JP3411647B2 - Pneumatic tire wheels - 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 a good uniformity and comprising an assembly of a pneumatic tire and a rim.

[0002]

2. Description of the Related Art In automobiles, the quality and performance of the individual components that make up the vehicle have risen and the vehicle has become more sophisticated. There is a growing demand for demand. It is useful to improve the uniformity of pneumatic tire wheels in order to improve riding comfort and comfort. This wheel uniformity is not that the tire wheel is 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, RFV is suppressed and 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 It is common practice to assemble the rim according to the position of the rim that has become the minimum.

Regarding the reduction of the RFV of a tire wheel in which a pneumatic tire is mounted on a rim, for example, in JP-A-3-189201, RRO at the shoulder portion of the tire wheel is measured on the circumference, and It is disclosed that a spacer is interposed between the bead portion of the tire and the flange of the rim corresponding to a portion having a large value.

[0005]

However, as described above, it is theoretically possible to improve the wheel uniformity by measuring the RFV of the tire itself and the RRO of the rim and assembling the rim. The difference between the maximum value and the minimum value of the RFV waveform of the wheel assembled on the rim sometimes becomes 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.

Further, in the method disclosed in Japanese Patent Laid-Open No. 3-189201, since the rim assembly and the operation of injecting air are repeated, there is a disadvantage that the workability of the rim assembly is significantly impaired, and a large external force acts on the tire wheel. In that case, the relative position between the tire and the rim may change and it may be necessary to make a correction again.

Therefore, an object of the present invention is to provide a pneumatic tire mounted on the rim by making the bead seat of the rim and the inner circumference of the bead portion of the pneumatic tire into proper shapes and selecting the material of the inner circumference of the bead portion. Then, the pneumatic tire wheel having a good uniformity in which the bead portion is fixed to a predetermined bead seat position is completed.

[0008]

SUMMARY OF THE INVENTION The present invention provides a pneumatic tire having a bead portion reinforced by embedding a bead core on the inner edge of a sidewall connected to a tread portion and a toroidal body, and a pneumatic tire tightly attached to the bead portion. In a pneumatic tire wheel consisting of an assembly with a rim having a bead seat provided for taper fitting, a pneumatic tire has an annular member with an inner surface taper made of a rigid material integrally fixed to the inner circumference of the bead portion, A pneumatic tire wheel with good uniformity, characterized in that the rim has a bead seat with a tapered finish that matches the inner surface taper of the annular member.

Further, the rim is provided with a pair of bead seats having a taper from the width end to the width center, and at least one of the bead seats is configured to be separable from the rim. Being integrally configured so that the other bead seat can be separated from the rim,
The taper of both bead seats is formed toward one side in the width direction of the rim, and in a mounting posture in which an annular member is assembled to these bead seats, a bead seat having a taper from the width center of the rim toward the width end is It is more preferable to have a lock member for fixing the ring member.

FIG. 1 shows a typical example of a cross section of a main part of a tire wheel of the present invention. In the figure, 1 is a sidewall, 2 is a bead core, 3 is a bead portion, 4 is a pneumatic tire, 5 is a bead seat, and 6 is a bead seat. The rim 7 is an annular member. The pneumatic tire wheel of the present invention includes a pneumatic tire 4 having a bead portion 3 reinforced by embedding a bead core 2 at an inner edge of a sidewall 1 which is continuous with a tread portion and a toroidal portion, and a bead portion 3 of the pneumatic tire 4. It consists of an assembly with a rim 6 having a bead seat 5 for a tight taper fit. In addition, a normal bead wire may be used for the bead core 2, but the actual bead wire is 61-88804.
As disclosed in Japanese Unexamined Patent Publication (Kokai), a thin steel rubber-reinforced steel reinforcing element may be spirally wound to use a bead core having a rectangular cross section, or a mild steel filament may be used as an inner core, A bead core may be formed by winding a small diameter filament around the entire inner core.

The pneumatic tire 4 has an annular member 7 having an inner surface taper made of a rigid material integrally fixed to the inner circumference of the bead portion 3, and the rim 6 conforms to the inner surface taper of the annular member 7. A bead seat 5 having a tapered finish is provided. As the material of the annular member 7, it is preferable to use a metal material such as steel or aluminum, but a resin material may be used. The ring member 7 is preferably fixed to the inner circumference of the bead portion 3 by vulcanization adhesion. Further, the rim 6 may be fixed by a lock member 8 such as a bolt, a pin or a stopper as shown in FIGS. Further, from the viewpoint of air sealing, it is preferable that the surface of the annular member, which is the fitting portion with the bead sheet, be smooth, and if necessary, an O-ring or the like may be used.

