WO2009089952A1

WO2009089952A1 - Pneumatic vehicle tire

Info

Publication number: WO2009089952A1
Application number: PCT/EP2008/065953
Authority: WO
Inventors: Axel Binder; Jozef Deeskinazi; Frank Voit; Jean-Luc Weiss
Original assignee: Continental Aktiengesellschaft
Priority date: 2008-01-17
Filing date: 2008-11-21
Publication date: 2009-07-23
Also published as: DE102008004886A1

Abstract

The invention relates to a pneumatic vehicle tire (1) having a bead core (2) wound from wire (10), said bead core comprising a carcass (3) having a main part (8) and having a cover part (9), which extends radially toward the outside at the axial delimiting side of the bead core (2), wherein the wound bead core (2) has a maximum dimension b in the radial extension thereof, and a maximum dimension a in the radial extension thereof, where b > a, and wherein the cover part (9) of the carcass (3) extends up to a radial position Ru toward the outside, where (RK + 3 mm) > Ru ≥ (RK - 3mm) applies to Ru, wherein RK indicates the radial position of the radial maximum extension of the bead core (2) toward the outside.

Description

description

Vehicle tires

The invention relates to a vehicle pneumatic tire for passenger cars with a profiled tread and with two tire sidewalls, each formed in the radially lower portion of each tire sidewall formed of wire

Bead core for mounting the pneumatic vehicle tire on a rim, with a carcass - in particular radial design - with its main part of a bead core in a tire sidewall radially outward through the tire sidewall through the axial extent of the tire tread into the other tire sidewall and there extends radially inward on an axial boundary side of the second bead core to below the bead core and extends radially outward with an envelope portion on the other axial boundary side of the bead core.

Modern pneumatic vehicle tires for passenger cars often have this construction. In this case, the bead core is usually formed with the largest possible axial width and the lowest possible radial height, on which a cross-sectionally triangular hard apex of hard rubber material is placed. The main part of the carcass abuts the axial (towards the equatorial plane of the pneumatic vehicle tire) inside of the apex and the bead core. The turnup member abuts against the axial (away from the vehicle pneumatic tire) outer side of the bead core and the apex and extends radially enough into the tire sidewall to be in abutting contact with the body of the carcass above the apex.

The maximum axial extent of the bead core is at most as large as the radial extent in such pneumatic vehicle tires. The large axial extent of the bead core allows a secure fit of the pneumatic vehicle tire on the rim. The big radial Extension of the carcass turnup part, in conjunction with its return to the main part of the main part of the carcass, ensures a symmetrical tensile force introduction over the main part of the carcass and the turnup part of the carcass into the bead core during production and operation of the pneumatic vehicle tire. This avoids slipping out of the carcass under the bead core during manufacture of the pneumatic vehicle tire and undesirably high torsion of the bead core, which could lead to breakage and failure of the bead core. The training requires a lot of material and costs. Effects which may occur due to splicing of the carcass in the region of the tire sidewall, such as constricting effects due to the stiffening of the carcass occurring in the splice region, in particular for carcass materials critical therefor, may have an increased effect in the large extent of the turnup portion of the carcass.

Occasionally, completely different yet more elaborate design principles have been proposed for mounting a pneumatic vehicle tire on the rim or for securing the carcass in the tire bead. For example, pneumatic vehicle tires have occasionally been proposed in which several parallel bead cores have been used in a tire bead to secure the carcass. Such a design is known for example from EP 1705035 Al. The carcass wrapped around a bead core is here additionally clamped between the parallel bead cores. The total axial extension width of the total bead core formed by the individual axially juxtaposed bead cores is also greater here than the radial extent of the overall bead core formed. The large width of the bead core in conjunction with the clamping action of the bead cores arranged side by side ensures the seat on the rim, an undesirable release of the carcass during manufacture and prevents failure of the entire bead core by torsion. This training with multiple bead cores requires a lot of material, manufacturing and costs.

