reference example. The pneumatic tire 150 includes an annular rubber tube 28 instead of the assembly 400. The tube 28 is disposed around the entire circumference of the tire cover 20 in the circumferential direction so as to be in contact with the carcass 25 inside the tire cover 20. The tube 28 is filled with compressed air. When a temporary dynamic load is applied to the pneumatic tire 150 at the contact point of the pneumatic tire 150, the surface pressure of the contact surface increases, and the air at the filling pressure is pushed (flows) to other parts. As a result, the contact area becomes wider and the surface pressure decreases, so that the filling pressure and the surface pressure of the contact surface (ground pressure) are balanced, and the cushioning action of the pneumatic tire 150 ends. When the temporary dynamic load is eliminated and the load applied to the pneumatic tire 150 is only the static load, the surface pressure of the contact surface further decreases, and the air at the filling pressure is pushed back (flows) to the position recessed by the cushioning, thereby supporting the static load. Then, as the contact area narrows back to its original state, the surface pressure under static load and the filling pressure are balanced, and the shape of the pneumatic tire 150 is restored. The carcass 25 of the tire cover 20 to be fitted to a vehicle has sufficient strength (i.e., reaction force) to prevent expansion or bursting even when filled with air at a load-bearing pressure equal to or greater than the maximum load (safety factor) that the vehicle can bear. Since the pneumatic tire 150 is filled with air adjusted to an appropriate pressure that provides a good balance between load support and cushioning, the pneumatic tire 150 maintains an approximately perfect circular shape and supports static load. That is, in the pneumatic tire 150, the filled air has a load support function and a cushioning function.

[0048] <1-2. Second example of the first airless tire> A first airless tire 100A according to a second example of the first embodiment will be described with reference to Figures 4A to 7. Since the basic configuration is similar to the first example of the first embodiment, differences will be described below. Note that the same reference numerals as those in the first example of the first embodiment indicate the same configuration, and the preceding description will be referred to.

[0049] The first airless tire 100A according to the second example of the first embodiment includes an assembly 400A instead of the assembly 400. The assembly 400A includes a support portion 40 and a buffer portion 30A. That is, the assembly 400A is different from the assembly 400 in that the buffer portion 30A is included instead of the buffer portion 30. The buffer portion 30A includes a first buffer portion 31A and a second buffer portion 32A. As shown in FIG. 6, the first buffer portion 31A and the second buffer portion 32A have cutout portions 33 formed at regular intervals in the circumferential direction. By forming the cutout portions 33, the first buffer portion 31A and the second buffer portion 32A are easily adapted to the convex shape of the sidewall portion 22. As a result, the elastic force of the first buffer portion 31A and the second buffer portion 32A is easily applied to the inner surface of the sidewall portion 22. This makes it easier for the shape of the tire cover 20 to be restored to a perfect circle when an external force is applied to the first airless tire 100A and the tire cover 20 is bent.

[0050] Also, the first buffer section 31A and the second buffer section 32A may each include a plurality of stacked sheet members. In this case, each of the plurality of sheet members included in the first buffer section 31A has a third end 31a, and the plurality of sheet members included in the first buffer section 31A have different lengths from the first edge section 41 to the third end 31a. Also, each of the plurality of sheet members included in the second buffer section 32A has a fourth end 32a, and the plurality of sheet members included in the second buffer section 32A have different lengths from the second edge section 42 to the fourth end 32a.

[0051] In this way, since the first buffer portion 31A and the second buffer portion 32A are composed of multiple sheet members, the first buffer portion 31A and the second buffer portion 32A are more likely to conform to the convex shape of the sidewall portion 22 than if they were composed of a single sheet member.

[0052] <1-3. Third Example of the First Airless Tire> A first airless tire 100B according to a third example of the first embodiment will be described with reference to Figures 8 to 10C. Since the basic configuration is similar to the first example of the first embodiment, differences will be described below. Note that the same reference numerals as those in the first example of the first embodiment indicate the same configuration, and the preceding description will be referred to.

[0053] A first airless tire 100B according to a third example of the first embodiment includes an assembly 400B instead of the assembly 400. The assembly 400B includes a support portion 40A and a buffer portion 30. That is, the assembly 400B differs from the assembly 400 in that the assembly 400B includes a support portion 40A instead of the support portion 40.

[0054] The support part 40A includes a first spacer 43A or a second spacer 43B and a connecting part 44. The support part 40A is different from the support part 40 in that the support part 40A includes a first spacer 43A or a second spacer 43B instead of the spacer 43. As shown in FIG. 8, the first spacer 43A is a compression coil spring member and has a (connected) annular shape without ends. The second spacer 43B is a continuous crank leaf spring and has a (connected) annular shape without ends. In an unloaded state before being attached to the tire cover 20, the circumferential lengths of the first spacer 43A and the second spacer 43B are both longer than the circumferential length of the tire cover 20. Each of the first spacer 43A and the second spacer 43B is compressed and attached to the tire cover 20.

[0055] The first spacer 43A is formed by spirally winding a rod-shaped metal member, and the second spacer 43B is formed by repeatedly crank-bending (or Z-bending) a plate-shaped metal member, etc. As shown in Figures 9B and 10B, the first spacer 43A has a circular cross section, and the second spacer 43B has a square cross section.

[0056] 9A and 9C, the first spacer 43A is attached in a compressed state to the tire cover 20. Similarly, as shown in Fig. 10A and 10C, the second spacer 43B is attached in a compressed state to the tire cover 20 such that the width direction of the plate is the left-right direction.

[0057] The first spacer 43A and the second spacer 43B apply pressure to the tire cover 20 by their stretching force. The load applied to the first airless tire 100B is supported by the stretching force of the first spacer 43A and the second spacer 43B and the reaction force of the carcass 25. Furthermore, the first spacer 43A and the second spacer 43B absorb impacts applied to the first airless tire 100B by deforming. That is, the first spacer 43A and the second spacer 43B have a cushioning function that absorbs impacts applied to the first airless tire 100B according to the degree of freedom of the shape (i.e., the degree of deformability).

[0058] <1-4. Fourth Example of the First Airless Tire> A first airless tire 100C according to a fourth example of the first embodiment will be described with reference to Figures 11 to 13C. Since the basic configuration is similar to the first example of the first embodiment, differences will be described below. Note that the same reference numerals as those in the first example of the first embodiment indicate the same configuration, and the preceding description will be referred to.

[0059] The first airless tire 100C according to the fourth example of the first embodiment includes an assembly 400C instead of the assembly 400. The assembly 400C includes a first compression coil spring 43C or a second compression coil spring 43D. The assembly 400C is different from the assembly 400 in that the buffer section 30 and the support section 40 are integrated, and both the first compression coil spring 43C and the second compression coil spring 43D serve as both the buffer section 30 and the support section 40. The first compression coil spring 43C has a (connected) annular shape without ends. The second compression coil spring 43D has a (connected) annular shape without ends. Both circumferential lengths are longer than the circumferential length of the tire cover 20. Each of the first compression coil spring 43C and the second compression coil spring 43D is compressed and attached to the tire cover 20.

