Pneumatic vehicle tires comprising a carcass ply.
Patent Information
- Application Number
- BR112023026743
- Authority / Receiving Office
- BR · BR
- Patent Type
- Patents
- Current Assignee / Owner
- Publication Date
- 2026-09-01
Smart Images
Figure 00000014_0000
Abstract
Description
1 / 10 Pneumatic vehicle tires comprising a carcass ply.
[0001] The present invention relates to a pneumatic vehicle tire, in particular a utility vehicle tire, having a tread with a tread surface and a circumferential groove on the shoulder side running in a convoluted manner around the circumference of the tire, and having a carcass with a carcass ply having strength members, wherein the carcass ply has, in a cross-section of the tire, a carcass ply line running through the center points of the carcass ply strength members, wherein said cross-section is the cross-section in the circumferential U direction that the tire would have in the new state if it were mounted on a standard wheel rim conforming to ETRTO without inflation pressure.
[0002] A pneumatic vehicle tire generally has an airtight inner layer, a carcass, in particular radial, which extends from the zenith region of the tire through the sidewalls to the bead region and is normally anchored therein by being laced around tension-resistant bead cords, a radially profiled tread located on the outside and a belt disposed between the tread and the carcass.
[0003] A pneumatic vehicle tire mounted on a wheel rim undergoes a change in its outer contour when, proceeding from a state without inflation pressure (i.e., at atmospheric pressure), the tire's inflation pressure is increased to the inflation pressure intended for tire operation. Pneumatic vehicle tires, whose carcass ply is oriented in the tire mounted without inflation pressure as is usual largely in a straight line from an axial center of the tire to the shoulder regions, undergo, specifically in the shoulder region, more growth Petition 870260002534, dated 12 / 01 / 2026, page 6 / 41 2 / 10 significantly more radially outward than at the axial center of the tire. This can lead to an opening of the circumferential groove and tangential stress at the base of the groove, which can result in fatigue cracks in the circumferential groove during tire operation.
[0004] In order to allow more uniform growth during the inflation of the pneumatic vehicle tire, EP 3212441 A1 describes the optimization of the carcass ply arrangement.
[0005] During operation, particularly during the first approximately 1000 km, the pneumatic vehicle tire may undergo additional growth, particularly in the shoulder region, due to cyclic deformation of the tire.
[0006] This growth in the shoulder region can also result in fatigue cracks in the circumferential grooves during further tire operation.
[0007] It is therefore an objective to provide a pneumatic vehicle tire that has enhanced circumferential groove fatigue resistance.
[0008] This is achieved by the fact that a point R on the carcass ply line defined by a projection of a circumferential groove center perpendicular to the carcass ply line has a first spacing D of at least 0.7 mm for a straight line connecting two points A and B on the carcass ply line, wherein the circumferential groove center is determined on a side surface applied to the tread surface radially from the outside, wherein the first spacing D is measured perpendicular to the straight line, and wherein point R is radially off the straight line and wherein point R is centrally located between points A and B as measured along the carcass ply line and has a second spacing D equal to each of the two points A and B, wherein the second spacing D is 1.0 to 2.0 times a Petition 870260002534, dated 12 / 01 / 2026, page 7 / 41 3 / 10 circumferential groove width measured along the sidewall surface.
[0009] It has been shown that the said local specification of the carcass ply line radially within the circumferential groove is exceptionally well suited to counteract growth caused by an increase in inflation pressure and by cyclic deformations during tire operation, in particular utility vehicle tires, specifically in the circumferential groove region.
[0010] As a result of tire inflation to the intended inflation pressure for operation and as a result of cyclical tire loading during operation, the carcass ply is subjected to significant tensile loads, resulting in straightening of the carcass ply and its carcass ply line and thus a reduction in camber in the region of point R of the carcass ply line, said camber being influenced by the first spacing D of at least 0.7 mm in the case of the new uninflated tire. This reduction in camber and straightening of the carcass ply neutralizes tire growth in the circumferential groove region, so that the total tire growth in this region is advantageously reduced. In contrast, a first spacing D of less than 0.7 mm results in only a slight influence on tire growth.