From JP-09-142112A, a pneumatic vehicle tire with completely deviating bead construction is known, in which two bead-core-like ones are used for weight reduction

Reinforcements, one of which is made of rubber embedded Kevlar fibers and the others are made of rubber-embedded nylon material which are radially superimposed. The bead-core-like reinforcement produced in this way is larger in its radial extent than in its axial extent. On the two bead core-like reinforcements, a small apex is additionally constructed, and above this a further, rubber-shaped part with a large radial extent. The turnup portion of the carcass extends radially outward axially along both bead core-like reinforcements and the long triangular rubber body portion to then make contact with the main portion of the carcass above the long triangular rubber body portion. The particular bead construction of superimposed bead-core reinforcements of rubber-embedded Kevlar fibers and embedded nylon material may allow for weight reduction over conventional standard bead designs in pneumatic vehicle tires. The preparation of several bead-core reinforcements is complex and requires additional effort to produce multiple reinforcements of different materials. The training for additional small apex and large triangular rubber building material as well as the long extended carcass ply turnup part require a lot of material, production and costs. As with conventional standard designs of tire beads, effects that may occur due to splicing of the carcass in the region of the tire sidewall, such as necking effects due to the stiffening of the carcass occurring in the splice region, especially in the case of critical carcass materials in the large extension region of the turnup portion of the carcass reinforced. The wide reaching into the tire sidewall reinforcements from the cover part and between the main part of the carcass and turnup part clamped triangular rubber construction part can adversely affect rolling resistance of the pneumatic vehicle tire. In addition, this training has a high unsprung mass and increased risk of

Concentricity inaccuracies. In addition, there is an increased risk of fiat spot events.

The invention has for its object to provide a pneumatic vehicle tire for

Passenger cars with a profiled tread and with two tire sidewalls, each having a wire wound bead core formed in the radially lower portion of each tire sidewall for attaching the pneumatic vehicle tire to a rim, comprising a carcass, especially a radial type, extending radially outwardly from the one tire core in the one tire sidewall through the tire sidewall through the axial extent of the tire tread to the other tire sidewall and extending radially inward on an axial perimeter side of the second bead core to below the bead core and extending radially outward with an envelope portion on the other axial perimeter side of the bead core the reduced cost of materials a secure fit and high durability of the bead is made possible.

According to the invention by the formation of a pneumatic vehicle tire for passenger cars with a profiled tread and two tire sidewalls, each with a formed in the radially lower portion of each tire sidewall wire wound bead core for mounting the pneumatic vehicle tire on a rim, with a carcass - in particular radial design - extending with its main part of a bead core in the one tire sidewall radially outward through the tire sidewall through the axial extent of the tire tread to the other tire side wall and there radially inward on an axial boundary side of the second bead core to below the bead core and with one

Envelope part at the other axial boundary side of the bead core extends radially outward, according to the features of claim 1 solved, in which the wound bead core in its radial extent a maximum dimension b and in its axial extent a maximum dimension a having b> a and the Turning the carcass up to a radial position Ru extends outward, where Ru applies

(Rκ + 3mm)> Ru≥ (R _K - 3mm), where R _K indicates the radial position of the radial maximum extent of the bead core to the outside.

The axially narrow and radially high bead core makes it possible that the introduced in the short carcass turnup only on one side over the main part of the carcass tensile force is insufficient to that around the narrow bead core Pulling turned envelope part in the manufacture and that no large torsional forces exert on the bead core that could cause torsional movements of the bead core, the risk of bead core failure is thus also minimized. The risk of unwanted loosening of the seat on the rim is also minimized. In addition to saving carcass material, the one usually formed between the main part of the carcass and the envelope can also be at least partially eliminated or at least more easily formed and installed together with other components, for example the tire sidewall. Disadvantages of conventional tires required for secure fit and Wulsthaltbarkeit high training of the envelope part there related disadvantages largely eliminated. Thus, the negative effects caused by the stiffening in the region of the splicing of the carcasses - such as constricting effects - are reduced. In addition, the unsprung mass and the rolling resistance of the vehicle air tire are positively influenced. Fiat spot effects can be reduced, concentricity improved.

