JP2011178308A - Non-pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-pneumatic tire capable of reducing a grounding pressure variation caused by rotation. <P>SOLUTION: This non-pneumatic tire includes: a support structure SS having an inside annular part 1, an outside annular part 3 arranged in a concentrically circular shape outside the inside annular part 1 and a plurality of connecting parts 4 and 5 for connecting the inside annular part 1 and the outside annular part 3 and respectively independent in the peripheral direction, and supporting a load from a vehicle; and an air sac 7 arranged outside the support structure SS, and having a skin part 71 forming a flat doughnut shape in the tire axial direction and a hollow part 72 formed so that air can be filled inside the skin part 71. <P>COPYRIGHT: (C)2011,JPO&INPIT

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, in Patent Document 1 below, for the purpose of developing a non-pneumatic tire having the same operating characteristics as a pneumatic tire, a reinforced annular band that supports a load applied to the tire, and the reinforced annular band, Non-pneumatic tires have been proposed that have a plurality of web spokes that transmit load forces by tension with a wheel or hub. The reinforced annular band adheres to an elastomer shear layer (shear modulus about 3-20 MPa), at least one first membrane adhered radially inward of the elastomer shear layer, and radially outward of the elastomer shear layer. And at least one second membrane.

Special Table 2005-500932 Publication

  However, in the non-pneumatic tire described in Patent Document 1, when a longitudinal load is applied so as to have the same amount of deflection, the longitudinal load varies depending on the positional relationship between the position of the web spoke and the center position of the contact surface. It turned out that it tends to be easy. That is, as shown in FIG. 8 (a), when the center position between the web spokes S is located at the contact surface center TC, the reaction force from the tire is small (soft), which is shown in FIG. 8 (b). Thus, when the position of the lower end of the web spoke S is located at the contact surface center TC, the reaction force from the tire becomes large (hard), and the circumferential variation of the tire rigidity is observed in the contact state between the two. As a result, the contact pressure varies with the rotation of the tire, so that the hitting sound and uneven wear become a problem.

  Further, as described above, the non-pneumatic tire described in Patent Document 1 has an annular band in which an elastomer shear layer is sandwiched between first and second membranes from the radially inner side and the radially outer side. The band is sheared and deformed so as to make the ground pressure distribution in the ground region uniform. However, as a result of analyzing the contact pressure distribution of the non-pneumatic tire of Patent Document 1 with the shear modulus of the elastomer shear layer being 10 MPa, the present inventor has found that the contact pressure distribution is not uniform and the contact pressure distribution is insufficient. It turned out to be.

  Therefore, an object of the present invention is to provide a non-pneumatic tire that can reduce the contact pressure fluctuation accompanying rotation.

The above object can be achieved by the present invention as described below.
That is, the non-pneumatic tire according to the present invention includes an inner annular portion, an outer annular portion provided concentrically outside the inner annular portion, and the inner annular portion and the outer annular portion connected in the circumferential direction. A support structure that supports a load from the vehicle, a skin that is provided outside the support structure and has a flat donut shape in the tire axial direction, and the skin And an air sac having a hollow portion formed so as to be filled with air inside the portion.

  The non-pneumatic tire of the present invention includes a support structure that supports a load from a vehicle. The support structure includes an inner annular portion, an outer annular portion provided outside the inner annular portion, and an inner annular portion. And a plurality of connecting portions that connect the outer annular portion. When the center position between the connecting parts is grounded at the center of the ground surface and when the lower end of the connecting part is located at the center of the ground surface, the tire rigidity changes in the circumferential direction, and the grounding accompanying the rotation of the tire occurs. Although the pressure fluctuation is likely to occur, the non-pneumatic tire of the present invention includes the air sac as described above on the outside of the support structure, and therefore reduces the ground pressure fluctuation due to the positional relationship between the connecting portion and the center position of the ground contact surface. Can do.

  In the non-pneumatic tire according to the present invention, it is preferable that the outer skin portion includes a cord extending in a radial direction so as to surround the hollow portion and arranged in parallel in the tire circumferential direction. According to this configuration, the outer sack portion can be reinforced with the cord to firmly configure the air sac, and the characteristics of the radial tire such as improved steering stability performance and grip performance can be retained.

