JP2006082587A - Core, and tire-rim-core assembly having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core capable of realizing excellent tire balance without increasing the weight and the cost, and a tire-rim-core assembly having the same. <P>SOLUTION: The tire-rim-core assembly 10 has a core 16 assembled to a rim 12. The core 16 has a supporting part 26 to support the load. The supporting part 26 has at least one projecting part 30 which is protruded outwardly in the tire radial direction and abutted on a tread back face 24B side in a run-flat traveling mode. Lubricant 32 is arranged on the inner side of the projecting part 30 in the tire radial direction. A plurality of through holes are formed in the projecting part 30, from which the lubricant 32 leaks outwardly in the tire radial direction from a supporting surface 20S side by the centrifugal force. The opening dimension of the through holes is set according to the viscosity of the lubricant 32. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a core for enabling run-flat running and a tire / rim / core assembly including the same.

  A tire / rim / core assembly including a rim, a core assembled to the rim, and a pneumatic tire is useful for run-flat running during emergency running such as puncture. In such a tire / rim / core assembly, there are many examples in which an annular member is assembled to the rim as seen from the direction of the tire rotation axis. The core is formed with a support portion that abuts and supports the back side of the tread during run-flat travel. The core is often made of metal or synthetic resin.

  In such a core, a support portion that supports a load by contacting the back side of the tread during run-flat travel is formed.

  By the way, in such a tire / rim / core assembly, during the run-flat running, the load on the tread portion supported by the support portion is large, and in many cases, it becomes impossible to run due to damage to the tread portion. For this reason, it has been proposed to apply a lubricant to the back side of the tread.

  In order to assemble the tire / rim / core assembly to which the lubricant is applied in this way, first, the lubricant is applied to the back side of the tread to form a lubricant layer, and then the core is inserted into the pneumatic tire. In addition, the pneumatic tire and the core are assembled into the rim at the same time.

  However, there is a problem in that a step of applying a lubricant to the back side of the tread is required at the time of rim assembly work, and man-hours are increased compared to the rim assembly step in a normal pneumatic tire. In addition, before the core is loaded into the pneumatic tire and the rim is assembled, the core is freely movable in the tire radial direction. There is a problem that the agent and the outer peripheral side of the core come into contact with each other, the film thickness of the lubricant layer becomes non-uniform, and the tire balance deteriorates.

  As measures to prevent such deterioration of tire balance, a lubricant, sealed in a separate container, is placed inside the core support, and the tire, rim, and core are supplied with lubricant during run-flat running. An assembly has been proposed (see, for example, Patent Document 1).

However, in the tire / rim / core assembly disclosed in Patent Document 1, it is necessary to provide a lubricant supply device having a valve or a plug that operates during run-flat running on the inside of the core. In addition to increasing the weight and cost of the core assembly, the system for supplying the lubricant is complicated.
JP 2001-163020 A

  In view of the above-described facts, an object of the present invention is to provide a core that improves the tire balance without increasing weight and cost, and a tire / rim / core assembly having the core.

  The invention according to claim 1 is a core that is provided inside the pneumatic tire and has a support portion that supports a load applied from the back side of the tread during run-flat travel, wherein the support portion is during run-flat travel. The support surface is in contact with the back surface of the tread and has one or more protrusions protruding outward in the tire radial direction. A plurality of through-holes that can leak to the side are formed in the convex portion, and the opening size of the through-hole is set according to the viscosity of the lubricant.

  Thereby, when performing the rim | limb assembly | work operation | work of a pneumatic tire using this core, the lubrication agent application | work operation | work to a tread back surface becomes unnecessary, and a rim | limb assembly operation is simplified. Also, there is no need to consider contact between the core and the back of the tread until the rim is assembled after the core is loaded into the pneumatic tire, and tire imbalance occurs due to contact of the lubricant with the core and stripping. There is nothing to do. Therefore, it is possible to realize a core that can improve the tire balance without increasing the weight and cost. In addition, such an effect is acquired without providing a special apparatus, an operation valve, etc.

  By the way, in order to cause the lubricant to leak from the through hole by centrifugal force, the range of the combination of the viscosity of the lubricant and the diameter of the through hole is important. If the through hole is too small or the viscosity of the lubricant is too high, the lubricant will not leak sufficiently to the outside of the support surface, so that a sufficient lubricating effect cannot be obtained. Further, if the through hole is too large or the viscosity of the lubricant is too low, the lubricant is spattered from the through hole by centrifugal force and adheres unevenly to the tire, so that the tire balance tends to deteriorate.

