Vehicle tires, especially commercial vehicle tires

Abstract

The invention relates to a vehicle tire, in particular a commercial vehicle tire, with a tread having at least one profile rib (1, 1', 1'') with cuts (3, 3', 3'') with a width (b E ) from 0.40 mm to 1.60 mm and a maximum depth (t E ) of at least 2.0 mm, wherein the incisions (3, 3', 3'') are perpendicular to the incision center line (m E ) extending cross-section, to the radial direction under a direction directed to the incision center surface (M E ) relative angles (β) of 10° to 45°. The maximum depth (t E ) of the cuts (3, 3', 3'') is at most 25% of the profile depth (T P ), whereby the incisions (3, 3', 3'') include those which, viewed in plan view, run parallel and immediately adjacent to each other and are perpendicular between the incision center lines (m ME ) have mutual distances (a1, a1'') of 1.0 mm to 10.0 mm.

Description

[0001] The invention relates to a vehicle tire, in particular a commercial vehicle tire, with a tread having at least one profile rib with cuts having a width of 0.40 mm to 1.60 mm and a maximum depth of at least 2.0 mm, wherein the cuts, viewed in the cross-section running perpendicular to the cut center line in plan view, run at an angle of 10° to 45° to the radial direction with respect to the cut center surface.

[0002] Such a vehicle tire is known, for example, from AT 367 690 B. The vehicle tire has a tread with a profile rib provided with cuts that, viewed in cross-section, extend at an angle of no more than 45° to the radial direction. In the illustrated embodiment, the cuts have a maximum depth approximately equal to the tread depth. As the tire rolls, the angle of the cuts increases under the resulting load. The tire is intended to provide good grip on snow and ice as tread wear progresses.

[0003] EP 0 846 579 A2 discloses a vehicle tire with a tread having positive profiles with cuts extending substantially in the axial direction in plan view and having a width of 0.3 mm to 1.0 mm. Viewed in plan view, the cuts have a wave-shaped cut section which, viewed in cross section, extends at an angle of 20° to 70°, in particular 30° to 50°, in this embodiment 45°, to the radial direction. This pneumatic vehicle tire is intended to have good grip properties on wet and dry road surfaces.

[0004] When designing cuts, there is a conflict of objectives between the improvement of the tread's grip on ice and / or snow-covered road surfaces by the cuts and the reduction in stiffness of the respective tread rib that results from the cuts, which impairs dry performance.

[0005] The invention is based on the object of improving the dry performance of a pneumatic vehicle tire of the type mentioned above while maintaining the highest possible grip on road surfaces covered with snow and / or ice.

[0006] The object is achieved according to the invention in that the maximum depth of the incisions is at most 25% of the profile depth, wherein the incisions include those which, viewed in plan view, run parallel and immediately adjacent to one another and have mutual distances of 1.0 mm to 10.0 mm determined vertically between the incision center lines.

[0007] The sipes are therefore clearly limited in depth and act as surface micro-grip elements, significantly improving grip, especially on new or slightly worn tires. Due to the small spacing between the sipes, the tread segments located between the sipes continue to exhibit particularly favorable deformation behavior when the tread flattens, making the sipe edges particularly beneficial for snow and ice grip. Because the sipes are significantly shallower than conventional sipes, the tread rib exhibits greater rigidity, improving dry performance.

[0008] According to a preferred embodiment, the mutual distances between the centerlines of the cuts, which, viewed in plan view, run parallel and immediately adjacent to one another, are up to 8.0 mm, in particular up to 6.0 mm, preferably up to 4.0 mm. This is favorable for the deformation behavior during flattening of the tread, thus further improving snow and ice grip.

[0009] A further preferred embodiment provides that the incisions, which have the aforementioned mutual spacings, are arranged within groups of at least two incisions each, with incisions belonging to the same group each being located in a separate tread rib circumferential section, which is delimited by two lines running transversely to the circumferential direction in plan view, wherein the lines run through the points of the incisions that are furthest apart from one another in the circumferential direction. This ensures that the incisions function effectively across the circumference of the tread rib and is thus further advantageous for grip on snow and ice.

