JP2006327378A - Run flat tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a side reinforcing type run flat tire in which occurrence of deformation or the like of a tire to affect damages or the like of a reinforced portion can be recognized from the outside of the tire. <P>SOLUTION: The run flat tire 100 has a reinforcing rubber layer 7 on the inner side of a side wall part 3 on a side face of the tire 100, and a load detection member 8 is arranged on the surface of the side wall part 3. The load detection member 8 generates irreversible changes such as deformation and discoloration when the predetermined vertical load (to be set as the vertical load to cause deformation of the tire 100 to possibly damage the reinforcing rubber layer 7) occurs. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a run-flat tire that enables safe driving even when the tire internal pressure decreases due to puncture or the like, and among them, a side-reinforcement type run-flat having a reinforcing member on a sidewall portion that is a side surface of the tire. Regarding tires.

  Run-flat tires that can continue to run safely even when the tire internal pressure decreases due to puncture or the like have been put into practical use. Such run-flat tires can run for a certain distance without having to change the tires in the event of a puncture, etc., and also eliminate the need for spare tires. The effect that the effective use of the luggage space in a car can be aimed at is also acquired.

  Such run-flat tires are roughly classified into two types of run-flat tires. One type is that a reinforcing member is provided in the sidewall portion of the tire, and even when the tire internal pressure is reduced, the reinforcing member can receive a vehicle load so that the tire can run without being flattened ( For example, see Patent Document 1). In the other type, a reinforcing member is disposed on the nesting in the tire, and when the tire internal pressure decreases, the nesting portion receives a vehicle load.

The run-flat tire described in Patent Document 1 has a position where the tread portion reinforcing layer and the side reinforcing layer are joined to a position different from the tire groove in order to improve durability during run-flat running. It is described that the buckling phenomenon of the tread portion is prevented.
JP2003-31218A

  In this type of side-reinforced run-flat tire, the inside of the sidewall portion is hard to ensure rigidity. For this reason, when an external force acts on a tire and it deform | transforms greatly, a reinforcement part may be damaged and it may peel from a sidewall part main body. When such peeling occurs, the rigidity becomes insufficient during run-flat running, and desired running characteristics cannot be obtained. However, such a breakage of the reinforcing portion cannot be recognized from the outside, and is not known until the run-flat running is actually performed.

  Therefore, an object of the present invention is to provide a side-reinforcement type run-flat tire that can recognize from the outside of the tire that a deformation or the like of the tire that affects the damage or the like of the reinforcing portion has occurred.

  In order to solve the above problems, a side-reinforcing run-flat tire according to the present invention is disposed inside a sidewall portion of a tire side surface portion, a reinforcing member that imparts rigidity to the sidewall portion, and a sidewall portion And a load detection member that is disposed on the outer surface and changes irreversibly depending on the load in the vertical direction of the tire.

  Deformation that leads to insufficient rigidity, such as the reinforcing member placed inside the tire sidewall peeling off from the sidewall section main body or its adhesiveness being reduced, is caused by the vertical load of the tire acting in a different way than usual. Occurs when the tire is deformed. By arranging a load detection member that changes irreversibly (including deformation such as detachment, breakage, hardening, etc.) due to the load in the vertical direction of the tire, the vertical direction of the tire that causes deformation that leads to insufficient rigidity When a load is generated, a predetermined change occurs in the load detection member at the same time, and then the load detection member remains unchanged even when the vertical load is removed and the tire itself returns from the deformed state to the original state. .

  According to the present invention, it is possible to determine whether or not a load in the vertical direction of the tire that causes deformation that leads to insufficient rigidity is generated based on whether or not the load detection member is changed. For this reason, the possibility of damage to the reinforcing member can be determined from the outside, and the run flat effect can be surely exhibited during run flat travel. Further, even when the run-flat tire is reused after the run-flat running, the possibility of damage to the reinforcing member can be determined from the outside, so that only an undamaged tire can be reused.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same reference numerals are given to the same components in the drawings as much as possible, and duplicate descriptions are omitted.

