Tire rim assembly

Abstract

This tire-rim assembly is obtained by assembling a non-pneumatic tire, which is provided with an inner cylinder, an outer cylinder that surrounds the inner cylinder from the outside in the tire radial direction, and an elastically deformable connection member that connects the inner cylinder and the outer cylinder to each other, to a rim provided with a flange section, a convex portion is provided in at least a portion of the inner cylinder in the circumferential direction, the convex portion protrudes further outward in the tire width direction than one of the tire width direction ends of the connection member in the tire radial direction inner side ends, a concave portion recessed axially outward is provided in at least a portion of the flange portion in the circumferential direction, and the convex portion fits into the concave portion.

Description

Technical Field

[0001] The present invention relates to a tire-rim assembly, and more particularly to a tire-rim assembly formed by mounting a non-pneumatic tire on a rim. Background Art

[0002] Conventionally, in a non-pneumatic tire, a rim divided into two parts in the axial direction is inserted from both axial sides, the tire is assembled to the rim, and then the tire and the rim are fixed using an additional fastener (for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 5879089 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] However, in the above-mentioned method, there is a concern that there is a possibility that durability may be reduced due to the influence of the gap generated between the tire and the rim.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tire-rim assembly in which a decrease in durability is suppressed.

[0009] Solutions for solving problems

[0010] The gist of the present invention is as follows.

[0011] (1) A tire-rim assembly, wherein a non-pneumatic tire is assembled on a rim having a flange portion, the non-pneumatic tire comprising an inner cylinder, an outer cylinder surrounding the inner cylinder from the radially outer side of the tire, and an elastically deformable connecting member connecting the inner cylinder and the outer cylinder to each other, wherein the tire-rim assembly is characterized in that:

[0012] A convex portion is provided on at least a portion of the inner cylinder in the circumferential direction, the convex portion protruding to a position further outward in the tire width direction than an end in the tire width direction of an inner end in the tire radial direction of the connecting member,

[0013] A recessed portion recessed toward the axial outer side is provided in at least a portion of the circumference of the flange portion.

[0014] The convex part is fitted into the concave part.

[0015] Effects of the Invention

[0016] According to the present invention, it is possible to provide a tire-rim assembly in which a decrease in durability is suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a side view of the tire rim assembly according to one embodiment of the present invention.

[0018] Figure 2 is a side view of a non-pneumatic tire.

[0019] Figure 3 yes Figure 2 A-A section view.

[0020] Figure 4 yes Figure 3 Magnified view of part B.

[0021] Figure 5 It is a perspective cross-sectional view of the main part of a non-pneumatic tire.

[0022] Figure 6 It is a partial perspective view of a non-pneumatic tire.

[0023] Figure 7 It is a partial perspective view of a non-pneumatic tire according to a modified example.

[0024] Figure 8 It is a three-dimensional cross-sectional view of the main part of the rim.

[0025] Fig. 9 It is a perspective cross-sectional view of a main part of a tire-rim assembly according to one embodiment of the present invention.

[0026] Fig.10 It is an enlarged cross-sectional view of a main part of a tire-rim assembly according to one embodiment of the present invention. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0028] <Tire and rim assembly>

[0029] Figure 1 FIG. 1 is a side view of a tire rim assembly 1 according to an embodiment of the present invention. Figure 1 As shown, the tire-rim assembly 1 is formed by assembling a non-pneumatic tire 2 to a rim 3. The non-pneumatic tire 1 of the present embodiment is mounted on, for example, a bicycle, a two-wheeled vehicle, a car, a handlebar-type electric wheelchair, etc. for use.

[0030] Here, the non-pneumatic tire 2 is formed into a toroidal shape, and the rim 3 is formed into a disc shape, and the center axes are located on a common axis. The common axis is referred to as the center axis O, and the direction along the center axis O is referred to as the tire width direction. In addition, when viewed from the tire width direction, the direction around the center axis O is referred to as the tire circumferential direction, and the direction intersecting the center axis O is referred to as the tire radial direction. The centers of the non-pneumatic tire 2 and the rim 3 in the tire width direction coincide with each other.

