Truck tires with higher hysteresis in the shoulder rib than in the center rib

Abstract

A heavy-duty truck tire (10) is provided having a first shoulder rib (44) made of a first material (40) located radially outside a third material (60). A first intermediate rib (46) and the first shoulder rib (44) define a first shoulder groove (48) having an outer sidewall (52) extending radially deeper into the tread than the first material (40) of the first shoulder rib (44). A center rib (42) is present and is made of a second material (50) located radially outside the third material (60). A first maximum tan(6) of the first material (40) is greater than a second maximum tan(6) of the second material (50). The first maximum tan(6) is 0.15 to 0.20, the second maximum tan(6) is 0.05 to 0.15, and the third maximum tan(6) is 0.05 to 0.15.

Description

Technical Field

[0001] The subject of this invention relates to a truck tire having a tread design that reduces tire rolling resistance while maintaining desired irregular wear performance. More specifically, this application relates to a tread characterized by having highly hysteretic shoulder ribs to prevent irregular wear in tread areas more susceptible to irregular wear, and having a less hysteretic center rib to minimize rolling resistance in tire areas less sensitive to irregular wear. Background Technology

[0002] Heavy-duty commercial vehicle tire manufacturers have made significant strides in developing tire architecture and materials, enabling them to improve tread wear resistance and reduce rolling resistance while simultaneously enhancing grip and resistance to road hazards. One challenge facing heavy-duty commercial vehicle tires is irregular tread wear. Irregular tread wear (also known as "uneven wear" or "abnormal wear") is a major concern for heavy-duty commercial vehicle tires because it gradually causes tire vibrations that the driver can perceive through the steering wheel. Wear can also lead to unsightly wear patterns. Both of these undesirable effects often result in tire failure at an early stage of their wear life. Generally, the more a tire is used with slow wear, the greater the impact of irregular wear on mileage.

[0003] Tires with good resistance to irregular wear set them apart from consumers because they are more likely to remain on the road and have higher mileage. Such tires should perform well in their expected performance characteristics, such as rolling resistance, but they should also perform well without compromising other performance characteristics, such as wear and irregular wear. This disclosure seeks to provide such heavy-duty commercial vehicle tires. Attached Figure Description

[0004] Referring to the accompanying drawings, the complete and feasible disclosure of the invention for those skilled in the art, including its best mode, is set forth in the specification, wherein:

[0005] Figure 1 This is a perspective view of a heavy-duty truck tire according to an exemplary embodiment.

[0006] Figure 2 This is a top view of a portion of the tire tread according to another exemplary embodiment.

[0007] Figure 3 This is a cross-sectional view of a tire according to another exemplary embodiment, wherein the first shoulder rib and the first intermediate rib are made of materials with different hysteresis.

[0008] Figure 4This is a cross-sectional view of a tire according to another exemplary embodiment, wherein the electrostatic discharge element is located in the central rib.

[0009] Figure 5 It is a cross-sectional view of the tread according to another exemplary embodiment, wherein the first shoulder rib and the first intermediate rib have the same hysteretic material.

[0010] The same or similar reference numerals are used in different accompanying drawings to represent the same or similar features. Detailed Implementation

[0011] Reference will now be made in detail to embodiments of the invention, with one or more examples of embodiments illustrated in the accompanying drawings. Each example is provided to illustrate the invention and is not intended to limit the invention. For example, features illustrated or described as part of one embodiment may be used with another embodiment to obtain a third embodiment. The invention is intended to include these and other modifications and variations.

[0012] This invention provides a design for a heavy-duty truck tire 10 that offers a trade-off between irregular wear and rolling resistance. The shoulder region of the tread 16 is the most sensitive area to irregular wear; therefore, the design places a higher hysteresis material in the shoulder region to minimize, reduce, or eliminate irregular wear in this area. Other areas of the tread 16 less susceptible to irregular wear (such as the center of the tread 16) are provided with a lower hysteresis material, resulting in better rolling resistance characteristics in these areas, thus producing an overall tire 10 with similarly good rolling resistance performance. The intermediate regions of the tread 16, i.e., those regions between the shoulder region and the center region, may include a higher hysteresis mixture to reduce irregular wear in these areas. In other embodiments, the intermediate regions of the tread 16 are provided with a lower hysteresis mixture, improving rolling resistance performance in this region and resulting in an overall improvement in the rolling resistance of the tire 10.

[0013] Figure 1A tire 10 is shown, which is a heavy-duty truck tire 10. At this point, tire 10 is not designed for use with or on automobiles, motorcycles, or light trucks (with a payload capacity of less than 4,000 pounds), but rather for use with and on heavy-duty trucks such as 18-wheelers, garbage trucks, fire trucks, school buses, or box trucks. Tire 10 can be a steering tire, drive tire, trailer tire, or all-position tire. Tire 10 includes a carcass / body 76 on which a tread 16 is disposed. The central axis 14 of tire 10 extends through the center of the carcass 76, and the lateral / axial direction 28 of tire 10 is parallel to the central axis 14. The radial direction 24 (also referred to as the thickness direction 24) of tire 10 is perpendicular to the central axis 14, and the tread 16 is positioned further away from the central axis 14 in the thickness direction 24 than the carcass 76. The tread 16 extends fully around the carcass 76 in the circumferential direction 26 of tire 10 and surrounds the central axis 360 degrees.

