Tires with an improved tread pattern

Abstract

According to an aspect of the present invention, a vehicle tire having a tread is provided. The tread comprises a set of continuous blocks arranged along the outer circumference of the tire and a plurality of first grooves arranged across the outer circumference of the tire, each of the plurality of first grooves being positioned between two of the set of continuous blocks. Each of the set of continuous blocks comprises a leading edge and a trailing edge, a first chamfer positioned on a first portion of the leading edge, and a second chamfer positioned on a first portion of the trailing edge, wherein the first chamfer has a first average width in the first portion of the leading edge, and the second chamfer has a second average width in the first portion of the trailing edge, the first average width being different from the second average width.

Description

[Technical Field]

[0001] This invention relates to vehicle tires. One possible application of the disclosed tire relates to an all-season tire intended for use on passenger cars or commercial vans. This disclosure can also be applied to other tires, such as winter tires or off-road tires. [Background technology]

[0002] All-season tires (used here as a typical example for readability) are known for providing good grip on snow-covered roads while also offering good performance on dry and wet roads. Such tires are intended for year-round use and do not require switching between summer and winter tires.

[0003] For example, all-season tires are known to have grooves that extend from the center of the tire tread, i.e., from the tire's equatorial plane, toward the tire's shoulder (sometimes called the "shoulder portion" or "side portion"). These grooves typically extend substantially axially and are configured to deliver water outward from the tire's contact patch with the road surface in order to provide contact between the tire blocks and the road surface. Contact between the blocks and the road is necessary to provide lateral road holding and, furthermore, to provide friction that allows the driver to control the vehicle's movement through acceleration, braking, and / or steering.

[0004] Furthermore, all-season tires are known to have sipes, which are small cuts within blocks that extend substantially axially. Such sipes are configured to trap snow within them and provide an additional edge to improve performance on snow-covered surfaces. Providing multiple sipes to further improve snow performance reduces the stiffness of the block and thus impairs dry and wet performance. Therefore, to achieve an acceptable trade-off between snow performance and wet / dry performance, all-season tires typically have only a few sipes per block, preferably only one per block.

[0005] To improve dry braking performance, chamfered edges can be applied to the trailing edges of tire blocks, thereby increasing the effective block surface area on the ground by utilizing the deformation of the tire during braking. Furthermore, chamfered edges can be applied to the leading edges of blocks to improve traction on snow-covered ground.

[0006] However, chamfering both edges of the block reduces the amount of material used in each block, thus compromising the block's stability and leading to a decrease in braking performance, particularly on wet and dry surfaces. Furthermore, chamfering both edge sides of the block reduces the amount of rubber surface in contact with the road surface, thereby reducing overall grip on wet and dry surfaces.

[0007] Therefore, the object of the present invention is to provide a tire that has improved grip on snow-covered roads without having the aforementioned drawbacks on wet and dry ground. [Overview of the Initiative]

[0008] This objective is achieved by providing an improved vehicle tire as described in the independent claim. Further embodiments are described in the dependent claims.

[0009] According to an aspect of the present invention, a vehicle tire having a tread is provided. The tread comprises a set of continuous blocks arranged along the outer circumference of the tire and a plurality of first grooves arranged across the outer circumference of the tire, each of the plurality of first grooves being positioned between two of the set of continuous blocks. Each of the set of continuous blocks comprises a leading edge and a trailing edge, a first chamfer positioned on a first portion of the leading edge, and a second chamfer positioned on a first portion of the trailing edge, wherein the first chamfer has a first average width in the first portion of the leading edge, and the second chamfer has a second average width in the first portion of the trailing edge, the first average width being different from the second average width.

[0010] Such tires offer a good trade-off between improving snow traction without compromising wet and dry traction. This is achieved, in particular, by providing asymmetrical chamfers on the leading and trailing edges of the block, i.e., by having chamfers of different widths on the leading and trailing edges of the block. This stems from a conceptual difference in the technical purpose of the chamfers on the leading and trailing edges of the block. The chamfer on the trailing edge of the block contributes to braking performance, especially on dry ground, while the chamfer on the leading edge contributes to traction, especially on snow-covered ground.

[0011] Due to this conceptual difference, chamfers of varying widths provide an optimal trade-off between braking performance on dry ground and traction on snow-covered ground. By providing this optimal asymmetry between the chamfers, a minimum amount of surface voids is created within each tread, resulting in a large overall contact surface area. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of a vehicle tire according to this disclosure. [Figure 2] The half-tread profile of the tire as disclosed herein is shown. [Figure 3] Figure 2 shows the individual blocks of the set of consecutive blocks. [Figure 4A] Figure 3 shows three cross-sections of different parts of the block. [Figure 4B] Figure 3 shows three cross-sections of different parts of the block. [Figure 4C] Figure 3 shows three cross-sections of different parts of the block. [Figure 5] This disclosure illustrates exemplary embodiments of the V-shaped directional tread pattern. [Figure 6] This disclosure illustrates exemplary embodiments of the S-shaped tread pattern. Detailed explanation

[0013] To overcome the shortcomings of the conventional technology described above, it is sometimes desirable to provide chamfers on both the front and rear edges of a block, even if the average width of the chamfer differs between the front and rear edges. This is rooted in the different effects that chamfers have on the front and rear edges of a block.

