JP3330978B2 - Wheels for pneumatic tires - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire wheel having excellent wheel uniformity, and more particularly, to a tire (a tire specified by JATMA or the like) adapted to the wheel as a tire wheel. In order to achieve satisfactory wheel uniformity, the radial runout of the tire wheel itself (so-called radial runout (hereinafter referred to as “RRO”)) is small, and the radial reaction force when the tire is rotated with a constant deflection applied So-called radial force variation (hereinafter referred to as "RFV")
An object of the present invention is to propose a pneumatic tire wheel capable of suppressing the occurrence of a tire.

[0002]

2. Description of the Related Art As the quality and performance of the individual members constituting a motor vehicle increase and become more sophisticated, ride comfort and livability, which have not been considered so important in the performance of the vehicle, have been considered. Strict demands have been made. There is a method of improving uniformity as a tire wheel integrating a pneumatic tire and a wheel to improve ride comfort and comfort. This wheel uniformity means that the tire wheel is not just a perfect circle on the shape, but that the deflection is equal everywhere on the circumference when the tire is rotated under the same load, and vice versa. It is necessary that the reaction force is uniform when rotated under the deflection of the actuator, and a method of measuring changes in RRO and RFV is generally used as an evaluation thereof. By reducing the 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 was measured, and the position of the tire where the waveform at that time became maximum was measured. The change in RRO of the bead sheet of the rim to which this tire was assembled was measured, and the waveform at that time was measured. A method of assembling the rim in accordance with the position of the rim that has been minimized is generally performed.

[0004] Regarding the reduction of RFV of a tire wheel in which a pneumatic tire is mounted on a rim, for example, Japanese Unexamined Patent Publication No.
No. 89201 discloses that the RRO in the shoulder portion of the tire wheel is measured on the circumference, and that a spacer is interposed between the bead portion of the tire and the flange of the rim corresponding to a location where the value is large. .

[0005]

However, as described above, the method of measuring the RFV of the tire itself and the RRO of the rim and assembling the rim should theoretically improve the wheel uniformity. , Rim assembled wheels RFV
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 such a phenomenon is caused by eccentric mounting because the rotational axes of the tire and the rim do not coincide with each other when the tire is assembled on the rim.

In the method disclosed in Japanese Patent Application Laid-Open No. 3-189201, the rim assembling operation and the air injecting operation are required repeatedly.
Further, when a large external force is applied to the tire wheels, the relative position between the tire and the rim may change and need to be corrected again.

SUMMARY OF THE INVENTION An object of the present invention is to improve the wheel so that the RFV of the tire wheel can be suppressed and an excellent wheel uniformity can be obtained. In particular, it is an object to improve a rim flange.

[0008]

SUMMARY OF THE INVENTION The present invention comprises a pair of inclined bead sheets, each inclined bead sheet extending axially outward at a distance and extending radially at their axially outward ends. Finally, in a pneumatic tire wheel having a rim having an outwardly reflexing flange, the rim corresponds to a position of a bead core embedded in a bead portion of the tire when the tire is assembled. hand,
A pneumatic tire wheel having a flange protrusion continuously raised over the entire circumference of the inner surface of the flange. Also, the protrusion allowance d of the flange protrusion portion
Is more preferably 0.3 or less with respect to the inclined bead sheet width w.

Here, the protrusion allowance d of the rim flange is a protrusion dimension 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 a portion where the bead base is seated. YEAR B
This is a portion corresponding to the bead sheet width P in OOK. FIG. 1 is a cross-sectional view of a relevant part showing how a pneumatic tire is assembled to a pneumatic tire wheel 1 of the present invention. The rim 6 of the pneumatic tire wheel 1 has a pair of inclined bead seats 8 extending axially outward and diverging at intervals, and radially extending from the axial outer ends of the inclined bead seats 8 and finally extending outward. It has a flange 9 that is bent in the opposite direction. The rim 6 has a raised flange 11 on the inner surface of the flange 9 corresponding to the position of the bead core 10 embedded in the bead 7 of the tire when the tire 5 is assembled. The top a of the flange protrusion 11
Is preferably within a range of a difference R between the inner and outer radii of the bead core 10 embedded in the bead part assembled with the rim.

The protrusion d of the flange protrusion preferably has a ratio to the inclined bead sheet width w of 0.3 or less, more preferably 0.05 to 0.15. If the ratio is larger than 0.3, the tip of the bead toe rides on the hump of the rim, and the rim disengagement is reduced.

FIG. 1 shows that the flange projection 11 has a shape that evenly adheres to the bead portion 7 of the tire over the entire circumference of the flange 9 after the injection of air for the rim assembling operation is stopped. The inner and outer peripheries as shown are not limited to annular projections separated by obtuse corner mounds, and the cross-sectional shape is shown in FIG.
It may be a projection having an arc shape as shown in FIG. 3 or other acute or obtuse angle. As shown in FIG. 3, a projection having a curved surface partially along the cross-sectional contour of the rim flange from the axially outer end of the inclined bead seat as shown in FIG. Preferably,

The flange protrusion 11 may be provided on at least one of the paired rim flanges. In the case of an asymmetrical rim having a one-piece rim and a well whose position is offset to one side from the center of the rim width, the flange protrusion 11 is connected to the flange 9 on the side where the well 12 is located.
(On the side where the beads are hard to adhere uniformly).

