阅读说明：本技术 充气轮胎 (Pneumatic tire ) 是由 根本雅行 于 2018-02-16 设计创作，主要内容包括：本发明提供了为了谋求质量的轻量化和滚动阻力的降低并且提高驾驶稳定性的充气轮胎1,该充气轮胎1具备：一张胎体20,具有卷起部22；以及增强层40,配设于胎体20的卷起部22与胎边芯12之间,胎体20的卷起部22的端部23配置于带束层25的轮胎径向内侧且带束层25的轮胎宽度方向上的内侧的区域,胎边芯12的外侧端部13与胎踵部17的距离Df在轮胎剖面高度Hs的20％以上且40％以下的范围内,增强层40的外侧端部41位于胎边芯12的外侧端部13的轮胎径向外侧且轮胎最大宽度位置P的轮胎径向上的位置的轮胎径向内侧,侧壁部4由60℃时的tanδ在0.04以上且0.10以下的范围内的胎侧橡胶33形成。(The present invention provides the pneumatic tire 1 of lightweight and rolling resistance for quality reduced and improve driving stability, which has: a carcass 20 has turnup 22；And enhancement layer 40, it is disposed between the turnup 22 of carcass 20 and bead-core 12, the end 23 of the turnup 22 of carcass 20 is configured at the tire radial direction inner side of belt 25 and the region of the inside on the tire width direction of belt 25, the outboard end 13 of bead-core 12 is with 17 distance Df of tire heel in 20% or more and 40% or less the range of tire profile height Hs, the outboard end 41 of enhancement layer 40 is located at the tire radial direction inner side of the position of the tire of the tire radial outside of the outboard end 13 of bead-core 12 and tire maximum width position P radially, sidewall rubber 33 of the tan δ in 0.04 or more and 0.10 or less range when sidewall portion 4 is by 60 DEG C is formed.)

1. a kind of pneumatic tire, which is characterized in that

Have:

Belt is disposed in the tire radial direction inner side of fetus face；

A pair of sidewalls portion is disposed in the two sides of the equatorial plane on tire width direction；

A pair of bead portion is disposed on the inside of the tire width direction of a pair of sidewall portion, has the tyre bead for being formed as circular Core；

Bead-core is disposed in the tire radial outside of the bead core；

One carcass is arranged each other throughout a pair of bead part, and has the tyre width from the bead core It turns back on the inside of direction to the turnup on the outside of tire width direction；With

Enhancement layer is disposed between the turnup of the carcass and the bead-core,

The end of the turnup of the carcass is configured at the tire radial direction inner side of the belt and the wheel of the belt The region of inside in tire width direction,

The outboard end of the tire of the bead-core radially is at a distance from the tire heel of the bead part in tire profile height 20% or more and 40% or less range in,

The outboard end of the tire of the enhancement layer radially is located at the wheel of the outboard end of the tire of the bead-core radially Tire radial outside and the tire radial direction inner side for being located at the position of the tire of tire maximum width position radially, the enhancement layer The medial end of tire radially is located at the tire radial outside of the bead core,

Sidewall rubber of the tan δ in 0.04 or more and 0.10 or less range when the sidewall portion is by 60 DEG C is formed.

2. pneumatic tire according to claim 1, wherein

In the enhancement layer, the outboard end of the enhancement layer at a distance from the outboard end of the bead-core In the range of 5mm or more and 15mm or less.

3. pneumatic tire according to claim 1 or 2, wherein

The enhancement layer has the reinforcing cord formed by steel,

The line footpath of the reinforcing cord in the range of 0.20mm or more and 0.30mm or less,

The insertion item number of the reinforcing cord in every 50mm of the enhancement layer is in 35 or more and 45 or less ranges.

4. pneumatic tire according to claim 1 or 2, wherein

Tan δ when JIS hardness when the enhancement layer is by 20 DEG C is in 85 or more and 95 or less range, 60 DEG C 0.14 with Rubber in upper and 0.22 or less range is formed.

5. pneumatic tire according to any one of claim 1 to 4, wherein

Sectional area in the meridian section of the pneumatic tire of the bead-core is in 110mm²Above and 160mm²Range below It is interior.

6. pneumatic tire according to any one of claim 1 to 5, wherein

The fetus face includes the bizet rubber to form tread surface and the tire radial direction inner side positioned at the bizet rubber Base portion rubber,

JIS hardness at 20 DEG C of the base portion rubber is in 75 or more and 81 or less range, and tan δ at 60 DEG C is 0.14 Above and in 0.22 or less range.

7. pneumatic tire according to any one of claim 1 to 6, wherein

The minimum value Dm of the thickness of the sidewall rubber is in the range of 1.0mm≤Dm≤3.5mm.

8. pneumatic tire according to any one of claim 1 to 7, wherein

Between the sidewall rubber or rim cushion rubber and the turnup of the carcass, when being equipped with by 20 DEG C Rubber of the tan δ in 0.06 or more and 0.12 or less range when JIS hardness is in 70 or more and 85 or less range, 60 DEG C The sidewall enhancement layer that glue is formed,

The thickness of the sidewall enhancement layer is formed in the range of 0.5mm or more and 2.0mm or less, the sidewall enhancement layer configuration In the position including tire maximum width position.

9. pneumatic tire according to any one of claim 1 to 8, wherein

The tire profile height in the range of 110mm or more and 170mm or less,

Aspect ratio is 55 or more.

Technical field

The present invention relates to a kind of pneumatic tires.

Background technique

For pneumatic tire, it is desirable that the various performances such as driving stability, therefore, in previous pneumatic tire, in order to full Sufficient these requirements have carried out various designs to structure.For example, in patent document 1,2, when making for carcass to be wound in bead core Turnup extends to tire radial outside and overlappingly terminates with the both ends of banding, or will wind up end and be configured at belt Near, thus seek the ensuring of driving stability, the raising of durability.In addition, in patent document 3, in the folding of casing ply Thus the outside configuration hard rubber layers and soft rubber layer in the portion of returning seek the raising of bead part durability without making tire Weight increases.

