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WO2008001773A1 - pneu apte à rouler dégonflé - Google Patents

pneu apte à rouler dégonflé Download PDF

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Publication number
WO2008001773A1
WO2008001773A1 PCT/JP2007/062806 JP2007062806W WO2008001773A1 WO 2008001773 A1 WO2008001773 A1 WO 2008001773A1 JP 2007062806 W JP2007062806 W JP 2007062806W WO 2008001773 A1 WO2008001773 A1 WO 2008001773A1
Authority
WO
WIPO (PCT)
Prior art keywords
bead
tire
vehicle
disposed
rubber
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/JP2007/062806
Other languages
English (en)
Japanese (ja)
Inventor
Masahiro Segawa
Kazutaka Hana
Koji Matsuyama
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyo Tire Corp
Original Assignee
Toyo Tire and Rubber Co Ltd
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
Priority claimed from JP2006176868A external-priority patent/JP4502333B2/ja
Priority claimed from JP2006304124A external-priority patent/JP4544636B2/ja
Priority claimed from JP2006305482A external-priority patent/JP4544637B2/ja
Application filed by Toyo Tire and Rubber Co Ltd filed Critical Toyo Tire and Rubber Co Ltd
Publication of WO2008001773A1 publication Critical patent/WO2008001773A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • B60C19/00—Tyre parts or constructions not otherwise provided for
    • B60C19/001—Tyres requiring an asymmetric or a special mounting
    • 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
    • B60C15/02—Seating or securing beads on rims
    • B60C15/0236—Asymmetric bead seats, e.g. different bead diameter or inclination angle
    • 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
    • B60C17/00—Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor
    • B60C17/0009—Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor comprising sidewall rubber inserts, e.g. crescent shaped 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
    • B60C17/00—Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor
    • B60C17/0009—Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor comprising sidewall rubber inserts, e.g. crescent shaped inserts
    • B60C17/0018—Tyres characterised by means enabling restricted operation in damaged or deflated condition; Accessories therefor comprising sidewall rubber inserts, e.g. crescent shaped inserts two or more inserts in each sidewall portion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C3/00—Tyres characterised by the transverse section
    • B60C3/06—Tyres characterised by the transverse section asymmetric

Definitions

  • the present invention is a so-called side reinforcing tape provided with a reinforcing rubber layer disposed in a sidewall portion.
  • the reinforced rubber layer supports the tire to suppress flattening, enabling run flat travel.
  • the pressure on the rim of the bead portion is weakened, so the fitting force with the rim is reduced, and the bead portion is easily detached from the rim. There was a problem.
  • Patent Document 3 a run flat tire is adopted which adopts a double bead structure on the vehicle outer side and does not adopt the double bead structure on the vehicle inner side. It has been proposed that the hardness of the reinforcing rubber layer on the side to be balanced should be greater at the inside of the vehicle than at the outside. Further, Patent Document 3 discloses that the void ratio at the vehicle outer side than the equatorial line of the tread is smaller than the void ratio at the vehicle inner side, and the rubber hardness at the vehicle outer side of the tread is greater than the rubber hardness at the vehicle inner side. There is.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 51 116507
  • Patent Document 2 Japanese Patent Application Laid-Open No. 53-138106
  • Patent Document 3 Japanese Patent Application Laid-Open No. 2006-218889
  • Patent Document 4 Japanese Patent Application Laid-Open No. 2001-130223
  • Patent Document 5 Japanese Patent Application Laid-Open No. 2002-205515
  • Patent Document 6 Japanese Patent Application Laid-Open No. 9 109621
  • Patent Document 7 Japanese Patent Application Laid-Open No. 91-118111
  • the present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a run-flat tire capable of improving the ride comfort while maintaining the bead removal performance.
  • the run flat tire according to the present invention comprises a pair of bead portions having an annular first bead, a sidewall portion extending outward from the bead portion in the tire radial direction, and a reinforcing rubber disposed on the sidewall portion.
  • a run flat tire comprising: a layer; and a tread portion in which outer peripheral side ends of the side wall portions are connected via a shoulder portion, the run flat tire being provided on the outer side in the tire width direction of the bead portion disposed on the vehicle outer side;
  • the above-mentioned distributive members are disposed on both sides
  • Each reinforcing rubber layer has a rubber hardness of 65 to 82 °
  • the belt layer disposed below the tread portion has a bending rigidity with respect to the longitudinal direction of 200 mm in tire circumferential direction length X tire width direction As the 0.9 to 2.
  • rubber hardness refers to the hardness according to JIS K6253 durometer hardness test (type A). Further, physical properties such as flexural rigidity are values measured by the method described in the examples.
  • the double bead structure adopted on the outside of the vehicle effectively removes the bead against the lateral force generated on the outside of the vehicle at the time of turning of the vehicle, which is the most likely cause of the bead coming off in the run flat traveling state. Can be prevented. For this reason, it is difficult to cause bead detachment due to buckling, and the rigidity of the belt layer can be lowered, so that the ride quality can be improved.