[0014] In the context of this disclosure, “chamfer” means the inclined side wall of a block extending radially inward from the outer block surface. The wall is inclined such that the width of the block, measured circumferentially, increases toward the bottom of the groove. Each chamfer is defined by its height and width. The chamfer height may correspond to the distance, measured radially, between the outer block surface and the radially innermost edge of the inclined wall. The chamfer height (= distance between the outer block surface and the radially innermost edge of the inclined wall) is typically lower than the total height of the block, for example, up to 50% or less of the total height of the block. The chamfer width may be measured perpendicular to the block and corresponds to the width of the inclined chamfer wall when it protrudes above the outer tread surface.

[0015] The chamfered edge of the trailing edge contributes to dry braking performance. When a vehicle brakes, the inertia of the vehicle's mass causes the tread blocks to deform and bend. In this way, some of the rubber surface located near the leading edge of the block loses contact with the road surface, thus reducing the contact area of ​​each block. A reduced contact area reduces friction, and therefore impairs the braking performance of the tire.

[0016] By providing a chamfer at the trailing edge, the inclined surface of the chamfer is pushed towards the ground during braking when the block bends, thus increasing the rubber surface contacting the ground. In this way, the surface loss at the tip of the block can be compensated, the contact surface is increased, and thereby, good braking performance can be obtained due to the increase in frictional force. Therefore, the chamfer at the trailing edge of the block contributes to dry and wet braking performance.

[0017] In contrast, the chamfer at the leading edge has been proven to function efficiently to contribute to traction, especially on a ground covered with snow. Generally, in order to increase the traction on a ground covered with snow, it is necessary to reduce the surface area of the block to increase the contact pressure between the block surface and the ground. Providing a chamfer at the leading edge has been shown to be a good position for reducing the surface area of the block surface. The increase in contact pressure provided by the chamfer at the leading edge, which results in a peak of contact pressure at the leading edge of the block in particular, enables the block, especially its leading edge, to penetrate into the snow more efficiently, and thus increases the traction of the tire on a ground covered with snow.

[0018] However, if a chamfer is provided not only at the trailing edge but also at the leading edge, the contact surface of the block with the road surface is further reduced. As a result, when the tire surface becomes smaller, the frictional force is reduced, so the performance of the tire on a wet ground and a dry ground deteriorates. In other words, by providing a chamfer at the leading edge for improving the traction on snow, the dry and wet traction is simultaneously impaired. Therefore, it is desirable to find a good trade-off between improving the traction on snow without degrading the wet traction and dry traction.

[0019] This can be achieved by applying two chamfered sections asymmetrically to the leading and trailing edges of the block, i.e., by applying chamfered sections with different widths to the leading and trailing edges. Preferably, the width of the chamfered section at the trailing edge is greater than the width of the chamfered section at the leading edge. In this way, wet and dry braking can be particularly improved, while good snow traction can already be achieved with relatively small chamfered section widths.

[0020] In some embodiments, it may be desirable to provide particularly good traction on snow. In such embodiments, it may be desirable to provide a chamfered edge with a wider width on the leading edge. Therefore, in order to maintain good traction on dry and wet ground, it may be desirable to provide a chamfered edge with a narrower width on the trailing edge to maintain a relatively large contact surface between the block and the ground.

[0021] Figure 1 is a schematic diagram of a vehicle tire according to this disclosure.

[0022] According to Figure 1, the tire 100 comprises a tread 110. The tread has a set of continuous blocks 10 and a plurality of grooves 12, each groove 12 positioned between two blocks 10 of the set of continuous blocks. Furthermore, sipes 14 may be positioned within each of the set of continuous blocks 10.

[0023] The blocks may be arranged continuously in the circumferential direction 120 of the tire.

[0024] A "groove" represents an indentation in the tread pattern. The width of the grooves may vary; for example, a first groove may be wider than a second groove, or they may be the same width or even smaller. For example, the width of a groove may be at least 2 mm. The width of a single groove does not necessarily have to be constant. For example, a groove may have a wider width towards the opening of the tread pattern and a narrower width radially inward. The depth of the grooves may also vary; in some cases, the grooves may extend to the total depth of the tread (the total depth of the tread is the maximum radially measured distance between the outermost radial portion of the tire and the bottom of the deepest groove), but this is not necessarily required. For example, a depth of at least 1 mm, preferably at least 3 mm, is conceivable.

[0025] "Sipes" also refer to cuts in the tread pattern. In this specification, "sipes" refer to cuts within a block, rather than "grooves" separating blocks. For example, the width of a sipe may be smaller than the width of a groove, for example, less than 2 mm. As with grooves, the width of a sipe does not need to be constant; means can be applied to allow it to widen towards the opening of the tread pattern and narrow radially inward. The depth of a sipe may also vary, and in some cases, a sipe may extend to the full depth, but this is not always necessary. For example, a depth of at least 1 mm, preferably at least 20% of the depth of the first groove, is conceivable.

