CN106274300B - Heavy duty tires - Google Patents
Heavy duty tires Download PDFInfo
- Publication number
- CN106274300B CN106274300B CN201610413056.9A CN201610413056A CN106274300B CN 106274300 B CN106274300 B CN 106274300B CN 201610413056 A CN201610413056 A CN 201610413056A CN 106274300 B CN106274300 B CN 106274300B
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- Prior art keywords
- tire
- cord layer
- radial direction
- tire radial
- organic fiber
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- 239000011324 bead Substances 0.000 claims abstract description 116
- 239000000835 fiber Substances 0.000 claims abstract description 77
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 59
- 239000010959 steel Substances 0.000 claims abstract description 59
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 40
- 230000002787 reinforcement Effects 0.000 claims abstract description 8
- 230000032798 delamination Effects 0.000 description 12
- 238000005452 bending Methods 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000004677 Nylon Substances 0.000 description 2
- 229920001778 nylon Polymers 0.000 description 2
- 229920001875 Ebonite Polymers 0.000 description 1
- 229920002978 Vinylon Polymers 0.000 description 1
- 239000004760 aramid Substances 0.000 description 1
- 229920003235 aromatic polyamide Polymers 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
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
- B60C15/00—Tyre beads, e.g. ply turn-up or overlap
-
- 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
- B60C15/00—Tyre beads, e.g. ply turn-up or overlap
- B60C15/06—Flipper strips, fillers, or chafing strips and reinforcing layers for the construction of the bead
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
Abstract
The invention provides a heavy load tire capable of improving durability of a bead portion. The heavy load tire has a carcass (6) composed of a carcass ply (6A), and the carcass ply (6A) comprises a main body part (6A) and a folded part (6 b). A first reinforcing section (11) located on the main body section (6a) side and a second reinforcing section (12) located on the turn-back section (6b) side are provided in the bead section (4). The first reinforcing part (11) comprises a first steel wire cord layer (21) and a second steel wire cord layer (22) with a U-shaped section. The second reinforcement (12) comprises: a first organic fiber cord layer (31) and a second organic fiber cord layer (32) covering the outer end of the second steel wire cord layer (22) on the turn-back part (6b) side from the tire axial outside.
Description
Technical Field
The present invention relates to a heavy duty tire capable of improving durability of a bead portion.
Background
For example, patent document 1 listed below proposes a heavy load tire in which a bead portion is provided with a reinforcing portion. The reinforcing portion of patent document 1 includes: a first steel cord layer extending in a tire radial direction from a main body part side of the carcass ply; and a second steel cord layer which is wound around the bead core from the inner side to the outer side of the tire shaft and has a substantially U-shaped section.
However, in the tire of patent document 1, when the bead portion is bent and deformed outward in the tire axial direction, stress concentrates on the end portion of the second steel cord layer, and further damage such as tire delamination tends to occur at the end portion. Therefore, there is room for further improvement in the prior art regarding the improvement of the durability of the bead portion.
Documents of the prior art
Patent document
Patent document 1: japanese laid-open patent publication No. 2012 and 106531
Disclosure of Invention
Problems to be solved by the invention
The present invention has been made in view of the above circumstances, and a main object thereof is to provide a heavy duty tire capable of improving durability of a bead portion, in which a first reinforcing portion is provided on a main body portion side of a carcass ply and a second reinforcing portion is provided on a turn-back portion side.
Means for solving the problems
The heavy load tire of the present invention has a carcass made of a carcass ply, the carcass ply comprising: a main body portion of a bead core extending from a tread portion to a bead portion via a sidewall portion; and a turn-back portion connected to the main body portion and turned back around the bead core from an inner side to an outer side in a tire axial direction, the bead portion being provided with: a first reinforcing portion at least a part of which extends in a tire radial direction inside the main body portion in a tire axial direction; and a second reinforcing portion at least a part of which extends in a tire radial direction outside the turn-up portion in a tire axial direction, the first reinforcing portion including: a first steel cord layer extending in a radial direction of the tire along an inner side of the main body in a tire axial direction; and a second steel cord layer at least a part of which overlaps the first steel cord layer, is wound around the bead core from the inner side to the outer side in the tire axial direction, has an outer end ending at the inner side in the tire radial direction than the outer end of the turn-up portion, and has a substantially U-shaped cross section, wherein the second reinforcing portion includes: a first organic fiber cord layer and a second organic fiber cord layer covering the outer ends of the second steel wire cord layer on the turn-back portion side from the tire axial outside.
