JP2012240525A - Non-pneumatic tire - Google Patents

Abstract

Disclosed is a non-pneumatic tire capable of improving braking performance by making the ground pressure distribution during braking uniform.
In a non-pneumatic tire T including a support structure SS that supports a load from a vehicle, the support structure SS includes an inner annular portion 1 and an intermediate annular shape provided concentrically outside the inner annular portion. Part 2, outer annular part 3 concentrically provided outside intermediate annular part 2, a plurality of inner connecting parts connecting inner annular part 1 and intermediate annular part 2, and outer annular part 3 and intermediate A plurality of outer connecting portions that connect the annular portion 2, and are divided into a plurality of zones S1, S2, S3 in the tire width direction WD, and the intermediate annular portions 21, 23 in the outermost zones S1, S3. maximum outer diameter of _{D21 max} is greater than the maximum outer diameter _{D23 max} of the intermediate annular portion 22 in the inner band S2.
[Selection] Figure 2

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 spokes that transmit load forces by tension with a wheel or hub.

  However, since the non-pneumatic tire described in Patent Document 1 has a gap between spokes adjacent to each other in the circumferential direction, the rigidity of the annular band is reduced in the region between the spokes. There is a problem that buckling occurs between the spokes, resulting in vibration, noise, abnormal wear of the tread, and destruction.

  In order to prevent such buckling of the grounding portion between the spokes, the following Patent Document 2 includes fins (corresponding to spokes) that connect the annular outer peripheral member and the inner peripheral member in the radial direction. The spoke structures arranged intermittently at intervals in the circumferential direction are made into unit structures divided into a plurality of bands in the tire width direction, and the positions of the fins are shifted in the circumferential direction between these unit structures. Non-pneumatic tires are described. In this non-pneumatic tire, the fins displaced in the circumferential direction improve the rigidity of the outer peripheral member between the fins in the adjacent band, thereby suppressing buckling of the outer peripheral member.

Special Table 2005-500932 Publication Japanese Patent No. 3966895

  However, the non-pneumatic tire described in Patent Document 2 has the same configuration as the non-pneumatic tire described in Patent Document 1 in each band, and suppresses the buckling of the ground contact portion between the spokes. It turned out that the effect was not enough. In particular, since a large load is applied to the shoulder during braking, the spokes in the outermost zone in the tire width direction are greatly deformed to cause buckling at the shoulder, resulting in uneven contact pressure distribution and poor braking performance. Turned out to be.

  Accordingly, an object of the present invention is to provide a non-pneumatic tire capable of improving braking performance by making the ground pressure distribution during braking uniform.

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 provided with a support structure that supports a load from a vehicle, and the support structure is provided concentrically on the inner annular portion and on the outer side of the inner annular portion. An intermediate annular portion, an outer annular portion concentrically provided on the outer side of the intermediate annular portion, a plurality of inner connecting portions that connect the inner annular portion and the intermediate annular portion, the outer annular portion, and the A plurality of outer connecting portions that connect the intermediate annular portion, and is divided into a plurality of zones in the tire width direction, and the maximum outer diameter of the intermediate annular portion in the outermost zone is the middle in the inner zone It is characterized by being larger than the maximum outer diameter of the annular portion.

  The effect of the non-pneumatic tire by this structure is demonstrated. Since the length of the outer connecting portion is determined by the difference between the outer diameter of the intermediate annular portion and the inner diameter of the outer annular portion, the maximum outer diameter of the intermediate annular portion in the outermost zone is larger than the maximum outer diameter of the intermediate annular portion in the inner zone. Is larger, the outer connecting portion in the outermost zone is shorter than the outer connecting portion in the inner zone. Thereby, since the outer connection part of an outermost zone becomes difficult to deform | transform compared with the outer connection part of an inner side zone, the support structure of the outermost zone which supports a shoulder part becomes difficult to deform | transform rather than an inner side band. As a result, since the buckling of the shoulder portion during braking can be suppressed, the ground pressure distribution during braking can be made uniform, and the braking performance can be improved.

  In the non-pneumatic tire according to the present invention, it is preferable that an outer diameter of the intermediate annular portion in the outermost zone increases toward the outer side in the tire width direction. According to this structure, since the outer side connection part of an outermost zone becomes short toward the tire width direction outer side, the buckling of a shoulder part can be suppressed effectively.

  In the non-pneumatic tire according to the present invention, it is preferable that a minimum outer diameter of the intermediate annular portion in the outermost zone is larger than a maximum outer diameter of the intermediate annular portion in the inner zone. According to this structure, since the outer side connection part of an outermost zone becomes shorter than the outer side connection part of an inner side band, the buckling of a shoulder part can be suppressed appropriately.

