Vehicle pneumatic tires with central circumferential ribs

Abstract

A vehicle pneumatic tire with a tread (1) is described, the tread having a profile and a central circumferential rib (3) defined by two at least substantially parallel sides (4, 4') of two circumferential grooves (2, 2') surrounding the entire vehicle pneumatic tire, the circumferential grooves extending at least approximately perpendicular to the axial direction A of the vehicle pneumatic tire, as they deviate from the radial direction of the plane perpendicular to the axial direction A by an angle γ of less than 15°, thus causing the width of the circumferential rib (3) to remain constant or increase with the depth of the profile. And increase. The circumferential rib (3) has grooves (6) spaced at regular intervals d in the circumferential direction, which extend along the profile line (10) from one side (4, 4') of the two parallel sides (4, 4') of the two surrounding circumferential grooves (2, 2'). At three to seven times the length of the interval d between these grooves (6) in the circumferential direction, in each case, there is a fine transverse groove (8) in the central circumferential rib (3) instead of the grooves (6), the width of which is B. Q The width B of the groove pattern (6) F The depth T is at least 2.5 times greater and the fine transverse grooves have the outline (10) of these groove patterns (6). F In the end regions of these groove patterns (6), at the length L of the profile (10) red And in the length L of the profile (10) red The fine transverse grooves (8) are at least partially reduced by 80% to 250% and have snow cavities (20) in their end regions. The width B of these snow cavities (20) perpendicular to the profile (10) is... s The width B of the fine transverse groove (8) Q At least 1.5 times the depth of these snow caves, T S The contour depth T of the fine transverse groove (8) Q At most 65%.

Description

Technical Field

[0001] This invention relates to a pneumatic tire with a profiled tread. The profile has two circumferential grooves that surround the entire tire. A central circumferential rib of the profile is defined by two parallel sides of the two circumferential grooves that extend perpendicularly to the axial direction A of the pneumatic tire. The circumferential rib has sipes spaced at regular intervals in the circumferential direction, extending along the profile from one of the parallel sides of the two circumferential grooves to the other. Background Technology

[0002] Pneumatic tires for vehicles, also applicable to winter use (often simply called winter tires), must keep the vehicle stable on the road even when the road is covered with snow or ice. This winter performance (including snow and ice performance) also includes safe cornering, as well as safe starting and braking.

[0003] To achieve these characteristics, the tread of a vehicle's pneumatic tire has a correspondingly designed profile.

[0004] The snow performance of a tire is mainly determined by three mechanisms: the friction between the rubber and the snow, the friction between the snow and the snow, and the edge (shear) action of the tire's profile structure.

[0005] Here, the friction force of the vehicle's pneumatic tire against snow is determined by the rubber material of the tread, especially the rubber material on the tread surface.

[0006] To increase snow-on-snow friction, vehicle pneumatic tires have grooves and other structures in their tread profile that can be filled with snow drawn from the road. According to WO 2018 / 103924 A1, when driving on snow-covered roads, circumferential grooves with a depth of 1.5 mm to 2.5 mm and a width 2.0 to 3.0 times that depth are quickly and reliably filled with snow. If the vehicle has an anti-skid control (ASR) or anti-lock braking system (ABS), the rapid filling of the structures in the tire's tread profile to generate snow-on-snow friction is particularly important, as the tire's tread profile grips the road after a short skid distance or short grip time, requiring snow-on-snow friction for this purpose.

[0007] The edge (shearing) action of the tread profile is achieved using sipes (also called tabs) spaced at regular intervals within the profile. These sipes are narrower than the grooves or recesses in the tread profile of a pneumatic tire, and are between 0.2 mm and 0.7 mm, preferably between 0.4 and 0.6 mm, and particularly preferably between 0.45 mm and 0.55 mm. The sipes are typically arranged in profile blocks within the tread profile, formed by grooves within the profile. If the profile block now crosses the contact patch of the pneumatic tire, i.e., when the profile block contacts the road as the tire rotates, the sipes in the profile block open, thus creating a grip edge to increase traction in snow. Here, the profile block element, defined by two sipes or by one sipe and one profile block edge, is tilted. The formation of the grip edge and the tilting of the profile block element increase with the depth of the sipes in the profile.

[0008] However, the depth T of the groove pattern F The sipes can be reduced at the edges of the blocks, for example, to improve handling of a vehicle's pneumatic tires. On the other hand, this structure of the sipe pattern (called the edge rise of the sipe pattern) reduces the formation of grip edges and the tilting of the contour block elements.

[0009] However, in the case of icy roads, tilting of the contour block element is disadvantageous because when the contour block crosses the contact area, the contact area between the contour block element present in the contour block and the icy road is reduced, so that only the reduced contact area contributes to the traction between the vehicle's pneumatic tires and the road.

[0010] In the context of snow grip and ice grip, the conflict between the goals of snow performance and ice performance can be mitigated by providing a zone profile in the circumferential ribs of the vehicle's pneumatic tire tread profile. Here, the circumferential ribs extend around the circumference of the tire and have a fixed position in the axial direction A of the vehicle's pneumatic tire. In this case, the axial direction A of the vehicle's pneumatic tire is the direction around which the vehicle's pneumatic tire, mounted on the rim, rotates within the vehicle. Such a circumferential rib is correspondingly defined by two circumferential grooves in the axial direction A. Thus, the sides of the circumferential grooves that define the circumferential ribs preferably extend parallel to each other and preferably in a circumferential direction perpendicular to the axial direction A. Thus, the sides of the circumferential grooves that define the circumferential ribs, or the edges of the circumferential ribs, have no directional component in the axial direction. Here, the circumferential ribs in the form of zone profiles have sipes spaced at regular intervals in the circumferential direction. Because these circumferential ribs lack contour blocks separated by grooves, especially transverse grooves that are transverse relative to the circumferential direction, the rib elements formed by the grooving pattern in the circumferential rib tilt to a reduced degree as they pass through the contact area. On the other hand, in this case, the rib elements are even well supported, so that the grooving pattern no longer opens wide enough to allow the resulting gripping edge to function effectively on the snow. In the case of these circumferential ribs, snow-on-snow friction is also minimal and is based solely on the circumferential grooves with full contour depth that define the circumferential ribs.