In the heavy duty tire according to the present invention, it is preferable that a bead apex extending outward in the tire radial direction from the bead core is provided in the bead portion between the main body portion and the folded-back portion, and the bead apex includes: inner triangular glue; and an outer bead apex disposed on the outer side of the inner bead apex in the tire radial direction and having a rubber hardness smaller than the inner bead apex, wherein the outer end of the first steel cord layer in the tire radial direction and the outer end of the second steel cord layer in the tire radial direction of the carcass ply are both located on the inner side of the tire radial direction than the outer end of the inner bead apex in the tire radial direction.
In the heavy load tire according to the present invention, it is preferable that, on the inner side in the tire axial direction of the main body, the outer end of the first wire cord layer in the tire radial direction is located on the outer side in the tire radial direction than the outer end of the turn-back portion, and the outer end of the second wire cord layer in the turn-back portion side and the outer end in the main body portion side are both located on the inner side in the tire radial direction than the outer end of the turn-back portion.
In the heavy load tire according to the present invention, it is preferable that, on the outer side in the tire axial direction of the turn-up portion, both the outer end of the first organic fiber cord layer in the tire radial direction and the outer end of the second organic fiber cord layer in the tire radial direction are located on the outer side in the tire radial direction than the outer end of the turn-up portion, and the first organic fiber cord layer covers the outer end of the second organic fiber cord layer.
In the heavy load tire according to the present invention, it is preferable that an inner end of the second reinforcing portion in the tire radial direction is located further toward the tire axial direction than the bead core, and in a normal state in which the tire is mounted on a normal rim and a normal internal pressure is applied, a distance in the tire radial direction from a bead base line to the inner end of the second reinforcing portion is 0.6 times or less a flange height from the bead base line to an outer end of a flange of the normal rim in the tire radial direction.
In the heavy duty tire according to the present invention, the second reinforcing section preferably has a layer adjacent section in which a distance between the cord of the first organic fiber cord layer and the cord of the second organic fiber cord layer is 0.5 to 1.8 mm.
In the heavy load tire according to the present invention, it is preferable that an inner end of the first steel cord layer in the tire radial direction is located on the inner side in the tire axial direction of the main body, an inner end of the first organic fiber cord layer in the tire radial direction is located on the outer side in the tire axial direction of the turn-up portion and on the outer side in the tire radial direction than the inner end of the first steel cord layer, and an inner end of the second organic fiber cord layer in the tire radial direction is located on the outer side in the tire axial direction of the turn-up portion and on the inner side in the tire radial direction than the inner end of the first steel cord layer.
In the heavy duty tire according to the present invention, it is preferable that the bead core has an upper surface extending in the tire axial direction outside the tire radial direction, the inner end of the first steel cord layer and the inner end of the second organic fiber cord layer are located on the inner side in the tire radial direction than the upper surface of the bead core, and the inner end of the first organic fiber cord layer is located on the outer side in the tire radial direction than the upper surface of the bead core.
Effects of the invention
The bead portion of the heavy load tire of the present invention is provided with: a first reinforcing portion at least a part of which extends in a tire radial direction inside the main body portion in a tire axial direction; and a second reinforcing portion at least a part of which extends in the tire radial direction outside the folded portion in the tire axial direction.
The first reinforcement portion includes: a first steel cord layer extending in a radial direction of the tire along an inner side of the main body in a tire axial direction; and a second steel cord layer at least partially overlapping the first steel cord layer, rolled up from the inner side to the outer side of the tire axial direction around the bead core, having an outer end ending at the inner side of the tire radial direction than the outer end of the turn-up part, and having a substantially U-shaped cross section. In such a first reinforcing portion, the first wire cord layer and the second wire cord layer are integrated, so that the bending rigidity of the bead portion can be improved, and further, the bead portion can be effectively suppressed from being largely bent outward in the tire axial direction with the bead core as a fulcrum.
The second reinforcement portion includes: a first organic fiber cord layer and a second organic fiber cord layer covering the outer ends of the second steel wire cord layer on the turn-back portion side from the tire axial outside. The organic fiber cord layer has higher flexibility than a steel cord layer and excellent adhesion to a rubber member. Therefore, the second reinforcing portion composed of the two organic fiber cord layers can relax the stress at the outer end of the second steel cord layer, and can suppress the tire delamination for a long time.