[0010] In the latter embodiment, a first advantageous development is that the groups include adjacent groups in the circumferential direction, which—based on the closest lines to each other—have a circumferential spacing of 5.0 mm to 40.0 mm, in particular 10.0 mm to 35.0 mm, and preferably 15.0 mm to 30.0 mm. This contributes to a particularly favorable balance between grip on snow- and / or ice-covered roads and dry performance.

[0011] A preferred variant of the first advantageous further development provides that the mutual spacing of the incisions arranged within a group is consistent, with the distance between the adjacent groups in the circumferential direction being at least 200%, in particular at least 300%, preferably at least 400%, of the mutual spacing. This contributes primarily to maintaining high profile rigidity and is therefore beneficial for dry performance.

[0012] In the latter embodiment, according to a second advantageous development, the groups include groups each with up to seven, in particular up to five, cuts. Such a number of cuts is also particularly advantageous in view of the conflicting objectives between grip on snow- and / or ice-covered roads and dry performance.

[0013] A third advantageous further development of the last-mentioned preferred embodiment is characterized in that the groups include groups in which the incisions, viewed in plan view, extend at an angle of 0° to 50° to the axial direction, in particular from 0° or in particular from 10° to 45°, preferably from 15° to 40°, particularly preferably from 20° to 35°, and most preferably from 25° to 30°. Depending on the angle, the incisions improve the grip properties, especially under forces acting in the axial direction, such as those that occur when cornering, or primarily under forces acting in the circumferential direction, which occurs particularly under traction and braking loads.

[0014] In the third advantageous further development, it is preferred if the tread is designed to be directional, wherein the cuts each have an incoming cut edge which first enters the ground when the tire rolls during forward travel and a outgoing cut edge, wherein the cuts, viewed in a cross-section oriented perpendicular to their cut center line in plan view, run inclined relative to the radial direction and the rolling direction during forward travel in such a way that a first auxiliary line running in the radial direction and through the incoming cut edge does not intersect the cut center surface and a second auxiliary line running in the radial direction and through the outgoing cut edge has an intersection point with the cut center surface.Such inclined cuts have particularly effective cutting edges under braking load and therefore contribute primarily to improving braking performance on ice and / or snow.

[0015] Furthermore, in the third advantageous further development, it is preferred if the incisions cross the profile rib.

[0016] A fourth advantageous development of the last-mentioned preferred embodiment is characterized in that the groups include groups in which the cuts extend at an angle of 0° to 15°, in particular up to 10°, particularly preferably 0°, to the circumferential direction, with the cuts ending on both sides within the tread rib. Such groups are particularly suitable for locally "softening" the tread rib and, especially under forces acting in the axial direction, contribute to improving grip on snow and / or ice-covered roads.

[0017] In the fourth advantageous development, it is advantageous if the sipes have a length, relative to the sipe centerline and projected in the circumferential direction, of 10.0 mm to 30.0 mm, in particular 15.0 mm to 25.0 mm. This contributes to maintaining high tread rib rigidity and is thus particularly beneficial for the conflicting objectives between grip on snow and / or ice-covered roads and dry performance.

[0018] A fifth advantageous development of the last-mentioned preferred embodiment is characterized in that the groups include groups in which the incisions are formed symmetrically with respect to a line running parallel to the incision centerlines of the incisions in plan view. This contributes to a uniform local reduction in the stiffness of the tread rib, which is beneficial, for example, for abrasion behavior and dry performance.

[0019] A sixth advantageous further development of the last-mentioned preferred embodiment is characterized in that the groups include groups in which the angles at which the incisions run to the radial direction, viewed in the cross-section running perpendicular to the incision center line in plan view, are the same.