[0011] The circumferential rib is located in the middle, and preferably centered, in the axial direction A. If there are other contour elements in the axial direction A, such as a contour block located between the circumferential rib and the shoulder closest to the circumferential rib, then the circumferential rib is centered. If the circumferential rib is centered in the tread of the vehicle's pneumatic tire in the axial direction A, then the circumferential rib is the central circumferential rib, and therefore, the two circumferential grooves define those sides of the circumferential rib that are equidistant from the shoulder closest to the circumferential rib in the axial direction A.

[0012] If, in such a circumferential rib, the grooving pattern of the zone profile has edge elevations at the edge of the circumferential rib, and these edge elevations are successively arranged in the circumferential direction, this will increase the circumferential stiffness of the circumferential rib at its edge, thereby increasing the wear on this area of ​​the circumferential rib.

[0013] EP 3 444 129 A1 discloses an intermediate circumferential rib with improved snow-on-snow friction, having a zone profile in which straight grooves and grooves at an angle relative to the axial direction A alternate in the circumferential direction, and the grooves additionally having bevels at their ends.

[0014] US2020 / 0031171 A1 discloses a central circumferential rib having straight grooves spaced at regular intervals in the circumferential direction at an angle relative to the axial direction A. At eight times the length of the circumferential spacing of these grooves, fine transverse grooves are arranged in place of the grooves in the central circumferential rib, forming the same angle relative to the axial direction A. The transverse grooves have recesses at their end regions that are deeper than the transverse grooves and have the same depth as the circumferential grooves defining the circumferential rib. The sides of the circumferential grooves defining the circumferential rib have a Z-shaped shape relative to the axial direction A and are not parallel to each other.

[0015] US2018 / 0345734 A1 discloses a central circumferential rib for a vehicle pneumatic tire with good snow and ice performance. These central circumferential ribs have straight sipes spaced at regular intervals in the circumferential direction and angled relative to the axial direction A. Five times the length of the circumferential spacing of these sipes, fine lateral grooves are arranged in place of the sipes in the central circumferential rib, forming the same angle relative to the axial direction A. These lateral grooves have recesses at their end regions that are deeper than the lateral grooves in the middle of the circumferential rib.

[0016] EP 3 421 263 B1 discloses a central circumferential rib for a vehicle pneumatic tire with good snow performance. These central circumferential ribs have straight sipes spaced at regular intervals in the circumferential direction and angled relative to the axial direction A, wherein a portion of every other sipe is replaced by a lateral groove that is deeper than the sipe.

[0017] US2018 / 0290498 A1 discloses circumferential ribs in the shoulder area of ​​a vehicle's pneumatic tire, these circumferential ribs having sipes spaced at regular intervals in the circumferential direction, wherein every four sipes in the circumferential direction, the end region has a groove portion that is wider and deeper than the sipes. When driving on snow-covered roads, the groove portion is provided for being filled with snow.

[0018] Although these profile structures are known, the problem to be solved remains to more effectively resolve the conflict between performance on snow and ice, while allowing for reduced tire wear due to abrasion. Summary of the Invention

[0019] This objective is achieved by a vehicle pneumatic tire as described in this invention.

[0020] Such a vehicle pneumatic tire has a tread with a profile and a central circumferential rib defined by two sides that are at least approximately parallel to each other and surround two circumferential grooves. These circumferential grooves extend at least approximately perpendicular to the axial direction A of the vehicle pneumatic tire, as they deviate from the radial direction of the plane perpendicular to the axial direction A by an angle γ of less than 15°, thus causing the width of the circumferential rib to remain constant or increase with increasing profile depth. The circumferential rib has sipes spaced at regular intervals d in the circumferential direction, extending along the profile from one side of the two parallel sides of the surrounding circumferential grooves to the other side. Furthermore, at three to seven times the length of the interval d along the circumferential direction, in each case, a fine lateral groove is arranged in the central circumferential rib instead of the sipes, the width of which is B. Q It is the width B of the groove pattern. F At least 2.5 times greater and the fine transverse grooves have the outline of these groove patterns, and wherein the depth T of these groove patterns is... F In the end regions of these groove patterns, at the length L of the profile... red Above and in the length L of the profile red The diameter is reduced by at least partially from 80% to 250%, and these fine transverse grooves have snow pits in their end regions, the width of which is perpendicular to the profile line. S It is the width B of the fine horizontal grooves. q At least 1.5 times and depth T S The contour depth T of the fine transverse grooves Q At most 65%.

[0021] Therefore, the tread of the pneumatic tire according to the present invention has two contours of circumferential grooves that surround the entire tire. These two circumferential grooves are adjacent circumferential grooves between the central circumferential rib in the tread.

[0022] Now, considering its cross-section perpendicular to the circumferential direction, each circumferential groove of a pneumatic tire has two sides in the axial direction A of the tire. Regarding the lowest point of the cross-section of the circumferential groove (the distance between this lowest point and the tread surface corresponds to the profile depth of the pneumatic tire), these two sides are located on one side or the other side of the lowest point in the axial direction A. Here, these two sides of the circumferential groove define the circumferential ribs of the tread, which are made of rubber material. Thus, the mutually facing sides of two adjacent circumferential grooves together define the circumferential ribs of the tread profile.

[0023] In the pneumatic tire of the present invention, the sides defining the circumferential ribs of the two circumferential grooves extend at least approximately parallel to each other and at least approximately perpendicular to the axial direction A of the pneumatic tire. Here, these sides defining the circumferential ribs deviate from the radial direction of the plane perpendicular to the axial direction A by an angle γ of less than 15°. This deviation of these sides defining the circumferential ribs causes the width of the circumferential ribs to remain constant or increase with increasing profile depth. Therefore, the two sides defining the circumferential ribs extend parallel to the circumferential direction of the pneumatic tire and have only a small deviation from the radial direction of the pneumatic tire, defined by the angle γ. The radial direction of the pneumatic tire is perpendicular to its axial direction A, about which the pneumatic tire rotates. Along the radial direction inward, i.e., along the central direction of the pneumatic tire, the profile depth of the tire profile increases. The sides defining the circumferential ribs now deviate from the radial direction of the pneumatic tire by an angle γ, causing the width of the circumferential ribs to remain constant or increase with increasing profile depth (i.e., inward). Accordingly, on the entire circumference of the pneumatic tire according to the invention, the circumferential ribs have a constant width B in the axial direction A at both the surface and at each profile depth. This width is defined by the spacing of these at least approximately parallel sides in that axial direction, but the width can increase inwards according to an angle γ that varies with the profile depth. In a preferred embodiment, the two sides defining the circumferential ribs of the two parallel circumferential grooves lie in two parallel planes perpendicular to the axial direction A. Thus, except in the bottom region of the circumferential grooves, the angle γ is 0 at the profile depth, and the width B remains constant at the profile depth of the profile. In a particularly preferred embodiment, the two circumferential grooves defining the circumferential ribs themselves also extend parallel to each other in two planes perpendicular to the axial direction A; that is, the lowest point of the cross-section of the circumferential groove perpendicular to the circumferential direction lies in one of the two planes perpendicular to the axial direction A on the entire tire circumference. Here, the two circumferential grooves are particularly preferably of the same width in the axial direction A on the entire tire circumference. Here, the design of the circumferential grooves does not take into account pure manufacturing tolerances in tire profile production.