  • it is possible to effectively prevent bead detachment it is possible to reduce the hardness of the reinforcing rubber layer which makes it unnecessary to make the hardness of the side reinforcing rubber layer greater than the outside on the vehicle inner side. It can improve.
  • the void ratio on the outer side of the vehicle is equal to or less than the void ratio on the inner side of the vehicle, with the tire equator line as a boundary.
  • the void ratio refers to a value as a percentage obtained by dividing the groove area of each region by the total area in the tread width.
  • the tread center buckles in a state where the internal pressure is lowered, and Even when the ground contact pressure at the dab portion increases, the pattern shear rigidity on the outer side of the vehicle with a small void ratio increases when turning the vehicle, and the cornering power increases, so the tire slip angle can be reduced. Since the moment in the bead removal direction which acts on the tire is smaller, the bead removal can be prevented more effectively.
  • At least the cap rubber has a rubber boundary line of different hardness at a position of 40 to 60% of the tread width, and the rubber hardness of the boundary line on the vehicle outside of the vehicle inner side
  • the hardness is preferably equal to or higher than the rubber hardness.
  • the tread center portion buckles in a state of reduced internal pressure and the contact pressure of the shoulder portion rises even when the vehicle turns.
  • the pattern shear rigidity on the outside of the vehicle with a low void ratio is higher, the cornering power is increased, so the tire slip angle can be reduced, and the moment in the bead removal direction acting on the tire is smaller. It is possible to prevent bead detachment more effectively.
  • the annular bulging portion is also provided on the outer side in the tire width direction of the bead portion disposed on the inner side of the vehicle, and the second bead is disposed in each of the pair of annular bulging portions. It is also possible.
  • the pair of annular bulging portions reinforced by the second bead can abut on the rim flange, so the mounting stability with the rim is enhanced, and bead detachment can be effectively prevented.
  • bead detachment due to buckling is less likely to occur, and the rigidity of the belt layer can be lowered, so that the riding comfort performance can be improved.
  • the bead detachment can be effectively prevented, the hardness of the reinforced rubber layer disposed in the sidewall portion can be reduced, and even with this, the riding comfort performance can be improved.
  • the cross-sectional height Hi from the inner periphery of the first bead disposed on the vehicle inner side to the tire maximum diameter point, and the inner periphery of the second bead disposed on the vehicle outer side to the tire maximum diameter point are preferred.
  • the section height is the height in the tire radial direction in the tire meridional section, and the tire is defined as a rim. It shall be measured in the state of no load which was equipped and filled up with specified internal pressure.
  • the specified rim refers to the standard rim determined by JATMA corresponding to the tire size.
  • the prescribed internal pressure is the force S which is the air pressure determined by JATMA, and is 180 kPa when the tire is for a passenger car.
  • the inventors of the present invention conducted intensive studies to find that the amplitude can be suppressed by asymmetrizing vibration modes that are generally formed substantially symmetrically on both sides in the tire width direction. It was found to be effective for reduction.
  • the above-described configuration of the present invention adopts the double bead structure only on the outside of the vehicle, and is most likely to be the cause of bead detachment during run flat traveling, and against lateral force generated on the vehicle outside during turning. It is possible to effectively prevent the bead from coming off.
  • tire vibration occurs with both ends of the first bead disposed on the inside of the vehicle and the second bead disposed on the outside of the vehicle.
  • the reinforcing material extending in the above is disposed. According to this configuration, it is possible to reduce the amplitude of the center portion from the shoulder portion that is the antinode of the tire vibration, and the above-described road noise reduction effect can be suitably enhanced.
  • Another run flat tire according to the present invention includes a pair of bead portions having an annular first bead, sidewall portions extending outward from the bead portions in the tire radial direction, and the sidewall portions.
  • the run flat tire includes a reinforced rubber layer and a tread portion connecting the outer peripheral side ends of the side wall portions to each other via a shoulder portion, and from the bead portion disposed on the vehicle outer side.
  • the tire has a ring-shaped bulging portion having a ring-shaped second bead while bulging outward in the tire width direction, and has a cross-sectional height Hi from the inner periphery of the first bead arranged on the vehicle inner side to the tire maximum diameter point
  • the section height Ho from the inner periphery of the second bead disposed on the vehicle outer side to the maximum diameter point of the tire satisfies the relationship of the force Hi_Ho> 15 mm.
  • This tire adopts a double bead structure only on the outside of the vehicle, and has a run flat It is possible to effectively prevent bead detachment against lateral force generated on the outside of the vehicle during cornering, which is the most likely cause of bead detachment during traveling. And, by adopting the double bead structure only on the vehicle outer side, tire vibration occurs with the first bead arranged on the vehicle inner side and the second bead arranged on the vehicle outer side at both ends, and their sectional heights By satisfying the above relationship (Hi-Ho> 15 mm), it is possible to achieve both of the assemblability of the rim and the anti-bead property, and the road noise can be reduced by the asymmetry of the structure.
