WO2017061491A1 - 空気入りタイヤ - Google Patents
空気入りタイヤ Download PDFInfo
- Publication number
- WO2017061491A1 WO2017061491A1 PCT/JP2016/079666 JP2016079666W WO2017061491A1 WO 2017061491 A1 WO2017061491 A1 WO 2017061491A1 JP 2016079666 W JP2016079666 W JP 2016079666W WO 2017061491 A1 WO2017061491 A1 WO 2017061491A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- tire
- belt
- width direction
- belt ply
- feature point
- Prior art date
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/01—Shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/0008—Tyre tread bands; Tread patterns; Anti-skid inserts characterised by the tread rubber
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/0041—Tyre tread bands; Tread patterns; Anti-skid inserts comprising different tread rubber layers
- B60C11/005—Tyre tread bands; Tread patterns; Anti-skid inserts comprising different tread rubber layers with cap and base layers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C3/00—Tyres characterised by the transverse section
- B60C3/04—Tyres characterised by the transverse section characterised by the relative dimensions of the section, e.g. low profile
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
- B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
- B60C9/1835—Rubber strips or cushions at the belt edges
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
- B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
- B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
- B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
- B60C9/28—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers characterised by the belt or breaker dimensions or curvature relative to carcass
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
- B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
- B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
- B60C2009/2012—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel with particular configuration of the belt cords in the respective belt layers
- B60C2009/2019—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel with particular configuration of the belt cords in the respective belt layers comprising cords at an angle of 30 to 60 degrees to the circumferential direction
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
- B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
- B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
- B60C2009/2012—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel with particular configuration of the belt cords in the respective belt layers
- B60C2009/2022—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel with particular configuration of the belt cords in the respective belt layers comprising cords at an angle of 60 to 90 degrees to the circumferential direction
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
- B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
- B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
- B60C2009/2074—Physical properties or dimension of the belt cord
- B60C2009/2083—Density in width direction
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/0008—Tyre tread bands; Tread patterns; Anti-skid inserts characterised by the tread rubber
- B60C2011/0016—Physical properties or dimensions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/0008—Tyre tread bands; Tread patterns; Anti-skid inserts characterised by the tread rubber
- B60C2011/0016—Physical properties or dimensions
- B60C2011/0033—Thickness of the tread
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/01—Shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered
- B60C2011/013—Shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered provided with a recessed portion
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C2011/0337—Tread patterns characterised by particular design features of the pattern
- B60C2011/0339—Grooves
- B60C2011/0341—Circumferential grooves
- B60C2011/0355—Circumferential grooves characterised by depth
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C2011/0337—Tread patterns characterised by particular design features of the pattern
- B60C2011/0386—Continuous ribs
- B60C2011/039—Continuous ribs provided at the shoulder portion
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C2200/00—Tyres specially adapted for particular applications
- B60C2200/06—Tyres specially adapted for particular applications for heavy duty vehicles
Definitions
- An aspect of the present invention aims to provide a pneumatic tire that can prevent damage to the tread rubber, improve riding comfort, and improve belt durability.
- a pneumatic tire that rotates about a rotation axis, a tread portion including a tread rubber, a side portion including side rubber provided on both sides of the tread portion in the tire width direction, and a carcass
- a belt layer disposed on the outer side in the tire radial direction than the carcass, and a plurality of the tread portions are provided in the tire width direction, each extending in the tire circumferential direction, and the circumferential main groove extending in the tire circumferential direction.
- a plurality of land portions having a contact surface that is partitioned by the main grooves and that contacts the road surface, and the tread rubber formed with the circumferential main grooves and the land portions is radially outer than the belt layer.
- the land portion is disposed on the outer side in the tire width direction than the shoulder main groove closest to the ground contact end of the tread portion among the plurality of circumferential main grooves, and includes the ground contact end.
- a surface of the shoulder land portion outside the ground contact end in the tire width direction is connected to a surface of the side portion, and passes through the ground contact surface in a meridional section of the tread portion passing through the rotation shaft.
- the belt layer includes a plurality of belt plies arranged in the tire radial direction, and the belt having the longest dimension in the tire width direction among the tire equatorial plane in the tire width direction and the plurality of belt plies.
- the distance from the end of the ply is S, it is preferable that the condition of 0.85 ⁇ S / C ⁇ 1.00 is satisfied.
- a fourth belt ply disposed on the outer side in the direction, and a cross ply belt layer is formed by the second belt ply and the third belt ply, and the first belt ply, the second belt ply, and the third belt ply
- Each of the belt ply and the fourth belt ply includes a plurality of belt cords and a belt rubber that covers the belt cords.
- the second belt ply and the third belt ply when the number of the belt cords arranged per 50 [mm] is BPc, the condition of 18 [lines] ⁇ BPc ⁇ 28 [lines] is satisfied. It is preferable to do.
- the belt cord of the first belt ply is inclined in the same direction as the belt cord of the second belt ply, and the tire equator plane and the surface of the tread portion intersect each other.
- the inclination angle of the belt cord of the first belt ply with respect to is ⁇ e, it is preferable to satisfy the condition of 45 [°] ⁇ ⁇ e ⁇ 70 [°].
- the condition of 70 ⁇ Hs is satisfied.
- a third imaginary line passing through the ground contact end and the intersection point in the meridional section and a fourth imaginary line parallel to the tire equator plane and passing through the intersection point are defined, and the third imaginary line is defined.
- the angle formed by the phantom line and the fourth phantom line is ⁇ a, it is preferable that the condition of 5 [°] ⁇ ⁇ a ⁇ 50 [°] is satisfied.
- the condition of D / C ⁇ 0.80 is satisfied. It is preferable to do.
- the present invention is preferably for heavy loads mounted on trucks and buses.
- a pneumatic tire that can prevent damage to the tread rubber, improve riding comfort, and improve belt durability.
- FIG. 1 is a meridional sectional view showing an example of a tire according to the present embodiment.
- FIG. 2 is a meridional sectional view of the tread portion according to the present embodiment.
- FIG. 3 is an enlarged view of a part of FIG.
- FIG. 4 is a perspective view showing a part of the tire according to the present embodiment.
- FIG. 5 is a schematic view in which a part of the tire according to the present embodiment is broken.
- FIG. 6 is a schematic diagram for explaining the curvature of the tire according to the present embodiment.
- FIG. 7 is a diagram illustrating a relationship between each feature point and the tire warping according to the present embodiment.
- FIG. 8 is a diagram showing the evaluation test results of the tire according to this embodiment.
- FIG. 9 is a perspective view illustrating a modified example of the shoulder land portion according to the embodiment.
- FIG. 10 is a side view of the shoulder land portion shown in FIG.
- the tire 1 travels on the road surface by rotating around the rotation axis AX while being mounted on a vehicle such as a truck and a bus.
- a direction parallel to the rotation axis AX of the tire 1 is appropriately referred to as a tire width direction
- a radial direction with respect to the rotation axis AX of the tire 1 is appropriately referred to as a tire radial direction
- the rotation direction around AX is appropriately referred to as the tire circumferential direction.
- a position far from or away from the tire equatorial plane CL in the tire width direction is appropriately referred to as a tire width direction outer side, and a position close to or approaching the tire equatorial plane CL in the tire width direction is appropriately designated.
