Non-pneumatic tire and method for manufacturing a non-pneumatic tire

Abstract

To provide a non-pneumatic tire which enables spoke durability to be improved and a method for manufacturing the same.SOLUTION: A non-pneumatic tire 1 comprises: an inner annular part 20; an outer annular part 30 disposed coaxially to the outer circumference side of the inner annular part 20; and a plurality of spokes 40 that connect the inner annular part 20 and the outer annular part 30 to be arranged in a tire circumference direction C. A partition line 80 formed by a split mold 100 split in a tire width direction Y during molding of the non-pneumatic tire 1 is disposed in the spokes 40. The partition line 80 extends in the longitudinal direction L1, L2 of the spokes 40.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a non-pneumatic tire and a method for manufacturing a non-pneumatic tire.

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. Generally, a non-pneumatic tire has a structure in which an inner peripheral side annular portion and an outer peripheral side annular portion arranged coaxially with each other are connected by a plurality of spokes. The plurality of spokes are arranged radially at intervals in the tire circumferential direction. A tread that contacts the road surface is provided on the outer peripheral surface of the outer annular portion. The non-pneumatic tire is formed by filling a resin material into a mold, for example, as described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when molding a non-pneumatic tire using a split mold, a linear partition line along the joint of the upper mold and the lower mold of the split mold is formed on the spoke. In a non-pneumatic tire as described in Patent Document 1, the proportion of the load applied to the spoke is high, and there is a concern that the durability of the spoke may be reduced due to the influence of the partition line where shear stress is likely to occur during tire rolling.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a non-pneumatic tire and a method for manufacturing a non-pneumatic tire that can improve the durability of the spoke.

Means for Solving the Problems

[0006] The non-pneumatic tire of the present invention comprises an inner annular portion, an outer annular portion arranged coaxially on the outer circumference of the inner annular portion, and a plurality of spokes connecting the inner annular portion and the outer annular portion and arranged along the circumferential direction of the tire, wherein the spokes are provided with partition lines formed by a split mold that divides the tire in the tire width direction during molding of the non-pneumatic tire, and the partition lines extend in the longitudinal direction of the spokes. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a non-pneumatic tire and a method for manufacturing a non-pneumatic tire that can improve the durability of the spokes. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view showing a non-pneumatic tire of an embodiment. [Figure 2] This is a cross-sectional view taken along line II-II in Figure 1. [Figure 3] Figure 2 is a perspective view of a portion of a non-pneumatic tire, seen from an oblique angle. [Figure 4] This is a side view showing one spoke according to the embodiment. [Figure 5] This is a plan view showing a split mold used in the manufacture of a non-pneumatic tire according to the embodiment. [Figure 6] Figure 5 is a side view of the split mold as seen along the direction of arrow VI. [Figure 7] Figure 5 shows a cross-sectional view VII-VII, which illustrates a portion of the upper and lower molds of a split mold. [Figure 8] Figure 7 shows the split mold in the opened state. [Figure 9] This figure shows an analytical model of shear stress applied to a spoke subjected to a longitudinal load, and is a diagram illustrating an embodiment of the present invention. [Figure 10] This figure shows an analytical model of shear stress applied to a spoke subjected to a longitudinal load, and is a comparative example outside of the present invention. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the drawings. Figure 1 is a side view of the non-pneumatic tire 1 of this embodiment, viewed from a direction parallel to the tire rotation axis (tire meridian), that is, from a direction along the front-to-back direction of the paper in Figure 1. The non-pneumatic tire 1 shown in Figure 1 is in an unloaded state. Figure 2 is a cross-sectional view taken along line II-II of Figure 1. Figure 3 is a partial perspective view of the non-pneumatic tire 1, taken from an oblique angle from the part shown in Figure 2.

[0010] In Figures 1 and 3, arrow C indicates the circumferential direction of the tire. In Figures 1 through 3, arrow X indicates the radial direction of the tire. In Figures 2 and 3, arrow Y indicates the width direction of the tire. In Figure 1, the tire width direction Y is the front-to-back direction of the paper. In Figure 2, the symbol E is the tire equatorial plane. In Figure 2, the tire circumferential direction C is the front-to-back direction of the paper.

[0011] The tire circumferential direction C is the direction around the tire rotation axis and is the same direction in which the non-pneumatic tire 1 rotates. The tire radial direction X is the direction perpendicular to the tire rotation axis. The tire width direction Y is the direction parallel to the tire rotation axis. In Figures 2 and 3, 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 E shown in Figure 2 is a plane perpendicular to the tire rotation axis and located at the center of the tire width direction Y.

[0012] The non-pneumatic tire 1 of this embodiment comprises an inner annular portion 20, an outer annular portion 30, a plurality of spokes 40, and a tread 50.

[0013] In the following, the thickness of the inner annular portion 20 and the outer annular portion 30 refers to 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 refers to the dimension in the direction along the tire width direction Y as shown in Figure 2.

[0014] The inner annular portion 20 is an annular portion along the tire circumferential direction C that constitutes the inner peripheral portion of the non-pneumatic tire 1. The thickness and width of the inner annular portion 20 are set to be constant in order to improve uniformity. A tire wheel (not shown) is disposed in the space on the inner peripheral side of the inner annular portion 20. The inner peripheral portion of the inner annular portion 20 is fitted and mounted on the outer peripheral portion of the rim of the tire wheel. When the inner annular portion 20 is mounted on the rim, the non-pneumatic tire 1 is mounted on the tire wheel. On the inner peripheral surface of the inner annular portion 20, fitting portions formed of convex portions, grooves, or the like may be provided for fitting with the rim.

[0015] The inner annular portion 20 can be formed of, for example, a resin material having elasticity, but the material is not limited to resin.

[0016] 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 achieving weight reduction and durability while satisfying the function of sufficiently transmitting the rotational force to the spokes 40. The thickness of the inner annular portion 20 is not particularly limited, but for example, it is preferably 2% or more and 7% or less of the tire section height H shown in FIG. 2, and more preferably 3% or more and 6% or less.

[0017] The inner diameter of the inner annular portion 20 is determined according to the dimensions of the rim of the tire wheel on which the non-pneumatic tire 1 is mounted, the use of the vehicle, and the like. For example, when assuming replacement of a general pneumatic tire, the inner diameter of the inner annular portion 20 may be, for example, dimensions such as 250 mm or more and 500 mm or less, but is not limited thereto.

