Non-pneumatic tire

Abstract

A non-pneumatic tire (1) is provided with: an inner cylinder (2); an outer cylinder (3) disposed on the tire outer peripheral side of the inner cylinder; and a connecting body (4) that connects the inner cylinder and the outer cylinder, the connecting body having: a plurality of unit connecting body sections (41) arranged along the tire circumferential direction; and a plurality of bridge sections (42) that connect the plurality of unit connection body sections to each other, each unit connection body section having an inner annular section (411), an intermediate annular section (412), and an outer connection body section (413), each bridge section connecting tire circumferential end sections (411t) of the inner annular sections that are adjacent to each other in the tire circumferential direction to each other, and each bridge section connecting a tire circumferential end section (411t) of the intermediate annular section (412) to each other in the tire circumferential direction. The tire circumferential end portions (412t) of the intermediate annular portions adjacent to each other in the tire circumferential direction are connected to each other, the length in the tire radial direction of each inner annular portion is longer than the length in the tire circumferential direction, and the length in the tire circumferential direction of each intermediate annular portion is longer than the length in the tire radial direction.

Description

Technical Field

[0001] The present invention relates to a non-pneumatic tire.

[0002] This application claims priority based on Japanese Patent Application No. 2022-170074, filed in Japan on October 24, 2022, the entire contents of which are incorporated herein by reference. Background Art

[0003] Conventionally, there is a non-pneumatic tire (for example, Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-83243 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] However, in conventional non-pneumatic tires, there is room for improvement in ride comfort performance.

[0009] An object of the present invention is to provide a non-pneumatic tire capable of improving ride comfort.

[0010] Solutions for solving problems

[0011] [1] A non-pneumatic tire comprising:

[0012] Inner tube;

[0013] an outer cylinder disposed on the tire outer peripheral side of the inner cylinder; and

[0014] a connecting body connecting the inner cylinder and the outer cylinder,

[0015] in,

[0016] The connecting body has:

[0017] A plurality of unit connection bodies arranged along the tire circumferential direction; and

[0018] a plurality of bridge portions, which connect the plurality of unit connection bodies to each other;

[0019] Each of the unit connection bodies has:

[0020] an inner annular portion having a pair of inner branch portions, the pair of inner branch portions being connected to each other on the inner tube, and moving away from each other in the tire circumferential direction as going to the outer side in the tire radial direction, then approaching each other and then connected to each other;

[0021] an intermediate annular portion having a pair of intermediate branches which are connected to each other at the tire outer peripheral side end of the inner annular portion and which move away from each other in the tire circumferential direction toward the tire radially outer side, then approach each other and are then connected to each other; and

[0022] an outer connecting body having a pair of outer branches connected to each other at the tire outer peripheral end of the intermediate annular portion and connected to the outer cylinder after being separated from each other in the tire circumferential direction as they go to the tire radially outer side,

[0023] Each of the bridge portions connects the tire circumferential direction end portions of the inner annular portions adjacent to each other in the tire circumferential direction.

[0024] The tire circumferential direction end portions of the intermediate annular portions adjacent to each other in the tire circumferential direction are connected to each other.

[0025] The length of each inner annular portion in the tire radial direction is longer than the length in the tire circumferential direction.

[0026] The length of each of the intermediate annular portions in the tire circumferential direction is longer than the length in the tire radial direction.

[0027] Effects of the Invention

[0028] According to the present invention, a non-pneumatic tire capable of improving riding comfort can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a side view showing a non-pneumatic tire according to an embodiment of the present invention as viewed from one side in the tire width direction.

[0030] Figure 2 It is magnified Figure 1 An enlarged view of a portion of a non-pneumatic tire.

[0031] Figure 3 It is used to illustrate Figure 2 An explanatory diagram of the behavior of a non-pneumatic tire when a load is applied.

[0032] Figure 4 This is an enlarged view showing a part of the non-pneumatic tire of Comparative Example 1 in an enlarged manner. DETAILED DESCRIPTION

[0033] The non-pneumatic tire of the present invention can be used for any mobile object (such as small vehicles, light vehicles, cars, other various vehicles, two-wheeled vehicles, wheelchairs, etc.), and is particularly suitable for small vehicles or light vehicles.

[0034] Hereinafter, embodiments of the non-pneumatic tire of the present invention will be described by way of example with reference to the drawings.

[0035] The same reference numerals are used to indicate the common components and locations in the drawings.

