Vehicle pneumatic tire

Abstract

A vehicle pneumatic tire having a tread with shoulder-side blocks (7) and centrally located blocks (7), wherein at least the shoulder-side blocks are spaced apart from one another by transverse grooves (6), and the shoulder-side blocks (7) have roll-in and roll-out edges (8), and wherein the blocks (7) are respectively provided with at least two incisions (10) extending in a plan view substantially parallel to one another and at an angle of at most 45° to the axial direction, having a width of 0.4 mm to 0.8 mm and a depth at their deepest location of at least 50% of the tread depth, wherein the blocks (7) also have microgrooves (11) arranged substantially parallel to the incisions (10) and / or transverse to the incisions (10), and wherein the microgrooves (11) are provided with a width of 0.2 mm to 0.7 mm and a depth of 0.2 mm to 0.7 mm; in at least one shoulder-side block at least one microgroove (11) is arranged which, in its extension, encloses an angle a of 0° to 15° with the circumferential direction (uR), and at both ends of the microgroove (11), in the region of the roll-in and roll-out edges (8), respectively, a funnel-shaped widening (12) is formed which respectively opens into the transverse groove (6) delimiting the block (7).

Description

TECHNICAL FIELD

[0001] The invention relates to a vehicle pneumatic tire having a tread with shoulder-side blocks belonging to a shoulder block row and with intermediate blocks between the shoulder-side block rows, wherein at least the blocks of the shoulder block row are spaced apart from one another by transverse grooves which enclose an angle in the range from 0° to 35° with the axial direction, and wherein the shoulder-side blocks and the intermediate blocks are each provided with at least two incisions which extend in a plan view substantially parallel to one another and at an angle of at most 45° to the axial direction, which incisions have a width of 0.4 mm to 0.8 mm and have a depth at their deepest location of at least 50% of the tread depth, wherein the blocks also have microgrooves which are arranged substantially parallel to the incisions and / or transversely to the incisions, and wherein the microgrooves have a width of 0.2 mm to 0.7 mm and a depth of 0.2 mm to 0.7 mm. BACKGROUND

[0002] It is known that in the case of vehicle pneumatic tires which are designed for use in winter, the blocks of the tread are uniformly "covered" with a plurality of very shallow microgrooves which extend parallel to one another. In contrast to conventional incisions formed in the blocks, such microgrooves do not close under the action of forces which arise during rolling, due to their small depth. The microgrooves usually extend in a plan view in the axial direction or at an angle of at most 90° to the axial direction. In the case of new tires, in particular so-called "soft compound" winter tires, the surface structure composed of microgrooves helps to absorb and discharge a water film which forms on a roadway covered with snow and / or ice during braking and acceleration, and in this way drains the tread. The thickness of the water film which forms on the roadway depends, inter alia, on the ambient temperature and the intensity of solar radiation. For example, in the case of an ambient temperature which is slightly below 0°C and intense solar radiation for a long period of time, a large amount of ice and / or snow melts, so that a relatively thick water film forms. In order to travel on such a roadway, it is advantageous to ensure that the water film is absorbed and discharged by the microgrooves, and at the same time the contact area of the tread blocks of the new tire is sufficiently large to ensure good force transmission from the tire to the ground. Such a vehicle pneumatic tire is known, for example, from DE 10 2017 211 128 A1, which is also of the type mentioned in the opening paragraph.

[0003] The expression "microgrooves arranged substantially parallel to the incisions" means that, in the case of incisions which deviate from a straight design, the microgrooves extend substantially parallel with respect to the center line of the incisions. Incisions which deviate from a straight design are, for example, incisions which extend in a wavelike or zigzag shape.

[0004] The microgroove can also deviate from the straight design and can extend, for example, in a wavelike or zigzag manner and can also have a design other than a cut, wherein in this case the center line of the microgroove is still substantially parallel to the center line of the cut.

[0005] In general, the arrangement of microgrooves leads to a slight deterioration of the wet grip performance. This is due to a slight turbulence on the road surface, which is also referred to as "microaquaplaning". SUMMARY

[0006] The object underlying the present application is therefore to design the tread of a tire of the type mentioned in the opening paragraph in such a way that the water film is still discharged by the microgrooves and that a good force transmission from the tire to the ground is still ensured. In addition, it is intended to improve the wet grip and at the same time to improve the ice and snow performance.

