DE7709502U1 - VEHICLE AIR TIRES FOR PASSENGER CARS - Google Patents

Description

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PATENT LAWYERS ~ lj

DR.-ING. R. DÖRING DIPL.-PHYS. DR. J. FRICKE

BRAUNSCHWEIG MUNICH

5201

Uniroyal Aktiengesellschaft Hüttenstr. 7, 5100 Aachen 1

"Pneumatic vehicle tires for passenger cars"

The invention relates to a pneumatic vehicle tire for passenger cars with a radial carcass and a belt arranged between the crown area of the carcass and the tread · «· like reinforcement, consisting of at least one folded layer and at least one unfolded layer of parallel to each other running, rubberized cord elements having cord material.

With regard to the driving behavior and durability of pneumatic vehicle tires for passenger cars, so-called radial tires with a belt-like reinforcement made of two or more than two layers of steel cord material have proven to be outstanding. It has been found, however, that steel cord materials for tire construction also give rise to certain problems both with regard to the manufacture and with regard to the behavior of the steel cord under high stresses.

There are also belt-like reinforcements for pneumatic vehicle tires

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known from several layers, in which the edges of an unfolded cord layer through the uxqfolded edge areas of an or several cord material strips are bordered to the belt-like reinforcement especially with high alternating loads and to give a better bond at high peripheral speeds.

It is the object of the present invention to further develop a pneumatic vehicle tire of the type specified in the introduction so that that on the one hand the advantages of a belt ply made of high strength Cord material can be retained, while at the same time the disadvantages of steel cord materials should largely be eliminated

According to the invention, this object is achieved in that an unfolded steel cord ply or aramid cord ply and a folded cord ply made from aramid cord elements are provided, the axial spacing of the fold edges of the fold cord ply essentially corresponds to the axial width of that enclosed by the fold regions corresponds to the unfolded cord layer.

In this way, the edges of the belt-like reinforcement become formed by a cord material containing aramid fibers * »by the folded edges of this cord material. This cord material is optimally suited to border the edges of the unfolded Cprdlage and the elastomeric material of the Tire against the influences of the edges of this cord layer too

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to protect reliably high stress and high peripheral speed of the tire. In addition, the folded cord layer can Aramid cord elements in the case of an unfolded layer and cord elements made of steel provide a much more favorable transition to ensure between the properties of the steel cord elements and the other building materials of the tire. Furthermore With the new design of the belt-like reinforcement, a reinforcement made only of steel cord is considerable Weight savings achieved without the known favorable properties of high-strength cord for the belt-like Reinforcement will be lost.

Due to the novel design of the belt-like reinforcement, a pneumatic vehicle tire is obtained that is specially designed for high stresses overall a much better bond, shows between the individual materials and elements used for the construction. Due to the high dimensional stability the folded layer with aramid cord elements can be used with the pneumatic vehicle tire also produce with even greater accuracy and shape retention. Although the aramid fibers are When it comes to organic fibers, the heat resistance of the new belt-like reinforcement is significantly higher than that of the otherwise common organic cord materials, which are used instead of steel cord for the production of belt-like reinforcements can be used.

The invention is illustrated below with the aid of schematic drawings

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\ gen explained in more detail using several exemplary embodiments.

> It show:

I Fig. 1 in detail a cross section through the radially outer

Ren area of a pneumatic vehicle tire according to the invention;

2 shows a modified one in a simplified schematic representation Embodiment of the belt-like reinforcement for the new pneumatic vehicle tire;

3 and 4 further modified exemplary embodiments for the belt-like reinforcement;

j Fig. 5 is a plan view of the belt-like reinforcement according to

j Fig. 4;

\ Fig. 6 a further embodiment for the possible

Formation of the belt-like reinforcement.

7 and 8 further modified exemplary embodiments for the belt-like reinforcement.

The i as shown in the cut-out and cross-section in Fig. 1 Vehicle pneumatic tire 1 is in a conventional manner from a carcass 2

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e.g. a radial carcass, and a belt-like reinforcement 5 arranged between the crown area of the carcass 2 and the tread 3 of the tire. In the example shown the belt-like reinforcement shown in section is formed symmetrically to the equatorial plane A of the tire. The running surface 3 is through in the axial direction Shoulder areas 4 of the tire limited.

In the example shown, the belt-like reinforcement 5 consists of an unfolded layer 6 and a folded layer 7, both of which are made of cord material. The unfolded cord layer 6 has mutually parallel cord elements made of steel. The parallel steel cord elements are in relation to the equatorial plane A is oriented essentially in the circumferential direction and can form an angle with the equatorial plane between 10 degrees and 30 degrees, preferably an angle of about 18 degrees to 22 degrees.