[0024] Typically, when the vehicle's pneumatic tires are new, the width B of the circumferential rib surface in the axial direction A is 17 mm to 40 mm, preferably 20 mm to 30 mm, and particularly preferably 22 mm to 28 mm.

[0025] Here, the circumferential rib has sipes spaced at regular intervals d in the circumferential direction. The sipes present in the circumferential rib extend along the profile line from one side of the two surrounding circumferential grooves that define the circumferential rib to the other side. Therefore, the sipes extend from one end of the circumferential rib in the axial direction A (formed by one side of one of the two surrounding circumferential grooves) to the other end of the circumferential rib in the axial direction A (formed by one side of the second of the two surrounding circumferential grooves). Here, all sipes extend along a fixed profile line, which also extends from one end of the circumferential rib in the axial direction A to the other end. The profile line defines the orientation of the sipes on the tread surface, regardless of the circumferential position of the sipes. In this case, the profile line is simply the main line along which the sipes extend from one end of the circumferential rib to the other. The actual direction of the sipe pattern on the tread surface may deviate from the main line because, in this case, the main line may have been given a sipe pattern direction that is substantially perpendicular to the main line in the tread surface, i.e., extending primarily perpendicular to the profile line in the tread surface. Here, the deviation from the main line is much smaller than the width B of the circumferential rib in the axial direction A. Typically, this deviation is at most 15% of the width B of the circumferential rib, preferably at most 5% of the width B of the circumferential rib, and particularly preferably 3% of the width B of the circumferential rib. The added direction has its main component, i.e., its main direction, in a direction that deviates typically no more than 20° from the perpendicular line of the profile line in the tread surface, preferably no more than 5° from the perpendicular line of the profile line in the tread surface, and particularly preferably no more than 2° from the perpendicular line of the profile line in the tread surface. The added direction typically oscillates or zigzags around the profile line in the direction of the main component, or has a zigzag or some other periodic direction in that direction, wherein the period can vary along the profile line. The added rib pattern preferably exists only on a portion of the tire profile. The rib pattern extends from the surface of the circumferential rib along the radial direction of the pneumatic tire to a depth T. F They also follow their orientation on the tread surface. Here, adjacent sipes in the circumferential direction have approximately the same spacing d in the circumferential direction. n And preferably, they extend parallel to each other. The spacing d between adjacent grooves in the circumferential direction is... nTypically, the spacing varies by at most 10%, preferably at most 5%, and particularly preferably at most 2% of the average spacing d over the entire circumference of the tire. This is based primarily on manufacturing tolerances during the production of pneumatic tires for vehicles. Typically, in the new state of a pneumatic tire, the regular spacing d of the sipes along the circumferential direction on the surface of the circumferential ribs is 3 mm to 9 mm, preferably 4 mm to 7 mm, and particularly preferably 5 mm to 6 mm.

[0026] At intervals three to seven times the length of the circumferential spacing d of these sipes, in each case, a fine lateral groove is arranged in place of these sipes in the circumferential rib of the pneumatic tire according to the invention. These fine lateral grooves may be arranged in the circumferential rib at a uniform or preferably varying spacing, wherein the spacing of the fine lateral grooves in the circumferential direction is, in each case, a multiple of the circumferential spacing d of the sipes. By arranging the fine lateral grooves at varying spacings in the circumferential direction, an improvement in the acoustic performance of the pneumatic tire according to the invention is achieved, because the fine lateral ribs in the circumferential rib avoid vibrations caused by specific resonant periods in the circumferential direction.

[0027] The width B of the fine transverse grooves in the intermediate circumferential rib of the vehicle pneumatic tire according to the present invention Q B is the width of the groove pattern in the middle circumferential rib. F At least 2.5 times, preferably the width B of the groove pattern. F The width B of the groove pattern is 2.5 to 5 times, particularly preferably 5 times. F The width B of the groove pattern is 2.75 to 4.5 times that of the groove pattern, and most preferably it is 2.75 to 4.5 times that of the groove pattern. F 2.8 to 4 times the width of the fine transverse grooves (B). Q and the width B of the groove pattern F It is the width of the shared outline line perpendicular to the fine horizontal grooves and the knife groove pattern.

[0028] Specifically, the fine lateral grooves in the intermediate circumferential rib of the vehicle tire according to the invention have the profile of a sipe pattern. In this way, at the tread surface of the vehicle tire according to the invention, the lateral grooves and sipe patterns of the intermediate circumferential rib have substantially the same shape. Therefore, the fine lateral grooves follow the same profile as the sipe patterns. Here, the profile of the fine lateral grooves and the profile of adjacent sipe patterns extend parallel to each other, offset from the distance d in the circumferential direction. Importantly, each fine lateral groove extends along the profile and cannot have an additional direction like the sipe patterns, which would have a component significantly perpendicular to the profile. The fine lateral grooves extend from the surface of the circumferential rib along the radial direction of the vehicle tire to a depth T. QAt the same time, it follows its direction on the tread surface.