[0011] It is essential here that the specific arrangement of the carcass canvas line corresponds to the position of the circumferential groove and its geometry. The position of the circumferential groove is incorporated into the arrangement of the carcass canvas line through the reference point R. The geometry of the circumferential groove, in particular the width of the circumferential groove, is incorporated into the arrangement of the carcass canvas line through the second spacing D of the two points A and B from point R. Here, point R is centrally located between points A and B as measured along the carcass canvas line. Petition 870260002534, dated 12 / 01 / 2026, page 8 / 41 4 / 10 and has a second equal spacing D for each of the two points A and B. According to the invention, the second spacing D is 1.0 to 2.0 times the circumferential groove width measured along the sidewall. The circumferential groove width can be from 10.0 mm to 20.0 mm. This makes it possible for the tire growth, especially in the circumferential groove region, to correspond to the arrangement and geometry of the circumferential groove and be optimized. Circumferential groove opening and tangential stresses at the base of the circumferential groove are thus reduced. This reduces the formation of fatigue cracks in the circumferential groove.
[0012] The severity of growth reduction in the circumferential groove region can be influenced by the selection of the first spacing D. It has been shown that, from a value of D = 0.7 mm, growth is reduced in such a way that the fatigue resistance of the circumferential groove is considerably improved.
[0013] A pneumatic vehicle tire, in particular a utility vehicle tire, is thus provided that it has enhanced circumferential groove fatigue resistance.
[0014] An advantageous embodiment is provided where the first spacing D is from 0.7 mm to 5.0 mm.
[0015] It has been demonstrated that such a first D spacing allows for particularly low growth in the shoulder region. This allows for a particularly low opening of the circumferential groove and further improves the fatigue resistance of the circumferential groove. A first D spacing greater than 5.0 mm may, depending on tire size and tire contour, result in a change in tire width and shoulder rib contour that is disadvantageous for tire contact patch and tire performance.
[0016] An advantageous embodiment is provided where the second spacing D is from 10 mm to 40 mm. Petition 870260002534, dated 12 / 01 / 2026, p. 9 / 41 5 / 10
[0017] It has been shown that such a second spacing D makes it possible to optimize growth suppression in the shoulder region, particularly in a manner appropriate to the usual width of the shoulder groove.
[0018] An advantageous embodiment is provided in which the carcass ply line throughout the region between points A and B is arranged so as to have a curvature directed towards an interior space of the tire.
[0019] This allows tire growth in the circumferential groove region as a result of straightening of the carcass ply under tensile force to be neutralized in a particularly efficient manner.
[0020] An advantageous embodiment is provided in which the carcass ply line axially within points A and B is arranged so as to have a curvature facing an outer tire space.
[0021] This further contributes to the tire growth in the circumferential groove region as a result of straightening of the carcass ply under tensile force being neutralized in a particularly efficient manner.
[0022] An advantageous embodiment is provided in which the two axial halves of the tire are formed in this manner.
[0023] It is therefore possible to improve the fatigue resistance of the circumferential grooves on the shoulder side in both halves of the tire.
[0024] An advantageous embodiment is provided in which the carcass ply strength members on a sidewall of the tire form an angle of no more than 10°, preferably no more than 5°, particularly preferably no more than 3°, with the radial direction rR.
[0025] The disadvantageous growth described appears in particular in tires that have a carcass ply whose sidewall strength members form an angle of no more than 10°, preferably of Petition 870260002534, dated 12 / 01 / 2026, p. 10 / 41 6 / 10 at most 5°, particularly preferably at most 3°, with the radial direction. The advantages of the invention are realized, in particular, in a tire with such an angle of the carcass resistance members, in particular, in a tire with a radial carcass.
[0026] An advantageous embodiment is provided in which the circumferential groove is the outermost axially circumferential groove having a third spacing of at least 20 mm from a tread surface edge measured along the axial direction aR.
[0027] The circumferential groove can therefore be what is known as a shoulder groove. The change in the carcass as a result of the filling generally increases axially outward. However, tire growth has only a low-level negative effect on circumferential grooves that are arranged at a third spacing of less than 20 mm from the edge of the tread surface. Therefore, this type of tire design for the axially outermost circumferential groove that has a third spacing of at least 20 mm from the edge of the tread surface is particularly advantageous. A circumferential groove, in particular, has a width of 10.0 mm to 20.0 mm.
