JP2023094278A - Non-pneumatic tire - Google Patents

Abstract

To provide a non-pneumatic tire which can improve durability of spokes.SOLUTION: A non-pneumatic tire includes a support structure, and a tread 50 which is positioned outside in a tire radial direction of the support structure and extends in a tire circumferential direction. The support structure includes an inner annular part, an outer annular part 30 which is arranged coaxially with the inner annular part outside in the tire radial direction in the inner annular part, and contains a resin, and a plurality of spokes which connect the inner annular part and the outer annular part 30 and are arrayed in the tire circumferential direction. The outer annular part 30 is provided with a heat insulation layer 31 extending in the tire circumferential direction and containing inorganic fibers. The inorganic fiber has thermal conductivity lower than that of the resin.SELECTED DRAWING: Figure 2

Description

The present invention relates to non-pneumatic tires.

Conventionally, there is known a non-pneumatic tire that supports a load from a vehicle and includes a support structure containing resin and a tread that is positioned radially outside the support structure and extends along the tire circumferential direction. It is Here, the support structure includes an inner annular portion, an outer annular portion arranged coaxially with the inner annular portion outside the inner annular portion in the tire radial direction, and connecting the inner annular portion and the outer annular portion to each other, and the tire and a plurality of spokes arranged along the circumferential direction.

Non-pneumatic tires are desired to improve the durability of the support structure. One of the factors that reduces the durability of the support structure is thermal oxidation deterioration of the support structure due to heat transfer from the heat generated by the tread to the support structure when the vehicle is running.

Therefore, Patent Literature 1 describes that the surfaces of spokes containing resin are coated with resin or rubber having a higher thermal conductivity than resin. Further, Patent Literature 2 describes that the surface of the outer annular portion containing resin is coated with resin or rubber having higher thermal conductivity than resin.

Japanese Patent No. 6423584 Japanese Patent No. 6302355

However, in Patent Documents 1 and 2, since heat transfer to the spokes is not sufficiently suppressed, the durability of the spokes is insufficient when the number of times the used non-pneumatic tire is retreaded increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a non-pneumatic tire capable of improving durability of spokes.

One aspect of the present invention is a non-pneumatic tire comprising a support structure and a tread located radially outside the support structure and extending along the tire circumferential direction, The support structure includes an inner annular portion, and is arranged coaxially with the inner annular portion outside the inner annular portion in the tire radial direction, and includes an outer annular portion containing a resin, the inner annular portion, and the outer annular portion. and a plurality of spokes arranged along the tire circumferential direction, wherein the outer annular portion extends along the tire circumferential direction and is provided with a heat insulating layer containing inorganic fibers, The inorganic fiber has a lower thermal conductivity than the resin.

The outer annular portion extends along the tire circumferential direction outward in the tire radial direction from the heat insulating layer, and is further provided with a reinforcing layer containing fiber reinforced plastic, and the fiber reinforced plastic is higher than the resin. may also have high thermal conductivity.

The resin may be urethane resin, the inorganic fiber may be glass wool or rock wool, and the fiber reinforced plastic may be carbon fiber reinforced plastic.

ADVANTAGE OF THE INVENTION According to this invention, the non-pneumatic tire which can improve durability of a spoke can be provided.

It is a side view which shows the non-pneumatic tire of this embodiment. FIG. 2 is a cross-sectional view taken along line II-II showing the structure of the outer annular portion and tread of FIG. 1; FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1; FIG. 4 is a partial perspective view of a non-pneumatic tire viewed obliquely from the portion shown in FIG. 3;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a non-pneumatic tire of this embodiment. A non-pneumatic tire 1 comprises a support structure 10 and a tread 50 . Here, the support structure 10 contains resin and supports the load from the vehicle. Further, the tread 50 is located outside the support structure 10 in the tire radial direction X and extends along the tire circumferential direction C. As shown in FIG. In addition, the support structure 10 includes an inner annular portion 20, an outer annular portion 30 arranged coaxially with the inner annular portion 20 outside the inner annular portion 20 in the tire radial direction X, and an inner annular portion 20 and the outer annular portion. and a plurality of spokes 40 connected to the portion 30 and arranged along the tire circumferential direction C. Details of the structure of the non-pneumatic tire 1 will be described later.

