JP2015054525A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire which can suppress an increase in mass and is excellent in steering stability when traveling at high speed.SOLUTION: An tire 30 related to this invention comprises a first bead 38 extending almost radially inward from a side wall positioned in an inside direction of a vehicle when this tire 30 is mounted on the vehicle, a second bead 40 extending almost radially outward from a side wall positioned in an outside direction of the vehicle, a first metal filler 44 and a second metal filler 48 that comprise many parallel metal cords, and a first organic fiber filler 46 and a second organic fiber filler 50 that comprise many parallel organic fiber cords. The first metal filler 44 is positioned axially outside of the first bead 38, and the first organic fiber filler 46 is positioned axially inside of the first bead 38. The second metal filler 48 is positioned axially inside of the second bead 40, and the second organic fiber filler 50 is positioned axially outside of the second bead 40.

Description

  The present invention relates to a pneumatic tire.

  Race tires are used in situations where high-speed turning, rapid acceleration and braking are repeated. Race tires are required to have high handling stability in these situations.

  In order to achieve high steering stability during turning, a method of increasing the rigidity of the tire sidewalls and bead portions (referred to herein as tire side portions) is employed. Since the side portion having high rigidity has a small amount of deformation even with a large lateral force during high-speed turning, the cornering force can be effectively generated in this tire. Thereby, the grip force of the tire is improved and high steering stability is realized.

  The rigidity of the side part of the tire can be increased by providing the side part with a reinforcing layer. FIG. 4 is a schematic view of a tire 2 provided with a conventional reinforcing layer. The tire 2 includes a tread 4, a sidewall 6, a bead 8, a carcass 10, a belt 12, and a reinforcing layer 14. In the tire 2 of FIG. 4, the reinforcing layer 14 is located on the outer side in the axial direction of the bead 8. The reinforcing layer 14 includes a cord made of metal or organic fiber. This reinforcing layer 14 contributes to the improvement of the rigidity of the side portion 16 of the tire 2. In FIG. 4, an alternate long and short dash line CL represents the equator plane of the tire 2. The shape of the tire 2 is symmetric with respect to the equator plane.

  The rigidity of the side portion 16 can be further increased by increasing the amount of the cord of the reinforcing layer 14. However, simply increasing the amount of cord leads to an increase in the mass of the tire 2. Furthermore, the reinforcing layer 14 having excessive rigidity can reduce the ground contact area of the tire 2 when traveling straight, and can cause a decrease in grip performance when traveling straight. Studies on the reinforcing layer in the side portion are reported in Japanese Patent Laid-Open Nos. 2000-177335 and 2001-191760.

  The tire disclosed in Japanese Patent Application Laid-Open No. 2000-177335 includes a carcass composed of three plies and a reinforcing layer. This reinforcing layer is located on the axially outer side of the bead and on the axially inner side of the third ply. The rigidity of the side portion is increased by the reinforcing layer and the ply. These reinforcing layers consist of steel cords or organic fiber cords. The shape of the tire is symmetric with respect to the equator plane.

  In the tire disclosed in Japanese Patent Application Laid-Open No. 2001-191760, an example in which the reinforcing layer is arranged on the outer side in the axial direction of the bead and an example in which the reinforcing layer is arranged on the inner side in the axial direction of the bead are shown. These reinforcing layers are formed by winding one or more cords in the circumferential direction. These reinforcing layers consist of steel cords or organic fiber cords. The shape of the tire is symmetric with respect to the equator plane.

JP 2000-177335 A JP 2001-191760

  When the vehicle turns at a high speed, a large load is applied to the tire. Most of this load is borne by the outer ring. Almost no load is applied to the inner ring. Therefore, improvement in steering stability during high-speed turning can be realized by suppressing deformation of the side portion of the outer ring.

  In FIG. 4, an arrow X represents an inner direction of the vehicle (referred to herein as “back side”) when the tire 2 is mounted on the vehicle. The arrow Y represents the direction of the outside of the vehicle (referred to herein as “front side”) when the tire 2 is mounted on the vehicle. When the vehicle turns at a high speed, both the front side portion 16b and the back side portion 16a of the outer tire 2 are deformed so that the central portion bends to the front side. That is, with respect to the front side portion 16b of the tire 2, the axially outer surface (outer surface 18) is deformed in the tensile direction, and the axially inner surface (inner surface 20) is deformed in the compression direction. As for the side portion 16a on the back side of the tire 2, its outer surface 22 is deformed in the compression direction, and its inner surface 24 is deformed in the pulling direction.

  The rigidity with respect to the pulling force of the reinforcing layer made of organic fibers is larger than the rigidity with respect to the compressive force. On the other hand, the reinforcing layer made of metal is excellent in both rigidity against tensile force and rigidity against compressive force, but the mass of the reinforcing layer made of metal is larger than the mass of the reinforcing layer made of organic fibers. In order to make the mass of the reinforcing layer made of metal equal to that of the reinforcing layer made of organic fibers, it is necessary to reduce the amount of metal. This reinforcing layer may not have sufficient rigidity. In the tire 2 of FIG. 4, the reinforcing layer 14 is positioned on the outer side in the axial direction of the bead 8 in both the front side portion 16 b and the back side portion 16 a. When the reinforcing layer 14 is made of an organic fiber cord, the reinforcing layer 14 may not have sufficient rigidity against compressive deformation of the outer surface 22 of the back side portion 16a. The tire 2 in FIG. 4 may not have sufficient rigidity when turning. The tire 2 is inferior in grip force at high-speed turning. The tire 2 is inferior in handling stability. In the tire 2 of FIG. 4, when the reinforcing layer 14 is made of a metal cord, the mass of the tire 2 is increased as compared with the tire 2 including the organic fiber reinforcing layer 14. The tire 2 causes a deterioration in fuel consumption performance. Or when the increase in the mass of the tire 2 is suppressed, this reinforcing layer may not have sufficient rigidity. The tire 2 is inferior in grip force at high-speed turning.