[0020] According to a further preferred embodiment, the angle at which the incisions extend to the radial direction, viewed in the cross-section running perpendicular to the incision center line in plan view, is 15° to 40°, in particular 20° to 35°, preferably 25° to 30°.

[0021] Further features, advantages and details of the invention will now be described in more detail with reference to the drawing, which schematically shows exemplary embodiments of the invention. Fig. 1 a plan view of a circumferential section of a profile rib of a tread of a commercial vehicle tire with a first embodiment of the invention, developed into the plane, Fig. 1a an enlarged section along the line la-la of the Fig. 1, Fig. 2 a plan view of a circumferential section of a profile rib developed into the plane with a second embodiment of the invention and Fig. 3 a plan view of a circumferential section of a profile rib developed into the plane with a third embodiment of the invention.

[0022] Vehicle tires designed according to the invention are tires for motor vehicles, in particular for multi-track motor vehicles, and preferably pneumatic vehicle tires of radial design for rims with a rim diameter of 13 inches to 24 inches. The tires are preferably commercial vehicle tires, which in particular have a rim diameter of 17.5, 19.5, or 22.5 inches.

[0023] Fig. 1 to Fig. 3 each show a development of a circumferential section of a central profile rib 1 ( Fig. 1), 1' ( Fig. 2), 1'' ( Fig. 3) of a tread of a commercial vehicle tire. The tread rib 1, 1', 1'' is laterally delimited by circumferential grooves 2 which, in the embodiments shown, are straight in plan view and which extend radially in the respective intended tread depth T P (indicated in Fig. 1a), which for commercial vehicle tires is preferably 10.0 mm to 25.0 mm.

[0024] The tread rib 1, 1', 1'' has an outer rib surface 1a located in the tread periphery and two rib edges 1b bordering said outer rib surface and located on the circumferential grooves 2. Furthermore, the tread rib 1, 1', 1'' is provided with a number of incisions 3 (tread rib 1), 3' (tread rib 1'), 3'' (tread rib 1'') extending from the outer rib surface 1b, which are elongated and straight in plan view, wherein the incisions 3, 3', 3'' are arranged in circumferentially successive groups G (incisions 3), G' (incisions 3'), G'' (incisions 3'').

[0025] The incisions 3, 3', 3' each have two incision edges 41, 42 located at the level of the outer rib surface 1a, aligned in their longitudinal extent, running parallel to one another and are each surrounded by two incision walls 5 ( Fig. 1a: Shown for incision 3) and an incision base 6 ( Fig. 1a: Shown for incision 3). The incisions 3, 3', 3'' each have an incision center line m located at the level of the rib outer surface 1a, following the course of the respective incision 3, 3', 3'' in plan view, and spaced correspondingly to the incision edges 41, 42. E , one from the incision center line m E outgoing incision center surface M, spaced in accordance with the incision walls 5 E ( Fig. 1a: Shown for notch 3), a perpendicular to the notch center surface M E determined constant width b E ( Fig. 1a) from 0.4 mm to 1.6 mm, in particular from 0.8 mm to 1.4 mm, and a maximum depth t determined in the radial direction and constant in the embodiments E (Depth at the deepest point, Fig. 1a: Shown for cut 3) of at least 2.0 mm and at most 25% of the tread depth T P ( Fig. 1a).

[0026] Each group G, G' is formed by three notches 3, 3' and each group G'' is formed by two notches 3'', whereby the notches 3, 3', 3'' belonging to the same group G, G', G'', viewed in plan view and related to their notch center lines m E , run parallel to one another and are located in a profile rib circumferential section U which is delimited by two lines L running transversely to the circumferential direction in plan view, wherein the lines L run through the points of the incisions 3, 3', 3'' which are furthest apart from one another in the circumferential direction on the tread periphery, i.e. on the rib outer surface 1a. The incisions 3, 3' each include two edge incisions 3, 3' and one central incision 3, 3' running between the edge incisions 3, 3'.

