WO2019116610A1 - Heavy-duty tire - Google Patents

Heavy-duty tire Download PDF

Info

Publication number
WO2019116610A1
WO2019116610A1 PCT/JP2018/022999 JP2018022999W WO2019116610A1 WO 2019116610 A1 WO2019116610 A1 WO 2019116610A1 JP 2018022999 W JP2018022999 W JP 2018022999W WO 2019116610 A1 WO2019116610 A1 WO 2019116610A1
Authority
WO
WIPO (PCT)
Prior art keywords
tire
slope
recess
air
inclination angle
Prior art date
Application number
PCT/JP2018/022999
Other languages
French (fr)
Japanese (ja)
Inventor
玲王 中里
大暉 佐藤
Original Assignee
株式会社ブリヂストン
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社ブリヂストン filed Critical 株式会社ブリヂストン
Publication of WO2019116610A1 publication Critical patent/WO2019116610A1/en

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
    • 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
    • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
    • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers

Definitions

  • the present disclosure relates to a heavy duty tire.
  • the temperature in the vicinity of the buttress portion tends to increase easily from the viewpoint of load capacity and size.
  • the road surface is repeatedly touched to and separated from the road surface, distortion occurs repeatedly in the buttress portion, and the buttress portion generates heat. Therefore, it is conceivable to form a recess in the buttress portion and allow air to flow into the recess to cool the buttress portion.
  • a recess is formed in the buttress portion, for example, there is a tire described in Japanese Patent Application Publication No. 2009-542528.
  • the present disclosure aims to provide a heavy duty tire with an improved cooling capacity of the buttress portion.
  • the heavy load tire according to the present disclosure is formed in a buttress portion, and is formed to be connected to a concave portion opened to the tire outer side and a side portion of the concave portion, and opened to the tire outer side.
  • an air entry / promoting portion having a slope formed to gradually increase the depth from the tire surface toward the bottom of the recess, and the inclination angle of the slope with respect to the tire surface is the width direction of the slope It depends on the position.
  • the cooling capacity of the buttress portion can be improved.
  • FIG. 5A is a cross-sectional view of the air cooling unit shown in FIG. 4 taken along line 5A-5A.
  • FIG. 5B is a cross-sectional view of the air cooling unit shown in FIG. 4 taken along line 5B-5B.
  • FIG. 5C is a cross-sectional view of the air cooling unit shown in FIG. 4 taken along line 5C-5C.
  • FIG. 6A is a cross-sectional view of the air cooling unit shown in FIG. 4 taken along line 6A-6A.
  • FIG. 6 (B) is a sectional view taken along line 6B-6B of the air-cooling unit shown in FIG. It is an expansion perspective view showing an air cooling part.
  • a heavy load tire 10 according to an embodiment of the present invention will be described using FIGS. 1 to 7.
  • the heavy load tire 10 according to this embodiment has the same structure as that of a general heavy load pneumatic tire except for an air cooling unit 32 described later.
  • the heavy load tire 10 includes a carcass 12 straddling a pair of bead cores (not shown).
  • a belt 14 is disposed on the radially outer side of the carcass 12.
  • the belt 14 comprises a plurality of belt layers.
  • the heavy load tire 10 according to the present embodiment includes a protective belt layer 16 including two protective belts 16A and 16B, a main intersecting belt layer 18 including two main intersecting belts 18A and 18B, and A small crossing belt layer 20 consisting of two small crossing belts 20A and 20B is provided.
  • the protective belts 16A and 16B, the main crossing belts 18A and 18B, and the small crossing belts 20A and 20B each have a general structure in which a plurality of cords arranged parallel to one another are coated with a covering rubber. .
  • the main crossing belt layer 18 is disposed outside the small crossing belt layer 20 in the tire radial direction, and the protective belt layer 16 is disposed outside the main crossing belt layer 18 in the tire radial direction.
  • the angle between the cord forming the small crossing belt layer 20 and the circumferential direction of the tire is 4 to 10 ° as an example, and the cord and the tire circumference forming the main crossing belt layer 18
  • the angle formed by the direction is 18 to 35 °
  • the angle formed by the cords constituting the protective belt layer 16 and the circumferential direction of the tire is 22 to 33 °.
  • the width of each belt layer in the belt 14 of the present embodiment will be described below.
  • the width of the small crossing belt 20A adjacent to the outer side in the tire radial direction of the small crossing belt 20B on the innermost side in the tire radial direction is formed slightly smaller than the width of the small crossing belt 20B.
  • the width of the main crossing belt 18B adjacent to the outer side of the small crossing belt 20A in the tire radial direction is wider than the small crossing belts 20A and 20B.
  • the width of the main crossing belt 18A adjacent to the tire radial direction outer side of the main crossing belt 18B is wider than the small crossing belts 20A and 20B and narrower than the main crossing belt 18B.
  • the width of the protective belt 16B adjacent to the tire radial direction outer side of the main crossing belt 18A is formed wider than the small crossing belts 20A and 20B and the main crossing belts 18A and 18B. Further, the width of the protective belt 16A adjacent to the tire radial direction outer side of the protective belt 16B and located on the outermost side of the belt 14 is narrower than the protective belt 16B and the main intersecting belt 18B, and the small intersecting belt 20A , 20B, and is wider than the main crossing belt 18A.
  • the protective belt 16A is an example of the outermost belt ply in the tire radial direction. Further, in the belt 14, the fifth protective belt 16 ⁇ / b> B is formed the widest as counted from the inner side in the radial direction.
  • the protective belt 16B is an example of a belt ply having a maximum width.
  • a tread rubber 24 constituting the tread 22 is disposed on the outer side in the tire radial direction of the belt 14.
  • the tread rubber 24 extends along the carcass 12 outward in the tire width direction of the belt 14, and a part of the belt 14 disposed outside in the tire width direction constitutes a part of the buttress portion 26.
  • the buttress portion 26 in the present embodiment is grounded from the position of 1/2 ⁇ H from the tire maximum width portion Wmax, where H is the tire radial dimension of the tire maximum width portion Wmax and the ground contact end 22E of the tread 22. It points to the area outside the tire between the end 22E.
  • the heavy load tire 10 is mounted on a standard rim specified in JATMA YEAR BOOK (2017, Japan Automobile Tire Association Standard), and the application size / ply rating in JATMA YEAR BOOK This is the case when the internal pressure of 100% of the air pressure (maximum air pressure) corresponding to the maximum load capacity (bold load in the internal pressure-load capacity correspondence table) is filled and the maximum load capacity is loaded.
  • JATMA YEAR BOOK 2017, Japan Automobile Tire Association Standard
  • a plurality of lug grooves 28 are formed in the tread 22 of the heavy load tire 10 in the tire circumferential direction.
  • the lug grooves 28 formed in the tread 22 extend outward in the tire width direction more than the ground contact end 22E of the tread 22, and as shown in FIG. 2, the end portion opens in the buttress portion 26 of the heavy load tire 10 ing.
  • the land portion between the lug grooves 28 adjacent in the tire circumferential direction is referred to as a lug block 30.
  • the buttress portion 26 is formed with a concave air cooling portion 32.
  • the air cooling portion 32 is formed on the side surface (buttress portion 26) of each lug block 30 partitioned by the lug grooves 28.
  • the air cooling unit 32 is configured to include a concave portion 34, a first air inflow promoting portion 36 as an example of an air inflow promoting portion, and a second air inflow promoting portion 38.
  • the air entry promotion portion is formed to be connected to the side of the recess 34 and is opened to the outside of the tire and has a depth dimension from the tire surface from the tire surface of the buttress portion 26 to the bottom portion 40 of the recess 34 It is a site that increases gradually.
  • the total area of the slopes 46 and 52 in plan view is larger than the area of the bottom 40 of the recess 34.
  • the recess 34 will be described. As shown in FIGS. 1 to 3, the recess 34 is formed in the buttress portion 26 and opens toward the tire outer side. Further, as shown in FIG. 4, the bottom portion 40 has a trapezoidal shape in which the bottom side 40A on the outer side in the tire radial direction (arrow A direction side) is wider than the upper side 40B on the inner side in the tire radial direction in plan view. Is equipped.
  • the bottom side 40A and the top side 40B are parallel to the tangential direction of the tire circumferential direction (arrow B direction), and the side 40C of the bottom 40 on the front side in the tire rotation direction (arrow B direction) and the tire of the bottom 40
  • the side 40D opposite to the rotational direction front side is inclined with respect to the tire radial direction (arrow A direction).
  • the bottom portion 40 has a trapezoidal shape, but may have another polygonal shape such as a square, a rectangle, or a triangle, or may have a circular shape or an elliptical shape.
  • Bottom portion 40 has a constant depth along the front (the direction of arrow B) in the rotational direction of the tire as shown in FIG. 5A, but as shown in FIG. 5B, the diameter of the tire is from the inside in the tire radial direction. It inclines so that depth may become shallow gradually toward the direction outside (arrow A direction side). Bottom portion 40 may be inclined in the direction along the tire rotation direction (arrow B direction). Also, the depth may be constant in the tire radial direction (arrow A).
  • the bottom portion 40 is disposed on the tire width direction outer side of the tire width direction end 16Be of the protective belt 16B formed the widest in the belt 14. Further, in the present embodiment, the tire width direction end 16Be of the protective belt 16B is located on the inner side in the tire width direction of the tire radial direction central portion of the recess 34. More specifically, the tire width direction end 16Be is disposed between the base 40A of the bottom 40 and the upper side 40B (see FIG. 4) on the side closer to the upper side 40B.
  • a recessed side wall 42 is formed as a side wall that constitutes a part of the recessed portion 34.
  • a recessed side wall 44 is formed as a side wall that constitutes another portion of the recessed portion 34.
  • the recess side wall 42 is inclined with respect to a normal line HL which is vertically stood on the surface of the buttress portion 26.
  • a normal line HL which is vertically stood on the surface of the buttress portion 26.
  • the recess side wall 44 is also inclined with respect to a normal line HL which is vertically erected on the surface of the buttress portion 26.
  • the first air access promotion unit 36 Next, the first air access promotion unit 36 will be described. As shown in FIGS. 4 and 5A, the first air inflow / outflow promoting portion 36 is disposed on the front side in the tire rotation direction (the arrow B direction) of the recess 34.
  • the first air entry and exit promoting portion 36 has a trapezoidal shape in a plan view, and has a slope 46 that inclines from the surface of the buttress portion 26 on the front side in the tire rotation direction (arrow B direction side) toward the bottom portion 40 of the recess 34 It is a concave part.
  • the slope 46 is smoothly connected to the bottom 40.
  • the slope 46 has been described as an example of a trapezoidal shape in plan view, but the slope 46 may be planarly viewed depending on the inclination direction of the bottom 40 (extension direction of the side 40C) and the surface shape of the buttress portion 26. It can also be formed into other polygonal shapes.
  • Sidewalls 48 having a steeper slope than the slope 46 are formed on the tire radial direction outer side (arrow A direction side) of the slope 46, and sidewalls 50 having a steeper slope than the slope 46 are formed on the inner side of the slope 46 in the tire radial direction. It is done.
  • the width of the first air inflow / outflow promoting portion 36 gradually increases from the front side in the tire rotational direction toward the concave portion 34 side.
  • the width of the end on the front side in the tire rotation direction of the first air inflow promotion portion 36 is W1
  • the width of the first air inflow promotion portion 36 on the concave 34 side is W3
  • the width of the slope 46 is constant, and the widths of the side walls 48 and 50 gradually increase from the front side in the tire rotation direction toward the recess 34 side.
  • the width of the first air inflow promotion portion 36 may be constant from the front side in the tire rotation direction toward the recess 34 side.
  • the width W3 of the first air inflow promotion portion 36 on the side of the recess 34 in the tire surface is set to be the same as the width W2 (tire radial direction) of the recess 34 in the tire surface.
  • the two-dot chain line (virtual line) in FIG. 4 indicates the opening of the recess 34 when the first air inflow / outflow facilitating portion 36 and the second air inflow / outflow facilitating portion 38 are not formed.
  • the inclination angle of the slope 46 with respect to the tire surface of the buttress portion 26 is smaller than the average inclination angle of the recess side wall 42 and the average inclination angle of the recess side wall 44. Further, the inclination angle of the slope 46 differs depending on the position in the width direction of the slope 46. Specifically, the inclination angle gradually decreases from one side to the other side in the width direction of the slope 46. 6 and 7, the inclination angle of the end on the inner side in the tire radial direction of the slope 46 is ⁇ 5, and the inclination angle of the end on the outer side in the tire radial direction of the slope 46 is ⁇ 6. Then, ⁇ 6 ⁇ 5.
  • the inclination angles ⁇ 5 and ⁇ 6 are, for example, 45 ° or less.
  • the inclination angles ⁇ 5 and ⁇ 6 may be in the range of 5 to 30 °.
  • the inclination angles ⁇ 5 and ⁇ 6 may be in the range of 15 ° to 25 °.
  • the cross section of the slope 46 is linear from the side 40C to the surface of the buttress portion 26.
  • an inclined portion 47 is formed which is larger than the inclination angles ⁇ 5 and ⁇ 6 of the slope 46 with respect to the tire surface.
  • the inclined portion 47 may be formed by a part of the imaginary recess side wall 43.
  • the average inclination angle ⁇ 7 of the inclined portion 47 with respect to the tire surface of the buttress portion 26 is equal to the average inclination angle ⁇ 3 of the recess side wall 42 described later.
  • the inclined portion 47 may have a shape different from that of the recess side wall 43. In this case, the average inclination angle ⁇ 7 is different from the average inclination angle ⁇ 3 of the recess side wall 42.
  • the inclination angle of the slope 46 gradually decreases, for example, at a constant rate, that is, linearly, from the inner side in the tire radial direction toward the outer side in the tire radial direction.
  • a straight ridge 49 is formed at the boundary between the slope 46 and the inclined portion 47.
  • the ridgeline 49 intersects with the side 40C of the bottom 40 at the tire radial direction end of the slope 46 and terminates.
  • the side 40C of the bottom portion 40 and the boundary 51 between the side wall 48 and the inclined portion 47 are also formed linearly. Therefore, the inclined portion 47 is formed in a substantially triangular shape.
  • the angle ⁇ 8 (FIGS.
  • the angle ⁇ 8 is preferably 30 ° or less. If the angle ⁇ 8 is larger than 30 °, the air flowing into the slope 46 of the first air entry / exit promoting portion 36 hardly reaches the bottom portion 40 of the recess 34 along the slope portion 47.
  • the inclination angle of the slope 46 may not be gradually reduced from one side to the other in the width direction at a constant rate, but may be gradually reduced in a part in the width direction. Also, a plurality of portions in which the inclination angle gradually decreases may be combined. The inclination angle of the slope 46 may be gradually reduced.
  • the second air access promotion unit 38 will be described. As shown in FIG. 4, of the side portions of the recess 34, the second side different from the first air inflow promotion portion 36 is next to the side with the small inclination angle of the slope 46 (the inclination angle ⁇ 6 side in FIG. 7). An air entry and exit promoting unit 38 is provided. Specifically, the second air inflow promotion portion 38 is disposed on the outer side (in the direction of arrow A) of the recess 34 in the tire radial direction. As shown in FIG.
  • the second air insertion / removal portion 38 is a concave portion having a slope 52 which is inclined from the surface of the buttress portion 26 toward the bottom portion 40 of the recess 34 when viewed in cross section.
  • the slope 52 has a substantially square shape in plan view.
  • the slope 52 is smoothly connected to the bottom 40.
  • the slope 52 has a substantially square shape, but may have another polygonal shape such as a rectangle or a trapezoid.
  • a side wall 54 having a steeper slope than the slope 52 is formed on the front side of the slope 52 in the tire rotation direction (arrow B direction side), and on the rear side of the slope 52 in the tire rotation direction Also, the side wall 56 having a steep slope is formed.
  • the angles formed by the side walls 54 and 56 with respect to the slope 52 are substantially the same.
  • the second air inflow promotion portion 38 of the present embodiment is formed such that the width dimension on the outer side in the tire radial direction is relatively smaller than the width dimension on the recess 34 side (dimension in the direction intersecting with the inclination direction of the slope 52). ing.
  • the shortest distance from the bottom side 40A of the slope 52 to the surface of the buttress portion 26 is longer than the shortest distance from the upper side 40B of the recess side wall 44 to the surface of the buttress portion 26.
  • the width of the slope 52 is constant from the bottom 40 of the recess 34 toward the outer side in the tire radial direction.
  • the end portions of the side wall 54 of the second air inflow promotion portion 38 and the side wall 48 of the first air inflow promotion portion 36 described above are connected to each other. Further, the end portions of the side wall 50 of the first air inflow promotion portion 36 and the recessed side wall 44 of the recessed portion 34 are connected to each other.
  • the slope 52 slopes more gently than the recess side wall 42 and the recess side wall 44 of the recess 34.
  • the inclination angle ⁇ 2 of the slope 52 with respect to the surface of the buttress portion 26 is 45 ° or less, similarly to the inclination angle ⁇ 1 of the slope 46 of the first air entry / exit promoting portion 36.
  • the inclination angle ⁇ 2 may be in the range of 5 to 30 °. When the inclination angle ⁇ 2 is smaller than 5 °, the cooling effect is reduced.
  • the inclination angle ⁇ 2 may be in the range of 15 ° to 25 °.
  • the cross section of the slope 52 is linear from the base 40A to the surface of the buttress portion 26. By making it linear in this way, the inclination angle of the slope 52 can be made constant, and the direction of air flow can be made easy to follow the slope 52.
  • the inclination angle ⁇ 1 of the slope 46 and the inclination angle ⁇ 2 of the slope 52 are the average inclination angle ⁇ 3 of the recess side wall 42 of the recess 34 and the average inclination angle of the recess side wall 44. It is smaller than ⁇ 4.
  • the average inclination angles ⁇ 3 and ⁇ 4 are larger than the inclination angles of the slopes 46 and 52.
  • the average inclination angles ⁇ 3 and ⁇ 4 are preferably larger than 40 °.
  • the cross section of the recess side wall 44 and the recess side wall 42 is rounded at the boundary with the surface of the buttress portion 26. Thereby, distortion of buttress part 26 by load can be controlled.
  • 5C is a cross-sectional view of the air-cooling unit shown in FIG. 4 taken along line 5C-5C.
  • the end on the concave portion 34 side of the slope 46 of the first air entry / exit promoting portion 36 is the entire side 40C on the front side in the tire rotation direction Are linked across the. Further, an end of the slope 52 of the second air inflow promotion portion 38 on the concave portion 34 side is connected to the entire bottom side 40A of the bottom portion 40 of the concave portion 34 on the front side in the tire rotation direction.
  • the heavy load tire 10 when the heavy load tire 10 is rotated by traveling, a speed difference is generated between the tire surface and the surrounding air, and the air flows into the concave portion 34 of the air cooling portion 32 formed in the buttress portion 26.
  • the air on the front side in the tire rotation direction of the air-cooling unit 32 flows into the recess 34 as indicated by an arrow C in FIG. 3 via the first air in / out promotion part 36 on the front side in the tire rotation direction.
  • the air flowing into the recess 34 flows along the bottom 40 of the recess 34 and cools the bottom 40 of the recess 34.
  • the inclination angles ⁇ 5 and ⁇ 6 of the slope 46 of the first air entry promotion portion 36 with respect to the tire surface are both 45 ° or less, and the recess side wall 42 which is the side wall of the recess 34 and the recess side wall 44 are more gently inclined than the recess side wall It is connected to the bottom 40 of 34. Therefore, the air on the front side in the tire rotational direction of the recess 34 can be smoothly guided to the inside of the recess 34 along the slope 46.
  • the inclination angles ⁇ 5 and ⁇ 6 of the slope 46 with respect to the tire surface of the buttress portion 26 differ depending on the position in the width direction of the slope 46, turbulent flow is likely to occur in the air flowing into the bottom portion 40 of the recess 34.
  • the inclination angle of the slope 46 with respect to the tire surface gradually decreases from one side to the other in the width direction of the slope 46 ( ⁇ 6 ⁇ 5).
  • an inclined portion 47 is formed which is larger than the inclination angle of the slope 46. Therefore, the air flowing from the slope 46 toward the bottom 40 of the recess 34 is likely to be separated at the slope 47.
  • the arrow F direction is a direction from the side with a large inclination angle ( ⁇ 5) to the side with a small angle ( ⁇ 6), in other words, from the inside in the tire radial direction to the outside in the tire radial direction.
  • bottom 40 can be cooled effectively. That is, the air-cooling unit 32 provided with the first air-inflow promotion unit 36 promotes the inflow of air into the recess 34 compared to the case where the first air-inflow promotion unit 36 is not provided, and the buttress unit 26 can be made more effective. It can be cooled.
  • the air that has flowed along the bottom portion 40 is directed to the slope 52 of the second air inflow promoting portion 38 disposed next to the side with the smaller inclination angle of the slope 46 (outside in the tire radial direction) among the side portions of the recess 34. Exhausted along the tire. Therefore, the air introduced from the front side in the tire rotational direction can be sequentially discharged to the outside of the tire.
  • the air-cooling unit 32 the inflow of air into the recess 34 is promoted as compared with the case where the second air inflow promotion unit 38 is not provided, and the buttress unit 26 can be cooled more effectively.
  • the first air inflow promoting portion 36 and the second air inflow promoting portion 38 that is, the two air inflow promoting portions are formed, it is possible to secure the air inlet / outlet to the recess 34, Ventilation can be improved.
  • the tire is directed from the second air inflow promoting portion 38 toward the bottom 40 of the recess 34. It is possible to promote the inflow of air (translational wind) heading backward in the traveling direction.
  • the end on the concave portion 34 side of the slope 46 of the first air entry / exit promoting portion 36 is the entire side 40C on the front side in the tire rotation direction Are linked across the.
  • the end of the slope 52 of the second air inflow promotion portion 38 on the concave 34 side is connected to the entire side 40 A of the bottom 40 of the concave 34 on the front side in the tire rotation direction.
  • the bottom 40 of the recess 34 of the air-cooling unit 32 is disposed outside the tire width direction end 16Be of the protective belt 16B in the tire width direction, and the tire width direction end 16Be of the protective belt 16B that is most susceptible to temperature rise. It is located in the vicinity. Therefore, the heat generated near the tire width direction end 16Be of the protective belt 16B can be effectively dissipated to the outside of the tire through the bottom 40 of the recess 34, and the tire width direction of the protective belt 16B having the maximum width The temperature rise in the vicinity of the end 16Be can be effectively suppressed.
  • the tire width direction end 16Be of the protective belt 16B is located inside the tire width direction center of the bottom 40 of the recess 34 in the tire width direction.
  • the tire radial direction inner portion of the direction end portion 16Be and the tire radial direction outer portion can be equally cooled.
  • the first air inflow promoting portion 36 is disposed on the front side in the tire rotational direction of the recess 34 as the air inflow promoting portion at two or more locations, and the second air inflow promoting portion 38 is disposed outward of the recess 34 in the tire radial direction.
  • the arrangement and the number of the air entry promotion parts are not limited to this.
  • FIG. 7 is a plan view schematically showing a modification of the air cooling section 32, and only the bottom of the recess 34 and the slope of the air entry and exit promoting section are described.
  • the tire width direction end 16Be of the belt ply (protective belt 16B) of the maximum width constituting the belt is located inside the tire width direction of the bottom portion 40 of the recess 34.
  • the tire width direction end 16Be May be disposed at a position slightly outside the tire width direction inside of the bottom portion 40 of the recess 34.
  • the bottom portion 40 of the recess 34 is not located on the tire width direction outer side of the tire width direction end 16Ae of the protective belt 16A disposed on the outermost side in the tire radial direction in the belt 14. May be extended outward in the tire radial direction, and the bottom 40 of the recess 34 may be located on the tire width direction outer side of the tire width direction end 16Ae of the outermost protective belt 16A.
  • the bottom portion 40 of the recess 34 By arranging the bottom portion 40 of the recess 34 on the tire width direction outer side of the tire width direction end 16Ae of the outermost protection belt 16A in the tire radial direction, the bottom portion 40 can be brought close to the tire width direction end 16Ae. Thereby, the temperature rise near the tire width direction end 16Ae can be suppressed, and the durability of the tread rubber 24 near the tire width direction end 16Ae can be maintained, and a crack is formed on the surface of the tread 22 in the tire width direction. It is possible to suppress the progress toward the tread rubber 24 near 16Ae.
  • the total area of the slopes 46 and 52 in plan view is larger than the area of the bottom 40 of the recess 34, but may be equal to or less than the area of the bottom 40 of the recess 34.
  • the end of the first air inflow promotion portion 36 on the opposite side to the concave portion 34 ends at the tire surface of the buttress portion 26, but the first air outflow promotion portion 36 in the concave 34 side
  • the opposite end may be connected (opened) to the lug groove 28 (not shown).
  • the air in the lug groove 28 can also be made to flow into the recess 34.
  • the end of the second air inflow promotion portion 38 on the opposite side to the concave portion 34 ends at the tire surface of the buttress portion 26, but the concave portion 34 of the second air inflow promotion portion 38
  • the end opposite to the side may be connected (opened) to the lug groove 28 or the tread end (not shown).

