JP2006290070A - Pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire capable of preventing a bead part from being detached from a rim when air pressure inside the tire is deteriorated by obstacles such as a flat tire, and suitably assembling to a general rim. <P>SOLUTION: This tire comprises a jig mounting part 16 installed on an outer wall 13 positioned outside a rim flange 8a in a tire radial direction, and a locking jig 17 mounted to the jig mounting part 16, projecting outside in the tire width direction and inside in the tire radial direction from an outermost peripheral position E of the rim flange 8a, and locking the rim flange 8a when air pressure inside the tire is lowered. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pneumatic tire capable of preventing a bead portion from coming off the rim when the air pressure inside the tire is reduced due to a failure such as puncture.

  As such a pneumatic tire, the following Patent Document 1 proposes a tire structure shown in FIG. The tire includes an annular bulging portion 30 that bulges outward from the bead portion 1 along the rim flange 8a in the tire width direction. The annular bulging portion 30 has an inner diameter smaller than the outer diameter of the rim flange 8a, and prevents the bead portion 1 from moving inward in the tire width direction when the air pressure inside the tire is reduced. Can produce drag. The same document also discloses a double bead structure in which a second bead different from the bead 1a is arranged on the annular bulging portion 30.

  The countermeasure against rim detachment is particularly important in a run-flat tire that can travel safely over an appropriate distance even in a state where the air pressure inside the tire is lowered due to a failure such as puncture (run-flat state). In particular, in the side support type run flat tire in which the reinforcing rubber layer is arranged on the side wall portion, the amount of deflection of the side wall portion is increased, so that the rim is likely to be detached. A double bead structure is applied to Patent Document 2 below. Examples have been disclosed.

  However, in the tire structure described above, when assembling the rim, it is necessary to pass one bead portion over the well portion of the rim and attach it to the bead seat, and then lift the annular bulge portion outward to get over the rim flange. Therefore, there has been a problem that the rim assembly work becomes very difficult. Such a problem is more remarkable in the double bead structure in which the annular bulge is reinforced by the second bead.

  In Patent Document 3 below, a pneumatic tire is proposed in which a bead portion is fixed to a rim by screwing a screw passed through a rim flange to prevent the rim from coming off. However, in such a tire, a through hole for a screw needs to be provided in the rim flange, and a general rim cannot be used as it is. Also, when assembling the rim, the position of the tire in the circumferential direction must be adjusted in order to align the positions of the screw holes provided in the tire and the through holes provided in the rim flange. There is a problem of complication. Patent Document 4 below also discloses a run-flat tire that can fix the bead portion to the rim, but a special rim is also required.

Patent Document 5 below proposes an instrument that prevents the rim from coming off by pressing the bead portion from the inner side in the tire width direction to the outer side when the air pressure inside the tire decreases. However, such an instrument is inserted into the tire in the middle of assembling the rim and set in the well portion of the rim. Therefore, it is necessary to work in a narrow gap between the bead portion of the tire and the rim flange, and complication of the rim assembling work is inevitable.
Japanese Patent Laid-Open No. 50-82701 JP 51-116507 A JP 11-2117010 A JP 2003-136924 A Japanese Patent Laid-Open No. 7-251613

  The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent the bead portion from coming off from the rim when the air pressure inside the tire is reduced due to a failure such as puncture, and to be suitably assembled to a general rim. It is to provide a pneumatic tire that can be used.

  The above object can be achieved by the present invention having the following configuration. That is, the pneumatic tire according to the present invention includes a pair of bead portions, sidewall portions extending outward in the tire radial direction from the bead portions, and tread portions connecting the tire radial outer ends of the sidewall portions. In a pneumatic tire provided with a jig mounting portion provided on an outer wall located on the outer side in the tire radial direction of the rim flange when a specified rim is mounted, and attached to the jig mounting portion, And a locking jig that protrudes outward in the tire width direction and inward in the tire radial direction and locks to the rim flange when the air pressure inside the tire decreases.

