Tire with improved tread pattern

Abstract

According to aspects of the present disclosure, there is provided a tire for a vehicle, the tire including a tread. The tread comprises: a set of consecutive blocks arranged along the circumference of the tire; and a plurality of first grooves arranged on a circumference of the tire, where each groove of the plurality of first grooves is arranged between two blocks of the set of consecutive blocks. Each block of the set of consecutive blocks includes a leading edge and a trailing edge. Each of the leading and trailing edges includes a first portion disposed at a shoulder region of the tire, a second portion disposed at an axially inward location of the first portion, and a third portion disposed at an axially inward location of the second portion. Each block of the set of consecutive blocks further includes a first chamfer disposed at least at one of the leading edge and the trailing edge. The first chamfer has a first average width in the first portion, a second average width in the second portion, and a third average width in the third portion. A first average width projected in a circumferential direction of the tire corresponds to a first projected average width, a second average width projected in the circumferential direction of the tire corresponds to a second projected average width, and a third average width projected in the circumferential direction of the tire corresponds to a third projected average width. At least two of the first projected average width, the second projected average width, and the third projected average width are substantially equal.

Description

TECHNICAL FIELD

[0001] The present invention relates to a vehicle tire. One possible application of the disclosed tire relates to all-season tires intended to equip passenger vehicles or commercial vans. The present disclosure can also apply to other tires, such as winter tires or tires for off-road applications. BACKGROUND

[0002] All-season tires are known - used here as a typical example to facilitate readability - for providing good grip on snow-covered road surfaces, while also providing good performance on dry and wet road surfaces. Such tires are intended to be used throughout the year, so that there is no longer a need to change between summer and winter tires.

[0003] For example, known all-season tires comprise grooves extending from the center of the tire's tread (i.e. from the tire's equatorial plane) towards the tire's shoulder (sometimes also referred to as "shoulder portion" or "side portion"). These grooves, which generally extend in a substantially axial direction, are configured to transport water outward from the tire's contact imprint with the road, to provide contact between the tire block and the road surface. Contact between the block and the road is necessary to provide friction, which provides lateral road holding and further allows the driver to control the movement of the vehicle by accelerating, braking and / or steering.

[0004] Furthermore, known all-season tires have sipes, which are small incisions in the block, extending in a substantially axial direction. Such sipes are configured to trap snow therein and provide additional edges to improve performance on snow-covered road surfaces. Since the provision of multiple sipes (which would further improve snow performance) reduces the stiffness of the block, and thus compromises dry / wet performance, it is common to provide only a few sipes per block, preferably only one sipe per block, in all-season tires, to achieve an acceptable compromise between snow and wet / dry performance.

[0005] To improve braking performance, a chamfer can be applied on the rear edge of the tire block, which allows to increase the effective block surface on the ground with the deformation of the tire during braking. However, the chamfer can also reduce the traction of the tire on wet and dry ground.

[0006] Furthermore, since the block can be inclined with respect to the circumferential direction of the tire, the circumferential stress applied to the block generally varies over the axial extension of the block, which can cause an uneven distribution of the wear energy over the axial width of the tread.

[0007] Therefore, it would be desirable to provide a tire having improved braking performance while providing a more uniform distribution of wear energy. SUMMARY

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

[0009] According to various aspects of the present invention, a tire for a vehicle is provided, the tire including a tread. The tread includes a set of continuous blocks arranged along the circumference of the tire, and a plurality of first grooves arranged on the circumference of the tire, wherein each of the plurality of first grooves is arranged between two blocks in the set of continuous blocks. Each block in the set of continuous blocks includes a leading edge and a trailing edge. Each leading edge and trailing edge includes a first portion disposed at a shoulder area of ​​the tire, a second portion disposed at an axially inward position of the first portion, and a third portion disposed at an axially inward position of the second portion. Each block in the set of continuous blocks also includes a first chamfer disposed at at least one of the leading edge and the trailing edge. The first chamfer has a first average width in the first portion, a second average width in the second portion, and a third average width in the third portion. The first average width projected onto the circumferential direction of the tire corresponds to a first projected average width, the second average width projected onto the circumferential direction of the tire corresponds to a second projected average width, and the third average width projected onto the circumferential direction of the tire corresponds to a third projected average width. At least two of the first average projection width, the second average projection width, and the third average projection width are substantially equal.

[0010] Due to the chamfering, this type of tire allows for improved braking performance, especially on both wet and dry surfaces. Because the projected average chamfer width is substantially equal in at least two of the three portions of the corresponding edge, block deformation is reduced. In this way, the average chamfer width directly corresponds to the angle of inclination of the corresponding edge relative to the circumferential direction. That is, the portion that is more inclined relative to the circumferential direction has a smaller (non-projected) average chamfer width—sometimes referred to hereinafter as "smaller bead wrapping"—compared to the portion that is less inclined relative to the circumferential direction. Correspondingly, the portion that is less inclined relative to the circumferential direction is provided with a chamfer with a larger (non-projected) average width—sometimes referred to hereinafter as "wider chamfer."

[0011] Because the more circumferentially inclined portions typically experience higher circumferential stresses during normal tire rolling, these portions suffer the greatest excessive strain. Therefore, smaller chamfers should be applied here to locally increase the block stiffness and make the more circumferentially inclined portions better resistant to higher stresses. Portions less circumferentially inclined typically experience lower circumferential stresses and can therefore have wider chamfers, which benefits braking and steering performance.