2 shows the structure of the outer annular portion 30. As shown in FIG. The outer annular portion 30 extends along the tire circumferential direction C, and is provided with a heat insulating layer 31 containing inorganic fibers. lower than Therefore, even if the heat generated by the tread 50 is transferred to the outer annular portion 30 while the vehicle is running, the heat is less likely to be transferred from the outer annular portion 30 to the spokes 40 . As a result, thermal oxidation deterioration of the spokes 40 is suppressed, and the durability of the spokes 40 is improved. This increases the number of times a used non-pneumatic tire 1 can be retreaded.

In addition, although the heat insulating layer 31 is arranged at the inner end portion of the outer annular portion 30 in the tire radial direction X in FIG. 2 , the position at which the heat insulating layer 31 is arranged is not particularly limited. Moreover, although the heat insulating layer 31 is provided over the entire area of the outer annular portion 30 in the tire width direction Y in FIG. At this time, the width of the heat insulating layer 31 with respect to the width of the outer annular portion 30 is preferably 70% or more, more preferably 90% or more. When the width of the heat insulating layer 31 is 70% or more of the width of the outer annular portion 30, even if the heat generated by the tread 50 is transferred to the outer annular portion 30 while the vehicle is running, the heat is not transferred from the outer annular portion 30 to the spokes 40. become difficult. Note that the heat insulating layer 31 is preferably not exposed in the tire width direction Y from the viewpoint of appearance.

The thermal conductivity κ of inorganic fibers is not particularly limited, but is, for example, 0.03 W/(m·K) or more and 0.10 W/(m·K) or less.

Examples of inorganic fibers include, but are not limited to, glass wool (κ=0.033 to 0.050 W/(m·K)) and rock wool (κ=0.035 to 0.047 W/(m·K)). etc.

The thickness of the heat insulating layer 31, that is, the length in the tire radial direction X is preferably 0.5 mm or more and 4 mm or less, and more preferably 1 mm or more and 2 mm or less. When the thickness of the heat insulating layer 31 is 0.5 mm or more, even if the heat generated by the tread 50 is transferred to the outer annular portion 30 while the vehicle is running, the heat is less likely to be transferred from the outer annular portion 30 to the spokes 40 . On the other hand, if the thickness of the heat insulating layer 31 is 4 mm or less, the rigidity of the outer annular portion 30 can be ensured.

The thermal conductivity of the resin contained in the outer annular portion 30 is not particularly limited, but is, for example, 0.20 W/(m·K) or more and 0.50 W/(m·K) or less.

The resin contained in the outer annular portion 30 is not particularly limited, but examples thereof include thermoplastic elastomers, crosslinked rubbers, and other resins. Among these, urethane resin (κ=0.21 W/(m·K)) is preferable. A known urethane resin used for the support structure 10 can be used as the urethane resin. The resin contained in inner annular portion 20 and spokes 40 may be the same as or different from the resin contained in outer annular portion 30 .

Although the thickness of the outer annular portion 30 is not particularly limited, it is, for example, 4 mm or more and 15 mm or less.

Further, the outer annular portion 30 extends along the tire circumferential direction C, and is further provided with a reinforcing layer 32 containing fiber-reinforced plastic. Therefore, the occurrence of buckling in which the outer annular portion 30 bends in the tire radial direction X at the center portion in the tire width direction Y is suppressed. As a result, the rigidity of the non-pneumatic tire 1 is ensured, and the ground contact of the tread 50 to the road surface is improved. Here, the fiber-reinforced plastic has a higher thermal conductivity than the resin contained in the outer annular portion 30 , and the reinforcing layer 32 is arranged outside the heat insulating layer 31 in the tire radial direction X. As shown in FIG. Therefore, even if the heat generated by the tread 50 is transferred to the outer annular portion 30 while the vehicle is running, the heat is less likely to be transferred from the outer annular portion 30 to the spokes 40 .

Examples of fiber-reinforced plastics include, but are not limited to, carbon fiber reinforced plastics (CFRP; κ = 2 to 300 W/(m K)), glass fiber reinforced plastics (GFRP; κ = 0.42 W/(m K )) and the like. Among these, CFRP is preferred.

Although the thickness of the reinforcing layer 32 is not particularly limited, it is, for example, 1 mm or more and 4 mm or less.

