JP6076704B2 - 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 support the load by compressing the ground contact part, but this type of tire is heavy and stiff, and it is difficult to ensure good riding comfort and handling stability like pneumatic tires Met.

  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 to and from the wheel by tension.

  In the non-pneumatic tire of Patent Document 1, the web spoke has a function of supporting a load by tension between the wheel and the annular band. The load bearing force is generated by the tension in the web spokes that are not bonded to the ground contact portion of the annular band. As described above, in order to appropriately generate tension in the web spoke, it is necessary to increase the rigidity of the annular band and suppress deformation. However, when the rigidity of the annular band is increased, the ground contact length in the tire circumferential direction is shortened and the ground contact area is reduced, which leads to deterioration in steering stability and an increase in rolling resistance.

  On the other hand, in Patent Document 2 below, the tread can be relatively displaced in the tire radial direction and the tire width direction with respect to the ring-shaped member by a link mechanism for the purpose of reducing rolling resistance and improving riding comfort and steering stability. A link type non-pneumatic tire is described.

  Patent Document 3 listed below describes a non-pneumatic tire having a load support structure including a plurality of support elements and a connection structure that connects the support elements to each other in the circumferential direction. Further, the support element and the connection structure are connected via a flexible joint. In this non-pneumatic tire, the support element and the flexible joint are bent to support the load.

  However, the non-pneumatic tire of Patent Document 2 has a very large number of parts for configuring the link mechanism, and a burden is imposed on the manufacturing process. This non-pneumatic tire is lighter than a general solid tire, but since many metal parts are used for the link mechanism, the weight of the entire tire tends to be larger than that of a pneumatic tire. Furthermore, since the link mechanism is complicated, durability may deteriorate. The non-pneumatic tire of Patent Document 3 also has a complicated structure for the load support structure, is difficult to manufacture, and costs high. Furthermore, since the tire inner surface is hollow, sufficient lateral rigidity cannot be obtained, and good steering stability cannot be obtained.

Special Table 2005-500932 Publication JP 2010-100284 A JP 2003-320808 A

  Therefore, an object of the present invention is to provide a non-pneumatic tire capable of suppressing deterioration in steering stability and increase in rolling resistance while maintaining durability.

The above object can be achieved by the present invention as described below.
That is, the non-pneumatic tire of the present invention is a non-pneumatic tire including a support structure that supports a load from a vehicle.
The support structure includes an inner annular portion, an outer annular portion provided concentrically on the outer side of the inner annular portion, and a connecting portion that connects the inner annular portion and the outer annular portion,
In the cross section in the tire width direction, the connecting portion includes a first connecting portion extending from one side in the tire width direction of the inner annular portion toward the other side in the tire width direction of the outer annular portion, and the first connecting portion. And a second connecting portion extending from the other side in the tire width direction of the inner annular portion toward one side in the tire width direction of the outer annular portion. .

  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 a connecting portion that connects the inner annular portion and the outer annular portion. The connecting portion crosses the first connecting portion and the first connecting portion extending from one side in the tire width direction of the inner annular portion toward the other side in the tire width direction of the outer annular portion in the cross section in the tire width direction. And a second connecting portion extending from the other side in the tire width direction of the inner annular portion toward one side in the tire width direction of the outer annular portion. That is, the connecting portion has a substantially X-shaped configuration in which the first connecting portion and the second connecting portion intersect in the cross section in the tire width direction. According to this configuration, when a vertical load is applied to the tire, the connecting portion is compressed in the tire radial direction and deforms so as to spread in the tire width direction to support the load. Thereby, since the tension along the tire width direction can be generated in the first connecting portion and the second connecting portion, buckling can be prevented and durability can be maintained. In addition, the non-pneumatic tire of the present invention is not configured to support the load by the tension of the connecting portion that is not coupled to the ground contact portion of the outer annular portion, so there is no need to increase the rigidity of the outer annular portion, and the tire circumferential direction The contact length can be secured. Thereby, since the reduction of the contact area can be suppressed, the deterioration of the steering stability can be suppressed, and since the contact pressure can be dispersed in a wide contact surface, the increase in rolling resistance can be suppressed.

  In the non-pneumatic tire according to the present invention, it is preferable that the connecting portion is divided into a plurality of portions in the tire circumferential direction. Since the connecting portion is divided into a plurality in the tire circumferential direction, the flexibility of the outer annular portion is improved and the contact length in the tire circumferential direction is extended, so that the contact area is increased. Thereby, improvement of steering stability and reduction of rolling resistance can be aimed at.

