In a non-pneumatic tire, central portions in an extension direction of first elastic connecting plates (21) and central portions in an extension direction of second elastic connecting plates (22) are spaced from each other in a tire width direction (H) by a distance of 0.25 to 0.9 times an outer tube width (W1) serving as a size in the tire width direction (H) of an outer tubular body (13), edges of a first side in the tire width direction (H) of first end portions (21a) of the first elastic connecting plates (21) are disposed at the same positions in the tire width direction (H) as edges of the first side in the tire width direction (H) of the outer tubular body (13) or disposed inside in the tire width direction (H) of the edge of the first side in the tire width direction (H) of the outer tubular body (13) within a distance of 0.1 times the outer tube width (W1) or less, and edges of a second side in the tire width direction (H) of first end portions (22a) of the second elastic connecting plates (22) are disposed at the same positions in the tire width direction (H) as an edge of the second side in the tire width direction (H) of the outer tubular body (13) or disposed inside in the tire width direction (H) of the edge of the second side in the tire width direction (H) of the outer tubular body (13) within a distance of 0.1 times the outer tube width (W1) or less.

TECHNICAL FIELD

The present invention relates to a non-pneumatic tire that can be used without being filled with pressurized air.

This application is a National Stage of International Application No. PCT/JP2014/078356 filed Oct. 24, 2014, claiming priorities based on Japanese Patent Application Nos. 2013-237104, filed Nov. 15, 2013, and 2013-237105, filed Nov. 15, 2013, the contents of all of which are incorporated herein by reference in their entirety.

BACKGROUND ART

In a pneumatic tire of the related art that is filled with pressurized air and used, the occurrence of a blowout is a structurally unavoidable problem.

In order to solve this problem, in recent years, for example, as disclosed in the following Patent Document 1, a non-pneumatic tire including an attachment body attached to an axle, an outer tubular body configured to surround the attachment body from the outside in a tire radial direction, and a connecting member configured to connect the attachment body and the outer tubular body while allowing a displacement therebetween has been proposed.

DOCUMENT OF RELATED ART

Patent Document

SUMMARY OF INVENTION

Technical Problem

However, in the non-pneumatic tire of the related art, cornering performance of the tire should be improved more.

In addition, the inventor(s) of the application has found that, in the non-pneumatic tire of the related art, during traveling of the non-pneumatic tire, unintended lateral force in a tire width direction occurs.

In consideration of the above-mentioned circumstances, the present invention is directed to provide a non-pneumatic tire capable of improving cornering performance, suppressing generation of a lateral force during traveling, and improving steering stability.

Solution to Problem

A non-pneumatic tire according to the present invention includes: an attachment body attached to an axle; an outer tubular body configured to surround the attachment body from the outside in a tire radial direction; and connecting members configured to connect the attachment body and the outer tubular body while allowing a displacement therebetween; the connecting members including first elastic connecting plates positioned on a first side thereof in a tire width direction and second elastic connecting plates positioned on a second side thereof in the tire width direction, which are disposed different positions in the tire width direction; wherein central portions of the first elastic connecting plates in a direction in which the first elastic connecting plates extend between the attachment body and the outer tubular body and central portions of the second elastic connecting plates in a direction in which the second elastic connecting plates extend between the attachment body and the outer tubular body are separated from each other in the tire width direction by a distance of 0.25 to 0.9 times an outer tube width serving as a size in the tire width direction of the outer tubular body; edges of the first side in the tire width direction of first end portions of the first elastic connecting plates connected to the outer tubular body are disposed at the same position in the tire width direction as an edge of the first side in the tire width direction of the outer tubular body, or disposed inside in the tire width direction of the edge of the first side in the tire width direction of the outer tubular body within a distance of 0.1 times the outer tube width or less; and edges of the second side in the tire width direction of first end portions of the second elastic connecting plates connected to the outer tubular body are disposed at the same position in the tire width direction as an edge of the second side in the tire width direction of the outer tubular body, or disposed inside in the tire width direction of the edge of the second side in the tire width direction of the outer tubular body and disposed within a distance of 0.1 times the outer tube width or less.

According to the present invention, since the central portions of the first elastic connecting plates and the central portions of the second elastic connecting plates are spaced apart from each other in the tire width direction by a distance of 0.25 to 0.9 times the outer tube width, all of the elastic connecting plates are limited from cushioning each other when they are deformed, an increase in weight of the non-pneumatic tire can be limited while increasing lateral stiffness serving as stiffness in the tire width direction of the connecting members. That is, when an interval in the tire width direction between the central portions of the first elastic connecting plates and the central portions of the second elastic connecting plates is smaller than 0.25 times the outer tube width, a member width serving as the size in the tire width direction of each of the connecting members cannot be easily secured, and an increase in lateral stiffness of the connecting member may become difficult. In addition, when the interval is larger than 0.9 times the outer tube width in the tire width direction, the member width of the connecting member is excessively large, and limitation of an increase in weight of the non-pneumatic tire becomes difficult.

Here, as an increase in weight of the non-pneumatic tire is limited while increasing lateral stiffness of the connecting members in this way, a cornering force generated upon cornering of the non-pneumatic tire can be received by the connecting members.

Further, in the non-pneumatic tire, the edges of the first side in the tire width direction of the first end portions of the first elastic connecting plates are disposed at the same positions in the tire width direction as the edge of the first side in the tire width direction of the outer tubular body (hereinafter, referred to as “a first side edge of the outer tubular body”), or disposed inside in the tire width direction of the first side edge of the outer tubular body within a distance of 0.1 times the outer tube width or less. Moreover, the edges of the second side in the tire width direction of the first end portions of the second elastic connecting plates are disposed at the same positions in the tire width direction as the edge of the second side in the tire width direction of the outer tubular body (hereinafter, referred to as “the second side edge of the outer tubular body”) or disposed inside in the tire width direction of the second side edge of the outer tubular body within a distance of 0.1 times the outer tube width or less.