In addition, in patent document 4, having the first casing ply and the second casing ply, make the folding outward of the first casing ply The end for the part returned is located at the inside of banding, has sidewall enhancement layer on the outside of the tire width direction of bead-core, thus comes Durability, driving stability is sought to ensure.In addition, in patent document 5, being equipped with two casing plies, and a casing ply Folded-back part outer end be located at belt tire axial outer end tire axial on the inside of, bead part be equipped with along tyre bead triangle The cord reinforcement that glue extends in tire radius direction, even if also can in the case where use under situation with a low load factor as a result, Play high driving stability.

Summary of the invention

Problems to be solved by the invention

Here, the fuel efficiency of vehicle is taken seriously in recent years, it is accompanied by this, lightweight and rolling is required for pneumatic tire The reduction of dynamic resistance.For lightweight, the component for constituting pneumatic tire is reduced, for example, can be by setting carcass Lightweight is sought for one.But in the case where carcass is set as one, can rigidly it reduce, therefore driving stability is feared Fearness can reduce.As the method for improving driving stability as far as possible, such as the base portion rubber for improving fetus face can be enumerated Hardness.But in the case where improving the hardness of base portion rubber, rolling resistance can probably become larger, and can probably be unable to ensure Performance required by pneumatic tire.As described above, lightweight and being decreased without for rolling resistance is sought to drop driving stability Low is very difficult.

The present invention is to complete in view of the above problems, and its purpose is to provide a kind of lightweights and rolling that can seek quality The reduction of dynamic resistance, and improve the pneumatic tire of driving stability.

Technical solution

In order to solve the problem above-mentioned, reach purpose, pneumatic tire of the invention is characterized in that having: belt is matched Set on the tire radial direction inner side of fetus face；A pair of sidewalls portion is disposed in the two sides of the equatorial plane on tire width direction；One To bead part, it is disposed on the inside of the tire width direction of a pair of sidewall portion, has the bead core for being formed as circular；Tyre bead Core is disposed in the tire radial outside of the bead core；One carcass is arranged each other throughout a pair of bead part, And has and turn back on the inside of the tire width direction of the bead core to the turnup on the outside of tire width direction；And enhancing Layer, is disposed between the turnup of the carcass and the bead-core, the end configuration of the turnup of the carcass In the region of the inside in the tire radial direction inner side of the belt and the tire width direction of the belt, the bead-core Tire outboard end radially at a distance from the tire heel of the bead part tire profile height 20% or more and In 40% or less range, the outboard end of the tire of the enhancement layer radially is located at the tire of the bead-core radially The tire radial outside of outboard end and the tire radial direction inner side for being located at the position of the tire of tire maximum width position radially, The medial end of the tire of the enhancement layer radially is located at the tire radial outside of the bead core, and the sidewall portion is by 60 DEG C When sidewall rubber of the tan δ in 0.04 or more and 0.10 or less range formed.

In above-mentioned pneumatic tire, it is preferred that in the enhancement layer, the outboard end of the enhancement layer and institute The distance of the outboard end of bead-core is stated in the range of 5mm or more and 15mm or less.

In above-mentioned pneumatic tire, it is preferred that the enhancement layer has the reinforcing cord formed by steel, the enhancing curtain The line footpath of line in the range of 0.20mm or more and 0.30mm or less, the reinforcing cord in every 50mm of the enhancement layer Item number is embedded in 35 or more and 45 or less ranges.

In above-mentioned pneumatic tire, it is preferred that the JIS hardness when enhancement layer is by 20 DEG C is 85 or more and 95 or less In the range of, 60 DEG C when rubber of the tan δ in 0.12 or more and 0.20 or less range formed.

In above-mentioned pneumatic tire, it is preferred that the section in the meridian section of the pneumatic tire of the bead-core Product is in 110mm²Above and 160mm²In following range.

In above-mentioned pneumatic tire, it is preferred that the fetus face include the bizet rubber to form tread surface and Positioned at the base portion rubber of the tire radial direction inner side of the bizet rubber, JIS hardness at 20 DEG C of the base portion rubber 75 with In upper and 81 or less range, tan δ at 60 DEG C is in 0.14 or more and 0.22 or less range.

In above-mentioned pneumatic tire, it is preferred that the minimum value Dm of the thickness of the sidewall rubber 1.0mm≤Dm≤ In the range of 3.5mm.

In above-mentioned pneumatic tire, it is preferred that in the sidewall rubber or the institute of rim cushion rubber and the carcass It states between turnup, tan δ when JIS hardness when being equipped with by 20 DEG C is in 70 or more and 85 or less range, 60 DEG C exists The sidewall enhancement layer that rubber in 0.06 or more and 0.12 or less range is formed, the thickness of the sidewall enhancement layer are formed in In the range of 0.5mm or more and 2.0mm or less, sidewall enhancement layer is configured at the position including tire maximum width position It sets.

In above-mentioned pneumatic tire, it is preferred that the tire profile height is in 110mm or more and 170mm model below In enclosing, aspect ratio is 55 or more.

Beneficial effect

Pneumatic tire of the invention plays the reduction of the lightweight and rolling resistance that can seek quality, and it is steady to improve driving Qualitative effect.

Detailed description of the invention

Fig. 1 is the meridian sectional view for indicating the major part of pneumatic tire of embodiment.

Fig. 2 is that the A of Fig. 1 schemes in detail.

Fig. 3 is that the B of Fig. 1 schemes in detail.

Fig. 4 is the explanatory diagram about the carcass and enhancement layer observed from the direction C-C of Fig. 3.

