VEHICLE AIR TIRES

Description

[0001] The invention relates to a pneumatic vehicle tire with a tread with profile blocks, each with a block outer surface and at least one cut, which in plan view runs at an angle of 0° to 50° to the axial direction, traverses the respective profile block and divides it into profile block segments, having a width of 0.4 mm to 1.2 mm, two cut walls and a cut center surface spaced at the same distance from the cut walls, wherein the traversing cut is designed to the maximum depth at least in a cut region which in plan view runs over part of the cut, which has a bulge spaced from the block outer surface, which, viewed in the corresponding cross section perpendicular to the cut center surface, extends between a constant first depth related to the cut center surface and running through the radially outermost point of the bulge in a radial direction through a constant first depth determined in the radial direction,radially outer boundary line and a radially inner boundary line related to the incision center surface and extending at a constant second depth determined in the radial direction through the radially innermost point of the bulge, wherein in profile block segments of the profile blocks at least one additional incision which is elongated in plan view and has a width of 0.3 mm to 1.0 mm and a maximum depth is formed, which encloses supplementary angles deviating from 90° by up to 60° with the traversing incision and has an incision end section in the region radially outside the bulge of the traversing incision, wherein the point of maximum depth of the additional incision lies radially within the level of the radially outer boundary line of the bulge.

[0002] Such a pneumatic vehicle tire is known, for example, from US 2010 / 0078107 A1. According to one exemplary embodiment, this pneumatic vehicle tire has a tread with three central rows of tread blocks with tread blocks having cuts which, in plan view, run at least substantially in the axial direction and traverse the respective tread block and have a width of at most 1.0 mm. Each cut has a bulge which is spaced from the outer surface of the block and which, viewed in cross-section perpendicular to the central surface of the cut, is formed between a radially outer boundary line and a radially inner boundary line. In each tread block segment there is in each case an additional cut which is elongated in plan view and has a width of at most 1.0 mm and a maximum depth which corresponds to the maximum depth of the cuts, the additional cut being connected to theThe traversing cut(s) includes a supplementary angle of approximately 90° and merges into the traversing cut(s) and therefore has a cut end section in the area radially outside the bulge. This pneumatic vehicle tire is designed to provide good traction, braking, and handling performance while maintaining even tread wear.

[0003] JP 2013 023 023 A discloses a pneumatic vehicle tire with a tread comprising profile blocks with radially undulating incisions extending through them. The profile blocks are further provided with additional incisions extending from their outer block surfaces, which are only superficially formed and are therefore commonly known as "microgrooves" or "carvings." Viewed from above, the additional incisions run at an angle of 30° to 60° to the axial direction and absorb the meltwater film that forms when driving on ice. This tire is said to exhibit good ice grip properties while maintaining high block stiffness.

[0004] US 2006 169 377 A1 discloses a pneumatic vehicle tire with a tread comprising profile blocks provided with incisions that, viewed both in plan view and in the radial direction, extend in a zigzag pattern, so that the corresponding zigzag waves overlap one another. The profile blocks are further provided with additional incisions extending from the outer surface of the blocks, which are only superficial and have a depth of 0.1 mm to 1.0 mm. Profile blocks with such incisions and additional incisions are also intended to provide high block rigidity.

[0005] Furthermore, WO 2019 048 092 A1 discloses a pneumatic vehicle tire with a directional tread having tread blocks, each provided with at least two cuts which, when viewed from above, extend at an angle of 0° to 45° to the axial direction, have a width of 0.4 mm to 1.0 mm, and a maximum depth of 70% to 100% of the tread depth. Viewed in cross-section, the cuts each have an arcuate central cut section forming a bulge, which points away from the incoming block edge region, wherein the bulges of the two cuts have different maximum deflections, and wherein the maximum deflection of the bulge of the cut closest to the incoming block edge region is greater than the maximum deflection of the bulge of the cut closest to the outgoing block edge region.These cuts result in a favorable tilting behavior of the tread blocks, thereby maintaining a high net contact area, which is beneficial for the grip properties and enables even wear of the tread blocks.