[0012] In other words, providing a chamfer makes the projected average chamfer width of at least two of the three sections substantially equal, resulting in a more uniform response to stresses applied in the circumferential direction, and thus further resulting in a more uniform distribution of wear energy across the width of the tread. Attached Figure Description

[0013] Figure 1 A sketch of a vehicle tire according to this disclosure is shown.

[0014] Figure 2 The half-tread profile of a tire according to this disclosure is shown.

[0015] Figure 3 It shows Figure 2 A single block in a set of consecutive blocks.

[0016] Figures 4A to 4C It shows Figure 3 Three sections in different parts of the block.

[0017] Figure 5 A close-up view of an exemplary chamfer according to this disclosure is shown.

[0018] Figure 6 The tire tracks according to this disclosure are shown.

[0019] Figure 7 An exemplary embodiment of a V-shaped directional tread pattern according to the present disclosure is shown.

[0020] Figure 8 An exemplary embodiment of an S-shaped tread pattern according to the present disclosure is shown. Detailed Implementation

[0021] In order to overcome the disadvantages of the prior art as described above, it is desirable to provide a chamfer having a projected average width in three parts, wherein the projected average width is substantially constant in at least two of the three parts.

[0022] In the context of this disclosure, a "chamfer" refers to an inclined sidewall of a block extending radially inward from the surface of the outer block. The wall is inclined such that the width of the block, measured in the circumferential direction, increases toward the bottom of the groove. Each chamfer is defined by a height and a width. The chamfer height may correspond to the distance between the outer block surface and the radially innermost end of the inclined wall, measured in the radial direction. The height of the chamfer (= distance between the outer block surface and the radially innermost end of the inclined wall) is typically less than the total height of the block and may be, for example, at most 50% or less of the total height of the block. The width of the chamfer may be measured perpendicular to the block and corresponds to the width of the inclined chamfered wall when projected onto the outer tread surface. For clarity, this width is also referred to in this disclosure as the "(non-projected) chamfer width".

[0023] Tire tread blocks typically have portions with varying tilt angles along their axial extension. Due to the varying tilt angles, the circumferential stress applied to the portions of the blocks changes, causing portions of the block with a higher tilt angle relative to the circumferential direction to experience higher stresses than portions with a lower tilt angle relative to the circumferential direction.

[0024] Therefore, it is desirable to provide a chamfer on at least one edge of the block, the chamfer having a substantially equal projected average chamfer width in at least two of the three portions of the edge. This allows for improved braking performance by means of a larger chamfer in the more inclined portion of the edge, while also providing a more uniform and optimized wear condition, as wear energy is reduced particularly in the more inclined block portion (relative to the circumferential direction) that experiences the maximum circumferential stress.

[0025] In other words, this disclosure provides a synergistic effect between improved braking performance on the one hand and reduced and optimized wear energy on the other.

[0026] Figure 1 A sketch of a vehicle tire according to this disclosure is shown.

[0027] according to Figure 1 The tire 100 includes a tread 110. The tread includes a set of continuous blocks 10 and grooves 12, the grooves being arranged between two blocks 10 of the set of continuous blocks. In addition, sipes 14 may be arranged in each of the blocks of the set of continuous blocks 10.

[0028] The blocks can be arranged continuously along the circumferential direction of the tire at 120°.

[0029] A "groove" refers to a cut in the tread pattern. The width of a groove can vary; for example, a first groove can have a wider width than a second groove, or it can have the same or even smaller width. For example, the width of a groove can be at least 2 mm. The width of a single groove does not necessarily have to be constant: for example, a groove can have a wider opening toward the tread pattern and a smaller width in the radially inward direction. Furthermore, the depth of the groove can vary, and sometimes a groove can extend across the full tread depth (where the full tread depth is the maximum distance between the outermost radial portion of the tire and the bottom of the deepest groove, measured in the radial direction), but this is not always the case. For example, a depth of at least 1 mm, preferably at least 3 mm, is considered.

[0030] "Sipes" also refers to cuts in the tread pattern. As used herein, "sipes" refers to cuts within the tread blocks, not "grooves" that separate the blocks. For example, the width of a sipe can be less than the width of a groove, and for example, less than 2 mm. As with grooves, the width of a sipe does not necessarily have to be constant, and means that allow for a wider opening toward the tread pattern and a smaller width in the radially inward direction can be applied. Furthermore, the depth of a sipe can vary, and sometimes a sipe can extend to its full depth, but this is not always the case. For example, a depth of at least 1 mm is considered, preferably at least 20% of the depth of the first groove.

[0031] In the context of this disclosure, "circumferential direction" 120 refers to a direction perpendicular to the axial direction 130, which is parallel to the direction in which the tire normally rolls, i.e., parallel to the tangential direction relative to the circumference of the tire. Regarding Figure 1 The circumferential direction 120 is therefore a direction in a plane parallel to the yz plane.

[0032] In the context of this disclosure, "axial direction" 130 refers to a direction parallel to the axis of the vehicle on which the tires are normally mounted. Therefore, according to Figure 1 The axial direction 130 is parallel to the x-axis and therefore perpendicular to the yz plane.

[0033] In the context of this disclosure, "radial direction" 140 refers to a direction perpendicular to the axial direction. The radial direction is parallel to the connection between the tire center 150 and the tread surface. Therefore, 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.

[0034] In the context of this disclosure, "equatorial plane" refers to a plane perpendicular to the axial direction 130° that cuts the cross-sectional width of the tire into two equal halves. Therefore, the equatorial plane is parallel to the yz plane and corresponds to the centerline of the tread's width direction.

[0035] Furthermore, any numerical angles given in this paper should be considered absolute values, i.e., not limited to the orientation of the corresponding angle.

