JPH05338402A - Rim for pneumatic tire - Google Patents

Abstract

PURPOSE:To prevent air from being reserved between the outside surface of a bead part of a tire and a rim flange at the time of assembling a rim, to prevent rim slippage, to prevent fluctuation of rim assembly precision made along with elapse of hours due to traveling and to maintain traveling stability. CONSTITUTION:An air flow passage 7 having one end in a region of an inward surface 4A of a rim flange 4 between an inward point A on the outside in the radial direction of a bead heel part and an outward point B at which a bead part 6 of a tire apart from the rim flange 4 is provided on the rim flange 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prevents air accumulation from occurring between an outer surface of a bead portion of a tire and a rim flange when assembling a pneumatic tire to the rim, and prevents rim displacement. The present invention relates to a rim for a pneumatic tire, which can prevent the rim assembly accuracy from varying with time and maintain the running stability of the tire.

[0002]

2. Description of the Related Art Pneumatic tires, such as passenger cars, tend to operate at higher speeds. For this reason, the tires are fitted to the rim with a large fitting force so as to prevent rim displacement.

[0003]

When assembling such a tire with a rim, as shown in FIG. 9, the bead bottom surface b of the bead portion a is firmly fitted to the rim seat portion d of the rim c without any gap. However, the bead outer surface f guided by the flange e of the rim c is located between the lower side of the outer surface f and the flange e by the outer surface f coming into close contact with the tip end of the flange e at the time of rim assembly. A void g is generated in

The gap g gradually decreases as the outer surface f becomes familiar with the use of the tire, but the rim assembly accuracy changes as the gap g decreases.
The fitting state between the tire and the rim changes, and the balance and the force variation distribution state of the initial rim assembly state change. This causes poor balance and deterioration of force variation. Further, since the contact area between the bead portion and the rim is reduced, a rim shift occurs between the bead portion and the rim seat when sudden braking is applied, which hinders straightness and reduces durability.

In the case of a rim-assembled tire, the force variation is checked before shipping. However, there is a difference in the assembly accuracy between the rim assembly in the factory and the rim assembly performed by the user himself. Exists. Therefore, in order to prevent the occurrence of the above-mentioned force variation, it has been demanded that a rim be formed in which the void does not occur even when the user assembles the rim without paying special attention. ..

[0006] In order to prevent rim displacement, various improvements have been hitherto made on the shape of the bead portion of the tire. However, changing the shape of the tire, especially the cross-sectional shape of the bead portion changes the shape. As a result, the running performance and durability of the tire tend to be deteriorated, and it is difficult to solve the above problems.

The inventors have paid attention to the rim on which the bead portion of the tire fits, and the inward surface of the rim flange facing the outer surface of the bead portion of the tire is provided with a space between the bead portion and the inward surface of the rim flange. The inventors have found that by providing an air flow passage for letting air out, it is possible to prevent the generation of voids during rim assembly without modifying the tire itself, and completed the present invention.

The present invention is based on the provision of an air flow path in the rim flange of the rim, and tends to occur during sudden braking by reducing the gap between the bead portion and the rim flange during assembly of the rim. The purpose of the invention is to provide a rim for pneumatic tires that can prevent vibration from occurring by preventing the occurrence of force variations while preventing rim displacement and increasing durability while maintaining tire running stability for a long period of time. There is.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a rim flange portion of a rim having a bead seat portion having an arcuate bead heel portion and provided with a rim flange is provided with an inner point on the outer side in the radial direction of the bead heel portion. , The air that has one end in the area of the inward surface of the rim flange between the bead portion of the tire and the outer point where it separates from the rim flange under normal internal pressure conditions and that escapes the air between the bead portion of the tire and the rim flange A pneumatic tire rim having a flow passage.

The air flow passage may be provided on the inward surface of the rim flange, and the other may be formed as a concave line extending outward in the tire radial direction beyond the outer point, and one end of the air inflow passage may be formed inward. And the other end may be a hole opened at the outer surface of the rim flange.

[0011]

Since the airflow passage having the above-described structure is provided on the inward surface of the rim flange, the bead outer surface and the rim assembly are
Air flow passages exist even when the bead abuts the rim flange. Therefore, when the rim is assembled, the air present between the bead outer surface and the rim flange as the bead outer surface approaches the inward surface of the rim flange portion can be discharged to the outside through the air flow passage. As shown, air does not remain in the void formed along the outer surface of the bead near the bottom of the bead.

