JPH0327401B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rubber tire, and more particularly to a rubber tire for agricultural machinery which is adapted to be used with very low internal pressure filling or without internal pressure filling.

Rubber tires for agricultural machinery used for work on soft ground such as fields are able to obtain a wide tread contact area with extremely low internal pressure or no internal pressure to prevent them from sinking into the soil during work. Because of this necessity, so-called rubber tires are used, such as tires for passenger cars or trucks and buses, which have virtually no reinforcement, such as a carcass made of cord ply.

When fixing such a rubber tire to a used rim as a wheel, it is easy to fix the bead of the tire to the used rim with adhesive, as has already been proposed, but there are concerns about reliability. Rather, it is more practical to not omit the bead ring, but to use it to harden the bead portion of the tire and provide tightness to the rim base of the rim in use.

However, if the conventional practice of embedding a bead ring, which requires non-stretchability, as one piece in the bead portion of a tire is followed, vulcanization molding of the tire is time-consuming.

The object of the present invention is to prevent the vulcanization molding operation of the tire from having a non-stretchable bead ring or equivalent means for restraining and fixing the bead portion of the tire to the rim used during tire manufacturing. An object of the present invention is to provide a rubber tire for agricultural machinery that simplifies rim assembly work.

This invention provides a pair of sidewall portions 3 which extend inwardly in the radial direction of the crown portion 2 along with the crown portion 2 in a toroidal shape at both side edges of the crown portion 2 having the treaded land portion 1, and these sidewall portions 3. A pair of bead portions 4 that limit the inner peripheral edge of
In a tire having a crown part 2, a sidewall part 3, and a bead part 4 made of rubber that are substantially integrally molded, a two-piece tire that is applied from the outside of both sides of the tire and fitted into both bead parts 4 is used. Each of the bead portions 4 that is compatible with the rim base R _b and the rim flange R _f of the type of rim R used includes a pair of circumferential grooves 7 that face each other and open laterally, and an inner and/or The tire has inner ribs 11, 11' extending inwardly along the outer periphery, and each bead portion 4 is guided by the inner ribs 11, 11'.
This rubber tire for agricultural machinery is characterized in that it is used in combination with a tension support cylinder 9 made of synthetic resin that fits into a circumferential groove 7 and prevents the bead portion 4 from being pressed against the rim flange R _f . .

Here, a non-stretchable bead ring 8 that fits into the groove bottom of the circumferential groove 7 is applied to the bead portion 4, and the bead portion 4 is tension-supported to the rim flange R _f via this bead ring 8. It is an elastically deformable, thin-walled cylindrical body that is restrained by pressure contact by the cylinder 9, and that the tension support cylinder 9, excluding the restraining edges 10 and 10' at both ends, provides a buffering effect against excessive external force acting on the tire. In terms of implementation, it is preferable to have the following.

The present invention will be explained below based on the drawings.

FIG. 1 is a sectional view of a wheel assembly using a rubber tire for agricultural machinery according to the present invention.

In the illustrated tire, the tire 1 has a pair of lugs 5 which extend inwardly in the radial direction of the crown part 2 in a toroidal shape together with the crown part 2 at both side edges of the crown part 2 having treaded land parts as shown in the example of lugs 5. The crown part 2, the sidewall part 3, and the bead part 4 are made of rubber that are substantially integrally molded.
In this embodiment, the crown portion 2 has a substantially flat shape in the width direction of the tire 1 together with the top surface of the lugs 5, and the lugs 5 extend along the tread circumference alternately on the left and right with the equatorial plane E-E of the tire in between. The sidewall portions 3 are arranged at intervals, and each of the sidewall portions 3 has a curve that narrows toward the inside of the tire 1, so that the entire sidewall portion 3 has a leaf-like cross-sectional shape.

In principle, this tire 1 is made of a single piece of rubber without embedded reinforcement, such as a carcass with a cord layer as a reinforcing material, a breaker, or a bead core made of a steel wire wound body. It is possible to provide buried reinforcement of the cord layer.

Now, each bead portion 4 is provided with a pair of circumferential grooves 7 which face each other and open laterally, and further along the inner and/or outer periphery of this circumferential groove 7,
An inner surface rib 11 and/or 11' (see FIG. 2) is formed to project inwardly from the tire 1. An example in which inner ribs 11, 11' are provided twice along both the inner and outer circumferential edges is omitted.

Reference numeral 9 in the figure is a tension support cylinder made of synthetic resin, which has the above-mentioned circumferential groove 7 and inner rib 1 at both ends.
1 and 11', the intermediate region between the two restraining edges 10 is a thin-walled cylindrical part, and the restraining edge 10 remains in the circumferential groove 7, and the bead part 4 However, as shown in the figure, a removable non-stretchable bead ring 8 may be fitted in advance into the circumferential groove 7 and used as a reinforcing core for the bead portion 4.

Of course, this bead ring 8 can be made of a conventional steel wire wound body, but it differs from the conventional one in that it is not buried in the bead portion.

The tension support cylinder 9 is required to be lightweight and to have enough elasticity to provide a buffering effect against excessive external force acting on the tire, which can be achieved by using a hard synthetic resin material. The restraining end 10 of the tension support cylinder 9 is 1/1 of the thickness of the bead ring 8.
It is also possible to have a wall thickness T that is 1 to 1/2 times as large, and make the wall thickness comparable to the wall thickness T of the restraining end 10 over the entire tension support cylinder 9, but as shown in the figure. By making the wall thickness t of the intermediate region thinner than that of the restraining end 10, even when an excessive force in the lateral direction is applied to the tire, a moderate degree of flexing is produced, and the resulting effective cushioning action allows the restraining end 10 or the bead ring 8 to rim flange
It is desirable to protect the bead portion 4 sandwiched between R _f .