  According to the pneumatic tire of the present invention, when the air pressure inside the tire is lowered and protrudes to the outer side in the tire width direction and the inner side in the tire radial direction from the outermost peripheral position of the rim flange, the locking treatment for locking to the rim flange is performed. By providing the tool, when a failure such as a puncture occurs, the bead portion can be prevented from moving inward in the tire width direction, and rim removal can be effectively prevented. In addition, since the jig mounting part is provided on the outer wall located on the outer side in the tire radial direction of the rim flange, the locking jig can be mounted after the tire rim assembly is completed as usual. The rim assembling work is not complicated. Moreover, it is not necessary to use a special rim as the rim, and a general rim can be suitably used. Here, the specified rim refers to a standard rim determined by JATMA corresponding to the tire size. When the specified rim is mounted, the bead portion of the tire is properly fitted to the bead seat and the rim flange of the specified rim. Refers to the state.

  In the above, it has an inner peripheral side surface that bulges outward in the tire width direction from the bead portion and faces an outer peripheral curved surface of the rim flange, and the outer wall located in the vicinity of the maximum width position of the rim flange. What has an annular bulging part is preferable. Since the outer wall on which the jig mounting portion is provided is positioned in the vicinity of the maximum width position of the rim flange, the locking jig can be formed in a compact manner, and the mounting operation becomes easier. In the present invention, since the locking jig is locked to the rim flange when the air pressure inside the tire is lowered, it is necessary to make the inner diameter of the annular bulge portion smaller than the outer diameter of the rim flange as in the prior art. Absent. As a result, when assembling the rim, it is not necessary to lift the annular bulging portion outward and get over the rim flange, and the rim assembling work is facilitated while ensuring the rim detachment resistance.

  As a preferred embodiment of the pneumatic tire according to the present invention, the jig mounting portion has a plurality of female screw portions provided along the tire circumferential direction, and the female screw portion has a male screw that penetrates the locking jig. By screwing, one in which the locking jig is attached to the jig attaching portion can be mentioned. As a result, the mounting structure of the locking jig with respect to the jig mounting portion can be easily configured, and the locking jig can be mounted uniformly and firmly in the tire circumferential direction, and the rim removal resistance is excellent. Can be secured. According to the above configuration, it is necessary to align the internal thread portion provided in the tire and the external thread that penetrates the locking jig, but it is only necessary to adjust the circumferential position of the locking jig. The assembling work is not complicated. Note that the attachment structure of the locking jig is not limited to this.

  In the above, it is preferable that the locking jig is an annular member having an inner diameter smaller than the outer diameter of the rim flange. According to the above configuration, the locking jig that protrudes inward in the tire radial direction from the outermost peripheral position of the rim flange can be easily configured, and the protruding portion forms an annular shape, and the rim removal resistance is effective. Can be improved. In addition, handling of the locking jig is facilitated, and workability at the time of mounting on the jig mounting portion is improved.

  In the above, it is preferable that the locking jig has a protrusion inscribed in the rim flange in a state where the locking jig is attached to the jig attaching portion. According to the above configuration, when attaching the locking jig to the jig mounting portion, the positioning of the locking jig in the tire radial direction can be performed by inscribing the protrusion to the rim flange. Work becomes easier. Further, when the locking jig is an annular member, the protrusion can be fitted into the rim flange by extending in a ring or substantially ring shape, and the locking jig is temporarily fixed to the rim, Installation work can be performed easily.

  In the above, what is provided with the reinforcement rubber layer which is distribute | arranged to the said sidewall part and suppresses a bending deformation of a tire when the air pressure inside a tire falls is preferable. The tire having such a configuration is a side support type run-flat tire. In the run-flat state, the tire is supported by a reinforcing rubber layer, and run-flat running is possible. In run-flat running, the pressure on the rim of the bead portion is weakened due to a decrease in the air pressure inside the tire and the amount of deflection of the sidewall portion increases, but even in such a state, it can be safely run without causing rim disengagement. There is a need. Therefore, in the side support type run-flat tire, measures against rim detachment are very important, and the present invention having the above-described effects is particularly useful.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a tire meridian cross-sectional view when a specified rim of a pneumatic tire according to the present invention is mounted. In this embodiment, an example of a side support type run-flat tire is shown, but the present invention is not limited to this. FIG. 2 is a cross-sectional view of a main part of a bead portion of the run flat tire shown in FIG.