  In the tire 2 of FIG. 4, an example in which the reinforcing layer 14 is positioned on the outer side in the axial direction of the bead 8 is shown. In tires that require stronger side surface rigidity, such as racing tires, reinforcement layers may be provided on both the inside and outside of the bead in the axial direction. It can be seen that similar problems can occur with this tire. That is, when the reinforcing layer is made of an organic fiber cord, the reinforcing layer may not have sufficient rigidity against compressive deformation on the inner surface of the front side portion and compressive deformation on the outer surface of the back side portion. This tire is inferior in grip force at high-speed turning. When the reinforcing layer is made of a metal cord, the mass of the tire is increased as compared with a tire having a reinforcing layer made of organic fibers. Alternatively, when the increase in the mass of the tire is suppressed, the reinforcing layer may not have sufficient rigidity. Similar problems may occur in the tire disclosed in Japanese Patent Laid-Open No. 2000-177335 and the tire disclosed in Japanese Patent Laid-Open No. 2001-191760.

  An object of the present invention is to provide a tire that suppresses an increase in mass and has excellent steering stability during high-speed traveling.

  The tire according to the present invention has a tread whose outer surface forms a tread surface, a pair of sidewalls that extend substantially inward in the radial direction from the end of the tread, and an inner direction of the vehicle when the tire is mounted on the vehicle. A first bead that extends substantially inward in the radial direction from the sidewall located at the position, a second bead that extends substantially outward in the radial direction from the sidewall located outside the vehicle when the tire is mounted on the vehicle, and a tread. And a carcass bridged between both beads along the inside of the sidewall, a first metal filler having a cord made of many parallel metals, and a cord made of many organic fibers juxtaposed A first organic fiber filler, a second metal filler having a cord made of a large number of metals arranged in parallel, and a large number of the organic fibers arranged in parallel And a second organic fiber filler having a over de. The first metal filler is located outside the first bead in the axial direction. The first organic fiber filler is located on the inner side in the axial direction of the first bead. The second metal filler is located on the inner side in the axial direction of the second bead. The second organic fiber filler is located on the outer side in the axial direction of the second bead.

  Preferably, the Young's modulus of the cord of the second metal filler is larger than the Young's modulus of the cord of the first metal filler.

  Preferably, the Young's modulus of the cord of the second organic fiber filler is larger than the Young's modulus of the cord of the first organic fiber filler.

  Preferably, an absolute value of an angle formed by the cord of the first metal filler and the cord of the second metal filler with respect to the circumferential direction is 20 ° or more and 45 ° or less.

  Preferably, an absolute value of an angle formed by the cord of the first organic fiber filler and the cord of the second organic fiber filler with respect to the circumferential direction is 20 ° or more and 45 ° or less.

  Preferably, in the radial direction, a ratio (Hm1 / H) of a height Hm1 from the base line to the outer end of the first metal filler with respect to a height H from the base line to the tread surface on the equator plane of the tire is It is 0.3 or more and 0.9 or less.

  Preferably, in the radial direction, a ratio (Hc1 / H) of the height Hc1 from the base line to the outer end of the first organic fiber filler with respect to the height H is 0.2 or more and 0.8 or less.

  Preferably, in the radial direction, the ratio of the height Hm2 from the base line to the outer end of the second metal filler (Hm2 / H) with respect to the height H is 0.2 or more and 0.8 or less.

  Preferably, in the radial direction, a ratio (Hc2 / H) of the height Hc2 from the base line to the outer end of the second organic fiber filler with respect to the height H is 0.3 or more and 0.9 or less.

  In the tire according to the present invention, the second organic fiber filler is located outside the second bead located on the front side of the tire. When the vehicle turns at a high speed and a force is applied to the outer ring tire so that the center portion of the front side portion is deformed to the front side, the second organic fiber filler causes the front side portion to be Sufficient rigidity against tensile deformation. Further, in this tire, the second metal filler is located inside the second bead. By this second metal filler, the front side portion has sufficient rigidity against compressive deformation of the inner surface. In the tire according to the present invention, deformation of the front side portion can be effectively suppressed.

  In the tire according to the present invention, the first organic fiber filler is located inside the first bead located on the back side of the tire. When force is applied to the outer ring tire so that the center part of the side part on the back side is deformed to the front side, the first organic fiber filler allows the side part on the back side to be sufficiently resistant to tensile deformation on the inner surface. Have high rigidity. In the tire, the first metal filler is located outside the first bead. Due to the first metal filler, the side portion on the back side has sufficient rigidity against compressive deformation of the outer surface. In the tire according to the present invention, deformation of the back side portion can be effectively suppressed.

  In the tire according to the present invention, the deformation of the front side portion and the rear side portion of the outer ring during high-speed turning can be effectively suppressed. This tire is excellent in gripping power when turning at high speed. This tire is excellent in handling stability.