  In the non-pneumatic tire according to the present invention, it is preferable that the plurality of connecting portions divided in the tire circumferential direction have an interval between adjacent connecting portions of 0 to 5 mm. If the interval between the connecting portions is wide, the contact pressure becomes non-uniform and noise may increase. When the distance between the connecting portions is within this range, the ground pressure does not become uneven, and the ground contact area can be expanded while suppressing an increase in noise.

Front view showing an example of the non-pneumatic tire of the present invention The perspective view which shows a part of non-pneumatic tire of FIG. Tire meridian cross section of non-pneumatic tire Front view showing a non-pneumatic tire according to another embodiment The perspective view which shows the connection part which concerns on other embodiment. The perspective view which shows the connection part which concerns on other embodiment. The perspective view which shows the connection part which concerns on other embodiment. The perspective view which shows the connection part which concerns on other embodiment. The perspective view which shows the connection part which concerns on other embodiment. Front view showing a non-pneumatic tire according to another embodiment Front view showing a non-pneumatic tire according to another embodiment Front view showing a non-pneumatic tire of Comparative Example 1

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

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

  As shown in the front view of FIG. 1, the non-pneumatic tire T of the present embodiment includes an inner annular portion 1, an outer annular portion 2 provided concentrically on the outer side, and an inner annular portion. 1 and a connecting portion 3 for connecting the outer annular portion 2 to each other.

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

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

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

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

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

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

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

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

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

  Of the above elastic materials, a polyurethane resin is preferably used from the viewpoint of moldability / workability and cost. In addition, as an elastic material, you may use a foaming material, 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.

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

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

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

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

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

  The width of the outer annular portion 2 in the tire width direction is appropriately determined depending on 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 2 can be set to the same level as that of the inner annular portion 1 when the reinforcing layer 7 is provided on the outer periphery of the outer annular portion 2 as shown in FIG. In the case where such a reinforcing layer 7 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 is provided over the entire circumference of the tire. Although the connection part 3 may be comprised as a continuous body continuous in the tire circumferential direction CD, in the present embodiment, an example in which the connection part 3 is divided into a plurality in the tire circumferential direction CD is shown.

  As shown in FIG. 3, the connecting portion 3 extends in the tire width direction cross section from the tire width direction one side WD1 of the inner annular portion 1 toward the tire width direction other side WD2 of the outer annular portion 2. The second connecting part 32 extending from the other side WD2 in the tire width direction of the inner annular part 1 toward the one side WD1 in the tire width direction of the outer annular part 2 so as to intersect with the first connecting part 31. It consists of and. That is, the connection part 3 has a substantially X-shaped configuration in which the first connection part 31 and the second connection part 32 intersect each other in the tire width direction cross section.

  According to the present invention, when a vertical load is applied to the non-pneumatic tire T, the connecting portion 3 is compressed in the tire radial direction RD and deforms so as to spread in the tire width direction WD to support the load. Thereby, since tension (indicated by an arrow in FIG. 3) along the tire width direction WD can be generated in the first connecting portion 31 and the second connecting portion 32, buckling is prevented and durability is maintained. it can. Moreover, since the non-pneumatic tire T of the present invention is not configured to support a load by the tension of the connecting portion 3 that is not coupled to the ground contact portion of the outer annular portion 2, it is not necessary to increase the rigidity of the outer annular portion 2. The ground contact length in the tire circumferential direction CD can be secured. Thereby, since the reduction of the contact area can be suppressed, the deterioration of the steering stability can be suppressed, and since the contact pressure can be dispersed in a wide contact surface, the increase in rolling resistance can be suppressed.

  In the present embodiment, the first connecting portion 31 and the second connecting portion 32 connect the inner annular portion 1 and the outer annular portion 2 at both ends in the tire width direction WD, respectively, but are not limited thereto. The 1st connection part 31 and the 2nd connection part 32 may each be made to connect the inner side annular part 1 and the outer side annular part 2 in an inner part rather than the both ends of the tire width direction WD.

  It is preferable that the 1st connection part 31 and the 2nd connection part 32 which were seen from tire circumferential direction CD are symmetrical shapes with respect to the tire equatorial plane C. In the present embodiment, as shown in FIG. 3, the cross-sectional shape of the first connecting portion 31 in the tire width direction cross section and the cross-sectional shape of the second connecting portion 32 in the tire width direction cross section are symmetrical with respect to the tire equatorial plane C. It is trying to become. Therefore, although the 1st connection part 31 is demonstrated below, the 2nd connection part 32 is also the same.