  • FIG. 1 A tire meridional cross section showing a run flat tire according to a first embodiment of the present invention
  • FIG. 2 A developed view showing an example of a tread pattern of the run flat tire shown in FIG.
  • FIG. 3 A tire meridian cross section showing a run flat tire according to a second embodiment of the present invention
  • FIG. 4 A tire meridian cross section showing a run flat tire according to a third embodiment of the present invention
  • FIG. ) Vibration mode diagram of a test tire according to Example 5-1 and (b) Comparative example 5-1 Description of symbols
  • FIG. 1 is a tire meridional cross-sectional view showing a run flat tire according to a first embodiment of the present invention when the specified rim is attached.
  • FIG. 2 is a development view showing an example of the tread pattern of the run flat tire shown in FIG.
  • the run flat tire of the present invention includes a pair of bead portions 1, sidewall portions 2 extending outward from the bead portions 1 in the tire radial direction, and sidewall portions 2.
  • a tread portion 4 is provided, the outer peripheral side ends of which are connected via a shoulder portion 3.
  • a bundle of bead wires made of, for example, steel wire is provided with an annular bead la (corresponding to the first bead) and a bead filler 15 arranged in an annular shape in the circumferential direction of the tire.
  • the bead portion 1 is firmly fitted on the tire casing 8 in a state of being reinforced by the carcass layer 5.
  • the bead portion 1 is disposed on the tire outer peripheral side of the rim base 8 b of the rim 8 and is pressed against the rim flange 8 a by the air pressure inside the tire.
  • an inner liner layer 6 for air pressure retention is disposed on the inner peripheral side of the carcass layer 5. Further, on the outer peripheral side of the carcass layer 5, a belt layer 7 for reinforcing by squeezing effect is disposed, and on the outer peripheral surface of the belt layer 7, a tread pattern is formed by tread rubber.
  • organic fibers such as polyester, rayon, nylon, and aramid are used. All of these materials should improve adhesion to rubber. Usually, surface treatment, adhesion treatment and the like are performed.
  • the belt layer 7 will be described later.
  • reinforcing rubber layers 9a and 9b having a tire meridional section having a substantially crescent shape are disposed on the inner side of the carcass layer 5 of the sidewall portion 2.
  • Examples of the raw material rubber for the above-mentioned rubber layer and the like include natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), butyl rubber (IIR) and the like, and these are used alone. Or used as a mixture of two or more. Further, these rubbers are reinforced with a filler such as carbon black and silica, and at the same time, a vulcanizing agent, a vulcanization accelerator, a plasticizer, an antiaging agent and the like are appropriately blended.
  • SBR styrene butadiene rubber
  • BR butadiene rubber
  • IR isoprene rubber
  • IIR butyl rubber
  • a double bead structure is adopted only on the outer side of the vehicle when the tire is attached. That is, an annular bulging portion 10 having an inner circumferential side surface 11 provided on the outer side in the tire width direction of the bead portion 1 disposed on the vehicle outer side and facing the outer circumferential curved surface of the rim flange 8a when the specified rim is mounted And an annular bead lb (corresponding to the second bead) disposed in the bulging portion 10.
  • the inner peripheral side surface 11 of the annular bulging portion 10 is in contact with the outer peripheral curved surface of the rim flange 8a, and there is a reduced diameter portion that holds the tip of the rim flange 8a.
  • a bead lb is provided on the outer periphery side of the diameter reducing portion.
  • the annular bulging portion 10 is provided with a bead lb and is connected to the sidewall portion 2 gently with the portion at the top substantially.
  • the annular bulging portion 10 is not limited to the shape shown in the present embodiment, and may have, for example, a semicircular or trapezoidal cross section of the tire meridian line.
  • the hardness of the rubber mainly constituting the annular bulging portion 10 is determined by maintaining the bead release resistance and the rim shift performance while taking into consideration that the rubber hardness of the reinforcing rubber layer 9a on the vehicle outer side is reduced. 66 to 76 ° is preferable in improving the
  • the annular bulging portion 10 is provided with a bead lb in which a bead wire has an annular shape in the tire circumferential direction.
  • the bead lb of the present embodiment is disposed so as to be positioned on the tire outer peripheral side and the tire width direction outer side from the outermost radius point of the center position force S rim flange 8a when the rim is attached.
  • the bead wire constituting the bead lb is not limited to one composed of the same steel wire bundle as the bead la, for example, one composed of the organic fiber bundle or rubber made of fiber reinforced rubber. It may be a bead or the like.
  • the force rim protector 12 is provided with the rim protector 12 for protecting the rim flange 8a when the specified rim is mounted on the outer side in the tire width direction of the bead portion 1 disposed inside the vehicle. It is also possible to form a shape which is connected to the side wall portion 2 from the position separated from the rim flange 8a without providing it.