  In the tire according to the present invention, fillers made of organic fiber cords are arranged where tensile deformation occurs during turning, and fillers made of metal cords are arranged where compressive deformation occurs. By the arrangement of the filler, rigidity capable of withstanding a large lateral force at the time of turning is realized, and an increase in the mass of the filler is prevented. In the tire according to the present invention, an increase in mass is prevented. In the tire according to the present invention, the deterioration of the fuel consumption performance is suppressed.

FIG. 1 is a cross-sectional view showing a part of a tire according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a part of the tire of FIG. FIG. 3 is an enlarged cross-sectional view showing a part of the tire of FIG. FIG. 4 is a cross-sectional view showing a part of a conventional pneumatic tire.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  FIG. 1 shows a pneumatic tire 30. In FIG. 1, the vertical direction is the radial direction of the tire 30, the horizontal direction is the axial direction of the tire 30, and the direction perpendicular to the paper surface is the circumferential direction of the tire 30. Moreover, in FIG. 1, arrow X represents the back side, and arrow Y represents the front side. In FIG. 1, an alternate long and short dash line CL represents the equator plane of the tire 30.

  The tire 30 includes a tread 32, a sidewall 34, a clinch 36, a first bead 38, a second bead 40, a carcass 42, a belt 52, an inner liner 54, a chafer 56, a first metal filler 44, and a first organic fiber filler. 46, a second metal filler 48 and a second organic fiber filler 50 are provided. The tire 30 is a tubeless type. The tire 30 is attached to a passenger car.

  The tread 32 has a shape protruding outward in the radial direction. The tread 32 forms a tread surface 58 that contacts the road surface. The tread 32 is made of a crosslinked rubber having excellent wear resistance, heat resistance, and grip properties.

  The pair of sidewalls 34 extend substantially inward in the radial direction from the end of the tread 32. The radially outer end of the sidewall 34 is joined to the tread 32. A radially inner end of the sidewall 34 is joined to a clinch 36. The sidewall 34 is made of a crosslinked rubber having excellent cut resistance and weather resistance. This sidewall 34 prevents the carcass 42 from being damaged.

  The pair of clinches 36 are positioned substantially inside the sidewall 34 in the radial direction. The clinch 36 is located outside the bead and carcass 42 in the axial direction. The clinch 36 is made of a crosslinked rubber having excellent wear resistance. The clinch 36 contacts the rim flange.

  The first bead 38 extends substantially inward in the radial direction from the side wall 34 located on the back side of the pair of side walls 34. The first bead 38 includes a core 60 and an apex 62 that extends radially outward from the core 60. The core 60 has a ring shape along the circumferential direction of the tire 30. The core 60 includes a wound non-stretchable wire. A typical material for the wire is steel. The apex 62 is tapered outward in the radial direction. The apex 62 is made of a highly hard crosslinked rubber.

  The second bead 40 extends substantially inward in the radial direction from the side wall 34 located on the front side of the pair of side walls 34. The second bead 40 includes a core 64 and an apex 66 that extends radially outward from the core 64. The core 64 has a ring shape along the circumferential direction of the tire 30. The core 64 includes a wound non-stretchable wire. A typical material for the wire is steel. The apex 66 tapers outward in the radial direction. The apex 66 is made of a highly hard crosslinked rubber.

  The carcass 42 includes a first ply 42a and a second ply. The first ply 42 a and the second ply 42 b are bridged between the first bead 38 and the second bead 40, and extend along the tread 32 and the sidewall 34. FIG. 2 is an enlarged cross-sectional view showing the back side portion 68a of the tire 30, and FIG. 3 is an enlarged cross-sectional view showing the front side portion 68b of the tire 30. As shown in FIG. As shown in FIGS. 2 and 3, the first ply 42 a is folded from the inner side toward the outer side around the core. By this folding, a main portion 70 and a folding portion 72 are formed in the first ply 42a. The second ply 42b is folded back from the inner side in the axial direction to the outer side around the core. By this folding, a main portion 74 and a folding portion 76 are formed in the second ply 42b. The end of the folded portion 72 of the first ply 42a is located outside the end of the folded portion of the second ply 42b in the radial direction.

  Each carcass ply includes a large number of cords arranged in parallel and a topping rubber. The absolute value of the angle formed by each cord with respect to the equator plane is 75 ° to 90 °. In other words, the carcass 42 has a radial structure. The cord is made of organic fiber. Examples of preferable organic fibers include polyester fibers, nylon fibers, rayon fibers, polyethylene naphthalate fibers, and aramid fibers. The carcass 42 may be formed from a single ply.

  The belt 52 is located on the radially inner side of the tread 32. The belt 52 is laminated with the carcass 42. The belt 52 reinforces the carcass 42. The belt 52 includes an inner layer 52a and an outer layer 52b. As is clear from FIG. 1, the width of the inner layer 52a is slightly larger than the width of the outer layer 52b in the axial direction. Although not shown, each of the inner layer 52a and the outer layer 52b is composed of a large number of cords arranged in parallel and a topping rubber. Each cord is inclined with respect to the equator plane. The absolute value of the tilt angle is usually 10 ° to 35 °. The inclination direction of the cord of the inner layer 52a with respect to the equator plane is opposite to the inclination direction of the cord of the outer layer 52b with respect to the equator plane. A preferred material for the cord is steel. An organic fiber may be used for the cord. The belt 52 may include three or more layers.

