JPH0712762B2 - Tire and rim assembly - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a tire-rim assembly that can be suitably used particularly for heavy-duty vehicles and that has improved rim removal resistance without impairing rim assembly performance.

[Conventional technology]

In recent years, tubeless use of heavy-duty tires used for light trucks, trucks, buses, etc. has been promoted.

Further, in the tire-rim assembly adopted for such tubeless construction, as shown in FIG.
The seating angle α is deepened to 15 degrees in order to increase the seating pressure between the bead base portion a and the bead seat b at the time of filling with the internal pressure and to hold the bead portion c more firmly and airtightly. (In a passenger car, it is usually set to 5 degrees.) This is because heavy-duty tires are used at higher loads and higher internal pressures than passenger car tires, so the bead portion is more firmly fixed and its durability is improved. Need to maintain sex.

[Problems to be Solved by the Invention]

However, when the seating angle α is deepened in this way, the bead c portion moves inward along the bead seat b during puncture and when the internal pressure is insufficient, so that the bead c is likely to be detached in the rim well. In particular, since heavy-duty tires have extremely high bead rigidity, it is difficult to adopt the conventional rim disengagement prevention measures, such as making the rim assembly difficult, by causing the fitting hump to hit the bead seat.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a tire-rim assembly capable of solving the above-mentioned problems, based on the fact that a toe portion provided on a bead is fitted into an annular groove recessed in the rim.

[Means for Solving the Problems]

In order to achieve the above object, the tire-rim assembly of the present invention is an assembly consisting of a tire having a pair of beads and a wheel rim having a well for tire mounting, wherein at least one bead of the tire is A toe portion that is located on the inner side in the tire axial direction of the non-extensible bead core and that extends inward in the radial direction; a curved surface that extends concavely from the lower end of the toe portion and a joint surface that extends in the tire axial direction and that is continuous with the curved surface. In the tire meridional section formed through a bead base portion having an inclination angle α with respect to the tire axis of 12 to 18 degrees and outwardly in the radial direction, the wheel rim includes a well and a rim base continuous to the axially outer side thereof. A rim flange at the outer end in the axial direction is provided, and the rim base and the vicinity of the inner end in the axial direction of the flat portion extending substantially in the axial direction of the tire are recessed outside the flat portion. An annular groove for fitting the toe portion is formed, and the bead base portion is inclined at the outer end in the axial direction of the flat portion in a radial direction at an inclination angle β with respect to the tire shaft of 12 to 18 degrees in the tire suspension. While forming a bead seat portion for seating, the ratio W1 / W3 of the width W1 of the bead base portion and the width W3 of the bead seat portion is 0.5 or more and 1.0 or less, and from the inner end in the axial direction of the toe portion. The bead width W2 between the axial outer end of the bead base and the distance W4 from the axial outer end of the bead seat to the groove center of the annular groove.
The ratio W2 / W4 is 0.7 or more and 1.0 or less, and further, the radial height H1 from the lower end of the toe portion to the outer end of the bead base portion and the height from the lower end of the annular groove to the outer end of the bead seat portion. The ratio H1 / H2 to H2 is 0.7 or more and 1.2 or less.

[Action]

In the tire-rim assembly thus configured, the toe portion extending inward in the tire radial direction is provided on the bead of the tire, and the annular groove is provided on the wheel rim. Therefore, the toe portion and the annular groove are fitted to each other. By doing so, it is possible to prevent the bead from being detached from the rim well and coming off the rim. Also, unlike the conventional hump, the annular groove is recessed inward of the bead seat in the radial direction, and the toe part has rubber elasticity, so the rim assembly performance may be impaired even in a tire with a highly rigid bead. Absent.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, a tire 1 used in the present invention has a toroidal shape having a bead 3 through which a bead core 2 passes, a side wall 4 extending outward from the bead 3 in a radial direction, and a tread 5 connecting between upper ends thereof. A heavy-duty tire forming a carcass 6 having both ends of a main body 6A passing through a red 5 and a side wall 4 and being locked to a bead core 2 is arranged between the beads 3, and a toe part is provided on the bead 3. 7
Is formed.