[0036] Figure 1 This is a side view showing a non-pneumatic tire 1 according to an embodiment of the present invention as viewed from one side in the tire width direction. Figure 2 It is magnified Figure 1 FIG. 1 is an enlarged view of a portion of a non-pneumatic tire 1 .

[0037] like Figure 1 As shown, the non-pneumatic tire 1 is configured to be provided on the outer peripheral side of a wheel W connected to an axle (not shown). The non-pneumatic tire 1 may be configured integrally with the wheel W, or may be configured separately from the wheel W. The non-pneumatic tire 1 and the wheel W are arranged coaxially with the center axis O of the axle (not shown). That is, the center axis O of the axle (not shown) coincides with the tire center axis O of the non-pneumatic tire 1.

[0038] In this specification, the direction parallel to the tire center axis O is called the "tire width direction", the direction perpendicular to the tire center axis O is called the "tire axis perpendicular direction", the radial and circumferential directions centered on the tire center axis O are called the "tire radial direction" and the "tire circumferential direction", respectively, the side close to the tire center axis O is called the "tire radial inner side" or "tire inner circumferential side", and the side away from the tire center axis O is called the "tire radial outer side" or "tire outer circumferential side".

[0039] In this specification, when describing the structure (shape, size, etc.) of the non-pneumatic tire 1, unless otherwise specified, the structure is described in a state where the non-pneumatic tire 1 is not grounded and no load is applied to the non-pneumatic tire 1.

[0040] like Figure 1-2 As shown, the non-pneumatic tire 1 includes an inner tube 2, an outer tube 3 and a connecting body 4. Figure 1 As shown, the non-pneumatic tire 1 preferably further includes a tread member T formed of rubber or the like on the tire outer peripheral side of the outer tube 3. Figure 2 The tread member T is omitted in the figure.

[0041] In addition, Figure 2 In the drawings, in order to facilitate understanding of the structure described in this specification, dotted shading is applied to a part of the non-pneumatic tire 1.

[0042] The connecting body 4 and the outer tube 3 are configured to be elastically deformable. The inner tube 2 may also be configured to be elastically deformable.

[0043] The inner tube 2, the connecting body 4, and the outer tube 3 can be integrally formed of the same material (that is, as one component) by injection molding or the like.

[0044] The materials constituting the connecting body 4 and the outer tube 3 are preferably elastomers, for example, resins such as thermoplastic elastomers.

[0045] The inner tube 2 is also preferably made of the same material as that of the connecting body 4 and the outer tube 3 .

[0046] It is preferable that the cross-sectional shape of the connected body 4 in the direction perpendicular to the tire axis is substantially the same over the entire length of the connected body 4 in the tire width direction.

[0047] The inner tube 2, the connecting body 4 and the outer tube 3 preferably have substantially the same length in the tire width direction. The inner tube 2, the connecting body 4 and the outer tube 3 preferably have substantially the same length in the tire width direction as the non-pneumatic tire 1.

[0048] The inner tube 2 is configured to be integrally connected to the wheel W or to be configured separately from the wheel W and attached to the wheel W.

[0049] The outer tube 3 is disposed on the tire outer peripheral side of the inner tube 2 .

[0050] The connecting body 4 is located between the inner tube 2 and the outer tube 3 , and connects the inner tube 2 and the outer tube 3 .

[0051] like Figure 2 As shown, the connection body 4 includes a plurality of unit connection body portions 41 arranged along the tire circumferential direction and a plurality of bridge portions 42 connecting the plurality of unit connection body portions 41 to each other.

[0052] like Figure 2 As shown, each unit connecting body portion 41 includes an inner annular portion 411 , an intermediate annular portion 412 , and an outer connecting body portion 413 .

[0053] The inner annular portion 411 has a pair of inner branches 411b that are opposite to each other in the tire circumferential direction. The pair of inner branches 411b are connected to each other on the inner tube 2, and gradually move away from each other in the tire circumferential direction as they go toward the outer side of the tire radial direction, then gradually approach each other, and then connect to each other. In this way, the inner annular portion 411 is configured to be annular. The inner annular portion 411 is divided into an inner hole 411h on its inner circumferential side. The inner hole 411h penetrates the connecting body 4 in the tire width direction. In the example of the accompanying drawings, the inner branches 411b constituting each side are formed by combining small sides that are not straight but gently curved.

