Airless tires

Abstract

To suppress deformation in a tire diametrical direction of an inner peripheral ring of an airless tire.SOLUTION: Each of a plurality of reinforcing members provided in an airless tire extends in a circumferential direction in the inside of an inner peripheral ring, and is arranged in parallel with each other in a tire width direction. The stiffness to a bending moment in the circumferential direction of the inner peripheral ring increases as it goes from a center portion toward a vehicle side end portion in the tire width direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 discloses a non-pneumatic tire in which the support structure includes an inner annular portion, an outer annular portion concentrically arranged on the outside of the inner annular portion, and a plurality of connecting portions connecting the inner and outer annular portions, and the inner peripheral side of the inner annular portion is provided with a convex streak having a longitudinal cross-sectional shape that has a portion that widens on the inner peripheral side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-269413 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a vehicle is moving or stopped, an upward load is input from the ground to the airless tire. As a result, a force that tends to curve and deform the inner ring into a convex shape downward is likely to act between the connection parts between the inner ring and each of a pair of spokes that are adjacent to each other in the circumferential direction near the contact surface. Therefore, there is a risk that deformation in the tire radial direction will occur in the inner ring of the airless tire.

[0005] An object of the present invention is to suppress deformation of an inner ring of an airless tire in the tire radial direction. [Means for solving the problem]

[0006] The airless tire according to one aspect of the present invention has a plurality of reinforcing members each extending circumferentially inside the inner ring and disposed in parallel to one another in the tire width direction, and the rigidity of the inner ring against bending moment in the circumferential direction increases from the center to the vehicle side end in the tire width direction. Effect of the Invention

[0007] According to the present invention, deformation of the inner ring of an airless tire in the tire radial direction can be suppressed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic partial side view of an airless tire according to an embodiment, showing the state in which the airless tire is mounted on a vehicle wheel. [Diagram 2] FIG. 2 is a schematic partial side view showing a part of the airless tire shown in FIG. 1, illustrating an arrangement relationship between a vehicle wheel and an inner ring, an outer ring, spokes, and reinforcing members provided in the airless tire. [Diagram 3] FIG. 3 is a schematic partial cross-sectional view of the airless tire and vehicle wheel according to FIG. 2 taken along line AA. [Figure 4] FIG. 2 is a partial perspective view of a vehicle wheel to which an airless tire according to an embodiment is attached. [Diagram 5] FIG. 5 is an exploded perspective view showing the structure of the vehicle wheel shown in FIG. 4, illustrating the arrangement relationship between the first wheel and the second wheel. [Figure 6] FIG. 6 is a perspective view showing a part of the first wheel according to FIG. 5. [Figure 7] FIG. 2 is a schematic partial cross-sectional view of the airless tire and vehicle wheel according to FIG. 1 taken along line BB. [Figure 8] FIG. 2 is a schematic partial cross-sectional view taken along line BB of the airless tire and vehicle wheel in FIG. 1, illustrating a state in which a lateral force caused by the turning of the vehicle acts on the airless tire and the vehicle wheel arranged in a negative camber state. [Figure 9]FIG. 2 is a schematic partial cross-sectional view taken along line BB of the airless tire and vehicle wheel in FIG. 1, illustrating a state in which a lateral force caused by the turning of the vehicle acts on the airless tire and the vehicle wheel arranged in a positive camber state. [Figure 10] FIG. 4 is a schematic partial cross-sectional view corresponding to FIG. 3, illustrating a reinforcing member of the airless tire according to the first embodiment. [Figure 11] FIG. 4 is a schematic partial cross-sectional view corresponding to FIG. 3, illustrating a reinforcing member of an airless tire according to a modified example of the first embodiment. [Figure 12] FIG. 4 is a schematic partial cross-sectional view corresponding to FIG. 3, illustrating a reinforcing member of an airless tire according to a modified example of the first embodiment. [Figure 13] 1 is a graph for explaining the rigidity of an inner ring of an airless tire according to a first embodiment and its modified example against a bending moment in a circumferential direction, the graph showing a change in the rigidity in the tire width direction. FIG. [Figure 14] FIG. 5 is a schematic partial cross-sectional view corresponding to FIG. 3, illustrating a reinforcing member of an airless tire according to a second embodiment. [Figure 15] FIG. 10 is a schematic partial cross-sectional view corresponding to FIG. 3, illustrating a reinforcing member of an airless tire according to a modified example of the second embodiment. [Figure 16] FIG. 10 is a schematic partial cross-sectional view corresponding to FIG. 3, illustrating a reinforcing member of an airless tire according to a modified example of the second embodiment. [Figure 17] 13 is a graph for explaining the rigidity of the inner ring of the airless tire according to the second embodiment and its modified example against a bending moment in the circumferential direction, the graph showing the change in the rigidity in the tire width direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an airless tire according to an embodiment will be described with reference to the drawings. In each drawing, UP and DN respectively indicate the upper and lower sides in the vertical direction of the vehicle. In each drawing, IS indicates the direction of the airless tire toward the vehicle side, and OS indicates the direction opposite to the vehicle side. In addition, the diameter direction of the airless tire is called the tire radial direction. The tire radial inner side refers to the direction facing the center of the airless tire in the tire radial direction. The tire radial outer side refers to the direction opposite to the tire radial inner side. In addition, the direction around the rotation axis of the airless tire is called the circumferential direction. In addition, the same symbols are used for elements having the same functions, and duplicate explanations will be omitted.