[0007] According to the application, the object proposed is achieved in that at least one block belonging to the shoulder block row, preferably all blocks belonging to the shoulder block row, is / are provided with at least one microgroove, which, in the extent of its extension, encloses an angle a of 0° to 15°, preferably an angle a of 0° to 8°, with the (tire) circumferential direction; and in that at the two ends of the microgroove, in the region of the rolling-in and rolling-out edges, respectively, a funnel-shaped widening is formed, which respectively opens into the transverse groove delimiting the block.

[0008] The microgroove(s) oriented substantially in the circumferential direction has / have an enlargement in the form of a funnel-shaped widening at its / their two ends. These enlargements are embodied funnel-shaped, whereby an enlargement is achieved both in terms of the width and the depth of the groove. Here, the depth increases in a ramped manner in the direction of the transverse groove. It is important that the funnel-shaped widening is arranged at the two ends of the microgroove, in the region of the rolling-in and rolling-out edges of the block and opens into the transverse groove delimiting the block. By this, a strong water absorption and drainage into the transverse groove can be achieved, in order to reduce the turbulence on wet roads and on icy roads, whereby the wet grip performance is improved. In addition, the rolling-out and rolling-in edges of the block are interrupted by the funnel-shaped recess, whereby the remaining block edges are subjected to greater pressure and these edges can therefore penetrate deeper into the snow. The funnel-shaped recess can also receive snow, which increases the snow-to-snow adhesion. By this, the ice and snow performance is improved.

[0009] Conveniently, one to four, preferably one to two, microgrooves are arranged in at least one block belonging to the shoulder block row, which microgrooves, in the extent of their longitudinal extension, enclose an equal angle a of 0° to 15°, preferably an angle a of 0° to 8°, with the circumferential direction; and in that at the two ends of the microgrooves, respectively, a funnel-shaped widening is formed. By this, the wet grip performance and the ice and snow performance are greatly improved and a good force transmission to the ground is also ensured.

[0010] Advantageously, the microgroove is provided with a width of 0.5 mm and a depth of 0.5 mm outside the funnel-shaped widening. Thereby it is achieved that the microgroove absorbs the shallow water film on the ice in an optimal manner and connects the funnel-shaped recess with the end of the microgroove, while at the same time the stiffness and the contact area of the sipe are not significantly reduced.

[0011] Conveniently, the depth of the funnel-shaped widening increases in a ramped manner towards the end of the microgroove and is 1.0 mm to 3.0 mm, preferably 1.5 mm, at the deepest position located at the outermost end of the microgroove, i.e. close to the transverse groove. Thus, for example, in case of a preferred depth of 1.5 mm at its deepest position, the funnel-shaped widening is 1.0 mm deeper than the microgroove with a preferred depth of 0.5 mm. This ensures that water is absorbed and drained into the transverse groove and provides a volume sufficient to receive snow for snow-to-snow friction without disadvantageously reducing the stiffness.

[0012] The term "microgroove" comprises the groove itself and the funnel-shaped widening arranged in the area of both ends of the microgroove.

[0013] Conveniently: the funnel-shaped widening has a maximum width in the range of 1.0 mm to 3.0 mm, preferably 2.0 mm, wherein the maximum width is formed on the surface of the sipe at the outer end of the funnel-shaped widening; and the funnel-shaped widening has a smaller width at its bottom / underside in the range of 0.2 mm to 1.5 mm, preferably 0.4 mm to 1.0 mm. The width on the surface of the sipe is always greater than the width of the bottom / underside of the funnel-shaped widening. The greater surface width improves the absorption of water and snow and the drainage, while the smaller depth only slightly reduces the stiffness and increases the snow-to-snow friction.

[0014] In an embodiment of the application, the width of the bottom / underside narrows gradually from the starting position of the funnel-shaped widening towards the transverse groove. The reduction in the bottom width only slightly reduces the stiffness of the sipe and advantageously increases the snow-to-snow friction.

[0015] Conveniently, the funnel-shaped widening has two side faces which open into the bottom of the funnel-shaped widening, wherein the side faces each enclose an angle β of 10° to 50°, preferably 15° to 30°, particularly preferably approximately 20°, with the radial direction. Thereby the stiffness is only slightly reduced and the snow-to-snow adhesion is advantageously increased.

