JP2023087567A - Core for run flat driving and tire, core, rim assembly - Google Patents

Abstract

To prevent a centroid of a core from being deviated by a centrifugal force to deterioration in uniformity.SOLUTION: A core 30 for run flat driving has a spiral shape, is attached to a rim 20 with a tire 10, and may support a load of the tire 10 during run flat driving. Ends 30a, 30b of the core 30 are respectively fixed to middle portions of the core 30. A tire, core, rim assembly 1 uses the core 30 for run flat driving.SELECTED DRAWING: Figure 1

Description

The present invention relates to a run-flat running core and a tire/core/rim assembly.

Conventionally, as a tire-rim assembly in which a tire is mounted on a rim, a helical core is mounted on the rim together with the tire. is known to enable running in a run-flat state (see, for example, Patent Document 1).
According to the helical core, one end is inserted into the inside of the tire, and inserted while rotating in the circumferential direction of the spiral along the tire, thereby increasing the outer diameter from the inner diameter of the bead portion. A large core can be easily inserted inside the tire.

British Patent Application Publication No. 2189749

However, since the conventional core has a helical shape, it is deformed by centrifugal force when the vehicle is running so that the outer diameter becomes larger. However, there is a problem that the uniformity deteriorates due to the misalignment.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent deterioration of uniformity due to deviation of the center of gravity of the core due to centrifugal force.

The gist and configuration of the present invention are as follows.
(1) A core for run-flat driving, which has a helical shape and is attached to a rim together with the tire, and is capable of supporting a load applied to the tire from the vehicle during run-flat driving,
A core for run-flat running, wherein each end of said core for run-flat running is fixed to a middle portion of said core for run-flat running.

(2) a steel pipe having a helical shape;
The core for run-flat running according to the above (1), further comprising a cushioning member that covers the outer periphery of the steel pipe.

(3) The run-flat running core according to (2) above, wherein the steel pipe is a rectangular steel pipe.

(4) (2) or (3) above, wherein the entire outer periphery of the steel pipe is covered with the buffer member in the range from the end portion to the midway portion of each of the run-flat running cores; core for run-flat running described in .

(5) Any one of the above (2) to (4), wherein the inner diameter of the steel pipe is 62.5 mm or more larger than the rim diameter of the rim in the region where the core for run-flat running contacts the rim. 1. A run-flat running core according to claim 1.

(6) A vehicle comprising: the tire; the rim; and the core for run-flat driving according to any one of the above (1) to (5) attached to the rim together with the tire. A tire/core/rim assembly.

According to the present invention, it is possible to prevent the centrifugal force from deviating the center of gravity of the core and deteriorating the uniformity.

1 is a cross-sectional view along the axis of a tire in a run-flat state of a tire/core/rim assembly provided with a run-flat driving core according to an embodiment of the present invention; FIG. 2 is a perspective view of the run-flat traveling core shown in FIG. 1 ; FIG. 3 is an explanatory view showing a fixing structure of the core for run-flat running shown in FIG. 2 between an end portion and a middle portion of a steel pipe; FIG. 2 is a perspective view of the core for run-flat running shown in FIG. 1 before it is attached to a tire; FIG. 10 is a cross-sectional view of a core for run-flat traveling according to a modification; FIG. 11 is a cross-sectional view of a core for run-flat traveling according to another modification; FIG. 11 is a perspective view of a core for run-flat traveling according to still another modification before being attached to a tire.

Embodiments of the present invention will be exemplified in detail below with reference to the drawings.

As shown in FIG. 1, a tire/core/rim assembly 1 according to one embodiment of the present invention includes a tire 10, a rim 20, and a runflat running core 30 (hereinafter referred to as “core 30”). ), and the core 30 is assembled to the rim 20 together with the tire 10 and attached to the rim 20 .

The tire 10 is a pneumatic tire mainly made of synthetic rubber. The tire 10 is, for example, a tubeless tire made of synthetic rubber having, as an internal structure, a pair of beads, a carcass that straddles the pair of beads in a toroidal shape, and a belt or the like arranged outside the crown of the carcass in the tire radial direction. can be The tire 10 is attached to the rim 20 at the pair of bead portions 11 .