  The 1st connection part 31 is formed with the plate-shaped member like the perspective view of FIG. The first connecting portion 31 has a substantially rectangular plate shape, and the plate width direction PW coincides with the tire circumferential direction CD. The extending direction PL of the first connecting portion 31 is a direction inclined with respect to the tire width direction WD, and the inclination angle with respect to the tire width direction WD is preferably 15 to 50 °.

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

  As the number of connection parts 3 constituted by the first connection part 31 and the second connection part 32, while sufficiently supporting the load from the vehicle, from the viewpoint of reducing weight, improving power transmission, and improving durability, 20-200 are preferable and 30-100 are more preferable. FIG. 1 shows an example in which 40 connecting portions 3 are provided.

  As for the some connection part 3 divided | segmented into tire circumferential direction CD, it is preferable that the space | interval p of adjacent connection parts 3 is 0-5 mm. When the distance p is larger than 5 mm, the ground pressure becomes non-uniform, which may increase noise. Further, from the viewpoint of improving uniformity, the interval p is preferably constant.

  The thickness t of the first connecting portion 31 in the tire radial direction RD is preferably 1 to 10 mm from the viewpoint of reducing the weight and improving the durability while sufficiently transmitting the force from the inner annular portion 1 and the outer annular portion 2. 3 to 7 mm is more preferable. Further, the thickness t of the first connecting portion 31 in the tire radial direction RD is smaller than the plate width of the first connecting portion 31. Note that the thickness t of the first connecting portion 31 does not have to be constant along the extending direction PL.

  The tensile modulus of the first connecting portion 31 is preferably 5 to 180,000 MPa from the viewpoint of reducing weight, improving durability, and improving lateral rigidity while sufficiently transmitting the force from the inner annular portion 1 and the outer annular portion 2. 7 to 50000 MPa is more preferable. When raising the tensile modulus of the 1st connection part 31, the fiber reinforcement material which reinforced the elastic material with the fiber etc. is preferable.

  In this embodiment, as shown in FIG. 1, an example is shown in which a reinforcing layer 7 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 layer 8 is provided in the further outer side of the reinforcement layer 7 is shown. The reinforcing layer 7 can use the above-described reinforcing fibers. Further, the tread layer 8 may be formed of rubber similarly to the conventional pneumatic tire, but may be formed of the above elastic material. Moreover, it is possible to provide the same pattern as a conventional pneumatic tire as a tread pattern.

[Other Embodiments]
(1) As another embodiment of the present invention, as shown in FIG. 4, 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, An intermediate annular portion 4 provided concentrically outside the inner annular portion 1, an outer annular portion 2 provided concentrically outside the intermediate annular portion 4, an inner annular portion 1 and an intermediate annular portion 4, , And a plurality of inner connecting portions 5 provided independently in the tire circumferential direction CD, and an outer connecting portion 6 that connects the outer annular portion 2 and the intermediate annular portion 4. In the cross section in the tire width direction, a first outer connecting portion 61 extending from the tire width direction one side WD1 of the intermediate annular portion 4 toward the tire width direction other side WD2 of the outer annular portion 2, and a first outer connecting portion 61 in the tire width direction of the intermediate annular portion 4 so as to intersect with 61 Or one that is composed of a second outer coupling portion 62 which extends toward the outer annular portion 2 of the tire on one widthwise side WD1 from WD2. At this time, the shape of the inner connecting portion 5 is not particularly limited. For example, the inner connecting portion 5 is a plate-like body continuous in the tire width direction WD, that is, a plate shape in which the plate width direction matches the tire width direction WD. It may be the body.

  The shape of the intermediate annular portion 4 is preferably a cylindrical shape with a constant thickness from the viewpoint of improving uniformity. However, the shape of the intermediate annular portion 4 is not limited to a cylindrical shape, and may be a polygonal cylindrical shape.

  The thickness of the intermediate annular portion 4 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 5 and the outer connecting portion 6. -9% is more preferable.

  The tensile modulus of the intermediate annular portion 4 is preferably 8000 to 18000 MPa, more preferably 10,000 to 50000 MPa, from the viewpoint of sufficiently reinforcing the inner connecting portion 5 and the outer connecting portion 6 to improve durability and load capacity. preferable.