- the inner side in the tire width direction is referred to as the tire radial direction
- the position far from or away from the rotational axis AX is appropriately referred to as the outer side in the tire radial direction
- the tire radial direction is referred to as the position closer to or closer to the rotational axis AX as appropriate. It is referred to as the direction inner side.
- the inner side in the vehicle width direction of the vehicle is appropriately referred to as the vehicle inner side
- the outer side in the vehicle width direction of the vehicle is appropriately referred to as the outer side of the vehicle.
- the vehicle inner side means a position close to or approaching the center of the vehicle in the vehicle width direction of the vehicle.
- the vehicle outer side means a position far from or away from the center of the vehicle in the vehicle width direction of the vehicle.
- FIG. 1 shows a meridional section passing through the rotation axis AX of the tire 1.
- FIG. 1 shows a cross section of the tire 1 on one side of the tire equatorial plane CL in the tire width direction.
- the tire 1 has a symmetric structure and shape with respect to the tire equatorial plane CL in the tire width direction.
- the tire 1 includes a tread portion 2 in which a tread pattern is formed, side portions 3 provided on both sides of the tread portion 2 in the tire width direction, and a bead portion 4 connected to the side portion 3. Is provided. When the tire 1 travels, the tread portion 2 comes into contact with the road surface.
- the tire 1 includes a carcass 5, a belt layer 6 disposed outside the carcass 5 in the tire radial direction, and a bead core 7.
- the carcass 5, the belt layer 6, and the bead core 7 function as strength members (frame members) of the tire 1.
- the tire 1 includes a tread rubber 8 and a side rubber 9.
- the tread portion 2 includes a tread rubber 8.
- the side part 3 includes a side rubber 9.
- the tread rubber 8 is disposed on the outer side in the tire radial direction than the belt layer 6.
- the carcass 5 is a strength member that forms the skeleton of the tire 1.
- the carcass 5 functions as a pressure vessel when the tire 1 is filled with air.
- the carcass 5 includes a plurality of carcass cords made of organic fibers or steel fibers, and carcass rubber that covers the carcass cords.
- the carcass 5 is supported by the bead core 7 of the bead part 4.
- the bead core 7 is disposed on each of one side and the other side of the carcass 5 in the tire width direction.
- the carcass 5 is folded back at the bead core 7.
- the belt layer 6 is a strength member that holds the shape of the tire 1.
- the belt layer 6 is disposed between the carcass 5 and the tread rubber 8 in the tire radial direction.
- the belt layer 6 fastens the carcass 5.
- the rigidity of the carcass 5 is increased by the tightening force applied by the belt layer 6.
- the belt layer 6 reduces the impact of the tire 1 when traveling and protects the carcass 5. For example, even if the tread portion 2 is damaged, the belt layer 6 prevents the carcass 5 from being damaged.
- the belt layer 6 has a plurality of belt plies arranged in the tire radial direction.
- the belt layer 6 is a so-called four-sheet belt and has four belt plies.
- the belt ply includes a first belt ply 61 disposed on the innermost side in the tire radial direction, a second belt ply 62 disposed on the inner side in the tire radial direction after the first belt ply 61, and a tire subsequent to the second belt ply 62. It includes a third belt ply 63 disposed on the radially inner side and a fourth belt ply 64 disposed on the most radially outer side of the tire.
- the first belt ply 61 and the second belt ply 62 are adjacent to each other.
- the second belt ply 62 and the third belt ply 63 are adjacent to each other.
- the third belt ply 63 and the fourth belt ply 64 are adjacent to each other.
- the dimensions of the belt plies 61, 62, 63, 64 in the tire width direction are different.
- the dimension of the second belt ply 62 is the largest
- the dimension of the third belt ply 63 is large after the second belt ply 62
- the dimension of the first belt ply 61 is large after the third belt ply 63
- the dimension of the fourth belt ply 64 is the smallest.
- the belt plies 61, 62, 63, 64 include a plurality of metal fiber belt cords and a belt rubber that covers the belt cords.
- a cross ply belt layer is formed by the second belt ply 62 and the third belt ply 63 that are adjacent to each other in the tire radial direction.
- the second belt ply 62 and the third belt ply 63 are arranged so that the belt cord of the second belt ply 62 and the belt cord of the third belt ply 63 intersect.
- the bead portion 4 is a strength member that fixes both ends of the carcass 5.
- the bead core 7 supports the carcass 5 to which tension is applied by the internal pressure of the tire 1.
- the bead portion 4 includes a bead core 7 and a bead filler rubber 7F.
- the bead core 7 is a member in which a bead wire 7W is wound in a ring shape.
- the bead wire 7W is a steel wire.
- the bead filler rubber 7F fixes the carcass 5 to the bead core 7. Further, the bead filler rubber 7 ⁇ / b> F adjusts the shape of the bead part 4 and increases the rigidity of the bead part 4.
- the bead filler rubber 7 ⁇ / b> F is disposed in a space formed by the carcass 5 and the bead core 7.
- the bead filler rubber 7 ⁇ / b> F is disposed in a space formed by folding the end portion in the tire width direction of the carcass 5 at the position of the bead core 7.
- a bead core 7 and a bead filler rubber 7F are disposed in a space formed by folding the carcass 5.
- the tread rubber 8 protects the carcass 5.
- the tread rubber 8 includes an under tread rubber 81 and a cap tread rubber 82.
- the under tread rubber 81 is provided on the outer side in the tire radial direction than the belt layer 6.
- the cap tread rubber 82 is provided on the outer side in the tire radial direction than the under tread rubber 81.
- the tread pattern is formed on the cap tread rubber 82.
- a plurality of tread portions 2 are provided in the tire width direction, each of which is divided by a circumferential main groove 10 extending in the tire circumferential direction, and a plurality of land portions having a contact surface that is in contact with the road surface. 20.
- the circumferential main groove 10 and the land portion 20 are formed in the cap tread rubber 82 of the tread rubber 8.
- the land portion 20 has a ground contact surface 30 that can come into contact with the road surface when the tire 1 travels.
- the center land portion 21 includes a tire equatorial plane CL.
- the tire equatorial plane CL (tire equatorial line) passes through the center land portion 21.
- One second land portion 22 is provided on each side of the tire equatorial plane CL in the tire width direction.
- One shoulder land portion 23 is provided on each side of the tire equatorial plane CL in the tire width direction.
- the ground surface 30 of the land portion 20 that can contact the road surface includes a ground surface 31 of the center land portion 21, a ground surface 32 of the second land portion 22, and a ground surface 33 of the shoulder land portion 23.
- a part of the fourth belt ply 64 is disposed immediately below the center main groove 11.
- the fourth belt ply 64 is not disposed immediately below the shoulder main groove 12.
- a third belt ply 63 is disposed immediately below the shoulder main groove 12. The term “directly below” refers to the same position in the tire width direction and the inner position in the tire radial direction.
- FIG. 2 is a diagram showing a meridional section of the tread portion 2 according to the present embodiment.
- FIG. 3 is an enlarged view of a part of FIG.
- FIG. 4 is a perspective view showing a part of the tire 1 according to the present embodiment.
- FIG. 5 is a schematic view in which a part of the tire 1 according to the present embodiment is broken.
- the meridional section of the tread portion 2 refers to a section passing through the rotation axis AX and parallel to the rotation axis AX.
- the tire equatorial plane CL passes through the center of the tread portion 2 in the tire width direction.
- the outer diameter of the tire 1 means that the tire 1 is mounted on an applicable rim, has a prescribed air pressure, and the outer diameter of the tire 1 in an unloaded state is Say.
