JP6529833B2 - Non pneumatic tire - Google Patents

Description

  The present invention relates to a non-pneumatic tire comprising a support structure supporting a load from a vehicle as a tire structural member, preferably a non-pneumatic tire that can be used as a substitute for a pneumatic tire. It relates to the tire.

  Pneumatic tires have the ability to support loads, absorb shock from the ground, and transmit power such as power (acceleration, stop, change of direction), which makes them suitable for many vehicles, especially bicycles, motorcycles, automobiles, It is adopted in the track.

  In particular, these capabilities have greatly contributed to the development of automobiles and other motor vehicles. Furthermore, the impact absorption capacity of the pneumatic tire is also useful in carts for transporting medical devices and electronic devices, and other applications.

  Conventional non-pneumatic tires include, for example, solid tires, spring tires, cushion tires and the like, but they do not have the excellent performance of pneumatic tires. For example, while solid tires and cushion tires support load by compression of the ground contact portion, such tires are heavy, stiff and do not have the shock absorbing capability as pneumatic tires do. In addition, in the non-pneumatic tire, although it is possible to enhance the elasticity to improve the cushioning property, there is a problem that the load supporting ability or the durability which the pneumatic tire has is deteriorated.

  Therefore, the present inventor has proposed the non-pneumatic tires described in the following Patent Documents 1 and 2 as non-pneumatic tires capable of reducing the contact pressure dispersion while improving the durability. The non-pneumatic tires of Patent Documents 1 and 2 connect an inner annular portion, an outer annular portion concentrically provided on the outer side of the inner annular portion, the inner annular portion and the outer annular portion, And a plurality of connecting portions provided independently in the direction, and the plurality of connecting portions extend from one tire width direction side of the inner annular portion toward the other tire width direction side of the outer annular portion And an elongated plate-shaped second extending from the other side in the tire width direction of the inner annular portion toward the one tire width direction side of the outer annular portion. The connecting portions are alternately arranged along the tire circumferential direction.

  However, it is known that the non-pneumatic tires of Patent Documents 1 and 2 have a possibility that the temperature and strain become large due to bending of the connecting part during traveling, leading to failure, and further improvement of durability is desired.

JP, 2015-39986, A JP, 2014-100933, A

  Then, the objective of this invention is providing the non-pneumatic tire which improved durability.

The above object can be achieved by the present invention as described below.
That is, the non-pneumatic tire according to the present invention is a non-pneumatic tire comprising a support structure for supporting a load from a vehicle,
The support structure connects the inner annular portion, the outer annular portion concentrically provided on the outer side of the inner annular portion, the inner annular portion and the outer annular portion, and is independent in the circumferential direction of the tire. And a plurality of connection parts provided
The plurality of connecting portions are long plate-shaped first connecting portions that extend from one tire width direction side of the inner annular portion toward the other tire width direction side of the outer annular portion, and the inner annular portion And an elongated plate-shaped second connecting portion extending from the other side in the tire width direction toward the one side in the tire width direction of the outer annular portion is alternately arranged along the tire circumferential direction. Yes,
The first connecting portion or the second connecting portion is characterized in that a through hole penetrating in the circumferential direction of the tire is formed.

  The operation and effect of the present invention according to this configuration will be described. At the time of tire rolling, an air flow relatively flowing along the tire circumferential direction is generated in the space between the inner annular portion and the outer annular portion. By forming the through holes penetrating in the tire circumferential direction in the first connection portion or the second connection portion, the air flow flowing in the through holes can cool the first connection portion or the second connection portion from the inside. Thereby, the temperatures of the first connecting portion and the second connecting portion can be reduced, and the durability of the 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 projecting portion on the inner peripheral surface of the through hole, the air flow flowing in the through hole is turbulently flowed by the projecting portion and flows on the inner peripheral surface to promote heat exchange with the inner peripheral surface of the through hole. Therefore, the first connection portion or the second connection portion 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 air flow flowing in the through hole collides with the protrusion a plurality of times and becomes turbulent, the cooling effect of the first connection portion or the second connection 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 configuration, since the air flow flowing in the through hole collides with the projecting portion at a plurality of locations and forms a turbulent flow, the cooling effect of the first connection portion or the second connection portion can be enhanced. Furthermore, by providing a gap between the adjacent protrusions, the flow velocity of the air flow is improved, so that the cooling effect of the first connection portion and the second connection portion can be enhanced.

