Non-pneumatic tire

Abstract

To provide a non-pneumatic tire enabling improvement of drainage performance while maintaining grip performance.SOLUTION: A non-pneumatic tire (tire 1) comprises: an inner annular portion 20; an outer annular portion 30 coaxially disposed on an outer peripheral side X1 of the inner annular portion 20; a plurality of spokes 40 that connect the inner annular portion 20 and the outer annular portion 30 and are arranged along a tire circumferential direction C; and a tread 50 provided on an outer peripheral surface of the outer annular portion 30, where holes 60 penetrating the outer annular portion 30 and the tread 50 are formed in the outer annular portion 30 and the tread 50.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] In recent years, non-pneumatic tires that do not cause problems such as punctures and do not require air pressure adjustment have been developed. In general, a non-pneumatic tire has a structure in which an outer peripheral side annular portion provided with a tread on its outer peripheral surface and an inner peripheral side annular portion coaxially arranged inside the outer peripheral side annular portion are connected by a plurality of radially arranged spokes.

[0003] The grip performance of a non-pneumatic tire in a state where the road surface is dry depends on the tread contact area. Since non-pneumatic tires generally have higher rigidity and a smaller tread contact area than pneumatic tires, there is a desire to increase the tread contact area of non-pneumatic tires in order to maintain grip performance.

[0004] On the other hand, in order to improve the drainage performance of a non-pneumatic tire in a state where the road surface is wet, it is necessary to provide grooves in the tread of the non-pneumatic tire.

[0005] However, since the drainage performance depends on the groove volume of the tread, if the groove volume of the tread is increased to improve the drainage performance, the tread contact area becomes smaller and the grip performance becomes weaker.

[0006] Patent Document 1 and Patent Document 2 disclose non-pneumatic tires in which fine grooves or tread patterns are formed in the tread portion.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] Patent Documents 1 and 2 do not disclose a non-pneumatic tire that enhances drainage performance while maintaining grip performance.

[0009] Therefore, an object of the present invention is to provide a non-pneumatic tire that enhances drainage performance while maintaining grip performance.

Means for Solving the Problems

[0010] The non-pneumatic tire of the present invention includes an inner annular portion, an outer annular portion coaxially disposed on the outer peripheral side of the inner annular portion, a plurality of spokes that connect the inner annular portion and the outer annular portion and are arranged along the tire circumferential direction, and a tread provided on the outer peripheral surface of the outer annular portion. The non-pneumatic tire is characterized in that holes penetrating the outer annular portion and the tread are formed in the outer annular portion and the tread.

Effects of the Invention

[0011] According to the present invention, it is possible to provide a non-pneumatic tire that enhances drainage performance while maintaining grip performance.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7A

Figure 7B

Figure 7C

Figure 7D

Figure 7E

Figure 7F

Figure 8

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments will be described with reference to FIGS. 1 to 6. FIG. 1 is a side view of a tire 1 which is a non-pneumatic tire of the embodiment, viewed from a direction parallel to the tire rotation axis (tire meridian). The tire 1 shown in FIG. 1 is in an unloaded state. FIG. 2 is a sectional view taken along line II-II of FIG. 1. FIG. 3 is a partial perspective view of the tire 1, showing the portion shown in FIG. 2, viewed obliquely from an oblique angle. FIG. 4 is a partial perspective view of the tire 1, showing the portion shown in FIG. 2, viewed from a direction different from that of FIG. 3. FIG. 5 is a sectional view of the hole portions formed in the outer annular portion and the tread, and is a sectional view taken along line V-V of FIG. 3. FIG. 6 is a partial perspective view of the tire 1 of FIG. 1, viewed obliquely from the surface side of the tread 50.

[0014] In FIGS. 1, 3, 4, and 6, arrow C indicates the tire circumferential direction. In FIGS. 1 to 6, arrow X indicates the tire radial direction. In FIGS. 2 to 6, arrow Y indicates the tire width direction. The tire width direction Y in FIG. 1 is the front-back direction of the paper surface. Reference sign S1 in FIG. 2 is the tire equatorial plane. The tire circumferential direction C in FIG. 2 is the front-back direction of the paper surface. FIG. 6 is described upside down compared with FIGS. 2 to 5.

[0015] The tire circumferential direction C is the direction around the tire rotation axis and is the same as the direction in which the tire 1 rotates. The tire radial direction X is the direction perpendicular to the tire rotation axis. In FIGS. 2 to 6, the outer side (outer peripheral side) of the tire radial direction X is shown as X1, and the inner side (inner peripheral side, tire rotation axis side) of the tire radial direction X is shown as X2. The tire width direction Y is the direction parallel to the tire rotation axis. In FIGS. 2 to 4, one side of the tire width direction Y is shown as Y1, and the other side of the tire width direction Y is shown as Y2. The tire equatorial plane S1 shown in FIG. 2 is a plane perpendicular to the tire rotation axis and is located at the center of the tire width direction Y.

[0016] The tire 1 of the embodiment includes an inner annular portion 20, an outer annular portion 30, a plurality of spokes 40, and a tread 50.

[0017] Hereinafter, the thickness of the inner annular portion 20 and the outer annular portion 30 is the dimension in the direction along the tire radial direction X. The width of the inner annular portion 20 and the outer annular portion 30 is the dimension in the direction along the tire width direction Y.

[0018] The inner annular portion 20 is an annular portion along the tire circumferential direction C that constitutes the inner circumferential portion of the tire 1. The thickness and width of the inner annular portion 20 are set to be constant over the tire circumferential direction in order to improve uniformity. A tire wheel (not shown) is disposed in the space on the inner circumferential side of the inner annular portion 20. The inner circumferential portion of the inner annular portion 20 is fitted and mounted on the outer circumferential portion of the rim of the tire wheel. When the inner annular portion 20 is mounted on the rim, the tire 1 is mounted on the tire wheel. On the inner circumferential surface of the inner annular portion 20, a fitting portion composed of convex portions, grooves, or the like may be provided for fitting with the rim of the tire wheel.

[0019] The inner annular portion 20 can be formed of, for example, a resin material having elasticity, but the material is not limited to resin.

[0020] The inner annular portion 20 transmits the rotation of the tire wheel to the spokes 40 and the outer annular portion 30. The thickness of the inner annular portion 20 is determined from the viewpoint of satisfying the function of sufficiently transmitting the rotational force to the spokes 40 while achieving weight reduction and durability. The thickness of the inner annular portion 20 is not particularly limited, and examples thereof include a thickness of 2% or more and 7% or less, or 3% or more and 6% or less of the tire section height. The inner diameter of the inner annular portion 20 corresponds to the dimensions of the rim of the tire wheel on which the tire 1 is mounted and the use of the vehicle, etc. For example, when assuming the replacement of a general pneumatic tire, the inner diameter of the inner annular portion 20 may be, for example, a dimension of 250 mm or more and 500 mm or less, but is not limited thereto. The width of the inner annular portion 20 corresponds to the use of the vehicle on which the tire 1 is mounted, the length of the axle, etc. For example, when assuming the replacement of a general pneumatic tire, the width of the inner annular portion 20 may be, for example, a dimension of 100 mm or more and 300 mm or less, but is not limited thereto.

[0021] As shown in FIG. 2, on the outer peripheral portion of the inner annular portion 20 facing the outer annular portion 30, a pair of inner inclined surfaces 21 that approach the outer annular portion 30 as they extend from both ends in the tire width direction Y toward the center in the tire width direction Y are formed. That is, the pair of inner inclined surfaces 21 includes a first inner inclined surface 211 on the Y1 side in the tire width direction Y from the center in the tire width direction Y and a second inner inclined surface 212 on the Y2 side in the tire width direction Y from the center in the tire width direction Y of the outer peripheral surface 20a. The first inner inclined surface 211 is inclined inward in the tire radial direction X2 (upper side in FIG. 2) as it extends toward the end on the Y1 side in the tire width direction Y of the outer peripheral surface 20a. The second inner inclined surface 212 is inclined inward in the tire radial direction X as it extends toward the end on the Y2 side in the tire width direction Y of the outer peripheral surface 20a. That is, the inner inclined surface 21 has a cross-sectional mountain shape that is inclined inward in the tire radial direction X as it extends from the center in the tire width direction Y toward both sides in the tire width direction Y, and is configured to include the first inner inclined surface 211 and the second inner inclined surface 212.

