JP2019034668A - Pneumatic tire - Google Patents

Abstract

To provide a pneumatic tire capable of suppressing deformation of a reinforcement member having elasticity.SOLUTION: A pneumatic tire includes: a side wall part 5 positioned on both sides in a tire width direction; a bead part 20 positioned inside in a tire radial direction of the side wall part 5; a plurality of protectors 30 which are provided so as to project from the surface of the side wall part 5 within a range of 30% or more and 70% or less of the tire sectional height from an inner end 25 in a tire radial direction of the bead part 20 to the outside in the tire peripheral direction in at least one side wall part 5 out of the side wall part 5, and extend in a tire circumferential direction; a plurality of spiral reinforcement members 40 which are formed in a spiral form and has a spiral central axis CS arranged inside a protector 30 in a direction extending to the tire circumferential direction; and an elastic reinforcement member 50 which is covered with the spiral reinforcement member 40.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a pneumatic tire.

  In a pneumatic tire used for a vehicle traveling on an unpaved road, stones on the road surface often come into contact with the sidewall portion while the vehicle is traveling, and the sidewall portion is easily damaged. For this reason, some conventional pneumatic tires reinforce the sidewall portion in order to suppress damage to the sidewall portion. For example, the pneumatic tire for construction vehicles described in Patent Document 1 is provided with at least two convex protectors extending in the tire circumferential direction on the sidewall portion, and by embedding an elastic reinforcing material inside the protector, The reinforcement effect by the protector is enhanced.

Japanese Patent No. 3628279

  However, when a resilient member is used as the reinforcing member disposed in the protector of the sidewall portion, when the green tire is vulcanized, the reinforcing member may be deformed by the pressure during vulcanization molding. There is. Specifically, the reinforcing member may be deformed in a direction in which the thickness of the reinforcing member in the thickness direction of the sidewall portion is reduced by the pressure during vulcanization molding. In this case, if the thickness of the reinforcing member becomes too thin, there is a possibility that damage to the sidewall portion when a stone or the like on the road surface comes into contact with the protector becomes difficult to suppress by the reinforcing member. As described above, the deformation of the reinforcing member has an influence on the reinforcement by the reinforcing member, but the reinforcing member made of the elastic member is not deformed and the reinforcing member is not disposed on the sidewall portion. It was very difficult.

  This invention is made | formed in view of the above, Comprising: It aims at providing the pneumatic tire which can suppress a deformation | transformation of the reinforcing member which has elasticity.

  In order to solve the above-described problems and achieve the object, a pneumatic tire according to the present invention includes a sidewall portion positioned on both sides in the tire width direction, and a bead portion positioned on the tire radial direction inner side of the sidewall portion. And at least one of the sidewall portions, within the range of 30% to 70% of the tire cross-section height from the inner end portion in the tire radial direction of the bead portion to the outer side in the tire circumferential direction. A plurality of protectors that protrude from the surface of the sidewall portion and extend in the tire circumferential direction, and are formed in a spiral shape, and are arranged inside the protector so that the central axis of the spiral extends in the tire circumferential direction. A plurality of spiral reinforcing members, and an elastic reinforcing member covered with the spiral reinforcing members.

  In the pneumatic tire, it is preferable that the plurality of spiral reinforcing members and the elastic reinforcing members are arranged concentrically around the tire center.

  In the pneumatic tire, the elastic reinforcing member has a 100% modulus in a range of 5 to 25 times the 100% modulus of the rubber composition of the sidewall portion adjacent to the spiral reinforcing member. Is preferred.

  In the pneumatic tire, the elastic reinforcing member preferably has a breaking strength within a range of 10 MPa to 50 MPa and a breaking elongation of 150% or more.

  In the pneumatic tire, the protector has a semicircular shape in the meridional section of the pneumatic tire, and the helical reinforcing member has an outer diameter φs with respect to a semicircle diameter φp of the protector. The range is preferably 0.1 ≦ (φs / φp) ≦ 0.9.

  In the pneumatic tire, the helical reinforcing member preferably has a wire diameter φw in a range of 0.5 mm ≦ φw ≦ 10.0 mm.

  The pneumatic tire according to the present invention has an effect that the deformation of the elastic reinforcing member can be suppressed.

FIG. 1 is a meridional cross-sectional view showing a main part of a pneumatic tire according to an embodiment. FIG. 2 is a side view of the pneumatic tire viewed in the AA direction in FIG. 1. FIG. 3 is a detailed view of part B of FIG. FIG. 4 is an explanatory diagram of the protector, the spiral reinforcing member, and the elastic reinforcing member when the protector shown in FIG. 3 is viewed in the CC direction. FIG. 5 is a side view of the spiral reinforcing member and the elastic reinforcing member shown in FIG. FIG. 6 is a modified example of the pneumatic tire according to the embodiment, and is an explanatory diagram in the case of two protectors. FIG. 7 is a modified example of the pneumatic tire according to the embodiment, and is an explanatory diagram when a part of the protectors is discontinuous. FIG. 8 is a modified example of the pneumatic tire according to the embodiment, and is an explanatory diagram when all the protectors are discontinuous. FIG. 9A is a chart showing the results of a performance test of a pneumatic tire. FIG. 9B is a chart showing the results of the performance test of the pneumatic tire.

  Hereinafter, an embodiment of a pneumatic tire according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be replaced by those skilled in the art and can be easily conceived, or those that are substantially the same.

Embodiment
In the following description, the tire width direction refers to a direction parallel to the rotational axis of the pneumatic tire, the inner side in the tire width direction refers to the direction toward the tire equator in the tire width direction, and the outer side in the tire width direction refers to the tire width. The direction opposite to the direction toward the tire equatorial plane. Further, the tire radial direction means a direction orthogonal to the tire rotation axis, the tire radial direction inner side means the direction toward the tire rotation axis in the tire radial direction, and the tire radial direction outer side means from the tire rotation axis in the tire radial direction. The direction to leave. Further, the tire circumferential direction refers to a direction rotating around the tire rotation axis. In the following description, the meridional section refers to a section when the tire is cut along a plane including the tire rotation axis.