[0014] The tread 16 is characterized by five ribs 30, 32, 42, 44, and 46, which are separated by four longitudinal grooves 34, 56, 58, and 48 extending in the circumferential direction 26, and all these features extend 360 degrees around the central axis 14. Shoulder ribs 30 and 44 are the outermost ribs of the tread 16 in the axial direction 28 and are located at the edge of the rolling tread width of the tread 16. Ribs 30, 32, 42, 44, and 46 may each be composed of a plurality of tread blocks 60, which may have various shapes, sizes, and configurations. Although five ribs and four longitudinal grooves are shown, any number of ribs and grooves may be present in other exemplary embodiments. Reference Figure 2 Another embodiment of the tread 16 is shown, in which five ribs 30, 32, 42, 44, 46 and four longitudinal grooves 34, 56, 58, 48 are also present; however, the construction of these elements is different from... Figure 1 The implementation schemes differ in that ribs 30, 32, 42, 44, and 46 do not have tread blocks, and shoulder ribs 30 and 44 are not the two outermost features of the tread 16 in the lateral direction 28. A first sacrificial rib 62 is located near the first shoulder rib 30, and a second sacrificial rib 64 is located near the second shoulder rib 44; these sacrificial ribs 62 and 64 are tread elements located at the edges of the tread 16 in the lateral direction 28. The first sacrificial rib 62 separates from the first shoulder rib 30 into a first space 124, and the second sacrificial rib 64 separates from the second shoulder rib 44 into a second space 126. Spaces 124 and 126 may have a width of less than 2 mm, but in other implementations, the width of spaces 124 and 126 is 2 mm or greater.

[0015] When tire 10 is new, sacrificial ribs 62 and 64 may have an outer radius smaller than that of adjacent shoulder ribs 30 and 44 and be located within the width of the rolling tread. Furthermore, when tire 10 is new, the sacrificial rib contacts the ground, and when tire 10 is worn, the sacrificial rib may also contact the ground.

[0016] The tread 16 includes a micro-groove pattern 122, which is closed and extends from grooves 34, 56, 58, 48 and from the first space 124 and the second space 126 to reduce stress singularities that may occur at the rib edges of these features. The micro-groove pattern 122 has a width of less than 2 mm and extends only a short distance into ribs 30, 32, 42, 46, 44. There is no micro-groove pattern 122 in the sacrificial ribs. The localized compressive properties of the micro-groove pattern 122 help disperse / absorb this stress, resulting in a lower likelihood of irregular wear on the tread 16 compared to ribs 30, 32, 42, 46, 44 without the micro-groove pattern 122.

[0017] The micro-groove pattern 122 is oriented at a zero-degree angle to the lateral direction 28 and can be described as an oriented micro-groove pattern. A non-zero angle can be from 2 degrees to 85 degrees. The directionality of the micro-groove pattern 122 is oriented such that it forms an angle toward the forward rolling direction of the tire 10.

[0018] The radial centerline 22 of tire 10 is located at the center of tread 16 in the lateral direction 28. A center rib 42 is located at the center of tread 16 such that the radial centerline 22 is located within the center rib 42. The inner and outer orientations described herein are referenced to this centerline 22, where the inner orientation means that something is positioned toward the centerline 22 in the lateral direction 28, and where the outer orientation means that something is positioned further away from the centerline 22 in the lateral direction 28. Intermediate ribs 32 and 46 are located outside the center rib 42 in the lateral direction 28. The first intermediate rib 32 and center rib 42 define a first center rib groove 56, and the second intermediate rib 46 and center rib 42 define a second center rib groove 58. A first shoulder rib 30 is adjacent to and outside the first intermediate rib 32, and the two ribs 30 and 32 define a first shoulder groove 34 between them. The second shoulder rib 44 is adjacent to and outside the second intermediate rib 46, and the two ribs 44 and 46 define a second shoulder groove 48 between them. Grooves 34, 48, 56, and 58 are open grooves.

[0019] Figure 3This is a cross-sectional view of a tire 10 according to another exemplary embodiment, illustrating the features of the tire 10 to be discussed hereafter. The tire 10 has a crown portion that engages with the road surface, and a pair of sidewalls 12, 100 extending radially from the crown and separated from each other in a transverse direction 28 on opposite sides of the tire 10. In the radial direction 24, a first bead 18 is located at the end of the first sidewall 12, and a second bead 102 is located at the end of the second sidewall 100. The first bead 18 includes a bead core composed of a steel bar 108 and filler rubber 104, and the second bead 102 similarly has a bead core composed of filler rubber 106 and a steel bar 110. The bead cores with bars 108, 110 serve to hold the tire 10 on the rim and maintain its strength to withstand the internal stresses from inflation on the rim to prevent slippage. Steel bars 108 and 110 are surrounded by filler rubbers 104 and 106, and in some cases may be completely surrounded by filler rubbers 104 and 106 in all directions. In some embodiments, the bead core is surrounded by a winding structure made of nylon. The steel bars 108 and 110 shown are single pieces with a rectangular cross-sectional shape. This single piece may actually be a plurality of bars arranged together in a rectangular shape. The winding structure is wound around the filler rubbers 104 and 106 to isolate components 104, 106, 108, and 110 from other elements of the tire 10, such as reinforcing ply 78 and filler. The winding structure may have a stiffness of 14 MPa and may be made of compound rubber and fabric (in some cases, it may be nylon ply rubber), the filler rubbers 104 and 106 may be compound rubber and may have a stiffness of 28 MPa, and the steel bars 108 and 110 may be made of steel or aluminum and may have a stiffness of 30,000,000 MPa in some embodiments.