[0010] As shown in FIG. 1, an airless tire 1 according to the embodiment is attached to a vehicle wheel 100 fixed to an axle of a vehicle (not shown), for example, a passenger car.

[0011] As shown in Figures 1 and 4, the vehicle wheel 100 includes a substantially cylindrical rim 101 extending in the tire width direction and made of a metal such as aluminum, and a circular disk 102 that covers an opening on the side of the rim 101 opposite the vehicle side.

[0012] 4 to 6, a plurality of grooves 103 may be formed on the outer peripheral surface 105 of the vehicle wheel 100. In the illustrated example, the grooves 103 are recesses that are formed at approximately equal intervals in the circumferential direction on the outer peripheral surface 105 of the vehicle wheel 100 and extend in the tire width direction. The grooves 103 have a substantially rectangular cross-sectional shape when viewed in the axial direction parallel to the tire width direction, and also have a substantially rectangular cross-sectional shape when viewed in the axial direction perpendicular to the tire width direction and the tire radial direction.

[0013] Due to the formation of the groove portion 103, the outer peripheral surface 105 of the vehicle wheel 100 becomes an uneven surface. More specifically, the outer peripheral surface 105 of the vehicle wheel 100 includes an outer peripheral main surface 106 having a maximum outer diameter in the tire radial direction, and a bottom surface 104 of the groove portion 103. Moreover, the groove portion 103 is formed so as to leave the outer peripheral main surface 106 at both ends of the outer peripheral surface 105 in the tire width direction. In other words, the groove portion 103 is formed so as to be surrounded by the outer peripheral main surface 106 in the circumferential direction and the tire width direction.

[0014] The dimensions of the groove portion 103, such as the depth in the tire radial direction, the width in the tire width direction, or the width in the vehicle wheel 100 circumferential direction, can be set appropriately depending on the outer diameter of the vehicle wheel 100, the inner diameter of the airless tire, etc. The cross-sectional shape of the groove portion 103 is not limited to the example shown in the figure, and it may be a shape that becomes wider toward the inside in the tire radial direction, for example, a T-groove shape.

[0015] As illustrated in Fig. 5 or 6, the vehicle wheel 100 may include a first wheel 100a disposed on one side in the tire width direction and a second wheel 100b disposed on the other side. In other words, the vehicle wheel 100 may be divided into the first wheel 100a and the second wheel 100b in the tire width direction. The first wheel 100a and the second wheel 100b have substantially the same outer diameter. In the illustrated example, the first wheel 100a and the second wheel 100b are set to have substantially the same width in the tire width direction, but this is not limited thereto, and one of the widths may be larger than the other.

[0016] A first flange 107a is formed at the end of the first wheel 100a in the tire width direction, extending radially inward and circumferentially at a predetermined width. Similarly, a second flange 107b is formed at the end of the second wheel 100b in the tire width direction, extending radially inward and circumferentially at a predetermined width. The first flange 107a and the second flange 107b are arranged so that they can come into contact with each other.

[0017] At predetermined positions of the first flange 107a and the second flange 107b, through holes 108a, 108b are formed, respectively, penetrating in the tire width direction. The first flange 107a and the second flange 107b are brought into contact with each other, and the through holes 108a of the first flange 107a and the through holes 108b of the second flange 107b are arranged to overlap in the tire width direction, and then fastened in the tire width direction using, for example, bolts and nuts, whereby the first wheel 100a and the second wheel 100b are fixed together, and the vehicle wheel 100 is formed.

[0018] A first groove 103a that opens toward the side opposite to the vehicle is formed in a first outer peripheral surface 105a of the first wheel 100a. A second groove 103b that opens toward the vehicle is formed in a second outer peripheral surface 105b of the second wheel 100b. The groove 103 is formed by aligning the openings of the first groove 103a and the second groove 103b and fastening the first wheel 100a and the second wheel 100b together.

[0019] The inner circumferential surface 12 of the inner ring 10 of the airless tire 1, which will be described later, is disposed on the outer circumferential surface 105 of the vehicle wheel 100 configured in this manner, thereby mounting the airless tire 1 to the vehicle wheel 100. When the outer circumferential surface 105 of the vehicle wheel 100 has a plurality of groove portions 103 and the inner circumferential surface 12 of the inner ring 10 has a plurality of protrusions 13, which will be described later, the airless tire 1 is mounted to the vehicle wheel 100 so that the plurality of groove portions 103 and the plurality of protrusions 13 fit together.

[0020] In addition, when the vehicle wheel 100 is divided into the first wheel 100a and the second wheel 100b, the first wheel 100a is inserted from one side in the tire width direction of the inner ring 10 by matching the circumferential concaves and convexes so that the inner peripheral surface 12 of the inner ring 10 and the first outer peripheral surface 105a of the first wheel 100a come into contact with each other. Then, the second wheel 100b is inserted from the other side in the tire width direction of the inner ring 10 by matching the circumferential concaves and convexes so that the inner peripheral surface 12 of the inner ring 10 and the second outer peripheral surface 105b of the second wheel 100b come into contact with each other. Then, by fastening and fixing the first wheel 100a and the second wheel 100b, the airless tire 1 can be attached to the vehicle wheel 100 with the multiple grooves 103 and the multiple protrusions 13 engaged with each other. Therefore, the airless tire 1 can be easily attached to the vehicle wheel 100.