  In the non-pneumatic tire according to the present invention, it is preferable that the outer connecting portion is provided to be shifted from each other in the tire circumferential direction for each of the plurality of bands. According to this configuration, even when grounding between adjacent outer connecting portions in the outermost zone, the outer connecting portion of another zone can support the load, and therefore, the outer connecting portion of the outermost zone can be deformed. Further, the effect of suppressing the buckling of the shoulder portion is enhanced.

  In the non-pneumatic tire according to the present invention, it is preferable that the outer connecting portion in the outermost zone is more than the outer connecting portion in the inner zone. According to this configuration, since the load per outer connecting portion is reduced, the deformation of the outer connecting portion in the outermost band is further suppressed, and the effect of suppressing the buckling of the shoulder portion is enhanced.

Front view showing an example of the non-pneumatic tire of the present invention Tire meridian cross-sectional view showing an example of the non-pneumatic tire of the present invention Tire meridian cross-sectional view showing a non-pneumatic tire of another embodiment Tire meridian cross-sectional view showing a non-pneumatic tire of another embodiment Tire meridian cross-sectional view showing a non-pneumatic tire of another embodiment The side view which shows the non-pneumatic tire of other embodiment The side view which shows the non-pneumatic tire of other embodiment

  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, and FIG. 2 is a tire meridian cross-sectional view including the axis of the non-pneumatic tire. Here, O indicates the axial center, and H1 indicates the tire cross-sectional height.

  The non-pneumatic tire T of the present invention includes a support structure SS that supports a load from a 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.

  In the non-pneumatic tire T of the present invention, as shown in the front view of FIG. 1, the support structure SS has an inner annular portion 1, an intermediate annular portion 2 provided concentrically on the outer side, and a concentric circle on the outer side. Outer annular portion 3 provided in a shape, a plurality of inner coupling portions 4 that couple inner annular portion 1 and intermediate annular portion 2, and a plurality of outer coupling portions that couple outer annular portion 3 and intermediate annular portion 2 And 5.

  Further, the support structure SS is divided into a plurality of bands in the tire width direction WD. In the present embodiment, the band is divided into three bands S1, S2 and S3, the band located on both outer sides in the tire width direction WD is the outermost band S1, S3, and the band located in the center in the tire width direction WD is the inner side. This is referred to as band S2. The width of each band does not need to be equal to the tire width direction WD and may be different. Here, an example is shown in which the tire is divided into three bands in the tire width direction WD, but the number of divisions is not limited to three.

  The width of the support structure SS in the tire width direction WD is appropriately determined according to the use, the length of the axle, and the like, but is preferably 100 to 300 mm, and preferably 130 to 250 mm when an alternative to a general pneumatic tire is assumed. Is more preferable.

  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%, and 3 to 6% of the tire cross-section height H1 from the viewpoint of reducing weight and improving durability while sufficiently transmitting force to the inner connecting portion 4. More preferred.

  An inner diameter d1 and an outer diameter D1 of the inner annular portion 1 are constant in the tire width direction WD and are the same in all bands. Although the inner diameter d1 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, etc., the inner annular portion 1 is provided with the intermediate annular portion 2 in the present invention. Can be made significantly smaller than before. 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 entire width of the inner annular portion 1 in the tire width direction WD is appropriately determined according to the application, the length of the axle, and the like, but is preferably 100 to 300 mm, and preferably 130 to 250 mm when an alternative to a general pneumatic tire is assumed. Is more 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. In addition, the tensile modulus in this invention is a value of the tensile stress at the time of 10% elongation when a tensile test is performed 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. .

  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 intermediate annular portion 2 is provided concentrically outside the inner annular portion 1. The intermediate annular portion 2 of the present invention is divided for each band, the intermediate annular portion 2 in both outer zones S1, S3 is the intermediate annular portion 21, 23, respectively, and the intermediate annular portion 2 in the inner zone S2 is the intermediate annular portion 22. (Hereinafter, when there is no need to identify each intermediate annular portion, it is expressed as an intermediate annular portion 2).

  The intermediate annular portions 21, 22, and 23 are preferably cylindrical shapes having a constant thickness from the viewpoint of improving uniformity. However, the shape of the intermediate annular portions 21, 22, 23 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 H1 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 d1 of the inner annular portion 1 and less than the inner diameter d3 of the outer annular portion 3. However, the inner diameter of the intermediate annular portion 2 is a value obtained by subtracting the inner diameter d1 of the inner annular portion 1 from the inner diameter d3 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. A value of 20 to 80% is preferably an inner diameter added to the inner diameter d1 of the inner annular portion 1, and a value of 30 to 60% is more preferably an inner diameter added to the inner diameter d1 of the inner annular portion 1. .