Abstract

This heavy-duty tire comprises: a recess that is formed in a buttress part and that opens toward an outer side of the tire; and a first air entrance/exit promoting part that is formed so as to be connected to a side part of the recess, opens toward the outer side of the tire, and has a slope formed such that the depth dimension from the tire surface gradually increases from the tire surface toward a bottom part of the recess. The sloping angle of the slope with respect to the tire surface differs depending on the position, in the width direction, of the slope.

Description

重荷重用タイヤHeavy duty tire
　本開示は、重荷重用タイヤに関する。 The present disclosure relates to a heavy duty tire.
　重荷重用タイヤでは、荷重負荷能力やサイズの観点から、バットレス部付近の温度が上昇し易い傾向にある。走行により路面に対して接地、及び離間が繰り返されるとバットレス部に繰り返し歪みが生じてバットレス部が発熱をする。このため、バットレス部に凹部を形成し、凹部に空気を流入させてバットレス部を冷却することが考えられる。バットレス部に凹部を形成したタイヤとしては、例えば、特表２００９－５４２５２８号公報に記載のタイヤがある。 In a heavy load tire, the temperature in the vicinity of the buttress portion tends to increase easily from the viewpoint of load capacity and size. When the road surface is repeatedly touched to and separated from the road surface, distortion occurs repeatedly in the buttress portion, and the buttress portion generates heat. Therefore, it is conceivable to form a recess in the buttress portion and allow air to flow into the recess to cool the buttress portion. As a tire in which a recess is formed in the buttress portion, for example, there is a tire described in Japanese Patent Application Publication No. 2009-542528.
　バットレス部に凹部を形成することで、バットレス部をある程度冷却することは可能であるが、負荷荷重が大きくなると歪みが増え、発熱が大きくなるため、冷却能力の向上が求められている。 It is possible to cool the buttress portion to a certain extent by forming the concave portion in the buttress portion, but since the strain increases and the heat generation increases as the load load increases, it is required to improve the cooling capacity.
　本開示は上記事実を考慮し、バットレス部の冷却能力を向上させた重荷重用タイヤの提供を目的とする。 In light of the above-described facts, the present disclosure aims to provide a heavy duty tire with an improved cooling capacity of the buttress portion.
　本開示に係る重荷重用タイヤは、バットレス部に形成され、タイヤ外側に向けて開口する凹部と、前記凹部の側部に連結して形成され、タイヤ外側に向けて開口すると共に、タイヤ表面から前記凹部の底部に向けて前記タイヤ表面からの深さ寸法が漸増するように形成されたスロープを有する空気出入促進部と、を備え、前記タイヤ表面に対する前記スロープの傾斜角度は、前記スロープの幅方向位置によって異なる。 The heavy load tire according to the present disclosure is formed in a buttress portion, and is formed to be connected to a concave portion opened to the tire outer side and a side portion of the concave portion, and opened to the tire outer side. And an air entry / promoting portion having a slope formed to gradually increase the depth from the tire surface toward the bottom of the recess, and the inclination angle of the slope with respect to the tire surface is the width direction of the slope It depends on the position.
　本開示の重荷重用タイヤによれば、バットレス部の冷却能力を向上させることができる。 According to the heavy load tire of the present disclosure, the cooling capacity of the buttress portion can be improved.
本実施形態に係る重荷重用タイヤのバットレス部付近を示す断面図である。It is a sectional view showing near buttress part of a tire for heavy load concerning this embodiment. 本実施形態に係る重荷重用タイヤのバットレス部付近を示す側面図である。It is a side view showing near buttress part of a tire for heavy load concerning this embodiment. 本実施形態に係る重荷重用タイヤのバットレス部付近を示す斜視図である。It is a perspective view which shows buttress part vicinity of the tire for heavy loads which concerns on this embodiment. バットレス部に設けた空冷部を示す拡大平面図である。It is an enlarged plan view which shows the air-cooling part provided in the buttress part. （Ａ）は、図４に示す空冷部の５Ａ－５Ａ線断面図である。（Ｂ）は、図４に示す空冷部の５Ｂ－５Ｂ線断面図である。（Ｃ）は、図４に示す空冷部の５Ｃ－５Ｃ線断面図である。FIG. 5A is a cross-sectional view of the air cooling unit shown in FIG. 4 taken along line 5A-5A. FIG. 5B is a cross-sectional view of the air cooling unit shown in FIG. 4 taken along line 5B-5B. FIG. 5C is a cross-sectional view of the air cooling unit shown in FIG. 4 taken along line 5C-5C. （Ａ）は、図４に示す空冷部の６Ａ－６Ａ線断面図である。（Ｂ）は、図４に示す空冷部の６Ｂ－６Ｂ線断面図である。FIG. 6A is a cross-sectional view of the air cooling unit shown in FIG. 4 taken along line 6A-6A. FIG. 6 (B) is a sectional view taken along line 6B-6B of the air-cooling unit shown in FIG. 空冷部を示す拡大斜視図である。It is an expansion perspective view showing an air cooling part.
　図１から図７を用いて、本発明の一実施形態に係る重荷重用タイヤ１０について説明する。本実施形態の重荷重用タイヤ１０は、後述する空冷部３２以外の構造は、一般的な重荷重用の空気入りタイヤと同様の構成である。 A heavy load tire 10 according to an embodiment of the present invention will be described using FIGS. 1 to 7. The heavy load tire 10 according to this embodiment has the same structure as that of a general heavy load pneumatic tire except for an air cooling unit 32 described later.
　図１に示すように、重荷重用タイヤ１０は、図示しない一対のビードコアを跨るカーカス１２を備えている。
（ベルトの構成）
　カーカス１２のタイヤ径方向外側にはベルト１４が配置されている。ベルト１４は、複数のベルト層を具備している。具体的には、本実施形態に係る重荷重用タイヤ１０は、２枚の保護ベルト１６Ａ，１６Ｂからなる保護ベルト層１６、２枚の主交錯ベルト１８Ａ，１８Ｂからなる主交錯ベルト層１８、及び、２枚の小交錯ベルト２０Ａ，２０Ｂからなる小交錯ベルト層２０を備えている。なお、保護ベルト１６Ａ，１６Ｂ、主交錯ベルト１８Ａ，１８Ｂ、及び小交錯ベルト２０Ａ，２０Ｂは、各々、互いに平行に並べられた複数本のコードを被覆ゴムでコーティングした一般的な構造のものである。 As shown in FIG. 1, the heavy load tire 10 includes a carcass 12 straddling a pair of bead cores (not shown).
(Belt configuration)
A belt 14 is disposed on the radially outer side of the carcass 12. The belt 14 comprises a plurality of belt layers. Specifically, the heavy load tire 10 according to the present embodiment includes a protective belt layer 16 including two protective belts 16A and 16B, a main intersecting belt layer 18 including two main intersecting belts 18A and 18B, and A small crossing belt layer 20 consisting of two small crossing belts 20A and 20B is provided. The protective belts 16A and 16B, the main crossing belts 18A and 18B, and the small crossing belts 20A and 20B each have a general structure in which a plurality of cords arranged parallel to one another are coated with a covering rubber. .
　主交錯ベルト層１８は、小交錯ベルト層２０のタイヤ径方向外側に配置されており、保護ベルト層１６は、主交錯ベルト層１８のタイヤ径方向外側に配置されている。 The main crossing belt layer 18 is disposed outside the small crossing belt layer 20 in the tire radial direction, and the protective belt layer 16 is disposed outside the main crossing belt layer 18 in the tire radial direction.
　本実施形態の重荷重用タイヤ１０では、一例として小交錯ベルト層２０を構成するコードとタイヤ周方向とがなす角度は、４～１０°であり、主交錯ベルト層１８を構成するコードとタイヤ周方向とがなす角度は、１８～３５°であり、保護ベルト層１６を構成するコードとタイヤ周方向とがなす角度は、２２～３３°である。 In the heavy load tire 10 according to the present embodiment, the angle between the cord forming the small crossing belt layer 20 and the circumferential direction of the tire is 4 to 10 ° as an example, and the cord and the tire circumference forming the main crossing belt layer 18 The angle formed by the direction is 18 to 35 °, and the angle formed by the cords constituting the protective belt layer 16 and the circumferential direction of the tire is 22 to 33 °.
　以下に、本実施形態のベルト１４における各ベルト層の幅について説明する。
　タイヤ径方向最内側の小交錯ベルト２０Ｂのタイヤ径方向外側に隣接する小交錯ベルト２０Ａの幅は、小交錯ベルト２０Ｂの幅よりも若干狭く形成されている。
　小交錯ベルト２０Ａのタイヤ径方向外側に隣接する主交錯ベルト１８Ｂの幅は、小交錯ベルト２０Ａ，２０Ｂよりも幅広に形成されている。
　主交錯ベルト１８Ｂのタイヤ径方向外側に隣接する主交錯ベルト１８Ａの幅は、小交錯ベルト２０Ａ，２０Ｂよりも幅広で、かつ主交錯ベルト１８Ｂよりも幅狭に形成されている。
　主交錯ベルト１８Ａのタイヤ径方向外側に隣接する保護ベルト１６Ｂの幅は、小交錯ベルト２０Ａ，２０Ｂ、及び主交錯ベルト１８Ａ、１８Ｂよりも幅広に形成されている。
　また、保護ベルト１６Ｂのタイヤ径方向外側に隣接し、ベルト１４の最外側に位置する保護ベルト１６Ａの幅は、保護ベルト１６Ｂ、及び主交錯ベルト１８Ｂよりも幅狭で、かつ、小交錯ベルト２０Ａ，２０Ｂ、及び主交錯ベルト１８Ａよりも幅広に形成されている。なお、保護ベルト１６Ａは、タイヤ径方向最外側のベルトプライの一例である。
　また、ベルト１４において、径方向内側から数えて５枚目の保護ベルト１６Ｂが最も幅広に形成されている。この保護ベルト１６Ｂは、最大幅のベルトプライの一例である。 The width of each belt layer in the belt 14 of the present embodiment will be described below.
The width of the small crossing belt 20A adjacent to the outer side in the tire radial direction of the small crossing belt 20B on the innermost side in the tire radial direction is formed slightly smaller than the width of the small crossing belt 20B.
The width of the main crossing belt 18B adjacent to the outer side of the small crossing belt 20A in the tire radial direction is wider than the small crossing belts 20A and 20B.
The width of the main crossing belt 18A adjacent to the tire radial direction outer side of the main crossing belt 18B is wider than the small crossing belts 20A and 20B and narrower than the main crossing belt 18B.
The width of the protective belt 16B adjacent to the tire radial direction outer side of the main crossing belt 18A is formed wider than the small crossing belts 20A and 20B and the main crossing belts 18A and 18B.
Further, the width of the protective belt 16A adjacent to the tire radial direction outer side of the protective belt 16B and located on the outermost side of the belt 14 is narrower than the protective belt 16B and the main intersecting belt 18B, and the small intersecting belt 20A , 20B, and is wider than the main crossing belt 18A. The protective belt 16A is an example of the outermost belt ply in the tire radial direction.
Further, in the belt 14, the fifth protective belt 16 </ b> B is formed the widest as counted from the inner side in the radial direction. The protective belt 16B is an example of a belt ply having a maximum width.
　ベルト１４のタイヤ径方向外側には、トレッド２２を構成するトレッドゴム２４が配置されている。トレッドゴム２４は、カーカス１２に沿ってベルト１４のタイヤ幅方向外側へ延び、ベルト１４のタイヤ幅方向外側へ配置されている一部が、バットレス部２６の一部を構成している。 A tread rubber 24 constituting the tread 22 is disposed on the outer side in the tire radial direction of the belt 14. The tread rubber 24 extends along the carcass 12 outward in the tire width direction of the belt 14, and a part of the belt 14 disposed outside in the tire width direction constitutes a part of the buttress portion 26.
　本実施形態におけるバットレス部２６とは、タイヤ最大幅部Ｗmaxとトレッド２２の接地端２２Ｅとのタイヤ径方向寸法をＨとしたときに、タイヤ最大幅部Ｗmaxから１／２×Ｈの位置から接地端２２Ｅまでの間のタイヤ外側の領域を指す。 The buttress portion 26 in the present embodiment is grounded from the position of 1/2 × H from the tire maximum width portion Wmax, where H is the tire radial dimension of the tire maximum width portion Wmax and the ground contact end 22E of the tread 22. It points to the area outside the tire between the end 22E.