The rim 20 can be an applied rim. "Applicable rim" means an industrial standard effective in the region where the tire is produced and used, such as JATMA (Japan Automobile Tire Manufacturers Association) JATMA YEAR BOOK in Japan and ETRTO (The European Tire and Rim Technical Organization in Europe). ) in the STANDARDS MANUAL of ETRTO and in the YEAR BOOK of TRA (The Tire and Rim Association, Inc.) in the United States or will be described in the future. Design Rim in YEAR BOOK) (that is, the above "rim" includes sizes that can be included in the above industrial standards in the future in addition to current sizes. Examples of "sizes to be described in the future" (Examples include sizes listed as "FUTURE DEVELOPMENTS" in the 2013 edition of ETRTO.) However, if the size is not listed in the above industrial standards, use a rim with a width that corresponds to the bead width of the tire. say.

Rim 20 includes a disc 21 , a pair of rim flanges 22 , a pair of bead seats 23 , a well 24 and a pair of humps 25 . The rim 20 is fixed at a disc 21 to a vehicle hub (not shown). The bead portion 11 of the tire 10 is attached to the bead seat 23 . The rim flange 22 extends radially outward and widthwise outward of the rim 20 from the bead seat 23 in order to support the bead portion 11 of the tire 10 mounted on the bead seat 23 from the side surface. The well 24 has a concave shape that is concave radially inward of the rim 20 between the pair of bead seats 23 so that the tire 10 can be easily attached to and removed from the rim 20 . The hump 25 is provided between the bead seat 23 and the well 24 and has a shape protruding radially outward of the rim 20 with respect to the bead seat 23 in order to prevent the bead portion 11 of the tire 10 from falling into the well 24. It has become.

The core 30 according to one embodiment of the present invention is loaded inside the tire 10 and then assembled and mounted on the rim 20 together with the tire 10. By supporting such a load, the tire/core/rim assembly 1 can run in a run-flat state, that is, run-flat.

As shown in FIGS. 1 and 2, the core 30 has a spiral shape. In other words, the core 30 has a shape that moves in the axial direction while rotating around the axis of the tire 10 .

In this embodiment, the core 30 includes a steel pipe 31 as a helical member having a helical shape, a cushioning member 32 covering the outer periphery of one end portion 31A of the steel pipe 31 in the helical direction, and a A buffer member 33 covering the outer periphery of the other end portion 31B is provided.

The steel pipe 31 has a circular cross section, and by being compressed in the direction of the rotation axis of the tire 10, it is possible to generate a force in the direction of the rotation axis of the tire 10 that can position the core 30. It has a predetermined rigidity that can withstand deformation due to force.

The cushioning member 32 and the cushioning member 33 are made of a material capable of absorbing shock, such as an elastic body such as rubber, urethane, or elastomer. In the present embodiment, the cushioning member 32 and the cushioning member 33 are ring-shaped having gaps 32a and 33a that are divided in the circumferential direction, respectively. A mounting groove 32b extending along the circumferential direction around the axis of the tire 10 is provided on the side surface of the cushioning member 32 facing the cushioning member 33 side. One end portion 31A of the steel pipe 31 in the spiral direction is arranged inside the mounting groove 32b and fixed to the cushioning member 32 so that its tip is aligned with the gap 32a of the cushioning member 32. As shown in FIG. Similarly, a side surface of the cushioning member 33 facing the cushioning member 32 side is provided with a mounting groove 33b extending along the circumferential direction about the axis of the tire 10 . The other end portion 31B of the steel pipe 31 in the spiral direction is arranged inside the mounting groove 33b and fixed to the cushioning member 33 so that its tip is aligned with the joint 33a of the cushioning member 33 .
The structure for fixing the steel pipe 31 to the cushioning member 32 or the cushioning member 33 includes various methods such as press-fitting into the mounting grooves 32b and 33b, fastening using a fastening member such as a bolt, bonding using an adhesive, or welding. configuration can be employed.