- the tread width of the tread portion 2 is that the tire 1 is mounted on an applicable rim, has a specified air pressure, and the unloaded tire 1 The linear distance between both ends of the tread pattern.
- the ground contact edge T of the tread portion 2 is in contact with the flat plate when the tire 1 is mounted on the applicable rim, set to a specified air pressure, placed perpendicular to the flat plate in a stationary state, and a load corresponding to the specified mass is applied. This refers to the end of the portion in the tire width direction.
- the term explained below is the term in the condition when the tire 1 when it is new is mounted on the applicable rim, the specified air pressure is set, and there is no load.
- the ground contact width and the ground contact end T are mounted on the rim of the tire 1, set to a specified air pressure, placed in a stationary state perpendicular to the flat plate, and applied with a load corresponding to a specified mass. Sometimes measured dimensions and positions. When a load corresponding to a specified mass is applied, the grounding end T is measured, and the position of the measured grounding end T is positioned on the surface of the tread portion 2 in a no-load state.
- a virtual line passing through the ground contact surface 30 of the land portion 20 is defined as a first virtual line VL1.
- a first imaginary line VL1 indicates a profile of the ground contact surface 30 of the tire 1 when the tire 1 is mounted on the applied rim and has a prescribed air pressure and is in a no-load state.
- the distance between the opening end 12Kb on the outer side in the tire radial direction and the bottom 12B of the shoulder main groove 12 may be the groove depth B.
- the average value of the distance between the opening end portion 12Ka and the bottom portion 12B and the distance between the opening end portion 12Kb and the bottom portion 12B in the tire radial direction may be set as the groove depth B. If the positions of the opening end 12Ka and the opening end 12Kb in the tire radial direction are substantially equal, one of the two opening ends 12Ka and 12Kb and the bottom of the shoulder main groove 12 are used.
- the distance from 12B may be the groove depth B.
- a virtual line parallel to the tire equatorial plane CL and passing through the intersection point P is defined as a fourth virtual line VL4.
- the fourth imaginary line VL4 is a straight line that passes through the intersection point P when the tire 1 is mounted on the applied rim, has a prescribed air pressure, and is in a no-load state.
- an angle formed by the third imaginary line VL3 and the fourth imaginary line VL4 is defined as an angle ⁇ a.
- the side wall portion 12Sb in the meridional section of the tread portion 2, is inclined outward in the tire width direction toward the outer side in the tire radial direction with respect to the fifth virtual line VL5.
- an angle formed by the fifth imaginary line VL5 and the side wall portion 12Sb on the outer side in the tire width direction of the shoulder main groove 12 is defined as an angle ⁇ b.
- the distance between the opening end portion 12Kb on the outer side in the tire width direction of the shoulder main groove 12 in the tire width direction and the ground contact end T is defined as a distance F.
- the distance F is the dimension of the ground contact surface 33 of the shoulder land portion 23 in the tire width direction.
- the distance F is the distance between the opening end 12Kb and the ground contact end T when the tire 1 is mounted on the applicable rim and has a prescribed air pressure and is in an unloaded state.
- the dimension of the center land portion 21 in the tire width direction in the meridional section of the tread portion 2 is defined as a dimension G.
- the dimension G is a dimension of the center land portion 21 when the tire 1 is mounted on the applicable rim, has a prescribed air pressure, and is in an unloaded state.
- the dimension G is a dimension of the ground contact surface 31 of the center land portion 21 in the tire width direction.
- the distance between the tire equatorial plane CL in the tire width direction and the portion of the side portion 3 on the outermost side in the tire width direction is defined as a distance H.
- the distance H is a distance between the tire equatorial plane CL and the portion of the side portion 3 on the outermost side in the tire width direction when the tire 1 is mounted on the applied rim and has a prescribed air pressure and is in an unloaded state.
- the distance H is half the total width.
- the tire outer diameter at the tire equatorial plane CL is defined as a tire outer diameter J.
- the tire outer diameter J is a diameter of the tire 1 on the tire equatorial plane CL when the tire 1 is mounted on an applicable rim, has a prescribed air pressure, and is in a no-load state.
- the tire outer diameter at the opening end portion 12Ka on the inner side in the tire width direction of the shoulder main groove 12 is defined as a tire outer diameter K.
- the tire outer diameter K is the diameter of the tire 1 at the open end 12Ka when the tire 1 is mounted on an applicable rim and has a prescribed air pressure and is in an unloaded state.
- the distance between the bottom 12B of the shoulder main groove 12 and the belt layer 6 in the tire radial direction is defined as a distance M.
- the third belt ply 63 is disposed directly below the bottom 12B of the shoulder main groove 12.
- the distance M is the bottom surface 12B of the shoulder main groove 12 and the outer surface of the third belt ply 63 disposed immediately below the bottom portion 12B when the tire 1 is mounted on the applicable rim and has a specified air pressure and is in an unloaded state. And the distance.
- the tire diameter of the second belt ply 62 and the third belt ply 63 that form a cross ply belt layer with the ground contact surface 33 of the shoulder land portion 23 in the tire radial direction is defined as a distance N.
- the distance N is determined by attaching the tire 1 to the applicable rim, setting the air pressure to a specified level, and in the no-load state, the end of the third belt ply 63 in the tire width direction and the third belt ply 63 of the ground contact surface 33. This is the distance in the tire radial direction from the portion immediately above the end.
- a plurality of recesses 40 are provided in the tire circumferential direction on the side surface 34 of the shoulder land portion 23 on the outer side in the tire width direction than the ground contact end T.
- the recess 40 is a lug groove formed in the side surface 34.
- the recess 40 extends in the tire radial direction.
- the dimension of the recess 40 in the tire circumferential direction is defined as a dimension U.
- the dimension U of the recessed part 40 is a dimension when the tire 1 is mounted on the applied rim, the air pressure is regulated, and no load is applied.
- the dimension of the recess 40 in the tire circumferential direction is smaller than the dimension of the recess 40 in the tire radial direction.
- the dimension between the recesses 40 adjacent in the tire circumferential direction is defined as a dimension V.
- the dimension V is the dimension of the interval between the adjacent recesses 40 when the tire 1 is mounted on the applicable rim and has a prescribed air pressure and is in an unloaded state.
- the dimension V is larger than the dimension U.
- a plurality of sipes 41 are provided in the tire circumferential direction on the side surface 34 of the shoulder land portion 23.
- the sipe 41 has a shallower groove depth and a smaller groove width than the concave portion 40 (lug groove).
- the sipe 41 extends in the tire radial direction.
- a plurality of sipes 41 are provided between the recesses 40 adjacent in the tire circumferential direction.
- the dimension between sipes 41 adjacent in the tire circumferential direction is defined as a dimension W.
- the dimension W is the dimension of the interval between the adjacent sipes 41 when the tire 1 is mounted on the applicable rim and has a prescribed air pressure and is in an unloaded state.
- the dimension W is smaller than the dimension of the sipe 41 in the tire radial direction.
- the lug groove (recess) 40 is a groove in which the opening of the groove is maintained even when the lug groove is grounded, assuming that the lug groove is grounded.
- the sipe 41 is a groove that is closed without maintaining the opening of the sipe 41 when it is assumed that the sipe 41 is grounded.