[0020] Beads 18 and 102 also include bead fillers 92 and 94, which are made of rubber and located within beads 18 and 102 and extend into adjacent sidewalls 12 and 100. Bead fillers 92 and 94 engage a winding structure surrounding filler rubber 104 and 106, and engage reinforcing ply 78 and wear strips 96 and 98. Wear strips 96 and 98 are located on the exterior of beads 18 and 102 and are designed to engage the rim. Tire 10 includes a structure designated as reinforcing ply 78, which is located within the first bead 18 and extends through the first sidewall 12 and the crown and into the second sidewall 100 and the second bead 102. Reinforcing ply 78 is wound around the first bead core and has portions that may be referred to as return carcass ply, which are embedded within bead fillers 92. The opposite ends of the reinforcing ply 78 also wrap around the filler rubber 106 and steel strip 110 in the second bead 102 and terminate within the bead filler 94. The reinforcing ply 78 provides strength and flexibility to the tire 10 and is a supporting structure for bearing the inflation pressure that carries the load of the tire 10. The reinforcing ply 78 is a composite material comprising metal cords and compound rubber. The reinforcing ply 78 is stiffer than the filler rubbers 104 and 106 in its cord direction.

[0021] Another element of the tire 10 extending from the first bead 18 to the second bead 102 is an inner liner 82, which is located inside the first bead 18 and forms part of the outer side of the first bead 18 and extends to the sidewall 12. The inner liner 82 then extends axially in the direction 28 across the entire inner side of the crown, and then extends into and forms part of the inner side of the second sidewall 100 and the outer surface of the second bead 102. The inner liner 82 in the second bead 102 is arranged in a mirror manner similar to its presence in the first bead 18. The inner liner 82 is made of a fluid-impermeable material, such that fluid between the tire 10 and the rim is retained therein to maintain the inflation pressure of the tire 10. The inner liner 82 controls air retention, has low-temperature crack resistance, and good resistance to flexural fatigue. The inner liner 82 can be made as a single layer or can be multilayered. The inner liner 82 forms the inner and outer surfaces of the sidewalls 12 and 100.

[0022] The first sidewall 12 includes a side 88 made of rubber that forms all or at least a portion of the outwardly facing surface of the first sidewall 12. The side 88 may be located solely in the first sidewall 12, or it may be located in both the first sidewall 12 and the first bead 18, or it may be located in both the first sidewall 12 and the tire crown. In some embodiments, the side 88 may be located in the tire crown, the first sidewall 12, and the first bead 18. The side 88 does not extend across the tire crown to the second sidewall 100. The second sidewall 100 includes a side 90 that forms all or a portion of the outwardly facing surface of the second sidewall 100 and may be located solely in the second sidewall 100, or it may have a portion in the tire crown and / or the second bead 102. The side 90 does not extend into the first sidewall 12 and may be constructed in the same manner as previously discussed with respect to the side 88.

[0023] Another component of the tire 10 is a tread wall 84, which is located at the axial end of the tread 16 and extends from there into and engages with the sidewall 88. The tread wall 84 is made of a different rubber composition than the sidewall 88 and forms part of the outer surface of the tire 10. The tread wall 84 is located in the tread crown and extends into the first sidewall 12. A tread wall 86 is located at the opposite end of the tread 16 in the lateral direction 28 and engages with the sidewall 90, and may be a mirror image and configured identically to the tread wall 84 discussed. Tread walls 84 and 86 are made of a different material than the third material 60 and have a different hysteresis than the third material 60.

[0024] The tread includes a buffer layer 80 that sits atop the reinforcing ply 32 within the tread and provides a flat surface on which the belt layer 66 may be disposed. The buffer layer 80 is made of rubber and bonds the reinforcing ply 32, belt layer 66, belt edge layer 112, and belt edge layer 114. The belt layer 66 is located within the tread and is composed of a first belt 116, a second belt 118, and a third belt 120. Although the belt layer 66 is shown as comprising three belts 116, 118, and 120, in other embodiments, any number of belts may be present in the belt layer 66. The belts 116, 118, and 120 provide reinforcement within the tread to improve wear and cornering ability. The steel belts 116, 118, and 120 allow the tire 10 to maintain its shape. The belt edge layers 112 and 114 act as wedges between the belt layer 66 and the third material 60 to suppress stress and are present for the durability of the tire 10. The first belt 116 is the belt of the belt layer 66 furthest from the central axis 14 in the radial direction 24, and it engages the third material 60 and the second belt 118, but does not engage with the buffer layer 80 and the belt edge layers 112, 114. The first belt 116 extends in the axial direction 28 across the center of the tire 10 to the other side.

[0025] The second belt 118 engages with the first belt 116 and is positioned inwardly from the first belt in the radial direction 24. The second belt 118 engages with belt edge layers 112, 114 and extends outwardly from them in the radial direction 24. The second belt 118 also engages with the third belt 120 but does not engage with the buffer layer 80. The third belt 120 engages with the buffer layer 80 and extends outwardly from the buffer layer in the radial direction 24. The third belt 120 is located below the belt edge layers 112, 114 in the radial direction 24 and engages with these layers 112, 114. The second belt 118 and the third belt 120 are not engaged with the first material 40, the second material 50, and the third material 60.

