Vehicle pneumatic tire

Abstract

This invention relates to a vehicle pneumatic tire having a tread implemented in relation to the direction of travel, the tread having at least one intermediate row of tread blocks (2) defined on both sides by circumferential grooves (4, 5), the at least one intermediate row of tread blocks having tread blocks (6) separated from each other by lateral grooves (7), the lateral grooves extending parallel to each other in a top view, merging into the circumferential grooves (4, 5), each having a groove centerline (m). QR ), wherein each of the transverse grooves (7) has a first groove section (7a) and a second groove section (7b), the first groove section merging into a circumferential groove (5)10, relative to the axial direction and referring to the groove centerline (m QR The second groove segment extends at an angle (α) of 5° to 25°, connecting to the first groove segment and inclined in the opposite direction to the first groove segment (7a) in the axial direction, wherein (7a, 7b) first enter the ground with their interconnected areas as the tire rolls forward. An additional groove (8) is formed in each tread block (6), which extends along the extension line of the first groove segment (7a) in the top view, is narrower and shallower than the first groove segment, and extends between the lateral groove (7) and another of the two circumferential grooves (4).

Description

Technical Field

[0001] This invention relates to a vehicle pneumatic tire having a tread implemented in relation to the direction of travel, the tread having at least one intermediate row of tread blocks defined on both sides by circumferential grooves, the at least one intermediate row of tread blocks having tread blocks separated from each other by lateral grooves, the lateral grooves extending parallel to each other in a top view, merging into the circumferential grooves, each having a groove centerline, wherein each lateral groove has a first groove segment and a second groove segment, the first groove segment merging into a circumferential groove, extending at an angle of 5° to 25° relative to the axial direction and referring to the groove centerline, the second groove segment connecting to the first groove segment, and inclined in the opposite direction relative to the first groove segment relative to the axial direction, wherein, as the tire rolls forward, these groove segments first enter the ground with their interconnected areas. Background Technology

[0002] Such pneumatic tires for vehicles are known, for example, from EP 3 300 926 A1. The tire has a tread with two intermediate rows of tread blocks, each defined by circumferential grooves and divided into tread blocks by lateral grooves, wherein the lateral grooves widen funnel-shaped towards the circumferential grooves on the shoulder side. The lateral grooves have two groove segments connected to each other at an obtuse angle, wherein a bottom ridge is formed in the end segment inside the block of one groove segment. Correspondingly, additional grooves extending between adjacent lateral grooves are formed in the tread blocks, dividing the corresponding tread block into two block segments of substantially the same size, wherein the additional grooves widen funnel-shaped and extend at an angle of 5° to 15° relative to the circumferential direction. According to one embodiment, the tread is configured to be relative to the direction of travel. This tire should be suitable as an all-season tire, and particularly in terms of its handling performance (determined especially by the tread stiffness) balances water drainage capacity and snow grip.

[0003] In tires of the type described at the outset, the lateral grooves formed on the tread (which, due to their groove segments, have at least one inflection point in their direction) are particularly responsible for good snow grip, especially during cornering. The groove segments lengthen the drainage path toward the circumferential grooves and increase the risk of creating eddies in flowing water, thus reducing the drainage capacity of the lateral grooves compared to those without inflection points. Additional grooves formed in the tread blocks, as known from EP 3 300 926A1, cannot compensate for the reduction in drainage capacity caused by the angled groove segments to the desired extent. Summary of the Invention

[0004] Therefore, the objective of this invention is to take measures for vehicle pneumatic tires of the type described at the outset, which optimally compensate for the reduction in drainage capacity caused by the angled "emission path" of the lateral grooves under hydroplaning conditions while maintaining the tread stiffness required for good handling performance.

[0005] According to the present invention, the proposed objective is achieved in such a way that an additional groove is formed in each tread block, the additional groove extending along the extension line of the first groove section in a top view, being narrower and shallower than the first groove section, the additional groove extending between the transverse groove and another of the two circumferential grooves.