[0026] In the context of this disclosure, “circumferential direction” 120 means a direction parallel to the direction in which the tire normally rolls, i.e., a direction perpendicular to the axial direction 130 which is parallel to the tangential direction to the outer circumference of the tire. With respect to Figure 1, the circumferential direction 120 is therefore a direction that lies in a plane parallel to the yz plane.

[0027] In the context of this disclosure, “axial direction” 130 means the direction parallel to the axis of the vehicle to which the tire is normally mounted. Thus, according to Figure 1, the axial direction 130 is parallel to the x-axis and therefore perpendicular to the yz-plane.

[0028] In the context of this disclosure, “radial direction” 140 means the direction perpendicular to the axial direction. The radial direction is parallel to the connection between the center 150 of the tire and the tread surface. Thus, the radial direction lies in a plane parallel to the yz plane and substantially perpendicular to the axial direction 130 and the circumferential direction 120.

[0029] In the context of this disclosure, “equator plane” refers to a plane perpendicular to the axial direction 130 and cutting the cross-sectional width of the tire into two equal halves. Thus, the equatorial plane is parallel to the yz plane and corresponds to the widthwise centerline of the tread.

[0030] Furthermore, any numerical angle given herein should be considered an absolute value, that is, not limited to the direction of each angle.

[0031] Figure 2 shows the half-tread profile of the tire according to this disclosure.

[0032] As shown in Figure 2, the tread comprises a set of continuous blocks 10 arranged along the outer circumference of the tire. In the context of this disclosure, “continuous blocks” means that the tread comprises a plurality of blocks that are continuous with one another across the outer circumference of the tire. While the present invention is preferably provided for all blocks of the tire, some blocks that may be located between the individual blocks 10 of the set of continuous blocks may not have the chamfered portion according to the present invention.

[0033] Generally, the block 10 is intended to provide contact with the ground when the tire is rolling. The edges and surface of the block are configured to provide frictional force between the tire and the ground for grip, enabling general road holding, as well as the driver's control of the vehicle's movement through acceleration, braking, or steering.

[0034] As shown in Figure 2, the tread further comprises a plurality of first grooves 12 arranged around the outer circumference of the tire, each of the plurality of first grooves 12 positioned between two blocks 10 of a set of continuous blocks. Preferably, the grooves 12 begin near the equatorial plane 16 of the tire and extend toward the shoulder end of the tread (sometimes called the “shoulder,” “shoulder region,” “shoulder portion,” or “side portion”) and open at the outer edge of the tire. The grooves 12 are generally defined by adjacent blocks 10.

[0035] The primary purpose of the grooves 12 is to guide water along the grooves 12 toward the tire's shoulder as the tire rolls on the road surface, thereby draining water from the contact patch. Thus, the grooves 12 improve tire performance, especially on wet road surfaces. Furthermore, since the grooves define continuous blocks, they also provide edges for the blocks to improve snow performance. In addition, the grooves allow for greater flexibility of the tread elements, thus improving wear performance, resulting in reduced slippage of the blocks on the ground and a decrease in wear-inducing effects.

[0036] Furthermore, as shown in Figure 2, the tread may further comprise a plurality of sipes 14. In the illustrated tread pattern, each of the plurality of sipes 14 may preferably extend substantially along the shape of each of the set of continuous blocks 10. However, other arrangements and shapes of sipes on the outer surface of the tread, such as corrugated, zigzag, etc., are also possible. Sipes do not necessarily have to follow the shape of the blocks. For example, sipes may be included only along a portion of the shape of the block, or may have a different angle of inclination with respect to the circumferential direction than the underlying block or portion of the block. Also, some sipes may have walls that extend radially toward the center of the tire, while some sipes may have corrugated, zigzag, etc., shapes radially. Furthermore, such sipes may be inclined with respect to the radial direction. Some sipes may have projections near the bottom of the sipe. Sipes 14 can trap snow within them and provide an additional edge to the tread. This improves traction on snow-covered ground.

[0037] In some embodiments, the multiple sipes 14 may define an edge component (EI) corresponding to the ratio of the sum of the axial protrusion lengths (SAP) of the multiple sipes to the outer circumference (C) of the tread, thereby,

[0038]

number

[0039] The tire circumference C is measured at the outermost radial ring of the inflated tire. The same specifications as those described below for tire footprint measurement apply to the inflation pressure and ambient temperature.

[0040] A high edge component provides better ability to capture snow, thereby improving the tire's traction on snow-covered ground. However, a high edge component also results in low rigidity of the block, which generally deteriorates the braking / acceleration performance on dry ground. When the edge component is within any of the above ranges, the balance between traction on snow-covered ground and braking / acceleration performance on dry ground is particularly good.