  In the non-pneumatic tire according to the present invention, a first belt layer formed by laminating a belt ply including a first cord disposed adjacent to the outer peripheral surface of the support structure and inclined with respect to the tire equator line. It is preferable to provide. According to this configuration, the outer annular portion of the support structure is reinforced by the first belt layer. Therefore, the load applied to the tire is transmitted to the outer annular portion by the tension of the connecting portion, and is reliably supported by the entire support structure.

  In the non-pneumatic tire according to the present invention, it is preferable that the non-pneumatic tire includes a first belt layer disposed adjacent to the outer peripheral surface of the support structure and made of a ring-shaped metal plate. According to this configuration, since the outer annular portion of the support structure is reinforced by the first belt layer as described above, the load applied to the tire is transmitted to the outer annular portion by the tension of the connecting portion, and the entire support structure It is definitely supported by.

  In the non-pneumatic tire according to the present invention, it is preferable that the non-pneumatic tire includes a first belt layer that is disposed adjacent to the outer peripheral surface of the support structure and is formed of a laminated body of cords extending along the tire circumferential direction. According to this configuration, since the outer annular portion of the support structure is reinforced by the first belt layer as described above, the load applied to the tire is transmitted to the outer annular portion by the tension of the connecting portion, and the entire support structure It is definitely supported by.

  In the non-pneumatic tire according to the present invention, the support structure preferably includes an intermediate annular portion provided concentrically outside the inner annular portion and inside the outer annular portion. According to this configuration, since the non-pneumatic tire according to the present invention includes the intermediate annular portion, when the position of the coupling portion between the coupling portion and the outer annular portion is grounded, the deformation (strain) concentrated on the coupling portion is intermediate. The annular portion can also be burdened, and the deformation of the support structure can be made uniform. As a result, in the non-pneumatic tire according to the present invention, the tire rigidity hardly varies in the circumferential direction due to the positional relationship between the position of the connecting portion and the center of the contact surface, and the contact pressure variation due to rotation decreases.

  The non-pneumatic tire according to the present invention preferably includes a reinforcing member disposed on the outer peripheral surface of the air bag and a tread disposed on the outer peripheral side of the reinforcing member to constitute a ground contact surface. According to this configuration, the air sac is restrained from the outer peripheral side by the reinforcing material, and the flat shape can be maintained in a state where the internal pressure during inflation is applied. During running, the tread disposed on the outer peripheral side of the reinforcing material is grounded to protect the air sac from impacts and trauma, and to transmit the driving force of the tire to the road surface.

  In the non-pneumatic tire according to the present invention, it is preferable that the reinforcing member includes a second belt layer in which a belt ply including a second cord inclined with respect to the tire equator line is laminated inside and outside. In such a configuration, since the tension is generated in the second belt layer according to the internal pressure of the air sac, the cornering force can be improved. In addition, the second belt layer can increase the rigidity of the tread surface portion and ensure good wear resistance.

  In the non-pneumatic tire according to the present invention, it is preferable that the reinforcing member includes a belt reinforcing layer including a third cord extending along the tire circumferential direction. In such a configuration, a tension is generated in the belt reinforcing layer according to the internal pressure of the air sac, so that the cornering force can be improved. When the reinforcing material includes the second belt layer, the reinforcing effect can be effectively enhanced by laminating the belt reinforcing layer on the outer periphery of the second belt layer.

Front view showing an example of the non-pneumatic tire of the present invention Tire meridian cross-sectional view schematically showing an example of the non-pneumatic tire of the present invention The figure explaining the form of the cord contained in an outer skin part Plan view with non-pneumatic tire partially broken Tire meridian cross-sectional view showing an example in which the air bag is divided in the tire axial direction Air pressure, contact length, and contact shape of the air bag in the non-pneumatic tire of FIG. Front view showing another embodiment of the support structure Explanatory drawing for demonstrating the subject of the conventional non-pneumatic tire

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing an example of a non-pneumatic tire of the present invention. FIG. 2 is a tire meridian cross-sectional view schematically showing an example of the non-pneumatic tire of the present invention. 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. Furthermore, the non-pneumatic tire T of the present embodiment includes a first belt layer 6, an air bag 7, a reinforcing material 8, and a tread 9 on the outer peripheral side of the support structure SS.