Drawings
Fig. 1 is a cross-sectional view of a heavy duty tire according to an embodiment of the present invention.
Fig. 2 is an enlarged cross-sectional view of the bead portion of fig. 1.
Fig. 3 is an enlarged view of a layer abutting portion of the second reinforcing part of fig. 2.
Fig. 4 is an enlarged cross-sectional view of a bead portion according to another embodiment of the present invention.
Fig. 5 is an enlarged cross-sectional view of a bead portion according to another embodiment of the present invention.
Fig. 6 is an enlarged cross-sectional view of a bead portion of a heavy duty tire of a comparative example.
Detailed Description
Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
Fig. 1 shows a tire meridian cross-sectional view of a heavy load pneumatic tire (hereinafter, also simply referred to as "tire") 1 according to the present embodiment, which includes a rotation axis in a normal state. The tire 1 of the present embodiment is a tire for an inner tube in which an inner tube (not shown) is mounted in a tire cavity, but is not limited to such an embodiment.
The "normal state" is a no-load state in which the tire is mounted on the normal rim R and the normal internal pressure is applied. Hereinafter, unless otherwise specified, the dimensions and the like of each portion of the tire are all values measured in this normal state.
The "regular Rim" is a Rim defined by the specification in a specification system including the specification to which the tire conforms, and is defined for each tire, for example, as "standard Rim" in JATMA, "Design Rim" in TRA, and "Measuring Rim" in ETRTO.
The "normal internal pressure" refers to an air pressure specified by each specification for each TIRE in a specification system including the specification under which the TIRE is compliant, and is "maximum air pressure" in JATMA, a maximum value described in "TIRE LOAD conditions associated with TIREs cooling requirements" in TRA, and "INFLATION requirements" in ETRTO.
As shown in fig. 1, the tire 1 of the present embodiment has a toroidal carcass 6 from a tread portion 2 through a sidewall portion 3 to a bead core 5 of a bead portion 4. The carcass 6 is formed of, for example, at least 1 ply of carcass plies 6A. The carcass ply 6A is formed by arranging steel carcass cords at an angle of 70 to 90 ° with respect to the tire circumferential direction, for example.
The carcass ply 6A includes a main body portion 6A and a folded portion 6 b. The main body portion 6a extends from the tread portion 2 to the bead core 5 of the bead portion 4 via the sidewall portion 3. The folded portion 6b is connected to the main body portion 6a and is folded around the bead core 5 from the inner side to the outer side in the tire axial direction.
In a preferred embodiment, a belt layer 7 is disposed radially outside the carcass 6 and inside the tread portion 2. The belt layer 7 is formed of a plurality of belt plies using steel belt cords, for example. The belt layer 7 of the present embodiment has a four-layer structure formed of, for example, first to fourth belt plies 7A to 7D.
Fig. 2 shows an enlarged view of the bead unit 4. A bead apex 8 extending outward in the tire radial direction from the bead core 5 is disposed in the bead portion 4; and a first reinforcing portion 11 and a second reinforcing portion 12 for reinforcing the bead portion 4.
The bead core 5 is formed by winding a bead wire made of, for example, steel wire in a plurality of layers and rows, and has a polygonal cross section. The bead core 5 of the present embodiment is, for example, formed in a flat hexagonal shape in cross section, and has an upper surface 5a extending outward in the tire radial direction in the tire axial direction, and a lower surface 5b extending inward in the tire radial direction in the tire axial direction. As a preferred embodiment, the bead core 5 of the present embodiment includes: a core main body 9 composed of, for example, a bead wire, and a wrapping layer 10 covering the periphery of the core main body 9. The wrapping layer 10 is made of canvas made of organic fiber such as nylon, for example, and is used to fix the bead wire.
The bead apex 8 extends outward in the tire radial direction from the bead core 5, for example, and is tapered. The bead apex 8 of the present embodiment includes: for example, an inner apex 13, and an outer apex 14 disposed radially outward of the inner apex 13 in the tire.
The inner apex 13 is located between the main portion 6a and the folded portion 6b, for example, extends outward in the tire radial direction from the bead core 5, and has a substantially triangular cross section. The outer end 15 of the inner apex 13 in the tire radial direction is located on the tire axial direction outer side surface of the main body portion 6a, for example. The outer end 15 of the inner apex 13 is preferably located radially outward of the outer end 16 of the folded portion 6b in the tire, for example.