Fig. 5 is the D-D direction view of Fig. 4

Fig. 6 is the improvement of the pneumatic tire of embodiment, is the explanatory diagram about sidewall enhancement layer.

Fig. 7 is the improvement of the pneumatic tire of embodiment, is the explanatory diagram about sidewall enhancement layer.

Fig. 8 is the improvement of the pneumatic tire of embodiment, is the explanatory diagram about sidewall enhancement layer.

Fig. 9 A is the chart for indicating the result of performance test of pneumatic tire.

Fig. 9 B is the chart for indicating the result of performance test of pneumatic tire.

Fig. 9 C is the chart for indicating the result of performance test of pneumatic tire.

Fig. 9 D is the chart for indicating the result of performance test of pneumatic tire.

Specific embodiment

Hereinafter, being described in detail based on embodiment of the attached drawing to pneumatic tire of the invention.It should be noted that this Invention is not limited by present embodiment.In addition, including that those skilled in the art can set in the constituent element of following embodiments The element or substantially the same element changed and can be readily apparent that.

In the following description, tire radially refers to the direction with the rotating shaft direct cross of pneumatic tire 1, and tire radial direction inner side is Towards the side of rotary shaft in finger wheel tire radial direction, tire radial outside refers to the side in tire radial direction far from rotary shaft.In addition, Tire circumferentially refers to using rotary shaft as the circumferencial direction of center axis.In addition, tire width direction refers to the side parallel with rotary shaft To tire width direction inside refers in tire width direction towards the side of equatorial plane (tire equator line) CL, tire Refer to the side in tire width direction far from equatorial plane CL on the outside of width direction.Equatorial plane CL refers to and inflated wheel The rotating shaft direct cross of tire 1, and the plane that the center of the tyre width from pneumatic tire 1 passes through.Tyre width is to be located at tire The width on tire width direction between the part in the outside of width direction, that is, from tire in tire width direction Equatorial plane CL farthest the distance between part.Tire equator line refers on equatorial plane CL and along pneumatic tire The line of 1 tire circumferential direction.

Fig. 1 is the meridian sectional view for indicating the major part of pneumatic tire 1 of embodiment.What is observed with meridian section In the case of, pneumatic tire 1 shown in FIG. 1 is equipped with fetus face 2 in the outermost part as tire radial direction, fetus face 2 The profile of peripheral surface composition pneumatic tire 1.The peripheral surface of fetus face 2 is when attaching has the vehicle driving of pneumatic tire 1 The face contacted with road surface, the peripheral surface are formed as tread surface 3.It is formed in tread surface 3 a plurality of along tire circumferentially extending Circumferential major trough (illustration omitted), the slots such as band slot (illustration omitted) that extend along tire width direction.

Fetus face 2 includes the bizet rubber 31 to form tread surface 3 and inside positioned at the tire diameter of bizet rubber 31 The base portion rubber 32 of side.That is, fetus face 2 is by bizet rubber 31 and base portion rubber 32 in the radially superimposed composition of tire.These Bizet rubber 31 and the rubber of base portion rubber 32 are mutually different, that is, bizet rubber 31 and the rubber hardness of base portion rubber 32 are mutual It is different.Specifically, rubber of JIS hardness when bizet rubber 31 is by 20 DEG C in 62 or more and 68 or less range is constituted, Rubber of the JIS hardness in 75 or more and 81 or less range when base portion rubber 32 is by 20 DEG C is constituted.In addition, bizet rubber 31 Also different from the viscoplasticity of base portion rubber 32, tan δ at 60 DEG C of bizet rubber 31 is in 0.08 or more and 0.16 range below Interior, in contrast, tan δ at 60 DEG C of base portion rubber 32 is in 0.14 or more and 0.22 or less range.

It should be noted that in the present embodiment, JIS hardness at 20 DEG C refers to by measuring under conditions of 20 DEG C , according to JIS K6253 JIS-A hardness represented by rubber hardness.Tan δ in addition, in the present embodiment, at 60 DEG C Refer to according to JIS K6394, using viscoplasticity spectrometer (Toyo Seiki makes made), is answered in temperature 60 C, frequency 20Hz, static state Value when being measured under conditions of change 10%, dynamic strain ± 2%.

Shoulder portion 5 is located at the both ends of the fetus face 2 on tire width direction, is arranged in the tire radial direction inner side of shoulder portion 5 There is the sidewall portion 4 being made of sidewall rubber 33.That is sidewall portion 4 is disposed in two of the pneumatic tire 1 on tire width direction At the two of side, that is, the two sides of the equatorial plane CL on tire width direction are configured with a pair of sidewalls portion 4.Constitute sidewall portion 4 Sidewall rubber 33 by 20 DEG C when JIS hardness in 50 or more and 54 or less range, 60 DEG C when tan δ 0.04 or more And the rubber in 0.10 or less range is constituted.It should be noted that tan δ at 60 DEG C of preferably sidewall rubber 33 exists In 0.05 or more and 0.11 or less range.

In addition, sidewall portion 4 is formed as the minimum value Dm of the thickness of sidewall rubber 33 in 1.0mm≤Dm≤3.5mm range It is interior.The minimum value Dm of the thickness of sidewall rubber 33 is in the position of tire maximum width position P and the end 251a of cross belt 251 Between setting, the thickness of the sidewall rubber 33 at the most thin position of the thickness of sidewall rubber 33.Tire maximum width in this case Position P is following position: 1 wheel rim of pneumatic tire being assembled in regulation wheel rim, filling provides internal pressure, and not to pneumatic tire 1 Apply load no load condition when, in addition to from the tire width direction other than the structure outstanding of the surface of sidewall portion 4 The maximum position of size tire position radially.

