Pneumatic vehicle tire

Abstract

The invention relates to a pneumatic vehicle tyre having a tread and side walls, the tread having at least one shoulder-side profile rib (1) with an inner section (3) located inside a ground contact surface and a shoulder section (4) located outside the ground contact surface, the shoulder section has a half (4 ') which adjoins the lateral edge (line L) of the ground contact surface and a half (4' ') which adjoins the side wall, and wherein elongated, approximately rectangular or rectangular recesses (6, 7) are formed in the shoulder section (4), which recesses extend at an angle (alpha) which differs from 90 DEG by at most 10 DEG with respect to the circumferential direction. The recesses (6, 7) are arranged in groups (G), wherein each group (G) is assigned at least three depressions (6, 7) which run one behind the other in the circumferential direction, parallel to one another and only in the half (4 '') of the shoulder section (4) adjoining the side wall, said depressions having a depth (t1, t2) of 0.3 mm to 1.0 mm and a width (b1, b2) of 0.4 mm to 2.0 mm, the depressions (6, 7) arranged in the same group (G) having a distance (a2) from one another in the circumferential direction, the distance is smaller than the distance (a4) measured as the minimum distance between the groups (G) which are successive in the circumferential direction.

Description

Technical Field

[0001] The present invention relates to a vehicle pneumatic tire, which has a tread and a sidewall, wherein the tread has at least one tread rib on the shoulder side, the at least one tread rib on the shoulder side has an inner section located within the ground contact surface and a shoulder section located outside the ground contact surface, the shoulder section has a half portion adjacent to the lateral edge of the ground contact surface and a half portion adjacent to the sidewall, wherein elongated, approximately rectangular or rectangular depressions are formed in the shoulder section, and these depressions extend at an angle of at most 10° different from 90° relative to the circumferential direction. Background Art

[0002] Such a pneumatic vehicle tire is known, for example, from DE 10 2018 119 892 A1. The pneumatic vehicle tire has a tread with two central tread ribs and two shoulder-side tread ribs, wherein the tread ribs are separated from each other by circumferential grooves. The central tread rib is provided with pocket grooves that merge into the corresponding adjacent circumferential grooves, which pocket grooves are opposite to the cuts that end on one side of the central tread rib. The shoulder-side tread ribs are structured into tread blocks by transverse grooves, wherein each tread block is provided with a cut-shaped depression extending transversely to the circumferential direction in the shoulder section located outside the ground contact surface. The tire should achieve good steering stability on icy and snowy tracks and have uniform wear behavior in the area of ​​the central tread ribs.

[0003] In principle, it is known that depressions formed in the shoulder section of the tread rib on the shoulder side of the tread (the so-called off-shoulder area) can help improve traction on soft ground, in particular on snow, slush or mud.

[0004] Furthermore, it is known that such depressions can have a favorable influence on the air flow over the tires during driving, thereby favorably influencing the aerodynamics of the vehicle and thus favorably influencing driving safety. In this regard, the so-called boundary layer separation plays a crucial role. Boundary layer separation is a fluid mechanical effect that causes the flow around an object to not follow the contour of the object. In particular, a turbulent region known as "dead water" or "wake" is formed between the main laminar flow and the contour of the object. That is, the dead water or wake is an area located behind the object being circulated, in which the flow velocity is significantly affected by the object. Boundary layer separation is the cause of flow separation, which leads to the formation of a recirculation area that increases the flow resistance. Therefore, the flow separation that occurs during driving of a motor vehicle has an adverse effect on the aerodynamics of the vehicle. Summary of the invention

[0005] The invention is therefore based on the object of significantly improving the effect of depressions on the aerodynamics of the vehicle in a pneumatic vehicle tire of the type mentioned in the introduction, while also maintaining good traction behavior on soft ground.

[0006] According to the invention, this object is achieved in that the recesses are arranged in groups, wherein each group is assigned at least three recesses which follow one another in the circumferential direction, extend parallel to one another and extend only in the half of the adjacent sidewalls of the shoulder section, wherein the recesses have a depth of 0.3 mm to 1.0 mm and a width of 0.4 mm to 2.0 mm, wherein the recesses arranged in the same group have distances from one another in the circumferential direction which are smaller than the distances measured as the minimum distance between groups which follow one another in the circumferential direction.