  FIG. 1 is a meridional cross-sectional view showing a main part of a pneumatic tire 1 according to an embodiment. The pneumatic tire 1 according to this embodiment has a specified mounting direction with respect to the vehicle, that is, a direction when the vehicle is mounted. For this reason, when mounted on the vehicle, the pneumatic tire 1 is mounted on the rim of the vehicle in the specified mounting direction. Is done. Moreover, the pneumatic tire 1 according to the present embodiment is a radial tire for construction vehicles called an OR tire (Off the Road Tire). The pneumatic tire 1 shown in FIG. 1 as the present embodiment has a tread portion 2 disposed on the outermost portion in the tire radial direction when viewed in the meridional section, and the surface of the tread portion 2, that is, the concerned A portion that comes into contact with the road surface when the vehicle (not shown) on which the pneumatic tire 1 is mounted is formed as a tread surface 3.

  A plurality of lug grooves 15 are formed in the tread surface 3 at predetermined intervals in the tire circumferential direction. The lug groove 15 refers to a lateral groove having a groove width of 10 mm or more in the case of a tire for construction vehicles, for example. Further, the lug groove 15 extends in the tire width direction and opens at the tire ground contact end T, and further opens at tread ends on both sides in the tire width direction. At this time, the lug groove 15 may extend in parallel to the tire width direction, or may extend while being inclined with respect to the tire width direction. In the present embodiment, only the lug grooves 15 are formed on the tread surface 3, but circumferential grooves extending in the tire circumferential direction may be formed on the tread surface 3.

  In addition, a tread end means the both ends of the tread pattern part of a tire. The tire ground contact end T is a tire when the pneumatic tire 1 is mounted on a specified rim to apply a specified internal pressure and is placed perpendicular to the flat plate in a stationary state and a load corresponding to the specified load is applied. The maximum width position in the tire axial direction on the contact surface between the flat plate and the flat plate.

  Here, the specified rim refers to “applied rim” defined in JATMA, “Design Rim” defined in TRA, or “Measuring Rim” defined in ETRTO. The specified internal pressure means “maximum air pressure” specified by JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” specified by TRA, or “INFLATION PRESSURES” specified by ETRTO. The specified load means “maximum load capacity” defined in JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined in TRA, or “LOAD CAPACITY” defined in ETRTO.

  Both ends of the tread portion 2 in the tire width direction are formed as shoulder portions 4, and sidewall portions 5 are disposed from the shoulder portion 4 to a predetermined position inside the tire radial direction. That is, the sidewall portions 5 are disposed at two places on both sides of the pneumatic tire 1 in the tire width direction.

  Further, the bead portions 20 are located on the inner side in the tire radial direction of the respective sidewall portions 5, and the bead portions 20 are disposed at two locations on both sides of the tire equatorial plane CL, like the sidewall portions 5. ing. That is, a pair of bead portions 20 is disposed on both sides of the tire equatorial plane CL in the tire width direction. The tire equatorial plane CL in this case refers to a plane that passes through the center point of the pneumatic tire 1 in the tire width direction and is orthogonal to the tire rotation axis. Each of the pair of bead parts 20 is provided with a bead core 21, and two bead cores 21 are provided in each bead part 20. The two bead cores 21 provided in each bead part 20 are arranged side by side in the tire width direction, that is, each bead part 20 has an inner bead core 21a and an inner bead core that are relatively located on the inner side in the tire width direction. An outer bead core 21b located on the outer side in the tire width direction of 21a is disposed. Thus, the bead core 21 in which two beads are disposed in the bead portion 20 is formed by winding a bead wire, which is a steel wire, in a ring shape.

  A bead filler 22 is provided outside the bead core 21 in the tire radial direction. The bead fillers 22 are provided corresponding to the bead cores 21, and each bead filler 22 is disposed on the outer side in the tire radial direction of the corresponding bead core 21. That is, the bead filler 22 is arranged on the outer side in the tire radial direction of the outer bead core 21b and the inner bead filler 22a disposed on the outer side in the tire radial direction of the inner bead core 21a corresponding to the inner bead core 21a. An outer bead filler 22b is provided. The bead filler 22 is a rubber material that is disposed in a space formed by folding an end portion in the tire width direction of the carcass 6 to be described later outward in the tire width direction at the position of the bead core 21.

  The bead portion 20 is configured so that it can be attached to a rim wheel having a specified rim having a 5 ° taper. In other words, the pneumatic tire 1 according to the present embodiment is such that the portion that fits with the bead portion 20 is inclined from the inner side to the outer side in the tire width direction at an inclination angle of 5 ° ± 1 ° with respect to the rotation axis of the rim wheel. It can be mounted on a defined rim that is inclined in a direction toward the radially outer side.

  A breaker 7 is disposed inside the tread portion 2 in the tire radial direction. The breaker 7 has, for example, a multilayer structure in which a first breaker 71 and a second breaker 72 are laminated, and a plurality of breaker cords made of an organic fiber material such as steel or nylon are coated with a coat rubber and rolled. Is done. Further, the breaker 7 has different breaker cord angles with respect to the tire circumferential direction between the first breaker 71 and the second breaker 72. In other words, the breaker 7 having the first breaker 71 and the second breaker 72 is configured as a so-called cross-ply structure in which the breaker cord directions are crossed and stacked. The first breaker 71 and the second breaker 72 are arranged such that the first breaker 71 is disposed on the inner side in the tire radial direction, and the second breaker 72 is located on the outer side in the tire radial direction of the first breaker 71 with respect to the first breaker 71. Are stacked and arranged.

  On the inner side in the tire radial direction of the breaker 7 and on the tire equatorial plane CL side of the sidewall portion 5, a carcass 6 including a carcass cord of a bias ply is disposed between the bead portions 20 on both sides in the tire width direction. Are provided continuously. The carcass 6 has a multilayer structure formed by laminating two sheets of a first carcass 61 and a second carcass 62, and is bridged in a toroidal shape between bead cores 21 disposed on both sides in the tire width direction. Consists of the tire skeleton.

  Specifically, the carcass 6 is disposed from one bead portion 20 to the other bead portion 20 of the pair of bead portions 20 located on both sides in the tire width direction, and the first carcass 61 and the second carcass 62 are disposed. Are wound around the bead core 21 along the bead core 21 so as to wrap the bead core 21 and the bead filler 22. That is, of the stacked first carcass 61 and second carcass 62, the first carcass 61 positioned relatively inside passes from the inner side of the inner bead core 21a in the tire width direction to the inner side of the inner bead core 21a in the tire radial direction. The bead portion 20 is folded around the inner bead core 21a so as to be disposed on the outer side in the tire width direction of the inner bead core 21a. In addition, the second carcass 62 that is positioned relatively outside of the first carcass 61 and the second carcass 62 passes from the inner side in the tire width direction of the outer bead core 21b to the inner side in the tire radial direction of the outer bead core 21b, and is outer bead core. The bead portion 20 is folded around the outer bead core 21b so as to be disposed on the outer side in the tire width direction of 21b. Accordingly, the first carcass 61 and the second carcass 62 are respectively disposed between the inner side and the outer side of the bead core 21 in the tire width direction.

