JPH0655902A - Wheel for pneumatic tire - Google Patents

Abstract

PURPOSE:To enhance wheel unformity when a pneumatic tire is mounted on a rim by improving a rim that is a constituting member of a wheel. CONSTITUTION:A wheel 1 for a pneumatic tire is provided with a rim 6 in which a pair of tilt bead sheets 8 are respectively extended in a widened state toward the outside at an interval in the axial direction, and a flange 9 extended from the outside end in the radial direction of each tilt beat sheet 8, and finally bent outward. This rim 6 is provided with a flange projecting part 11 projected on the inner face of the flange 9 corresponding to a position of a bead core 10 embedded in a bead part 7 of a tire 5 when the tire 5 is mounted on the rim 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel for a pneumatic tire having excellent wheel uniformity, more specifically, a tire wheel which is fitted with a tire (a tire whose standard is specified by JATMA, etc.) suitable for the wheel. In order to achieve satisfactory wheel uniformity, there is little radial runout of the tire wheel itself, the so-called radial runout (hereinafter referred to as "RRO"), and the radial reaction force when the tire is rotated with a certain deflection. , So-called radial force variation (hereinafter referred to as "RFV")
The present invention intends to propose a wheel for a pneumatic tire capable of suppressing the above.

[0002]

2. Description of the Related Art As the quality and performance of the individual components that make up an automobile increase and the quality of automobiles increases, the ride quality and comfort that have not been given much importance in the past have been considered. There is a growing demand for demand. There is a method of improving uniformity as a tire wheel in which a pneumatic tire and a wheel are integrated to improve riding comfort and comfort. This wheel uniformity is not that the tire wheel is just a perfect circle in shape, but that the deflection is equal everywhere around the tire when the tire is rotated under the same load, and, conversely, it is constant. It is necessary for the reaction force to be uniform when rotated under the deflection of, and the method of measuring changes in RRO and RFV is generally used as the evaluation. By reducing this RRO and RFV,
Excellent wheel uniformity is obtained.

In order to improve wheel uniformity,
The change in RFV of the tire itself after vulcanization molding is measured, and the position of the tire at which the waveform is maximized is measured, and the change in RRO of the bead seat of the rim to which this tire is assembled is measured, and the waveform at that time is A method of assembling the rim according to the position of the rim that has become the minimum is generally performed.

Regarding the reduction of RFV of a tire wheel in which a pneumatic tire is mounted on a rim, for example, Japanese Patent Laid-Open No. 3-1 is used.
Japanese Patent No. 89201 discloses that RRO at the shoulder portion of the tire wheel is measured on the circumference and a spacer is interposed between the bead portion of the tire and the flange of the rim corresponding to a place where the value is large. .

[0005]

However, the method of measuring the RFV of the tire itself and the RRO of the rim and assembling the rim as described above should theoretically improve the wheel uniformity, but in reality, the wheel uniformity should be improved. , RFV of rim assembled wheel
The difference between the maximum value and the minimum value of the waveform may be larger than that of the tire itself, which may worsen the wheel uniformity. It is considered that the cause of such a phenomenon is caused by eccentric mounting because the rotational axes of the tire and the rim do not match when the tire is assembled to the rim.

In the method disclosed in Japanese Patent Laid-Open No. 3-189201, the rim assembly work and the air injection operation need to be repeated, so that the workability of the rim assembly work is significantly impaired.
Further, when a large external force is applied to the tire wheel, the relative position between the tire and the rim may change and it may be necessary to make a correction again.

The present invention has an object of suppressing RFV of a tire wheel and obtaining excellent wheel uniformity. Therefore, when the tire is mounted on a rim, the wheel is improved so that concentric mounting can be easily guided. In particular, the task is to improve the rim flange.

