JP2008001160A - Supporting element, pneumatic run-flat tire, and tire/rim assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a tire bead portion hard to separate from a rim during run-flat traveling. <P>SOLUTION: A bead retaining portion 28B projecting out to tire axial direction outside is provided on a leg portion 28 of a supporting element 12. During run-flat traveling, a load of the supporting element 12 is acted to radially inside, and the bead retaining portion 28B presses the bead portion 25 on a bead seat 16B. Therefore, the bead portion 25 becomes hard to separate from the rim 16. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, when a tire is punctured, a support disposed inside the tire, a pneumatic run-flat tire paired with the support, and a support used as a rim so that the vehicle can travel a considerable distance in the state. The present invention relates to a mounted tire / rim assembly.

  As a tire / rim assembly (so-called run-flat tire) that can run in a flat manner, that is, even if the tire internal pressure becomes 0 kPa due to puncture or the like, the tire / rim assembly can be run with a certain distance. A core type is known in which a core (support) made of metal or synthetic resin is attached to the rim. This core type has a rotating core type incorporated in the rim, and one or two convex portions formed of a metal plate or the like that supports the tread portion of the tire during run flat running in a tire radial cross section attached to the rim. A core type having a shape (double mountain shape) is known (for example, see Patent Documents 1 and 2).

However, the rotating core type has a problem in versatility in that a special wheel for fixing the rotating core is required.
On the other hand, the latter core type having one or two protrusions is provided with rubber legs at both ends of the support, and these legs can be attached to a conventional rim together with the tire bead. Therefore, there is an advantage of high versatility. In this core type, the leg portion is disposed so as to contact the inside of the bead portion of the tire and ride on the hump portion of the rim.
Japanese Patent Laid-Open No. 10-297226. Japanese Patent Application Laid-Open No. 2004-50003.

  By the way, in the run-flat running with the tire internal pressure of 0 kPa, the tire bead receives a force in the direction in which the tire bead portion falls into the rim drop (force inward in the tire axial direction) due to tire deflection. Therefore, in order to prevent the tire bead portion from coming off the rim and to support the tire bead portion during run-flat running, the support body needs to ensure sufficient rigidity in the tire axial direction.

Conventionally, since the leg width (dimension in the tire axial direction) is simply widened to increase the rigidity of the leg portion, there is a problem that the rim assemblability deteriorates (a large force is required when assembling the rim) and support. There were problems such as plastic deformation of the body.
The present invention has been made to solve the above problems, and has an object to make it difficult for the tire bead portion to come off the rim during run-flat running.

  According to the first aspect of the present invention, an annular support portion that is disposed inside the tire and receives a load during run-flat travel, and is disposed on both sides in the axial direction of the support portion and is disposed on the inner side in the tire axial direction of the tire bead portion. A support having an annular leg portion made of an elastic body assembled to a rim together with a tire bead portion, wherein the leg portion protrudes outward in a tire axial direction, and a part of the tire bead portion is a bead seat of the rim. It has the projection part pinched | interposed between, It is characterized by the above-mentioned.

Next, the operation of the support according to claim 1 will be described.
When the support body according to claim 1 is inserted into a pneumatic tire and attached to a rim, the protrusion of the leg portion sandwiches a part of the tire bead portion with the bead seat of the rim, so that the run flat The tire bead portion is difficult to come off during running. Further, since the tire bead portion is difficult to be detached from the rim, it is not necessary to increase the rigidity of the support body in order to prevent the tire bead portion from coming off the rim, and the support body is easily deformed when the rim is assembled. .

  The invention according to claim 2 is characterized in that, in the support body according to claim 1, the projection is located on the outer side in the tire radial direction of the bead core embedded in the tire bead.

Next, the operation of the support according to claim 2 will be described.
In the tire bead portion, the bead core is formed of a metal wire with high rigidity. The support force of the part is improved.

  According to a third aspect of the present invention, in the support according to the first or second aspect, the support portion has an extending portion positioned on the outer side in the tire radial direction of the bead core embedded in the tire bead portion. It is characterized by that.

Next, the operation of the support according to claim 3 will be described.
In the tire bead portion, the bead core is formed of a metal wire having high rigidity. Therefore, a support portion having rigidity higher than that of the elastic body in which the embedded portion of the bead core is disposed on the outer side in the tire radial direction is directed to the bead seat side. By holding down, the supporting force of the tire bead portion is further improved.

  According to a fourth aspect of the present invention, in the support body according to any one of the first to third aspects, one leg portion disposed on a side closer to the drop portion of the rim is separated from the drop portion. The bending rigidity in the axial direction is set to be lower than that of the other leg portion arranged on the far side.