　また、トレッド２２の接地端２２Ｅとは、重荷重用タイヤ１０をＪＡＴＭＡ ＹＥＡＲ ＢＯＯＫ（２０１７、日本自動車タイヤ協会規格）に規定されている標準リムに装着し、ＪＡＴＭＡ　ＹＥＡＲ　ＢＯＯＫでの適用サイズ・プライレーティングにおける最大負荷能力（内圧－負荷能力対応表の太字荷重）に対応する空気圧（最大空気圧）の１００％の内圧を充填し、最大負荷能力を負荷したときのものである。なお、使用地又は製造地において、ＴＲＡ規格、ＥＴＲＴＯ規格が適用される場合は各々の規格に従う。 In addition, with the ground contact end 22E of the tread 22, the heavy load tire 10 is mounted on a standard rim specified in JATMA YEAR BOOK (2017, Japan Automobile Tire Association Standard), and the application size / ply rating in JATMA YEAR BOOK This is the case when the internal pressure of 100% of the air pressure (maximum air pressure) corresponding to the maximum load capacity (bold load in the internal pressure-load capacity correspondence table) is filled and the maximum load capacity is loaded. When the TRA standard or the ETRTO standard is applied at the place of use or production site, each standard is followed.
　重荷重用タイヤ１０のトレッド２２には、複数のラグ溝２８がタイヤ周方向に複数本形成されている。トレッド２２に形成されるラグ溝２８は、トレッド２２の接地端２２Ｅよりもタイヤ幅方向外側へ延びており、図２に示すように、その端部が重荷重用タイヤ１０のバットレス部２６に開口している。なお、本実施形態において、タイヤ周方向に隣接するラグ溝２８間の陸部分をラグブロック３０と呼ぶ。 A plurality of lug grooves 28 are formed in the tread 22 of the heavy load tire 10 in the tire circumferential direction. The lug grooves 28 formed in the tread 22 extend outward in the tire width direction more than the ground contact end 22E of the tread 22, and as shown in FIG. 2, the end portion opens in the buttress portion 26 of the heavy load tire 10 ing. In the present embodiment, the land portion between the lug grooves 28 adjacent in the tire circumferential direction is referred to as a lug block 30.
　図１～図３に示すように、バットレス部２６には、凹状の空冷部３２が形成されている。本実施形態では、ラグ溝２８で区画される各ラグブロック３０の側面（バットレス部２６）に空冷部３２が形成されている。 As shown in FIGS. 1 to 3, the buttress portion 26 is formed with a concave air cooling portion 32. In the present embodiment, the air cooling portion 32 is formed on the side surface (buttress portion 26) of each lug block 30 partitioned by the lug grooves 28.
（空冷部の詳細）
　図４に示すように、空冷部３２は、凹部３４と、空気出入促進部の一例としての第１空気出入促進部３６と、第２空気出入促進部３８とを含んで構成されている。空気出入促進部は、凹部３４の側部に連結して形成され、タイヤ外側に向けて開口すると共に、バットレス部２６のタイヤ表面から凹部３４の底部４０に向けてタイヤ表面からの深さ寸法が漸増する部位である。平面視した際のスロープ４６，５２の面積の合計は、凹部３４の底部４０の面積よりも大きい。 (Details of air cooling unit)
As shown in FIG. 4, the air cooling unit 32 is configured to include a concave portion 34, a first air inflow promoting portion 36 as an example of an air inflow promoting portion, and a second air inflow promoting portion 38. The air entry promotion portion is formed to be connected to the side of the recess 34 and is opened to the outside of the tire and has a depth dimension from the tire surface from the tire surface of the buttress portion 26 to the bottom portion 40 of the recess 34 It is a site that increases gradually. The total area of the slopes 46 and 52 in plan view is larger than the area of the bottom 40 of the recess 34.
（凹部の詳細）
　先ず、最初に凹部３４について説明する。図１から図３に示すように、凹部３４は、バットレス部２６に形成され、タイヤ外側に向けて開口している。また、図４に示すように、凹部３４は、平面視で、タイヤ径方向外側（矢印Ａ方向側）の底辺４０Ａが、タイヤ径方向内側の上辺４０Ｂよりも幅広の台形状を呈した底部４０を備えている。なお、底辺４０Ａ、及び上辺４０Ｂは、タイヤ周方向（矢印Ｂ方向）の接線方向に対して平行であり、底部４０のタイヤ回転方向前方（矢印Ｂ方向）側の辺４０Ｃ、及び底部４０のタイヤ回転方向前方側とは反対方向側の辺４０Ｄは、タイヤ径方向（矢印Ａ方向）に対して傾斜している。
　なお、本実施形態では、底部４０は台形状であるが、正方形、長方形、三角形等、その他の多角形状であってもよいし、円形、楕円形状であってもよい。 (Details of recess)
First, the recess 34 will be described. As shown in FIGS. 1 to 3, the recess 34 is formed in the buttress portion 26 and opens toward the tire outer side. Further, as shown in FIG. 4, the bottom portion 40 has a trapezoidal shape in which the bottom side 40A on the outer side in the tire radial direction (arrow A direction side) is wider than the upper side 40B on the inner side in the tire radial direction in plan view. Is equipped. The bottom side 40A and the top side 40B are parallel to the tangential direction of the tire circumferential direction (arrow B direction), and the side 40C of the bottom 40 on the front side in the tire rotation direction (arrow B direction) and the tire of the bottom 40 The side 40D opposite to the rotational direction front side is inclined with respect to the tire radial direction (arrow A direction).
In the present embodiment, the bottom portion 40 has a trapezoidal shape, but may have another polygonal shape such as a square, a rectangle, or a triangle, or may have a circular shape or an elliptical shape.
　底部４０は、図５（Ａ）に示すようにタイヤ回転方向前方（矢印Ｂ方向）に沿って深さは一定であるが、図５（Ｂ）に示すように、タイヤ径方向内側からタイヤ径方向外側（矢印Ａ方向側）に向けて深さが徐々に浅くなるように傾斜している。なお、底部４０は、タイヤ回転方向（矢印Ｂ方向）に沿う方向において傾斜していてもよい。また、タイヤ径方向に沿う（矢印Ａ）方向において、深さが一定でもよい。 Bottom portion 40 has a constant depth along the front (the direction of arrow B) in the rotational direction of the tire as shown in FIG. 5A, but as shown in FIG. 5B, the diameter of the tire is from the inside in the tire radial direction. It inclines so that depth may become shallow gradually toward the direction outside (arrow A direction side). Bottom portion 40 may be inclined in the direction along the tire rotation direction (arrow B direction). Also, the depth may be constant in the tire radial direction (arrow A).
　図１に示すように、本実施形態の凹部３４では、ベルト１４の中で最も幅広に形成された保護ベルト１６Ｂのタイヤ幅方向端部１６Ｂｅのタイヤ幅方向外側に底部４０が配置されている。また、本実施形態では、保護ベルト１６Ｂのタイヤ幅方向端部１６Ｂｅが、凹部３４のタイヤ径方向中央部のタイヤ幅方向内側に位置している。より詳細には、タイヤ幅方向端部１６Ｂｅは、底部４０の底辺４０Ａと上辺４０Ｂ（図４参照）の間で、上辺４０Ｂに近い側に配置されている。 As shown in FIG. 1, in the recess 34 of the present embodiment, the bottom portion 40 is disposed on the tire width direction outer side of the tire width direction end 16Be of the protective belt 16B formed the widest in the belt 14. Further, in the present embodiment, the tire width direction end 16Be of the protective belt 16B is located on the inner side in the tire width direction of the tire radial direction central portion of the recess 34. More specifically, the tire width direction end 16Be is disposed between the base 40A of the bottom 40 and the upper side 40B (see FIG. 4) on the side closer to the upper side 40B.
　図４に示すように、底部４０のタイヤ回転方向前方（矢印Ｂ方向）側とは反対側には、凹部３４の一部を構成している側壁としての凹部側壁４２が形成されている。底部４０のタイヤ径方向内側（矢印Ａ方向とは反対方向）には、凹部３４の他の一部を構成している側壁としての凹部側壁４４が形成されている。 As shown in FIG. 4, on the side opposite to the front side in the tire rotation direction (arrow B direction) of the bottom portion 40, a recessed side wall 42 is formed as a side wall that constitutes a part of the recessed portion 34. On the inner side in the tire radial direction of the bottom portion 40 (in the direction opposite to the arrow A direction), a recessed side wall 44 is formed as a side wall that constitutes another portion of the recessed portion 34.
　図５（Ａ）に示すように、凹部側壁４２はバットレス部２６の表面に垂直に立てた法線ＨＬに対して傾斜している。底部４０のタイヤ回転方向前方（矢印Ｂ方向）側に、凹部側壁４２と逆方向かつ同様の角度で傾斜する凹部側壁４３があると仮定する。また、図５（Ｂ）に示すように、凹部側壁４４もバットレス部２６の表面に垂直に立てた法線ＨＬに対して傾斜している。底部４０のタイヤ径方向外側（矢印Ａ方向）には、凹部側壁４４と逆方向かつ同様の角度で傾斜する凹部側壁４５があると仮定する。そうすると、凹部３４は、底部４０からタイヤ外側に向けて広がるように形成されたものとなる。 As shown in FIG. 5A, the recess side wall 42 is inclined with respect to a normal line HL which is vertically stood on the surface of the buttress portion 26. As shown in FIG. It is assumed that there is a recessed side wall 43 which is inclined in the opposite direction and at the same angle as the recessed side wall 42 on the front side in the tire rotation direction (arrow B direction) of the bottom 40. Further, as shown in FIG. 5B, the recess side wall 44 is also inclined with respect to a normal line HL which is vertically erected on the surface of the buttress portion 26. It is assumed that there is a recess side wall 45 which is inclined in the opposite direction and at the same angle as the recess side wall 44 on the tire radial direction outer side (arrow A direction) of the bottom 40. As a result, the recess 34 is formed so as to extend from the bottom 40 toward the tire outer side.
（第１空気出入促進部）
　次に、第１空気出入促進部３６について説明する。
　図４、及び図５（Ａ）に示すように、凹部３４のタイヤ回転方向前方（矢印Ｂ方向）側には第１空気出入促進部３６が配置されている。第１空気出入促進部３６は、平面視で台形状を呈し、タイヤ回転方向前方側（矢印Ｂ方向側）のバットレス部２６の表面から凹部３４の底部４０に向けて傾斜するスロープ４６を有した凹状の部分である。なお、スロープ４６は、底部４０と滑らかに接続されている。
　なお、本実施形態では、スロープ４６は平面視で台形状の例で説明したが、底部４０の傾斜方向（辺４０Ｃの延出方向）、バットレス部２６の表面形状によって、スロープ４６は、平面視で他の多角形状に形成することもできる。 (First air access promotion part)
Next, the first air access promotion unit 36 will be described.
As shown in FIGS. 4 and 5A, the first air inflow / outflow promoting portion 36 is disposed on the front side in the tire rotation direction (the arrow B direction) of the recess 34. The first air entry and exit promoting portion 36 has a trapezoidal shape in a plan view, and has a slope 46 that inclines from the surface of the buttress portion 26 on the front side in the tire rotation direction (arrow B direction side) toward the bottom portion 40 of the recess 34 It is a concave part. The slope 46 is smoothly connected to the bottom 40.
In the present embodiment, the slope 46 has been described as an example of a trapezoidal shape in plan view, but the slope 46 may be planarly viewed depending on the inclination direction of the bottom 40 (extension direction of the side 40C) and the surface shape of the buttress portion 26. It can also be formed into other polygonal shapes.
　スロープ４６のタイヤ径方向外側（矢印Ａ方向側）にはスロープ４６よりも傾斜が急な側壁４８が形成され、スロープ４６のタイヤ径方向内側にはスロープ４６よりも傾斜が急な側壁５０が形成されている。 Sidewalls 48 having a steeper slope than the slope 46 are formed on the tire radial direction outer side (arrow A direction side) of the slope 46, and sidewalls 50 having a steeper slope than the slope 46 are formed on the inner side of the slope 46 in the tire radial direction. It is done.