Front view showing an example of the non-pneumatic tire of the present invention AA cross section of the non-pneumatic tire of FIG. 1 A perspective view showing a part of the non-pneumatic tire of FIG. 1 A partial enlarged view of the non-pneumatic tire of FIG. 1 Tire meridional section view of a non-pneumatic tire according to another embodiment Tire meridional section 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 A view of a through hole according to another embodiment viewed from the axial direction The perspective view which shows a part of non-pneumatic tire which concerns on other embodiment Cross-sectional view of a first connecting portion of a non-pneumatic tire according to another embodiment

  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 the non-pneumatic tire T. As shown in FIG. 2A is a cross-sectional view taken along the line A-A of FIG. 1, and FIG. 2B is a perspective view showing a part of the non-pneumatic tire T. As shown in FIG. FIG. 3 is a diagram showing a part of FIG. 1 in an enlarged manner. Here, O indicates the axis and H indicates the tire cross sectional height.

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

  In the non-pneumatic tire T of this embodiment, as shown in the front view of FIG. 1, the support structure SS includes an inner annular portion 1, an outer annular portion 2 concentrically provided on the outer side thereof, and an inner annular portion A plurality of connecting portions 3 are provided, which connect 1 and the outer annular portion 2 and are provided independently in the tire circumferential direction CD.

  From the viewpoint of improving uniformity, the inner annular portion 1 preferably has a cylindrical shape having a constant thickness. Moreover, it is preferable to provide the unevenness | corrugation etc. for maintaining fitting property for the mounting | wearing with an axle and a rim | limb on the inner peripheral surface of the inner side cyclic | annular part 1. FIG.

  The thickness of the inner annular portion 1 is preferably 2 to 7% of the tire cross-sectional height H, 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 dimensions of the rim or axle on which the non-pneumatic tire T is mounted. However, when substitution of a common pneumatic tire is assumed, 250-500 mm is preferable and 330-440 mm is more preferable.

  The width of the inner annular portion 1 in the tire width direction is appropriately determined in accordance with the application, the length of the axle, etc. However, assuming replacement of a general pneumatic tire, it is preferably 100 to 300 mm, 130 to 250 mm. More preferable.

  The tensile modulus of the inner annular portion 1 is preferably 5 to 180000 MPa, and more preferably 7 to 50000 MPa from the viewpoint of achieving weight reduction, improvement in durability, and mounting properties while sufficiently transmitting force to the connecting portion 3. The tensile modulus in the present invention is a value calculated from the 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, but when manufacturing the support structure SS, the inner annular portion 1, the outer annular portion 2, and the connecting portion 3 can be integrally formed. It is preferable to use basically the same material except for the reinforcing structure.

  The elastic material in the present invention refers to a material which is subjected to a tensile test according to JIS K7312 and has a tensile modulus of 100 MPa or less calculated from a tensile stress at 10% elongation. 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. As an elastic material used as a base material, thermoplastic elastomer, crosslinked rubber, and other resins may be mentioned.

  Examples of thermoplastic elastomers include polyester elastomers, polyolefin elastomers, polyamide elastomers, polystyrene elastomers, polyvinyl chloride elastomers, polyurethane elastomers and the like. In addition to natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IIR), nitrile rubber (NBR), hydrogenated nitrile rubber (hydrogenated NBR) as a rubber material constituting a crosslinked rubber material Examples thereof include synthetic rubbers such as chloroprene rubber (CR), ethylene propylene rubber (EPDM), fluororubber, silicone rubber, acrylic rubber and urethane rubber. These rubber materials may be used in combination of two or more as needed.

  Other resins include thermoplastic resins or thermosetting resins. The thermoplastic resin may, for example, be a polyethylene resin, a polystyrene resin, or a polyvinyl chloride resin, and the thermosetting resin may, for example, be an epoxy resin, a phenol resin, a polyurethane resin, a silicone resin, a polyimide resin or a melamine resin.