Accordingly, when the non-pneumatic tire corners and a camber is input, an occurrence of stress at the first end portions of all of the elastic connecting plates can be limited. That is, when the first end portions of the first elastic connecting plates and the second elastic connecting plates overhang the first side edge or the second side edge of the outer tubular body outward in the tire width direction, the camber is directly input into the first end portions, and the stress generated at the first end portions may be significantly increased. In addition, when the first end portions of the first elastic connecting plates and the second elastic connecting plates are spaced apart from the first side edge or the second side edge of the outer tubular body in the tire width direction by a distance larger than 0.1 times the outer tube width, a stress concentration place may be easily formed in the first end portions.

Additionally, since a generation of the stress in the first end portions of all of the elastic connecting plates upon cornering can be limited in this way, as described above, in combination with an easy reception of the cornering force generated upon cornering by the connecting member, for example, a posture of the non-pneumatic tire upon cornering can be stabilized, and cornering performance can be improved.

In addition, the first elastic connecting plates and the second elastic connecting plates may extend toward opposite sides in a tire circumferential direction while extending inward from the outer tubular body in the tire radial direction, and a distance in the tire width direction between the central portions in the tire width direction of the first end portions of all of the elastic connecting plates may be 0.7 times the outer tube width or less.

In this case, since all of the elastic connecting plates extend toward opposite sides in the tire circumferential direction while extending from the outer tubular body inward in the tire radial direction, when the compressive load in the tire radial direction is applied to the non-pneumatic tire upon traveling of the non-pneumatic tire and the connecting members are compressively deformed in the tire radial direction, forces from the first end portions of all of the elastic connecting plates toward opposite sides in the tire circumferential direction are applied to the outer tubular body. Here, since all of the elastic connecting plates are disposed at different positions in the tire width direction, as the above-mentioned forces are applied to the outer tubular body from the first end portions of all of the elastic connecting plates, a moment around an axis extending in the tire radial direction is generated in a portion of the outer tubular body to which the connecting members are connected.

The inventor(s) of the application has found that the above-mentioned moment is generated in the non-pneumatic tire and the moment generates an unintended lateral force upon traveling of the non-pneumatic tire.

Here, the distance in the tire width direction between the central portions in the tire width direction of the first end portions of all of the elastic connecting plates connected to the outer tubular body is 0.7 times the outer tube width or less. Accordingly, generation of the above-mentioned moment can be limited without a complex structure, and linearity of the non-pneumatic tire can be increased to improve the steering stability.

Accordingly, not only the cornering performance but also the linearity can be improved, and steering stability of the non-pneumatic tire can be reliably improved.

In addition, a cylindrical tread member fitted onto the outer tubular body may be provided, and an outer circumferential surface of the tread member may form a curved surface shape protruding outward in the tire radial direction when seen in a cross-sectional view in the tire width direction.

In this case, since the outer circumferential surface of the tread member forms the curved surface shape protruding outward in the tire radial direction when seen in the cross-sectional view in the tire width direction and a large force is applied to the end portion of the outer tubular body when the camber is input, the above-mentioned effect of improving the cornering performance can be remarkably exhibited.

In addition, a plurality of curved sections curved in the tire circumferential direction may be formed on at least one elastic connecting plate of the first elastic connecting plates and the second elastic connecting plates in an extension direction in which the elastic connecting plates extend in a tire side view when the non-pneumatic tire is seen from the tire width direction, curved directions of the curved sections neighboring in the extension direction may be opposite to each other, and a cross-sectional area of an inflection section of the elastic connecting plate disposed between the curved sections neighboring in the extension direction may be smaller than a cross-sectional area of another portion of the elastic connecting plate.

In this case, since the curved directions of the curved sections neighboring in the extension direction are opposite to each other, when the compressive load in the tire radial direction is applied to the non-pneumatic tire, the inflection section cannot be easily deformed but are mainly displaced, and the load applied to the inflection section in the elastic connecting plate can be limited in comparison with another portion.

Additionally, since the cross-sectional area of the inflection section is smaller than the cross-sectional area of the other portion of the elastic connecting plate except for the inflection section, a reduction in weight can be achieved while preventing a decrease in strength of the connecting member.

In addition, the cross-sectional area of the elastic connecting plate may be gradually reduced toward the inflection section in the extension direction.

In this case, a reduction in weight can be effectively achieved while suppressing generation of a stress concentration place in the elastic connecting plate.

In addition, at least one of a size in the tire width direction and a size in the tire circumferential direction of the inflection section of the elastic connecting plate may be smaller than other portions.

In this case, the non-pneumatic tire that exhibits the above-mentioned effects can be reliably obtained.

In addition, the first elastic connecting plates and the second elastic connecting plates may extend outward in the tire width direction from the attachment body toward the outer tubular body.

In this case, since the first elastic connecting plates and the second elastic connecting plates extend outward in the tire width direction from the attachment body toward the outer tubular body, for example, the force applied to the end portion of the outer tubular body when the camber is input can be easily received by the connecting members based on the shape of the elastic connecting plates, and the cornering performance can be further improved.

In addition, all of the elastic connecting plates may extend outward in the tire width direction from the outer tubular body toward the attachment body.

In this case, since all of the elastic connecting plates extend outward in the tire width direction from the outer tubular body toward the attachment body, the member width serving as the size in the tire width direction of the connecting members can be easily secured while suppressing a generation of the above-mentioned moment. Accordingly, the lateral stiffness of the connecting members can be improved, and the steering stability of the non-pneumatic tire can be improved more.

Advantageous Effects of Invention

According to the present invention, cornering performance of the tire can be improved. In addition, a lateral force generated during traveling can be limited, and steering stability can be improved.

DESCRIPTION OF EMBODIMENTS

First Embodiment

Hereinafter, a first embodiment of a non-pneumatic tire according to the present invention will be described with reference toFIGS. 1 to 6.