[0054] The intermediate annular portion 412 has a pair of intermediate branches 412b that are opposite to each other in the tire circumferential direction. The pair of intermediate branches 412b are connected to each other at the tire outer peripheral side end of the inner annular portion 411, and gradually move away from each other in the tire circumferential direction as they go to the outer side of the tire radial direction, then gradually approach each other, and then connect to each other. In this way, the intermediate annular portion 412 is configured in an annular shape. The intermediate annular portion 412 is divided into an intermediate hole 412h on its inner circumferential side. The intermediate hole 412h penetrates the connecting body 4 in the tire width direction. In the example of the accompanying drawings, the intermediate branches 412b constituting each side are formed by combining small sides that are not straight but gently curved.

[0055] The outer connecting body 413 has a pair of outer branches 413b facing each other in the tire circumferential direction. The pair of outer branches 413b are connected to each other at the tire outer peripheral side end of the intermediate annular portion 412, and are connected to the outer cylinder 3 after gradually moving away from each other in the tire circumferential direction as they go to the outer side of the tire radial direction. The tire outer peripheral side ends of the pair of outer branches 413b of the outer connecting body 413 are separated from each other in the tire circumferential direction. In the example of the attached figure, the outer branches 413b constituting each side are not straight lines but gently curved.

[0056] The outer annular portion 43 is formed by the outer connecting body 413 and the outer cylinder connecting portion 3a of the outer cylinder 3 that connects the tire outer peripheral side ends of the pair of outer branch portions 413b of the outer connecting body 413 to each other. The outer annular portion 43 is formed in an annular shape. The outer annular portion 43 defines an outer hole 43h on its inner peripheral side. The outer hole 43h penetrates the connecting body 4 in the tire width direction. The outer annular portion 43 is formed in a substantially triangular shape having a base on the tire outer peripheral side.

[0057] The inner annular portions 411 adjacent to each other in the tire circumferential direction are separated from each other in the tire circumferential direction. The inner annular portion 411 has a pair of tire circumferential end portions 411t on both sides of the inner annular portion 411 in the tire circumferential direction. The pair of tire circumferential end portions 411t of the inner annular portion 411 respectively correspond to the portions of the pair of inner branches 411b of the inner annular portion 411 that change direction in a manner of moving toward each other after moving away from each other in the tire circumferential direction toward the outer side of the tire radial direction. In other words, they correspond to the vertex portions of the pair of inner branches 411b of the inner annular portion 411 that protrude toward one side and the other side of the tire circumferential direction, respectively. The pair of tire circumferential end portions 411t of the inner annular portion 411 can be like Figure 2 The example may be smoothly curved, or it may be bent and have angles.

[0058] Each bridge portion 42 connects tire circumferential direction end portions 411 t of the inner annular portions 411 adjacent to each other in the tire circumferential direction.

[0059] exist Figure 2In the illustrated example, each bridge portion 42 extends along the tire circumferential direction (that is, substantially parallel to the tire circumferential direction) and extends in a curved line shape that curves convexly toward the tire inner peripheral side.

[0060] However, the shape of each bridge portion 42 may be arbitrary.

[0061] The middle annular portion 412 has a pair of tire circumferential end portions 412t on both sides of the middle annular portion 412. The pair of tire circumferential end portions 412t of the middle annular portion 412 respectively correspond to the portions of the pair of middle branches 412b of the middle annular portion 412 that change direction in a manner of moving toward each other after moving away from each other in the tire circumferential direction as moving toward the outer side of the tire radial direction. In other words, they correspond to the vertex portions of the pair of middle branches 412b of the middle annular portion 412 that protrude toward one side and the other side of the tire circumferential direction, respectively. The pair of tire circumferential end portions 412t of the middle annular portion 412 can be like Figure 2 The example may be smoothly curved, or it may be bent and have angles.

[0062] The tire circumferential direction end portions 412t of the intermediate annular portions 412 adjacent to each other in the tire circumferential direction are connected to each other.

[0063] picture Figure 2 As in the example of FIG. 4 , the outer connecting body portions 413 adjacent to each other in the tire circumferential direction are preferably spaced apart from each other in the tire circumferential direction.

[0064] like Figure 2 As shown, the length D1 of each inner annular portion 411 in the tire radial direction is longer than the length E1 in the tire circumferential direction. Figure 2 In the side view of such a non-pneumatic tire 1 , each inner annular portion 411 has a vertically long shape.