  The inner liner 54 is located inside the carcass 42. The inner liner 54 is joined to the inner surface of the carcass 42. The inner liner 54 is made of a crosslinked rubber. The inner liner 54 is made of rubber having excellent air shielding properties. A typical base rubber of the inner liner 54 is butyl rubber or halogenated butyl rubber. The inner liner 54 holds the internal pressure of the tire 30.

  The pair of chafers 56 are located in the vicinity of the first bead 38 and the second bead 40, respectively. When the tire 30 is assembled into the rim, the chafer 56 contacts the rim. By this contact, the vicinity of the bead is protected. In this embodiment, the chafer 56 is integral with the clinch 36. Therefore, the material of the chafer 56 is the same as the material of the clinch 36. The chafer 56 may be made of a cloth and rubber impregnated in the cloth.

  In FIG. 2, the arrow x represents the axial direction. In the present specification, the outside in the axial direction is referred to as “outside”, and the inside in the axial direction is referred to as “inside”. Arrow y represents the radial direction. In this specification, the radially outer side is referred to as “upper side” and the radial inner side is referred to as “lower side”.

  The first metal filler 44 extends substantially vertically in a cross section perpendicular to the circumferential direction. The first metal filler 44 is located outside the first bead 38. The first metal filler 44 is located outside the carcass 42. The first metal filler 44 is laminated with the folded portion 72 of the first ply 42a. The lower end 78 of the first metal filler 44 is located above the lower end 80 of the core 60 and below the upper end 82 of the core 60. Although not shown, the first metal filler 44 is composed of a large number of parallel cords made of metal and a topping rubber. A preferred material for the cord is steel.

  The first metal filler 44 shown in FIG. 2 is composed of one layer. The first metal filler 44 may be composed of two or more layers.

  The first organic fiber filler 46 includes an outer layer 46a and an inner layer 46b. The outer layer 46a extends substantially in the vertical direction. The outer layer 46 a is located inside the first bead 38. The outer layer 46 a is located inside the carcass 42. The outer layer 46a is laminated with the main portion 70 of the first ply 42a. The lower end 84 of the outer layer 46 a is located above the lower end 80 of the core 60 and below the upper end 82 of the core 60. The inner layer 46b extends substantially in the vertical direction in a cross section perpendicular to the circumferential direction. The inner layer 46 b is located inside the first bead 38. The inner layer 46b is located inside the outer layer 46a. The inner layer 46b is laminated with the outer layer 46a.

  The lower end 84 of the outer layer 46a is located below the lower end 86 of the inner layer 46b. The upper end 88 of the outer layer 46a is located below the upper end 90 of the inner layer 46b. The lower end 84 of the outer layer 46a may be located above the lower end 86 of the inner layer 46b. The upper end 88 of the outer layer 46a may be located below the upper end 90 of the inner layer 46b.

  Although not shown, each of the outer layer 46a and the inner layer 46b is made of a large number of parallel cords made of organic fibers and a topping rubber. Examples of the organic fiber include nylon fiber, polyester fiber, rayon fiber, polyethylene naphthalate fiber, and aramid fiber.

  The first organic fiber filler 46 shown in FIG. 2 is composed of two layers, an outer layer 46a and an inner layer 46b. The first organic fiber filler 46 may be composed of a single layer. The first organic fiber filler 46 may be composed of three or more layers.

  In FIG. 3, the arrow x represents the axial direction, and the arrow y represents the radial direction. As shown in FIG. 3, the second metal filler 48 extends in a substantially vertical direction in a cross section perpendicular to the circumferential direction. The second metal filler 48 is located inside the second bead 40. The second metal filler 48 is located inside the carcass 42. The second metal filler 48 is laminated with the main portion 70 of the first ply 42a. The lower end 92 of the second metal filler 48 is located above the upper end 94 of the core 64. Although not shown, the second metal filler 48 is composed of a large number of parallel cords made of metal and a topping rubber. A preferred material for the cord is steel.

  The second metal filler 48 shown in FIG. 3 is composed of one layer. The second metal filler 48 may be composed of two or more layers.

  The second organic fiber filler 50 includes an inner layer 50b and an outer layer 50a. The inner layer 50b extends in a substantially vertical direction in a cross section perpendicular to the circumferential direction. The inner layer 50 b is located outside the first bead 38. The inner layer 50 b is located outside the carcass 42. The inner layer 50b is laminated with the folded portion 72 of the first ply 42a. The lower end 96 of the inner layer 50 b is located above the lower end 98 of the core 64 and below the upper end 94 of the core 64. The outer layer 50a extends substantially in the vertical direction in a cross section perpendicular to the circumferential direction. The outer layer 50 a is located outside the second bead 40. The outer layer 50a is located outside the inner layer 50b. The outer layer 50a is laminated with the inner layer 50b. The lower end 100 of the outer layer 50 a is located above the lower end 98 of the core 64 and below the upper end 94 of the core 64.

  The lower end 100 of the outer layer 50a is located below the lower end 96 of the inner layer 50b. The upper end 102 of the outer layer 50a is located below the upper end 104 of the inner layer 50b. The lower end 100 of the outer layer 50a may be located above the lower end 96 of the inner layer 50b. The upper end 102 of the outer layer 50a may be located above the upper end 104 of the inner layer 50b.