[0029] The depth T of the tread pattern of the intermediate circumferential rib of the pneumatic tire of the present invention F In the length L of the outline red The depth T of such a groove pattern is at least partially reduced in the end region. F The depth T is limited to a reduced depth in one or both end regions of the groove pattern. F,1 These areas are adjacent to the two circumferential grooves that define the circumferential ribs. Thus, such a groove pattern has one or two edge rises. Only some or all of the groove patterns on the intermediate circumferential ribs may have one or two such edge rises. For all groove patterns with edge rises, the depth T... F The reduction can be the same or different. The length L of the edge rise in the profile is... red In their respective cases, they begin at one end of the circumferential rib surface in the axial direction A (i.e., on one of the two sides of one of the two circumferential grooves that define the circumferential rib) and end at a specific point on the profile.

[0030] In approximately equal to or greater than the length L S Specifically, the length L of the outline red Between 80% and 250%, the fine transverse grooves of the circumferential ribs have snow pits in their end regions. Therefore, these snow pits at the ends of the fine transverse grooves extend along the profile along the length L. S Extending upwards, it also begins at one of the two sides of one of the two circumferential grooves that define the circumferential rib. The purpose of these snow cavities, which form a cavity in the tire profile, is to be quickly filled with snow from the road during driving operations, thereby rapidly increasing snow grip through snow-on-snow friction.

[0031] Here, the snow cavity at the end of the fine transverse groove has a width of B. S and depth T S The width B of the fine lateral grooves is measured perpendicular to the profile line of the grooves and parallel to the tire surface extending therefrom. Q At least 1.5 times the depth of the fine transverse grooves, which is the profile depth T. Q At most 65%. Therefore, the further geometry of the snow cavity disposed in the intermediate circumferential rib of the vehicle pneumatic tire according to the invention is related to the size of the fine lateral grooves in the circumferential rib. The profile of the snow cavity perpendicular to the fine lateral grooves is wider than the fine lateral grooves, specifically at least 1.5 times the width of the fine lateral grooves, and this profile is also the profile of the sipe pattern. In contrast, the depth T of the snow cavity SThe contour depth T is less than that of the fine transverse grooves. Q Specifically, this makes the depth T of the snow cave... S The contour depth T of the fine transverse grooves Q At most 65%. Here, the depth T of the snow cave... S and the contour depth T of the fine transverse grooves Q These respectively represent the extent to which snow pockets or fine lateral grooves extend from the tread surface of the pneumatic tire along the radial direction of the tire. Here, the radial direction points inward from the tire surface toward and is perpendicular to the axis of rotation of the pneumatic tire. Therefore, in the intermediate circumferential rib of the pneumatic tire according to the invention, snow pockets are provided at the ends of the fine lateral grooves extending from one side of the circumferential rib to the other. These snow pockets have a length L in the lateral direction (i.e., parallel to the tire surface) defined by the profile line along the associated fine lateral groove. S and the width B perpendicular to the outline S The defined range. Here, width B S It was intentionally made to be larger than the width B of the fine transverse grooves. Q And length L S The length L of the edge of the raised portion of the groove pattern selected with respect to the circumferential rib is... red They have similar dimensions, or are even larger to some extent. In short, snow caves therefore have a large cross-sectional area at the tire surface, allowing them to be filled with snow during driving on snow-covered roads. Furthermore, the finite depth T of the snow cave... S This allows snow pockets to fill quickly, resulting in increased snow grip through snow-on-snow friction. This grip is particularly advantageous if the vehicle has anti-skid control (ASR) or anti-lock braking system (ABS) and can therefore quickly utilize the improved friction.

[0032] In addition, the length L of the raised edge of the groove pattern along the profile line is equivalent to... red 80% to 250% of the snow cave length L S Having a length L of the edge raised portion red Approximately the same size, or greater than the length L of the raised edge. red Therefore, the snow cavity is intentionally positioned at the same location in the axial direction as the edge rise of the sipe pattern, because the snow cavity, as a cavity, thus counteracts the hardening of the circumferential rib at that axial location (i.e., at its end in the axial direction A) caused by the edge rise, and thus makes the circumferential stiffness (i.e., the elasticity of the circumferential rib) more uniform in the axial direction A. This is beneficial for achieving more uniform tread wear of the vehicle pneumatic tire according to the invention. This uniformity is based on all dimensions of the snow cavity, i.e., not only their length L S And its width B S and its depth TS .

[0033] By providing precisely defined snow pockets in the profile structure of the intermediate circumferential ribs with a consistent dart pattern (which is partially replaced by fine lateral grooves), the snow-on-snow friction of vehicle pneumatic tires and the wear performance of vehicle pneumatic tires can be improved.

[0034] In a preferred embodiment, the intermediate circumferential rib of the vehicle pneumatic tire according to the invention is its central circumferential rib. In this position, the circumferential rib is in direct contact with the road at least under normal conditions during driving operations, thus ensuring that, in the case of snow-covered roads, the circumferential snow pockets are filled with snow rapidly and with maximum certainty, and correspondingly, snow-on-snow friction is generated rapidly.

[0035] In another embodiment, fine lateral grooves are arranged circumferentially in place of the sipes at different multiples of the length of the circumferentially spaced interval d in the intermediate circumferential grooves of the pneumatic tire according to the invention. By arranging the fine lateral grooves at different intervals in the tire circumference, wherein the order of the different multiples can still be repeated periodically on the tire circumference, the acoustic performance of the pneumatic tire according to the invention is improved, as discussed above. The order of the multiples can, for example, consist of exactly two different multiples, such as four and five, which repeat irregularly or regularly. Thus, in this example, every three or four sipes are replaced by fine lateral grooves, which have snow pockets of the aforementioned size at their ends.

[0036] In a preferred embodiment, at four to six times the length of the circumferential spacing d of these sipes, particularly preferably four to five times the length of the circumferential spacing d of these sipes, fine lateral grooves with snow pockets are arranged in place of the aforementioned sipes in the middle circumferential rib of the pneumatic tire according to the invention. In particular, these spacings of the fine lateral grooves achieve an appropriate tilting of the profile block elements, thereby achieving both advantageous snow performance and advantageous ice performance due to the circumferential ribs.

[0037] Preferably, in the intermediate circumferential rib of the vehicle pneumatic tire according to the invention, the width B of the fine lateral grooves is... Q B is the width of the groove pattern. F Up to 5 times. This also helps to tilt contour block elements in the proper form and prevent individual contour block elements from tilting excessively.

[0038] In the pneumatic tire of the vehicle according to the invention, the snow pockets of the fine lateral grooves of the intermediate circumferential rib are preferably arranged symmetrically with respect to the profile of the fine lateral grooves. This facilitates achieving a consistent inclination of the profile block elements adjacent to the fine lateral grooves.