Although the reinforcing layer 32 is arranged adjacent to the heat insulating layer 31 in FIG. Not limited. Specifically, the reinforcing layer 32 may be provided inside the outer annular portion 30 or may be provided on the surface of the outer annular portion 30 on the tread 50 side. Moreover, although the reinforcing layer 32 is provided over the entire tire width direction Y in FIG. 2 , it may not be provided over the entire tire width direction Y. At this time, the width of the reinforcing layer 32 is preferably smaller than the width of the heat insulating layer 31 . As a result, even if the heat generated by the tread 50 is transferred to the outer annular portion 30 while the vehicle is running, the heat is less likely to be transferred from the outer annular portion 30 to the spokes 40 . Furthermore, the reinforcement layer 32 may be omitted.

The outer annular portion 30 is obtained, for example, by sequentially molding each layer into a cylindrical shape.

The non-pneumatic tire 1 is obtained, for example, by vulcanizing and bonding the support structure 10 and the tread rubber composition using a vulcanizing adhesive.

The tread rubber composition includes, but is not limited to, natural rubber and carbon black, and may further include sulfur, silica, and the like. Here, the tread rubber composition may contain synthetic rubber such as polyisoprene rubber, styrene-butadiene rubber, etc. together with natural rubber or instead of natural rubber.

When retreading the used non-pneumatic tire 1, for example, after removing the tread 50 from the non-pneumatic tire 1 by buffing, a vulcanizing adhesive is used to attach the support structure 10 and the tread The rubber composition is vulcanized and adhered.

The details of the structure of the non-pneumatic tire 1 (see FIG. 1) will be described below. FIG. 1 is a side view of the non-pneumatic tire 1 of the present embodiment viewed from a direction parallel to the tire rotation axis (tire meridian), that is, from a direction along the front and back direction of the paper in FIG. The non-pneumatic tire 1 shown in FIG. 1 is in an unloaded state. FIG. 3 is a cross-sectional view taken along line II-II of FIG. FIG. 4 is a partial perspective view of the non-pneumatic tire 1, obliquely viewing the portion shown in FIG.

1 and 4, arrow C indicates the tire circumferential direction. 1, 3 and 4, the arrow X indicates the tire radial direction. 3 and 4, arrow Y indicates the tire width direction. The tire width direction Y in FIG. 1 is the front-back direction of the paper surface. Symbol E in FIG. 3 is the tire equatorial plane. The tire circumferential direction C in FIG. 3 is the front-back direction of the paper surface.

The tire circumferential direction C is the direction around the tire rotation axis and the same direction as the direction in which the non-pneumatic tire 1 rotates. The tire radial direction X is a direction perpendicular to the tire rotation axis. The tire width direction Y is a direction parallel to the tire rotation axis. 3 and 4, one side in the tire width direction Y is indicated as Y1, and the other side in the tire width direction Y is indicated as Y2. The tire equatorial plane E shown in FIG. 3 is a plane orthogonal to the tire rotation axis and located at the center in the tire width direction Y. As shown in FIG.

In the following, the thickness of the inner annular portion 20 and the outer annular portion 30 is the dimension along the tire radial direction X. As shown in FIG. The widths of the inner annular portion 20 and the outer annular portion 30 are dimensions along the tire width direction Y shown in FIG.

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 constant to improve uniformity. A tire wheel (not shown) is arranged in a 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 attached to the outer peripheral portion of the rim of the tire wheel. With the inner annulus 20 mounted on the rim, the non-pneumatic tire 1 is mounted on the tire wheel. The inner peripheral surface of the inner annular portion 20 may be provided with a fitting portion configured by a protrusion, a groove, or the like for fitting with the rim.

The inner annular portion 20 can be made of, for example, an elastic resin material, but the material is not limited to resin.

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 torque to the spokes 40 . Although the thickness of the inner annular portion 20 is not particularly limited, for example, it is preferably 2% or more and 7% or less, more preferably 3% or more and 6% or less of the tire cross-sectional height H shown in FIG.

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 application of the vehicle, and the like. For example, when assuming a substitute for a general pneumatic tire, the inner annular portion 20 may have an inner diameter of 250 mm or more and 500 mm or less, but is not limited to this.

The width of the inner annular portion 20 is appropriately determined according to the application of the vehicle on which the non-pneumatic tire 1 is mounted, the length of the axle, and the like. For example, when assuming a substitute for a general pneumatic tire, the width of the inner annular portion 20 may be 100 mm or more and 300 mm or less, but is not limited to this.

The outer annular portion 30 is an annular portion along the tire circumferential direction C that constitutes the outer peripheral portion of the non-pneumatic tire 1 . The outer annular portion 30 is arranged concentrically 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 constant to improve uniformity.