[0006] Therefore, the implementation of the additional grooves is specifically coordinated with the tread's direction of travel. Because these additional grooves extend along the extension line of the first tread section, water absorbed by the additional grooves is drained with almost no eddies into the first tread section of the lateral grooves and from there into the circumferential grooves into which that section merges, thus significantly improving drainage capacity. Since the additional grooves are narrower and shallower than the first tread section, the stiffness of the tread blocks, crucial for good handling performance, remains unchanged.

[0007] According to a preferred embodiment, viewed in a top view and referring to the centerline of the additional groove, the additional groove extends at an angle relative to the axial direction, the angle differing from the angle formed by the extension of the first groove section relative to the axial direction by a maximum of 10°, particularly a maximum of 5°, and especially preferably a maximum of 2°. This measure facilitates the rapid drainage of water absorbed by the additional groove into the first groove section of the transverse groove, and thus provides additional advantages for drainage capacity in the transverse groove area.

[0008] Another preferred embodiment is characterized by:

[0009] Each tread block has an inward (einlaufend) block edge that first enters the ground as the tire rolls forward, and an outward (auslaufend) block edge at the lateral groove, wherein the inward and outward block edges each have a block edge segment in each groove section.

[0010] The additional groove has a first groove edge and a second groove edge.

[0011] The first groove edge is connected to the block edge segment located in the first groove section of the driven-out block edge, and the second groove edge is connected to the block edge segment located in the second groove section of the driven-out block edge.

[0012] Through the extended groove edges, water flows from the additional grooves into the transverse grooves in a manner with almost no or virtually no eddies, thus further improving drainage.

[0013] In the preferred embodiment described above, it is particularly advantageous, for reasons mentioned above, that, when viewed in a top view, the edge of the first groove extends along a straight extension line of the block edge segment to which it is connected.

[0014] According to another preferred embodiment, the additional groove has a depth of 1.0 mm to 2.0 mm, particularly 1.3 mm to 1.7 mm, and / or a width of 1.0 mm to 2.0 mm, particularly 1.3 mm to 1.7 mm, in the radial direction. These features are also advantageous for good drainage.

[0015] Furthermore, for drainage purposes, with reference to the center line of the groove, the second groove section and the first groove section form an angle of 100° to 130°, preferably 110° to 120°, and particularly preferably 113° to 117°.

[0016] Another preferred embodiment features a lateral groove having two groove sides and a groove bottom, the groove bottom having a bottom section extending over the entire second groove section, the bottom section extending into the first groove section at an end section and having a partial recess reaching the groove sides, the partial recess being formed at least partially in or adjacent to the end section, wherein the lateral groove is shallowest in the area of ​​the bottom section other than the partial recess. The locally shallower lateral groove strengthens the tread block arrangement and is therefore advantageous for handling performance. The partial recess increases the volume or cross-section of the lateral groove in the confluence area of ​​the additional groove, i.e., in an area critical to drainage capacity.

[0017] In the preferred embodiment described above, it is advantageous that the volume of the local depression is formed at least most of the second groove section.

[0018] Furthermore, in the preferred embodiment described above, it is advantageous that the local depression has a depth of 0.5 mm to 1.5 mm, particularly 0.8 mm to 1.2 mm, and / or a length of 1.5 mm to 4.0 mm measured along the center line of the groove.

[0019] Furthermore, in the preferred embodiment described above, it is advantageous that the end section of the bottom section has a groove centerline m. QRThe relevant length projected in the axial direction is 40% to 60%, especially at least 50%, of the length of the first groove section measured in a similar manner. In the area of ​​the bottom section other than the end sections, a deeper confluence area leading to the circumferential grooves is retained in the first groove section, thereby particularly advantageously balancing the stiffness of the tread block row and the drainage capacity of the lateral grooves extending therein.

[0020] Furthermore, in the preferred embodiment described above, it is advantageous that, apart from localized depressions, the bottom section extends to a constant depth of 40% to 60% of the tread depth, measured radially. This helps to balance the aforementioned characteristics.

[0021] Furthermore, in the preferred embodiment described above, it is advantageous that the bottom of the transverse groove has a bottom section extending only within the first groove section, which has a maximum radial distance of 1.0 mm to 2.0 mm from the tread depth and preferably decreases in the direction of the circumferential groove into which the first groove section merges. This bottom section is located in the deeper merging region of the transverse groove leading to the circumferential groove described above, and is beneficial to the drainage capacity of the transverse groove.