[0060] As shown in Fig. 12B, the first compression coil spring 43C is formed by bending a plate-shaped member such as resin so as to have a semicircular cross section, while as shown in Fig. 13B, the second compression coil spring 43D is formed by bending a plate-shaped member such as resin so as to have an elliptical cross section.

[0061] 12A and 12B, the first compression coil spring 43C is mounted on the tire cover 20 in a compressed state so that the diameter of its semicircular cross section is in the left-right direction (i.e., the width direction of the tire cover 20). Also, as shown in Figs. 13A and 13B, the second compression coil spring 43D is mounted on the tire cover 20 in a compressed state so that the major axis of its elliptical cross section is in the left-right direction.

[0062] The first compression coil spring 43C and the second compression coil spring 43D apply pressure to the tire cover 20 by their extension forces. The load applied to the first airless tire 100C is supported by the extension forces of the first compression coil spring 43C and the second compression coil spring 43D and the reaction force of the carcass 25. In addition, the first compression coil spring 43C and the second compression coil spring 43D absorb impacts applied to the first airless tire 100C and restore deformation of the first airless tire 100C caused by the load.

[0063] <1-5.Effects> According to the first embodiment described above in detail, the following effects are achieved.

[0064] (1) In the assemblies 400, 400A, 400B, 400C, the support parts 40, 40A, 43C, 43D are disposed in close contact with the inner surface of the tread portion 21 of the tire cover 20, so that the longitudinal arch structure of the first airless tire 100, 100A, 100B, 100C is maintained. Furthermore, even if there is no support pillar connecting the support parts 40, 40A, 43C, 43D to the wheel 10 and compressed air is not filled in the tire cover 20, the support parts 40, 40A, 43C, 43D can efficiently support the static load and dynamic load applied to the first airless tire 100, 100A, 100B, 100C. Furthermore, since there is no support pillar, it is possible to reduce vibration and noise transmitted to the vehicle body via the first airless tire 100, 100A, 100B, 100C. Therefore, the first airless tires 100, 100A, 100B, 100C can have load-bearing performance, vibration-damping performance, and quietness performance.

[0065] (2) In assemblies 400, 400A, 400B, 400C, the first buffer portions 31, 31A, 43C, 43D and the second buffer portions 32, 32A, 43C, 43D, which have elasticity and flexibility, push the sidewall portion 22 of the tire cover 20 in the width direction of the tire cover 20, thereby pressing the first end portion 23a and the second end portion 23b against the rim 12, thereby preventing the tire cover 20 from coming off the rim 12. Furthermore, when a load is applied to the first airless tire 100, 100A, 100B, 100C and the support portions 40, 40A, 43C, 43D are deflected, the elastic forces of the first buffer portions 31, 31A, 43C, 43D and the second buffer portions 32, 32A, 43C, 43D assist the support portions 40, 40A, 43C, 43D in restoring to their original shape, and the first airless tire 100, 100A, 100B, 100C is thereby provided with buffer performance.

[0066] (3) In the first airless tire 100, 100A, 100B, the support portion 40, 40A includes the connecting portion 44 that connects the first buffer portion 31, 31A and the second buffer portion 32, 32A, and thus when the support portion 40, 40A is subjected to a load, the first buffer portion 31, 31A and the second buffer portion 32, 32A can be prevented from moving away from each other in the width direction. As a result, when the support portion 40, 40A is subjected to a load, the first buffer portion 31, 31A and the second buffer portion 32, 32A are pressurized, and the shape of the first airless tire 100, 100A, 100B is maintained by the elastic force of the first buffer portion 31, 31A and the second buffer portion 32, 32A.

[0067] (4) In the first airless tire 100, 100A, the support portion 40 and the buffer portion 30, 30A are integral members. Therefore, the first buffer portion 31, 31A and the second buffer portion 32, 32A can be displaced in response to bending of the support portion 40, and the elastic force of the first buffer portion 31, 31A and the second buffer portion 32, 32A can easily assist in the restoration of the support portion 40.

[0068] (5) In the first airless tire 100A, the first buffer portion 31A and the second buffer portion 32A have the cutout portions 33 formed at regular intervals, which makes it easy for the first buffer portion 31A and the second buffer portion 32A to conform to the convex shape of the sidewall portion 22 of the tire cover 20. Furthermore, the elastic force of the first buffer portion 31A and the second buffer portion 32A easily applies pressure to the inner surface of the sidewall portion 22. As a result, when a load is applied to the first airless tire 100A and it bends, the shape of the first airless tire 100A can be restored and maintained to be substantially circular.

[0069] (6) In the first airless tire 100, 100A, when the first buffer portion 31, 31A and the second buffer portion 32, 32A include a plurality of sheet members having different lengths, the first buffer portion 31, 31A and the second buffer portion 32, 32A can suitably expand the tire cover 20 in the width direction. This allows the sidewall portion 22 of the tire cover 20 to be suitably maintained in a convex shape protruding in the width direction. As a result, the lateral arch structure of the first airless tire 100, 100A can be suitably maintained.

[0070] (7) In the first airless tires 100B, 100C, the inextensible tire cover 20 serves as a casing for the first and second spacers 43A, 43B and the first and second compression coil springs 43C, 43D. By mounting an annular compression spring member having a circumferential length longer than that of the tire cover 20 to the tire cover 20, the extension force of the compression spring member constantly pressurizes the tire cover 20. Therefore, the compression spring member can support the load applied to the first airless tires 100B, 100C. Furthermore, when the first airless tires 100B, 100C receive an impact, the compression spring member can freely deform to absorb the impact.

[0071] Second embodiment <2-1. First example of the second airless tire> 15 to 17D, a second airless tire 200 according to a first example of the second embodiment will be described. The same reference numerals as those in the first embodiment indicate the same configuration, and the preceding description will be referred to.

[0072] The second airless tire 200 and second airless tires 200A, 200B described below are tires of a medium width and are wider than the first airless tires 100, 100A, 100B, 100C. The second airless tires 200, 200A, 200B are applied to medium-weight mobile objects such as two-wheeled vehicles (i.e., motorcycles) and three-wheeled vehicles equipped with a power source such as an engine or a motor.

[0073] 15, the second airless tire 200 includes a tire cover 120 that can be attached to a wheel 110, and an assembly 410. The wheel 110 may be a conventional wheel for pneumatic tires, for example, a wheel conforming to the ISO standard. In this embodiment, a conventional wheel for pneumatic tires is used as the wheel 110. The second airless tires 200, 200A, 200B include the assembly 410 instead of the tire cover 120 being filled with compressed air.

[0074] The wheel 110 includes a rim 112, a hub 111, and a number of spokes 113. The wheel 110 has a similar configuration to the wheel 10, and details thereof will be omitted. The tire cover 120 is a non-stretchable member made of rubber, resin, or the like, and includes a tread portion 121, sidewall portions 122 extending to both sides, two bead portions 123, a carcass 125, a first end portion 123a, and a second end portion 123b. The tire cover 120 has a similar configuration to the tire cover 20, and details thereof will be omitted. The tire cover 120 can be a tire cover for a conventional pneumatic tire, and can also be filled with air.

[0075] 16, the assembly 410 includes the buffer section 130 and the support section 140. The support section 140 is a separate member from the buffer section 130. The support section 140 includes a ring-shaped spacer 143 and a band-shaped connecting section 144 that is rolled into a ring shape.