Outer annular portion 30 transmits the rotation of inner annular portion 20 and spokes 40 to the road surface via 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 the torque from the spokes 40 to the road surface. Although the thickness of the outer annular portion 30 is not particularly limited, it is preferably 2% or more and 7% or less, and more preferably 2% or more and 5% or less, of the tire cross-sectional height H shown in FIG.

The inner diameter of the outer annular portion 30 is appropriately determined according to the dimensions of the rim of the tire wheel on which the non-pneumatic tire 1 is mounted, the application of the vehicle, and the like. For example, when assuming a substitute for a general pneumatic tire, the inner diameter of the outer annular portion 30 may be 420 mm or more and 750 mm or less, but is not limited to this.

The width of the outer annular portion 30 is appropriately determined according to the application of the vehicle on which the non-pneumatic tire 1 is mounted. For example, when assuming a substitute for a general pneumatic tire, the width of the outer annular portion 30 may be 100 mm or more and 300 mm or less, but is not limited to this.

A 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 a plurality of spokes 40 are arranged concentrically with each other. Each of the plurality of spokes 40 is arranged independently along the tire circumferential direction C. As shown in FIG. As shown in FIG. 1 , when the non-pneumatic tire 1 is in an unloaded state, the plurality of spokes 40 extend linearly in the radial direction substantially parallel to the tire radial direction X when viewed from the side.

As shown in FIGS. 3 and 4 , the plurality of spokes 40 of this embodiment includes a plurality of first spokes 41 and a plurality of second spokes 42 . Neither the first spoke 41 nor the second spoke 42 extends parallel to the tire radial direction X when viewed along the tire circumferential direction C. The first spokes 41 are inclined to one side in the tire axial direction, that is, the tire width direction Y. As shown in FIG. The second spokes 42 are slanted opposite to the first spokes 41 . The first spokes 41 and the second spokes 42 are alternately arranged in the tire circumferential direction C. As shown in FIG.

Specifically, as shown in FIGS. 3 and 4 , the first spokes 41 are arranged from the Y1 side, which is one side of the outer annular portion 30 in the tire width direction Y, to the other side of the inner annular portion 20 in the tire width direction Y. It extends obliquely toward the Y2 side. The second spokes 42 extend obliquely from the Y2 side, which is the other side in the tire width direction Y, of the outer annular portion 30 toward the Y1 side, which is one side of the inner annular portion 20 in the tire width direction Y. .

The inclination angles of the first spoke 41 and the second spoke 42 are the same. Therefore, the first spokes 41 and the second spokes 42 adjacent to each other in the tire circumferential direction C are arranged in a substantially X shape when viewed along the tire circumferential direction C. As shown in FIG. As shown in FIG. 3, the first spokes 41 and the second spokes 42 are inclined at an angle θ with respect to the tire width direction Y, and the angle θ is, for example, 30° or more and 60° or less. is preferred.

As shown in FIG. 3 , each of the first spokes 41 and the second spokes 42 has the same shape symmetrical with respect to the tire equatorial plane E when viewed in the tire circumferential direction C. As shown in FIG. Therefore, hereinafter, the first spokes 41 and the second spokes 42 are collectively referred to as the spokes 40 when there is no need to distinguish between the first spokes 41 and the second spokes 42 and they can be collectively described. .

The spokes 40 are plate-shaped and extend obliquely from the inner annular portion 20 toward the outer annular portion 30 at the angle θ as described above. As shown in FIG. 4 , the spoke 40 has a plate thickness t along the tire circumferential direction smaller than a plate width w, and the direction of the plate thickness t is along the tire circumferential direction C. As shown in FIG. That is, the spokes 40 are formed in a plate shape extending along the plane in the tire radial direction X and the tire width direction Y. As shown in FIG. The plate width w here is the dimension in the direction perpendicular to the direction of inclination in which the spokes 40 extend when the spokes 40 are viewed from the direction along the tire circumferential direction C, as shown in FIG. be. In this embodiment, all the spokes 40 have the same plate thickness t. Moreover, the plate width w of all the spokes 40 is the same.

Since the spokes 40 have a long plate shape, even if the plate thickness t is reduced, the durability of the spokes 40 can be improved by setting the plate width w wide. Furthermore, by reducing the plate thickness t and increasing the number of spokes 40, it is possible to reduce the interval between the spokes 40 adjacent in the tire circumferential direction C while maintaining the rigidity of the non-pneumatic tire 1 as a whole. As a result, the contact pressure caused by the spokes 40 when the tire rolls is dispersed, and the contact pressure can be reduced.