[0031] In addition, the non-pneumatic tire 2 has a function of absorbing vibrations transmitted from the ground to the axle, and the rim 3 has a function of connecting the axle and the non-pneumatic tire 2. The non-pneumatic tire 2 and the rim 3 can be formed of different materials. For example, the non-pneumatic tire 2 can be formed of a material with a relatively small elastic modulus to ensure vibration absorption performance, and the rim 3 can be formed of a material with a larger elastic modulus than the non-pneumatic tire 2 to ensure firmness. In addition, for example, the rim 3 can also be formed of a material with a relatively small specific gravity to achieve overall lightweight tire rim assembly 1. The following describes the structures of the non-pneumatic tire 2 and the rim 3 in detail in this order.

[0032] <<Non-pneumatic tire>>

[0033] Figure 2 is a side view of a non-pneumatic tire. Figure 1 , Figure 2 As shown, the non-pneumatic tire 2 includes an inner cylinder 21, an outer cylinder 22 surrounding the inner cylinder 21 from the outer side of the tire radial direction, and a plurality of elastically deformable connecting members 23 connecting the inner cylinder 21 and the outer cylinder 22. In addition, the non-pneumatic tire 1 also includes a tread 24 embedded in the outer cylinder 22.

[0034] The elastic modulus of the material forming the inner cylinder 21 , the outer cylinder 22 , and the connecting member 23 can be set to, for example, 100 MPa or more and 1500 MPa or less.

[0035] The inner cylinder 21 is mounted on the axle by means of the rim 3. The central axis of the inner cylinder 21 and the central axis of the outer cylinder 22 are configured to be coaxial with the central axis O. The inner cylinder 21, the outer cylinder 22 and the connecting member 23 are configured in a state where the central parts of the tire width direction are consistent with each other. In the present embodiment, the inner cylinder 21, the outer cylinder 22 and the connecting member 23 are integrally formed of a thermoplastic resin. Thus, the non-pneumatic tire 2 can be formed by injection molding, which is suitable for mass production. As a thermoplastic resin, for example, it can be only one resin, or a mixture of two or more resins, or a mixture of one or more resins and one or more elastomers, and for example, it can also contain additives such as an anti-aging agent, a plasticizer, a filler or a pigment. In addition, the inner cylinder 21, the outer cylinder 22 and the connecting member 23 can also be formed separately. The inner cylinder 21, the outer cylinder 22 and the connecting member 23 can also be formed of materials other than thermoplastic resins.

[0036] A plurality of connecting members 23 are arranged between the inner cylinder 21 and the outer cylinder 22 in a point-symmetrical manner with respect to the central axis O. The connecting members 23 adjacent to each other in the tire circumferential direction are arranged separately without contacting each other. As shown in the figure, the connecting member 23 has a curved shape when viewed from the side, and is a structure in which two parts 23a and 23c with a smaller inclination angle relative to the tire radial direction are connected by a part 23b with a larger inclination angle relative to the tire radial direction. As a result, the inner end of the part 23a connected to the inner cylinder 21 in the tire radial direction is located at a position closer to the tire circumferential direction than the outer end of the part 23c connected to the outer cylinder 22 in the tire radial direction. By doing so, the connecting member 23 can be used as a leaf spring that is easily elastically deformed in the tire radial direction.

[0037] The tread 24 is formed into a cylindrical shape extending along the tire width direction with the central axis O as the center. The tread 24 covers not only the outer peripheral surface of the outer cylinder 22, but also the outer end of the outer cylinder 22 in the tire radial direction in the side surface facing the tire width direction. The elastic modulus of the material forming the tread 24 is smaller than the elastic modulus of the material forming the other parts of the non-pneumatic tire 2. The outer peripheral surface of the tread 24 is in a curved shape convex toward the outer side of the tire radial direction when viewed in longitudinal section along the tire width direction and the tire radial direction. The tread 24 is formed, for example, of vulcanized rubber or thermoplastic material formed by vulcanization of natural rubber and / or rubber composition. From the viewpoint of wear resistance, it is preferred to form the tread 24 from vulcanized rubber. As thermoplastic materials, for example, thermoplastic elastomers or thermoplastic resins can be listed. Examples of thermoplastic elastomers include amide thermoplastic elastomers (TPA), ester thermoplastic elastomers (TPC), olefin thermoplastic elastomers (TPO), styrene thermoplastic elastomers (TPS), polyurethane thermoplastic elastomers (TPU), thermoplastic rubber crosslinked bodies (TPV), or other thermoplastic elastomers (TPZ) specified in JIS K6418. Examples of thermoplastic resins include polyurethane resins, olefin resins, vinyl chloride resins, and polyamide resins.