  As shown in the front view of FIG. 1, the non-pneumatic tire T according to the present embodiment includes an inner annular portion 1, an intermediate annular portion 2 provided concentrically on the outer side thereof, and an outer side thereof. A concentric outer ring part 3, an inner ring part 1, an intermediate ring part 2, a plurality of inner connection parts 4 that are independent in the circumferential direction, an outer ring part 3, and an intermediate ring part 2 And a plurality of outer connecting portions 5 that are independent of each other in the circumferential direction. In this embodiment, the support structure SS includes the intermediate annular portion 2, but the intermediate annular portion 2 is not always necessary, and the intermediate annular portion 2 is not provided, and the inner connecting portion 4 and the outer connecting portion 5 are continuous. However, you may comprise one connection part.

  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 3 to 6% from the viewpoint of reducing weight and improving durability while sufficiently transmitting force to the inner connecting portion 4. More preferred.

  The inner annular portion 1 has an inner diameter that is appropriately determined in accordance with the dimensions of the rim on which the non-pneumatic tire T is mounted, the axle, and the like. It can be made much smaller. 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 axial width of the inner annular portion 1 is appropriately determined according to the application, the length of the axle, and the like, but when an alternative to a general pneumatic tire is assumed, it is preferably 100 to 300 mm, more preferably 130 to 250 mm. preferable.

  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 inner connecting portion 4. 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. From the viewpoint of enabling integral molding when the support structure SS is manufactured, the inner annular portion 1, the intermediate annular portion 2, and the outer annular portion 3 are used. The inner connecting portion 4 and the outer connecting portion 5 are preferably basically made of 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, and what used said thermoplastic elastomer, crosslinked rubber, and other resin foamed can be used.

  In the support structure SS integrally formed of an elastic material, the inner annular portion 1, the intermediate annular portion 2, the outer annular portion 3, the inner connecting portion 4, and the outer connecting portion 5 are preferably reinforced with reinforcing fibers. .

  Examples of the reinforcing fibers include reinforcing fibers such as long fibers, short fibers, woven fabrics, and non-woven fabrics. As a form using long fibers, fibers arranged in the tire axial 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 intermediate annular portion 2 is not limited to a cylindrical shape, and may be a polygonal cylindrical shape.

  The thickness of the intermediate annular portion 2 is preferably 3 to 10% of the tire cross-section height H from the viewpoint of reducing the weight and improving the durability while sufficiently reinforcing the inner connecting portion 4 and the outer connecting portion 5. -9% is more preferable.

  The inner annular portion 2 has an inner diameter that exceeds the inner diameter of the inner annular portion 1 and less than the inner diameter of the outer annular portion 3. However, as the inner diameter of the intermediate annular portion 2, the inner diameter of the inner annular portion 1 is subtracted from the inner diameter of the outer annular portion 3 from the viewpoint of improving the reinforcing effect of the inner connecting portion 4 and the outer connecting portion 5 as described above. A value of 20 to 80% of the value is preferably the inner diameter added to the inner diameter of the inner annular portion 1, and a value of 30 to 60% is more preferably the inner diameter added to the inner diameter of the inner annular portion 1. .

  The axial width of the intermediate annular portion 2 is appropriately determined according to the application 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 intermediate annular portion 2 is preferably 8000 to 18000 MPa, more preferably 10,000 to 50000 MPa from the viewpoint of sufficiently reinforcing the inner connecting portion 4 and the outer connecting portion 5 to improve durability and load capacity. preferable.

  Since the tensile modulus of the intermediate annular portion 2 is preferably higher than that of the inner annular portion 1, a fiber reinforced material in which a thermoplastic elastomer, a crosslinked rubber, or other resin is reinforced with fibers or the like is preferable.

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

  The inner diameter of the outer annular portion 3 is appropriately determined according to its use and the like, but since the intermediate annular portion 2 is provided in the present invention, the inner diameter of the outer annular portion 3 can be made larger than before. However, when an alternative to a general pneumatic tire is assumed, 420 to 750 mm is preferable, and 480 to 680 mm is more preferable.

  The axial width of the outer annular portion 3 is appropriately determined according to the application and the like, but is preferably 100 to 300 mm, and more preferably 130 to 250 mm when an alternative to a general pneumatic tire is assumed.

  The tensile modulus of the outer annular portion 3 is preferably 5 to 180000 MPa and more preferably 7 to 50000 MPa from the viewpoint of reducing weight and improving durability while sufficiently transmitting the force from the outer connecting portion 5.

  When the tensile modulus of the outer annular portion 3 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 3 with the reinforcing fiber, the adhesion between the outer annular portion 3 and the first belt layer 6 is sufficient.