[0006] Cuts formed in tread blocks are crucial for grip, especially under winter driving conditions and on wet roads. The improvement in grip is achieved primarily through longer gripping edges, which the cuts provide. For good grip, it is therefore desirable to create a large number of cuts in the tread blocks. However, care must be taken to ensure that the tread blocks do not become "too soft," as otherwise the respective gripping edges will "roll up" under braking due to the pronounced tilting movement of the tread blocks, reducing the effectiveness of the gripping edges.

[0007] To counteract this effect, it is known to provide incisions with bulges inside the incision. These bulges restrict the freedom of movement of the tread block segments formed by the incisions, which is particularly beneficial for tread blocks with numerous incisions, such as those commonly found in winter tire treads. The restricted freedom of movement results in the tread block segments deforming less under load, allowing the incision and block edges to better develop their gripping properties, thus improving snow grip properties in particular.

[0008] The invention is based on the object of further improving the grip properties of a pneumatic vehicle tire of the type mentioned above while maintaining good driving characteristics on dry roads.

[0009] The object is achieved according to the invention in that the traversing cut has a maximum depth of 70% to 100% of the profile depth, wherein the location of the maximum depth of the additional cut lies radially outside the level of the radially inner boundary line of the bulge of the traversing cut.

[0010] The additional sipes provide additional grip edges, improving grip on wet and snowy road surfaces. Their specific orientation relative to the traversing sipe results in several beneficial effects. The grip edges provided by the additional sipes have a significantly different orientation than the sipe edges of the traversing sipes, creating a multidirectional grip structure on the outer surface of the block that significantly improves grip. Furthermore, the additional sipes "divide" the block segments into small "segment areas," allowing the block segments to adhere particularly well to ice-covered road surfaces, resulting in a beneficially large net contact area on ice and thus good ice grip. Furthermore, the additional sipes absorb meltwater that forms when driving on ice.Since the additional sipes have a barely noticeable and evenly distributed impact on block stiffness—due partly to their orientation and partly to the bulges in the traversing sipes—a particularly advantageous tilting behavior of the tread blocks is maintained, which is particularly beneficial for power transmission, especially on dry roads. The measures taken thus enable improved grip on ice- and snow-covered roads, as well as on wet roads, while simultaneously maintaining good handling characteristics on dry roads.

[0011] The additional incisions have almost no effect on the block stiffness, which helps to maintain good driving characteristics on dry roads.

[0012] Preferably, the maximum depth of the additional cut is 1.5 mm to 3.0 mm. Such additional cuts enable advantageous meltwater absorption, particularly while maintaining high block stiffness, thus providing a favorable compromise in this regard.

[0013] A further preferred embodiment is characterized in that the radially outer boundary line of the bulge of the traversing incision has a radial distance of 1.0 mm to 2.9 mm, in particular of at least 1.2 mm, from the outer surface of the block. A bulge formed at such a defined distance from the outer surface of the block is advantageous for the function of the bulge and thus for the function of the incision and block edges as gripping edges.

[0014] According to a further preferred embodiment, the bulge of the traversing cut has a plane of symmetry extending in a radial direction with a constant depth, wherein the point of maximum depth of the additional cut lies radially outside the plane of symmetry, and wherein the constant depth at which the plane of symmetry extends is preferably 0.5 mm to 1.5 mm greater than the maximum depth of the additional cut. The additional cut thus ends in the radially outer half of the bulge. This also contributes to maintaining high block rigidity and is particularly advantageous for treads made of a soft rubber material. Such treads have proven to be quite advantageous for winter tires.

[0015] According to another preferred embodiment, the additional cut runs straight in plan view. This allows for a particularly uniform influence on the stiffness of the tread block segments.

[0016] A further preferred embodiment provides that the additional sipe flows into the traversing sipe or ends in front of it at a distance of 0.1 mm to 0.3 mm, determined in plan view as an extension of the sipe centerline. Flowing additional sipes are advantageous for drainage of the tread block because meltwater that forms is passed from the additional sipes into the corresponding traversing sipe. Ending additional sipes slightly reduce stiffness and are particularly advantageous for treads made of soft rubber.

[0017] Preferably, the traversing incision has a radially outer incision section extending in the radial direction between the bulge and the block outer surface with a length of 1.0 mm to 2.0 mm determined in the radial direction relative to the incision center surface.