  Among the above-mentioned elastic materials, a polyurethane resin is preferably used from the viewpoint of moldability / processability and cost. In addition, as an elastic material, you may use a foaming material and can use the thing which made said thermoplastic elastomer, crosslinked rubber, and other resin foam.

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

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

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

  Although the internal diameter of the outer side annular part 2 is suitably determined according to the use etc., when substitution of a common pneumatic tire is assumed, 420-750 mm is preferable and 480-680 mm is more preferable.

  The width in the tire width direction of the outer annular portion 2 is appropriately determined in accordance with the application etc., but when substituting for a general pneumatic tire is assumed, 100 to 300 mm is preferable, and 130 to 250 mm is more preferable.

  The tensile modulus of the outer annular portion 2 can be set to the same degree 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, it is preferably 5 to 180000 MPa, and more preferably 7 to 50000 MPa, from the viewpoint of achieving weight reduction and improvement in durability while sufficiently transmitting the force from the connecting portion 3.

  In order to increase the tensile modulus of the outer annular portion 2, a fiber reinforced material in which an elastic material is reinforced with fibers or the like is preferable. By reinforcing the outer annular portion 2 with reinforcing fibers, adhesion between the outer annular portion 2 and the belt layer or the like is also sufficient.

  The connecting portions 3 connect the inner annular portion 1 and the outer annular portion 2, and a plurality of connecting portions 3 are provided so as to be independent in the tire circumferential direction CD by, for example, leaving an appropriate gap therebetween.

  The plurality of connecting portions 3 are configured by arranging the first connecting portions 31 and the second connecting portions 32 along the tire circumferential direction CD. Under the present circumstances, it is preferable that the 1st connection part 31 and the 2nd connection part 32 are arranged by turns along tire peripheral direction CD. Thereby, the contact pressure distribution at the time of tire rolling can be made smaller.

  Moreover, it is preferable to make constant the pitch p of the tire circumferential direction CD between the 1st connection part 31 and the 2nd connection part 32 from a viewpoint of improving uniformity. 0-10 mm is preferable and, as for the pitch p, 0-5 mm is more preferable. If the pitch p is larger than 10 mm, the ground pressure may become non-uniform, which may cause noise to increase.

  The first connecting portion 31 is extended from one tire width direction WD1 of the inner annular portion 1 toward the other tire width direction WD2 of the outer annular portion 2. On the other hand, the second connecting portion 32 is extended from the tire width direction other side WD2 of the inner annular portion 1 toward the tire width direction one side WD1 of the outer annular portion 2. That is, the 1st connection part 31 and the 2nd connection part 32 which adjoin are arrange | positioned in substantially X shape, when it sees from tire circumferential direction CD.

  It is preferable that the 1st connection part 31 and the 2nd connection part 32 which were seen from tire peripheral direction CD are a symmetrical shape with respect to the tire equatorial plane C, as shown to FIG. 2A. Therefore, the first connecting portion 31 will be mainly described below.

  The first connecting portion 31 has a long plate shape extending from the inner annular portion 1 to the outer annular portion 2. The plate thickness t of the first connecting portion 31 is smaller than the plate width w, and the plate thickness direction PT faces the tire circumferential direction CD. That is, the first connection portion 31 has a plate shape extending in the tire radial direction and the tire width direction. By setting the first connecting portion 31 and the second connecting portion 32 in such a long plate shape, even if the plate thickness t is made thin temporarily, the first connecting portion 31 and the second connecting portion 31 can be made wide by setting the plate width w wide. Since the second connection portion 32 can obtain a desired rigidity, the durability can be improved. In addition, by increasing the number of the first connecting portions 31 and the second connecting portions 32 while reducing the plate thickness t, the gap between the connecting portions adjacent to each other in the tire circumferential direction CD is reduced while maintaining the rigidity of the entire tire. As a result, the contact pressure distribution at the time of tire rolling can be reduced.