The carcass 6 is a rewinding portion that rewinds the non-stretchable bead core 2 made of a bundle of metal cords from the tire inside to the outside.
The carcass 6 is formed of a plurality of plies having 6B at both ends of the main portion 6A. As the carcass 6, for example, an organic fiber cord such as nylon, polyester, aromatic polyamide or an inorganic fiber cord such as a metal fiber is attached to the tire equator. 2070
Cross ply structure in which cords between plies cross each other, or radial structure using plies with a cord angle of 70 to 90 degrees with respect to the tire equator. Can be adopted.

Note that FIG. 1 illustrates a radial structure having two plies, and a tough belt layer 9 arranged at an inclination angle of 30 degrees or less with respect to the tire equator is provided outside the carcass 6. By placing the tread 5 over almost the entire width, the tread rigidity is increased, and high-speed running stability, puncture resistance, etc. are improved.

Further, a taper extends from the bead core 2 along the side wall 4 between the main body portion 6A and the winding portion 6B of the carcass 6,
A bead apex 10 made of hard rubber is provided to enhance the rigidity of the bead 3.

As shown in FIG. 2, the bead 3 has a carcass 6
The inner side of the tire in the axial direction is provided with an inwardly-facing piece made of hard rubber having a substantially triangular shape and a lower end protruding inward in the radial direction and having a hardness of 65 to 95 degrees. The lower end portion forms a toe portion 7 that is located on the inner side in the tire axial direction of the bead core 2 and extends to the inner side in the tire radial direction. The toe portion 7 has a curved surface, for example, an arc surface, which smoothly extends in a concave shape from the lower surface outward in the radial direction.
A bead base portion 15 is adjacently provided via a joint surface 13 which is continuous with the curved surface and extends substantially in the tire axial direction so as to be substantially horizontal in the drawing.

The bead base portion 15 extends radially outward from the axial outer end of the joint surface 13 at an inclination angle α of 12 to 18 degrees with respect to the tire axis in the tire meridional section, and the outer end of the bead base portion 15 is a bead. It breaks on the outside.

The bead 3 can be reinforced by a chafer (not shown) or the like, as in the conventional tire.

Next, a wheel rim 11 used in the present invention, a well 12 recessed in the center of the wheel rim 11, a pair of rim bases 16 connected on the outer side of the well 12 in the axial direction, and further each rim base 16
Rim flange 17 that projects radially outward at the outer axial end of
And with.

In addition, the rim base 16 has a flat portion 21 extending in the tire axial direction.
At the axially outer end of the tire meridional section, the inclination angle β with respect to the tire axis is 12 to 18 degrees, preferably the inclination angle α.
A bead seat portion 20 for seating the bead base portion 15 is formed by inclining outward in the radial direction in conformity with the above. Further, the flat portion 21 is provided with an annular groove 19 in the circumferential direction near the inner end in the axial direction, into which the flat portion 21 is recessed and the toe portion 7 is fitted. This allows the well 12 to be continuous with the annular groove 19 without a radial projection such as that of a conventional hump. The term "approximately in the axial direction of the tire" can prevent interference with the joint surface 13 and prevent poor fitting between the toe portion 7 and the annular groove 19 and poor seating between the bead base portion 15 and the bead seat portion 20. , Including the tilt direction parallel to the tire axis or inclined at a shallow angle with respect to the tire axis.

And, the mounting of the tire 1 on the wheel rim 11 is as follows.
This can be performed in the same manner as a normal tire and rim. For example, by inserting the bead 3 into the well 12 over the rim flange 17 and then filling the air with the air valve, the bead 3 is moved along the rim base 16. The bead base 15 is seated on and pressed by the bead seat 20, and the toe 7 is fitted into the annular groove 19, so that the bead 3 is moved to the wheel rim.
Firmly held at 11.

Since the rim base 16 does not have a protruding portion such as a conventional hump, the highly rigid bead 3 can be easily moved by the internal pressure, and the toe portion 7 is a rubber elastic body and has a strong bead core 2 in the tire axial direction. Since it is provided inside, it is possible to ride from the well 12 to the rim base 16.

Here, in order to surely and easily fit the bead portion 3 and the wheel rim 11, the ratio W1 / W3 of the width W1 of the bead base portion 15 and the width W3 of the bead seat portion 20 is 0.5 or more and The ratio W2 / W4 of 1.0 or less and the bead width W2 and the distance W4 from the outer end of the bead seat portion 20 to the groove center P of the annular groove 19 is 0.7 or more and 1.0 or less, and the toe portion 7 lower end to the bead base portion 15 The ratio H1 / H2 between the height H1 to the outer end and the height H2 from the lower end of the annular groove 19 to the outer end of the bead seat portion 20 needs to be 0.7 or more and 1.2 or less.