[0018] A further advantageous embodiment is characterized in that the tread blocks include those that have at least one of the additional incisions in each tread block segment, with at least 30% of all tread blocks of the tread being designed in this way. Such tread blocks are particularly evenly drained and evenly "softened." The larger number of additional incisions provides a large number of additional gripping edges.

[0019] Furthermore, the softening and drainage behavior of the tread blocks is particularly uniform if the tread blocks include those which are bordered by grooves which run at an angle of 0° to 60° to the axial direction, with the additional cuts running parallel to these grooves in plan view and, in particular, at the same distances from them.

[0020] According to a further preferred embodiment, the additional incisions include those in which the supplementary angles deviate from 90° by up to 45°, preferably by up to 30°, particularly preferably by up to 10°.

[0021] Preferably, the additional cuts include those where the supplementary angles are 90°.

[0022] Preferably, the profile blocks include those which each have at least two profile block segments, each with one of the additional incisions, wherein the additional incisions are aligned with one another within the respective profile block in plan view.

[0023] A further preferred embodiment consists in that additional incisions are provided in edge-side profile block segments, each of which has an incision end section facing the block edge of the profile block and which is shallower than the other additional incision, wherein the additional incisions preferably end at a distance in front of the block edge.

[0024] A further preferred embodiment is characterized in that the bulge is formed from at least one projection, in particular a dome-shaped projection, located on one incision wall of the traversing incision, and at least one depression located on the other incision wall of the traversing incision, which depression corresponds to the projection, wherein the bulge is formed in particular by at least one central incision section which runs in an arcuate manner in the cross-section of the traversing incision.

[0025] 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 view of a profile block of a tread of a pneumatic vehicle tire with a first embodiment of the invention, Fig. 1a a top view of the profile block Fig. 1 , Fig. 1b a section along the line Ib-Ib of the Fig. 1a , Fig. 2 a view of a profile block of a tread of a pneumatic vehicle tire with a second embodiment of the invention, Fig. 2a a top view of the profile block Fig. 2 , Fig. 2b a section along the line IIb-IIb of the Fig. 2a and Fig. 3 an enlarged view of detail Z 3 of the Fig. 1b .

[0026] Pneumatic vehicle tires designed according to the invention are tires for motor vehicles, in particular for multi-track motor vehicles, and preferably tires of radial design for passenger cars, vans or light trucks (light trucks with a GVW ≤ 7.5 t), wherein the tires are intended for driving under winter driving conditions or for year-round use.

[0027] Fig. 1 and Fig. 2 show a profile block 1 ( Fig.1 ), 1' ( Fig. 2 ), which each belongs to a tread of a pneumatic vehicle tire. The circumferential direction of the tire is indicated by a double arrow U. The profile block 1, 1' is laterally Fig. 1 and Fig. 2 by merely indicated circumferential grooves 2 and by transverse grooves 3, also merely indicated, running between the circumferential grooves 2. The tread has a plurality of profile blocks 1 and / or 1'.

[0028] The circumferential grooves 2 and preferably also the transverse grooves 3 are each radially spaced to the profile depth TP ( Fig. 1b , Fig. 2b : indicated for each transverse groove 3), which is usually 6.5 mm to 12.0 mm, in particular 7.0 mm to 9.5 mm.

[0029] The profile block 1, 1' has a block outer surface 4 in the tread periphery, which is delimited at the circumferential grooves 2 by a block edge 5 each and at the transverse grooves 3 by a block edge 6 each, and is provided with four deeper cuts 7 extending from the block outer surface 4 and of a corresponding design, and with additional cuts 8 (profile block 1), 8' (profile block 1') extending from the block outer surface 4 and which are shallower in the radial direction than the deeper cuts 7.

[0030] The deeper cuts 7 pass through the profile block 1, 1' and, viewed in plan view (see Fig. 1a , Fig. 2a ), straight and in the axial direction and thus parallel to the block edges 6, whereby the deeper cuts 7 are evenly distributed within the profile block 1, 1' and give it profile block segments 1a. As Fig. 1a and Fig. 2a show, each incision 7 has an incision center line m E1 which is straight in plan view and aligned in its direction of extension, with respect to which the incision 7 - corresponding to the mentioned course - runs at an angle of 0° to the axial direction in the embodiments.