  Although the plate thickness t of the first connecting portion 31 may be constant along the extending direction PL, as shown in FIG. 3, the plate thickness t of the first connecting portion 31 is from the inner annular portion 1 to the outer annular portion 2. It is preferable that it is gradually increasing. In this case, the plate thickness t at the tire radial direction outer end 31 a 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, and more preferably 10 to 20 mm, from the viewpoint of achieving weight reduction and improvement in durability while sufficiently transmitting the forces 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 at the central portion of the first connection 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 tire radial direction height of the first connection portion 31 is h, the range of ± 25% of h from the tire radial direction height center 31c of the first connection portion 31 in the tire radial direction is defined as the range The board width w at the narrowest part of the inside is set to be larger than the board thickness t. In addition, let the tire radial inside be + side, and let the tire radial outside be-side. Moreover, the board width w of the 1st connection part 31 is measured by the shortest distance between the width direction both ends.

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

  The first connecting portion 31 is a reinforcing portion 311 in which the plate width is gradually increased toward the inner annular portion 1 or the outer annular portion 2 near 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, the durability of the first connection portion 31 can be further 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 31 c of the first connecting portion 31.

  It is preferable that at least one curved portion curved in the tire radial direction is formed in the first connecting portion 31 viewed from the tire circumferential direction CD, and the curved portion curved in the tire radial direction extends along the extending direction PL It is more preferable that a plurality be 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 radial direction of the tire are alternately formed. 1-15 are preferable and, as for the number of curved parts, 3-10 are more preferable. By forming at least one curved portion on the tread side where the stress in the first connection portion 31 is increased, the stress of the first connection 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, and more preferably 100 to 200 from the viewpoint of weight reduction, improvement of power transmission, and improvement of durability while sufficiently supporting a load from a 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 weight and improving durability and improving lateral rigidity while sufficiently transmitting the force from the inner annular portion 1 and the outer annular portion 2. -50000MPa is more preferred. In the case of increasing the tensile modulus of the connection portion 3, a fiber reinforced material in which an elastic material is reinforced with a fiber or the like is preferable.

  FIG. 5 is a cross-sectional view (V-V cross-sectional view) obtained by cutting the first connection portion 31 shown in FIG. 2A in a direction orthogonal to the extending direction PL. In the first connecting portion 31 or the second connecting portion 32, a through hole 4 penetrating in the tire circumferential direction CD is formed. In the present embodiment, the three through holes 4 are respectively formed in the first connecting portion 31 and the second connecting portion 32, but the number of the through holes 4 is the size of the first connecting portion 31, the second connecting portion 32, etc. Can be set as appropriate.

  The axial direction of the through hole 4 in the present embodiment coincides with the tire circumferential direction CD. The cross-sectional area of a plane perpendicular to the axial direction of the through hole 4 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% of the plate width w. The open end of the through hole 4 is not limited to a circle, and may be a triangle, a polygon such as a quadrangle, an ellipse, or the like.

  On the inner circumferential surface 4 c of the through hole 4, a protrusion 5 extending in the circumferential direction of the through hole 4 is formed. The protrusion 5 has a front wall 5a located forward in the tire rotation direction, a rear wall 5b located rearward of the front wall 5a with respect to the tire rotation, and an upper surface 5c most projecting from the inner circumferential 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 projecting portion 5 has a rectangular plate shape as a whole. Although the cross-sectional shape of the protrusion part 5 is carrying out substantially rectangular shape, it is not limited to this, A trapezoidal shape, triangle shape, etc. may be sufficient. 5-80% is preferable with respect to the radius of the internal peripheral surface 4c from the internal peripheral surface 4c of the protrusion part 5, 10-50% is more preferable.

  It is preferable that a plurality of protrusions 5 be formed at intervals in the axial direction of the through hole 4. In the example shown in FIG. 5, four protrusions 5 are formed side by side along the axial direction of the through hole 4. In addition, although four protrusion parts 5 are provided in this embodiment, one to three protrusion parts 5 may be sufficient, and five or more may be sufficient.