　図４に示すように、タイヤ径方向において、第１空気出入促進部３６の幅は、タイヤ回転方向前方側から凹部３４側に向けて漸増している。換言すれば、第１空気出入促進部３６のタイヤ回転方向前方側の端部の幅をＷ１とし、第１空気出入促進部３６の凹部３４側の幅（凹部３４と接続されている部分の幅。タイヤ径方向に測定。）をＷ３とすると、Ｗ３＞Ｗ１である。スロープ４６の幅は一定であり、側壁４８，５０の幅が、タイヤ回転方向前方側から凹部３４側に向けて漸増している。なお、第１空気出入促進部３６の幅が、タイヤ回転方向前方側から凹部３４側に向けて一定であってもよい。 As shown in FIG. 4, in the tire radial direction, the width of the first air inflow / outflow promoting portion 36 gradually increases from the front side in the tire rotational direction toward the concave portion 34 side. In other words, the width of the end on the front side in the tire rotation direction of the first air inflow promotion portion 36 is W1, and the width of the first air inflow promotion portion 36 on the concave 34 side (width of the portion connected to the concave 34) When W3 is measured in the tire radial direction, W3> W1. The width of the slope 46 is constant, and the widths of the side walls 48 and 50 gradually increase from the front side in the tire rotation direction toward the recess 34 side. The width of the first air inflow promotion portion 36 may be constant from the front side in the tire rotation direction toward the recess 34 side.
　さらに、本実施形態では、タイヤ表面における第１空気出入促進部３６の凹部３４側の幅Ｗ３が、タイヤ表面における凹部３４の幅Ｗ２（タイヤ径方向）と同一に設定されている。なお、図４の２点鎖線（仮想線）は、第１空気出入促進部３６、及び第２空気出入促進部３８が形成されていなかった場合の、凹部３４の開口部を示している。 Furthermore, in the present embodiment, the width W3 of the first air inflow promotion portion 36 on the side of the recess 34 in the tire surface is set to be the same as the width W2 (tire radial direction) of the recess 34 in the tire surface. The two-dot chain line (virtual line) in FIG. 4 indicates the opening of the recess 34 when the first air inflow / outflow facilitating portion 36 and the second air inflow / outflow facilitating portion 38 are not formed.
　図５（Ａ）、（Ｂ）に示すように、バットレス部２６のタイヤ表面に対するスロープ４６の傾斜角度は、凹部側壁４２の平均傾斜角度、凹部側壁４４の平均傾斜角度よりも小さい。また、このスロープ４６の傾斜角度は、スロープ４６の幅方向位置によって異なる。具体的には、この傾斜角度は、スロープ４６の幅方向の一方から他方に漸減している。図６、図７において、スロープ４６のタイヤ径方向内側の端部におけるタイヤ表面に対する傾斜角度をθ５とし、スロープ４６のタイヤ径方向外側の端部におけるタイヤ表面に対する傾斜角度をθ６とする。そうすると、θ６＜θ５である。この傾斜角度θ５，θ６は、それぞれ例えば４５°以下である。図５（Ａ）に示される傾斜角度θ１は、例えば傾斜角度θ５，θ６の平均値である。換言すれば、θ１＝（θ５＋θ６）／２である。 As shown in FIGS. 5A and 5B, the inclination angle of the slope 46 with respect to the tire surface of the buttress portion 26 is smaller than the average inclination angle of the recess side wall 42 and the average inclination angle of the recess side wall 44. Further, the inclination angle of the slope 46 differs depending on the position in the width direction of the slope 46. Specifically, the inclination angle gradually decreases from one side to the other side in the width direction of the slope 46. 6 and 7, the inclination angle of the end on the inner side in the tire radial direction of the slope 46 is θ5, and the inclination angle of the end on the outer side in the tire radial direction of the slope 46 is θ6. Then, θ6 <θ5. The inclination angles θ5 and θ6 are, for example, 45 ° or less. The inclination angle θ1 shown in FIG. 5A is, for example, an average value of the inclination angles θ5 and θ6. In other words, θ1 = (θ5 + θ6) / 2.
　ここで、この傾斜角度θ５，θ６が４５°より大きいと、タイヤ表面に沿って流れる空気の向きを、スロープ４６に沿うように変えることが困難になる。なお、この傾斜角度θ５，θ６は、５～３０°の範囲内であってもよい。傾斜角度θ５，θ６が５°よりも小さいと、冷却効果が少なくなる。なお、傾斜角度θ５，θ６は、１５°～２５°の範囲内にであってもよい。
　なお、スロープ４６の断面は、辺４０Ｃからバットレス部２６の表面にかけて直線状である。このように断面直線状とすることにより、スロープ４６の傾斜角度をその断面において一定にして、空気の流出入の向きをスロープ４６に沿わせ易くすることができる。 Here, if the inclination angles θ5 and θ6 are larger than 45 °, it becomes difficult to change the direction of the air flowing along the tire surface along the slope 46. The inclination angles θ5 and θ6 may be in the range of 5 to 30 °. When the inclination angles θ5 and θ6 are smaller than 5 °, the cooling effect is reduced. The inclination angles θ5 and θ6 may be in the range of 15 ° to 25 °.
The cross section of the slope 46 is linear from the side 40C to the surface of the buttress portion 26. By making the cross-section straight in this way, the inclination angle of the slope 46 can be made constant in the cross-section, and the direction of air flow can be made easy to follow the slope 46.
　スロープ４６と凹部３４の底部４０との間には、タイヤ表面に対してスロープ４６の傾斜角度θ５，θ６よりも大きく傾斜する傾斜部４７が形成されている。図５（Ａ）に示すように、この傾斜部４７は、仮想的な凹部側壁４３の一部で形成されていてもよい。この場合、バットレス部２６のタイヤ表面に対する傾斜部４７の平均傾斜角度θ７は、後述する凹部側壁４２の平均傾斜角度θ３と等しい。
　なお、傾斜部４７は、凹部側壁４３とは別の形状であってもよい。この場合、平均傾斜角度θ７は、凹部側壁４２の平均傾斜角度θ３と異なる。 Between the slope 46 and the bottom portion 40 of the recess 34, an inclined portion 47 is formed which is larger than the inclination angles θ5 and θ6 of the slope 46 with respect to the tire surface. As shown in FIG. 5A, the inclined portion 47 may be formed by a part of the imaginary recess side wall 43. In this case, the average inclination angle θ7 of the inclined portion 47 with respect to the tire surface of the buttress portion 26 is equal to the average inclination angle θ3 of the recess side wall 42 described later.
The inclined portion 47 may have a shape different from that of the recess side wall 43. In this case, the average inclination angle θ7 is different from the average inclination angle θ3 of the recess side wall 42.
　図７に示すように、スロープ４６の傾斜角度は、タイヤ径方向内側からタイヤ径方向外側に向かって、例えば一定の割合、つまり直線的に漸減している。これにより、スロープ４６と傾斜部４７との境界に直線状の稜線４９が形成されている。この稜線４９は、スロープ４６のタイヤ径方向内側の端部で、底部４０の辺４０Ｃと交わって終端している。底部４０の辺４０Ｃと、側壁４８と傾斜部４７との境界５１もそれぞれ直線的に形成されている。したがって、傾斜部４７は略三角形に形成されている。
　スロープ４６と傾斜部４７とがなす角度θ８（図５（Ａ）、図６（Ａ））は、タイヤ径方向外側（矢印Ａ方向側）に向かうにしたがって漸減し、図４、図７におけるスロープ４６の側壁４８側の端部、換言すれば図６（Ａ）に示される断面位置で最小となる。この角度θ８は、３０°以下であることが好ましい。角度θ８が３０°より大きいと、第１空気出入促進部３６のスロープ４６に流入した空気が、傾斜部４７に沿って凹部３４の底部４０に達することが難くなる。 As shown in FIG. 7, the inclination angle of the slope 46 gradually decreases, for example, at a constant rate, that is, linearly, from the inner side in the tire radial direction toward the outer side in the tire radial direction. Thus, a straight ridge 49 is formed at the boundary between the slope 46 and the inclined portion 47. The ridgeline 49 intersects with the side 40C of the bottom 40 at the tire radial direction end of the slope 46 and terminates. The side 40C of the bottom portion 40 and the boundary 51 between the side wall 48 and the inclined portion 47 are also formed linearly. Therefore, the inclined portion 47 is formed in a substantially triangular shape.
The angle θ8 (FIGS. 5A and 6A) formed by the slope 46 and the inclined portion 47 gradually decreases toward the outer side in the tire radial direction (arrow A direction side), and the slope in FIGS. 4 and 7 The end on the side wall 48 side of 46, in other words, the cross-sectional position shown in FIG. The angle θ8 is preferably 30 ° or less. If the angle θ8 is larger than 30 °, the air flowing into the slope 46 of the first air entry / exit promoting portion 36 hardly reaches the bottom portion 40 of the recess 34 along the slope portion 47.
　なお、スロープ４６の傾斜角度は、幅方向の一方から他方まで一定の割合で漸減していなくてもよく、幅方向の一部分で漸減していてもよい。また、傾斜角度が漸減する部分が複数組み合わされていてもよい。スロープ４６の傾斜角度は、段階的に漸減していてもよい。 The inclination angle of the slope 46 may not be gradually reduced from one side to the other in the width direction at a constant rate, but may be gradually reduced in a part in the width direction. Also, a plurality of portions in which the inclination angle gradually decreases may be combined. The inclination angle of the slope 46 may be gradually reduced.
（第２空気出入促進部）
　次に、第２空気出入促進部３８について説明する。図４に示すように、凹部３４の側部のうち、スロープ４６の傾斜角度が小さい側（図７において、傾斜角度θ６側）の隣に、第１空気出入促進部３６とは別の第２空気出入促進部３８が設けられている。具体的には、第２空気出入促進部３８は、凹部３４のタイヤ径方向外側（矢印Ａ方向）側に配置されている。第２空気出入促進部３８は、図５（Ｂ）に示すように断面で見て、バットレス部２６の表面から凹部３４の底部４０に向けて傾斜するスロープ５２を有した凹状の部分である。スロープ５２は、平面視で略正方形を呈している。なお、スロープ５２は、底部４０と滑らかに接続されている。
　なお、本実施形態では、スロープ５２は略正方形状であるが、長方形、台形等、その他の多角形状であってもよい。 (2nd air access promotion part)
Next, the second air access promotion unit 38 will be described. As shown in FIG. 4, of the side portions of the recess 34, the second side different from the first air inflow promotion portion 36 is next to the side with the small inclination angle of the slope 46 (the inclination angle θ6 side in FIG. 7). An air entry and exit promoting unit 38 is provided. Specifically, the second air inflow promotion portion 38 is disposed on the outer side (in the direction of arrow A) of the recess 34 in the tire radial direction. As shown in FIG. 5 (B), the second air insertion / removal portion 38 is a concave portion having a slope 52 which is inclined from the surface of the buttress portion 26 toward the bottom portion 40 of the recess 34 when viewed in cross section. The slope 52 has a substantially square shape in plan view. The slope 52 is smoothly connected to the bottom 40.
In the present embodiment, the slope 52 has a substantially square shape, but may have another polygonal shape such as a rectangle or a trapezoid.
　図４に示すように、スロープ５２のタイヤ回転方向前方側（矢印Ｂ方向側）にはスロープ５２よりも傾斜が急な側壁５４が形成され、スロープ５２のタイヤ回転方向後方側にはスロープ５２よりも傾斜が急な側壁５６が形成されている。スロープ５２に対して側壁５４、５６がなす角度は、略同じ程度となっている。本実施形態の第２空気出入促進部３８は、凹部３４側の幅寸法（スロープ５２の傾斜方向とは交差する方向の寸法）よりも、タイヤ径方向外側の幅寸法が相対的に小さく形成されている。また、スロープ５２の、底辺４０Ａからバットレス部２６の表面までの最短距離は、凹部側壁４４の上辺４０Ｂからバットレス部２６の表面までの最短距離よりも長い。
　なお、スロープ５２の幅は、凹部３４の底部４０からタイヤ径方向外側に向けて一定である。 As shown in FIG. 4, a side wall 54 having a steeper slope than the slope 52 is formed on the front side of the slope 52 in the tire rotation direction (arrow B direction side), and on the rear side of the slope 52 in the tire rotation direction Also, the side wall 56 having a steep slope is formed. The angles formed by the side walls 54 and 56 with respect to the slope 52 are substantially the same. The second air inflow promotion portion 38 of the present embodiment is formed such that the width dimension on the outer side in the tire radial direction is relatively smaller than the width dimension on the recess 34 side (dimension in the direction intersecting with the inclination direction of the slope 52). ing. Further, the shortest distance from the bottom side 40A of the slope 52 to the surface of the buttress portion 26 is longer than the shortest distance from the upper side 40B of the recess side wall 44 to the surface of the buttress portion 26.