[0041] The tire according to FIG. 2 further has a void volume which is the volume of all the grooves, sipes, and recesses provided in the tread, and a volume of rubber provided in the tread, and these may together occupy the total volume of the tread. That is, if the total volume of the tire is V T and the void volume is V V and the rubber volume is V R then the total volume V T is V T =V V +V R In a preferred embodiment, the ratio V V of the void volume V R to the rubber volume V V / V R may be at least 0.20 and at most 0.40. Preferably, the ratio V V / V R may be at least 0.24 and at most 0.37, more preferably at least 0.28 and at most 0.35. The ratio V V / VR is directly related to the rigidity of the tread profile. Thus, the higher the ratio V V / V R , the greater the amount of voids in the tread, which indicates a decrease in the rigidity of the tread and benefits the performance on snow. The lower the ratio V V / V R , the greater the amount of rubber in the tread, which indicates an improvement in braking performance by increasing the rigidity. A specific range of void-to-rubber ratio provides an optimal trade-off between snow performance and dry performance, and provides a tire that exhibits good braking performance on dry ground and good traction on snow-covered ground.

[0042] Figure 3 shows the individual blocks of the sequence of blocks in Figure 2.

[0043] According to Figure 3, block 10 comprises a leading edge portion 20 and a trailing edge portion 30.

[0044] In the context of this disclosure, “leading edge” may also be referred to as “traction edge,” and refers to the edge of a block that primarily responds to longitudinal traction forces applied to the tire. Typically, the “leading edge” is longer than the side edge of the block and is the edge of the block that first encounters the ground when the tire block, rolling in the preferred rolling direction, enters the tire-to-ground contact patch.

[0045] The "trailing edge," sometimes called the "braking edge," refers to the edge of the tire block that primarily responds to longitudinal braking forces applied to the tire. Typically, the "trailing edge" is the edge of the block that is longer than the side edge and is the last edge that loses contact with the ground when the tire block, rolling in the preferred direction of rolling, leaves the tire's contact patch with the ground.

[0046] According to Figure 3, block 10 comprises a first chamfered portion 202 located on a first portion 22 of the leading edge portion 20, and a second chamfered portion 302 located on a first portion 32 of the trailing edge portion 30. The first chamfered portion 202 has a first average width in the first portion 22 of the leading edge portion 20, and the second chamfered portion 302 has a second average width in the first portion 32 of the trailing edge portion 30, the first average width being different from the second average width.

[0047] The width of the chamfer refers to the width measured perpendicular to each block edge. The average width of the chamfer in a given section is measured by measuring the width of each chamfer at multiple points within that section of each edge and dividing by the number of points. Mathematically, the average width of the chamfer in a section is...

[0048]

number

[0049]

number

[0050] In some embodiments, the second average width may be greater than the first average width, that is, the rear chamfer may be wider than the front chamfer.

[0051] As described above, the chamfered portion of the trailing edge directly contributes to the braking performance of the tire, especially on dry and wet roads, and thus dry and wet braking can be particularly improved by this configuration. Good traction on snow can already be achieved with a relatively small chamfered portion width at the leading edge, and as a result, by providing a wider chamfered portion at the trailing edge than at the leading edge, an optimal trade-off between dry / wet braking and snow traction can be achieved without significantly impairing block rigidity.

[0052] In some embodiments, the first average width differs from the second average width by at least 0.2 mm. Preferably, the first average width may differ from the second average width by at least 0.3 mm, more preferably at least 0.4 mm.

[0053] These width differences provide a good trade-off between braking performance, snow traction, and block stiffness, contributing to an overall improvement in tire grip.

[0054] In some embodiments, the first portion 22 of the leading edge 20 and the first portion 32 of the trailing edge 30 may be located in the shoulder region of the tire.

[0055] Since the edges of the tire's shoulder region are generally perpendicular to the tire's circumferential direction, these tread portions contribute particularly to the tire's braking and acceleration performance. Therefore, applying an asymmetrical chamfer to the tire's shoulder region provides significantly improved braking performance.

[0056] In some embodiments, the block 10 may further comprise a second portion 24 of the leading edge 20 and a second portion 34 of the trailing edge 30. The first portion 22 of the leading edge 20 may be positioned axially outward from the second portion 24 of the leading edge 20. Similarly, the first portion 32 of the trailing edge 30 may be positioned axially outward from the second portion 34 of the trailing edge 30.

[0057] In some embodiments, block 10 is - A third chamfered portion 204 is located on at least the second portion 24 of the leading edge portion 20, -May further include at least one of a fourth chamfered portion 304 located on at least a second portion 34 of the trailing edge portion 30.

[0058] Preferably, the block 10 includes both a third chamfer 204 and a fourth chamfer 304. By placing additional chamfers on the second portions 24 / 34 of the leading / trailing edges, the effect of the chamfers on the first portions 22 / 32 is further improved, i.e., the good trade-off between improved braking performance on wet and dry ground and improved traction and block stiffness on snow, leading to better overall grip of the tire.

[0059] In some embodiments, the third chamfer 204 may have a third average width in the second portion 24 of the leading edge 20, and the fourth chamfer 304 may have a fourth average width in the second portion 34 of the trailing edge 30. The third average width may differ from the fourth average width, preferably the fourth average width may be greater than the third average width, and more preferably the fourth average width may differ from the third average width by at least 0.2 mm. Preferably the fourth average width may differ from the third average width by at least 0.3 mm, more preferably at least 0.4 mm. Similar to the first chamfer 202 and the second chamfer 302, these features further improve the trade-off between braking performance and snow traction, and thus improve overall grip. Since the second portions 24, 34 are positioned axially inward than the first portions 22, 32, the provision of chamfers here further improves lateral road-holding performance.