  The first carcass 61 and the second carcass 62 arranged in this way are made by rolling a plurality of carcass cords made of steel or organic fiber materials such as aramid, nylon, polyester, rayon, etc. with a coat rubber. It is configured. These carcass cords are arranged to be inclined at an angle θ of 20 ° or more and 50 ° or less in absolute value with respect to the tire circumferential direction. Further, the carcass 6 is arranged such that the carcass cord of the first carcass 61 and the carcass cord of the second carcass 62 intersect each other.

  An inner liner 8 is formed along the carcass 6 on the inner side of the carcass 6 or on the inner side of the carcass 6 in the pneumatic tire 1.

  FIG. 2 is a side view of the pneumatic tire 1 viewed in the AA direction of FIG. Of the sidewall portions 5 located on both sides in the tire width direction, one sidewall portion 5 is provided with a plurality of protectors 30 that protrude from the surface of the sidewall portion 5 and extend in the tire circumferential direction. Specifically, the protector 30 is provided in the vehicle mounting direction among the sidewall portion 5 located on the inner side in the vehicle mounting direction and the sidewall portion 5 positioned on the outer side in the vehicle mounting direction when the pneumatic tire 1 is mounted on the vehicle. It is provided in the side wall part 5 located outside.

  The plurality of protectors 30 are all provided within a range of 30% to 70% of the tire cross-section height SH from the inner end 25 in the tire radial direction of the bead portion 20 to the outer side in the tire circumferential direction. Then, three protectors 30 are provided. The three protectors 30 are disposed at positions different from each other in the tire radial direction, and are formed over one circumference around the tire center AX that is the rotation axis of the pneumatic tire 1. That is, the three protectors 30 are arranged concentrically around the tire center AX.

  In this case, the tire cross-section height SH and the disposition position of the protector 30 in the tire radial direction define the distance in the tire width direction between the bead portions 20 located on both sides in the tire width direction and define the pneumatic tire 1. The height and arrangement position are the same when the bead portions 20 are assembled to the rim in the same width as the distance in the tire width direction.

  Moreover, it is preferable that the protector 30 is disposed so as to include a region near the tire maximum width position in the sidewall portion 5. In this case, the tire maximum width position is determined from the surface of the sidewall portion 5 when the pneumatic tire 1 is assembled to a specified rim to apply a specified internal pressure and no load is applied to the pneumatic tire 1. This is the position in the tire radial direction at the position where the dimension in the tire width direction is the maximum, excluding protruding structures.

  In the present embodiment, the three protectors 30 are all provided within the range of 30% to 70% of the tire cross-section height SH from the inner end 25 of the bead portion 20 to the outer side in the tire circumferential direction. All of the protectors 30 may not be disposed within this range. Among the plurality of protectors 30, at least a part of the protectors 30 may be disposed in the range of 30% or more and 70% or less of the tire cross-section height SH from the inner end 25 of the bead portion 20 to the outer side in the tire circumferential direction. That's fine.

  FIG. 3 is a detailed view of part B of FIG. FIG. 4 is an explanatory diagram of the protector 30, the spiral reinforcing member 40, and the elastic reinforcing member 50 when the protector 30 shown in FIG. 3 is viewed in the CC direction. The protector 30 has a semicircular shape in the meridional section of the pneumatic tire 1, protrudes outward in the tire width direction from the surface of the sidewall portion 5, and is formed in an annular shape centering on the tire center AX. Yes. Inside each protector 30 formed in an annular shape, a spiral reinforcing member 40 that is a reinforcing member made of a metal material is disposed. The spiral reinforcing member 40 is formed of a linear member in a spiral shape, and is disposed inside the protector 30 such that the central axis CS of the spiral extends in the tire circumferential direction. Further, an elastic reinforcing member 50 covered with the spiral reinforcing member 40 is disposed inside the protector 30.

  Of the helical reinforcing member 40 and the elastic reinforcing member 50 disposed inside the protector 30, the helical reinforcing member 40 is a linear member formed in a spiral shape, and has the same shape as, for example, a compression spring. It is formed with. That is, the spiral reinforcing member 40 is formed in a spiral shape while linear members adjacent in the length direction of the spiral are separated from each other. Further, the spiral reinforcing member 40 is disposed over the entire circumference of the protector 30 in the protector 30 so that the spiral central axis CS coincides with the extending direction of the protector 30. The spiral reinforcing member 40 is disposed inside each of the plurality of protectors 30, that is, a plurality of spiral reinforcing members 40 are provided in the same manner as the plurality of protectors 30. The plurality of spiral reinforcing members 40 are arranged concentrically around the tire center AX, like the plurality of protectors 30.

  In addition, the spiral reinforcement member 40 arrange | positioned over 1 circumference | surroundings of the protector 30 may be arrange | positioned over 1 circumference | surroundings of the protector 30, and the some spiral reinforcement member 40 may be arrange | positioned. The member 40 may be arranged over one circumference of the protector 30 by being arranged continuously in the tire circumferential direction.

  Further, the spiral reinforcing member 40 has a spiral outer diameter φs of 0.1 ≦ with respect to the diameter φp when the semicircle that is the shape of the protector 30 in the meridional section of the pneumatic tire 1 is regarded as a circle. It is formed within the range of (φs / φp) ≦ 0.9. In other words, the spiral reinforcing member 40 has a spiral outer diameter φs of 0.1 ≦ {φs / with respect to the radius of curvature rp of the semicircle that is the shape of the surface of the protector 30 in the meridional section of the pneumatic tire 1. (Rp × 2)} ≦ 0.9.