[0038] Figure 3 yes Figure 2 A-A section view. Figure 4 yes Figure 3 Magnified view of part B. Figure 5 It is a perspective cross-sectional view of the main part of a non-pneumatic tire. Figure 6 is a partial perspective view of a non-pneumatic tire. Figure 3 In the following figures, the tread 24 is omitted for simplicity.

[0039] like Figures 4 to 6 As shown, at least a portion of the circumference of the inner cylinder 21 is provided with a convex portion 21a, and the convex portion 21a protrudes to a position closer to the outside in the tire width direction than the tire width direction end of the tire radial inner end of the connecting member 23 (part 23a). In this example, the convex portion 21a is continuously provided over the entire circumference of the inner cylinder 21. Therefore, in this example, the width of the inner cylinder 21 in the tire width direction is larger than the width of the tire radial inner end of the connecting member 23 (part 23a) in the tire width direction.

[0040] Figure 7It is a partial stereoscopic view of a non-pneumatic tire of a modified example. In this modified example, the protrusion 21a is only provided in a part of the circumference of the inner cylinder 21. More specifically, a plurality of protrusions 21a are arranged at equal intervals in the circumference of the inner cylinder 21. In this example, the protrusion 21a is provided at a position adjacent to a portion 23a of the connecting member 23 on the inner side of the tire radial direction. This is to enhance the fit between the portion of the connecting member 23, which is a portion with greater deformation, and the rim 3. On the other hand, in the case where the protrusion 21a is provided only in a part of the circumference of the inner cylinder 21, it is not limited to the above-mentioned configuration, and for example, it can also be provided at a position not adjacent to the portion 23a of the connecting member 23 on the inner side of the tire radial direction, and further, it can also be provided at unequal intervals in the circumferential direction.

[0041] A tire side protrusion 25 protruding radially inward is provided on at least a portion (the entire circumference in the example shown) of the inner cylinder 21 in the circumferential direction. In addition, the tire side protrusion 25 is provided with one or more (a plurality in the example shown) through holes 26 penetrating in the tire width direction.

[0042] <<Rims>>

[0043] like Figure 1 As shown, the rim 3 includes a rim portion 3a, a plurality of spokes 3b extending radially inward from the rim portion 3a, and a vehicle mounting portion 3c connected to the radial inner ends of the plurality of spokes 3b. The vehicle mounting portion 3c is provided with a plurality of bolt through holes 3d in the circumferential direction. The rim 3 can be made of metal, for example.

[0044] Figure 8 It is a three-dimensional cross-sectional view of the main part of the rim. Figure 8 As shown, in this example, the rim 3 includes a first rim portion 31 and a second rim portion 32 divided into two parts in the tire width direction. When the non-pneumatic tire 2 is mounted on the rim 3, the divided first rim portion 31 and the second rim portion 32 are inserted and combined in the tire width direction.

[0045] The outer cylindrical portion 3c of the rim 3 has a flange portion 33 (33a, 33b). The flange portion 33 includes a first horizontal portion 34 (34a, 34b) extending in the axial direction (tire width direction), a vertical portion 35 (35a, 35b) extending from the axial outer end of the first horizontal portion 34 to the radial outer side, and a second horizontal portion 36 (36a, 36b) extending from the radial outer end of the vertical portion 35 to the axial inner side (the extension length is shorter than that of the first horizontal portion). Thus, a recess 37 (37a, 37b) recessed toward the axial outer side is formed in at least a portion of the circumference of the flange portion 33. In the example shown in the figure, the recess 37 is continuously provided over the entire circumference of the flange portion 33. On the other hand, it may also be provided with a recess 37 (37a, 37b) extending from the radial outer end of the vertical portion 35 to the axial inner side. Figure 7 Corresponding to the modified example, the recessed portion 37 is provided only in a part of the flange portion 33 in the circumferential direction.

