JP2017007363A - Non-pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-pneumatic tire having improved durability.SOLUTION: A non-pneumatic tire comprising a support structure for supporting a load applied from a vehicle is provided. The support structure comprises: an inside annular part 1: an outside annular part 2 which is disposed in a concentric state on an outside of the inside annular part 1; and plural connection parts 3 for connecting the inside annular part 1 and the outside annular part 2, and respectively independently provided on a tire peripheral direction. The plural connection parts 3 comprise long plate-state first connection parts 31 which extend from one side WD1 of the inside annular part 1 in a tire width direction to the other side WD2 of the outside annular part 2 in the tire width direction and long plate-state second connection parts 32 which extend from the other side WD2 of the inside annular part 1 in the tire width direction to one side WD1 of the outside annular part 2 in the tire width direction, they are arranged along the tire peripheral direction CD. The first connection parts 31 or the second connection parts 32 comprise respectively, a through hole 4 penetrating in the tire peripheral direction CD.SELECTED DRAWING: Figure 2B

Description

  The present invention relates to a non-pneumatic tire provided with a support structure that supports a load from a vehicle as a tire structural member, and preferably a non-pneumatic tire that can be used as a substitute for a pneumatic tire. It relates to tires.

  The pneumatic tire has a load supporting function, a shock absorbing ability from the ground contact surface, and a transmission ability (acceleration, stop, change of direction) such as power. For this reason, many vehicles, particularly bicycles, motorcycles, automobiles, It is used in trucks.

  In particular, these capabilities greatly contributed to the development of automobiles and other motor vehicles. Furthermore, the impact absorbing ability of pneumatic tires is useful for medical equipment and electronic equipment transport carts and other applications.

  Conventional non-pneumatic tires include, for example, solid tires, spring tires, cushion tires, and the like, but do not have the superior performance of pneumatic tires. For example, solid tires and cushion tires support the load by compressing the contact portion, but this type of tire is heavy and stiff, and does not have the ability to absorb shock like a pneumatic tire. Further, in the non-pneumatic tire, it is possible to improve the cushioning property by increasing the elasticity, but there is a problem that the load supporting ability or the durability as the pneumatic tire has is deteriorated.

  Therefore, the present inventor has proposed non-pneumatic tires described in Patent Documents 1 and 2 below as non-pneumatic tires that can reduce the contact pressure dispersion while improving durability. The non-pneumatic tires of Patent Documents 1 and 2 connect an inner annular portion, an outer annular portion provided concentrically outside the inner annular portion, the inner annular portion and the outer annular portion, A plurality of connecting portions provided independently in the direction, the plurality of connecting portions extending from one side in the tire width direction of the inner annular portion toward the other side in the tire width direction of the outer annular portion. A long plate-shaped first connecting portion, and a long plate-shaped second extending from the other side of the inner annular portion toward the one side of the tire width direction of the outer annular portion. The connecting portions are arranged alternately along the tire circumferential direction.

  However, the non-pneumatic tires of Patent Documents 1 and 2 have been found to have a risk of increasing the temperature and strain due to the bending of the connecting portion during travel, and further improvement in durability is desired.

JP2015-39986A JP 2014-100903 A

  Therefore, an object of the present invention is to provide a non-pneumatic tire with improved durability.

The above object can be achieved by the present invention as described below.
That is, the non-pneumatic tire of the present invention is a non-pneumatic tire including a support structure that supports a load from a vehicle.
The support structure connects an inner annular portion, an outer annular portion concentrically provided outside the inner annular portion, the inner annular portion and the outer annular portion, and is independent of each other in the tire circumferential direction. A plurality of connecting portions provided,
The plurality of connecting portions include a long plate-like first connecting portion extending from one side in the tire width direction of the inner annular portion toward the other side in the tire width direction of the outer annular portion, and the inner annular portion. The second plate-like second connecting portions extending from the other side in the tire width direction toward the one side in the tire width direction of the outer annular portion are alternately arranged along the tire circumferential direction. And
The first connecting part or the second connecting part is formed with a through hole penetrating in the tire circumferential direction.

