JP2002544045A - Vehicle pneumatic tire - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention comprises a radial carcass (14) having at least one layer and a tread having a pattern, the tread being in contact with a groove (18) formed over the entire pattern depth. Shoulder grooves (19) extending beyond the surface width (B), each of which is formed at least partially over the entire pattern depth, the envelope of the shoulder grooves in the tire cross-section being the reinforcing contour (11a) and more particularly a belt assembly (13) comprising at least two belt layers (13a, 13b), the belt assembly having a width exceeding the width of the contact surface of the tire, the reinforcing profile Of the vehicle pneumatic tire, the extension of which at least approximately corresponds to the extension of the belt assembly (13). To improve belt edge durability and reduce tread wear and rolling resistance, the reinforcement profile (11a) together with the belt assembly (13) begins at the latest at the lateral edge of the contact surface and at least approximately tangentially outward. In this way, the reinforcing profile (11a) and the belt assembly (13) extend at least approximately parallel to the ground profile over their entire length in the contact area with the elastic deflection of the tire.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a radial carcass having at least one layer (ply) and a tread having a pattern, wherein the tread extends over a groove formed over the entire pattern depth and a width of a contact surface. Extending shoulder grooves, each of which is formed at least locally over the entire pattern depth, the envelope of the shoulder grooves defining a reinforcing profile in the tire cross section, and more particularly consisting of at least two belt layers A vehicle pneumatic tire comprising a belt assembly, the belt assembly having a width greater than the width of the contact surface of the tire, wherein the extension of the reinforcing profile at least approximately corresponds to the extension of the belt assembly.

[0002] Vehicle pneumatic tires usually have a laterally curved profile, which profile comprises a curve with a constant radius or a plurality of curves with different radii. In this case, the central portion of the tread has the largest radius. Depending on the selected curve, the vertical pressure at the contact surface should be as uniform as possible during the elastic deflection of the tire during rolling. Belt assemblies arranged radially in the tread typically extend along this curve. Thus, the circumferential length of the belt assembly is such that the central area of the tire is longer than the edge area. This causes a slip motion at the contact surface when the tire rolls, increasing the stress on the belt edge. This not only adversely affects the durability of the belt, especially in the area of the edges, but also adversely affects rolling resistance and tread wear.

[0003] A number of ideas that have been patented or protected by patents have been developed to optimize the design of the outer contour of vehicle pneumatic tires (eg, European Patent Application Publication) to reduce rolling resistance or to achieve uniform wear. No. 0269301) and means for affecting the pressure of the tire in the contact surface and / or the contour of the contact surface. In this regard, reference is made, for example, to EP 0 235 519.

[0004] It is also known to flatten the tire cross-section to reduce rolling resistance. For this purpose, Austrian Patent No. 354273 proposes disposing a partial belt layer in the belt edge area. In this case, a wedge-shaped rubber layer is arranged between the partial belt layer and the innermost belt layer in the radial direction.

The object of the present invention is to significantly improve the durability of the belt edge and reduce tread wear without affecting the design of the outer contour of the tire, especially in the area of the tread and shoulder. The purpose is to construct or design vehicle pneumatic tires for passenger cars and utility vehicles so that they are uniform and have reduced rolling resistance.

In accordance with the invention, the object is to guide the reinforcing profile with the belt assembly at least approximately tangentially outward, starting at the latest at the lateral edge of the contact surface, so that the tire is brought into contact in an elastically flexed state of the tire The problem is solved in that the reinforcing profile and the belt assembly extend in the plane at least approximately parallel to the ground profile over their entire length.

By designing the reinforcing profile and the extension of the belt assembly according to the invention, under flexure and load conditions, the belt assembly extends along a profile parallel to the ground profile. The belt edge is therefore located at a diameter closer to the diameter of the belt in the center of the tire than in the case of a tire formed according to the prior art. This serves to adequately prevent unwanted slipping motion, thereby increasing belt edge durability, reducing rolling resistance, and equalizing tread wear.

[0008] The desired curve is still obtained over at least the majority of the width of the tread in contact with the ground. Thus, the tangential extension of the reinforcing profile and the extension of the belt assembly is initiated at a distance from the lateral edge of the contact surface, which is at most 15%, in particular less than 10%, of the width of the contact surface. It is desirable.