[0065] Here, the length D1 of the inner annular portion 411 in the tire radial direction refers to the maximum tire radial length (in the tire radial direction) of the outer edge shape of the inner annular portion 411 at each tire circumferential position. Figure 2 In the example above, it corresponds to the length of the arrow D1. ).

[0066] The length E1 of the inner annular portion 411 in the tire circumferential direction refers to the maximum tire circumferential length (in the tire circumferential direction) of the tire circumferential lengths at various tire radial positions of the outer edge shape of the inner annular portion 411. Figure 2 In the example above, it corresponds to the length of the arrow E1. ).

[0067] Likewise, Figure 2 As shown, the inner hole 411h defined by each inner annular portion 411 has a length F1 in the tire radial direction longer than a length G1 in the tire circumferential direction. That is, in a side view of the non-pneumatic tire 1, the inner hole 411h has a vertically long shape.

[0068] Here, the length F1 of the inner hole 411h in the tire radial direction refers to the largest tire radial length among the tire radial lengths of the inner hole 411h at various tire circumferential positions.

[0069] Furthermore, the length G1 of the inner hole 411 h in the tire circumferential direction refers to the largest tire circumferential direction length among the tire circumferential direction lengths of the inner hole 411 h at various tire radial direction positions.

[0070] like Figure 2 As shown, a length E2 of each intermediate annular portion 412 in the tire circumferential direction is longer than a length D2 in the tire radial direction. That is, in a side view of the non-pneumatic tire 1 , each intermediate annular portion 412 has a horizontally long shape.

[0071] Here, the length E2 of the intermediate annular portion 412 in the tire circumferential direction refers to the maximum tire circumferential length (in the tire circumferential direction) of the tire circumferential lengths at various tire radial positions of the outer edge shape of the intermediate annular portion 412. Figure 2 In the example above, it is equivalent to the length of the arrow E2. ).

[0072] The length D2 of the intermediate annular portion 412 in the tire radial direction refers to the maximum tire radial length (in the tire radial direction) of the outer edge shape of the intermediate annular portion 412 at each tire circumferential position. Figure 2 In the example above, it is equivalent to the length of the arrow D2. ).

[0073] Likewise, Figure 2 As shown, the length G2 of the intermediate hole 412h defined by each intermediate annular portion 412 in the tire circumferential direction is longer than the length F2 in the tire radial direction. That is, in the side view of the non-pneumatic tire 1, the intermediate hole 412h is horizontally long.

[0074] Here, the length G2 of the middle hole 412h in the tire circumferential direction refers to the largest tire circumferential length among the tire circumferential lengths of the middle hole 412h at various tire radial positions.

[0075] Furthermore, the length F2 of the center hole 412h in the tire radial direction refers to the largest tire radial length among the tire radial lengths of the center hole 412h at various tire circumferential positions.

[0076] like Figure 2 As shown, an inner additional hole 44h is defined between the inner tube 2, a pair of inner annular portions 411 adjacent to each other in the tire circumferential direction, and a bridge portion 42 connecting the pair of inner annular portions 411. The inner additional hole 44h penetrates the connection body 4 in the tire width direction.

[0077] Furthermore, an intermediate additional hole 45h is defined between a pair of inner annular portions 411 adjacent to each other in the tire circumferential direction, a bridge portion 42 connecting the pair of inner annular portions 411 to each other, and a pair of intermediate annular portions 412 connected to the tire outer peripheral side ends of the pair of inner annular portions 411. The intermediate additional hole 45h penetrates the connection body 4 in the tire width direction.

[0078] An outer additional hole 46h is defined between a pair of intermediate annular portions 412 adjacent to each other in the tire circumferential direction, a pair of outer connecting body portions 413 connected to the tire outer peripheral side ends of each of the intermediate annular portions 412, and the outer cylinder 3. The outer additional hole 46h penetrates the connecting body 4 in the tire width direction.