[0022] Each of the first inner inclined surface 211 and the second inner inclined surface 212 extends to the ends in the tire width direction Y of the outer peripheral surface 20a. That is, the inner inclined surface 21 extends to both ends in the tire width direction Y of the inner annular portion 20. Each of the first inner inclined surface 211 and the second inner inclined surface 212 is a flat surface along a direction intersecting the tire radial direction X and the tire circumferential direction C.

[0023] The outer annular portion 30 is an annular portion along the tire circumferential direction C that constitutes the outer peripheral portion of the tire 1. The outer annular portion 30 is arranged coaxially with the inner annular portion 20 on the outer peripheral side of the inner annular portion 20. The thickness and width of the outer annular portion 30 are set to be constant over the tire circumferential direction in order to improve uniformity.

[0024] The outer annular portion 30 can be formed of, for example, a resin material having elasticity, but the material is not limited to resin.

[0025] The outer annular portion 30 transmits the rotation of the inner annular portion 20 and the spokes 40 to the road surface via the tread 50. The thickness of the outer annular portion 30 is determined from the viewpoints of achieving weight reduction and durability while satisfying the function of sufficiently transmitting the rotational force from the spokes 40 to the road surface. The thickness of the outer annular portion 30 is not particularly limited, and examples thereof include a thickness of 2% or more and 7% or less, or 2% or more and 5% or less of the tire section height. The thickness of the outer annular portion 30 is, for example, 4 mm or more and 15 mm or less. The inner diameter of the outer annular portion 30 is adapted according to the dimensions of the rim of the tire wheel to which the tire 1 is mounted, the use of the vehicle, and the like. For example, when assuming an alternative to a general pneumatic tire, the inner diameter of the outer annular portion 30 may be a dimension such as 420 mm or more and 750 mm or less, but is not limited thereto. The width of the outer annular portion 30 is equal to the width of the inner annular portion 20.

[0026] As shown in FIG. 2, on the inner peripheral portion of the outer annular portion 30 facing the inner annular portion 20, a pair of outer inclined surfaces 31 are formed that approach the inner annular portion 20 as they go from both ends in the tire width direction Y toward the center in the tire width direction Y. That is, the pair of outer inclined surfaces 31 includes a first outer inclined surface 311 on the Y1 side in the tire width direction from the center in the tire width direction Y and a second outer inclined surface 312 on the Y2 side in the tire width direction from the center in the tire width direction Y of the inner peripheral surface 30a. The first outer inclined surface 311 is inclined outward in the tire radial direction X1 (lower side in FIG. 2) as it goes toward the end on the Y1 side in the tire width direction of the inner peripheral surface 30a. The second outer inclined surface 312 is inclined outward in the tire radial direction X as it goes toward the end on the Y2 side in the tire width direction of the inner peripheral surface 30a. That is, the outer inclined surface 31 has a cross-sectional mountain shape that is inclined outward in the tire radial direction X as it goes from the center in the tire width direction Y toward both sides in the tire width direction Y, and is configured to include the first outer inclined surface 311 and the second outer inclined surface 312.

[0027] Each of the first outer inclined surface 311 and the second outer inclined surface 312 extends to the end of the inner peripheral surface 30a in the tire width direction Y. That is, the outer inclined surface 31 extends to both ends of the outer annular portion 30 in the tire width direction Y. Each of the first outer inclined surface 311 and the second outer inclined surface 312 is a flat surface along a direction intersecting the tire radial direction X and along the tire circumferential direction C.

[0028] The plurality of spokes 40 connect the inner annular portion 20 and the outer annular portion 30. The inner annular portion 20 and the outer annular portion 30 connected by the plurality of spokes 40 are arranged coaxially with each other. Each of the plurality of spokes 40 is independently arranged along the tire circumferential direction C. As shown in FIG. 1, when the tire 1 is in an unloaded state, the plurality of spokes 40 extend substantially parallel to the tire radial direction X in a side view. The plurality of spokes 40 are arranged at equal intervals in the tire circumferential direction C.

[0029] As shown in FIGS. 2 to 4, the plurality of spokes 40 of the embodiment include a plurality of first spokes 41 and a plurality of second spokes 42. The extending directions of both the first spoke 41 and the second spoke 42 are not parallel to the tire radial direction X when viewed in the direction along the tire circumferential direction C. The first spoke 41 is inclined toward one side in the tire width direction Y. The second spoke 42 is inclined toward the side opposite to the first spoke 41. The first spoke 41 and the second spoke 42 are alternately arranged in the tire circumferential direction C.

[0030] As shown in FIGS. 2 to 4, the first spoke 41 generally extends obliquely from the Y1 side, which is one side of the outer annular portion 30 in the tire width direction Y, toward the Y2 side, which is the other side of the inner annular portion 20 in the tire width direction Y. The second spoke 42 generally extends obliquely from the Y2 side, which is the other side of the outer annular portion 30 in the tire width direction Y, toward the Y1 side, which is one side of the inner annular portion 20 in the tire width direction Y.

[0031] The inclination angles of the first spoke 41 and the second spoke 42 are the same. Therefore, the first spoke 41 and the second spoke 42 adjacent to each other in the tire circumferential direction C are arranged in a substantially X shape when viewed from the direction along the tire circumferential direction C. As shown in FIG. 2, the first spoke 41 is inclined at an angle θ with respect to the tire width direction Y, and the angle θ is preferably, for example, 30° or more and 60° or less. The second spoke 42 is also inclined in the opposite direction at the same angle θ.

[0032] As shown in FIG. 2, each of the first spoke 41 and the second spoke 42 in the state viewed from the direction along the tire circumferential direction C has the same shape that is symmetric with respect to the tire equatorial plane S1. Therefore, hereinafter, when there is no need to distinguish between the first spoke 41 and the second spoke 42 and they can be collectively described, the first spoke 41 and the second spoke 42 are collectively referred to as the spoke 40.

[0033] The spoke 40 is formed in a plate shape extending along the plane of the tire radial direction X and the tire width direction Y. The spoke 40 extends obliquely at an angle θ as described above from the inner annular portion 20 toward the outer annular portion 30. As shown in FIG. 3, the thickness direction of the plate thickness t of the spoke 40 is along the tire circumferential direction C. As shown in FIGS. 2 and 3, the plate width w of the spoke 40 is the width of the first intermediate portion 410 and the second intermediate portion 420 to be described later, and is the dimension in the direction orthogonal to the inclination direction in which the spoke 40 extends when the spoke 40 is viewed from the direction along the tire circumferential direction C. In the embodiment, the plate thickness t of all the spokes 40 is the same. Also, the plate width w of all the spokes 40 is the same.

[0034] Since the spoke 40 is in the shape of a long plate, even if the plate thickness t is reduced, the durability of the spoke 40 can be improved by setting the plate width w wider. Furthermore, by reducing the plate thickness t and increasing the number of spokes 40, the interval between the spokes 40 adjacent to each other in the tire circumferential direction C can be reduced while maintaining the rigidity of the entire tire 1. As a result, the contact pressure during tire rolling by the spokes 40 is dispersed, and the contact pressure can be reduced.

[0035] Note that although the spoke 40 of the embodiment is parallel to the tire radial direction X in a side view, the spoke 40 may extend obliquely with respect to the tire radial direction X so as to intersect the tire radial direction X in a side view.

[0036] The first spoke 41 has a first intermediate portion 410 as an intermediate portion extending between the inner annular portion 20 and the outer annular portion 30, a first inner connection portion 411 as an inner connection portion connecting the first intermediate portion 410 and the inner annular portion 20, and a first outer connection portion 412 as an outer connection portion connecting the first intermediate portion 410 and the outer annular portion 30.

[0037] The first intermediate portion 410 is a portion having the plate width w of the spoke 40 and is a portion that coincides with the inclination direction of the first spoke 41. The first intermediate portion 410 is located in the middle of the tire radial direction X between the inner annular portion 20 and the outer annular portion 30. The first intermediate portion 410 refers to a region in the tire radial direction X having portions where both side surfaces facing the tire width direction Y are linear.