As already mentioned, the outer contour of the tire is at least substantially maintained or not different or very little different from the usual outer contour of the tire known from the state of the art. Is desired. In this case, in order to achieve the design according to the invention, the mixed material or rubber material is replenished or inserted below the edge area of the belt assembly, and the edge area of the tread is formed by the mixed material or rubber material having a small edge area. .

In a preferred embodiment of the invention, this mixed or rubber material inserted below the edge area is realized by a relatively large volume formed sidewall. However, it may be formed by at least one rubber molded body to be inserted.

Other features, effects and details of the present invention will be described in detail with reference to the drawings. At this time, both figures are schematic diagrams.

The cross sections shown in both figures are respectively half cross sections of radially structured vehicle pneumatic tires for passenger cars. The other half of the tire is shaped to match.

The vehicle pneumatic tire of FIG. 1 formed according to the state of the art comprises a dread 1. This tread has a tread pattern. The tread extends laterally beyond the shoulder area to the upper area of the sidewall 2.

The cross-sectional view shows, for example, a total of five circumferential grooves 8 in the tread pattern and a transverse groove 9 extending to the circumferential groove 8 closest to the tire shoulder. This lateral groove ends in the upper sidewall area. Such transverse grooves need not extend exactly in the axial direction, but are often deviated by a small acute angle with respect to the axial direction. A number of lateral grooves are provided in both tread halves, forming a shoulder block that is not visible here.

The groove bottoms of the lateral groove 9 and the circumferential groove 8 are defined by an envelope over the entire circumference of the tire. FIG. 1 shows a cut contour of the envelope surface. This cutting profile is 1a
, And will be referred to below as the reinforcement profile.

A belt assembly 3 is provided in the tread 1 in a radial direction. This belt assembly has two belt layers (ply) 3a, 3b in the embodiment shown in FIG. Of the belt layers, the belt layer 3b located on the inner side in the radial direction is formed somewhat wider than the outer belt layer 3a. The two belt layers 3a, 3b can be constructed in a conventional manner, for example, of steel cord embedded in a suitable rubber mixture and extending parallel to one another in each belt layer. As usual, the steel cords of one belt layer and the steel cords of the other belt layer are arranged so as to intersect.

The tire shown in FIG. 1 further includes a radial ply carcass 4 formed in a single layer in the illustrated embodiment. This radial ply carcass extends outward from the inside through the bead core 5 a in the region of the bead 5 of the tire, and reaches the sidewall 2 again. Here, it reaches the height above the end area of the core compact.

When the tire is under load and rolling, the tire comes into contact with the road at a certain surface in the tread area, the contact surface. In FIG. 1, the maximum width of the contact surface under normal conditions (standard pressure and standard load according to ETRTO standard) is indicated by B. The belt assembly is formed wider than width B, as usual.

The tire shown in FIG. 1 has an outer profile, usually slightly bent, in the tread and shoulder areas. As a result, the vertical pressure acting on the contact surface when elastically flexing can be made as uniform as possible. This is necessary for the transmission of forces and for the generation of the desired inertia.

In the shoulder region, the reinforcing contour 1 a and the edge contours of the belt layers 3 a and 3 b extend along the curve of the carcass 4. Thus, these components or their contours also generally extend at least approximately parallel to one another in the shoulder region. The mutual extension of the reinforcing profile 1a, the belt layers 3a, 3b and the carcass 4 results from the building of the tire and the subsequent vulcanization in the vulcanizing mold. The vulcanization mold conforms to the desired outer contour of the tire and embosses the tread pattern. At this time, the belt assembly 3 is formed by forming at least a substantially constant pattern depth and at least a substantially constant pattern depth in the shoulder lateral groove 9 extending beyond the contact surface width of the tread. Extends along a selected curve.

The curved belt has different circumferential lengths in its central area and its edge area. This causes a slipping movement in the contact area when the tire rolls, increasing the stress on the belt edge. This also results in belt durability, as a result of uneven wear.
It adversely affects rolling resistance and pattern durability.

The tire shown in FIG. 2 formed according to the present invention comprises a carcass 14, a bead core 1
With respect to the formation and arrangement of the bead 15 with core 5a and the core molding 16, FIG.
It is formed so as to match. The outer contour and the inner contour are the same as in FIG.

The tire shown in FIG. 2 also has a tread pattern having a circumferential groove 18 and a shoulder lateral groove 19. Each of the shoulder lateral grooves extends beyond the tread edge (contact surface width B) from the peripheral groove 18 located on the shoulder side.