  Although not shown, each of the outer layer 50a and the inner layer 50b is made of a large number of cords made of organic fibers arranged in parallel and a topping rubber. Examples of the organic fiber include nylon fiber, polyester fiber, rayon fiber, polyethylene naphthalate fiber, and aramid fiber.

  The second organic fiber filler 50 shown in FIG. 3 is composed of two layers, an outer layer 50a and an inner layer 50b. The second organic fiber filler 50 may be composed of a single layer. The second organic fiber filler 50 may be composed of three or more layers.

  Hereinafter, the effect by this invention is demonstrated.

  When the vehicle turns at a high speed, a large load is applied to the tire 30. Most of this load is borne by the outer ring. At this time, both the front side portion 68b and the back side portion 68a of the tire 30 of the outer ring are deformed so that the central portion bends to the front side. That is, for the front side portion 68b of the tire 30, the outer surface 106 is deformed in the pulling direction, and the inner surface 108 is deformed in the compression direction. As for the side portion 68a on the back side of the tire 30, the outer surface 110 is deformed in the compression direction, and the inner surface 112 is deformed in the pulling direction.

  The rigidity with respect to the pulling force of the filler provided with the cord made of the organic fiber is larger than the rigidity with respect to the compressive force. On the other hand, the filler provided with the cord made of metal is excellent in both rigidity against tensile force and rigidity against the compression force, but the mass of the filler provided with the cord made of metal is larger than the mass of the filler provided with the cord made of organic fiber. . In order to make the mass of the filler provided with the cord made of metal equal to the mass of the filler provided with the cord made of organic fiber, it is necessary to make the density of the cord coarse. This filler may not have sufficient rigidity. In the tire 30 according to the present invention, the second organic fiber filler 50 is located outside the second bead 40 located on the front side of the tire 30. Due to the second organic fiber filler 50, the front side portion 68 b has sufficient rigidity against tensile deformation of the outer surface 106. In the tire 30, the second metal filler 48 is located inside the second bead 40. Due to the second metal filler 48, the front side portion 68 b has sufficient rigidity against compression deformation of the inner surface 108. In the tire 30 according to the present invention, the deformation of the front side portion 68b can be effectively suppressed.

  In the tire 30 according to the present invention, the first organic fiber filler 46 is located inside the first bead 38 located on the back side of the tire 30. Due to the first organic fiber filler 46, the back side portion 68 a has sufficient rigidity against tensile deformation of the inner surface 112. In the tire 30, the first metal filler 44 is located outside the first bead 38. Due to the first metal filler 44, the back side portion 68 a has sufficient rigidity against compression deformation of the outer surface 110. In the tire 30 according to the present invention, deformation of the back side portion 68a can be effectively suppressed.

  In the tire 30 according to the present invention, the deformation of the front side portion 68b and the deformation of the back side portion 68a in the outer ring during high-speed turning can be effectively suppressed. The tire 30 is excellent in gripping power during high-speed turning. The tire 30 is excellent in handling stability.

  In the tire 30 according to the present invention, fillers made of organic fiber cords are arranged where tensile deformation occurs during turning, and fillers made of metal cords are arranged where compression deformation occurs. By the arrangement of the filler, rigidity capable of withstanding a large lateral force at the time of turning is realized, and an increase in the mass of the filler is prevented. In the tire 30 according to the present invention, an increase in mass is prevented. In the tire 30, deterioration of fuel efficiency is suppressed.

  The Young's modulus Yc2 of the cord of the second organic fiber filler 50 is preferably larger than the Young's modulus Yc1 of the cord of the first organic fiber filler 46. When the vehicle turns at a high speed, the load applied to the outer ring is greater in the side portion 68 b on the front side of the tire 30 than in the side portion 68 a on the back side of the tire 30. By making the Young's modulus Yc2 larger than the Young's modulus Yc1, the rigidity of the second organic fiber filler 50 can be made larger than the rigidity of the first organic fiber filler 46. By increasing the rigidity of the second organic fiber filler 50, the tire 30 has sufficient rigidity against a large load during high-speed turning. The tire 30 is excellent in gripping power during high-speed turning. By making the rigidity of the first organic fiber filler 46 smaller than the rigidity of the second organic fiber filler 50, excessive rigidity of the tire 30 is suppressed. The tire 30 can secure a sufficient contact area of the tire 30 when traveling straight. The tire 30 is excellent in grip force when traveling straight.

  From the viewpoint of realizing a sufficient grip force during high-speed turning and straight traveling, the ratio (Yc2 / Yc1) of Young's modulus Yc2 to Young's modulus Yc1 is preferably 120 or more.

  The Young's modulus Ym2 of the cord of the second metal filler 48 is preferably larger than the Young's modulus Ym1 of the cord of the first metal filler 44. When the vehicle turns at a high speed, the load applied to the outer ring is greater in the side portion 68 b on the front side of the tire 30 than in the side portion 68 a on the back side of the tire 30. By making the Young's modulus Ym2 larger than the Young's modulus Ym1, the rigidity of the second metal filler 48 can be made larger than the rigidity of the first metal filler 44. By increasing the rigidity of the second metal filler 48, the tire 30 has sufficient rigidity against a large load during high-speed turning. The tire 30 is excellent in gripping power during high-speed turning. By making the rigidity of the first metal filler 44 smaller than the rigidity of the second metal filler 48, the tire 30 is prevented from being excessively rigid. The tire 30 can secure a sufficient contact area of the tire 30 when traveling straight. The tire 30 is excellent in grip force when traveling straight.