[0038] The first inner connection portion 411 is provided in a half region on the tire width direction Y2 side of the inner annular portion 20. The first inner connection portion 411 has a first inner transition portion 411b disposed on the inner side of the tire width direction Y and continuously transitioning from the first intermediate portion 410 to the inner annular portion 20, and a second inner transition portion 411a disposed on the outer side of the tire width direction Y and continuously transitioning from the first intermediate portion 410 to the inner annular portion 20. The first inner transition portion 411b is disposed on the side where the angle formed by the first intermediate portion 410 and the inner annular portion 20 is acute. The second inner transition portion 411a is disposed on the side where the angle formed by the first intermediate portion 410 and the inner annular portion 20 is obtuse.

[0039] The first inner transition portion 411b is disposed on the inner side in the tire width direction Y (on the tire equatorial plane S1 side). The first inner transition portion 411b is formed in a concave arc shape from the first intermediate portion 410 to the position of the tire equatorial plane S1 of the inner annular portion 20 and is continuous with the first inner inclined surface 211. That is, the first inner connecting portion 411 includes a first inner transition portion 411b having a shape that is continuously continuous from the first intermediate portion 410 to the first inner inclined surface 211. The first inner transition portion 411b is provided on the side where the angle formed by the first intermediate portion 410 and the inner annular portion 20 in the first inner connecting portion 411 is an acute angle. The first inner transition portion 411b of the embodiment is an example of the inner continuous portion according to the present disclosure that is continuously continuous with the first inner inclined surface 211.

[0040] Note that the first inner transition portion 411b of the embodiment is formed so as to be continuous with the first inner inclined surface 211 at the position of the tire equatorial plane S1, but may be continuous with the second inner inclined surface 212 at a position closer to the first inner connecting portion 411 than the tire equatorial plane S1, or may be formed so as to be continuous with the first inner inclined surface 211 beyond the tire equatorial plane S1.

[0041] The second inner transition portion 411a is disposed on the outer side in the tire width direction Y. The second inner transition portion 411a extends while gently curving to the end on the tire width direction Y2 side of the inner annular portion 20.

[0042] Due to the first inner transition portion 411b and the second inner transition portion 411a, the first inner connecting portion 411 has a shape that widens along the tire width direction Y as it approaches the inner annular portion 20.

[0043] The first outer connection part 412 is provided in a region that is half of the tire width direction Y1 side of the outer annular part 30. The first outer connection part 412 has a first outer transition part 412b that is arranged inside in the tire width direction Y and continuously transitions from the first intermediate part 410 to the outer annular part 30, and a second outer transition part 412a that is arranged outside in the tire width direction Y and continuously transitions from the first intermediate part 410 to the outer annular part 30. The first outer transition part 412b is arranged on the side where the angle formed by the first intermediate part 410 and the outer annular part 30 is an acute angle. The second outer transition part 412a is arranged on the side where the angle formed by the first intermediate part 410 and the outer annular part 30 is an obtuse angle.

[0044] The first outer transition part 412b is arranged inside in the tire width direction Y (on the tire equatorial plane S1 side). The first outer transition part 412b is formed in a concave arc shape from the first intermediate part 410 to the position of the tire equatorial plane S1 of the outer annular part 30 and is continuous with the second outer inclined surface 312. That is, the first outer connection part 412 includes the first outer transition part 412b having a shape that is continuously continuous from the first intermediate part 410 to the second outer inclined surface 312. The first outer transition part 412b is provided on the side where the angle formed by the first intermediate part 410 and the outer annular part 30 in the first outer connection part 412 is an acute angle. The first outer transition part 412b of the embodiment is an example of the outer continuous part according to the present disclosure that is continuously continuous with the second outer inclined surface 312.

[0045] Note that although the first outer transition part 412b of the embodiment is formed to be continuous with the second outer inclined surface 312 at the position of the tire equatorial plane S1, it may be formed to be continuous with the first outer inclined surface 311 at a position closer to the first outer connection part 412 than the tire equatorial plane S1, or may be formed to be continuous with the second outer inclined surface 312 beyond the tire equatorial plane S1.

[0046] The second outer transition part 412a is arranged outside in the tire width direction Y. The second outer transition part 412a extends while gently curving to the end on the tire width direction Y1 side of the outer annular part 30.

[0047] The first outer connecting portion 412 is formed by the first outer transition portion 412b and the second outer transition portion 412a, and has a shape that widens along the tire width direction Y as it approaches the outer annular portion 30.

[0048] The second spoke 42 has the same shape as the first spoke 41 and is symmetric with the first spoke 41 with respect to the tire equatorial plane S1.

[0049] As shown in FIGS. 2 to 4, the second spoke 42 includes a second intermediate portion 420 as an intermediate portion extending between the inner annular portion 20 and the outer annular portion 30, a second inner connecting portion 421 as an inner connecting portion connecting the second intermediate portion 420 and the inner annular portion 20, and a second outer connecting portion 422 as an outer connecting portion connecting the second intermediate portion 420 and the outer annular portion 30.

[0050] The second intermediate portion 420 is a portion having the plate width w of the spoke 40 and is a portion that coincides with the inclination direction of the second spoke 42. The second intermediate portion 420 is located at the middle in the tire radial direction X between the inner annular portion 20 and the outer annular portion 30. The second intermediate portion 420 refers to a region in the tire radial direction X having portions where both side surfaces facing the tire width direction Y are linear.

[0051] The second inner connecting portion 421 is provided in a half region on the Y1 side in the tire width direction of the inner annular portion 20. The second inner connecting portion 421 includes a first inner transition portion 421b disposed on the inner side in the tire width direction Y and continuously transitioning from the second intermediate portion 420 to the inner annular portion 20, and a second inner transition portion 421a disposed on the outer side in the tire width direction Y and continuously transitioning from the second intermediate portion 420 to the inner annular portion 20. The first inner transition portion 421b is disposed on the side where the angle formed by the second intermediate portion 420 and the inner annular portion 20 is acute. The second inner transition portion 421a is disposed on the side where the angle formed by the second intermediate portion 420 and the inner annular portion 20 is obtuse.

[0052] The first inner transition portion 421b is disposed on the inner side in the tire width direction Y (on the tire equatorial plane S1 side). The first inner transition portion 421b is formed in a concave arc shape from the second intermediate portion 420 to the position of the tire equatorial plane S1 of the inner annular portion 20, and is continuous with the second inner inclined surface 212. That is, the second inner connection portion 421 includes a first inner transition portion 421b having a shape that is continuously connected from the second intermediate portion 420 to the second inner inclined surface 212. The first inner transition portion 421b is provided on the side where the angle formed by the second intermediate portion 420 and the inner annular portion 20 in the second inner connection portion 421 is an acute angle. The first inner transition portion 421b of the embodiment is an example of the inner continuous portion according to the present disclosure that is continuously connected to the second inner inclined surface 212.

[0053] Note that the first inner transition portion 421b of the embodiment is formed to be continuous with the second inner inclined surface 212 at the position of the tire equatorial plane S1, but may be continuous with the first inner inclined surface 211 at a position closer to the second inner connection portion 421 than the tire equatorial plane S1, or may be formed to be continuous with the second inner inclined surface 212 beyond the tire equatorial plane S1.

[0054] The second inner transition portion 421a is disposed on the outer side in the tire width direction Y. The second inner transition portion 421a extends while gently curving to the end on the Y1 side in the tire width direction of the inner annular portion 20.

[0055] Due to the first inner transition portion 421b and the second inner transition portion 421a, the second inner connection portion 421 has a shape that widens along the tire width direction Y as it approaches the inner annular portion 20.

[0056] The second outer connection portion 422 is provided in a region that is half of the outer annular portion 30 on the tire width direction Y2 side. The second outer connection portion 422 includes a first outer transition portion 422b that is disposed inside in the tire width direction Y and continuously transitions from the second intermediate portion 420 to the outer annular portion 30, and a second outer transition portion 422a that is disposed outside in the tire width direction Y and continuously transitions from the second intermediate portion 420 to the outer annular portion 30. The first outer transition portion 422b is disposed on the side where the angle formed by the second intermediate portion 420 and the outer annular portion 30 is an acute angle. The second outer transition portion 422a is disposed on the side where the angle formed by the second intermediate portion 420 and the outer annular portion 30 is an obtuse angle.

