JP7518739B2 - Tire Assembly - Google Patents

Description

The present invention relates to a tire assembly.

2. Description of the Related Art There has been known a tire assembly in which a non-pneumatic tire having an inner cylinder, an outer cylinder, and a connecting member is mounted on the outer peripheral surface of a rim.
As an example of this type of tire assembly, as shown in Patent Document 1 below, a configuration is known in which an inner tube is divided at multiple locations along the circumferential direction, and a connecting means that extends continuously over the entire circumferential length of the inner tube is wound integrally around the outer circumferential surface of the inner tube.

Patent No. 4093318

However, the conventional tire assemblies described above had the problem that it was difficult to securely fasten the non-pneumatic tire to the rim, for example, due to deformation of the connecting means.

The present invention was made in consideration of the above-mentioned circumstances, and aims to provide a tire assembly that can securely fix a non-pneumatic tire to a rim.

In order to solve the above problems, the present invention proposes the following means.
The tire assembly of the present invention comprises a non-pneumatic tire having a rim, an inner tube surrounding the outer peripheral surface of the rim from the radial outside, an outer tube surrounding the inner tube from the radial outside, and a plurality of elastically deformable connecting members connecting the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube, wherein the inner tube has a dividing portion formed therein that divides the inner tube in the circumferential direction, and the outer peripheral surface of the inner tube has fixing recesses formed thereon on both sides circumferentially sandwiching the dividing portion, and a pair of engaging protrusions respectively fitted into a pair of the fixing recesses, a fixing device attached to the outer peripheral surface of the inner tube, and a fixing shaft that penetrates the inner tube radially, engages with the fixing device and the rim, and applies a force directed radially inward to the fixing device.

According to this invention, a dividing portion is formed in the inner tube, so that when the non-pneumatic tire is mounted on the rim, the dividing portion can be expanded to deform the inner tube, and the rim can be easily fitted inside the inner tube.
With a pair of engaging protrusions on the fixing device individually fitted into the fixing recesses of the inner tube, the fixing shaft applies a radially inward force to the fixing device, thereby making it possible to prevent the engaging protrusions from coming off the fixing recesses and the divided portion from widening, thereby enabling the non-pneumatic tire to be securely fixed to the rim.
Since the fixed shaft penetrates the inner tube in the radial direction and engages with the fixture and the rim, it is possible to prevent the non-pneumatic tire and the rim from being displaced relative to each other in the circumferential direction.

A first surface of the inner surface of the fixed recess, which is located on the dividing portion side along the circumferential direction and faces the circumferential direction, and a second surface of the surface of the engagement protrusion, which is located on the dividing portion side along the circumferential direction and faces the circumferential direction, may abut against each other, and at least one of the first surface and the second surface may extend toward the dividing portion side along the circumferential direction as it moves radially outward.

In this case, at least one of the first surface of the fixing recess and the second surface of the engagement protrusion extends radially outward and circumferentially toward the dividing section. The fixing shaft applies a radially inward force to the fixing device, and by pressing the first and second surfaces against each other, it becomes possible to generate a force on the inner tube that narrows the circumferential width of the dividing section, thereby firmly fixing the inner tube to the rim.

The outer peripheral surface of the rim may be provided with a mounting recess extending in the circumferential direction, and the inner peripheral surface of the inner tube may be formed with a fitting protrusion that fits into the mounting recess.

In this case, a circumferentially extending mounting recess is provided on the outer peripheral surface of the rim, and an engagement protrusion that fits into the mounting recess is formed on the inner peripheral surface of the inner tube, making it possible to restrict relative movement between the non-pneumatic tire and the rim in the width direction, and allowing the non-pneumatic tire to be stably fixed to the rim.
As described above, since a divided portion is formed in the inner tube, when the non-pneumatic tire is mounted on the rim, the divided portion is expanded to deform the inner tube, so that the fitting protrusion can be easily fitted into the mounting recess.

The inner tube may have a pair of divided surfaces that face each other in the circumferential direction and define the divided portion, and the inner tube may have first through holes that penetrate the divided portion in the radial direction and recess each of the pair of divided surfaces in the circumferential direction, and the fixed shaft may be inserted into the first through holes.