[0021] In the illustrated example, the first bottom surface 104a and the second bottom surface 104b of the first groove portion 103a and the second groove portion 103b are inclined so that the depth increases toward the tire width direction center of the vehicle wheel 100. Therefore, a plurality of groove portions 103 inclined so that the depth increases toward the tire width direction center are formed on the outer peripheral surface 105 of the vehicle wheel 100. In this case, the first wheel 100a and the second wheel 100b can be more easily inserted into the inner peripheral surface 12 of the inner peripheral ring 10.

[0022] Furthermore, by releasing the fastening between the first wheel 100a and the second wheel 100b, the airless tire 1 can be easily removed from the vehicle wheel 100. The vehicle wheel 100 and the airless tire 1 may be joined together by adhesive or the like.

[0023] An airless tire 1 according to the embodiment includes an inner ring 10, an outer ring 20, a plurality of spokes 30, and a plurality of reinforcing members 40, as shown in FIGS.

[0024] The inner ring 10 is a substantially cylindrical member extending in the tire width direction and made of an elastically deformable material such as resin or rubber. The inner ring 10 is disposed on the outer side of the vehicle wheel 100 in the tire radial direction.

[0025] As shown in Fig. 2 or 3, a plurality of protrusions 13 protruding toward the tire radial inward are formed on a part of the inner peripheral surface 12 of the inner ring 10. In the illustrated example, the protrusions 13 have a substantially rectangular cross-sectional shape when viewed in the axial direction parallel to the tire width direction, and also have a substantially rectangular cross-sectional shape when viewed in the axial direction perpendicular to the tire width direction and the tire radial direction. The protrusions 13 have a shape that can be fitted into each of the grooves 103 formed in the outer peripheral surface 105 of the vehicle wheel 100. In other words, the inner peripheral surface 12 of the inner ring 10 has a plurality of protrusions 13 that can be fitted into each of the grooves 103 formed in the outer peripheral surface 105 of the vehicle wheel 100.

[0026] Due to the formation of the protrusions 13, the inner circumferential surface 12 of the inner ring 10 becomes an uneven surface. More specifically, the inner circumferential surface 12 of the inner ring 10 includes an inner circumferential main surface 16 having the maximum inner diameter in the tire radial direction, and an upper surface 14 of the protrusions 13. The protrusions 13 are formed so as to leave the inner circumferential main surface 16 at both ends in the tire width direction of the inner circumferential surface 12. In other words, the protrusions 13 are formed so as to be surrounded by the inner circumferential main surface 16 in the circumferential direction and the tire width direction.

[0027] In the illustrated example, the protruding portion 13 is made of the same material as the inner circumferential ring 10, but they may be made of different materials. The shape of the protruding portion 13 can be set appropriately according to the shape of the outer circumferential surface 105 of the vehicle wheel 100. For example, the shape of the protruding portion 13 may be a shape that can be fitted into the groove portion 103 having a T-slot shaped cross section. In that case, the vehicle wheel 100 can be attached to the airless tire 1 more firmly.

[0028] The outer circumferential ring 20 is a substantially cylindrical member extending in the tire width direction, and is disposed on the outermost side in the tire radial direction of the airless tire 1. Thus, the outer circumferential ring 20 is disposed outside the inner ring 10 in the tire radial direction.

[0029] As illustrated in the drawings, the outer circumferential ring 20 may include a cylindrical outer circumferential body ring 21 disposed on the inner side of the outer circumferential ring 20 in the tire radial direction, and a cylindrical tread ring 22 disposed on the outer side of the outer circumferential body ring 21 in the tire radial direction. For example, the outer circumferential body ring 21 may be made of resin, and the tread ring 22 may be made of rubber. Also, the outer circumferential body ring 21 and the tread ring 22 may be integrally molded from the same material.

[0030] The spokes 30 are, for example, plate-shaped members extending in the tire radial direction between the inner ring 10 and the outer ring 20, and are made of an elastically deformable material such as resin or rubber. The inner ends of the spokes 30 in the tire radial direction are connected to a connecting portion 17 on the outer circumferential surface 15 of the inner ring 10, and the outer ends in the tire radial direction are connected to the inner circumferential surface of the outer ring 20. In other words, a plurality of spokes 30 are disposed between the inner ring 10 and the outer ring 20, extending from the inner ring 10 outward in the tire radial direction and connected to the outer ring 20. Therefore, the outer ring 20 is supported in the tire radial direction by the inner ring 10 via the plurality of spokes 30.

[0031] It should be noted that the shape of the spokes 30 is not limited to the illustrated example. For example, the cross-sectional shape of the spokes 30 when viewed in the axial direction parallel to the tire width direction may be curved or bent, and the cross-sectional shapes of the multiple spokes 30 may be different from each other.

[0032] The inner ring 10, the outer ring 20, and the spokes 30 may all be made of the same material or different materials. Furthermore, they may be integrally molded, or separate members may be joined together to form the airless tire 1.

[0033] 3, inside the inner ring 10, a plurality of reinforcing members 40 extending along the circumferential direction are arranged in parallel to one another in the tire width direction. The reinforcing members 40 are members that reinforce the inner ring 10, and may be formed by twisting reinforcing fibers such as metal wires, carbon fibers, glass fibers, or aramid fibers. In the illustrated example, the reinforcing members 40 are annular members extending in the circumferential direction of the inner ring 10.

