Tire and rim assembly

Abstract

To provide a tire-rim assembly which suppresses rim slip.SOLUTION: There is provided a tire-rim assembly in which a tire side projection projecting to a tire-radial-direction inside is provided in at least a part in a circumferential direction of an inner cylindrical body, a through hole penetrating in a tire width direction is provided in the tire side projection, a rim side projection projecting to a tire-radial-direction inside of a flange part is provided in at least a part in a circumferential direction of a rim, a hole part positioned on extension of the through hole is provided in the rim side projection, and the tire side projection and the rim side projection are fixed by a fastener fit into the through hole and the hole part.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present invention relates to a tire - rim assembly, particularly a tire - rim assembly in which a non - pneumatic tire is mounted on a rim.

Background Art

[0002] Conventionally, in non - pneumatic tires, as a mechanism for providing a rotation - stopping effect between the tire and the rim, a configuration has been proposed in which a key groove is provided on the outer peripheral surface of the rim and a protrusion is provided on the inner peripheral surface of the non - pneumatic tire (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above non - pneumatic tire, a key groove on the outer peripheral surface of the rim and a protrusion on the inner peripheral surface of the non - pneumatic tire are provided and fitted together, but rim slippage may occur.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a tire - rim assembly that suppresses rim slippage.

Means for Solving the Problems

[0006] The gist of the present invention is as follows. (1) A non - pneumatic tire including an inner cylinder, an outer cylinder surrounding the inner cylinder from the outside in the tire diameter direction, and an elastically deformable connecting member connecting the inner cylinder and the outer cylinder is assembled to a rim having a flange portion, and it is a tire - rim assembly, At least a portion of the inner cylinder body in the circumferential direction is provided with a tire-side projection that protrudes inward in the tire radial direction. The aforementioned tire-side protrusion is provided with a through hole that penetrates in the tire width direction. At least a portion of the rim in the circumferential direction is provided with a rim-side protrusion that projects inward in the tire radial direction of the flange portion. A hole is provided in the rim-side protrusion, located on the extension of the through hole. A tire-rim assembly characterized in that the tire-side protrusion and the rim-side protrusion are fixed by a fastener that fits into the through hole and the hole portion.

[0007] (2) The fastener is a bolt, The tire-rim assembly described in (1) above, wherein the tire-side protrusion and the rim-side protrusion are fixed together by fastening.

[0008] (3) The rim consists of a first rim portion and a second rim portion which are divided in the tire width direction, A first rim-side protrusion is provided on at least a portion of the circumferential direction of the first rim portion, projecting inward in the tire radial direction of the flange portion. A second rim-side protrusion is provided on at least a portion of the circumferential direction of the second rim portion, projecting inward in the tire radial direction of the flange portion. Each of the first rim-side protrusion and the second rim-side protrusion is provided with a hole located on the extension of the through hole. The tire-rim assembly according to (1) or (2) above, wherein the non-pneumatic tire, the first rim portion, and the second rim portion are fixed by the fastener. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a tire-rim assembly that suppresses rim slippage. [Brief explanation of the drawing]

[0010] [Figure 1] This is a side view of a tire-rim assembly according to one embodiment of the present invention. [Figure 2] It is a side view of a non-pneumatic tire. [Figure 3] It is a sectional view taken along line A-A of FIG. 2. [Figure 4] It is an enlarged view of part B of FIG. 3. [Figure 5] It is a perspective sectional view of a main part of a non-pneumatic tire. [Figure 6] It is a partial perspective view of a non-pneumatic tire. [Figure 7] It is a perspective sectional view of a main part of a rim. [Figure 8] It is a perspective sectional view of a main part of a tire-rim assembly according to an embodiment of the present invention. [Figure 9] It is a perspective sectional view of another main part of a tire-rim assembly according to an embodiment of the present invention. [[ID=***]] [[ID=***]] [Figure 10] It is a sectional view of another main part of a tire-rim assembly according to an embodiment of the present invention. [Figure 11] It is a side view of a non-pneumatic tire of a modified example.

Mode for Carrying Out the Invention

[0011] [[ID=...]]<0----0087> Hereinafter, embodiments of the present invention will be illustrated and described in detail with reference to the drawings.

