CS214652B2 - Tyre - Google Patents

Abstract

Pneumatic tyre comprises a beading reinforcement composed of a central core and surrounding bundle of wires. These wires are helically wound to form a continuous band through the beading. A binding agent is introduced in liq. form with low surface tension between the wires, so as to wet them completely and provide a corrosion protection to the bright metal wire surfaces. This binding agent firmly secures adjacent wires to one another, and bonds to the surrounding tyre material. The binding agent possesses a thermally non-recurrent, short-term polymer phase at the vulcanisation temp. of the main tyre material. Design is applied partic. to tubeless tyres for goods vehicles with radial reinforcement. The reinforcement can be prefabricated before bonding into the tyre and does not become twisted and thus exert a cracking effect upon the tyre wall. When the tyre is mounted on the wheel rim, before being inflated, the beading tends to adopt the correct position and to maintain this position subsequently.

Description

The invention relates to a tire with a bead cable, in particular. 'tubeless steep-side truck tires' and a radial carcass, the bead of which is formed by a tube and at least one layer around the tube several times in a helical wound and endless closed wire.

The bead cable ropes located in the tire bead serve both for anchoring the carcass reinforcement and for positioning the tire on the rim.

The cable ropes of the shoe of the type described are advantageous in comparison to the bundle cores of the shoe in that they have a considerably greater tensile strength and allow a radial rotation that is. For production and assembly reasons, it is desirable without permanently changing their cross-sections.

However, the radial pivotability of the known bead wires is so great that when the tire is used by rolling, cracks are formed at the outlet of the reinforcement wrapped around the bead cable. '' Tensile load '' on 'wrapped skeleton reinforcement. due to the bonding of the rubber between the carcass reinforcement and the shoe cable, the shoe cable acts such that the wound layers of the shoe cable cable rotate with respect to its soul. The internal friction in the bead cable and the work of rolling the tire tread causes the tire mass to heat up. This leads to changes in the mass structure of the tire in the bead region. Below the vulcanization temperature, the elasticity of the tire mass increases, above this temperature the tire mass becomes brittle. In the phase of increased elasticity of the carcass, the carcass reinforcement may perform larger pivotal movements, which may be so large that the outlet end of the carcass reinforcement can detach from the tire mass and tear it.

In order to avoid the cracks described, it is known, for example, from German Patent Application 2111 939 to arrange three cable wires in each tire bead which are tangential to each other and the carcass reinforcement is guided as a whole around the three wires, making them stable against shooting. However, this and other measures are very costly and do not imply any significantly better solution to the problems described.

SUMMARY OF THE INVENTION It is an object of the invention to improve known tires and to achieve this improvement by simple means. In particular, cracks in the sheath having only one prefabricated piece, i.e. the sheath strand, in each shoe as reinforcement should be prevented. Further, in the manufacture of the tire and its fitting, a favorable radial deformation of the reinforcement can be achieved by ensuring that the bead of the stretched tire rests automatically in the correct position on the rim prior to being filled with compressed air and is maintained in that position throughout the operation.

The above drawbacks are overcome by a cable cable tire according to the invention, the invention of which: the essence is that the bead 'cable' of the tire is completely saturated with the liquid binder.

There is thus obtained a perfect cable foot of the shoe which, compared to dimensionally the same embodiments, has a significantly higher stability against rotation and which, to an unprecedented extent, counteracts the formation of 'cracks' in the sheath in the carcass reinforcement areas under the action of rolling. However, this foot cable also satisfies the requirement of some radial elastic deformation which cannot be surrendered completely for manufacturing and assembly reasons.

Moreover, there is no longer any need for surface treatment such as. for example, copper, brass or bronze coat the steel wire wires to prevent rusting and to achieve greater rubber adhesion, and there is no need to add auxiliaries to the tire mass to achieve better bonding between the tire mass and the bead cable.

A further advantage is that the tire mass penetrates deep into the bead cable during vulcanization, thereby achieving a mechanical connection between the bead cable and the tire mass.

According to a particularly preferred embodiment of the invention, the binder forms dissolved organic polymers and other nonvolatile polyisocyanates and dispersed solids in organic solvents such as xylol or toluene.

Under certain circumstances, artificial resins may also be used as binders.

The invention is explained in more detail below in an exemplary embodiment in conjunction with the drawing.

FIG. 1 is a cross-sectional view of the bead including the rim of a partially illustrated tire.

FIG. 2 shows a detail on a larger scale.

The drawings show part of a tire for. trucks in a cut that is stored on a rim with steep sides.

Into the bead 1 of the tire, namely a tubeless rubber tire, a cable cable 2 is inserted, with which the carcass reinforcement 3 is provided. The cable cable 2 has an annular steel tube 4 having a flat cross section and two layers 5, 6 which are formed. the steel wire, endlessly closed and helically wound around an endless annular steel tube 4. The cable 2 of the bead 1 of the tire is saturated with a binder 7 before insertion, which, due to low surface tension, penetrates deeply into the cable 2 due to low surface tension. and at the same time partially or completely fills its internal cavities. After drying the binder 7, which is carried out at room temperature, all elements of the cable cable 2 are rigidly connected to one another. The bonding 7 also achieves a much better adherence between the cable wires 2 a

6.5 with the mass of the tire than previously, without the need for surface treatment of the cable 2, for example with copper, and without the need to add to the mass of the tire the means to ensure greater consistency with the copper-plated or similarly surface-treated cable.

It is also possible to use thermoplastics or synthetic resins having the desired properties.

The excellent properties achieved with binder have been reliably proven by tests.

A number of experiments were used to determine to what extent the torsion strength of cable 2 is influenced by the cross-section of the core, the diameter of the wire being wound and the number of shocks per thread and the binder supplied - 7.

To carry out the tests, the cable 2 was vertically tensioned and rotated 90 ° to the central axis of the cable 2 within ten seconds. The highest measured force is marked F. Then the cable 2 was unloaded. After this relief, the cable 2 has been moved in the direction of the vertical starting position.

The angle of rotation φ that remains is the difference between the start and end positions of the cable 2 and is a measure of permanent deformation.

The experimental values are recorded in Tables 1 and 2.

According to Table 1, cable ropes with a circular cross-section for sheaths with a diameter of 20 "were tested; according to Table 2, cable ropes with a circular oval cross-section for sheaths with a diameter of 22.5" with a slope of 18 'to the sheath axis were tested.

Overall, experiments show that structural changes such as the number of shocks, the diameter of the wire being wound, the shape of the cable core and the like have little effect on the cable. The use of the binder modified according to the invention increases the torsional forces obtained by two to three times and the Vedas to reduce the permanent deformation, measured by the angle of rotation φ, by about -o 50% for round cables and -80% for cable cables with oval cross section.

It is understood that the individual or combination of features apparent from the description and drawings are within the scope of the invention.

Table 1

Round cable for sheath 20 “

Kon- Edit the structure

F (N) Torque Angle of rotation φ Md (Nm)

1.1. (1X5.0) +

1.2. (1X5.0) + _{17 23} + 1—5 + X 1.8 excl

I 17 .23 _w + - ₇ - + —--- X 1.8 Chemosil

2.1. (1 Oct 5.0) + y—

2.2. (1X5.0) +10 ---

4+

3.1.

(1

6.0) + + -8-- X 1.8 w / o o

4- -г --- X 1.8 Chemosil

O

X 2.2 bez

3.2.

(1

6.0) + ₁₇ + —--- X 2.2. Chemosil ©

26.5 13.9 83 ' 73.5 38,627 45 ' , 29.4 15,455 75 78.5 41,20-2 45 39.2 20.6 75 ' 78.5 41,202 40 '

Chemosil is a registered trademark of Henkel & Cie,

T a b u 1 к а 2

Cable with oval cross-section for 22.5 “sheath (18 ° to the sheath axis)

Construction Repair F (N) Torque Md (Nm) Angle of rotation φ 4.1. (2X 6.0) + 17 8 - + 23 8 - X 1.8 bez 137.3 78,284 45 ’ 4.2. (2X 6.0) + 17 8 -AT 23 8 - X 1.8 Chemosil 230.5 131,405 8 ° 5.1. (2X 6.0) + 17 8 - + 23 7 - X 1.8 bez 117.7 67,336 45 ° 5.2. (2 X 6.0) + 17 8 - + 23 7 - X 1.8 Chemosil ® 210.3 120,565 8 ° 6.1. (12 X 3.5) + 16 7 - + 22nd 7 - X 1.8 bez 107.9 61,724 10 ° 6.2. [12 X 3.5) + 16 / - + 22nd 7 - X 1.8 Chemosil ® 156.96 89.78 8 ° 7.1. (14 Oct 4.0) + 15 Dec 6 4- 21 6 - X 2.2 without 215.8 123.45 15 ° 7.2. (14 Oct 4.0) + 15 Dec 6 - + 21 6 - X 2.2 Chemosil 490.5 280.57 8 °

®

Chemosil is a registered trademark of Henkel & Cie.

Claims (2)

A bead cable tire, in particular a tubeless tire for trucks with a radial carcass and steep sides, the bead cable being formed of a core and at least one layer around the core several times in a helix of a wound and infinitely closed wire, characterized by. The cable bead (2) of the tire bead (1) of the invention is completely saturated with the liquid binder (7). 2. The bead-cable tire of claim 1, wherein the binder (7) is dissolved organic polymers and other nonvolatile polyisocyanates and dispersed solids in organic solvents such as xylol or toluene. 2 sheets of eeverography drawings, n. P., Plant 7, Most