[0018] The width of the inner annular portion 20 is appropriately determined according to the use of the vehicle on which the non-pneumatic tire 1 is mounted and the like. For example, when assuming replacement of a general pneumatic tire, the width of the inner annular portion 20 may be dimensions such as 100 mm or more and 300 mm or less, but is not limited thereto.

[0019] An inner reinforcing layer 60 is embedded inside the inner annular portion 20 as a reinforcing layer. The inner reinforcing layer 60 serves the function of enabling the inner annular portion 20 to be fitted into the rim of the tire wheel with high elasticity and strength. The inner reinforcing layer 60 contains fiber-reinforced plastic. The inner reinforcing layer 60 may be, for example, a mesh-like arrangement of fiber-reinforced plastic cords such as GFRP, but is not limited to this. The inner reinforcing layer 60 can be embedded in the inner annular portion 20 by, for example, being placed in the mold during the molding of the inner annular portion 20 and filling it with resin material for the inner annular portion 20 during molding. Note that the inner reinforcing layer 60 is not limited to a layer containing fiber-reinforced plastic, and may be, for example, a metal plate.

[0020] The outer annular portion 30 is an annular part along the tire circumferential direction C that constitutes the outer circumference of the non-pneumatic tire 1. The outer annular portion 30 is located on the outer circumference side of the inner annular portion 20 and is arranged coaxially with the inner annular portion 20. The thickness and width of the outer annular portion 30 are set to be constant in order to improve uniformity.

[0021] The outer annular portion 30 can be formed from, for example, an elastic resin material, but the material is not limited to resin.

[0022] The outer annular portion 30 transmits the rotation of the inner annular portion 20 and spokes 40 to the road surface via the tread 50. The thickness of the outer annular portion 30 is determined from the viewpoint of achieving weight reduction and durability while satisfying the function of sufficiently transmitting rotational force from the spokes 40 to the road surface. The thickness of the outer annular portion 30 is not particularly limited, but for example, it is preferably 2% to 7% of the tire cross-sectional height H shown in Figure 2, and more preferably 2% to 5%.

[0023] The inner diameter of the outer annular portion 30 is determined appropriately according to the dimensions of the rim of the tire wheel on which the non-pneumatic tire 1 is mounted, the intended use of the vehicle, etc. For example, when considering a replacement for a general pneumatic tire, the inner diameter of the outer annular portion 30 may be between 420 mm and 750 mm, but is not limited to this.

[0024] The width of the outer annular portion 30 is determined appropriately according to the intended use of the vehicle on which the non-pneumatic tire 1 is fitted. For example, when considering a replacement for a general pneumatic tire, the width of the outer annular portion 30 may be between 100 mm and 300 mm, but is not limited to this.

[0025] An annular outer reinforcing layer 70 is embedded around the entire circumference of the outer annular section 30 as a reinforcing layer. The outer reinforcing layer 70 is embedded coaxially with the outer annular section 30. The outer reinforcing layer 70 is an example of a reinforcing layer embedded in the outer annular section 30.

[0026] The outer reinforcing layer 70 includes fiber-reinforced plastic. In this embodiment, the outer reinforcing layer 70 includes carbon fiber reinforced plastic (CFRP). Specifically, the outer reinforcing layer 70 is constructed as a flexible sheet by embedding mesh-woven carbon fibers in resin and laminating flexible material sheets. It is preferable that the resin constituting the outer reinforcing layer 70 is a different type of resin from the resin constituting the spokes 40, which will be described later. The outer reinforcing layer 70 is not limited to a layer containing fiber-reinforced plastic, and may be, for example, a metal plate.

[0027] The width of the outer reinforcing layer 70, i.e., the dimension in the tire width direction Y, is preferably about 135 mm. The tire width direction Y of the outer annular portion 30 is approximately equal to the tire width direction Y of the tread 50, which will be described later. The thickness of the outer reinforcing layer 70 embedded inside the outer annular portion 30, i.e., the dimension in the tire radial direction X, is naturally smaller than the thickness of the outer annular portion 30, and its thickness is preferably about 2.0 mm. The outer reinforcing layer 70 is preferably positioned in the center of the outer annular portion 30 in the tire radial direction X and in the center of the tire width direction Y.

[0028] Multiple 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 multiple spokes 40, are arranged coaxially with respect to each other. Each of the multiple spokes 40 is arranged independently along the tire circumferential direction C. As shown in Figure 1, when the non-pneumatic tire 1 is unloaded, the multiple spokes 40 extend linearly in the radial direction, substantially parallel to the tire radial direction X, when viewed from the side. In this embodiment, the multiple spokes 40 are arranged at equal intervals in the tire circumferential direction C, but they may also be arranged at a variable pitch in the tire circumferential direction C.

[0029] As shown in Figures 2 and 3, the spokes 40 of this embodiment include a plurality of first spokes 41 and a plurality of second spokes 42. The extending direction of both the first spokes 41 and the second spokes 42 is not parallel to the tire radial direction X when viewed along the tire circumferential direction C. The first spokes 41 are inclined toward one side in the tire axial direction, i.e., the tire width direction Y. The second spokes 42 are inclined toward the opposite side from the first spokes 41. The first spokes 41 and the second spokes 42 are arranged alternately in the tire circumferential direction C.

[0030] As shown in Figures 2 to 4, partition lines 80 formed during the manufacturing of the non-pneumatic tire 1 of this embodiment are positioned on the first spoke 41 and the second spoke 42. The configuration of the partition lines 80 will be described later.

[0031] As shown in Figures 2 and 3, the first spoke 41 extends inclined from one side of the outer annular portion 30 in the tire width direction Y, Y1, to the other side of the inner annular portion 20 in the tire width direction Y, Y2. The second spoke 42 extends inclined from the other side of the outer annular portion 30 in the tire width direction Y, Y2, to one side of the inner annular portion 20 in the tire width direction Y, Y1.