[0046] In addition, the rim 3 has rim-side protrusions 38 (first rim-side protrusions 38a, second rim-side protrusions 38b) extending radially outward from the axial inner end of the first horizontal portion 34, and fitting portions 39 (39a, 39b) extending axially inward from the second rim-side protrusions 38. The fitting portions 39a and 39b fit together. Although not shown in the figure, the first rim-side protrusions 38a and the second rim-side protrusions 38b are provided with holes located on the extension line of the through hole 26. The rim-side recessed portion 40 is defined by the first rim-side protrusions 38a, the second rim-side protrusions 38b, and the fitting portions 39 (39a, 39b).

[0047] Return to the description of the tire rim assembly. Fig. 9 It is a perspective cross-sectional view of a main part of a tire-rim assembly according to one embodiment of the present invention. Fig.10 FIG. 1 is an enlarged cross-sectional view of a main part of a tire rim assembly according to an embodiment of the present invention. Fig. 9 , Fig.10 As shown, when the first rim portion 31 and the second rim portion 32 are inserted into the non-pneumatic tire 2 from both sides in the tire width direction and the non-pneumatic tire 2 is assembled to the rim 3, the tire side convex portion 25 of the non-pneumatic tire 2 is fitted into the rim side concave portion 40 of the rim 3. In addition, the convex portion 21a of the non-pneumatic tire 2 is fitted into the concave portion 37 of the rim 3. In addition, a gap may be generated at the corner as shown in the figure.

[0048] In the present embodiment, the tire side protrusion 25 and the rim side protrusion 38 are fastened together and fixed by a fixing member (not shown) that is fitted into the through hole 26 of the non-pneumatic tire 2 and the hole portion of the rim 3 (provided at a position corresponding to the position of the through hole 26). Thus, the non-pneumatic tire 2, the first rim portion 31, and the second rim portion 32 are fixed by the fixing member. The fixing member can be a bolt.

[0049] Hereinafter, the effects of the tire rim assembly 1 according to the present embodiment will be described.

[0050] In the tire rim assembly 1 of the present embodiment, a convex portion 21a is provided in at least a portion of the circumference of the inner cylinder 21, which protrudes to a position closer to the tire width direction than the tire width direction end of the tire radial inner end of the connecting member 23, and a concave portion 37 is provided in at least a portion of the circumference of the flange portion 33, which is recessed toward the axial outer side, and the convex portion 21a is fitted into the concave portion 37. Therefore, the tire 2 and the rim 3 can be fitted with each other using complementary shapes, and the gap generated between the tire 2 and the rim 3 can be basically eliminated, so that the failure of the tire rim assembly 1 caused by a small gap can be suppressed. As described above, according to the tire rim assembly 1 of the present embodiment, durability can be improved. In addition, when additional fasteners are used, the fasteners are only partially fixed, but in the present embodiment, the inner cylinder 21 can be continuously and tightly fitted to the outer cylinder 22 throughout the entire circumference, thereby suppressing the peeling of the inner cylinder 21 caused by the generation of gaps linked to the rotation of the tire and the repeated tight fitting state, thereby further improving the durability of the tire rim assembly 1.

[0051] Here, it is preferable that the convex portion 21a is continuously provided over the entire circumference of the inner cylinder 21, and the concave portion 37 is continuously provided over the entire circumference of the flange portion 33. This is because the effect of fitting the non-pneumatic tire 2 and the rim 3 over the entire circumference can be obtained.