  The operational effects of the present invention with this configuration will be described. When the tire rolls, an air flow that flows relatively along the tire circumferential direction is generated in the space between the inner annular portion and the outer annular portion. By forming a through hole penetrating in the tire circumferential direction in the first connecting part or the second connecting part, the first connecting part or the second connecting part can be cooled from the inside by the air flow flowing in the through hole. Thereby, the temperature of a 1st connection part and a 2nd connection part can be reduced, and durability of a non-pneumatic tire can be improved.

  In the non-pneumatic tire according to the present invention, it is preferable that a protrusion extending in the circumferential direction of the through hole is formed on the inner peripheral surface of the through hole.

  By forming the protrusion on the inner peripheral surface of the through hole, the air flow flowing through the through hole becomes a turbulent flow by the protrusion and flows through the inner peripheral surface, thereby promoting heat exchange with the inner peripheral surface of the through hole. Therefore, the first connecting part or the second connecting part can be effectively cooled.

  In the non-pneumatic tire according to the present invention, it is preferable that a plurality of the projecting portions are formed at intervals in the axial direction of the through hole.

  According to this configuration, since the airflow flowing through the through hole collides with the protrusion a plurality of times and becomes a turbulent flow, the cooling effect of the first connecting portion or the second connecting portion can be enhanced.

  In the non-pneumatic tire according to the present invention, it is preferable that a plurality of the protruding portions are formed at intervals in the circumferential direction of the through hole.

  According to this structure, since the airflow which flows through the inside of a through-hole collides with a protrusion part in multiple places, and becomes a turbulent flow, the cooling effect of a 1st connection part or a 2nd connection part can be improved. Furthermore, since the flow velocity of an airflow improves by providing a clearance gap between adjacent protrusion parts, the cooling effect of a 1st connection part and a 2nd connection part can be heightened.

Front view showing an example of the non-pneumatic tire of the present invention AA sectional view of the non-pneumatic tire of FIG. The perspective view which shows a part of non-pneumatic tire of FIG. Partial enlarged view of the non-pneumatic tire of FIG. Tire meridian cross-sectional view of a non-pneumatic tire according to another embodiment Tire meridian cross-sectional view of a non-pneumatic tire according to another embodiment Sectional drawing which cut | disconnected the 1st connection part in the orthogonal direction with respect to the extending direction. The figure which looked at the penetration hole concerning other embodiments from the direction of an axis The perspective view which shows a part of non-pneumatic tire which concerns on other embodiment. Sectional drawing of the 1st connection part of the non-pneumatic tire concerning other embodiments.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the configuration of the non-pneumatic tire T of the present invention will be described. FIG. 1 is a front view showing an example of a non-pneumatic tire T. FIG. 2A is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 2B is a perspective view showing a part of the non-pneumatic tire T. FIG. 3 is an enlarged view of a part of FIG. Here, O indicates the shaft core, and H indicates the tire cross-sectional height.

  The non-pneumatic tire T includes a support structure SS that supports a load from the vehicle. The non-pneumatic tire T of the present invention only needs to be provided with such a support structure SS, and a member corresponding to a tread on the outer side (outer peripheral side) or inner side (inner peripheral side) of the support structure SS, A reinforcing layer, a member for fitting with an axle or a rim, and the like may be provided.

  As shown in the front view of FIG. 1, the non-pneumatic tire T of the present embodiment includes an inner annular portion 1, an outer annular portion 2 provided concentrically on the outer side, and an inner annular portion. 1 and the outer annular portion 2 are connected, and a plurality of connecting portions 3 provided independently in the tire circumferential direction CD are provided.

  The inner annular portion 1 is preferably a cylindrical shape having a constant thickness from the viewpoint of improving uniformity. Moreover, it is preferable to provide the inner peripheral surface of the inner annular portion 1 with irregularities or the like for maintaining fitting properties for mounting with an axle or a rim.