The cushioning member 32 and the cushioning member 33 are preferably made of rubber. During run-flat running, the outer peripheral surface of the cushioning member 32 and the cushioning member 33 always slips against the inner peripheral surface of the tread portion 12 of the tire 10, but the cushioning member 32 and the cushioning member 33 are made of rubber. By doing so, the cushioning member 32 and the cushioning member 33 can be made to slide moderately on the inner peripheral surface of the tire 10, and the durability of the tire 10 and the core 30 can be enhanced.
Also, the weight of the core 30 is preferably 1/4 or less of the total weight of the tire 10 and the rim 20 . As a result, the weight of the tire/core/rim assembly 1 can be prevented from becoming excessively heavy, and the deterioration of the sound and vibration performance of the tire 10 to the vehicle during normal running can be suppressed.

Here, one end 30a of the core 30 in the helical direction is fixed to an intermediate portion between the one end 30a and the other end 30b of the core 30. As shown in FIG. In this embodiment, one end of the steel pipe 31 in the spiral direction is fixed to the middle portion of the steel pipe 31 (the rear end of the one end side portion 31A) in a state where the abutment 32a of the buffer member 32 is mated with each other. , one end portion 30 a of the core 30 is fixed to the middle portion of the core 30 . As a result, the one end portion 30A of the core 30, which extends 360 degrees from one end 30a of the core 30 to the intermediate portion where the end 30a is fixed, has an annular closed shape. That is, the core 30 has a shape in which the pitch of the one end portion 30A is zero. The outer circumference of the steel pipe 31 at the one end side portion 30A of the core 30 , that is, the outer circumference of the one end side portion 31A of the steel pipe 31 is covered with the buffer member 32 .

Similarly, the other end 30b of the core 30 in the helical direction is fixed midway between the other end 30b of the core 30 and the one end 30a. In the present embodiment, the other end of the steel pipe 31 in the spiral direction is fixed to the middle portion of the steel pipe 31 (the rear end of the other end side portion 31B) with the abutment 33a of the buffer member 33 facing each other. Then, the other end 30b of the core 30 is fixed to the middle portion of the core 30. As shown in FIG. As a result, the other end side portion 30B, which is a portion within a range of 360 degrees from the other end portion 30b of the core 30 to the midway portion where the end portion 30b is fixed, also has an annular closed shape. . That is, the core 30 has a shape in which the pitch of the other end portion 30B is zero. The outer periphery of the steel pipe 31 at the other end portion 30B of the core 30 , that is, the outer periphery of the other end portion 31B of the steel pipe 31 is covered with the buffer member 33 .

An intermediate portion 30C between the one end portion 30A and the other end portion 30B of the core 30 has a spiral shape with a constant pitch.

As a fixing structure for fixing the one end 30a and the other end 30b of the core 30 to the middle portion of the core 30, a fastening structure using a fastening member such as a bolt, or an insertion type such as a quick coupler may be used. Various structures can be used, such as structures using fixtures.
In order to maintain reliability, a fastening structure using a fastening member such as a bolt is used as a fixing structure for fixing one end 30a and the other end 30b of the core 30 to the middle portion of the core 30, respectively. is preferably used.
For example, as shown in FIG. 3, the steel pipe 31 is divided into one end portion 31A, the other end portion 31B, and an intermediate portion 31C between the one end portion 31A and the other end portion 31B. The proximal ends of the portion 31A and the other end portion 31B are fastened and fixed to the corresponding ends of the intermediate portion 31C using brackets 34 and bolts 35, respectively, and the distal end portions of the one end portion 31A and the other end portion 31B are fixed. The other half of the connecting body 36 is inserted into the proximal ends of the one end side portion 31A and the other end side portion 31B and fastened with bolts 35. By fixing, one end portion 30a and the other end portion 30b of the core 30 can be configured to be fixed to the middle portion of the core 30, respectively. In this case, half of the connecting body 36 is fixed to the proximal ends of the one end portion 31A and the other end side portion 31B with bolts 35, and the other half of the connecting body 36 is attached to the one end portion 31A and the other end side portion. One end 30a and the other end 30b of the core 30 can be fixed to the middle part of the core 30 by inserting them into the tip of the core 31B and fastening and fixing them with bolts 37. FIG.