[0031] The further design of the deeper cuts 7 is explained below using a single deeper cut 7 formed in a profile block 1.

[0032] According to Fig. 3 the incision 7 is delimited by two opposing incision walls 9 and an incision base 10, has a constant width b E1 of 0.4 mm to 1.2 mm, in particular of up to 0.8 mm, determined between the incision walls 9, a maximum depth t E1 (depth at the deepest point of the incision 7) in the radial direction of 70% to 100%, in particular of a maximum of 95%, of the profile depth TP and an incision center surface F 1 (indicated by dashed lines) extending from the incision center line m E1 through the center of the incision 7. The incision center surface F 1 therefore has corresponding distances to the incision walls 9. The incision 7 has, in plan view perpendicular to the incision center line m E1 (cf. position of the section line Ib-Ib in Fig. 1a ) extending cross-section, a radially outer incision section 7a running in the radial direction, an arc-shaped, central incision section 7b and a radially inner incision section 7c running in the radial direction. In the embodiment shown, a rounded transition section 7d is formed between the central incision section 7b and the radially outer incision section 7a and between the central incision section 7b and the radially inner incision section 7c, which, viewed in the aforementioned cross-section, ensures a continuous (kink-free) transition between the incision sections 7a, 7b, 7c.

[0033] The radially outer incision section 7a has, in a cross-section oriented perpendicular to the incision center line m E1 in plan view, a length la, determined in the radial direction relative to the incision center surface F 1, of preferably 1.0 mm to 2.0 mm. The transition sections 7d each have a length ld, determined analogously to the length la, of preferably 0.2 mm to 0.9 mm. The radially inner incision section 7c extends in a continuation of the radially outer incision section 7a in a cross-section oriented perpendicular to the incision center line m E in plan view.

[0034] The arcuate central incision section 7b forms a bulge and, viewed in a cross-section oriented perpendicular to the incision center line m E1 in plan view, extends between a radially outer boundary line L a , which runs at a constant depth determined in the radial direction relative to the incision center surface F 1 , and a radially inner boundary line L i , which runs at a constant depth determined in the radial direction relative to the incision center surface F 1 . The central incision section 7b has a length lb, determined in the radial direction between the boundary lines L a , L i , of in particular 1.0 mm to 3.5 mm, preferably 1.5 mm to 3.0 mm, and also a plane of symmetry E 1 running at a constant depth t 1 determined in the radial direction. With regard to the plane of symmetry E 1, the tire curvature, i.e. the curvature of the tire contour, is not taken into account.The mentioned lengths la and ld are selected such that the boundary line La has a distance a 1 from the block outer surface 4 in the radial direction of 1.0 mm to 2.9 mm, in particular of at least 1.2 mm. The constant depth t 1 will be discussed in more detail later; its preferred size depends on a depth t E2 , which will also be mentioned later.

[0035] In Fig. 3 Furthermore, a straight reference line l 1 connecting the incision center surface F 1 between the radially outer incision section 7a and the radially inner incision section 7b is shown. The middle incision section 7b has, viewed in the aforementioned cross-section, a maximum deflection a of 0.5 mm to 1.5 mm in the plane of symmetry E 1, determined between the reference line l 1 and the incision center surface F 1. The arcuate middle incision section 7b results in a projection 12 formed on one incision wall 9, which has a circular segment-shaped cross-section, and a recess 13 formed on the other incision wall 9 and corresponding to the projection 12.The recess 13 projects into the incision wall 9 relative to the level of the associated incision wall 9 present in the area outside the central incision section 7b, and the projection 12 projects from the incision wall 9 relative to the level of the associated incision wall 9 present in the area outside the central incision section 7b.

[0036] According to Fig. 1 and Fig. 2 In each profile block segment 1a of the profile block 1, 1', one of the already mentioned additional cuts 8 (profile block 1), 8' (profile block 1') is formed, wherein the additional cuts 8, 8', viewed in plan view, are straight, parallel to the block edges 5 and aligned with each other ( Fig. 1a , Fig. 2a ) and extend radially into the respective profile block segment 1a. In the embodiment shown, the additional incisions 8, 8' have - relative to their straight incision center lines m E2 ( Fig. 1a , Fig. 2a ) - have the same distances to the block edge 5 located on the circumferential grooves 2.