[0016] Advantageously, the funnel-shaped widening has an approximately triangular or approximately semicircular or approximately trapezoidal cross section, wherein the maximum width of the widening is formed on the surface of the block and the minimum width is formed at the bottom of the widening. Thereby, the width from the microgroove outward to the lateral groove is enlarged, which optimizes the drainage and increases the pressure at the block edge to better press into the snow.

[0017] The funnel-shaped widening with an approximately triangular cross section, wherein the bottom of the funnel-shaped widening is rounded, preferably has side faces which each enclose an angle β in the range of 10° to 50°, preferably in the range of 15° to 30°, particularly preferably approximately 20°, with the radial direction. The funnel-shaped widening with an approximately trapezoidal cross section, wherein the bottom of the funnel-shaped widening is linear, preferably has side faces which each enclose an angle β in the range of 10° to 50°, preferably in the range of 15° to 30°, particularly preferably approximately 20°, with the radial direction.

[0018] Conveniently: the blocks belonging to each shoulder side of the shoulder block row each have 2 microgrooves which, in their extension, enclose an angle a in the range of 0° to 15°, preferably in the range of 0° to 8°, with the circumferential direction; and at both ends of the microgrooves, respectively, a funnel-shaped widening is formed which respectively opens into the lateral groove which bounds the block. Thereby, an optimal compromise between water uptake (sufficient volume) and drainage is maintained to absorb and drain a shallow water film and, on the other hand, only slightly reduce the contact area and the stiffness of the block.

[0019] Further advantageously: each block of the block row which adjoins the shoulder block row is respectively arranged with one or two microgrooves, wherein these blocks are likewise separated from one another by lateral grooves which enclose an angle in the range of 0° to 35° with the axial direction, which microgrooves, in their extension, enclose an angle a in the range of 0° to 15°, preferably in the range of 0° to 8°, with the circumferential direction; and at both ends of the microgroove(s), respectively, a funnel-shaped widening is formed which respectively opens into the lateral groove which bounds the block. Thereby, the above-mentioned properties are not only valid for the shoulder blocks, but also for those blocks which are arranged in the block row which adjoins the shoulder block row axially inward.

[0020] In a particular embodiment of the application, on the roll-in and roll-out edges of at least one block, Schneekanten are arranged, wherein the Schneekanten are protruding connections which protrude 0.2 mm to 1.0 mm, preferably 0.3 mm to 0.5 mm beyond the surface of the block and which have a width of 0.1 mm to 1.0 mm, preferably 0.3 mm to 0.5 mm. In the region of the funnel-like widening, the connections are naturally implemented as interrupted. Particular embodiments of protruding connections are disclosed, for example, in DE 10 2017 2215 82 A1, which are also referred to as "Schneekanten". The snow performance of the vehicle pneumatic tire is improved by pressing these protruding connections into the snow. Although the Schneekanten are interrupted in the region of the funnel-like widening, the water absorption and the drainage to the transverse grooves of the microgrooves with funnel-like widening is still ensured. In addition, the absorption of snow to improve the adhesion of snow to snow is retained. BRIEF DESCRIPTION OF DRAWINGS

[0021] Further features, advantages and details of the application will now be described in more detail by means of the drawings, which show schematically embodiments of the application. In the drawings:

[0022] Figure 1 a partially developed plan view of a tread of a vehicle pneumatic tire with an embodiment variant of the application is shown;

[0023] Figure 2 a detailed view A of the funnel-like widening of Figure 1 is shown;

[0024] Figure 3 a detailed view B of the funnel-like widening of Figure 1 is shown;

[0025] Figure 4 a cross-section A-A of the funnel-like widening of Figure 2 and is shown;

[0026] Figure 5 Figure 2 a cross-section B-B of the funnel-like widening of Figure 4 and is shown;

[0027] Figure 6 Figure 3 a detailed view B of the funnel-like widening of is shown;

[0028] Figure 7 Figure 3 a detailed view B of the funnel-like widening of Figure 6 is shown.