  Since the tensile modulus of the intermediate annular portion 4 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.

  (2) The first connecting portion 31 and the second connecting portion 32 (or the first outer connecting portion 61 and the second outer connecting portion 62) may have different rigidity and give a difference in rigidity between them. The rigidity of the present invention can be expressed by a longitudinal force necessary to bend a unit length (mm) when a prescribed mass (N) is applied to the tire. As a method for giving the rigidity difference, for example, there are the following methods.

  5A to 5E are perspective views of a connecting portion according to another embodiment. In FIG. 5, the inner annular portion 1 is omitted for convenience of explanation. In FIG. 5A, a hole is provided only in one of the first connecting portion 31 and the second connecting portion 32. In FIG. 5B, only one of the first connecting part 31 and the second connecting part 32 is provided with a slit. In FIG. 5C, a reinforcing rib is provided on one of the first connecting portion 31 and the second connecting portion 32. In FIG. 5D, the first connecting portion 31 and the second connecting portion 32 have different plate widths. In FIG. 5E, the thicknesses of the first connecting portion 31 and the second connecting portion 32 in the tire radial direction are different. In the examples of FIGS. 5A to 5E, the rigidity of the first connecting part 31 is higher than the rigidity of the second connecting part 32.

  For example, if the non-pneumatic tire T is mounted on the vehicle with the tire width direction one side WD1 as the vehicle inner side, the rigidity of the first connection portion 31 is made higher than the rigidity of the second connection portion 32, so Increases rigidity and improves gripping power when cornering. Furthermore, since the 2nd connection part 32 deform | transforms more easily than the 1st connection part 31, it becomes easy to contact the vehicle outer side of a tire, and a contact area spreads. As a result, the cornering performance can be improved by making the rigidity of the first connecting part 31 higher than the rigidity of the second connecting part 32. The rigidity of the first connection part 31 is preferably set to 1.2 times or more of the rigidity of the second connection part 32, and preferably 3 times or less of the rigidity of the second connection part 32. If the rigidity of the first connecting part 31 is greater than three times the rigidity of the second connecting part 32, the rigidity balance between the first connecting part 31 and the second connecting part 32 is deteriorated, and the uniformity may be deteriorated.

  On the other hand, if the non-pneumatic tire T is attached to the vehicle with the tire width direction one side WD1 as the vehicle inner side, the rigidity of the second connecting portion 32 is made higher than the rigidity of the first connecting portion 31, thereby allowing lane changes and curves. Since the 1st connection part 31 absorbs G by lateral force in this, a vibration can be suppressed and riding comfort can be improved. Furthermore, in the case of a camber angle of 0 ° and a negative camber, the shoulder rigidity inside the vehicle with a large ground contact area is high, so that cornering performance can be improved in addition to ride comfort.

  (3) In the above-mentioned embodiment, although the connection part 3 showed the example divided | segmented into plurality in tire circumferential direction CD, as shown to FIG. 6A, the same substantially X-shaped cross section over a tire circumference. It is good also as a continuous body which has a shape and continues in tire circumferential direction CD. Moreover, as shown to FIG. 6B, it is the same also about the outer side connection part 6 in the case of providing the intermediate | middle annular part 4. FIG.

  (4) In the above-described embodiment, an example in which curved portions are formed in the first connecting portion 31 and the second connecting portion 32 viewed from the tire circumferential direction CD has been described. However, the first connecting portion 31 and the second connecting portion are illustrated. The portion 32 may have a flat plate shape on which no curved portion is formed.

  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) Rolling resistance In the drum running test, rolling resistance was measured according to ISO28580. The result of Comparative Example 1 is evaluated as an index with the value of 100, and the larger the index, the lower the rolling resistance.

(2) Steering stability performance A test tire was mounted on the vehicle, and four panelists conducted a comprehensive sensory test on starting, turning and braking on the test course. The result of Comparative Example 1 is evaluated as an index with the value of 100, and the larger the index, the better the steering stability performance.

(3) Durability Performance Using an indoor drum testing machine equipped with a drum with a diameter of 1.7 mm, the air pressure is 0 kPa, the test speed is 80 km / h, and the tire load is started from 85% of the JIS standard at every specified time. The load was increased and the vehicle was finally run at 140%, and a running test was conducted. The case where no failure occurred after traveling 15000 km was marked as “◯”.