It should be noted that regulation wheel rim mentioned here refers to, as defined in JATMA " applying wheel rim " is provided by TRA " Design Rim (design wheel rim) " or as defined in ETRTO " Measuring Rim (measurement wheel rim) ".In addition, here Described wheel rim baseline BL is the tire axial line that rim diameter is passed through determined by the standard of JATMA.Furthermore, it is specified that internal pressure Refer to, as defined in JATMA " highest air pressure ", " the TIRE LOAD LIMITSAT VARIOUS COLD as defined in TRA It the maximum value of INFLATION PRESSURES (the loading of tire limit under various cold inflation pressures) " or is provided by ETRTO " INFLATION PRESSURES (the blowing pressure) ".

Tire radial direction inner side in a pair of sidewalls portion 4 for the two sides being located on tire width direction, is equipped with bead part 10. Bead part 10 is disposed at the two of the two sides of equatorial plane CL in the same manner as sidewall portion 4, that is, the wheel on tire width direction The two sides of tire equatorial plane CL are equipped with a pair of bead portion 10.It is equipped with bead core 11 in each bead part 10, in the tire of bead core 11 Radial outside is equipped with bead-core 12.Bead core 11 is that a plurality of steel bead wire is tied up to and is formed as circular annular component, tire Side core 12 is the rubber component for being disposed in the tire radial outside of bead core 11.

In addition, the tire radial direction inner side in fetus face 2 is equipped with belt 25.Belt 25 passes through multiple cross belts 251, it 252 is laminated and is arranged with banding coating 253.Wherein, cross belt 251,252 covers by steel or has using coating rubber The a plurality of belt cord of machine fibrous material formation simultaneously carries out rolling processing and constitutes, and is configured to have 20 ° in terms of absolute value Above and 55 ° of belt angles below.In addition, multiple cross belts 251,252 are configured to so-called oblique construction, that is, definition It is mutually different relative to the belt angle at the inclination angle of tire circumferential direction for the machine direction of belt cord, make the fiber of belt cord Direction is laminated with intersecting.In addition, 253 pairs of banding coating using coating rubbers covering by steel or organic fibrous material shape At one or more of cords carry out rolling processing and constitute, and have it is below at 0 ° or more and 10 ° in terms of absolute value Belt angle.In addition, one or more cord of banding coating 253 will be constituted along tire for banding coating 253 Circumferential is in repeatedly and to be helically wound in the outer peripheral surface of cross belt 251,252, is thus configured at cross belt to stacking 251,252 tire radial outside.

Interior Bao Jing is continuously equipped in the tire radial direction inner side of belt 25 and the side equatorial plane CL of sidewall portion 4 To the carcass 20 of the cord of layer.The carcass 20 has the single layer structure that is made of a casing ply, throughout a pair of bead portion 10 that It is arranged between this.That is, a carcass 20 is annularly erected between the bead core 11 for being disposed in the two sides of tire width direction, To constitute the skeleton of pneumatic tire 1.

Specifically, carcass 20 is matched from the bead part 10 of the side in the bead part 10 of two sides for being located at tire width direction If to the bead part 10 of another party, in a manner of encasing bead core 11 and bead-core 12, from bead core 11 at bead part 10 Tire width direction in lateral edge bead core 11 turn back on the outside of tire width direction.Carcass 20 has in this way from bead core 11 It turns back on the inside of tire width direction to part, that is, turnup 22 on the outside of tire width direction.The turnup 22 of carcass 20 is in tyre bead The tire radial outside that is positioned against of the tire radial outside of core 11 is arranged with extending, and the turnup 22 of carcass 20 is from tyre width It is Chong Die with the part, that is, main part 21 being arranged each other throughout a pair of bead portion 10 in carcass 20 on the outside of direction.Bead-core 12 It is disposed in being surrounded by bead core 11, the main part 21 of carcass 20 and turnup 22 for the tire radial outside of bead core 11 Region.

In the carcass 20 with turnup 22, the periphery of the entire carcass 20 in the meridian section by pneumatic tire 1 In the case that the long periphery length with turnup 22 is compared, (the outer girth of the outer girth of turnup 22/entire carcass 20) In In 0.20 or more and 0.35 or less range.The outer girth of entire carcass 20 in this case refers to will be at two in meridian section The overall length of carcass 20 that turnup 22 and main part 21 are combined, on the direction of carcass 20.In addition, turnup 22 is outer Girth refers to the end 23 of the end of the tire radial direction inner side of turnup 22 and the tire radial outside of turnup 22 (referring to Fig. 2) Between, the overall length of turnup 22 on the direction of turnup 22.

In addition, the casing ply of carcass 20 is covered using coating rubber to be had by steel or aramid fiber, nylon, polyester, artificial silk etc. The a plurality of body cord of machine fibrous material formation simultaneously carries out rolling processing and constitutes, circumferential relative to tire as body cord The carcass angle at inclination angle is formed as in terms of absolute value at 85 ° or more and 95 ° or less.In addition, in body cord, as carcass The line footpath of the diameter of cord is every on the direction of body cord arrangement in the range of 1100T/2 or more and 1670T/2 or less The insertion item number of body cord in 50mm is in 45 or more and 55 or less ranges.

The tire radial direction inner side of the turnup 22 of bead core 11 and carcass 20 at bead part 10, tire width direction Outside is equipped with the rim cushion rubber 34 for constituting bead part 10 relative to the contact surface of rim flange.In addition, in pneumatic tire 1 inner surface is equipped with the liner 35 as permeation-proof gas-bearing formation.The liner 35 is formed in the inside of carcass 20 along carcass 20 or is somebody's turn to do The private side of the pneumatic tire 1 of carcass 20.