Next, the operation of the support according to claim 4 will be described.
The drop portion of the rim is formed on one side (toward the outside in the vehicle width direction when the vehicle is mounted) with respect to the center in the width direction of the rim.
When mounting the support body and pneumatic tire on the rim, first, the support body is inserted into the pneumatic tire, and then the legs of the support body and the pneumatic body are processed in the same process as a normal rim assembly. Attach the bead part of the tire to the bead seat part of the rim.

In a general rim assembly, first, the rim is placed horizontally with the drop part on the upper side, then the pneumatic tire and the support are inclined, and the lower bead part and the leg part have the upper rim flange. The lower bead part and leg part are sequentially pushed downward in the circumferential direction so as to get over.
Next, the upper bead portion and the leg portion are sequentially pushed downward in the circumferential direction so that the upper bead portion and the leg portion ride over the upper rim flange. Since the bending rigidity in the axial direction is set lower than that of the other leg, it is easy to deform in the axial direction, and less force is required when pushing the bead and leg close to the drop part. Improves.

  The invention according to claim 5 is characterized in that, in the support body according to claim 4, the one leg portion and the other leg portion have the same radial rigidity. .

Next, the operation of the support according to claim 5 will be described.
By setting the rigidity of one leg and the rigidity of the other leg to be the same, the left and right of the tread can be supported in a well-balanced manner during run-flat running.

  A sixth aspect of the present invention is a pneumatic run flat tire mounted on a rim together with the support body according to any one of the first to fifth aspects, wherein the support body is provided at a tire bead portion. At the same time, a step portion that contacts the inner surface in the tire radial direction of the protrusion when formed on the rim is formed.

Next, the operation of the pneumatic run-flat tire according to claim 6 will be described.
In a normal pneumatic tire, the inner surface of the tire bead portion forms a smooth curve inclined with respect to the tire radial direction when viewed in a cross section along the rotation axis.
On the other hand, in the pneumatic run flat tire according to claim 6, a step portion is formed on the inner surface of the tire bead portion, and when the tire is mounted on the rim together with the support portion, the leg of the support portion is attached to the step portion. The protrusion formed on the portion is easily hooked, and the support of the tire bead portion is improved in comparison with the normal pneumatic tire.

  The tire / rim assembly according to claim 7 is provided by mounting the support according to any one of claims 1 to 5 and the pneumatic run-flat tire according to claim 6 on a rim. It is characterized by that.

Next, the operation of the tire / rim assembly according to claim 7 will be described.
By attaching the support according to any one of claims 1 to 5 and the pneumatic run-flat tire according to claim 6 to a rim, the protrusion of the leg portion is one of the tire bead portions. The tire bead portion is not easily detached from the rim during run-flat running. Further, since the tire bead portion is difficult to be detached from the rim, it is not necessary to increase the rigidity of the support body in order to prevent the tire bead portion from coming off the rim, and the support body is easily deformed when the rim is assembled. .

  As described above, according to the support of the present invention, the tire bead portion can be made difficult to come off from the rim during the run-flat running.

  According to the pneumatic tire of the present invention, it is possible to make it difficult for the tire bead portion to come off from the rim during run-flat traveling by being assembled to the rim together with the support body according to any one of claims 1 to 5. , Has an excellent effect.

  Moreover, according to the tire / rim assembly of the present invention, there is an excellent effect that the tire bead portion is not easily detached from the rim during run-flat running.

[First Embodiment]
A tire / rim assembly 10 according to a first embodiment of the present invention will be described with reference to the drawings. Here, the tire / rim assembly 10 shown in FIG. 1 is for a passenger car, and a support 12 and a pneumatic tire 14 are assembled to a rim 16 such as JATMA standard corresponding to the pneumatic tire 14.
In FIG. 1, reference numeral 16A is a flange, reference numeral 16B is a bead sheet, reference numeral 16C is a hump portion, and reference numeral 16D is a drop portion.

  The pneumatic tire 14 according to the embodiment includes a pair of bead cores 18, a toroidal carcass 20 extending over both bead cores 18, and a plurality of (two in this embodiment) belts positioned at the crown portion of the carcass 20. A layer 22 is provided, and a rubber layer is disposed outside the carcass 20. As is well known, the rubber layer disposed on the outer side of the carcass 20 is selected and used for each part such as the tread part 23, the side part 24, and the bead part 25.

The pneumatic tire 14 of this embodiment is different from a normal tire only in the shape of a bead portion 25 described later, and the other is formed based on a standard such as JATMA.
The bead portion 25 is bent in the vicinity of the flange 16A of the rim 16, and a step portion 30 is formed on the tire inner surface side. The step portion 30 is located outside the bead base portion 25A of the bead portion 25 in the tire radial direction. Note that the stepped portion 30 is preferably close to being parallel to the tire rotation axis.