[0057] The first outer transition portion 422b is disposed inside in the tire width direction Y (on the tire equatorial plane S1 side). The first outer transition portion 422b is formed in a concave arc shape from the second intermediate portion 420 to the position of the tire equatorial plane S1 of the outer annular portion 30 and is continuous with the first outer inclined surface 311. That is, the second outer connection portion 422 includes the first outer transition portion 422b having a shape that is continuously continuous from the second intermediate portion 420 to the first outer inclined surface 311. The first outer transition portion 422b is provided on the side where the angle formed by the second intermediate portion 420 and the outer annular portion 30 in the second outer connection portion 422 is an acute angle. The first outer transition portion 422b of the embodiment is an example of the outer continuous portion according to the present disclosure that is continuously continuous with the first outer inclined surface 311.

[0058] Note that the first outer transition portion 422b of the embodiment is formed to be continuous with the first outer inclined surface 311 at the position of the tire equatorial plane S1, but may be continuous with the second outer inclined surface 312 at a position closer to the second outer connection portion 422 than the tire equatorial plane S1, or may be formed to be continuous with the first outer inclined surface 311 beyond the tire equatorial plane S1.

[0059] The second outer transition portion 422a is disposed outside in the tire width direction Y. The second outer transition portion 422a extends while gently curving to the end on the tire width direction Y2 side of the outer annular portion 30.

[0060] The second outer connection part 422 has a shape that widens along the tire width direction Y as it approaches the outer annular part 30, due to the first outer transition part 422b and the second outer transition part 422a.

[0061] As described above, the plate thickness t of all the spokes 40 in the embodiment is the same. The plate thickness t of the spoke 40 is not particularly limited, but in order for the spoke 40 to sufficiently receive the rotational force from the inner annular part 20 and the outer annular part 30 and be able to flexibly deform moderately when receiving a load, it is preferably 1 mm or more and 30 mm or less, and more preferably 5 mm or more and 25 mm or less.

[0062] As described above, the plate width w of all the spokes 40 in the embodiment is the same. The plate width w of the spoke 40 is the width of the first intermediate part 410 and the second intermediate part 420. The plate width w of the spoke 40 is not particularly limited, but in order for the spoke 40 to sufficiently receive the rotational force from the inner annular part 20 and the outer annular part 30 and be able to flexibly deform moderately when receiving a load, it is preferably 5 mm or more and 25 mm or less, and more preferably 10 mm or more and 20 mm or less. Also, from the viewpoint of being able to disperse the ground pressure while improving durability, the plate width w is preferably 110% or more of the plate thickness t, and more preferably 115% or more.

[0063] The number of spokes 40 is preferably 80 or more and 300 or less, and more preferably 100 or more and 200 or less, from the viewpoint of being able to sufficiently support the load from the vehicle, being able to achieve weight reduction, and being able to improve both power transmission performance and durability.

[0064] The interval in the tire circumferential direction C between the plurality of spokes 40 is preferably set to be, for example, 1.0 mm or more and 4.1 mm or less. In the embodiment, the intervals in the tire circumferential direction C between the plurality of spokes 40 are equal, but they may be unequal intervals.

[0065] Examples of the dimension of the spoke 40 in the tire radial direction X include dimensions such as 45 mm or more and 75 mm or less, but it is not limited thereto.

[0066] The spoke 40 can be formed of the elastic materials listed below. First, as the characteristics of the elastic material, from the viewpoint of imparting appropriate rigidity while ensuring sufficient durability, a tensile test is conducted according to JIS K7312, and the tensile modulus calculated from the tensile stress at 10% elongation is preferably 3 MPa or more and 12 MPa or less.

[0067] In the spoke 40, when the tensile modulus calculated from the tensile stress at 10% elongation is less than 3 MPa, sufficient rigidity cannot be obtained, and the spokes 40 adjacent to each other in the tire circumferential direction C may come into contact. On the other hand, when the tensile modulus calculated from the tensile stress at 10% elongation exceeds 12 MPa, the rigidity becomes excessively high and the riding comfort deteriorates.

[0068] Examples of the elastic material used as the base material of the spoke 40 include thermoplastic elastomers, crosslinked rubbers, and other resins.

[0069] Examples of the thermoplastic elastomer include polyester elastomer, polyolefin elastomer, polyamide elastomer, polystyrene elastomer, polyvinyl chloride elastomer, polyurethane elastomer, and the like.

[0070] As the rubber material constituting the crosslinked rubber, either natural rubber or synthetic rubber can be used. Examples of the synthetic rubber include styrene butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IIR), nitrile rubber (NBR), hydrogenated nitrile rubber (hydrogenated NBR), chloroprene rubber (CR), ethylene propylene rubber (EPDM), fluororubber, silicone rubber, acrylic rubber, urethane rubber, and the like. These rubber materials may be used in combination of two or more as necessary.

[0071] Examples of other resins include thermoplastic resins and thermosetting resins. Examples of thermoplastic resins include polyethylene resins, polystyrene resins, polyvinyl chloride resins, and the like. Examples of thermosetting resins include epoxy resins, phenolic resins, polyurethane resins, silicone resins, polyimide resins, melamine resins, and the like.

[0072] Among the above elastic materials, polyurethane resin is preferably used for the spoke 40 from the viewpoints of moldability, processability, and cost. Note that a foamed material can also be used as the elastic material. That is, a foamed product of the above thermoplastic elastomer, crosslinked rubber, or other resin can be used.

[0073] Note that the elastic material used as the base material of the spoke 40 may be reinforced with reinforcing fibers. Examples of the reinforcing fibers include long fibers, short fibers, woven fabrics, non-woven fabrics, and the like. Examples of the types of reinforcing fibers include rayon cords, polyamide cords such as nylon-6,6, polyester cords such as polyethylene terephthalate, aramid cords, glass fiber cords, carbon fibers, steel cords, and the like.

[0074] Note that the reinforcement of the elastic material is not limited to reinforcement with reinforcing fibers. For example, reinforcement by adding particulate fillers may be performed. Examples of the particulate fillers to be added include carbon black, silica, ceramics such as alumina, and fillers of other inorganic materials.

[0075] Incidentally, the above-described inner annular portion 20 and outer annular portion 30 are preferably formed of the same resin material as the spoke 40. In that case, for example, by an injection molding method, the inner annular portion 20, the outer annular portion 30, and the spoke 40 can be integrally molded.

[0076] As described above, the spoke 40 includes intermediate portions (the first intermediate portion 410 and the second intermediate portion 420), inner connection portions (the first inner connection portion 411 and the second inner connection portion 421), and outer connection portions (the first outer connection portion 412 and the second outer connection portion 422). The intermediate portions (the first intermediate portion 410 and the second intermediate portion 420) of the spoke 40 may extend inclined with respect to the tire radial direction X when the tire 1 is viewed in the tire circumferential direction C.

[0077] According to the present embodiment, the rigidity of the tire 1 can be improved.

[0078] When the intermediate portions (the first intermediate portion 410 and the second intermediate portion 420) of the spoke 40 are inclined, large stresses are applied to the inner connection portions (the first inner connection portion 411 and the second inner connection portion 421) and the outer connection portions (the first outer connection portion 412 and the second outer connection portion 422) on the side where the angles formed with the inner annular portion 20 and the outer annular portion 30 become acute angles. Since the inner connection portions (the first inner connection portion 411 and the second inner connection portion 421) and the outer connection portions (the first outer connection portion 412 and the second outer connection portion 422) continuous with the respective inclined surfaces are provided at that portion, stress is less likely to concentrate, and the rigidity can be improved.

[0079] As shown in FIGS. 2 to 4, the plurality of spokes 40 include a plurality of first spokes 41 and a plurality of second spokes 42.

[0080] As shown in FIG. 2, the intermediate portion (the first intermediate portion 410) of the first spoke 41 may be inclined to one side with respect to the tire width direction Y. The intermediate portion (the second intermediate portion 420) of the second spoke 42 may be inclined to the side opposite to the first spoke 41. The first spoke 41 and the second spoke 42 may be alternately arranged in the tire circumferential direction C.

[0081] According to the present embodiment, since the first spoke 41 and the second spoke 42 are each inclined in the tire width direction Y, an excessive increase in rigidity is suppressed, and the riding comfort can be improved.

