JP3118418B2 - Pneumatic tire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention eliminates joints in a carcass ply and a belt ply, thereby improving uniformity and durability of a tire.
Cutting / joining work according to a predetermined cord angle of a cord-like fabric material, which was necessary when forming a conventional ply, and storage work of the joined ply forming material necessary for each type of tire, and these The present invention relates to a pneumatic tire that can reduce equipment and the like related to each operation and can save labor in tire production.

[0002]

2. Description of the Related Art A carcass A and a belt layer B which form a skeleton of a pneumatic tire.
Conventionally, as shown in FIG. 18, sheet-like ply forming materials da and db in which carcass cords and belt cords are arranged at predetermined cord angles αa and αb, respectively, and these ply forming materials da and db are used as tire circles. It is wound in the circumferential direction, and the starting end portion e1 and the ending portion e2 of the winding are overlapped and connected (jointed) for each turn.

However, these joints j
In a and jb, the cords have a dense arrangement in which the cords overlap in the thickness direction, so that the rigidity is unevenly increased and the weight balance is impaired, which causes a decrease in uniformity.

Therefore, in order to improve such uniformity, in addition to reducing the width of the joint portions ja and jb, for example, measures such as dispersing and distributing the joint portions ja and jb in a circumferential direction with good balance are taken. However, in today's world where tires are required to have higher performance and the number of plies is reduced in order to reduce weight, etc., these distributed arrangements are not effective enough, and new measures are strongly desired. It is rare.

On the other hand, as shown in FIG. 19, conventionally, as shown in FIG. 19, each of the ply forming materials da and db is made of a rubberized fabric material fa or fb in which cords are aligned in the width direction, and a length ka corresponding to each ply width. , Kb and the cord angles αa, α
b to form a plurality of sheet pieces f, and the sheet pieces f are formed by sequentially joining non-cutting edge portions g. However, in the tire, in both the carcass and the belt layer, the cord material, the cord interval, the cord angle, and the ply width are different depending on the size, type, required performance, and the like of the tire. In addition to this, an excessive space is required for the storage management, and the equipment cost and the manufacturing cost are increased.

Accordingly, the present invention provides a continuous carcass ply in which carcass cords are sequentially folded in a U-shape in the tire axial direction at both ends of the ply to form a meandering arrangement, and a continuous belt ply in which a belt cord is continuously circulated in the tire circumferential direction. In addition to removing the joint part itself from the tire and improving uniformity, it is necessary to create, store and store various types of ply forming materials that were required for each type of tire. It is an object of the present invention to provide a pneumatic tire capable of reducing such facilities and the like, thereby saving labor and cost in tire production.

The inventor of the present invention disclosed in Japanese Patent Laid-Open No. 5-27021.
In the gazette of No. 1, the belt-shaped body of the belt cord is turned around at both sides of the ply while being folded in a V-shape.
A belt layer composed of a continuous belt ply having a cord angle of 25 degrees has been proposed. In Japanese Patent Application No. Hei 7-320707, a carcass cord is folded in a U-shape sequentially in the tire axial direction at both ends of the ply to meander. A carcass consisting of an array of continuous carcass plies has been proposed.

[0008] However, the former is intended to impart a moderate elasticity to the belt layer while maintaining the jointless structure, and to improve the uneven wear resistance while maintaining the running performance. It is an object of the present invention to improve the bead durability by reducing the stress acting on both ends of the carcass ply and increasing the adhesion to rubber at both ends by forming a meandering arrangement. Therefore, both of them have completely different purposes from the present application, and do not refer to uniformity at all. In addition, since the uniformity is intertwined with factors due to the belt layer and carcass,
The adoption of the jointless structure of only one of the belt layer and the carcass has little effect on the improvement of the uniformity. On the contrary, equipment costs and manufacturing costs are increased, for example, a new device is required.

As described above, only by adopting the jointless structure in both the belt layer and the carcass, the effect of improving the uniformity can be effectively achieved, and the equipment cost and the manufacturing cost can be reduced, thereby saving labor in tire manufacturing. Can be promoted.

[0010]

Means for Solving the Problems In the present invention, claim 1 is provided.
The described invention is a pneumatic tire including a carcass that passes through a tire body from a tread portion to a bead portion having a bead core from sidewall portions on both sides of the tire ,
The carcass passes between the bead cores through the tire body.
Along the toroidal main part and the lower surface of the bead core.
A winding portion, and the carcass is wound up with the main portion.
In the state where the barbed part is deployed, one outer edge
Many turning points lined up at equal intervals and the other outer edge
Turning points on both sides with the same number of turning points equally spaced in the direction
Alternately and while turning the turning point in the circumferential direction,
Do not cross each other, at least in the main part.
Meandering arrangement with carcass cords folded substantially parallel
Including one or more folded carcass plies formed by
Together, the belt layer, one or a plurality of belt cords aligned parallel and rubberized strip, from the continuous belt ply obtained by circulating continuously at an angle of 0-30 degrees with respect to the tire equator And the bead core is
A bead code that is substantially continuous with the carcass code
Continuous winding around the upper side of the cascade cord
Core part or bead core that is not continuous with the carcass cord
Around the top of the carcass cord and circumferentially
Pneumatic tire characterized by having a core part
is there.