[0060] In some embodiments, the sum of the first average width and the third average width may differ from the sum of the second average width and the fourth average width. Preferably, the sum of the second average width and the fourth average width may be greater than the sum of the first average width and the third average width. More preferably, the sum of the second average width and the fourth average width may be at least 0.2 mm greater than the sum of the first average width and the third average width. This provides a further improvement in the trade-off between braking performance and snow traction, and therefore results in improved overall grip.

[0061] In some embodiments, block 10 may further comprise a third portion 26 of the leading edge 20 and a third portion 36 of the trailing edge 30. The third portion 26 of the leading edge 20 may be positioned axially inward of the second portion 24 of the leading edge 20. Similarly, the third portion 36 of the trailing edge 30 may be positioned axially inward of the second portion 34 of the trailing edge 30.

[0062] Therefore, the front edge 20 of block 10 may include a first portion 22, a second portion 24, and a third portion 26, named in order from the outermost axial direction to the innermost axial direction. Similarly, the rear edge 30 of block 10 may include a first portion 32, a second portion 34, and a third portion 36, named in order from the outermost axial direction to the innermost axial direction. If there are three portions for one edge, the first portions 22, 32 may be called "shoulder portions," the second portions 24, 34 may be called "intermediate portions," and the third portions 26, 36 may be called "central portions." The central portions may be positioned adjacent to the equatorial plane 16 of the tire.

[0063] In some embodiments, block 10 is - A fifth chamfered portion 206 located at least on the third portion 26 of the leading edge 20, -The system may further include a sixth chamfered portion 306 located on at least the third portion 36 of the trailing edge 30.

[0064] The fifth chamfered portion 206 may have a fifth average width in the third portion 26 of the leading edge portion 20, and the sixth chamfered portion 306 may have a sixth average width in the third portion 36 of the trailing edge portion 30.

[0065] In some embodiments, the fifth average width may differ from the sixth average width, preferably the sixth average width may be greater than the fifth average width, and more preferably the fifth average width may be at least 0.2 mm greater than the sixth average width. Preferably the fifth average width may differ from the sixth average width by at least 0.3 mm, more preferably at least 0.4 mm.

[0066] In some embodiments, the sum of the first average width, the third average width, and the fifth average width may differ from the sum of the second average width, the fourth average width, and the sixth average width. Preferably, the sum of the first average width, the third average width, and the fifth average width may differ from the sum of the second average width, the fourth average width, and the sixth average width by at least 0.2 mm and up to 3.5 mm.

[0067] The difference in the sum of the average widths directly characterizes the difference between the width of the chamfered portion of the front edge 20 and the width of the chamfered portion of the rear edge 30. Preferably, the sum of the average widths of the rear edge 30, i.e., the sum of the first average width, the third average width, and the fifth average width, may be greater than the sum of the average widths of the front edge 20, i.e., the sum of the second average width, the fourth average width, and the sixth average width.

[0068] As shown in Figure 3, the axial extensions of the corresponding edge portions may differ between the edges; that is, as shown in Figure 3, the second portion 34 of the rear edge 30 may have a larger axial extension than the corresponding second portion 24 of the front edge 20. Generally, the third portions 26, 36 of the front edge 20 and the rear edge 30 may have axial extensions of at least 25% and up to 40% of the half-footprint width of the tire. Thus, the third portions 26, 36 preferably begin adjacent to the equatorial plane 16 of the tire and extend axially outward to a width of 25% to 40% of the half-footprint width of the tire.

[0069] The second portions 24, 34 of the leading edge 20 and trailing edge 30 may have axial extensions of at least 25% and up to 55% of the half-footprint width of the tire. Thus, the second portions 24, 34 preferably begin from the axially outer ends of the third portions 26, 36 and extend axially outward to a width of 65% to 80% of the half-footprint width of the tire.

[0070] The first portions 22, 32 of the leading edge 20 and trailing edge 30 may have axial extensions of at least 20% and up to 35% of the half-footprint width of the tire. Thus, the first portions 22, 32 preferably begin at the axial outer ends of the second portions 24, 34 and extend axially outward to the axial outer ends of the tire, i.e., cover the entire half-footprint width axially outward from the second portions 24, 34.

[0071] In some embodiments, the separation between the two parts, the leading edge and the trailing edge, Recesses at the edges of adjacent parts, Changes in the inclination angle of each edge of the tire with respect to the circumferential direction, The direction or magnitude of the curvature of each edge, Gradual increase or decrease in the width of the chamfered area. A groove extending substantially circumferentially through the block, or It may be defined by any of these combinations.

[0072] For example, as shown in Figure 3, the recess 222 can separate the second portion 24 of the leading edge 20 from the third portion 26 of the leading edge 20. Furthermore, the recess 224 can separate the first portion 22 of the leading edge 20 from the second portion 24 of the leading edge 20. Similarly, the recess 322 can separate the second portion 34 of the trailing edge 30 from the third portion 36 of the trailing edge, and the recess 324 can separate the first portion 32 of the trailing edge 30 from the second portion 34 of the trailing edge 30.