[0007] When driving, the depressions create turbulence in the air flowing through the rotating tire, which changes the boundary layer separation and thus reduces the dead zone, which has a positive effect on the aerodynamic properties of the vehicle. By grouping and appropriately sizing the depressions, high lateral stiffness is maintained in the shoulder section, so that when driving on soft ground, the edges provided by the depressions act as particularly effective grip edges. As a result, good traction behavior is still guaranteed on soft ground.

[0008] According to a preferred embodiment, a maximum of five depressions are assigned to each of these groups. Such groups with a limited number of depressions are advantageous with regard to the transverse rigidity in the shoulder section.

[0009] The groups are preferably arranged such that they are each assigned exactly three depressions. With the aid of these groups, a particularly advantageous compromise can be achieved between the favorable influence of the depressions on the aerodynamics of the vehicle and the traction behavior on soft ground.

[0010] According to another preferred embodiment, the recess has a length of 3.0 mm to 7.5 mm, which helps to maintain a high lateral stiffness.

[0011] An advantageous development of the aforementioned preferred embodiment is characterized in that the group is arranged such that the length of the central recess(es) is at least 2.0 mm greater than the length of the individual edge-side recesses. This measure has a beneficial effect on the turbulence of the air flowing through the rotating tire during driving, which is generated by the recesses, and thus has further advantages for vehicle aerodynamics, wherein the recesses have a particularly low influence on the transverse stiffness in the shoulder section.

[0012] In the advantageous development mentioned, it is advantageous if the central depression(s) protrude beyond the respective edge depressions on the side facing away from the sidewall. This measure is also particularly advantageous for the transverse rigidity in the shoulder section.

[0013] Another preferred embodiment is that the recesses arranged in the same group are spaced 0.5 mm to 2.0 mm apart from one another. Since rubber ridges are formed between the recesses in this way, the recesses have edges at the level of the shoulder side edges that are particularly advantageous for traction behavior on soft ground.

[0014] Another preferred embodiment is characterized in that the groups are arranged such that the width of the central recess(es) is 150% to 250%, in particular 180% to 220% of the width of the respective edge recesses, wherein the widths of the edge recesses are preferably identical. The turbulence in the passing air caused by such recesses is particularly advantageous for the aerodynamic properties.

[0015] According to another preferred embodiment, it is proposed that the depressions have a preferably uniform distance measured transversely to the circumferential direction from the ends of the half of the shoulder section adjoining the sidewalls, which is 1.0 mm to 2.0 mm. This also facilitates the effect of the depression edges and thus has a favorable influence on the traction behavior on soft ground.

[0016] The angle at which the depressions extend relative to the circumferential direction preferably differs from 90° by at most 5°. The inclination of the corresponding edge is close to 90°, which is an additional advantage for the traction properties on soft ground.

[0017] Another preferred embodiment is characterized in that the shoulder-side tread rib is provided with transverse grooves, wherein the group in which the depressions are arranged is respectively located in its own circumferential section of the shoulder-side tread rib, which extends between two transverse grooves and to the sidewall. This also helps to increase the rigidity of the shoulder section and thus facilitates the traction properties on soft ground.

[0018] In the aforementioned preferred embodiment, it is advantageous if, in the half of the adjacent sidewall of the shoulder section, each or every other transverse groove is formed with an elongated, approximately rectangular or rectangular further depression adjacent to the transverse groove, extending at an angle differing by at most 10° from 90° with respect to the circumferential direction, the further depression having a depth of 0.3 mm to 1.0 mm, in particular 0.4 mm to 0.6 mm, and a width of 0.4 mm to 2.0 mm, in particular 0.6 mm to 1.0 mm, wherein the further depression preferably extends parallel to the depressions arranged in groups and in particular has a depression edge connected tangentially to one of the groove edges of the transverse groove. The further depression assists the effect of the depressions arranged in groups.

[0019] Furthermore, it is preferred that the groups are arranged such that the depressions are designed symmetrically about a median plane extending perpendicularly to the shoulder sides, in the longitudinal extension of the depressions and centrally through the group. Such a symmetrical group ensures an at least largely uniform effect on the stiffness, thus facilitating the traction properties on soft ground.