[0012] <Tire-Rim Assembly> FIG. 1 is a side view of a tire-rim assembly 1 according to an embodiment of the present invention. As shown in FIG. 1, this tire-rim assembly 1 is formed by assembling a non-pneumatic tire 2 to a rim 3. Note that the non-pneumatic tire 1 of the present embodiment is used by being mounted on, for example, a bicycle, a motorcycle, an automobile, a handle-type electric wheelchair, or the like.

[0013] Here, the non-pneumatic tire 2 is formed in an annular shape, the rim 3 is formed in a disc shape, and each central axis is located on the common axis. This common axis is referred to as the central axis O, and the direction along the central axis O is referred to as the tire width direction. Also, when viewed from the tire width direction, the direction that circulates around the central axis O is referred to as the tire circumferential direction, and the direction that intersects this central 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.

[0014] 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 may be formed of different materials. For example, the non-pneumatic tire 2 may be formed of a material with a relatively small elastic modulus in order to ensure vibration absorption performance, and the rim 3 may be formed of a material with an elastic modulus larger than that of the non-pneumatic tire 2 in order to ensure robustness. Also, for example, the rim 3 may be formed of a material with a relatively small specific gravity to reduce the weight of the entire tire-rim assembly 1. Hereinafter, the configurations of the non-pneumatic tire 2 and the rim 3 will be described in detail in this order.

[0015] <<Non-pneumatic tire>> FIG. 2 is a side view of the non-pneumatic tire. As shown in FIGS. 1 and 2, the non-pneumatic tire 2 includes an inner cylindrical body 21, an outer cylindrical body 22 that surrounds the inner cylindrical body 21 from the outside in the tire radial direction, and a plurality of elastically deformable connecting members 23 that connect the inner cylindrical body 21 and the outer cylindrical body 22 to each other. Further, the non-pneumatic tire 1 further includes a tread 24 externally fitted to the outer cylindrical body 22.

[0016] The elastic modulus of the material forming the inner cylindrical body 21, the outer cylindrical body 22, and the connecting member 23 can be, for example, 100 MPa or more and 1500 MPa or less.

[0017] The inner cylinder 21 is attached to the axle via the rim 3. The central axes of the inner cylinder 21 and the outer cylinder 22 are arranged coaxially with the central axis O. The inner cylinder 21, the outer cylinder 22, and the connecting member 23 are arranged so that their respective center portions in the tire width direction coincide with each other. In this embodiment, the inner cylinder 21, the outer cylinder 22, and the connecting member 23 are integrally formed from a thermoplastic resin. This makes it possible to form the non-pneumatic tire 2 by injection molding, which is suitable for mass production. The thermoplastic resin may be, for example, a single resin, a mixture containing two or more resins, or a mixture containing one or more resins and one or more elastomers, and may also contain additives such as antioxidants, plasticizers, fillers, or pigments. The inner cylinder 21, the outer cylinder 22, and the connecting member 23 may each be formed as separate bodies. The inner cylinder 21, the outer cylinder 22, and the connecting member 23 may be formed from materials other than thermoplastic resin.

[0018] Multiple connecting members 23 are arranged between the inner cylinder 21 and the outer cylinder 22 so as to be point-symmetric with respect to the central axis O. Adjacent connecting members 23 in the tire circumferential direction are spaced apart and not in contact with each other. As shown in the figure, the connecting member 23 has a bent shape in side view, and is configured such that two parts 23a and 23c with a small angle of inclination with respect to the tire radial direction are connected by a part 23b with a large angle of inclination with respect 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 on one side in the tire circumferential direction than the outer end of the part 23c connected to the outer cylinder 22 in the tire radial direction. In this way, the connecting member 23 can be used as a leaf spring that is easily elastically deformed in the tire radial direction.