The inner apex 13 is preferably made of hard rubber having a rubber hardness of 80 to 95 °, for example. The term "rubber hardness" as used herein means a durometer A hardness measured in accordance with JIS-K6253 using a type A durometer in an environment of 23 ℃.
The outer apex 14 is formed, for example, with a rubber hardness smaller than that of the inner apex 13. The outer bead apex 14 extends radially inward from, for example, an outer end 15 of the inner bead apex 13 toward the folded portion 6b, and is connected to the inner bead apex 13 via a boundary surface 17.
The first reinforcement 11 includes a first steel cord layer 21 and a second steel cord layer 22. Each of the steel cord layers 21 and 22 is formed by arranging a plurality of steel cords obliquely at an angle of 20 to 60 degrees with respect to the tire circumferential direction, for example. The steel cords of the first steel cord layer 21 and the steel cords of the second steel cord layer 22 are arranged, for example, in mutually opposite directions with an inclination. The number of steel cords arranged in each layer 21, 22 is preferably 20 to 40 per 50mm layer width, for example.
The first wire cord layer 21 extends in the tire radial direction along the tire axial direction inside of the body portion 6 a. In the first steel cord layer 21 of the present embodiment, for example, at least a part thereof is in contact with the body portion 6 a. However, the arrangement of the first steel cord layer 21 is not limited to this embodiment.
The outer end 23 of the first wire cord layer 21 in the tire radial direction is located on the tire radial direction outer side than the outer end 16 of the turn-up portion 6b, for example. This effectively improves the bending rigidity of the bead unit 4 on the inner side in the tire axial direction. The outer end 23 of the first wire cord layer is located, for example, radially inward of the tire from the outer end 15 of the inner apex 13. This can suppress concentrated strain in the vicinity of the outer end 23 of the first wire cord layer 21. Therefore, the tire delamination starting from the outer end 23 can be suppressed.
In order to increase the rigidity of the bead portion 4 and suppress the tire delamination starting from the outer end 23, the height H2 in the tire radial direction from the bead base line BL to the outer end 23 of the first wire cord layer 21 is preferably 0.85 to 0.95 times the height H1 of the inner apex in the tire radial direction from the bead base line BL to the outer end 15 of the inner apex 13, for example. In the present specification, the bead base line BL is a tire axial line passing through a rim diameter position determined by a specification to which the tire is subjected.
The inner end 24 of the first wire cord layer 21 in the tire radial direction is located, for example, on the inner side of the body portion 6a in the tire axial direction. In a preferred embodiment, the inner end 24 of the first wire cord layer 21 is located on the inner side in the tire radial direction with respect to the upper surface 5a of the bead core 5 and on the outer side in the tire radial direction with respect to the lower surface 5b of the bead core 5, for example. In the case where a load is applied to the tire, there is substantially no deformation in the vicinity of the bead core 5. Therefore, according to the present embodiment, the tire delamination starting from the inner end 24 of the first wire cord layer 21 can be suppressed.
The second steel cord layer 22 is wound around the bead core 5 from the inner side to the outer side in the tire axial direction and has a substantially U-shaped cross section. On the main body 6a side, the outer end 25 of the second wire cord layer 22 in the tire radial direction is positioned outside the inner end 24 of the first wire cord layer 21 in the tire radial direction. Thereby, at least a part of the second steel cord layer 22 overlaps the first steel cord layer 21.
In a preferred embodiment, the outer end 25 of the second wire cord layer 22 is located radially inward of the outer end 15 of the inner apex 13 and the outer end 23 of the first wire cord layer 21, for example. In a more preferred embodiment, the outer end 25 of the second wire cord layer 22 is located radially inward of the outer end 16 of the turn-up portion 6b in the tire. Thus, in the present embodiment, the outer end 16 of the turn-up portion 6b in the tire radial direction is located between the outer end 23 of the first wire cord layer 21 and the outer end 25 of the second wire cord layer 22. Thereby, the outer end positions of the layers are dispersed in the tire radial direction, the rigidity distribution of the bead portion 4 is made uniform, and the stress concentration at the bead portion 4 is suppressed.