(Support)
As shown in FIG. 1, the annular support body 12 is provided with an annular support portion 26. The support part 26 of this embodiment is formed from a cylindrical metal plate. The support portion 26 is formed with a plurality (two in the present embodiment) of enlarged diameter portions 26A and 26B that are spaced apart from each other in the central portion in the axial direction, and a concave portion 26C that is convex radially inward is formed therebetween. Has been. The side surface opposite to the enlarged diameter portion 26B as viewed from the enlarged diameter portion 26A and the side surface opposite to the enlarged diameter portion 26A as viewed from the enlarged diameter portion 26B are side portions 26D and 26E extended radially inward. It has become. Further, flange portions 26F and 26G extending in the axial direction are formed in the radially inner portions of the side portions 26D and 26E, respectively.

  On both sides in the axial direction of the support portion 26, leg portions 28 formed of an elastomer as an elastic body are provided. The leg portion 28 includes a main body portion 28A that is disposed inside the bead portion 25 and extends in the radial direction. A bead presser portion 28B that protrudes outward in the tire axial direction is provided on the outer end side of the main body portion 28A in the tire radial direction. It is provided integrally with the portion 28A.

The outer surface in the tire axial direction of the main body portion 28A and the inner surface in the tire radial direction of the bead holding portion 28B are formed in a shape along the inner surface (including the stepped portion 30) of the bead portion 25. Are in close contact with the inner surface (including the stepped portion 30).
The bead holding portion 28B is formed so as to be located outside the bead core 18 in the tire radial direction and span the entire width of the stepped portion 30, and flange portions 26F and 26G are embedded in the bead holding portion 28B. In addition, the flange portions F and 26G have a constant width portion located at least on the outer side in the tire radial direction of the bead core 18 from the tip.

(Function)
First, the assembly procedure of the tire / rim assembly 10 will be briefly described.
First, a lubricant is applied to the inner peripheral surface (the back side of the tread portion) of the pneumatic tire 14 to suppress wear when contacting the support 12.

Next, the support body 12 is disposed inside the pneumatic tire 14 to be in a semi-assy state.
In the semi-assy state, the inner surface side of the bead portion 25 (the portion radially inward from the step portion 30) is supported by the leg portion 28 of the support body 12 provided with the bead pressing portion 28B. The support 12 does not move in the tire even when it is fixed to the tire 14 and is shaken by transportation or the like.

  Further, during transportation, the outer peripheral surface of the support 12 does not come into contact with the lubricant applied to the inner surface of the pneumatic tire 14, and rotation imbalance occurs due to the uneven adhesion of the lubricant. Absent. Therefore, it is not necessary to attach a member for fixing the support 12 to the pneumatic tire 14 during transportation, and workability is good.

The semi-assembled pneumatic tire 14 and the support 12 are assembled to the rim 16 as follows using a rim assembling machine or the like, and the tire / rim assembly 10 as shown in FIG. can get.
In the rim assembly, first, the rim 16 is horizontally arranged with the drop portion 16D on the upper side, then the semi-assy pneumatic tire 14 and the support body 12 are inclined, and the lower bead portion 25 and the leg portion 28 are provided. The lower bead portion and the leg portion are sequentially pushed downward in the circumferential direction so as to get over the upper rim flange.
Next, the upper bead portion 25 and the leg portion 28 are sequentially pushed downward in the circumferential direction so that the upper bead portion and the leg portion get over the upper flange 16A.

  Further, the pneumatic tire 14 and the support 12 in the semi-assy state are in a state in which the leg portion 28 is in close contact with the bead toe from the step portion 30 of the bead portion 25 and is fixed to the bead portion 25. The leg portion 28 and the bead portion 25 are not displaced when being pushed into the rim, and the rim assembly property is improved.

In the tire / rim assembly 10 obtained in this way, a part of the bead portion 25, that is, a portion between the step portion 30 and the bead base portion 25A in the bead portion 25 is connected to the bead holding portion 28B of the leg portion 28. It is in a state of being sandwiched between the bead sheets 16B.
Thereafter, the tire / rim assembly 10 is filled with air and mounted on the automobile.

When the tire / rim assembly 10 is punctured or the like and the internal pressure is reduced, the back side of the tread portion 23 comes into contact with the support portion 26 of the support 12 to support the load, thereby enabling run-flat running.
During run-flat travel, the load of the support 12 acts radially inward, and the bead pressing portion 28B presses the bead portion 25 against the radially inner bead seat 16B, so that the bead portion 25 is difficult to come off the rim 16.