  The helical reinforcing member 40 disposed inside the protector 30 is disposed so as to be covered with a side rubber 5 a that is a rubber composition constituting the sidewall portion 5. An elastic reinforcing member 50 is inserted into the spiral reinforcing member 40. The elastic reinforcing member 50 is formed in a round bar shape whose outer diameter is smaller than the inner diameter of the spiral of the spiral reinforcing member 40, and the central axis of the round bar is the central axis CS of the spiral of the spiral reinforcing member 40. Is inserted inside the spiral of the spiral reinforcing member 40 in the direction along Thereby, the periphery of the elastic reinforcing member 50 is covered with the spiral reinforcing member 40. The elastic reinforcing member 50 is inserted into each of the plurality of helical reinforcing members 40. For this reason, a plurality of elastic reinforcing members 50 are arranged in the same manner as the spiral reinforcing member 40, and the plurality of elastic reinforcing members 50 are centered on the tire center AX similarly to the plurality of helical reinforcing members 40. Are arranged concentrically.

  FIG. 5 is a side view of the spiral reinforcing member 40 and the elastic reinforcing member 50 shown in FIG. In the helical reinforcing member 40 in which the linear member is formed in a spiral shape, the wire diameter φw, which is the outer diameter of the linear member, is in the range of 0.5 mm ≦ φw ≦ 10.0 mm. Further, the helical reinforcing member 40 has a helical pitch Ps in a range of 0.1 ≦ (Ps / φs) ≦ 3.0 with respect to the outer diameter φs. The wire diameter φw of the spiral reinforcing member 40 is preferably in the range of 1.0 mm ≦ φw ≦ 3.5 mm.

Further, the helical reinforcing member 40 made of a metal material is constituted by a member having a tensile strength measured in accordance with JIS Z2241, for example, of 300 N / mm ² or more, and constituted by a member of 900 N / mm ² or more. Is preferred. Further, as the spiral reinforcing member 40, a wire defined by JIS G3502 piano wire, JIS G3505 mild steel wire, JIS G3506 hard steel wire, JIS G4801 spring steel, or JIS G4308 stainless steel wire can be used. Further, the spiral reinforcing member 40 is manufactured using a metal wire defined by JIS G3521 hard steel wire, JIS G3522 piano wire, JIS G3532 iron wire, JIS G3560 spring oil temper wire, and JIS G4314 spring stainless steel wire. Is done.

  The elastic reinforcing member 50 covered with the helical reinforcing member 40 thus configured has a 100% modulus within a range of 5 to 25 times the 100% modulus of the side rubber 5a adjacent to the helical reinforcing member 40. It has become. For example, when the 100% modulus of the side rubber 5a is about 2 MPa, the 100% modulus of the elastic reinforcing member 50 falls within the range of 10 MPa to 50 MPa.

  The elastic reinforcing member 50 has a breaking strength in the range of 10 MPa to 50 MPa, and preferably in the range of 10 MPa to 40 MPa. Further, the elastic reinforcing member 50 has a breaking elongation of 150% or more, and is preferably in the range of 150% or more and 500% or less.

  As the elastic reinforcing member 50 having such physical properties, a metal salt of acrylic acid or methacrylic acid was dispersed in an ethylenically unsaturated nitrile-conjugated diene-based highly saturated rubber having a conjugated diene unit content of 30% by weight or less. A rubber composition obtained by crosslinking the composition with an organic peroxide can be used. More specifically, acrylic acid or methacrylic acid is used for 100 parts by weight of the total amount of rubber containing 40 parts by weight or more of ethylenically unsaturated nitrile-conjugated diene-based highly saturated rubber having a conjugated diene unit content of 30% by weight or less. A rubber composition containing 10 to 120 parts by weight of a metal salt and 0.3 to 10 parts by weight of an organic peroxide as a crosslinking agent can be used. Of course, various compounding agents usually used in the rubber industry such as a reinforcing agent, a crosslinking aid, a plasticizer, and a stabilizer can be added to the rubber composition as necessary.

  As the ethylenically unsaturated nitrile-conjugated diene-based highly saturated rubber, a copolymer of an ethylenically unsaturated nitrile such as acrylonitrile and methacrylonitrile and a conjugated diene such as 1,3-butadiene, isoprene and 1,3-pentadiene, Monomers copolymerizable with the above two types of monomers, such as vinyl aromatic compounds, (meth) acrylic acid, alkyl (meth) acrylates, alkoxyalkyl (meth) acrylates, cyanoalkyl (meth) acrylates, etc. And a multi-element polymer. Specifically, acrylonitrile-butadiene copolymer rubber, acrylonitrile-isoprene copolymer rubber, acrylonitrile-butadiene-isoprene copolymer rubber, acrylonitrile-butadiene-acrylate copolymer rubber, acrylonitrile-butadiene-acrylate-methacrylic acid copolymer. Examples thereof include polymer rubber. In particular, hydrogenated NBR is preferable.

  Examples of the metal salt of acrylic acid or methacrylic acid include poly zinc methacrylate.

  Examples of the organic peroxide include dicumyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, , 5-dimethyl-2,5-mono (t-butylperoxy) hexane and the like.

  Vulcanization molding at the time of manufacturing the pneumatic tire 1 according to the present embodiment is performed using a mold in which a groove for molding the protector 30 is formed. When performing vulcanization molding, the elastic reinforcing member 50 was inserted inside the spiral reinforcing member 40, and the sheet-shaped side rubber 5a was wound around the spiral reinforcing member 40 and formed on the mold. It fits in the molding groove of the protector 30 and performs vulcanization molding together with a so-called green tire before vulcanization molding. Since the vulcanization molding is performed at high temperature and high pressure, the side rubber 5a around the spiral reinforcing member 40 and the side rubber 5a of the green tire flow, and the spiral reinforcement is formed between the linear members of the spiral reinforcing member 40. The side rubber 5 a enters the inside of the member 40. Thus, the outer side of the spiral reinforcing member 40 is covered with the side rubber 5a, and the inner side is filled with the elastic reinforcing member 50 and the side rubber 5a.

  When the pneumatic tire 1 according to the present embodiment is mounted on a vehicle, first, the pneumatic tire 1 is mounted on the specified rim by fitting the bead portion 20 to a rim wheel having the specified rim. The tire 1 is assembled to the rim wheel. The pneumatic tire 1 is inflated when the rim is assembled, and the vehicle is fitted with the pneumatic tire 1 in the inflated state after the rim is assembled. The pneumatic tire 1 according to the present embodiment is used as, for example, a pneumatic tire 1 for a construction vehicle that is attached to a construction vehicle such as a wheel loader used in an underground mine.