  FIG. 1 shows a cross-sectional structure of a run flat tire according to the present invention. In the run flat tire 100, a portion in contact with the road surface is referred to as a tread portion 1, and a shoulder portion 2, a sidewall portion 3, and a bead portion 4 are successively formed on the side thereof.

  A bead wire 41 made of steel wire or the like is embedded in the bead portion 4. The bead wire 41 fixes the tire 100 to the wheel rim.

  In the tire 100, a carcass 5 made by knitting fibers in a form of folding outward and sandwiching the bead wire 41 on both sides is disposed. Further, an inner liner 6 that is a thin rubber layer for preventing leakage of air in the tire 100 is formed on the inner peripheral portion of the tire 100.

  Between the rubber part forming the tire outer periphery of the tread part 1 and the carcass 5, belt layers 11 and 12 made of knitted steel wires extend, and in the shoulder part 2 a fiber reinforcing layer 21 extends. is doing. A reinforcing rubber layer 7 is disposed between the carcass 5 and the inner liner 6 on the side surface portion of the tire 100 from the shoulder portion 2 to the bead portion 4 (a region including the inside of the sidewall portion 3). When the tire air pressure decreases, the reinforcing rubber layer 7 receives the vehicle load and suppresses deformation of the tire 100, thereby preventing the tire 100 from being completely crushed by the vehicle load and maintaining its running performance. That is, it is a so-called side reinforcing type run flat tire.

  Grooves 13 are formed on the surface of the tread portion 1 by a predetermined tread pattern. A load detection member 8 is disposed on the surface of the sidewall portion 3. The load detection member 8 is formed of, for example, rubber, resin, or the like, and is affixed on the surface or embedded in a groove formed on the surface. When the load detection member 8 is attached to the tire 100 and a predetermined vertical load is applied to the tire 100, the load is applied and deformed so that a predetermined irreversible change occurs. A member is selected. Examples of this change include detachment and peeling from the tire 100, breakage, cracking, and hardening of the member itself, and discoloration. The predetermined vertical load means that the tire 100 may be deformed to such an extent that the reinforcing rubber layer 7 is peeled off from the carcass 5 of the sidewall portion 3 due to the deformation of the tire accompanying the vertical load, or the tire itself is damaged. It is set as a vertical load with

  Note that the load detection member 8 is disposed at a position where damage due to disturbances other than the vertical load can be suppressed during normal traveling, for example, a position on the rim side when attached to the vehicle. Is preferred.

  According to the tire 100, when a load in the vertical direction is applied to the tire 100 so that the inner reinforcing rubber layer 7 may be damaged or peeled off, the load detection member 8 has a predetermined change. The change will remain even after the vertical load is removed. For this reason, the presence or absence of the possibility of damage to the reinforcing rubber layer 7 can be determined from the presence or absence of a change in the load detection member 8. Since the load detection member 8 is disposed at a position that is visually recognizable from the outside of the tire 100 on the surface of the sidewall portion 3, the reinforcing rubber layer 7 can be damaged without removing the tire 100 from the vehicle. The sex can be judged visually.

  As a result, the presence or absence of the run-flat function can be visually recognized from the outside, so that the run-flat tire that has lost its function is not left attached to the vehicle without knowing it, and the safety during run-flat is also improved. improves. In addition, even after run-flat driving, the presence or absence of functional loss can be visually recognized from the outside, so it is easy to determine whether or not it can be repaired and reused. Further resource saving can be realized.

1 is a cross-sectional structure diagram showing a first embodiment of a run-flat tire according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Tread part, 2 ... Shoulder part, 3 ... Side wall part, 4 ... Bead part, 5 ... Carcass, 6 ... Inner liner, 7 ... Reinforcement rubber layer, 8 ... Load detection member, 11 ... Belt layer, 13 ... Groove , 21 ... fiber reinforcing layer, 41 ... bead wire, 100 ... run-flat tire.

Claims (1)

A reinforcing member disposed inside the sidewall portion of the tire side surface portion and imparting rigidity to the sidewall portion;
A load detection member disposed on the outer surface of the sidewall portion, and irreversibly changes depending on the vertical load of the tire;
A run-flat tire characterized by comprising:

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