[0029] LIST OF REFERENCE SIGNS

[0030] 1.................Main groove

[0031] 2.................Left shoulder block row

[0032] 3.................Outboard midblock row

[0033] 4.................Center block row

[0034] 5.................Right shoulder block row

[0035] 6.................Transverse groove

[0036] 7.................(Sipe) block

[0037] 8.................Rolling-in and rolling-out edge

[0038] 9.................Sipe

[0039] 10................Cut

[0040] 11................Micro-sipe

[0041] 12................Funnel

[0042] 13................Maximum width of block surface of funnel

[0043] 14................Length of funnel

[0044] 15................Bottom of funnel

[0045] 16................Side of funnel

[0046] 17................Depth of funnel

[0047] P1................Arrow

[0048] uR................Circumferential direction

[0049] aR................Axial direction

[0050] rR radial direction DETAILED DESCRIPTION

[0051] The vehicle pneumatic tire according to the application is in particular a winter tire in a radial structure for a passenger motor vehicle, a van or a light truck.

[0052] Figure 1 The tread shown in the figures has three main grooves 1 extending substantially in the circumferential direction, which divide the tread pattern into four circumferentially encircling tread pattern areas, which are, from left to right: a left-hand shoulder block row 2, an outer half- central tread block row 3, a central block row 4, a right-hand shoulder block row 5. The left-hand shoulder block row 2, the outer half-central tread block row 3 and the right-hand shoulder block row 5 have tread blocks 7 separated from one another by transverse grooves 6, through which, on each tread block, roll-in and roll-out edges 8 are formed. The transverse grooves 6 are oriented in such a way that they enclose an angle in the range from 0 to 20° with the axial direction aR in the two shoulder block rows and in the range from 10° to 35°, preferably in the range from 20° to 25°, with the axial direction aR in the outer half-central block row. The central block row 4 is divided into individual tread blocks 7 by intersecting diagonal grooves 9. The direction of rolling of the tire when it is driven forward is indicated by the arrow P1. The width B of the ground contact surface corresponds to the width of the track measured in accordance with the E.T.R.T.O. standard in the static case with a load of 70% of the maximum load capacity and an internal pressure of 85%.

[0053] All the tread blocks 7 are respectively provided with at least three incisions 10 extending substantially parallel to one another in plan view and at an angle of at most 45° to the axial direction aR, which have a width of 0.4 mm to 0.8 mm and have a depth of at least 50% of the tread depth at their deepest point. The blocks 7 also have microgrooves 11 which are arranged substantially parallel to the incisions 10 and / or transversely to the incisions 10. The microgrooves 11 are provided with a width of 0.2 mm to 0.7 mm, preferably 0.5 mm, and a depth of 0.2 mm to 0.7 mm, preferably 0.5 mm. As Figure 2 and Figure 3 As shown in an enlarged plan view, at least one microgroove 11 is arranged in each block 7 belonging to the left-hand and right-hand shoulder block rows 2, 5 and to the outer half-central tread block row 3, which microgroove encloses an angle a in the range from 0° to 15°, preferably in the range from 0° to 8°, with the circumferential direction uR in the extent of its extension. At both end regions of the microgroove 11, respectively, a funnel-shaped widening 12 is formed, which respectively opens into the transverse groove 6 delimiting the block. By definition, the end of the microgroove is located at the roll-in or roll-out edge of the tread block.

[0054] The depth of the funnel-shaped widening 12 increases in a sloping manner towards the end of the microgroove 11, and is 1.0 mm to 3 mm, preferably 1.5 mm, at the deepest position 17 located at the outermost end of the microgroove. Therefore, for example, where the depth at its deepest position is preferably 1.5 mm, the funnel-shaped widening is 1.0 mm deeper than the microgroove, which preferably has a depth of 0.5 mm. See [reference needed]. Figure 5 and Figure 7 .

[0055] exist Figure 4 In detailed view A, the funnel-shaped widening portion 12 of the right shoulder block row 5 has a maximum width 13 within a range of 2 mm, wherein the maximum width 13 is formed on the surface of the tread block 7 at the outer end of the funnel-shaped widening portion 12. Figure 5 Shown in Figure 4 The cross-section AA of the funnel-shaped widening portion 12 is shown in the top view. At the bottom / bottom surface 15, the funnel-shaped widening portion 12 has a relatively small width in the range of 0.2 mm to 1.5 mm, preferably 0.4 mm to 1.0 mm, and is composed of straight lines. The width of the bottom surface of the funnel-shaped widening portion 12 decreases towards the outer end. The length 14 of each funnel-shaped widening portion is in the range of 1.0 mm to 2.5 mm, and preferably 1.5 mm. The funnel-shaped widening portion 12 has two side surfaces 16 that open to the bottom 15 of the funnel-shaped widening portion 12, wherein the side surfaces 16 form an angle β with the radial direction rR in the range of 10° to 50°, preferably about 20°.