[0076] The connecting portion 144 is formed of a material having inextensibility and flexibility, and connects the first buffer portion 131 and the second buffer portion 132 described later. The connecting portion 144 is disposed so as to be in close contact with the inner surface of the tread portion 121.

[0077] The spacer 143 is a non-shrinkable, flexible, annular member, and is made of, for example, hard rubber, thermoplastic resin (or special resin), carbon fiber, spring steel, steel, or the like. The spacer 143 has a width in the left-right direction, and is disposed so as to closely contact the inner surface of the connecting portion 144. The spacer 143 is formed in an arch shape including a central portion 145 that closely contacts the connecting portion 144, and a first straight portion 141 and a second straight portion 142 that extend from each of both ends of the central portion 145 toward the wheel 110. That is, the spacer 143 has a U-shaped radial cross section.

[0078] The first buffer portion 131 includes a first blade portion 131b and a first contact portion 131c. The first blade portion 131b has a third end portion 131a, and is disposed so as to contact the inner surface of the sidewall portion 122. The first contact portion 131c is bent with respect to the first blade portion 131b, and is disposed so as to contact a first straight portion 141 of the spacer 143.

[0079] The second buffer portion 132 includes a second wing portion 132b and a second contact portion 132c. The second wing portion 132b has a fourth end portion 132a and is disposed so as to contact the inner surface of the sidewall portion 122. The second contact portion 132c is bent with respect to the second wing portion 132b and is disposed so as to contact the second straight portion 142 of the spacer 143.

[0080] As shown in FIG. 16, first, the first buffer portion 131, the second buffer portion 132, and the connecting portion 144 of the assembly 410 are inserted inside the tire cover 120 and attached to the tire cover 120.

[0081] Next, spacer 143 is inserted between first buffer portion 131 and second buffer portion 132. At this time, first buffer portion 131 and second buffer portion 132 do not move in the left-right direction away from each other because first buffer portion 131 and second buffer portion 132 are connected by connecting portion 144. As a result, first straight portion 141 and second straight portion 142 come into contact with first contact portion 131c and second contact portion 132c, and apply pressure to first blade portion 131b and second blade portion 132b via first contact portion 131c and second contact portion 132c.

[0082] Then, with the assembly 410 attached to the tire cover 120, the first end 123a and the second end 123b are attached to the first rim 112a and the second rim 112b. The tire cover 120 is pressurized outward and pressed against the rim 112. This prevents the tire cover 120 from coming off the rim 112.

[0083] The carcass 125 suppresses outward stress of the connecting portion 144, the central portion 145, the first wing portion 131b, and the second wing portion 132b. As a result, the connecting portion 144, the first wing portion 131b, and the second wing portion 132b are in direct contact with the inner surface of the tire cover 120 to form a two-layered intimate structure. The central portion 145 is in close contact with the inner surface of the connecting portion 144. As a result, the annular shape of the tire cover 120 is maintained. In addition, the first wing portion 131b and the second wing portion 132b push the tire cover 120 outward in the left-right direction, thereby maintaining the shape of the sidewall portion 122 that bulges in the left-right direction.

[0084] When the tire cover 120 and the assembly 410 are attached to the wheel 110, the third end 131a of the first wing portion 131b is located radially outward of the wheel 110 relative to the first end 123a of the tire cover 120 and is displaceable. Also, the fourth end 132a of the second wing portion 132b is located radially outward of the wheel 110 relative to the second end 123b of the tire cover 120 and is displaceable. In other words, the second airless tire 200 does not include a support that physically connects the assembly 410 and the wheel 110, and the assembly 410 is not physically connected to the wheel 110 in a non-contact manner. Therefore, vibrations and noise transmitted from the second airless tire 200 to the vehicle body are reduced.

[0085] In the second airless tire 200, the spacer 143 maintains the vertical arch structure, thereby supporting the load applied to the second airless tire 200. Furthermore, the first buffer portion 131 and the second buffer portion 132 maintain the horizontal arch structure, thereby absorbing the impact applied to the second airless tire 200 and assisting the deflected support portion 140 in restoring its shape.

[0086] 17A to 17D, the action of the force applied to the second airless tire 200 will be described. As shown in Fig. 17A and Fig. 17D, when an upward load (external force) is applied to the second airless tire 200 at the ground contact point during running, the annular spacer 143 bends upward (inward) to absorb the external force, and the load (external force) is released to the outside in the portion other than the ground contact point. At the same time, the elasticity of the buffer section 130 suppressed by the carcass 125 applies an inward stress to the spacer 143 in the portion other than the ground contact point, causing the shape of the assembly 410 to be restored. As a result, the load applied to the second airless tire 200 is supported.

[0087] As shown in Fig. 17A and Fig. 17B, when an upward external force is applied to the second airless tire 200 at the ground contact surface, the spacer 143 bends to bulge forward in order to release the load at the front side, and the first wing portion 131b and the second wing portion 132b, which are restrained by the reaction force of the carcass 125 pushed out at the same time, are brought closer to each other in the left-right direction. When the load (external force) is removed, the elastic reaction force of the buffer portion 130 causes the wing portions to move away from each other in the left-right direction and return to their original shapes, and at the same time, the bent spacer 143 is pushed back backward, and the shape of the second airless tire 200 is restored. Within the movable range permitted by the non-extensible carcass 125, the buffer portion 130 is restrained from moving in the left-right direction, and the spacer 143 is restrained from moving up-down and forward-backward. As a result, shock absorption and load support occur in conjunction with each other.

[0088] As shown in FIGS. 17A and 17C, the rear side of the second airless tire 200 undergoes operations symmetrical to those of the front side of the second airless tire 200 shown in FIG. 17B.

[0089] That is, the spacer 143 receives the reaction force of the carcass 125, maintains the vertical arch structure, and supports the load applied to the second airless tire 200. The first wing portion 131b and the second wing portion 132b maintain the two-layer close contact structure between the assembly 410 and the tire cover 120, and further maintain the lateral arch structure, and absorb impacts applied to the second airless tire 200 while assisting the shape of the bent support portion 140 to be restored.

[0090] 20 and 21 show a pneumatic tire 250 for a motorcycle according to a reference example. In the pneumatic tire 250, compressed air is filled in the tire cover 120 instead of the assembly 410. When a temporary dynamic load is applied to the pneumatic tire 250 at the ground contact point of the pneumatic tire 250, the surface pressure of the ground contact surface increases, and the air at the filling pressure is pushed out (flows) to other parts. Therefore, the ground contact area becomes wider and the surface pressure decreases, so that the filling pressure and the surface pressure (ground pressure) of the ground contact surface are balanced, and the cushioning action of the pneumatic tire 250 ends. When the temporary dynamic load is eliminated and the load applied to the pneumatic tire 250 is only the static load, the surface pressure of the ground contact surface becomes even lower, and the air at the filling pressure is pushed back (flows) to the position recessed by the cushioning, supporting the static load. Then, the ground contact area returns to its original state and narrows, so that the surface pressure under static load and the filling pressure are balanced, and the shape of the pneumatic tire 250 is restored. The carcass 125 of the tire cover 120 to be fitted to a vehicle has enough strength (i.e., reaction force) to withstand the load of the vehicle and not expand or burst even when filled with air at a load-bearing pressure (safety factor) equal to or greater than the maximum load the vehicle can bear. Since the tire is filled with air adjusted to an appropriate pressure that provides a good balance between load support and cushioning, the pneumatic tire 250 is maintained in a substantially perfect circular shape and supports static load. That is, in the pneumatic tire 250, the filled air has a load support function and a cushioning function.