  When the pneumatic tire 1 is mounted on a vehicle, of the sidewall portions 5 located on both sides in the tire width direction, the sidewall portions 5 on the side where the protector 30 is formed are on the outside in the vehicle width direction of the vehicle. Wear it in the direction it is positioned. That is, when the pneumatic tire 1 is assembled to the rim wheel, the sidewall portion 5 on which the protector 30 is formed is positioned outside the vehicle width direction of the vehicle when the pneumatic tire 1 is mounted on the vehicle. Assemble the rim in the direction.

  When the vehicle equipped with the pneumatic tire 1 travels, the pneumatic tire 1 rotates while a portion of the tread surface 3 positioned below contacts the road surface. The vehicle travels by transmitting a driving force or a braking force to the road surface or generating a turning force by a frictional force between the tread surface 3 and the road surface. For example, when the driving force is transmitted to the road surface, power generated by a prime mover such as an engine of the vehicle is transmitted to the rim wheel and is transmitted from the rim wheel to the pneumatic tire 1.

  Here, since the vehicle to which the pneumatic tire 1 according to the present embodiment is mounted is a construction vehicle, stones, rocks, and the like are scattered on the road surface on which the vehicle travels. For this reason, when the vehicle is traveling, stones or the like on the road surface may come into contact with portions other than the tread surface 3 of the pneumatic tire 1. Stones or the like on the road surface may come into contact with, for example, the sidewall portion 5 located outside the vehicle in the vehicle width direction, that is, the sidewall portion 5 located outside the vehicle mounting direction. That is, since the sidewall portion 5 located on the outer side in the vehicle mounting direction is located on the outer surface side of the vehicle, similarly to the surface of the vehicle body, stones on the road surface are located on the outer side in the vehicle mounting direction. It is easy to contact the wall portion 5.

  Since the stone or the like is harder than the hardness of the side rubber 5a, when the stone or the like comes into contact with the sidewall portion 5 with a large force, the stone or the like causes a crack on the sidewall portion 5, A so-called side cut, which is a crack in the sidewall portion 5, may occur. When the side cut becomes deep, stones or the like may come into contact with the carcass 6 disposed inside the sidewall portion 5 and the carcass 6 may be damaged.

  On the other hand, in the pneumatic tire 1 according to the present embodiment, a plurality of protectors 30 are provided on the sidewall portion 5, so that stones or the like that contact the sidewall portion 5 come into contact with the protector 30. Since the protector 30 is formed so as to protrude from the surface of the sidewall portion 5, when the stone or the like comes into contact with the sidewall portion 5, the protector 30 easily comes into contact with the protector 30. When it comes into contact with the stone, it becomes difficult for stones or the like to contact the portions other than the protector 30 in the sidewall portion 5.

  When stones or the like come into contact with the protector 30 with a large force, the protector 30 may be cracked. However, the protector 30 is covered with a spiral reinforcing member 40 made of a metal material. A broken elastic reinforcing member 50 is provided. For this reason, stones and the like come into contact with the spiral reinforcing member 40 and the elastic reinforcing member 50, and the stones and the like are prevented from entering deeper positions in the sidewall portion 5. The sidewall portion 5 is reinforced against damage to the sidewall portion 5 due to stones or the like by the spiral reinforcing member 40 and the elastic reinforcing member 50 arranged inside the protector 30 in this way.

  Further, since the protector 30 is disposed within the range of 30% to 70% of the tire cross-section height SH from the inner end 25 in the tire radial direction of the bead portion 20 to the outer side in the tire circumferential direction, the sidewall 5 Can be effectively suppressed. That is, in the range of less than 30% of the tire cross-section height SH from the inner end 25 in the tire radial direction of the bead portion 20 to the outer side in the tire circumferential direction, the position in the tire radial direction is close to the tire center AX and away from the road surface. Because of the position, stones on the road surface are difficult to contact. Further, since the range exceeding 70% of the tire cross-section height SH from the inner end portion 25 in the tire radial direction of the bead portion 20 to the outer side in the tire circumferential direction is a position close to the tread portion 2, The damage to the sidewall portion 5 is less likely to occur.

  On the other hand, in the range from 30% to 70% of the tire cross-section height SH from the inner end portion 25 in the tire radial direction of the bead portion 20 to the tire circumferential direction outer side, stones on the road surface are easy to contact, and When a stone or the like comes in contact, the side wall portion 5 may be damaged, so the protector 30 in which the spiral reinforcing member 40 is disposed is disposed within this range. Thereby, the damage of the side wall part 5 by the stone etc. on a road surface can be suppressed effectively.

  Here, since the elastic reinforcing member 50 disposed inside the protector 30 has elasticity, when a large pressure is applied, the elastic reinforcing member 50 may be elastically deformed and crushed. For this reason, when the elastic reinforcing member 50 is disposed alone inside the protector 30, the elastic reinforcing member 50 may be deformed and crushed by the pressure during vulcanization molding when the green tire is vulcanized. There is. Since the pressure applied to the green tire at the time of vulcanization molding is a force in the direction of pressing the green tire from the inside against a mold disposed outside the green tire, the elastic reinforcing member 50 is caused by the pressure at the time of vulcanization molding. Is deformed, the elastic reinforcing member 50 is crushed in the direction in which the thickness in the thickness direction of the sidewall portion 5 is reduced. When the thickness of the elastic reinforcing member 50 is reduced, the elastic reinforcing member 50 itself is damaged when a stone or the like comes into contact with the elastic reinforcing member 50, and it is difficult to suppress damage to the sidewall portion 5 by the elastic reinforcing member 50. There is a fear.

  On the other hand, in the pneumatic tire 1 according to the present embodiment, the elastic reinforcing member 50 is covered with the helical reinforcing member 40 made of a metal material, so that the pressure during vulcanization molding of the green tire is the elastic reinforcing member. When acting around 50, this pressure is received by the spiral reinforcing member 40, so that a large pressure is unlikely to act on the elastic reinforcing member 50. For this reason, the elastic reinforcing member 50 is not easily crushed by the pressure during vulcanization molding, and the shape of the round bar is maintained. As a result, deformation of the elastic reinforcing member 50 that is a reinforcing member having elasticity can be suppressed.

  Further, since the deformation of the elastic reinforcing member 50 can be suppressed, it is more reliable that the stone or the like enters a deeper position in the sidewall portion 5 when the stone or the like contacts the elastic reinforcing member 50. Can be suppressed. As a result, the sidewall portion 5 can be reinforced more reliably, and damage to the sidewall portion 5 can be suppressed.