[0019] The tread 24 is formed in a cylindrical shape extending in the tire width direction with respect to the central axis O. The tread 24 covers not only the outer circumferential surface of the outer cylinder 22 but also the outer end in the tire radial direction of the side surface facing the tire width direction. The elastic modulus of the material forming the tread 24 is smaller than that of the material forming the other parts of the non-pneumatic tire 2. The outer circumferential surface of the tread 24 exhibits a curved shape that is convex outward in the tire radial direction when viewed in a longitudinal cross-section along both the tire width direction and the tire radial direction. The tread 24 is formed of, for example, vulcanized rubber obtained by vulcanizing natural rubber and / or a rubber composition, or a thermoplastic material. From the viewpoint of wear resistance, it is preferable to form the tread 24 with vulcanized rubber. Examples of thermoplastic materials include thermoplastic elastomers or thermoplastic resins. Examples of thermoplastic elastomers include amide-based thermoplastic elastomers (TPA), ester-based thermoplastic elastomers (TPC), olefin-based thermoplastic elastomers (TPO), styrene-based thermoplastic elastomers (TPS), urethane-based thermoplastic elastomers (TPU), thermoplastic rubber crosslinks (TPV), or other thermoplastic elastomers (TPZ) as specified in JIS K6418. Examples of thermoplastic resins include urethane resins, olefin resins, vinyl chloride resins, or polyamide resins.

[0020] Figure 3 is a cross-sectional view of section AA in Figure 2. Figure 4 is an enlarged view of section B in Figure 3. Figure 5 is a perspective cross-sectional view of the main part of the non-pneumatic tire. Figure 6 is a partial perspective view of the non-pneumatic tire. However, for simplification, the tread 24 is not shown in Figures 3 onward.

[0021] As shown in Figures 4 to 6, a protrusion 21a is provided on at least a portion of the inner cylinder 21 in the circumferential direction, projecting outward in the tire width direction from the inner end in the tire radial direction of the connecting member 23 (part 23a). In this example, the protrusion 21a is provided continuously around 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 greater than the width of the connecting member 23 (part 23a) in the tire width direction at the inner end in the tire radial direction.

[0022] A tire-side projection 25 is further provided on at least a portion of the inner cylinder 21 in the circumferential direction (the entire circumference in the illustrated example), projecting inward in the tire radial direction. One or more (multiple in the illustrated example) through holes 26 are provided in the tire-side projection 25, penetrating in the tire width direction. In the illustrated example, the multiple through holes 26 are not provided at equal intervals, but they can be provided at equal intervals. One or more through holes 26 are sufficient, but it is more preferable that one or more through holes 26 are provided within any 90° range centered on the central axis O in a side view.

[0023] <<Rim>> As shown in Figure 1, the rim 3 comprises 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 radially inward ends of the plurality of spokes 3b. The vehicle mounting portion 3c is provided with a plurality of bolt through holes 3d around its circumference. The rim 3 can be made of, for example, metal.

[0024] Figure 7 is a perspective cross-sectional view of the main part of the rim. As shown in Figure 7, in this example, the rim 3 consists of a first rim portion 31 and a second rim portion 32, which are divided in the tire width direction. When mounting the non-pneumatic tire 2 onto the rim 3, these divided first rim portion 31 and second rim portion 32 are inserted and combined in the tire width direction.

[0025] The outer cylindrical portion 3c of the rim 3 is provided with a flange portion 33 (33a, 33b). The flange portion 33 consists of a first horizontal portion 34 (34a, 34b) extending axially (in the tire width direction), a vertical portion 35 (35a, 35b) extending radially outward from the axial outer end of the first horizontal portion 34, and a second horizontal portion 36 (36a, 36b) extending axially inward from the radial outer end of the vertical portion 35 (its extended length is shorter than that of the first horizontal portion). As a result, recesses 37 (37a, 37b) that are recessed axially outward are formed on at least a portion of the circumferential direction of the flange portion 33. In the illustrated example, the recesses 37 are provided continuously around the entire circumference of the flange portion 33. On the other hand, the recesses 37 may be provided only on a portion of the circumferential direction of the flange portion 33.

[0026] Furthermore, the rim 3 has rim-side protrusions 38 (first rim-side protrusion 38a, second rim-side protrusion 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 protrusion 38. The fitting portions 39a and 39b are fitted together. Although not shown in the figure, each of the first rim-side protrusion 38a and the second rim-side protrusion 38b is provided with a hole located on the extension of the through hole 26. The rim-side recess 40 is defined by the first rim-side protrusion 38a, the second rim-side protrusion 38b, and the fitting portions 39 (39a, 39b).

