JP6045401B2 - Non-pneumatic tire - Google Patents

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 having a solid rubber structure support the load by compressing the contact portion, but this type of tire is heavy and stiff, and does not have a shock absorbing ability like a pneumatic tire. Therefore, solid tires and cushion tires have not been adopted for passenger cars where ride comfort performance is important.

  In the following Patent Document 1, a cylindrical outer member, a cylindrical inner member, and a plurality of axial members coupled to the inner and outer members and extending in the axial direction for the purpose of improving shock absorption capability and steering stability. Non-pneumatic tires having an annular body of elastic material with a number of rib members are described. In this non-pneumatic tire, since the rib member is a plate shape extending in the axial direction with a substantially constant thickness, the rigidity is substantially constant in the tire width direction, and the maximum contact pressure at the center in the tire width direction is increased. .

  In Patent Document 2 below, for the purpose of uniforming the contact pressure distribution, an outer peripheral ring and an inner peripheral ring arranged concentrically are connected by a web of elastic material, and the side surface of the web is connected to the side surface. A non-pneumatic tire is described in which a plurality of ribs of elastic material that are connected to the outer peripheral ring and the inner peripheral ring and extend laterally are provided at intervals in the tire circumferential direction. In this non-pneumatic tire, since the web continuous in the tire circumferential direction is disposed at the center in the tire width direction, the contact pressure at the center in the tire width direction is particularly high.

  By the way, when the contact pressure is not uniform, a hitting sound generated when a portion with a high contact pressure hits the road surface can cause noise. As described above, in the non-pneumatic tires of Patent Document 1 and Patent Document 2, the contact pressure at the center in the tire width direction is high, and noise is likely to increase.

JP-A-60-236803 Japanese Patent Laid-Open No. 2-179503

  Accordingly, an object of the present invention is to provide a non-pneumatic tire that can reduce the noise by making the contact pressure uniform.

The above object can be achieved by the present invention as described below.
That is, the non-pneumatic tire of the present invention includes an inner annular portion, an outer annular portion provided concentrically outside the inner annular portion, and extends from the inner annular portion to the outer annular portion, respectively in the tire circumferential direction. In a non-pneumatic tire having a support structure including a plurality of independently provided connecting portions,
When the connecting portion is divided into three regions in the tire width direction, a region located in the center is defined as a central region, and regions located on both sides of the central region are defined as a first end region and a second end region, respectively. Then
Each cross-sectional shape of the connecting portion in a cross section orthogonal to the extending direction is such that the average thickness in the tire circumferential direction in the central region is a tire circumference in a region where the first end region and the second end region are combined. When the two to six connecting portions that are smaller than the average thickness in the direction and are continuous in the tire circumferential direction among the plurality of connecting portions are taken as one unit, the average of the connecting portions in each unit in the central region The total thickness is configured to be smaller than the total average thickness in the first end region and the total average thickness in the second end region.

  The non-pneumatic tire of the present invention includes an inner annular portion, an outer annular portion concentrically provided outside the inner annular portion, and extends from the inner annular portion to the outer annular portion, and is provided independently in the tire circumferential direction. A support structure including a plurality of connecting portions. When the connecting portion is divided into the first end region, the central region, and the second end region in the tire width direction, each cross-sectional shape of the connecting portion has an average thickness in the tire circumferential direction in the central region. The first end region and the second end region are configured to be smaller than the average thickness in the tire circumferential direction. Furthermore, each cross-sectional shape of a connection part is the average thickness in the center area | region of the connection part in each unit, when 2-6 connection parts which continue in a tire peripheral direction are made into one unit among several connection parts. Is configured to be smaller than the sum of the average thickness in the first end region and the sum of the average thickness in the second end region. According to this configuration, the total rigidity in the central region of the two to six connecting portions existing in each unit is equal to the total rigidity in the first end region and the total rigidity in the second end region. Can be made smaller. As a result, in the ground contact surface where 2 to 6 connecting parts in each unit are grounded, the maximum ground pressure in the center region in the tire width direction decreases and approaches the maximum ground pressure in the end region, so the ground pressure is uniform. Noise can be reduced.