  In addition, a plurality of spiral reinforcing members 40 and elastic reinforcing members 50 are provided, and the plurality of helical reinforcing members 40 and elastic reinforcing members 50 are arranged concentrically around the tire center AX. For this reason, any position of the sidewall portion 5 in the tire circumferential direction can be equally reinforced by the spiral reinforcing member 40 and the elastic reinforcing member 50. Thereby, even if a stone etc. contact in any position of the tire peripheral direction of the sidewall part 5, damage to the sidewall part 5 can be suppressed. As a result, the sidewall portion 5 can be more reliably reinforced by the spiral reinforcing member 40 and the elastic reinforcing member 50.

  Further, since the elastic reinforcing member 50 has a 100% modulus within a range of 5 to 25 times the 100% modulus of the side rubber 5a adjacent to the spiral reinforcing member 40, the elastic reinforcing member 50 is prevented from peeling off. Thus, the reinforcing effect of the elastic reinforcing member 50 can be ensured more reliably. That is, if the 100% modulus of the elastic reinforcing member 50 is less than five times the 100% modulus of the side rubber 5a adjacent to the spiral reinforcing member 40, it may be difficult to ensure the reinforcing effect of the elastic reinforcing member 50. There is. Further, when the 100% modulus of the elastic reinforcing member 50 exceeds 25 times the 100% modulus of the side rubber 5a adjacent to the spiral reinforcing member 40, the difference from the 100% modulus of the side rubber 5a is too large. When the portion 5 is deformed, the elastic reinforcing member 50 may be easily peeled off from the sidewall portion 5.

  On the other hand, when the 100% modulus of the elastic reinforcing member 50 is within the range of 5 to 25 times the 100% modulus of the side rubber 5a adjacent to the spiral reinforcing member 40, the elastic reinforcing member 50 is peeled off. While suppressing, the reinforcement effect in the elastic reinforcement member 50 can be ensured more reliably. As a result, the sidewall portion 5 can be reinforced more reliably.

  In addition, since the elastic reinforcing member 50 has a breaking strength within a range of 10 MPa or more and 50 MPa or less and an elongation at break of 150% or more, the elastic reinforcing member 50 has a more reinforcing effect while suppressing the peeling of the elastic reinforcing member 50. It can be surely secured. That is, when the breaking strength of the elastic reinforcing member 50 is less than 10 MPa, it may be difficult to ensure the reinforcing effect of the elastic reinforcing member 50. Further, when the breaking strength of the elastic reinforcing member 50 exceeds 50 MPa, the difference in hardness of the side rubber 5a is too large, so that the elastic reinforcing member 50 is easily peeled from the side wall portion 5 when the side wall portion 5 is deformed. There is a fear. Further, when the elongation at break of the elastic reinforcing member 50 is less than 150%, the followability to the deformation of the sidewall portion 5 is lowered.

  On the other hand, when the breaking strength of the elastic reinforcing member 50 is within the range of 10 MPa or more and 50 MPa or less and the breaking elongation is 150% or more, the followability of the elastic reinforcing member 50 to the sidewall portion 5 is ensured and elastic reinforcement is performed. The peeling of the member 50 can be suppressed, and the reinforcing effect of the elastic reinforcing member 50 can be ensured more reliably. As a result, the sidewall portion 5 can be reinforced more reliably.

  Further, since the outer diameter φs of the helical reinforcing member 40 is in the range of 0.1 ≦ (φs / φp) ≦ 0.9 with respect to the diameter φp of the semicircle of the protector 30, the helical reinforcing member 40 is more reliably helical. The reinforcing member 40 can suppress damage to the sidewall portion 5 and can prevent the spiral reinforcing member 40 from peeling off. That is, when the outer diameter φs of the helical reinforcing member 40 is (φs / φp) <0.1 with respect to the semicircular diameter φp of the protector 30, the outer diameter φs of the helical reinforcing member 40 is small. Therefore, the strength of the spiral reinforcing member 40 may be insufficient. In this case, when the stone or the like comes into contact with the protector 30, it may be difficult to suppress damage to the sidewall portion 5 due to the contacted stone or the like by the spiral reinforcing member 40. When the outer diameter φs of the spiral reinforcing member 40 is (φs / φp)> 0.9 with respect to the semicircular diameter φp of the protector 30, the outer diameter φs of the spiral reinforcing member 40 is Since the diameter of the semicircle of the protector 30 is too large, the spiral reinforcing member 40 may be easily exposed when a stone or the like contacts the protector 30. When the spiral reinforcing member 40 is exposed over a wide range due to the exposure of the spiral reinforcing member 40, the restraining force of the spiral reinforcing member 40 by the side rubber 5a is weakened. Therefore, the spiral reinforcing member 40 and the elastic reinforcing member There is a possibility that 50 may be peeled off from the sidewall portion 5 and easily lost.

  On the other hand, when the outer diameter φs of the spiral reinforcing member 40 is within the range of 0.1 ≦ (φs / φp) ≦ 0.9 with respect to the diameter φp of the semicircle of the protector 30, the spiral reinforcing member It is possible to secure the strength of the member 40 and more reliably suppress damage to the sidewall portion 5 and to prevent the spiral reinforcing member 40 from peeling from the sidewall portion 5. As a result, the loss of the spiral reinforcing member 40 and the elastic reinforcing member 50 can be suppressed while the sidewall portion 5 is reinforced with the helical reinforcing member 40 more reliably.

  Further, since the spiral reinforcing member 40 has a wire diameter φw in the range of 0.5 mm ≦ φw ≦ 10.0 mm, the weight of the spiral reinforcing member 40 is excessively increased or the rigidity is excessively increased. While suppressing, damage to the sidewall portion 5 can be more reliably suppressed by the spiral reinforcing member 40. That is, when the wire diameter φw of the spiral reinforcing member 40 is φw <0.5 mm, the wire diameter φw of the spiral reinforcing member 40 is too thin, and the strength of the spiral reinforcing member 40 may be insufficient. . In this case, when the stone or the like comes into contact with the protector 30, it may be difficult to suppress damage to the sidewall portion 5 due to the contacted stone or the like by the spiral reinforcing member 40. Further, when the wire diameter φw of the spiral reinforcing member 40 is φw> 10.0 mm, the wire diameter φw of the spiral reinforcing member 40 is too thick, so that the weight of the spiral reinforcing member 40 increases and the air enters There is a possibility that the weight of the tire 1 increases excessively. In addition, when the wire diameter φw of the spiral reinforcing member 40 is too large, the rigidity of the spiral reinforcing member 40 is too high, which has a great influence on the characteristics of the pneumatic tire 1 or between the side rubber 5a. There is a possibility that the difference in elasticity becomes large and it becomes easy to peel off.