Particularly advantageous is the embodiment according to the features of claim 2, wherein for the dimensions of the maximum extent in the radial direction b and in the axial direction applies: b> 3 a. This allows an optimization of the contact surface between carcass and bead core, a significant reduction of the torsional stresses of the bead core and a better adaptation of the geometry of the bead core to the geometry of the tire bead.

Particularly advantageous is the embodiment according to the features of claim 3, wherein the wound bead core has a rectangular cross section with x turns of the wound wire in the axial direction and y turns of the wound wire in the radial direction, with y> x.

Particularly advantageous is the embodiment according to the features of claim 4, wherein the wire has a circular cross-section and applies to the number of turns x in the axial direction and y in the radial direction: y> 3x. Particularly advantageous is the design according to the features of claim 5, wherein the number of turns in the axial direction x = 2 and the number of turns in the radial direction x> 6 - in particular x = 8 - is. This can be achieved in a simple manner, a very high burst pressure of the tire.

Particularly advantageous is the training according to the features of claim 6, wherein the vehicle pneumatic tire is formed free of apexes.

Particularly advantageous is the training according to the features of claim 7, wherein the envelope part on the axially outer, away from the vehicle pneumatic tire boundary side extends radially outward.

Particularly advantageous is the embodiment according to the features of claim 8, wherein the wound wire of the bead core is a rubberized steel wire.

The invention will be explained in more detail below with reference to the embodiments schematically illustrated in FIGS. 1 to 3. Show here

1 is a cross-sectional view of a pneumatic vehicle tire for passenger cars FIG. 2 is an enlarged view of the lower tire sidewall region of FIG. 1 FIG. 3 is an enlarged view of the tire core of FIGS. 1 and 2.

In Fig. 1, the structure of a pneumatic vehicle tire 1 is exemplified. The pneumatic vehicle tire is formed symmetrically to the equatorial plane shown in dashed lines. For simplicity, only the right half is shown.

The pneumatic vehicle tire 1 is a pneumatic vehicle tire of a passenger car type, in which a carcass 3 of a radial type outside an air-impermeable inner layer 14 over the right shoulder region and the one inside a right bead region formed around a bead core 2 for attachment of the pneumatic vehicle tire 1 on a rim

Tire crown area to the left shoulder area, not shown, and in the left Bead region formed bead core 2 ranges to which it is placed in a conventional manner. In a conventional manner, in the bead area not shown in detail rim flange 4 and starting from the rim flange 4 starting up in the shoulder region reaching a side wall rubber material 12 is launched.

Arranged over the circumference of the tire, outside the carcass plies of the radial design, are several belt plies of a belt 6 with reinforcements embedded in rubber. In the two shoulder regions shoulder strips of known type, which are not shown in detail, are also applied in a known manner. The conclusion of the tire structure forms in a known manner a profiled tread. 7

The carcass 3 consists in known manner of one or two superimposed layers of embedded in rubber parallel reinforcing members. The strength members are conventional known strength members for use in carcasses of passenger cars. In the exemplary embodiment, the strength members are textile

Reinforcements, such as cords of rayon, polyester or similar as for the production of carcasses known as suitable textile reinforcements.

The carcass 3 extends with its main part 8 from the tire crown area axially outward to the tire shoulder and from there radially inward through the side wall through to the bead core 2, on the axially inner side facing the tire equatorial side of the bead core 2 along closely to the bead core 2 to radially below the bead core 2, then radially below the bead core 2 axially outward to the axially outer side facing away from the pneumatic vehicle tire side of the bead core 2 and in extension in a folded radially outward envelope part 9 of the carcass in tight

Touch contact to the bead core 2 along its axial outer side radially outward to a radial position Ru, in which it ends.

The bead core 2 is a bead core wound from rubberized steel wire. As can be seen in Fig. 3, the bead core 2 in the radial direction R is spiral from an endless bead wire with y in the radial direction one above the other in touching contact wound wire turns wound up. In the axial direction A, in each case x such wire turns are arranged next to one another in touching contact with one another.

For the number of turns x in the axial direction A and y in the radial direction R, y> 3x.