[0008]

SUMMARY OF THE INVENTION The present invention comprises a pair of sloping bead seats, each sloping bead seat diverging axially outwardly at intervals and radially expanding at their axially outer ends. In a pneumatic tire wheel that finally has a rim having a flange that outwardly bends, the rim corresponds to the position of the bead core embedded in the bead portion of the tire when the tire is assembled. hand,
The pneumatic tire wheel is characterized in that it has a raised flange protrusion on the inner surface of the flange. Also, the inclined bead seat width w of the protrusion allowance d of the flange protrusion
Is more preferably 0.3 or less.

Here, the protrusion margin d of the rim flange is the protrusion size from the upright wall surface of the rim flange to the top a of the flange protrusion, and the inclined bead seat width w is the portion where the bead base is seated and JATMA. YEAR B
This is a portion corresponding to the bead sheet width P in OOK. FIG. 1 is a cross-sectional view of a main part showing a state in which a pneumatic tire is assembled to the pneumatic tire wheel 1 of the present invention. The rim 6 of the pneumatic tire wheel 1 has a pair of slanted bead seats 8 that extend outward in the axial direction at intervals, and spread radially from the outer ends in the axial direction of each slanted bead seat 8 and finally reach the outer side. It has a flange 9 which bends in the direction. The rim 6 has a flange protrusion 11 that is raised on the inner surface of the flange 9 corresponding to the position of the bead core 10 embedded in the bead portion 7 of the tire when the tire 5 is assembled. Top a of this flange protrusion 11
The positional relationship in the radial direction is preferably within the range of the inner-outer radius difference R of the bead core 10 embedded in the bead portion assembled to the rim.

The projection margin d of the flange projection is preferably 0.3 or less, more preferably 0.05 to 0.15, in proportion to the inclined bead seat width w. This is because if the ratio is greater than 0.3, the tip of the bead toe rides on the hump of the rim, and the rim dismountability deteriorates.

As long as the flange protruding portion 11 has a shape that is in close contact with the bead portion 7 of the tire evenly over the entire circumference of the flange 9 after the injection of air for the rim assembly work is cut off, the flange protruding portion 11 shown in FIG. As shown in FIG. 2, the inner and outer circumferences are not limited to the annular protrusions separated by obtuse-angled corner mounds, and the sectional shape is as shown in FIG.
It may be an arcuate shape as shown in Fig. 3 or other projections having an acute angle or an obtuse angle, and as shown in Fig. 3, a projection having a curved surface which partially extends from the axially outer end of the inclined bead seat to the cross-sectional contour of the rim flange. It is preferable that It is more preferable that the flange protruding portion 11 is continuously provided over the entire circumference of the rim 6, but it may be intermittent as long as the air sealability is not impaired.

The flange protrusion 11 may be provided on at least one of the paired rim flanges. In the case of a 1-piece slim rim having an asymmetrical shape in which the position of the well is offset to the one side from the center of the rim width, the flange protrusion 11 is provided on the side of the flange 9 on which the well 12 is located.
It is preferably provided on the side (where the beads do not easily adhere uniformly).

[0013]

[Function] When the pneumatic tire 5 is assembled to the rim 6,
The bead portion 7 of the tire is mounted on the rim 6 as shown in FIG. 1 by successively overcoming the flange 9 of the rim 6 partially on the outer periphery thereof, and then, on the inner cavity of the pneumatic tire 5 or the tube housed in this. It is assembled to the rim 6 by injecting air into the rim 6 (not shown) and increasing its pressure until it reaches the normal internal pressure, and this pressure causes the bead portion 7 to move along the inclined bead seat 8 to the bead portion 7. It is pushed until the outer surface contacts the flange 9.