- the inclination direction of the belt cord of the second belt ply 62 and the inclination direction of the belt cord of the third belt ply 63 with respect to the tire equator line are different.
- the belt cord of the second belt ply 62 is inclined toward one side in the tire width direction toward one side in the tire circumferential direction.
- the belt cord of the third belt ply 63 is inclined toward the other side in the tire width direction toward one side in the tire circumferential direction.
- the inclination angle of the belt cord of the second belt ply 62 with respect to the tire equator line is defined as an angle ⁇ c.
- an inclination angle of the belt cord of the third belt ply 63 with respect to the tire equator line is defined as an angle ⁇ d.
- the tire 1 has a plurality of feature points. Each feature point will be described sequentially.
- the shoulder main groove 12 When the tire 1 turns or rides on the curb, the shoulder main groove 12 is deformed so as to expand, and the shoulder land portion 23 is displaced outward in the tire width direction, the value (B + C) depends on the groove depth B. Thus, the value A approaches.
- the feature point 1 defines the degree of approximation of the distance A and the sum of the groove depth B and the distance C when the shoulder land portion 23 is displaced outward in the tire width direction.
- Feature point 2 defines the rising degree of the side surface 34 of the shoulder land portion 23.
- Feature point 3 specifies that the circumferential main groove 10 (shoulder main groove 12) is not arranged outside 20 [%] of the distance C (half value of the contact width).
- Feature point 4 stipulates that the bottom 12B of the shoulder main groove 12 is not angular and the radius of curvature R is preferably large.
- Feature point 5 defines the ratio of groove depth B to distance E.
- Feature point 6 defines the rising degree of the side wall portion 12Sb on the outer side in the tire width direction among the inner surface of the shoulder main groove 12.
- Feature point 8 defines the ratio between the dimension of the ground contact surface 31 of the center land portion 21 and the dimension of the ground contact surface 33 of the shoulder land portion 23 in the tire width direction.
- Feature point 9 defines the ratio between the dimension of the ground contact surface 33 of the shoulder land portion 23 and the groove depth B in the tire width direction.
- Hs hardness indicating the resistance to the dent of the cap tread rubber 82 at room temperature (23 [° C.])
- loss coefficient indicating the ratio between the storage shear modulus and the loss shear modulus of the cap tread rubber 82 at 60 [° C.] is tan ⁇ .
- 0.21 ⁇ tan ⁇ (12C) It is preferable to satisfy the conditions of 0.05 ⁇ tan ⁇ ⁇ 0.23 (12D) It is more preferable that the above condition is satisfied.
- the feature point 12 defines the physical properties of the cap tread rubber 82 of the tread rubber 8 in which the circumferential main groove 10 and the land portion 20 are formed.
- Feature point 16 defines the ratio of half the ground contact width to half the total width.
- the first belt ply 61, the second belt ply 62, the third belt ply 63, and the fourth belt ply 64 each include a plurality of belt cords and a belt rubber that covers the belt cords.
- the second belt ply 62 and the third belt ply 63 forming the cross ply belt layer when the number of belt cords arranged per 50 [mm] is BPc, 18 [books] ⁇ BPc ⁇ 28 [books] (17A) Satisfy the conditions.
- the belt cord of the first belt ply 61 is inclined in the same direction as the belt cord of the second belt ply 62. That is, the first belt ply 61 and the second belt ply 62 are laminated such that the belt cord of the first belt ply 61 and the belt cord of the second belt ply 62 are inclined in the same direction.
- the inclination angle of the belt cord of the first belt ply 61 with respect to the tire equator line is ⁇ e, 45 [°] ⁇ ⁇ e ⁇ 70 [°] (17E) Satisfy the conditions.
- the feature point 19 defines the ratio between the dimension of the recess 40 provided on the side surface 34 of the shoulder land portion 23 and the dimension of the interval between the recesses 40.
- the feature point 20 defines the absolute value of the dimension of the recess 40.
- the characteristic point 21 defines a ratio between the dimension of the ground contact surface 33 of the shoulder land portion 23 in the tire width direction and the dimension of the interval between the sipes 41 provided on the side surface 34 of the shoulder land portion 23.
- the feature point 22 defines the relationship between the distance M of the tread rubber 8 immediately below the shoulder main groove 12 and the groove depth B.
- the feature point 23 defines a ratio between the half value of the second belt ply 62 and the half value of the ground contact width.
- FIG. 6 is a schematic diagram for explaining an evaluation test.
- the shoulder land portion 23 on the vehicle outer side of the evaluation test tire mounted on the vehicle was placed on the curb.
- the amount of deformation of the shoulder land portion 23 when the shoulder land portion 23 on the outside of the vehicle was mounted on the curb was measured.
- the shoulder land portion 23 is deformed so that the ground contact surface 33 of the shoulder land portion 23 is warped.
- a large amount of warping SH means that the shoulder land portion 23 is excessively deformed. If the warpage amount SH is large, there is a high possibility that a crack will occur on the inner surface of the shoulder main groove 12, the shoulder land portion 23 will be damaged, or a phenomenon called rib tear will occur.
- the rib tear is a phenomenon in which a part of the tread rubber 8 is peeled or damaged by the action of an external force. The smaller the amount of warpage SH, the more preferable from the viewpoints of suppressing the occurrence of cracks on the inner surface of the shoulder main groove 12, suppressing the breakage of the shoulder land portion 23, and suppressing the occurrence of rib tears.
- the tire according to the conventional example does not satisfy the condition of the feature point 1, and the value of (B + C) / A is larger than 1.15.
- the tires according to Examples A, B, C, D, and E satisfy the condition of feature point 1.
- the warping amount SH of the tire according to the conventional example is larger than 6 [mm].
- the amount of warping SH of the tires according to Examples A, B, C, D, and E is 6 [mm] or less.
- the tires according to Examples A, B, and C are tires that satisfy the condition of feature point 1 and do not satisfy the conditions of feature point 2 to feature point 24. As can be seen from Examples A, B, and C, the smaller the value of (B + C) / A, the smaller the warpage amount SH.
- Example D is a tire that satisfies the conditions of feature point 1, feature point 2, and feature point 3.
- the value of (B + C) / A of the tire according to Example B is substantially equal to the value of (B + C) / A of the tire according to Example D.
- the amount of warping SH of the tire according to Example D is smaller than the amount of warping SH of the tire according to Example B.
- the shoulder land portion 23 is prevented from warping during turning of the tire, and the steering stability performance is improved.
- the value of E / B is larger than 5.0, the rigidity of the shoulder land portion 23 becomes larger than the rigidity of the center land portion 21 and the behavior linearity of the vehicle with respect to the steering is deteriorated.
- the value of E / B is smaller than 2.0, the rigidity of the shoulder land portion 23 is extremely reduced, and the possibility that the shoulder land portion 23 warps during turning of the tire 1 increases.
- the shoulder land portion 23 is warped, the steering stability performance in turning of the tire 1 is deteriorated.
- the warpage of the shoulder land portion 23 is suppressed, and the shoulder main groove is suppressed. It is suppressed that a crack is generated on the inner surface of 12, the shoulder land portion 23 is damaged, and a rib tear is generated.
- a large value of (B + C) / A means that the volume of the cap tread rubber 82 is large.
- a small value of (B + C) / A means that the volume of the cap tread rubber 82 is small.