A non-pneumatic tire1includes an attachment body11attached to an axle (not shown), a ring member14including an inner tubular body12fitted onto the attachment body11and an outer tubular body13configured to surround the inner tubular body12from the outside in a tire radial direction, a plurality of connecting members15disposed between the inner tubular body12and the outer tubular body13in a tire circumferential direction and connecting the tubular bodies12and13to each other while allowing relative elastic displacement therebetween, and a tread member16disposed at an outer circumferential surface side of the outer tubular body13throughout the circumference.

Here, the attachment body11, the inner tubular body12, the outer tubular body13and the tread member16are disposed coaxially with a common axis. Hereinafter, the common axis is referred to as an axis O, a direction along the axis O is referred to as a tire width direction H, a direction perpendicular to the axis O is referred to as a tire radial direction, and a direction around the axis O is referred to as a tire circumferential direction. Further, the attachment body11, the inner tubular body12, the outer tubular body13and the tread member16are disposed such that central portions thereof in the tire width direction H coincide with each other.

In the ring member14, a size in the tire width direction H, i.e., a width, of the outer tubular body13is larger than that of the inner tubular body12. In addition, a plurality of protrusion sections12aprotruding inward in the tire radial direction and extending throughout the length in the tire width direction H are formed at an inner circumferential surface of the inner tubular body12at intervals in the tire circumferential direction.

As shown inFIGS. 1 and 2, the attachment body11includes a mounting tubular section17on which a front end portion of the axle is mounted, an outer ring section18configured to surround the mounting tubular section17from the outside in the tire radial direction, and a plurality of ribs19configured to connect the mounting tubular section17and the outer ring section18.

The mounting tubular section17, the outer ring section18and the ribs19are integrally formed of a metal material such as an aluminum alloy or the like. The mounting tubular section17and the outer ring section18are cylindrically formed and disposed coaxially with the axis O. The plurality of ribs19are disposed at equal intervals in the tire circumferential direction.

A plurality of key groove sections18arecessed inward in the tire radial direction and extending in the tire width direction H are formed at an outer circumferential surface of the outer ring section18at intervals in the tire circumferential direction. In the outer circumferential surface of the outer ring section18, each of the key groove sections18ais open at only first side out of both ends in the tire width direction H and closed at the second side. The protrusion sections12aof the inner tubular body12in the ring member14are fitted into the key groove sections18a.

Further, among wall surfaces that define the key groove sections18a, pairs of side wall surfaces opposite to each other in the tire circumferential direction are perpendicular to bottom wall surfaces. In addition, among outer surfaces of the protrusion sections12a, pairs of side wall surfaces rising from the inner circumferential surface of the inner tubular body12are perpendicular to top wall surfaces directed inward in the tire radial direction. The sizes in the tire circumferential direction of the protrusion sections12aand the key groove sections18aare equal to each other.

Here, concave sections18brecessed toward the second side of the tire width direction H and into which plate members28are fitted are formed at positions of edges of first side in the tire width direction H in the outer ring section18corresponding to the key groove sections18a. Through-holes are formed in the plate members28, and among wall surfaces that define the concave sections18b, female screw sections in communication with the through-holes of the plate members28fitted into the concave sections18bare formed in the wall surfaces directed toward first side in the tire width direction H. Further, a plurality of female screw sections and through-holes are formed at intervals in the tire circumferential direction.

Then, the ring member14is fixed to the attachment body11by screwing bolts into the female screw sections through the through-holes of the plate members28fitted into the concave sections18bin a state in which the inner tubular body12is fitted onto the attachment body11and the protrusion sections12aare fitted into the key groove sections18a. In this state, the protrusion sections12aare sandwiched between the plate members28and other end wall surfaces disposed at a second end in the tire width direction H and directed toward the first side, among the wall surfaces that define the key groove sections18a, in the tire width direction H.

Further, a plurality of hole arrays18c, in each of which a plurality of weight-reduction holes passing in the tire radial direction are disposed at intervals in the tire width direction H, are formed in the tire circumferential direction at intervals at portions of the outer ring section18disposed between the key groove sections18aneighboring in the tire circumferential direction. In addition, weight-reduction holes19apassing in the tire width direction H are also formed in the ribs19.

The tread member16is formed in a cylindrical shape and integrally covers on the outer circumferential surface side of the outer tubular body13of the ring member14throughout the region. The tread member16is formed of, for example, vulcanized rubber in which natural rubber or/and a rubber composition are vulcanized, a thermoplastic material, or the like. For example, a thermoplastic elastomer, a thermoplastic resin, or the like, is exemplified as the thermoplastic material. For example, an amide-based thermoplastic elastomer (TPA), an ester-based thermoplastic elastomer (TPC), an olefin-based thermoplastic elastomer (TPO), a styrene-based thermoplastic elastomer (TPS), a urethane-based thermoplastic elastomer (TPU), a thermoplastic rubber crosslinked body (TPV), another thermoplastic elastomer (TPZ), and the like, as defined in Japanese Industrial Standard JIS K6418, are exemplary examples of the thermoplastic elastomer. For example, a urethane resin, an olefin resin, polyvinyl chloride, a polyamide resin, and the like, are exemplary examples of the thermoplastic resin. Further, in view of abrasion resistance, the tread member16may be formed of vulcanized rubber.

The connecting members15connect the attachment body11and the outer tubular body13while allowing a relative elastic displacement therebetween. The connecting members15are connected to the attachment body11via the inner tubular body12. The connecting members15include first elastic connecting plates21and second elastic connecting plates22that are configured to connect the inner tubular body12and the outer tubular body13of the ring member14to each other.

The plurality of (in the example shown, 60) connecting members15are formed in the tire circumferential direction such that a plurality of first elastic connecting plates21are disposed in the tire circumferential direction at predetermined positions in the tire width direction H and a plurality of second elastic connecting plates22are disposed in the tire circumferential direction at other positions in the tire width direction H different from the predetermined positions in the tire width direction H.

That is, the plurality of first elastic connecting plates21are disposed in the tire circumferential direction at the same positions in the tire width direction H, and the plurality of second elastic connecting plates22are disposed in the tire circumferential direction at the same predetermined positions in the tire width direction H spaced apart from the first elastic connecting plates21in the tire width direction H.