[0036] Figure 2 The half-tread profile of a tire according to this disclosure is shown.

[0037] according to Figure 2 The tread comprises a set of continuous blocks 10 arranged along the circumference of the tire. In the context of this disclosure, "continuous blocks" means that the tread comprises a plurality of blocks that follow each other continuously on the circumference of the tire. While it is preferred that all blocks for a tire are provided according to the invention of this disclosure, some blocks that may be arranged between the individual blocks 10 in a set of continuous blocks may not include the chamfer according to the invention.

[0038] Typically, block 10 serves to provide contact with the ground when the tire is rolling. The edges and surfaces of the block are configured to provide friction between the tire and the ground for grip, thereby allowing general road holding and vehicle motion control by the driver through acceleration, braking, or steering.

[0039] according to Figure 2 The tread also includes a plurality of first grooves 12 arranged on the circumference of the tire, wherein each of the plurality of first grooves 12 is arranged between two blocks 10 in the set of consecutive blocks. Preferably, the grooves 12 begin near the equatorial plane 16 of the tire and extend toward the shoulder end of the tread to open at the outer edge of the tire. The grooves 12 are generally defined by adjacent blocks 10.

[0040] The primary purpose of the grooves 12 is to guide water along the grooves towards the tire shoulder as the tire rolls on the ground and to spray the water out from there, thus expelling water from the contact patch. Therefore, the grooves 12 provide improved tire performance, especially under wet and slippery road conditions. Furthermore, since the grooves define continuous blocks, they also provide edges to the blocks to improve snow performance. In addition, the grooves allow for improved wear performance because they allow for greater flexibility of the tread elements, reducing block slippage on the ground and consequently reducing the wear effects that cause wear.

[0041] Figure 2 The tire may also include a second groove 250 that extends through each of the consecutive blocks 10 in the set, thereby connecting two consecutive first grooves 12. Providing such a second groove allows the portion of the block 10 near the tire shoulder to be decoupled from the more central portion. This allows for better braking performance, while also enhancing steering and lateral road holding, because the portion of the block 10 primarily involved in braking (i.e., the portion near the tire shoulder) is mechanically decoupled from the more central portion that primarily contributes to steering and lateral road holding.

[0042] like Figure 2As further shown, the tread may also include a plurality of sipes 14. In the illustrated tread pattern, each of the plurality of sipes 14 may preferably extend generally along the shape of each block in the set of continuous blocks 10. However, other arrangements and shapes of the sipes on the outer tread surface are also possible, such as wavy shapes, serrated shapes, etc. The 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 a block, or these sipes may have a different angle of inclination relative to the circumferential direction than the block or a portion of the block below. Furthermore, while some sipes may have walls extending radially toward the center of the tire, some sipes may also have wavy shapes, serrated shapes, etc., in the radial direction. In addition, such sipes may also be inclined relative to the radial direction. Some sipes may include protrusions near the bottom of the sipe.

[0043] The sipes 14 trap snow within them and provide additional edges to the tread. This improves traction on snow-covered surfaces.

[0044] In some embodiments, the plurality of sipes 14 may define an edge component (EI) corresponding to the ratio between the sum of the projected lengths (SAP) of the plurality of sipes in the axial direction and the circumference (C) of the tread, such that

[0045]

[0046] The EI is at least 2 and at most 20. Preferably, the EI can be at least 2 and at most 16, more preferably at least 2 and at most 15.

[0047] The tire circumference C is measured at the outermost radial circumference of the tire when inflated. The same specifications as those described below for tire track measurement apply to inflation pressure and ambient temperature.

[0048] A high edge composition provides better snow-trapping capability, which improves tire traction on snow-covered surfaces. However, a high edge composition also results in lower block stiffness, which generally degrades braking / acceleration performance on dry surfaces. Edge compositions within one of the aforementioned ranges offer a particularly good trade-off between traction on snow-covered surfaces and braking / acceleration performance on dry surfaces.

[0049] In some implementation schemes, according to Figure 2 Tires can also have a void volume, which is the volume of all the grooves, sipes, and recesses in the tread, as well as the volume of the rubber contained in the tread, which together constitute the total volume of the tread. That is, if the total volume of the tire is V... T The void volume is V V The volume of the rubber is VR Then the total volume V T Will be V T =V V +V R In a preferred embodiment, the void volume V V With rubber volume V R The ratio between V V / V R It can be at least 0.20 and at most 0.40. Preferably, the ratio V V / V R It can be at least 0.24 and at most 0.37, more preferably at least 0.28 and at most 0.35.

[0050] Ratio V V / VR It is directly related to the stiffness of the tread profile. Therefore, a higher ratio V V / V R This indicates a higher amount of voids in the tread, which results in lower tread stiffness and is therefore beneficial for snow performance. A lower ratio V V / V R A higher amount of rubber in the tread results in higher stiffness and thus improved braking performance. A specific range of void-to-rubber ratios offers an optimal trade-off between performance on snow and dry surfaces, providing a tire that exhibits good braking performance on dry surfaces and good traction on snow-covered surfaces.

[0051] Figure 3 It shows Figure 2 A single block in a set of consecutive blocks.

[0052] according to Figure 3 Block 10 includes a leading edge 20 and a trailing edge 30.

[0053] In the context of this disclosure, "leading edge" (sometimes also referred to as "traction edge") refers to the edge of the block that primarily responds to longitudinal traction when it is applied to the tire. Typically, the "leading edge" is the edge of the block whose length is greater than the lateral edge of the block, and the leading edge first contacts the ground when the block of the tire, rolling in the preferred rolling direction, enters the tire-ground contact imprint.