  From the viewpoint of realizing sufficient grip force during high-speed turning and straight traveling, the ratio (Ym2 / Ym1) of Young's modulus Ym2 to Young's modulus Ym1 is preferably 120 or more.

  The angle formed by the cords of the first organic fiber filler 46 and the second organic fiber filler 50 with respect to the circumferential direction affects the rigidity of the tire 30. From the viewpoint of realizing high grip performance by increasing the rigidity of the side portion 68, the angle formed by the cords of the first organic fiber filler 46 and the second organic fiber filler 50 with respect to the circumferential direction is preferably 45 ° or less. Further, from the viewpoint of easy manufacture of the tire, the angle is preferably 20 ° or more.

  The angle formed by the cords of the first metal filler 44 and the second metal filler 48 with respect to the circumferential direction affects the rigidity of the tire 30. From the viewpoint of realizing high grip performance by increasing the rigidity of the side portion 68, the angle formed by the cords of the first metal filler 44 and the second metal filler 48 with respect to the circumferential direction is preferably 45 ° or less. Further, from the viewpoint of easy manufacture of the tire, the angle is preferably 20 ° or more.

  In the tire 30, the cord density of the first organic fiber filler 46 and the second organic fiber filler 50 affects the rigidity of the tire 30. The cord density of the first organic fiber filler 46 and the second organic fiber filler 50 is determined by measuring the number of cords (ends) present per 5 cm width of the filler in a cross section perpendicular to the extending direction of the cord. can get. The cord density of the first organic fiber filler 46 and the second organic fiber filler 50 is preferably 20 ends / 5 cm or more and 70 ends / 5 cm or less from the viewpoint that an excellent grip force during turning and straight traveling can be obtained.

  In the tire 30, the cord density of the first metal filler 44 and the second metal filler 48 affects the rigidity of the tire 30. The cord density of the first metal filler 44 and the second metal filler 48 is preferably 20 ends / 5 cm or more and 70 ends / 5 cm or less from the viewpoint that an excellent grip force during turning and straight traveling can be obtained.

  In FIG. 1, FIG. 2 and FIG. 3, a solid line BL represents a base line. In FIG. 1, the double-headed arrow H represents the height in the radial direction from the base line BL to the tread surface 58 on the equator plane of the tire 30. In FIG. 2, the double-headed arrow Hc1 represents the height in the radial direction from the base line BL to the upper end 90 of the first organic fiber filler 46. As shown in the figure, in the tire 30, the upper end 90 of the first organic fiber filler 46 is the upper end 90 of the inner layer 46b. The ratio of the height Hc1 to the height H (Hc1 / H) is preferably 0.2 or more. The back side portion 68a having the first organic fiber filler 46 having a ratio (Hc1 / H) of 0.2 or more has sufficient rigidity against tensile deformation of the inner surface 112 thereof. In this respect, the ratio (Hc1 / H) is more preferably equal to or greater than 0.3. The ratio (Hc1 / H) is preferably 0.8 or less. Excessive rigidity can be suppressed in the back side portion 68a having the first organic fiber filler 46 having a ratio (Hc1 / H) of 0.8 or less. In this respect, the ratio (Hc1 / H) is more preferably equal to or less than 0.6.

  In FIG. 2, a double-headed arrow Hm1 represents the height in the radial direction from the base line BL to the upper end 114 of the first metal filler 44. The ratio of the height Hm1 to the height H (Hm1 / H) is preferably 0.3 or more. The back side portion 68a having the first metal filler 44 with a ratio (Hm1 / H) of 0.3 or more has sufficient rigidity against the compressive deformation of the outer surface 110 thereof. In this respect, the ratio (Hm1 / H) is more preferably equal to or greater than 0.5. The ratio (Hm1 / H) is preferably 0.9 or less. Excessive rigidity can be suppressed in the back side portion 68a having the first metal filler 44 having a ratio (Hm1 / H) of 0.9 or less. In this respect, the ratio (Hm1 / H) is more preferably equal to or less than 0.8.

  In FIG. 3, the double arrow Hc <b> 2 represents the height in the radial direction from the base line BL to the upper end 104 of the second organic fiber filler 50. As shown in the drawing, in the tire 30, the upper end 104 of the second organic fiber filler 50 is the upper end 104 of the inner layer 50b. The ratio of the height Hc2 to the height H (Hc2 / H) is preferably 0.3 or more. The front side portion 68b having the second organic fiber filler 50 having a ratio (Hc2 / H) of 0.3 or more has sufficient rigidity against tensile deformation of the outer surface 106 thereof. In this respect, the ratio (Hc2 / H) is more preferably equal to or greater than 0.5. The ratio (Hc2 / H) is preferably 0.9 or less. In the front side portion 68b having the second organic fiber filler 50 having a ratio (Hc2 / H) of 0.9 or less, excessive rigidity can be suppressed. In this respect, the ratio (Hc2 / H) is more preferably equal to or less than 0.8.