  The pneumatic tire according to the present invention includes a pair of bead portions 1, a sidewall portion 2 extending from the bead portion 1 outward in the tire radial direction, and a tread portion connecting the tire radial direction outer ends of the sidewall portions 2. 3. In the bead portion 1, for example, an annular bead 1a made of a converging body of bead wires such as steel wires, and a bead filler 1b made of hard rubber having a substantially triangular cross section are arranged on the outer side in the tire radial direction of the bead 1a. Has been. The bead portion 1 is attached to the bead seat 8b of the rim 8, and if the air pressure is normal (for example, the air pressure determined by JATMA), the bead portion 1 is appropriately fitted to the rim flange 8a by the tire internal pressure, and the tire is fitted to the rim 8. Is done.

  The carcass layer 4 is formed of a carcass ply arranged so as to be bridged between the pair of bead portions 1. The carcass ply is composed of ply cords arranged at a predetermined angle with respect to the tire equator line C, and organic fibers such as steel, polyester, rayon, nylon, and aramid are preferably used as the ply cord. The end portion of the carcass ply is wound outward so as to sandwich the bead 1a and the bead filler 1b.

  An inner liner layer 5 for maintaining air pressure is disposed on the inner peripheral side of the carcass layer 4. Further, on the outer peripheral side of the carcass layer 4, a belt layer 6 composed of two belt plies laminated on the inside and outside is arranged to reinforce by the effect. Each belt ply is formed of a steel cord extending at a predetermined angle with respect to the tire equator line C, and the steel cords are arranged so as to cross each other in opposite directions between the plies. The belt ply is not limited to one made of a steel cord, and may be made of an organic fiber such as polyester, rayon, nylon, or aramid. A belt reinforcing layer 7 is disposed on the outer peripheral side of the belt layer 6, and a tread rubber having a tread pattern is disposed on the outer peripheral surface thereof.

  In the sidewall portion 2, a reinforcing rubber layer 9 in which the tire meridian cross section has a substantially crescent shape is disposed. Thereby, when the air pressure inside the tire decreases, the deflection deformation of the tire is suppressed, and run-flat running is possible. The reinforcing rubber layer 9 is made of, for example, rubber having a hardness of 65 to 90 ° according to a JISK6253 durometer hardness test (A type). The reinforcing rubber layer 9 can be applied to any reinforcing rubber layer used in a conventional side support type run-flat tire without any particular limitation such as hardness and thickness. The reinforcing rubber layer 9 is not limited to a single rubber layer, and may be composed of a plurality of rubber layers having different physical properties such as hardness.

  Examples of the raw rubber such as the rubber layer described above include natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), butyl rubber (IIR), and the like. Used in combination with more than one species. These rubbers are reinforced with fillers such as carbon black and silica, and a vulcanizing agent, a vulcanization accelerator, a plasticizer, an anti-aging agent and the like are appropriately blended.

  In the present embodiment, as shown in FIGS. 1 and 2, an annular bulging portion 10 bulging outward from the bead portion 1 in the tire width direction is provided. The annular bulging portion 10 has a substantially trapezoidal cross section and extends annularly along the tire circumferential direction. The annular bulging portion 10 includes an inner peripheral side surface 11 that faces the outer peripheral curved surface of the rim flange 8a, and a reinforcing rubber layer 9. The outer peripheral wall 12 that is gently connected to the outer wall on the outer side in the tire width direction, and the outer wall that is connected to the inner peripheral side surface 11 and the outer peripheral side surface 12 and that is located outside the rim flange 8a in the tire radial direction and in the vicinity of the maximum width position W. 13.