[0054] The "tailing edge," sometimes referred to as the "braking edge," is the edge of the block that primarily responds to longitudinal braking force when it is applied to the tire. Typically, the "tailing edge" is the edge of the block whose length is greater than the lateral edge of the block, and it is the last edge that loses contact with the ground when the block of the tire, rolling in the preferred rolling direction, leaves the tire-ground contact imprint.

[0055] The leading edge 20 includes a first portion 22 disposed in the shoulder area of ​​the tire, a second portion 24 disposed axially inside the first portion 22, and a third portion 26 disposed axially inside the second portion 24. The trailing edge 30 includes a first portion 32 disposed in the shoulder area of ​​the tire, a second portion 34 disposed axially inside the first portion 32, and a third portion 36 disposed axially inside the second portion 34.

[0056] The first portions 22 and 32 of the leading edge 20 and the trailing edge 30 can be referred to as the "shoulder portion", the second portions 24 and 34 of the leading edge 20 and the trailing edge 30 can be referred to as the "middle portion", and the third portions 26 and 36 of the leading edge 20 and the trailing edge 30 can be referred to as the "central portion". The central portion can be arranged adjacent to the equatorial plane 16 of the tire.

[0057] like Figure 3 As shown, the axial extensions of the corresponding edge portions can differ between the edges, i.e., as... Figure 3 As shown, the second portion 34 of the trailing edge 30 may have a larger axial extension than the corresponding second portion 24 of the leading edge 20. Typically, the third portions 26, 36 of the leading edge 20 and the trailing edge 30 may have an axial extension of at least 25% and at most 40% of the tire's half-track width. Therefore, 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 tire's half-track width.

[0058] The second portions 24, 34 of the leading edge 20 and the trailing edge 30 may have an axial extension of at least 25% and at most 55% of the tire's half-track width. Therefore, the second portions 24, 34 preferably begin at the axially outward end of the third portions 26, 36 and extend axially outward to a width of 65% to 80% of the tire's half-track width.

[0059] The first portions 22, 32 of the leading edge 20 and the trailing edge 30 may have an axial extension of at least 20% and at most 35% of the half-imprint width of the tire. Therefore, the first portions 22, 32 preferably begin at the axially outward end of the second portions 24, 34 and extend axially outward to the axially outward end of the tire, that is, covering the total portion of the axially outward half-imprint width from the second portions 24, 34.

[0060] In some implementations, the spacing between the two portions of the leading and trailing edges can be defined by any of the following:

[0061] - A recess in the corresponding edge between adjacent portions;

[0062] - The change in the tilt angle of the corresponding edge relative to the circumferential direction of the tire;

[0063] - The direction or magnitude of the curvature of the corresponding edge;

[0064] - Gradually increase or decrease the chamfer width;

[0065] - A groove extending through the block in a generally circumferential direction; or

[0066] - Their combination.

[0067] For example, such as Figure 3 As shown, 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.

[0068] Alternatively, other means of separation between the edge portions are possible. For example, such as... Figure 3 As shown, the groove 250 extending through block 10 in a generally circumferential direction can separate the first portions 22, 32 from the second portions 24, 34. Although only in Figure 3 The diagram shows a groove used to separate the first portions 22, 32 from the second portions 24, 34, but similar grooves can also be arranged between the second portions 24, 34 and the third portions 26, 36.

[0069] Furthermore, despite Figure 3 Only recesses 222, 224, 322, 324 and groove 250 are shown as means of separating adjacent edge portions, but other means, such as gradually increasing or decreasing the chamfer width, can be used.

[0070] Alternatively, the direction or magnitude of the curvature of the corresponding edge can be used to separate two adjacent edge portions, i.e., the change between concave and convex curvature and the increase or decrease of the curvature of the edge.

[0071] In addition, the tilt angle of the corresponding block relative to the circumferential direction of the tire can be used to determine the spacing between the edge portions.

[0072] According to one method, the inclination angle of a corresponding portion of an edge is determined by (i) the angle between a tangent applied to the corresponding edge of the block and (ii) the circumferential direction of the tire. If the corresponding portion of the edge includes a chamfer, the tangent is applied at the outermost circumferential end of the block (so that the width and shape of the chamfer are ignored). This method can be used if the corresponding portions of the edge are formed continuously or nearly continuously, i.e., without any substantial circumferential cuts in between, and exhibit a discontinuity, such as a significant change, in their inclination relative to the circumferential direction of the tire on the corresponding edge. This discontinuity then corresponds to the interval between adjacent edge portions.

[0073] Preferably, the tilt angle of the first portions 22 and 32 (i.e., the tilt angle of the tangent on the corresponding portion of the edge relative to the circumferential direction) can be at least 65° and at most 90° relative to the circumferential direction, preferably 75° and at most 90°, and more preferably at least 85° and at most 90° relative to the circumferential direction. The tilt angle of the second portions 24 and 34 relative to the circumferential direction can be at least 50° and at most 65°. Preferably, the tilt angle of the second portions 24 and 34 relative to the circumferential direction can be at least 50° and at most 60°. The tilt angle of the third portions 26 and 36 relative to the circumferential direction can be at least 20° and at most 50°. Preferably, the tilt angle of the third portions 26 and 36 relative to the circumferential direction can be at least 30° and at most 50°.

[0074] According to another method, if the inclination of the corresponding edge relative to the circumferential direction of the tire does not show any discontinuity, the method can be used, wherein the spacing between the edge portions is preferably based on the combination as described above. Figure 3 The axial extension of the imprint width, the recess in the corresponding edge, the curvature direction or magnitude of the corresponding edge, the gradual increase or decrease of the chamfer width, or the groove extending through the block in the generally circumferential direction are used to determine this.