In the exemplary embodiment illustrated in FIG. 3, two windings (x = 2) and eight windings (x = 8) in the radial direction A are selected. The bead core has a rectangular cross-section, in which the smaller base side points in the axial direction A and the larger base side in the radial direction R of the pneumatic vehicle tire.

The bead core 2 has a maximum extent a in the axial direction A and a maximum extent b in the radial direction R of the pneumatic vehicle tire.

For the dimensions of the maximum extent b in the radial direction R and the maximum extent a in the axial direction A, the following applies: b> 3a.

In the exemplary embodiment illustrated in FIG. 3, b = 4a.

As shown in Fig. 2 and Fig.3, the bead core 2 extends with its radially outer circumferential surface to a radial position R _K. For the measure of the maximum radial extension Ru of the turnup part 9 of the carcass 3 and the radial position R _{K of} the radial maximum extent of the bead core to the outside applies: (RK + 3mm)> R ₁₁ > (R _κ - 3mm).

In Fig. 3, an embodiment is shown in which Ru is 2mm smaller than R _K.

FIG. 2 shows another embodiment in which R _K = R _U - As shown in FIG. 1 and FIG. 2, the vehicle pneumatic tire is formed free of apexes. The rim flange 4 extends above the envelope part 9 directly above the bead core 2 in touching contact with the bead core 2 up to the main part 8 of the carcass 3.

As far as required in individual cases is in alternative - not shown - training on the bead core 2 a apex known type of hard rubber material placed.

LIST OF REFERENCE NUMBERS

(Part of the description)

1 pneumatic vehicle tire

2 bead core

3 carcass

4 rim flange profile

5

6 belts

7 Profiled tread

8 main part of the carcass

9 Cover part of the carcass

10 core wire

11

12 Sidewall rubber material

Claims

claims

1. Pneumatic vehicle tire (1) for passenger cars with a profiled tread

(7) and having two tire sidewalls, each having a bead core formed of wire (10) formed in the radially lower portion of each tire sidewall

(2) for mounting the pneumatic vehicle tire (1) on a rim, with a carcass

(3) - in particular of a radial type - extending with its main part (8) from a bead core (2) in the one tire sidewall radially outward through the

Tire sidewall through the axial extent of the tire tread to the other tire side wall and there radially inwardly on an axial boundary side of the second bead core (2) along below the bead core (2) extends and with an envelope part (9) on the other axial boundary side of the Bead core (2) extends radially outward, characterized in that the wound bead core (2) in its radial extent a maximum dimension b and in its axial extent a maximum dimension a having b> a and the turnup (9) of the carcass (3 ) extends outward to a radial position Ru, where Ru is (R _K + 3mm)>Ru> (R _K - 3mm), where R _{K is} the outward radial position of the radial maximum extent of the bead core (2).

2. pneumatic vehicle tire according to the features of claim 1, wherein for the dimensions of the maximum extent in the radial direction b and in the axial direction applies: b> 3 a.

A pneumatic vehicle tire according to the features of one or more of the preceding claims, wherein the wound bead core (2) has a rectangular cross-section with x

Windings of the wound wire (10) in the axial direction and with y turns of the wound wire (10) in the radial direction, with y> x.

4. pneumatic vehicle tire according to the features of claim 3, wherein the wire (10) has a circular cross section and applies to the number of turns x in the axial direction and y in the radial direction: y> 3x.

5. pneumatic vehicle tire according to the features of claim 3 or 4, wherein the number of turns in the axial direction x = 2 and the number of turns in the radial direction x> 6 - in particular x = 8 - is.

6. Pneumatic vehicle tire according to the features of one or more of the preceding claims, wherein the pneumatic vehicle tire (1) is formed free of apexes.

7. Pneumatic vehicle tire according to the features of one or more of the preceding claims, wherein the turn-up part (9) on the axial outer, of the vehicle pneumatic tire (1) facing away from the boundary side extends radially outward.

A pneumatic vehicle tire according to the features of one or more of the preceding claims, wherein the wound wire (10) of the bead core (2) is a rubberized steel wire.