[0020] The depth of the recess is preferably 0.4 mm to 0.6 mm.

[0021] According to another preferred embodiment, the distance between groups that follow each other in the circumferential direction, measured as the minimum distance, is 3.0 mm to 10.0 mm. This also helps to maintain high rigidity in the shoulder section. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Further features, advantages and details of the present invention will now be described in detail with the aid of the accompanying drawings which schematically illustrate embodiments of the present invention. In the drawings:

[0023] Figure 1 A top view showing a circumferential section of a tread rib on the shoulder side of a tread unfolded into a plane of a pneumatic vehicle tire adopting an embodiment of the present invention,

[0024] Figure 2 Show Figure 1 A magnified top view of detail Z2,

[0025] Figure 3 Shown along Figure 2 The section along line III-III in

[0026] Figure 4 Shown along Figure 2 The section along line IV-IV in

[0027] Figure 5 It is shown that considering the tire curvature, Figure 2 The view in the direction of sight indicated by arrow S5.

[0028] List of Reference Numerals

[0029] 1......................................Tread ribs on the shoulder side

[0030] 2...........................Circumferential groove on the shoulder side

[0031] 3...........................Internal section

[0032] 3a..........................External surface

[0033] 4...........................Shoulder section

[0034] 4a........................Shoulder side

[0035] 4', 4".......................Half

[0036] 5...........................Transverse grooves

[0037] 5a.............................Flute edge

[0038] 5b..........................Grooved bottom

[0039] 5c..........................Groove side

[0040] 5d..........................side

[0041] 6...........................Depression

[0042] 7...........................Depression

[0043] 8...........................Depression

[0044] 8a..........................Concave edge

[0045] a1, a2, a3, a4, a5, a QR ............distance

[0046] b1, b2, b3, b QR , b S ...............width

[0047] c1, c2.......................length

[0048] Δc.........................Protrusion

[0049] E1.........................Mid-plane

[0050] E2..........................Symmetry plane

[0051] G...........................Group

[0052] L...........................Line (lateral edge of ground contact surface)

[0053] m1, m2........................center line

[0054] S5..........................Arrow (direction of sight)

[0055] t1, t2, t3.....................Depth

[0056] t QR ..........................Maximum Depth

[0057] U1...........................Circumferential section

[0058] Z2...........................Details

[0059] α...........................angle DETAILED DESCRIPTION

[0060] The vehicle pneumatic tire implemented according to the present invention is a tire for motor vehicles, especially for multi-track motor vehicles, and is preferably a radial structure tire for passenger motor vehicles, vans or light trucks (small transport vehicles with an allowable total weight ≤ 3.5t, light trucks with an allowable total weight ≤ 7.5t).

[0061] Figure 1 A top view of a circumferential section of a shoulder-side tread rib 1 of a pneumatic vehicle tire is shown. The lateral edge of the ground contact surface of the tread is marked by a dotted line L, wherein the ground contact surface corresponds to the ground contact surface determined statically according to the ETRTO standard (according to the ETRTO standard, the load is 70% of the maximum load capacity at an internal pressure of 85%). The tread has a further shoulder-side tread rib in its second shoulder, which preferably differs in design from the shoulder-side tread rib 1, so that the tread has an asymmetrical shape with respect to the tire equatorial plane.

[0062] The shoulder-side tread rib 1 is delimited on the inner side of the tread by a shoulder-side circumferential groove 2 which, in the embodiment shown, extends straight in a top view and is implemented to reach a corresponding specified tread depth in the radial direction of typically 6.5 mm to 13.0 mm for the preferred tire type.

[0063] The tread rib 1 on the shoulder side has: an inner section 3 located within the ground contact surface and having an outer surface 3a located at the outer periphery of the tread; and a shoulder section 4 located outside the ground contact surface and extending toward the sidewall (not shown), the shoulder section having a shoulder side edge 4a located at the outer periphery of the tread and tangentially connected to the outer surface 3a (see Figure 5 ). The shoulder-side tread rib is provided with a plurality of transverse grooves 5 terminating within the shoulder-side tread rib 1 in its circumferential extension, each of which extends partially in the inner section 3 and partially in the shoulder section 4, and (when viewed in a top view), these transverse grooves preferably extend parallel to each other and at an angle of up to 30° to the axial direction. The transverse grooves 5 adjacent to each other in the circumferential direction have a distance a of 15.0 mm to 45.0 mm, in particular 20.0 mm to 35.0 mm, measured as the minimum possible distance, from each other on the outer surface 3a. QR .