  The inner connecting portion 4 connects the inner annular portion 1 and the intermediate annular portion 2, and a plurality of inner connecting portions 4 are provided so that each is independent in the circumferential direction, for example, by providing an appropriate interval therebetween. The inner connecting portion 4 is preferably provided regularly in the circumferential direction from the viewpoint of improving uniformity.

  As for the number of inner connection parts 4 provided over the entire circumference (when a plurality of inner connection parts 4 are provided in the axial direction, it is counted as one), while supporting the load from the vehicle sufficiently, weight reduction, improvement of power transmission, durability From the viewpoint of improving the quality, 10 to 80 are preferable, and 40 to 60 are more preferable. FIG. 1 shows an example in which 40 inner connecting portions 4 are provided.

  Examples of the shape of each inner connecting portion 4 include a plate-like body and a columnar body. In this embodiment, an example of a plate-like body is shown. These inner connection parts 4 are extended in the tire radial direction or the direction inclined from the tire radial direction in the front sectional view. In the present invention, from the viewpoint of improving the durability by increasing the break point and making it difficult to change the rigidity, the extending direction of the inner connecting portion 4 is preferably within ± 30 ° in the tire radial direction in the front sectional view. The tire radial direction is more preferably within ± 15 °. FIG. 1 shows an example in which the inner connecting portion 4 extends in a direction inclined by an angle θ from the tire radial direction. In this example, the adjacent inner connecting portions 4 are inclined by an angle θ in directions opposite to each other with respect to the tire radial direction.

  The thickness of the inner connecting portion 4 is preferably 2 to 12% of the tire cross-sectional height H from the viewpoint of reducing weight, improving durability, and improving lateral rigidity while sufficiently transmitting the force from the inner annular portion 1. 2 to 10% is more preferable.

  The tensile modulus of the inner connecting portion 4 is preferably 5 to 100 MPa, more preferably 7 to 80 MPa from the viewpoint of reducing weight, improving durability, and improving lateral rigidity while sufficiently transmitting the force from the inner annular portion 1. preferable.

  When the tensile modulus of the inner connecting portion 4 is increased, a fiber reinforced material obtained by reinforcing an elastic material with fibers or the like is preferable.

  The outer connecting portion 5 connects the outer annular portion 3 and the intermediate annular portion 2, and a plurality of outer connecting portions 5 are provided so that each of them is independent in the circumferential direction, for example, by providing an appropriate interval therebetween. The outer connecting portion 5 is preferably provided regularly in the circumferential direction from the viewpoint of improving uniformity.

  In addition, the outer side connection part 5 and the inner side connection part 4 may be provided in the same position of a perimeter, and may be provided in a different position. That is, the outer connecting portion 5 and the inner connecting portion 4 do not necessarily extend so as to be continuous in the same direction as shown in FIG.

  As for the number of outer connecting parts 5 provided over the entire circumference (when a plurality of outer connecting parts 5 are provided in the axial direction, they are counted as one), while supporting the load from the vehicle sufficiently, weight reduction, improvement of power transmission, durability From the viewpoint of improving the quality, 10 to 80 are preferable, and 40 to 60 are more preferable. FIG. 1 shows an example in which 40 outer connecting portions 5 are provided in the same manner as the inner connecting portions 4. In addition, the number of the outer side connection parts 5 and the number of the inner side connection parts 4 do not necessarily need to be the same, and you may provide more outer side connection parts 5 than the inner side connection parts 4. FIG.

  Examples of the shape of each outer connecting portion 5 include a plate-like body and a columnar body. In this embodiment, an example of a plate-like body is shown. These outer connecting portions 5 extend in a tire radial direction or a direction inclined from the tire radial direction in a front sectional view. In the present invention, from the viewpoint of improving the durability by increasing the break point and making it difficult to change the rigidity, the extending direction of the outer connecting portion 5 is preferably within ± 30 ° in the tire radial direction in the front sectional view. The tire radial direction is more preferably within ± 15 °. FIG. 1 shows an example in which the outer connecting portion 5 is extended in a direction inclined from the tire radial direction. Further, in this example, the adjacent outer connecting portions 5 are inclined by an angle θ in opposite directions to the tire radial direction.

  The thickness of the outer connecting portion 5 is preferably 2 to 12% of the tire cross-sectional height H from the viewpoint of reducing weight, improving durability, and improving lateral rigidity while sufficiently transmitting the force from the inner annular portion 1. 2 to 10% is more preferable.