  In the non-pneumatic tire according to the present invention, the connecting portion gradually changes in the tire circumferential direction thickness in the tire width direction in each of the first end region, the central region, and the second end region. It is preferable.

  According to this configuration, since there is no sudden change in the thickness in the tire circumferential direction within each region, the connecting portion is less likely to be distorted and is less likely to fail.

  In the non-pneumatic tire according to the present invention, it is preferable that the thickness of the connecting portion in the tire circumferential direction is gradually changed over the entire tire width direction.

  According to this configuration, since there is no sudden change in the thickness in the tire circumferential direction over the entire tire width direction, the connecting portion is less likely to be distorted and is less likely to fail.

  In the non-pneumatic tire according to the present invention, it is preferable that the connecting portion is formed continuously from one tire end in the tire width direction to the other tire end.

  According to this structure, since the connection part is continuously formed in the tire width direction, durability is high.

  In the non-pneumatic tire according to the present invention, the connecting portion in each unit has a thickness at the second position where the total thickness at the first position in the tire width direction is symmetric with respect to the first position and the tire equatorial plane. It is preferable to be provided so as to be the same as the total.

  According to this configuration, when viewed by each unit, the rigidity of the tire is symmetrical with respect to the tire equatorial plane, and the balance is good.

  In the non-pneumatic tire according to the present invention, it is preferable that the plurality of connecting portions are configured such that two connecting portions having a symmetrical shape with respect to the tire equatorial plane are alternately arranged in the tire circumferential direction.

  According to this configuration, when viewed as a whole tire, the rigidity of the tire is symmetrical with respect to the tire equatorial plane, and the balance is good. Further, since the structure is simple, it is easy to manufacture a non-pneumatic tire.

Front view showing an example of the non-pneumatic tire of the present invention Non-pneumatic tire viewed from the right side Sectional drawing of the connection part in the cross section orthogonal to the extending direction Sectional drawing of the connection part which concerns on other embodiment. Side view showing a non-pneumatic tire according to another 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. Here, O indicates a tire shaft, and H indicates a tire cross-sectional height.

  The non-pneumatic tire T of the present invention has 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.

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

  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 1 to 20% of the tire cross-section height H and more preferably 2 to 10% from the viewpoint of reducing weight and improving durability while sufficiently transmitting force to the connecting portion 3. preferable.

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

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

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

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

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

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

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

  Of the above elastic materials, a polyurethane resin is preferably used from the viewpoint of moldability / workability and cost. In addition, as an elastic material, you may use a foaming material, 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 outer annular portion 2, and the connecting portion 3 are preferably reinforced by 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 outer annular portion 2 is preferably a cylindrical shape with a constant thickness from the viewpoint of improving uniformity. The thickness of the outer annular portion 2 is preferably 1 to 20% of the tire cross-section height H, and preferably 2 to 10% from the viewpoint of reducing weight and improving durability while sufficiently transmitting the force from the connecting portion 3. More preferred.

  The inner diameter of the outer annular portion 2 is appropriately determined according to its use. 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.

  Although the width | variety of the tire axial direction of the outer side annular part 2 is suitably determined according to a use etc., when substitution of a general pneumatic tire is assumed, 100-300 mm is preferable and 130-250 mm is more preferable.

  The tensile modulus of the outer annular portion 2 can be set to the same level as that of the inner annular portion 1 when the reinforcing layer 4 is provided on the outer periphery of the outer annular portion 2 as shown in FIG. When such a reinforcing layer 4 is not provided, 5 to 180000 MPa is preferable, and 7 to 50000 MPa is more preferable from the viewpoint of reducing weight and improving durability while sufficiently transmitting the force from the connecting portion 3.