In this case, a first through hole that passes radially through the dividing portion is formed in the inner tube, so assembly can be easily performed by inserting a fixed shaft that passes radially through the inner tube into the first through hole.

The pair of engagement protrusions may be provided in multiple sets spaced apart in the width direction, and the pair of fixing recesses may be provided in multiple sets spaced apart in the width direction and spaced apart from the first through hole in the width direction.

In this case, since a plurality of pairs of engaging projections and a plurality of pairs of fixing recesses are provided at intervals in the width direction, it is possible to reliably prevent the inner tube from deforming in a manner that would widen the separated portion.
Since the fixing recess is spaced apart from the first through hole in the width direction, it is possible to prevent the fixing recess and the first through hole from coming close to each other, and the strength of the inner tube can be ensured.

A second through hole may be formed radially through the rim, a female thread may be formed in the fastener, the fastener shaft may be a headed bolt having a head and a shaft, the head may be placed on the inner peripheral surface of the rim, and the shaft may be screwed into the female thread of the fastener.

In this case, the shaft portion of the fixed shaft is inserted into the second through hole from the inner surface side of the rim and screwed into the female threaded portion of the fixing device, so that it is possible to rotate the fixed shaft around its axis by clamping the head with a wrench or the like on the radial inside of the rim, where the space is wider than between the inner tube and the outer tube, thereby providing excellent operability.
In addition, a general-purpose wheel on which a pneumatic tire is mounted may be used as the wheel, and the second through hole may be a through hole into which an air injection valve was inserted.

This invention allows a non-pneumatic tire to be securely fixed to the rim.

1 is a side view of a tire assembly according to one embodiment. 2 is a perspective view including a cross section taken along line II-II of FIG. 1. FIG. 2 is a perspective view including a partial cross section of FIG. 1 . 4 is a cross-sectional view taken along line IV-IV in FIG. 1.

Hereinafter, a tire assembly 1 according to the present embodiment will be described with reference to FIGS. 1 to 4. FIG.
1 and 2, a tire assembly 1 includes a wheel 2 having a rim 12, a non-pneumatic tire 3, a tread member 4, a fixing device 5, and a fixed shaft 6. The tire assembly 1 is mounted on, for example, a bicycle, a wheelchair, a two-wheeled vehicle, an automobile, or the like.

The rim 12, the non-pneumatic tire 3, and the tread member 4 are each formed in an annular shape, and their respective central axes are located on a common axis. This common axis is called the central axis O, and the direction along the central axis O is called the width direction. In addition, when viewed from the width direction, the direction going around the central axis O is called the circumferential direction, and the direction intersecting the central axis O is called the radial direction.
The center portions in the width direction of the wheel 2, the non-pneumatic tire 3, and the tread member 4 are aligned with each other.

The wheel 2 comprises a hub 11 attached to an axle, a rim 12 surrounding the hub 11 from the outside in the radial direction, and a number of spokes 13 connecting the outer circumferential surface of the hub 11 and the inner circumferential surface of the rim 12.

The hub 11 is formed in a cylindrical shape and disposed coaxially with the central axis O. The spokes 13 connect the outer peripheral surface of the hub 11 to the inner peripheral surface of the rim 12. The multiple spokes 13 are provided over the entire circumferential area between the outer peripheral surface of the hub 11 and the inner peripheral surface of the rim 12.
The rim 12 extends continuously over its entire circumferential length and is formed in a tubular shape that opens radially outward, as shown in Fig. 2. This provides an attachment recess 16 that extends continuously over its entire circumferential length on the outer circumferential surface of the rim 12. A second through hole 33 is formed in the rim 12 and passes through it in the radial direction. One second through hole 33 is provided in the rim 12.
The wheel 2 is the same as a general-purpose wheel on which a pneumatic tire is mounted, and the second through hole 33 is a through hole into which an air injection valve is inserted. Note that the mounting recess 16 and the second through hole 33 do not necessarily have to be provided in the rim 12.

The non-pneumatic tire 3 has an inner tube 21 that surrounds the outer peripheral surface of the rim 12 from the outside in the radial direction, an outer tube 22 that surrounds the inner tube 21 from the outside in the radial direction, and a plurality of elastically deformable connecting members 23 that connect the outer peripheral surface of the inner tube 21 and the inner peripheral surface of the outer tube 22. The Young's modulus of the material forming the non-pneumatic tire 3 is, for example, 30 MPa or more and 1500 MPa or less.