[0082] That is, in the first spoke 41, the middle part (the first middle part 410) may be inclined outward with respect to the tire circumferential direction C. In the second spoke 42, the middle part (the second middle part 420) may be inclined to the opposite side (inner side) of the first spoke 41.

[0083] The spokes 40 are formed in a substantially X shape when the tire 1 is viewed in the tire circumferential direction C. By being formed in this way, the load on the tire 1 is simultaneously applied to the first spoke 41 and the second spoke 42. Therefore, the load on the tire 1 is evenly distributed to the first spoke 41 and the second spoke 42, and an excessive burden on the first spoke 41 and the second spoke 42 can be suppressed.

[0084] The tread 50 is provided on the outer peripheral surface of the outer annular portion 30. The tread 50 constitutes the outermost peripheral portion of the tire 1. The tread 50 includes tread rubber 51. The tread rubber 51 has a tread surface 51a that contacts the road surface on its outer peripheral surface. There is no particular limitation on the type of rubber material of the tread rubber 51, and general vulcanized rubber or the like as the rubber constituting the tread of a vehicle tire can be used. The tread surface 51a of the tread rubber 51 may be provided with a tread pattern formed of a plurality of grooves and lands in the same manner as a conventional pneumatic tire. Note that the tread rubber 51 may have a structure in which a plurality of rubber layers having different components and characteristics are laminated (for example, two layers or three layers). Further, the tread 50 may be formed of resin.

[0085] In addition, the tire 1 of the embodiment may further be provided with a reinforcing layer for improving the rigidity and ground contact performance of the tire 1 over the entire circumference of the tire. The reinforcing layer is provided over the entire circumference of the tire and may be, for example, embedded inside the outer annular portion 30 or provided between the outer annular portion 30 and the tread 50.

[0086] The non-pneumatic tire 1 is obtained, for example, by vulcanizing and bonding the outer annular portion 30 and the tread 50 using a vulcanizing adhesive.

[0087] The rubber composition for a tread is not particularly limited. For example, it includes natural rubber and carbon black, and may further include sulfur, silica, etc. Here, the rubber composition for a tread may include synthetic rubbers such as polyisoprene rubber and styrene-butadiene rubber together with natural rubber or instead of natural rubber.

[0088] As shown in FIGS. 2 to 4, holes 60 are formed in the outer annular portion 30 and the tread 50. The holes 60 are formed so as to penetrate the outer annular portion 30 and the tread 50.

[0089] According to the present embodiment, it is possible to provide a tire 1 which is a non-pneumatic tire with improved drainage performance while maintaining grip performance.

[0090] That is, the grip performance of the non-pneumatic tire in a state where the road surface is dry depends on the tread contact area. Generally, non-pneumatic tires have higher rigidity and a smaller tread contact area than pneumatic tires. Therefore, there is a desire to increase the tread contact area of non-pneumatic tires. On the other hand, in order to improve the drainage performance of non-pneumatic tires in a state where the road surface is wet, it is preferable to provide grooves in the treads of non-pneumatic tires. However, the drainage performance depends on the groove volume of the tread. Therefore, if the groove volume of the tread is increased, the tread contact area becomes smaller and the grip performance weakens. Therefore, in the present embodiment, holes 60 are formed in the outer annular portion 30 and the tread 50 of the tire 1. The holes 60 are formed so as to penetrate the outer annular portion 30 and the tread 50.

[0091] By configuring in this way, the moisture on the road surface is drained to the inner peripheral side X2 in the tire diameter direction X of the tire 1 through the holes 60 on the tire contact surface. Therefore, it is possible to improve the drainage performance without increasing the groove width of the tread. Furthermore, since there is no need to increase the groove width, the tread contact area can be increased and the grip performance can be maintained. Therefore, it is possible to maintain the grip performance while improving the drainage performance.

[0092] FIG. 5 is a cross-sectional view of the holes 60 formed in the outer annular portion 30 and the tread 50, and is a cross-sectional view taken along line V-V of FIG. 3. As shown in FIGS. 3 to 5, the hole 60 includes an inner opening 61 formed on the inner side in the tire diameter direction (X2 side) and an outer opening 62 formed on the outer side in the tire diameter direction (X1 side). The hole 60 includes an inner hole 63 formed in the outer annular portion 30 and an outer hole 64 formed in the tread 50. That is, the hole 60 includes an inner opening 61 formed on the inner side in the tire diameter direction of the outer annular portion 30 and an outer opening 62 formed on the outer side in the tire diameter direction of the tread 50. The hole 60 is formed to extend from the inner opening 61 through the inner hole 63 and the outer hole 64 to the outer opening 62.

[0093] In the hole 60 of the present embodiment, a virtual axis A connecting the center of gravity point G1 (center point G1) of the virtual surface forming the inner opening 61 and the center of gravity point G2 (center point G2) of the virtual surface forming the outer opening 62 extends along the tire diameter direction X. That is, the virtual axis A is not inclined with respect to the tire diameter direction X. However, the present invention is not limited to this, and the virtual axis A may be inclined with respect to the tire diameter direction X. For example, it may be inclined in the tire width direction Y or may be inclined in the tire circumferential direction C.

[0094] In the present embodiment, the shapes of the inner opening 61 and the outer opening 62 are circular, for example, perfect circles. However, the inner opening 61 and the outer opening 62 are not limited to this. For example, the shapes of the inner opening 61 and the outer opening 62 may be an oval shape including an ellipse and an oblong, a quadrangular shape including a rectangle and a square, or other polygons. The inner opening 61 and the outer opening 62 may be an opening long in the tire width direction Y or may be an opening long in the tire circumferential direction C.

[0095] The area S10 of the virtual plane forming the outer opening 62 and the area S11 of the virtual plane forming the inner opening 61 may be the same or different. In the present embodiment, the area S10 of the virtual plane forming the outer opening 62 is the same as the area S11 of the virtual plane forming the inner opening 61. For example, as shown in FIG. 5, the widthwise diameter L2 of the virtual plane forming the outer opening 62 may be the same as the widthwise diameter L1 of the virtual plane forming the inner opening 61.

[0096] As shown in FIGS. 3 and 4, the hole 60 may be arranged in the outer annular portion 30 and the tread 50 so as to avoid a plurality of spokes 40.

[0097] Specifically, the inner opening 61 of the hole 60 may be arranged at a position avoiding the first outer connection portion 412 of the first spoke 41 in the outer annular portion 30. Further, the inner opening 61 of the hole 60 may be arranged at a position avoiding the second outer connection portion 422 of the second spoke 42 in the outer annular portion 30.

[0098] As shown in FIGS. 3 and 4, the spoke 40 and the hole 60 may be arranged side by side in the tire width direction Y in the outer annular portion 30.

[0099] That is, the first spoke 41 and the hole 60 may be arranged side by side in the tire width direction Y in the outer annular portion 30. The second spoke 42 and the hole 60 may be arranged side by side in the tire width direction Y in the outer annular portion 30.

[0100] FIG. 6 is a partial perspective view of the non-pneumatic tire 1 in which the hole 60 is formed, obliquely viewed from the surface side (tread surface 51a side) of the tread 50. By arranging the inner opening 61 of the hole 60 at a position avoiding the second outer connection portion 422 of the second spoke 42 in the outer annular portion 30, the outer openings 62 are alternately arranged on one side and the other side in the tire width direction Y along the tire circumferential direction C.

[0101] According to this embodiment, while ensuring the rigidity of the tire 1, the drainage performance of the tire 1 can be enhanced.

[0102] Next, a method for manufacturing the tire 1 according to this embodiment will be described.

[0103] The method for manufacturing the tire 1 according to this embodiment includes a step of integrally forming an inner annular portion 20, an outer annular portion 30 coaxially disposed on the outer peripheral side of the inner annular portion 20, and a plurality of spokes 40 that connect the inner annular portion 20 and the outer annular portion 30 and are arranged along the tire circumferential direction C, a step of adhering a tread 50 to the outer peripheral surface of the outer annular portion 30, and a step of forming a hole portion 60 that penetrates the outer annular portion 30 and the tread 50.