[0091] <2-2. Second example of the second airless tire> A second airless tire 200A according to a second example of the second embodiment will be described with reference to Fig. 18. Since the basic configuration is similar to the first example of the second embodiment, differences will be described below. Note that the same reference numerals as those in the first example of the second embodiment indicate the same configuration, and the preceding description will be referred to.

[0092] A second airless tire 200A according to a second example of the second embodiment includes an assembly 410A instead of the assembly 410. The assembly 410A includes a support portion 140A and a buffer portion 130. The buffer portion 130 includes a first buffer portion 131 and a second buffer portion 132. The support portion 140A includes a split spacer 143A and a split spacer 143B, and a connecting portion 144. That is, the support portion 140A includes the split spacers 143A and 143B instead of the spacer 143.

[0093] The split spacer 143A is formed in an arch shape including a first straight portion 141A, a second straight portion 142A, and a central portion 145A. The central portion 145A has a width in the left-right direction and is in close contact with the connecting portion 144. The first straight portion 141A and the second straight portion 142A extend from both ends of the central portion 145A toward the wheel 110. Similarly, the split spacer 143B is formed in an arch shape including a first straight portion 141B, a second straight portion 142B, and a central portion 145B. The split spacers 143A and 143B are similar to the spacer 143 of the support portion 140 of the second airless tire 200.

[0094] The width in the left-right direction of each of the central portions 145A and 145B is half or approximately half the width in the left-right direction of the central portion 145 of the spacer 143. That is, the support portion 140A includes, instead of one spacer 143, split spacers 143A and 143B that are split into two.

[0095] 18, the split spacers 143A and 143B are attached to the inside of the tire cover 120 in place of the spacer 143. That is, the split spacers 143A and 143B are inserted between the first buffer portion 131 and the second buffer portion 132. The split spacers 143A and 143B are arranged such that the center portions 145A and 145B are in close contact with the connecting portion 144, the first straight portion 141A is in contact with the first contact portion 131c, the second straight portion 142A is in contact with the first straight portion 141B, and the second straight portion 142B is in contact with the second contact portion 132c.

[0096] Since the spacer is divided into multiple pieces, when a vehicle equipped with the second airless tire 200A runs on an uneven road surface, the divided spacer 143A and the divided spacer 143B are displaced individually, making it easier for the tread portion 121 to adapt to the road surface shape. As a result, the ground contact area of ​​the second airless tire 200A is increased, the second airless tire 200A stably supports the load, and the gripping force of the second airless tire 200A is improved. Note that the support portion 140A may be provided with a divided spacer divided into three or more pieces instead of one spacer 143.

[0097] In the second airless tire 200A, the divided spacers 143A, 143B have the same function as the spacer 143. That is, the divided spacers 143A, 143B support a load applied to the second airless tire 200A by maintaining a vertical arch structure. Furthermore, the first buffer portion 131 and the second buffer portion 132 maintain a horizontal arch structure, thereby absorbing impacts applied to the second airless tire 200A and assisting in the restoration of the shape of the bent support portion 140A.

[0098] <2-3. Third Example of the Second Airless Tire> A second airless tire 200B according to a third example of the second embodiment will be described with reference to Fig. 19. Since the basic configuration is similar to the first example of the second embodiment, differences will be described below. Note that the same reference numerals as those in the first example of the second embodiment indicate the same configuration, and the preceding description will be referred to.

[0099] A second airless tire 200B according to a third example of the second embodiment includes an assembly 410B instead of the assembly 410. The assembly 410B includes a support portion 140B and a buffer portion 130A. The buffer portion 130A includes a first buffer portion 131A and a second buffer portion 132A. The support portion 140B includes a spacer 143C and a connecting portion 144A. The configuration of the assembly 410B is similar to that of the assembly 400 of the first airless tire 100.

[0100] In the second airless tire 200B, the spacer 143C supports a load applied to the second airless tire 200B by maintaining the vertical arch structure. Furthermore, the first buffer portion 131A and the second buffer portion 132A maintain a horizontal arch structure, thereby absorbing an impact applied to the second airless tire 200B and assisting the deflected support portion 140B in restoring its shape.

[0101] <2-4.Effects> The second embodiment described above in detail provides the same advantages as the advantages (1) to (3) of the first embodiment described above. In addition, the second airless tire 200B further provides the same advantages as the advantages (4) to (7) of the first embodiment described above. Furthermore, the second embodiment provides the following advantages.

[0102] (8) In the second airless tire 200, since the support portion 140 is formed in an arch shape, when the central portion 145 is deflected by a load, the first straight portion 141 and the second straight portion 142 are restored by receiving the elastic force of the buffer portion 130. Therefore, by forming the support portion 140 in an arch shape, the load-bearing performance and buffer performance of the second airless tire 200 can be improved.

[0103] (9) In the second airless tire 200A, by configuring the support portion 140A with a plurality of divided spacers 143A, 143B, the load applied to the second airless tire 200A can be divided and supported. Furthermore, when the wide second airless tire 200A runs on an uneven road surface and an inclined road surface, the divided spacers 143A, 143B individually displace to accommodate the shape of the road surface. As a result, the ground contact area of ​​the second airless tire 200A is expanded, enabling the second airless tire 200A to stably support the load and increasing the grip of the second airless tire 200A.

[0104] (10) In the second airless tire 200A, each of the divided spacers 143A, 143B is formed in an arch shape, so that when one of the divided spacers is deflected under load, the straight portion of that divided member receives the elastic force of the straight portion of the other divided spacer and returns to its original shape. Therefore, by forming each divided spacer in an arch shape, the load-bearing performance and cushioning performance of the second airless tire 200A can be improved.

[0105] (11) In the second airless tire 200, 200A, the support portions 140, 140A and the buffer portion 130 are separate members, and the first contact portion 131c and the second contact portion 132c of the buffer portion 130 contact both sides of the support portions 140, 140A, thereby preventing the support portions 140, 140A from moving in the width direction. Furthermore, the elastic force of the first wing portion 131b and the second wing portion 132b of the buffer portion 130 allows the shape of the second airless tire 200, 200A to be restored.

[0106] Third embodiment <3-1. First example of the third airless tire> A third airless tire 300 according to a first example of the third embodiment will be described with reference to Figures 22 to 26F. Since the basic configuration is similar to that of the second embodiment, differences will be described below. The third airless tire 300 and a third airless tire 300A described below are relatively wide tires, and are wider than the second airless tires 200, 200A, 200B. The third airless tires 300, 300A are applied to relatively heavy mobile objects such as four-wheeled vehicles (i.e., automobiles) equipped with a power source such as an engine or a motor.