[0022] According to another preferred embodiment, the second groove segment extends into the circumferential groove into which the first groove segment does not merge.

[0023] According to an alternative preferred embodiment, a third groove segment is connected to the second groove segment within the tread block row. This third groove segment extends to the circumferential grooves into which the first groove segment does not merge, and the third groove segment is inclined in the same direction as the first groove segment about the axial direction. Preferably, the third groove segment...

[0024] a. Narrower than the first groove segment and narrower than the second groove segment; and / or

[0025] b. Extending at an angle relative to the axial direction, with reference to the groove centerline, this angle differs from the angle formed by the first groove segment extending relative to the axial direction by a maximum of 5°; and / or

[0026] c. Referring to the center line of the groove, form an obtuse angle with the second groove section; and / or

[0027] d. Having a length related to the centerline of the groove, projected in the axial direction, which is 15% to 30%, especially 20% to 25%, of the width of the axial projection of the intermediate tread block row.

[0028] The third groove section provides a zigzag orientation to the lateral grooves and is particularly advantageous for snow grip. Advantageously, through the third groove section, the drainage capacity of the lateral grooves is almost unaffected by the additional grooves with special extensions as described in the solution for the combined purpose. Therefore, the additional grooves particularly enhance water introduction into the first groove section, while the third groove section connects to the second groove section.

[0029] Furthermore, which is beneficial to the tread's water drainage capacity, the first groove section merges into the circumferential groove of the tread block row that defines the middle on the outer side of the tread, and the additional groove merges into the circumferential groove of the tread block row that defines the middle on the inner side of the tread. Attached Figure Description

[0030] Other features, advantages, and details of the invention will now be described in detail with the aid of the accompanying drawings, which schematically illustrate embodiments of the invention. In the drawings:

[0031] Figure 1 shows a simplified top view of a circumferential section of the tread of a vehicle pneumatic tire having a first embodiment of the present invention, unfolded into a planar shape.

[0032] Figure 2 shows an enlarged top view of detail Z2 in Figure 1.

[0033] Figure 3 shows a reduced cross section along line III-III in Figure 2.

[0034] Figure 4 shows a reduced cross section along line IV-IV in Figure 2.

[0035] Figure 5 shows a reduced cross section along line VV in Figure 2.

[0036] Figure 6 shows a reduced cross section along line VI-VI of Figure 2.

[0037] Figure 7 shows a reduced cross section along line VII-VII of Figure 2.

[0038] Figure 8 shows the reduced cross section along line VIII-VIII of Figure 2, and

[0039] Figure 9 shows a top view of a tread block having a second embodiment of the present invention.

[0040] List of reference numerals

[0041] 1...................tread

[0042] 2....................The middle row of tire tread blocks

[0043] 3....................Tread ribs on the shoulder side of the tire

[0044] 4....................Central circumferential groove

[0045] 5....................Circular grooves on the shoulder side of the tire

[0046] 6....................tread blocks

[0047] 6a, 6b...............block segments

[0048] 7................... Horizontal grooves

[0049] 7a...................groove section

[0050] 7b...................grooved section

[0051] 7c...................groove section

[0052] 8....................Additional Groove

[0053] 8a, 8b...............Gutter edge

[0054] 8c...................Groove side

[0055] 9....................block edge

[0056] 9a, 9b, 9c...block edge segments

[0057] 10...................block edge

[0058] 10a, 10b, 10c... Block edge segments

[0059] 11...................grooved side

[0060] 12................... Groove side

[0061] 13................... Grooved bottom

[0062] 13', 13"............bottom section

[0063] 13'a.................End section

[0064] 14...................Dent

[0065] 15a, 15b.............grooving

[0066] R.................... Arrow (Scrolling direction)

[0067] AA.................. line (tire equatorial plane)

[0068] a1................... Spacing

[0069] b PB b QR b N ...........width

[0070] l a ,l' a , l c , l V ........length

[0071] m QR ...................Groove center line

[0072] S a,min S b,min ...the narrowest position

[0073] S a,max .................Widest position

[0074] t1, t N , t N ............depth

[0075] T P ...tread depth

[0076] Z2...................Details

[0077] α, α', β, γ, δ, ε, θ angle Detailed Implementation

[0078] The pneumatic tire of the present invention is a tire for motor vehicles, especially multi-rail motor vehicles, and preferably a radially constructed tire for passenger cars, vans or light trucks (light-duty vehicles with a permissible gross weight ≤ 7.5t), wherein the tire is designed to operate under winter driving conditions.