  The thickness of the inner annular portion 1 is preferably 2 to 7% of the tire cross-section height H and more preferably 3 to 6% from the viewpoint of reducing weight and improving durability while sufficiently transmitting force to the connecting portion 3. preferable.

  The inner diameter of the inner annular portion 1 is appropriately determined in accordance with the rim on which the non-pneumatic tire T is mounted and the dimensions of the axle. However, when an alternative to a general pneumatic tire is assumed, 250 to 500 mm is preferable, and 330 to 440 mm is more preferable.

  The width in the tire width direction of the inner annular portion 1 is appropriately determined according to the use, the length of the axle, and the like. However, when an alternative to a general pneumatic tire is assumed, 100 to 300 mm is preferable, and 130 to 250 mm is preferable. More preferred.

  The tensile modulus of the inner annular portion 1 is preferably 5 to 180000 MPa, more preferably 7 to 50000 MPa, from the viewpoint of reducing weight, improving durability, and wearing properties while sufficiently transmitting force to the connecting portion 3. The tensile modulus in the present invention is a value calculated from a tensile stress at 10% elongation by conducting a tensile test according to JIS K7312.

  The support structure SS in the present invention is formed of an elastic material. However, the inner ring portion 1, the outer ring portion 2, and the connection portion 3 are used from the viewpoint of enabling integral molding when the support structure SS is manufactured. Are preferably basically the same material except for the reinforcing structure.

  The elastic material in the present invention refers to a material having a tensile modulus calculated from a tensile stress at 10% elongation by a tensile test according to JIS K7312 and 100 MPa or less. The elastic material of the present invention preferably has a tensile modulus of 5 to 100 MPa, more preferably 7 to 50 MPa from the viewpoint of imparting adequate rigidity while obtaining sufficient durability. Examples of the elastic material used as the base material include thermoplastic elastomers, crosslinked rubbers, and other resins.

  Examples of the thermoplastic elastomer include polyester elastomer, polyolefin elastomer, polyamide elastomer, polystyrene elastomer, polyvinyl chloride elastomer, polyurethane elastomer and the like. Rubber materials constituting the crosslinked rubber material include natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IIR), nitrile rubber (NBR), hydrogenated nitrile rubber (hydrogenated NBR). And synthetic rubbers such as chloroprene rubber (CR), ethylene propylene rubber (EPDM), fluorine rubber, silicon rubber, acrylic rubber, and urethane rubber. These rubber materials may be used in combination of two or more as required.

  Examples of other resins include thermoplastic resins and thermosetting resins. Examples of the thermoplastic resin include polyethylene resin, polystyrene resin, and polyvinyl chloride resin, and examples of the thermosetting resin include epoxy resin, phenol resin, polyurethane resin, silicon resin, polyimide resin, and melamine resin.

  Of the above elastic materials, a polyurethane resin is preferably used from the viewpoint of moldability / workability and cost. In addition, as an elastic material, you may use a foaming material, The thing which foamed said thermoplastic elastomer, crosslinked rubber, and other resin can also be used.

  In the support structure SS integrally formed of an elastic material, the inner annular portion 1, the outer annular portion 2, and the connecting portion 3 are preferably reinforced by reinforcing fibers.

  Reinforcing fibers include reinforcing fibers such as long fibers, short fibers, woven fabrics, and non-woven fabrics, but as a form using long fibers, fibers arranged in the tire width direction and fibers arranged in the tire circumferential direction It is preferable to use a net-like fiber assembly composed of:

  Examples of the types of reinforcing fibers include rayon cords, polyamide cords such as nylon-6,6, polyester cords such as polyethylene terephthalate, aramid cords, glass fiber cords, carbon fibers, and steel cords.

  In the present invention, in addition to reinforcement using reinforcing fibers, it is possible to perform reinforcement with a granular filler or reinforcement with a metal ring or the like. Examples of the particulate filler include ceramics such as carbon black, silica, and alumina, and other inorganic fillers.