[0104] The step of forming the hole portion 60 may be performed after the outer annular portion 30 and the tread 50 are adhered. That is, the hole portion 60 may be formed in the adhered outer annular portion 30 and tread 50. Thereby, the hole portion 60 that penetrates the outer annular portion 30 and the tread 50 can be easily formed in one step. Alternatively, an inner hole portion 63 is formed in the outer annular portion 30, an outer hole portion 64 is formed in the tread 50, and the outer annular portion 30 in which the inner hole portion 63 is formed and the tread 50 in which the outer hole portion 64 is formed are adhered to form the hole portion 60 that penetrates the outer annular portion 30 and the tread 50. In this case, the step of adhering the tread 50 to the outer peripheral surface of the outer annular portion 30 and the step of forming the hole portion 60 that penetrates the outer annular portion 30 and the tread 50 are performed simultaneously. Thereby, the hole portion 60 can be formed using a hole formed in advance by molding or the like.

[0105] Hereinafter, with reference to FIGS. 7A to 8, non-pneumatic tires according to Modification Examples 1 to 6 will be described. FIGS. 7A to 7F are views showing Modification Examples 1 to 6 of the hole portion, and are cross-sectional views corresponding to FIG. 5. FIG. 8 is a partial perspective view of the non-pneumatic tire 1 in which the hole portion of Modification Example 6 is formed, as seen obliquely from the surface side of the tread 50.

[0106] As shown in FIGS. 7A to 7F, also in the non-pneumatic tire according to the modified example, the hole portion 60 includes an inner opening 61 and an outer opening 62.

[0107] Also in the modified example, the shapes of the inner opening 61 and the outer opening 62 are circular, for example, a perfect circle. However, also in the modified example, the inner opening 61 and the outer opening 62 are not limited to this. For example, the shapes of the inner opening 61 and the outer opening 62 in the modified example may be an oval shape including an ellipse and an oblong, a quadrangular shape including a rectangle and a square, or other polygons. The inner opening 61 and the outer opening 62 may be an opening long in the tire width direction Y or an opening long in the tire circumferential direction C.

[0108] <Modified Example 1> FIG. 7A is a view showing Modified Example 1 of the hole portion 60. In Modified Example 1, the area S10 of the virtual surface forming the outer opening 62 is different from the area S11 of the virtual surface forming the inner opening 61. For example, as shown in FIG. 7A, the width direction diameter L10 of the virtual surface forming the outer opening 62 may be different from the width direction diameter L11 of the virtual surface forming the inner opening 61.

[0109] Thereby, it is possible to control the intrusion and drainage of moisture and the intrusion and discharge of stones or the like on the ground contact surface of the tire 1. In addition, while ensuring the rigidity of the tire 1, the maximum opening area can be ensured.

[0110] That is, since the area S10 of the virtual surface forming the outer opening 62 is different from the area S11 of the virtual surface forming the inner opening 61, the hole portion 60 has a tapered shape. By controlling the taper angle, the intrusion and drainage of moisture and the intrusion and discharge of stones or the like on the ground contact surface of the tire 1 change. Therefore, it is possible to control the intrusion mode and drainage mode of moisture and the intrusion mode and discharge mode of stones or the like on the ground contact surface of the tire 1.

[0111] The area S10 of the virtual surface forming the outer opening 62 may be larger than the area S11 of the virtual surface forming the inner opening 61. For example, as shown in FIG. 7A, the widthwise diameter L10 of the virtual surface forming the outer opening 62 may be larger than the widthwise diameter L11 of the virtual surface forming the inner opening 61.

[0112] Thereby, while ensuring the rigidity of the tire 1, the opening area on the outer surface side of the tire can be ensured.

[0113] That is, by making the area S10 of the virtual surface forming the outer opening 62 larger than the area S11 of the virtual surface forming the inner opening 61, the volume of the members constituting the tire 1 can be ensured on the inner side X2 in the tire radial direction X. Therefore, while ensuring the rigidity of the tire 1, the area S10 of the outer opening 62 can be increased. Furthermore, by controlling the taper angle, the area S10 of the virtual surface forming the outer opening 62 can be made the maximum opening area, and the intrusion mode and drainage mode of moisture, and the intrusion mode and discharge mode of stones, etc. on the grounding surface of the tire 1 can be controlled. Specifically, by ensuring the opening area on the outer surface side of the tire that comes into contact with the moisture on the road surface, it becomes easier to ensure drainage performance.

[0114] <Modification Example 2> FIG. 7B is a view showing a second modification of the hole portion 60. As shown in FIG. 7B, in the non-pneumatic tire according to the second modification, the virtual axis A connecting the center of gravity point G1 (center point G1) of the virtual surface forming the inner opening 61 and the center of gravity point G2 (center point G2) of the virtual surface forming the outer opening 62 may be inclined with respect to the tire radial direction X.

[0115] According to the present embodiment, the drainage efficiency of moisture and the discharge efficiency of stones, etc. on the grounding surface of the tire 1 can be controlled.

[0116] That is, by inclining the virtual axis line A connecting the center of gravity point G1 (center point G1) of the virtual surface forming the inner opening 61 and the center of gravity point G2 (center point G2) of the virtual surface forming the outer opening 62 with respect to the tire diameter direction X, the drainage direction of moisture can be controlled. Further, as shown in FIG. 7B, the area S10 of the virtual surface forming the outer opening 62 and the area S11 of the virtual surface forming the inner opening 61 may be made different, and the virtual axis line A may be inclined with respect to the tire diameter direction X. Thereby, the hole 60 has an asymmetric taper shape. By controlling the taper angle, the drainage of moisture and the discharge of stones and the like on the ground contact surface of the tire 1 change. Therefore, the drainage mode of moisture and the discharge mode of stones and the like on the ground contact surface of the tire 1 can be controlled.

[0117] Here, in FIG. 7B and FIG. 7C described later, one side Y1 in the tire width direction Y is defined as the outer side Y1 in the tire width direction Y, and the other side Y2 in the tire width direction Y is defined as the inner side (equator side) Y2 in the tire width direction Y. As shown in FIG. 7B, the virtual axis line A of the hole 60 in the second modification is inclined toward the inner side Y2 in the tire width direction Y as it goes toward the inner side X2 in the tire diameter direction X.

[0118] Thereby, the moisture on the ground contact surface of the tire 1 can be drained to the inner side Y2 in the tire width direction Y. Also, stones and the like can be discharged to the inner side Y2 in the tire width direction Y. Thereby, it is possible to suppress the moisture and the like on the ground contact surface of the tire 1 from being discharged to the outer side Y1 in the tire width direction Y, for example, to the outside of the vehicle body.

[0119] Further, by inclining the virtual axis line A connecting the center of gravity point G1 (center point G1) of the virtual surface forming the inner opening 61 and the center of gravity point G2 (center point G2) of the virtual surface forming the outer opening 62 toward the inner side Y2 in the tire width direction Y as it goes toward the inner side X2 in the tire diameter direction X, the taper angle of the outer side Y1 in the tire width direction Y with respect to the tire diameter direction X of the hole 60 increases. Therefore, moisture is easily and efficiently drained to the inner side Y2 in the tire width direction Y. Also, stones and the like are easily and efficiently discharged to the inner side Y2 in the tire width direction Y.

[0120] <Modification Example 3> FIG. 7C is a diagram showing Modification Example 3 of the hole portion 60. As shown in FIG. 7C, also in the non-pneumatic tire according to Modification Example 3, the virtual axis A is inclined with respect to the tire radial direction X. And in the non-pneumatic tire according to Modification Example 3, the virtual axis A is inclined toward the outer side Y1 in the tire width direction Y as it goes toward the inner side X2 in the tire radial direction X.

[0121] According to the present embodiment, moisture or the like on the ground contact surface of the tire 1 can be efficiently drained to the outer side Y1 in the tire width direction Y.

[0122] Also, by inclining the virtual axis A connecting the center of gravity point G1 (center point G1) of the virtual surface forming the inner opening 61 and the center of gravity point G2 (center point G2) of the virtual surface forming the outer opening 62 toward the outer side Y1 in the tire width direction Y as it goes toward the inner side X2 in the tire radial direction X, the taper angle of the inner side Y2 in the tire width direction Y with respect to the tire radial direction X of the hole portion 60 becomes larger. Therefore, moisture or the like is easily and efficiently drained to the outer side Y1 in the tire width direction Y.

