JPS5939325B2 - Bead element for tires - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the construction of bead elements used in pneumatic tires.

2. Description of the Related Art Conventionally, as a bead element used in automobile tires, one in which a flattened steel wire 1 is wound in multiple layers in the thickness direction, as shown in FIG. 1, is known.

Also, as shown in Figure 2A, wires made by arranging a plurality of #19 hard steel wires 2 in the row direction, covering them with rubber 3, and winding them in multiple layers in the layer direction are commonly used. .

However, in both cases, the strength decreases because the wires become dispersed and disordered during vulcanization when attached to the tire, causing the overall shape to deform or shift.As a result, a safety factor of 10 times the required stress is expected. The disadvantage is that it has to be designed in a way that is wasteful.

In order to eliminate this shape deformation and reliably maintain a constant shape, a steel strip 4 is formed to have an uneven cross section as shown in Figure 2, and then wound in multiple layers in the thickness direction as shown in Figure 1. is considered.

However, forming the cross-sectional shape of the strip steel plate, explosion welding at the end to prevent slipping, etc. required time and effort, and manufacturing efficiency was poor.The zero-cross strip steel plate also had the disadvantage of low tensile strength and insufficient performance. .

Alternatively, a single hot or cold-formed steel bar is bent, both ends of which are welded to form an endless ring, and both top and bottom surfaces of this endless ring are formed (for example, Utility Model No. 49-36603
No. 2) has been proposed.

However, this method also had the drawback of poor manufacturing efficiency, such as not only requiring time and effort to form a single steel bar and welding both ends of the rod, but also requiring time and effort to form both the top and bottom surfaces.

The present invention eliminates the above-mentioned drawbacks, and embodiments thereof will be described below with reference to the drawings.

Embodiment As shown in FIG. 3A, a flattened steel wire 5 of a certain size having the required tensile strength, hardness, and elasticity is wound onto a reel 6, which is hung on a frame 7, and one end of which is continuously sent out via a feed roller 8. As shown in FIG. 4, the forming machine 9 gives the required radius of curvature so that both sides 12 and 13 of the flattened steel wire in the width direction t form an inner diameter and an outer diameter, respectively, so that it becomes approximately truncated conical. Wind.

The molding machine may be a molding machine having a curvature roller 10 used for molding springs, rings, etc., as shown in FIG.

The bead element is wound in several rows and then cut to form a bead element as shown in FIG.

As shown in FIG. 4, the bead element according to the present invention can have a substantially truncated conical shape by controlling the roller 10 and winding the bead element in multiple rows while sequentially increasing or decreasing the diameter.

The under-bead element of the present invention as shown in FIG. 4 is inserted into the bead portion 11 of the tire so that the inclination of the truncated conical shape approximately matches the inclination of the bead seat 14 of the rim as shown in FIG. .

As is clear from the above embodiments, the present invention involves winding a square steel wire or a flattened steel wire having a large tensile strength and elasticity in several rows in the width direction so as to give a required radius of curvature so as to form a truncated cone shape. Unlike conventional bead wires, when installed inside a tubeless tire, the overall shape does not deform or shift, especially in the lateral direction, and can reliably maintain a constant shape. Since the inclination of the bead seat and the inclination of the bead element match, a large surface pressure can be obtained between the bead seat and the tire bead portion, and tire detachment and air leakage can be prevented.

In addition, the bead element of the present invention is a square steel wire or a flattened steel wire wound vertically so that both sides in the width direction form the inner diameter and outer diameter, respectively, so the cross section is quadratic considering the surface on which force acts. A bead element with a large moment and high strength can be obtained.

Since the sympathetic type is carried out by a feed roller, there is no need to stop after winding and set the winding as in the conventional case, and continuous production is possible.

The end of the winding does not need to be welded or otherwise prevented from slipping, and can be simply fixed with a rubber tape, for example.

Therefore, it has excellent effects such as significantly improving manufacturing efficiency.

[Brief explanation of the drawing]

Figures 1 and 2 (A 9) are sectional views of essential parts of a bead element showing a conventional example, Figure 3 (A) 5 is a manufacturing process diagram of the bead element according to the present invention, and Figure 4 shows an embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view of the bead element shown in FIG. steel wire,
3...Rubber, 4...Strip steel plate, 6...
... Reel, 7... Mount, 8...
Roller, 9...Forming machine, 10...Roller with curvature, 11...Bead part, 12.13.
...Side, 14...Bead seat.

Claims (1)

[Claims] 1. A piece of rectangular steel wire or flattened steel wire having elasticity is wound into a substantially truncated conical shape by sequentially changing the radius of curvature so that both sides in the width direction form an inner diameter and an outer diameter, respectively. A tire bead element characterized by: