SK278270B6 - Cushioning ply for car tyre - Google Patents

Abstract

The fibres in the last layer of the cushioning ply, nearest to runner of the cover created with the use of the polyamide cord close the angle of 5 degrees with the external cladding surface. This band width is 60 percent of the width closed to the bottom layers, the prolongation related to this fiber breaking is 8 percent and the prestress, before a vulcanization is started, is 1 percent.

Description

Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile tire bumper belt comprising at least three layers of rubberized steel cord bands, wherein the first layer closest to the radial skeleton of the tire is formed by a web. wherein the fibers or wires form an angle of 20 [deg.] with the circumferential surfaces of the jacket, the fibers or wires of one cord layer crossing the wires or fibers of the previous layer, and the bumper layer nearest the casing tread is formed from an aromatic polyamide rubber cord.

BACKGROUND OF THE INVENTION

In the manufacture of tires, the carcass uses textile, steel cord fabric or high-strength cord as a buffer, mostly in the flat state. At present, a bumper belt consisting of two steel cord inserts with a bearing angle of 15-25 ° is used for the production of radial pneumatic shells with respect to the circumferential surfaces of the sheath. This construction creates a rigid reinforced belt. When driving at the point of contact between the tire and the road, the circular shape of the bumper becomes the shape of a string. Due to the circumferential stiffness of the bumper, large shear deformations occur between the individual layers of the bumper, which are manifested by energy losses, increased rolling resistance and reduced resistance to high speeds. Previous radial envelope designs have always sought to maintain the maximum circumferential rigidity of the bumper belt. In the present case, however, a reduction in rolling resistance can only be achieved by reducing the adhesion between the road and the tread of the tire. Reducing the rolling resistance by reducing energy losses is the subject of the use of a corrugated bumper strip according to EP 0-191124 and EP 0-264539, where metal or plastic is used as the material but its construction excludes the use of crossed steel or textile cords.

SUMMARY OF THE INVENTION

The above-mentioned drawbacks are eliminated by an automotive tire bumper belt comprising at least three layers of rubber cord bands, wherein the first layer closest to the radial skeleton of the tire is formed by a belt whose filament or wires clamp at an angle of 18 ° with the circumferential surfaces of the tire. a strip of which the fibers or wires form an angle of 20 ° to the circumferential surfaces of the jacket, the fibers or wires of one cord crossing the wires or fibers of the preceding layer and the bumper layer nearest to the tread of the jacket is formed from an aromatic polyamide rubber cord; according to the invention, characterized in that the fibers of the last strip form an angle of 0 to 5 ° with the circumferential surfaces of the jacket, the strip having a width of at least 60% of the width of the backsheets, an elongation at break of at least 8% and

An advantage of the novel buffer strip construction according to the invention is that it forms a circumferentially elastic strip which elastically adapts to the shape of the road at the point of contact and at the same time is sufficiently rigid outside the track. In this way it reduces the energy losses resulting from the shear loading of the individual layers of the bumper belt, especially in the tire arm. This is manifested by a reduction in rolling resistance, an increase in resistance at high speeds, as well as a reduction in the weight of the shell with sufficient retention of 5 lateral stiffness.

DETAILED DESCRIPTION OF THE INVENTION

After forming the carcass skeleton with bead ropes, a bumper belt for passenger car tires, e.g. size 155/70 R 13.

Example 1

1. Radial carcass layer: Aromatic polyamide rubber cord with an angle of 18 ° to the circumferential surfaces of the shell, width 140 mm.

2. Radial carcass layer: rubberized steel cord with 20 ° angle to the circumferential surface of the shell, layer width

130 mm. The cord is laid so that the wires cross the fibers of the previous layer.

3. Radial carcass ply - Nearest to tread: Aromatic polyamide rubber cord at an angle of 0 ° to the circumferential surfaces of the shell, layer width 135 mm.

The cord is preloaded by opening the sheath into the vulcanization mold by 2.5% relative to the circumference of the sheath prior to vulcanization.

Example 2

1. Radial carcass layer: Aromatic polyamide rubber cord with an angle of 18 ° to the peripheral surfaces, width 140 mm.

2. Radial carcass layer: rubberized cord of aromatic polyamide with an angle of 20 ° to the circumferential surfaces of the casing, width 130 mm. The cord is stored so. so that its fibers cross the fibers of the previous layer.

3rd layer from radial skeleton: as in Example 1.

Example 3

1. Radial carcass layer: rubberized steel cord with an angle of 18 ° to the circumferential surfaces of the shell, layer width 140 mm.

2. Radial carcass layer: rubberized cord of aromatic polyamide with an angle of 20 ° to the circumferential surfaces of the casing, width 130 mm.

3. Radial skeleton layer: as in Example 1.

Example 4

1. Radial carcass ply: aro50 rubberized polyamide cord with 18 ° angle to the circumferential surfaces of the jacket, width 140 mm.

2. Radial carcass layer: rubberized steel cord with an angle of 20 ° to the circumferential surfaces of the shell, layer width 130 mm. The cord is laid so that the wires cross the fibers of the previous layer.

3. Radial carcass ply: A rubberized polyamide cord with an angle of 18 ° to the circumferential surfaces of the shell, 120 mm wide.

4. Radial skeleton layer: - as in Example 1.

In Example 3, layer no. 2 and in Example 4, layers no. 2 and 3 are arranged so that their wires or fibers intersect the fibers or wires of the preceding layer.

After the bumper belt and sidewall tread have been placed, the preparation of the green tire is complete.

Claims (1)

PATENT CLAIMS A bumper belt for automobile tires consisting of at least three layers of strips of rubber-coated aromatic polyamide or rubberized steel cord 5, where the first layer closest to the radial skeleton of the tire consists of a belt whose fibers or wires clamp at an angle of 18 ° with circumferential surfaces. the layer consists of a strip whose fibers or wires form an angle of 20 ° to the circumferential surfaces of the jacket, 10 where the fibers or wires of one cord layer cross the wires or fibers of the preceding layer and the bumper layer nearest to the tread is formed from an aromatic rubber cord The fiber of the last 15 web is at an angle of up to 5 [deg.] with the circumferential surfaces of the jacket having a width of at least 60% of the width of the backsheets, an elongation at break of at least 8% and a pre-vulcanization of at least 1%.