The width of the slope 52 is constant from the bottom 40 of the recess 34 toward the outer side in the tire radial direction.
　なお、第２空気出入促進部３８の側壁５４と、前述した第１空気出入促進部３６の側壁４８とは、互いに端部同士が接続されている。また、第１空気出入促進部３６の側壁５０と凹部３４の凹部側壁４４とは、互いに端部同士が接続されている。 The end portions of the side wall 54 of the second air inflow promotion portion 38 and the side wall 48 of the first air inflow promotion portion 36 described above are connected to each other. Further, the end portions of the side wall 50 of the first air inflow promotion portion 36 and the recessed side wall 44 of the recessed portion 34 are connected to each other.
　スロープ５２は、凹部３４の凹部側壁４２、凹部側壁４４よりも緩やかに傾斜している。図５（Ｂ）に示すように、バットレス部２６の表面に対するスロープ５２の傾斜角度θ２は、第１空気出入促進部３６のスロープ４６の傾斜角度θ１と同様に、４５°以下である。ここで、この傾斜角度θ２が４５°より大きいと、タイヤ表面に沿って流れる空気の向きを、スロープ４６に沿うように変えることが困難になる。なお、傾斜角度θ２は、５～３０°の範囲内であってもよい。傾斜角度θ２が５°よりも小さいと、冷却効果が少なくなる。また、傾斜角度θ２は、１５°～２５°の範囲内であってもよい。
　なお、スロープ５２の断面は、底辺４０Ａからバットレス部２６の表面にかけて直線状である。このように直線状とすることにより、スロープ５２の傾斜角度を一定にして空気の流出入の向きを、スロープ５２に沿わせ易くすることができる。 The slope 52 slopes more gently than the recess side wall 42 and the recess side wall 44 of the recess 34. As shown in FIG. 5B, the inclination angle θ2 of the slope 52 with respect to the surface of the buttress portion 26 is 45 ° or less, similarly to the inclination angle θ1 of the slope 46 of the first air entry / exit promoting portion 36. Here, if the inclination angle θ2 is larger than 45 °, it becomes difficult to change the direction of the air flowing along the tire surface along the slope 46. The inclination angle θ2 may be in the range of 5 to 30 °. When the inclination angle θ2 is smaller than 5 °, the cooling effect is reduced. In addition, the inclination angle θ2 may be in the range of 15 ° to 25 °.
The cross section of the slope 52 is linear from the base 40A to the surface of the buttress portion 26. By making it linear in this way, the inclination angle of the slope 52 can be made constant, and the direction of air flow can be made easy to follow the slope 52.
　図５（Ａ），（Ｂ）に示すように、スロープ４６の傾斜角度θ１、及びスロープ５２の傾斜角度θ２は、凹部３４の凹部側壁４２の平均傾斜角度θ３、及び凹部側壁４４の平均傾斜角度θ４よりも小さい。換言すれば、平均傾斜角度θ３、θ４は、スロープ４６、５２の傾斜角度よりも大きい。平均傾斜角度θ３、θ４は、４０°よりも大きいことが好ましい。
　なお、凹部側壁４４、凹部側壁４２の断面は、バットレス部２６の表面との境界部分においてＲ状とされている。これにより、荷重によるバットレス部２６の歪みを抑制することができる。
　なお、図５（Ｃ）は、図４に示す空冷部の５Ｃ－５Ｃ線断面図である。 As shown in FIGS. 5A and 5B, the inclination angle θ1 of the slope 46 and the inclination angle θ2 of the slope 52 are the average inclination angle θ3 of the recess side wall 42 of the recess 34 and the average inclination angle of the recess side wall 44. It is smaller than θ4. In other words, the average inclination angles θ3 and θ4 are larger than the inclination angles of the slopes 46 and 52. The average inclination angles θ3 and θ4 are preferably larger than 40 °.
The cross section of the recess side wall 44 and the recess side wall 42 is rounded at the boundary with the surface of the buttress portion 26. Thereby, distortion of buttress part 26 by load can be controlled.
5C is a cross-sectional view of the air-cooling unit shown in FIG. 4 taken along line 5C-5C.
　図４に示すように、本実施形態の空冷部３２では、第１空気出入促進部３６のスロープ４６の凹部３４側の端部が、凹部３４の底部４０におけるタイヤ回転方向前方側の辺４０Ｃ全体に渡って連結されている。また、第２空気出入促進部３８のスロープ５２の凹部３４側の端部が、凹部３４の底部４０におけるタイヤ回転方向前方側の底辺４０Ａ全体に渡って連結されている。 As shown in FIG. 4, in the air-cooling unit 32 of the present embodiment, the end on the concave portion 34 side of the slope 46 of the first air entry / exit promoting portion 36 is the entire side 40C on the front side in the tire rotation direction Are linked across the. Further, an end of the slope 52 of the second air inflow promotion portion 38 on the concave portion 34 side is connected to the entire bottom side 40A of the bottom portion 40 of the concave portion 34 on the front side in the tire rotation direction.
（作用、効果）
　以下に本実施形態の重荷重用タイヤ１０の作用、効果を説明する。
　重荷重用タイヤ１０が走行により回転すると、トレッド２２が路面に対して接地、及び離間が繰り返される。これにより、トレッド２２に繰り返し歪みが生じ、特にバットレス部２６が多く発熱をする。 (Action, effect)
The operation and effects of the heavy load tire 10 of the present embodiment will be described below.
When the heavy load tire 10 is rotated by traveling, the tread 22 is repeatedly brought into contact with and separated from the road surface. As a result, the tread 22 is repeatedly distorted, and particularly the buttress portion 26 generates a large amount of heat.
　また、重荷重用タイヤ１０が走行により回転すると、タイヤ表面と周囲の空気との間に速度差が生じ、バットレス部２６に形成された空冷部３２の凹部３４に空気が流れ込む。具体的には、タイヤ回転方向前方側の第１空気出入促進部３６を介して、空冷部３２のタイヤ回転方向前方側の空気が、図３の矢印Ｃで示すように、凹部３４に流れ込む。そして、凹部３４に流入した空気は、凹部３４の底部４０に沿って流れ、凹部３４の底部４０を冷却する。 In addition, when the heavy load tire 10 is rotated by traveling, a speed difference is generated between the tire surface and the surrounding air, and the air flows into the concave portion 34 of the air cooling portion 32 formed in the buttress portion 26. Specifically, the air on the front side in the tire rotation direction of the air-cooling unit 32 flows into the recess 34 as indicated by an arrow C in FIG. 3 via the first air in / out promotion part 36 on the front side in the tire rotation direction. Then, the air flowing into the recess 34 flows along the bottom 40 of the recess 34 and cools the bottom 40 of the recess 34.
　第１空気出入促進部３６のスロープ４６のタイヤ表面に対する傾斜角度θ５，θ６は何れも４５°以下であり、凹部３４の側壁である凹部側壁４２、及び凹部側壁４４よりも緩やかに傾斜して凹部３４の底部４０に接続している。このため、凹部３４のタイヤ回転方向前方側の空気をスロープ４６に沿って凹部３４の内部にスムーズに導くことができる。 The inclination angles θ5 and θ6 of the slope 46 of the first air entry promotion portion 36 with respect to the tire surface are both 45 ° or less, and the recess side wall 42 which is the side wall of the recess 34 and the recess side wall 44 are more gently inclined than the recess side wall It is connected to the bottom 40 of 34. Therefore, the air on the front side in the tire rotational direction of the recess 34 can be smoothly guided to the inside of the recess 34 along the slope 46.
　また、バットレス部２６のタイヤ表面に対するスロープ４６の傾斜角度θ５，θ６が、スロープ４６の幅方向位置によって異なるので、凹部３４の底部４０に流入する空気に乱流が生じ易くなる。具体的には、図７に示すように、タイヤ表面に対するスロープ４６の傾斜角度は、スロープ４６の幅方向の一方から他方に漸減している（θ６＜θ５）。また、スロープ４６と凹部３４の底部４０との間に、スロープ４６の傾斜角度よりも大きく傾斜する傾斜部４７が形成されている。したがって、スロープ４６から凹部３４の底部４０に向けて流れる空気が傾斜部４７で剥離し易くなる。すると、凹部３４の辺４０Ｃ付近において、例えば矢印Ｆ方向に流れる乱流が生じ易くなる。矢印Ｆ方向は、傾斜角度が大きい側（θ５）から小さい側（θ６）、換言すれば、タイヤ径方向内側からタイヤ径方向外側に向かう方向である。 Further, since the inclination angles θ5 and θ6 of the slope 46 with respect to the tire surface of the buttress portion 26 differ depending on the position in the width direction of the slope 46, turbulent flow is likely to occur in the air flowing into the bottom portion 40 of the recess 34. Specifically, as shown in FIG. 7, the inclination angle of the slope 46 with respect to the tire surface gradually decreases from one side to the other in the width direction of the slope 46 (θ6 <θ5). Further, between the slope 46 and the bottom 40 of the recess 34, an inclined portion 47 is formed which is larger than the inclination angle of the slope 46. Therefore, the air flowing from the slope 46 toward the bottom 40 of the recess 34 is likely to be separated at the slope 47. Then, in the vicinity of the side 40C of the recess 34, for example, turbulence flowing in the direction of the arrow F is likely to occur. The arrow F direction is a direction from the side with a large inclination angle (θ5) to the side with a small angle (θ6), in other words, from the inside in the tire radial direction to the outside in the tire radial direction.
　そして、凹部３４に流入した空気は、凹部３４の底部４０に沿って流れるので、底部４０を効果的に冷却することができる。即ち、第１空気出入促進部３６を備えた空冷部３２は、第１空気出入促進部３６が無い場合に比較して凹部３４への空気の流入が促進され、バットレス部２６をより効果的に冷却することができる。 And since the air which flowed in into crevice 34 flows along with bottom 40 of crevice 34, bottom 40 can be cooled effectively. That is, the air-cooling unit 32 provided with the first air-inflow promotion unit 36 promotes the inflow of air into the recess 34 compared to the case where the first air-inflow promotion unit 36 is not provided, and the buttress unit 26 can be made more effective. It can be cooled.
　そして底部４０に沿って流れた空気は、凹部３４の側部のうち、スロープ４６の傾斜角度が小さい側（タイヤ径方向外側）の隣に配置された第２空気出入促進部３８のスロープ５２に沿ってタイヤ外へ排出される。したがって、タイヤ回転方向前方側から流入させた空気を順次タイヤ外側に排出させることができる。これにより、空冷部３２では、第２空気出入促進部３８が無い場合に比較して、凹部３４への空気の流入が促進され、バットレス部２６をより効果的に冷却することができる。 Then, the air that has flowed along the bottom portion 40 is directed to the slope 52 of the second air inflow promoting portion 38 disposed next to the side with the smaller inclination angle of the slope 46 (outside in the tire radial direction) among the side portions of the recess 34. Exhausted along the tire. Therefore, the air introduced from the front side in the tire rotational direction can be sequentially discharged to the outside of the tire. Thus, in the air-cooling unit 32, the inflow of air into the recess 34 is promoted as compared with the case where the second air inflow promotion unit 38 is not provided, and the buttress unit 26 can be cooled more effectively.
　このように、本実施形態では、第１空気出入促進部３６及び第２空気出入促進部３８、つまり２箇所の空気出入促進部が形成されているので、凹部３４に対する空気の出入り口を確保でき、通風性を向上させることができる。 As described above, in the present embodiment, since the first air inflow promoting portion 36 and the second air inflow promoting portion 38, that is, the two air inflow promoting portions are formed, it is possible to secure the air inlet / outlet to the recess 34, Ventilation can be improved.
　さらに、凹部３４のタイヤ径方向外側の第２空気出入促進部３８が凹部３４のタイヤ進行方向前方側に位置したときには、該第２空気出入促進部３８から凹部３４の底部４０に向けて、タイヤ進行方向の後方に向かう空気（並進風）の流入を促進することができる。 Furthermore, when the second air inflow promoting portion 38 on the tire radial direction outer side of the recess 34 is located on the front side in the tire advancing direction of the recess 34, the tire is directed from the second air inflow promoting portion 38 toward the bottom 40 of the recess 34. It is possible to promote the inflow of air (translational wind) heading backward in the traveling direction.