[0075] More preferably, in this method, in addition to one or more of the criteria described above, a tilt angle may also be used. For example, the third portions 26, 36 (for at least one possible extension within this range) starting from the equatorial plane adjacent to the tire and extending axially outward to a width of 25% to 40% of the tire's half-track width, exhibit a tilt angle of at least 20° and at most 50° relative to the circumferential direction, preferably at least 30° and at most 50° relative to the circumferential direction. Similarly, the second portions 24, 34, starting from the axially outer end of the third portion and extending axially outward to a width of 65% to 80% of the tire's half-track width, exhibit a tilt angle of at least 50° and at most 65° relative to the circumferential direction, preferably at least 50° and at most 60°. Similarly, the first portions 22, 32, starting from the outer axial end of the second portion and extending axially outward to the outer axial end of the tire, exhibit an inclination angle of at least 65° and at most 90° relative to the circumferential direction, preferably 75° and at most 90° relative to the circumferential direction, and more preferably at least 85° and at most 90° relative to the circumferential direction.

[0076] Furthermore, combinations of possible methods for separating edge portions are possible. As an example, Figure 3 The combination of recesses 224, 324 and grooves 250 for separation between the first portions 22, 32 and the second portions 24, 34 is shown, and further conceivable combinations exist.

[0077] according to Figure 3 Block 10 also includes a first chamfer 25. Preferably, the first chamfer 25 may be located at the leading edge 20. However, the first chamfer may also be located at the trailing edge 30, as shown by the second chamfer 35. In some embodiments, the block may include a first chamfer 25 located at the leading edge 20 and a second chamfer 35 located at the trailing edge 30.

[0078] The first chamfer 25 has a first average width in the first part, a second average width in the second part, and a third average width in the third part.

[0079] The width of a chamfer refers to the width measured perpendicular to the edge of the corresponding block, as described above. The average width of the chamfers in a section can be defined by measuring the width of the corresponding chamfer at multiple points within that section along the corresponding edge and dividing by the number of points. Mathematically, the average width of the chamfers in a section... The chamfer width can be calculated by integrating over the total length of the corresponding section and dividing the integral by the length of the corresponding section:

[0080]

[0081] Where L is the total length of the corresponding edge portion. It is the length of the infinitesimal element of the corresponding edge portion, and It is the chamfer width at that location on the corresponding edge portion. .

[0082] Figure 4A to 4C Three cutting lines, CS1, CS2 and CS3, are also shown. Figure 3 It shows Figures 4A to 4C Three sections in different parts of the block.

[0083] like Figure 4A As shown, block 10 can include chamfers of different widths in different parts.

[0084] Figure 4A A cross-sectional view of block 10 cut along line CS1 is shown. Therefore, Figure 4A A first chamfer 25 is shown in the first portion 22 of the leading edge 20 of block 10, and a second chamfer 35 is shown in the first portion 32 of the trailing edge 30 of block 10. As described above, the chamfer width is measured perpendicular to the block tangent. Figure 4B The first average width 212 of the first chamfer 25 in the first portion 22 of the leading edge 20 and the fourth average width 312 of the second chamfer 35 in the first portion 32 of the trailing edge 30 are shown.

[0085] Figure 4B A cross-sectional view of block 10 cut along line CS2 is shown. Therefore, Figure 4B A first chamfer 25 is shown in the second portion 24 of the leading edge 20 of block 10, and a second chamfer 35 is shown in the second portion 34 of the trailing edge 30 of block 10. Figure 4C The second average width 214 of the first chamfer 25 in the second portion 24 of the leading edge 20 and the fifth average width 314 of the second chamfer 35 in the second portion 34 of the trailing edge 30 are shown.

[0086] Figure 4C A cross-sectional view of block 10 cut along line CS3 is shown. Therefore, Figure 4C A first chamfer 25 is shown in the third portion 26 of the leading edge 20 of block 10, and a second chamfer 35 is shown in the third portion 36 of the trailing edge 30 of block 10. Figures 4A to 4C The third average width 216 of the first chamfer 25 in the third portion 26 of the leading edge 20 and the sixth average width 316 of the second chamfer 35 in the second portion 34 of the trailing edge 30 are shown.

[0087] The widths of the first chamfer 25 and the second chamfer 35 can vary within specific portions. For example, the first chamfer 25 may have a first width in a first position within the first portion 22 of the leading edge 20, and a second width different from the first width in a second position within the first portion 22 of the leading edge 20. The same applies to the second chamfer 35.

[0088] Therefore, as mentioned above, the average width of the chamfer can be calculated for each section. For simplicity, Figure 3 The cross-sectional view shown illustrates Figure 5 Three sections in different parts of the block are considered to show the sections at the locations where the chamfer locally has a corresponding average width in the respective parts.

[0089] The projected chamfer width usually corresponds to

[0090]

[0091] in, It is the tilt angle of the corresponding edge relative to the circumferential direction of the tire at the position of the corresponding edge portion. .

[0092] The first average width projected onto the tire in the circumferential direction corresponds to the first average projection width, the second average width projected onto the tire in the circumferential direction corresponds to the second average projection width, and the third average width projected onto the tire in the circumferential direction corresponds to the third average projection width.

[0093] If the chamfer width and tilt angle In some If the width is constant, then the average width of the projection is... It can be calculated as

[0094]

[0095] in, It is the tilt angle of the corresponding edge relative to the circumferential direction of the tire;

[0096] In cases where the corresponding edge can be curved ( depending on ), or in the case where the chamfer width varies on the extension of the corresponding edge portion ( depending on The average width of the projection can be calculated as (according to equation (2)).