  The tensile modulus of the outer connecting portion 5 is preferably 5 to 100 MPa, more preferably 7 to 80 MPa from the viewpoint of reducing weight, improving durability, and improving lateral rigidity while sufficiently transmitting the force from the inner annular portion 1. preferable.

  In order to increase the tensile modulus of the outer connecting portion 5, a fiber reinforced material obtained by reinforcing an elastic material with fibers or the like is preferable.

  The first belt layer 6 is disposed adjacent to the outer peripheral surface of the support structure SS. The belt plies 6a and 6b constituting the first belt layer 6 include a cord 61 inclined at an angle of 10 to 60 degrees with respect to the tire equator line CL, and are laminated inside and outside so that the cord directions are opposite to each other. Has been. As the cord 61, a cord constituting a belt layer of a general tire can be used, and examples of the material include organic fibers such as polyester, rayon, nylon, and aramid, steel, and the like.

  The first belt layer 6 is not limited to the above-described one in which the belt plies 6a and 6b are laminated. That is, you may comprise the 1st belt layer 6 with the ring-shaped metal plate which does not have directionality, for example. Moreover, you may comprise the 1st belt layer 6 with the laminated body of the cord extended along a tire peripheral direction. As the cord, the above cord constituting the belt layer of a general tire can be used.

  The air sac 7 has an outer skin portion 71 that has a donut shape that is flat in the tire axial direction, and a hollow portion 72 that is formed inside the outer skin portion 71 so as to be able to be filled with air. The inner peripheral surface of the air bag 7 on the inner side in the tire radial direction is joined to the first belt layer 6. A valve (not shown) that penetrates the first belt layer 6 and communicates with the hollow portion 72 is provided on the inner periphery of the support structure SS. By filling the air through the valve, the air sac 7 is inserted into the support structure SS. Can be freted. The gas filled in the air sac 7 is not limited to air, and may be nitrogen gas or the like.

  FIG. 3 is a diagram for explaining the form of the cord 73 included in the outer skin portion 71. FIG. 4 is a plan view showing the non-pneumatic tire T partially broken. As shown in FIGS. 3 and 4, the outer skin portion 71 includes a cord (first cord) 73 extending in the radial direction RD so as to surround the hollow portion 72 and juxtaposed in the tire circumferential direction CD. The radial direction RD is a direction perpendicular to the tire circumferential direction CD, and the cord 73 extends in a substantially annular shape in the cross section of the tire meridian. As the cord 73, a cord constituting a carcass of a general tire can be used, and examples of the material thereof include organic fibers such as polyester, rayon, nylon, and aramid.

  In the outer skin portion 71 of the present embodiment, a long rubber-coated cord formed by topping a single cord 73 with rubber is spirally wound so as to extend substantially in the radial direction RD. Therefore, it can be easily formed into a flat endless tube shape as shown in FIG. 2, and an excellent uniformity can be realized. In addition, since the carcass rewinding process is unnecessary, the number of man-hours for manufacturing is reduced as compared with the conventional method. For the topping of the cord 73, for example, polyurethane may be adopted in addition to rubber. In order to maintain the internal pressure at the time of inflation, the inner surface of the outer skin portion 71 facing the hollow portion 72 is covered with a substance having low air permeability such as halogenated butyl rubber.

  Since the non-pneumatic tire T of the present invention includes the air sac 7 as described above outside the support structure SS, it is possible to reduce ground pressure fluctuation due to the positional relationship between the outer connecting portion 5 and the center position of the ground surface. . Further, when the non-pneumatic tire T is grounded, the connecting portions 4 and 5 of the support structure SS are likely to be deformed (bent), causing bending fatigue and lowering the durability. In the non-pneumatic tire T of the present invention including the air sac 7, since the connecting portions 4 and 5 and the air sac 7 respectively bear the deflection of the entire tire, the connecting portion 4 and the non-pneumatic tire T are compared with the case where there is no air sac 7. 5 deformation can be reduced, and durability is also improved.

  The air bladder 7 has a flat shape in the tire axial direction as described above, but the balance between durability and steering stability performance can be changed by the magnitude of the flatness ratio. Specifically, when the flatness of the air sac 7 is increased, the durability is improved, and when the flatness is decreased, the steering stability is improved. Therefore, the balance of tire performance can be easily changed by adjusting the flatness of the air sac 7. The flatness of the air sac 7 is preferably 15 to 30%.