  • the reinforcing rubber layers 9a and 9b disposed on both sides each have a rubber hardness of 65 to 82 °, preferably a rubber hardness of 65 to 79 °. If the rubber hardness is less than 65 °, the run flat durability and the bead off performance become insufficient. If the rubber hardness exceeds 82 °, the ride comfort can not be improved.
  • the rubber hardness may be different between the reinforcing rubber layer 9 b disposed on the vehicle inner side and the reinforcing rubber layer 9 a disposed on the vehicle outer side. Also, in that case, it is preferable that the reinforcing rubber layer 9a be larger than the reinforcing rubber layer 9b as the rubber hardness that the lateral force generated on the outside during turning of the vehicle is likely to cause bead detachment during run flat traveling.
  • the reinforcing rubber layer 9a disposed on the vehicle outer side is preferably larger than the reinforcing rubber layer 9b disposed on the vehicle inner side, preferably having a maximum thickness of 0.5 mm or more, preferably 0.8 to 1: 1.5 mm. Only the maximum thickness is large. Specifically, for example, the maximum thickness of the reinforcing rubber layer 9a disposed on the vehicle outer side is 9. 8 to 13. 5 mm, and the maximum thickness of the reinforcing rubber layer 9b disposed on the vehicle inner side is 9 to 12 mm. Me. .
  • the reinforcing rubber layers 9a and 9b are not limited to those formed of a single rubber layer, and may be formed of a plurality of rubber layers having different physical properties such as hardness. In that case, the average value of the rubber hardness of each layer may be within the above range.
  • the reinforcing rubber layer 9a disposed on the vehicle outer side is formed of a single rubber layer
  • the reinforcing rubber layer 9b disposed on the vehicle inner side is formed of two rubber layers
  • the carcass layer 5 is composed of two layers
  • the reinforcing rubber layer 9 b is disposed on the inner side of each carcass layer 5 located in the side wall portion 2.
  • a reinforcing rubber layer 9 a is disposed inside the two carcass layers 5 located in the sidewall portion 2.
  • the reinforcing layer 16 may be disposed substantially along the inner peripheral surface of the annular bulging portion 10.
  • the inner peripheral surface of the annular bulging portion 10 can be reinforced to suppress abrasion.
  • the reinforcing layer 16 include steel cords and chains made of organic fibers such as rayon, nylon, polyester, and aramid.
  • the belt layer 7 disposed below the tread portion 4 has a bending stiffness in the longitudinal direction of 200 mm in the circumferential direction of the tire and a length in the width direction of the tire of 0.9 to 2.
  • 1 X as bending stiffness per 100 mm. It is 10 6 N * m 2 , preferably 1.2 to 2.0 ⁇ 10 6 N.m 2 .
  • the bending stiffness is measured by sampling from a product tire. The belt layer is cut out to dimensions of 250 mm in the circumferential direction of the tire and 100 mm in the width direction of the tire, and this is used as a sample for the Shimadzu photograph tester Conduct a three-point bending test.
  • the bending rigidity of the belt layer 7 in the longitudinal direction is less than 0.9 X 10 6 Nm 2 , the buckling becomes extremely large during cornering, so that the bead is caused by the belt breakage or the belt breakage. There is a problem of detachment. In addition, if it exceeds 2. 1 ⁇ 10 6 N * m 2 , the ride quality can not be improved.
  • a material having a bending stiffness lower than that of a conventional run flat tire is used, and steel, aramid, PEN, polyester or the like is used. All of these materials are usually subjected to surface treatment, adhesion treatment and the like to improve adhesion to rubber.
  • the bending stiffness can be adjusted by the thickness of the material, the number of threads, the inclination angle, etc. in addition to the type of cord.
  • the belt layer 7 has, for example, a two-layer structure, and cords are arranged symmetrically at an angle of preferably 19 to 27 ° with respect to the tire equator line.
  • the outer layer of the belt layer 7 may be provided with a belt reinforcing layer, in which case the bending stiffness is measured without the belt reinforcing layer.
  • the belt reinforcing layer is, for example, a cord arranged or spirally wound in the tire circumferential direction.
  • organic fibers such as polyester, rayon, nylon, and aramid, metal fibers such as steel, and the like are used.
  • the tread portion 4 has, for example, a tread pattern as shown in FIG.
  • the tread pattern formed in the tread portion 4 has a tire equatorial line CL as a boundary of the region A1 outside the vehicle.
  • the void ratio be equal to or less than the void ratio of the area A2 inside the vehicle. More preferably, the void ratio of the region A1 outside the vehicle is 75 to 96% of the void ratio of the region A2 inside the vehicle. If this value is too small, uneven wear on the inside of the vehicle tends to increase.
  • the void ratio of the region A1 outside the vehicle is 25 to 35. /.
  • the void ratio of area A2 inside the vehicle is 30 to 40. / o is preferable.
  • four circumferential grooves and five types of oblique grooves are formed, but it is possible to adjust the void ratio S by the thickness and formation density of these.