In order to further exert the above-described effects, the height H3 in the tire radial direction from the bead base line BL to the outer end 25 of the second wire cord layer 22 on the main body portion 6a side is preferably 0.55 times or more, more preferably 0.60 times or more, and preferably 0.70 times or less, more preferably 0.65 times or less the inner apex height H1.
The outer end 26 of the second wire cord layer 22 on the turn-up portion 6b side is located radially inward of the outer end 16 of the turn-up portion 6b in the tire. Such a second wire cord layer 22 is advantageous for improving the riding comfort without excessively improving the rigidity of the bead portion 4 on the outer side in the tire axial direction.
As described above, in the first reinforcing portion 11 including the first wire cord layer 21 and the second wire cord layer 22, the layers 21 and 22 are integrated, so that the bending rigidity of the bead portion 4 can be improved, and further, the bead portion 4 can be effectively suppressed from being largely deformed in bending toward the outer side in the tire axial direction with the bead core 5 as a fulcrum.
The second reinforcement 12 includes a first organic fiber cord layer 31 and a second organic fiber cord layer 32. Each of the organic fiber cord layers 31 and 32 is formed by arranging a plurality of organic fiber cords obliquely at an angle of 20 to 60 degrees with respect to the tire circumferential direction, for example. The respective cords of the first organic fiber cord layer 31 and the respective cords of the second organic fiber cord layer 32 are, for example, arranged obliquely in opposite directions to each other.
The number of the organic fiber cords arranged in each layer 31, 32 is preferably 20 to 40 per 50mm layer width, for example. As the organic fiber cord, for example, a nylon cord, a polyester cord, an aramid cord, a high-tenacity vinylon cord, or the like is preferably used. Such an organic fiber cord layer has higher flexibility than a steel cord layer and excellent adhesion to a rubber member.
The first organic fiber cord layer 31 and the second organic fiber cord layer 32 are overlapped with each other, and cover the outer end 26 of the second steel wire cord layer 22 on the turn-up portion 6b side from the tire axial outside. The second reinforcing part 12 formed of two organic fiber cord layers has flexibility superior to that of a steel cord layer and adhesion to a rubber member, and thus can relax stress at the outer ends 24 of the second steel cord layer 22, and can suppress tire delamination for a long time.
The outer end 33 of the first organic fiber cord layer 31 in the tire radial direction is located further outward in the tire radial direction than the outer end 16 of the folded portion 6 b. In a preferred embodiment, the outer end 33 of the first organic fiber cord layer 31 is located radially outward of the outer end 15 of the inner apex 13 of the tire. Specifically, the height H4 in the tire radial direction from the bead base line BL to the outer end 33 of the first organic fiber cord layer 31 is, for example, 1.05 to 1.15 times the inner apex height H1.
In a further preferred embodiment, the outer end 33 of the first organic fiber cord layer 31 is located radially inward of the outer end 18 of the outer apex 14 in the tire. This can suppress the concentrated strain in the vicinity of the outer end 33 of the first organic fiber cord layer 31, and can suppress the tire delamination starting from the outer end 33.
The inner end 34 of the first organic fiber cord layer 31 in the tire radial direction is located on the outer side of the turn-up portion 6b in the tire axial direction and on the outer side in the tire radial direction than the inner end 24 of the first steel cord layer 21. In a preferred embodiment, the inner end 34 of the first organic fiber cord layer 31 is located radially outward of the upper surface 5a of the bead core 5 in the tire radial direction. During running of the tire, the vicinity of the inner end 34 of the first organic fiber cord layer 31 is restrained from deformation by the rim flange, and the deformation is reduced. Therefore, as described above, even if the first organic fiber cord layer 31 is shortened, there is no fear of tire delamination, and the tire weight can be reduced.
The outer end 35 of the second organic fiber cord layer 32 in the tire radial direction is located further outward in the tire radial direction than the outer end 16 of the turn-up portion 6 b. Thereby, the second organic fiber cord layer 32 covers the outer end 16 of the fold back portion 6 b. Therefore, the tire delamination starting from the outer end 16 of the folded portion 6b can be effectively suppressed.
In a preferred embodiment, the outer end 35 of the second organic fiber cord layer 32 is located, for example, radially inward of the tire from the outer end 33 of the first organic fiber cord layer 31 in the tire radial direction, and is covered with the first organic fiber cord layer 31. This effectively suppresses the tire delamination from the outer end 35 of the second organic fiber cord layer 32.