Further, the plurality of connecting members15are disposed between the inner tubular body12and the outer tubular body13of the ring member14at positions that are axially symmetrical with respect to the axis O. In addition, all of the connecting members15have the same shape and the same size. Further, the width of the connecting members15is smaller than that of the outer tubular body13.

Additionally, the first elastic connecting plates21neighboring in the tire circumferential direction do not come in contact with each other, and the second elastic connecting plates22neighboring in the tire circumferential direction do not come in contact with each other either. Further, the first elastic connecting plates21and the second elastic connecting plates22neighboring them in the tire width direction H do not come in contact with each other either.

Further, widths of the first elastic connecting plates21and the second elastic connecting plates22are equal to each other. In addition, the thicknesses of the first elastic connecting plates21and the second elastic connecting plates22are also equal to each other.

Here, first end portions21aof the first elastic connecting plates21connected to the outer tubular body13are disposed closer to first side in the tire circumferential direction than the second end portions21bconnected to the inner tubular body12, and first end portions22aof the second elastic connecting plates22connected to the outer tubular body13are disposed closer to the second side in the tire circumferential direction than the second end portions22bconnected to the inner tubular body12.

In addition, the first end portions21aand22aof the first elastic connecting plate21and the second elastic connecting plate22in each of the connecting members15are disposed at different positions in the tire width direction H and connected to the same positions in the tire circumferential direction on the inner circumferential surface of the outer tubular body13.

In each of the first elastic connecting plates21and the second elastic connecting plates22, a plurality of curved sections21dto21fand22dto22fcurved in the tire circumferential direction are formed at intermediate portions21cand22cdisposed between the first end portions21aand22aand the second end portions21band22bin an extension direction in which the elastic connecting plates21and22extend, in a tire side view when the tire1is seen from the tire width direction H. Further, the curved sections21dto21fand22dto22fare portions of the first and second elastic connecting plates21and22having curvatures, respectively, when seen in the tire side view.

In both types of the elastic connecting plates21and22, among the plurality of curved sections21dto21fand22dto22f, curved directions of the curved sections21dto21fand22dto22fneighboring in the extension direction are directed in opposite directions.

The plurality of curved sections21dto21fformed in the first elastic connecting plates21have first curved sections21dcurved to protrude toward the second side in the tire circumferential direction, second curved sections21edisposed between the first curved sections21dand the first end portions21aand curved to protrude toward the first side in the tire circumferential direction, and third curved sections21fdisposed between the first curved sections21dand the second end portions21band curved to protrude toward the first side in the tire circumferential direction.

The plurality of curved sections22dto22fformed in the second elastic connecting plates22have first curved sections22dcurved to protrude toward the first side in the tire circumferential direction, second curved sections22edisposed between the first curved sections22dand the first end portions22aand curved to protrude toward the second side in the tire circumferential direction, and third curved sections22fdisposed between the first curved sections22dand the second end portions22band curved to protrude toward the second side in the tire circumferential direction.

In the example shown, the first curved sections21dand22dhave larger radii of curvature in the tire side view than the second curved sections21eand22eand the third curved sections21fand22fFurther, the first curved sections21dand22dare disposed at central portions in the extension direction of the first elastic connecting plates21and the second elastic connecting plates22.

Further, lengths of both types of the elastic connecting plates21and22are equal to each other, and the second end portions21band22bof both types of the elastic connecting plates21and22are connected to positions spaced apart by the same angle (for example, 20° to 135°) from the positions opposite to the first end portions21aand22ain the tire radial direction at the first side and the second side on the outer circumferential surface of the inner tubular body12in the tire circumferential direction around the axis O when seen in the tire side view. In addition, the first curved sections21dand22d, the second curved sections21eand22e, and the third curved sections21fand22fof the first elastic connecting plates21and the second elastic connecting plates22are directed to protrude in opposite directions in the tire circumferential direction and have the same size.

Accordingly, as shown inFIG. 4, a shape in the tire side view of each of the connecting members15is linearly symmetrical with respect to an imaginary line L extending in the tire radial direction and passing through the first end portions21aand22aof both types of the elastic connecting plates21and22.

As shown inFIG. 5, the central portion in the tire width direction H of the connecting members15coincides with the central portion in the tire width direction H of the outer tubular body13. The connecting members15are disposed line-symmetrically with respect to a reference line S perpendicular to the axis O and passing the central portion in the tire width direction H of the outer tubular body13in a front view when the connecting members15are seen in a direction perpendicular to both of the axis O and the imaginary line L.

A member width serving as a size in the tire width direction H of the connecting member15is equal to or smaller than an outer tube width W1serving as a size in the tire width direction H of the outer tubular body13, and moreover, in the example shown, equal to or smaller than a size in the tire width direction H of each of the attachment body11and the inner tubular body12. The member width of the connecting member15is a distance in the tire width direction H between both edges outside in the tire width direction H of the connecting member15. The edges outside in the tire width direction H of the connecting member15are edges outside in the tire width direction H of both of the elastic connecting plates21and22. Further, in the embodiment, the member width of the connecting member15is constant throughout the length of the connecting member15. Both of the edges outside in the tire width direction H of the connecting member15are formed in linear shapes extending in parallel to the reference line S, and smoothly extend with no step difference when seen in the front view.

Sizes in the tire width direction H of both of the elastic connecting plates21and22are constant throughout the length in the extension direction. Here, in the embodiment, a central portion in the extension direction of the first elastic connecting plate21and a central portion in the extension direction of the second elastic connecting plate22are spaced apart from each other by the distance of 0.25 to 0.9 times the outer tube width W1in the tire width direction H, so an interval W2in the tire width direction H between the central portion of the first elastic connecting plate21and the central portion of the second elastic connecting plate22is 0.25 W1to 0.9 W1. Further, in the example shown, in both types of the elastic connecting plates21and22of the connecting members15, edges inside in the tire width direction H are spaced apart in the tire width direction H throughout the length from first end portions of the connecting members15to arrive at the second end portions, and intervals in the tire width direction H of the edges are constant throughout the lengths of the connecting members15. When seen in the front view, the edges inside in the tire width direction H of both types of the elastic connecting plates21and22are formed in a linear shape extending in parallel to the reference line S, and smoothly extend with no step difference.