[0073] Alternatively, other means of separation between the edge portions are also possible. For example, as shown in Figure 3, a groove 250 extending substantially circumferentially through the block 10 may separate the first portions 22, 32 from the second portions 24, 34. Although such a groove is shown only in Figure 3 to separate the first portions 22, 32 from the second portions 24, 34, a similar groove may be located between the second portions 24, 34 and the third portions 26, 36.

[0074] Furthermore, although only the recesses 222, 224, 322, 324 and groove 250 are shown in Figure 3 as means for separating adjacent edge portions, other means such as gradually increasing or decreasing the width of the chamfer can be used.

[0075] Alternatively, changes in the direction or magnitude of the curvature of each edge can be used, namely changes between concave and convex curvature, as well as increases or decreases in edge curvature, to separate two adjacent edge portions.

[0076] Furthermore, the angle of inclination of each block relative to the circumferential direction of the tire can be used to determine the separation between the edge portions.

[0077] According to one approach, the angle of inclination of each portion of the edge is determined by the angle between (i) the tangent applied to each edge of the block and (ii) the circumferential direction of the tire. If each portion of the edge has a chamfer, the tangent is applied to the outermost circumferential end of the block (neglecting the width and shape of the chamfer). This approach can be used when each portion of the edge is formed continuously or substantially continuously, i.e., without substantial circumferential cuts in between, and there is a discontinuity in the inclination of each edge with respect to the circumferential direction of the tire, for example, a significant change. In this case, the discontinuity corresponds to a separation between adjacent edge portions.

[0078] Preferably, the inclination angle of the first portions 22, 32 (i.e., the inclination angle of the tangent on each portion of the edge with respect to the circumferential direction) may be at least 65 degrees and a maximum of 90 degrees with respect to the circumferential direction, preferably 75 degrees and a maximum of 90 degrees with respect to the circumferential direction, and more preferably at least 85 degrees and a maximum of 90 degrees with respect to the circumferential direction. The inclination angle of the second portions 24, 34 may be at least 50 degrees and a maximum of 65 degrees with respect to the circumferential direction. Preferably, the inclination angle of the second portions 24, 34 may be at least 50 degrees and a maximum of 60 degrees with respect to the circumferential direction. The inclination angle of the third portions 26, 36 may be at least 20 degrees and a maximum of 50 degrees with respect to the circumferential direction. Preferably, the inclination angle of the third portions 26, 36 may be at least 30 degrees and a maximum of 50 degrees with respect to the circumferential direction.

[0079] According to another approach that may be used when each edge does not exhibit discontinuity in the inclination of the tire with respect to the circumferential direction, the separation between edge portions is preferably determined according to an axial extension of the footprint width as described above in relation to Figure 3, a recess in each edge, the direction or magnitude of the curvature of each edge, a gradual increase or decrease in the chamfer width, or a groove that extends substantially circumferentially through the block.

[0080] More preferably, in this approach, the inclination angle may be used in addition to one or more of the aforementioned criteria. For example, the third portions 26, 36, which begin adjacent to the equatorial plane of the tire and extend axially outward to a width of 25% to 40% of the half-footprint width of the illustrated tire, have an inclination angle of at least 20 degrees and a maximum of 50 degrees with respect to the circumferential direction for at least one of the possible extensions within this range, which may be at least 30 degrees and a maximum of 50 degrees with respect to the circumferential direction. Similarly, the second portions 24, 34, which begin at the axial outer end of the third portion and extend axially outward to a width of 65% to 80% of the half-footprint width of the tire, exhibit an inclination angle of at least 50 degrees and a maximum of 65 degrees with respect to the circumferential direction, which may be at least 50 degrees and a maximum of 60 degrees. Similarly, the first portions 22, 32, which begin at the axial outer end of the second portion and extend axially outward to the axial outer end of the tire, exhibit an inclination angle of at least 65 degrees and a maximum of 90 degrees with respect to the circumferential direction, preferably 75 degrees and a maximum of 90 degrees with respect to the circumferential direction, and more preferably at least 85 degrees and a maximum of 90 degrees with respect to the circumferential direction.

[0081] Furthermore, various combinations of means for separating the edge portions are also possible. As an example, Figure 3 shows a combination of recesses 224, 324 and grooves 250 for separating the first portions 22, 32 and the second portions 24, 34, and there are other possible combinations.

[0082] Figure 3 further shows the three cutting lines CS1, CS2, and CS3. Figures 4A to 4C show three cross-sections of different parts of the block in Figure 3.

[0083] As shown in Figures 4A to 4C, the block 10 may have chamfered portions of different widths in different parts.

[0084] Figure 4A shows a cross-sectional view of block 10 cut along line CS1. Thus, Figure 4A shows a first chamfer 202 located on the front edge 20 of block 10 and a second chamfer 302 located on the rear edge 30 of block 10. As described above, the chamfer width is measured perpendicular to the block tangent. As shown in Figure 4A, the first chamfer width 212 of the first chamfer 202 may be smaller than the second chamfer width 312 of the second chamfer 302. Preferably, the first chamfer width 212 of the first chamfer 202 may be at least 0.2 mm smaller than the second chamfer width 312 of the second chamfer 302.