- the value of (B + C) / A is larger than 1.15, the volume of the cap tread rubber 82 becomes excessive. If the volume of the cap tread rubber 82 is excessive, the effect of improving the riding comfort is reduced even if the volume of the cap tread rubber 82 is increased. Further, when the volume of the cap tread rubber 82 is excessive, heat generation of the tread rubber 8 is hindered when the tire 1 travels. As a result, the belt layer 6 is adversely affected and the belt durability performance is lowered.
- the value of (B + C) / A is smaller than 0.80, the volume of the cap tread rubber 82 is too small. As a result, the riding comfort is deteriorated.
- the belt cord of the first belt ply 61 which is the feature point 17B, is inclined in the same direction as the belt cord of the second belt ply 62, 45 [°] ⁇ ⁇ e ⁇ 70 [°] (17E) Satisfy the conditions.
- the condition of the characteristic point 17B rigidity by the belt layer 6 that can improve riding comfort is ensured, and belt durability can be improved.
- the feature point 14 15 [books] ⁇ BP1 ⁇ 25 [books] (14A) Satisfy the conditions. By satisfying the condition of the feature point 14, rigidity by the belt layer 6 that can improve riding comfort is ensured. When the condition of the feature point 14 is satisfied, the feeling of pushing up when the tire 1 passes through the road surface step is suppressed.
- the tread rubber 8 is suppressed from being peeled or chipped.
- the value of (B + C) / A is larger than 1.15, the shoulder land portion 23 is easy to move, and when the shoulder land portion 23 comes into contact with the curb, it is easy to bald.
- the value of (B + C) / A is smaller than 0.80, the contact pressure of the shoulder land portion 23 becomes high, and when the shoulder land portion 23 comes into contact with the curb, it is easy to chip.
- the tread rubber 8 is more effectively suppressed from being peeled or chipped.
- the angle ⁇ a is larger than 50 [°]
- the contact pressure of the shoulder land portion 23 becomes high, and the shoulder land portion 23 is easily chipped when it contacts the curb.
- the angle ⁇ a is smaller than 5 °
- the shoulder land portion 23 is easy to move, and when the shoulder land portion 23 comes into contact with the curb, it is easy to bald.
- the condition of the feature point 16 is satisfied. If the value of C / H is larger than 0.96 or the value of C / H is smaller than 0.76 without satisfying the condition of the feature point 16, the stability of the tread portion 2 is reduced. There is a high possibility that the tread rubber 8 and the side rubber 9 move excessively during the travel of the tire 1. If the tread rubber 8 and the side rubber 9 move excessively, the rolling resistance of the tire 1 deteriorates. By satisfying the condition of the feature point 16, the behavior of the tread rubber 8 and the side rubber 9 when the ground contact surface 30 of the tread portion 2 contacts the road surface is stabilized, and the ground contact surface 30 stably contacts the road surface. Therefore, the rolling resistance of the tire 1 is reduced.
- the condition of the feature point 8 when the condition of the feature point 8 is satisfied, the difference in rigidity between the center portion of the tread portion 2 including the center land portion 21 and the shoulder portion of the tread portion 2 including the shoulder land portion 23 is reduced, so that the shoulder The occurrence of uneven wear in the part is suppressed.
- the value of F / G is larger than 1.30, the rigidity of the shoulder portion becomes excessive, and the shoulder uneven wear resistance performance decreases.
- the value of F / G is smaller than 0.80, the rigidity of the shoulder portion becomes too small, and even in this case, the shoulder uneven wear resistance performance is lowered.
- a tire for evaluation test of tire size 315 / 60R22.5 is mounted on a rim of 22.5 “ ⁇ 9.00”, filled with a standard maximum air pressure (900 [kPa]), and attached to an indoor drum testing machine.
- the vehicle is run at 45 [km], a load of 34.8 [kN] is applied to the tire as an initial value of the load, and the load is increased by 5 [%] (by 1.74 [kN]) every 12 hours. Measured the distance traveled until it broke.
- Index evaluation was performed using the measurement result of the tire according to the conventional example as a reference (100). The larger the value, the better the belt durability.
- Examples 1, 2, 3, 4, and 5 are tires that satisfy the conditions of the feature point 1 and the feature point 22, but do not satisfy the conditions of the feature point 23, the feature point 17A, the feature point 17B, and the feature point 14. .
- numerical values are changed within the range of the feature point 1 and the feature point 22.
- Examples 6, 7, and 8 are tires that satisfy the conditions of the feature point 1, the feature point 22, and the feature point 23 but do not satisfy the conditions of the feature point 17A, the feature point 17B, and the feature point 14.
- the numerical value is changed within the range of the feature point 23.
- the value of (B + C) / A is 1.00, and the value of B / (B + M) is 0.68.
- Examples 9, 10, and 11 are tires that satisfy the conditions of feature point 1, feature point 22, feature point 23, and feature point 17A, but do not satisfy the conditions of feature point 17B and feature point 14.
- the numerical values are changed within the range of the feature point 17A.
- the value of (B + C) / A is 1.00
- the value of B / (B + M) is 0.68
- the value of S / C is 0. 93.
- Examples 15, 16, and 17 are tires that satisfy all of the conditions of the feature point 1, the feature point 22, the feature point 23, the feature point 17A, the feature point 17B, and the feature point 14.
- the numerical value is changed within the range of the feature point 14.
- the value of (B + C) / A is 1.00
- the value of B / (B + M) is 0.68
- the value of S / C is 0.00.
- the value of BPc is 23 [lines]
- the angle ⁇ e is 60 [°].
- FIG. 9 is a perspective view showing a modified example of the shoulder land portion 23.
- FIG. 10 is a side view of the shoulder land portion 23 shown in FIG.
- the shoulder land portion 23 is a rib that is a continuous land portion.
- a lug groove 42 connected to the recess 40 is provided on the ground contact surface 33 of the shoulder land portion 23.
- the sipe (41) is not provided on the side surface 34, but may be provided.