[0026] The tire crown includes a plurality of ribs 30, 32, 42, 46, and 44, which define an outer surface 20 of the tread 16 on its outer radial surface. This outer surface is the portion of the tread 16 that engages with the ground during the use of the tire 10. A first shoulder groove 34 defined between a first shoulder rib 30 and a first intermediate rib 32 is formed by an outer sidewall 36 and an inner sidewall 38. The dividing line between the two sidewalls 36 and 38 is the center of the first shoulder groove 34 located in the lateral direction 28, such that the outer sidewall 36 is the outer half of the groove 34, and the inner sidewall 38 is the inner side of the groove 34. A second shoulder groove 48 is similarly formed by an outer sidewall 52 and an inner sidewall 54, the outer sidewall being the outer half of the second shoulder groove 48, and the inner sidewall being the inner half of the second shoulder groove 48 in the lateral direction 28.

[0027] An electrostatic discharge element 72 is present within the tire 10 and serves as a pathway for discharging static electricity accumulated in the vehicle through the tire 10 and into the ground. Portions of the bead 18, 102 and sidewalls 12, 100 may be conductive, allowing electricity to have a path into the crown portion of the tire 10. However, the third material 60 may not be conductive, allowing electricity to accumulate within the tire 10 without being discharged, as the third material 60 may act as an insulator or may not allow for good conductivity. The electrostatic discharge element 72 is conductive and is joined at one radial end to the second belt 118 of the belt layer 66 and at the other radial end to the bottom of the first material 40. The electrostatic discharge element 72 is embedded within the third material 60, which may not be a good conductor. Electricity traveling to the belt layer 66 can then flow through the electrostatic discharge element 72 to the first material 40, which may be a good conductor, allowing electricity to flow from the electrostatic discharge element 72 into the first material 40 and then into the ground. In this embodiment, the electrostatic discharge element 72 is not located on the outside of the tire 10, but is completely contained within the tire 10 and is not visible. The electrostatic discharge element 72 may extend a full 360 degrees around the central axis 14 in the circumferential direction 26, or the electrostatic discharge element 72 may extend less than 360 degrees around the central axis 14.

[0028] The tread includes a base tread layer that forms part of the tread 16 and is located below the tread 16 in the radial direction 24, engaging both the tread 16 and the belt layer 66. The base tread layer extends along most of the entire tread in the axial direction 28. The base tread layer may be made of a material that minimizes heat generated from the steel belts in the tread 16 and belt layer 66. The base tread layer may also act as an oil migration barrier, providing desired viscosity and exhibiting low hysteresis. However, these properties can be eliminated or modified as needed in various tires 10.

[0029] Hysteresis can be measured by the tan(δ) value of the rubber at a specific point on the tire. The loss factor "tan(δ)" is a dynamic property of the rubber compound. It is measured on a viscosity analyzer (Metravib VA4000) according to standard ASTM D5992-96. As used herein, the accurate test method standard ASTM D5992-96 that can be used is the 2018 version. The response of a test sample consisting of two cylindrical spheres (each 2 mm thick and 1 cm in diameter) was recorded. This test sample was made from a sample taken from the mid-tire section of the tire at the height of the area of ​​interest, which was thick enough to form the test sample as close to the equatorial plane as possible. The sample was subjected to a simple alternating sinusoidal shear load at a frequency of 10 Hz at a temperature of 60 °C. The frequency sweep covered the amplitude of deformation from 0.1% to 25% peak-to-peak (on the outward cycle) and then from 25% to 1% peak-to-peak (on the return cycle). The results used here are the loss factor tan(δ) and the complex dynamic shear modulus. The complex dynamic shear modulus for a strain of 25% applied during the test is denoted as “G*25”. The maximum value of tan(δ) observed during the outward circulation is denoted as “maximum tan(δ)”. The complex dynamic shear modulus (G*25) for a strain of 25% at 60°C was also obtained during this test, and is referred to herein as G*25 to further characterize the properties of the rubber provided in tire 10.

[0030] The first material 40 is located in the first shoulder rib 30 and the second shoulder rib 44, and is the portion forming the outer surface 20 of these ribs 30, 44 and engaging with the ground during use. The first material 40 has a higher hysteresis than the second material 50, and is different from the third material 60, and in some cases its hysteresis may be higher than that of the third material 60. The maximum tan(δ) is an indicator of hysteresis, such that a material with a higher maximum tan(δ) has a higher hysteresis than a material with a lower maximum tan(δ). The maximum tan(δ) of the first material 40 may be 0.18. According to certain exemplary embodiments, the maximum tan(δ) of the first material 40 may be 0.15 to 0.20, 0.15 to 0.16, 0.15 to 0.17, 0.15 to 0.18, 0.15 to 0.19, 0.16 to 0.20, 0.17 to 0.20, 0.18 to 0.20, 0.19 to 0.20, 0.16 to 0.19, 0.16 to 0.18, 0.16 to 0.17, 0.17 to 0.19, 0.18 to 0.19, 0.16, 0.17, 0.19, or 0.20. As used herein, when a numerical range is listed, the range also includes the upper and lower limits of the range. In some embodiments, the G*25 of the first material 40 is 1.83 MPa. In other embodiments, the G*25 of the first material 40 is 1.6 MPa to 2.0 MPa, 1.6 MPa to 1.9 MPa, 1.6 MPa to 1.8 MPa, 1.6 MPa to 1.7 MPa, 1.9 MPa to 2.0 MPa, 1.8 MPa to 2.0 MPa, 1.7 MPa to 2.0 MPa, 1.7 MPa to 1.8 MPa, 1.6 MPa, 1.7 MPa, 1.8 MPa, 1.9 MPa, 2.0 MPa, 1.65 MPa, 1.75 MPa, 1.85 MPa, or 1.95 MPa.