[0097]

[0098] Where L is the total length of the corresponding edge portion. It is the length of the infinitesimal element of the corresponding edge portion. It is the position of the corresponding edge part. The width of the chamfer at that location, and The corresponding edge is in position The angle of inclination relative to the circumferential direction.

[0099] Figure 5 A close-up view of an exemplary chamfer according to this disclosure is shown.

[0100] For simplicity, Figure 5 The block itself is not shown. However, it will be understood that a chamfer is applied to the edges of the block. Figure 5 The reference marks used correspond to the reference marks used with respect to the first chamfer 25 on the leading edge 20. However, it should be understood that, regarding Figure 5 The same quantities described can also be applied to the second chamfer 35 on the trailing edge 30.

[0101] In addition, for the sake of simplicity, Figure 5 The chamfer shown is assumed to have a constant width in each individual section, and the angle of inclination is constant in each individual section.

[0102] The chamfer 25 in the first portion 22 of the leading edge 20 may have a first average width 212 ( In the second portion 24 of the leading edge 20, the chamfer 25 may have a second average width 214. In the third portion 26 of the leading edge 20, the chamfer 25 may have a third width 216. Preferably, the angle of inclination relative to the circumferential direction (i.e., relative to the equatorial plane 16) may vary among the portions 22, 24, and 26. In some examples, the first portion 22 of the leading edge may be inclined close to the equatorial plane 16. Then, the average width of the first projection is 222 ( ) can be calculated according to equation (4) as

[0103]

[0104] That is, if the corresponding edge portion has a 90° tilt angle relative to the equatorial plane, then the average width is equal to the average width of the projection.

[0105] Similarly, chamfer 25 may have a second average width 214 in the second portion 24 of the leading edge 20. In the second part 24, the leading edge 20 may be tilted at an angle relative to the equatorial plane 16. This angle can be smaller than Therefore, the average width of the second projection is 224 ( ), or it can be calculated using equation (4) as

[0106]

[0107] Furthermore, the chamfer 25 may have a third average width 216 in the third portion 26 of the leading edge 20. In Part 3, Section 26, the leading edge 20 may be tilted at an angle relative to the equatorial plane 16. This angle can be smaller than Therefore, the average width of the third projection is 226 ( It can also be calculated using equation (4) as follows.

[0108]

[0109] according to Figure 5 The average width of the first projection is 222 ( The average width of the second projection is 224 ( ), and the average width of the third projection is 226 ( At least two of the projections are substantially equal. Preferably, the average widths of all three projections, 222, 224, and 226, can be substantially equal. Figure 5 In the example shown, this can be achieved by providing a chamfer with a larger average width for the block portion that is less inclined relative to the equatorial plane 16.

[0110] For example, the third average width 216 of the first chamfer 25 in the third part 26 may be higher than the second average width 214 of the first chamfer 25 in the second part 24. Furthermore, the second average width 214 of the first chamfer 25 in the second part 24 may be higher than the first average width 212 of the first chamfer 25 in the first part 22.

[0111] As described above, since the average chamfer width directly corresponds to the inclination angle of the corresponding edge relative to the circumferential direction, this arrangement provides improved braking and traction performance, as well as reduced and more evenly distributed wear energy across the width of the tread. Therefore, it effectively compensates for the stress experienced on different parts of the tire block.

[0112] In some embodiments, a first chamfer 25 may be positioned at the leading edge 20 of the block 10. Chamfers at the leading edge have proven effective in improving traction, particularly on snow-covered surfaces. Generally, to increase traction on snow-covered surfaces, the surface area of ​​the block should be reduced to allow for increased contact pressure between the block surface and the ground. Providing a chamfer at the leading edge has been shown to be a good location for reducing the surface area of ​​the block. The increased contact pressure provided by the chamfer at the leading edge, particularly resulting in a peak contact pressure at the leading edge of the block, allows the block, especially its leading edge, to dig more effectively into the snow, thereby increasing tire traction on snow-covered surfaces. Therefore, providing this arrangement at the leading edge particularly improves traction.

[0113] In some embodiments, block 10 may further include a second chamfer 35 disposed at the rear edge 30 of block 10. The chamfer on the rear edge contributes to dry braking performance. When a vehicle brakes, the tread blocks deform and bend due to the inertia of the vehicle's mass. This causes some of the rubber surfaces facing the leading edge of the block to lose contact with the road surface, thereby reducing the contact surface of each block. The reduced contact surface results in reduced friction, which thus impairs the braking performance of the tire. By providing a chamfer on the rear edge, during braking, as the block bends, the inclined surface of the chamfer is pushed towards the ground, thereby increasing the rubber surface in contact with the ground. This compensates for the surface loss at the leading edge of the block, and the increased contact area leads to better braking performance due to the increased friction. Therefore, the chamfer on the rear edge of the block contributes to both dry and wet braking performance.

[0114] The second chamfer 35 may have a fourth average width 312 in the first portion 32 of the trailing edge 30, a fifth average width 314 in the second portion 34 of the trailing edge 30, and a sixth average width 316 in the third portion 36 of the trailing edge 30. Similarly, the fourth average width 312 projected onto the circumferential direction of the tire may correspond to a fourth projected average width, the fifth average width 314 projected onto the circumferential direction of the tire may correspond to a fifth projected average width, and the sixth average width 316 projected onto the circumferential direction of the tire may correspond to a sixth projected average width. At least two of the fourth, fifth, and sixth projected average widths may be substantially equal.