[0085] Figure 4B shows a cross-sectional view of block 10 cut along line CS2. Thus, Figure 4B shows a third chamfer 204 located on the front edge 20 of block 10 and a fourth chamfer 304 located on the rear edge 30 of block 10. As shown in Figure 4B, the width 214 of the third chamfer 204 may be substantially equal to the width 314 of the fourth chamfer 304. Furthermore, the width 212 of the first chamfer may be smaller than the width 312 of the second chamfer, so the sum of the widths 212 and 214 may still be smaller than the sum of the widths 312 and 314.

[0086] Alternatively, the width 214 of the third chamfered portion 204 may be smaller than the width 314 of the fourth chamfered portion 304. Preferably, the width 214 of the third chamfered portion 204 may be at least 0.2 mm smaller than the width 314 of the fourth chamfered portion 304.

[0087] Figure 4C shows a cross-sectional view of block 10 cut along line CS3. Thus, Figure 4C shows a fifth chamfer 206 located on the front edge 20 of block 10 and a sixth chamfer 306 located on the rear edge 30 of block 10. As shown in Figure 4C, the width 216 of the fifth chamfer 206 may be greater than the width 316 of the sixth chamfer 306. However, if the absolute difference between the first chamfer width 212 and the second chamfer width 312 is greater than the absolute difference between the fifth chamfer width 216 and the sixth chamfer width 316, and the third chamfer width 214 and the fourth chamfer width 314 are equal, then the first chamfer width 212 may be smaller than the second chamfer width 312. Therefore, the sum of the first chamfer width 212, the third chamfer width 214, and the fifth chamfer width 216 may still be smaller than the sum of the second chamfer width 312, the fourth chamfer width 314, and the sixth chamfer width 316.

[0088] Alternatively, the width 216 of the fifth chamfered portion 206 may be less than or equal to the width 316 of the sixth chamfered portion 306.

[0089] Figure 5 shows an exemplary embodiment of the V-shaped directional tread pattern according to this disclosure.

[0090] As shown in Figure 5, some embodiments of the tread may include a second set of continuous blocks 50, which are positioned opposite the equatorial plane 16 of the tire and generally correspond to a first set of continuous blocks 10. In some embodiments, as shown in Figure 5, the second set of continuous blocks 50 can be axially symmetric with respect to the first set of blocks 10, resulting in a V-shaped tread pattern with a preferred rolling direction. The V-shape offers the advantage of improved drainage characteristics, as water can be drained from the contact patch by two opposing first grooves located in the axial directions of the tread on opposite sides when the tire rolls in the preferred rolling direction. This can improve traction on wet surfaces. While a directional pattern with a preferred rolling direction is advantageous on wet surfaces, other embodiments are also possible.

[0091] For example, Figure 6 shows an exemplary embodiment of an S-shaped tread pattern according to the present disclosure. In some embodiments, according to Figure 6, the tread may comprise a second set of continuous blocks 50 in addition to a first set of continuous blocks 10. The second set of continuous blocks 50 may be positioned on the opposite side of the tire's equatorial plane 16. In contrast to the embodiments described above, which include a V-shaped tread pattern, the second set of continuous blocks 50 may be provided point-symmetrically with respect to the first set of blocks 10, resulting in an S-shaped tread pattern that does not have a preferred rolling direction.

[0092] Tire footprint measurement In the context of this disclosure, “tire footprint” means all parts of the tire that are in contact with the ground when the tire is inflated and under load. The tire footprint provides information about the behavior of the tread profile under normal conditions; that is, from the tire footprint, it is possible to know which parts of the blocks are in contact with the road surface under static load conditions.

[0093] When analyzing tire footprints, each tire is generally inflated to a pressure appropriate to its type. For standard passenger car radial tires with a nominal section width of 195 mm or less, a tire pressure of 1.9 bar is used. For standard passenger car radial tires with a nominal section width of 205 mm or more, a tire pressure of 2.0 bar is used. For reinforced passenger car radial tires of any size, a pressure of 2.3 bar is used. For tires used in commercial vans and trucks, the standardized inflation pressure set by the European Tire and Rim Technology Association (ETRTO) is used. All measurements are taken at room temperature.

[0094] Next, loads are applied to the tire under the following conditions: For passenger car radial tires, a weight equivalent to 88% of the tire load index according to the ETRTO chart is applied to the tire. Tires for commercial vans and trucks are loaded to a weight corresponding to the ETRTO single load rating standard. To perform the measurements, ink may be applied to the tread profile, then the tire is pressed onto a card according to the above specifications, leaving an ink footprint that can then be analyzed. The footprint is evaluated for three tire sections placed at equal intervals of 120 degrees around the circumference of the tire. The metrics analyzed within the footprint are then averaged across the three measured sections.