[0034] At least a part of each of the reinforcing members 40 may have an inner diameter set so as to be disposed closer to the inner circumferential main surface 16 than the outer circumferential surface 15 of the inner ring 10 in an axial view parallel to the tire width direction. That is, a distance T1 between the reinforcing member 40 and the outer circumferential surface 15 of the inner ring 10 in the tire radial direction may be greater than a distance T2 between the reinforcing member 40 and the inner circumferential main surface 16. In other words, each of the reinforcing members 40 may include a portion disposed closer to the inner circumferential main surface 16 having the maximum inner diameter among the inner circumferential surface 12 than the outer circumferential surface 15 of the inner ring 10 in the tire radial direction.

[0035] The shape of the reinforcing member 40 in the circumferential direction of the inner ring 10 is not limited to annular. For example, it may be an arc-shaped shape extending in the circumferential direction of the inner ring 10, and in this case, a plurality of reinforcing members may be arranged in the circumferential direction. In the illustrated example, the cross-sectional shape of the cross section S of the reinforcing member 40 perpendicular to the circumferential direction of the inner ring 10 is circular, but is not limited to this. Various cross-sectional shapes, such as an oval, an ellipse, a rectangle, a polygon, etc., can be appropriately set.

[0036] The reinforcing member 40 will be described in more detail below. In the following description, the central portion of the inner ring 10 in the tire width direction refers to a region extending with a predetermined tire width direction dimension from the tire width direction center of the inner ring 10 toward the vehicle side and toward the opposite side from the vehicle side. The tire width direction dimension of the central portion may be, for example, half the tire width direction dimension of the inner ring 10.

[0037] (First embodiment) In the example shown in FIG. 10, among the multiple reinforcing members 40, the more the reinforcing members 40 are disposed closer to the vehicle side than the center of the inner ring 10 in the tire width direction, the larger the cross-sectional area of ​​the cross section S perpendicular to the circumferential direction of the inner ring 10. In other words, the cross-sectional area of ​​the cross section S perpendicular to the circumferential direction of the inner ring 10 of each of the multiple reinforcing members 40 may increase from the center of the inner ring 10 toward the vehicle side end in the tire width direction. For example, as shown in the figure, the cross-sectional area of ​​the cross section S1 of the reinforcing member 40a located closest to the vehicle in the tire width direction is larger than the cross-sectional area of ​​the cross section S2 of the reinforcing member 40b located adjacent thereto. Note that the cross-sectional area may increase from the center of the inner ring 10 toward the vehicle side end in the tire width direction.

[0038] 11, the interval between adjacent reinforcing members 40 in the tire width direction may be reduced from the center of the inner ring 10 in the tire width direction toward the vehicle side end. For example, as shown in the figure, the interval U1 between the reinforcing member 40a and the reinforcing member 40b is smaller than the interval U2 between the reinforcing member 40b and the reinforcing member 40c adjacent to the center side. The interval may be reduced from the center of the inner ring 10 in the tire width direction toward the vehicle side end.

[0039] 12, the reinforcing member 40 disposed in a position closer to the vehicle side end portion than to the center portion of the inner ring 10 in the tire width direction may have a smaller distance from the inner circumferential main surface 16 in an axial view parallel to the tire width direction. In other words, each of the multiple reinforcing members 40 may be disposed in a cross section perpendicular to the circumferential direction of the inner ring 10, closer to the center in the tire radial direction of the inner ring 10, the closer to the vehicle side end portion from the center portion of the inner ring 10 in the tire width direction. Therefore, the ratio of the distance between the reinforcing member 40 and the outer circumferential surface 15 to the distance between the reinforcing member 40 and the inner circumferential main surface 16 of the inner ring 10 increases from the center portion of the inner ring 10 in the tire width direction toward the vehicle side end portion. For example, as shown in the figure, the value of T3 / T4, which is the ratio of the distance T3 between the reinforcing member 40a and the outer peripheral surface 15 to the distance T4 between the reinforcing member 40a and the inner peripheral main surface 16, is greater than the value of T5 / T6, which is the ratio of the distance T5 between the reinforcing member 40b and the outer peripheral surface 15 to the distance T6 between the reinforcing member 40b and the inner peripheral main surface 16. Each of the multiple reinforcing members 40 may be disposed in a cross section perpendicular to the circumferential direction of the inner ring 10 at a position closer to the center of the inner ring 10 in the tire radial direction as it moves from the center of the inner ring 10 in the tire width direction toward the vehicle side end.

[0040] A plurality of reinforcing members 40 configured as described above are disposed inside the inner ring 10. As shown in Fig. 13, the stiffness K of the inner ring 10 against a bending moment M in the circumferential direction, which will be described later, is configured to increase from the center toward the vehicle side end in the tire width direction of the inner ring 10. Note that the stiffness K may be configured to increase from the center toward the vehicle side end in the tire width direction of the inner ring 10.