  The shape of the outer annular portion 2 is preferably a cylindrical shape with a constant thickness from the viewpoint of improving uniformity. The thickness of the outer annular portion 2 is preferably 2 to 7% and 2 to 5% of the tire cross-section height H from the viewpoint of reducing weight and improving durability while sufficiently transmitting the force from the connecting portion 3. More preferred.

  The inner diameter of the outer annular portion 2 is appropriately determined according to its application and the like, but is preferably 420 to 750 mm, and more preferably 480 to 680 mm when an alternative to a general pneumatic tire is assumed.

  The width in the tire width direction of the outer annular portion 2 is appropriately determined according to its use and the like, but is preferably 100 to 300 mm, more preferably 130 to 250 mm, assuming an alternative to a general pneumatic tire.

  The tensile modulus of the outer annular portion 2 can be set to the same level as that of the inner annular portion 1 when the reinforcing layer 8 is provided on the outer periphery of the outer annular portion 2 as shown in FIG. When such a reinforcing layer 8 is not provided, 5 to 180000 MPa is preferable, and 7 to 50000 MPa is more preferable from the viewpoint of reducing weight and improving durability while sufficiently transmitting the force from the connecting portion 3.

  When the tensile modulus of the outer annular portion 2 is increased, a fiber reinforced material obtained by reinforcing an elastic material with fibers or the like is preferable. By reinforcing the outer annular portion 2 with the reinforcing fiber, adhesion between the outer annular portion 2 and the belt layer becomes sufficient.

  The connecting portion 3 connects the inner annular portion 1 and the outer annular portion 2, and a plurality of connecting portions 3 are provided so that each of them is independent in the tire circumferential direction CD, with an appropriate interval between them.

  The plurality of connecting portions 3 are configured by arranging the first connecting portion 31 and the second connecting portion 32 along the tire circumferential direction CD. At this time, it is preferable that the first connecting portions 31 and the second connecting portions 32 are alternately arranged along the tire circumferential direction CD. Thereby, contact pressure dispersion at the time of tire rolling can be further reduced.

  In addition, the pitch p in the tire circumferential direction CD between the first connecting portion 31 and the second connecting portion 32 is preferably constant from the viewpoint of improving uniformity. The pitch p is preferably 0 to 10 mm, and more preferably 0 to 5 mm. If the pitch p is larger than 10 mm, the contact pressure becomes non-uniform and noise may increase.

  The first connecting portion 31 is extended from the tire width direction one side WD1 of the inner annular portion 1 toward the tire width direction other side WD2 of the outer annular portion 2. On the other hand, the second connecting portion 32 extends from the other side WD2 in the tire width direction of the inner annular portion 1 toward one side WD1 in the tire width direction of the outer annular portion 2. That is, the adjacent first connecting part 31 and second connecting part 32 are arranged in an approximately X shape when viewed from the tire circumferential direction CD.

  The first connecting portion 31 and the second connecting portion 32 viewed from the tire circumferential direction CD are preferably symmetrical with respect to the tire equatorial plane C as shown in FIG. Therefore, below, the 1st connection part 31 is mainly demonstrated.

  The first connecting portion 31 has a long plate shape extending from the inner annular portion 1 to the outer annular portion 2. The first connecting portion 31 has a plate thickness t smaller than the plate width w, and the plate thickness direction PT faces the tire circumferential direction CD. That is, the 1st connection part 31 is plate shape extended in a tire radial direction and a tire width direction. By making the first connecting portion 31 and the second connecting portion 32 into such a long plate shape, even if the plate thickness t is reduced, the first connecting portion 31 and Since the 2nd connection part 32 can obtain desired rigidity, durability can be improved. Further, by increasing the number of the first connecting portions 31 and the second connecting portions 32 while reducing the plate thickness t, the clearance between the connecting portions adjacent to each other in the tire circumferential direction CD is reduced while maintaining the rigidity of the entire tire. Therefore, the contact pressure dispersion during rolling of the tire can be reduced.