[0115] The average width of the projection of the second chamfer 35 can be compared with the reference. Figure 6 The average projection widths 222, 224, and 226 are determined in the same manner as those described.

[0116] Preferably, the average width of the fourth projection, the average width of the fifth projection, and the average width of the sixth projection can be substantially equal.

[0117] In this case, the fourth average width 316 of the second chamfer 35 in the third part 36 may be higher than the second average width 314 of the second chamfer 35 in the second part 34. Furthermore, the second average width 314 of the second chamfer 35 in the second part 34 may be higher than the first average width 312 of the second chamfer 35 in the first part 32.

[0118] This arrangement provides even improved braking and traction performance, as well as further reduced and more evenly distributed wear energy across the tread width.

[0119] In some implementations, at least one of the first projected average width 222, the second projected average width 224, and the third projected average width 226 may be at least 1 mm and at most 3.5 mm, preferably at least 1 mm and at most 2 mm. The projected average width is related to the chamfer width. Within the provided range, they ensure an optimal balance between dry abrasion, wet abrasion, and snow performance.

[0120] While the above implementation involves blocks with three parts, blocks with more parts (e.g., four or more parts) are also possible. This can be achieved, for example, through sub-segmentation, i.e., dividing a part into one or more consecutively formed sub-parts.

[0121] Figure 6 The tire tracks according to this disclosure are shown.

[0122] The process for measuring tire tracks according to this disclosure is described elsewhere in this document.

[0123] Figure 6 The imprint shown depicts a series of blocks 10 and grooves 12 between these blocks. The gaps between the blocks are formed by the grooves 12 and chamfers 25 and 35 that may be located on the leading edge 20 and / or the trailing edge 30.

[0124] according to Figure 6 The imprint may include the imprint width W, measured in the axial direction, at the widest axial extension of the imprint. According to Figure 6 The imprint may also include a central region C that accounts for 80% of the width of the imprint, the central region having two outer edges arranged at opposite axial ends of the central region.

[0125] according to Figure 7 The imprint may also include two external lengths measured in the circumferential direction at the outer edge of the central region C. and Therefore, an imprint can have an average imprint length, corresponding to the average of the two external lengths:

[0126]

[0127] Therefore, tire imprint ratio It can be defined as the average imprint length The ratio between the tire track width W and the tire track width W. In some embodiments, the tire track ratio can be at least 0.6 and at most 1.0. Preferably, the tire track ratio can be at least 0.7 and at most 0.9.

[0128] Tire track ratio can be considered a measure of the "roundness" of the track – a lower tire track ratio suggests a more rounded track, while a higher tire track ratio suggests a more rectangular track. Therefore, tire track ratio indicates the effect of traction / braking force on the track, especially in the area near the tire shoulder.

[0129] A more rectangular tire track can result in higher stress applied to the shoulder and center sections, especially during braking. Therefore, the tire track ratio can be associated with the preferred choice of chamfer width, as a larger chamfer width is more beneficial for braking performance on a more rectangular track, while the opposite applies to a more rounded track.

[0130] Figure 7 An exemplary embodiment of a V-shaped directional tread pattern according to the present disclosure is shown.

[0131] according to Figure 7 Some embodiments of the tread may include a second set of continuous blocks 50, which typically corresponds to a first set of continuous blocks 10, arranged on opposite sides of the tire's equatorial plane 16. In some embodiments, such as Figure 8 As shown, the second set of continuous blocks 50 can be arranged symmetrically with respect to the first set of blocks 10, thereby creating a V-shaped tread pattern with a preferred rolling direction. The V-shape provides the advantage of improved water drainage performance because when the tire rolls in the preferred rolling direction, water can be expelled from the contact patch by means of two opposing first grooves in opposite axial directions of the tread. Therefore, traction on wet roads can be improved. While a directional tread pattern with a preferred rolling direction is advantageous for wet road surfaces, other embodiments are also possible.

[0132] For example, Figure 8 Exemplary embodiments of an S-shaped tread pattern according to this disclosure are shown. For some embodiments, according to Tire footprint measurement In addition to the first set of continuous blocks 10, the tread may also include a second set of continuous blocks 50. The second set of continuous blocks 50 may be arranged on opposite sides of the equatorial plane 16 of the tire. Compared with the above embodiment including a V-shaped tread pattern, the second set of continuous blocks 50 may be arranged to be symmetrical with respect to the first set of blocks 10, thereby producing an S-shaped tread pattern that does not have a preferred rolling direction.

[0133] Tire void volume and rubber volume measurement

[0134] In the context of this disclosure, "tire track" refers to all the portions of a tire that are in contact with the ground when the tire is inflated and under load. Tire tracks provide information about the behavior of the tread profile under normal conditions; that is, the tire tracks indicate which portions of the block are in contact with the ground under static load conditions.

[0135] When analyzing tire tracks, the corresponding tire is typically inflated, with the pressure depending on the tire type. For standard radial passenger tires with a nominal section width of 195 mm or less, a tire pressure of 1.9 bar is used. For standard radial passenger tires with a nominal section width of 205 mm or more, a tire pressure of 2.0 bar is used. For reinforced radial passenger tires of all sizes, a pressure of 2.3 bar is used. For tires for commercial vans, trucks, etc., standardized inflation pressures according to the European Tire and Rim Technology Organization (ETRTO) are used. All measurements are performed at room temperature.