Fig. 2 is that the A of Fig. 1 schemes in detail.The tire diameter that the end 23 of the turnup 22 of carcass 20 is configured at belt 25 is inside The region of inside on the tire width direction of side and belt 25.Specifically, from 10 side of bead part to tire radial outside Extend the turnup 22 that ground is arranged to extend near belt 25, the end 23 of the tire radial outside of turnup 22 is in banding Enter between the main part 21 and belt 25 of carcass 20 near layer 25.That is the end 23 of the turnup 22 of carcass 20 The cross belt 251 and tire near tire radial direction inner side in multiple cross belts 251,252 possessed by the belt 25 Between the main part 21 of body 20, also, the tyre width for the end 251a being located on the tire width direction of the cross belt 251 On the inside of direction.The end 23 of the turnup 22 of carcass 20 is in the radial main part 21 and belt 25 by carcass 20 of tire as a result, Clamping.

Fig. 3 is that the B of Fig. 1 schemes in detail.Bead part 10 has tyre bead base portion 15.Tyre bead base portion 15 is the tire diameter of bead part 10 Surface inwardly, with from the inside of tire width direction towards outside and to tire radial outside extend direction, phase Tire rotary shaft is formed obliquely.End on the inside of the tire width direction of tyre bead base portion 15 is set as tire toe 16, tire toe 16 be the innermost end, that is, bead part inner terminal of the tire of bead part 10 radially.In addition, the tire of tyre bead base portion 15 is wide The end for spending the outside on direction is tire heel 17, and tire heel 17 is formed as the curved protruded to the surface side of pneumatic tire 1. That is the surface in the outside on the tire width direction of tyre bead base portion 15 and pneumatic tire 1 passes through the meridian in pneumatic tire 1 The tire heel 17 for being formed as arc-shaped when section view connects.

The outboard end 13 of the tire of bead-core 12 radially and the 17 distance Df of tire heel of bead part 10 are cutd open in tire In 20% or more and 40% or less the range of face height Hs.The measuring point of 17 side of tire heel of distance Df in this case is will The distance on tire width direction between a pair of bead portion 10 be set as pneumatic tire 1 being secured to the state of regulation wheel rim away from The intersection point 17a of tire heel 17 and wheel rim baseline BL from the case where.Therefore, strictly speaking, distance Df is the wheel of bead-core 12 The outboard end 13 of tire radially is at a distance from the intersection point 17a of tire heel 17 and wheel rim baseline BL.

In addition, tire profile height Hs is part and the wheel rim baseline positioned at fetus face 2 near tire radial direction outward side The distance of the tire radial direction of BL.That is tire profile height Hs, which refers to, is assembled in regulation wheel rim for 1 wheel rim of pneumatic tire, fill out Fill regulation internal pressure, and to pneumatic tire 1 apply load no load condition when tire outside diameter and rim diameter difference 1/ 2.Preferably as described above as defined in bead-core 12 outboard end 13 and 17 distance Df of tire heel for 40mm or more and 50mm or less.

Moreover it is preferred that the sectional area in the meridian section of the pneumatic tire 1 of bead-core 12 is in 110mm²Above and 160mm²In following range, preferably tire profile height Hs is in the range of 110mm or more and 170mm or less.Moreover, Preferably the aspect ratio of the pneumatic tire 1 of present embodiment is 55 or more.

In addition, being equipped with enhancement layer 40 between the turnup 22 and bead-core 12 of carcass 20.The tire diameter of enhancement layer 40 Upward outboard end 41 is located at the tire radial outside of the outboard end 13 of the tire of bead-core 12 radially and tire is maximum The tire radial direction inner side of the position of the tire of width position P radially.In addition, the medial end of the tire of enhancement layer 40 radially 42 are located at the tire radial outside of bead core 11.

That is in the range of where the bead-core 12 of tire radially, enhancement layer 40 from tire width direction two Side is clamped by the turnup 22 of bead-core 12 and carcass 20.In addition, in the position of the tire radial outside of bead-core 12, enhancement layer 40 are clamped from the two sides of tire width direction by the main part 21 and turnup 22 of carcass 20.It should be noted that preferably The 13 distance Dr of outboard end of the tire of the outboard end 41 of the tire of enhancement layer 40 radially and bead-core 12 radially exists In the range of 5mm or more and 15mm or less.

Fig. 4 is the explanatory diagram about the carcass 20 and enhancement layer 40 observed from the direction C-C of Fig. 3.Enhancement layer 40 has There is the reinforcing cord 43 formed by steel, cover a plurality of reinforcing cord 43 using coating rubber and carries out rolling processing and constitute.Increase Strong cord 43 is in tire peripheral, oblique angle A C in 15 ° or more and 25 ° or less of range.Therefore, reinforcing cord 43 and carcass Body cord 24 possessed by 20 is arranged across.Preferably reinforcing cord 43 and body cord 24 65 ° or more and 75 ° with Under range in be arranged across.

Fig. 5 is the D-D direction view of Fig. 4.The line footpath of reinforcing cord 43In 0.20mm or more and 0.30mm range below It is interior.In addition, on the direction orthogonal with the extending direction of reinforcing cord 43 of enhancement layer 40, on the direction that i.e. reinforcing cord 43 arranges Every 50mm in reinforcing cord 43 insertion item number in 35 or more and 45 or less ranges.

The pneumatic tire 1 of present embodiment is mainly used for referred to as SUV, and (Sport Utility Vehicle: sports type is more Function vehicle) the vehicle for having both cross-country traveling ability and comfort.Big driving force can be transferred to road surface by the tire for being secured to SUV, In addition, there is biggish outer diameter mostly in order to also assure driving stability.By pneumatic tire 1 used in such vehicle When being secured to vehicle, wheel is embedded in bead part 10 and the state after wheel rim is assembled in wheel and inflates is secured to vehicle.

Underlying tread surface 3 and road surface when the vehicle driving of attaching pneumatic tire 1, in tread surface 3 Contact, while the pneumatic tire 1 rotates.Vehicle is by the frictional force between tread surface 3 and road surface by driving force, brake force It is transferred to road surface, or generates turning power, is thus travelled.For example, passing through vehicle institute when transferring a driving force to road surface The power that the engine prime movers having generate is passed to wheel, is transferred to bead part 10 from wheel, then be transferred to inflation Tire 1.