[0064] Each transverse groove 5 has two groove edges 5a extending partially on the outer surface 3a and partially on the shoulder side 4a; a groove bottom 5b, two groove side faces 5c and an end side face 5d ( Figure 3 ) defined; also having a maximum depth t of 70% to 100% of the tread depth measured in the radial direction within the inner section 3 QR ( Figure 3 ) and a width b of 3.0 mm to 6.0 mm measured at the level of the outer surface 3a as the minimum possible distance between the groove edges 5a QR Furthermore, each transverse groove 5 tapers in a manner known per se towards its end on the outside of the tread ( Figure 3 , Figure 5 ) and terminates at a distance a1 measured transversely to the circumferential direction at the level of the shoulder side edge 4a in front of the sidewall (not shown) (see Figure 5 ).

[0065] The shoulder section 4 has, at the level of the shoulder side edge 4a, a width b measured transversely to the circumferential direction. S (See Figure 5 ), and is composed of a half 4' adjacent to the lateral edge of the ground contact surface (line L) and a half 4" adjacent to the sidewall. Therefore, the "division" of the shoulder segment 4 into halves 4', 4" involves a width bS .

[0066] In the half 4" adjacent to the sidewall, a plurality of approximately rectangular depressions 6, 7 are formed, which are distributed in the circumferential direction, extend in groups G, extend elongated in a top view from the shoulder side edge 4a, wherein the groups G are respectively located in their own circumferential sections U1 of the tread rib 1 on the shoulder side, which extend between two transverse grooves 5 and extend from the circumferential groove 2 on the shoulder side to the sidewall. A single group G is arranged in each circumferential section U1.

[0067] "Approximately rectangular" means that the corner areas of the recesses 6 and 7 may be rounded, or curved (e.g., arc-shaped) boundary edges may be provided at the longitudinal ends of the recesses 6 and 7 instead of straight boundary edges. "Approximately rectangular" also means that in each recess 6 and 7, a surface may be constructed that surrounds the recess, extends on the shoulder side 4a, and is rectangular in a top view, and that occupies at least 95% of the projection area of ​​the corresponding recess 6 and 7 in the horizontal plane of the shoulder side 4a.

[0068] Further configurations of the recesses 6 , 7 will be explained below with reference to a separate group G.

[0069] according to Figure 2 and Figure 5 , group G consists of a straight and completely half 4" ( Figure 2 ), namely two shorter, edge-side recesses 7 and a longer, central recess 6 extending in the region between the edge-side recesses 7. The recess 6 has a center line m1 ( Figure 2 ), and the recesses 7 each have a center line m2 oriented along their longitudinal extension ( Figure 2 ).