In a more preferred embodiment, the height H5 in the tire radial direction from the bead base line BL to the outer end 35 of the second organic fiber cord layer 32 is 0.95 to 1.05 times the inner apex height H1. Such a synergistic effect of the second organic fiber cord layer 32 and the inner apex 13 can effectively suppress the bending deformation of the bead portion 4 to the outer side in the tire axial direction.
The inner end 36 of the second organic fiber cord layer 32 in the tire radial direction is located on the tire axial direction outer side of the folded portion 6b and on the tire radial direction inner side of the inner end 34 of the first organic fiber cord layer 31.
In a preferred embodiment, the inner end 36 of the second organic fiber cord layer 32 is disposed, for example, radially inward of the upper surface 5a of the bead core 5 and radially outward of the lower surface 5b of the bead core 5. Even in the case where a load is applied to the tire, there is substantially no deformation in the vicinity of the bead core 5, and therefore, the tire delamination starting from the inner end 36 of the second organic fiber cord layer 32 can be suppressed.
In a more preferred embodiment, the inner end 36 of the second organic fiber cord layer 32 is preferably located radially inward of the inner end 24 of the first steel cord layer 21 in the tire, for example. This makes it possible to disperse the positions of the inner ends of the respective layers, which tend to have uneven rigidity, and further suppress damage to the bead portions such as tire separation.
In a normal state, the distance L1 from the bead base line BL to the inner end 37 of the second reinforcing portion 12 in the tire radial direction (the inner end 36 of the second organic fiber cord layer 32 in the present embodiment) in the tire radial direction is preferably 0.6 times or less the flange height Hf from the bead base line BL to the outer end of the flange of the normal rim in the tire radial direction. This reduces the shear stress acting on the inner end 37 of the second reinforcing portion 12, and thus prevents the tire from delaminating from the inner end 37.
In order to further exhibit the above-described effects, in the present embodiment, the distance L2 from the bead base line BL to the inner end 34 of the first organic fiber cord layer 31 in the tire radial direction is preferably 0.6 times or less, more preferably 0.5 times or less, of the above-described flange height Hf.
The second reinforcing part 12 has a layer abutting part 38 that abuts the organic fiber cord layers 31, 32. As shown in fig. 3, the layer adjacent part 38 preferably has a distance t1 between the cord 31c of the first organic fiber cord layer 31 and the cord 32c of the second organic fiber cord layer 32 of, for example, 0.5 to 1.8 mm. Such a layer abutting portion 38 can effectively absorb shear deformation generated between the respective organic fiber cord layers 31, 32.
Fig. 4 and 5 show enlarged views of a bead portion of a heavy duty tire according to another embodiment of the present invention. The same reference numerals are given to the structures in fig. 4 and 5 that are common to the above-described embodiments.
In the embodiment shown in fig. 4, the inner end 37 of the second reinforcing portion 12 is disposed on the inner side in the tire radial direction of the bead core 5. With this embodiment, fixing the inner end 37 of the second reinforcing portion 12 between the bead core 5 and the rim flange effectively suppresses the occurrence of tire delamination starting from the inner end 37.
In the embodiment shown in fig. 5, the inner end 37 of the second reinforcing portion 12 is located on the tire axial direction inner side of the bead core 5. Such a second reinforcing portion 12 can further reinforce the bead portion 4, and is advantageous in suppressing bending deformation thereof.
In the embodiment shown in fig. 4 and 5, the inner end 37 of the second organic fiber cord layer 32 constitutes the inner end 37 of the second reinforcing part. However, without being limited to this embodiment, the inner end 34 of the first organic fiber cord layer 31 may constitute the inner end 37 of the second reinforcing portion. With this embodiment, since the first organic fiber cord layer 31 covers the inner end 36 of the second organic fiber cord layer 32, the durability of the bead portion 4 can be further improved.
Although the heavy duty tire according to the embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described specific embodiment, and can be implemented by being modified into various embodiments.
[ examples ]
Based on the specifications of table 1, a heavy-duty tire having the basic structure of fig. 1 and having a bead portion size of 12.00R20 of fig. 2, 4, or 5 was manufactured. As a comparative example, a heavy load tire having a bead portion provided with only the first reinforcing portion as shown in fig. 6 was manufactured. The durability of the bead portion of each test tire was tested. The common specification and test method of each test tire are as follows.