When using pneumatic tire 1, as described above, the load in various directions acts on each portion, after these load are by inflating The pressure of air, the skeleton for being set as pneumatic tire 1 carcass 20 bear.For example, due to the weight of vehicle, the bumps on road surface Acted between fetus face 2 and bead part 10 load of tire radial direction mainly by the pressure of the air after inflating, carcass 20 It bears.Like this, carcass 20 needs the load for bearing to act on pneumatic tire 1, therefore, in the previous inflation for being secured to SUV In tire 1, it is equipped with multiple carcasses 20 mostly, for example, having overlappingly configured two carcasses 20 in previous pneumatic tire 1.

In contrast, in the pneumatic tire of present embodiment 1, only it is configured with a carcass 20.Entire carcass 20 as a result, Quality mitigate, therefore the quality of pneumatic tire 1 can be mitigated.

It should be noted that in the case where carcass 20 is set as one, for ensuring that the component of intensity is reduced, therefore, The rigidity as entire carcass 20 can reduce under normal conditions, but in the present embodiment, by the end of the turnup 22 of carcass 20 Portion 23 is configured at the region of the inside on the tire width direction of the tire radial direction inner side of belt 25 and belt 25.As a result, The both ends of the tire of the turnup 22 of carcass 20 radially are fixed, therefore can serve as the component for ensuring intensity, 22 edge of turnup The configuration of sidewall portion 4 is between fetus face 2 and bead part 10, thus ensuring that the rigidity of sidewall portion 4.

In addition, being equipped with enhancement layer 40, the outboard end of enhancement layer 40 between the turnup 22 and bead-core 12 of carcass 20 Portion 41 is located at the tire radial outside of the outboard end 13 of bead-core 12 and is located at the tire of tire maximum width position P radially Position tire radial direction inner side, therefore can moderately improve the rigidity of sidewall portion 4.Even if being acted on as a result, in big load It, also can be by being rolled by portion 22 and enhancement layer 40 ensures rigid sidewall portion 4 and suitably holds in the case where pneumatic tire 1 By, therefore driving stability can be improved, moreover it is possible to ensure ride comfort performance.

Moreover, the outboard end 13 of bead-core 12 exists with the 17 distance Df of tire heel of bead part 10 in bead-core 12 In 20% or more and 40% or less the range of tire profile height Hs, therefore side wall also can suitably be improved by bead-core 12 The rigidity in portion 4.That is the outboard end 13 and 17 distance Df of tire heel in bead-core 12 is less than tire profile height Hs's In the case where 20%, the size of the tire of bead-core 12 radially is too small, it is thus possible to can not can suitably play and pass through tyre bead Core 12 come improve sidewall portion 4 rigidity effect.In addition, the outboard end 13 and 17 distance Df of tire heel in bead-core 12 is super In the case where cross tire section height Hs 40%, the size of the tire of bead-core 12 radially is excessive, it is thus possible to can be because of tire Side core 12 and the rigidity for excessively improving sidewall portion 4.In this case, ride comfort performance be I'm afraid since the rigidity of sidewall portion 4 is excessively high It can reduce.In contrast, in the outboard end 13 of bead-core 12 with 17 distance Df of tire heel tire profile height Hs's In the case where in 20% or more and 40% or less range, can be obtained by bead-core 12 improves the rigidity of sidewall portion 4 extremely The effect for the degree that ride comfort performance will not reduce.

In the pneumatic tire 1 of present embodiment, as described above, can be sought by constituting carcass 20 by a carcass light Quantization, and driving stability is improved by the rigidity of raising sidewall portion 4, but in general, improving the rigid of sidewall portion 4 Property in the case where, there are rolling resistance deteriorate trend.In contrast, in the pneumatic tire of present embodiment 1, sidewall portion 4 Sidewall rubber 33 of the tan δ in 0.04 or more and 0.10 or less range when by 60 DEG C is formed, and is commonly used in using tan δ ratio The rubber of the low low fever of the rubber of sidewall portion 4.The rigidity of sidewall portion 4 can be improved as a result, and reduces rolling resistance.It is tied Fruit is to seek the lightweight of quality and the reduction of rolling resistance, and improve driving stability.

In addition, in enhancement layer 40, the outboard end 41 and the 13 distance Dr of outboard end of bead-core 12 of enhancement layer 40 In the range of 5mm or more and 15mm or less, therefore it more reliably can moderately improve the rigidity of sidewall portion 4.That is increasing Enhancement layer 40 is arranged with the 13 distance Dr of outboard end of bead-core 12 less than in the case where 5mm in the outboard end 41 of layer 40 by force Range it is less big, the range enhanced by enhancement layer 40 is little, it is thus possible to which meeting is difficult enhancement layer 40 are arranged To improve the rigidity of sidewall portion 4.In this case, may be difficult to effectively improve driving stability enhancement layer 40 are arranged Property.In addition, in the case where the outboard end 41 of enhancement layer 40 and the 13 distance Dr of outboard end of bead-core 12 are more than 15mm, The range that enhancement layer 40 is arranged may be made to become excessive.In this case, the range enhanced by enhancement layer 40 becomes larger, Therefore, the rigidity of sidewall portion 4 becomes excessively high, may be difficult to ensure ride comfort performance.

In contrast, the outboard end 41 of enhancement layer 40 and bead-core 12 13 distance Dr of outboard end 5mm with In the case where in upper and 15mm or less range, the range that enhancement layer 40 is arranged more reliably can be set as range appropriate.By This can more reliably enhance range appropriate when by enhancement layer 40 to enhance sidewall portion 4, more reliably can moderately mention The rigidity of high side wall portion 4.As a result, can more reliably ensure ride comfort performance, and ensure driving stability.