[0052] On the other hand, it is also preferable that the convex portion 21a is provided only in a part of the circumference of the inner cylinder 21, and the concave portion 37 is provided only in a part of the circumference of the flange portion 33. In this case, compared with the case where the convex portion 21a is provided over the entire circumference, the following effect can be obtained: the non-pneumatic tire 2 and the rim 3 are partially fitted in the circumferential direction while suppressing the increase in weight. As described above, in this case, the convex portion 21a is preferably provided at a position adjacent to the portion 23a of the connecting member 23 on the inner side of the tire radial direction. The reason for this is that since the connecting member 23 is a portion that deforms greatly, by strengthening the fitting of this portion with the rim 3, the durability can be effectively improved.

[0053] Preferably, if Fig.10As shown, the width of the convex portion 21a in the tire radial direction gradually decreases from the inner side to the outer side in the tire width direction, and the width of the concave portion 37 in the tire radial direction gradually decreases from the inner side to the outer side in the tire width direction. The reason for this is that, according to the wedge effect, the gap between the non-pneumatic tire 2 and the rim 3 can be further eliminated and the durability of the tire rim assembly 1 can be further improved. In addition, in this case, the upper surface and / or the lower surface of the convex portion 21a are inclined relative to the tire width direction as shown in the figure, and the inclination angle θ1 of the upper surface of the convex portion 21a relative to the tire width direction is not particularly limited, for example, it can be set to 1° to 15°, and the inclination angle θ2 of the lower surface of the convex portion 21a relative to the tire width direction is not particularly limited, for example, it can be set to 2° to 5°. On the other hand, the upper surface and / or the lower surface of the convex portion 21a can also be made parallel to the tire width direction.

[0054] In the above embodiment, the protruding width (maximum protruding width in the tire width direction) of the convex portion 21 a is not particularly limited, and can be set to 3% to 5% of the width of the tire radial inner end of the connecting member 23 in the tire width direction.

[0055] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. For example, the curved shape of the connecting member 23 can be appropriately changed within a range in which appropriate elastic deformation can be performed.

[0056] [Contribution to the Sustainable Development Goals (SDGs) led by the United Nations]

[0057] In order to realize a sustainable society, SDGs are advocated. One embodiment of the present invention is considered to be a technology that contributes to "No. 12_Responsible consumption and production" and "No. 13_Concrete measures for climate change".

[0058] Description of Reference Numerals

[0059] 1. Tire-rim assembly; 2. Non-pneumatic tire; 21. Inner cylinder; 22. Outer cylinder; 23. Connecting member; 24. Tread; 25. Tire side protrusion; 26. Through hole; 3. Rim; 31. First rim portion; 32. Second rim portion; 33. Flange portion; 34. First horizontal portion; 35. Vertical portion; 36. Second horizontal portion; 37. Concave portion; 38. Rim side protrusion; 39. Fitting portion; 40. Rim side concave portion.

Claims

1. A tire-rim assembly, which is formed by assembling a non-pneumatic tire on a rim having a flange portion, the non-pneumatic tire comprising an inner cylinder, an outer cylinder surrounding the inner cylinder from the radially outer side of the tire, and an elastically deformable connecting member connecting the inner cylinder and the outer cylinder to each other, wherein the tire-rim assembly is characterized in that: A convex portion is provided on at least a portion of the inner cylinder in the circumferential direction, the convex portion protruding to a position further outward in the tire width direction than an end in the tire width direction of an inner end in the tire radial direction of the connecting member, A recessed portion recessed toward the axial outer side is provided in at least a portion of the circumference of the flange portion. The convex part is fitted into the concave part.

2. The tire-rim assembly according to claim 1, wherein: The convex portion is continuously arranged over the entire circumference of the inner cylinder. The recessed portion is provided continuously over the entire circumference of the flange portion.

3. The tire-rim assembly according to claim 1, wherein: The convex portion is only provided on a part of the circumference of the inner cylinder. The recessed portion is provided only in a portion of the flange portion in the circumferential direction.

4. The tire-rim assembly according to claim 2 or 3, wherein: The width of the protrusion in the tire radial direction gradually decreases from the inner side to the outer side in the tire width direction. The width of the recessed portion in the tire radial direction gradually decreases from the inner side to the outer side in the tire width direction.

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