The outer end of the bead base portion 15 and the outer end of the bead seat portion 20 are located at the intersections on the respective extension lines of the bead outer surface and the lower surface of the bead base portion 15 and on the extension lines of the inner surface of the rim flange 17 and the upper surface of the bead seat 20. Defined at the intersection. These set values are obtained by the results of various experiments conducted by the present inventor, and the tire 1 and the wheel rim 11 used in the experiments are set.
Table 1 shows the specifications and the experimental results are shown in Fig. 3 (a). ~ (D).

As shown in FIGS. 3 (a) to (d), when the ratio W1 / W3 exceeds 1, when the ratio W2 / W4 is less than 0.7 and when the ratio W2 / W4 exceeds 1, the front toe part 7 is It is difficult to fit in the annular groove 19, and the rim is likely to come off.

If the ratio W1 / W3 is less than 0.5, the seating area between the bead base portion 15 and the bead seat portion 20 becomes insufficient, and the rim removal resistance and the bead holding ability are poor.

Further, when the ratio H1 / H2 is less than 0.7, the fitting becomes insufficient and the rim removal resistance performance is deteriorated, and when the ratio H1 / H2 exceeds 1.2, the rim assembly performance is impaired.

By setting the regulation range as described above, the fourth
It is possible to mount the conventional tire on the wheel rim 11 and the conventional tire as shown in FIG.

〔The invention's effect〕

As described above, the tire-rim assembly of the present invention has a toe portion extending inward in the tire radial direction on the bead of the tire, and an annular groove into which the toe portion can be fitted on the wheel rim. Since it is provided inside, it is possible to greatly improve the anti-rim disengagement performance without impairing the rim assembly performance, and it is possible to enhance the traveling safety.

In addition, this product can be easily formed by additional processing to conventional tires and rims, can suppress the increase in production cost, and is compatible with conventional tires and rims for convenience of use. It can have many effects.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view showing a bead portion, and FIG. 3 (a) shows a relationship between rim removal resistance performance and a ratio W1 / W3. Fig. 3 (b) is a diagram showing the relationship between the rim removal resistance performance and the ratio W2 / W4, and Fig. 3 (c) is a diagram showing the relationship between the rim removal resistance performance and the ratio H1 / H2. 3 (d) is a diagram showing the relationship between the rim assembly performance and the ratio H1 / H2, and FIG. 4 is a sectional view for explaining the conventional technique. 1 ... Tire, 2 ... Bead core, 3 ... Bead, 7 ...
… Toe part, 11 …… wheel rim, 12 …… well, 15 …… bead base part, 19 …… annular groove, 20 …… bead seat part, 21 ……
Flat part.

Claims (1)

[Claims] 1. An assembly comprising a tire having a pair of beads and a wheel rim having a well for mounting the tire, wherein the beads of the tire are located inward of the non-extensible bead core in the tire axial direction and in the radial direction. An inwardly extending toe portion, a curved surface extending in a concave shape from the lower end of the toe portion, and a tilt angle α with respect to the tire axis in the tire meridian section formed through a joint surface continuous to this curved surface and extending substantially in the tire axial direction are 12 to 18 The wheel rim includes a well, a rim base connected to the axially outer side of the well, and a rim flange at the axially outer end thereof, and the rim base is substantially the same. An annular groove for fitting the toe portion is formed by recessing the vicinity of the axial inner end of the flat portion extending in the tire axial direction outside the flat portion while leaving the flat portion, and the axial outer portion of the flat portion. In the tire meridional section, the inclination angle β with respect to the tire axis forms a bead seat portion for seating the bead base portion while inclining outward in the radial direction at 12 to 18 degrees, while the width W1 of the bead base portion and the bead seat portion. The width W3 of the bead portion is 0.5 or more and 1.0 or less, and the bead width W2 between the axially inner end of the toe portion and the axially outer end of the bead base portion, and the bead seat portion. Ratio of the distance W4 from the axial outer end of the to the groove center of the annular groove W2
/ W 0.7 or more and 1.0 or less, moreover, the radial height H1 from the toe portion lower end to the outer end of the bead base portion, and the height H2 from the annular groove lower end to the outer end of the bead seat portion. ratio
A tire and rim assembly with H1 / H2 of 0.7 or more and 1.2 or less.