As a result, the non-uniformity of the accuracy of the rim assembly with respect to the circumferential direction, which has been apt to occur due to the reduction of the air gap with the passage of time in the past, is reduced. The force variation due to such factors will not increase. As a result, vibration does not increase even when the vehicle runs for a long period of time, so that running stability and riding comfort can be maintained, and the bead portion and rim of the tire can be fitted and abutted evenly. Since it can hold, it can prevent rim displacement during sudden braking and enhance durability. Moreover, the workability of assembling the rim does not deteriorate even when the rim according to the present application is used without paying special attention to the work when assembling the rim.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 4, a rim 1 for a pneumatic tire (hereinafter referred to as a rim 1) has a bead heel portion 3 having an arc shape at one end of a cylindrical bead seat portion 2 and has a rim flange portion 4
The pneumatic tire T is fitted to the rim 1.

The pneumatic tire T has sidewall portions 23, 23 extending inward in the tire radial direction from both ends of the tread portion 22, and a bottom surface 6a located inside the sidewall portion 23 in the radial direction. A pair of bead portions 6 and 6 to be seated on the bead seat portion 2 of the above, and a toroid passing through the sidewall portions 23 and 23 and the tread portion 22 between the bead cores 26 and 26 provided in the bead portions 6 and 6, respectively. The carcass 27 in the shape of a belt is bridged, and the belt layer 29 is arranged on the outer side in the radial direction and inside the tread portion 22.

The carcass 27 is a so-called radial or semi-radial direction array in which the carcass cords are arranged at an angle of 60 to 90 degrees in the present embodiment with respect to the equator C of the tire, and the carcass cords are nylon or polyester. Fiber cords of rayon, aromatic polyamide, etc. are adopted.

The belt layer 29 is provided with belt cords which are obliquely arranged on the respective belt plies forming the belt layer 29 and intersect with each other. The belt cords, like the carcass 27, are made of nylon, polyester, rayon, or the like. Steel cords are used in addition to fiber cords such as aromatic polyamide.

In the present embodiment, the bead portion 6 is provided with a reinforcing layer 31 for wrapping the carcass 27. The reinforcing layer 31 is a steel cord, an organic fiber cord having a strength such as an aromatic polyamide, and the carcass cord of the carcass 27. The reinforcing layer 31 enhances the rigidity of the bead portion 6 by forming a sheet shape that is juxtaposed in a direction intersecting with.

The bead portion 6 is provided with a chafer 32 capable of forming a bead bottom surface 6a and a bead outer surface 6b on the outer side of the reinforcing layer 31. In the present embodiment, the chafer 3 is provided.
The hardness of the rubber 2 is higher than that of the other rubber of the bead portion 6, and the hardness thereof is set to 65 degrees or more of the JISA hardness.

The rim flange 4 has an inward surface 4A and an inward point A on the outer side in the radial direction of the bead heel portion 3 which is continuous with the bead seat portion 2 and has an arc shape. Bead part 6 is rim flange 4
An air flow passage 7 is provided in a region between the outer point B and the outer point B.

In the present embodiment, the air flow passage 7 is formed by a recessed line 9 having one end located in the vicinity of the inner point A and the other end extending radially outward beyond the outer point B. .. It is desirable to dispose four or more recessed lines 9 in the circumferential direction and at positions where adjacent recessed lines 9, 9 are separated from each other.

The groove width W of the groove 9 is 5 to 10 mm,
The groove depth H is preferably in the range of 0.5 to 1.0 mm. Further, the bead portion 6 can be prevented from being damaged by making the ridge portion of the concave line 9 smooth and continuous.

Therefore, during the rim assembling work, the air in the gap formed between the rim flange 4 and the outer surface 6b of the bead portion 6 is discharged through the air flow passage 7 formed by the concave groove 9, A normal internal pressure is applied to the inside of the rim flange 4 and the outer surface 6b of the bead portion 6 due to the internal pressure.
Is pressed toward the inwardly facing surface 4a.

As a result, the air accumulated between the outer surface 6b and the inward surface 4A of the rim flange 4 is removed through the air flow passage 7 formed by the groove 9, and as a result, the bead portion 6 is removed from the rim flange 4. Since it is possible to bring the tires closer to each other, the accuracy of tire rim assembly is improved. Since the recessed line 9 has its starting point outside the inward point A located on the outside in the radial direction of the bead heel portion 3, even when the rim assembly work is performed, air is prevented from being diffused in the tire inner cavity and is airtight. It can retain sex.