[0027] Within each group G, G', G'' the incisions 3, 3', 3'' are arranged with respect to a plane parallel to the incision center lines m Ethe line L running through incisions 3, 3', 3'' S symmetrical, with the line L S for each group G, G', viewed in plan view, with the incision center line m E of the central incision 3, 3' and for each group G'', viewed in plan view, in the area between the incision center lines m E which has two 3'' incisions.

[0028] The tread, which is Fig. 1, is designed to be directional in a manner not shown, wherein the commercial vehicle tire is to be mounted on a vehicle, such as a truck, in such a way that it has the rolling direction symbolized by the arrow R when driving forward. The sipes 3 of the groups G run, viewed in plan view and relative to the sipe center lines m E, to the axial direction at an angle α of 0° and traverse the central tread rib 1, so that they open into the circumferential grooves 2. As a result of the directional design of the tread and the orientation of the cuts 3 to the axial direction (angle α), when the tire rolls forward, the cut edge 41 enters the ground before the cut edge 42 at each cut 3. The cut edge 41 is referred to below as the incoming cut edge 41 and the cut edge 42 is referred to below as the outgoing cut edge 42. The immediately adjacent cuts 3 belonging to a group G point, viewed in plan view, to the cut center lines m Erelative to and determined perpendicular to these, mutual distances a1 of 1.0 mm to 10.0 mm, in particular up to 8.0 mm, preferably up to 6.0 mm, particularly preferably up to 4.0 mm. Furthermore, groups G which are immediately adjacent, i.e. consecutive, in the circumferential direction - relative to the lines L which are closest to one another - have a distance a2 from one another determined in the circumferential direction, which is 5.0 mm to 40.0 mm, in particular 10.0 mm to 35.0 mm, and preferably 15.0 mm to 30.0 mm. Preferably, the distances a1, a2 are additionally coordinated with one another in such a way that each distance a2 is at least 200%, in particular at least 300%, preferably at least 400%, of a distance a1.

[0029] According to Fig. 1a the incisions 3, in plan view, run perpendicular to the corresponding incision center line m E aligned cross-section (cf. position of line la-la in Fig. 1), to the radial direction under a plane directed to the incision center surface M E relative angle β of 10° to 45°, in particular of 15° to 40°, preferably of 20° to 35°, and particularly preferably of 25° to 30°, wherein the angles β of the incisions 3 overlap. In Fig. 1a, an auxiliary line h1 running in the radial direction and through the incoming incision edge 41 and an auxiliary line h2 running in the radial direction and through the outgoing incision edge 42 are drawn for an incision 3. The incisions 3 are inclined (angle β) relative to the rolling direction during forward travel (arrow R) such that the auxiliary line h1 defines the incision center area M E does not intersect and the auxiliary line h2 with the cutting center area M E has an intersection point S.

[0030] A tread which Fig. 2, is also designed to be directional in a manner not shown, wherein the commercial vehicle tire is to be mounted on a vehicle in such a way that it has the rolling direction symbolized by the arrow R when driving forward. The cuts 3' therefore each have an incoming cut edge 41 and a outgoing cut edge 42. The cuts 3' differ from the cuts 3 ( Fig. 1) in that these, viewed in plan view and related to the incision center lines m E , to the axial direction at an angle γ of up to 50°, deviating from 0°. The inclination of the incisions 3' in the cross-section relative to the rolling direction during forward travel (arrow R) is analogous to that of incisions 3 (cf. Fig. 1a: Shown for notches 3, angle β). Furthermore, the notches 3' located within a group G' - analogous to the notches 3 ( Fig. 1) - mutual distances a1 and circumferentially adjacent groups G' - analogous to the groups G ( Fig. 1) - mutual distances a2.