　なお、第１空気出入促進部３６のスロープ４６の傾斜角度θ５，θ６が４５°よりも大きくなると、タイヤ表面に沿って流れる空気の向きをスロープ４６に沿うように変えることが困難になる。一方、第１空気出入促進部３６のスロープ４６の傾斜角度θ５，θ６が５°よりも小さくなると、凹部３４の冷却効果が少なくなってしまう。第２空気出入促進部３８のスロープ５２の傾斜角度θ２についても同様である。 When the inclination angles θ5 and θ6 of the slope 46 of the first air insertion / removal promotion portion 36 become larger than 45 °, it becomes difficult to change the direction of the air flowing along the tire surface to follow the slope 46. On the other hand, when the inclination angles θ5 and θ6 of the slope 46 of the first air insertion and promotion part 36 are smaller than 5 °, the cooling effect of the recess 34 is reduced. The same applies to the inclination angle θ2 of the slope 52 of the second air inflow promotion section 38.
　図４に示すように、本実施形態の空冷部３２では、第１空気出入促進部３６のスロープ４６の凹部３４側の端部が、凹部３４の底部４０におけるタイヤ回転方向前方側の辺４０Ｃ全体に渡って連結されている。また、第２空気出入促進部３８のスロープ５２の凹部３４側の端部が、凹部３４の底部４０におけるタイヤ回転方向前方側の辺４０Ａ全体に渡って連結されている。これにより、第１空気出入促進部３６から流入させた空気を、凹部３４の底部４０の幅方向全体に渡って流入させ、第２空気出入促進部３８から流出させることができ、底部４０を効果的に冷却することができる。また、第２空気出入促進部３８からも効率的に空気を流入させることができる。 As shown in FIG. 4, in the air-cooling unit 32 of the present embodiment, the end on the concave portion 34 side of the slope 46 of the first air entry / exit promoting portion 36 is the entire side 40C on the front side in the tire rotation direction Are linked across the. Further, the end of the slope 52 of the second air inflow promotion portion 38 on the concave 34 side is connected to the entire side 40 A of the bottom 40 of the concave 34 on the front side in the tire rotation direction. As a result, the air introduced from the first air inflow promoting portion 36 can be made to flow in the entire width direction of the bottom 40 of the recess 34 and flow out from the second air inflow promoting portion 38, and the bottom 40 is effective. Can be cooled. In addition, air can be efficiently made to flow from the second air entry and exit promoting unit 38 as well.
　重荷重用タイヤ１０が回転したときにトレッド２２は、ベルト１４の最大幅付近、即ち、ベルト１４を構成している最も幅広に形成された保護ベルト１６Ｂのタイヤ幅方向端部１６Ｂｅ付近が温度上昇しやすい。 When the heavy load tire 10 rotates, the temperature of the tread 22 rises in the vicinity of the maximum width of the belt 14, that is, in the tire width direction end 16Be of the widest protection belt 16B constituting the belt 14. Cheap.
　本実施形態では、空冷部３２の凹部３４の底部４０が、保護ベルト１６Ｂのタイヤ幅方向端部１６Ｂｅのタイヤ幅方向外側に配置され、最も温度上昇し易い保護ベルト１６Ｂのタイヤ幅方向端部１６Ｂｅ近傍に位置している。このため、保護ベルト１６Ｂのタイヤ幅方向端部１６Ｂｅ近傍で発生した熱を、凹部３４の底部４０を介してタイヤ外へ効果的に放熱することができ、最大幅の保護ベルト１６Ｂのタイヤ幅方向端部１６Ｂｅ近傍の温度上昇を効果的に抑制することができる。 In the present embodiment, the bottom 40 of the recess 34 of the air-cooling unit 32 is disposed outside the tire width direction end 16Be of the protective belt 16B in the tire width direction, and the tire width direction end 16Be of the protective belt 16B that is most susceptible to temperature rise. It is located in the vicinity. Therefore, the heat generated near the tire width direction end 16Be of the protective belt 16B can be effectively dissipated to the outside of the tire through the bottom 40 of the recess 34, and the tire width direction of the protective belt 16B having the maximum width The temperature rise in the vicinity of the end 16Be can be effectively suppressed.
　また、本実施形態の重荷重用タイヤ１０では、保護ベルト１６Ｂのタイヤ幅方向端部１６Ｂｅが、凹部３４の底部４０のタイヤ径方向中央部のタイヤ幅方向内側に位置しているので、該タイヤ幅方向端部１６Ｂｅのタイヤ径方向内側部分と、タイヤ径方向外側部分とを均等に冷却することができる。 Further, in the heavy load tire 10 of the present embodiment, the tire width direction end 16Be of the protective belt 16B is located inside the tire width direction center of the bottom 40 of the recess 34 in the tire width direction. The tire radial direction inner portion of the direction end portion 16Be and the tire radial direction outer portion can be equally cooled.
［その他の実施形態］
　以上、本発明の一実施形態について説明したが、本開示は、上記に限定されるものでなく、上記以外にも、その主旨を逸脱しない範囲内において種々変形して実施可能であることは勿論である。 Other Embodiments
As mentioned above, although one Embodiment of this invention was described, this indication is not limited above, Of course, it can be variously deformed and implemented in the range which does not deviate from the main point besides the above. It is.
　上記実施形態では、２箇所以上の空気出入促進部として、凹部３４のタイヤ回転方向前方側に第１空気出入促進部３６を配置し、凹部３４のタイヤ径方向外側に第２空気出入促進部３８を配置したが、空気出入促進部の配置や数は、これに限らない。 In the above embodiment, the first air inflow promoting portion 36 is disposed on the front side in the tire rotational direction of the recess 34 as the air inflow promoting portion at two or more locations, and the second air inflow promoting portion 38 is disposed outward of the recess 34 in the tire radial direction. However, the arrangement and the number of the air entry promotion parts are not limited to this.
　以下に、空気出入促進部と凹部３４の位置関係等を変更した変形例を説明する。図７は空冷部３２の変形例を模式的に示す平面図であり、凹部３４の底部、及び空気出入促進部のスロープのみを記載している。 Below, the modification which changed the positional relationship etc. of an air inflow promotion part and the recessed part 34 is demonstrated. FIG. 7 is a plan view schematically showing a modification of the air cooling section 32, and only the bottom of the recess 34 and the slope of the air entry and exit promoting section are described.
　凹部３４の底部４０のタイヤ幅方向内側に、ベルトを構成している最大幅のベルトプライ（保護ベルト１６Ｂ）のタイヤ幅方向端部１６Ｂｅが位置するものとしたが、該タイヤ幅方向端部１６Ｂｅを、凹部３４の底部４０のタイヤ幅方向内側から若干外れた位置に配置してもよい。 The tire width direction end 16Be of the belt ply (protective belt 16B) of the maximum width constituting the belt is located inside the tire width direction of the bottom portion 40 of the recess 34. The tire width direction end 16Be May be disposed at a position slightly outside the tire width direction inside of the bottom portion 40 of the recess 34.
　図示の例では、ベルト１４においてタイヤ径方向の最外側に配置されている保護ベルト１６Ａのタイヤ幅方向端１６Ａｅのタイヤ幅方向外側に、凹部３４の底部４０が位置していなかったが、底部４０をタイヤ径方向外側へ延ばして、最外側の保護ベルト１６Ａのタイヤ幅方向端１６Ａｅのタイヤ幅方向外側に凹部３４の底部４０が位置するようにしてもよい。 In the illustrated example, the bottom portion 40 of the recess 34 is not located on the tire width direction outer side of the tire width direction end 16Ae of the protective belt 16A disposed on the outermost side in the tire radial direction in the belt 14. May be extended outward in the tire radial direction, and the bottom 40 of the recess 34 may be located on the tire width direction outer side of the tire width direction end 16Ae of the outermost protective belt 16A.
　重荷重用タイヤ１０が悪路等を走行することで、トレッド２２の表面に亀裂が生じる場合がある。タイヤ径方向最外側の保護ベルト１６Ａのタイヤ幅方向端１６Ａｅ付近が発熱して温度が上昇すると、タイヤ幅方向端１６Ａｅ付近の周囲のトレッドゴム２４の耐久性が低下し、トレッド２２の表面に生じた亀裂が、耐久性の低下したゴム部分に向けて進展する場合がある。 When the heavy load tire 10 travels on a rough road or the like, a crack may occur on the surface of the tread 22. When heat is generated near the tire width direction end 16Ae of the outermost protection belt 16A in the tire radial direction to raise the temperature, the durability of the tread rubber 24 around the tire width direction end 16Ae decreases and occurs on the surface of the tread 22 Cracks may develop towards the less durable rubber portion.
　タイヤ径方向最外側の保護ベルト１６Ａのタイヤ幅方向端１６Ａｅのタイヤ幅方向外側に、凹部３４の底部４０を配置することで、タイヤ幅方向端１６Ａｅに底部４０を近づけることができる。これにより、タイヤ幅方向端１６Ａｅ近傍の温度上昇を抑制することができ、タイヤ幅方向端１６Ａｅ近傍のトレッドゴム２４の耐久性を維持することができ、トレッド２２の表面に亀裂がタイヤ幅方向端１６Ａｅ近傍のトレッドゴム２４に向けて進展することを抑制できる。 By arranging the bottom portion 40 of the recess 34 on the tire width direction outer side of the tire width direction end 16Ae of the outermost protection belt 16A in the tire radial direction, the bottom portion 40 can be brought close to the tire width direction end 16Ae. Thereby, the temperature rise near the tire width direction end 16Ae can be suppressed, and the durability of the tread rubber 24 near the tire width direction end 16Ae can be maintained, and a crack is formed on the surface of the tread 22 in the tire width direction. It is possible to suppress the progress toward the tread rubber 24 near 16Ae.
　上記実施形態では、平面視した際のスロープ４６，５２の面積の合計が、凹部３４の底部４０の面積よりも大きかったが、凹部３４の底部４０の面積以下であってもよい。 In the above embodiment, the total area of the slopes 46 and 52 in plan view is larger than the area of the bottom 40 of the recess 34, but may be equal to or less than the area of the bottom 40 of the recess 34.
　上記実施形態では、第１空気出入促進部３６の凹部３４側とは反対側の端部が、バットレス部２６のタイヤ表面で終端していたが、第１空気出入促進部３６の凹部３４側とは反対側の端部がラグ溝２８に連結（開口）していてもよい（図示せず）。これにより、タイヤ側面の空気に加え、ラグ溝２８内の空気を凹部３４に流入させることもできる。また、上記実施形態では、第２空気出入促進部３８の凹部３４側とは反対側の端部が、バットレス部２６のタイヤ表面で終端していたが、第２空気出入促進部３８の凹部３４側とは反対側の端部がラグ溝２８やトレッド端に連結（開口）していてもよい（図示せず）。 In the above embodiment, the end of the first air inflow promotion portion 36 on the opposite side to the concave portion 34 ends at the tire surface of the buttress portion 26, but the first air outflow promotion portion 36 in the concave 34 side The opposite end may be connected (opened) to the lug groove 28 (not shown). Thereby, in addition to the air on the tire side surface, the air in the lug groove 28 can also be made to flow into the recess 34. Further, in the above embodiment, the end of the second air inflow promotion portion 38 on the opposite side to the concave portion 34 ends at the tire surface of the buttress portion 26, but the concave portion 34 of the second air inflow promotion portion 38 The end opposite to the side may be connected (opened) to the lug groove 28 or the tread end (not shown).
　２０１７年１２月１２日に出願された日本国特許出願２０１７－２３７７０２号の開示は、その全体が参照により本明細書に取り込まれる。
　本明細書に記載されたすべての文献、特許出願、および技術規格は、個々の文献、特許出願、および技術規格が参照により取り込まれることが具体的かつ個々に記された場合と同程度に、本明細書中に参照により取り込まれる。 The disclosure of Japanese Patent Application No. 2017-237702, filed December 12, 2017, is incorporated herein by reference in its entirety.
All documents, patent applications and technical standards described herein are as specific and individually as individual documents, patent applications and technical standards are incorporated by reference. Incorporated herein by reference.