  The inner and outer diameters of the intermediate annular portion 22 in the inner zone S2 are constant in the tire width direction WD. Further, the inner and outer diameters of the intermediate annular portions 21 and 23 in the outermost zones S1 and S3 are also constant in the tire width direction WD.

In the present invention, the maximum outer diameter D21 _max of the intermediate annular portion 21 in the outermost zone S1 and the maximum outer diameter D23 _max of the intermediate annular portion 23 in the outermost zone S3 are the maximum outer diameter of the intermediate annular portion 22 in the inner zone S2. It is larger than D22 _max . In the present embodiment, since the outer diameters of the outermost zones S1 and S3 are constant in the tire width direction WD, the outer diameter at any position in the outermost zones S1 and S3 is the maximum outer diameters D21 _max and D23 _max. It corresponds to. Similarly, since the outer diameter of the inner band S2 is constant in the tire width direction WD, the outer diameter of any position in the inner band S2 also corresponds to the maximum outer diameter D22 _max.

  The width in the tire width direction WD including the intermediate annular portions 21, 22, and 23 is appropriately determined depending on the application and the like, but is preferably 100 to 300 mm when an alternative to a general pneumatic tire is assumed. 250 mm is more preferable.

  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 H1, and preferably 2 to 5% from the viewpoint of reducing the weight and improving the durability while sufficiently transmitting the force from the outer connecting portion 5. Is more preferable.

  An inner diameter d3 and an outer diameter D3 of the outer annular portion 3 are constant in the tire width direction WD, and are the same in all bands. The inner diameter d3 of the outer annular portion 3 is appropriately determined according to its use and the like. However, since the intermediate annular portion 2 is provided in the present invention, the inner diameter d3 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 overall width of the outer annular portion 3 in the tire width direction WD 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 can be set to the same level as that of the inner annular portion 1 when the reinforcing layer 6 is provided on the outer periphery of the outer annular portion 3 as shown in FIG. In the case where such a reinforcing layer 6 is not provided, 5 to 180000 MPa is preferable, and 7 to 50000 MPa is more preferable from the viewpoint of reducing the weight and improving the 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, adhesion between the outer annular portion 3 and the belt layer becomes 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 parts 4 are preferably provided with a certain interval from the viewpoint of improving uniformity.

  As the number of the inner connecting portions 4 provided over the entire circumference (when a plurality of inner connecting portions 4 are provided in the tire width direction WD, it is counted as one), while sufficiently supporting the load from the vehicle, weight reduction, improvement of power transmission, From the viewpoint of improving durability, 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 4 to 12% of the tire cross-sectional height H1 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. 6 to 10% is more preferable.

  The tensile modulus of the inner connecting portion 4 is preferably 5 to 50 MPa, more preferably 7 to 20 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 portions 5 are preferably provided at regular intervals 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 the number of outer connecting portions 5 provided over the entire circumference (when one is provided in the tire width direction WD, it is counted as one), while sufficiently supporting the load from the vehicle, weight reduction, improvement of power transmission, From the viewpoint of improving durability, 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.

  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 4 to 12% of the tire cross-sectional height H1 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. 6 to 10% is more preferable.

  The tensile modulus of the outer connecting portion 5 is preferably 5 to 50 MPa, more preferably 7 to 20 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.

  In the present embodiment, as shown in FIG. 1, an example is shown in which a reinforcing layer 6 that reinforces bending deformation of the outer annular portion 3 is provided outside the outer annular portion 3 of the support structure SS. Moreover, in this embodiment, as shown in FIG. 1, the example in which the tread layer 7 is provided in the further outer side of the reinforcement layer 6 is shown. As the reinforcing layer 6 and the tread layer 7, it is possible to provide the same layers as those of a conventional pneumatic tire belt layer. Moreover, it is possible to provide the same pattern as a conventional pneumatic tire as a tread pattern.