[0039] The width B of the snow cavity of the fine transverse groove of the intermediate circumferential rib of the vehicle pneumatic tire according to the invention is perpendicular to the profile line. S Preferably, the width B of the fine transverse grooves Q Two to three times the width of the snow cave (B). S The width B of the fine transverse grooves is particularly preferred. Q 2.2 to 2.5 times. This is beneficial for achieving good snow-on-snow friction, while also achieving proper tilting of the contour block elements and consistent elasticity of the intermediate circumferential ribs in the axial direction A.

[0040] The depth T of the snow cavity in the fine lateral grooves of the intermediate circumferential rib of the vehicle pneumatic tire according to the present invention S The preferred profile depth T of the fine transverse grooves Q The profile depth T of 35% to 60%, particularly preferably fine transverse grooves. Q The depth of the fine lateral grooves is 40% to 58%, and very particularly preferably 50% to 55%. This also helps to achieve good snow-on-snow friction after a short time, while achieving proper tilting of the contour block elements and consistent elasticity of the intermediate circumferential ribs in the axial direction A, and thus consistent tire wear.

[0041] The fine transverse grooves of the intermediate circumferential rib of the vehicle pneumatic tire according to the invention are preferably located in the end region along the profile length L. red 95% to 200% of them have a length L S (At this length, the depth T of the groove pattern) F The snow cavity is reduced in the end region of the groove pattern, and the fine transverse grooves are particularly preferably in the profile length L. red 105% to 130% of the length L S (The depth of the groove pattern decreases in the end region of the groove pattern along this length) snow cavity. Specifically, the correspondence between the raised portion of the groove pattern and the snow cavity position facilitates achieving a uniform height of the intermediate circumferential rib in the axial direction A. Thus, even with the presence of the raised portion of the groove pattern, the circumferential stiffness at the side of the circumferential rib is approximately the same as that at the center of the circumferential rib. Therefore, the wear on the rubber material of the circumferential rib is at least approximately uniform across the entire width of the circumferential rib along the axial direction.

[0042] According to the invention, the fine transverse grooves of the intermediate circumferential rib of the vehicle pneumatic tire have a profile length L of 2.5 mm to 8 mm in the end region. S The profile length L is particularly preferably between 3.5 mm and 7 mm. SThe snow cavity is preferably located on the upper part of the profile, and very particularly preferably on a length of 4 mm to 5.5 mm. Here, good snow-on-snow friction and high uniformity of elasticity of the intermediate circumferential rib in the axial direction A are achieved.

[0043] The snow cavity of the fine lateral grooves in the middle circumferential rib of the vehicle pneumatic tire according to the present invention has a bottom region and a side region. The bottom region is at a depth T S The snow cave is defined radially. However, here, the depth T S The axial and circumferential directions can vary by up to 20%, preferably up to 5%, and particularly preferably up to 1%. The side surface defines the snow cavity by a surface extending from the bottom surface to the surface of the vehicle's pneumatic tire. In particular, in this case, the side surface can extend parallel to the profile line or perpendicular to the profile line as the end face of the snow cavity. The surface of the bottom region of the snow cavity preferably transitions into the side surface with a radius of curvature of 0.2 mm to 1.5 mm, particularly preferably with a radius of curvature of 0.5 mm to 1.25 mm, and very particularly preferably with a radius of curvature of 0.8 mm to 1.1 mm. This further improves the rapid filling of the snow cavity with snow during driving operations on snow, which correspondingly achieves good snow-on-snow friction more quickly.

[0044] In one embodiment, the snow cavity of the fine lateral grooves in the central circumferential rib of the vehicle pneumatic tire according to the invention has a bottom region and an end face serving as a side surface. The surface of the bottom region typically transitions into the end face with a radius of curvature of 0.2 mm to 1.5 mm, preferably 0.5 mm to 1.25 mm, and particularly preferably 0.8 mm to 1.1 mm. This further improves the rapid filling of the snow cavity with snow during driving operations on snow, which correspondingly achieves good snow-on-snow friction more quickly.

[0045] Typically, the snow pockets of the fine lateral grooves in the central circumferential rib of the pneumatic tire according to the invention have a bottom region that is radially inward, i.e., toward the center of the pneumatic tire, adjacent to the sipes along the profile. This promotes the tilting of the profile block elements in the circumferential rib, especially the tilting of the profile block elements adjacent to the corresponding lateral grooves, so that the lateral grooves do not deteriorate due to the depth T of the snow pocket. S The profile depth T relative to the fine transverse ribs Q It decreases as it decreases.

[0046] Here, the groove patterns in the bottom area of ​​the snow cave typically have the same width B as those groove patterns on the circumferential ribs that have not yet been replaced by fine transverse grooves. F This further promotes the consistent tilt of the contour block elements on the circumference and the consistent elasticity of the circumferential ribs in the axial direction A.

[0047] The groove pattern in the bottom region of the snow cave preferably has the same depth T as those groove patterns on the circumferential ribs that have not yet been replaced by fine transverse grooves in the middle of the circumferential ribs. F This further promotes the consistent tilt of the contour block elements on the circumference and the consistent elasticity of the circumferential ribs in the axial direction.

[0048] In one embodiment, the profile of the sipes of the central circumferential rib of the pneumatic tire according to the invention is a straight line, which is preferably perpendicular to the parallel sides of the two surrounding circumferential grooves.

[0049] In one embodiment, the profile of the sipes of the intermediate circumferential rib of the pneumatic tire according to the invention is slightly angled at the middle of the circumferential rib. Therefore, in this case, the profile can be formed by two straight lines that are angled relative to each other and form an angle β of 140° to 170°, preferably 150° to 165°.

[0050] In a specific embodiment of the pneumatic tire of the present invention, the profile of the sipe pattern in the end region of the sipe pattern deviates from the axial direction A of the pneumatic tire of the vehicle by an angle α of less than 20°, preferably less than 15°, and particularly preferably less than 8°.

[0051] In a specific embodiment of the pneumatic tire for vehicles according to the invention, the sipes of the intermediate circumferential rib, extending along the profile, are wavy on a portion of the profile. In this portion of the profile, the actual direction of the sipes deviates from the main line of the profile. The direction of the sipes adds a wavy component perpendicular to the profile. Instead of the wavy component, the direction of the sipes may also add serrated lines and some other oscillating components.