Claims (7)

  1. 　バットレス部に形成され、タイヤ外側に向けて開口する凹部と、
    　前記凹部の側部に連結して形成され、タイヤ外側に向けて開口すると共に、タイヤ表面から前記凹部の底部に向けて前記タイヤ表面からの深さ寸法が漸増するように形成されたスロープを有する空気出入促進部と、
    　を備え、
    　前記タイヤ表面に対する前記スロープの傾斜角度は、前記スロープの幅方向位置によって異なる、重荷重用タイヤ。     A recess formed in the buttress portion and opening toward the outside of the tire;
    It has a slope formed so as to be connected to the side of the recess and opened toward the outside of the tire and having a depth dimension gradually increasing from the tire surface toward the bottom of the recess from the tire surface. The air entry and exit promotion department,
    Equipped with
    A heavy duty tire, wherein the inclination angle of the slope with respect to the tire surface differs depending on the widthwise position of the slope.
  2. 　前記タイヤ表面に対する前記スロープの傾斜角度は、前記凹部の側壁の平均傾斜角度よりも小さい、請求項１に記載の重荷重用タイヤ。 The heavy duty tire according to claim 1, wherein the inclination angle of the slope with respect to the tire surface is smaller than the average inclination angle of the side wall of the recess.
  3. 　前記タイヤ表面に対する前記スロープの傾斜角度は、前記スロープの幅方向の一方から他方に漸減しており、
    　前記スロープと前記凹部の底部との間に、前記スロープの傾斜角度よりも大きく傾斜する傾斜部が形成されている、請求項１又は請求項２に記載の重荷重用タイヤ。     The inclination angle of the slope with respect to the tire surface is gradually reduced from one to the other in the width direction of the slope,
    The heavy load tire according to claim 1 or 2, wherein an inclined portion which is inclined more than the inclination angle of the slope is formed between the slope and the bottom of the recess.
  4. 　前記凹部の側部のうち、前記スロープの傾斜角度が小さい側の隣に、前記空気出入促進部とは別の空気出入促進部が設けられている、請求項３に記載の重荷重用タイヤ。 4. The heavy load tire according to claim 3, wherein an air inflow / outflow promotion portion other than the air in / out acceleration / promotion portion is provided on the side of the concave portion next to the side where the inclination angle of the slope is small.
  5. 　前記凹部の底部のタイヤ幅方向内側に、ベルトを構成している最大幅のベルトプライのタイヤ幅方向端部が位置している、請求項１～請求項４の何れか１項に記載の重荷重用タイヤ。 The heavy load according to any one of claims 1 to 4, wherein a tire width direction end portion of a belt ply having the largest width that constitutes the belt is located inside the tire width direction of the bottom of the recess. Heavy duty tires.
  6. 　前記最大幅のベルトプライのタイヤ幅方向端部が、前記底部のタイヤ径方向中央部のタイヤ幅方向内側に位置している、請求項５に記載の重荷重用タイヤ。 The heavy load tire according to claim 5, wherein the end in the tire width direction of the belt ply having the maximum width is positioned inside in the tire width direction of the tire radial direction center portion of the bottom portion.
  7. 　前記スロープを平面視した際の面積の合計が、前記凹部の底部を平面視したときの面積よりも大きく設定されている、請求項１～請求項６の何れか１項に記載の重荷重用タイヤ。 The heavy duty tire according to any one of claims 1 to 6, wherein a total of areas when the slope is viewed in plan is set larger than an area when the bottom of the recess is viewed in plan. .
PCT/JP2018/022999 2017-12-12 2018-06-15 Heavy-duty tire WO2019116610A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2017237702A JP2019104362A (en) 2017-12-12 2017-12-12 Tire for heavy load
JP2017-237702 2017-12-12