Although the spokes 40 of the present embodiment are parallel to the tire radial direction X when viewed from the side, the spokes 40 are arranged obliquely with respect to the tire radial direction X so as to intersect with the tire radial direction X when viewed from the side. good too.

As shown in FIGS. 3 and 4, the first spokes 41 include a first inner connecting portion 411 connected to the inner annular portion 20 on the Y2 side in the tire width direction, and a first inner connecting portion 411 connected to the Y1 side of the outer annular portion 30 in the tire width direction. and a connecting first outer connection portion 412 . The second spoke 42 has a second inner connecting portion 421 connected to the inner annular portion 20 on the Y1 side in the tire width direction, and a second outer connecting portion 422 connected to the Y2 side in the tire width direction of the outer annular portion 30. , have Each of the first outer connection portion 412 and the second outer connection portion 422 is an example of a connection portion of the spokes 40 connected to the outer annular portion 30 in this embodiment.

As shown in FIG. 3 , 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 . A side surface 411a of the first inner connecting portion 411 on the tire width direction Y2 side extends to the end portion 20b of the inner annular portion 20 on the tire width direction Y2 side while gently curving. A side surface 411b on the tire width direction Y1 side of the first inner connection portion 411 extends to the position of the tire equatorial plane E of the inner annular portion 20 while curving toward the tire width direction Y1 side.

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. . A side surface 412a of the first outer connecting portion 412 on the tire width direction Y1 side extends to the end portion 30a of the outer annular portion 30 on the tire width direction Y1 side while gently curving. A side surface 412b of the first outer connection portion 412 on the tire width direction Y2 side extends to the position of the tire equatorial plane E of the outer annular portion 30 while curving toward the tire width direction Y2 side.

The first inner connection portion 411 is provided in a half region of the inner annular portion 20 on the tire width direction Y2 side. The first outer connection portion 412 is provided in a half region of the outer annular portion 30 on the tire width direction Y1 side.

As shown in FIG. 3 , 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 . A side surface 421a of the second inner connection portion 421 on the tire width direction Y1 side extends to the end portion 20a of the inner annular portion 20 on the tire width direction Y1 side while being gently curved. A side surface 421b of the second inner connection portion 421 on the tire width direction Y2 side extends to the position of the tire equatorial plane E of the inner annular portion 20 while curving toward the tire width direction Y2 side.

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 in the tire width direction as it approaches the outer annular portion 30. there is A side surface 422a of the second outer connection portion 422 on the tire width direction Y2 side extends to the end portion 30b of the outer annular portion 30 on the tire width direction Y2 side while gently curving. A side surface 422b of the second outer connection portion 422 on the tire width direction Y1 side extends to the position of the tire equatorial plane E of the outer annular portion 30 while curving toward the tire width direction Y1 side.

The second inner connecting portion 421 is provided in a half region of the inner annular portion 20 on the tire width direction Y1 side. The second outer connection portion 422 is provided in a half region of the outer annular portion 30 on the tire width direction Y2 side.

As described above, all the spokes 40 of this embodiment have the same plate thickness t. The dimension of the plate thickness t is not particularly limited. , preferably 1 mm or more and 30 mm or less, more preferably 5 mm or more and 25 mm or less.

As described above, all the spokes 40 of this embodiment have the same plate width w. The plate width w of the spokes 40 is not particularly limited, but in order to sufficiently receive the rotational force from the inner annular portion 20 and the outer annular portion 30 and to allow moderate bending deformation when receiving a load, It is preferably 5 mm or more and 25 mm or less, more preferably 10 mm or more and 20 mm or less. In addition, the plate width w is preferably 110% or more of the plate thickness t, more preferably 115% or more, from the viewpoint of improving the durability and dispersing the contact pressure.

The number of spokes 40 is 80 or more and 300 or less from the viewpoint of enabling weight reduction while sufficiently supporting the load from the vehicle and improving power transmission performance and durability. , and more preferably 100 or more and 200 or less.

Spokes 40 may be formed from any of the elastic materials listed below. First, as the characteristics of the elastic material, a tensile test was performed according to JIS K7312: 1996 from the viewpoint of imparting appropriate rigidity while ensuring sufficient durability, and the tensile stress at 10% elongation was calculated. It is preferable that the tensile modulus obtained is 3 MPa or more and 12 MPa or less.