[0032] The inclination angles of the first spoke 41 and the second spoke 42 are the same. Therefore, when viewed from a direction along the tire circumferential direction C, the first spoke 41 and the second spoke 42 adjacent to each other in the tire circumferential direction C are arranged in a roughly X shape. As shown in Figure 2, the first spoke 41 and the second spoke 42 are inclined at an angle θ with respect to the tire width direction Y, and this angle θ is preferably, for example, 39° or more and 49° or less.

[0033] As shown in Figure 2, when viewed from a direction along the tire circumferential direction C, the first spoke 41 and the second spoke 42 each have the same shape, symmetrical with respect to the tire equatorial plane E. Therefore, in the following, there is no need to distinguish between the first spoke 41 and the second spoke 42, and when they can be described together, the first spoke 41 and the second spoke 42 will be collectively referred to as spoke 40.

[0034] The spoke 40 is plate-shaped and extends diagonally from the inner annular portion 20 toward the outer annular portion 30 at an angle θ as described above. As shown in Figure 3, the plate thickness t of the spoke 40 along the tire circumferential direction is smaller than the plate width w, and the direction of the plate thickness t is along the tire circumferential direction C. That is, the spoke 40 is formed in a plate shape that extends along the plane of the tire radial direction X and the tire width direction Y. The plate width w referred to here is the dimension in the direction perpendicular to the inclination direction in which the spoke 40 extends, i.e., the length direction of the spoke 40, when the spoke 40 is viewed from the direction along the tire circumferential direction C, as shown in Figure 2. The plate width w of the first spoke 41 is the dimension in the direction perpendicular to the length direction L1 of the first spoke 41, when the spoke 40 is viewed from the direction along the tire circumferential direction C, as shown in Figures 2 and 3. Furthermore, the plate width w of the second spoke 42 is the dimension perpendicular to the longitudinal direction L2 of the second spoke 42 when the spoke 40 is viewed from a direction along the tire circumferential direction C, as shown in Figures 2 and 3. In this embodiment, the plate thickness t of all spokes 40 is the same. Also, the plate width w of all spokes 40 is the same. In addition, the length dimension of the spoke 40 is greater than the plate width w.

[0035] The spoke 40 is a long, plate-like shape and has a first surface 401 and a second surface 402 facing the thickness direction T of the spoke 40, and a first side surface 403 and a second side surface 404 facing the width direction of the spoke 40. The first surface 401 is the surface on the front side of the paper in Figure 2, and the second surface 402 is the surface on the back side of the paper in Figure 2. The first side surface 403 is the side surface of the spoke 40 on the tire width direction Y1, and the second side surface 404 is the side surface of the spoke 40 on the tire width direction Y2.

[0036] Figure 4 is a side view of one spoke 40 when viewed from the side of a non-pneumatic tire 1. As shown in Figure 4, the spoke 40 of this embodiment has a tapered shape that gradually increases from the inner end 40a, which is one end on the inner annular portion 20 side, to the outer end 40b, which is the other end on the outer annular portion 30 side, when viewed from the side of the tire. In the configuration shown in Figure 4, the outer circumference is thicker than the inner circumference, and the plate thickness t gradually increases from the inner end 40a to the outer end 40b. Note that the plate thickness t of the spoke 40 may be constant from the inner end 40a to the outer end 40b.

[0037] In this embodiment, the multiple spokes 40 are arranged at equal intervals in the tire circumferential direction C. That is, in the multiple spokes 40, the distance between the centers of the plate thickness t of adjacent pairs of spokes 40 in the tire circumferential direction C is equal. The multiple spokes 40 may also be arranged at a variable pitch in the tire circumferential direction C.

[0038] Since the spokes 40 are long, flat plates, even if the plate thickness t is reduced, the durability of the spokes 40 can be maintained by setting a wider plate width w.

[0039] In this embodiment, the spokes 40 are parallel to the tire radial direction X in a side view, but the spokes 40 may also be arranged diagonally to the tire radial direction X so as to intersect with the tire radial direction X in a side view.

[0040] The first spoke 41 and the second spoke 42 will be described in detail below with reference to Figures 2 and 3.

[0041] The first spoke 41 has a first straight section 410, a first inner connecting section 411 connecting the first straight section 410 to the inner annular section 20, and a first outer connecting section 412 connecting the first straight section 410 to the outer annular section 30. The first inner connecting section 411 is provided in half of the inner annular section 20 on the tire width direction Y2 side. The first outer connecting section 412 is provided in half of the outer annular section 30 on the tire width direction Y1 side.

[0042] The first straight section 410 extends inclined from the outer annular section 30 towards the inner annular section 20 towards the inner annular section 20 towards the tire width direction Y2. That is, the first straight section 410 coincides with the inclination direction of the first spoke 41. The plate width w of the first straight section 410 is constant in the length direction L1.

[0043] As shown in Figure 2, the first inner connecting portion 411 of the first spoke 41 has a shape that widens along the tire width direction Y as it approaches the inner annular portion 20 from the first straight portion 410. The second side surface 404 of the first inner connecting portion 411, side surface 411a, on the tire width direction Y2 side, extends in a gentle curve to the end 20b of the inner annular portion 20 on the tire width direction Y2 side. The first side surface 403 of the first inner connecting portion 411, side surface 411b, on the tire width direction Y1 side, extends in a curve toward the tire width direction Y1 to the position of the tire equatorial plane E of the inner annular portion 20. In other words, the plate width w of the first inner connecting portion 411 increases as it approaches the inner annular portion 20 from the first straight portion 410 side.

[0044] The first outer connecting portion 412 of the first spoke 41 has the same shape as the first inner connecting portion 411, and has a shape that widens along the tire width direction as it approaches the outer annular portion 30 from the first straight portion 410. The first side surface 403 of the first outer connecting portion 412, which is the side surface 412a on the tire width direction Y1 side, extends in a gentle curve to the end 30a of the outer annular portion 30 on the tire width direction Y1 side. The second side surface 404 of the first outer connecting portion 412, which is the side surface 412b on the tire width direction Y2 side, extends in a curve toward the tire width direction Y2 to the position of the tire equator plane E of the outer annular portion 30. In other words, the plate width w of the first outer connecting portion 412 increases as it approaches the outer annular portion 30 from the first straight portion 410 side.