  Further, in the non-pneumatic tire T of the present invention, even when the air sac 7 is punctured during traveling, the air sac 7 has a flat shape, and the tension of the connecting portion of the support structure SS causes the vehicle to Since the load can be supported, it is possible to secure a travel distance (for example, 80 km / h or less) equal to that of a pneumatic run-flat tire. Furthermore, since the air sac 7 has a flat shape, even when bursting during high-speed driving, the tire diameter hardly changes and the stability of the vehicle is hardly impaired.

  The reinforcing member 8 includes a second belt layer 10 disposed on the outer periphery of the annular air bag 7 and a belt reinforcing layer 11 disposed on the outer periphery of the second belt layer 10. As shown in FIG. 4, the belt plies 10a and 10b constituting the second belt layer 10 include a cord (second cord) 101 inclined at an angle of 10 to 60 degrees with respect to the tire equator line CL. They are stacked on the inside and outside so that the directions are opposite to each other. As the cord 101, a cord constituting a belt layer of a general tire can be used. Examples of the material include organic fibers such as polyester, rayon, nylon, and aramid, and steel.

  The belt reinforcing layer 11 includes a cord (third cord) 111 extending substantially parallel to the tire circumferential direction CD, and reinforces the restraint of the air bag 7 by the second belt layer 10 from the outer peripheral side. As the cord 111, a cord constituting a belt reinforcing layer of a general tire such as the organic fiber described above can be used. The belt reinforcing layer 11 is formed by winding a single cord 111 covered with rubber or a small band-like ply made of a plurality of cords 111 covered with rubber in a spiral manner along the tire circumferential direction CD. It may be a thing.

  As the tread 9, a tread rubber disposed in a tread portion of a general tire can be used. In FIG. 2, the reinforcing material 8 is depicted as being open at both ends, but actually, the tread 9 entirely covers the reinforcing material 8 including both ends, and the second belt layer 10 and The belt reinforcing layer 11 is embedded under the tread 9. A tread pattern corresponding to required tire performance and use conditions is formed on the outer peripheral surface of the tread 9, and constitutes a ground contact surface that is a contact portion with the road surface.

  As an example of the non-pneumatic tire T, the tire outer diameter D is 540 mm, the tire width is 140 mm, the tire cross-section height H is 30 mm, the tread thickness is 6 mm, the air bag 7 has a cross-sectional height a of 19 mm, An example in which the internal pressure is 550 kPa is exemplified. Further, as another example of the non-pneumatic tire T, the tire outer diameter D is 640 mm, the tire width is 210 mm, the tire cross-section height H is 35 mm, the tread thickness is 7 mm, the cross-section height a of the air bag 7 is 23 mm, An example in which the internal pressure of the air bag 7 is 650 kPa is exemplified. The tire cross-section height H is preferably 5 to 15% of the tire outer diameter D. The cross-sectional height a of the air sac 7 is preferably 40 to 80% of the tire cross-sectional height H, and more preferably 60 to 80%. Although the internal pressure of the air bag 7 is increased or decreased according to the vehicle weight, it is preferably approximately 400 to 700 kPa.

<Other embodiments>
In the above-described embodiment, an example in which one air sac 7 continuous in the tire axial direction is provided, but in the present invention, a plurality of air sac 7 may be provided by being divided in the tire axial direction. FIG. 5 shows an example in which the air bag 7 is divided into two in the tire axial direction and an example in which the air bag 7 is divided into three. FIG. 6 shows the air pressure, contact length, and contact shape of the air sac in these non-pneumatic tires. FIG. 6 is an example of a size equivalent to a general tire 155 / 55R14.

  As shown in FIG. 5, by dividing the air sac 7 into a plurality in the tire axial direction and changing the air pressure of each air sac, the ground contact shape can be controlled. That is, as shown in FIG. 5 (a), the air sac 7 is divided into two parts and the respective air pressures are adjusted to change the contact length ratio between the in and out sides according to the vehicle camber, thereby making the contact shape asymmetric. be able to. Thereby, it is possible to reduce uneven wear and improve exercise performance. In addition, as shown in FIG. 5B, the air sac 7 is divided into three parts, and the ground contact length on the center side is made longer than the contact length on the in and out sides by adjusting the respective air pressure, and the ground contact shape is rounded. Can be used. Thereby, improvement of exercise performance and improvement of drainage can be aimed at. Furthermore, there is an advantage that the risk of puncture can be reduced by dividing the air sac 7 into a plurality in the tire axial direction.