  • the tread portion 4 has a boundary line TB of rubber different in hardness at least at a position A3 where the cap rubber is 40 to 60% of the tread width W, and the rubber hardness of the vehicle outside of the boundary line TB is the vehicle It is preferable that the hardness is equal to or higher than the inner rubber hardness. More preferably, the rubber hardness on the outside of the vehicle at the boundary line TB is 102 to 115% of the rubber hardness on the inside of the vehicle. If this value is too large, uneven wear on the inside of the vehicle tends to increase.
  • the rubber hardness on the outer side of the boundary line TB of the vehicle is preferably 65 to 75 °, and the rubber hardness on the inner side of the vehicle is preferably 62 to 70 °. From the viewpoint of durability, the boundary line T of rubber with different hardness
  • B is preferably disposed at the bottom of the groove.
  • the reinforcing rubber layer disposed on the inner side of the vehicle is formed of two rubber layers, but the reinforcing rubber layer disposed on the inner side of the vehicle includes one rubber layer. You may also form in. In that case, the reinforcing rubber layer is disposed on the inside of the two carcass layers located on the side wall also inside the vehicle.
  • the force carcass layer may be constituted by one layer.
  • the inner peripheral side surface of the annular bulging portion may be separated from the outer peripheral side curved surface of the rim flange at normal internal pressure.
  • the tread pattern has four circumferential grooves and five types of oblique grooves, and the tread pattern is particularly limited in the present invention. It is not decided.
  • a belt layer is cut out from the product tire to a dimension of 250 mm in the circumferential direction of the tire and 100 mm in the width direction of the tire, and this is used as a sample to carry out a 3-point bending test with an autograph tester manufactured by Shimadzu Corporation. At this time, by setting the distance between fulcrums to 200 mm and the test speed of 1 mm / sec, bending rigidity in the circumferential direction per 200 x 100 mm is obtained.
  • the calculation method is based on Chapter 5 of Tire Engineering (Grand Prix Publishing).
  • a test tire was mounted on the left front of a real car (domestic 3000cc class FR car), and the car went on a so-called J-turn traveling straight from a straight ahead to a 20 m radius circular course.
  • Each test tire was run-flat at an internal pressure of OkPa, and the bead release resistance was evaluated by the running speed (proportional to the lateral G) when bead removal occurred.
  • the driving speed started from 25 km / h, and the vehicle was driven in 5 km / h increments until bead detachment occurred.
  • Comparative example 1 — 1 is evaluated as an index of 100, and the larger the value, the higher the running speed when bead detachment occurs, that is, the better the bead detachment resistance.
  • the run-flat tire of each example can improve bead removal performance and ride comfort.
  • Comparative Example 1 1 to 5 where the double bead structure was not adopted, the bead declination was significantly deteriorated due to the decrease in the bending rigidity of the belt layer and the decrease in the PAD hardness.
  • the improvement effect of the riding comfort is reduced as in Comparative Example 1-16:! 18 unless the bending rigidity and PAD hardness of the belt layer are reduced.
  • Example 3-:!-3-3 the bead detachment is greatly improved.
  • Comparative Example 3-:!-3-4 the bead detachment was significantly deteriorated due to the decrease in the bending rigidity of the belt layer and the decrease in the PAD hardness.
  • the second embodiment has the same configuration as the first embodiment except for the configuration described below, so the common points are omitted and the differences are mainly described. Note that the same reference numerals are given to the same members * portions as the members * portions described in the first embodiment, and the redundant description will be omitted.
  • FIG. 3 is a tire meridional cross-sectional view showing a run flat tire according to a second embodiment of the present invention when the specified rim is attached.
  • the right side is the outside of the vehicle.
  • double bead structures are adopted on both sides in the tire width direction. That is, a pair of annular bulging portions 10 having an inner peripheral side surface 11 provided on the outer side in the tire width direction of the bead portion 1 and facing the outer peripheral curved surface of the rim flange 8a when the specified rim is attached And an annular bead lb disposed on each of the
  • the reinforcing rubber layers 9a and 9b are not limited to those formed of a single rubber layer as in the present embodiment, but may be formed of plural rubber layers having different physical properties such as hardness.
  • the reinforcing rubber layer 9a is composed of two rubber layers, according to the equation ⁇ (ha 'X ta') + (ha "X ta") / (ta, + ta ")
  • the calculated value may be within the range of the rubber hardness of the above-mentioned reinforced rubber layer 9a, where ta ′, ha, is the maximum thickness of one of the rubber layers constituting the reinforced rubber layer 9a, and the rubber hardness And ta ", ha" are the other maximum thickness, rubber hardness.
  • the reinforcing rubber layers 9a and 9b on both sides are formed of a single rubber layer, and the force S disposed inside the two-layered carcass layer 5 located in the sidewall portion 2,
  • the present invention is not limited to this.
  • at least one of the reinforcing rubber layers may be formed of two rubber layers, and the carcass layer 5 may be interposed between the two layers.
  • the belt layer 7 disposed below the tread portion 4 has a bending stiffness in the longitudinal direction of 200 mm in the circumferential direction of the tire and 100 mm in the width direction of the tire.