[0041] The graph in FIG. 13 is a graph in which the change in the stiffness K with respect to the bending moment M in the circumferential direction of the inner ring 10 is represented by a curve L in the tire width direction. The horizontal axis indicates the position of the inner ring 10 in the tire width direction, and Ti, Tc, and To respectively indicate the vehicle side end, center, and end opposite the vehicle side in the tire width direction. The increase rate J of the stiffness K is the inclination of the curve L at a certain tire width direction position. As illustrated in the figure, the increase rate J of the stiffness K may be configured to increase from the center of the inner ring 10 toward the vehicle side end in the tire width direction. The increase rate J may be configured to increase from the center of the inner ring 10 toward the vehicle side end in the tire width direction.

[0042] Second embodiment In the description of this embodiment, only the configurations that differ from the preceding embodiments and variants (hereinafter, the preceding embodiments, etc.) will be described, and elements that have the same functions as elements already described in the preceding embodiments, etc. will be given the same symbols and their descriptions will be omitted.

[0043] As shown in the example of FIG. 14, among the multiple reinforcing members 40, the more the reinforcing members 40 are disposed on the opposite side to the vehicle side from the center of the inner ring 10 in the tire width direction, the larger the cross-sectional area of ​​the cross section S may be. In other words, the cross-sectional area of ​​the cross section S of each of the multiple reinforcing members 40, which is perpendicular to the circumferential direction of the inner ring 10, may increase from the center of the inner ring 10 to the end on the opposite side to the vehicle side in the tire width direction. For example, as shown in the figure, the cross-sectional area of ​​the cross section S3 of the reinforcing member 40d located on the most opposite side to the vehicle side in the tire width direction is larger than the cross-sectional area of ​​the cross section S4 of the reinforcing member 40e located next to it. Note that the cross-sectional area may increase from the center of the inner ring 10 in the tire width direction to the end on the opposite side to the vehicle side.

[0044] 15, the interval between adjacent reinforcing members 40 in the tire width direction may be reduced from the center of the inner ring 10 in the tire width direction toward the end opposite the vehicle side. For example, as shown in the figure, the interval U3 between the reinforcing member 40d located closest to the vehicle side in the tire width direction and the reinforcing member 40e located adjacent thereto is smaller than the interval U4 between the reinforcing member 40e and the reinforcing member 40f adjacent to the center side of the inner ring 10 in the tire width direction. The interval may be reduced from the center of the inner ring 10 in the tire width direction toward the end opposite the vehicle side.

[0045] As illustrated in FIG. 16, the reinforcing member 40 disposed in a position closer to the end portion opposite the vehicle side than the center portion of the inner ring 10 in the tire width direction may have a smaller distance from the inner circumferential main surface 16 in an axial view parallel to the tire width direction. In other words, each of the reinforcing members 40 may be disposed in a position closer to the center in the tire radial direction of the inner ring 10 in a cross section perpendicular to the circumferential direction of the inner ring 10, the closer to the center in the tire radial direction of the inner ring 10 from the center portion of the inner ring 10 in the tire width direction toward the end portion opposite the vehicle side. For example, as illustrated in the figure, the value of T7 / T8, which is the ratio of the distance T7 between the reinforcing member 40d and the outer circumferential surface 15 to the distance T8 between the reinforcing member 40d and the inner circumferential main surface 16, is larger than the value of T9 / T10, which is the ratio of the distance T9 between the reinforcing member 40e and the outer circumferential surface 15 to the distance T10 between the reinforcing member 40e and the inner circumferential main surface 16. In addition, each of the multiple reinforcing members 40 may be arranged in a position closer to the center of the inner ring 10 in the tire radial direction, the closer the position is from the center of the inner ring 10 in the tire width direction to the end opposite the vehicle side, in a cross section perpendicular to the circumferential direction of the inner ring 10.

[0046] A plurality of reinforcing members 40 configured as described above are disposed inside the inner ring 10. As shown in Fig. 17, the stiffness K of the inner ring 10 against the bending moment M in the circumferential direction is configured to increase from the center toward the end on the vehicle side in the tire width direction, and also to increase from the center toward the end on the opposite side to the vehicle side in the tire width direction. Note that the stiffness K may be configured to increase from the center of the inner ring 10 toward the end on the opposite side to the vehicle side in the tire width direction.

[0047] 17 is a graph in which the change in the stiffness K with respect to the bending moment M in the circumferential direction of the inner ring 10 is represented by a curve L, similar to the graph in FIG. 13. As illustrated in the figure, the increase rate J of the stiffness K may be configured to increase from the center of the inner ring 10 in the tire width direction toward the end portion opposite the vehicle side. The increase rate J may be configured to increase from the center of the inner ring 10 in the tire width direction toward the end portion opposite the vehicle side.

[0048] Next, the effects of the airless tire 1 according to the embodiment will be described with reference to FIG. 2 and FIG. 7 to FIG.

[0049] By attaching the airless tire 1 according to the embodiment to a vehicle wheel 100, the vehicle is supported on the ground via the airless tire 1. In addition, the driving force or braking force of the vehicle is transmitted to the ground via the vehicle wheel 100 and the airless tire 1. In addition, the area of ​​the outer circumferential surface of the outer circumferential ring 20 that comes into contact with the ground becomes the contact surface.