[0079] As described above, in the present embodiment, the connection body 4 includes the plurality of unit connection body portions 41 arranged along the tire circumferential direction and the plurality of bridge portions 42 connecting the plurality of unit connection body portions 41 to each other. Each unit connecting body 41 includes an inner annular portion 411 having a pair of inner branch portions 411b connected to each other on the inner tube 2 and moving away from each other in the tire circumferential direction toward the outer side of the tire radial direction, then approaching each other and then connecting to each other; an intermediate annular portion 412 having a pair of intermediate branch portions 412b connected to each other at the tire outer peripheral side end portion of the inner annular portion 411 and moving away from each other in the tire circumferential direction toward the outer side of the tire radial direction, then approaching each other and then connecting to each other; and an outer connecting body 413 having a pair of outer branch portions 413b connected to each other at the tire outer peripheral side end portion of the intermediate annular portion 412 and moving away from each other in the tire circumferential direction toward the outer side of the tire radial direction, then connecting to the outer tube 3. Each bridge portion 42 connects the tire circumferential end portions 411t of the inner annular portions 411 adjacent to each other in the tire circumferential direction. The tire circumferential end portions 412t of the intermediate annular portions 412 adjacent to each other in the tire circumferential direction are connected to each other. The length D1 of each inner annular portion 411 in the tire radial direction is longer than the length E1 in the tire circumferential direction, and the length E2 of each intermediate annular portion 412 in the tire circumferential direction is longer than the length D2 in the tire radial direction. The outer annular portion 43 is composed of the outer connecting body portion 413 and the outer cylinder connecting portion 3a in the outer cylinder 3 that connects a pair of outer branch portions 413b of the outer connecting body portion 413 to each other.

[0080] The longitudinally long inner annular portion 411 is less likely to be compressed in the tire radial direction than the transversely long middle annular portion 412. In addition, since the outer annular portion 43 is in a substantially triangular shape having a base on the outer circumferential side of the tire, it is easy to follow the shape of the ground contact surface and to support the load in the tire radial direction. Thus, the middle annular portion 412 is configured to be more easily compressed in the tire radial direction than the inner annular portion 411 and the outer annular portion 43. Since the inner annular portion 411, the middle annular portion 412, and the outer annular portion 43 are connected to each other directly or through other parts (such as the bridge portion 42), deformation above a certain degree is suppressed.

[0081] Figure 3 FIG. 2 shows the state of the non-pneumatic tire 1 of the present embodiment when a load is applied (and when the tire is grounded). Figure 3 In the figure, the solid line indicates the state when the load is applied (and thus when the ground is applied), and the dotted line indicates the state when the load is applied (and therefore when the ground is applied). Figure 2 Such a state where no load is applied (and thus, no ground connection is performed). Figure 3 As shown by the solid line in the middle, in the non-pneumatic tire 1 of the present embodiment, when a load is applied, the connecting body 4 is allowed to be compressed and deformed toward the inner side of the tire radial direction of the ground contact surface, and the outer tube 3 is allowed to deform in a manner along the shape of the ground contact surface. During this period, the inner annular portion 411 and the outer annular portion 43 are maintained in a state of not being compressed and deformed much in the tire radial direction, while flattening the intermediate annular portion 412 in the tire radial direction. That is, the intermediate annular portion 412 is compressed and deformed to a greater extent in the tire radial direction than both the inner annular portion 411 and the outer annular portion 43. As a result, the impact and vibration transmitted from the road side are effectively absorbed by the intermediate annular portion 412, and the impact and vibration can be effectively suppressed from being transmitted to the vehicle body side. As a result, the ride comfort performance can be improved.

[0082] The horizontally long middle annular portion 412 allows deformation in the tire radial direction, while the vertically long inner annular portion 411 allows shear deformation in the tire circumferential direction. Since the vertically long inner annular portion 411 allows shear deformation in the tire circumferential direction, the horizontally long middle annular portion 412 connected to the inner annular portion 411 is easily deformed accordingly. As a result, the impact and vibration transmitted from the road surface side are more effectively absorbed by the middle annular portion 412.

[0083] Furthermore, due to the presence of the bridge portion 42, the intermediate additional hole 45h is defined on the tire outer peripheral side of the bridge portion 42, so that the intermediate additional hole 45h functions as a buffer, and can suppress the connection portion 47 of the tire circumferential end portions 412t of the pair of intermediate annular portions 412 on the tire outer peripheral side of the intermediate additional hole 45h from deforming in a manner of excessively bulging upward (tire inner peripheral side). As a result, the ride comfort performance can be further improved.

[0084] In addition, according to this embodiment, if Figure 3 As shown, when a load is applied, the connecting body 4 can be compressed and deformed in a plurality of unit connecting body portions 41 (and further, in a plurality of unit connecting body portions 41, the middle annular portion 412 is compressed and deformed to a greater extent in the tire radial direction than both the inner annular portion 411 and the outer annular portion 43). As a result, the compression deformation can be performed in a wide range, and accordingly, the stress is dispersed, so that the stress concentration in one place can be suppressed. As a result, the durability can be improved.

