JPH01306301A - Rim for tubeless tire - Google Patents

Abstract

PURPOSE:To facilitate a rim assembly and to prevent a rim off by respectively specifying the angles made by the height of a hump, the depth of a hollow, the rise line of the hollow and a rim diameter. CONSTITUTION:The height H of a hump is made to be (rim diameter -0.3mm to rim diameter +0.5mm). The rim off of a tyre is thus prevented at the trouble generation time of the reduction of the type air pressure, air leakage, etc. The depth D of a hollow is taken in 2mm at least and the angle gamma made by the rise line of the hollow and the rim diameter is taken at 70-85 deg.. The adhesion of the head toe 10 of a tyre and a hollow 15 is well performed, no air is leaked, the hanging of the tyre bead toe 10 and hump 5 becomes better and the rim assembly is easily performed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a rim for tubeless tires that is easy to assemble, that prevents the tire bead toe from coming off the rim, and that can effectively prevent air leakage. This invention relates to rims for passenger car tires.

[Conventional technology]

Conventionally, tubeless tires (hereinafter simply referred to as tires)
It is well known that when a tire becomes flat or its air pressure decreases, the tire bead tends to come off the rim, making it difficult for the vehicle to run.

In order to prevent such troubles, for example, as shown in FIG. 2, a recess 15 is provided in the bead seat portion of the rim 1, and the bead toe 10 of the tire is made to have a protruding structure, and the recess 15 and the bead toe 10 are mating,
It is known that the bead of the tire does not easily come off the rim even if the tire banks or the air pressure decreases.

However, in the case of such tires, both the rim and the tire (build toe) must have a special shape and structure, so they lack versatility and are usually
Since variations in tire bead width are unavoidable, this variation in bead width has a practical drawback in that it becomes difficult to fit the tire onto the rim.

[Purpose of the invention]

The object of the present invention is to provide a rim that is not a tire with a special shape or structure, but is versatile enough to allow conventional tires to be used as is, is easy to assemble, and is unlikely to come off the rim. It is to be.

[Structure of the invention]

The rim according to the present invention includes sequentially the following steps on the extension line of the beat sheet:
For rims with depressions and humps, the height of the hump (
H) (rim diameter -0.3mm to rim diameter +0.5mm)
, <The depth of the recess (D) is at least 2 mm, and the angle (T) between the rising line of this recess and the rim diameter
is set to 70° to 856°.

FIG. 1 is a partial cross-section showing one example of such a rim of the present invention. As shown in the figure, the rim 1 of the present invention has a recess 15 and a hump 5 sequentially on an extension line of a bead seat inclined at an angle α with respect to the rim diameter, and the depth D of the recess 15 and the recess 15 The feature is that the angle γ between the rising line of the rim and the rim and the height H of the hump 5 are specified.

In the present invention, the height H of the hump 5 is [rim diameter - 0
. The effect of preventing the rim from coming off will be reduced, and on the other hand, if the height H of this hump 5 is [
If the diameter is larger than rim diameter + 0.5mm), and
If the depth D of the recess 15 is too small, it is not preferable because it becomes difficult for the tire bead tow 10 to fit into the recess 15 and the tire is likely to come off the rim in the event of trouble such as air leakage. The upper limit of the depth D of this recess 15 is not particularly limited, but if it is too deep, the bead toe 10 of the tire that has moved due to the tire bank or decrease in air pressure will not be able to completely fit into the recess 15. This may cause air leakage. In other words, when the tire is mounted on the rim, the bead toe 10 of the tire is compressed (referred to as a shimshiro of the tire bead toe), so the bead toe may move into the depression 15 due to air leakage or the like. When, bead tow 1 due to this shimeshiro
If the depth D of the recess 15 is too large than the zero expansion, the bead toe and the recess will not come into close contact with each other, resulting in air leakage. Considering this relationship with Shimeshiro,
The upper limit of the depth of the recess is preferably about 4 mm, but if the recess is deep, it is possible to fill the bottom of the recess with packing or the like to prevent air leakage caused by the bead tow shimmy.

Furthermore, if the angle T between the rising line of the recess 15 and the rim diameter is too small, it will be difficult for the tire bead toe 10 to catch on the hump 5 and fit into the recess 15, which is undesirable; on the other hand, if it is too large, Since it becomes difficult to assemble the rim, it is best to set the angle in the range of 706 to 85 degrees.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

In the Examples, fitting pressure and rim detachment performance as representative values of rim assembly performance were measured by the following measuring method.

Fitting pressure (rim assembly performance): The air pressure required to completely fit the tire onto the rim. Therefore, the smaller the fitting pressure, the easier (better) the rim assembly is.

Rim detachment performance: The tire was run on a circle with a radius of 25 m at 60 km/hr, the air pressure was gradually lowered, and the rim detachability was evaluated based on the air pressure at which the tire fell off the rim. therefore,
It means that the smaller the air pressure is, the better the rim removal performance is (the rim is less likely to come off).

Example, Comparative Example Tire size is 205/60R15, standard diameter is 380.2 mm, 5H is 0.31, D is 3+n+a,
The rim assembly performance and rim detachment performance when mounted on the rim shown in FIG. 1 where γ is 75° were investigated by measuring the fitting pressure and rim detachment air pressure, and the results are shown in the table.

For comparison, the above tire was mounted on a normal rim without a recess as shown in Fig. 1, and the fitting pressure and disengagement air pressure were measured, and the results are shown in the table.

From Table 1, it can be seen that the tires of the present invention have the same rim assembly performance (fitting pressure) and are significantly superior in rim removal performance compared to the comparative tires.

[Effects of the Invention] The rim of the present invention is not a special tire, but can be applied to a conventional tire and easily assembled into the rim, and even if the tire becomes punctured or the air pressure decreases,
To effectively prevent a tire from coming off a rim and enable a vehicle to run continuously.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing one example of the rim of the present invention, and FIG.
The figure is a sectional view of a tire mounted on a conventional rim. 1...Rim, 5...Hump, 10...Bead toe, 15...(Bomi. Agent: Patent attorney Shin Ogawa -

Claims (1)

[Claims] For a rim with depressions and humps sequentially provided on the extension line of the beat seat of the rim, the height of the hump (H) is (rim diameter - 0.3 mm to rim diameter + 0.5 mm), and the depth of the depression (D) be at least 2 mm, and the angle (T) between the rising line of this recess and the rim diameter should be between 70° and 85°.
° Rim for tubeless tires.