Vehicle pneumatic tires

Abstract

Vehicle pneumatic tires with a tread (2), bead areas and two sidewalls (4, 4'), wherein at least one of the two sidewalls (4, 4') has a protective element (5, 5') that protects against abrasion, extends around the sidewall (4, 4') and locally thickens the sidewall (4, 4'), and is provided with a structure (8) comprising a plurality of radially extending grooves (9) having a width (b1) of 0.5 mm to 1.0 mm, between which preferably rectangular, radially elongated surfaces (10) are located, having a width (b2) of 3.0 mm to 10.0 mm, characterized in that the grooves (9) include those which extend at particularly regular intervals and which are each interrupted at least at one point in their course by a connecting web (11) formed flush with the surfaces (10), which has a width (b3) of has a thickness of 0.3 mm to 0.7 mm.

Description

[0001] The invention relates to a vehicle pneumatic tire with a tread, bead areas and two sidewalls, wherein at least one of the two sidewalls has a protective element that protects against abrasion, surrounds the sidewall and locally thickens the sidewall, and is provided with a structure consisting of a plurality of radially extending grooves having a width of 0.5 mm to 1.0 mm, between which there are preferably rectangular, radially elongated surfaces having a width of 3.0 mm to 10.0 mm.

[0002] Protective elements on sidewalls are typically rubber ribs formed on the respective sidewall, encircling its circumference and locally thickening the sidewall. These protective elements protrude outwards from the rest of the sidewall contour and are dimensioned in such a way as to intercept and prevent abrasion and resulting damage to the tire in the sidewall area.

[0003] A pneumatic tire of the type mentioned above is known, for example, from JP 2006 213 128 A. At least one sidewall of this tire is provided, in the area of ​​its greatest cross-sectional width, with a rubber protective layer that circumferentially encircles the sidewall and thickens locally. This protective layer has a thickness between 1.0 mm and 5.0 mm and a radial extent between 10.0 mm and 50.0 mm. This rubber protective layer is provided with a multitude of radially extending grooves, each with a width of 0.2 mm to 2.0 mm and a depth of 1.0 mm to 5.0 mm. These very narrow grooves can be closely spaced or have a spacing of 4.0 mm to 10.0 mm.

[0004] From EP 2 255 979 A2, a vehicle pneumatic tire with sidewalls is known, wherein a circumferential protective element is provided on one sidewall, which locally thickens the sidewall and is formed from circumferentially spaced ribs with a trapezoidal cross-section and grooves running between the ribs. Such protective elements are said to be advantageous for venting the vulcanization mold.

[0005] EP 2 055 507 A1 discloses a vehicle tire with sidewalls, at least one of which is provided with a circumferentially circumferential protective element. This element consists of a lower, continuous circumferential rib and several webs adjoining the rib, spaced apart from each other in the circumferential direction and extending perpendicular to the circumferential direction. Such protective elements are intended to have a low rubber volume and to stiffen the sidewall area.

[0006] From JP H08 282 219 A, a vehicle tire with sidewalls is known on which narrow ribs run spaced apart in the circumferential direction. Viewed in the tire cross-section, the ribs are curved at their base, which lies against the sidewall, along a radius that differs from the radius of the sidewall in the tire cross-section. During the manufacture of the vehicle tire, such ribs are intended to conceal irregularities on the sidewall.

[0007] JP 2009 090 950 A discloses a vehicle tire with sidewalls having a decorative surface element on one of the sidewalls, wherein the surface element is provided with parallel, triangular-shaped projections with a height of 0.1 mm to 1.0 mm.

[0008] From DE 10 2014 206 912 A1, a vehicle tire with sidewalls is known which are reinforced in their radially outer area with a protective rubber layer. The protective layer has a thickness of up to 4.0 mm at its thickest point and is provided with a network of cuts consisting of at least one circumferentially circular cut and a plurality of cuts extending transversely to the circumferential direction, and is thus divided into block elements. The rubber protective layer is intended, for example, to provide protection when driving off-road and not to impair the rolling resistance of the vehicle tire.

[0009] The narrow grooves and the relatively wide rectangular areas between them result in a protective element designed with a material distribution that positively impacts the flexibility and durability of the tire sidewall. Furthermore, the structure of the protective element has proven particularly suitable for concealing sidewall indentations – constrictions at the overlapping points of the tire carcass. However, the venting of the vulcanization mold in its side shells, which forms the sidewalls of a raw tire with such a design, has proven problematic. If sufficient air release between the raw tire and the vulcanization mold cannot be ensured during the molding process, the visual appearance of the structure on the protective element is compromised.