[0085] According to the present embodiment, the connecting body 4 is in a mesh shape, which is different from the case where the connecting body 4 is Figure 4 Compared to the structure in which a plurality of columnar portions, which are connected to each other and extend along the bending line and are arranged at intervals along the circumferential direction of the tire as in the comparative example 1 shown, the length of each of the columnar portions is shorter. Therefore, the width of each columnar portion can be reduced while maintaining the same degree of rigidity and stress under load, thereby achieving lightweighting.

[0086] In the following, when describing the shapes of the inner annular portion 411, the middle annular portion 412, and the outer annular portion 43 in the side view of the non-pneumatic tire 1, the shapes refer to the shapes of the wall thickness center lines of the wall portions of the inner annular portion 411, the middle annular portion 412, and the outer annular portion 43 in the side view of the non-pneumatic tire 1 (i.e., if it is the inner annular portion 411, it is the inner branch 411b, if it is the middle annular portion 412, it is the middle branch 412b, and if it is the outer annular portion 43, it is the outer branch 413b and the outer tube connecting portion 3a).

[0087] like Figure 2 As shown, each inner annular portion 411 preferably has a substantially rhombus shape in a side view of the non-pneumatic tire 1. In this case, the substantially rhombus shape of each inner annular portion 411 preferably has a relatively longer diagonal line of its two diagonals parallel to the tire radial direction.

[0088] Thus, when a load is applied, the inner annular portion 411 can more effectively compress the intermediate annular portion 412 in the tire radial direction while maintaining the inner annular portion 411 in a state where the inner annular portion 411 is not greatly compressed and deformed in the tire radial direction, thereby further improving the ride comfort performance.

[0089] However, each inner annular portion 411 only needs to have a length D1 in the tire radial direction longer than a length E1 in the tire circumferential direction as described above, and may have any shape in a side view of the non-pneumatic tire 1 .

[0090] From the same point of view, Figure 2As shown, in the side view of the non-pneumatic tire 1, the inner holes 411h defined by each inner annular portion 411 are preferably substantially rhombic. In this case, the substantially rhombic shape of each inner hole 411h is preferably such that the relatively longer of its two diagonals is parallel to the tire radial direction.

[0091] However, each inner hole 411h only needs to have a length F1 in the tire radial direction longer than a length G1 in the tire circumferential direction as described above, and may have any shape in a side view of the non-pneumatic tire 1 .

[0092] like Figure 2 As shown, in the side view of the non-pneumatic tire 1, each intermediate annular portion 412 is preferably in a substantially trapezoidal shape. In this case, the substantially trapezoidal shape of each intermediate annular portion 412 is preferably such that its height direction is parallel to the radial direction of the tire. In addition, in this case, the substantially trapezoidal shape of each intermediate annular portion 412 is preferably such that the relatively longer of its two bases is located at a position radially inward of the tire than the relatively shorter base.

[0093] Thus, when a load is applied, the intermediate annular portion 412 can be more effectively compressed in the tire radial direction by the inner annular portion 411 and the outer connecting body portion 413 , thereby further improving the ride comfort performance.

[0094] From the same viewpoint, each intermediate annular portion 412 also preferably has a substantially elliptical shape in a side view of the non-pneumatic tire 1. In this case, the substantially elliptical shape of each intermediate annular portion 412 preferably has a minor axis parallel to the tire radial direction.

[0095] From a similar viewpoint, each intermediate annular portion 412 also preferably has a substantially rhombus shape in a side view of the non-pneumatic tire 1 .

[0096] However, each intermediate annular portion 412 only needs to have a length E2 in the tire circumferential direction longer than a length D2 in the tire radial direction as described above, and may have any shape in a side view of the non-pneumatic tire 1 .

[0097] From the same point of view, Figure 2 As shown, in the side view of the non-pneumatic tire 1, the intermediate holes 412h defined by each intermediate annular portion 412 are preferably substantially trapezoidal. In this case, the substantially trapezoidal shape of each intermediate hole 412h is preferably such that its height direction is parallel to the tire radial direction. In addition, in this case, the substantially trapezoidal shape of each intermediate hole 412h is preferably such that the relatively longer of its two bases is located at a position radially inward of the tire than the relatively shorter base.