[0079] Figure 1 shows a circumferential section of the tread 1 of a vehicle pneumatic tire. The tread 1 has tread patterns implemented in relation to the direction of travel, wherein the vehicle pneumatic tire is mounted on a vehicle such that the vehicle pneumatic tire has a rolling direction indicated by the arrow R when traveling forward. The tire equatorial surface is indicated by the dashed line AA.

[0080] The tread 1 has a central row of tread blocks 2 and shoulder ribs 3 in each half of the tread, wherein the shoulder ribs 3 are shown schematically only and may be implemented in a manner known per se. The central row of tread blocks 2 is separated from each other by central circumferential grooves 4 extending straight along the tire equatorial plane (line AA) in the top view, and is further separated from each other by shoulder ribs 5 extending straight along the shoulder side in the top view. The circumferential grooves 4 and 5 are respectively set with tread depth T. P (Figures 3 and 7) In practice, the tread depth is typically 6.5 mm to 13.0 mm for the preferred tire type.

[0081] Each intermediate tread block 2 has a width b along the axial direction at the periphery of the tread. PB Furthermore, in the embodiment, multiple lateral grooves 7 extending in a zigzag pattern and parallel to each other in the top view are used to divide the tread blocks 6. These lateral grooves extend between the central circumferential groove 4 and the corresponding circumferential grooves 5 on the shoulder side. The lateral grooves 7 are formed in the intermediate tread block rows 2, such that one intermediate tread block row 2 is implemented symmetrically with respect to the tire equatorial plane (line AA) relative to another intermediate tread block row 2. Another design scheme of the tread blocks 6 and the lateral grooves 7 is described below with reference to a single lateral groove 7 and the tread blocks 6 adjacent to the lateral grooves 7, and with reference to Figures 2 to 8.

[0082] According to Figure 2, the transverse groove 7 consists of groove segment 7a that merges into the circumferential groove 5 on the shoulder side, groove segments 7b that terminate within the middle tread block row 2 on both sides, and groove segment 7c that merges into the central circumferential groove 4. The groove centerline m following the groove direction is marked. QR (Coincides with section line VII-VII).

[0083] In the top view, the groove section 7a extends straight, and with reference to the groove centerline m... QR The grooved section extends at an angle α of 5° to 25°, particularly 10° to 20°, and preferably 13° to 17° relative to the axial direction, and the grooved section has an angle m with respect to the groove centerline. QR The relevant length l projected in the axial direction a This length is the width b of the middle tread block column 2. PB 40% to 60%, especially 45% to 55%.

[0084] In the top view, the grooved section 7b extends straight, tilted in the opposite direction to the grooved section 7a about the axial direction, and references the groove centerline m. QR An angle β that forms 100° to 130°, preferably 110° to 120°, and particularly preferably 113° to 117° with respect to the grooved section.

[0085] The inclination of groove sections 7a and 7b causes the inner ends of the interconnected sections 7a and 7b to enter the ground before the ends of the other sections as the tire rolls forward (arrow R). Therefore, groove sections 7a and 7b enter the ground through their interconnected areas.

[0086] In the top view, grooved section 7c extends in a straight line; it is inclined in the same direction as grooved section 7a in the axial direction; referencing the groove centerline m... QR Extending at an angle γ relative to the axial direction, this angle differs from the angle α of groove section 7a by a maximum of 5°; referencing the groove centerline m QR It forms an obtuse angle δ with the groove section 7b; and has an angle with the groove centerline m. QR The relevant length l projected in the axial direction c This length is the width b of the middle tread block column 2. PB 15% to 30%, especially 20% to 25%.