In addition, in both types of the elastic connecting plates21and22, a distance W3in the tire width direction H between the central portions in the tire width direction H of the first end portions21aand22ais 0.7 times the outer tube width W1or less, i.e., 0.7W1or less. Further, load centers of the first end portions21aand22amay be disposed on the central portions in the tire width direction H of the first end portions21aand22aof the elastic connecting plates21and22, and the load centers may be disposed within a certain range including the central portions of the first end portions21aand22a. Here, the load center is a portion at which a maximum load is applied to each of the first end portions21aand22aof the elastic connecting plates21and22when the compressive load in the tire radial direction is applied to the non-pneumatic tire1.

Further, the edges outside in the tire width direction H of the first end portions21aand22aof both types of the elastic connecting plates21and22are disposed inside in the tire width direction H of the edges outside in the tire width direction H of the outer tubular body13within a distance of 0.1 times the outer tube width W1or less, so a spacing distance W4in the tire width direction H between the edges of the first end portions21aand22aof both of the elastic connecting plates21and22and the edge of the outer tubular body13is 0.1W1or less. That is, an edge of the first side in the tire width direction H of the first end portion21aof the first elastic connecting plate21is disposed inside in the tire width direction H of an edge of the first side in the tire width direction H of the outer tubular body13(hereinafter, referred to as a “first side edge of the outer tubular body13”) within a distance of 0.1 times the outer tube width W1or less. In addition, an edge of the second side in the tire width direction H of the first end portion22aof the second elastic connecting plate22is disposed inside in the tire width direction H of an edge of the second side in the tire width direction H of the outer tubular body13(hereinafter, referred to as “the second side edge of the outer tubular body13”) within a distance of 0.1 times the outer tube width W1or less. In the example shown, the spacing distance W4of the first elastic connecting plates21is equal to the spacing distance W4of the second elastic connecting plates22.

Further, the edges outside in the tire width direction H of the first end portions21aand22aof both of the elastic connecting plates21and22may be disposed at the same positions in the tire width direction H as the edges outside in the tire width direction H of the outer tubular body13, and the spacing distance W4may be 0. That is, an edge of first side in the tire width direction H of the first elastic connecting plate21may be disposed at the same position in the tire width direction H as the first side edge of the outer tubular body13to be flush with the first side edge, and an edge of the second side in the tire width direction H of the second elastic connecting plate22may be disposed at the same position in the tire width direction H as the second side edge of the outer tubular body13to be flush with the second side edge.

Here, in the embodiment, the ring member14and the plurality of connecting members15are integrally formed of a synthetic resin material. Further, the synthetic resin material may be only one kind of resin material, a mixture including two or more kinds of resin materials, or a mixture including one or more kinds of resin materials and one or more kinds of elastomers. Further, the synthetic resin material may include additives such as an anti-oxidant, a plasticizing agent, a filler, a pigment, or the like.

Further, in the embodiment, as shown inFIG. 1, the ring member14is split into first split ring member23disposed at first side in the tire width direction H, and a second split ring member24disposed at the second side in the tire width direction H. Further, in the example shown, the ring member14is split at a central portion in the tire width direction H.

Additionally, the first split ring member23is integrally formed with the first elastic connecting plates21, and the second split ring member24is integrally formed with the second elastic connecting plates22.

Further, in the embodiment, the first split ring member23and the first elastic connecting plates21are integrally formed by injection molding, and the second split ring member24and the second elastic connecting plates22are also integrally formed by injection molding.

Hereinafter, a member formed by integrally forming the first split ring member23and the first elastic connecting plates21is referred to as a first split case body31, and a member formed by integrally forming the second split ring member24and the second elastic connecting plates22is referred to as a second split case body32.

Here, the injection molding may be a general method of simultaneously forming each of the first and second split case bodies31and32as a whole or of forming each of the first and second split case bodies31and32, may be insert molding in which one of the first and the second split ring members23and24and one of the first and second elastic connecting plates21and22may be formed as an insert part and the others may be formed of injection molding, or may be a so-called two-color formation or the like.

In addition, in each of the first and second split case bodies31and32, the one and the second split ring members23and24and the first and second elastic connecting plates21and22may be formed of different materials or may be formed of the same material. Further, the material may be a metal material, a resin material, or the like, or may be a resin material, in particular, a thermoplastic resin, in view of a reduction in weight.

Further, when each of the first and second split case bodies31and32is simultaneously formed by injection molding as a whole, the plurality of protrusion sections12aformed at the inner tubular body12may be a gate portion.

In each of the first and second split case bodies31and32, central portions in the tire width direction H of the first and second elastic connecting plates21and22coincide with a central portion in the tire width direction H of the outer tubular body13, and the inner tubular body12has a width smaller than that of the outer tubular body13.

Additionally, edges in the tire width direction H of the outer tubular body13of the first split ring member23and the outer tubular body13of the second split ring member24are connected by, for example, welding, fusion, adhesion, or the like. Further, among these, in the case of welding, for example, hot plate welding or the like may be employed.

In addition, edges in the tire width direction H of the inner tubular body12of the first split ring member23and the inner tubular body12of the second split ring member24are separated from each other in the tire width direction H. Accordingly, the generation of burrs on the inner circumferential surface of the inner tubular body12fitted onto the attachment body11is prevented.

In addition, the first split case body31and the second split case body32have the same shape and the same size as shown inFIG. 3in a state before these case bodies31and32are connected as described above.