The folded cord ply 7 consists of a cord material strip with a width that is significantly greater than that of the cord material 6. the Folded cord ply 7 consists of cord elements made of aramid fibers that are parallel to one another. The parallel aramid cord elements are also oriented essentially in the circumferential direction and can form an angle of between 10 and 30 degrees with the equatorial plane A, preferably an angle of 18 degrees up to 26 degrees.

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The angles which the cord elements of the layers 6 and 7 enclose with the equatorial plane A can be for both layers be the same or different, the course of the cord elements preferably being opposite in their central regions is oriented. The angle difference between cord elements of layer 6 and cord elements of layer 7 can be absolute seen - between 0 degrees and 15 degrees * where the in relation to the equatorial plane A, angles formed in the case of the position 6 or in the case of the folded position 7 can be greater.

The edge areas of the folded sheet 7 are around the edges of the unfolded Layer 6 turned over to form fold areas 9 and 10, the middle one in the example shown Area 8 of the folded layer 7 radially inside the unfolded tone Steel cord ply 6 comes to lie, the cord elements of ply 6 and those of the area 8 of the layer 7 are thus crossed, while those of the fold areas 9 and 10 are directed in the same direction, preferably but exist with an angular deviation.

In Fig. 2 is the total axial width of the belt-like reinforcement 12 denoted by B. Here, too, it is assumed that dor Belt is constructed symmetrically to the equatorial plane A. The folded edges 15 and 16 formed by the folded layer 14 have a mutual axial distance which corresponds to the width B of the belt-like reinforcement 12. The ones from the folding areas 18 and 19 of the folded sheet 14 enclosed unfolded

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Steel cord layer 13 has a width S that is practically only about twice the material thickness of the folded layer 14 smaller than the total width B of the belt-like reinforcement _J. The axial width of the folded areas 18 and 19 is indicated by U and V, respectively.

In the exemplary embodiments according to FIGS. 1 and 2, the widths U and W of the two folding areas are the same. The width is expediently between 5% and 35% of the total width B of the belt-like reinforcement, specifically for each folding area 9 or 10 and 18 or 19.

The fold areas 18 and 19 of the belt 12 according to FIG. 2 can, however, also have a significantly greater width, which is approximately between 50 and 60 % of the total width B of the belt 12 for each fold area. In the area of the lower limit, the free edges of the fold areas 18 and 19 meet approximately in the equatorial plane A. In the area of the upper limit there is a certain overlap of the free edges of the fold areas 18 and 19 in the equatorial area.

The belt-like reinforcement, as shown in the belt 22 of FIG. 3, can also be asymmetrical with respect to the Equatorial plane A be formed. The asymmetry is mainly due to the different widths U and W of the two folding areas 26 and 27 of the folded position 23 reached. Here, too, the free edges of the unfolded layer 24 are

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chen included. The unequal fold areas 26 and 27 are connected to one another in one piece by the central region 25 of the folded layer 23.

For the belts 5 _f 12, 22, the alternative is that the unfolded, enclosed belt ply can also consist of aramid cord.

The belt-like reinforcement can also consist of more than two strips of cord material be constructed.

An embodiment of a three-part belt-like reinforcement 32 shows Fig. 4. Here, an unfolded position corresponds to position 6 in FIG. 1 and a folded position 34 corresponds of the folded layer 7 in Fig. 1 is provided, with the to the middle area 35 of the folded layer 34 over the folded edges adjoining fold areas 36 and 37 correspond to the fold layers 9 and 10 of FIG. These fold areas 36, 37 are located with their free edges at a considerable mutual axial distance on both sides of the equatorial plane A. In the same or at another level with them, a third strip of material 38 is preferably arranged in the middle, which is preferably made of a steel cord material consists. This steel cord material has cord elements 41 (see FIG. 5) running parallel to one another. the with respect to the cord elements 40 of the unfolded layer 33 are inclined in opposite directions. While the cord elements 40 with the

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The equatorial plane enclose an angle of about 18 to 22 degrees, the cord elements 41 of the third, likewise unfolded ply 38 can form an angle with the equatorial plane include between 15 degrees and 90 degrees.

In the example shown in FIGS. 4 and 5, the cord elements 39 have the folded layer 34 in the folded regions 36, 37 and Cord elements 40 of the unfolded layer 33 with respect to the equatorial plane have the same inclination as large and in the same direction. your Angular deviation can be 0 degrees to 15 degrees.