[0031] According to Fig. 3 the incisions 3'', viewed in plan view and related to the incision center lines m E , to the circumferential direction at an angle δ of 0° and axially adjacent to each other within each group G'', whereby the incisions 3'' are spaced from the rib edges 1b and end closed on both sides within the profile rib 1''. The incisions 3'' each have a pointing towards the incision center line m E relative length c projected in the circumferential direction E from 10.0 mm to 30.0 mm, in particular from 15.0 mm to 25.0 mm. The incisions 3'' belonging to a group G'' point to the incision center lines m Erelative to and determined perpendicular to these, mutual distances a1'' of 1.0 mm to 4.0 mm. Groups G'' which follow one another in the circumferential direction have - relative to the associated nearest lines L - a distance a2'' determined in the circumferential direction, which is 5.0 mm to 40.0 mm, in particular 10.0 mm to 35.0 mm, and preferably 15.0 mm to 30.0 mm. Preferably, the distances a1'', a2'' are additionally coordinated with one another in such a way that each distance a2'' is at least 200%, in particular at least 300%, preferably at least 400% of a distance a1''. The arrangement of the group G'' is further such that the incisions 3'' which belong to different groups G'' run in alignment with one another in plan view. The notch 3'' closest to a rib edge 1b in each group G'' points to the nearest rib edge 1b - relative to its notch center line m E- a distance a3'' of at least 3.0 mm, measured on the outer surface 1a of the rib in the axial direction. The incisions 3'' belonging to a group G'' can have different lengths c E have.

[0032] The invention is not limited to the described embodiments.

[0033] The tread has at least one tread rib with incisions running circumferentially. The tread rib(s) can be structured in a block-like manner with transverse grooves passing through it in tread blocks and / or with transverse grooves ending in a blind groove. The tread rib is bordered on at least one side by a circumferential groove that runs arbitrarily in plan view, for example in a zigzag shape. Furthermore, the incisions can be straight in plan view, for example, or curved or wavy in whole or in section. In the case of incisions that run curved or wavy in at least section, the incision center lines follow the curved or wavy course, whereby the angle at which such incisions run in plan view to the axial direction is determined with respect to a line connecting the ends of the incision center line and which runs straight in plan view. Each group comprises in particular two to seven incisions.The incisions do not have to be arranged in groups. List of reference symbols 1, 1', 1 middle profile rib 1a Rib outer surface 1b Rib edge 2 circumferential grooves 3, 3', 3'' incision 41, 42 cutting edge 5 cutting wall 6 Incision reason a1, a2, a1'', a2'', a3'' distance b E Width c E length G, G', G'' group h1, h2 auxiliary line L Line L S line m E Incision centerline M E Incision center area R arrow (rolling direction) S intersection point t E maximum depth T P Tread depth U Profile rib circumferential section α, β, γ, δ angles QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] AT 367 690 B

[0002] EP 0 846 579 A2

[0003]