[0031] The second material 50 is located in the central rib 42, the first intermediate rib 32, and the second intermediate rib 46, and is the portion of these ribs 42, 32, 46 that forms the outer surface 20 and engages with the ground during use. The second material 50 has a different hysteresis than the third material 60. The maximum tan(δ) of the second material 50 may be 0.11. According to some exemplary embodiments, the maximum tan(δ) of the second material 50 may be 0.05 to 0.15, 0.05 to 0.14, 0.05 to 0.13, 0.05 to 0.12, 0.05 to 0.11, 0.05 to 0.10, 0.05 to 0.09, 0.05 to 0.08, 0.05 to 0.07, 0.05 to 0.06, 0.0 6 to 0.15, 0.07 to 0.15, 0.08 to 0.15, 0.09 to 0.15, 0.10 to 0.15, 0.11 to 0.15, 0.12 to 0.15, 0.13 to 0.15, 0.14 to 0.15, 0.07 to 0.14, 0.07 to 0.13, 0.07 to 0.12, 0.07 to 0.11, 0.07 to 0.10, 0.07 to 0.09, 0.07 to 0.08, 0.08 to 0.14, 0.09 to 0.14, 0.10 to 0.14, 0.11 to 0.14, 0.12 to 0.14, 0.13 to 0.14, 0.08 to 0.13, 0.08 to 0.12, 0.08 to 0.11, 0.08 to 0.10, 0.08 to 0. 09, 0.09 to 0.13, 0.10 to 0.13, 0.11 to 0.13, 0.12 to 0.13, 0.09 to 0.12, 0.09 to 0.11, 0.09 to 0.10, 0.10 to 0.12, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.12, 0.13, 0.14 or 0.15.

[0032] In some embodiments, the G*25 of the second material 50 is 1.85 MPa. In other embodiments, the G*25 of the second material 50 is 1.6 MPa to 2.0 MPa, 1.6 MPa to 1.9 MPa, 1.6 MPa to 1.8 MPa, 1.6 MPa to 1.7 MPa, 1.9 MPa to 2.0 MPa, 1.8 MPa to 2.0 MPa, 1.7 MPa to 2.0 MPa, 1.7 MPa to 1.8 MPa, 1.6 MPa, 1.7 MPa, 1.8 MPa, 1.9 MPa, 2.0 MPa, 1.65 MPa, 1.75 MPa, 1.85 MPa, or 1.95 MPa.

[0033] The third material 60 is located in all ribs 30, 32, 42, 44, and 46, but not the outward portions of these ribs in the radial direction 24, and does not engage with the ground when the tire 10 is new. The third material also constitutes the sacrificial ribs 62 and 64 and the undercarriage tread of the tire 10. The maximum tan(δ) of the third material 60 may be 0.10. According to certain exemplary embodiments, the maximum tan(δ) of the third material 60 may be 0.05 to 0.15, 0.05 to 0.14, 0.05 to 0.13, 0.05 to 0.12, 0.05 to 0.11, 0.05 to 0.10, 0.05 to 0.09, 0.05 to 0.08, 0.05 to 0.07, 0.05 to 0.06, 0.0 6 to 0.15, 0.07 to 0.15, 0.08 to 0.15, 0.09 to 0.15, 0.10 to 0.15, 0.11 to 0.15, 0.12 to 0.15, 0.13 to 0.15, 0.14 to 0.15, 0.07 to 0.14, 0.07 to 0.13, 0.07 to 0.12, 0.07 to 0.11, 0.07 to 0.10, 0.07 to 0.09, 0.07 to 0.08, 0.08 to 0.14, 0.09 to 0.14, 0.10 to 0.14, 0.11 to 0.14, 0.12 to 0.14, 0.13 to 0.14, 0.08 to 0.13, 0.08 to 0.12, 0.08 to 0.11, 0.08 to 0.10, 0.08 to 0. 09, 0.09 to 0.13, 0.10 to 0.13, 0.11 to 0.13, 0.12 to 0.13, 0.09 to 0.12, 0.09 to 0.11, 0.09 to 0.10, 0.10 to 0.12, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.12, 0.13, 0.14 or 0.15.

[0034] In some embodiments, the G*25 of the third material 60 is 1.51 MPa. In other embodiments, the G*25 of the third material 60 is 1.0 MPa to 1.75 MPa, 1.0 MPa to 1.7 MPa, 1.0 MPa to 1.6 MPa, 1.0 MPa to 1.5 MPa, 1.0 MPa to 1.4 MPa, 1.0 MPa to 1.3 MPa, 1.0 MPa to 1.2 MPa, 1.0 MPa to 1.1 MPa, or 1.1 MPa to 1.75 MPa. MPa, 1.2MPa to 1.75MPa, 1.3MPa to 1.75MPa, 1.4MPa to 1.75MPa, 1.5MPa to 1.75MPa, 1.6MPa to 1.75MPa, 1.7MPa to 1.75MPa, 1.1MPa to 1.7MPa, 1.1MPa to 1.6MPa, 1.1MPa to 1.5MPa, 1.1MPa to 1.4MPa MPa, 1.1MPa to 1.3MPa, 1.1MPa to 1.2MPa, 1.2MPa to 1.7MPa, 1.3MPa to 1.7MPa, 1.4MPa to 1.7MPa, 1.5MPa to 1.7MPa, 1.6MPa to 1.7MPa, 1.2MPa to 1.6MPa, 1.2MPa to 1.5MPa, 1.2MPa to 1.4MPa, 1. 2MPa to 1.3MPa, 1.3MPa to 1.6MPa, 1.4MPa to 1.6MPa, 1.5MPa to 1.6MPa, 1.3MPa to 1.5MPa, 1.3MPa to 1.4MPa, 1.0MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, 1.5MPa, 1.6MPa, 1.7MPa or 1.75MPa.