Publications (1)

Publication Number Publication Date
WO2019116610A1 true WO2019116610A1 (en) 2019-06-20

Family

ID=66820211

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/022999 WO2019116610A1 (en) 2017-12-12 2018-06-15 Heavy-duty tire

Country Status (2)

Country Link
JP (1) JP2019104362A (en)
WO (1) WO2019116610A1 (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000103206A (en) * 1998-09-29 2000-04-11 Bridgestone Corp Pneumatic tire
JP2004066851A (en) * 2002-08-01 2004-03-04 Bridgestone Corp Pneumatic tire
JP2005081919A (en) * 2003-09-05 2005-03-31 Yokohama Rubber Co Ltd:The Pneumatic tire for heavy load
JP2007203964A (en) * 2006-02-03 2007-08-16 Bridgestone Corp Pneumatic tire
JP2010132045A (en) * 2008-12-02 2010-06-17 Bridgestone Corp Tire
JP2010280327A (en) * 2009-06-05 2010-12-16 Sumitomo Rubber Ind Ltd Pneumatic tire
US20140034201A1 (en) * 2011-04-15 2014-02-06 Bridgestone Corporation Pneumatic tire for two-wheeled motor vehicle

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000103206A (en) * 1998-09-29 2000-04-11 Bridgestone Corp Pneumatic tire
JP2004066851A (en) * 2002-08-01 2004-03-04 Bridgestone Corp Pneumatic tire
JP2005081919A (en) * 2003-09-05 2005-03-31 Yokohama Rubber Co Ltd:The Pneumatic tire for heavy load
JP2007203964A (en) * 2006-02-03 2007-08-16 Bridgestone Corp Pneumatic tire
JP2010132045A (en) * 2008-12-02 2010-06-17 Bridgestone Corp Tire
JP2010280327A (en) * 2009-06-05 2010-12-16 Sumitomo Rubber Ind Ltd Pneumatic tire
US20140034201A1 (en) * 2011-04-15 2014-02-06 Bridgestone Corporation Pneumatic tire for two-wheeled motor vehicle

Also Published As

Publication number Publication date
JP2019104362A (en) 2019-06-27

Similar Documents

Publication Publication Date Title
JP6111808B2 (en) Pneumatic tire
US20130118664A1 (en) Heavy duty tire
JP5557875B2 (en) Pneumatic tire
WO2015025790A1 (en) Pneumatic tire
WO2014083758A1 (en) Pneumatic tire
WO2019116621A1 (en) Heavy-duty tire
WO2019116610A1 (en) Heavy-duty tire
WO2019116611A1 (en) Heavy-duty tire
WO2019116622A1 (en) Heavy-duty tire
WO2019116625A1 (en) Heavy-duty tire
JP2020066279A (en) Pneumatic tire
WO2019116626A1 (en) Heavy-duty tire
JP6912973B2 (en) Pneumatic tires
WO2014141715A1 (en) Pneumatic tire
JP6029957B2 (en) Pneumatic tire
JP6012442B2 (en) Pneumatic tire
JP2020001669A (en) Pneumatic tire

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: 18887474

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18887474

Country of ref document: EP

Kind code of ref document: A1