[Other Embodiments]
(1) In the non-pneumatic tire T of the present invention, it is preferable that the outer diameter of the intermediate annular portion 2 in the outermost zones S1 and S3 increases toward the outer side in the tire width direction WD. Specifically, as shown in FIG. 3A, the outer diameter of the intermediate annular portion 21 in the outermost zone S1 increases toward the outer side in the tire width direction WD so as to become the maximum outer diameter D21 _max from the minimum outer diameter D21 _min. It has become. Similarly, the outer diameter of the intermediate annular portion 23 in the outermost band S3 is becomes larger toward the tire width direction WD outwards as the maximum outer diameter _{D23 max} from the minimum outside diameter _{D23 min.} That is, the intermediate annular portion 21 and the intermediate annular portion 23 have a cylindrical shape whose diameter increases toward the outer side in the tire width direction WD. Also in this case, the maximum outer diameter D21 _max of the intermediate annular portion 21 in the outermost zone S1 and the maximum outer diameter D23 _max of the intermediate annular portion 23 in the outermost zone S3 are the maximum outer diameter of the intermediate annular portion 22 in the inner zone S2. It is larger than the diameter D22 _max .

(2) In the embodiment shown in FIG. 3A, the minimum outer diameters D21 _min and D23 _min in the outermost bands S1 and S3 are larger than the maximum outer diameter D22 _max in the inner band S2, but this is not limitative. It is not a thing. FIG. 3B shows an example in which the minimum outer diameters D21 _min and D23 _min are made equal to the maximum outer diameter D22 _max and the intermediate annular portions 21, 22, and 23 are continued in the tire width direction WD. According to this configuration, the rigidity change of the support structure SS can be suppressed at the boundary between the outermost zones S1 and S3 and the inner zone S2.

(3) Further, FIG. 3C shows an example in which the minimum outer diameters D21 _min and D23 _min in the outermost bands S1 and S3 are smaller than the maximum outer diameter D22 _max in the inner band S2. Even in this case, the maximum outer diameter D21 _max of the intermediate annular portion 21 in the outermost zone S1 and the maximum outer diameter D23 _max of the intermediate annular portion 23 in the outermost zone S3 are the same as those of the intermediate annular portion 22 in the inner zone S2. It is larger than the maximum outer diameter D22 _max .

  (4) In the above-described embodiment, the outer connecting portion 5 is continuous in the tire width direction WD, but the outer connecting portion 5 is divided into a plurality of bands, and is shifted from each other in the tire circumferential direction for each band. May be. FIG. 4A is a side view of the non-pneumatic tire T, and a coupling portion between the outer connecting portion 5 and the outer annular portion 3 is indicated by a broken line. In this example, the outer coupling portion 5 of the inner zone S2 is positioned at the center of the outer coupling portion 5 adjacent to the outermost zones S1 and S3 in the tire circumferential direction.

  (5) In the above embodiment, the number of the outer coupling portions 5 of the outermost bands S1 and S3 and the number of the outer coupling portions 5 of the inner band S2 are the same, but the outer coupling portions 5 in the outermost bands S1 and S3 are: It is preferable that there are more than the outer connection parts 5 in the inner zone S2. FIG. 4B shows an example in which the outer connecting portion 5 of the outermost bands S1 and S3 is provided twice as much as the outer connecting portion 5 of the inner band S2. Note that the number of outer connecting portions 5 in the outermost zone S1 and the outermost zone S3 is not necessarily the same.

  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.

Ground pressure distribution First, while a longitudinal load of 2500 N is applied, the non-pneumatic tire is gradually rolled (rotated), that is, the position of the outer end point of the outer spoke (corresponding to the outer connecting portion 5) is set to the ground surface. While gradually changing with respect to the center position, the distribution of the contact pressure on the contact surface is measured in each contact state. Next, the distribution of the ground pressure in each ground state is calculated from the distribution of the ground pressure, and evaluation is performed using the value of the ground pressure dispersion in the ground state where the value of the dispersion becomes the maximum. Furthermore, the same evaluation was performed with a longitudinal load of 3500 N applied. This is indicated by an index when the maximum value of ground pressure dispersion in Comparative Example 1 is 100, and the smaller this value is, the better.

Example 1
Inner ring (corresponding to the inner annular part), intermediate ring (corresponding to the intermediate annular part), outer ring (corresponding to the outer annular part), inner spoke (corresponding to the inner connecting part) in the dimensions and physical properties shown in Table 1 A non-pneumatic tire including a support structure provided with outer spokes (corresponding to an outer connecting portion), three reinforcing layers provided on the outer periphery thereof, and tread rubber was evaluated. The support structure was 140 mm wide and was equally divided into three zones in the tire width direction. The intermediate ring was configured as shown in FIG. Further, as shown in FIG. 4B, the outer spokes were provided so as to be larger in the outermost band than in the inner band, and were shifted from each other in the tire circumferential direction for each band. The results of ground pressure dispersion are also shown in Table 1.

Example 2
A non-pneumatic tire having the same structure as that of Example 1 except that the intermediate ring has the configuration shown in FIG. 3B was produced, and the performance was evaluated. The results of ground pressure dispersion are also shown in Table 1.