The pneumatic tire wheel of the present invention is not suitable for the rim assembly procedure including the step of overcoming the rim flange 9 as shown in FIG. 5 because the annular member 7 fixed to the bead portion is a rigid material. . Therefore, in the pneumatic tire wheel as shown in FIG. 1, a pair of bead seats 5 having a taper extending from the width end to the width center of the rim 6 is separable so that the rim 6 can be separated. On the bead seat 5, from the width center of the rim 6 to the rim flange 9 respectively.
It is preferable to move the bead portion 3 in each direction and assemble the rims, and then integrate the divided rims 6 to form a tire wheel.

In the pneumatic tire wheel as shown in FIG. 2, the rim 6 uses a rim 6 having no rim flange in which one of the bead seats 5 is integrated with the rim and only the other is separable. After fixing the bead portion 3 having the annular member 7 to the bead sheet 5 on the side integrated with the other and attaching the bead sheet member 10 to the other, the other similar bead portion 3 on the bead sheet member 10 is fixed. It is preferable to form a pneumatic tire wheel by assembling the rim.

In a pneumatic tire wheel as shown in FIG. 3, a rim 6 having no rim flange 9 having a pair of bead seats 5 having a taper tapering toward one side in the width direction of the rim is used. , The bead portion 3 having the annular member 7 was fitted in the direction of the arrow 11 from the side of the bead seat 5 having a smaller outer diameter, and assembled to the rim 6 in sequence, and the annular member 7 was assembled to these bead seats 5. It is preferable to form the pneumatic tire wheel by fixing the annular member 7 with the lock member 8 to the bead seat 5 having a taper tapering toward the width end of the rim in the mounted posture. A pneumatic tire wheel as shown in FIG. 4 has the same structure as the pneumatic tire wheel shown in FIG. 3 except that the shape of the annular member 7 and the shape of the lock member 8 are different.

When the rigid member 7 as shown in FIGS. 2 and 3 is fixed to the bead portion 3, the rigidity is naturally higher than that of the conventional tire. Therefore, in order to secure the rigidity of the conventional tire, the reinforcing member of the tire can be simplified and reduced in weight in the present invention, and the weight of the entire wheel can be reduced.

[0016]

In the conventional pneumatic tire wheel, the pneumatic tire 4 is partly mounted on the bead portion 3 of the tire by first covering the outer periphery of the rim flange 9 and then the rest of the pneumatic tire 4 is passed over. Then, air is injected into the inner cavity of the pneumatic tire or a tube (not shown) housed in the inner cavity, and the pressure is increased to reach the regular internal pressure, whereby the pneumatic tire 4 is attached to the rim 6. The bead portion 3 is pushed along the bead seat 5 by this pressure until the outer surface of the bead portion 3 contacts the rim flange 9.

At this time, since the rim assembly work is apt to be discontinued while the clearance S is unevenly formed on the circumference between the bead portion 3 and the rim 6, the pneumatic tire itself is sufficiently caused by this. Despite being molded and vulcanized with the same uniformity, the RRO as a pneumatic tire wheel was large, and RFV was also generated along with it.

Further, in a pneumatic tire wheel, a proper tightening margin is usually attached to the rim 6 at the bead portion 3 of the tire. In order for the bead seat 5 and the inner circumference of the bead portion 3 to be closely fitted to each other, the surface pressure of the pneumatic tire 4 against the rim 6 caused by this interference is made uniform over the entire circumference. In the case of conventional pneumatic tire wheels, this surface pressure is generated by the fitting of metal (rim side) and rubber (tire side), but the characteristic of rubber is flexibility (deformability).
As a result, when the tire is assembled on the rim, the surface pressure does not act evenly over the entire circumference of the rim 6, and therefore the bead portion 3 is fixed at a predetermined fixed position on the same circumference of the rim 6 over the entire circumference of the rim 6. It is difficult to align them evenly, and the fixed position is likely to change due to the flexibility of the rubber once fixed, and there is a high possibility that the fixed position will change before it is finally fixed. ing.

On the other hand, in the pneumatic tire wheel of the present invention, an inner tapered member 7 made of a rigid material is integrally fixed to the inner circumference of the bead portion 3 of the pneumatic tire 4, and the rim 6 is By providing the bead seat 5 with a taper finish that matches the inner surface taper of the annular member 7, the surface pressure at the time of fitting the tire and the rim is not uniform over the entire circumference of the rim in the conventional fitting between rubber and metal. In contrast to the uniform operation, in the case of the present invention, the fitting between the rigid material and the metal is performed, so the above-mentioned uneven fitting is unlikely to occur, and the planned position is maintained over the entire circumference of the rim 6. The bead portion 3 is fixed to, and once fixed, the fixed position hardly changes until the end of the rim work, so that the uniformity of the pneumatic tire wheel is improved. Further, by fixing the rigid material 7 to the bead portion 3, the bead structure can be simplified and the weight of the tire can be reduced, and as a result, the weight of the entire wheel can be reduced.