[0050] 2 and 7, when the airless tire 1 is in a grounded state, an upward force Fz is input from the ground to the ground contact surface of the outer ring 20. At this time, in accordance with deformation occurring near the ground contact surface of the airless tire 1, a force in the direction of arrow C acts on a pair of circumferentially adjacent spokes 30 near the ground contact surface of the airless tire 1, which tends to widen the distance between them. As a result, moments of different magnitudes or directions are generated in the direction of arrow D, for example, about an axis parallel to the tire width direction, at the connection portions 17 between the inner ring 10 and each of the pair of spokes 30. A circumferential bending moment M that tends to pull the inner ring 10 away from the vehicle wheel 100 is easily input to the region between the connection portions 17 located directly above the ground contact surface. Therefore, a force in the direction of arrow E tends to act between the connecting portions 17 of the inner ring 10, tending to deform the inner ring 10 into a convex curve downward, and due to this force, the region located directly above the contact surface of the inner ring 10 tends to deform radially downward in the tire. In the airless tire 1 according to the embodiment, the inner ring 10 includes the reinforcing member 40, and therefore deformation of the inner ring 10 in the tire radial direction can be suppressed even when such a force acts.

[0051] If the amount of deformation in the downward direction in the tire radial direction caused by the force in the direction of the arrow E in the area located directly above the ground contact surface of the inner ring 10 is defined as deformation amount δ, the rigidity K against the bending moment M can be expressed as the ratio between the bending moment M and the deformation amount δ. For example, it can be expressed as K=M / δ.

[0052] Furthermore, when the vehicle is steered and turns, an angle (slip angle) is generated between the vehicle's direction of travel and a plane perpendicular to the tire width direction of the airless tire 1, and a lateral force in the tire width direction is input to the contact surface of the airless tire 1.

[0053] 8, the vehicle wheel 100 and the airless tire 1 are arranged in a negative camber state, in which the upper part is closer to the vehicle side than the lower part. When the vehicle turns, an upward force Fz and a lateral force Fy are input from the ground to the contact surface of the airless tire 1. At this time, the bending moment M caused by the force Fz and the lateral force Fy increases from the end opposite the vehicle side to the end on the vehicle side in the tire width direction.

[0054] (1) The airless tire 1 according to the first embodiment includes an inner ring 10 disposed radially outward of a vehicle wheel 100, an outer ring 20 disposed radially outward of the inner ring 10, a plurality of spokes 30 extending radially outward from the inner ring 10 and connecting to the outer ring 20, and a plurality of reinforcing members 40 reinforcing the inner ring 10. Each of the reinforcing members 40 extends circumferentially inside the inner ring 10 and is disposed in parallel to one another in the tire width direction. The stiffness K of the inner ring 10 against a bending moment M in the circumferential direction increases from the center toward the vehicle side end in the tire width direction.

[0055] For this reason, even when the airless tire 1 is positioned in a negative camber state, a lateral force Fy directed toward the vehicle in the tire width direction is input due to turning of the vehicle, and a larger bending moment M is input in the tire width direction from the center of the inner ring 10 toward the vehicle side end, it is possible to suppress deformation of the inner ring 10 in the tire radial direction on the vehicle side in the tire width direction.

[0056] The rigidity K may increase from the center of the inner ring 10 toward the vehicle side end in the tire width direction. This makes it possible to suppress localized deformation in the tire radial direction at the center of the inner ring 10 even if a larger bending moment M is input from the center of the inner ring 10 toward the vehicle side end in the tire width direction.

[0057] (2) In the airless tire 1 according to the first embodiment, the increase rate J of the stiffness K increases from the center of the inner ring 10 toward the vehicle side end in the tire width direction.

[0058] Therefore, even if the rate of increase of the circumferential bending moment M input to the inner ring 10 becomes larger from the center in the tire width direction toward the vehicle side end, deformation of the inner ring 10 in the tire radial direction on the vehicle side in the tire width direction can be more reliably suppressed.

[0059] The rate of increase J of stiffness K may be greater from the center of the inner ring 10 toward the vehicle side end in the tire width direction. This makes it possible to suppress localized deformation in the tire radial direction at the center of the inner ring 10 even if the rate of increase of the circumferential bending moment M input to the inner ring 10 is greater from the center in the tire width direction toward the vehicle side end.

[0060] (3) In the airless tire 1 according to the first embodiment, the inner circumferential surface 12 of the inner ring 10 has a plurality of protrusions 13 that can fit into each of the plurality of grooves 103 formed in the outer circumferential surface 105 of the vehicle wheel 100.

[0061] Therefore, the position of the inner ring 10 relative to the vehicle wheel 100 in the tire width direction and the circumferential direction is restricted. Therefore, when a force acts on the inner ring 10 to curve and deform it in the tire radial direction, the displacement of the inner ring 10 relative to the vehicle wheel 100 in the tire width direction and the circumferential direction can be suppressed.

[0062] (4) In the airless tire 1 according to the first embodiment, each of the multiple reinforcing members 40 includes a portion that is disposed in a position, in the tire radial direction, closer to the inner circumferential main surface 16, which has the largest inner diameter among the inner circumferential surface 12 of the inner ring 10, than to the outer circumferential surface 15 of the inner ring 10.

[0063] Therefore, the rigidity K of the inner ring 10 in the tire radial direction can be increased at a position closer to the vehicle wheel 100. In other words, the rigidity K of the inner ring 10 can be increased at a position farther from the central axis of the bending moment M. This makes it possible to more reliably suppress deformation of the inner ring 10 in the tire radial direction due to input of the bending moment M.