The inner tube 21 and the outer tube 22 are arranged coaxially with the central axis O. The inner tube 21, the outer tube 22, and the connecting member 23 are arranged with their respective widthwise centers aligned with each other.

The inner peripheral surface of the inner tube 21 is formed with a fitting protrusion 27 that fits into the mounting recess 16 of the rim 12. The fitting protrusion 27 extends continuously over the entire circumferential length of the inner tube 21, excluding the dividing portion 15 described later. The fitting protrusion 27 is provided at the center of the width direction on the inner peripheral surface of the inner tube 21. The width of the inner tube 21 is wider than the width of the rim 12. The part of the inner peripheral surface of the inner tube 21 that is located outside the fitting protrusion 27 in the width direction abuts against the outer peripheral surface of the rim 12. The fitting protrusion 27 becomes smaller in width direction toward the inside in the radial direction. As shown in FIG. 2, the fitting protrusion 27 has a symmetrical shape with respect to a straight line that passes through the center of the width direction of the inner tube 21 and extends in the radial direction in a vertical cross-sectional view along both the width direction and the radial direction.

The multiple connecting members 23 are provided at intervals in the circumferential direction between the outer peripheral surface of the inner tube 21 and the inner peripheral surface of the outer tube 22. The multiple connecting members 23 are provided at equal intervals in the circumferential direction. As shown in FIG. 1, the multiple connecting members 23 extend at an angle in the same direction relative to the radial direction when viewed in the width direction. The connecting members 23 are formed in a plate shape and are provided with the front and back surfaces facing the circumferential or radial direction and the side surfaces facing the width direction.

The inner cylinder 21, the outer cylinder 22, and the connecting member 23 are integrally formed from a thermoplastic resin. The thermoplastic resin may be, for example, only one type of resin, a mixture containing two or more types of resin, or a mixture containing one or more types of resin and one or more types of elastomer, and may further contain additives such as an antioxidant, a plasticizer, a filler, or a pigment.
The inner cylinder 21, the outer cylinder 22, and the connecting member 23 may be formed separately from each other. The inner cylinder 21, the outer cylinder 22, and the connecting member 23 may be formed from a material other than a thermoplastic resin.

The tread member 4 is formed to be elastically deformable and is fitted onto the outer tube 22. The Young's modulus of the material forming the tread member 4 is smaller than the Young's modulus of the material forming the non-pneumatic tire 3. As shown in FIG. 2, the outer peripheral surface of the tread member 4 has a curved shape that protrudes radially outward in a longitudinal cross-sectional view along both the width direction and the radial direction.

The tread member 4 is formed of, for example, vulcanized rubber obtained by vulcanizing natural rubber and/or a rubber composition, or a thermoplastic material. From the viewpoint of abrasion resistance, it is preferable to form the tread member 4 from vulcanized rubber. Examples of the thermoplastic material include a thermoplastic elastomer and a thermoplastic resin.
Examples of the thermoplastic elastomer include amide-based thermoplastic elastomers (TPA), ester-based thermoplastic elastomers (TPC), olefin-based thermoplastic elastomers (TPO), styrene-based thermoplastic elastomers (TPS), urethane-based thermoplastic elastomers (TPU), thermoplastic rubber crosslinked bodies (TPV), and other thermoplastic elastomers (TPZ), which are specified in JIS K6418.
Examples of the thermoplastic resin include urethane resin, olefin resin, vinyl chloride resin, and polyamide resin.

In this embodiment, the inner tube 21 is formed with a dividing portion 15 that divides the inner tube 21 in the circumferential direction. The dividing portion 15 has a circumferential width when the inner tube 21 is fixed to the outer circumferential surface of the rim 12. The inner tube 21 has a pair of dividing surfaces 15a that face each other in the circumferential direction and define the dividing portion 15. One dividing portion 15 is provided. Note that multiple dividing portions 15 may be provided at intervals in the circumferential direction.