[0010] The invention is therefore based on the objective of finding measures that enable proper venting of the vulcanization mold forming the raw tire without having to accept impairments of the aforementioned design of the structure on the protective elements of the sidewalls.

[0011] The problem set out in the invention is solved by including grooves which run at regular intervals and which are interrupted at least at one point in their course by a connecting web which is level with the surfaces and has a width of 0.3 mm to 0.7 mm.

[0012] The connecting ribs formed in the grooves are created by corresponding recesses in the side shells of the vulcanization mold. These recesses ensure that, especially during the final stage of molding the raw tire, air is expelled through vent holes or venting units located in the areas of the side shells that form the surfaces of the structure. The tiny ribs formed by the recesses in the side wall of the grooves leave the desired external appearance of the structure largely unaffected.

[0013] In a preferred embodiment of the invention, each groove is interrupted at least at one point along its course by a connecting rib formed flush with the surfaces. The design of the protective element, in particular its thickness and radial extent, as well as the selected mutual spacing of the grooves, may necessitate the support of venting of the tire mold by connecting ribs in the groove, which, as mentioned, are recesses in the sidewall. Depending on the aforementioned embodiment, it may also be sufficient, according to a further preferred embodiment, if every second or third groove is interrupted at least at one point along its course by a connecting rib formed flush with the surfaces.

[0014] Depending on the thickness of the protective element or the point in the protective element where it has the greatest thickness, the grooves have a depth of up to 1.5 mm, in particular up to 0.8 mm.

[0015] In a particularly preferred embodiment, the protective element has its greatest thickness at a point circumferentially around the sidewall and with respect to an imaginary outer contour without the protective element. At this point, the protective element has an edge that runs around the circumference of the tire. This edge is formed by the thickness of the protective element decreasing continuously from this point towards the tread and towards the bead area, with connecting ribs in the grooves preferably adjoining the edge directly. Such a design of the protective element is particularly advantageous for good flexibility of the tire sidewall and the durability of the tire. The recesses in the side shells of the vulcanization mold, corresponding to the connecting ribs, are formed at a point that is particularly critical with regard to venting.

[0016] In an alternative, equally advantageous embodiment, the protective element has a constant or largely constant thickness over its radial extent with respect to an imaginary outer contour without the protective element. In protective elements designed in this way, the grooves also have a constant depth, which corresponds at most to the thickness of the protective element, and is in particular 0.3 mm to 0.5 mm less.

[0017] In a possible and preferred embodiment, the protective element on the tire sidewall is furthermore formed in the area of ​​the tire's greatest cross-sectional width. Such an arrangement of protective elements is particularly advantageous on the sidewalls of van tires. For off-the-road tires, it is advantageous if the protective elements on the tire sidewalls are formed radially outside the area of ​​the tire's greatest cross-sectional width. However, it is also possible to form the protective elements on the sidewalls radially within the area of ​​the tire's greatest cross-sectional width.

[0018] Further features, advantages, and details of the invention will now be described in more detail with reference to the drawing, which partly schematically depicts exemplary embodiments of the invention. The drawings show... Fig. 1 the course of the outer contour of a vehicle pneumatic tire between a tire shoulder and a bead area with an embodiment of the invention, Fig. 2 an enlarged view of detail D1 from Fig. 1, Fig. 3 a top view of a circumferential section of a side wall, Fig. 4 an enlarged view of detail D2 from Fig. 3, Fig. 5 a sectional view along line VV of the Fig. 4, Fig. 6 a sectional view along line VI-VI of the Fig. 4 and Fig. 7 another variant in a to Fig. 2 analog representations.

[0019] The invention relates to the design of sidewalls of radial vehicle tires, in particular vehicle tires for vans, light trucks or off-the-road tires.