The core 30 contacts the bead seat 23 and/or the hump 25 of the rim 20 on the inner peripheral surface of a predetermined range from one end 30a to the other end 30b in the direction along the spiral direction. At the same time, it is configured to contact the bead seat 23 and/or the hump 25 of the rim 20 on the inner peripheral surface of a predetermined range from the other end 30b toward the one end 30a in the direction along the spiral direction. be.

The range in which the core 30 contacts the bead seat 23 and/or the hump 25 is 360 degrees or more from one end 30a and 360 degrees or more from the other end 30b when viewed from the axial direction of the tire 10. A range is preferred, and more preferably a range of 360 degrees from one end 30a and a range of 360 degrees from the other end 30b.
As shown in FIG. 1, in the present embodiment, the core 30 includes an inner peripheral surface of a cushioning member 32 provided in a one end side portion 30A within a range of 360 degrees from one end portion 30a, and the other end portion. The inner peripheral surface of the cushioning member 33 provided in the other end portion 30B within a range of 360 degrees from the portion 30b is configured to contact the bead seat 23 and the hump 25 of the rim 20. As shown in FIG. That is, in the present embodiment, the core 30 has a 360-degree range between one end 30a of the core 30 in the spiral direction and the middle portion of the core 30 to which the one end 30a is fixed. 360 degrees between the inner peripheral surface of the buffer member 32 provided in the part and the other end 30b in the spiral direction of the core 30 and the middle part of the core 30 to which the one end 30b is fixed The inner peripheral surface of the cushioning member 33 provided in the range of .theta.
With such a configuration, the fastening structure between one end 30a provided with the cushioning member 32 and the intermediate portion of the core 30 and the fastening structure between the other end 30b provided with the cushioning member 33 and the intermediate portion can be simplified. As a result, the cost of the core 30 or the tire/core/rim assembly 1 can be reduced.

The inner peripheral surfaces of the cushioning member 32 and the cushioning member 33 are stepped. The cushioning member 32 and the cushioning member 33 are positioned between the bead portion 11 and the hump 25 by engaging the hump 25 with the stepped shape.

No cushioning member is provided between the one end portion 30A and the other end portion 30B of the core 30, and the intermediate portion 31C of the helical steel pipe 31 with a predetermined pitch is exposed as an intermediate portion 30C. there is The intermediate portion 30C is not in contact with the rim 20 because no cushioning member is provided.
The length in the spiral direction of the intermediate portion 30</b>C that does not contact the rim 20 is preferably 360 degrees or more and 540 degrees or less when viewed from the axial direction of the tire 10 . As a result, when the one end portion 30a and the other end portion 30b of the core 30 are fixed to the intermediate portion of the core 30, respectively, the intermediate portion 30C can be easily elastically deformed. Fixing work can be easily performed.

As shown in FIG. 1 , the core 30 has a larger diameter than the inner diameter of the bead portion 11 of the tire 10 . In this embodiment, the outer diameter of the core 30 centered on the axis of the tire 10 is maximum at the one end portion 30A and the other end portion 30B where the cushioning members 32 and 33 are provided. The outer diameter at the maximum portion is larger than the rim flange 22 . As a result, during run-flat running, the core 30 contacts the inner peripheral surface of the tread portion 12 of the tire 10 at the outer peripheral surfaces of the one end portion 30A and the other end portion 30B, that is, the outer peripheral surfaces of the cushioning members 32 and 33. As a result, deflection of the tire 10 during run-flat running can be suppressed, and damage to the tire 10 due to deflection can be prevented.
The outer peripheral surfaces of the cushioning member 32 and the cushioning member 33, which face radially outward, are preferably cylindrical, respectively, but when viewed in a cross-section perpendicular to the circumferential direction of the tire 10, they are curved slightly outwardly. A plane is more preferable. As a result, the corners of the cushioning member 32 and the cushioning member 33 come into contact with each other, compared to the case where the outer peripheral surfaces of the cushioning member 32 and the cushioning member 33 facing radially outward about the axis of the tire 10 are angular. The local strong deformation of the tire 10 that occurs as a result can be suppressed, and the durability of the tire 10 can be enhanced.