[0028] An advantageous embodiment is provided in which the tire has a nominal aspect ratio of 45% to 80%.
[0029] The nominal aspect ratio is determined in accordance with the ETRTO standard. The nominal aspect ratio is normally indicated on the tire sidewall surface.
[0030] An advantageous embodiment is provided in which the tire is a utility vehicle tire, preferably a truck tire.
[0031] The appearance of growth-related fatigue in the circumferential groove region can be reduced, particularly in the case of utility vehicle tires, especially truck tires, by the design embodiment according to the invention of the tire of Petition 870260002534, dated 12 / 01 / 2026, p. 11 / 41 7 / 10 pneumatic vehicle. The invention is therefore particularly advantageous for utility vehicle tires, in particular truck tires, which have a nominal aspect ratio of 45% to 80%.
[0032] All embodiments of the pneumatic vehicle tire according to the invention that are represented in this descriptive report are merely examples of the design embodiment of the invention. Consequently, additional embodiments of the invention, which are the subject matter of the invention, unless otherwise explicitly explained in the descriptive report, are also provided by individual features or a plurality of features of a single embodiment or by the combination of features of different embodiments.
[0033] Features, advantages and additional details of the invention will now be explained in more detail with reference to the schematic drawings, which represent exemplary embodiments. In the drawings: Figure 1 shows a cross-sectional view of a pneumatic vehicle tire according to the invention.
[0034] Figure 1 shows a cross-sectional section of a pneumatic vehicle tire 1, in particular a utility vehicle tire, according to the invention. The cross-sectional section is selected perpendicular to the circumferential direction U. The cross-sectional section is embodied as the cross-sectional section that the tire 1 would have in the new state if the tire were mounted on a standard wheel rim conforming to ETRTO without inflation pressure.
[0035] The essential components of which the pneumatic vehicle tire 1 is composed are a largely airtight inner layer, a carcass, in particular radial, which has a carcass ply and conventionally extends from the zenith region of the Petition 870260002534, dated 12 / 01 / 2026, page 12 / 41 8 / 10 pneumatic vehicle tire through the sidewalls 12 to bead regions and is anchored therein by being looped around tension-resistant bead cords 15, a radially profiled tread 2 located on the outside of the carcass and a belt disposed between the tread 2 and the carcass.
[0036] The tread 2 has a tread surface and a circumferential groove 3 on the shoulder side running in a convoluted manner around the circumference of the tire. Said groove may be what is known as a shoulder groove. The circumferential groove 3 may be the outermost axially circumferential groove 3 having a third spacing 16 of at least 20 mm from a tread surface edge 17 measured along the axial direction aR.
[0037] The carcass ply has strength members that are arranged, to a large extent, parallel to each other and on the sidewalls 12 of the tire form an angle of no more than 10°, preferably no more than 5°, particularly preferably no more than 3°, with the radial direction rR. The carcass may be in the form of a radial carcass. The carcass ply 4 has, in the cross-section of the tire, a carcass ply line 4 running through the central points of the strength members of the carcass ply.
[0038] The tire according to the invention is distinguished by the fact that, in the illustrated cross-section, a point R of the carcass ply line 4 defined by a perpendicular projection from a center 7 of the circumferential groove 3 to the carcass ply line 4 has a first spacing D of at least 0.7 mm to a straight line 6 connecting two points A and B of the carcass ply line.
[0039] In this case, the center 7 of the circumferential groove is determined on a lateral surface 8 applied to the band surface. Petition 870260002534, dated 12 / 01 / 2026, page 13 / 41 9 / 10 of the radial tread from the outside. The first spacing D is measured perpendicular to the straight line 6. Point R is positioned radially off the straight line 6. Point R is centrally located between points A and B as measured along the carcass canvas line 4 and has a second equal spacing D for each of the two points A and B. The second spacing D is 1.0 to 2.0 times a circumferential groove width 9 measured along the sidewall 8.
[0040] The first spacing D can be from 0.7 mm to 5.0 mm. The second spacing D can be from 10 mm to 40 mm. The width 9 of the circumferential groove 3 can be from 10.0 mm to 20.0 mm.