[0035] In some embodiments, the electrostatic discharge element 72 may be made of rubber, and its hysteresis may be different from or the same as the hysteresis of the first material 40, the second material 50, and the third material 60. The maximum tan(δ) of the electrostatic discharge element 72 may be 0.15. According to some exemplary embodiments, the maximum tan(δ) of the electrostatic discharge element 72 may be 0.05 to 0.17, 0.05 to 0.16, 0.05 to 0.15, 0.05 to 0.14, 0.05 to 0.13, 0.05 to 0.12, 0.05 to 0.11, 0.05 to 0.10, 0.05 to 0.09, 0.05 to 0.08, 0.05 to 0.07, 0.05 to 0.06, 0.06 to 0.17, 0.06 to 0.16, 0.06 to 0.15, 0.06 to 0.14, 0.06 to 0.13, 0.06 to 0.12, 0.06 to 0.11, 0.06 to 0.10, 0.06 to 0.09, 0.06 to 0.08, 0.06 to 0.07, 0.07 to 0.16, 0.08 to 0.16, 0.09 to 0.16, 0.10 to 0.16, 0.11 to 0.16, 0.12 to 0.16, 0.13 to 0.16, 0.14 to 0.16, 0.15 to 0.16, 0.07 to 0.15, 0.08 to 0.15, 0. 0.9 to 0.15, 0.10 to 0.15, 0.11 to 0.15, 0.12 to 0.15, 0.13 to 0.15, 0.14 to 0.15, 0.07 to 0.14, 0.07 to 0.13, 0.07 to 0.12, 0.07 to 0.11, 0.07 to 0.10, 0.07 to 0.09, 0.07 to 0.08, 0.08 to 0.14, 0.09 to 0.14, 0.10 to 0.14, 0.11 to 0.14, 0.12 to 0.14, 0.13 to 0.1 4. 0.08 to 0.13, 0.08 to 0.12, 0.08 to 0.11, 0.08 to 0.10, 0.08 to 0.09, 0.09 to 0.13, 0.10 to 0.13, 0.11 to 0.13, 0.12 to 0.13, 0.09 to 0.12, 0.09 to 0.11, 0.09 to 0.10, 0.10 to 0.12, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.12, 0.13, 0.14, 0.16 or 0.17.

[0036] In some embodiments, the G*25 of the electrostatic discharge element 72 is 1.39 MPa. In other embodiments, the G*25 of the electrostatic discharge element 72 is 1.0 MPa to 1.75 MPa, 1.0 MPa to 1.7 MPa, 1.0 MPa to 1.6 MPa, 1.0 MPa to 1.5 MPa, 1.0 MPa to 1.4 MPa, 1.0 MPa to 1.3 MPa, 1.0 MPa to 1.2 MPa, 1.0 MPa to 1.1 MPa, or 1.1 MPa to 1.7 MPa. 5MPa, 1.2MPa to 1.75MPa, 1.3MPa to 1.75MPa, 1.4MPa to 1.75MPa, 1.5MPa to 1.75MPa, 1.6MPa to 1.75MPa, 1.7MPa to 1.75MPa, 1.1MPa to 1.7MPa, 1.1MPa to 1.6MPa, 1.1MPa to 1.5MPa, 1.1MPa to 1. 4MPa, 1.1MPa to 1.3MPa, 1.1MPa to 1.2MPa, 1.2MPa to 1.7MPa, 1.3MPa to 1.7MPa, 1.4MPa to 1.7MPa, 1.5MPa to 1.7MPa, 1.6MPa to 1.7MPa, 1.2MPa to 1.6MPa, 1.2MPa to 1.5MPa, 1.2MPa to 1.4MPa, 1 0.2MPa to 1.3MPa, 1.3MPa to 1.6MPa, 1.4MPa to 1.6MPa, 1.5MPa to 1.6MPa, 1.3MPa to 1.5MPa, 1.3MPa to 1.4MPa, 1.0MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, 1.5MPa, 1.6MPa, 1.7MPa or 1.75MPa.

[0037] The first material 40 and the third material 60 constitute the first shoulder rib 30 and the second shoulder rib 44, wherein the boundary between the two materials 40 and 60 is located at the first space 124 and the second space 126, and at the first shoulder groove 34 and the second shoulder groove 48. These boundaries are located at the outer sidewalls 36 and 52, and do not extend to the bottom of the grooves 34 and 48, such that the grooves 34 and 48 and the spaces 124 and 126 extend to a greater depth in the radial direction 24 than the first material 40 extends to a greater depth in the radial direction 24. The second material 50 forms a boundary with the third material 60, which extends into the tread 16 in the radial direction 24 by the same distance as the boundary between the first material 40 and the third material 60 extends into the tread in the same radial direction. This boundary is located at the two sidewalls of the inner sidewalls 38 and 54, and the central rib grooves 56 and 58. The grooves 34, 56, and 58 extend further into the tread 16 in the radial direction 24 than the second material 50 extends further. The hysteresis, measured by the maximum tan(δ) value, is greater in the first material 40 than in the second material 50, resulting in less irregular wear in the shoulder region of the tread 16, which is sensitive to irregular wear, while exhibiting better rolling resistance in the center and intermediate regions of the tread 16, which are less sensitive to irregular wear.