Here, the ratio of the wall thickness between the restraining end 10 and the intermediate region T/
t can range from 1 to 4, preferably from 1.5 to 4, although it depends on the type and nature of the synthetic resin material used.

In this invention, the rim base R _b and the rim flange R _f of the rim R used are made up of two rim halves R _l and R _r that are fitted onto the pair of bead parts 4 from the outside on both sides of the tire, respectively. The two rim halves R _l and R _r are adapted and joined together, for example by bolted connection. As shown in the figure, the rim R used is slightly sloped downward toward the abutting surfaces of the two rim halves R _l and R _r , and also has a restraining end 10 of the tension support cylinder 9 and a bead ring. 8 fitted into the circumferential groove 7, the bead portion 4 is reinforced, and when assembling the tire with the rim R, an appropriate tightening allowance is provided between the bead portion 4 and the rim R to be used, and a firm rim assembly is achieved. be done.

The inwardly directed ribs 11, 11' serve here to maintain concentricity during the fit between the circumferential groove 7 and the restraining end 10 of the tension support cylinder.

In Figure 1, number 12 indicates the rim flange.
An example is shown in which an external rib is provided that protrudes outward along the rim flange R _f to prevent dirt from entering between R _f and the bead portion 4 during field work.

In the case where the bead ring 8 shown in the present invention is not used, the restraining end 10 of the tension support cylinder 9 also serves this function, and in this case, the wall thickness of the restraining end 10 corresponds to that of the bead ring 8.

In assembling the tire and rim shown in the figure, first the bead rings 8 are fitted into the circumferential grooves 7 of both bead portions 4 of the tire 1, and then the tension support cylinder 9 is inserted between the bead rings 8 and the inner surface rib 1.
Fit along lines 1 and 11'. Then, apply the rim halves R _l and R _r of the used rim R from the left and right sides of the tire 1, push them into the bead parts 4, 4, and place the used rim R at the equatorial plane E-E position of the tire as shown in Figure 1. After matching at the deix portion, the assembly as a tire wheel is completed by fixing this portion together by tightening bolts.

Also, the tension support cylinder 9 is not used without the bead ring 8.
In the case where the bead portion 4 is fixed to the rim R with only the above-described series of steps, the work of fitting the bead ring 8 into the circumferential groove 7 is simply omitted.

When using the tire wheel assembled in this way for work, if the tire wheel is to be used without internal pressure filling, it is sufficient to attach the tire wheel as is to the vehicle, or if the tire wheel is to be applied with extremely low internal pressure, it can be attached to the base of the rim. After injecting air from a valve (not shown), it can be installed on the vehicle.

As described above, the agricultural machinery tire of this invention is
Since the bead part 4 is reinforced when assembling the rim, there is no need to bury the bead ring during tire manufacture, making the vulcanization process much easier, and compared to tires with embedded bead rings. It is extremely easy to assemble the tire rim, and the bead portion 4 is supported by the tension support cylinder 9, making it easier to assemble the rim R.
Since it is firmly restrained and held against the rim base R _b and rim flange R _f , there is no concern that the bead part 4 will come off the rim even under no or very low internal pressure, making it suitable for use as a transportation wheel for agricultural machinery. The utility value is extremely large.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of a wheel using an agricultural rubber tire of the present invention, and FIG. 2 is a cross-sectional view of a main part of a bead portion of another example. 1... Tire, 2... Crown part, 3... Sidewall part, 4... Bead part, 5... Lug, 6
... Inner cavity of tire 1, 7 ... Circumferential groove, 8 ... Bead ring, 9 ... Tension support cylinder, 10 ... Restriction end, 11, 11' ... Inner rib.

Claims (1)

[Scope of Claims] 1. A pair of sidewall portions 3 extending inwardly in the radial direction of the crown portion 2 along with the crown portion 2 in a toroidal shape at both side edges of the crown portion 2 having the treaded land portion 1; A tire comprising a pair of bead parts 4 that limit the inner peripheral edge of the sidewall part 3, and in which the crown part 2, the sidewall part 3, and the bead part 4 are made of rubber that are substantially integrally molded. Each of the bead portions 4, which fit the rim base R _b and rim flange R _f of a split type used rim R used by fitting both bead portions 4 from one side to the other, has a pair of sideways opening facing each other. It has a circumferential groove 7 and an inner surface rib 11, 11' extending inward of the tire along the inner and/or outer periphery of each circumferential groove 7, and under the guidance of the inner surface rib 11, 11'. At each bead part 4
A rubber tire for agricultural machinery, characterized in that it is used in combination with a tension support cylinder 9 made of synthetic resin that fits into a circumferential groove 7 and prevents the bead portion 4 from being pressed against the rim flange R _f . 2. A non-stretchable bead ring 8 that fits into the groove bottom of the circumferential groove 7 is applied to the bead portion 4, and the bead portion 4 is connected to the rim flange via this bead ring 8.
A rubber tire for agricultural machinery according to claim 1, characterized in that R _f is restrained from being pressed against R f by a tension support cylinder 9. 3 The tension support cylinder 9 has restraining edges 10 and 1 at both ends.
A rubber tire for agricultural machinery according to claim 1 or 2, which is made of an elastically deformable, thin-walled cylindrical body that provides a buffering effect against excessive external force acting on the tire, except for 0'. .