According to the present invention, in this tire, the circumferential groove 18 formed over the entire depth of the pattern is provided.
And the reinforcing profile 11a with the transverse groove 19 starting from the entire depth of the pattern is designed to extend at least approximately tangentially and axially outward at the latest in the region of the lateral edge of width B of the contact surface. . Therefore, the reinforcing contour 11a of the lateral groove 19
No longer extends along the contour of the carcass 14. Two belt layers 13a, 1
3b, with the width of the ply 13b being wider, again arranged to project laterally from the width B of the contact surface of the tire and to extend along the reinforcing profile 11a towards the shoulder area. Have been. It is advantageous if the reinforcing profile 11a and the belt assembly 13 are designed to extend at least approximately parallel to the ground profile when the tire is elastically deflected.

Preferably, over a large part of the width B of the contact surface, the unloaded tire curves to a certain extent and this curve extends along the tread 11 or its reinforcing contour 11 a and the belt assembly 13. And advantageous. Thus, the tangential orientation of the reinforcing profile 11a and the belt assembly 13 at the earliest starts at a distance from the edge of width B, which is 15%, in particular at most 10%, from that edge.

The contouring according to the invention can basically be achieved by a certain stacking of the mixed material and by vulcanization of the green tire in a mold forming the reinforcing contour 11 a in the region of the shoulder groove 19. Furthermore, for example, the edge material of the tread 11 is made of somewhat less material, and the material above the sidewall mixture is supplemented in the area below the edge area of the belt assembly 13. In that case, alternatively or additionally,
One or more rubber moldings having a suitable cross-section and a suitable cross-sectional area or volume can be incorporated during the assembly of a green tire.

The present invention is not limited to the illustrated embodiment. The invention is also applicable to vehicle pneumatic tires of useful vehicles and provides good results with respect to belt edge improvement, durability and rolling resistance. Of course, multiple layers of carcass can be provided instead of single layer carcass, and more than two belt layers can be provided in the belt assembly. Furthermore, the tread can be formed in two parts, so that the tread can have a so-called cap / base structure. Below the tread, i.e. between the belt assembly and the tread, a separate thin rubber layer, so-called lower molded rubber, can also be provided. Of course, the shoulder lateral groove may be connected to a shallow groove having a decorative function at the outer end region and extending into the upper sidewall region.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a vehicle pneumatic tire formed in accordance with the prior art.

FIG. 2 is a partial cross-sectional view of an embodiment of a vehicle pneumatic tire formed in accordance with the present invention.

──────────────────────────────────────────────────続 き The continuation of the front page (72) Inventor Wies Burghardt, Hannover, Germany, Kiesel-Gurweg, 20

Claims (5)

[Claims] 1. A radial carcass having at least one layer and a tread having a pattern, the tread having a groove formed over the entire pattern depth, and a shoulder groove extending beyond the width of the contact surface. The shoulder grooves are each formed at least partially over the entire pattern depth, the envelope of the shoulder grooves defines a reinforcing profile in the tire cross section, and more particularly a belt assembly comprising at least two belt layers. A reinforcing profile (11a) for a vehicle pneumatic tire, wherein the belt assembly has a width exceeding the width of the contact surface of the tire, and the extension of the reinforcement profile at least approximately corresponds to the extension of the belt assembly. Is a belt assembly (13)
Starting at the lateral edge of the contact surface at the latest and at least approximately tangentially outwardly, so that in the resilient deflection of the tire the reinforcing profile (11a) and the belt assembly (13) in the contact surface A vehicle pneumatic tire extending at least approximately parallel to a ground profile over its entire length. 2. The tangential extension of the reinforcing profile (11a) and the belt assembly (13) is initiated at a distance from the lateral edge of the contact surface, the distance being defined by the width of the contact surface (11).
2. The vehicle pneumatic tire according to claim 1, wherein at most 15% of B). 3. Under the edge area of the belt assembly (13), the mixed material or the rubber material is supplemented or inserted, and the edge area of the tread (11) is formed by the small mixed material or the rubber material. The vehicle pneumatic tire according to claim 1 or 2, wherein: 4. Sidewalls (12) connecting radially within the belt edge.
4. The vehicle pneumatic tire according to claim 3, wherein the range (a) is formed to have a relatively large volume. 5. The vehicle pneumatic tire according to claim 3, wherein the replenished mixed material or rubber material is inserted below the belt assembly in the form of at least one rubber molded body.