- the tire 1 that can improve the belt durability while preventing the tread rubber 8 from being damaged and improving the riding comfort.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
Abstract
Description
図1は、本実施形態に係るタイヤ1の一例を示す断面図である。タイヤ1は、空気入りタイヤである。タイヤ1は、トラック及びバスに装着される重荷重用タイヤである。トラック及びバス用タイヤ(重荷重用タイヤ)とは、日本自動車タイヤ協会(japan automobile tire manufacturers association:JATMA)から発行されている「日本自動車タイヤ協会規格(JATMA YEAR BOOK)」のC章に定められるタイヤをいう。なお、タイヤ1は、乗用車に装着されてもよいし、小型トラックに装着されてもよい。
次に、本明細書で使用する用語について、図1、図2、図3、図4、及び図5を参照して説明する。図2は、本実施形態に係るトレッド部2の子午断面を示す図である。図3は、図2の一部を拡大した図である。図4は、本実施形態に係るタイヤ1の一部を示す斜視図である。図5は、本実施形態に係るタイヤ1の一部を破断した模式図である。トレッド部2の子午断面とは、回転軸AXを通り、回転軸AXと平行な断面をいう。タイヤ赤道面CLは、タイヤ幅方向においてトレッド部2の中心を通る。
次に、本実施形態に係るタイヤ1の特徴点について説明する。タイヤ1は複数の特徴点を有する。各特徴点について順次説明する。
0.80 ≦ (B+C)/A ≦ 1.15 …(1A)
の条件を満足する。より好ましくは、
0.80 ≦ (B+C)/A ≦ 1.05 …(1B)
の条件を満足する。
5[°] ≦ θa ≦ 50[°] …(2A)
の条件を満足する。より好ましくは、
10[°] ≦ θa ≦ 40[°] …(2B)
の条件を満足する。
D/C ≦ 0.80 …(3)
の条件を満足する。
タイヤ1の子午断面において、ショルダー主溝12の底部12Bは円弧状である。底部12Bの曲率半径Rは、2.0[mm]以上である。すなわち、
2.0 ≦ R …(4A)
の条件を満足する。より好ましくは、
2.0 ≦ R ≦ 5.0 …(4B)
の条件を満足する。
2.0 ≦ E/B ≦ 5.0 …(5)
の条件を満足する。
5[°] ≦ θb ≦ 45[°] …(6A)
の条件を満足する。より好ましくは、
5[°] ≦ θb ≦ 20[°] …(6B)
の条件を満足する。
12[mm] ≦ B ≦ 25[mm] …(7C)
の条件を満足する。より好ましくは、
15[mm] ≦ B ≦ 17[mm] …(7D)
の条件を満足する。
0.80 ≦ F/G ≦ 1.30 …(8)
の条件を満足する。
1.5 ≦ F/B ≦ 4.0 …(9)
の条件を満足する。
J > K …(10A)
J > L …(10B)
0.05 ≦ (K-L)/(J-L) ≦ 0.85 …(10C)
の条件を満足する。
1.0 ≦ N/B ≦ 1.4 …(11)
の条件を満足する。
室温(23[℃])におけるキャップトレッドゴム82のへこみに対する抵抗を示す硬度をHs、60[℃]におけるキャップトレッドゴム82の貯蔵剪断弾性率と損失剪断弾性率との比を示す損失係数をtanδ、としたとき、
70 ≧ Hs …(12A)
の条件を満足する。より好ましくは、
65 ≦ Hs ≦ 70 …(12B)
の条件を満足する。また、
0.21 ≧ tanδ …(12C)
の条件を満足することが好ましく、
0.05 ≦ tanδ ≦ 0.23 …(12D)
の条件を満足することがより好ましい。
キャップトレッドゴム82を300[%]伸ばすのに要した引張応力を示す300[%]伸長時モジュラスをMd、としたとき、
9.0[MPa] ≦ Md ≦ 17.1[MPa] …(13A)
の条件を満足する。
13.0[MPa] ≦ TB ≦ 23.3[MPa] …(13B)
の条件を満足する。
444[MPa] ≦ EB ≦ 653[MPa] …(13C)
の条件を満足する。
第1ベルトプライ61において、50[mm]当たりに配置されるベルトコードの数をBP1、としたとき、
15[本] ≦ BP1 ≦25[本] …(14A)
の条件を満足する。好ましくは、
17[本] ≦ BP1 ≦23[本] …(14B)
の条件を満足する。
新品時におけるベルトプライ61,62,63,64それぞれのベルトゴムを100[%]伸ばすのに要した引張応力を示す100[%]伸張時モジュラスをMbp、としたとき、
5.5[MPa] ≦ Mbp …(15)
の条件を満足する。
0.76 ≦ C/H ≦ 0.96 …(16)
の条件を満足する。
第1ベルトプライ61、第2ベルトプライ62、第3ベルトプライ63、及び第4ベルトプライ64はそれぞれ、複数のベルトコードと、ベルトコードを被覆するベルトゴムとを含む。クロスプライベルト層を形成する第2ベルトプライ62及び第3ベルトプライ63において、50[mm]当たりに配置されるベルトコードの数をBPc、としたとき、
18[本] ≦ BPc ≦ 28[本] …(17A)
の条件を満足する。好ましくは、
20[本] ≦ BPc ≦ 26[本] …(17B)
の条件を満足する。
45[°] ≦ θc ≦ 70[°] …(17C)
45[°] ≦ θd ≦ 70[°] …(17D)
の条件を満足する。なお、上述したように、第2ベルトプライ62のベルトコードの傾斜方向と第3ベルトプライ63のベルトコードの傾斜方向とは、異なる。
45[°] ≦ θe ≦ 70[°] …(17E)
の条件を満足する。
1.0 ≦ F/U …(18)
の条件を満足する。
0.10 ≦ U/V ≦ 0.60 …(19)
の条件を満足する。
5[mm] ≦ U ≦20[mm] …(20)
の条件を満足する。
3 ≦ F/W ≦ 10 …(21)
の条件を満足する。
0.60 ≦ B/(B+M) ≦ 0.75 …(22)
の条件を満足する。
0.85 ≦ S/C ≦ 1.00 …(23)
の条件を満足する。
タイヤ幅方向におけるベルト層6の端部は、ショルダー主溝12よりもタイヤ幅方向内側又はタイヤ幅方向外側に配置される。すなわち、ベルトプライ61,62,63,64の端部は、ショルダー主溝12の直下に配置されない。本実施形態において、タイヤ幅方向における第4ベルトプライ64の端部は、ショルダー主溝12のタイヤ幅方向内側の開口端部12Kaよりもタイヤ幅方向内側に配置される。タイヤ幅方向における第1,第2,第3ベルトプライ61,62,63の端部は、ショルダー主溝12のタイヤ幅方向外側の開口端部12Kbよりもタイヤ幅方向外側に配置される。
本実施形態によれば、上述の特徴点1から特徴点24のうち、少なくとも特徴点1を満足することにより、タイヤ1が車両に装着された状態で旋回したり縁石に乗り上げたりした場合において、ショルダー陸部23が過度に変形することが抑制される。
5[°] ≦ θa ≦ 50[°] …(2A)
D/C ≦ 0.80 …(3)
の条件を満足することにより、タイヤの反り返り量SHを抑制することができる。
0.80 ≦ (B+C)/A ≦ 1.15 …(1A)
0.60 ≦ B/(B+M) ≦ 0.75 …(22)
の条件を満足することにより、トレッドゴム8の破損を防止するとともに、タイヤ1が装着された車両の乗心地を改善することができ、ベルト層6の耐久性であるベルト耐久性能も向上することができる。
0.85 ≦ S/C ≦ 1.00 …(23)
の条件を満足する。S/Cの値が大きいことは、ベルト層6によりトレッド部2の剛性が高くなることを意味する。S/Cの値が小さいことは、トレッド部2の剛性が低いことを意味する。S/Cの値が1.00よりも大きい場合、トレッド部2の剛性が高くなり過ぎて乗心地が悪化する。S/Cの値が0.85よりも小さい場合、トレッド部2の剛性が低くなり過ぎて乗心地が悪化する。特徴点23の条件を満足することにより、乗心地を改善することができるベルト層6による剛性が確保される。
18[本] ≦ BPc ≦ 28[本] …(17A)
の条件を満足する。特徴点17Aの条件を満足することにより、乗心地を改善することができるベルト層6による剛性が確保される。
45[°] ≦ θe ≦ 70[°] …(17E)
の条件を満足する。特徴点17Bの条件を満足することにより、乗心地を改善することができるベルト層6による剛性が確保されるとともに、ベルト耐久性能も向上させることができる。
15[本] ≦ BP1 ≦25[本] …(14A)
の条件を満足する。特徴点14の条件を満足することにより、乗心地を改善することができるベルト層6による剛性が確保される。特徴点14の条件が満足されることにより、タイヤ1が路面の段差を通過したときにおける突き上げ感が抑制される。
70 ≧ Hs …(12A)
の条件を満足する。特徴点12の条件を満足することにより、乗心地を改善することができる。
上述した、特徴点1、特徴点22、特徴点23、特徴点17A、特徴点17B、及び特徴点14の条件を満足するタイヤと満足しないタイヤとについて、(1)乗心地、及び(2)ベルト耐久性能についての評価試験を行った。