  On the other hand, when the wire diameter φw is in the range of 0.5 mm ≦ φw ≦ 10.0 mm, the spiral reinforcing member 40 ensures the strength of the spiral reinforcing member 40 and more reliably forms the sidewall. While suppressing the damage of the part 5, it can suppress that the weight of the helical reinforcement member 40 increases too much and that the rigidity of the helical reinforcement member 40 becomes too high. As a result, the loss of the spiral reinforcing member 40 and the elastic reinforcing member 50 is suppressed while the sidewall portion 5 is more reliably reinforced by the helical reinforcing member 40 without significantly changing the weight and characteristics of the pneumatic tire 1. can do.

  Moreover, since the helical pitch Ps with respect to the outer diameter φs of the helical reinforcing member 40 is in the range of 0.1 ≦ (Ps / φs) ≦ 3.0, the weight of the helical reinforcing member 40 increases excessively. The damage to the sidewall portion 5 can be more reliably suppressed by the spiral reinforcing member 40 while suppressing the rigidity from becoming too high. That is, when the helical pitch Ps with respect to the outer diameter φs of the helical reinforcing member 40 is (Ps / φs) <0.1, the helical pitch Ps is too small, so that the weight of the helical reinforcing member 40 increases. However, the weight of the pneumatic tire 1 may increase too much. Further, when the helical pitch Ps is too small, the rigidity of the helical reinforcing member 40 is too high, so that it has a great influence on the characteristics of the pneumatic tire 1 or there is a difference in elasticity with the side rubber 5a. There is a possibility that the spiral reinforcing member 40 may be easily peeled off from the side rubber 5a. Further, when the spiral pitch Ps with respect to the outer diameter φs of the spiral reinforcing member 40 is (Ps / φs)> 3.0, the spiral pitch Ps is too large, so that the strength of the spiral reinforcing member 40 is insufficient. There is a risk that when the stone or the like comes into contact with the protector 30, the spiral reinforcing member 40 may make it difficult to suppress damage to the sidewall portion 5 due to the stone or the like that has come into contact.

  On the other hand, when the helical pitch Ps with respect to the outer diameter φs of the helical reinforcing member 40 is within the range of 0.1 ≦ (Ps / φs) ≦ 3.0, the strength of the helical reinforcing member 40 is ensured. As a result, the damage to the sidewall portion 5 is more reliably suppressed, and the weight of the spiral reinforcing member 40 is excessively increased and the rigidity of the spiral reinforcing member 40 is suppressed from being excessively increased. be able to. As a result, the loss of the spiral reinforcing member 40 and the elastic reinforcing member 50 is suppressed while the sidewall portion 5 is more reliably reinforced by the helical reinforcing member 40 without significantly changing the weight and characteristics of the pneumatic tire 1. can do.

[Modification]
In addition, in the pneumatic tire 1 which concerns on embodiment mentioned above, although the three protectors 30 are provided, the protector 30 may be other than three. FIG. 6 is a modified example of the pneumatic tire 1 according to the embodiment, and is an explanatory diagram in the case where there are two protectors 30. As shown in FIG. 6, the protector 30 in which the elastic reinforcing member 50 covered with the spiral reinforcing member 40 is disposed, the protector 30 formed over one circumference in the tire circumferential direction defines the tire center AX. Two may be arranged concentrically around the center. Alternatively, four or more protectors 30 may be arranged concentrically around the tire center AX.

  Moreover, in the pneumatic tire 1 which concerns on embodiment mentioned above, although the protector 30 is continuously formed over 1 round, the protector 30 does not necessarily need to be formed over 1 round. FIG. 7 is a modified example of the pneumatic tire 1 according to the embodiment, and is an explanatory diagram in a case where some of the protectors 30 are discontinuous. FIG. 8 is a modified example of the pneumatic tire 1 according to the embodiment, and is an explanatory diagram when all the protectors 30 are discontinuous. As shown in FIG. 7, the protector 30 in which the elastic reinforcing member 50 covered with the spiral reinforcing member 40 is disposed is concentrically arranged among the plurality of protectors 30 arranged in the tire radial direction. Some of the protectors 30 may not be formed over one circumference in the tire circumferential direction. That is, some protectors 30 among the plurality of protectors 30 may be divided in the tire circumferential direction and discontinuously formed in the tire circumferential direction. In this case, the helical reinforcing member 40 and the elastic reinforcing member 50 disposed in the protector 30 formed discontinuously in the tire circumferential direction are also divided in the tire circumferential direction in the same manner as the protector 30, and in the tire circumferential direction. Discontinuously arranged.

  Or as for the some protector 30 by which the elastic reinforcement member 50 covered by the helical reinforcement member 40 is arrange | positioned inside, as shown in FIG. 8, all the protectors 30 are formed discontinuously in the tire circumferential direction. May be. In this case, it is preferable to arrange so that the position in the tire circumferential direction of the portion where the protector 30 is divided does not become the same position in all the protectors 30. That is, it is preferable to arrange the end portions 31 of the divided portions of the protectors 30 so that the positions in the tire circumferential direction are not the same in all the protectors 30. Thereby, even if the protector 30 is formed discontinuously in the tire circumferential direction, any protector 30 is disposed at any position on the tire circumference. Thus, the protector 30 should just be arrange | positioned 1 or more in any position on a tire periphery.

  In other words, the helical reinforcing member 40 and the elastic reinforcing member 50 disposed inside the protector 30 are any of the tire circumferences in the sidewall portion 5 where the helical reinforcing member 40 and the elastic reinforcing member 50 are disposed. It is sufficient that at least one is disposed at the position. Since one or more protectors 30 in which the spiral reinforcing member 40 and the elastic reinforcing member 50 are disposed are disposed at any position on the tire circumference, the protector 30 is disposed at any position on the tire circumference. The side wall part 5 can be reinforced and a side cut can be reduced.

  Moreover, in the pneumatic tire 1 which concerns on embodiment mentioned above, although the protector 30 is provided in the sidewall part 5 located in the vehicle mounting direction outer side among the sidewall parts 5 located in the both sides in a tire width direction. The protector 30 may be provided on the sidewall portion 5 other than this. For example, the protector 30 may be provided on the sidewall portions 5 on both sides in the tire width direction. The protector 30 should just be provided in at least one side wall part 5 among the side wall parts 5 located in the both sides in a tire width direction.