[0098] Furthermore, each of the intermediate holes 412h also preferably has a substantially elliptical shape in the side view of the non-pneumatic tire 1. In this case, the substantially elliptical shape of each of the intermediate holes 412h preferably has a minor axis parallel to the tire radial direction.

[0099] However, each intermediate hole 412h only needs to have a length G2 in the tire circumferential direction longer than a length F2 in the tire radial direction as described above, and may have any shape in a side view of the non-pneumatic tire 1 .

[0100] like Figure 2 As shown, in each unit connecting body portion 41, the length D1 of the inner annular portion 411 in the tire radial direction is preferably longer than the length D2 of the intermediate annular portion 412 in the tire radial direction. In addition, in each unit connecting body portion 41, the length E2 of the intermediate annular portion 412 in the tire circumferential direction is preferably longer than the length E1 of the inner annular portion 411 in the tire circumferential direction.

[0101] Thus, when a load is applied, the intermediate annular portion 412 can be more effectively compressed in the tire radial direction by the inner annular portion 411 and the outer connecting body portion 413 , thereby further improving the ride comfort performance.

[0102] Likewise, Figure 2 As shown, in each unit connecting body portion 41, the length F1 of the inner hole 411h defined by the inner annular portion 411 in the tire radial direction is preferably longer than the length F2 of the middle hole 412h defined by the middle annular portion 412 in the tire radial direction. In addition, in each unit connecting body portion 41, the length G2 of the middle hole 412h defined by the middle annular portion 412 in the tire circumferential direction is preferably longer than the length G1 of the inner hole 411h defined by the inner annular portion 411 in the tire circumferential direction.

[0103] like Figure 2 As shown, in the side view of the non-pneumatic tire 1, each outer annular portion 43 preferably has a roughly triangular shape having a base substantially parallel to the tire circumferential direction on the tire outer peripheral side. In this case, the base of the roughly triangular shape of each outer annular portion 43 is formed by the wall thickness center line of the outer cylinder connecting portion 3a of the outer cylinder 3. In this case, the roughly triangular shape of each outer annular portion 43 is preferably parallel to the tire radial direction in its height direction. In addition, in this case, the roughly triangular shape of each outer annular portion 43 is preferably a roughly isosceles triangle.

[0104] Thus, when a load is applied, the outer annular portion 43 can more effectively compress the intermediate annular portion 412 in the tire radial direction while maintaining the state in which the outer annular portion 43 is not greatly compressed and deformed in the tire radial direction, thereby further improving the ride comfort performance.

[0105] Likewise, Figure 2As shown, in the side view of the non-pneumatic tire 1, the outer holes 43h defined by each outer annular portion 43 preferably have a substantially triangular shape having a base substantially parallel to the tire circumferential direction on the tire outer peripheral side. In this case, the substantially triangular shape formed by each outer hole 43h is preferably parallel to the tire radial direction in its height direction. In addition, in this case, the substantially triangular shape formed by each outer hole 43h is preferably a substantially isosceles triangle.

[0106] like Figure 2 As shown, each unit connection body portion 41 preferably has the same shape as each other. In addition, each unit connection body portion 41 is preferably symmetrical with respect to the tire radial direction axis of each tire circumferential center position.

[0107] Example

[0108] Models of the non-pneumatic tire 1 of Example 1 and Comparative Example 1 were prepared and evaluated by analysis, and thus described.

[0109] The model of the non-pneumatic tire 1 of Example 1 has Figure 2 The structure shown.

[0110] like Figure 4 As shown, the model of the non-pneumatic tire 1 of Comparative Example 1 is different in shape only from the model of Example 1. More specifically, the model of Comparative Example 1 is a model in which a plurality of columnar portions of the connecting body 4, which respectively connect the inner tube 2 and the outer tube 3 to each other and extend along the bending line, are arranged at intervals from each other along the tire circumferential direction.

[0111] The tire size of the models of Example 1 and Comparative Example 1 is PCR155 / 70R13, and the material properties are the same.

[0112] For Example 1 and Comparative Example 1, the results of analyzing stress, longitudinal stiffness and weight are shown in the following Table 1. In addition, the numerical values ​​shown in Table 1 all represent indexes when the numerical value of the analysis result of Comparative Example 1 is set to 100. The numerical values ​​of stress, longitudinal stiffness and weight shown in Table 1 all represent that the higher the numerical value, the higher the stress, longitudinal stiffness and weight, respectively. In addition, the stress in Table 1 represents the index value of the maximum value of stress generated in each model when the load is applied to each model.