Mounting a rim: 20X 8.50V
Tire internal pressure: 850kPa
< durability of bead portion >
The test tire was run on a roller tester under the following conditions, and the running distance until the bead portion was damaged was measured. As a result, assuming that the value of comparative example 1 is 100, the greater the numerical value, the more excellent the durability of the bead portion.
Speed: 20km/h
Longitudinal load: 73.46KN
The test results are shown in table 1.
[ Table 1]
From the test results, it was confirmed that the durability of the bead portion of the example tire was improved.
Description of the reference numerals
2 tread portion
3 side wall part
4 bead part
5 bead core
6a main body part
6b folded part
6A carcass ply
6 tyre body
11 first reinforcement part
12 second reinforcement part
21 first Steel cord layer
22 second Steel cord layer
31 first organic fiber cord layer
32 second organic fiber cord layer
Claims (8)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2015129631A JP6463226B2 (en) | 2015-06-29 | 2015-06-29 | Heavy duty tire |
| JP2015-129631 | 2015-06-29 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106274300A CN106274300A (en) | 2017-01-04 |
| CN106274300B true CN106274300B (en) | 2020-05-12 |
Family
ID=57651272
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610413056.9A Expired - Fee Related CN106274300B (en) | 2015-06-29 | 2016-06-14 | Heavy duty tires |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP6463226B2 (en) |
| CN (1) | CN106274300B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6790845B2 (en) * | 2017-01-13 | 2020-11-25 | 住友ゴム工業株式会社 | Pneumatic tires for heavy loads |
| JP6790846B2 (en) * | 2017-01-13 | 2020-11-25 | 住友ゴム工業株式会社 | Pneumatic tires for heavy loads |
| JP7024185B2 (en) * | 2017-01-13 | 2022-02-24 | 住友ゴム工業株式会社 | Pneumatic tires for heavy loads |
| JP6311810B1 (en) * | 2017-02-28 | 2018-04-18 | 横浜ゴム株式会社 | Pneumatic tire |
| JP6773013B2 (en) * | 2017-12-06 | 2020-10-21 | 横浜ゴム株式会社 | Pneumatic tires |
| JP7480554B2 (en) | 2020-03-30 | 2024-05-10 | 住友ゴム工業株式会社 | Heavy duty pneumatic tires |
| KR102710834B1 (en) * | 2022-11-01 | 2024-09-26 | 금호타이어 주식회사 | Pneumatic tire |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61275010A (en) * | 1985-05-29 | 1986-12-05 | Sumitomo Rubber Ind Ltd | Pneumatic radial tire for heavy-load use |
| JP2012106531A (en) * | 2010-11-15 | 2012-06-07 | Sumitomo Rubber Ind Ltd | Tire for heavy load |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4944122B1 (en) * | 1968-05-29 | 1974-11-26 | ||
| JPS6092905A (en) * | 1983-10-27 | 1985-05-24 | Sumitomo Rubber Ind Ltd | Radial tire for heavy load |
| JP2857485B2 (en) * | 1989-11-25 | 1999-02-17 | 住友ゴム工業 株式会社 | 15 ゜ taper tubeless tire |
| JP2682902B2 (en) * | 1991-02-15 | 1997-11-26 | 住友ゴム工業株式会社 | Tubeless radial tires for heavy loads |
| JP2000127719A (en) * | 1998-10-22 | 2000-05-09 | Ohtsu Tire & Rubber Co Ltd :The | Pneumatic radial tire |
| JP5682210B2 (en) * | 2010-10-05 | 2015-03-11 | 横浜ゴム株式会社 | Pneumatic tire |
-
2015
- 2015-06-29 JP JP2015129631A patent/JP6463226B2/en active Active
-
2016
- 2016-06-14 CN CN201610413056.9A patent/CN106274300B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61275010A (en) * | 1985-05-29 | 1986-12-05 | Sumitomo Rubber Ind Ltd | Pneumatic radial tire for heavy-load use |
| JP2012106531A (en) * | 2010-11-15 | 2012-06-07 | Sumitomo Rubber Ind Ltd | Tire for heavy load |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106274300A (en) | 2017-01-04 |
| JP6463226B2 (en) | 2019-01-30 |
| JP2017013538A (en) | 2017-01-19 |
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