Claims

[1] Vehicle tyres, in particular commercial vehicle tyres, with a tread having at least one profile rib (1, 1', 1'') with cuts (3, 3', 3'') with a width (b E ) from 0.40 mm to 1.60 mm and a maximum depth (t E ) of at least 2.0 mm, wherein the incisions (3, 3', 3'') are perpendicular to the incision center line (m E ) extending cross-section, to the radial direction under a direction directed to the incision center surface (M E ) relative angles (β) of 10° to 45°, characterized in that the maximum depth (t E ) of the cuts (3, 3', 3'') not more than 25% of the profile depth (T P ), wherein the incisions (3, 3', 3'') include those which, viewed in plan view, run parallel and immediately adjacent to one another and are perpendicular between the incision center lines (m ME ) have mutual distances (a1, a1'') of 1.0 mm to 10.0 mm. [2] Vehicle tyre according to claim 1, characterized by that the mutual distances (a1, a1'') between the incision center lines (m ME ) of the incisions (3, 3', 3''), which, viewed in plan view, run parallel and immediately adjacent to one another, are up to 8.0 mm, in particular up to 6.0 mm, preferably up to 4.0 mm. [3] Vehicle tyre according to claim 1 or 2, characterized by in that the incisions (3, 3', 3''), which have the mutual distances (a1, a1''), are arranged within groups (G, G', G'') each having at least two incisions (3, 3', 3''), wherein incisions (3, 3', 3'') belonging to the same group (G, G', G'') are located in a separate profile rib circumferential section (U), which is delimited by two lines (L) running transversely to the circumferential direction in plan view, wherein the lines (L) run through the points of the incisions (3, 3', 3'') which are spaced apart from one another the furthest in the circumferential direction. [4] Vehicle tyre according to claim 3, characterized by that the groups (G, G', G'') include groups (G, G', G'') which are adjacent in the circumferential direction and which - based on the lines (L) closest to one another - have a distance (a2, a2'') determined in the circumferential direction of 5.0 mm to 40.0 mm, in particular of 10.0 mm to 35.0 mm, and preferably of 15.0 mm to 30.0 mm. [5] Vehicle tyre according to claim 4, characterized by that the mutual distances (a1, a1'') of the incisions (3, 3', 3'') arranged within a group (G, G', G'') correspond, wherein the distance (a2) which the groups (G, G', G'') adjacent in the circumferential direction have is at least 200%, in particular at least 300%, preferably at least 400%, of a mutual distance (a1, a1''). [6] Vehicle tyre according to one of claims 3 to 5, characterized bythat the groups (G, G', G'') include groups (G, G', G'') which each have up to seven, in particular up to five, incisions (3, 3', 3''). [7] Vehicle tyre according to one of claims 3 to 6, characterized by that the groups (G, G', G'') include groups (G, G') in which the incisions (3, 3'), viewed in plan view, run at an angle (α, γ) to the axial direction of 0° to 50°, in particular of 0° or in particular of 10° to 45°, preferably of 15° to 40°, particularly preferably of 20° to 35°, and most preferably of 25° to 30°. [8] Vehicle tyre according to claim 7, characterized bythat the tread is designed to be directional, wherein the cuts (3) each have an incoming cut edge (41) which first enters the ground when the tire rolls during forward travel (arrow R) and a outgoing cut edge (42), wherein the cuts (3), in plan view perpendicular to their cut center line (m E ) aligned cross-section, are inclined relative to the radial direction and the rolling direction during forward travel (arrow R) in such a way that a first auxiliary line (h1) running in the radial direction and through the incoming cutting edge (41) defines the cutting center area (M E ) and a second auxiliary line (h2) running in the radial direction and through the outgoing cutting edge (42) with the cutting center surface (M E ) has an intersection point (S). [9] Vehicle tyre according to claim 7 or 8, characterized bythat the incisions (3, 3') cross the profile rib (1, 1'). [10] Vehicle tyre according to one of claims 3 to 8, characterized by that the groups (G, G', G'') include groups (G'') in which the incisions (3'') run at an angle (δ) of 0° to 15°, in particular of up to 10°, particularly preferably of 0°, to the circumferential direction, the incisions (3'') ending on both sides within the profile rib (1''). [11] Vehicle tyre according to claim 10, characterized by that the incisions (3'') have a line on the incision center line (m E ) projected length in the circumferential direction (C E ) from 10.0 mm to 30.0 mm, in particular from 15.0 mm to 25.0 mm. [12] Vehicle tyre according to one of claims 3 to 11, characterized by that the groups (G, G', G'') include groups (G, G', G'') in which the incisions (3, 3', 3'') are arranged with respect to a plane parallel to the incision center lines (m E) of the incisions (3, 3', 3'') running line (L S ) are symmetrical. [13] Vehicle tyre according to one of claims 3 to 12, characterized by that the groups (G, G', G'') include groups (G, G', G'') in which the angles (β) under which the incisions (3, 3', 3'') are perpendicular to the incision center line (m E ) running cross-section, to the radial direction, coincide. [14] Vehicle tyre according to one of claims 1 to 13, characterized by that the angle (β) at which the cuts (3, 3', 3'') are perpendicular to the cut center line (m E ) extending cross-section, to the radial direction, is 15° to 40°, in particular 20° to 35°, preferably 25° to 30°.

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