[0045] As shown in Figures 2 and 3, the first spoke 41 has edges 413a and 413b at both ends in the width direction D1 of the first surface 401 and the second surface 402. Specifically, the edge 413a of the first surface 401 is the part where the first surface 401 intersects with the second side surface 404 on the tire width direction Y2 side of the first spoke 41. The edge 413a of the second surface 402 is the part where the second side surface 404 on the tire width direction Y2 side of the first spoke 41 intersects with the second surface 402. The edge 413b of the first surface 401 is the part where the first side surface 403 on the tire width direction Y1 side of the first spoke 41 intersects with the first surface 401. The edge 413b of the second surface 402 is the part where the first side surface 403 on the tire width direction Y1 side of the first spoke 41 intersects with the second surface 402. In other words, the edges 413a and 413b of the first spoke 41 correspond to the contour line B of the first spoke 41 when the spoke 40 is viewed along the tire circumferential direction C. As shown in Figures 2 and 3, the contour line B of the first spoke 41 extends linearly in the first straight section 410 and curvedly in the first inner connection section 411 and the first outer connection section 412.

[0046] The second spoke 42 has the same shape as the first spoke 41 and is symmetrical to the first spoke 41 on the tire equatorial plane E.

[0047] The second spoke 42 has a second straight section 420, a second inner connecting section 421 connecting the second straight section 420 to the inner annular section 20, and a second outer connecting section 422 connecting the second straight section 420 to the outer annular section 30. The second inner connecting section 421 is provided in half of the inner annular section 20 on the tire width direction Y1 side. The second outer connecting section 422 is provided in half of the outer annular section 30 on the tire width direction Y2 side.

[0048] The second straight section 420 extends inclined from the outer annular section 30 on the tire width direction Y2 side toward the inner annular section 20 on the tire width direction Y1 side. That is, the second straight section 420 coincides with the inclination direction of the second spoke 42. The plate width w of the second straight section 420 is constant in the length direction L2.

[0049] As shown in Figure 2, the second inner connecting portion 421 of the second spoke 42 has a shape that widens along the tire width direction Y as it approaches the inner annular portion 20 from the second straight portion 420. The first side surface 403 of the second inner connecting portion 421, which is the side surface 421a on the tire width direction Y1 side, extends in a gentle curve to the end 20a of the inner annular portion 20 on the tire width direction Y1 side. The second side surface 404 of the second inner connecting portion 421, which is the side surface 421b on the tire width direction Y2 side, extends in a curve toward the tire width direction Y2 to the position of the tire equatorial plane E of the inner annular portion 20. In other words, the plate width w of the second inner connecting portion 421 increases as it approaches the inner annular portion 20 from the second straight portion 420 side.

[0050] The second outer connecting portion 422 of the second spoke 42 has the same shape as the second inner connecting portion 421, and has a shape that widens along the tire width direction as it approaches the outer annular portion 30 from the second straight portion 420. The side surface 422a of the second outer connecting portion 422, which is the second side surface 404 on the tire width direction Y2 side, extends in a gentle curve to the end 30b of the outer annular portion 30 on the tire width direction Y2 side. The side surface 422b of the second outer connecting portion 422 on the tire width direction Y1 side curves toward the tire width direction Y1 and extends to the position of the tire equatorial plane E of the outer annular portion 30. In other words, the plate width w of the second inner connecting portion 421 increases as it approaches the outer annular portion 30 from the second straight portion 420 side.

[0051] As shown in Figures 2 and 3, the second spoke 42 has edges 423a and 423b at both ends in the width direction D2 of the first surface 401 and the second surface 402. Specifically, the edge 423a of the first surface 401 is the part where the first side surface 403 on the tire width direction Y1 side of the second spoke 42 intersects with the first surface 401. The edge 423a of the second surface 402 is the part where the first side surface 403 on the tire width direction Y1 side of the first spoke 41 intersects with the second surface 402. The edge 423b of the first surface 401 is the part where the second side surface 404 on the tire width direction Y2 side of the second spoke 42 intersects with the first surface 401. The edge 423b of the second surface 402 is the part where the second side surface 404 on the tire width direction Y2 side of the second spoke 42 intersects with the second surface 402. In other words, the edges 423a and 423b of the second spoke 42 correspond to the contour line B of the second spoke 42 when the spoke 40 is viewed along the tire circumferential direction C. As shown in Figures 2 and 3, the contour line B of the second spoke 42 extends linearly in the second straight section 420 and curvedly in the second inner connection section 421 and the second outer connection section 422.

[0052] As described above, the plate thickness t of all spokes 40 in this embodiment is the same. The dimension of the plate thickness t is not particularly limited, but in order for the spokes 40 to receive sufficient rotational force from the inner annular portion 20 and the outer annular portion 30, and to be able to deform appropriately when subjected to a load, it is preferably 1 mm to 30 mm, and more preferably 5 mm to 25 mm.

[0053] As described above, the plate width w of all spokes 40 in this embodiment is the same. The plate width w of the spokes 40 is not particularly limited, but it is preferably 5 mm to 25 mm, and more preferably 10 mm to 20 mm, in order to sufficiently receive the rotational force from the inner annular portion 20 and the outer annular portion 30, while also allowing for appropriate deflection and deformation when a load is applied. Furthermore, the plate width w is preferably 110% or more of the plate thickness t, and more preferably 115% or more, from the viewpoint of improving durability and distributing the ground pressure.

[0054] The number of spokes 40 is preferably 80 to 300, and more preferably 100 to 200, from the viewpoint of being able to adequately support the load from the vehicle, reduce weight, and improve both power transmission and durability.

[0055] The spacing between multiple spokes 40 in the tire circumferential direction C is preferably set to, for example, 1.0 mm or more and 4.1 mm or less. In this embodiment, the spacing between multiple spokes 40 in the tire circumferential direction C is equal, but it may be unequal.

[0056] The spokes 40 can be formed from the elastic materials listed below. First, regarding the properties of the elastic material, from the viewpoint of providing appropriate rigidity while ensuring sufficient durability, it is preferable that the tensile modulus calculated from the tensile stress at 10% elongation, after conducting a tensile test in accordance with JIS K7312:1996, is between 3 MPa and 12 MPa.