FIG. 4 is a diagram illustrating the state of progress of the rim assembly for the conventional pneumatic tire 4, in which the degree of tight fitting of the bead portion 7 is strengthened as the tightening margin for the inclined bead seat 8 increases. However, since the frictional resistance at the bead portion 7 that prevents this movement is not always equal over the entire circumference of the bead portion, one point on the circumference of the rim flange first contacts the outer surface of the bead portion of the tire, and The bead heel 13 approaches the position of the rim flange where the bead heel 13 is scheduled to adhere against the resistance to compressive deformation starting at. However, in this case, in practice, the bead heel 1 is often used.
Since the clearance S between the rim 3 and the rim flange 9 is unevenly generated on the circumference, the rim assembly work tends to be discontinued,
Due to this, although the pneumatic tire itself was molded and vulcanized with sufficient uniformity, the RRO as a tire wheel was large, and as a result, RFV was generated.

On the other hand, according to the present invention, under the same transition of the rim as described above, the rim flange 9 is designed so that the clearance S between the bead portion and the rim flange is minimized and the clearance S is uniform over the entire circumference. Improved. With this improvement, first, the bead heel 13 uniformly contacts the flange protruding portion 11 of the rim 6, and after the compression deformation, the outer surface of the bead portion contacts the outwardly curved flange 9 and appropriate pressure is applied to the rim assembly. Since the work is completed, the rotational axis of the pneumatic tire 5 is easily aligned with the rotational axis of the rim 6, and the RRO as a tire wheel becomes small, so that the RFV can be effectively suppressed. Of.

[0016]

EXAMPLE A tubeless tire for a passenger car having a size of 205 / 65R15, a flange projection 1 as shown in FIG.
Using each tire wheel incorporated in the applicable rim provided with No. 1 (15 × 6JJ, conforming to JATMA standard), RRO and RFV with respect to the flange protrusion 11 of the rim were measured, and thereby wheel uniformity was evaluated. The results are shown in Table 1. The values in Table 1 are 5 per measurement.
It is a value obtained by averaging them by repeating the operation, and the unit is RRO.
Is mm and RFV is kgf.

[0017]

[Table 1]

As is clear from Table 1, the embodiment has smaller RRO and RFV than the conventional example and is excellent in wheel uniformity.

[0019]

According to the present invention, a rim can be assembled by using a normal tire without changing the contour shape of the tire by the same operation as the conventional one, and further, by providing a flange protruding portion on the rim, the rim assembly is formed. After the end, the bead portion of the tire surely adheres evenly to the rim over the entire circumference and accurate positioning can be performed, so the RRO of the tire wheel integrated with the rim assembly can be reduced and effective RFV suppression It is possible to obtain excellent wheel uniformity.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view after a pneumatic tire 5 has been assembled to a rim 6 of a pneumatic tire wheel 1 (embodiment) according to the present invention.

FIG. 2 is a partial cross-sectional view after the pneumatic tire 5 has been assembled to the rim 6 of the pneumatic tire wheel 2 according to the present invention.

FIG. 3 is a partial cross-sectional view after assembling the pneumatic tire 5 to the rim 6 of the pneumatic tire wheel 3 according to the present invention.

[FIG. 4] Conventional pneumatic tire wheel 4 (conventional example)
FIG. 6 is a partial cross-sectional view after the pneumatic tire 5 is assembled to the rim 6 of FIG.

[Explanation of symbols]

 1, 2, 3, 4 Wheels for pneumatic tires 5 Pneumatic tires 6 Rims 7 Beads 8 Inclined bead seats 9 Flange 10 Bead cores 11 Flange protrusions 12 Wells 13 Bead heels a Tops of flange protrusions d Projection allowance w Inclined bead seats Width R Inner and outer radius difference of bead core S Clearance

Claims (2)

[Claims] 1. A pair of inclined bead sheets, each inclined bead sheet extending toward the outside in the axial direction at intervals, radially expanding at the axially outer ends thereof, and finally bending outward. In a pneumatic tire wheel having a rim having a flange, the rim is raised on the inner surface of the flange corresponding to the position of the bead core embedded in the bead portion of the tire when the tire is assembled. A wheel for a pneumatic tire, which has a flange protrusion. 2. The pneumatic tire wheel according to claim 1, wherein the ratio of the protrusion margin (d) of the flange protrusion to the inclined bead seat width (w) is 0.3 or less.