In addition, when they are connected as described above, the non-pneumatic tire1is obtained by abutting and connecting the edges in the tire width direction H of the outer tubular bodies13of the first split case body31and the second split case body32such that the connecting members15are line-symmetrical as described above in the tire side view when in a state in which orientations in the tire width direction H of both of the split case bodies31and32are opposite to each other while matching positions in the tire circumferential direction of the first split case body31and the second split case body32.

As described above, according to the non-pneumatic tire1of the embodiment, since the central portion of the first elastic connecting plate21and the central portion of the second elastic connecting plate22are spaced apart from each other in the tire width direction H by a distance of 0.25 to 0.9 times the outer tube width W1, both of the elastic connecting plates21and22can be limited from cushioning each other when they are deformed, and an increase in weight of the non-pneumatic tire1can be limited while increasing lateral stiffness serving as stiffness in the tire width direction H of the connecting member15. That is, when the interval W2in the tire width direction H between the central portion of the first elastic connecting plate21and the central portion of the second elastic connecting plate22is smaller than 0.25 times the outer tube width W1, the member width of the connecting member15cannot be easily secured, and an increase in lateral stiffness of the connecting member15may become difficult. In addition, when the interval W2is larger than 0.9 times the outer tube width W1in the tire width direction H, the member width of the connecting member15is excessively large, and limitation of an increase in weight of the non-pneumatic tire1may become difficult.

Here, as the increase in weight of the non-pneumatic tire1is limited while increasing lateral stiffness of the connecting member15, the cornering force generated upon cornering of the non-pneumatic tire1can be easily received by the connecting members15.

Further, in the non-pneumatic tire1, the edge of the first side in the tire width direction H of the first end portion21aof the first elastic connecting plate21is disposed at the same position in the tire width direction H as the first side edge of the outer tubular body13, or disposed inside in the tire width direction H of the first side edge of the outer tubular body13within a distance of 0.1 times the outer tube width W1or less. Moreover, the edge of the second side in the tire width direction H of the first end portion22aof the second elastic connecting plate22is disposed at the same position in the tire width direction H as the second side edge of the outer tubular body13, or disposed inside in the tire width direction H of the second side edge of the outer tubular body13within a distance of 0.1 times the outer tube width W1or less.

Accordingly, when the non-pneumatic tire1corners and a camber is input, stress occurring at the first end portions21aand22aof both of the elastic connecting plates21and22can be limited. That is, when the first end portions21aand22aof the first elastic connecting plate21and the second elastic connecting plate22overhang the first side edge or the second side edge of the outer tubular body13outward in the tire width direction H and cambers are directly input into the first end portions21aand22a, and stress occurring at the first end portions21aand22amay be significantly increased. In addition, when the first end portions21aand22aof the first elastic connecting plate21and the second elastic connecting plate22are spaced apart from the first side edge or the second side edge of the outer tubular body13by a distance larger than 0.1 times the outer tube width W1in the tire width direction H, the occurrence of stress concentration places may be easily formed in the first end portions21aand22a.

Additionally, since the stress occurring at the first end portions21aand22aof the elastic connecting plates21and22upon cornering can be limited in the way described above, in combination with an easy reception of the cornering force occurring upon cornering by the connecting member15, for example, a posture of the non-pneumatic tire1upon cornering or the like can be stabilized, and cornering performance can be improved.

In addition, since both of the elastic connecting plates21and22extend in the tire circumferential direction to be directed in opposite directions while extending from the outer tubular body13inward in the tire radial direction, when the compressive load in the tire radial direction is applied to the non-pneumatic tire1upon traveling of the non-pneumatic tire1and the connecting member15is compressed and deformed in the tire radial direction, as shown inFIG. 6, a force is applied to the outer tubular body13from each of the first end portions21aand22aof both of the elastic connecting plates21and22toward an opposite side in the tire circumferential direction. Here, since both of the elastic connecting plates21and22are disposed at different positions in the tire width direction H, as the above-mentioned force is applied from each of the first end portions21aand22aof both of the elastic connecting plates21and22to the outer tubular body13, a moment around the reference line S (an axis extending in the tire radial direction) is generated at a portion of the outer tubular body13to which the connecting member15is connected.

The inventor(s) of the present invention has found that the above-mentioned moment is generated at the non-pneumatic tire1, and the moment generates an unintended lateral force during traveling of the non-pneumatic tire1.

Here, in both types of the elastic connecting plates21and22, the distance W3in the tire width direction H between the central portions in the tire width direction H of the first end portions21aand22aconnected to the outer tubular body13is 0.7 times the outer tube width W1or less. Accordingly, generation of the above-mentioned moment can be limited without a complex structure, and linearity of the non-pneumatic tire1can be increased to improve steering stability.

Accordingly, not only cornering performance but also linearity can be improved, and steering stability of the non-pneumatic tire1can be reliably improved.

Second Embodiment

Next, a non-pneumatic tire according to a second embodiment of the present invention will be described with reference toFIG. 7.

Further, in the second embodiment, the same portions as the components of the first embodiment will be designated by the same reference numerals, a description thereof will be omitted, and only differences will be described.

In a non-pneumatic tire2of the embodiment, as shown inFIG. 7, an outer circumferential surface of the tread member16forms a convex shape protruding outward in the tire radial direction when seen in a cross-sectional view in the tire width direction H, and an outer diameter of the tread member16is gradually reduced as it recedes from a maximum outer diameter portion16athereof in the tire width direction H. Further, an outer diameter of the tread member16is a distance in the tire radial direction between the outer circumferential surface of the tread member16and the axis O. The maximum outer diameter portion16aof the tread member16is disposed at the central portion in the tire width direction H of the non-pneumatic tire1.

Further, in the embodiment, the first end portions21aand22aof the first elastic connecting plate21and the second elastic connecting plate22are connected at positions in the tread member16deviated from the maximum outer diameter portion16ain the tire width direction H. In the example shown, the first end portions21aand22aof the first and second elastic connecting plates21and22are connected to positions on the inner circumferential surface of the outer tubular body13to interpose the maximum outer diameter portion16aof the tread member16between both sides in the tire width direction H.