[0020]

【Example】

[Test Example 1] A tubeless tire for passenger cars having a size of 205 / 65R15 was applied to an applicable rim (15 × 6JJ, J
RRO and RFV tests were performed using tire wheels incorporated in accordance with the ATMA standard) to evaluate wheel uniformity. The inventive pneumatic tire wheel shown in FIG. 1 was used in Example 1, and the conventional pneumatic tire wheel shown in FIG. 5 was used in the conventional example. Further, for the tire wheels used in Example 1 and the conventional example, the same structure as the conventional product was used except for the rim and the bead portion. Table 1 shows the test results
Shown in. The values in Table 1 are mm for RRO and kg for RFV.
It is a unit of f, and the smaller the value, the better the wheel uniformity.

[0021]

[Table 1]

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

Test Example 2 In the tire using the annular member 7 shown in FIG. 2, the reinforcing material of the bead portion was simplified, and the rigidity was evaluated by pressing the tire against the flat plate at 500 kg and then rotating the flat plate. The lateral stiffness obtained from the displacement and force when pulled in the direction parallel to the axis was taken, and the weight of the tire and tire wheel was measured as an evaluation of weight reduction. The conventional example is provided with a bead filler having a height of 50 mm and a chafer with a wire insert having a width of 30 mm, and Example 2 is a tire used in the conventional example except that the annular member 7 is fixed. The same as in Examples 3 and 4
Is the same as the tire used in Example 2, except that the bead filler heights are 25 mm and 5 mm, respectively, and Example 5 does not have a chafer with a wire insert.

[0024]

[Table 2]

From the results shown in Table 2, in Example 2, the wheel rigidity was slightly increased as compared with the conventional example, but the lateral rigidity was remarkably improved. In addition, in Examples 3 to 5, the total balance between lateral rigidity and wheel weight is superior to the conventional example.

[0026]

The pneumatic tire wheel of the present invention can surely fix the bead portion at a predetermined fitting position with the bead portion on the same circumference of the bead seat, and once fixed,
The fixed position does not fluctuate until the end of the rim work, improving uniformity. Further, even if the structure of the bead portion is simplified, the rigidity is not lowered and the weight can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a rim assembly procedure of an inventive pneumatic tire wheel used in an embodiment.

FIG. 2 is a cross-sectional view of the essential parts showing the rim assembly procedure of another invention pneumatic tire wheel.

FIG. 3 is a cross-sectional view of essential parts showing a rim assembly procedure of another invention pneumatic tire wheel.

FIG. 4 is a cross-sectional view of an essential part showing a rim assembling procedure of another invention pneumatic tire wheel.

FIG. 5 is a cross-sectional view of essential parts showing a rim assembly procedure of a conventional tire wheel used in a conventional example.

[Explanation of symbols]

1 side wall 2 bead core 3 bead part 4 pneumatic tires 5 bead sheets 6 rims 7 ring member 8 Lock member 9 rim flange 10 Bead sheet member 11 Pneumatic tire mounting direction S clearance

Claims (4)

(57) [Claims] 1. A pneumatic tire having a bead portion reinforced by embedding a bead core on an inner edge of a sidewall connected to a tread portion and a toroidal body, and a bead sheet used for tight taper fitting to the bead portion of the pneumatic tire. In a pneumatic tire wheel composed of an assembly with a rim, the pneumatic tire has an annular taper member with an inner taper made of a rigid material integrally fixed to the inner circumference of the bead portion, and the rim has an inner taper of the annular member. A pneumatic tire wheel with good uniformity, which is equipped with a bead seat having a taper finish compatible with. 2. The pneumatic tire according to claim 1, wherein the rim is provided with a pair of bead seats having a taper from the width end to the width center, and at least one of the bead seats is configured to be separable from the rim. Wheel. 3. The pneumatic tire wheel according to claim 2, wherein one of the bead seats is integrated with the rim, and the other bead seat is separable from the rim. 4. A bead having a taper formed on both bead seats toward one side in the width direction of the rim, and a taper heading from the width center of the rim to the width end in a mounting posture in which an annular member is assembled to these bead seats. The pneumatic tire wheel according to claim 1, wherein the seat has a lock member for fixing the annular member.