The cushioning member 32 and the cushioning member 33 have a plurality of rectangular concave portions 32c and 33c extending radially about the axis of the tire 10 on both side surfaces of the tire 10 facing the axial direction. , and only one concave portion is labeled.) may be arranged in the circumferential direction at regular intervals. With such a configuration, the cushioning member 32 and the cushioning member 33 can be made lighter while ensuring a predetermined strength in the radial direction about the axis of the tire 10 .

According to the tire/core/rim assembly 1 or core 30 of the present embodiment having the above configuration, the maximum diameter of the core 30 around the axis of the tire 10 is larger than the inner diameter of the bead portion 11 of the tire 10. Since it is large, the outer peripheral surface of the core 30 contacts the inner peripheral surface of the tread portion 12 of the tire 10 when the internal pressure of the tire 10 is lowered, as shown in FIG. As a result, during run-flat running, the load applied from the vehicle to the tire 10 is supported by the core 30 to suppress deflection of the tire 10, thereby enabling run-flat running while suppressing damage to the tire 10. .

Here, in the tire/core/rim assembly 1 or the core 30 of the present embodiment, one end 30a of the core 30 in the direction along the spiral direction is fixed to an intermediate portion of the core 30, and the core Since the other end 30b in the direction along the spiral direction of the core 30 is fixed to the middle portion of the core 30, even if the core 30 is subjected to centrifugal force during normal high-speed running, the core 30 is 30A and 30B of the rim 20 contacting the bead seat 23 and/or the hump 25 can be prevented from being deformed so as to increase in outer diameter due to the centrifugal force. Therefore, the one end portion 30A and the other end portion 30B of the core 30 contacting the bead seat 23 and/or the hump 25 of the rim 20 climb over the corresponding hump 25, and the core 30 falls off the rim 20. You can prevent it from happening.

Further, in the tire/core/rim assembly 1 or core 30 of the present embodiment, the core 30 has a steel pipe 31 having a spiral shape and cushioning members 32 and 33 covering the outer circumference of the steel pipe 31. With this configuration, even if an impact load is applied to the tire 10 due to, for example, going over a step during run-flat running, the impact load can be absorbed by the elastic deformation of the cushioning members 32 and 33 . As a result, damage to the core 30 can be suppressed even if an impact load is applied to the tire 10 due to, for example, going over a step during run-flat running.
In particular, in the present embodiment, in the entire range of the one end portion 30A and the other end portion 30B that come into contact with the bead seat 23 and/or the hump 25 of the rim 20 of the core 30, the outer circumference of the steel pipe 31 is provided with cushioning members 32, 33. Since the tire 10 is covered with the elastic deformation of the cushioning members 32 and 33, the shock load applied to the tire 10 when going over a step or the like can be absorbed by the elastic deformation of the shock absorbing members 32 and 33. Damage to the core 30 due to the load can be more effectively suppressed.

Further, in the tire/core/rim assembly 1 or core 30 of the present embodiment, the core 30 has a steel pipe 31 having a spiral shape and cushioning members 32 and 33 covering the outer periphery of the steel pipe 31. With this configuration, the rigidity of the core 30 in the axial direction of the tire 10 can be ensured by the high bending and torsional rigidity of the steel pipe 31 . As a result, the core 30 attached to the rim 20 together with the tire 10 generates a large force in the axial direction, thereby preventing the core 30 from coming off the rim 20 .

Further, in the tire/core/rim assembly 1 or core 30 of the present embodiment, the core 30 has a steel pipe 31 having a spiral shape and cushioning members 32 and 33 covering the outer periphery of the steel pipe 31. With this configuration, the core 30 can be easily manufactured, and the cost of the core 30 or the tire/core/rim assembly 1 can be reduced.