[0087] Each tread block 6 has a block edge 9 at an adjacent lateral groove 7 (shown for lateral groove 7 in Figure 2) and a block edge 10 at an adjacent other lateral groove 7, wherein, as the tire rolls forward (arrow R), in each tread block 6, the block edge 9 enters the ground before the block edge 10. Therefore, the block edge 9 is also referred to below as the "entering block edge 9", and the block edge 10 is also referred to below as the "exiting block edge 10". The block edges 9 and 10 are each composed of block edge segments 9a and 10a extending in groove segment 7a, block edge segments 9b and 10b extending in groove segment 7b, and block edge segments 9c and 10c extending in groove segment 7c, wherein the block edge segments 9a, 9b, 9c, 10a, 10b, and 10c each extend straight in the top view.

[0088] The transverse grooves 7 are perpendicular to the groove centerline m in the top view between block edges 9 and 10 or between corresponding block edge segments 9a, 9b, 9c, 10a, 10b, and 10c. QR Measured width b QR In the grooved section 7a, the width b QRFrom the end of the groove section 7a located inside the tread block row 2, towards the shoulder side of the circumferential groove 5, the groove continuously decreases in the extension portions of the block edge sections 9a and 10a, wherein the narrowest position S of the groove section 7a is... a,min Width b at the location QR The thickness ranges from 2.5mm to 4.0mm, especially from 3.5mm to 4.5mm, and is at its widest position S. a,max The narrowest point is S. a,min Width b at the location QR 110% to 130%, especially 115% to 125%. In grooved section 7b, width b QR The groove continuously decreases in the direction towards groove section 7c, with the narrowest point S in groove section 7b being... b,min Width b at the location QR It is at position S a,min Width b at the location QR 85% to 95%. In grooved section 7c, width b QR It is constant and is implemented as less than S. b,min The width at the location is at least 1.5 mm, preferably at least 2.0 mm.

[0089] The transverse groove 7 is defined throughout the groove sections 7a, 7b, and 7c by the groove side 11 originating from the edge 9 of the entering block, the groove side 12 originating from the edge 10 of the exiting block, and the groove bottom 13. This is perpendicular to the groove centerline m. QR When viewed in a directional cross section, the grooved sides 11, 12 extend at an angle ε of 0° to 7° relative to the radial direction (Figs. 4 to 6), wherein the angle ε of the grooved sides 11, 12 is preferably up to 5° in the grooved sections 7a, 7b (Figs. 4, 5) and preferably up to 3° in the grooved section 7c (Fig. 6).

[0090] The grooved bottom 13 has a bottom section 13' extending over the grooved sections 7c, 7b and extending into the grooved section 7a with an end section 13'a, and a bottom section 13' extending only in the grooved section 7a. The bottom section 13' has a trapezoidal partial recess 14 in the grooved section 7b, which is adjacent to the end section 13'a in a top view. Alternatively, the partial recess 14 (refer to FIG. 7) may be formed at least partially in the end section 13'a. The end section 13'a has a groove centerline m. QR The relevant length l' projected in the axial direction a This length is the length of the grooved section 7a. a 40% to 60%, especially at least 50%. As shown in Figure 7, the tread depth T in the bottom section 13' (including its end section 13'a) is measured radially in the area other than the recess 14. PThe recess 14 extends at a constant depth t1 of 40% to 60% of the bottom section 13'. The recess 14 has a depth t in the radial direction relative to the horizontal of the bottom section 13' of 0.5 mm to 1.5 mm, particularly 0.8 mm to 1.2 mm. V and along the center line m of the groove QR The length l, measured at the level of the bottom section 13'a, ranges from 1.5 mm to 4.0 mm. V (Refer to the position of section line VII-VII in Figure 2). The bottom section 13”, which extends only in the groove section 7a, has a spacing a1 in the radial direction from the horizontal distance of 1.0 mm to 2.0 mm from the tread depth in the region of its end section 13'a closest to the bottom section 13', and decreases to the tread depth T in the direction of the circumferential groove 5 toward the shoulder side. P .