[0107] 22, the third airless tire 300 includes a tire cover 220 that can be attached to a wheel 210, and an assembly 420. The wheel 210 may be a conventional wheel for a pneumatic tire, for example, a wheel conforming to the ISO standard. In this embodiment, a conventional wheel for a pneumatic tire is used as the wheel 210. The third airless tire 300, 300A includes an assembly 410 instead of the tire cover 220 being filled with compressed air.

[0108] The wheel 210 includes a rim 212, a hub 211, and a plurality of spokes 213. The wheel 210 has a similar configuration to the wheel 10, and details thereof will be omitted. As shown in FIGS. 23A to 23C, the tire cover 220 is an inextensible member, and includes a tread portion 221, sidewall portions 222 extending to both sides, two bead portions 223, a carcass 225, two bead fillers 224, a first end portion 223a, and a second end portion 223b. The bead filler 224 is a reinforcing material for the bead portion 223, and increases the rigidity of the bead portion 223. The tire cover 220 can be a conventional pneumatic tire cover, and can also be filled with air.

[0109] 23A to 23C, the assembly 420 includes a buffer section 230 and a support section 240. The support section 240 is a separate member from the buffer section 230. The support section 240 includes a circular ring-shaped spacer 243 and a band-shaped connecting section 244 that is rolled into a circular ring shape.

[0110] The connecting portion 244 is formed of a material having inextensibility and flexibility, and connects a first buffer portion 231 and a second buffer portion 232, which will be described later. The connecting portion 244 is similar to the connecting portion 144 of the support portion 140 of the second airless tire 200. The connecting portion 244 is disposed so as to be in close contact with the inner surface of the tread portion 221.

[0111] The spacer 243 includes seven divided spacers 243a to 243g. The spacer 243 does not have to be divided, that is, it may be a single spacer. The spacer 243 may include two to six divided spacers, or seven or more divided spacers.

[0112] Each of the divided spacers 243a-243g is formed in an arch shape including a central portion and a first straight portion and a second straight portion extending from each of both ends of the central portion toward the wheel 210. In other words, each of the divided spacers 243a-243g has a U-shaped radial cross section and is similar to the spacer 143 of the support portion 140 of the second airless tire 200.

[0113] The divided spacers 243a to 243g are arranged side by side in the left-right direction inside the tire cover 220. The divided spacers 243a to 243g are arranged such that the center portion of each of the divided spacers 243a to 243g is in close contact with the inner surface of the connecting portion 244 and the first straight portion of each of the divided spacers 243b to 243g is in contact with the second straight portion of the adjacent divided spacer on the front side. The first straight portion of the divided spacer 243a is in contact with the first buffer portion 231, and the second straight portion of the divided spacer 243g is in contact with the second buffer portion 232.

[0114] The first cushioning portion 231 includes a first blade portion 231b and a first contact portion 231c bent relative to the first blade portion 231b. The first blade portion 231b has a third end portion 231a. The first cushioning portion 231 is disposed such that the first blade portion 231b contacts the inner surface of the sidewall portion 222 and the first contact portion 231c contacts the first linear portion of the split spacer 243a.

[0115] The second cushioning portion 232 includes a second blade portion 232b and a second contact portion 232c bent relative to the second blade portion 232b. The second blade portion 232b has a fourth end portion 232a. The second cushioning portion 232 is disposed such that the second blade portion 232b contacts the inner surface of the sidewall portion 222 and the second contact portion 232c contacts the second linear portion of the split spacer 243g.

[0116] As shown in FIGS. 24A to 24C, first, the first buffer portion 231, the second buffer portion 232, and the connecting portion 244 of the assembly 420 are inserted inside the tire cover 220 and attached to the tire cover 220.

[0117] Next, the split spacers 243a to 243g are inserted between the first buffer section 231 and the second buffer section 232. At this time, since the first buffer section 231 and the second buffer section 232 are connected by the connecting section 244, the first buffer section 231 and the second buffer section 232 do not move in the left-right direction away from each other. As a result, the first straight section of the split spacer 243a contacts the first contact section 231c and presses the first wing section 231b. Also, the second straight section of the split spacer 243g contacts the second contact section 232c and presses the second wing section 232b.

[0118] Then, with the assembly 420 attached to the tire cover 220, the two bead portions 223 are attached to the two side surfaces of the rim 212. The tire cover 220 is pressurized outward and pressed against the rim 212. This prevents the tire cover 220 from coming off the rim 212.

[0119] The carcass 225 suppresses outward stress on the connecting portion 244, the central portion of the divided spacers 243a to 243g, the first wing portion 231b, and the second wing portion 232b. As a result, the connecting portion 244, the first wing portion 231b, and the second wing portion 232b are in direct contact with the inner surface of the tire cover 220 to form a two-layered intimate structure. The central portion of the divided spacers 243a to 243g is in close contact with the inner surface of the connecting portion 244. As a result, the annular shape of the tire cover 220 is maintained. In addition, the first wing portion 231b and the second wing portion 232b push the tire cover 220 in the left-right direction to expand the tire cover 220, thereby maintaining the shape of the sidewall portion 222 that bulges in the left-right direction.

[0120] When the tire cover 220 and the assembly 420 are attached to the wheel 210, the third end 231a of the first wing portion 231b is located radially outward of the wheel 210 relative to the first end 223a of the tire cover 220 and is displaceable. Also, the fourth end 232a of the second wing portion 232b is located radially outward of the wheel 210 relative to the second end 223b of the tire cover 220 and is displaceable. That is, the third airless tire 300 does not include a support that physically connects the assembly 420 and the wheel 210, and the assembly 420 is not physically connected to the wheel 210 in a non-contact manner. Therefore, vibration and noise transmitted from the third airless tire 300 to the vehicle body are reduced.

[0121] In the third airless tire 300, the spacer 243 maintains the vertical arch structure, thereby supporting a load applied to the third airless tire 300. Furthermore, the first buffer portion 231 and the second buffer portion 232 maintain a horizontal arch structure, thereby absorbing an impact applied to the third airless tire 300 and assisting the bending support portion 240 in restoring its shape.

[0122] 25A to 25D, the action of forces applied to the third airless tire 300 will be described. As shown in Fig. 25A and Fig. 25D, when an upward external force is applied to the third airless tire 300 at the ground contact portion while traveling, the divided spacer to which the external force is applied among the circular divided spacers 243a to 243g is displaced upward so as to absorb the external force. The other divided spacers continue to apply downward stress to the carcass 225 so as to maintain the shape of the tire cover 220. The load applied to the third airless tire 300 is distributed and supported by the divided spacers 243a to 243g.

[0123] In this embodiment, the spacer 243 is divided into a plurality of divided spacers 243a-243g, and the divided spacers 243a-243g are individually displaced to maintain the vehicle posture in accordance with the road surface shape and increase the ground contact area of ​​the third airless tire 300. As shown in Fig. 26A, when the vehicle body tilts to the right with respect to the road surface, the second blade portion 232b is displaced to the right and increases in size, and the divided spacers 243a-243g also tilt to the right. As a result, even when the vehicle body tilts, the ground contact area of ​​the tread portion 221 remains approximately the same as when the vehicle body is not tilted, and reduction in the ground contact area of ​​the tread portion 221 is suppressed.