[0064] (5) In the airless tire 1 according to the first embodiment, the cross-sectional area of ​​the cross section S of each of the multiple reinforcing members 40, which is perpendicular to the circumferential direction of the inner ring 10, increases from the center of the inner ring 10 toward the vehicle side end in the tire width direction.

[0065] Therefore, at least the same effect as that according to the configuration (1) above can be obtained.

[0066] The cross-sectional area may increase from the center of the inner ring 10 toward the vehicle side end in the tire width direction. This makes it possible to suppress local deformation in the tire radial direction at the center of the inner ring 10.

[0067] (6) In the airless tire 1 according to the first embodiment, the distance in the tire width direction between adjacent reinforcing members 40 among the multiple reinforcing members 40 decreases from the center of the inner ring 10 toward the vehicle side end in the tire width direction.

[0068] Therefore, at least the same effect as that according to the configuration (1) above can be obtained, and an increase in the weight of the airless tire 1 can be suppressed.

[0069] The interval may be decreased from the center of the inner ring 10 in the tire width direction toward the vehicle side end portion. This makes it possible to suppress local deformation in the tire radial direction at the center portion of the inner ring 10.

[0070] (7) In the airless tire 1 according to the first embodiment, each of the multiple reinforcing members 40 is disposed in a position in a cross section perpendicular to the circumferential direction of the inner ring 10, the closer to the center of the inner ring 10 in the tire radial direction, the closer the position is from the center of the inner ring 10 in the tire width direction to the vehicle side end.

[0071] Therefore, at least the same effect as that according to the configuration (1) above can be obtained, and an increase in the weight of the airless tire 1 can be suppressed.

[0072] Each of the reinforcing members 40 may be disposed at a position closer to the center in the tire radial direction of the inner ring 10 in a cross section perpendicular to the circumferential direction of the inner ring 10, the closer it is to the vehicle side end from the center of the inner ring 10 in the tire width direction. This makes it possible to suppress localized deformation in the tire radial direction at the center of the inner ring 10.

[0073] Next, in the example shown in Fig. 9, the vehicle wheel 100 and the airless tire 1 are arranged in a positive camber state, in which the upper part is mounted so as to be farther away from the vehicle side than the lower part. In addition, when the vehicle turns, an upward force Fz and a lateral force Fy are input from the ground to the contact surface of the airless tire 1. At this time, the bending moment M caused by the force Fz and the lateral force Fy becomes larger from the center of the inner ring 10 toward the vehicle side in the tire width direction, and also becomes larger from the center toward the end portion opposite the vehicle side. In other words, the bending moment M becomes larger from the center of the inner ring 10 toward both ends in the tire width direction.

[0074] (8) In the airless tire 1 according to the second embodiment, the rigidity K of the inner ring 10 increases from the center in the tire width direction toward the end opposite the vehicle side.

[0075] Therefore, when the airless tire 1 is positioned in a positive camber state and a lateral force Fy directed toward the vehicle side in the tire width direction is input, a larger bending moment M is input in the tire width direction from the center of the inner ring 10 toward the vehicle side end, and even if a larger bending moment M is input from the center toward the end opposite the vehicle side, deformation of the inner ring 10 in the tire radial direction on the vehicle side in the tire width direction and on the opposite side from the vehicle side can be suppressed.

[0076] The rigidity K of the inner ring 10 may increase from the center of the inner ring 10 toward the end opposite the vehicle side in the tire width direction. This makes it possible to suppress localized deformation in the tire radial direction at the center of the inner ring 10 even if a larger bending moment M is input from the center of the inner ring 10 toward the end on the vehicle side and a larger bending moment M is input from the center toward the end opposite the vehicle side.

[0077] (9) In the airless tire 1 according to the second embodiment, the increase rate J of the stiffness K increases from the center of the inner ring 10 in the tire width direction toward the end opposite the vehicle side.

[0078] Therefore, even if the rate of increase of the bending moment M input to the inner ring 10 becomes larger from the center in the tire width direction toward the vehicle side end, and also becomes larger from the center in the tire width direction toward the end opposite the vehicle side, deformation of the inner ring 10 in the tire radial direction on the vehicle side in the tire width direction and on the opposite side from the vehicle side can be more reliably suppressed.

[0079] The rate of increase J of stiffness K may be greater from the center of the inner ring 10 toward the end opposite the vehicle side in the tire width direction. This makes it possible to suppress localized deformation in the tire radial direction at the center of the inner ring 10 even in cases where the rate of increase of bending moment M input to the inner ring 10 is greater from the center in the tire width direction toward the end on the vehicle side and is also greater from the center in the tire width direction toward the end opposite the vehicle side.

[0080] (10) In the airless tire 1 of the second embodiment, the cross-sectional area of ​​a cross section S of each of the multiple reinforcing members 40 perpendicular to the circumferential direction of the inner ring 10 increases from the center of the inner ring 10 in the tire width direction toward the end opposite the vehicle side.

[0081] Therefore, at least the same effect as that of the configuration (8) above can be obtained.

[0082] The cross-sectional area may increase from the center of the inner ring 10 in the tire width direction toward the end opposite the vehicle side. This makes it possible to suppress localized deformation in the tire radial direction at the center of the inner ring 10.

[0083] (11) In the airless tire 1 according to the second embodiment, the distance in the tire width direction between adjacent reinforcing members 40 among the multiple reinforcing members 40 decreases from the center of the inner ring 10 in the tire width direction toward the end opposite the vehicle side.