  The plate thickness t of the first connecting portion 31 may be constant along the extending direction PL, but the plate thickness t of the first connecting portion 31 is changed from the inner annular portion 1 to the outer annular portion 2 as shown in FIG. It is preferable that it is increasing gradually toward. In this case, the plate thickness t at the tire radial direction outer end 31a of the first connecting portion 31 is set to be smaller than the plate width w.

  The plate thickness t is preferably 8 to 30 mm, more preferably 10 to 20 mm, from the viewpoint of reducing the weight and improving the durability while sufficiently transmitting the force from the inner annular portion 1 and the outer annular portion 2.

  In FIG. 2A, the plate width w is constant along the extending direction PL in the central portion of the first connecting portion 31, but is not limited thereto. As shown in FIGS. 4A and 4B, the plate width w may be changed along the extending direction PL. In this case, assuming that the height in the tire radial direction of the first connecting portion 31 is h, the range is ± 25% of h from the tire radial direction height center 31c of the first connecting portion 31 toward the tire radial direction. The plate width w at the narrowest portion is set to be larger than the plate thickness t. The inner side in the tire radial direction is the + side and the outer side in the tire radial direction is the-side. Further, the plate width w of the first connecting portion 31 is measured by the shortest distance between both ends in the width direction.

  The plate width w is preferably 5 to 25 mm, more preferably 10 to 20 mm, from the viewpoint of reducing the weight and improving the durability while sufficiently transmitting the force from the inner annular portion 1 and the outer annular portion 2. In addition, the plate width w is preferably 110% or more, more preferably 115% or more of the plate thickness t from the viewpoint of reducing the contact pressure dispersion while improving durability.

  The first connecting portion 31 includes a reinforcing portion 311 having a gradually increasing plate width toward the inner annular portion 1 or the outer annular portion 2 in the vicinity of the coupling portion with the inner annular portion 1 and in the vicinity of the coupling portion with the outer annular portion 2. It is preferable to have. Thereby, durability of the 1st connection part 31 can further be improved. The range in which the reinforcing portion 311 is provided is preferably outside the range of ± 25% of h from the tire radial direction height center 31c of the first connecting portion 31.

  The first connecting portion 31 viewed from the tire circumferential direction CD is preferably formed with at least one curved portion that curves in the tire radial direction, and the curved portion that curves in the tire radial direction extends along the extending direction PL. More preferably, a plurality are formed. When a plurality of curved portions are formed, curved portions that are convex inward in the tire radial direction and curved portions that are convex outward in the tire radial direction are alternately formed. 1-15 are preferable and, as for the number of a curved part, 3-10 are more preferable. By forming at least one bending portion on the tread side of the first connecting portion 31 where the stress is increased, the stress of the first connecting portion 31 can be effectively dispersed. 5-200 mm is preferable and, as for the curvature radius of a curved part, 20-150 mm is more preferable.

  The number of connecting portions 3 is preferably 80 to 300, more preferably 100 to 200, from the viewpoint of reducing weight, improving power transmission, and improving durability while sufficiently supporting a load from the vehicle. FIG. 1 shows an example in which 50 first connecting portions 31 and 50 second connecting portions 32 are provided.

  The tensile modulus of the connecting portion 3 is preferably 5 to 180000 MPa from the viewpoint of reducing the weight, improving the durability, and improving the lateral rigidity while sufficiently transmitting the force from the inner annular portion 1 and the outer annular portion 2. ˜50000 MPa is more preferable. In order to increase the tensile modulus of the connecting portion 3, a fiber reinforced material obtained by reinforcing an elastic material with fibers or the like is preferable.

  FIG. 5 is a cross-sectional view (VV cross-sectional view) in which the first connecting portion 31 shown in FIG. 2A is cut in a direction orthogonal to the extending direction PL. The first connecting portion 31 or the second connecting portion 32 is formed with a through hole 4 that penetrates in the tire circumferential direction CD. In the present embodiment, the three through holes 4 are formed in the first connecting part 31 and the second connecting part 32, respectively, but the number of the through holes 4 is the size of the first connecting part 31 and the second connecting part 32, etc. Can be set as appropriate.