[0124] 26B, when the road surface is inclined so that the right side is higher and the left side is lower, second blade portion 232b is displaced to the right and spreads out. Segment spacers 243a-243g are positioned successively higher from segment spacer 243a to segment spacer 243g according to the inclination of tread portion 221. This prevents a reduction in the contact area of ​​tread portion 221 even if the road surface is inclined.

[0125] 26C, when the center in the width direction of the third airless tire 300 runs over a fallen object on the road surface, the center of the tread portion 221 deforms and bulges upward. In response to the deformation of the tread portion 221, the central divided spacer 243d and the divided spacers 243c and 243e on either side of it are displaced upward. As a result, even when the third airless tire 300 runs over a fallen object, a reduction in the contact area of ​​the tread portion 221 is suppressed.

[0126] 26D, when the right side of the third airless tire 300 runs over a curb, the right side of the tread portion 221 deforms so as to bulge upward. In response to the deformation of the tread portion 221, the second blade portion 232b is displaced upward and spreads to the right, and the divided spacers 243f, g are displaced upward. As a result, even when the third airless tire 300 runs over a curb, a reduction in the contact area of ​​the tread portion 221 is suppressed.

[0127] As shown in Figures 26E and 26F, when the third airless tire 300 passes over a step, the tread portion 221 deforms so as to rise upward uniformly in the width direction. In response to the deformation of the tread portion 221, the first wing portion 231b is displaced upward and spreads to the left, and the second wing portion 232b is displaced upward and spreads to the right. In addition, the divided spacers 243a to 243g are displaced upward uniformly. As a result, even when the third airless tire 300 passes over a step, a reduction in the contact area of ​​the tread portion 221 is suppressed.

[0128] As shown in Fig. 25A and Fig. 25B, when an upward external force is applied to the third airless tire 300 at the ground contact surface, the divided spacers 243a to 243g are displaced forward at the front side to release the load, and the first wing portion 231b and the second wing portion 232b, which are restrained by the reaction force of the carcass 225 pushed out at the same time, are brought closer to each other in the left-right direction. When the dynamic load is removed, the wing portions are separated from each other in the left-right direction by the reaction force of the elasticity of the buffer portion 230 and return to their original shapes, and at the same time, the bent spacer 243 is pushed back backward, and the shape of the third airless tire 300 is restored. Within the movable range permitted by the non-extensible carcass 225, the buffer portion 230 is restrained from moving in the left-right direction, and the divided spacers 243a to 243g are restrained from moving in the up-down and front-rear directions. As a result, shock absorption and load support occur in conjunction with each other.

[0129] As shown in FIGS. 25A and 25C, the rear side of the third airless tire 300 undergoes operations symmetrical to those of the front side of the third airless tire 300 shown in FIG. 25B.

[0130] That is, the divided spacers 243a-243g maintain the vertical arch structure by receiving the reaction force of the carcass 225, and support the load applied to the third airless tire 300. The first wing portion 231b and the second wing portion 232b maintain the two-layer close contact structure between the assembly 420 and the tire cover 220, and further the horizontal arch structure, and absorb impacts applied to the third airless tire 300 and assist the shape of the bent support portion 240 to be restored.

[0131] 29A and 29B show a pneumatic tire 350 for an automobile according to a reference example. In the pneumatic tire 350, compressed air is filled in the tire cover 220 instead of the assembly 420. When a temporary dynamic load is applied to the pneumatic tire 350 at the ground contact point of the pneumatic tire 350, the surface pressure of the ground contact surface increases, and the air at the filling pressure is pushed out (flows) to other parts. Therefore, the ground contact area becomes wider and the surface pressure decreases, so that the filling pressure and the surface pressure (ground pressure) of the ground contact surface are balanced, and the cushioning action of the pneumatic tire 350 ends. When the temporary dynamic load is eliminated and the load applied to the pneumatic tire 350 is only the static load, the surface pressure of the ground contact surface becomes even lower, and the air at the filling pressure is pushed back (flows) to the position recessed by the cushioning, supporting the static load. Then, the ground contact area returns to its original state and narrows, so that the surface pressure under static load and the filling pressure are balanced, and the shape of the pneumatic tire 350 is restored. The carcass 225 of the tire cover 220 to be fitted to a vehicle has enough strength (i.e., reaction force) to not expand or burst even when filled with air at a load-bearing pressure equal to or greater than the maximum load (safety factor) that the vehicle can bear. Since the air is filled with an appropriate pressure that provides a good balance between load support and cushioning, the pneumatic tire 350 is maintained in a substantially perfect circular shape and supports the load. That is, in the pneumatic tire 350, the filled air has a load support function and a cushioning function.

[0132] <3-2. Second example of the third airless tire> A third airless tire 300A according to a second example of the third embodiment will be described with reference to Fig. 27 and Fig. 28. Since the basic configuration is similar to the first example of the third embodiment, differences will be described below. Note that the same reference numerals as those in the first example of the third embodiment indicate the same configuration, and the preceding description will be referred to.

[0133] A third airless tire 300A according to a second example of the third embodiment includes an assembly 420A instead of the assembly 420. The assembly 420A includes a support portion 240A and a buffer portion 230. The buffer portion 230 includes a first buffer portion 231 and a second buffer portion 232. The support portion 240A includes either one of a combination of five first spacers 243A and five first casings 245A and a combination of five second spacers 243B and five second casings 245B, and a connecting portion 244.

[0134] The first spacer 243A is a compression coil spring member and is a ring-shaped compression spring, similar to the first spacer 43A. The first spacer 243A has a circular radial cross section. The first spacer 243A has a circumferential length longer than the circumferential length of the first casing 245A in an unloaded state. The second spacer 243B is a continuous crank leaf spring and is a ring-shaped compression spring, similar to the second spacer 43B. The second spacer 243B has a rectangular radial cross section. The second spacer 243B has a circumferential length longer than the circumferential length of the second casing 245B in an unloaded state.

[0135] The first casings 245A are formed in an annular shape, are inextensible and flexible, and have an opening that opens toward the wheel 210. Each of the first casings 245A houses the first spacer 243A in a compressed state through the opening. The first casings 245A have an inner peripheral surface in an arc shape that corresponds to the outer peripheral surface of the first spacer 243A.

[0136] The second casings 245B are formed in an annular shape, are inextensible and flexible, and have an opening that opens toward the wheel 210. The second casings 245B each accommodate a second spacer 243B in a compressed state through the opening. The second casings 245B each have a planar inner peripheral surface that corresponds to the outer peripheral surface of the second spacer 243B.

[0137] 28, either a first set in which the first spacers 243A are housed in five first casings 245A, or a second set in which the second spacers 243B are housed in five second casings 245B, is selected and attached to the connecting portion 244. Then, the assembly 420A is attached to the tire cover 220.

[0138] Then, with the assembly 420A attached to the tire cover 220, the two bead portions 223 are attached to the rim 212. This prevents the tire cover 220 from coming off the rim 212.

[0139] The carcass 225 suppresses outward stress of the connecting portion 244, the support portion 240A (specifically, the five first casings 245A or the five second casings 245B), and the buffer portion 230 (specifically, the first wing portion 231b and the second wing portion 232b). As a result, the connecting portion 244, the first wing portion 231b, and the second wing portion 232b are in direct and intimate contact with the inner surface of the tire cover 220, forming a two-layer intimate structure.