As described above, according to the non-pneumatic tire2of the embodiment, since the outer circumferential surface of the tread member16forms a curved surface shape protruding outward in the tire radial direction when seen in a cross-sectional view in the tire width direction H and a large force is easily applied to the end portion of the outer tubular body13when camber is input, an effect of improving the above-mentioned cornering performance can be remarkably achieved.

Third Embodiment

Next, a non-pneumatic tire according to a third embodiment of the present invention will be described with reference toFIG. 8.

Further, in the third embodiment, the same portions as the components of the first embodiment will be designated by the same reference numerals, a description thereof will be omitted, and only differences will be described.

In a non-pneumatic tire3of the embodiment, each of both types of the elastic connecting plates21and22extends outward in the tire width direction H from the attachment body11toward the outer tubular body13. Edges outside in the tire width direction H of each of both types of the elastic connecting plates21and22are formed in linear shapes inclined with respect to the reference line S when seen in the front view. A member width of the connecting member15is gradually increased from the second end portion of the connecting member15connected to the attachment body11toward the first end portion thereof connected to the outer tubular body13. Both edges outside in the tire width direction H of the connecting member15are gradually directed outward in the tire width direction H and smoothly extend with no step difference from the second end portion to the first end portion of the connecting member15.

As described above, according to the non-pneumatic tire3of the embodiment, each of both types of the elastic connecting plates21and22extends outward in the tire width direction H from the attachment body11toward the outer tubular body13. For this reason, for example, a force applied to the end portion of the outer tubular body13when camber is input can be easily received by the connecting members15based on the shapes of the elastic connecting plates21and22, and the cornering performance can be further improved.

Further, the technical scope of the present invention is not limited to the embodiments but various modifications may be made without departing from the spirit of the present invention.

For example, instead of the embodiment, the second end portions21band22bof the first elastic connecting plate21and the second elastic connecting plate22may be connected to, for example, opposite positions on the outer circumferential surface of the inner tubular body12with the axis O interposed therebetween in the tire radial direction, or may be connected to positions on the outer circumferential surface of the inner tubular body12opposite to the first end portions21aand22aof first elastic connecting plate21and the second elastic connecting plate22in the tire radial direction, or the like.

In addition, instead of the embodiment, the first end portions21aand22aof both of the elastic connecting plates21and22may be connected to the inner circumferential surface of the outer tubular body13at different positions in the tire circumferential direction.

Further, a gap in the tire width direction H may not be formed between the inner tubular body12of the first split ring member23and the inner tubular body12of the second split ring member24.

In addition, the ring member14may be split into three or more parts in the tire width direction H, or may not be split.

In addition, the ring member14and the plurality of connecting members15may not be integrally formed with each other.

Furthermore, the ring member14and the connecting members15are not limited to those described in the embodiment. For example, the outer tubular body and the attachment body may be directly connected via the connecting members without the inner tubular body while allowing a relative elastic displacement therebetween.

In addition, in both types of the elastic connecting plates21and22, the distance W3in the tire width direction H between the central portions in the tire width direction H of the first end portions21aand22amay not be 0.7 times the outer tube width W1or less.

Fourth Embodiment

Next, a non-pneumatic tire according to a fourth embodiment of the present invention will be described with reference toFIGS. 9 and 10.

Further, in the second embodiment, the same portions as the components of the first embodiment will be designated by the same reference numerals, a description thereof will be omitted, and only differences will be described.

As shown inFIGS. 9 and 10, in the non-pneumatic tire of the embodiment, in both types of the elastic connecting plates21and22, an area of a cross section of inflection sections21g,21h,22gand22hdisposed between the curved sections21dto21fand22dto22fneighboring in the extension direction perpendicular to the extension direction, i.e., a cross-sectional area, is smaller than that of the other portions. Further, the inflection sections21g,21h,22gand22hof both types of the elastic connecting plates21and22are boundary regions of the curved sections21dto21fand22dto22fneighboring in the extension direction, and are regions in which curved directions of the curved sections21dto21fand22dto22fneighboring each other are switched when seen in the tire side view.

In the example shown, cross-sectional areas of both types of the elastic connecting plates21and22are gradually reduced toward the inflection sections21g,21h,22gand22hin the extension direction.

In addition, in both types of the elastic connecting plates21and22, sizes of the inflection sections21g,21h,22gand22hin both the tire width direction H and the tire circumferential direction are smaller than those of other portions.

As shown inFIG. 10, in both types of the elastic connecting plates21and22, both edges in the tire width direction H are bent in the tire width direction H to gradually approach each other toward the inflection sections21g,21h,22gand22hin the extension direction. In addition, both of the edges in the tire width direction H of both types of the elastic connecting plates21and22are formed in curved shapes that continuously extend without corners or stepped sections throughout the length in the extension direction. Further, only one out of both of the edges in the tire width direction H in both types of the elastic connecting plates21and22may be formed in the curved shapes as described above.

Sizes in the tire width direction H of both types of the elastic connecting plates21and22are gradually reduced toward the inflection sections21g,21h,22gand22hfrom the first end portions21aand22aand the second end portions21band22b, and are gradually reduced from centers in the extension direction of the first curved sections21dand22dtoward the inflection sections21g,21h,22gand22h, respectively. In addition, sizes in the tire width direction H of both types of the elastic connecting plates21and22are equal to each other in the centers of the extension direction of the first end portions21aand22a, the second end portions21band22b, and the first curved sections21dand22d.

As shown inFIG. 9, in both types of the elastic connecting plates21and22, the sizes in the tire circumferential direction, i.e., the thicknesses of the inflection sections21g,21h,22gand22h, are smallest. In both types of the elastic connecting plates21and22, the thickness of each of the first end portions21aand22aand the second end portions21band22bis largest, and then the thicknesses of the first curved sections21dand22dare the next largest.

The first to third the curved sections21dto21fand22dto22fand the inflection sections21g,21h,22gand22hare smoothly connected in the extension direction without intervening corners or stepped sections in the tire side view.