[0070] like Figure 2As shown, the recesses 6 and 7 arranged in the group G are designed to be symmetrical about a middle plane E1, which is formed by extending the center line m1 of the recess 6 and a straight line extending perpendicular to the shoulder side edge 4a and passing through the center line m1. The middle plane E1 is also the symmetry plane of the middle recess 6. Each recess 7 has a symmetry plane E2 extending parallel to the middle plane E1. Recesses 6, 7: extend at an angle α of 90° with respect to the center lines m1, m2 respectively relative to the circumferential direction; have a distance a2 of 0.5 mm to 2.0 mm between each other (also with respect to the center lines m1, m2) measured perpendicularly to the center lines m1, m2; also have a width b1 (recess 6) and a width b2 (recess 7) measured perpendicularly to the center lines m1, m2 in a top view at the level of the shoulder side edge 4a, a length c1 (recess 6) and a length c2 (recess 7) measured along the center lines m1, m2 at the level of the shoulder side edge 4a, and a depth t1 ( Figure 4 , depression 6) and depth t2( Figure 4 , depression 7). Depth t1, t2 ( Figure 4 ) is 0.3 mm to 1.0 mm, in particular 0.4 mm to 0.6 mm, wherein in this embodiment, the depth t1 is consistent with the depth t2. The widths b1 and b2 ( Figure 2 ) is 0.4 mm to 2.0 mm, wherein in this embodiment, the width b1 is 150% to 250%, in particular 180% to 220%, of the width b2, and wherein the width b2 is preferably 0.6 mm to 1.0 mm in size. The lengths c1, c2 are 3.0 mm to 7.5 mm, wherein in this embodiment, the length c1 is at least 2.0 mm greater than the length c2. The recesses 6, 7 have a distance a3 of 1.0 mm to 2.0 mm measured transversely to the circumferential direction, which is consistent with the end of the half 4" abutting the side wall, wherein the recess 6 protrudes beyond the recess 7 on the side facing away from the side wall by a protrusion Δc calculated based on the difference in lengths c1, c2 and related to the end of the center lines m1, m2. According to Figure 4 The recesses 6 , 7 are embodied in a U-shape when viewed in a plan view in a section oriented perpendicularly to the center lines m1 , m2 .

[0071] according to Figure 1 The groups G that are consecutive to each other in the circumferential direction have center lines m2 ( Figure 2 ) and measured in the circumferential direction, which is greater than the above-mentioned distance a2 ( Figure 2 ). The distance a4 is preferably 3.0 mm to 10.0 mm.

[0072] according to Figure 1 In the half 4" adjacent to the side wall, every other transverse groove 5 is formed with an elongated, approximately rectangular depression 8 adjacent to the transverse groove 5, extending along the extension of the transverse groove 5 in a top view, extending at an angle of 90° relative to the circumferential direction (see Figure 2 and Figure 5 The depression 8 has a depth t3 of 0.3 mm to 1.0 mm, in particular 0.4 mm to 0.6 mm, measured perpendicularly to the horizontal plane of the shoulder side edge 4a. Figure 3 , Figure 4 ); 0.4mm to 2.0mm, especially 0.6mm to 1.0mm width b3 ( Figure 2 ); and the half 4 "between the ends of the side walls of the 1.0mm to 2.0mm distance a3 ( Figure 2 ); and the corresponding distance a5 measured in the circumferential direction between the concave grooves 7 of the corresponding group G that are closest in the circumferential direction. The distance a5 is the distance between the center line m2 of the corresponding concave groove 7 ( Figure 2 ) and the center line of the recess 8, which is not shown in the drawings, and is greater than the distance a2 ( Figure 2 ).according to Figure 5 The depression 8 has a depression edge 8a which abuts against the shoulder side edge 4a and is tangentially connected to the groove edge 5a (without bending).

[0073] The invention is not restricted to the described exemplary embodiments.

[0074] The depressions adjacent to the transverse grooves are optional. The depressions arranged in groups can in particular include up to five depressions. These depressions can extend at an angle of up to 10°, in particular up to 5°, with respect to the circumferential direction. In addition, when viewed in a top view, these depressions can be implemented as rectangles. The depressions arranged in different groups can extend at different angles. The depressions arranged in the same group have a circumferential distance between each other about the center line of the depressions, which is less than the distance measured as the minimum distance between the groups that follow each other in the circumferential direction. The distance measured as the minimum distance between the groups that follow each other in the circumferential direction is related to the center line of the depressions of the edge sides that are closest to each other in these groups.

Claims

1. A pneumatic vehicle tire, comprising a tread and a sidewall, wherein the tread comprises at least one shoulder-side tread rib (1), the at least one shoulder-side tread rib comprising an inner section (3) located within the ground contact surface and a shoulder section (4) located outside the ground contact surface, the shoulder section comprising a half (4') adjacent to a lateral edge (line L) of the ground contact surface and a half (4") adjacent to the sidewall, wherein an elongated, approximately rectangular or rectangular depression (6, 7) is formed in the shoulder section (4), the depression extending at an angle (α) differing from 90° by at most 10° with respect to the circumferential direction, It is characterized in that The depressions (6, 7) are arranged in groups (G), wherein each group (G) is assigned at least three depressions (6, 7) which follow one another in the circumferential direction, extend parallel to one another and extend only in the half (4") of the shoulder section (4) adjoining the sidewall, the depressions having a depth (t 1 , t 2 ) and 0.4mm to 2.0mm width (b 1 , b 2 ), wherein the recesses (6, 7) arranged in the same group (G) have a distance (a) from each other in the circumferential direction 2 ), said distance being less than the distance (a) measured as the minimum distance between the groups (G) that are consecutive to each other in the circumferential direction. 4 ).