[0084] Therefore, at least the same effect as that according to the configuration of (8) above can be obtained, and an increase in the weight of the airless tire 1 can be suppressed.

[0085] The interval may be decreased from the center of the inner ring 10 in the tire width direction toward the end opposite the vehicle side. This makes it possible to suppress localized deformation in the tire radial direction at the center of the inner ring 10.

[0086] (12) In the airless tire 1 of the second embodiment, each of the multiple reinforcing members 40 is arranged in a position in a cross section perpendicular to the circumferential direction of the inner ring 10, closer to the center of the inner ring 10 in the tire radial direction as it moves from the center of the inner ring 10 in the tire width direction toward the end opposite the vehicle side.

[0087] Therefore, at least the same effect as that according to the configuration of (8) above can be obtained, and an increase in the weight of the airless tire 1 can be suppressed.

[0088] Each of the reinforcing members 40 may be disposed at a position closer to the center in the tire radial direction of the inner ring 10 in a cross section perpendicular to the circumferential direction of the inner ring 10, the closer it is to the end portion opposite the vehicle side from the center of the inner ring 10 in the tire width direction. This makes it possible to suppress localized deformation in the tire radial direction at the center of the inner ring 10.

[0089] In the above embodiment, the airless tire 1 is attached to the vehicle wheel 100 of a passenger car, but it goes without saying that the airless tire 1 may be attached to the vehicle wheel of a commercial vehicle such as a light truck or a large truck. [Explanation of symbols]

[0090] 1. Airless tires 10 Inner Ring 12 Inner surface 13 Convex 15 Outer surface 16 Inner circumference main surface 20 Outer Ring 30 spokes 40 Reinforcement member 100 Vehicle Wheels 103 Groove 105 Outer surface J Increase rate K stiffness S,S1,S2,S3,S4 cross section U1,U2,U3,U4 interval

Claims

1. An inner ring disposed on the outer side of the vehicle wheel in a tire radial direction; an outer circumferential ring disposed radially outward of the inner circumferential ring; A plurality of spokes extending from the inner ring outward in a tire radial direction and connected to the outer ring; A plurality of reinforcing members for reinforcing the inner circumferential ring; Equipped with Each of the plurality of reinforcing members extends along a circumferential direction inside the inner ring and is arranged in parallel to one another in the tire width direction, The rigidity of the inner ring against the bending moment in the circumferential direction increases from the center portion toward the vehicle side end portion in the tire width direction. Airless tires.

2. The airless tire according to claim 1 , wherein the rate of increase in rigidity increases from a center portion of the inner ring toward a vehicle side end portion in a tire width direction.

3. 3. The airless tire according to claim 1, wherein an inner peripheral surface of the inner ring is provided with a plurality of protrusions that can be fitted into a plurality of grooves formed in an outer peripheral surface of the vehicle wheel.

4. 4. The airless tire according to claim 1, wherein each of the plurality of reinforcing members includes a portion that is disposed in a position, in a tire radial direction, closer to an inner circumferential main surface, which has a maximum inner diameter, of the inner circumferential surface of the inner circumferential ring than to an outer circumferential surface of the inner circumferential ring.

5. 5. The airless tire according to claim 1, wherein a cross-sectional area of ​​each of the reinforcing members in a cross section perpendicular to the circumferential direction increases from a central portion of the inner ring toward a vehicle-side end portion in the tire width direction.

6. 6. The airless tire according to claim 1, wherein a distance in the tire width direction between adjacent reinforcing members among the plurality of reinforcing members decreases from a central portion of the inner ring toward a vehicle side end portion in the tire width direction.

7. 7. The airless tire according to claim 1, wherein each of the plurality of reinforcing members is disposed in a position closer to a center of the inner ring in a tire radial direction, the closer the position is to a vehicle-side end portion of the inner ring in a cross section perpendicular to the circumferential direction of the inner ring.

8. 8. The airless tire according to claim 1, wherein the rigidity of the inner ring increases from a central portion toward an end portion on a vehicle side in a tire width direction and increases from the central portion toward an end portion opposite to the vehicle side.

9. 9. The airless tire according to claim 8, wherein the rate of increase in rigidity is greater from a central portion of the inner ring toward an end portion on a vehicle side in a tire width direction and is greater from the central portion toward an end portion opposite to the vehicle side.

10. 10. The airless tire according to claim 8, wherein a cross-sectional area of ​​each of the reinforcing members in a cross section perpendicular to the circumferential direction increases from a central portion of the inner ring in the tire width direction toward an end portion on a vehicle side, and also increases from the central portion toward an end portion on an opposite side to the vehicle side.

11. 11. The airless tire according to claim 8, wherein a distance in the tire width direction between adjacent reinforcing members among the plurality of reinforcing members decreases from a central portion of the inner ring in the tire width direction toward an end portion on a vehicle side, and also decreases from the central portion toward an end portion opposite to the vehicle side.

12. 12. The airless tire according to claim 8, wherein each of the plurality of reinforcing members is disposed in a cross section of the inner ring perpendicular to the circumferential direction, at a position closer to a center in the tire radial direction of the inner ring as the position moves from a central portion of the inner ring in the tire width direction toward the vehicle side end portion, and is disposed in a position closer to the center in the tire radial direction of the inner ring as the position moves from the central portion toward the end portion opposite the vehicle side.

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