[0052] In a particular embodiment, the depth T of these groove patterns F In their respective cases, at one end region or preferably both end regions of the groove pattern, respectively, along the length L of the profile line. red The upper part is reduced by at least 7% to 35%, preferably in each case in the length L of the profile. red The upper part is reduced by at least 12% to 30%, and particularly preferably by the length L of the profile. red The depth T of all tool groove patterns is reduced by at least 16% to 23%. F Preferably, in the two end regions of the groove pattern, at this length L of the profile... red The upper part decreases.

[0053] In other specific embodiments, the depth T of these groove patterns F In their respective cases, at one end region or preferably both end regions of the groove pattern, respectively, along the length L of the profile line.red The upper part is reduced by at least 1.5 mm to 9 mm, preferably in each case in the length L of the profile. red The length of the profile is reduced by at least 2.5 mm to 7.5 mm, and particularly preferably in each case by the length L of the profile. red The depth T of all tool groove patterns is reduced by at least 3.5mm to 5.5mm. F Preferably, in the two end regions of the groove pattern, at this length L of the profile... red The upper part decreases.

[0054] In the above embodiment, the depth T of the groove pattern in its end region F,1 T F,2 The depth T can be reduced to varying degrees in different grooving patterns to achieve greater consistency in circumferential stiffness. Specifically, in grooving patterns that are continuous along the circumferential direction, the depth T of the grooving pattern in its end region... F It can be alternately reduced to the first depth T F,1 Second depth T F,1 .

[0055] Typically, the depth T of the tread pattern of the intermediate circumferential rib of the pneumatic tire of the vehicle according to the invention is... F The reduction in the end region is 25% to 85%, preferably 35% to 75%, and particularly preferably 40% to 55%.

[0056] The depth T of the groove pattern in its end region F,1 T F,2 In embodiments where the depth T is reduced to varying degrees in different groove patterns, the first depth T F,1 Typically reduced by 25% to 60%, while the second depth T F,2 Typically reduced by 60% to 85%, preferably, the first depth T F,1 Reduced by 35% to 55%, while the second depth T F,2 Reduced by 65% ​​to 80%, and particularly preferably, the first depth T F,1 Reduced by 40% to 50%, while the second depth T F,2 This reduces the circumferential ribs by 70% to 75%. This promotes the elastic consistency of the circumferential ribs along their sides in the circumferential direction. Attached Figure Description

[0057] The invention will now be described in more detail based on exemplary embodiments, as shown in the accompanying drawings:

[0058] Figure 1 : This shows details of the tread surface of a vehicle pneumatic tire according to the invention, spanning the entire width of the tread;

[0059] Figure 2 It shows Figure 1 The details of the central circumferential rib in the circumferential direction of the vehicle pneumatic tire according to the invention are shown.

[0060] Figure 3 It shows Figure 1 The figure shown is a 3D detail of the outline of the central circumferential rib of a vehicle pneumatic tire according to the present invention.

[0061] List of reference numerals

[0062] 1. Tread

[0063] 2. 2' circumferential grooves

[0064] 3 weeks towards the ribs

[0065] 4. Side of the 4' circumferential groove

[0066] 6. Groove pattern

[0067] 8 Fine horizontal grooves

[0068] 10-shaped profile

[0069] 20 Snow Cave

[0070] 21. The bottom area of ​​the snow cave

[0071] 22. Side surface of the snow cave

[0072] 23. End surface of the snow cave

[0073] 25. The groove pattern below the snow cave.

[0074] Axial direction

[0075] B. Width of the circumferential rib in the axial direction A

[0076] B F Width of the groove pattern

[0077] B Q Width of fine transverse grooves

[0078] B S The width of the snow cave perpendicular to its outline

[0079] d. Spacing of the groove pattern in the circumferential direction

[0080] d n Spacing between adjacent groove patterns in the circumferential direction

[0081] L red The depth of the groove pattern decreases upon which the profile length is reduced.

[0082] LS The length of the snow cave along its outline

[0083] T F Depth of the groove pattern

[0084] T F,1 The reduced depth of the first groove pattern in the edge region

[0085] T F,2 The reduced depth of the second groove pattern in the edge region

[0086] T Q Depth of fine transverse grooves

[0087] T S The depth of the snow cave

[0088] U circumferential direction

[0089] α is the angle by which the profile of the sipe pattern in the end region of the sipe pattern deviates from the axial direction A of the inflatable tire.

[0090] β is the angle between two straight lines that form an angle with each other and create a profile.

[0091] The two surrounding circumferential grooves define the angle at which the two sides of the circumferential rib deviate radially from the plane perpendicular to the axial direction A. Detailed Implementation

[0092] Figures 1 to 3 An exemplary embodiment of a vehicle pneumatic tire according to the present invention is shown. The vehicle pneumatic tire of this type has a tread with a contoured design. Figure 1 The surface details of the tread 1 of a vehicle pneumatic tire according to the invention, spanning its entire width, are shown. Various contour elements are visible in the outline of the tread 1, with a circumferential rib 3, i.e., a central circumferential rib, displayed in the middle of the tread 1. The circumferential rib 3 extends in the direction of rotation along the entire circumference of the vehicle pneumatic tire according to the invention and is defined by two circumferential grooves 2, 2' surrounding the entire circumference of the vehicle pneumatic tire according to the invention. These two circumferential grooves 2, 2' extend parallel to each other and perpendicular to the axial direction A of the vehicle pneumatic tire. These two circumferential grooves 2, 2' have the same cross-section perpendicular to the circumferential direction over the entire tire circumference. Here, these two circumferential grooves 2, 2' have two sides defining them in the axial direction A. In each case, one of the two sides 4, 4' of the circumferential grooves 2, 2' defines the circumferential rib 3. Figure 2 The figure also shows details of the circumferential rib 3 in the circumferential direction. The figure also shows the circumferential grooves 2, 2' that define the circumferential rib 3, and the sides 4, 4' of these circumferential grooves define the circumferential rib 3. Figure 3The circumferential rib 3 is also shown, this time in a three-dimensional display, where the circumferential rib 3 itself is shown in a planar view in an unfolded perspective, as shown below. Figure 2 As shown. Here, in particular, a view of the circumferential rib 3 in the axial direction A is shown, in which brief details of the circumferential rib 3 in the circumferential direction U are shown. Here, the circumferential grooves 2 and 2' that define the circumferential rib 3 can also be seen. Only in the case of the circumferential groove 2 at the bottom of this display, the side 4 of the circumferential groove 2, which forms the edge of the circumferential rib 3 can also be seen. The side 4, 4' of the circumferential grooves 2, 2' that define the circumferential rib 3 extend in two parallel planes perpendicular to the axial direction A. Therefore, the straight side 4, 4' is perpendicular to the tread surface and extends along the circumferential direction. Thus, the spacing of the side 4, 4' in the axial direction A predefines the width B of the circumferential rib 3, which is constant in the radial direction of the tire and is 27 mm in the exemplary embodiment. Thus, the side 4, 4' transitions with curvature into the groove base of the circumferential grooves 2, 2' in the bottom region of the circumferential grooves 2, 2', as Figure 3 As shown.