  In the present embodiment, the axial direction of the through hole 4 coincides with the tire circumferential direction CD. The cross-sectional area of the surface of the through hole 4 perpendicular to the axial direction is constant in the axial direction. Both open ends of the through hole 4 are circular, that is, the through hole 4 is a circular hole. The diameter of the through hole 4 is, for example, 20% with respect to the plate width w. The opening end of the through hole 4 is not limited to a circle, but may be a polygon such as a triangle or a rectangle, an ellipse or the like.

  A protruding portion 5 extending in the circumferential direction of the through hole 4 is formed on the inner peripheral surface 4 c of the through hole 4. The protrusion 5 has a front wall surface 5a positioned in front of the tire rotation direction, a rear wall surface 5b positioned rearward of the front wall surface 5a with respect to the tire rotation direction, and an upper surface 5c protruding most from the inner peripheral surface 4c. ing. In the present embodiment, when viewed in the axial direction of the through hole 4, the front wall surface 5a and the rear wall surface 5b have a substantially rectangular shape, and the protruding portion 5 has a rectangular plate shape as a whole. The cross-sectional shape of the protrusion 5 is substantially rectangular, but is not limited to this, and may be trapezoidal or triangular. 5-80% of the maximum height from the inner peripheral surface 4c of the protrusion part 5 is preferable with respect to the radius of the inner peripheral surface 4c, and 10-50% is more preferable.

  A plurality of protruding portions 5 are preferably formed at intervals in the axial direction of the through hole 4. In the example shown in FIG. 5, four protruding portions 5 are formed side by side along the axial direction of the through hole 4. In the present embodiment, four protrusions 5 are provided, but the protrusions 5 may be 1 to 3, or 5 or more.

  In the present embodiment, as shown in FIG. 1, an example is shown in which a reinforcing layer 8 that reinforces bending deformation of the outer annular portion 2 is provided outside the outer annular portion 2 of the support structure SS. Moreover, in this embodiment, as shown in FIG. 1, the example in which the tread 9 is provided in the further outer side of the reinforcement layer 8 is shown. As the reinforcing layer 8 and the tread 9, it is possible to provide the same material as the belt layer of the conventional pneumatic tire. In addition, you may form the tread 9 with resin. Moreover, it is possible to provide the same pattern as a conventional pneumatic tire as a tread pattern.

  In the present invention, it is preferable that a width direction reinforcing layer for increasing rigidity in the tire width direction is further disposed between the outer end in the tire radial direction of the connecting portion 3 and the tread 9. Thereby, buckling in the tire width direction center part of the outer side annular part 2 is suppressed, and durability of the connection part 3 can further be improved. The width direction reinforcing layer is embedded in the outer annular portion 2 or disposed outside the outer annular portion 2. Examples of the reinforcing layer in the width direction include steel cords, cords made of fiber reinforced plastic such as CFRP, GFRP, etc. arranged substantially parallel to the tire width direction, cylindrical metal rings, high modulus resin rings, etc. Is done.

[Other Embodiments]
(1) In the above-described embodiment, the protruding portion 5 has a rectangular plate shape, but the protruding portion 5 may have a triangular plate shape as shown in FIG. In addition, it is preferable that a plurality of protruding portions 5 are formed at intervals in the circumferential direction of the through hole 4. FIG. 6B shows an example in which two rectangular plate-like protrusions 5 are formed to face each other. FIG. 6C shows an example in which four triangular plate-like protrusions 5 are formed at equal intervals in the circumferential direction of the through-hole 4.

  (2) In the present invention, as shown in FIG. 7, at least one projecting body 6 projecting in the direction intersecting the tire circumferential direction CD is provided on the side surface of the first connecting portion 31 or the second connecting portion 32. The first connecting portion 31 or the second connecting portion 32 may be formed along the extending direction PL.