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

  The connecting portion 3 connects the inner annular portion 1 and the outer annular portion 2, and a plurality of connecting portions 3 are provided so as to be independent from each other in the tire circumferential direction CD with an appropriate interval therebetween.

  FIG. 2 is a view of the non-pneumatic tire T of FIG. 1 as viewed from the right side, and is a development view in which the outer annular portion 2 is extended on a plane. The connecting portion 3 viewed through the outer annular portion 2 is shown by a solid line.

  The connecting portion 3 has a plate shape extending from the inner annular portion 1 to the outer annular portion 2 in the tire radial direction. Moreover, the connection part 3 is extended in the tire width direction WD. The connection part 3 of this embodiment is formed continuously from one tire end in the tire width direction WD to the other tire end.

  When the connecting portion 3 is divided into three regions in the tire width direction WD, the region located in the center is defined as the center region B, and the regions located on both sides of the center region B are defined as the first end region A and the second end, respectively. A partial area C is assumed. In the present embodiment, the width of the central region B in the tire width direction WD is set to 1/3 of the entire width of the connecting portion 3 so that the center of the central region B coincides with the tire equatorial plane P. That is, the first end region A, the central region B, and the second end region C are each 1/3 of the entire width of the connecting portion 3.

  In the present embodiment, the plurality of connecting portions 3 are configured by alternately arranging two connecting portions 31 and 32 having a symmetrical shape with respect to the tire equatorial plane P in the tire circumferential direction CD.

  FIG. 3 shows a cross-sectional shape in a cross section orthogonal to the extending direction of the connecting portion 31 (the tire radial direction in the present invention). As described above, since the connecting portion 31 and the connecting portion 32 have a symmetrical shape with respect to the tire equatorial plane P, only the connecting portion 31 is shown in FIG.

  In the cross-sectional shape of the connecting portion 31 in the cross section orthogonal to the extending direction, the thickness in the tire circumferential direction CD gradually increases or decreases from one tire end toward the other tire end. Both end edges in the tire circumferential direction CD of the connecting portion 31 are curves that are convex toward the center of the connecting portion 31. Thereby, as for the connection part 31, the thickness of tire circumferential direction CD is changing gradually over the whole tire width direction. In the present invention, each connecting portion 3 preferably has an asymmetric shape with respect to the tire equatorial plane P. Thereby, when the outer annular portion 2 on the outer side in the tire radial direction of the connecting portion 3 contacts the ground during rolling of the tire, the connecting portion 3 does not contact with the entire tire width direction at the same time. Is input.

  Each cross-sectional shape of the connecting portion 3 of the present invention is such that the tire circumferential direction CD in the region where the average thickness tb in the tire circumferential direction CD in the central region B is the sum of the first end region A and the second end region C. It is configured to be smaller than the average thickness tac. In the present embodiment, since the first end region A and the second end region C have the same width, the average thickness tac is the average thickness ta in the tire circumferential direction CD in the first end region A and the second end region C. The average value (ta + tc) / 2 with the average thickness tc in the tire circumferential direction CD. The average thickness tb in the central region B is preferably 15% to 95% of the average thickness tac in the combined region of the first end region A and the second end region C, and is 25% to 95%. More preferably. If it is less than 15%, the central region B tends to be distorted and the durability may be deteriorated. If it is larger than 95%, it is difficult to reduce the contact pressure in the central region B.

  Two to six connecting portions 3 that are continuous in the tire circumferential direction CD among the plurality of connecting portions 3 are defined as one unit. The length L in the tire circumferential direction CD of one unit can be determined by the tire contact length. Here, the contact length refers to the tire circumferential direction length of the contact surface at a load 0.7 times the maximum load capacity defined by JATMA corresponding to pneumatic tires of the same tire size. The number of connecting portions 3 within the ground contact length is determined by the number of connecting portions 3 in the entire tire, the interval between the connecting portions 3, etc., but 2 to 6 is preferable. In the present embodiment, the six connecting portions 3 are one unit.