[0038] refer to Figure 4 Another embodiment of tire 10 is shown, which includes many features similar to those previously discussed. Figure 3 The similar features discussed make it unnecessary to repeat them. Figure 3 and Figure 4 One difference between the implementation schemes lies in the placement of the electrostatic discharge element 72 within the tire 10. Figure 4 In this configuration, an electrostatic discharge element 72 extends from the belt layer 66 to the outer surface 20 and forms part of the outer surface 20. Specifically, the electrostatic discharge element 72 engages the first belt 116 at its radially innermost end, and its radially outermost end forms part of the outer surface 20. The electrostatic discharge element 72 is located at the radial centerline 22 and engages both the second material 50 and the third material 60, but not the first material 40. The electrostatic discharge element 72 is located in the central rib 42 and has high conductivity, allowing electricity accumulated in the vehicle to be guided into the belt layer 66 and discharged from the belt layer 66 via the electrostatic discharge element 72, directly entering the ground from there.

[0039] Figure 5 Another embodiment of tire 10 is shown, which is similar to the previously mentioned embodiment. (Return to reference) Figure 3 The proposed implementation scheme is discussed, and this information need not be repeated. Figure 5The difference in the implementation is that the second material 50 located in the first intermediate rib 32 and the second intermediate rib 46 is replaced by the first material 40. This implementation also reduces irregular wear in the intermediate ribs 32, 46 due to the higher hysteresis of the first material 40, making these ribs 32, 46 less likely to experience irregular wear. To improve the trade-off between irregular wear and rolling resistance, a mixture of lower hysteresis second material 50 is present in the center rib 42. The disclosed implementation shows a pair of shoulder ribs 30, 44 and a single center rib 42 between the two intermediate ribs 32 and 46. However, it should be understood that if an even number of ribs are present in the tread 16 in other implementations, two center ribs 42 will be present. Furthermore, there are additional exemplary implementations in which more than two intermediate ribs 32, 46 are present, and in other forms of the tire 10, any number of intermediate ribs 32, 46 may be included in the tread 16. In all configurations, one or more center ribs 42 will include second material 50, and two shoulder ribs 30, 44 will include first material 40, wherein intermediate ribs 32, 46 include either first material 40 or second material 50 or both. In some embodiments, each of ribs 30, 44, 42, 32, 46 includes either first material 40 or second material 50, and does not include either first material 40 or second material 50, while in other arrangements, there are ribs within the tread 16 that are not sacrificial ribs 62, 64 and do not include either first material 40 or second material 50. Furthermore, although shown to extend the same distance in the radial direction 24 into the tread 16, the first material 40 and the second material 50 may extend different distances in the radial direction 24 into the tread 16.

[0040] The maximum tan(δ) of the first material 40 is greater than the maximum tan(δ) of the second material 50 to improve the trade-off between irregular wear and rolling resistance. The second material 50, with its lower hysteresis, reduces the overall rolling resistance of the tire 10 by being placed in the less sensitive irregular wear area of ​​the tread 16. In some embodiments, the hysteresis of the first material 40 is 30% or more greater than that of the second material 50. In this regard, if the maximum tan(δ) of the first material 40 is 0.18 and the maximum tan(δ) of the second material 50 is 0.11, then to calculate how much greater the first material 40 is than the second material 50 (P), it can be calculated as follows:

[0041]

[0042]

[0043]

[0044] The first material 40, the second material 50, and the third material 60 can be laminated into the tire 10 using a co-extrusion process. The tread design incorporating the layers of different materials into the tire can be seen in U.S. Patent No. 11,254,166, entitled "Methods and Apparatuses for Assembling Tire Components," which is owned by the assignee of this application and whose entire contents are incorporated herein by reference for all purposes. In this arrangement, the third material 60 is located outside both the first material 40 and the second material 50 in the axial direction 28 and inside them in the radial direction 24. The third material 60 may be present within all ribs 30, 32, 42, 44, and 46, and the third maximum tan(δ) differs from the first maximum tan(δ) and the second maximum tan(δ). The higher and lower hysteresis of the first material 40, the second material 50, and the third material 60 is imparted based on the materials constituting materials 40, 50, and 60, such as rubber, silica, carbon black, sulfur, or other fillers, and is not higher or lower based on the belt or other components, thereby causing the layer to become a structure. The maximum tan(δ) of materials 40, 50, and 60 is generated from the tread mixture 16, rather than from the tread 16 itself which is a structure.

[0045] Tire 10 can be an original equipment manufactured tire, produced and applied to a new vehicle. Tire 10 can also be a retreaded tire, in which a used outer tire 76 is fitted with a new tread 16. Tread 16 can therefore be provided as a retreaded tire belt or tire 10. Tread 16 allows for the provision of steering and trailer tires 10 without the coupling sacrificial ribs 62, 64.

[0046] Although the subject matter of the invention has been described in detail with respect to specific embodiments and methods, it should be understood that modifications, variations, and equivalents of such embodiments will be readily conceived by those skilled in the art upon understanding the foregoing. Therefore, the scope of this disclosure is by way of example rather than limitation, and this disclosure does not exclude obvious such modifications, variations, and / or additions to the subject matter.