[0091] Figure 1 also shows that in each tread block 6, an additional groove 8 is formed extending between the lateral groove 7 and the central circumferential groove 4, wherein the additional grooves 8 located in the middle tread block row 2 extend parallel to each other in the top view. According to Figure 2, viewed in the top view, the additional grooves 8 are straight and extend along the extension line of the groove segment 7a and merge into the groove segment 7b. The additional groove 8 has a groove centerline m. N Two groove edges 8a and 8b extend straight and parallel to each other in the top view around the periphery of the tread block 6, wherein groove edge 8a connects to the end of the block edge segment 10a located inside the tread block 6, and wherein groove edge 8b intersects with the block edge segment 10b. See the groove centerline m in the top view. N The additional groove 8 extends at an angle α' relative to the axial direction, and this angle differs from the angle α of the first groove section 7a by a maximum of 10°, particularly a maximum of 5°, and especially preferably a maximum of 2°. In the illustrated embodiment, the groove centerline m N The angle α' between the groove edge 8a and the axial direction is chosen such that the groove edge 8a connects to the block edge segment 10a without any inflection point in the top view and thus extends along the straight continuation line of the block edge segment.

[0092] According to Figure 8, the additional groove 8 is implemented as a U-shape when viewed in cross-section, and the additional groove has a width b that is 1.0 mm to 2.0 mm, particularly 1.3 mm to 1.7 mm, measured perpendicular to the groove edges 8a and 8b in the top view and between them. N (Refer to Figure 2); Depth t measured radially in the direction of 1.0 mm to 2.0 mm, especially 1.3 mm to 1.7 mm. N; and two groove sides 8c emanating from the groove edges 8a, 8b, which, when viewed in cross-section of the additional groove 8, extend at an angle θ of 0° to 6°, particularly at least 2°, relative to the radial direction. Therefore, the additional groove 8 is narrower and shallower over its entire extension than the grooved section 7a.

[0093] As already described, the groove side 12 of the transverse groove 7, which connects to the exiting block edge 10, extends at an angle ε relative to the radial direction within the groove section 7a, and thus has a groove side section 12a extending at this angle and connecting to the block edge section 10a. Preferably, the angle ε of the groove side section 12a coincides with the angle θ of the groove side 8c connected to the groove edge 8a, so that this groove side 8c extends on the flat extending surface of the groove side section 12a, thus transitioning into the groove side section without an inflection point.

[0094] As shown in Figure 1, each of the additional grooves 8 divides the tread block 6 into a block segment 6a and a block segment 6b with a smaller outer surface area relative to the block segment. The block segment 6a is defined by the sections of the circumferential grooves 4 and 5, the additional grooves 8, the groove section 7a connected to the additional groove (refer to Figure 2), and the corresponding transverse grooves 7. The block segment 6b is defined by the section of the central circumferential groove 4, the groove sections 7b and 7c of the transverse grooves 7, and the corresponding additional grooves 8.

[0095] Figure 9 shows a view of tread block 6, a variant of tread block 6 according to the first embodiment (refer to Figure 1), differing in that three grooves 15a are formed in block segment 6a and one groove 15b is formed in block segment 6b. Viewed in the top view and referring to the axial direction, groove 15a extends in the opposite direction to the additional groove 8 and traverses block segment 6a. Viewed in the top view, groove 15b extends parallel to the additional groove 8. Grooves 15a and 15b each have a width of 0.4 mm to 1.2 mm, and a depth at their deepest point in the radial direction equal to the tread depth T. P (Figures 3 and 7) 75% to 100%, especially as high as 95%.

[0096] The present invention is not limited to the described embodiments.

[0097] The lateral grooves 7 can, in particular, consist only of groove segments 7a and 7b, thus the lateral grooves merge into the corresponding circumferential grooves with groove segment 7b. Groove segment 7c is therefore optional. Furthermore, the local recess 14 is also optional. The lateral grooves 7 can also have a constant width. Additional grooves 8 can merge into the lateral grooves 7 on the extension of groove segment 7a, more precisely into groove segment 7b, such that the additional grooves 8 interrupt the block edge segment 10b at its end segment located in the block edge segment 10, and thus the two groove edges 8a and 8b connect to the block edge segment 10b. Therefore, in this embodiment, the groove edge 8a does not connect to the end of the block edge segment 10a. The tread has at least one intermediate tread block row, which is provided with lateral grooves and additional grooves in the manner described above.