[0027] Returning to the description of the tire-rim assembly, Figure 8 is a perspective cross-sectional view of a key part of a tire-rim assembly according to one embodiment of the present invention. Figure 9 is a perspective cross-sectional view of another key part of a tire-rim assembly according to one embodiment of the present invention. Figure 10 is a cross-sectional view of yet another key part of a tire-rim assembly according to one embodiment of the present invention. As shown in Figures 8 to 10, when the non-pneumatic tire 2 is assembled to the rim 3 by inserting the first rim portion 31 and the second rim portion 32 from both sides in the tire width direction, the tire-side protrusion 25 of the non-pneumatic tire 2 is fitted into the rim-side recess 40 of the rim 3. Also, the protrusion 21a of the non-pneumatic tire 2 is fitted into the recess 37 of the rim 3. Note that gaps may be present at the corners as shown in the figures.

[0028] In this embodiment, the tire-side protrusion 25 and the rim-side protrusion 38 are fixed together by fastening a fastener 41 that fits into the through-hole 26 of the non-pneumatic tire 2 and the hole in the rim 3 (located at a position corresponding to the through-hole 26). As a result, the non-pneumatic tire 2, the first rim portion 31, and the second rim portion 32 are fixed together by the fastener 41. The fastener can be a bolt.

[0029] More specifically, the rim 3 consists of a first rim portion 31 and a second rim portion 32, which are divided into two parts in the tire width direction. At least a portion of the circumferential direction of the first rim portion 31 is provided with a first rim-side projection 38a that protrudes inward in the tire diameter direction of the flange portion 33a, and at least a portion of the circumferential direction of the second rim portion 32 is provided with a second rim-side projection 38b that protrudes inward in the tire diameter direction of the flange portion 33b. Each of the first rim-side projection 38a and the second rim-side projection 38b is provided with a hole located on the extension of the through hole 26, and the non-pneumatic tire 2, the first rim portion 31, and the second rim portion 32 are fixed together by a fastener 41. As shown in Figure 10, etc., the size of the through hole 26, the hole in the first rim portion 31, and the hole in the second rim portion 32 can be designed to match the shape of the fastener 41. In the illustrated example, the through hole 26 and the hole in the second rim portion 32 have the same diameter, while the diameter of the hole in the first rim portion 31 is smaller. Also, in the illustrated example, the hole in the first rim portion 31 terminates without passing through the first rim-side projection 38a, while the hole in the second rim portion 32 passes through the second rim-side projection 38b. Therefore, in the illustrated example, the fastener 41 can be inserted from the second rim portion 32 side. Alternatively, the fastener 41 can be inserted from the first rim portion 31 side, by having the through hole in the first rim portion 31 pass through and the hole in the second rim portion 32 not pass through.

[0030] Figure 11 is a side view of a modified non-pneumatic tire. In this modified example, the tire-side protrusions 25 are provided only on a portion of the inner cylinder 21 in the circumferential direction. More specifically, multiple tire-side protrusions 25 are arranged at equal intervals in the circumferential direction of the inner cylinder 21. Each tire-side protrusion 25 has only one through-hole 26. In this example, the center of the tire-side protrusions 25 is located adjacent to the inner portion 23a of the connecting member 23 in the tire radial direction. This is because the connecting member 23 is a part that deforms significantly, and this arrangement strengthens the fit between this portion and the rim 3. On the other hand, when the tire-side protrusions 25 are provided only on a portion of the inner cylinder 21 in the circumferential direction, the arrangement is not limited to the above. For example, they can be provided at a position not adjacent to the inner portion 23a of the connecting member 23 in the tire radial direction, or they can be provided at non-equal intervals in the circumferential direction.