[0020] Fig. Figure 1 shows a cross-section of the outer contour 1 of a sidewall 4 of a vehicle tire between a shoulder-side tread run-off area 2a of a tread 2 and the outer contour 3 of a bead area. The sidewall 4 has a protective element 5 that covers the area with the greatest cross-sectional width of the vehicle tire, protects the sidewall 4 from abrasion, and surrounds the sidewall 4 in an annular manner, locally thickening the sidewall 4 in a manner to be described later. The (imaginary) outer contour 1 without the protective element 5 is shown with a dashed line l1 above the radial extent of the protective element 5. The protective element 5 is designed such that it is located at or in the immediate vicinity of the point with the greatest cross-sectional width of the tire – this point is shown in Figure 1. Fig. 1 marked with a line l2 - its greatest thickness d1 ( Fig. 2), with respect to the contour shown with the dashed line l1. At the point of greatest thickness d1, the protective element 5 has an edge 6 that runs circularly around the circumference of the side wall 4. Radially outside (in Fig. 1 and Fig. 2 above) the edge 6, the thickness of the protective element 5 decreases continuously towards the tread exit 2a, such that, viewed in cross-section, the protective element 5 has no thickness at its radially outer edge and transitions tangentially and without kinks into the outer contour 1. Radially within (in Fig. 1 and Fig. 2 below) the edge 6, the thickness of the protective element 5 also decreases continuously towards the bead area and ends at a step 7 that is recessed towards the outer contour 1. At the recessed step 7, the thickness d2 ( Fig. 2) The thickness d1 of the protective element 5 is 0.5 mm to 0.8 mm, and at the point of greatest thickness, it is 0.8 mm to 1.7 mm. The protective element 5 also has a convex outer contour radially outside the edge 6 and a concave outer contour radially inside the edge 6. In the radial direction, the protective element 5 extends over a height h of 15 mm to 90 mm, preferably 30 mm to 45 mm, and particularly preferably 38 mm to 42 mm. The protective element 5 is further configured on the side wall 4 such that approximately 65% ​​of its height h is located radially outside the edge 6.

[0021] In an alternative embodiment of the protective element 5, it has a rounded edge instead of a pronounced edge 6. In another embodiment, not shown separately, the protective element 5 is designed such that it also forms a recessed step at its radially outer edge relative to the outer contour 1 of the side wall 4.

[0022] Fig. Figure 3 shows a top view of a circumferential section of the side wall 4 with a section of the protective element 5. The outer surface of the protective element 5 has a structure 8 consisting of radially extending grooves 9, interrupted at one point, and radially extending elongated, rectangular or largely rectangular surfaces 10 located between them. The sectional view in Fig. Figure 5 shows an exemplary cross-sectional design of the grooves 9 with a U-shaped cross-section, two lateral groove flanks inclined at an angle of 5° to 15°, and a groove base connecting them. The grooves 9 have a depth t of up to 0.8 mm and, on the outer surface of the protective element 5, a particularly constant width b1 of 0.5 mm to 1.0 mm. In a preferred embodiment, the maximum depth t corresponds to the width b1. Towards the radially outer edge of the protective element 5, the depth t of the grooves 9 decreases, so that they no longer have any depth at the radially outer edge of the protective element 5. The rectangular surfaces 10 between adjacent grooves 9 have a width b2 ( Fig. 4) from 3.0 mm to 10.0 mm. Between the grooves 9, radially oriented elongated "blocks" are thus present, which ensure the protective function of the protective element 5 and improve the flexibility of the side wall 4. The structure 8 may be partially overlaid by other surface structures.

[0023] As already mentioned and especially Fig. As shown in Figure 4, the grooves 9 in the area of ​​edge 6 are interrupted in their course by connecting webs 11. Each connecting web 11 borders edge 6 and is otherwise radially outside edge 6. As shown in the sectional view in Fig. Figure 6 shows that each connecting web 11 has a constant width b3 of 0.4 mm to 0.7 mm, and its height corresponds to the depth of the groove 9 at that point. The connecting webs 11 are, for example, isosceles trapezoidal in cross-section, as shown in Figure 6. Fig. 6 shown, with groove 9 ( Fig. 4) sloping web flanks at an acute angle of 5° to 15° 11a.

[0024] In Fig. In every third area 10, a circle k is drawn. The circles k represent the positions of venting units, so-called Eurovents, provided in the vulcanization mold that forms and vulcanizes the tire. The sidewalls of a tire are usually formed by side shells of the vulcanization mold, whereby, when the raw tire is inserted into the mold, it is necessary to ensure that air is released between the raw tire and the side shells. This function is performed, for example, by venting valves, the aforementioned Eurovents, inserted into vent holes.

[0025] Adequate ventilation must also be ensured in the area of ​​the protective element 5. The connecting webs 11 interrupting the grooves 9 are formed by recesses, and the grooves 9 by protrusions in the vulcanization mold. The aforementioned recesses ensure a largely unimpeded flow of residual air into the venting units during the final stage of molding the raw tire into the vulcanization mold. During the process described in the Fig. In the embodiment shown in 1 to 6, the venting units are provided in the side shell of the vulcanization mold in those areas where the section of surfaces 10 extending radially outside the edge 6 is formed.