  In the above-described embodiment, an example in which only one intermediate annular portion 2 is provided has been described. However, in the present invention, a plurality of intermediate annular portions 2 may be provided. Thereby, it is possible to make the inner diameter of the inner annular portion 1 smaller.

  The shape of the support structure SS is not limited to that shown in FIG. FIG. 7 shows another embodiment of the support structure SS. In the example of Fig.7 (a), the inner side connection part 4 and the outer side connection part 5 are continuously extended in the tire radial direction in the front view cross section.

  In the example of FIG. 7B, 40 inner connecting parts 4 and 80 outer connecting parts 5 are provided. By increasing the number of the outer coupling parts 5 more than the number of the inner coupling parts 4, the interval between the adjacent outer coupling parts 5 is narrowed, and the buckling of the grounding part between the outer coupling parts 5 can be suppressed. . Further, the inner connecting portion 4 extends in the tire radial direction, but the two adjacent outer connecting portions 5 are inclined in directions opposite to each other with respect to the tire radial direction. Two outer connecting portions 5 are arranged in a Y shape when viewed from the tire axial direction. By causing the coupling portion between the outer coupling portion 5 and the intermediate annular portion 2 and the coupling portion between the inner coupling portion 4 and the inner annular portion 2 to approach each other, the intermediate annular portion 2 is subjected to the deflection of the outer coupling portion 5. Can do. Further, a gap is provided between the coupling portion between the inner coupling portion 4 and the intermediate annular portion 2 and the coupling portion between the outer coupling portion 5 and the intermediate annular portion 2. Thereby, it becomes difficult to transmit the compressive force of the inner side connection part 4 directly to the outer side connection part 5, and it can prevent that the distortion | strain of the outer side connection part 5 becomes large. Furthermore, by providing a gap between the coupling portions between the outer connecting portion 5 and the intermediate annular portion 2, the intermediate annular portion 2 between them can share the tension of the inner connecting portion 4 and the outer connecting portion 5.

DESCRIPTION OF SYMBOLS 1 Inner ring part 2 Middle ring part 3 Outer ring part 4 Inner connection part 5 Outer connection part 6 1st belt layer 7 Air bag 8 Reinforcement material 9 Tread 10 2nd belt layer 11 Belt reinforcement layer 71 Outer skin part 72 Hollow part SS Support Structure T Non-pneumatic tire

Claims (9)

An inner annular portion, an outer annular portion concentrically provided on the outer side of the inner annular portion, and a plurality of connecting portions that connect the inner annular portion and the outer annular portion and are independent in the circumferential direction. A support structure for supporting a load from the vehicle;
An air sac having an outer skin part formed in a donut shape that is flat in the tire axial direction, and a hollow part formed inside the outer skin part so as to be able to be filled with air. Non-pneumatic tire provided.   The non-pneumatic tire according to claim 1, wherein the outer skin portion includes a cord that extends in a radial direction so as to surround the hollow portion and is arranged in parallel in a tire circumferential direction.   3. The first belt layer according to claim 1, further comprising a first belt layer that is disposed adjacent to an outer peripheral surface of the support structure and includes a belt ply including a first cord that is inclined with respect to the tire equator line. Non-pneumatic tire.   3. The non-pneumatic tire according to claim 1, further comprising a first belt layer disposed adjacent to an outer peripheral surface of the support structure and made of a ring-shaped metal plate.   3. The non-pneumatic tire according to claim 1, further comprising a first belt layer that is disposed adjacent to an outer peripheral surface of the support structure and includes a cord laminated body that extends along a tire circumferential direction.   The non-pneumatic tire according to claim 1, wherein the support structure includes an intermediate annular portion provided concentrically outside the inner annular portion and inside the outer annular portion. A reinforcing member disposed on the outer peripheral surface of the air bag;
The non-pneumatic tire according to any one of claims 1 to 6, further comprising a tread disposed on an outer peripheral side of the reinforcing member and constituting a ground contact surface.   The non-pneumatic tire according to claim 7, wherein the reinforcing member includes a second belt layer formed by laminating a belt ply including a second cord inclined with respect to the tire equator line inside and outside.   The non-pneumatic tire according to claim 7 or 8, wherein the reinforcing member includes a belt reinforcing layer including a cord extending along a tire circumferential direction.

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