[0123] <Modification Example 4> FIG. 7D is a diagram showing Modification Example 4 of the hole portion 60. Also in Modification Example 4, the area S10 of the virtual surface forming the outer opening 62 is different from the area S11 of the virtual surface forming the inner opening 61. As shown in FIG. 7D, in the non-pneumatic tire according to Modification Example 4, the area S10 of the virtual surface forming the outer opening 62 is smaller than the area S11 of the virtual surface forming the inner opening 61. For example, as shown in FIG. 7D, the width direction diameter L10 of the virtual surface forming the outer opening 62 may be smaller than the width direction diameter L11 of the virtual surface forming the inner opening 61.

[0124] According to the present embodiment, stones on the road surface are easily discharged from the tire 1, and stone biting by the tire 1 can be suppressed.

[0125] <Modification Example 5> FIG. 7E is a view showing a fifth modification of the hole portion 60. The tread 50 of the fifth modification includes a groove portion 600 extending in the tire circumferential direction C. That is, the hole portion 60 of the fifth modification is configured to include the groove portion 600. In the fifth modification, the groove depth X10 of the groove portion 600 is smaller than the thickness X11 of the tread 50.

[0126] As shown in FIG. 7E, the width L20 of the groove portion 600 forming the outer opening portion 62 may be larger than the width direction diameter L11 of the virtual surface forming the inner opening portion 61. However, it is not limited to this, and the width L20 of the groove portion 600 may be the same as the width direction diameter L11 of the inner opening portion 61.

[0127] According to this modification, while ensuring the rigidity of the tire 1, the drainage performance of the tire 1 can be improved.

[0128] That is, the moisture on the road surface is efficiently collected by the groove portion 600 and ejected from the inner hole portion 63 toward the inner side X2 in the tire radial direction X. Further, since the groove depth X10 of the groove portion 600 is smaller than the thickness X11 of the tread 50, the tread also exists at the bottom of the groove portion 600. Therefore, while ensuring the rigidity of the tire 1, the drainage performance of the tire 1 can be improved. In addition, since the hole portion 60 is provided, the drainage performance can be improved without making the groove larger than necessary. Furthermore, since there is no need to make the groove larger, the tread contact area can be increased and the grip performance can be maintained.

[0129] <Sixth Modification> FIG. 7F is a view showing a sixth modification of the hole portion 60. The tread 50 of the sixth modification includes a groove portion 600 extending in the tire circumferential direction C. That is, the hole portion 60 of the fifth modification is configured to include the groove portion 600. In the sixth modification, the groove depth X20 of the groove portion 600 is equal to the thickness X21 of the tread 50.

[0130] Note that, as shown in FIG. 7F, the width L20 of the groove portion 600 forming the outer opening 62 may be larger than the width direction diameter L11 of the virtual surface forming the inner opening 61. However, it is not limited to this, and the width L20 of the groove portion 600 may be the same as the width direction diameter L11 of the inner opening 61.

[0131] According to the present embodiment, the volume of the groove portion 600 as the outer hole portion 64 increases. Therefore, the drainage performance of the tire 1 is further improved, and slip can be suppressed. In addition, since the hole portion 60 is provided, the drainage performance can be enhanced without making the groove larger than necessary. Furthermore, since there is no need to enlarge the groove, the tread contact area can be increased, and the grip performance can be maintained.

[0132] FIG. 8 is a partial perspective view of the non-pneumatic tire 1 in which the hole portion 60 of the modified example 6 is formed, as viewed obliquely from the surface side of the tread 50. As shown in FIG. 8, in the non-pneumatic tire according to the modified example 6, the groove portion 600 is a rib-shaped groove portion extending over the tire circumferential direction C of the tread 50.

[0133] When the groove portion 600 is a rib-shaped groove portion, the moisture that has entered the groove portion 600 from the road surface moves in the rotation direction of the tire 1, that is, in the tire circumferential direction C. Therefore, the resistance received from the moisture that has entered the groove portion 600 is small, and the high-speed stability of the tire 1 is enhanced. The hole portion 60 may be arranged so as to be connected to the rib-shaped groove portion. It is preferable that the hole portion 60 is arranged so as to be connected to the rib-shaped groove portion. That is, it is preferable that the hole portion 60 is configured to include the rib-shaped groove portion. Thereby, the drainage performance is enhanced.

[0134] Note that the groove portion 600 may be a lug-shaped groove portion formed in the tire width direction Y of the tread 50. Further, the groove portion 600 may be a block-shaped groove portion. The lug-shaped groove portion is a groove portion 600 formed to extend from a position closer to the center portion in the tire width direction Y of the tire 1 to the end portion in the tire width direction Y. The lug-shaped groove portion may be an opening opened at the end portion in the tire width direction Y of the tire 1.

[0135] The rib-lug type groove part is a combination of a rib type groove part and a lug type groove part.

[0136] When the groove part 600 is a rib-lug type groove part, it has both the high-speed stability performance of the above-mentioned rib type groove part and the high-speed stability performance of the lug type groove part. The hole part 60 may be arranged so as to be connected to the rib-lug type groove part. That is, the hole part 60 may be configured to include the rib-lug type groove part. Thereby, the drainage performance is enhanced.

[0137] The block type groove part is a groove part 600 in which a rib type groove part extending in the tire circumferential direction C and a rib type groove part inclined with respect to the tire circumferential direction C are combined. The block type groove part may be a groove part 600 in which a rib type groove part extending in the tire circumferential direction C, a rib type groove part inclined with respect to the tire circumferential direction C, and a lug type groove part are combined.

[0138] When the groove part 600 is a block type groove part, similar to the above-mentioned rib-lug type groove part, it has both the high-speed stability performance of the rib type groove part and the high-speed stability performance of the lug type groove part. The hole part 60 may be arranged so as to be connected to the block type groove part. That is, the hole part 60 may be configured to include the block type groove part. Thereby, the drainage performance is enhanced.

[0139] As shown in the above Modification Examples 5 and 6, the outer hole part 64 of the hole part 60 may be configured to include the groove part 600 formed in the tread 50. Thereby, the drainage performance of the tire 1 can be further enhanced. Further, since the hole part 60 is provided, the drainage performance can be enhanced without making the groove larger than necessary. Furthermore, since there is no need to make the groove larger, the tread contact area can be increased and the grip performance can be maintained.

[0140] It should be noted that the ratio of the area of the groove to the total area of the contact surface and the groove 600 when the outer surface of the tread 50 of the tire 1 is viewed in plan is preferably 15% or more and 30% or less. If it is less than 15%, the drainage performance may not be sufficient depending on the use of the tire. If it exceeds 30%, a decrease in grip performance, wear resistance, etc. may be observed.

[0141] According to the tire 1 of the embodiment, the following effects can be obtained.

[0142] (1) In the tire 1 according to the embodiment, the hole portion 60 penetrating the outer annular portion 30 and the tread 50 is formed in the outer annular portion 30 and the tread 50.

[0143] Thereby, it is possible to provide the tire 1 which is a non-pneumatic tire having enhanced drainage performance while maintaining grip performance.

[0144] (2) In the tire 1 of (1), the hole portion 60 may include an inner opening 61 and an outer opening 62. The inner opening 61 is formed inside in the tire radial direction X. The outer opening 62 is formed outside in the tire radial direction X. The area S10 of the virtual surface forming the outer opening 62 may be different from the area S11 of the virtual surface forming the inner opening 61.

[0145] Thereby, it is possible to control the intrusion and drainage of moisture on the grounding surface of the tire 1, and the intrusion and discharge of stones and the like.

[0146] (3) In the tire 1 of (2), the area S10 of the virtual surface forming the outer opening 62 may be larger than the area S11 of the virtual surface forming the inner opening 61.

[0147] Thereby, while ensuring the rigidity of the tire 1, it is possible to ensure the maximum opening area and enhance the drainage performance.

[0148] (4) In the tire 1 of (2), the hole portion 60 includes an inner hole portion 63 and an outer hole portion 64. The inner hole portion 63 is formed in the annular portion (outer annular portion 30). The outer hole portion 64 is formed in the tread 50. The area S10 of the virtual surface forming the outer opening 62 may be smaller than the area S11 of the virtual surface forming the inner opening 61.

[0149] Thereby, stones on the road surface are easily discharged from the tire 1, and stone biting by the tire 1 can be suppressed.