  Each cross-sectional shape of the connecting portion 3 is a central region B of the connecting portion 3 in each unit when 2 to 6 connecting portions 3 continuous in the tire circumferential direction CD among the plurality of connecting portions 3 are taken as one unit. The total average thickness Tb of the first end region A is configured to be smaller than the total average thickness Ta of the first end region A and the average thickness Tc of the second end region C. Tb = tb1 + tb2 + tb3 + tb4 + tb5 + tb6, where tb1, tb2, tb3, tb4, tb5, and tb6 are the average thicknesses in the central region B of the six connecting portions 3, respectively. Similarly, Ta = ta1 + ta2 + ta3 + ta4 + ta5 + ta6, and the second ends of the six connecting portions 3 when the average thicknesses in the first end region A of the six connecting portions 3 are ta1, ta2, ta3, ta4, ta5 and ta6, respectively. Assuming that the average thickness in the partial region C is tc1, tc2, tc3, tc4, tc5, and tc6, respectively, Tc = tc1 + tc2 + tc3 + tc4 + tc5 + tc6. The total average thickness Tb in the central region B is preferably 15% to 95% of the total average thickness Ta in the first end region A and the total average thickness Tc in the second end region C. 25% to 95% is more preferable. If it is less than 15%, the central region B tends to be distorted and the durability may be deteriorated. If it is larger than 95%, it is difficult to reduce the contact pressure in the central region B.

  According to these configurations, the total rigidity in the central region B of the six connecting portions 3 existing in each unit is equal to the total rigidity in the first end region A and the second end region C. It can be made smaller than the total rigidity. As a result, the maximum contact pressure in the center region in the tire width direction decreases and approaches the maximum contact pressure in the end region within the contact surface where the six connecting portions 3 in each unit contact, so that the contact pressure is made uniform. Noise can be reduced.

  The number of connecting portions 3 of the entire tire is preferably 10 to 80, and 40 to 60 from the viewpoint of reducing weight, improving power transmission, and improving durability while sufficiently supporting the load from the vehicle. More preferred.

  The thickness of the connecting portion 3 in the tire circumferential direction CD is 1 to 1 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 inner annular portion 1 and the outer annular portion 2. 30% is preferable, and 1 to 20% is more preferable. In addition, the thickness of the connecting portion 3 in the tire circumferential direction CD is preferably 2 mm or more in order to ensure durability.

  The width of the connecting portion 3 in the tire axial direction is appropriately determined according to the use 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 connecting portion 3 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. .

  In the present embodiment, as shown in FIG. 1, an example is shown in which a reinforcing layer 4 that reinforces bending deformation of the outer annular portion 2 is provided outside the outer annular portion 2 of the support structure SS. Moreover, in this embodiment, as shown in FIG. 1, the example in which the tread rubber 5 is provided in the further outer side of the reinforcement layer 4 is shown. As the reinforcing layer 4 and the tread rubber 5, the same belt layer as that of a conventional pneumatic tire can be provided. Moreover, it is possible to provide the same pattern as a conventional pneumatic tire as a tread pattern.

[Other Embodiments]
(1) Various cross-sectional shapes of the plurality of connecting portions 3 can be employed in addition to those shown in FIG. An example of the cross-sectional shape of another connecting portion 3 is shown in FIG. FIG. 4A shows an example in which the thickness of the central region B is smaller than that of the first end region A and the second end region C. FIG. 4B shows an example in which the thickness of the central region B is smaller than that of the first end region A and the second end region C, and the whole is symmetrical with respect to the tire equatorial plane. FIG. 4C shows an example in which the thickness of the central region B in FIG. FIG. 4D shows an example in which the thicknesses of the first end region A and the second end region C of FIG. 4B are changed at a constant rate in the tire width direction. FIG. 4E shows an example in which the thicknesses of the first end region A, the central region B, and the second end region C are constant. FIG. 4F shows an example in which the thicknesses of the first end region A, the central region B, and the second end region C are changed at a constant rate in the tire width direction. FIG. 4G and FIG. 4H show an asymmetric example with respect to the tire width direction WD.