Claims

1. A vehicle pneumatic tire having a tread implemented in relation to the direction of travel, the tread having at least one intermediate row of tread blocks (2) defined on both sides by circumferential grooves (4, 5), the at least one intermediate row of tread blocks having tread blocks (6) separated from each other by lateral grooves (7) extending parallel to each other in a top view and merging into the circumferential grooves (4, 5), each of the lateral grooves having a groove centerline (m). QR ), in, These transverse grooves (7) each have a first groove segment (7a) and a second groove segment (7b), the first groove segment merging into one of these circumferential grooves (5) and relative to the axial direction and referring to the center line of the groove (m). QR The second groove segment extends at an angle (α) of 5° to 25°, connecting to the first groove segment and tilting in the opposite direction to the first groove segment (7a) relative to the axial direction, wherein the first groove segment and the second groove segment (7a, 7b) first enter the ground at their interconnecting area as the tire rolls forward. Its features are, An additional groove (8) is formed in each tread block (6), which extends in the extension line of the first groove section (7a) in the top view and is narrower and shallower relative to the first groove section. The additional groove extends between the transverse groove (7) and another circumferential groove (4) of the two circumferential grooves. The transverse groove (7) has two groove sides (11, 12) and a groove bottom (13), the groove bottom having a bottom section (13') extending over the entire second groove section (7b), the bottom section extending into the first groove section (7a) at an end section (13'a) and having a partial recess (14) reaching the groove sides (12, 13), the partial recess being formed at least partially in or adjacent to the end section (13'a), wherein the transverse groove (7) is most shallow in the area of ​​the bottom section (13') other than the partial recess (14).

2. The vehicle pneumatic tire according to claim 1, characterized in that, Observe in the top view and refer to the center line (m) of the additional groove (8). N The additional groove extends at an angle (α') relative to the axial direction, and this angle differs by a maximum of 10° from the angle (α) formed by the extension of the first groove segment (7a) relative to the axial direction.

3. The vehicle pneumatic tire according to claim 2, characterized in that, Observe in the top view and refer to the center line (m) of the additional groove (8). N The additional groove extends at an angle (α') relative to the axial direction, and this angle differs by a maximum of 5° from the angle (α) formed by the extension of the first groove segment (7a) relative to the axial direction.

4. The vehicle pneumatic tire according to claim 2, characterized in that, Observe in the top view and refer to the center line (m) of the additional groove (8). N The additional groove extends at an angle (α') relative to the axial direction, and this angle differs by a maximum of 2° from the angle (α) formed by the extension of the first groove segment (7a) relative to the axial direction.

5. The vehicle pneumatic tire according to claim 1 or 2, characterized in that, Each tread block (6) has an ingress block edge (9) that first enters the ground as the tire rolls forward (arrow R) and an outgress block edge (10) at these lateral grooves (7), wherein the ingress block edge (9) and the outgress block edge (10) each have a block edge segment (9a, 9b, 10, 10b) in each first groove segment and second groove segment (7a, 7b). The additional groove (8) has a first groove edge and a second groove edge (8a, 8b). The first groove edge (8a) is connected to the block edge section (10a) of the driven block edge (10) located in the first groove section (7a), and the second groove edge (8b) is connected to the block edge section (10b) of the driven block edge (10) located in the second groove section (7b).

6. The vehicle pneumatic tire according to claim 5, characterized in that, Viewed from above, the edge of the first groove (8a) extends along the straight extension line of the block edge segment (10a) to which it is connected.

7. The vehicle pneumatic tire according to claim 1, characterized in that, The additional groove (8) has a depth of 1.0 mm to 2.0 mm in the radial direction (t N ), and / or a width of 1.0 mm to 2.0 mm (b N ).

8. The vehicle pneumatic tire according to claim 7, characterized in that, The additional groove (8) has a depth of 1.3 mm to 1.7 mm in the radial direction (t N ).

9. The vehicle pneumatic tire according to claim 7, characterized in that, The additional groove (8) has a width of 1.3 mm to 1.7 mm (b N ).