  Nuts 14 having female thread portions are embedded in the annular bulging portion 10 at a plurality of locations at predetermined intervals along the tire circumferential direction. The nut 14 is exposed at the outer wall 13 to form a jig mounting portion 16, and is configured such that a bolt 15 (corresponding to the male screw) penetrating the locking jig 17 can be screwed. The locking jig 17 of the present embodiment is an annular member as shown in FIG. 3, and a jig mounting portion is formed by screwing a bolt 15 penetrating a through hole formed at a location corresponding to a location where the nut 14 is embedded. 16 is attached.

  The inner diameter D1 of the locking jig 17 is set smaller than the outer diameter D2 of the rim flange 8a (the diameter at the outermost peripheral position E of the rim flange 8a). Therefore, the locking jig 17 attached to the jig attaching portion 16 protrudes outward in the tire width direction and inward in the tire radial direction from the outermost peripheral position E of the rim flange 8a. When the air pressure inside the tire decreases due to a failure such as puncture, the locking jig 17 is locked to the rim flange 8a to prevent the bead portion 1 from moving inward in the tire width direction, so that the rim is effectively removed. Can be prevented.

  The material of the locking jig 17 is not particularly limited as long as it has mechanical strength and rigidity that can be locked to the rim flange 8a to ensure rim removal resistance. For example, metal, FRP, It can be composed of hard rubber or the like. By constituting the locking jig 17 with a rigid material, it is possible to exhibit a rim removal resistance equal to or higher than that of a tire having an annular bulging portion 30 as shown in FIG. 7 or a tire having a double bead structure. it can.

  The inner diameter D3 of the annular bulging portion 10 is preferably equal to or greater than the outer diameter D2 of the rim flange 8a. This eliminates the need to lift the annular bulging portion 10 outward and ride over the rim flange 8a when assembling the rim of the tire, thus facilitating rim assembling work. In such a case, the jig mounting portion 16 is positioned on the outer side in the tire radial direction from the outermost peripheral position E of the rim flange 8a, but the locking jig 17 protrudes on the inner side in the tire radial direction from the outermost peripheral position E as described above. By doing so, the rim removal resistance is secured.

  The locking jig 17 may be attached to the outer walls on both sides in the tire width direction, but may be attached to at least one of the outer walls, and at least attached to the vehicle outer side when the vehicle is mounted. preferable. When high-speed turning is performed during run-flat traveling, lateral force due to centrifugal force acts on the vehicle, and the bead portion 1 located on the outside of the vehicle easily disengages inside the tire width direction beyond the hump 8c of the rim 8. Therefore, by attaching the locking jig 17 to at least the vehicle outer side, it is possible to ensure rim removal resistance. Similarly, the annular bulging portion 10 may be formed on the outer side in the tire width direction of the bead portions 1 on both sides, but may be formed on at least one side, and at least on the side that becomes the vehicle outer side when the vehicle is mounted. What is formed is preferable.

[Another embodiment]
(1) FIG. 4 is a cross-sectional view of an essential part showing a locking jig of a different form from the above-described embodiment. The locking jig 18 is provided with a protrusion 19 projecting inward in the tire width direction on the inner peripheral side. The protrusion 19 is designed to be inscribed in the rim flange 8 a in a state where the locking jig 18 is attached to the jig mounting portion 16, and when the locking jig 18 is attached to the jig mounting portion 16. The protrusion 19 is inscribed in the rim flange 8a, whereby the locking jig 18 can be positioned in the tire radial direction. Further, the protrusion 19 is preferably extended in the circumferential direction. When the protrusion 19 extends in a ring shape or a substantially ring shape, the protrusion 19 can be fitted into the rim flange 8a. Thereby, the locking jig 18 can be temporarily fixed to the rim 8, and the mounting operation of the locking jig 18 becomes easier.

  (2) The locking jig is not limited to a single annular member as in the above-described embodiment, and may be composed of a plurality of members, such as the locking jig 20 shown in FIG. . Further, if the locking jig is attached to the jig mounting portion and protrudes to the outer side in the tire width direction and the inner side in the tire radial direction from the outermost peripheral position E of the rim flange 8a, the locking jig is arranged in the tire circumferential direction. For example, a locking jig having a circular shape in plan view may be attached to a plurality of locations along the tire circumferential direction. In any of the above cases, it is preferable that the projections as described above are formed, whereby positioning in the tire radial direction can be easily performed.