[0140] In addition, either the first casing 245A pressed by the stretching force of the first spacer 243A or the second casing 245B pressed by the stretching force of the second spacer 243B is brought into close contact with the connecting portion 244, thereby maintaining the annular shape of the tire cover 220. Furthermore, the first wing portion 231b and the second wing portion 232b push the tire cover 220 open in the left-right direction, thereby maintaining the shape of the sidewall portion 222 bulging in the left-right direction.

[0141] Since the spacer of the support portion 240A is divided into five pieces, the load applied to the third airless tire 300A is divided and supported. Also, in response to deformation of the tread portion 221 accompanying a change in the road surface shape, the spacers at the corresponding positions among the five spacers are displaced and adapt to the change in the road surface shape, thereby suppressing a reduction in the contact area of ​​the tread portion 221.

[0142] The support portion 240A includes either a first set of a first spacer 243A and a first casing 245A, or a second set of a second spacer 243B and a second casing 245B, but the number of divisions of the spacer is not limited.

[0143] <3-3.Effects> The third embodiment described above in detail provides the same advantages as the advantages (1) to (3) of the first embodiment and the advantages (8) to (11) of the second embodiment. The third airless tire 300A further provides the same advantages as the advantages (4) to (7) of the first embodiment. Furthermore, the third airless tire 300A provides the following advantages.

[0144] (12) In the third airless tire 300A, the first spacer 243A or the second spacer 243B, which has a circumferential length longer than that of the casing, is compressed and stored in the casing, and the casing is attached to the inside of the tire cover 220, so that the casing, which is pressurized by the elongation force of the first spacer 243A or the second spacer 243B, comes into close contact with the tire cover 220 and maintains that state. Therefore, the first spacer 243A or the second spacer 243B can support the load applied to the third airless tire 300A. Furthermore, when the third airless tire 300A receives an impact, the first spacer 243A or the second spacer 243B deforms toward the opening of the casing, thereby absorbing the impact.

[0145] (Summary) Fig. 30 shows the configuration, force relationship, and force direction common to the first airless tire, the second airless tire, and the third airless tire. As shown in Fig. 30, the load of the vehicle body weight, impact load, etc., which is an external force, faces inward toward the wheel side at the contact surface, but faces outward in the opposite direction at the horizontal position (half the vertical height position) and at the upper part (symmetrical position of the contact surface) because the external force is released outward due to the stress of the assembly, which is a ring. Since the stress is a resistance force generated in the assembly that receives the external force, it faces in the opposite direction to the external force at all positions. Since the tire cover is attached and fixed to the wheel rim at the bead portion, the reaction force generated in the non-extensible tire cover faces inward toward the wheel side at all positions.

[0146] Generally, forces are transmitted in the order of pressure (external force) → resistance (stress) → support (reaction force), but the positional relationship is different only at the contact surface of this airless tire. That is, at the contact surface of this airless tire, the order is load (external force) → tire cover (reaction force) → assembly (stress), which is contradictory compared to general force transmission. This airless tire solves this contradiction by utilizing its annular shape. In detail, the external force received at the contact surface is transferred from the inside to the outside of this airless tire at a position other than the contact surface, via the assembly where stress is generated. And, at a position other than the contact surface, the reaction force generated on the tire cover supports the external force that has moved to the outside with the back support. Therefore, at a position other than the contact surface, forces are normally transmitted in the order of external force → stress generated on the assembly → reaction force generated on the tire cover, and a force relationship that supports the load is established.

[0147] Next, the hollow structure will be described. This airless tire has a two-layered annular structure in which a non-shrinkable assembly that generates stress is placed in close contact with the inside of a non-stretchable tire cover that generates a reaction force. When a load is applied to the ground contact surface, the non-shrinkable and flexible assembly is pushed upward by the external force and bends into an elliptical shape in the front-rear direction. The assembly is in close contact with the inside of the non-stretchable tire cover that generates a reaction force, and the upper part, which is the symmetrical position of the ground contact surface, functions as a vertical reaction force, and the horizontal position functions as a horizontal reaction force, forming an arched annular structure. Therefore, this two-layered annular structure enables the hollow structure to support a load.

[0148] Next, the pillar-less structure will be explained. At the contact surface, the external force is directed toward the inside, which is the wheel side, but at this position, the reaction force that supports the external force does not function. The reaction forces generated in the non-stretchable tire cover are all directed inward, just like in a pneumatic tire, by setting the bead on the wheel rim. Only at the contact surface where the direct load is applied, the external force and the reaction force are directed in the same inward direction, so there is no structural load support only around the contact surface. The non-contractible assembly where stress is generated is closely arranged inside the non-stretchable tire cover where the reaction force is generated, so the load is supported around the entire circumference of this airless tire. At the contact surface, the reaction force generated in the tire cover that is the only one in contact with the wheel and the external force of the load load are directed in the same inward direction, but the load is supported, proving the realization of the pillar-less structure of this airless tire. As an effect of this pillar-less structure, no resistance force that supports the load is generated in the tire cover that is in contact with the wheel, so vibrations and noise generated at the contact surface during driving are less likely to be transmitted to the vehicle body.

[0149] This airless tire has the same tensile structure as a pneumatic tire. The non-stretchable tire cover attached to the wheel rim envelops the assembly that mediates the load, confining and suppressing the stress inside the reaction force, thereby realizing the tensile structure. In this tensile structure, the reaction force due to the elasticity of the buffer part pushes the sidewall part apart, tightly bonding the two layers of the tire cover and the assembly, and centering the wheel to support the load. In addition, the load applied to the ground contact surface is mediated by the assembly, and the tire cover where the reaction force is generated is tightly bonded all around, reducing the surface pressure and making it possible to make the assembly compact (lightweight). Therefore, the double wheel structure and two-layer tightly bonded structure of the annular tire cover and assembly in this airless tire make it possible to achieve a pillar-less hollow structure.

Claims

1. An assembly for an airless tire configured to be disposed around a circumferential direction of a tire cover inside the tire cover, the tire cover having a first end and a second end attached to a rim of a wheel of the tire and being inextensible, the assembly comprising: A support part that is formed in an annular shape, has a first edge part and a second edge part along a circumferential direction of the annular shape, has non-shrinkage and flexibility, and is disposed so as to be in close contact with an inner surface of a tread part of the tire cover; A buffer portion having elasticity and flexibility and disposed so as to be in close contact with an inner surface of the side portion of the tire cover, The support portion and the buffer portion are an integral member or separate members, the buffer portion includes a first buffer portion extending from the first edge portion toward the first end portion around the entire circumference of the annular shape, and a second buffer portion extending from the second edge portion toward the second end portion, The first buffer portion has a third end portion that is positioned radially outward of the wheel and displaceable relative to the first end portion, The second buffer portion has a fourth end portion that is located radially outward from the second end portion and displaceable. Assembly for airless tires.

2. The support portion is a belt-shaped member having a width along a width direction of the tire cover and a thickness along a radial direction of the tire cover, and is rolled into a ring shape, The support portion and the buffer portion are an integral member, the first edge portion is one of two ends of the band-shaped member along a circumferential direction, The second edge portion is the other of the two ends. Assembly for an airless tire according to claim 1.