[0093] The circumferential ribs are divided by a groove pattern 6 extending from one of the parallel sides 4, 4' of the two surrounding circumferential grooves 2, 2' to the other, spanning the entire width B of the circumferential rib 3. The groove patterns 6 are spaced apart from each other at a regular interval d in the circumferential direction U; in the exemplary embodiment, this interval is 5.5 mm at the surface of the circumferential rib 3. Here, each groove pattern 6 extends along a profile line 10. The profile lines 10 of all groove patterns 6 in the circumferential rib 3 have the same shape. The profile line 10 is formed by two straight lines, each forming an angle α of 15° with the axial direction A and intersecting at the middle of the circumferential rib 3. Accordingly, these two straight lines form an angle β of 150° with each other. Except for the edge regions of the circumferential rib 3, wavy lines are superimposed on the profile lines 10 in the direction of the groove patterns 6, such that the groove patterns 6 have a wavy orientation in the middle of the circumferential rib 3. With the vehicle's pneumatic tires in a new condition, the contour depth of the circumferential grooves 2 and 2' is 8mm, and the depth T of the sipe pattern 6 in the middle of the circumferential rib 3 is... F The depth T of the groove pattern 6 is 7mm. In the end region of the groove pattern 6, the depth T of the groove pattern 6 is... F Decrease. In an exemplary embodiment, depth T F At the two end regions, at the length L of the profile 10 red It decreases by 21%. In an exemplary embodiment, the depth T of the profile is... F Along the profile line 10 at a length L of 5.5 mm red The depth decreases. Every other groove 6 has a depth T of only 1.75 mm in its end region. F,1 The depth T of other groove patterns F,2 Reduced to contour depth T in the end regionF 50%, therefore at the same length L red The top is 3.5mm.

[0094] In the circumferential rib 3, the groove pattern 6 is replaced by fine transverse grooves 8 at regular intervals in the circumferential direction U. In the exemplary embodiment shown, this interval alternately reaches four, five, or six times the length of the interval d of the groove pattern 6 in an irregular sequence. Here, the fine transverse grooves 8 are arranged at irregular intervals to avoid the circumferential rib 3 vibrating due to resonance that might be caused by the regular interval of the fine transverse grooves 8. In the exemplary embodiment, the width B of the fine transverse grooves 8 is... Q It is the width B of the groove pattern 6. F Three times. In an exemplary embodiment, the width B of the groove pattern 6 F The width B of the fine transverse groove 8 is 0.5mm. Q Correspondingly, the depth T of the fine transverse grooves is 1.5 mm. Q The diameter is 8 mm. The transverse groove 8 extends along the same profile line 10 as the grooving pattern 6. Here, the grooving pattern 8 extends only along the profile line 10 and has no other component perpendicular to the profile line, as in the case of the wavy direction of the grooving pattern 6.

[0095] Furthermore, each of the fine transverse grooves 8 has a snow cavity 20 in its end region. Here, the end region of the profile 10 extending from one circumferential groove 2 to another circumferential groove 2' (these circumferential grooves define the circumferential rib 3) is the region of the profile 10 that, in each case, begins from the circumferential grooves 2 and 2' and then extends inward into the circumferential rib 3. Thus, here, the snow cavity 20 has a length L along the profile 10. S In an exemplary embodiment, the length L of the snow cave 20 S Equal to the length L of the raised part of the groove pattern 6 red Correspondingly, the length L of the snow cave S It is also equal to 21% of the length of the profile line 10. Furthermore, the snow cavity 20 also has a surface parallel to the tread 1 and a range perpendicular to the profile line 10. In an exemplary embodiment, the width B of the snow cavity 20... S The width B of the fine horizontal groove 8 Q It is twice the size of the snow cave, therefore 3mm. Furthermore, the snow cave 20 also has a depth T in the radial direction. S In an exemplary embodiment, the depth T of the snow cave 20 S The contour depth T is exactly the same as the fine horizontal groove 8. Q Half of it. Correspondingly, the contour depth T of the snow cave. S The value is 4mm. Especially from Figure 3 Further details of the Snow Cave 20 design can be seen in the image. At depth T... SAt the snow cavity 20, there is a bottom region 21. In the exemplary embodiment shown, the bottom region 21 is substantially parallel to the surface of the tread 1. Furthermore, the snow cavity 20 has a side surface 22. In the exemplary embodiment shown, the side surface 22 initially extends parallel to the profile line 10 and perpendicular to the surface of the tread 1, such that the surface has a radial component. Additionally, one side surface 22 of the snow cavity is configured as an end face 23, i.e., a face perpendicular to the profile line 10. There is a transition with a radius of curvature of 1 mm between the bottom region 21 and the side surface 22 (especially the end face 23). Furthermore, the bottom region 21 of the snow cavity 20 has a sipe pattern 25 extending along the profile line 10 of the fine transverse groove 8 in its middle. The width of the sipe pattern 25 corresponds to the width B of the sipe pattern 6. F The depth of the groove pattern 25 corresponds to the depth T of the other groove patterns 6 of the circumferential rib 3. FAs in all embodiments of the pneumatic tire for vehicles according to the invention, a prominent feature of the exemplary central circumferential rib 3 is that, due to the provision of snow pockets 20, the central circumferential rib has good snow-on-snow friction, which can be obtained in a short time due to the rapid filling of the snow pockets 20 and, in addition, through the consistent inclination of the provided contour block elements, thus achieving a good trade-off between snow behavior (snow performance) and ice behavior (ice performance) for the circumferential rib 3. Furthermore, the design of the snow pockets 20 allows the transverse rib 3 to obtain very consistent elasticity or circumferential stiffness in the axial direction A. Here, the snow pockets 20 located at the edges of the circumferential rib 3 substantially compensate for the raised portion at the ends of the sipes 6 of the circumferential rib 3. Based on the parameters described in this specification, the structure of the intermediate circumferential rib of the pneumatic tire for vehicles according to the invention has been discussed in detail. This structure must be adapted accordingly to the size of the pneumatic tire for each case. In particular, the circumferential rib 3 of the pneumatic tire for vehicles according to the invention is used for pneumatic tires with a width between 195 mm and 315 mm. In this case, the tire height can be between 35% and 65% of the width of the pneumatic tire. The rim on which such a pneumatic tire is mounted can have a diameter between 15 inches and 22 inches. Depending on the corresponding circumference of the pneumatic tire, a different number of sipes 6 and fine lateral grooves 8 can be provided on the circumference of such tire. Here, the number of sipes 6 and lateral grooves 8 can increase with the increase of the circumference, or can increase only proportionally with the increase of the circumference. For example, this proportion can be, for example, between 5% and 20%. Generally, the pneumatic tire according to the invention can of course also have other sizes, as long as the advantageous characteristics of the described circumferential ribs can be used in the pneumatic tire. Finally, it should be noted that the invention has been discussed based on a large number of detailed exemplary embodiments. However, these are examples of the invention. Other embodiments of the pneumatic tire according to the invention may correspondingly have only individual features of the exemplary embodiments, or simultaneously have features of the different exemplary embodiments described, unless otherwise explicitly stated.