Comparative Example 1
With the dimensions and physical properties shown in Table 1, as shown in FIG. 7, the inner annular portion 1, the intermediate annular portion 4, the outer annular portion 2, the inner spoke (corresponding to the inner connecting portion 5), the outer spoke (the outer connecting portion). 6), a non-pneumatic tire including a three-layer reinforcing layer 7 provided on the outer periphery thereof, and a tread layer 8 was manufactured, and the above performance was evaluated. The inner connecting part 5 and the outer connecting part 6 are plate-like bodies that are continuous in the tire width direction. Table 1 also shows the results of rolling resistance, steering stability performance, and durability performance.

Example 1
A support structure including an inner annular portion 1, an outer annular portion 2, and outer spokes (corresponding to the connecting portion 3) as shown in FIG. A non-pneumatic tire including the reinforcing layer 7 of the layer and the tread layer 8 was produced, and the performance was evaluated. Table 1 also shows the results of rolling resistance, steering stability performance, and durability performance.

Example 2
With the dimensions and physical properties shown in Table 1, as shown in FIG. 6B, the inner annular portion 1, the intermediate annular portion 4, the outer annular portion 2, the inner spoke (inner connecting portion 5), the outer spoke (in the outer connecting portion 6). A non-pneumatic tire provided with a support structure provided with a corresponding structure), three reinforcing layers 7 provided on the outer periphery of the support structure, and a tread layer 8 was evaluated. As in Comparative Example 1, the inner connecting portion 5 was a plate-like body that was continuous in the tire width direction. Table 1 also shows the results of rolling resistance, steering stability performance, and durability performance.

Example 3
With the dimensions and physical properties shown in Table 1, as shown in FIG. 1, a support structure including an inner annular portion 1, an outer annular portion 2, and outer spokes (corresponding to connecting portions 3), 3 provided on the outer periphery thereof. A non-pneumatic tire including the reinforcing layer 7 of the layer and the tread layer 8 was produced, and the performance was evaluated. Table 1 also shows the results of rolling resistance, steering stability performance, and durability performance.

Example 4
A non-pneumatic tire was produced in the same manner as in Example 4 except that the distance between adjacent outer spokes (corresponding to the connecting portion 3) was different, and the performance was evaluated. Table 1 also shows the results of rolling resistance, steering stability performance, and durability performance.

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

  From the results in Table 1, the following can be understood. Compared with Comparative Example 1, the non-pneumatic tires of Examples 1 to 4 can suppress deterioration in steering stability and increase in rolling resistance while maintaining durability performance. In the second embodiment, compared to the first embodiment, since the inner spokes are arranged, the rigidity is improved and the steering stability performance is improved, but the ground contact area is reduced and the rolling resistance is increased. In the third embodiment, compared to the first embodiment, since the spokes are divided, the ground contact area is widened, the steering stability performance is improved, and the rolling resistance is reduced. Compared with Example 3, Example 4 has a slightly wider circumferential distance between the spokes, so that the rigidity is slightly lowered and the ground contact area is widened, so that the steering stability performance is lowered, but the rolling resistance is small. It has become.

DESCRIPTION OF SYMBOLS 1 Inner annular part 2 Outer annular part 3 Connection part 4 Middle annular part 5 Inner connection part 6 Outer connection part 31 1st connection part 32 2nd connection part 61 1st outer connection part 62 2nd outer connection part SS Support structure T Non-pneumatic tire CD Tire circumferential direction WD Tire width direction WD1 Tire width direction one side WD2 Tire width direction other side

Claims (3)

In a non-pneumatic tire including a support structure that supports a load from a vehicle,
The support structure includes an inner annular portion, an outer annular portion provided concentrically on the outer side of the inner annular portion, and a connecting portion that connects the inner annular portion and the outer annular portion,
In the cross section in the tire width direction, the connecting portion includes a first connecting portion extending from one side in the tire width direction of the inner annular portion toward the other side in the tire width direction of the outer annular portion, and the first connecting portion. A second connecting portion extending from the other side of the tire annular direction of the inner annular portion toward the one side of the outer annular portion of the outer annular portion ,
A non-pneumatic tire characterized in that at least one curved portion that is curved in the tire radial direction is formed in the first coupling portion and the second coupling portion as seen from the tire circumferential direction .   The non-pneumatic tire according to claim 1, wherein the connecting portion is divided into a plurality of portions in the tire circumferential direction.   The non-pneumatic tire according to claim 2, wherein the plurality of connecting portions divided in the tire circumferential direction have an interval between adjacent connecting portions of 0 to 5 mm.

Images