3. The first buffer portion and the second buffer portion have cutout portions formed at regular intervals. Assembly for an airless tire according to claim 1.

4. the first buffer section and the second buffer section each include a plurality of stacked sheet members, Each of the plurality of sheet members included in the first buffer section has the third end, Each of the plurality of sheet members included in the second buffer section has the fourth end, The plurality of sheet members included in the first buffer section have different lengths from the first edge portion to the third end portion, The plurality of sheet members included in the second buffer section have different lengths from the second edge portion to the fourth end portion. Assembly for an airless tire according to claim 1.

5. The support portion is a compression spring member having a circular ring shape, The circumferential length of the support portion in an unloaded state before being attached to the tire cover is longer than the circumferential length of the tire cover. Assembly for an airless tire according to claim 1.

6. The support portion and the buffer portion are separate members, The support portion includes a plurality of divided members arranged in a width direction of the tire. Assembly for an airless tire according to claim 1.

7. Each of the plurality of divided members is formed in an arch shape including a central portion in contact with an inner surface of the tire cover, and a first straight portion and a second straight portion extending from each of both ends of the central portion, a first linear portion of one of the plurality of divided members is disposed so as to be in contact with the first buffer portion; a second linear portion of another divided member among the plurality of divided members is disposed so as to be in contact with the second buffer portion, the first straight line portion of each remaining divided member among the plurality of divided members is disposed so as to be in contact with the second straight line portion of an adjacent divided member; 7. An assembly for an airless tire according to claim 6.

8. The support portion and the buffer portion are separate members, The support portion is formed in an arch shape including a central portion in contact with the inner surface of the tire cover and straight portions extending from both ends of the central portion, One of the straight portions is disposed so as to be in contact with the first buffer portion, The other straight portion is disposed so as to be in contact with the second buffer portion. Assembly for an airless tire according to claim 1.

9. The support portion and the buffer portion are separate members, the first buffer portion includes a first wing portion having the third end portion and disposed so as to be in close contact with an inner surface of the side portion, and a first contact portion bent with respect to the first wing portion and disposed so as to be in contact with the support portion, the second buffer portion includes a second wing portion having the fourth end portion and disposed so as to be in close contact with an inner surface of the side portion, and a second contact portion bent with respect to the second wing portion and disposed so as to be in contact with the support portion. Assembly for an airless tire according to claim 1.

10. The support portion further includes a connecting portion formed of a material having non-extensibility and flexibility, the connecting portion connecting the first buffer portion and the second buffer portion such that the first buffer portion and the second buffer portion are in close contact with an inner surface of the side portion. Assembly for an airless tire according to claim 1.

11. The support portion includes one or more casings arranged in a width direction of the tire cover and one or more compression spring members housed in each of the casings, Each of the casings is formed in a toroidal shape, is inextensible and flexible, and has an opening that opens toward the wheel; Each of the compression spring members is formed in a circular ring shape having a circumferential length longer than a circumferential length of the casing. Assembly for an airless tire according to claim 1.

12. a tire cover having a first end and a second end attached to a rim of the wheel and being inextensible; An assembly for an airless tire configured to be disposed around the entire circumference of the tire cover in the circumferential direction, The assembly comprises: A support part that is formed in a circular ring shape, has a first edge part and a second edge part along a circumferential direction of the circular ring shape, has non-shrinkage and flexibility, and is disposed so as to be in close contact with an inner surface of a tread part of the tire cover; A buffer portion having elasticity and flexibility and disposed so as to be in close contact with an inner surface of the side portion of the tire cover, The support portion and the buffer portion are an integral member or separate members, the buffer portion includes a first buffer portion extending from the first edge portion toward the first end portion around the entire circumference of the annular shape, and a second buffer portion extending from the second edge portion toward the second end portion, The first buffer portion has a third end portion that is positioned radially outward of the wheel and displaceable relative to the first end portion, The second buffer portion has a fourth end portion that is located radially outward from the second end portion and displaceable. Airless tires.

13. The support portion is a belt-shaped member having a width along a width direction of the tire cover and a thickness along a radial direction of the tire cover, and is rolled into a circular ring shape, The support portion and the buffer portion are an integral member, the first edge portion is one of two ends of the band-shaped member along a circumferential direction, The second edge portion is the other of the two ends.

13. An airless tire as claimed in claim 12.

14. The first buffer portion and the second buffer portion have cutout portions formed at regular intervals.

13. An airless tire as claimed in claim 12.

15. the first buffer section and the second buffer section each include a plurality of stacked sheet members, Each of the plurality of sheet members included in the first buffer section has the third end, Each of the plurality of sheet members included in the second buffer section has the fourth end, The plurality of sheet members included in the first buffer section have different lengths from the first edge portion to the third end portion, The plurality of sheet members included in the second buffer section have different lengths from the second edge portion to the fourth end portion.

13. An airless tire as claimed in claim 12.

16. The support portion is a compression spring member having a circular ring shape, The circumferential length of the support portion in an unloaded state before being attached to the tire cover is longer than the circumferential length of the tire cover.

13. An airless tire as claimed in claim 12.

17. The support portion and the buffer portion are separate members, The support portion includes a plurality of divided members arranged in a width direction of the tire.

13. An airless tire as claimed in claim 12.

18. Each of the plurality of divided members is formed in an arch shape including a central portion in contact with an inner surface of the tire cover, and a first straight portion and a second straight portion extending from each of both ends of the central portion, a first linear portion of one of the plurality of divided members is disposed so as to be in contact with the first buffer portion; a second linear portion of another divided member among the plurality of divided members is disposed so as to be in contact with a second buffer portion; the first straight line portion of each remaining divided member among the plurality of divided members is disposed so as to be in contact with the second straight line portion of an adjacent divided member; 18. An airless tire as claimed in claim 17.

19. The support portion and the buffer portion are separate members, The support portion is formed in an arch shape including a central portion in contact with the inner surface of the tire cover and straight portions extending from both ends of the central portion, One of the straight portions is disposed so as to be in contact with the first buffer portion, The other straight portion is disposed so as to be in contact with the second buffer portion.

13. An airless tire as claimed in claim 12.

20. The support portion and the buffer portion are separate members, the first buffer portion includes a first wing portion having the third end portion and disposed so as to be in close contact with the inner surface, and a first contact portion bent with respect to the first wing portion and disposed so as to be in contact with the support portion, the second buffer portion includes a second wing portion having the fourth end portion and disposed so as to be in close contact with the inner surface, and a second contact portion bent with respect to the second wing portion and disposed so as to be in contact with the support portion.

13. An airless tire as claimed in claim 12.

21. The support portion further includes a connecting portion formed of a material having non-extensibility and flexibility, and connecting the first buffer portion and the second buffer portion such that the first buffer portion and the second buffer portion are in close contact with the inner surface of the tire cover.

13. An airless tire as claimed in claim 12.

22. The support portion includes one or more casings arranged in a width direction of the tire cover and one or more compression spring members housed in each of the casings, Each of the casings is formed in a toroidal shape, is inextensible and flexible, and has an opening that opens toward the wheel; Each of the compression spring members is formed in a circular ring shape having a circumferential length longer than a circumferential length of the casing.

13. An airless tire as claimed in claim 12.