[0113]

Table 1

[0114]

[0115] According to the results shown in Table 1, it can be seen that the stress of Example 1 is the same as that of Comparative Example 1 and the longitudinal rigidity is lower. This means that the stress and durability of Example 1 are the same as those of Comparative Example 1, and it can be constructed softer than Comparative Example 1, which can improve the riding comfort performance. In addition, the stress of Example 1 is the same as that of Comparative Example 1 and the weight is lower. This means that the stress and durability of Example 1 are the same as those of Comparative Example 1 and it can achieve lightweighting compared with Comparative Example 1.

[0116] Industrial Applicability

[0117] The non-pneumatic tire of the present invention can be used for any mobile object (such as small vehicles, light vehicles, cars, other various vehicles, two-wheeled vehicles, wheelchairs, etc.), and is particularly suitable for small vehicles or light vehicles.

[0118] Description of Reference Numerals

[0119] 1. Non-pneumatic tire; 2. Inner tube; 3. Outer tube; 3a. Outer tube connecting part; 4. Connecting body; 41. Unit connecting body; 411. Inner annular part; 411b. Inner branch; 411t. Tire circumferential end; 411h. Inner hole; 412. Intermediate annular part; 412b. Intermediate branch; 412t. Tire circumferential end; 412h. Intermediate hole; 413. Outer connecting body; 413b. Outer branch; 42. Bridging part; 43. Outer annular part; 43h. Outer hole; 44h. Inner additional hole; 45h. Intermediate additional hole; 46h. Outer additional hole; W. Wheel; T. Tread member; O. Tire center axis; 1'. Non-pneumatic tire of comparative example.

Claims

1. A non-pneumatic tire, It includes: Inner tube; An outer cylinder disposed on the tire outer circumference side of the inner cylinder; as well as a connecting body connecting the inner cylinder and the outer cylinder, in, The connecting body has: A plurality of unit connection bodies arranged along the tire circumferential direction; and a plurality of bridge portions, which connect the plurality of unit connection bodies to each other; Each of the unit connection bodies has: an inner annular portion having a pair of inner branch portions, the pair of inner branch portions being connected to each other on the inner tube, and moving away from each other in the tire circumferential direction as going to the outer side in the tire radial direction, then approaching each other and then connected to each other; an intermediate annular portion having a pair of intermediate branches which are connected to each other at the tire outer peripheral side end of the inner annular portion and which move away from each other in the tire circumferential direction toward the tire radially outer side, then approach each other and are then connected to each other; and an outer connecting body having a pair of outer branches connected to each other at the tire outer peripheral end of the intermediate annular portion and connected to the outer cylinder after being separated from each other in the tire circumferential direction as they go to the tire radially outer side, Each of the bridge portions connects the tire circumferential direction end portions of the inner annular portions adjacent to each other in the tire circumferential direction. The tire circumferential direction end portions of the intermediate annular portions adjacent to each other in the tire circumferential direction are connected to each other. The length of each inner annular portion in the tire radial direction is longer than the length in the tire circumferential direction. The length of each of the intermediate annular portions in the tire circumferential direction is longer than the length in the tire radial direction.

2. The non-pneumatic tire according to claim 1, wherein: The outer annular portion is formed by the outer connecting body and the outer tube connecting portion of the outer tube that connects the pair of outer branches of the outer connecting body to each other. When a load is applied to the non-pneumatic tire, the intermediate annular portion is compressively deformed to a greater extent in the tire radial direction than both the inner annular portion and the outer annular portion.

3. The non-pneumatic tire according to claim 1, wherein: Each of the inner annular portions is substantially rhombus-shaped.

4. The non-pneumatic tire according to claim 1, wherein: Each of the intermediate annular portions is approximately trapezoidal, elliptical or rhombus-shaped.

5. The non-pneumatic tire according to claim 1, wherein: The outer annular portion is formed by the outer connecting body and the outer tube connecting portion of the outer tube that connects the pair of outer branches of the outer connecting body to each other. The outer annular portion has a substantially triangular shape having a base on the outer peripheral side of the tire.

6. The non-pneumatic tire according to any one of claims 1 to 5, wherein: The connecting body and the outer tube are configured to be elastically deformable.

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