  As shown in FIG. 4, various shapes can be adopted for the cross-sectional shape of the connecting portion 3, but the connecting portion 3 has the first end region A, the central region B, and the second end region C. Within each region, it is preferable that the thickness in the tire circumferential direction gradually changes in the tire width direction WD. Specifically, the cross-sectional shapes as shown in FIGS. 4 (a), 4 (b), 4 (d), (f), (g) and (h) are preferable.

  Furthermore, it is preferable that the connection part 3 has the thickness of the tire circumferential direction CD changed gradually over the whole tire width direction. Specifically, the cross-sectional shapes as shown in FIGS. 4 (a), (b), (d), (g), and (h) are preferable. In other words, if there is a step at the boundary between adjacent regions as shown in FIGS. 4E and 4F, distortion may occur and cause a failure.

  (2) In the above-described embodiment, the example in which the plurality of connecting portions 3 are configured by alternately arranging the two connecting portions 31 and 32 in the tire circumferential direction CD is not limited to this. For example, as shown in FIG. 5, six connecting portions 3 and three connecting portions 32 may be arranged together and alternately arranged to constitute six connecting portions 3 in one unit.

  Although the connection part 3 in each unit showed the example comprised by two types of connection parts 31 and 32 symmetrical with respect to the tire equator surface, you may be comprised by three or more types of connection parts. However, the connecting portion 3 in each unit has a tire circumference at the second position where the total thickness in the tire circumferential direction CD at the first position in the tire width direction WD is symmetric with respect to the first position and the tire equatorial plane P. It is preferable to be provided so as to be the same as the total thickness in the direction CD. Thereby, when viewed in each unit, the rigidity of the tire is symmetrical with respect to the tire equatorial plane P, and the balance is good.

  (3) In the above-described embodiment, the example in which the connecting portion 3 extends in parallel to the tire width direction WD is shown, but the present invention is not limited to this. However, the connecting portion 3 is preferably arranged so that the central axis is 0 ± 15 ° with respect to the tire width direction WD. By setting the central axis of the connecting portion 3 to 0 ± 15 ° with respect to the tire width direction WD, buckling due to a force from the tire width direction WD can be suppressed.

  (4) As another embodiment of the present invention, the inner annular portion 1, the intermediate annular portion provided concentrically outside the inner annular portion 1, and the outer annular portion provided concentrically. An outer annular portion 2, a plurality of inner connecting portions that extend from the inner annular portion 1 to the intermediate annular portion and are provided independently in the tire circumferential direction CD, and extend from the intermediate annular portion to the outer annular portion 2, in the tire circumferential direction In a non-pneumatic tire having a support structure including a plurality of outer connecting portions provided independently on a CD, a region located in the center when the outer connecting portion is divided into three regions in the tire width direction. Is a central region, and regions located on both sides of the central region are a first end region and a second end region, respectively, each cross-sectional shape of the outer connecting portion in a cross section orthogonal to the extending direction is the central region In the tire circumferential direction The average thickness is smaller than the average thickness in the tire circumferential direction in the region where the first end region and the second end region are combined, and is continuous in the tire circumferential direction among the plurality of outer connecting portions. In the case where the six outer connecting portions are one unit, the sum of the average thicknesses in the central region of the outer connecting portions in each unit is the sum of the average thicknesses in the first end region and the second end. What is comprised so that it may become smaller than the sum total of the average thickness in a partial area | region. In the present invention, the cross-sectional shapes of the plurality of outer coupling portions may be set as described above, and the shape, number, arrangement, etc. of the plurality of inner coupling portions are not particularly limited.

  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.