  As described above, since the bead portion 25 is difficult to be detached from the rim, it is not necessary to increase the rigidity of the support 12 in order to prevent the bead portion 25 from coming off, and the support 12 can be easily deformed when the rim is assembled. Becomes easier.

  Further, in the pneumatic tire 14 of the present embodiment, a step portion 30 that is substantially parallel to the axial direction is formed on the inner surface of the bead portion 25, and the bead pressing portion 28 </ b> B is formed with respect to the step portion 30. Therefore, a force that shifts the bead portion 25 in the axial direction is not generated, and the supportability of the bead portion 25 is good during run-flat travel.

  Further, since the flange portions 26F and 26G of the support portion 26 formed of a metal plate are disposed on the outer side in the radial direction of the bead core 18, the bead portion 25 is simply pressed rather than pressed by the elastomer portion of the leg portion 28. Supportability is good.

[Second Embodiment]
A tire / rim assembly 10 according to a second embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description is abbreviate | omitted.
As shown in FIG. 2, in the support body 12 of this embodiment, the diameter of the flange part 26F on the side close to the drop part 16D is set larger than the diameter of the flange part 26G on the opposite side.

The inner diameter of the leg portion 28 is set to be the same on the left and right, and the dimension in the radial direction of the leg portion 28 fixed to the flange portion 26F near the drop portion 16D is the leg portion fixed to the flange portion 26G on the opposite side. The bending rigidity in the axial direction of the leg portion 28 having a long radial dimension fixed to the flange portion 26F close to the drop portion 16D is set to be longer than the radial dimension of the diameter portion 28. It is set to be lower than the bending rigidity in the axial direction of the leg portion 28 having a short directional dimension. In order to support the left and right sides of the tread portion 23 in a well-balanced manner during run flat running, The radial rigidity and the radial rigidity of the opposite leg portion 28 are set to be the same.

(Function)
In order to obtain the tire / rim assembly 10 using the support body 12 of the present embodiment, the rim assembly is performed as described in the first embodiment with the legs 28 having a long radial dimension on the upper side.
Here, the upper bead part 25 and the leg part 28 are sequentially pushed downward in the circumferential direction so that the upper bead part 25 and the leg part 28 get over the upper flange 16A. Since the bending rigidity in the axial direction is set lower than that of the lower leg portion 28, it is easy to be deformed in the axial direction, and less force is required to push the bead portion 25 and the leg portion 28 that are attached last, and the rim Assemblability improves.

  In the present embodiment, the radial dimensions of the leg portions 28 are changed on the left and right sides in order to make the left and right leg portions 28 have different axial rigidity. However, the axial stiffness is changed by changing the hardness of the elastomer. Also good. At this time, it is preferable to set the shape of each leg 28 so that the radial rigidity is the same between the left and right legs 28.

1 is a cross-sectional view of a tire / rim assembly according to a first embodiment. It is sectional drawing of the tire and rim assembly which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Tire / rim assembly 12 Support body 14 Pneumatic tire 16 Rim 16B Bead sheet 16D Drop part 18 Bead core 25 Bead part 28 Leg part 28B Bead presser part

Claims (7)

An annular support portion that is disposed inside the tire and receives a load during run-flat traveling, and an elasticity that is provided on both sides in the axial direction of the tire bead portion and mounted on the rim together with the tire bead portion. A support having an annular leg formed of a body,
The said leg part protrudes to a tire axial direction outer side, and has a projection part which clamps a part of said tire bead part between the bead seats of the said rim | limb, The support body characterized by the above-mentioned.   The support according to claim 1, wherein the protrusion is located on the outer side in the tire radial direction of a bead core embedded in the tire bead.   3. The support according to claim 1, wherein the support part has an extending part located on a tire radial direction outer side of a bead core embedded in the tire bead part. 4.   One leg portion disposed on the side of the rim close to the drop portion has a lower bending rigidity in the axial direction than the other leg portion disposed on the side far from the drop portion. The support according to any one of claims 1 to 3.   The support according to claim 4, wherein the one leg and the other leg are set to have the same radial rigidity. A pneumatic run flat tire mounted on a rim together with the support body according to any one of claims 1 to 5,
A pneumatic run-flat tire characterized in that a tire bead portion is formed with a step portion that comes into contact with the inner surface in the tire radial direction of the protrusion when mounted on a rim together with the support.   A tire / rim assembly, comprising: a support body according to any one of claims 1 to 5; and a pneumatic run-flat tire according to claim 6 mounted on a rim.

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