The inner tube 21 is formed with a first through hole 14 that penetrates the dividing portion 15 in the radial direction and recesses each of the pair of dividing surfaces 15a in the circumferential direction. In other words, the inner diameter of the first through hole 14 is larger than the width of the dividing portion 15. As shown in FIG. 4, the first through hole 14 is formed in the center of the inner tube 21 in the width direction. When viewed from the radial direction, the centers of the first through hole 14 and the dividing portion 15 are aligned with each other.

On the outer circumferential surface of the inner cylinder 21, fixing recesses 17 are formed separately on both sides that sandwich the dividing portion 15 in the circumferential direction.
The pair of fixing recesses 17 are provided at the same widthwise position and spaced apart in the circumferential direction. The pair of fixing recesses 17 are provided in multiple sets spaced apart in the widthwise direction and are spaced apart in the widthwise direction from the first through hole 14. The pair of fixing recesses 17 are also spaced apart in the circumferential direction from the first through hole 14. The pair of fixing recesses 17 are formed on the outer circumferential surface of the inner tube 21, with one set on each side sandwiching the first through hole 14 in the widthwise direction.

Note that a portion of the fixed recess 17 may be located at the same widthwise position or the same circumferential position as the first through hole 14. The fixed recess 17 may be formed over the entire length of the outer peripheral surface of the inner tube 21, excluding both widthwise ends. The fixed recess 17 may penetrate the inner tube 21 in the radial direction.

The fixing device 5 is formed of, for example, a metal material. As shown in Figs. 2 and 3, the fixing device 5 is attached to the outer peripheral surface of the inner tube 21 and spans the dividing portion 15 in the circumferential direction. The fixing device 5 is formed in a plate shape with the front and back surfaces facing in the radial direction. A female thread portion 5a is formed in the fixing device 5, penetrating it in the radial direction. The female thread portion 5a is formed in the center of the fixing device 5 when viewed from the radial direction. The fixing device 5 is spaced radially outward from the outer peripheral surface of the inner tube 21.

The fixing device 5 is provided with a pair of engagement protrusions 18 that are respectively fitted into a pair of fixing recesses 17. The pair of engagement protrusions 18 are provided at the same widthwise position with a circumferential gap. The pair of engagement protrusions 18 are provided in multiple sets with a gap in the widthwise direction, and are spaced apart in the widthwise direction from the female threaded portion 5a. The pair of engagement protrusions 18 are also spaced apart in the circumferential direction from the female threaded portion 5a. The pair of engagement protrusions 18 are provided on the inner surface of the fixing device 5 facing inward in the radial direction, with one set on each side of the female threaded portion 5a sandwiched in the widthwise direction. The widthwise size of the engagement protrusions 18 is the same over the entire radial length.

Note that a portion of the engagement protrusion 18 may be located at the same widthwise position or at the same circumferential position relative to the female thread portion 5a. The engagement protrusion 18 may be provided over the entire widthwise length of the fastener 5.

As shown in Figures 3 and 4, the first surface 17a of the inner surface of the fixing recess 17, which is located on the dividing portion 15 side along the circumferential direction and faces the circumferential direction, and the second surface 18a of the surface of the engagement protrusion 18, which is located on the dividing portion 15 side along the circumferential direction and faces the circumferential direction, are in contact with each other. The fixing device 5 is attached to the outer peripheral surface of the inner tube 21 via the engagement protrusion 18. The inner surface of the fixing device 5 facing inward in the radial direction is spaced radially outward from the outer peripheral surface of the inner tube 21.

At least one of the first surface 17a and the second surface 18a extends toward the dividing portion 15 in the circumferential direction as it moves radially outward. As shown in FIG. 3, in a vertical cross-sectional view along both the circumferential and radial directions, at least one of the first surface 17a and the second surface 18a extends toward the dividing portion 15 in the circumferential direction as it moves radially outward.

In the illustrated example, both the first surface 17a and the second surface 18a extend radially outwardly toward the dividing portion 15 along the circumferential direction.
Both widthwise end faces of the inner surface of the fixing recess 17 and both widthwise end faces of the surface of the engaging protrusion 18 are in contact with each other. Note that both widthwise end faces of the inner surface of the fixing recess 17 and both widthwise end faces of the surface of the engaging protrusion 18 may be separated from each other in the width direction.
The lower end surface of the engagement projection 18 is located above the bottom surface of the fixing recess 17 .