  • the flexural rigidity is 0.9 to 2. 1 x 10 6 N 'm 2 and preferably 1. 2 to 2. 0 ⁇ 10 6 ⁇ m'.
  • the bending test was carried out in the same manner as in the first embodiment described above.
  • Comparative example 4 The riding comfort in 5 points is made into 5 points, and 10 points are evaluated as a full mark, and the bearing center is better, and the said index is large and preferable.
  • the J-turn travel was performed in the same manner as in the first embodiment described above, and the bead resistance was evaluated.
  • Comparative Example 4 _ 1 is evaluated as an index of 100, and the larger the value, the higher the running speed when bead detachment occurs, that is, the bead is excellent in bead detachment resistance.
  • the tire has the tire structure shown in FIG. 3, the bending rigidity of the belt layer as shown in Table 4, the rubber hardness (PAD hardness) of the reinforcing rubber layer on both sides, and the difference in the maximum thickness of the reinforcing rubber layer on both sides Omm
  • the riding comfort performance can be improved while maintaining the anti-bead performance.
  • Comparative Examples 4 to 45 in which the double bead structure is not employed, the anti-bead resistance performance is significantly deteriorated, and further, the flexural rigidity or PAD hardness of the belt layer is high, and Comparative Example 4 _ 1 At 4 to 3, the ride performance is degraded.
  • Comparative Examples 4_ 6 to 4_8 even when the double bead structure is adopted, the ride comfort performance is not improved as in Comparative Examples 4_ 6 to 4_8 unless the bending rigidity and the PAD hardness of the belt layer are reduced.
  • the third embodiment has the same configuration and effects as the first embodiment except for the configuration described below, so the common points are omitted and the differences are mainly described. Note that the same reference numerals are given to the same members * portions as the members * portions described in the first embodiment, and the redundant description will be omitted.
  • FIG. 4 is a tire meridional cross-sectional view showing a run flat tire according to a third embodiment of the present invention when the specified rim is attached.
  • a belt layer 7 for reinforcement by hoop effect is disposed, and on the outer periphery thereof, a tread rubber 13 is disposed.
  • the carcass layer 5 and the belt layer 7 are each made of a cord material arranged at a predetermined angle.
  • the cord material organic fibers such as polyester, nylon, nylon, aramid, steel, etc. are preferably used.
  • FIG. 4 shows the outside of the vehicle on the right side and the inside of the vehicle on the left side, and in the present invention, the double bead structure is adopted only on the outside of the vehicle. That is, an annular bulging portion 10 having an annular bead lb is provided while bulging outward from the bead portion 1 disposed on the vehicle outer side in the tire width direction.
  • the inner circumferential side surface 11 of the annular bulging portion 10 may be gradually separated from the outer peripheral curved surface of the rim flange 8a, but in the present embodiment, it is in contact with the outer peripheral curved surface.
  • the hardness of the rubber mainly constituting the annular bulging portion 10 further maintains the bead detachment resistance and the rim deviation performance in consideration of reducing the rubber hardness of the reinforcing rubber layer 9a as described later. In order to improve the ride quality, 65 to 78 ° is preferable.
  • the cross-sectional height Hi from the inner periphery of the bead la disposed on the vehicle inner side to the tire maximum diameter point P and the tire from the inner periphery of the bead lb disposed on the vehicle outer side It is set to satisfy the relationship between the section height Ho and the force Hi_Ho> 15 mm, which makes it possible to achieve both reduction in road noise and improvement in anti-bead resistance performance.
  • the present invention adopts the double bead structure only on the vehicle outer side, the difference in the amount of deflection of the side wall portions 2 on both sides in the run flat state tends to be large. Due to this, the asymmetry of the contact pressure distribution on the tread surface becomes large, which may cause problems such as occurrence of uneven wear and deterioration in steering stability. Therefore, in the present embodiment, the thickness of the reinforcing rubber layer 9a is reduced by increasing the rubber hardness of the reinforcing rubber layer 9b inside the vehicle with respect to the reinforcing rubber layer 9a outside the vehicle. It balances the amount of deflection.
  • the rubber hardness of the reinforcing rubber layer 9a is 60 to 82 °
  • the rubber hardness of the reinforcing rubber layer 9b is 65 to 90.
  • the rubber hardness of the reinforcing rubber layer 9b is made equal to or higher than that of the reinforcing rubber layer 9a, and the maximum thickness is increased by 0.5 mm or more.
  • the rubber hardness of the reinforcing rubber layer 9a disposed on the vehicle outer side is 60 to 82 ° as described above, and preferably 65 to 78 °. If this is less than 60 °, the durability during runflat running becomes insufficient, and if it exceeds 82 °, balance with the deflection inside the vehicle should be taken. Tend to result in uneven wear on the tread surface and a deterioration in ride comfort.