[0136] The tires were then loaded under the following conditions: for radial passenger tires, a load corresponding to 88% of the tire load index according to ETRTO specifications was applied. For tires used in commercial vans, trucks, etc., a load corresponding to the ETRTO single load rating was applied. For measurement, ink was applied to the tire tread profile, and the tire was then pushed against a card according to the aforementioned specifications, leaving an ink imprint, which could then be analyzed. The imprint was evaluated on three tire sections at 120° intervals around the tire circumference. The measurements analyzed in the imprint were then averaged across the three measurement sections.

[0137] List of Figures

[0138] In the context of this application, tire void volume is also measured under tread conditions. That is, the tire is inflated in the same manner as described above regarding tire tread measurement. The void volume is measured by a laser measurement system capable of detecting the relative depth of each pixel relative to the tread surface. Thus, by integrating all measured pixels, the total void volume in the contact tread can be calculated. The total tread volume can be calculated as the product of the tire's tread width (FW) and circumference (C) multiplied by the weighted average depth of the first groove. The total rubber volume is the difference between the total tread volume and the total void volume.

[0139] The measurements given in this disclosure are taken under tread conditions and on new tires that have not been exposed to wear prior to the measurements.

[0140] ​

[0141]

Claims

1. A tire for a vehicle, the tire comprising a tread, the tread comprising: A set of continuous blocks arranged along the circumference of the tire; and A plurality of first grooves are arranged on the circumference of the tire, wherein each of the plurality of first grooves is arranged between two blocks in a set of consecutive blocks; Each block in the set of consecutive blocks includes: Leading edge and trailing edge; Each leading edge and trailing edge includes a first portion disposed at the shoulder area of ​​the tire, a second portion disposed at an axially inner position of the first portion, and a third portion disposed at an axially inner position of the second portion. A first chamfer, wherein the first chamfer is disposed at least at one of the leading edge and the trailing edge. The first chamfer has a first average width in the first part, a second average width in the second part, and a third average width in the third part; The first average width projected onto the tire in the circumferential direction corresponds to a first average projection width, the second average width projected onto the tire in the circumferential direction corresponds to a second average projection width, and the third average width projected onto the tire in the circumferential direction corresponds to a third average projection width. Wherein at least two of the first average projection width, the second average projection width, and the third average projection width are substantially equal.

2. The tire according to claim 1, wherein the first average projected width, the second average projected width, and the third average projected width are substantially equal.

3. The tire according to any one of the preceding claims, wherein at least one of the first projected average width, the second projected average width and the third projected average width is at least 1 mm and at most 3.5 mm.

4. The tire according to any one of the preceding claims, wherein the third average width of the first chamfer in the third portion is greater than the second average width of the first chamfer in the second portion.

5. The tire according to any one of the preceding claims, wherein the second average width of the first chamfer in the second portion is greater than the first average width of the first chamfer in the first portion.

6. The tire according to any one of the preceding claims, wherein the first chamfer is disposed on the leading edge of the block.

7. The tire of claim 6, further comprising a second chamfer disposed on the trailing edge of the block.

8. The tire of claim 7, wherein the second chamfer has a fourth average width in the first portion of the trailing edge, a fifth average width in the second portion of the trailing edge, and a sixth average width in the third portion of the trailing edge; The fourth average width projected onto the tire in the circumferential direction corresponds to the fourth average projection width, the fifth average width projected onto the tire in the circumferential direction corresponds to the fifth average projection width, and the sixth average width projected onto the tire in the circumferential direction corresponds to the sixth average projection width. Wherein, at least two of the fourth average projection width, the fifth average projection width, and the sixth average projection width are substantially equal.

9. The tire according to claim 8, wherein the fourth average projected width, the fifth average projected width, and the sixth average projected width are substantially equal.

10. The tire according to any one of the preceding claims, wherein the tire defines an imprint area when in contact with the road under normal conditions, the imprint area comprising: Imprint width, which is measured in the axial direction at the widest axial extension of the imprint, and A central region, which occupies 80% of the imprint width, has two outer edges arranged at opposite axial ends of the central region; Two external lengths, which are measured in the circumferential direction at the outer edge of the central region; Average footprint length, which corresponds to the average of the two external lengths; and The tire track ratio is defined as the ratio between the average track length and the track width, and the tire track ratio is at least 0.6 and at most 1.

0.

11. The tire according to any one of the preceding claims, wherein The third portion of the leading edge or the trailing edge has an axial extension of at least 25% and at most 40% of the half-track width of the tire. The second portion of the leading or trailing edge has an axial extension of at least 25% and at most 55% of the half-track width of the tire, and The first portion of the leading or trailing edge has an axial extension of at least 20% and at most 35% of the half-imprint width of the tire.

12. The tire according to any one of the preceding claims, wherein the interval between the two portions of said leading edge and said trailing edge is defined by any one of the following: Recesses in the corresponding edges between adjacent portions; The change in the tilt angle of the corresponding edge relative to the circumferential direction of the tire; The direction or magnitude of the curvature of the corresponding edge; Gradually increase or decrease the chamfer width; A groove extending through the block in a generally circumferential direction; or Their combination.

13. The tire according to any one of the preceding claims, the tire further comprising a second groove extending through each of the set of consecutive blocks, thereby connecting two consecutive first grooves.

14. The tire according to any one of the preceding claims, wherein the tread further comprises: Multiple sipes define an edge component EI, the EI corresponding to the ratio between the sum of the projected lengths SAP of the multiple sipes in the axial direction and the circumference C of the tread, such that... The EI is at least 2 and at most 20.

15. The tire according to any one of the preceding claims, wherein the ratio between the void volume and the rubber volume is at least 0.20 and at most 0.40, and preferably at least 0.28 and at most 0.35.

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