[0026] At the in Fig. In the embodiment shown in Figure 7, based on a section of the outer contour 1' of a sidewall 4', a protective element 5' is provided which has a constant or largely constant thickness d1' of 0.8 mm to 1.7 mm over its radial extent. The protective element 5' therefore has a recessed step relative to the outer contour 1' at both its radially outer and radially inner edges. In the illustrated embodiment, the protective element 5' is located radially within the point of greatest cross-sectional width of the tire. Analogous to the protective element 5 of the first embodiment, the protective element 5' is provided with a structure comprising grooves and surfaces between the grooves. The arrangement, dimensioning, and design of the grooves with connecting webs are carried out in the manner already described.The grooves have a constant depth, which corresponds at most to the thickness d1' of the protective element 5', and in particular is 0.3 mm to 0.5 mm less than this.

[0027] In another embodiment, not shown separately, the protective element designed according to the invention is formed radially outside the point with the greatest cross-sectional width on the sidewall. Such an arrangement of protective elements is particularly advantageous for so-called off-the-road tires.

[0028] The invention is not limited to the illustrated and described embodiments. If the venting holes or venting units are positioned differently in the side shells of the vulcanization mold, it may be advantageous to interrupt the grooves 9 at a different location or at several locations along their course, as in the embodiment according to Fig.1 to 6, for example, in their radial section located within edge 6. Furthermore, not every groove 9 needs to be interrupted by connecting webs 11, but, for example, only every second or every third. The grooves 9 preferably run exactly in the radial direction, but can also run at a small acute angle of up to 15° to the radial direction. The radial extent of the protective element can vary around the circumference of the side wall. Reference symbol list 1, 1' Outer contour 2 treads 2a Tread strip exit 3 Outer contour bead area 4.4' side wall 5.5' Protective element 6-edge 7 receding step 8 Structure 9 Nut 10 area 11 Connecting bridge 11a Bridge flank b1, b2, b3 width d1, d2, d1' Thickness D1, D2 Detail h height k circle l1, l2 line t depth

Claims

[1] Vehicle pneumatic tire with a tread (2), bead areas and two sidewalls (4, 4'), wherein at least one of the two sidewalls (4, 4') has a protective element (5, 5') that protects against abrasion, extends around the sidewall (4, 4') and locally thickens the sidewall (4, 4'), and is provided with a structure (8) of a plurality of radially extending grooves (9) having a width (b1) of 0.5 mm to 1.0 mm, between which there are preferably rectangular, radially elongated surfaces (10) having a width (b2) of 3.0 mm to 10.0 mm, characterized by , that the grooves (9) include those which run at particularly regular intervals and which are each interrupted at least at one point in their course by a connecting web (11) which is level with the surfaces (10) and which has a width (b3) of 0.3 mm to 0.7 mm. [2] Vehicle pneumatic tires according to claim 1, characterized by , that each groove (9) is interrupted at least at one point in its course by a connecting web (11) formed at the same level as the surfaces (10). [3] Vehicle pneumatic tires according to claim 1, characterized by , that every second or third groove (9) is interrupted at least at one point in its course by a connecting web (11) formed at the same level as the surfaces (10). [4] Vehicle pneumatic tires according to any one of claims 1 to 3, characterized by , that the grooves (9) have a depth (t) of up to 1.5 mm, in particular up to 0.8 mm. [5] Vehicle pneumatic tires according to any one of claims 1 to 4, characterized by , that the protective element (5) is formed on the sidewall (4) in the area of ​​the greatest cross-sectional width of the tire. [6] Vehicle pneumatic tires according to any one of claims 1 to 4, characterized by, that the protective element (5') on the sidewall (4) is formed radially inside or radially outside the point with the greatest cross-sectional width of the tire. [7] Vehicle pneumatic tires according to any one of claims 1 to 6, characterized by , that the protective element (5) has its greatest thickness (d1) at a point and with respect to an imaginary outer contour without protective element (5), wherein the protective element (5) has an edge (6) circumferentially around the tire circumference at this point, which is formed by the fact that the thickness of the protective element (5) decreases continuously from this point towards the tread (1) and towards the bead area, wherein connecting webs (11) in the grooves (9) preferably connect directly to the edge (6). [8] Vehicle pneumatic tires according to any one of claims 1 to 6, characterized by, that the protective element (5') has a constant or largely constant thickness (d1') over its radial extent with respect to an imaginary outer contour without a protective element (5'). [9] Vehicle pneumatic tires according to any one of claims 1 to 8, characterized by , that the protective element (5, 5') extends in a radial direction over 15 mm to 90 mm, preferably over 30 to 45 mm, particularly preferably over 38 mm to 42 mm.

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