  • the rubber hardness of the reinforcing rubber layer 9b disposed inside the vehicle is 65 to 90 ° as described above, and preferably the rubber hardness is 70 to 85 °. If this is less than 65 °, uneven wear tends to occur on the tread surface, which makes it difficult to balance the amount of sag on the outside of the vehicle, and if it exceeds 90 °, the ride comfort tends to deteriorate.
  • the reinforcing rubber layer 9b preferably has a rubber hardness equal to or higher than that of the reinforcing rubber layer 9a within the range of 65 to 90 °, and preferably has a rubber hardness 5 ° or more higher than that of the reinforcing rubber layer 9a.
  • the reinforcing rubber layer 9b disposed inside the vehicle has a maximum thickness that is larger by 5% to 13% at which the maximum thickness is 4% or more larger than that of the reinforcing rubber layer 9a disposed outside the vehicle. That is, when the maximum thickness of the reinforcing rubber layer 9a is 100, it is more preferable that the maximum thickness of the reinforcing rubber layer 9b is 105 to 113, preferably 104 or more.
  • the reinforcing rubber layers 9a and 9b are not limited to those formed of a single rubber layer, and may be formed of a plurality of rubber layers having different physical properties such as rubber hardness.
  • the reinforcing rubber layer 9a is composed of two rubber layers, according to the equation ⁇ (ha 'X ta') + (ha "X ta") / (ta '+ ta ") Calculated value It should be within the range of rubber hardness of the above-mentioned reinforced rubber layer 9a, where ta,, ha, is the maximum thickness of one of the rubber layers constituting the reinforced rubber layer 9a, and the rubber hardness Yes, ta "and ha" are the other maximum thickness and rubber hardness.
  • the reinforcing rubber layer 9a is formed of a single rubber layer, and the reinforcing rubber layer 9b intervenes one layer of the carcass layer 5
  • the carcass layer 5 is composed of two layers, and the reinforcing rubber layer 9 b is formed on the inner peripheral side of each carcass layer 5 located in the side wall portion 2. Are arranged.
  • the width is substantially 5 to 15%, preferably 10 to 15% of the maximum belt width WB, substantially in the tire circumferential direction. It is preferable to provide a reinforcement (not shown) extending at an angle of 0 °. According to this configuration, it is possible to reduce the amplitude of the center portion that is the antinode of the tire vibration, and it is possible to preferably enhance the road noise reduction effect.
  • the constituent materials of the carcass layer 5 and the belt layer 7 described above can be preferably used.
  • the road noise reduction effect according to the present invention is mainly due to the vibration mode having the asymmetry described above, and the arrangement of the reinforcing member does not excessively increase the weight of the tire.
  • specific examples of the run flat tire according to the third embodiment of the present invention will be described.
  • the evaluation item in an Example etc. measured as follows.
  • Comparative Example 5-1 is evaluated on the basis of an index of 100, and the larger the value is, the larger the traveling speed when bead detachment occurs, that is, the better the bead detachment resistance.
  • test tire was mounted on a real car (domestic 3000cc class FR car) and air pressure was 200kPa for both front and rear, a microphone was attached to the driver's seat ear and road noise level of 200 ⁇ 400Hz was measured at constant speed of 60km Zh. .
  • Comparative Example 5 _ 1 is taken as 100 to measure the measured value. The smaller the value is, the smaller the road noise level is.
  • the hump pressure was evaluated as an index of rim setability. Comparative example 5-1 is evaluated as an index of 100, and the larger the value is, the worse the rim assembling property is, and it is shown.
  • Tires having a tire structure shown in FIG. 4 and a tire size of 245/401 ⁇ 18 as shown in Table 5 are given as Examples 5-1 and 5-2.
  • the rubber hardness of the reinforcing rubber layer on the outer side of the vehicle was 76 °
  • the rubber hardness of the reinforcing rubber layer on the inner side of the vehicle was 78 °, in order to balance the deflection of the side wall portions on both sides.
  • the maximum thickness of the reinforcing rubber layer disposed outside the vehicle was made smaller than that inside the vehicle, and the difference between them was 10% of the maximum thickness of the reinforcing rubber layer disposed outside the vehicle.
  • the reinforcing rubber layers on both sides were each composed of a single layer rubber layer having a rubber hardness of 77 °. Further, the reinforcing rubber layers on both sides were set to the same maximum thickness, and both of them were in the middle of the maximum thicknesses of the reinforcing rubber layers on both sides in the example.
  • the test tester is the same as Example 5-1 except that the value of Hi-Ho is as shown in Table 5.
  • the samples were prepared and set as Comparative Examples 5-2 and 5-3, respectively.
  • Table 5 shows the evaluation results of each example.
  • FIG. 5 is a vibration mode diagram of a test tire according to (a) Example 5-1 and (b) comparative example 5-1, wherein the initial shape before the tire vibrates is indicated by a broken line BL, and the tire is shown in FIG.
  • the vibration mode of is indicated by a solid line SL.
  • Such a vibration mode diagram can be created from the experimentally obtained amplitude and phase of the transfer function.