[0057] If the tensile modulus calculated from the tensile stress at 10% elongation in spoke 40 is less than 3 MPa, sufficient rigidity cannot be obtained, and adjacent spokes 40 in the tire circumferential direction C may come into contact with each other. On the other hand, if the tensile modulus calculated from the tensile stress at 10% elongation exceeds 12 MPa, the rigidity becomes excessively high, resulting in a deterioration of ride comfort.

[0058] Elastic materials used as the base material for spoke 40 include thermoplastic elastomers, cross-linked rubber, and other resins.

[0059] Examples of thermoplastic elastomers include polyester elastomers, polyolefin elastomers, polyamide elastomers, polystyrene elastomers, polyvinyl chloride elastomers, and polyurethane elastomers.

[0060] The rubber material used to make up the crosslinked rubber can be either natural rubber or synthetic rubber. Examples of synthetic rubbers 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, and urethane rubber. Two or more of these rubber materials may be used in combination as needed.

[0061] Other resins include thermoplastic resins and thermosetting resins. Examples of thermoplastic resins include polyethylene resin, polystyrene resin, and polyvinyl chloride resin. Examples of thermosetting resins include epoxy resin, phenolic resin, polyurethane resin, silicone resin, polyimide resin, and melamine resin.

[0062] From the viewpoint of moldability, processability, and cost, polyurethane resin is preferably used for the spokes 40 among the elastic materials mentioned above. Foamed materials can also be used as the elastic material. That is, foamed thermoplastic elastomers, crosslinked rubbers, and other resins can be used.

[0063] Furthermore, the elastic material used as the base material for the spokes 40 may be reinforced with reinforcing fibers. Examples of reinforcing fibers include long fibers, short fibers, woven fabrics, and nonwoven fabrics. Examples of types of reinforcing fibers include rayon cord, polyamide cord such as nylon-6,6, polyester cord such as polyethylene terephthalate, aramid cord, glass fiber cord, carbon fiber, and steel cord.

[0064] Furthermore, reinforcement of elastic materials is not limited to reinforcement with reinforcing fibers. For example, reinforcement may be carried out by adding granular fillers. Examples of granular fillers that can be added include carbon black, silica, ceramics such as alumina, and other inorganic material fillers.

[0065] Incidentally, it is preferable that the inner annular portion 20 and the outer annular portion 30 described above are formed from the same resin material as the spokes 40. In that case, the inner annular portion 20, the outer annular portion 30, and the spokes 40 can be integrally molded, for example, by a casting method.

[0066] The tread 50 is provided on the outer peripheral surface 32 of the outer annular portion 30. The tread 50 constitutes the outermost outer part of the non-pneumatic tire 1. As shown in Figures 2 and 3, the tread 50 includes tread rubber 51. The tread rubber 51 has a tread surface 51a on its outer peripheral surface that contacts the road surface. There are no particular restrictions on the type of rubber material used for the tread rubber 51; general vulcanized rubber used to constitute the tread of vehicle tires can be used. The tread surface 51a of the tread rubber 51 is provided with a tread pattern formed by multiple grooves and flat areas, similar to conventional pneumatic tires.

[0067] The tread rubber 51 may also be composed of multiple layers of rubber with different components and properties (for example, two or three layers). The tread 50 may also be made of resin. The tread rubber 51 is bonded to the outer circumferential surface 32 of the outer annular portion 30 by a vulcanizing adhesive layer 52.

[0068] Next, we will explain partition line 80.

[0069] The partition line 80 is formed linearly on the spoke 40 by a dividing mold 100 that divides the tire in the tire width direction Y during the molding of the non-pneumatic tire 1. First, before describing the specific configuration of the partition line 80, the basic configuration of the dividing mold 100 will be described with reference to Figures 5 and 6. Figure 5 is a plan view showing the dividing mold 100 used in the manufacture of the non-pneumatic tire 1 according to the embodiment. Figure 6 is a side view of the dividing mold 100 shown in Figure 5, viewed along the direction of arrow VI. Note that in Figure 6, part of the outer mold 102 is omitted from the illustration so that the shape of the inner mold 101 in side view can be confirmed.

[0070] In Figures 5 and 6, arrow F indicates the radial direction of the split mold 100, arrow F1 indicates the inner radial direction approaching the central axis of the split mold 100 in the mold radial direction F, and arrow F2 indicates the outer radial direction opposite to the inner radial direction F1. In Figure 5, arrow G indicates the circumferential direction of the split mold 100. In Figure 6, the mold circumferential direction G of the split mold 100 is the front-back direction of the paper. In Figure 6, arrow I indicates the axial direction of the split mold 100, as well as the up-down direction during molding by the split mold 100.

[0071] As shown in Figures 5 and 6, the split mold 100 comprises an inner mold 101 consisting of an upper mold 110 and a lower mold 120, and an outer mold 102 positioned on the outer circumference of the inner mold 101. The split mold 100 is formed in an annular shape as a whole to match the shape of the non-pneumatic tire 1. The inner mold 101 is divided into the upper mold 110 and the lower mold 120 in the axial direction of the split mold 100.

[0072] The inner mold 101 primarily forms the spokes 40. The upper mold 110 and lower mold 120 that constitute the inner mold 101 have forming surfaces on opposite sides. The upper mold 110 and lower mold 120 are opened in the tire width direction Y of the non-pneumatic tire 1 to be formed. That is, the non-pneumatic tire 1 is formed so that the axial direction of the split mold 100 coincides with the tire width direction Y. The partition line 80 is formed along the joint where the upper mold 110 and lower mold 120 contact each other when the split mold 100 is closed. Specifically, when the split mold 100 is closed, the upper mold 110 is shifted in the mold circumferential direction G relative to the lower mold 120, and as the spokes 40 are formed in this state, a step is created on the first surface 401 and the second surface 402 of the spokes 40. This step is the partition line 80.

[0073] Next, the detailed configuration of partition line 80 will be explained with reference to Figures 2 to 4.