Claims

1. A vehicle pneumatic tire having a tread (1) having a profile and having an intermediate circumferential rib (3) defined by two sides (4, 4') that are at least approximately parallel to each other and surround two circumferential grooves (2, 2') around the entire vehicle pneumatic tire, the circumferential grooves extending at least approximately perpendicular to the axial direction A of the vehicle pneumatic tire, because they deviate from the radial direction of the plane perpendicular to the axial direction A by an angle γ of less than 15°, thus causing the width of the circumferential rib (3) to remain constant or increase with increasing profile depth, wherein, The circumferential rib (3) has grooves (6) spaced at regular intervals d in the circumferential direction. These grooves extend along the profile line (10) from one side (4, 4') of the two surrounding circumferential grooves (2, 2') to the other side. At three to seven times the length of the interval d between these grooves (6) in the circumferential direction, in each case, a fine transverse groove (8) is arranged in place of the grooves (6) in the intermediate circumferential rib (3). The width of this fine transverse groove is B. Q The width B of the groove pattern (6) F At least 2.5 times and the fine transverse grooves have the outline (10) of these groove patterns (6), and wherein the depth T of these groove patterns (6) is F In the end regions of these groove patterns (6), at the length L of the profile (10) red The upper part is at least partially reduced, and the length L of the profile (10) is reduced. red Between 80% and 250%, these fine transverse grooves (8) have snow pits (20) in their end regions, the width B of which is perpendicular to the profile (10). s The width B of the fine transverse groove (8) Q At least 1.5 times and depth T S The contour depth T of the fine transverse groove (8) Q At most 65%.

2. The vehicle pneumatic tire as described in claim 1, characterized in that, The intermediate circumferential rib (3) is the central circumferential rib (3) of the vehicle's pneumatic tire.

3. The vehicle pneumatic tire as described in claim 1 or 2, characterized in that, At different multiples of the length of the spacing d between these groove patterns (6) along the circumferential direction, fine transverse grooves (8) are arranged in the intermediate circumferential rib (3) in place of the groove patterns (6).

4. The vehicle pneumatic tire as described in claim 1, characterized in that, These snow caves (20) are arranged symmetrically with respect to the outline (10) of these fine transverse grooves (8).

5. The vehicle pneumatic tire as described in claim 1, characterized in that, The width B of these snow pits (20) perpendicular to the outline (10) S The width B of the fine transverse groove (8) Q Two to three times that.

6. The vehicle pneumatic tire as described in claim 1, characterized in that, The width B of these snow pits (20) perpendicular to the outline (10) S The width B of the fine transverse groove (8) Q 2.2 to 2.5 times that.

7. The vehicle pneumatic tire as described in claim 1, characterized in that, The depth T of these snow caves (20) S The contour depth T of the fine transverse groove (8) Q 35% to 60%.

8. The vehicle pneumatic tire as described in claim 1, characterized in that, The depth T of these snow caves (20) S The contour depth T of the fine transverse groove (8) Q 40% to 58%.

9. The vehicle pneumatic tire as described in claim 1, characterized in that, The depth T of these snow caves (20) S The contour depth T of the fine transverse groove (8) Q 50% to 55%.

10. The vehicle pneumatic tire as described in claim 1, characterized in that, These snow pits (20) have a bottom region (21) that is adjacent to the groove pattern (25) along the outline (10) in the radial direction.

11. The vehicle pneumatic tire as described in claim 10, characterized in that, The grooving patterns (25) in the bottom region (21) of these snow caves (20) have the same depth T as the grooving patterns (6) in the middle of the circumferential rib (3) that have not yet been replaced by fine transverse grooves (8). F .

12. The vehicle pneumatic tire as described in claim 1, characterized in that, The groove pattern (6) extending along the profile (10) has a wavy shape on a part of the profile (10).

13. The vehicle pneumatic tire as described in claim 1, characterized in that, The depth T of these groove patterns (6) F In their respective cases, in one or both end regions of these groove patterns (6), the length L of the profile (10) red The above will be reduced by at least 7% to 35%.

14. The vehicle pneumatic tire as described in claim 1, characterized in that, The depth T of these groove patterns (6) F In their respective cases, in one or both end regions of these groove patterns (6), the length L of the profile (10) red The above will be reduced by at least 12% to 30%.

15. The vehicle pneumatic tire as described in claim 1, characterized in that, The depth T of these groove patterns (6) F In their respective cases, in one or both end regions of these groove patterns (6), the length L of the profile (10) red The above will be reduced by at least 16% to 23%.

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