10. The vehicle pneumatic tire according to claim 1, characterized in that, Refer to the center line of the groove (m) QR The second groove segment (7b) and the first groove segment (7a) form an angle (β) of 100° to 130°.

11. The vehicle pneumatic tire according to claim 10, characterized in that, Refer to the center line of the groove (m) QR The second groove segment (7b) and the first groove segment (7a) form an angle (β) of 110° to 120°.

12. The vehicle pneumatic tire according to claim 10, characterized in that, Refer to the center line of the groove (m) QR The second groove segment (7b) and the first groove segment (7a) form an angle (β) of 113° to 117°.

13. The vehicle pneumatic tire according to claim 1, characterized in that, The volume of the local depression (14) is formed at least most of the second groove section (7b).

14. The vehicle pneumatic tire according to claim 1, characterized in that, The local depression (14) has a depth of 0.5 mm to 1.5 mm (t V ), and / or along the center line of the groove (m QR The measured lengths ranged from 1.5 mm to 4.0 mm (l) V ).

15. The vehicle pneumatic tire according to claim 14, characterized in that, The local depression (14) has a depth of 0.8 mm to 1.2 mm (t V ).

16. The vehicle pneumatic tire according to claim 1, characterized in that, The end section (13'a) of the bottom section (13') has a groove centerline (m) QR Related to the length projected in the axial direction (l') a The length is the distance between the first groove segment (7a) and the groove centerline (m). QR Related to this, the length projected in the axial direction (l) a 40% to 60% of ).

17. The vehicle pneumatic tire according to claim 16, characterized in that, The end section (13'a) of the bottom section (13') has a groove centerline (m) QR Related to the length projected in the axial direction (l') a The length is the distance between the first groove segment (7a) and the groove centerline (m). QR Related to this, the length projected in the axial direction (l) a At least 50% of ().

18. The vehicle pneumatic tire according to claim 1, characterized in that, In addition to the local depression (14), the bottom section (13') has a tread depth (T) measured in the radial direction. P The constant depth (t1) extension is 40% to 60%.

19. The vehicle pneumatic tire according to claim 1, characterized in that, The groove bottom (13) of the lateral groove (7) has a bottom section (13'') extending only in the first groove section (7a), the bottom section being a distance from the tread depth (T). p The horizontal radial direction has a maximum spacing of 1.0 mm to 2.0 mm (a1).

20. The vehicle pneumatic tire according to claim 19, characterized in that, The bottom section (13'') decreases in the direction of the circumferential groove (5) into which the first groove section (7a) merges.

21. The vehicle pneumatic tire according to claim 1, characterized in that, The second groove section (7b) extends to the circumferential groove (4) into which the first groove section (7a) does not merge.

22. The vehicle pneumatic tire according to claim 1, characterized in that, Within the tread block (2), a third groove section (7c) is connected to the second groove section (7b). The third groove section extends to the circumferential groove (4) into which the first groove section (7a) does not merge, and the third groove section is inclined in the same direction as the first groove section (7a) about the axial direction. The third groove section (7c) is inclined in the same direction about the axial direction as the first groove section (7a). a. Narrower than the first groove segment (7a) and narrower than the second groove segment (7b); and / or b. Refer to the center line of the groove (m) QR ), extending at an angle (γ) relative to the axial direction, which differs by a maximum of 5° from the angle (α) formed by the first groove segment (7a) extending relative to the axial direction; and / or c. Refer to the center line of the groove (m) QR ), forming an obtuse angle (δ) with the second groove section (7b); and / or d. Having a groove centerline (m) QR Related to this, the length projected in the axial direction (l) c The length is the width (b) of the axial projection of the middle tread block row (2). PB 15% to 30%.

23. The vehicle pneumatic tire according to claim 22, characterized in that, The third groove section (7) and the center line of the groove (m) QR Related to this, the length projected in the axial direction (l) c ) is the width (b) of the axial projection of the middle tread block row (2). PB 20% to 25% of ).

24. The vehicle pneumatic tire according to claim 1, characterized in that, The first groove segment (7a) merges into the circumferential groove (5) that defines the middle tread block row (2) on the outer side of the tread, and the additional groove (8) merges into the circumferential groove (4) that defines the middle tread block row (2) on the inner side of the tread.

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