[0074] As shown in Figures 2 and 3, the partition line 80 extends in the longitudinal direction of the spoke 40. As shown in Figure 4, the partition line 80 is positioned on the first surface 401 and the second surface 402 of the spoke 40, with one side in its longitudinal direction extending toward the inner annular portion 20 and the other side extending toward the outer annular portion 30. In this embodiment, the partition line 80 positioned on the first surface 401 and the second surface 402 of the first spoke 41 extends substantially parallel to the direction in which the edges 413a and 413b of the first straight portion 410 extend. Similarly, the partition line 80 positioned on the first surface 401 and the second surface 402 of the second spoke 42 extends substantially parallel to the direction in which the edges 423a and 423b extend. Note that the partition line 80 positioned on the first spoke 41 may extend at a predetermined angle with respect to the direction in which the edges 413a and 413b of the first straight portion 410 extend. Furthermore, the partition line 80 positioned on the second spoke 42 may extend at a predetermined angle with respect to the direction in which the edges 423a and 423b of the second straight section 420 extend.

[0075] In this embodiment, the partition line 80 extends along the length of the spoke 40 such that one end 81 contacts the inner annular portion 20 and the other end 82 contacts the outer annular portion 30. That is, the partition line 80 extends from the inner annular portion 20 to the outer annular portion 30 on the first spoke 41, and extends from the inner annular portion 20 to the outer annular portion 30 on the second spoke 42.

[0076] Furthermore, the partition line 80 is located approximately in the center of the plate width direction perpendicular to the length direction of the spoke 40. Specifically, the partition line 80 on the first spoke 41 is located approximately in the center of the plate width direction D1 of the first spoke 41 in the first straight section 410 and extends along the length direction L1. The partition line 80 on the second spoke 42 is located approximately in the center of the plate width direction D2 of the second spoke 42 in the second straight section 420 and extends along the length direction L2.

[0077] Furthermore, as shown in Figures 2 and 3, the partition lines 80 do not contact the edges 413a, 413b, 423a, and 423b of the first surface 401 and the second surface 402. Specifically, the partition line 80 positioned on the first spoke 41 is spaced apart from the edges 413a and 413b on the first surface 401 and spaced apart from the edges 413a and 413b on the second surface 402. Similarly, the partition line 80 positioned on the second spoke 42 is spaced apart from the edges 423a and 423b on the first surface 401 and spaced apart from the edges 423a and 423b on the second surface 402. In other words, when the spoke 40 is viewed in the tire circumferential direction C, the partition line 80 is positioned away from the contour line B of the spoke 40 on the first surface 401 or the second surface 402 without contacting the contour line B of the spoke 40.

[0078] Here, the spokes 40 of the non-pneumatic tire 1 are subjected to a higher proportion of load compared to other parts when the tire is rolling. In particular, the partition line 80, which is a step that occurs on the spokes 40, has one end 81 and the other end 82, and the edges 413a, 413b, 423a, 423b of the spokes 40 tend to be susceptible to stress. If the partition line 80 extends to both ends of the spoke 40 in the width direction, shear stress is generated at the intersection of the partition line 80 and the edges 413a, 413b, 423a, 423b, etc., causing shear yielding of the resin, which in turn causes cracks to propagate and lead to spoke fracture.

[0079] In this embodiment, the partition lines 80 arranged on the spokes 40 do not come into contact with the edges 413a, 413b, 423a, and 423b, and extend along the length of the spokes 40, thus preventing the generation of shear stress. Therefore, the durability of the spokes 40 can be improved.

[0080] Next, a method for manufacturing the non-pneumatic tire 1 according to this embodiment will be described.

[0081] The non-pneumatic tire 1 includes a molding step of forming an inner annular portion 20, an outer annular portion 30, and a support structure that will become spokes 40 using a split mold 100, and a tread forming step of forming a tread 50 on the outer peripheral surface 32 of the outer annular portion 30.

[0082] In the molding process, resin is filled into the closed split mold 100, heated (for example, 100°C to 160°C), and then cooled. After cooling, the mold is opened in the tire width direction Y, and the support structure is removed from the split mold. This forms the inner annular portion 20, the outer annular portion 30, and the spokes 40 on which the partition lines 80 are positioned. In other words, the spokes 40 on which the partition lines 80 are positioned are formed by filling the split mold 100 with resin and then removing the split mold 100. The partition lines 80 positioned on the spokes 40 are positioned to extend along the length of the spokes 40 by using the split mold 100.

[0083] In the tread formation process, a vulcanizing adhesive is applied to the outer circumferential surface of the support structure. Then, the tread rubber composition is attached to the outer circumferential surface 32 of the outer annular portion 30 to which the vulcanizing adhesive has been applied, and the support structure and the tread rubber composition are vulcanized and bonded by heating and pressurizing using a vulcanizing device. The tread rubber composition is not particularly limited, but for example, it may contain natural rubber and carbon black, and may further contain sulfur, silica, etc. Here, the tread rubber composition may contain synthetic rubber such as polyisoprene rubber or styrene-butadiene rubber together with natural rubber, or in place of natural rubber.

[0084] Through this manufacturing process, a non-pneumatic tire 1 is produced.

[0085] Next, the configuration of the inner mold 101 of the split mold 100, which forms the spokes 40 on which the partition lines 80 along the longitudinal direction are arranged, will be described with reference to Figures 7 and 8. Figure 7 is a cross-sectional view taken along line VII-VII in Figure 5, showing the spacers 112 of the upper mold 110 and the spacers 122 of the lower mold 120 as seen along the circumferential direction G of the mold. Figure 8 shows the split mold shown in Figure 7 in the opened state. In Figure 7, the positional relationship between the inner annular portion 20, the outer annular portion 30, and the spokes 40 formed by the split mold 100 and the inner mold 101 is shown by a dashed line.

[0086] In Figures 7 and 8, arrow F indicates the radial direction of the split mold 100, arrow F1 indicates the inner radial direction approaching the central axis of the split mold 100 in the mold radial direction F, and arrow F2 indicates the outer radial direction opposite to the inner radial direction F1. In Figures 7 and 8, the mold circumferential direction G is the front-back direction of the paper.

[0087] As shown in Figures 7 and 8, the upper mold 110 has an annular base 111, a plurality of spacers 112 for dividing the space in which the spokes 40 are formed, etc. The spacers 112 are plate-shaped and extend downward from the lower surface of the base 111, i.e., the surface facing the lower mold 120 when the mold is closed. The plurality of spacers 112 are arranged intermittently along the circumferential direction G of the mold at intervals that allow spokes 40 of a desired plate thickness t to be formed. Each spacer 112 extends from one end to the other of the base 111 in the radial direction F of the mold, i.e., in the width direction of the base 111.