[0031] The following describes the effects and advantages of the tire-rim assembly of this embodiment. In the tire-rim assembly 1 of this embodiment, a tire-side projection 25 is provided on at least a portion of the inner cylinder 21 in the circumferential direction, projecting inward in the tire radial direction. A through hole 26 is provided in the tire-side projection 25, penetrating in the tire width direction. A rim-side projection 38 is provided on at least a portion of the rim 3 in the circumferential direction, projecting inward in the tire radial direction of the flange portion 33. A hole is provided in the rim-side projection 38, located on the extension of the through hole 26. The tire-side projection 25 and the rim-side projection 38 are fixed together by a fastener 41 that fits into the through hole 26 and the hole. This firmly fixes the non-pneumatic tire 2 and the rim 3, suppressing rim slippage (especially circumferential slippage). The fastener 41 also serves as a fastener when assembling the first rim portion 31 and the second rim portion 32, which are divided into two parts in the tire width direction. In particular, in this embodiment, multiple through holes 26 are provided, especially at positions corresponding to each connecting member 23, which allows for stronger fixing of areas with significant deformation and effectively suppresses rim slippage.

[0032] In particular, in the embodiment shown in Figure 1, the tire-side protrusion 25 and the rim-side protrusion 38 are formed around the entire circumference, resulting in high rigidity and making it less likely for the rim slip suppression effect to be lost due to damage or other reasons. On the other hand, as shown in Figure 11, if the tire-side protrusion 25 and the rim-side protrusion 38 are provided only on a part of the circumference, weight reduction can be achieved.

[0033] Furthermore, it is preferable that the fastener 41 is a bolt, and that the tire-side protrusion 25 and the rim-side protrusion 38 are fastened together. This is because the above effects can be obtained with a simple configuration.

[0034] In the above embodiment, the protruding width of the convex portion 21a (maximum protruding width in the tire width direction) is not particularly limited, but can be 3 to 5% of the width in the tire width direction at the inner end of the connecting member 23 in the tire radial direction.

[0035] Although embodiments of the present invention have been described above, the present invention is not limited in any way to the embodiments described above. For example, the curved shape of the connecting member 23 can be appropriately changed within a range that allows for appropriate elastic deformation.

[0036] [Contribution to the United Nations-led Sustainable Development Goals (SDGs)] The SDGs have been proposed to realize a sustainable society. One embodiment of this invention is considered to be a technology that can contribute to "No. 12: Responsible Consumption and Production" and "No. 13: Climate Action," among others. [Explanation of Symbols]

[0037] 1: Tire and rim assembly, 2: Non-pneumatic tires, 21: Inner cylinder, 22: Outer cylinder, 23: Connecting member, 24: Tread, 25: Protruding part on the side of the tire, 26: Through hole, 3: Rim, 31: First rim section, 32: Second rim section, 33: Flange section, 34: First horizontal section, 35: Vertical part, 36: Second horizontal section, 37: recessed, 38: Rim side protrusion, 39: Fitting part, 40: Rim-side recess, 41: Fixture

Claims

1. A tire-rim assembly comprising a non-pneumatic tire having an inner cylinder, an outer cylinder surrounding the inner cylinder from the outside in the tire radial direction, and an elastically deformable connecting member connecting the inner cylinder and the outer cylinder to each other, is assembled to a rim having a flange portion, At least a portion of the inner cylinder body in the circumferential direction is provided with a tire-side projection that protrudes inward in the tire radial direction. The aforementioned tire-side protrusion is provided with a through hole that penetrates in the tire width direction. At least a portion of the rim in the circumferential direction is provided with a rim-side protrusion that projects inward in the tire radial direction of the flange portion. A hole is provided in the rim-side protrusion, located on the extension of the through hole. A tire-rim assembly characterized in that the tire-side protrusion and the rim-side protrusion are fixed by a fastener that fits into the through hole and the hole portion.

2. The aforementioned fastener is a bolt, The tire-rim assembly according to claim 1, wherein the tire-side protrusion and the rim-side protrusion are fixed together by fastening.

3. The rim consists of a first rim portion and a second rim portion, which are divided in the tire width direction. A first rim-side protrusion is provided on at least a portion of the circumferential direction of the first rim portion, projecting inward in the tire radial direction of the flange portion. A second rim-side protrusion is provided on at least a portion of the circumferential direction of the second rim portion, projecting inward in the tire radial direction of the flange portion. Each of the first rim-side protrusion and the second rim-side protrusion is provided with a hole located on the extension of the through hole, The tire-rim assembly according to claim 1 or 2, wherein the non-pneumatic tire, the first rim portion, and the second rim portion are fixed by the fastener.

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