  Therefore, in the invention according to claim 2, the penetration degree of the lubricant is in the range of 280 to 340, the diameter of the through hole is in the range of 2 to 4 mmφ, and the number of the through holes is 50. It is characterized by being in a range of ˜100.

  The blending penetration is based on the measurement method of JISK2220-5.3.2. The higher the blending penetration is, the softer the fluidity is, and the lower the hardness is, the harder the fluidity is.

  According to the second aspect of the present invention, a sufficient lubrication effect is obtained, and the lubricant does not adhere unevenly in the tire and the tire balance is not deteriorated.

  The invention according to claim 3 is the rim, the core according to claim 1 or 2 assembled to the rim, and the lubricant provided on the inner side in the tire radial direction of the convex portion of the core. And a pneumatic tire assembled to the rim.

  As a result, it is possible to realize a tire / rim / core assembly with good tire balance without increasing weight or cost.

  Since the present invention has the above configuration, the following effects can be obtained.

  According to the first aspect of the present invention, when the rim assembling work of the pneumatic tire is performed using this core, the lubricant application work on the back surface of the tread becomes unnecessary, and the rim assembling work is simplified. Also, there is no need to consider contact between the core and the back of the tread until the rim is assembled after the core is loaded into the pneumatic tire, and tire imbalance occurs due to contact of the lubricant with the core and stripping. There is nothing to do. Therefore, it is possible to realize a core that can improve the tire balance without increasing the weight and cost.

  According to the second aspect of the present invention, a sufficient lubricating effect can be obtained, and there is no case where the lubricant is unevenly adhered in the tire and the tire balance is not deteriorated.

  According to the third aspect of the present invention, it is possible to realize a tire / rim / core assembly with good tire balance without increasing the weight and cost.

  Hereinafter, embodiments will be described and embodiments of the present invention will be described. FIG. 1 is a tire radial direction cross-sectional view showing a configuration of a tire / rim / core assembly according to an embodiment of the present invention.

  A tire / rim / core assembly 10 according to an embodiment of the present invention includes a rim 12, a pneumatic tire 14 assembled to the rim 12, a rim 12 and an inner side of the pneumatic tire 14. And the core 16 according to the present invention.

  The rim 12 is a standard rim corresponding to the size of the pneumatic tire 14.

  The pneumatic tire 14 includes a pair of bead portions 18, a toroidal carcass 20 extending over both bead portions 18, and a plurality (two in this embodiment) of belt layers positioned at the crown portion of the carcass 20. 22 and a tread portion 24 formed on the upper portion of the belt layer 22.

  The core 16 includes a ring-shaped support portion 26 formed of a plate-shaped member, and two ring-shaped anchoring portions 28 that are provided on the outer peripheral surface side of the rim 12 and engage with the support portion 26. When the pneumatic tire 14 is crushed due to a decrease in internal pressure, the inner side of the tread portion 24 of the pneumatic tire 14 comes into contact with the support portion 26 and is supported by the rim 12 via the mooring portion 28.

  The support portion 26 has one or more convex portions 30 that protrude outward in the tire radial direction. The convex portion 30 has a support surface 30S that comes into contact with the inner peripheral surface side of the tread portion 24 during run-flat travel. A lubricant 32 is disposed on the inner side in the tire radial direction of the support surface 30S, that is, on the back side of the support surface 30S.

  As shown in FIG. 2, a plurality of through holes 34 penetrating the support surface 30 </ b> S are formed in the convex portion 30. The opening size of the through hole 34 is set according to the viscosity of the lubricant 32 so that the lubricant 32 can leak out to the support surface 30S side by the centrifugal force acting by the rotation of the tire / rim / core assembly 10. Has been. In this embodiment, the penetration of the lubricant 32 is in the range of 280 to 340, and the diameter of the through hole 34 is in the range of 2 to 4 mmφ.

  Further, the number of the through holes 34 is set in a range of 50 to 100 so that the amount of leakage of the lubricant 32 is fixed.

  According to the present embodiment, when the rim assembling work of the pneumatic tire is performed using the core 16, the lubricant application work on the tread back surface 24B is not required, and the rim assembling work is simplified. Further, it is not necessary to consider the contact between the core 16 and the tread back surface 24B until the rim is assembled after the core 16 is loaded into the pneumatic tire 14, and the lubricant 32 is contacted and peeled off by the core 16. No tire unbalance will occur. Therefore, it is possible to realize the tire / rim / core assembly 10 with good tire balance without increasing the weight and cost.