Furthermore, in the tire/core/rim assembly 1 or core 30 of the present embodiment, the one end side portion 30A and the other end side portion 30A within a range of 360 degrees from the respective ends 30a and 30b of the spiral core 30 Since the portion 30B is configured to contact the bead seat 23 and/or the hump 25 of the rim 20, during run-flat running, the core is removed from the road surface through the tread portion 12 of the tire 10 over the entire circumference of the tire 10. The load transmitted to 30 can be supported by the rim 20 to improve stability during run-flat running.

Furthermore, in the tire/core/rim assembly 1 or core 30 of this embodiment, as shown in FIG. It has a helical shape with both ends 30a and 30b open in a state where it is not fixed to the middle portion of the tube. Therefore, by inserting the spiral core 30 into the tire 10 from one end 30 a and inserting it along the tire 10 while rotating it in the circumferential direction of the spiral, the inner diameter of the bead portion 11 is increased. The core 30 having a large outer diameter can be easily inserted into the tire 10 . After the core 30 is loaded inside the tire 10 as described above, one end 30a of the core 30 is fixed to the middle portion of the core 30, and the other end 30b is connected to the core. The core 30 having the configuration shown in FIG. Therefore, according to the tire/core/rim assembly 1 or the core 30 of the present embodiment, the core 30 can be easily loaded into the tire 10, and the core 30 can be easily loaded while the vehicle is running. It is possible to prevent the core 30 from being deformed by centrifugal force so as to increase the outer diameter, the deformation causing the core 30 to move from its original position, shifting the center of gravity, and deteriorating the uniformity.

Furthermore, in the tire/core/rim assembly 1 or core 30 of the present embodiment, an intermediate portion 30C that is not in contact with the rim 20 is provided between the one end portion 30A and the other end portion 30B of the core 30. Therefore, the intermediate portion 30C plays the role of a spring that axially supports between the one end portion 30A and the other end portion 30B of the core 30, thereby The portion 30B can be more reliably positioned on the bead seat 23 and/or the hump 25 of the rim 20. As a result, the load transmitted from the road surface to the core 30 via the tread portion 12 of the tire 10 is reliably supported by the rim 20 during run-flat running, thereby enhancing stability during run-flat running. In addition, when the vehicle is running, the core 30 is deformed by centrifugal force so that the outer diameter thereof increases, and the deformation causes the core 30 to move from its original position, thereby shifting the center of gravity and deteriorating uniformity. can be prevented more effectively.

The inner diameter of the steel pipe 31 is preferably larger than the rim diameter of the rim 20 by 62.5 mm or more in the range where the core 30 contacts the rim 20 . Here, the rim diameter of the rim 20 is a rim diameter defined by JATMA, ETRTO, and TRA.
In this embodiment, the inner diameter of the one end portion 31A and the inner diameter of the other end portion 31B of the steel pipe 31 in the one end portion 30A and the other end portion 30B of the core 30 are larger than the rim diameter of the rim 20 by 62.5 mm or more. is preferred.
As described above, in the structure in which the one end 30a and the other end 30b of the core 30 are fixed to the middle portion of the core 30, the one end portion 30A and the other end portion 30B of the core 30 are Since the inner diameter is a constant annular shape, when the core 30 is loaded inside the tire 10 and then the tire 10 is assembled to the rim 20 together with the core 30, the cushioning member 32, 33 must be elastically deformed to the extent that it can ride over the rim flange 22 .
On the other hand, in the range where the core 30 contacts the rim 20, the inner diameter of the steel pipe 31 is made 62.5 mm or more larger than the rim diameter of the rim 20, so that the core 30 is placed inside the tire 10. After loading, when the tire 10 is assembled with the core 30 onto the rim 20, the cushioning members 32, 33 are easily elasticized between the steel tube 31 and the rim 20 by the desired amount necessary to overcome the rim flange 22. It can be transformed. As a result, when the tire 10 is assembled to the rim 20 together with the core 30, the cushioning members 32 and 33 can easily get over the rim flange 22 of the rim 20, and the tire 10 loaded with the core 30 can be mounted. The assembly work to the rim 20 can be made easier.