  (3) In the above-described embodiment, the example in which the locking jig 17 is attached to the jig mounting portion 16 by screwing the bolt 15 penetrating the locking jig 17 to the nut 14 has been shown. The attachment structure of the locking jig in the present invention is not limited to this. For example, in the annular bulging portion 10 shown in FIG. 6, a hard member 25 having an engagement recess 24 is embedded to constitute a jig mounting portion 22, and the engagement recess 24 is formed by the locking jig 21. The engaging convex part 23 formed integrally with is configured to be engageable. According to such a configuration, the engaging jig 21 can be easily attached with one touch by inserting the engaging convex portion 23 into the engaging concave portion 24. These male and female relationships (concave / convex relationship) may be reversed. In the present invention, in the attachment structure of the locking jig, a snap fit, a gusset mechanism, fixation by a male / female pin or the like, adhesion by an adhesive or an adhesive tape, or the like may be used, or they may be used in combination. .

  (4) The annular bulging portion 10 is not limited to the shape shown in the present embodiment. For example, the tire meridian cross section may be a semicircular shape or a triangular shape. However, it is preferable to have a substantially trapezoidal cross section because it is easy to provide the jig mounting portion. Further, the inner peripheral side surface 11 of the annular bulging portion 10 may be separated from the outer peripheral curved surface of the rim flange 8a.

Tire meridian cross-sectional view of the pneumatic tire according to the present invention when the specified rim is mounted Cross section of the main part of the bead Top view of locking jig Sectional drawing of the principal part of the bead part which concerns on another form of this invention. The top view of the latching jig which concerns on another form of this invention Sectional drawing of the principal part of the bead part which concerns on another form of this invention. Cross section of the tire meridian of a conventional pneumatic tire

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bead part 2 Side wall part 3 Tread part 8 Rim 8a Rim flange 9 Reinforcement rubber layer 10 Annular bulging part 11 Inner peripheral side face 13 Outer side wall 14 Nut 15 Bolt 16 Jig attachment part 17 Locking jig 18 Locking jig 19 Protrusions 21 Locking jig 22 Jig mounting part 23 Engaging convex part 24 Engaging concave part 25 Hard member D1 Inner diameter D2 of locking jig D3 outer diameter of rim flange D3 Inner diameter of annular bulge E Outermost circumference of rim flange Position W Maximum rim flange position

Claims (6)

In a pneumatic tire comprising a pair of bead portions, sidewall portions extending outward in the tire radial direction from the bead portions, and tread portions connecting the respective tire radial direction outer ends of the sidewall portions,
A jig mounting portion provided on an outer wall located on the outer side in the tire radial direction of the rim flange when the specified rim is mounted;
A locking jig that is attached to the jig mounting portion and projects to the outer side in the tire width direction and the inner side in the tire radial direction than the outermost peripheral position of the rim flange, and locks to the rim flange when the air pressure inside the tire decreases. And a pneumatic tire.   An annular bulge having an inner peripheral side surface that bulges outward in the tire width direction from the bead portion and faces an outer peripheral side curved surface of the rim flange, and the outer wall located near the maximum width position of the rim flange. The pneumatic tire according to claim 1, further comprising a portion. The jig mounting portion has a plurality of female screw portions provided along the tire circumferential direction,
The pneumatic tire according to claim 1, wherein the locking jig is attached to the jig mounting portion by screwing a male screw that penetrates the locking jig with the female screw portion.   The pneumatic tire according to any one of claims 1 to 3, wherein the locking jig is an annular member having an inner diameter smaller than an outer diameter of the rim flange.   The pneumatic tire according to any one of claims 1 to 4, wherein the locking jig has a protrusion inscribed in the rim flange in a state where the locking jig is attached to the jig attaching portion.   The pneumatic tire according to any one of claims 1 to 5, further comprising a reinforcing rubber layer that is disposed in the sidewall portion and suppresses deformation of the tire when an air pressure inside the tire decreases.

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