As described above, according to the non-pneumatic tire of the embodiment, in the first and second elastic connecting plates21and22, among the plurality of curved sections21dto21fand22dto22f, curved directions of the curved sections21dto21fand22dto22fneighboring in the extension direction are opposite to each other. For this reason, as shown by a two-dot chain line inFIG. 5, when a compressive load in the tire radial direction is applied to the non-pneumatic tire1, since the inflection sections21g,21h,22gand22hcannot be easily deformed but are mainly displaced in the first and second elastic connecting plates21and22, loads applied to the inflection sections21g,21h,22gand22hcan be limited in comparison with the other portions.

Additionally, since cross-sectional areas of the inflection sections21g,21h,22gand22hare smaller than cross-sectional areas of the other portions of the first and second elastic connecting plates21and22except for the inflection sections21g,21h,22gand22h, a reduction in weight can be achieved while preventing a decrease in strength of the connecting member15.

In addition, since the cross-sectional areas of the first and second elastic connecting plates21and22are gradually reduced toward the inflection sections21g,21h,22gand22hin the extension direction, a reduction in weight can be effectively achieved while limiting the occurrence of stress concentration places in the first and second elastic connecting plates21and22.

In addition, since both of a size in the tire width direction H and a size in the tire circumferential direction of the first and second elastic connecting plates21and22are smaller than those of the other portions of the inflection sections21g,21h,22gand22h, the non-pneumatic tire1that exhibits the above-mentioned effects can be reliably obtained.

Further, in a variant of the present invention, the cross-sectional area of each of both types of the elastic connecting plates21and22may be reduced in only the inflection sections21g,21h,22gand22hof both types of the elastic connecting plates21and22.

In addition, in the embodiment, while both of the size in the tire width direction H and the size in the tire circumferential direction of both of the elastic connecting plates21and22are smaller than those of other portions of the inflection sections21g,21h,22gand22h, only one thereof may be smaller.

In addition, in each of both types of the elastic connecting plates21and22, as holes passing in the tire circumferential direction are formed in the inflection sections21g,21h,22gand22h, cross-sectional areas of the inflection sections21g,21h,22gand22hmay be smaller than the other portions.

Fifth Embodiment

Next, a non-pneumatic tire according to a third embodiment of the present invention will be described with reference toFIG. 11.

Further, in the third embodiment, the same portions as the components of the first embodiment will be designated by the same reference numerals, a description thereof will be omitted, and only differences will be described.

In the non-pneumatic tire3of the embodiment, both types of the elastic connecting plates21and22extend outward in the tire width direction H from the outer tubular body13toward the attachment body11. Edges outside in the tire width direction H of both types of the elastic connecting plates21and22are formed in linear shapes inclined with respect to the reference line S when seen in the front view. The member width of the connecting member15is gradually increased from a first end portion of the connecting member15connected to the outer tubular body13toward the second end portion connected to the attachment body11. Both of the edges outside in the tire width direction H of the connecting member15are gradually directed outward in the tire width direction H and smoothly extend with no step difference from the first end portion toward the second end portion of the connecting member15.

As described above, according to the non-pneumatic tire3of the present invention, since both types of the elastic connecting plates21and22extend outward in the tire width direction H from the outer tubular body13toward the attachment body11, the member width of the connecting member15can be easily secured while suppressing the generation of the above-mentioned moment. Accordingly, the lateral stiffness of the connecting member15can be improved, and the steering stability of the non-pneumatic tire3can be further improved.

Further, the technical scope of the present invention is not limited to the embodiments but various modifications may be made without departing from the spirit of the present invention.

For example, the plurality of connecting members15may be formed between the inner tubular body12and the outer tubular body13in the tire width direction H.

In addition, instead of the embodiment, for example, the second end portions21band22bof the first elastic connecting plate21and the second elastic connecting plate22may be connected to positions opposite to each other on the outer circumferential surface of the inner tubular body12with the axis O interposed therebetween in the tire radial direction, or may be connected to positions on the outer circumferential surface of the inner tubular body12opposite to the first end portions21aand22aof the first elastic connecting plate21and the second elastic connecting plate22in the tire radial direction, or the like.

In addition, instead of the embodiment, the first end portions21aand22aof both of the elastic connecting plates21and22may be connected to different positions in the tire circumferential direction on the inner circumferential surface of the outer tubular body13.

Further, a gap in the tire width direction H may not be formed between the inner tubular body12of the first split ring member23and the inner tubular body12of the second split ring member24.

In addition, the ring member14may be split into three or more parts in the tire width direction H, or may not be split.

In addition, the ring member14and the plurality of connecting members15may not be integrally formed with each other.

Furthermore, the ring member14and the connecting members15are not limited to the embodiment. For example, the outer tubular body and the attachment body may be directly connected via the connecting members while allowing a relative elastic displacement therebetween without the inner tubular body.

In addition, the central portion in the extension direction of the first elastic connecting plate21and the central portion in the extension direction of the second elastic connecting plate22may not be separated in the tire width direction H by a distance of 0.25 to 0.9 times the outer tube width W1.

Further, an edge of first side in the tire width direction H of the first end portion21aof the first elastic connecting plate21may not be disposed at the same position in the tire width direction H as first side edge of the outer tubular body13, or may be disposed inside in the tire width direction H of the first side edge within a distance of 0.1 times the outer tube width W1or less. Furthermore, an edge of the second side in the tire width direction H of the first end portion22aof the second elastic connecting plate22may not be formed at the same position in the tire width direction H as the second side edge of the outer tubular body13, or may not be disposed inside in the tire width direction H of the second side edge within a distance of 0.1 times the outer tube width W1or less.

In addition, the components of the above-mentioned embodiments may be appropriately substituted with known components, and the above-mentioned variants may be appropriately combined without departing from the spirit of the present invention.

INDUSTRIAL APPLICABILITY

According to the present invention, cornering performance of a tire can be improved. In addition, according to the present invention, a lateral force generated upon traveling can be limited, and steering stability can be improved.