[0056] like Figure 6 and Figure 7 As shown, the funnel-shaped widened portion 12 of the left shoulder tread block row and the outer half-center tread block row is... Figure 4 and Figure 5 The difference between the funnel-shaped widened portion and the funnel-shaped widened portion is that the bottom / bottom surface 15 of the former is not composed of a straight line, but is composed of an arc. The two sides 16 leading to the bottom 15 of the funnel-shaped widened portion 12 also form an angle β with the radial direction rR in the range of 10° to 50°, preferably about 20°.

Claims

1. A vehicle pneumatic tire having a tread having shoulder-side blocks (7) belonging to shoulder block rows (2, 5) and intermediate blocks (7) between the shoulder block rows (2, 5), wherein at least the blocks (7) of the shoulder block rows (2, 5) are spaced apart from each other by lateral grooves (6) at an angle ranging from 0° to 35° with respect to the axial direction, and wherein the shoulder-side blocks (7) and the intermediate blocks (7) are respectively provided with being generally parallel to each other in a top view and with respect to the axial direction of the vehicle pneumatic tire. At least two cuts (10) extending at a maximum angle of 45°, the cuts having a width of 0.4 mm to 0.8 mm and a depth at their deepest point being at least 50% of the tread depth, wherein the block (7) on the shoulder side and the block (7) in the middle also have microgrooves (11), the microgrooves being generally parallel to and / or transverse to the cuts (10), and wherein the microgrooves (11) have a width of 0.2 mm to 0.7 mm and a depth of 0.2 mm to 0.7 mm. Its features are, At least one microgroove (11) is arranged in at least one block (7) belonging to the shoulder block row (2, 5), the at least one microgroove forming an angle α of 0° to 15° with the circumferential direction (uR) of the vehicle pneumatic tire within its extension range; and funnel-shaped widening portions (12) are formed at both ends of the at least one microgroove (11) in the regions of the roll-in and roll-out edges (8), the funnel-shaped widening portions correspondingly opening into the lateral grooves (6) of the at least one block (7) defining the shoulder block row (2, 5).

2. The vehicle pneumatic tire according to claim 1, characterized in that, At least one microgroove (11) is arranged in all blocks (7) belonging to the shoulder block rows (2, 5).

3. The vehicle pneumatic tire according to claim 1, characterized in that, The at least one microgroove forms an angle α of 0° to 8° with the circumferential direction (uR) of the vehicle's pneumatic tire within its extension range.

4. The vehicle pneumatic tire according to claim 1, characterized in that, One to four microgrooves (11) are arranged in at least one block (7) belonging to the shoulder block row (2, 5), which form an equal angle α of 0° to 15° with the circumferential direction (uR) within their extension range; and funnel-shaped widening portions (12) are formed at both ends of the microgrooves arranged in at least one block (7) belonging to the shoulder block row (2, 5).

5. The vehicle pneumatic tire according to claim 4, characterized in that, One to two microgrooves (11) are arranged in at least one block (7) belonging to the shoulder block row (2, 5).

6. The vehicle pneumatic tire according to claim 4 or 5, characterized in that, The microgrooves arranged in at least one block (7) belonging to the shoulder block rows (2, 5) form an equal angle α of 0° to 8° with the circumferential direction (uR) within their extension range.

7. The vehicle pneumatic tire according to claim 1 or 4, characterized in that, The microgrooves (11) arranged in at least one block (7) belonging to the shoulder block rows (2, 5) have a width of 0.5 mm and a depth of 0.5 mm outside the funnel-shaped widening portion (12).

8. The vehicle pneumatic tire according to claim 1, characterized in that, The depth of the funnel-shaped widened portion (12) increases toward the end of the at least one microgroove in a sloping manner and is 1.0 mm to 3.0 mm at the deepest position (17) at the outermost end of the at least one microgroove (11).