  In the present embodiment, as shown in FIG. 1, an example in which a reinforcing layer 8 for reinforcing the bending deformation of the outer annular portion 2 is provided outside the outer annular portion 2 of the support structure SS is shown. 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 as the belt layer of the conventional pneumatic tire. The tread 9 may be made of 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 to further arrange a width direction reinforcing layer between the tire radial direction outer end of the connecting portion 3 and the tread 9 to enhance the rigidity in the tire width direction. Thereby, the buckling of the outer annular portion 2 at the center in the tire width direction can be suppressed, and the durability of the connecting portion 3 can be further improved. The widthwise reinforcing layer is embedded in the outer annular portion 2 or disposed outside the outer annular portion 2. As the width direction reinforcing layer, a steel cord, a fiber reinforced plastic cord such as CFRP, GFRP, etc. arranged substantially parallel to the tire width direction, a cylindrical metal ring, a high modulus resin ring, etc. are illustrated. Be done.

[Other embodiments]
(1) In the above-mentioned embodiment, although the protrusion part 5 is made into the rectangular plate shape, the protrusion part 5 may be a triangular plate shape like Fig.6 (a). Moreover, it is preferable that the protrusion part 5 is formed in multiple numbers at intervals in the circumferential direction of the through hole 4. FIG. 6 (b) 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 protrusion 6 protruding in the direction intersecting with the tire circumferential direction CD is provided on the side surface of the first connection portion 31 or the second connection portion 32. You may form along the extending direction PL of 1 connection part 31 or 2nd connection part 32. FIG.

  At the time of tire rolling, an air flow relatively flowing along the tire circumferential direction is generated in the space between the inner annular portion 1 and the outer annular portion 2. The air flow is turbulently flowed through the side surface of the first connection portion 31 or the second connection portion 32 by the projecting portion 6 which protrudes in the direction intersecting the tire circumferential direction CD, and flows through the first connection portion 31 or the second connection In order to promote heat exchange with the part 32, the first connection part 31 or the second connection 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 the endurance of non-pneumatic tire T can be improved.

  The protrusion 6 is respectively provided to a side 31b facing inward in the tire radial direction among four side faces of the first connecting portion 31 and a side 32b facing inside in the tire radial direction among four side faces of the second connecting portion 32. It is formed. The side surface 31 b and the side surface 32 b 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 perpendicular to the extending direction PL. The protrusion 6 protrudes from the side surface 31 b of the first connection portion 31 inward in the tire radial direction. The cross-sectional shape of the protrusion 6 is substantially rectangular. However, the cross-sectional shape of the protruding member 6 is not limited to the rectangular shape, and may be trapezoidal or triangular.

  The protrusion 6 has a front wall 6a located forward in the tire rotation direction, a rear wall 6b located rearward of the front wall 6a in the tire rotation direction, and an upper surface most projecting from the side 31b of the first connecting portion 31. And 6c.

  45-150 degrees is preferable, and, as for angle (theta) 1 which the front wall surface 6a of the protrusion 6 and the side surface 31b of the 1st connection part 31 to make, 90-135 degrees are more preferable. In the present embodiment, the angle θ1 is 90 °. 45-150 degrees is preferable and, as for angle (theta) 2 which the rear wall surface 6b of the protrusion 6 and the side surface 31b of the 1st connection part 31 to make, 90-135 degrees are more preferable. In the present embodiment, the angle θ2 is 90 °. The upper surface 6 c of the protrusion 6 is substantially parallel to the side surface 31 b of the first connecting portion 31.

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

  It is preferable that the rigidity of the protrusion 6 be smaller than the rigidity of the first connection portion 31 and the second connection portion 32. The protrusion 6 is formed of any of the above-mentioned elastic materials, but among the above-mentioned elastic materials, it is preferable to be formed of crosslinked rubber or polyurethane resin, and it is particularly preferable to be formed of crosslinked rubber. From a viewpoint of suppressing that a ride comfort deteriorates, 0.2-5 Mpa is preferable, and, as for the tensile modulus of the protruding body 6, 0.5-2 Mpa is more preferable.

  The protrusion 6 and the first connecting portion 31 and the second connecting portion 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 the first connecting portion 31 and the second connecting portion 32, the protrusion 6 may be formed integrally with the first connecting portion 31 and the second connecting portion 32, The separately formed projecting members 6 may be integrated with the first connecting portion 31 and the second connecting portion 32 by adhesion or welding.