(1) Noise performance A vehicle equipped with a non-pneumatic tire was run on a noise measurement course at a speed of 60 km / h with two passengers, and the sound pressure at the ears was measured from the driver's seat window. In the performance evaluation, when the sound pressure was subjected to frequency analysis, attention was paid to the frequency region where noise is generated in Comparative Example 1, and the maximum noise level was investigated. This is indicated by an index when the noise in Comparative Example 1 is 100, and the smaller this value, the better.

(2) Durability Performance Use an indoor drum testing machine equipped with a drum with a diameter of 1.7 mm, set the test speed to 80 km / h, start the tire load from 85% of the JIS standard, and increase the load every specified time. I finally made it run at 140%. The distance traveled until the failure occurred was measured and shown as an index when Comparative Example 1 was set to 100. The larger this value, the better the durability performance.

Example 1
A support structure including an inner ring (corresponding to the inner annular portion), an outer ring (corresponding to the outer annular portion), and a spoke (corresponding to the connecting portion), provided on the outer periphery, with the dimensions and physical properties shown in Table 1. A non-pneumatic tire including three reinforcing layers and tread rubber was produced, and the above performance was evaluated. The cross-sectional shape of the spoke was the shape shown in FIG. The plurality of spokes were arranged as shown in FIG. The tire width was 140 mm. The evaluation results are also shown in Table 1.

Examples 2-7
The same as Example 1 except that the thickness of the spoke was changed. The evaluation results are also shown in Table 1.

Comparative Example 1
Example 1 was the same as Example 1 except that the spoke thickness was constant in the tire width direction. The evaluation results are also shown in Table 1.

  From the results in Table 1, the following can be understood. In the non-pneumatic tires of Examples 1 to 7, the maximum level of noise was smaller than that of Comparative Example 1, and the noise was reduced. Moreover, since Examples 6 and 7 had an area where the average thickness was 1.5 mm and the minimum thickness was less than 2 mm, the durability deteriorated.

DESCRIPTION OF SYMBOLS 1 Inner ring part 2 Outer ring part 3 Connection part 31 Connection part 32 Connection part SS Support structure T Non-pneumatic tire

Claims (5)

An inner annular portion, an outer annular portion concentrically provided outside the inner annular portion, and a plurality of connecting portions that extend from the inner annular portion to the outer annular portion and are independently provided in the tire circumferential direction. In a non-pneumatic tire having a support structure comprising:
When the connecting portion is divided into three regions in the tire width direction, a region located in the center is defined as a central region, and regions located on both sides of the central region are defined as a first end region and a second end region, respectively. Then
Each cross-sectional shape of the connecting portion in a cross section orthogonal to the extending direction is such that the average thickness in the tire circumferential direction in the central region is a tire circumference in a region where the first end region and the second end region are combined. When the two to six connecting portions that are smaller than the average thickness in the direction and are continuous in the tire circumferential direction among the plurality of connecting portions are taken as one unit, the average of the connecting portions in each unit in the central region The total thickness is configured to be smaller than the total average thickness in the first end region and the total average thickness in the second end region ,
The non-pneumatic tire is characterized in that the connecting portion is formed continuously from one tire end in the tire width direction to the other tire end .   The thickness of the tire circumferential direction gradually changes in the tire width direction in each of the first end region, the central region, and the second end region. Item 2. The non-pneumatic tire according to Item 1.   The non-pneumatic tire according to claim 1 or 2, wherein a thickness of the connecting portion in the tire circumferential direction is gradually changed over the entire tire width direction. The connecting portion in each unit is provided such that the total thickness at the first position in the tire width direction is the same as the total thickness at the second position that is symmetric with respect to the first position and the tire equatorial plane. The non-pneumatic tire according to any one of claims 1 to 3 , wherein the non-pneumatic tire is provided. Wherein the plurality of connecting portions, one of claims 1-4, characterized in that two connecting portions having a symmetrical shape with respect to the tire equatorial plane is constructed are disposed alternately in the tire circumferential direction The non-pneumatic tire according to item 1.

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