タイヤサイズ315/60R22.5の評価試験用タイヤを22.5“×9.00”のリムに装着し、規格最大空気圧(900[kPa])を充填して、6×4トラクター・トレーラーに装着し、テストコースにおいてテストドライバーによりフィーリング評価を実施した。特徴点1、特徴点22、特徴点23、特徴点17A、特徴点17B、及び特徴点14の条件を全て満足していない従来例に係るタイヤのフィーリング評価を基準(20)とした。5人のテストドライバーでフィーリング評価を実施し、5人の評価点の合計を評価点とした。したがって、従来例に係るタイヤのフィーリングの評価の基準は100である。従来例に係るタイヤの評価結果を基準(100)して指数評価を行った。数値が大きいほど乗心地が優れている。
タイヤサイズ315/60R22.5の評価試験用タイヤを22.5“×9.00”のリムに装着し、規格最大空気圧(900[kPa])を充填して、室内ドラム試験機に取り付け、時速45[km]で走行させ、荷重の初期値として34.8[kN]の荷重をタイヤに与え、12時間毎に荷重を5[%]ずつ(1.74[kN]ずつ)増加させ、タイヤが破壊するまでの走行距離を測定した。従来例に係るタイヤの測定結果を基準(100)として指数評価を行った。数値が大きいほどベルト耐久性能に優れている。
図9は、ショルダー陸部23の変形例を示す斜視図である。図10は、図9に示すショルダー陸部23の側面図である。上述の実施形態においては、ショルダー陸部23は、連続陸部であるリブであった。本実施形態においては、ショルダー陸部23の接地面33に、凹部40と接続されるラグ溝42が設けられる。ラグ溝42が設けられることにより、ショルダー陸部23は、断続陸部であるブロック列となる。なお、本実施形態においては、側面34にサイプ(41)が設けられていないが、設けられてもよい。
2[mm] ≦ X ≦ 28[mm] …(25)
の条件を満足する。
35 ≦ Y ≦60 …(26)
の条件を満足する。
Claims (9)
- 回転軸を中心に回転する空気入りタイヤであって、
トレッドゴムを含むトレッド部と、
前記トレッド部のタイヤ幅方向両側に設けられサイドゴムを含むサイド部と、
カーカスと、
前記カーカスよりもタイヤ径方向外側に配置されるベルト層と、
を備え、
前記トレッド部は、タイヤ幅方向に複数設けられそれぞれがタイヤ周方向に延在する周方向主溝と、前記周方向主溝によって区画され路面と接触する接地面を有する複数の陸部と、を有し、
前記周方向主溝及び前記陸部が形成される前記トレッドゴムは、前記ベルト層よりもタイヤ径方向外側に配置され、
前記陸部は、複数の前記周方向主溝のうち前記トレッド部の接地端に最も近いショルダー主溝よりもタイヤ幅方向外側に配置され前記接地端を含むショルダー陸部を含み、
前記接地端よりもタイヤ幅方向外側の前記ショルダー陸部の表面は、前記サイド部の表面と接続され、
前記回転軸を通る前記トレッド部の子午断面において前記接地面を通る第1仮想線と、
前記ショルダー主溝の底部を通り前記第1仮想線と平行な第2仮想線と、
前記第2仮想線と前記接地端よりもタイヤ幅方向外側の前記ショルダー陸部の表面との交点と、
前記回転軸と直交しタイヤ幅方向において前記トレッド部の中心を通るタイヤ赤道面と、が規定され、
タイヤ幅方向における前記タイヤ赤道面と前記交点との距離をA、
前記ショルダー主溝の溝深さをB、
タイヤ幅方向における前記タイヤ赤道面と前記接地端との距離をC、としたとき、
0.80 ≦ (B+C)/A ≦ 1.15、
の条件を満足し、
タイヤ径方向における前記ショルダー主溝の底部と前記ベルト層との距離をM、としたとき、
0.60 ≦ B/(B+M) ≦ 0.75、
の条件を満足する、
空気入りタイヤ。 - 前記ベルト層は、タイヤ径方向に配置される複数のベルトプライを含み、
タイヤ幅方向における前記タイヤ赤道面と複数の前記ベルトプライのうちタイヤ幅方向における寸法が最も長いベルトプライの端部との距離をS、としたとき、
0.85 ≦ S/C ≦ 1.00、
の条件を満足する、
請求項1に記載の空気入りタイヤ。 - 前記ベルトプライは、タイヤ径方向に配置される複数のベルトプライのうち最もタイヤ径方向内側に配置される第1ベルトプライと、前記第1ベルトプライと隣り合い前記第1ベルトプライに次いでタイヤ径方向内側に配置される第2ベルトプライと、前記第2ベルトプライと隣り合い前記第2ベルトプライに次いでタイヤ径方向内側に配置される第3ベルトプライと、最もタイヤ径方向外側に配置される第4ベルトプライとを含み、
前記第2ベルトプライと前記第3ベルトプライとによってクロスプライベルト層が形成され、
前記第1ベルトプライ、前記第2ベルトプライ、前記第3ベルトプライ、及び前記第4ベルトプライはそれぞれ、複数のベルトコードと、前記ベルトコードを被覆するベルトゴムとを含み、
前記第2ベルトプライ及び前記第3ベルトプライにおいて、50[mm]当たりに配置される前記ベルトコードの数をBPc、としたとき、
18[本] ≦ BPc ≦ 28[本]、
の条件を満足する、
請求項1又は請求項2に記載の空気入りタイヤ。 - 前記第1ベルトプライの前記ベルトコードは、前記第2ベルトプライの前記ベルトコードと同一方向に傾斜し、
前記タイヤ赤道面と前記トレッド部の表面とが交差するタイヤ赤道線に対する前記第1ベルトプライの前記ベルトコードの傾斜角度をθe、としたとき、
45[°] ≦ θe ≦ 70[°]、
の条件を満足する、
請求項3に記載の空気入りタイヤ。 - 前記第1ベルトプライにおいて、50[mm]当たりに配置される前記ベルトコードの数をBP1、としたとき、
15[本] ≦ BP1 ≦25[本]、
の条件を満足する、
請求項3又は請求項4に記載の空気入りタイヤ。 - 室温における前記トレッドゴムの硬度をHs、としたとき、
70 ≧ Hs、
の条件を満足する、
請求項1から請求項5のいずれか一項に記載の空気入りタイヤ。 - 前記子午断面において前記接地端と前記交点とを通る第3仮想線と、
前記タイヤ赤道面と平行であり前記交点を通る第4仮想線と、が規定され、
前記第3仮想線と前記第4仮想線とがなす角度をθa、としたとき、
5[°] ≦ θa ≦ 50[°]、
の条件を満足する、
請求項1から請求項6のいずれか一項に記載の空気入りタイヤ。 - タイヤ幅方向における前記タイヤ赤道面と前記ショルダー主溝のタイヤ幅方向外側の開口端部との距離をD、としたとき、
D/C ≦ 0.80、
の条件を満足する、
請求項1から請求項7のいずれか一項に記載の空気入りタイヤ。 - トラック及びバスに装着される重荷重用である、
請求項1から請求項8のいずれか一項に記載の空気入りタイヤ。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE112016004569.7T DE112016004569T9 (de) | 2015-10-06 | 2016-10-05 | Luftreifen |
CN201680056563.XA CN108136856B (zh) | 2015-10-06 | 2016-10-05 | 充气轮胎 |
AU2016334764A AU2016334764B2 (en) | 2015-10-06 | 2016-10-05 | Pneumatic tire |
CA3001106A CA3001106A1 (en) | 2015-10-06 | 2016-10-05 | Pneumatic tire |
US15/763,067 US20180272806A1 (en) | 2015-10-06 | 2016-10-05 | Pneumatic Tire |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015198702A JP6661949B2 (ja) | 2015-10-06 | 2015-10-06 | 空気入りタイヤ |
JP2015-198702 | 2015-10-06 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2017061491A1 true WO2017061491A1 (ja) | 2017-04-13 |
Family
ID=58487670
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2016/079666 WO2017061491A1 (ja) | 2015-10-06 | 2016-10-05 | 空気入りタイヤ |
Country Status (7)
Country | Link |
---|---|
US (1) | US20180272806A1 (ja) |
JP (1) | JP6661949B2 (ja) |
CN (1) | CN108136856B (ja) |
AU (1) | AU2016334764B2 (ja) |
CA (1) | CA3001106A1 (ja) |
DE (1) | DE112016004569T9 (ja) |