  The pneumatic tire 1 according to the above-described embodiment is a pneumatic tire 1 having a so-called bias structure in which the carcass cords of the stacked carcass 6 intersect each other, but covered with the spiral reinforcing member 40. The pneumatic tire 1 in which the protector 30 in which the elastic reinforcing member 50 is disposed is provided in the sidewall portion 5 may be the pneumatic tire 1 having a radial structure.

〔Example〕
9A and 9B are tables showing the results of performance tests of the pneumatic tire 1. Hereinafter, the performance evaluation test performed on the pneumatic tire 1 of the conventional example and the pneumatic tire 1 according to the present invention will be described. In the performance evaluation test, the number of side cuts, the length of the side cut, the depth of the side cut, and the presence or absence of the deformed elastic reinforcing member 50 were evaluated.

  In these performance evaluation tests, the pneumatic tire 1 having a tire size of 18.00-25 (32PR) is assembled to a rim wheel conforming to the TRA standard, and the air pressure is adjusted to 750 kPa. The test was carried out by attaching to the front wheel on the opposite side of the cockpit of an underground mine dump truck used as a vehicle and running for 3 months.

  Among the evaluation items, the number of side cuts was obtained by counting the number of side cuts that occurred in the sidewall portion 5 where the protector 30 was provided. For the length of the side cut and the depth of the side cut, the length and the depth of the side cut generated in the sidewall portion 5 provided with the protector 30 were measured, and the average length and depth were calculated.

  The presence or absence of the deformed elastic reinforcing member 50 was evaluated by cutting the pneumatic tire 1 after the test running at a meridional section and observing the degree of deformation of the elastic reinforcing member 50. The deformation of the elastic reinforcing member 50 is crushed when the elastic reinforcing member 50 is crushed and deformed in a predetermined direction from the circular shape that is the shape of the elastic reinforcing member 50 in the meridional section of the pneumatic tire 1. This was done by measuring the thickness at the thickest position in the direction. Whether the elastic reinforcing member 50 is deformed or not is determined when the thickness at the thickest position in the direction in which the elastic reinforcing member 50 is crushed is less than 50% of the circular diameter before being crushed. 50 indicates that the elastic reinforcing member 50 is not deformed when it is 50% or more. Note that the presence or absence of the deformed elastic reinforcing member 50 is not performed using the pneumatic tire 1 after the test run, but the pneumatic tire 1 having the same form as the pneumatic tire 1 to be tested is cut in a meridional section and elastic. You may evaluate by observing the deformation | transformation degree of the reinforcement member 50. FIG.

  The evaluation test was conducted on 10 types of pneumatic tires of Conventional Examples 1 and 2 which are examples of the conventional pneumatic tire 1 and Examples 1 to 8 which are the pneumatic tire 1 according to the present invention. Among these pneumatic tires 1, the pneumatic tire according to Conventional Example 1 is not provided with the protector 30 on the sidewall portion 5, and therefore is not provided with the reinforcing member disposed inside the protector 30. . Further, in the pneumatic tire of Conventional Example 2, although the protector 30 is provided on the sidewall portion 5 and the reinforcing member is disposed inside the protector 30, the reinforcing member is only the elastic reinforcing member 50. Yes.

  On the other hand, Examples 1-8 which are examples of the pneumatic tire 1 which concerns on this invention are provided with the protector 30 in all the side wall parts 5, and the reinforcement member arrange | positioned inside the protector 30 is helical. The elastic reinforcing member 50 is covered with the reinforcing member 40. In addition, the pneumatic tire 1 according to Examples 1 to 8 has the breaking strength and breaking elongation of the elastic reinforcing member 50, the ratio of the outer diameter φs of the helical reinforcing member 40 to the semicircular diameter φp of the protector 30, and the helical reinforcement. The wire diameter φw of the member 40 is different.

  As a result of performing an evaluation test using these pneumatic tires 1, the pneumatic tire 1 according to Examples 1 to 8 has a side cut length and depth as a conventional example as shown in FIGS. 9A and 9B. On the other hand, it can be generally reduced, and deformation of the elastic reinforcing member 50 can be suppressed. That is, the pneumatic tire 1 according to Examples 1 to 8 can suppress deformation of the elastic reinforcing member 50 having elasticity.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Tread part 3 Tread surface 4 Shoulder part 5 Side wall part 5a Side rubber 6 Carcass 7 Breaker 8 Inner liner 15 Lug groove 20 Bead part 21 Bead core 22 Bead filler 25 Inner end part 30 Protector 40 Spiral reinforcement member 50 Elasticity Reinforcing member

Claims (6)

Sidewall portions located on both sides in the tire width direction;
A bead portion located on the inner side in the tire radial direction of the sidewall portion;
The sidewall within a range of 30% or more and 70% or less of the tire cross-section height from the inner end portion in the tire radial direction of the bead portion to the outer side in the tire circumferential direction in at least one of the sidewall portions. A plurality of protectors that protrude from the surface of the portion and extend in the tire circumferential direction;
A plurality of helical reinforcement members formed in a spiral shape and disposed inside the protector in a direction in which the central axis of the spiral extends in the tire circumferential direction;
An elastic reinforcing member covered by the helical reinforcing member;
A pneumatic tire characterized by comprising:   The pneumatic tire according to claim 1, wherein the plurality of spiral reinforcing members and the elastic reinforcing member are arranged concentrically around a tire center.   3. The elastic reinforcing member according to claim 1, wherein the elastic reinforcing member has a 100% modulus in a range of 5 to 25 times the 100% modulus of the rubber composition of the sidewall adjacent to the spiral reinforcing member. Pneumatic tires.   The pneumatic tire according to any one of claims 1 to 3, wherein the elastic reinforcing member has a breaking strength in a range of 10 MPa to 50 MPa and a breaking elongation of 150% or more. The protector has a semicircular shape in the meridional section of the pneumatic tire,
5. The spiral reinforcing member has an outer diameter φs in a range of 0.1 ≦ (φs / φp) ≦ 0.9 with respect to a diameter φp of a semicircle of the protector. Pneumatic tire described in 2.   The pneumatic tire according to claim 1, wherein the helical reinforcing member has a wire diameter φw in a range of 0.5 mm ≦ φw ≦ 10.0 mm.

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