[0013]

[Function] When assembling the pneumatic tire 5 to the rim 6,
The bead portion 7 of the tire is mounted on the rim 6 as shown in FIG. 1 by partially and sequentially riding over the flange 9 of the rim 6 on the outer periphery thereof, and thereafter, the inner cavity of the pneumatic tire 5 or a tube housed therein. Air is injected into the rim 6 (not shown), and the pressure is increased until the pressure reaches the normal internal pressure, whereby the bead portion 7 is attached to the rim 6 along the inclined bead sheet 8. It is pushed forward until the outer surface contacts the flange 9.

FIG. 4 illustrates the progress of the rim assembly with respect to the conventional pneumatic tire 4. As shown in FIG. 4, the degree of tight fitting of the bead portion 7 increases as the interference with the inclined bead sheet 8 increases. However, since the frictional resistance at the bead portion 7 that hinders this movement is not always uniform over the entire circumference of the bead portion, a point on the circumference of the rim flange first comes into contact with the outer surface of the bead portion of the tire. The bead heel 13 approaches the rim flange position where the bead heel 13 is to be brought into close contact against the compressive deformation resistance that starts. However, in this case, in practice, often bead heel 1
Since the gap S between the rim flange 3 and the rim flange 9 is unevenly formed on the circumference, the rim assembling work tends to be discontinued.
Although the pneumatic tire itself is formed and vulcanized with a sufficient uniformity, RRO as a tire wheel is large, and as a result, RFV is generated.

On the other hand, according to the present invention, under the same rim assembly transition as described above, the clearance S between the bead portion and the rim flange is made as small as possible, and the clearance S is made uniform over the entire circumference. Was improved. With this improvement, first, the bead heel 13 uniformly contacts the flange protrusion 11 of the rim 6, and after the compression deformation thereof, the outer surface of the bead contacts the outwardly bent flange 9 to apply an appropriate compression to the rim assembly. Since the work is finished, the rotation axis of the pneumatic tire 5 is easily aligned with the rotation axis of the rim 6, and the RRO as a tire wheel becomes small, so that RFV can be effectively suppressed. It is.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A tubeless tire for a passenger car having a size of 205 / 65R15 is mounted on a flange protrusion 1 as shown in FIG.
RRO and RFV for the flange rim 11 of the rim were measured using each tire wheel incorporated into the applicable rim (15 × 6JJ, conforming to JATMA standard) provided with No. 1 and thereby the wheel uniformity was evaluated. Table 1 shows the results. The values in Table 1 indicate that the measurement was performed 5 times per condition.
It is a value obtained by averaging them, 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, it is possible to assemble a rim by using a normal tire without changing the contour shape of the tire and by performing the same operation as in the prior art. After the end, the bead portion of the tire is surely in close contact with the rim over the entire circumference and accurate positioning can be performed, so that the RRO of the tire wheel integrated by the rim assembly can be reduced and the effective RFV is suppressed. The result is an excellent wheel uniformity.

[Brief description of the drawings]

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

FIG. 2 is a partial cross-sectional view after the pneumatic tire 5 is 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 the pneumatic tire 5 is assembled to the rim 6 of the pneumatic tire wheel 3 according to the present invention.

FIG. 4 shows a conventional pneumatic tire wheel 4 (conventional example).
FIG. 4 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 Wheel for pneumatic tires 5 Pneumatic tires 6 Rim 7 Beads 8 Inclined bead seat 9 Flange 10 Bead core 11 Flange protrusion 12 Well 13 Bead heel a Top of flange protrusion d Projection allowance w Inclined bead seat Width R Bead core inner / outer radius difference S Clearance

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-103004 (JP, A) JP-A-52-141901 (JP, A) JP-A-59-220406 (JP, A) JP-A-60-1985 53401 (JP, A) JP-A-3-189201 (JP, A) JP-A 63-171201 (JP, U) JP-A 58-98205 (JP, U) JP-A 52-33801 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60B 21/00

Claims (2)

(57) [Claims] 1. A pair of inclined bead sheets, each inclined bead sheet extending axially outwardly and divergently at intervals, and radially expanding at their axially outer ends and eventually reflexing outward. In a pneumatic tire wheel having a rim having a flange which fits, the rim corresponds to a position of a bead core embedded in a bead portion of the tire when the tire is assembled, and the entire inner surface of the flange is formed. Week
A wheel for a pneumatic tire having a flange protrusion continuously raised over the entire length. 2. The pneumatic tire wheel according to claim 1, wherein the ratio of the protrusion allowance (d) of the flange protrusion to the inclined bead seat width (w) is 0.3 or less.