[0037] How Fig. 1a and Fig. 2a show, the incision center lines m E2 of the additional incisions 8, 8', viewed in plan view, enclose two supplementary angles α with the incision center line(s) m E1 of the traversing incision(s) 7 adjacent to the respective profile block segment 1a. The two supplementary angles α complement each other in a known manner to 180°, with each supplementary angle α deviating from 90° by up to 60°, in particular by up to 45°, preferably by up to 30°, particularly preferably by up to 10°. In the exemplary embodiments shown, the supplementary angles α are each 90°.

[0038] Each additional incision 8, 8' has a constant width b E2 of 0.3 mm to 1.0 mm, in particular of 0.4 mm to 0.6 mm, and in the radial direction a maximum depth t E2 ( Fig. 1b , Fig. 2b ) which - how Fig. 3 for additional incisions 8 in a profile block 1 - is designed such that the additional incision 8, 8' ends in the radial direction between the radially outer boundary line L a and the radially inner boundary line L i . The maximum depth t E2 is 1.5 mm to 3.0 mm, whereby the mentioned lengths la , lb , ld or the length lb and the distance a 1 are adapted accordingly to the respective maximum depth t E2 .

[0039] The already mentioned constant depth t 1 , in which the plane of symmetry E 1 runs, is preferably 0.5 mm to 1.5 mm greater than the maximum depth t E2 of the additional incisions 8, 8'.

[0040] According to Fig. 1b the additional incisions 8 in the middle profile block segments 1a of the profile block 1 open into the two adjacent crossing incisions 7. The additional incisions 8 in the edge-side profile block segments 1a open at one end into the adjacent crossing incision 7 and exit from the profile block 1 at their other end. Each additional incision 8 has, at its end facing the outer side of the curved, middle incision section 7b, an incision end section 8a which is shallower than the other additional incision 8, which borders on the radially outer incision section 7a and the middle incision section 7b and, in the exemplary embodiment, is located exclusively in the area radially outside the middle incision section 7b. In the area outside the incision end section 8a, the additional incision 8 has the aforementioned maximum depth t E2.

[0041] According to Fig. 2b the additional incisions 8' running in the middle profile block segments 1a of the profile block 1' end within the middle profile block segments 1a and have a distance a 2 ( Fig. 2a ) from 0.1 mm to 0.3 mm. Each additional incision 8' has, at its end facing the outer side of the curved, central incision section 7b, an incision end section 8'a which is shallower than the other additional incision 8' and is located in the area radially outside the central incision section 7b. A thin rubber area 11 remains between each additional incision 8' and the traversing incision(s) 7 adjacent to the respective profile block segment 1a, wherein the mentioned incision end section 8'a is preferably designed such that the thin rubber area 11 has a constant thickness. In the area outside the incision end section 8'a, each additional incision 8' has the mentioned maximum depth t E2.

[0042] The invention is not limited to the described embodiments.

[0043] The additional incisions can also have two incision end sections that are radially shallower than the other additional incisions and, in plan view, can run, for example, in a wave-like or zigzag-like pattern or the like. Furthermore, additional incisions can be provided that are provided with local projections and corresponding depressions on the incision walls. The additional incisions are designed such that the point of maximum depth lies radially within the level of the radially outer boundary line of the bulge. The "point of maximum depth" is understood to mean the area in which the maximum depth exists.

[0044] The incisions traversing the tread blocks, viewed in plan view and relative to their incision centerlines, run at an angle of 0° to 50° to the axial direction. The incisions may, at least in sections, be wave-shaped in plan view, with the underlying wave being, in particular, a "rounded" wave, for example, a sine wave, a rectangular wave, a trapezoidal wave, or a zigzag wave.

[0045] Both the additional cuts and the traversing cuts can be curved (arched) overall in plan view, so that they have curved (circular) cut center lines in plan view. For example, additional cuts can be undulating and curved in plan view and / or cuts can be undulating and curved in plan view. The specified angles and supplementary angles for additional cuts and / or cuts that are curved overall in plan view are determined with respect to a straight line connecting the ends of the continuously curved cut center line.For example, if a combination of traversing cuts with straight cut center lines in plan view and additional cuts with curved cut center lines in plan view is planned, the supplementary angles are determined between the straight cut center line of the respective traversing cut and the straight line connecting the ends of the continuously curved cut center line of the additional cut.