WO (1) | WO2017061491A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3725548A4 (en) * | 2017-12-13 | 2021-07-07 | Bridgestone Corporation | PNEUMATIC |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6910104B2 (ja) * | 2015-10-06 | 2021-07-28 | 横浜ゴム株式会社 | 空気入りタイヤ |
JP7283014B2 (ja) * | 2019-09-09 | 2023-05-30 | Toyo Tire株式会社 | 空気入りタイヤ |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009113544A (ja) * | 2007-11-02 | 2009-05-28 | Yokohama Rubber Co Ltd:The | 空気入りタイヤ |
WO2009133826A1 (ja) * | 2008-05-01 | 2009-11-05 | 株式会社ブリヂストン | 重荷重用空気入りタイヤ |
JP2012153193A (ja) * | 2011-01-24 | 2012-08-16 | Yokohama Rubber Co Ltd:The | 空気入りタイヤ |
WO2013042254A1 (ja) * | 2011-09-22 | 2013-03-28 | 横浜ゴム株式会社 | 空気入りタイヤ |
WO2014057547A1 (ja) * | 2012-10-10 | 2014-04-17 | 横浜ゴム株式会社 | 空気入りタイヤ |
JP2015147484A (ja) * | 2014-02-06 | 2015-08-20 | 横浜ゴム株式会社 | 空気入りタイヤ |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6368405A (ja) * | 1986-09-11 | 1988-03-28 | Toyo Tire & Rubber Co Ltd | 重荷重用ラジアルタイヤ |
JPH02270608A (ja) | 1989-04-13 | 1990-11-05 | Bridgestone Corp | 重荷重用空気入りタイヤ |
JP3332338B2 (ja) * | 1998-02-05 | 2002-10-07 | 住友ゴム工業株式会社 | 重荷重用ラジアルタイヤ |
CN101722794B (zh) * | 2008-10-16 | 2011-12-21 | 横滨橡胶株式会社 | 充气轮胎 |
JP5639596B2 (ja) * | 2009-11-25 | 2014-12-10 | 株式会社ブリヂストン | 重荷重用空気入りラジアルタイヤ |
JP5974895B2 (ja) * | 2012-10-10 | 2016-08-23 | 横浜ゴム株式会社 | 空気入りタイヤ |
CN104703815B (zh) * | 2012-10-10 | 2016-12-28 | 横滨橡胶株式会社 | 充气轮胎 |
JP6111134B2 (ja) * | 2013-04-23 | 2017-04-05 | 横浜ゴム株式会社 | 空気入りタイヤ |
-
2015
- 2015-10-06 JP JP2015198702A patent/JP6661949B2/ja active Active
-
2016
- 2016-10-05 AU AU2016334764A patent/AU2016334764B2/en not_active Ceased
- 2016-10-05 CA CA3001106A patent/CA3001106A1/en not_active Abandoned
- 2016-10-05 WO PCT/JP2016/079666 patent/WO2017061491A1/ja active Application Filing
- 2016-10-05 CN CN201680056563.XA patent/CN108136856B/zh not_active Expired - Fee Related
- 2016-10-05 DE DE112016004569.7T patent/DE112016004569T9/de not_active Expired - Fee Related
- 2016-10-05 US US15/763,067 patent/US20180272806A1/en not_active Abandoned
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009113544A (ja) * | 2007-11-02 | 2009-05-28 | Yokohama Rubber Co Ltd:The | 空気入りタイヤ |
WO2009133826A1 (ja) * | 2008-05-01 | 2009-11-05 | 株式会社ブリヂストン | 重荷重用空気入りタイヤ |
JP2012153193A (ja) * | 2011-01-24 | 2012-08-16 | Yokohama Rubber Co Ltd:The | 空気入りタイヤ |
WO2013042254A1 (ja) * | 2011-09-22 | 2013-03-28 | 横浜ゴム株式会社 | 空気入りタイヤ |
WO2014057547A1 (ja) * | 2012-10-10 | 2014-04-17 | 横浜ゴム株式会社 | 空気入りタイヤ |
JP2015147484A (ja) * | 2014-02-06 | 2015-08-20 | 横浜ゴム株式会社 | 空気入りタイヤ |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3725548A4 (en) * | 2017-12-13 | 2021-07-07 | Bridgestone Corporation | PNEUMATIC |
US11491821B2 (en) | 2017-12-13 | 2022-11-08 | Bridgestone Corporation | Tire |
Also Published As
Publication number | Publication date |
---|---|
JP2017071278A (ja) | 2017-04-13 |
AU2016334764A1 (en) | 2018-04-12 |
DE112016004569T5 (de) | 2018-08-23 |
US20180272806A1 (en) | 2018-09-27 |
JP6661949B2 (ja) | 2020-03-11 |
CN108136856A (zh) | 2018-06-08 |
DE112016004569T9 (de) | 2018-11-29 |
AU2016334764B2 (en) | 2020-01-16 |
CN108136856B (zh) | 2020-04-03 |
CA3001106A1 (en) | 2017-04-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6217726B2 (ja) | 空気入りタイヤ | |
WO2017061490A1 (ja) | 空気入りタイヤ | |
WO2017061509A1 (ja) | 空気入りタイヤ | |
WO2017061506A1 (ja) | 空気入りタイヤ | |
WO2017061491A1 (ja) | 空気入りタイヤ | |
JP2017071271A (ja) | 空気入りタイヤ | |
WO2017061505A1 (ja) | 空気入りタイヤ | |
JP6963884B2 (ja) | 空気入りタイヤ |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 16853645 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 15763067 Country of ref document: US |
|
ENP | Entry into the national phase |
Ref document number: 3001106 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 112016004569 Country of ref document: DE |
|
ENP | Entry into the national phase |
Ref document number: 2016334764 Country of ref document: AU Date of ref document: 20161005 Kind code of ref document: A |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 16853645 Country of ref document: EP Kind code of ref document: A1 |