As shown in FIG. 5, the steel pipe 31 can also be a rectangular steel pipe. In this case, the steel pipe 31 is preferably a rectangular steel pipe with a triangular to hexagonal cross section, but may be a polygonal steel pipe with a hexagonal or higher cross section.
When the core 30 receives a radial load from the tread portion 12 of the tire 10 during run-flat running, the load causes the steel pipe 31 to slide on the cushioning members 32 and 33 in the direction of rotation about its axis. As a result, there is a risk that the cushioning members 32 and 33 will collapse in the axial direction and the core 30 will fall off the rim 20 . On the other hand, the steel pipe 31 is a square steel pipe and is mounted in the mounting grooves 32b and 33b of the cushioning members 32 and 33 having rectangular cross sections, so that the steel pipe 31 is centered on the axis of the cushioning members 32 and 33. It is possible to prevent the core 30 from falling off from the rim 20 due to the cushioning members 32 and 33 falling down in the axial direction. In addition, since the cushioning members 32 and 33 are prevented from collapsing in the axial direction, stability during run-flat running can be enhanced.
By fixing the steel pipe 31 to the cushioning members 32 and 33 by means of adhesion or the like while keeping the steel pipe 31 as a round steel pipe having a circular cross section, the steel pipe 31 can move around its axis with respect to the cushioning members 32 and 33 . It is also possible to adopt a configuration that suppresses the occurrence of slippage in the direction of rotation. This structure also prevents the steel pipe 31 from slipping on the cushioning members 32 and 33 in the direction of rotation about its axis. can be suppressed from falling off from the rim 20.
Further, when the steel pipe 31 is a square steel pipe and is mounted in the mounting grooves 32b, 33b of the cushioning members 32, 33 having square cross sections, the cushioning members 32, 33 are made easy to form uneven portions, so that the cushioning members The joints 32a and 33a of 32 and 33 can be easily fastened.

As shown in FIG. 6, the core 30 has a steel pipe 31 in the range of one end side portion 30A and the other end side portion 30B from each end portion 30a, 30b to a midway portion to which the end portions 30a, 30b are fixed. can be configured such that the entire outer circumference of is covered with cushioning members 32 and 33 . More specifically, the core 30 is such that the one end portion 31A of the steel pipe 31 corresponding to the one end portion 30A of the core 30 is embedded in the cushioning member 32 so that the entire outer circumference of the one end portion 31A is the cushioning member 32. In addition, the other end side portion 31B of the steel pipe 31 corresponding to the other end side portion 30B of the core 30 is embedded inside the buffer member 33, and the outer periphery of the other end side portion 31B is entirely covered with the buffer member 33. can also be configured. With such a configuration, it is possible to prevent the steel pipe 31 from slipping on the core 30 in the direction of rotation about its axis, and to prevent the core 30 from collapsing in the axial direction.
As shown in FIG. 6, the core 30 is placed between the ends 30a, 30b and the steel pipe 31 in the range of the one end side portion 30A and the other end side portion 30B from the respective ends 30a, 30b to the midway portion where the ends 30a, 30b are fixed. When the entire outer circumference is covered with the cushioning members 32 and 33, the steel pipe 31 is preferably a rectangular steel pipe with a square cross section and fixed to the cushioning members 32 and 33 by adhesion. This further effectively suppresses slippage of the steel pipe 31 with respect to the core 30 in the direction of rotation about its axis, and further effectively suppresses the core 30 from collapsing in the axial direction. be able to.