The fixed shaft 6 penetrates the inner tube 21 in the radial direction and engages with the fixing device 5 and the rim 12. The fixed shaft 6 is inserted into the first through hole 14 of the inner tube 21. The outer diameter of the fixed shaft 6 is larger than the width of the dividing portion 15 and smaller than the inner diameter of the first through hole 14.

The fixed shaft 6 is a headed bolt having a head 6a and a shaft 6b. The shaft 6b is inserted into the second through hole 33 (FIG. 2) from the inner peripheral surface side of the rim 12 and screwed into the female threaded portion 5a of the fixing device 5. The head 6a is placed on the inner peripheral surface of the rim 12. As a result, the fixed shaft 6 engages with the fixing device 5 and the rim 12, applying a force to the fixing device 5 in a radially inward direction, and as shown in FIG. 3, the second surface 18a of the engagement protrusion 18 is pressed against the first surface 17a of the fixing recess 17 of the inner tube 21, generating a force in the inner tube 21 in a direction narrowing the circumferential width of the dividing portion 15, and the inner peripheral surface of the inner tube 21 tightens the outer peripheral surface of the rim 12.

In addition, a through hole may be formed in the fixing device 5 instead of the female thread portion 5a, and a nut may be screwed onto the portion of the shaft portion 6b of the fixed shaft 6 that protrudes radially outward from the fixing device 5.
A through hole may be formed in the fixing device 5 instead of the female threaded portion 5a, the head 6a of the fixing shaft 6 may be placed on the outer surface of the fixing device 5 facing radially outward, and a nut may be screwed onto the portion of the shaft portion 6b of the fixing shaft 6 that protrudes radially inward from the inner surface of the rim 12.
A through hole may be formed in the fixing device 5 instead of the female threaded portion 5a, a female threaded portion may be formed in the rim 12 instead of the second through hole 33, the head 6a of the fixing shaft 6 may be placed on the outer surface of the fixing device 5 facing radially outward, and the shaft portion 6b of the fixing shaft 6 may be screwed into the female threaded portion of the rim 12.

As described above, according to the tire assembly 1 of this embodiment, the dividing portion 15 is formed in the inner tube 21, so that when the non-pneumatic tire 3 is mounted on the rim 12, it is possible to expand the dividing portion 15 to deform the inner tube 21, and the rim 12 can be easily installed inside the inner tube 21.

With a pair of engagement protrusions 18 on the fixing device 5 individually fitted into the fixing recesses 17 of the inner tube 21, the fixing shaft 6 applies a radially inward force to the fixing device 5, so that it is possible to prevent the engagement protrusions 18 from coming off the fixing recesses 17 and the dividing portion 15 from being expanded, and the non-pneumatic tire 3 can be securely fixed to the rim 12.
Since the fixed shaft 6 penetrates the inner tube 21 in the radial direction and engages with the fixing device 5 and the rim 12, it is possible to prevent the non-pneumatic tire 3 and the rim 12 from shifting in their relative positions in the circumferential direction.

At least one of the first surface 17a of the fixing recess 17 and the second surface 18a of the engagement protrusion 18 extends radially outward and circumferentially toward the dividing section 15. This allows the fixing shaft 6 to apply a radially inward force to the fixing device 5, and presses the first surface 17a and the second surface 18a against each other, generating a force on the inner tube 21 that narrows the circumferential width of the dividing section 15, thereby firmly fixing the inner tube 21 to the rim 12.

A circumferentially extending mounting recess 16 is provided on the outer peripheral surface of the rim 12, and an engagement protrusion 27 that engages with the mounting recess 16 is formed on the inner peripheral surface of the inner tube 21. This makes it possible to restrict the relative movement of the non-pneumatic tire 3 and the rim 12 in the width direction, and allows the non-pneumatic tire 3 to be stably fixed to the rim 12.
As described above, since the dividing portion 15 is formed in the inner tube 21, when the non-pneumatic tire 3 is mounted on the rim 12, the dividing portion 15 is expanded to deform the inner tube 21, so that the fitting protrusion 27 can be easily fitted into the mounting recess 16.