  When the tire rolls, an air flow that flows relatively along the tire circumferential direction is generated in the space between the inner annular portion 1 and the outer annular portion 2. This air flow becomes a turbulent flow by the protruding portion 6 protruding in the direction intersecting the tire circumferential direction CD, and flows through the side surface of the first connecting portion 31 or the second connecting portion 32, and the first connecting portion 31 or the second connecting portion. Since the heat exchange with the part 32 is promoted, the first connecting part 31 or the second connecting part 32 can be effectively cooled. Thereby, the temperature of the 1st connection part 31 and the 2nd connection part 32 can be reduced, and durability of the non-pneumatic tire T can be improved.

  The ridges 6 are respectively provided on the side surface 31b facing the inner side in the tire radial direction among the four side surfaces of the first connecting portion 31, and on the side surface 32b facing the inner side in the tire radial direction among the four side surfaces of the second connecting portion 32. Is formed. The side surface 31b and the side surface 32b are substantially parallel to the tire circumferential direction CD.

  FIG. 8 is a cross-sectional view of the first connecting portion 31 cut in a direction orthogonal to the extending direction PL. The protruding body 6 protrudes from the side surface 31b of the first connecting portion 31 toward the inside in the tire radial direction. The cross-sectional shape of the protrusion 6 is substantially rectangular. However, the cross-sectional shape of the protrusion 6 is not limited to a rectangular shape, and may be a trapezoidal shape, a triangular shape, or the like.

  The protrusion 6 includes a front wall surface 6a positioned in front of the tire rotation direction, a rear wall surface 6b positioned rearward of the front wall surface 6a with respect to the tire rotation direction, and an upper surface that protrudes most from the side surface 31b of the first connecting portion 31. 6c.

  The angle θ1 formed between the front wall surface 6a of the ridge 6 and the side surface 31b of the first connecting portion 31 is preferably 45 to 150 °, and more preferably 90 to 135 °. In the present embodiment, the angle θ1 is 90 °. The angle θ2 formed between the rear wall surface 6b of the protrusion 6 and the side surface 31b of the first connecting portion 31 is preferably 45 to 150 °, and more preferably 90 to 135 °. In the present embodiment, the angle θ2 is 90 °. The upper surface 6 c of the projecting body 6 is substantially parallel to the side surface 31 b of the first connecting portion 31.

  10-90% is preferable with respect to plate | board thickness t, and the width | variety by the side surface 31b side of the protrusion 6 is more preferable 20-50%. Moreover, 5-50% is preferable with respect to plate width w, and the height of the protrusion 6 is more preferable 10-30%.

  The rigidity of the protrusion 6 is preferably smaller than the rigidity of the first connecting part 31 and the second connecting part 32. The protrusion 6 is formed of any of the above-described elastic materials, but is preferably formed of a crosslinked rubber or a polyurethane resin among the above-described elastic materials, and is particularly preferably formed of a crosslinked rubber. The tensile modulus of the ridge 6 is preferably 0.2 to 5 MPa, more preferably 0.5 to 2 MPa, from the viewpoint of suppressing deterioration in riding comfort.

  The protruding body 6 and the first connecting part 31 and the second connecting part 32 may be formed of the same material or may be formed of different materials. When the protrusion 6 is formed of a material different from that of the first connection part 31 and the second connection part 32, the protrusion 6 may be formed integrally with the first connection part 31 and the second connection part 32. You may integrate the protrusion body 6 and the 1st connection part 31 and the 2nd connection part 32 which were shape | molded separately by adhesion | attachment or welding.

  Furthermore, a second through-hole 7 penetrating in the tire circumferential direction CD may be formed in the protrusion 6. By forming the second through-hole 7 penetrating in the tire circumferential direction CD in the protrusion 6, the flow velocity of the air flow passing through the second through-hole 7 is improved, so the first connecting portion 31 or the second connecting portion. The cooling effect of 32 can be enhanced. In the present embodiment, the three second through holes 7 are formed in the protruding body 6, but the number of the second through holes 7 can be appropriately set depending on the size of the protruding body 6.