In the embodiment according to FIGS. 4 and 5, both can Unfolded layers 33 and 38 consist of steel cord. The steel cord ply 38 can have any axial width between about 1596 and 100% of the width S of the unfolded layer 33. When the sum of the width of the unfolded ply 38 and the two Fold areas 36 and 37 are larger than the total width B of the belt-like reinforcement, the fold areas 36 overlap, the free edges of the layer 38 on the side of the layer 38 facing away from the position, as can be seen in a similar manner from the Example according to FIG. 6 results.

Alternatively, the belt ply 38 can also consist of aramid cord or nylon cord; the latter with a possible cord angle course up to about 0 degrees.

As Fig. 6 shows, the folded position can also consist of two separate,

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Material strips 45 and 49 arranged at a mutual axial distance on both sides of the equatorial plane A exist. Each material strip forms a fold edge 46 or 50 and two fold areas 47, 48 and 51 »52 emanating from this. In the example shown, the two material strips 45 and 49 each include the free edges of two unfolded cord layers 43 and 44, the latter being one has greater axial width than the radially outer layer 43. For each individual strip of material 45 to. 49, the two associated folding areas can have the same or different axial width, wherein the greater axial width can be in the radially outer or in the radially inner folding area. The belt-like reinforcement can be designed symmetrically to the equatorial plane or asymmetrically with respect to the two folding strips 45 and 49, the asymmetry resulting from different widths of the corresponding folding areas. However, the width of the fold areas 47, 48 or 51 and 52 is expediently between about 10 and 40 % of the total width B of the belt-like reinforcement 42. The belt layer 44 is preferably a steel cord layer, whereas the belt layer 43 is either a steel cord layer, an aramid cord layer or a nylon cord layer can be.

As FIGS. 7 and 8 show, two folded belt layers 60, 61 made of aramid cord can also be present. The distance b should be in the range of 15 96 of the width B and the distance c should be in the range of 10 % of the width B. The layers are asymmetrical

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Trically designed and arranged one inside the other.

Cord elements made of aramid fibers are used as cord elements for the folding layer a, as already mentioned above. Included an aramid fiber, which is commercially available under the trademark Kevlar from Dupont, is preferred.

Expectations

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Claims (6)

t · t «· ι - 12 - claims 1. Pneumatic vehicle tires for passenger cars with a radial carcass and a belt-like reinforcement arranged between the crown area of the carcass and the tread, consisting of at least one folded layer and at least one unfolded layer of mutually parallel, Cord material having rubberized cord elements, characterized in that an unfolded cord layer (6) made of steel cord or aramid cord elements (40) and a cord layer (7) made of aramid cord elements (39) are, the axial distance (B) of the folding edges (15 * 16) of the folding cord layer being essentially the axial width (S) corresponds to the unfolded cord layer (6) enclosed by the fold regions (9 »10). 2. Pneumatic vehicle tire according to claim 1, characterized in that the angle between the aramid cord elements (39) the folded layer (34) and the equatorial plane (A) of the tire (1) between about 10 degrees and 30 degrees, preferably at about 18 to 22 degrees, and the angle between the cord elements (40) of the unfolded layer (6) and the aramid cord elements (39) of the folded layer (7) is between 0 degrees and 15 degrees. 3. Pneumatic vehicle tire according to claim 1 or 2, characterized in that 7709502 07/07/77 - 13 - indicates that the width (U, W) of the drop areas (18,19) of the folded layer (s) between about 5% and 40% of the width (B) of the belt-like reinforcement (12) located. 4. Pneumatic vehicle tire according to claim 2 or 3, characterized in that a further unfolded Cord layer (38) is provided with cord elements (£ 1) running parallel to one another, which have a width between 15 to almost 100% of the width (B) of the belt-like reinforcement (32), and the angle between the cord elements (41) of the further unfolded layer (38) and the equatorial plane (A) is between 0 degrees and 90 degrees. 5. Pneumatic vehicle tire according to claim 1 to 4, characterized in that the Faltcordlagfc consists of two im Mutually axially spaced cord material strips (45, 49) consists of aramid cord elements. 6. Pneumatic vehicle tire according to claim 1 to 5, characterized in that the unfolded layer by a second folded layer is replaced and both folded layers (60,61) are made of aramid cord and are asymmetrical - and that the axial width (D) of the inner folded layer (61) 80% to approximately 100% of the width (B) of the outer fold layer (60). PI. 7709502 07/07/77