[0041] As illustrated, the carcass ply line 4 across the region between points A and B may have a curvature 10 facing an inner tire space 13. The carcass ply line 4 axially within points A and B may be arranged so as to have a curvature 11 facing an outer tire space 14.
[0042] The two axial halves of tire 1 may have a corresponding pattern of the carcass ply line 4.
[0043] The tire may have a nominal aspect ratio of 45% to 80%. The nominal aspect ratio is determined according to the ETRTO standard. The nominal aspect ratio is normally indicated on the tire sidewall surface. List of reference designations (Part of the descriptive report) Pneumatic vehicle tire Tread Circumferential groove Carcass canvas line Straight line Center of the circumferential groove Petition 870260002534, dated 12 / 01 / 2026, page 14 / 41 10 / 10 Lateral surface Circumferential groove width Curvature Curvature Side wall Tire interior space Tire outer space Receipt Third spacing Tread surface edge A, B Points D First spacing D Second spacing R Point aR Axial direction rR Radial direction U Circumferential direction Petition 870260002534, dated 12 / 01 / 2026, page 15 / 41
Claims
1 / 3 CLAIMS 1. Pneumatic vehicle tire (1), in particular a utility vehicle tire, comprising: a tread (2) having a tread surface and a circumferential groove (3) on the shoulder side running in a convoluted manner around the circumference of the tire, and a carcass having a carcass ply having strength members, wherein the carcass ply has, in a cross-section of the tire, a carcass ply line (4) running through the center points of the carcass ply strength members, wherein said cross-section is the perpendicular cross-section in the circumferential U direction that the tire (1) would have in the new state if mounted on a standard wheel rim conforming to ETRTO without inflation pressure,characterized in that a point R of the carcass ply line (4) defined by a projection of a center (7) of the circumferential groove (3) perpendicular to the carcass ply line (4) has a first spacing D of at least 0.7 mm to a straight line (6) connecting two points A and B of the carcass ply line, wherein the center (7) of the circumferential groove is determined on a lateral surface (8) applied to the tread surface radially from the outside, wherein the first spacing D is measured perpendicular to the straight line (6), and wherein the point R is radially outside the straight line (6) and wherein the point R is centrally located between points A and B as measured along the carcass ply line (4) and has a second spacing D equal to each of the two points A and B, wherein the second spacing D is 1.0 to 2,0 times a width (9) of the circumferential groove (3) measured along the lateral surface (8). Petition 870260002534, dated 12 / 01 / 2026, p. 16 / 41 2 / 3, 2. Pneumatic vehicle tire (1), according to claim 1, characterized in that the first spacing D is from 0.7 mm to 5.0 mm.
3. Pneumatic vehicle tire (1), according to any of the preceding claims, characterized in that the second spacing D is from 10 mm to 40 mm.
4. Pneumatic vehicle tire (1), according to any of the preceding claims, characterized in that the carcass ply line (4) throughout the region between points A and B is arranged so as to have a curvature (10) facing an inner tire space (13).
5. Pneumatic vehicle tire (1), according to any of the preceding claims, characterized in that the carcass ply line (4) axially within points A and B is arranged so as to have a curvature (11) facing an outer tire space (14).
6. Pneumatic vehicle tire (1), according to any of the preceding claims, characterized in that the two axial halves of the tire are formed in this manner.
7. Pneumatic vehicle tire (1), according to any of the preceding claims, characterized in that the carcass ply strength members (4) in a sidewall of the tire form an angle of no more than 10°, preferably no more than 5°, particularly preferably no more than 3°, with the radial direction rR.
8. Pneumatic vehicle tire (1), according to any of the preceding claims, characterized in that the circumferential groove (3) is the outermost axially circumferential groove that has a third spacing of at least 20 mm from a tread surface edge measured along the axial direction aR.
9. Pneumatic vehicle tire (1), according to any of the preceding claims, characterized in that the tire has a nominal aspect ratio of 45% to 80%.
10. Pneumatic vehicle tire (1), according to any of the preceding claims, characterized in that the tire is a utility vehicle tire, preferably a truck tire. Petition 870260002534, dated 12 / 01 / 2026, p. 18 / 41