9. The vehicle pneumatic tire according to claim 8, characterized in that, The depth of the funnel-shaped widened portion (12) is 1.5 mm at the deepest position (17) located at the outermost end of the at least one microgroove (11).

10. The vehicle pneumatic tire according to claim 1, characterized in that, The funnel-shaped widening portion (12) has a maximum width (13) in the range of 1.0 mm to 3.0 mm, wherein the maximum width (13) is formed on the surface of at least one block (7) of the shoulder block row (2, 5) at the outer end of the funnel-shaped widening portion (12); and the funnel-shaped widening portion (12) has a smaller width in the range of 0.2 mm to 1.5 mm at its bottom / bottom surface (15).

11. The vehicle pneumatic tire according to claim 10, characterized in that, The funnel-shaped widened portion (12) has a maximum width (13) of 2.0 mm.

12. The vehicle pneumatic tire according to claim 10, characterized in that, The funnel-shaped widened portion (12) has a smaller width in the range of 0.4 mm to 1.0 mm at its bottom / bottom surface (15).

13. The vehicle pneumatic tire according to claim 1, characterized in that, The funnel-shaped widening portion (12) has two sides (16) that lead to the bottom / bottom surface (15) of the funnel-shaped widening portion (12), wherein the sides (16) form an angle β between 10° and 50° with the radial direction (rR) of the vehicle's pneumatic tire.

14. The vehicle pneumatic tire according to claim 13, characterized in that, The side (16) forms an angle β between 15° and 30° with the radial direction (rR) of the vehicle's pneumatic tire.

15. The vehicle pneumatic tire according to claim 13, characterized in that, The side (16) forms an angle β of approximately 20° with the radial direction (rR) of the vehicle's pneumatic tires.

16. The vehicle pneumatic tire according to claim 1, characterized in that, The funnel-shaped widening portion (12) has an approximately trapezoidal cross section, wherein the maximum width (13) of the funnel-shaped widening portion (12) is located on the surface of at least one block (7) of the shoulder block row (2, 5), while the minimum width is located at the bottom / bottom surface (15) of the funnel-shaped widening portion (12).

17. The vehicle pneumatic tire according to claim 1, characterized in that, The funnel-shaped widened portion (12) has an approximately triangular or approximately semi-circular cross section.

18. The vehicle pneumatic tire according to claim 1, characterized in that, Each shoulder block (7) belonging to the shoulder block row (2, 5) has two microgrooves that form an angle α of 0° to 15° with the circumferential direction (uR) within their extension range; and funnel-shaped widening portions (12) are formed at the two ends of the microgrooves (11), which respectively enter the transverse grooves (6) that define each shoulder block (7).

19. The vehicle pneumatic tire according to claim 18, characterized in that, The two microgrooves form an angle α of 0° to 8° with the circumferential direction (uR) within their extension range.

20. The vehicle pneumatic tire according to claim 1, characterized in that, Each block (7) of a block row (3) adjacent to the shoulder block row (2), wherein the blocks are also separated from each other by transverse grooves (6) at an angle of 0° to 35° with respect to the axial direction, is provided with one or two microgrooves (11), which form an angle α of 0° to 15° with respect to the circumferential direction (uR) within their extension range; and funnel-shaped widening portions (12) are formed at the two ends of the one or two microgrooves (11), which respectively open into the transverse grooves (6) defining each block (7).

21. The vehicle pneumatic tire according to claim 20, characterized in that, The one or two microgrooves (11) form an angle α of 0° to 8° with the circumferential direction (uR) within their extension range.

22. The vehicle pneumatic tire according to claim 1, characterized in that, Snow ribs are arranged on the in-roll-in and out-roll-out edges (8) of at least one block (7) on the shoulder side, wherein the snow ribs are protruding connecting portions that extend beyond the surface of the block by 0.2 mm to 1.0 mm and have a width of 0.1 mm to 1.0 mm.

23. The vehicle pneumatic tire according to claim 22, characterized in that, The connecting portion extends 0.3 mm to 0.5 mm beyond the surface of the block.

24. The vehicle pneumatic tire according to claim 22, characterized in that, The connecting part has a width of 0.3 mm to 0.5 mm.

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