[0088] The spacer 112 is composed of a first extension piece 112a and a second extension piece 112b. The first extension piece 112a is triangular plate-shaped and is formed such that its length extending downward increases towards the outer diameter direction F2, as shown in Figure 8. That is, the first extension piece 112a has an inclined portion S1 that slopes downward toward the outer diameter direction F2. The second extension piece 112b is triangular plate-shaped and is formed such that its length extending downward increases towards the inner diameter direction F1. That is, the second extension piece 112b has an inclined portion S2 that slopes downward toward the inner diameter direction F1. The first extension piece 112a and the second extension piece 112b are integrated in a state of contact in the thickness direction, which is the circumferential direction G of the mold. Note that the first extension piece 112a of the spacer 112 shown in Figure 8 is located closer to the viewer in Figure 8 than the second extension piece 112b, but the first extension piece 112a of a spacer 112 adjacent to the spacer 112 shown in Figure 8 in the mold circumferential direction G is located further back in Figure 8 than the second extension piece 112b. In other words, the positions of the first extension pieces 112a and second extension pieces 112b of multiple spacers 112 arranged in the mold circumferential direction G are alternately swapped in the mold circumferential direction G. That is, when the divided mold 100 is closed, the spacer 112 is arranged so that its first extension piece 112a faces the first extension piece 112a of an adjacent spacer 112 in the mold circumferential direction G. Also, when the divided mold 100 is closed, the spacer 112 is arranged so that its second extension piece 112b faces the second extension piece 112b of an adjacent spacer 112 in the mold circumferential direction G.

[0089] As shown in Figures 7 and 8, the lower mold 120 has an annular base 121, a plurality of spacers 122 for defining the space in which the spokes 40 are formed, etc. The spacers 122 are plate-shaped and extend upward from the upper surface of the base 121, i.e., the surface facing the upper mold 110 when the mold is closed. The plurality of spacers 122 are intermittently arranged along the circumferential direction G of the mold at intervals that allow spokes 40 of a desired plate thickness t to be formed.

[0090] The spacer 122 is composed of a first extension piece 122a and a second extension piece 122b. The first extension piece 122a is triangular plate-shaped and is formed such that its length extending upward increases towards the inner diameter direction F1, as shown in Figure 8. That is, the first extension piece 122a has an inclined portion S3 that slopes upward toward the inner diameter direction F1. The second extension piece 122b is triangular plate-shaped and is formed such that its length extending upward increases towards the outer diameter direction F2. That is, the second extension piece 122b has an inclined portion S4 that slopes upward toward the outer diameter direction F2. The first extension piece 122a and the second extension piece 122b are integrated in a state of contact in the thickness direction, which is the circumferential direction G of the mold. Note that the first extension piece 122a is located closer to the viewer in Figure 8 than the second extension piece 122b, but the first extension piece 122a of a spacer 122 adjacent to a spacer 122 in the mold circumferential direction G shown in Figure 8 is located further back in Figure 8 than the second extension piece 122b. In other words, the positions of the first extension pieces 122a and second extension pieces 122b of multiple spacers 122 arranged in the mold circumferential direction G are alternately swapped in the mold circumferential direction G. That is, when the divided mold 100 is closed, spacer 122 is arranged so that its first extension piece 122a faces the first extension piece 122a of an adjacent spacer 122 in the mold circumferential direction G. Similarly, when the divided mold 100 is closed, spacer 112 is arranged so that its second extension piece 122b faces the second extension piece 122b of an adjacent spacer 122 in the mold circumferential direction G.

[0091] Spacers 112 and 122 are configured such that when the mold is closed, the inclined portion S1 and inclined portion S3 come into contact, and the inclined portion S2 and inclined portion S4 come into contact. That is, the joint P between the upper mold 110 and the lower mold 120 is formed by the portion where the inclined portions S1 and S3 come into contact, and the portion where the inclined portions S2 and S4 come into contact.

[0092] As shown in Figure 7, the width direction Y of the molded non-pneumatic tire 1 coincides with the axial direction I of the split mold 100. Also, the tire circumferential direction C of the molded non-pneumatic tire 1 coincides with the mold circumferential direction G of the split mold 100. Furthermore, the position of the joint P of the upper mold 110 and the lower mold 120 coincides with the position where the spokes 40 are formed. Specifically, the first spoke 41 is molded in a space where the joint P formed by the inclined portions S1 and S3 and the joint P formed by the inclined portions S1 and S3 of adjacent spacers 112 and 122 face each other in the mold circumferential direction G. The first spoke 41 is also molded such that its inclination angle is approximately equal to the inclination angle of the joint P. As a result, a partition line 80 extending along the length direction L1 is formed on the first surface 401 and the second surface 402 of the first spoke 41. The second spoke 42 is formed in a space where the joint P formed by the inclined portions S2 and S4 of the second spoke 42 and the joint P formed by the inclined portions S2 and S4 of the adjacent spacers 112 and 122 face each other in the circumferential direction G of the mold. The second spoke 42 is also formed such that its inclination angle is approximately equal to the inclination angle of the joint P. As a result, a partition line 80 extending along the longitudinal direction L2 is formed on the first surface 401 and the second surface 402 of the second spoke 42.

[0093] Furthermore, in the split mold 100, when the mold is closed, the first extension piece 112a of the upper mold 110 overlaps with the second extension piece 122b of the lower mold 120, and the second extension piece 112b of the upper mold 110 overlaps with the first extension piece 121b of the lower mold 120. This configuration suppresses the occurrence of misalignment of the upper mold 110 in the mold circumferential direction G relative to the lower mold 120, and has the effect of reducing the step height of the partition line 80. As a result, the durability of the molded spokes 40 can be further improved. [Examples]

[0094] The following describes the examples. A non-pneumatic tire of an example manufactured by the above manufacturing method and having the same configuration as the above embodiment, and a non-pneumatic tire of a comparative example were evaluated using an FEM analysis model.

[0095] The comparative non-pneumatic tire has the same configuration as the embodiment except for the position of the partition lines arranged on the spokes. The partition lines of the comparative example are arranged on the first and second surfaces of the spokes so as to extend linearly in the tire radial direction X from the center in the tire width direction Y.