[0046] The arcuate central sipe section mentioned in connection with the exemplary embodiments forms a bulge spaced from the tread periphery. The bulge is formed at least from a local projection formed on one sipe wall and a local depression formed on the other sipe wall and opposite the projection, wherein the projection and the depression in particular have corresponding shapes such that the width of the sipe is constant in the region of the bulge. The bulge does not have to extend over the entire sipe, but can be formed locally, for example as a dome-shaped curvature, such that it is located exclusively in an sipe region which, in plan view, extends over part of the sipe and is designed to the maximum depth of the sipe. The shape of the bulge is variable.Furthermore, the incisions can each have a plurality of bulges, which follow one another in particular in the radial direction and form an S-shaped central incision section.

[0047] Each bulge runs between a radially outer boundary line and a radially inner boundary line. The radially outer boundary line is referenced to the center surface of the incision and runs at a constant depth determined in the radial direction through the radially outermost point of the bulge. The same applies to the radially inner boundary line. In the case of correspondingly asymmetrical bulges, the radially outermost point of the bulge and the radially innermost point of the bulge are not located in the same cross-sectional plane. In this case, the radially outermost point of the bulge is offset from the radially innermost point of the bulge in the direction of extension of the incision.

[0048] The tread comprises tread blocks, each of which is provided with at least one traversing incision with a bulge. Preferably, at least 30% of the tread blocks are provided with traversing incisions with bulges and additional incisions. Bezugszeichenliste

[0049] 1, 1'Tread block 1aTread block segment 2Circumferential groove 3Transverse groove 4Block outer surface 5,6Block edge 7Cut 7aradial outer cut section 7bmiddle cut section 7cradial inner cut section 7dtransition section 8, 8'Additional cut 8a, 8'aCut end section 9Cut wall 10Cut base 11Rubber area 12Protrusion 13Recess amaximum deflection a 1 , a 2 Distance b E1 , b E2 Width E 1 Symmetry plane F 1 Cut center surface L a radial outer boundary line L i radial inner boundary line la , lb , ld Length l 1 Reference line m E1 , m E2 Cut center line U Double arrow (circumferential direction) t 1 Depth t E1 , t E2 Maximum depth TP Tread depth Z 3 Detail αSupplement angle

Claims

1. Pneumatic vehicle tyre having a tread with profile blocks (1, 1') which each have a block outer surface (4) and have at least one sipe (7) which, in plan view, extends at an angle of 0° to 50° to the axial direction, crosses through the respective profile block (1, 1') and divides the latter into profile-block segments (1a), said at least one sipe having a width (bE1) of 0.4 mm to 1.2 mm, having two sipe walls (9) and having a sipe central surface (F1) which is spaced apart correspondingly from the sipe walls (9), wherein the through-crossing sipe (7), at least in a sipe region extending over a part of the sipe (7) in plan view, is formed to the maximum depth (tE1) and has a convexity (7b) which is spaced apart from the block outer surface (4) and which, when viewed in the corresponding cross section perpendicular to the sipe central surface (F1), is formed between a radially outer delimitation line (La) based on the sipe central surface (F1) that extends at a constant first depth, as determined in a radial direction, through the radially outermost point of the convexity (7b) and a radially inner delimitation line (Li) based on the sipe central surface (F1) that extends at a constant second depth, as determined in the radial direction, through the radially innermost point of the convexity (7b), wherein, in profile-block segments (1a) of the profile blocks (1, 1'), there is formed in each case at least one additional sipe (8, 8') which is elongate in plan view and has a width (bE2) of 0.3 mm to 1.0 mm and has a maximum depth (tE2), said at least one additional sipe including with the through-crossing sipe (7) supplementary angles (α) which deviate from 90° by up to 60° and having a sipe end portion (8a, 8'a) in the region radially outside the convexity (7b) of the through-crossing sipe (7), wherein the point of maximum depth (tE2) of the additional sipe (8, 8') is situated radially within the level of the radially outer delimitation line (La) of the convexity (7b), characterized in that the through-crossing sipe (7) has a maximum depth (tE1) of 70% to 100% of the profile depth, wherein the point of maximum depth (tE2) of the additional sipe (8, 8') is situated radially outside the level of the radially inner delimitation line (Li) of the convexity (7b) of the through-crossing sipe (7).