  In FIG. 3, the double-headed arrow Hm2 represents the height in the radial direction from the base line BL to the upper end 116 of the second metal filler 48. The ratio of the height Hm2 to the height H (Hm2 / H) is preferably 0.2 or more. The front side portion 68b having the second metal filler 48 having a ratio (Hm2 / H) of 0.2 or more has sufficient rigidity against compressive deformation of the inner surface 108 thereof. In this respect, the ratio (Hm2 / H) is more preferably equal to or greater than 0.3. The ratio (Hm2 / H) is preferably 0.8 or less. The front side portion 68b having the second metal filler 48 having a ratio (Hm2 / H) of 0.8 or less can suppress excessive rigidity. In this respect, the ratio (Hm2 / H) is more preferably equal to or less than 0.6.

  Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be construed in a limited manner based on the description of the examples.

[Example 1]
A tire of Example 1 having the configuration shown in FIG. 1 was obtained. Table 1 shows the specifications of the tire. In the table, “filler (outside / outside)” indicates a filler disposed on the outer side in the radial direction of the bead in the front side portion. In Example 1, since the organic fiber filler is arrange | positioned here, this corresponds to a 2nd organic fiber filler. Similarly, “filler (inside / inside)” refers to a filler arranged on the inner side in the radial direction of the bead in the front side portion. Since the metal filler is disposed here, this corresponds to the second metal filler. The phrase “filler (back / outside)” refers to a filler disposed on the radially outer side of the bead in the side portion on the back side. Since the metal filler is disposed here, this corresponds to the first metal filler. “Filler (back / inside)” refers to a filler disposed on the inner side in the radial direction of the bead in the side portion on the back side. Since the organic fiber filler is disposed here, this corresponds to the first organic fiber filler.

  For all the fillers, the angle formed by the cord with the circumferential direction was 45 °. In the table, the number of the second organic fiber filler is 2 indicates that the second organic fiber filler has an inner layer and an outer layer. Similarly, the number of first organic fiber fillers being 2 indicates that the first organic fiber filler has an inner layer and an outer layer. The material of the cords of the first organic fiber filler and the second organic fiber filler was aramid fiber. The material of the cords of the first metal filler and the second metal filler was steel. The cord density of the first organic fiber filler and the second organic fiber filler was 40 ends / 5 cm, and the cord density of the first metal filler and the second metal filler was 40 ends / 5 cm.

[Comparative Example 1]
A tire of Comparative Example 1 was obtained in the same manner as in Example 1 except that the filler was not included.

[Comparative Example 2]
There is no filler of “Filler (front / inside)” and “Filler (back / inside)”, and the filler “Filler (back / outside)” is composed of two fillers with cords made of organic fibers. In the same manner as in Example 1, a tire of Comparative Example 2 was obtained. The ratio (Hm1 / H) is the ratio of the height of the “filler (back / outside)” organic fiber filler to the tread height.

[Comparative Example 3]
Except for having "Filler (front / inside)" and "Filler (back / inside)" filler, the "Filler (front / outside)" is composed of a single filler with a metal cord. In the same manner as in Example 1, a tire of Comparative Example 3 was obtained. The ratio (Hc2 / H) is the ratio of the height of the metal filler of the “filler (outside / outside)” to the tread height.

[Comparative Example 4]
A tire of Comparative Example 4 was obtained in the same manner as in Example 1 except that “Filler (inside / inside)” and “Filler (back / outside)” were changed to fillers having cords made of organic fibers. This filler has an inner layer and an outer layer. The ratio (Hm2 / H) is a ratio of the height of the organic filler to the tread height of the “filler (inside / inside)”. The ratio (Hm1 / H) is the ratio of the height of the “filler (back / outside)” organic fiber filler to the tread height.

[Comparative Example 5]
A tire of Comparative Example 5 was obtained in the same manner as in Example 1 except that "Filler (front / outside)" and "Filler (back / inside)" were composed of a single filler having a metal cord. . The ratio (Hc2 / H) is a ratio of the height of the metal filler of the “filler (outside / outside)” to the tread height. The ratio (Hc1 / H) is the ratio of the height of the metal filler of the “filler (back / inside)” to the tread height.

[Example 2-4]
Example except that the Young's modulus of the cord of the second organic fiber filler and the Young's modulus of the cord of the second metal filler were changed and the ratio (Yc2 / Yc1) and ratio (Ym2 / Ym1) were as shown in Table 2 below. In the same manner as in Example 1, a tire of Example 2-4 was obtained.

[Example 5-7]
A tire of Example 5-7 was obtained in the same manner as in Example 1 except that the Young's modulus of the cord of the second organic fiber filler was changed and the ratio (Yc2 / Yc1) was as shown in Table 2 below.

[Example 8-10]
Tires of Examples 8-10 were obtained in the same manner as in Example 1 except that the Young's modulus of the cord of the second metal filler was changed and the ratio (Ym2 / Ym1) was as shown in Table 3 below.

[Examples 11-14]
Example 11 is the same as Example 3 except that the angles of the cords of the second organic fiber filler, second metal filler, first organic fiber filler, and first metal filler with respect to the circumferential direction are as shown in Table 4 below. A tire of -14 was obtained.

[Examples 15-18]
Tires of Examples 15-18 were obtained in the same manner as in Example 3 except that the angles of the cords of the second organic fiber filler and the first organic fiber filler with respect to the circumferential direction were as shown in Table 5 below.

[Examples 19-22]
Tires of Examples 19-22 were obtained in the same manner as in Example 3 except that the angles of the cords of the second metal filler and the first metal filler with respect to the circumferential direction were as shown in Table 6 below.