  Furthermore, the second through holes 7 penetrating in the tire circumferential direction CD may be formed in the protrusion 6. By forming the second through holes 7 penetrating in the tire circumferential direction CD in the protrusion 6, the flow velocity of the air flow passing through the second through holes 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 protrusion 6, but the number of the second through holes 7 can be appropriately set according to the size of the protrusion 6 or the like.

  The axial direction of the second through hole 7 in the present embodiment coincides with the tire circumferential direction CD. The cross-sectional area by the surface perpendicular to the axial direction of the second through hole 7 is constant in the axial direction. Both open ends of the second through holes 7 are circular, that is, the second through holes 7 are circular holes. The diameter of the second through hole 7 is, for example, 10 to 50% of the height of the protrusion 6. The open end of the second through hole 7 is not limited to a circular shape, and may be a triangular shape, a polygonal shape such as a rectangular shape, or an elliptical shape.

  (3) In the non-pneumatic tire according to the present invention, the first connecting portion and the second connecting portion may be in the form of a long plate whose plate width direction coincides with the tire circumferential direction CD.

  Hereinafter, an example etc. which show the composition and effect of the present invention concretely are described. In addition, the evaluation item in an Example etc. measured as follows.

Durability Using an indoor drum tester equipped with a drum with a diameter of 1.7 m, the air pressure is 180 kPa, the test speed is 80 km / h, the tire load starts from 85% of the JIS standard, and the load is increased every specified time Finally, the car was run at 140%, and a driving test was conducted until it broke down. The surface temperature of the connection part during this endurance test was measured every 15 minutes. The lower the surface temperature, the more advantageous the durability. The index is based on the temperature of Comparative Example 1 as 100. The larger the value, the better the durability.

Comparative Example 1
A non-pneumatic tire shown in FIG. 2B from which the through holes (including the protrusions) are removed is taken as Comparative Example 1. The results of durability are shown in Table 1.

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

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

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

Example 4
The non-pneumatic tire shown in FIG. The results of durability 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.

  The following can be understood from the results of Table 1. The non-pneumatic tire of Example 1 has improved durability as compared with Comparative Example 1. In addition, the non-pneumatic tire of Example 2 is further improved in durability as compared to Example 1, and the non-pneumatic tire of Example 3 is further improved in durability as compared to Example 2; The non-pneumatic tire of No. 4 had further improved durability as compared with Example 3.

DESCRIPTION OF SYMBOLS 1 inner side annular part 2 outer side annular part 3 connection part 4 through-hole 5 protrusion part 6 protrusion 7 2nd through-hole 31 1st connection part 32 2nd connection part SS support structure T non-pneumatic tire CD tire circumferential direction WD tire Width direction WD1 Tire width direction one side WD2 Tire width direction other side

Claims (3)

In a non-pneumatic tire comprising a support structure for supporting a load from a vehicle,
The support structure connects the inner annular portion, the outer annular portion concentrically provided on the outer side of the inner annular portion, the inner annular portion and the outer annular portion, and is independent in the circumferential direction of the tire. And a plurality of connection parts provided
The plurality of connecting portions are long plate-shaped first connecting portions that extend from one tire width direction side of the inner annular portion toward the other tire width direction side of the outer annular portion, and the inner annular portion And an elongated plate-shaped second connecting portion extending from the other side in the tire width direction toward the one side in the tire width direction of the outer annular portion is alternately arranged along the tire circumferential direction. Yes,
A through hole penetrating in the tire circumferential direction is formed in the first connection portion or the second connection portion ,
The non-pneumatic tire according to claim 1, wherein a protrusion extending in a circumferential direction of the through hole is formed on an inner peripheral surface of the through hole . Non pneumatic tire according to claim 1 wherein the protrusions, characterized in that formed with a plurality at intervals in the axial direction of the through hole. The non-pneumatic tire according to claim 1 or 2 , wherein a plurality of the projecting portions are formed at intervals in the circumferential direction of the through hole.

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