2. Pneumatic vehicle tyre according to Claim 1, characterized in that the maximum depth (tE2) of the additional sipe (8) is 1.5 mm to 3.0 mm.

3. Pneumatic vehicle tyre according to Claim 1 to 2, characterized in that the radially outer delimitation line (La) of the convexity (7b) of the through-crossing sipe (7) is at a distance (a1) of 1.0 mm to 2.9 mm, in particular of at least 1.2 mm, from the block outer surface (4) in the radial direction.

4. Pneumatic vehicle tyre according to one of Claims 1 to 3, characterized in that the convexity (7b) of the through-crossing sipe (7) has a plane of symmetry (E1) which extends at a constant depth (t1), as determined in a radial direction, wherein the point of maximum depth (tE2) of the additional sipe (8, 8') is situated radially outside the plane of symmetry (E1), and wherein the constant depth (t1) at which the plane of symmetry (E1) extends is preferably 0.5 mm to 1.5 mm greater than the maximum depth (tE2) of the additional sipe (8, 8').

5. Pneumatic vehicle tyre according to one of Claims 1 to 4, characterized in that the additional sipe (8) extends rectilinearly in plan view.

6. Pneumatic vehicle tyre according to one of Claims 1 to 5, characterized in that the additional sipe (8) opens out into the through-crossing sipe (7) or ends at a distance (a2) of 0.1 mm to 0.3 mm in front of the latter, as determined in an extension of the sipe central line (mE2) in plan view.

7. Pneumatic vehicle tyre according to one of Claims 1 to 6, characterized in that the through-crossing sipe (7) has a radially outer sipe portion (7a) which extends in the radial direction between the convexity (7b) and the block outer surface (4) and which has a length (la) based on the sipe central surface (F1) of 1.0 mm to 2.0 mm, as determined in the radial direction.

8. Pneumatic vehicle tyre according to one of Claims 1 to 7, characterized in that the profile blocks (1, 1') include those which have in each profile-block segment (1a) at least one of the additional sipes (8, 8'), wherein in particular at least 30% of all of the profile blocks (1, 1') of the tread are designed in this way.

9. Pneumatic vehicle tyre according to one of Claims 1 to 8, characterized in that the profile blocks (1, 1') include those which are adjoined by channels extending at an angle of 0° to 60° to the axial direction, wherein, in plan view, the additional sipes (8, 8') extend parallel to and in particular at corresponding distances from said channels.

10. Pneumatic vehicle tyre according to one of Claims 1 to 9, characterized in that the additional sipes (8, 8') include those for which the supplementary angles (α) deviate from 90° by up to 45°, preferably by up to 30°, particularly preferably by up to 10°.

11. Pneumatic vehicle tyre according to one of Claims 1 to 10, characterized in that the additional sipes (8, 8') include those for which the supplementary angles (α) are 90°.

12. Pneumatic vehicle tyre according to one of Claims 1 to 11, characterized in that the profile blocks (1, 1') include those which have in each case at least two profile-block segments (1a) with in each case one of the additional sipes (8, 8'), wherein, in plan view, the additional sipes (8, 8') within the respective profile block (1, 1') extend in a manner aligned with one another.

13. Pneumatic vehicle tyre according to one of Claims 1 to 12, characterized in that additional sipes (8, 8') are provided in peripheral profile block segments (1a) and each have a sipe end portion which faces towards the block periphery of the profile block (1, 1') and which is shallower than the rest of the additional sipe (8, 8'), wherein the additional sipes (8, 8') preferably end at a distance in front of the block periphery.

14. Pneumatic vehicle tyre according to one of Claims 1 to 13, characterized in that the convexity (7b) is formed from at least one projection (12) situated on one sipe wall (9) of the through-crossing sipe (7), in particular a dome-shaped projection, and at least one depression (13) situated on the other sipe wall (9) of the through-crossing sipe (7) and corresponding to the projection (12), wherein the convexity (7b) is formed in particular by at least one middle sipe portion (7b) which extends in an arcuate manner in the cross section of the through-crossing sipe (7).