  In addition, the penetration of the lubricant is set within the above range, and the size and number of the through holes 34 are set within the above range, so that a sufficient lubricating effect can be obtained, and the lubrication can be achieved. The agent does not adhere unevenly in the tire and the tire balance is not deteriorated.

<Experimental example>
The inventor evaluated the performance of the tire / rim / core assembly according to the above-described embodiment by performing an experiment. In this experimental example, the size of the pneumatic tire is all PSR225160R17.

  In this experimental example, a tire is attached to a front-wheel drive passenger car having a displacement of 3000 cc, the tire internal pressure of the tire / rim / core assembly according to the above embodiment is set to 0 kPa, and two passengers get on the front seat as a load condition. The vehicle was run at 90 km / h until a failure occurred in the tire / rim / core assembly.

  The present inventor first uses a tire / rim / core assembly (hereinafter referred to as a tire / rim / core assembly of a reference example) in which a lubricant is applied to the back surface of the tread instead of the inside of the tire of the convex portion 30. The experiment was conducted.

  Table 1 shows the conditions of the tire / rim / core assembly of the reference example.

参考例のタイヤ・リム・中子組立体を用いた実験では、タイヤ・リム・中子組立体に故障が生じるまでの走行距離を求めた。そして、この走行距離に対応する指数をランフラット耐久性の基準値として１００とした。この指数も表１に併せて示す。

In the experiment using the tire / rim / core assembly of the reference example, the travel distance until the failure occurred in the tire / rim / core assembly was obtained. The index corresponding to the travel distance was set to 100 as a reference value for run-flat durability. This index is also shown in Table 1.

  Furthermore, the present inventor used the tire / rim / core assembly of Example 1 that was subjected to the conditions shown in Table 1 as the tire / rim / core assembly according to the above embodiment.

  Then, an experiment was performed in the same manner as the tire / rim / core assembly of the reference example, and the travel distance until the failure occurred in the tire / rim / core assembly was obtained. Then, an index for relative evaluation with respect to the tire / rim / core assembly of the reference example was calculated. The calculated index is also shown in Table 1.

  Table 1 shows that the larger the index, the better the performance. That is, the larger the index, the higher the run flat durability (that is, the longer the run flat travelable distance).

  In addition, the inventor used the tire / rim / core assembly of Example 2 which was subjected to the conditions shown in Table 1. In the second embodiment, the lubricant consistency is lowered as compared with the tire / rim / core assembly of the first embodiment and the reference example.

  In the experiment using the tire / rim / core assembly of Example 2, the distance traveled until the failure occurred in the tire / rim / core assembly in the same manner as the tire / rim / core assembly of the reference example. Thus, an index for relative evaluation with respect to the tire / rim / core assembly of the reference example was calculated. The calculated index is also shown in Table 1.

  As can be seen from Table 1, all of the tire / rim / core assemblies of Example 1 and Reference Example had good run-flat durability. Moreover, in the tire / rim / core assembly of Example 2, it was confirmed that the lubricating function was not so excellent and the lubricant was slightly too hard.

  The embodiments of the present invention have been described with reference to the embodiments. However, the above embodiments are merely examples, and various modifications can be made without departing from the scope of the invention. Needless to say, the scope of rights of the present invention is not limited to the above embodiment.

1 is a tire radial direction cross-sectional view showing a configuration of a tire / rim / core assembly according to an embodiment of the present invention. It is a fragmentary perspective view of the core which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Tire / rim | core assembly 12 Rim 14 Pneumatic tire 16 Core 24 Tread part 24B Tread back surface 26 Support part 30 Convex part 30S Support surface 32 Lubricant 34 Through-hole

Claims (3)

A core that is provided inside the pneumatic tire and has a support portion that supports a load applied from the back side of the tread during run flat running,
The support portion has one or more convex portions that protrude to the outer side in the tire radial direction, having a support surface that comes into contact with the back side of the tread during run flat running,
A plurality of through holes in which the lubricant provided on the inner side in the tire radial direction of the convex portion can be leaked to the support surface side by centrifugal force is formed in the convex portion,
An opening dimension of the through hole is set according to a viscosity of the lubricant. The lubricant has a penetration of 280 to 340,
The diameter of the through hole is in the range of 2 to 4 mmφ,
The core according to claim 1, wherein the number of the through holes is in a range of 50 to 100. With the rim,
The core according to claim 1 or 2, assembled to the rim,
The lubricant provided on the inner side in the tire radial direction of the convex portion of the core;
A pneumatic tire assembled to the rim;
A tire / rim / core assembly characterized by comprising:

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