[0096] Figure 9 is a diagram showing an analytical model of shear stress on a spoke subjected to a longitudinal load, and is a diagram of an example. Figure 10 is a diagram showing an analytical model of shear stress on a spoke subjected to a longitudinal load, and is a diagram of a comparative example. In Figures 9 and 10, the shading of the analytical model indicates the magnitude of the stress, with darker shading indicating a greater stress on the spoke.

[0097] As shown in Figure 10, in the comparative example, it can be seen that greater stress is applied to the areas where the partition line is placed. In particular, it can be seen that stress is concentrated at the points where the partition line intersects with the edges of the spokes in the width direction. In contrast, in the embodiment, as shown in Figure 9, the stress on the spokes is more distributed compared to the comparative example. In particular, it can be seen that the stress on the edges of the spokes in the width direction is smaller. According to the results of the embodiment, the partition line 80 is placed on the spokes 40 so as to extend along the length direction of the spokes 40, and this can be seen as improving the durability of the tire.

[0098] The non-pneumatic tire 1 of the above-described embodiment provides the following effects.

[0099] (1) The non-pneumatic tire 1 according to this embodiment comprises an inner annular portion 20, an outer annular portion 30 arranged coaxially on the outer circumference 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, wherein the spokes 40 are provided with partition lines 80 formed by a divided mold 100 that divides the non-pneumatic tire 1 in the tire width direction Y during molding, and the partition lines 80 extend along the longitudinal directions L1, L2 of the spokes 40.

[0100] As a result, the partition line 80, which is prone to generating shear stress during tire rolling, extends along the length of the spoke 40, thus preventing the generation of shear stress. Therefore, the durability of the tire can be improved.

[0101] (2) Furthermore, it is preferable that the partition line 80 be located approximately in the center of the plate width direction D1, D2 of the spoke 40.

[0102] As a result, even if shear stress is generated in the partition line 80 during tire rolling and a crack occurs starting from the partition line 80, the crack is less likely to intersect with both ends of the spoke in the width direction D1 and D2, thereby reliably improving the durability of the spoke 40.

[0103] (3) The spokes 40 are long, plate-shaped, and the partition lines 80 are positioned on at least one of the first surface 401 and the second surface 402 that are opposite to the plate thickness direction T of the spokes 40, and are spaced apart from the edges 413a, 413b, 423a, and 423b at both ends of the plate width directions D1 and D2 of the first surface 401 and the second surface 402.

[0104] As a result, the partition lines 80 positioned on the spokes 40 do not come into contact with the edges 413a, 413b, 423a, and 423b, and extend along the length of the spokes 40, thus preventing the generation of shear stress.

[0105] (4) The inner annular portion 20 and the outer annular portion 30 have an inner reinforcing layer 60 and an outer reinforcing layer 70.

[0106] As a result, the strength of the inner annular portion 20 and the outer annular portion 30 is improved, thereby suppressing the occurrence of cracks from one end 81 of the partition line 80 located on the inner annular portion 20 side and the other end 82 located on the outer annular portion 30 side.

[0107] (5) The spokes 40 include a first spoke 41 that is inclined toward one side in the tire axial direction and a second spoke 42 that is inclined toward the opposite side from the first spoke 41, and the first spokes 41 and the second spokes 42 are arranged alternately in the tire circumferential direction C.

[0108] The first spoke 41 and the second spoke 42 are arranged in a roughly X shape when viewed from a direction along the tire circumferential direction C. Since the first spoke 41 and the second spoke 42 are each inclined in the direction of the tire axis, excessive rigidity is suppressed, thereby improving ride comfort.

[0109] (6) The method for manufacturing the non-pneumatic tire 1 according to this embodiment is a manufacturing method for manufacturing the non-pneumatic tire 1, and includes a molding step of filling a divided mold 100 with resin and then removing the divided mold 100 to form spokes 40 on which partition lines 80 are arranged.

[0110] This makes it possible to manufacture a highly durable non-pneumatic tire 1, which has spokes 40 with partition lines 80 arranged along the length directions L1, L2 of the spokes 40.

[0111] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and modifications, improvements, etc., that can be made to the extent that the objectives of the present invention can be achieved are also included within the scope of the present invention.

[0112] The spokes 40 in this embodiment include a first spoke 41 and a second spoke 42 that intersect in a substantially X-shape when viewed from a direction along the tire circumferential direction C. However, the spokes 40 are not limited to this and may consist of plate-shaped portions that extend straight in the tire radial direction X.

[0113] Although the spokes 40 in the embodiment were elongated plate-shaped, their shape is not particularly limited. For example, they may be cylindrical. [Explanation of Symbols]

[0114] 1. Non-pneumatic tires 20 Inner annular portion 30 Outer annular part 40 spokes 80 partition lines 100-part mold C Tire circumferential direction Y Tire width direction

Claims

1. The inner annular part, The outer annular portion is arranged coaxially on the outer circumference side of the inner annular portion, A non-pneumatic tire comprising a plurality of spokes connecting the inner annular portion and the outer annular portion, arranged along the circumferential direction of the tire, The spokes are provided with partition lines formed by a dividing mold that divides the tire in the width direction during the molding of a non-pneumatic tire. The partition line is a non-pneumatic tire extending in the longitudinal direction of the spokes.

2. The non-pneumatic tire according to claim 1, wherein the partition line is located approximately in the center of the spoke in the width direction.

3. The spokes are in the shape of long plates, The non-pneumatic tire according to claim 1, wherein the partition line is arranged on at least one of the first surface and the second surface facing each other in the thickness direction of the spoke, and is spaced apart from the edges at both ends of the first surface and the second surface in the width direction.

4. The non-pneumatic tire according to claim 1, wherein the inner annular portion and the outer annular portion have a reinforcing layer.

5. The aforementioned spokes are A first spoke that is inclined to one side in the direction of the tire axis, It includes a second spoke that is inclined to the opposite side from the first spoke, The non-pneumatic tire according to any one of claims 1 to 4, wherein the first spoke and the second spoke are arranged alternately in the circumferential direction of the tire.

6. A manufacturing method for producing a non-pneumatic tire as described in claim 1, A method for manufacturing a non-pneumatic tire, comprising a molding step of filling a divided mold with resin and then removing the divided mold to form the spokes on which the partition lines are arranged.

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