A first through hole 14 that radially penetrates the dividing portion 15 is formed in the inner tube 21, so that the fixed shaft 6 that radially penetrates the inner tube 21 can be easily assembled by inserting it into the first through hole 14.
Since a plurality of pairs of engaging projections 18 and a plurality of pairs of fixing recesses 17 are provided at intervals in the width direction, deformation of the inner tube 21 that would cause the dividing portion 15 to expand can be reliably prevented.
Since the fixing recess 17 is spaced apart from the first through hole 14 in the width direction, it is possible to prevent the fixing recess 17 and the first through hole 14 from coming close to each other, thereby ensuring the strength of the inner tube 21.

The shaft portion 6b of the fixed shaft 6 is inserted into the second through hole 33 from the inner peripheral surface side of the rim 12 and screwed into the female thread portion 5a of the fixing device 5. Therefore, inside the rim 12 in the radial direction, where the space is wider than between the inner tube 21 and the outer tube 22, it is possible to pinch the head portion 6a with a wrench or the like and rotate the fixed shaft 6 around its axis, providing excellent operability.

The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

The tire assembly 1 does not have to have a tread member 4.

In addition, the components in the above-described embodiments may be replaced with well-known components as appropriate without departing from the spirit of the present invention, and the above-described embodiments and variations may be combined as appropriate.

REFERENCE SIGNS LIST 1 tire assembly 2 wheel 3 non-pneumatic tire 4 tread member 5 fixing device 5a female thread portion 6 fixing shaft 6a head portion 6b shaft portion 12 rim 14 first through hole 15 divided portion 15a divided surface 16 mounting recess 17 fixing recess 17a first surface 18 engaging projection 18a second surface 21 inner tube 22 outer tube 23 connecting member 27 fitting projection 33 second through hole

Claims (6)

Rim and
a non-pneumatic tire having an inner tube surrounding an outer circumferential surface of the rim from the outside in the radial direction, an outer tube surrounding the inner tube from the outside in the radial direction, and a plurality of elastically deformable connecting members connecting the outer circumferential surface of the inner tube and the inner circumferential surface of the outer tube,
A dividing portion that divides the inner cylinder in a circumferential direction is formed in the inner cylinder,
A fixing recess is formed on each side of the outer circumferential surface of the inner cylinder, the fixing recess being formed on each side of the dividing portion in the circumferential direction.
a fixing device provided with a pair of engagement projections respectively fitted into the pair of fixing recesses and attached to an outer circumferential surface of the inner cylinder;
a fixed shaft that radially penetrates the inner cylinder, engages with the fastener and the rim, and applies a radially inward force to the fastener. a first surface of the inner surface of the fixing recess that is located on the dividing portion side along the circumferential direction and faces the circumferential direction, and a second surface of the surface of the engagement projection that is located on the dividing portion side along the circumferential direction and faces the circumferential direction are in contact with each other;
The tire assembly according to claim 1 , wherein at least one of the first surface and the second surface extends radially outward and circumferentially toward the divided portion. A mounting recess extending in a circumferential direction is provided on an outer peripheral surface of the rim,
The tire assembly according to claim 1 or 2, wherein an engagement protrusion that is fitted into the mounting recess is formed on an inner circumferential surface of the inner cylinder. the inner cylinder has a pair of divided surfaces that are opposed to each other in a circumferential direction and define the divided portion,
The inner cylinder is formed with a first through hole that penetrates the divided portion in a radial direction and recesses each of the pair of divided surfaces in a circumferential direction,
The tire assembly according to claim 1 , wherein the fixed shaft is inserted into the first through hole. The pair of engagement projections are provided in a plurality of sets spaced apart in the width direction,
The tire assembly according to claim 4 , wherein a plurality of pairs of the fixing recesses are provided at intervals in the width direction and are spaced apart from the first through hole in the width direction. A second through hole is formed in the rim so as to extend radially therethrough,
A female screw portion is formed in the fastener,
The fixed shaft is a headed bolt having a head and a shaft,
The tire assembly according to claim 1 , wherein the head portion is placed on an inner peripheral surface of the rim, and the shaft portion is screwed into the female thread portion of the fastener.

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