[0095] Measurement of tire void volume and rubber volume In the context of this application, the tire void volume is also measured under footprint conditions. That is, the tire is inflated in the same manner as described above for tire footprint measurement. The void volume is measured for each pixel by a laser measurement system capable of detecting its relative depth to the tread surface. Thus, the total void volume within the contact patch can be calculated by integrating over all measured pixels. The total tread volume can be calculated as the product of the tire's footprint width (FW) and circumference (C) multiplied by the weighted average depth of the first groove. In this case, the total volume of rubber is the difference between the total tread volume and the total void volume.

[0096] The measurements given in this disclosure refer to measurements taken under footprint conditions on new tires that have not been exposed to wear prior to the measurement. [Explanation of Symbols]

[0097] 10 blocks 12 The first groove 14 sipes 16 Equatorial plane 20 Front edge 22, 32 Part 1 24, 34 Part 2 26, 36 Third part 30 Trailing edge 202 First chamfered section 204 Third chamfered section 206 Fifth chamfered section 212 First width 214 The third width 216 The fifth width 222, 224, 322, 324 recesses 250 groove 302 Second chamfered section 304 Fourth chamfered section 306 Sixth chamfered section 312 Second width 314 The fourth width 316 The sixth width

Claims

1. A vehicle tire having a tread, wherein the tread is A set of continuous blocks arranged along the outer circumference of the aforementioned tire, A plurality of first grooves arranged over the outer circumference of the tire, each of the plurality of first grooves comprising a plurality of first grooves arranged between two blocks of the set of continuous blocks, Each of the consecutive blocks in the aforementioned set is The leading edge and the trailing edge, It comprises a first chamfered portion located on the first portion of the front edge and a second chamfered portion located on the first portion of the rear edge. The first chamfered portion has a first average width in the first part of the leading edge, and the second chamfered portion has a second average width in the first part of the trailing edge. A vehicle tire in which the first average width is different from the second average width.

2. The tire according to claim 1, wherein the second average width is greater than the first average width.

3. The tire according to claim 1 or 2, wherein the first average width differs from the second average width by at least 0.2 mm.

4. The tire according to any one of claims 1 to 3, wherein the first portion of the leading edge and the trailing edge is positioned in the shoulder region of the tire.

5. Each of the consecutive blocks in the aforementioned set is The second portion of the aforementioned front edge and rear edge is further comprising The tire according to any one of claims 1 to 4, wherein the first portion of the leading edge and the first portion of the trailing edge are positioned axially outward with respect to the second portion.

6. Each of the consecutive blocks in the aforementioned set is A third chamfered portion is provided, which is located at least on the second portion of the front edge. The tire according to claim 5, further comprising at least one of a fourth chamfered portion disposed on at least the second portion of the trailing edge.

7. The tire according to claim 6, wherein the third chamfered portion has a third average width in the second portion of the front edge, and the fourth chamfered portion has a fourth average width in the second portion of the rear edge, and the average width of the third is different from the average width of the fourth, preferably the average width of the fourth is greater than the average width of the third, and more preferably the average width of the fourth is at least 0.2 mm different from the average width of the third.

8. The tire according to claim 6 or 7, wherein the sum of the first average width and the third average width is different from the sum of the second average width and the fourth average width.

9. Each of the consecutive blocks in the aforementioned set is The third portion of the aforementioned front edge and rear edge is further comprising The tire according to any one of claims 5 to 8, wherein the third portion of the front edge and the rear edge is positioned axially inward of the second portion.

10. Each of the consecutive blocks in the aforementioned set is The device further comprises a fifth chamfered portion located at least on the third portion of the leading edge, and a sixth chamfered portion located at least on the third portion of the trailing edge, The tire according to claim 9, wherein the fifth chamfered portion has a fifth average width in the third portion of the front edge, and the sixth chamfered portion has a sixth average width in the third portion of the rear edge.

11. The tire according to claim 10, wherein the sum of the first average width, the third average width, and the fifth average width is different from the sum of the second average width, the fourth average width, and the sixth average width.

12. The tire according to claim 11, wherein the sum of the first average width, the third average width, and the fifth average width differs from the sum of the second average width, the fourth average width, and the sixth average width by at least 0.2 mm and at most 3.5 mm.

13. The third portion of the front edge or the rear edge has an axial extension of at least 25% and up to 40% of the half-footprint width of the tire, The second portion of the front edge or the rear edge has an axial extension of at least 25% and up to 55% of the half-footprint width of the tire, The first portion of the front edge or the rear edge has an axial extension of at least 20% and up to 35% of the half-footprint width of the tire. The tire according to any one of claims 9 to 12.

14. The separation between the two portions, the leading edge and the trailing edge, Recesses at the edges of adjacent parts, The change in the inclination angle of each edge of the tire with respect to the circumferential direction, The direction or magnitude of the curvature of each of the aforementioned edges, Gradual increase or decrease in the width of the chamfered area. A groove extending substantially circumferentially through the aforementioned block, or A tire according to any one of claims 5 to 13, defined by any combination of these.

15. The aforementioned tread, The tread further comprises a plurality of sipes, each sipe determining an edge component EI corresponding to the ratio of the sum of the axial protrusion lengths of the plurality of sipes (SAP) to the outer circumference C of the tread, [Math 1] The tire according to any one of claims 1 to 14, wherein the EI is at least 2 and at most 20.

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