In this embodiment, the bypass grooves 11 extending in the tire circumferential direction are provided in the region between the inner points A and the outer points B between the adjacent recesses 9 as shown in FIG. As a result, when the rim is assembled, the air can be exhausted evenly from the respective recessed ridges 9 and the uniformity of the rim assembly accuracy can be further enhanced.

5 and 6 show another embodiment of the air flow passage 7. In this example, the protrusion 12 protruding inward in the tire axial direction is provided on the inward surface 4A from the vicinity of the inward point A outward in the radial direction and beyond the outward point B. In this example, the air flow passages 7 are formed on both sides of the ridge 12 and along the ridge 12. Therefore, the air flow passage 7 has one end in the area of the inward surface 4A of the rim flange 4 between the inner point A and the outer point B, and allows the air between the bead portion 6 and the rim flange 4 to escape. You can The height H1 of the ridge 12 is 0.
It is preferable that the width is 5 to 1.0 mm and the width W1 is 5 to 10 mm.

FIGS. 7 and 8 show another embodiment in which the other end of the air flow passage 7 is formed by a hole 10 which is a circular hole opening at the outward surface 4B of the rim flange 4. In this example, a plurality of holes 10 ... Are made to penetrate through the inward surface 4A of the rim flange 4 in the circumferential direction and at intervals with respect to the outward surface 4B.

In the present embodiment, as shown in FIG. 8, a longitudinal groove 15 is formed on the inward surface 4A and extends in the radial direction through one end of the hole 10 in the range between the inward point A and the outward point B. By providing a connecting groove 17 composed of the vertical grooves 15 and a circumferential groove 16 connecting the vertical grooves 15, one end side of each hole 10 is made to communicate with each other. The height of the holes in the radial direction of the tire can be set at any position between the inner points A and the outer points B, and the connecting groove 17 may be omitted by increasing the number of holes 10 installed.

The hole area per hole 1 pc in the one end side of the hole 10 is in the range of 8mm ² ~30mm ^2. 8 mm ²
There is a risk of deforming the strength decreases greatly rim flange 4 of the exhaust is tire cavity exceeds one 30 mm ² become insufficient air leakage occurs easily and the rim flange 4 is less than. A hole area of about 10 mm ² is suitable.
The hole can be set to any shape such as an ellipse or a square, as well as a circle. As described above, the present invention can be modified in various modes.

[0029]

As described above, in the rim for a pneumatic tire of the present invention, the rim flange portion has an inner point radially outward of the bead heel portion and an outer point at which the bead portion of the tire separates from the rim flange. Since an air flow passage having one end in the area of the inward surface of the rim flange between the rim flange and the rim flange is provided, it is possible to prevent air accumulation between the bead portion and the rim flange during rim assembly, improve rim assembly accuracy, and improve rim assembly. It is possible to prevent the deviation, prevent the rim assembly accuracy from fluctuating over time due to running, and maintain the running stability of the tire.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an enlarged main part thereof.

FIG. 3 is a partial side view showing a rim flange of a rim.

FIG. 4 is a circumferential sectional view showing a bead outer surface and a rim flange of a tire.

FIG. 5 is a sectional view showing another embodiment.

FIG. 6 is a circumferential sectional view thereof.

FIG. 7 is a cross-sectional view showing another embodiment.

FIG. 8 is a circumferential sectional view thereof.

FIG. 9 is a cross-sectional view showing a conventional technique.

[Explanation of symbols]

 2 bead seat part 3 bead heel part 4 rim flange 4A inward surface 4B outward surface 6 bead part 7 air flow passage 9 concave line 10 hole A inward point B outward point T pneumatic tire

Claims (3)

[Claims] 1. A bead of a tire at a normal inner pressure state, at an inner point on the outer side in the radial direction of the bead heel portion, at the rim flange portion of a rim having a bead seat portion having a circular arc bead heel portion and provided with a rim flange. Part having an end in the area of the inward surface of the rim flange between the part and the outer point away from the rim flange, and providing an air flow passage for releasing air between the bead part of the tire and the rim flange. Rims for tires. 2. The air flow passage is a recessed line which is provided on an inward surface of a rim flange and has one end located near the inward point and the other end extending beyond the outward point. The rim for a pneumatic tire according to claim 1. 3. The air flow passage is a hole, the other end of which opens at an outer surface of the rim flange.
Rim for the pneumatic tire described.