In the spokes 40, if 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 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 poor riding comfort.

Examples of the elastic material used as the base material of the spokes 40 include thermoplastic elastomers, crosslinked rubbers, and other resins.

Examples of thermoplastic elastomers include polyester elastomers, polyolefin elastomers, polyamide elastomers, polystyrene elastomers, polyvinyl chloride elastomers, polyurethane elastomers, and the like.

Either natural rubber or synthetic rubber can be used as the rubber material constituting the crosslinked rubber. 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), fluorine rubber, silicone rubber, acrylic rubber, urethane rubber, and the like. These rubber materials may be used in combination of two or more as needed.

Other resins include thermoplastic resins and thermosetting resins. Examples of thermoplastic resins include polyethylene resins, polystyrene resins, and polyvinyl chloride resins. Thermosetting resins include epoxy resins, phenol resins, polyurethane resins, silicone resins, polyimide resins, melamine resins, and the like.

Among the above elastic materials, urethane resin is preferably used for the spokes 40 from the viewpoint of moldability, workability and cost. A foam material can also be used as the elastic material. That is, foamed thermoplastic elastomers, crosslinked rubbers, and other resins can be used.

The elastic material used as the base material of the spokes 40 may be reinforced with reinforcing fibers. Examples of reinforcing fibers include long fibers, short fibers, woven fabrics, non-woven fabrics, and the like. 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, and steel cords.

Reinforcement of the elastic material is not limited to reinforcement with reinforcing fibers. For example, reinforcement by the addition of particulate fillers may be provided. Granular fillers to be added include carbon black, silica, ceramics such as alumina, fillers of other inorganic materials, and the like.

By the way, the inner annular portion 20 and the outer annular portion 30 described above are preferably formed of the same resin material as the spokes 40. In that case, for example, the inner annular portion 20 and the outer annular portion 20 are formed by cast molding. 30 and spokes 40 can be integrally molded.

The tread 50 is provided on the outer peripheral surface of the outer annular portion 30 and constitutes the outermost peripheral portion of the non-pneumatic tire 1 . The tread 50 is formed by vulcanizing and bonding the support structure 10 and a tread rubber composition. The tread 50 has a tread surface 51 that contacts the road surface on its outer peripheral surface. A tread 51 of the tread 50 is provided with a tread pattern formed of a plurality of grooves and land portions in the same manner as a conventional pneumatic tire.

Note that the tread 50 may have a structure in which a plurality of vulcanized rubber layers having different components and properties are laminated (for example, two layers or three layers).

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and the above embodiments may be modified as appropriate within the scope of the present invention.

1 non-pneumatic tire 10 support structure 20 inner annulus 20a, 20b end 30 outer annulus 30a, 30b end 31 insulation layer 32 reinforcement layer 40 spokes 41 first spokes 42 second spokes 411 first inner connection Part 411a, 411b Side 412 First outer connecting part 412a, 412b Side 421 Second inner connecting part 421a, 421b Side 422 Second outer connecting part 422a, 422b Side 50 Tread 51 Tread surface C Tire circumferential direction E Tire equatorial plane O Axis X Tire Radial Direction Y Tire Width Direction

Claims (3)

A non-pneumatic tire comprising a support structure and a tread positioned radially outward of the support structure and extending along the tire circumferential direction,
The support structure includes an inner annular portion, and is arranged coaxially with the inner annular portion outside the inner annular portion in the tire radial direction, and includes an outer annular portion containing a resin, the inner annular portion, and the outer annular portion. and a plurality of spokes arranged along the tire circumferential direction,
The outer annular portion extends along the tire circumferential direction and is provided with a heat insulating layer containing inorganic fibers,
The non-pneumatic tire, wherein the inorganic fiber has a lower thermal conductivity than the resin. The outer annular portion extends outward in the tire radial direction from the heat insulating layer along the tire circumferential direction, and is further provided with a reinforcing layer containing fiber reinforced plastic,
A non-pneumatic tire according to claim 1, wherein said fiber reinforced plastic has a higher thermal conductivity than said resin. The resin is a urethane resin,
The inorganic fiber is glass wool or rock wool,
3. A non-pneumatic tire according to claim 2, wherein said fiber reinforced plastic is carbon fiber reinforced plastic.

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