Example 3
A non-pneumatic tire having the same configuration as that of Example 1 except that the intermediate ring has the configuration shown in FIG. 3A was produced, and the performance was evaluated. The results of ground pressure dispersion are also shown in Table 1.

Example 4
A non-pneumatic tire having the same number as the outer spokes in Example 1 except that the same number was used in the outermost zone and the inner zone as shown in FIG. 4A was produced, and the performance was evaluated. The results of ground pressure dispersion are also shown in Table 1.

Comparative Example 1
Inner ring (corresponding to the inner annular part), intermediate ring (corresponding to the intermediate annular part), outer ring (corresponding to the outer annular part), inner spoke (corresponding to the inner connecting part) in the dimensions and physical properties shown in Table 1 A non-pneumatic tire including a support structure provided with outer spokes (corresponding to an outer connecting portion), three reinforcing layers provided on the outer periphery thereof, and tread rubber was evaluated. The support structure was 140 mm wide and was equally divided into three zones in the tire width direction. The intermediate ring has a constant inner diameter and outer diameter in the tire width direction, and has the same shape in all three zones. Further, as shown in FIG. 4A, the outer spokes were provided in the same number in the outermost band and the inner band, and were shifted from each other in the tire circumferential direction for each band. The results of ground pressure dispersion are also shown in Table 1.

Comparative Example 2
A non-pneumatic tire having the same outer spokes as in Comparative Example 1 except that the outermost spoke was larger than the inner zone in the outermost zone was produced, and the performance was evaluated. The results of ground pressure dispersion are also shown in Table 1.

From the results in Table 1, the following can be understood.
Compared with the non-pneumatic tire of Comparative Example 2, the non-pneumatic tires of Examples 1 to 3 greatly improve the contact pressure distribution at the time of high load load while suppressing the contact pressure distribution at the time of low load load to the same extent. Is able to. Similarly, the non-pneumatic tire of Example 4 greatly improves the contact pressure dispersion at the time of high load load while suppressing the contact pressure distribution at the time of a low load load to the same level as the non-pneumatic tire of Comparative Example 1. Has been able to. Since the non-pneumatic tire of the present invention is close to a state where a high load is applied in this evaluation during braking, the ground pressure distribution during braking can be reduced, that is, the ground pressure distribution during braking can be made uniform. The braking performance can be improved. In addition, the non-pneumatic tire of Example 1 has a smaller ground pressure dispersion at the time of high load load than the non-pneumatic tire of Example 4, and similarly, the non-pneumatic tire of Comparative Example 2 is the non-pneumatic tire of Comparative Example 1. Compared to pneumatic tires, the contact pressure dispersion at high load is small. From these results, it can be seen that the ground contact pressure at the time of braking can be made more uniform by increasing the outer connecting portions in the outermost zone than the outer connecting portions in the inner zone.

DESCRIPTION OF SYMBOLS 1 Inner annular part 2 Middle annular part 3 Outer annular part 4 Inner coupling part 5 Outer coupling part 21 Middle annular part 22 Middle annular part 23 Middle annular part SS Support structure S1 Outermost zone S2 Inner zone S3 Outermost zone T Non-air pressure tire

Claims (5)

In a non-pneumatic tire including a support structure that supports a load from a vehicle,
The support structure includes an inner annular portion, an intermediate annular portion provided concentrically outside the inner annular portion, an outer annular portion provided concentrically outside the intermediate annular portion, and the inner annular portion. A plurality of inner connecting portions that connect the outer annular portion and the intermediate annular portion, and a plurality of outer connecting portions that connect the outer annular portion and the intermediate annular portion, and are divided into a plurality of bands in the tire width direction. Has been
A non-pneumatic tire in which the maximum outer diameter of the intermediate annular portion in the outermost zone is larger than the maximum outer diameter of the intermediate annular portion in the inner zone.   The non-pneumatic tire according to claim 1, wherein an outer diameter of the intermediate annular portion in the outermost zone increases toward the outer side in the tire width direction.   The non-pneumatic tire according to claim 1 or 2, wherein a minimum outer diameter of the intermediate annular portion in the outermost zone is larger than a maximum outer diameter of the intermediate annular portion in the inner zone.   The non-pneumatic tire according to any one of claims 1 to 3, wherein the outer connecting portion is provided so as to be shifted from each other in the tire circumferential direction for each of the plurality of bands. The non-pneumatic tire according to any one of claims 1 to 4, wherein the outer connecting portion in the outermost zone is larger than the outer connecting portion in the inner zone.

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