  • the transfer function is disclosed in detail in Japanese Patent Laid-Open No. 2004-82858. As shown in the figure, when vibration is input to the tread portion of the tire within a frequency range of 200 to 400 Hz, a plurality of measurement points (circles in FIG. It corresponds to the mark).
  • vibration modes substantially symmetrical with respect to the tire equator are formed with the first beads arranged in the pair of bead portions at both ends, and it is possible to Part.
  • This vibration mode is a cross-section secondary mode in which the tire maximum width portion is a node and the buttress portion and the lower side are antinodes.
  • the vibration nodes and antinodes are substantially at the same position on the vehicle outer side and the vehicle inner side.
  • Example 5-1 the first bead disposed in the bead portion on the inner side of the vehicle and the second bead disposed in the annular bulging portion on the outer side of the vehicle are both ends, It can be seen that vibration modes asymmetric to the tire equator are formed. It has a double bead structure on the outside of the vehicle The vibration mode has an asymmetry to suppress the amplitude.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Tires In General (AREA)

Abstract

L'invention concerne un pneu apte à rouler dégonflé qui présente des couches (9a, 9b) en caoutchouc renforcé placées dans les parties de paroi latérale et présentant une partie annulaire gonflée (10) et un deuxième cordon annulaire (1b). La partie annulaire gonflée (10) est formée sur le côté externe, dans la direction latérale du pneu, d'une partie (1) de cordon placée sur le côté externe du véhicule et a une surface périphérique interne (11) opposée à la surface périphérique externe courbée d'une bride de couronne lorsqu'une couronne spécifiée est installée sur le pneu. Le deuxième cordon annulaire (1b) est placé dans la partie annulaire gonflée (10). Les deux couches en caoutchouc renforcé (9a, 9b) placées sur les deux côtés ont une dureté comprise dans la plage de 65° à 82°. Des couches de ceinture (7) placées sur le côté inférieur de la partie (4) de la bande de roulement ont une rigidité en flexion longitudinale comprise dans la plage allant de 0,9 à 2,1 × 106 N.m2.
PCT/JP2007/062806 2006-06-27 2007-06-26 pneu apte à rouler dégonflé Ceased WO2008001773A1 (fr)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP2006-176868 2006-06-27
JP2006176868A JP4502333B2 (ja) 2006-06-27 2006-06-27 ランフラットタイヤ
JP2006-304124 2006-11-09
JP2006304124A JP4544636B2 (ja) 2006-11-09 2006-11-09 ランフラットタイヤ
JP2006305482A JP4544637B2 (ja) 2006-11-10 2006-11-10 ランフラットタイヤ
JP2006-305482 2006-11-10

Publications (1)

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WO2008001773A1 true WO2008001773A1 (fr) 2008-01-03

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014188178A1 (fr) 2013-05-22 2014-11-27 Cantab Anti-Infectives Limited Dérivés polymyxine et leur utilisation dans le cadre d'une thérapie combinée en association avec d'autres antibiotiques
JP2019111859A (ja) * 2017-12-21 2019-07-11 Ｔｏｙｏ Ｔｉｒｅ株式会社 空気入りタイヤ

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51116507A (en) * 1975-04-02 1976-10-14 Toyo Tire & Rubber Co Ltd Assembly of pneumatic tyre and rim
JP2000343912A (ja) * 1999-06-04 2000-12-12 Topy Ind Ltd ダンパー部を有するタイヤ
WO2006028083A1 (fr) * 2004-09-09 2006-03-16 Toyo Tire & Rubber Co., Ltd. Pneu à flancs renforcés et procédé de fabrication du pneu à flancs renforcés
WO2006085450A1 (fr) * 2005-02-08 2006-08-17 Toyo Tire & Rubber Co., Ltd. Pneu a affaissement limite

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51116507A (en) * 1975-04-02 1976-10-14 Toyo Tire & Rubber Co Ltd Assembly of pneumatic tyre and rim
JP2000343912A (ja) * 1999-06-04 2000-12-12 Topy Ind Ltd ダンパー部を有するタイヤ
WO2006028083A1 (fr) * 2004-09-09 2006-03-16 Toyo Tire & Rubber Co., Ltd. Pneu à flancs renforcés et procédé de fabrication du pneu à flancs renforcés
WO2006085450A1 (fr) * 2005-02-08 2006-08-17 Toyo Tire & Rubber Co., Ltd. Pneu a affaissement limite

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014188178A1 (fr) 2013-05-22 2014-11-27 Cantab Anti-Infectives Limited Dérivés polymyxine et leur utilisation dans le cadre d'une thérapie combinée en association avec d'autres antibiotiques
JP2019111859A (ja) * 2017-12-21 2019-07-11 Ｔｏｙｏ Ｔｉｒｅ株式会社 空気入りタイヤ
JP6993865B2 (ja) 2017-12-21 2022-02-10 Ｔｏｙｏ Ｔｉｒｅ株式会社 空気入りタイヤ

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