In addition, enhancement layer 40 has the reinforcing cord 43 formed by steel, the line footpath of reinforcing cord 43In 0.20mm or more And in the range of 0.30mm or less, in addition, the insertion item number of the reinforcing cord 43 in every 50mm is at 35 or more and 45 or less In the range of, therefore the rigidity of sidewall portion 4 more reliably can be set as size appropriate.That is in the line of reinforcing cord 43 DiameterLess than the reinforcing cord 43 in 0.20mm or every 50mm insertion item number less than 35 in the case where, may be difficult to Ensure the rigidity of enhancement layer 40 itself, may be difficult to effectively improve the rigidity of sidewall portion 4 enhancement layer 40 are arranged.It should In the case of, it may be difficult to effectively improve driving stability.In addition, in the line footpath of reinforcing cord 43More than 0.30mm or In the case that the insertion item number of reinforcing cord 43 in the every 50mm of person is more than 45, the rigidity of enhancement layer 40 itself may be made to become Must be excessively high, the rigidity of sidewall portion 4 may be made to become excessively high because enhancement layer 40 are arranged.In this case, may be difficult to ensure Ride comfort performance.

In contrast, in the line footpath of reinforcing cord 43In the range of 0.20mm or more and 0.30mm or less, every 50mm In reinforcing cord 43 insertion item number in 35 or more and 45 or less ranges in the case where, can be by enhancement layer 40 itself Rigidity be set as size appropriate, the rigidity of sidewall portion 4 can be set as size appropriate by the way that the enhancement layer 40 is arranged.It is tied Fruit is more reliably to ensure ride comfort performance, and improve driving stability.

In addition, the sectional area in the meridian section of the pneumatic tire 1 of bead-core 12 is in 110mm²Above and 160mm²It is below In range, therefore the rigidity of sidewall portion 4 more reliably can be set as size appropriate.That is in the sectional area of bead-core 12 Less than 110mm²In the case where, the sectional area of bead-core 12 is too small, it is thus possible to can not can suitably play through bead-core 12 To improve the rigid effect of sidewall portion 4.In addition, the sectional area in bead-core 12 is more than 160mm²In the case where, bead-core 12 Sectional area it is excessive, it is thus possible to the rigidity of sidewall portion 4 can be excessively improved because of bead-core 12.In this case, due to sidewall portion 4 Rigidity it is excessively high, ride comfort performance probably can reduce.

In contrast, in the sectional area of bead-core 12 in 110mm²Above and 160mm²In the case where in following range, energy The effect for making the rigidity of sidewall portion 4 improve the degree that will not be reduced to ride comfort performance is obtained by bead-core 12.It is tied Fruit is more reliably to ensure ride comfort performance, and improve driving stability.

In addition, bead-core 12 outboard end 13 and 17 distance Df of tire heel in 40mm or more and 50mm feelings below Under condition, the rigidity of sidewall portion 4 more reliably can be set as size appropriate.That is bead-core 12 outboard end 13 with In the case that the distance Df of tire heel 17 is less than 40mm, the size of the tire of bead-core 12 radially is too small, it is thus possible to can nothing Method suitably plays through bead-core 12 effect for improving the rigidity of sidewall portion 4.In addition, in the outboard end 13 of bead-core 12 In the case where being more than 50mm with 17 distance Df of tire heel, the size of the tire of bead-core 12 radially is excessive, it is thus possible to meeting The rigidity of sidewall portion 4 is excessively improved because of bead-core 12.In this case, since the rigidity of sidewall portion 4 is excessively high, ride comfort performance It can probably reduce.

In contrast, in the outboard end 13 of bead-core 12 with 17 distance Df of tire heel in 40mm or more and 50mm or less In the range of in the case where, can be obtained by bead-core 12 makes the rigidity of sidewall portion 4 improve to ride comfort performance and will not drop The effect of low degree.As a result, can more reliably ensure ride comfort performance, and improve driving stability.

In addition, JIS hardness at 20 DEG C of the base portion rubber 32 of fetus face 2 is in 75 or more and 81 or less range, 60 DEG C when tan δ therefore, fever when tyre rotation can be inhibited in 0.14 or more and 0.22 or less range, and by tyre surface The rigidity in portion 2 is set as size appropriate.That is the rubber hardness of the base portion rubber 32 measured under conditions of 20 DEG C is less than 75 In the case where, the rigidity of fetus face 2 may be made to become too low and be difficult to ensure driving stability.In addition, in 20 DEG C of condition In the case that the rubber hardness of the base portion rubber 32 of lower measurement is more than 81, the rigidity of fetus face 2 may be made to become excessively high and difficult To ensure ride comfort performance.In addition, in the case that the tan δ of the base portion rubber 32 at 60 DEG C is less than 0.14, although can inhibit Fever when tyre rotation, but may be difficult to ensure the rubber hardness of base portion rubber 32, it is difficult to ensure driving stability.This Outside, in the case that the tan δ of the base portion rubber 32 at 60 DEG C is more than 0.22, when may be difficult to effectively inhibit tyre rotation Fever, it is difficult to reduce rolling resistance.

In contrast, the tan δ in the rubber hardness of base portion rubber 32 in 75 or more and 81 or less range, at 60 DEG C In the case where in 0.14 or more and 0.22 or less range, fever when tyre rotation can be inhibited, and by the rigid of fetus face 2 Property is set as size appropriate.As a result, rolling resistance can be reduced more reliably, it is ensured that ride comfort performance, and improve and drive Sail stability.