  In the present embodiment, the axial direction of the second through hole 7 coincides with the tire circumferential direction CD. The cross-sectional area of the second through hole 7 by a plane perpendicular to the axial direction is constant in the axial direction. Both open ends of the second through hole 7 are circular, that is, the second through hole 7 is a circular hole. The diameter of the second through hole 7 is, for example, 10 to 50% with respect to the height of the protrusion 6. The opening end of the second through hole 7 is not limited to a circle, but may be a polygon such as a triangle or a rectangle, an ellipse, or the like.

  (3) In the non-pneumatic tire of the present invention, the first connecting portion and the second connecting portion may have a long plate shape in which the plate width direction coincides with the tire circumferential direction CD.

  Examples and the like specifically showing the configuration and effects of the present invention will be described below. In addition, the evaluation item in an Example etc. measured as follows.

Durability Using an indoor drum testing machine equipped with a drum with a diameter of 1.7m, the air pressure is 180kPa, the test speed is 80km / h, the tire load starts from 85% of the JIS standard, and the load is increased every specified time. Finally, it was run at 140% and a running test was conducted until it broke down. The surface temperature of the connecting portion during this durability test was measured every 15 minutes. The lower the surface temperature, the more advantageous the durability. It shows with an index when the temperature in Comparative Example 1 is 100, and the larger this value, the better the durability.

Comparative Example 1
A non-pneumatic tire shown in FIG. 2B except for a through hole (including a protruding portion) was used as Comparative Example 1. The durability results are shown in Table 1.

Example 1
A non-pneumatic tire shown in FIG. The durability results are shown in Table 1.

Example 2
The non-pneumatic tire shown in FIG. The durability results are shown in Table 1.

Example 3
Example 3 was obtained by removing the second through hole from the non-pneumatic tire shown in FIG. The durability results are shown in Table 1.

Example 4
The non-pneumatic tire shown in FIG. The durability results are shown in Table 1.

  In each non-pneumatic tire, the outer diameter of the tire was 535 mm, the tire width was 140 mm, and the rim diameter was 14 inches.

  From the results in Table 1, the following can be understood. The non-pneumatic tire of Example 1 has improved durability as compared with Comparative Example 1. Further, the non-pneumatic tire of Example 2 is further improved in durability as compared with Example 1, and the non-pneumatic tire of Example 3 is further improved in durability as compared with Example 2. The non-pneumatic tire No. 4 was further improved in durability as compared with Example 3.

DESCRIPTION OF SYMBOLS 1 Inner ring part 2 Outer ring part 3 Connection part 4 Through-hole 5 Protrusion part 6 Projection body 7 2nd through-hole 31 1st connection part 32 2nd connection part SS Non-pneumatic tire CD Tire circumferential direction WD Tire Width direction WD1 Tire width direction one side WD2 Tire width direction other side

Claims (4)

In a non-pneumatic tire including a support structure that supports a load from a vehicle,
The support structure connects an inner annular portion, an outer annular portion concentrically provided outside the inner annular portion, the inner annular portion and the outer annular portion, and is independent of each other in the tire circumferential direction. A plurality of connecting portions provided,
The plurality of connecting portions include a long plate-like first connecting portion extending from one side in the tire width direction of the inner annular portion toward the other side in the tire width direction of the outer annular portion, and the inner annular portion. The second plate-like second connecting portions extending from the other side in the tire width direction toward the one side in the tire width direction of the outer annular portion are alternately arranged along the tire circumferential direction. And
A non-pneumatic tire characterized in that a through-hole penetrating in the tire circumferential direction is formed in the first connecting portion or the second connecting portion.   The non-pneumatic tire according to claim 1, wherein a projecting portion extending in a circumferential direction of the through hole is formed on an inner peripheral surface of the through hole.   The non-pneumatic tire according to claim 1 or 2, wherein a plurality of the protruding portions are formed at intervals in the axial direction of the through hole. The non-pneumatic tire according to any one of claims 1 to 3, wherein a plurality of the protruding portions are formed at intervals in a circumferential direction of the through hole.

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