Claims

1. A tread for a heavy-duty truck tire, the tread for the heavy-duty truck tire comprising: The first shoulder rib is made of a first material and a third material, wherein the first material is located outside the third material in the radial direction; A first intermediate rib, the first intermediate rib being partially made of the third material such that the third material is not located at the radially outermost point of the first intermediate rib, wherein the first intermediate rib and the first shoulder rib define a first shoulder groove, the first shoulder groove having an outer sidewall made of both the first material and the third material such that the first shoulder groove extends deeper into the tread in the radial direction than the first material of the first shoulder rib. A central rib, the central rib being made of a second material and the third material, wherein the second material is located outside the third material in the radial direction; The second tire shoulder rib is made of the first material and the third material, wherein the first material is located outside the third material in the radial direction; The second intermediate rib, which is partially made of the third material, is not located at the radially outermost point of the second intermediate rib, wherein the second intermediate rib and the second shoulder rib define a second shoulder groove having an outer sidewall made of both the first material and the third material, such that the second shoulder groove extends deeper into the tread in the radial direction than the first material of the second shoulder rib; Wherein the first maximum tan(δ) of the first material is greater than the second maximum tan(δ) of the second material; The third maximum tan(δ) of the third material is different from the first maximum tan(δ), and the third maximum tan(δ) is different from the second maximum tan(δ); Wherein the first maximum tan(δ) is 0.15 to 0.20; The second maximum tan(δ) is between 0.05 and 0.15; and The third maximum tan(δ) is between 0.05 and 0.

15.

2. The tread according to claim 1, wherein the second maximum tan(δ) is 0.10 to 0.

15.

3. The tread according to claim 1 or 2, wherein the first intermediate rib is made of the second material and the third material, such that the second material is located outside the third material in the radial direction; The inner sidewall of the first shoulder groove is made of both the second material and the third material, such that the first shoulder groove extends deeper into the tread in the radial direction than the second material of the first intermediate rib. The second intermediate rib is made of the second material and the third material, such that the second material is located outside the third material in the radial direction; and The inner sidewall of the second shoulder groove is made of both the second material and the third material, such that the second shoulder groove extends deeper into the tread in the radial direction than the second material of the second intermediate rib.

4. The tread according to claim 1 or 2, wherein the first intermediate rib is made of the first material and the third material, such that the first material is located outside the third material in the radial direction; The inner sidewall of the first shoulder groove is made of both the first material and the third material, such that the first shoulder groove extends deeper into the tread in the radial direction than the first material of the first intermediate rib. The second intermediate rib is made of the first material and the third material, such that the first material is located outside the third material in the radial direction; and The inner sidewall of the second shoulder groove is made of both the first material and the third material, such that the second shoulder groove extends deeper into the tread in the radial direction than the first material of the second intermediate rib.

5. The tread according to any one of claims 1 to 4, wherein the second material and the third material of the central rib partially define a first central rib groove, and wherein the second material and the third material of the central rib partially define a second central rib groove; The first central rib groove extends deeper into the tread in the radial direction than the second material of the central rib; and The second center rib groove extends deeper into the tread in the radial direction than the second material of the center rib.

6. The tread according to any one of claims 1 to 5, wherein the tread further comprises: A first sacrificial rib, the first sacrificial rib being made of the third material, wherein the first sacrificial rib is located outside the first shoulder rib in the axial direction; The second sacrificial rib, made of the third material, is located outside the second shoulder rib in the axial direction.

7. The tread according to any one of claims 1 to 6, wherein the tread further comprises: A belt layer, wherein the belt layer is located inside the first shoulder rib, the first intermediate rib, the center rib, the second shoulder rib, and the second intermediate rib in the radial direction; First sidewall; A first bead, the first bead engaging the first sidewall and located inside the first sidewall in the radial direction; Second sidewall; The second bead engages the second sidewall and is located inside the second sidewall in the radial direction; and An electrostatic discharge element through which charge travels, wherein the electrostatic discharge element is bonded to the third material and to at least one of the layers in the belt layer.

8. The tread according to claim 7, wherein the electrostatic discharge element is located in the first shoulder rib and engages the first material without extending to the outer surface of the tread.

9. The tread according to claim 7, wherein the electrostatic discharge element is located in the central rib and engages the second material and extends to the outer surface of the tread.

10. The tread according to claim 8 or 9, wherein the electrostatic discharge element has a complex shear modulus (G*25) of 1.0 MPa to 1.75 MPa at 60°C for 25% strain; The maximum tan(δ) of the electrostatic discharge element is 0.05 to 0.

17.

11. The tread according to claim 10, wherein the electrostatic discharge element has a complex shear modulus (G*25) of 1.39 MPa at 60°C for 25% strain; The maximum tan(δ) of the electrostatic discharge element is 0.

15.

12. The tread according to any one of claims 1 to 11, wherein: The first material has a complex shear modulus (G*25) of 1.6 MPa to 2.0 MPa at 60°C with 25% strain. The second material has a complex shear modulus (G*25) of 1.6 MPa to 2.0 MPa at 60°C and 25% strain; and The third material has a complex shear modulus (G*25) of 1.0 MPa to 1.75 MPa at 60°C with 25% strain.

13. The tread according to claim 12, wherein the first material has a complex shear modulus (G*25) of 1.83 MPa at 60°C with 25% strain; The second material has a complex shear modulus (G*25) of 1.85 MPa at 60°C and 25% strain; and The third material has a complex shear modulus (G*25) of 1.51 MPa at 60°C with 25% strain.

14. The tread according to any one of claims 1 to 13, wherein: The first maximum tan(δ) is 0.18; The second maximum tan(δ) is 0.11; and The third maximum tan(δ) is 0.

10.

15. The tread according to any one of the preceding claims, wherein the tread is a retreaded tire strip.

16. The tread according to any one of the preceding claims, wherein the first maximum tan(δ) is 30% or greater than the second maximum tan(δ).

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