The core 30 is not limited to the structure including the steel pipe 31 and the cushioning members 32, 33. As shown in FIG. A single member made of thermosetting resin, thermoplastic resin, or the like reinforced with any one or a combination of fibers, and formed into a helical shape without cushioning members 32 and 33. can be done.
In this case, a projection 40 is integrally provided at the base end of the one end portion 30A of the core 30, and a locking groove 41 having a shape corresponding to the projection 40 is provided at the tip of the one end portion 30A of the core 30, and the projection By engaging the locking groove 41 with the locking groove 41, one end portion 30a of the core 30 can be fixed to the middle portion of the core 30. As shown in FIG. In this case, one end portion 30a of the core 30 may be fixed to the intermediate portion of the core 30 so as not to move in the circumferential direction about the axis of the tire 10 . Although details are not shown, the other end portion 30B of the core 30 has the same structure as the one end portion 30A, and the other end portion 30b of the core 30 is fixed to the middle portion of the core 30. can be
The core 30 having the structure shown in FIG. 7 is preferably arranged in the well 24 of the rim 20 having a split structure, for example. As a result, the one end portion 30A and the other end portion 30B of the core 30 are supported by the side wall of the well 24 and are restrained from shifting in the axial direction, and the projection 40 is locked in the locking groove 41. can be ensured to remain in place.
In this case, the core 30 has a thick portion 42 in which the axial thickness of the tire 10 gradually increases from one end 30a and the other end 30b to the one end portion 30A and the other end portion 30B. When the protrusion 40 is engaged with the locking groove 41, the surfaces of the one end portion 30A and the other end portion 30B of the core 30 facing the axial direction of the tire 10 become planes perpendicular to the axial direction. It is preferable to As a result, the surfaces of the one end portion 30A and the other end portion 30B of the core 30 facing the axial direction of the tire 10 are effectively supported by the sidewalls of the well 24, and the protrusions 40 are removed from the locking grooves 41. Dropping can be suppressed.

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

For example, in the above embodiment, only the outer peripheries of the one end portion 31A and the other end portion 31B of the steel pipe 31 are covered with the cushioning members 32 and 33, and the middle portion 31C of the steel pipe 31 is not provided with a cushioning member. , if the outer periphery of the steel pipe 31 is covered with the shock absorbing members 32, 33 in the range of contact with the bead seat 23 and/or the hump 25 of the rim 20 of the core 30, for example, the entire steel pipe 31 from one end to the other end The range covered with the buffer member of the steel pipe 31 can be variously changed, for example, by covering with the buffer member.

In addition, the core 30 is a helical member, instead of the steel pipe 31, which is made of SUS, high-tensile steel, aluminum, titanium, carbon, aramid fiber, glass fiber, or a combination thereof. It is also possible to use a helical member formed in a helical shape from resin, thermoplastic resin, or the like, and to cover the outer periphery of this helical member with cushioning members 32 and 33 .

1: tire/core/rim assembly, 10: tire, 11: bead portion, 12: tread portion, 13: sidewall, 20: rim, 21: disc, 22: rim flange, 23: bead seat, 24: well, 25: hump, 30: core, 30A: one end portion, 30a: one end portion, 30B: other end portion, 30b: the other end portion, 30C: intermediate portion, 31: steel pipes 31, 31A: One end portion 31B: Other end portion 31C: Intermediate portion 32: Cushioning members 32, 32a: Abutment 32b: Mounting groove 33: Cushioning members 33, 33a: Abutment 33b: Mounting groove 34: Bracket 35: bolt, 36: connector, 37: bolt, 40: projection, 41: locking groove, 42: thick portion

Claims (6)

A core for run-flat driving, which has a helical shape and is attached to a rim together with the tire and capable of supporting a load applied to the tire from a vehicle during run-flat driving,
A core for run-flat running, wherein each end of said core for run-flat running is fixed to a middle portion of said core for run-flat running. a steel pipe having a spiral shape;
2. The core for run-flat running according to claim 1, further comprising a cushioning member covering an outer periphery of said steel pipe. The run-flat running core according to claim 2, wherein the steel pipe is a rectangular steel pipe. 4. The run-flat running according to claim 2 or 3, wherein the entire outer circumference of the steel pipe is covered with the shock-absorbing member in a range from the end portion to the intermediate portion of each of the cores for run-flat running. Core. The run according to any one of claims 2 to 4, wherein the inner diameter of the steel pipe is 62.5 mm or more larger than the rim diameter of the rim in the range of the core for running flat running that contacts the rim. Core for flat running. A tire/medium comprising the tire, the rim, and the core for run-flat traveling according to any one of claims 1 to 5 attached to the rim together with the tire. child-rim assembly.

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