In addition, the minimum value Dm of the thickness of sidewall rubber 33 in the range of 1.0mm≤Dm≤3.5mm, therefore, can be maintained Belt cutting-resisting property, and more reliably mitigate the quality of sidewall portion 4.That is the minimum value Dm of the thickness in sidewall rubber 33 In the case where 1.0mm, the thickness of sidewall rubber 33 is excessively thin, accordingly, it is possible to can make the guarantor when sidewall portion 4 nuzzles up kerb etc. The internal structures bodies such as shield carcass 20 are so that the performance i.e. belt cutting-resisting property that internal structure body does not damage reduces.In addition, in sidewall rubber In the case that the minimum value Dm of the thickness of glue 33 is more than 3.5mm, the thickness of sidewall rubber 33 is blocked up, accordingly, it is possible to can make side wall The quality in portion 4 becomes easy increase, it is difficult to mitigate the quality of pneumatic tire 1.

In contrast, the minimum value Dm of the thickness of sidewall rubber 33 is in the range of 1.0mm≤Dm≤3.5mm, therefore, energy Ensure to maintain the thickness of the sidewall rubber 33 of belt cutting-resisting property, and more reliably mitigates the quality of sidewall portion 4.Its result It is the lightweight that can ensure that belt cutting-resisting property, and more reliably seek the quality of pneumatic tire 1.

In addition, tire profile height Hs in the range of 110mm or more and 170mm or less, aspect ratio be 55 or more In the case of, the carcass 20 in the meridian section of pneumatic tire 1 is elongated, therefore, in the case where carcass 20 is one, compared to tire The case where body 20 is two, can make quality significantly lightweight.In addition, the arranging region of the tire of sidewall portion 4 radially also becomes Greatly, therefore, rubber of the tan δ when to sidewall rubber 33 using 60 DEG C in 0.04 or more and 0.10 or less range and The effect of the reduction rolling resistance of acquisition becomes larger.In addition, the arranging region of the tire of sidewall portion 4 radially becomes larger, it therefore, can be more It is obtained significantly by keeping the end 23 of carcass 20 Chong Die with belt 25 or enhancement layer 40 is arranged or setting distance Df For the effect for improving driving stability in 20% or more and 40% or less the range of tire profile height Hs.As a result, Can obtain more significantly can seek the lightweight of quality and the reduction of rolling resistance, and improve the effect of driving stability.

It should be noted that enhancement layer 40 has the enhancing formed by steel in the pneumatic tire 1 of above-mentioned embodiment Cord 43, but enhancement layer 40 can also not have reinforcing cord 43.Enhancement layer 40 can also not have reinforcing cord 43, and by such as Under rubber formed: JIS hardness at 20 DEG C, that is, measured under conditions of 20 DEG C foundation JIS K6253 JIS-A hardness Represented rubber hardness is in 85 or more and 95 or less range, and tan δ at 60 DEG C is in 0.12 or more and 0.20 model below In enclosing.Enhancement layer 40 is constituted by using the rubber with such physics value, can moderately improve the rigidity of sidewall portion 4 and Reinforcing cord 43 need not be used, rolling resistance can be inhibited.The reduction of rolling resistance can be sought as a result, and improves driving stability Property and ride comfort performance.

In addition it is also possible to which the enhancing component different from enhancement layer 40 is arranged in the pneumatic tire 1 of above-mentioned embodiment. Fig. 6~Fig. 8 is the improvement of the pneumatic tire 1 of embodiment, is the explanatory diagram about sidewall enhancement layer 50.As with enhancement layer 40 different enhancing components, for example, can be as shown in Figure 6 to 8, in sidewall rubber 33 or rim cushion rubber 34 and carcass Sidewall enhancement layer 50 is arranged between 20 turnup 22.JIS hardness when preferably sidewall enhancement layer 50 is by 20 DEG C 70 with In upper and 85 or less ranges, 60 DEG C when rubber of the tan δ in 0.06 or more and 0.12 or less range constitute, preferably It is that the thickness of sidewall enhancement layer 50 is formed in the range of 0.5mm or more and 2.0mm or less.

In addition, the position of configuration sidewall enhancement layer 50 is configured at the position including tire maximum width position P.Example It such as, can be as shown in fig. 6, being located near fetus face 2 with the outboard end 51 of tire radially, the tire of sidewall enhancement layer 50 The mode that medial end 52 radially is located between the turnup 22 and rim cushion rubber 34 of carcass 20 configures sidewall enhancing Layer 50.Alternatively, can be with as shown in fig. 7, being located near fetus face 2 with outboard end 51, medial end 52 be maximum wide in tire The mode slightly by the position of tire radial direction inner side near degree position P positioned at tire maximum width position P configures sidewall increasing Strong layer 50.Alternatively, can with as shown in figure 8, with medial end 52 be located at carcass 20 turnup 22 and rim cushion rubber 34 it Between, outboard end 51 is near tire maximum width position P positioned at tire maximum width position P slightly outside tire radial direction The mode of the position of side configures sidewall enhancement layer 50.That is sidewall enhancement layer 50 is located at the volume of carcass 20 with outboard end 51 Rise portion 22 end 23 tire radial direction inner side, and outboard end 51 be located at tire maximum width position P tire diameter it is outside Side, the mode that medial end 52 is located at the tire radial direction inner side of tire maximum width position P configure.

As described above, by the way that the sidewall enhancement layer 50 formed by the rubber harder than the rubber hardness of sidewall rubber 33 is configured In the range of 0.5mm or more and 2.0mm or less and it is configured at the position including tire maximum width position P for thickness, it can be more Readily insure that the rigidity of sidewall portion 4.As a result, when the rigidity of pneumatic tire 1 is set as desired size, tire could be used that Side enhancement layer 50 is adjusted, therefore can more reliably be set as the rigidity of desired size.In addition, when by by 60 DEG C Rubber of the tan δ in 0.06 or more and 0.12 or less range constitutes sidewall enhancement layer 50, even if being equipped with sidewall enhancement layer In the case where 50, can also rolling resistance be inhibited to become larger.As a result, can more reliably seek the reduction of rolling resistance, and mention High driving stability and ride comfort performance.