2. The vehicle pneumatic tire according to claim 1, It is characterized in that A maximum of five depressions (6, 7) are respectively assigned to the groups (G).

3. The vehicle pneumatic tire according to claim 1 or 2, It is characterized in that The groups (G) are arranged such that they are each assigned exactly three depressions (6, 7).

4. The vehicle pneumatic tire according to any one of claims 1 to 3, It is characterized in that The recess (6, 7) has a length (c 1 , c 2 ).

5. The vehicle pneumatic tire according to claim 4, It is characterized in that The group (G) is arranged such that the length (c 1 ) is greater than the length (c 2 ) at least 2.0mm larger.

6. The vehicle pneumatic tire according to claim 5, It is characterized in that The central recess (s) (6) protrudes beyond the respective edge recess (7) by a protrusion (Δc) on the side facing away from the side wall.

7. The vehicle pneumatic tire according to any one of claims 1 to 6, It is characterized in that The distance (a) between the recesses (6, 7) arranged in the same group (G) is 2 ) is 0.5mm to 2.0mm.

8. The vehicle pneumatic tire according to any one of claims 1 to 7, It is characterized in that The group (G) is arranged so that the width (b 1 ) is the width (b) of the depression (7) on each edge side 2 ), wherein the width (b 2 ) are preferably consistent.

9. The vehicle pneumatic tire according to any one of claims 1 to 8, It is characterized in that The depressions (6, 7) have a preferably uniform distance (a) measured transversely to the circumferential direction from the end of the half (4") of the shoulder section (4) adjacent to the sidewall, which abuts the sidewall. 3 ), the distance is 1.0mm to 2.0mm.

10. The vehicle pneumatic tire according to any one of claims 1 to 9, It is characterized in that The angle (α) at ​​which the recesses (6, 7) extend relative to the circumferential direction differs from 90° by at most 5°.

11. The vehicle pneumatic tire according to any one of claims 1 to 10, It is characterized in that The shoulder-side tread rib (1) is provided with transverse grooves (5), wherein the groups (G) in which the depressions (6, 7) are arranged are respectively located in their own circumferential sections (U) of the shoulder-side tread rib (1). 1 ) in which the circumferential section extends between two transverse grooves (5) and to the side wall.

12. The vehicle pneumatic tire according to claim 11, It is characterized in that In the half (4″) of the shoulder section (4) adjacent to the sidewall, each or every other transverse groove (5) is formed with an elongated, approximately rectangular or rectangular further depression (8) adjacent to the transverse groove (5) extending at an angle differing by at most 10° from 90° with respect to the circumferential direction, the further depression having a depth (t 3 ) and a width (b) of 0.4 mm to 2.0 mm, in particular 0.6 mm to 1.0 mm 3 ), wherein the further recess (8) preferably extends parallel to the recesses (6, 7) arranged in group (G) and in particular has a recess edge (8a) which is tangentially connected to one of the groove edges (5a) of the transverse groove (5).

13. A pneumatic vehicle tire according to any one of claims 1 to 12, It is characterized in that The group (G) is arranged such that the recesses (6, 7) are designed with respect to the middle plane (E 1 ) symmetrically, the median plane extending perpendicularly to the shoulder side edge (4a), over the longitudinal extension of the recess (6, 7) and centrally through the group (G).

14. A pneumatic vehicle tire according to any one of claims 1 to 13, It is characterized in that The depth (t 1 , t 2 ) is 0.4mm to 0.6mm.

15. A pneumatic vehicle tire according to any one of claims 1 to 14, It is characterized in that The distance (a) between the groups (G) that follow each other in the circumferential direction is measured as the minimum distance. 4 ) is 3.0mm to 10.0mm.

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