[0150] (5) In the tire 1 of (1) to (4), the hole portion 60 includes an inner hole portion 63 and an outer hole portion 64. The inner hole portion 63 is formed in the annular portion (outer annular portion 30). The outer hole portion 64 is formed in the tread 50. The outer hole portion 64 may include a groove portion 600 formed in the tread 50.

[0151] Thereby, the drainage performance of the tire 1 can be further enhanced.

[0152] (6) In the tire 1 of (1) to (5), the virtual axis A connecting the center of gravity point G1 (center point G1) of the virtual surface forming the inner opening 61 and the center of gravity point G2 (center point G2) of the virtual surface forming the outer opening 62 may be inclined with respect to the tire radial direction X.

[0153] Thereby, the drainage efficiency of moisture and the discharge efficiency of stones and the like on the grounding surface of the tire 1 can be controlled.

[0154] (7) In the tire 1 of (6), the virtual axis A may be inclined inward in the tire width direction Y as it goes inward X2 in the tire radial direction X.

[0155] Thereby, the moisture on the grounding surface of the tire 1 can be drained inward Y2 in the tire width direction Y. Also, stones and the like can be discharged inward Y2 in the tire width direction Y. Thereby, it is possible to suppress the moisture and the like on the grounding surface of the tire 1 from being discharged to the outside Y1 in the tire width direction Y, for example, to the outside of the vehicle body.

[0156] (8) In the tire 1 of (6), the virtual axis A may be inclined outward in the tire width direction Y as it goes inward X2 in the tire radial direction X.

[0157] Thereby, the moisture and the like on the grounding surface of the tire 1 can be efficiently drained to the outside Y1 in the tire width direction Y.

[0158] (9) In the tire 1 of (1) to (8), the spoke 40 has an intermediate portion (the first intermediate portion 410, the second intermediate portion 420), an inner connection portion (the first inner connection portion 411, the second inner connection portion 421), and an outer connection portion (the first outer connection portion 412, the second outer connection portion 422). The intermediate portion (the first intermediate portion 410, the second intermediate portion 420) extends between the inner annular portion 20 and the outer annular portion 30. The inner connection portion (the first inner connection portion 411, the second inner connection portion 421) connects the intermediate portion (the first intermediate portion 410, the second intermediate portion 420) and the inner annular portion 20. The outer connection portion (the first outer connection portion 412, the second outer connection portion 422) connects the intermediate portion (the first intermediate portion 410, the second intermediate portion 420) and the outer annular portion 30. The plurality of spokes 40 includes a plurality of first spokes 41 and a plurality of second spokes 42. In the first spoke 41, the intermediate portion (the first intermediate portion 410, the second intermediate portion 420) may be inclined to one side with respect to the tire width direction Y. In the second spoke 42, the intermediate portion (the first intermediate portion 410, the second intermediate portion 420) may be inclined to the side opposite to the first spoke 41. The first spoke 41 and the second spoke 42 may be alternately arranged in the tire circumferential direction C.

[0159] As a result, since the first spoke 41 and the second spoke 42 are each inclined in the tire width direction Y, an excessive increase in rigidity is suppressed, and the riding comfort is improved.

[0160] (10) In the tire 1 of (1) to (9), the hole portion 60 may be arranged in the outer annular portion 30 and the tread 50 while avoiding the plurality of spokes 40.

[0161] Thereby, the drainage performance of the tire 1 can be improved without affecting the strength of the spoke 40.

[0162] (11) In the tire 1 of (1) to (10), the spoke 40 and the hole portion 60 may be arranged side by side in the tire width direction Y in the outer annular portion 30.

[0163] Accordingly, while ensuring the rigidity of the tire 1, the drainage performance of the tire 1 can be enhanced.

[0164] (12) The method for manufacturing the tire 1 according to the embodiment includes a step of integrally forming an inner annular portion 20, an outer annular portion 30 coaxially disposed on the outer peripheral side of the inner annular portion 20, and a plurality of spokes 40 connecting the inner annular portion 20 and the outer annular portion 30 and arranged along the tire circumferential direction C, a step of adhering a tread 50 to the outer peripheral surface of the outer annular portion 30, and a step of forming a hole portion 60 penetrating the outer annular portion 30 and the tread 50 in the outer annular portion 30 and the tread 50.

[0165] Accordingly, the tire 1 with enhanced drainage performance while maintaining grip performance can be manufactured.

[0166] As described above, the embodiments of the present invention have been explained. However, the present invention is not limited to the above embodiments, and even if modifications, improvements, etc. are made within the range that can achieve the object of the present invention, they are included in the scope of the present invention.

[0167] For example, in addition to the form in which the spoke 40 is inclined with respect to the tire radial direction X, the spoke may be a straight spoke extending along the tire radial direction X.

Explanation of Reference Numerals

[0168] 1 Tire (Non-Pneumatic Tire) 20 Inner Annular Portion 30 Outer Annular Portion 40 Spoke 41 First Spoke 42 Second Spoke 50 Tread 410 First Intermediate Portion 411 First Inner Connection Portion 412 First Outer Connection Portion 420 Second Intermediate Portion 421 Second Inner Connection Portion 422 Second Outer Connection Portion 60 Hole Portion 61 Inner Opening 62 Outer opening 63 Inner hole part 64 Outer hole part 600 Groove part

Claims

1. an inner annular part, an outer annular part coaxially arranged on the outer peripheral side of the inner annular part, a plurality of spokes connecting the inner annular part and the outer annular part and arranged along the tire circumferential direction, a tread provided on the outer peripheral surface of the outer annular part, and a non-pneumatic tire comprising: a non-pneumatic tire in which holes penetrating the outer annular part and the tread are formed in the outer annular part and the tread.

2. The hole portion includes an inner opening formed on the inner side in the tire radial direction, and an outer opening formed on the outer side in the tire radial direction, and the area of the virtual surface forming the outer opening is different from the area of the virtual surface forming the inner opening. The non-pneumatic tire according to claim 1.

3. The area of the virtual surface forming the outer opening is larger than the area of the virtual surface forming the inner opening. The non-pneumatic tire according to claim 2.

4. The area of the virtual surface forming the outer opening is smaller than the area of the virtual surface forming the inner opening. The non-pneumatic tire according to claim 2.

5. The hole portion includes an inner hole formed in the outer annular part, and an outer hole formed in the tread, and the outer hole is configured to include a groove formed in the tread. The non-pneumatic tire according to claim 1.

6. The hole portion includes an inner opening formed on the inner side in the tire radial direction, and an outer opening formed on the outer side in the tire radial direction, and a virtual axis connecting the center of gravity point of the virtual surface forming the inner opening and the center of gravity point of the virtual surface forming the outer opening is inclined with respect to the tire radial direction. The non-pneumatic tire according to claim 1 or claim 2.

7. The virtual axis is inclined toward the inner side in the tire width direction as it goes toward the inner side in the tire radial direction. The non-pneumatic tire according to claim 6.

8. The virtual axis is inclined toward the outer side in the tire width direction as it goes toward the inner side in the tire radial direction. The non-pneumatic tire according to claim 6.

9. The spoke has an intermediate part extending between the inner annular part and the outer annular part, an inner connecting part connecting the intermediate part and the inner annular part, and an outer connecting part connecting the intermediate part and the outer annular part, The spoke includes a first spoke in which the intermediate part is inclined to one side with respect to the tire width direction, and a second spoke in which the intermediate part is inclined to the side opposite to the first spoke. The non-pneumatic tire according to claim 1 or claim 2, wherein the first spoke and the second spoke are alternately arranged in the tire circumferential direction.

10. The non-pneumatic tire according to claim 1 or claim 2, wherein the hole portions are arranged avoiding the spokes in the outer annular portion and the tread.

11. The non-pneumatic tire according to claim 1 or claim 2, wherein the spokes and the hole portions are arranged side by side in the tire width direction in the outer annular portion.

12. A step of integrally forming an inner annular portion, an outer annular portion coaxially arranged on the outer peripheral side of the inner annular portion, and a plurality of spokes connecting the inner annular portion and the outer annular portion and arranged along the tire circumferential direction; A step of adhering a tread to the outer peripheral surface of the outer annular portion; A method for manufacturing a non-pneumatic tire, comprising a step of forming hole portions penetrating the outer annular portion and the tread in the outer annular portion and the tread.

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