[Example 23]
A tire of Example 23 was obtained in the same manner as in Example 3 except that the second organic fiber filler and the first organic fiber filler were only one inner layer.

[Example 24]
A tire of Example 24 was obtained in the same manner as in Example 3 except that the number of the second metal filler and the first metal filler was two.

[Examples 25-30]
Tires of Examples 25-30 were obtained in the same manner as Example 3 except that the ratio (Hc2 / H) and the ratio (Hc1 / H) were as shown in Table 8 below.

[Examples 31-36]
Tires of Examples 31 to 36 were obtained in the same manner as in Example 3 except that the ratio (Hm2 / H) and the ratio (Hm1 / H) were as shown in Table 9 below.

[Grip strength]
A prototype tire was incorporated into a rim of 7J-16.0, and the tire was filled with air so that the internal pressure was 200 kPa. This tire was mounted on the rear wheel of a rear-driven automobile having a displacement of 3000 cc. A commercially available tire (size: 205 / 55R16) was attached to the front wheel and filled with air so that the internal pressure was 230 kPa. The car was run on a circuit course with asphalt on the road surface, and sensory evaluation was performed by the driver. The evaluation item is grip strength. The results are shown in Tables 1 to 9 below as indices with the result of Comparative Example 2 as 100. Larger values are preferred.

[Tire mass]
The mass of the tire was measured. The results are shown in Tables 1 to 9 below as index values with Comparative Example 2 taken as 100. It is shown that the smaller the numerical value, the smaller the mass. The smaller the value, the better.

  As shown in Tables 1 to 9, the tire according to the present invention has an excellent grip force while suppressing an increase in tire mass. From this evaluation result, the superiority of the present invention is clear.

  The tire according to the present invention can be applied to various vehicles.

2, 30 ... Tire 4, 32 ... Tread 6, 34 ... Sidewall 8 ... Bead 10, 42 ... Carcass 12 ... Belt, 52
16, 68 ... side part 16a, 68a ... back side part 16b, 68b ... front side part 18, 22, 106, 110 ... outer surface 20, 24, 108, 112 ... inner surface 36 ... Clinch 38 ... First bead 40 ... Second bead 42a ... First ply 42b ... Second ply 44 ... First metal filler 46 ... First organic fiber filler 48 ... Second metal filler 50 ... Second organic fiber filler 46a, 50a, 52b ... Outer layer 46b, 50b, 52a ... Inner layer 54 ... Inner liner 56 ... Chafer 58 ... Tread surface 60, 64 ... Core 62, 66 ... Apex 70, 74 ... Main part 72, 76 ... Folded part 78, 80, 84, 86, 92, 96, 98, 00 ... lower end 82,88,90,94,102,104,114,116 ... upper end

Claims (9)

A tread whose outer surface forms a tread surface, a pair of sidewalls each extending substantially inward in the radial direction from the end of the tread, and a radius from the sidewall located inward of the vehicle when the tire is mounted on the vehicle A first bead that extends substantially inward in the direction, a second bead that extends substantially outward in the radial direction from the side wall located outside the vehicle when the tire is mounted on the vehicle, and the inside of the tread and the side wall. A carcass spanned between the two beads, a first metal filler having a cord made of many parallel metals, and a first organic fiber filler having a cord made of many organic fibers juxtaposed. A second metal filler with a cord made of a large number of juxtaposed metals and a second organic filler with a cord made of a large number of juxtaposed organic fibers And a Wei filler,
The first metal filler is located outside the first bead in the axial direction;
The first organic fiber filler is located on the inner side in the axial direction of the first bead;
The second metal filler is located on the axially inner side of the second bead;
A pneumatic tire in which the second organic fiber filler is positioned on the outer side in the axial direction of the second bead.   The pneumatic tire according to claim 1, wherein the Young's modulus of the cord of the second metal filler is larger than the Young's modulus of the cord of the first metal filler.   The pneumatic tire according to claim 1 or 2, wherein the Young's modulus of the cord of the second organic fiber filler is larger than the Young's modulus of the cord of the first organic fiber filler.   The pneumatic tire according to any one of claims 1 to 3, wherein an absolute value of an angle formed by the cord of the first metal filler and the cord of the second metal filler with respect to a circumferential direction is 20 ° or more and 45 ° or less. .   The air according to any one of claims 1 to 4, wherein an absolute value of an angle formed by the cord of the first organic fiber filler and the cord of the second organic fiber filler with respect to a circumferential direction is 20 ° or more and 45 ° or less. Enter tire.   In the radial direction, the ratio (Hm1 / H) of the height Hm1 from the base line to the outer end of the first metal filler with respect to the height H from the base line to the tread surface on the equator plane of the tire is 0.3. The pneumatic tire according to any one of claims 1 to 5, which is 0.9 or more and 6 or less.   The ratio (Hc1 / H) of the height Hc1 from the base line to the outer end of the first organic fiber filler with respect to the height H in the radial direction is 0.2 or more and 0.8 or less. The pneumatic tire according to any one of 6.   The ratio (Hm2 / H) of the height Hm2 from the base line to the outer end of the second metal filler with respect to the height H in the radial direction is 0.2 or more and 0.8 or less. The pneumatic tire according to any one of the above.   The ratio (Hc2 / H) of the height Hc2 from the base line to the outer end of the second organic fiber filler with respect to the height H in the radial direction is 0.3 or more and 0.9 or less. The pneumatic tire according to any one of 8.

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