The invention according to claim 2 is characterized in that the band-like body is
The belt layer is formed by inclining at an angle of 5 to 30 degrees with respect to the equator of the tire, and turning around at a turning point on both side edges of the belt layer .

[0012] The invention according to claim 3, have a continuous core portion formed by winding a carcass cord and substantially bead cord continuous circumferentially, characterized in that provided on the bead core
You.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a pneumatic tire 1
A tread portion 2, a pair of sidewall portions 3 extending inward in the tire radial direction from both ends of the tread portion 2,
A toroidal tire base body 6 having a bead portion 4 located at an inner end of each sidewall portion 3 and reinforced by an annular bead core 5; A carcass 7 passing through the tire body 6 is bridged between the portions 4 and 4, and a radially outer side of the carcass 7 and an inner side of the tread portion 2,
A belt layer 9 is provided.

In the carcass 7, the carcass cords 10 are arranged at an angle of 75 to 90 degrees with respect to the tire equator C.
In the present embodiment, a toroidal main portion 11A that is formed of one continuous carcass ply 11 and extends between the bead cores 5 and 5 through the tire body 6 and around the bead core 5 And a winding portion 11B that is wound up from the inside in the tire axial direction. The winding portion 11B
Rises along the outer surface of the bead apex rubber 8 tapering outward from the bead core 5 in the radial direction, and the winding height H1 from the bead base line BL is smaller than the bead apex height H2, in this example. , The height of the rim flange F is smaller than the height HF. The bead base line BL is a bead base 4S which is a bead bottom surface.
Is a line in the tire axial direction passing through the outer end point in the tire axial direction,
It forms the reference line for selecting the rim diameter of the applicable rim.

[0015] Continuous carcass ply 11 in this case, without having the conventional joint portion, a cord ply to circumferentially continuous, as shown by expanding in Fig. 4 (I
FIG. 4 shows two codes 1 as described later in [0018].
0A and 10B are shown) , n turning points Li (i = 1 to n ) arranged at equal intervals in the circumferential direction at one outer edge E1 of the continuous carcass ply 11, and the other outer edge Edge E
2, the carcass cord 10 has n turning points Ri (i = 1 to n ), and the turning points on both sides are Ri-1, Li-
A meandering arrangement is obtained in which the turning points are turned alternately in the order of 1, Ri, Li, Ri + 1, and Li + 1, and the turning points are sequentially advanced in the circumferential direction.

In the continuous carcass ply 11, the number of cords per 5 cm of the ply width is about 15 to 30/5 cm, and the carcass cords 10 do not substantially cross each other at least in the main portion 11A. Arrange in parallel. If they intersect, a shearing force is generated, leading to cord breakage.

As shown in FIG. 3, the outer edges E1 and E2 of the plies are wound up to bead portions 4 or side wall portions 3, which are both side portions of the tire, in this example, the bead portions 4, so that the folding points are turned off. Ri and Li are arranged in the circumferential direction on both sides of the tire.

Further, the continuous carcass ply 11 can be formed by using one or more carcass cords 10 covered with rubber, and FIG.
Examples using A and 10B are shown. At this time, 2n point elements P are arranged at equal intervals in the circumferential direction on each outer edge E1, E2 of the continuous carcass ply 11, and each of the two point elements 2P constitutes one turning point. That is, one carcass cord 10A has a meandering arrangement in which folding is repeated every two point elements 2P.
0B is shifted by a half pitch in the circumferential direction with respect to the one carcass cord 10A, that is, the phase is shifted by one point element, and the turn is repeated every two point elements 2P. Thereby, each carcass cord 10A, 10B
At least the main part 11A is arranged in parallel without crossing.

FIG. 5 shows three carcass cords 10.
A, 10B, and 10C are used to form the carcass ply 11, and at this time, each outer edge E1,
E2 is provided with 3n point elements P, and each carcass code 1
0A, 10B, and 10C are arranged in a meandering manner by folding every three point elements 3P.
The phase is shifted by 1/3 pitch, that is, by one point element. Thereby, each carcass cord 10A, 10C
Achieve a parallel alignment of B, 10C.

When the continuous carcass ply 11 has two or more m layers, the meandering arrangement of the carcass cords 10 is repeated m times in the circumferential direction. At this time, as shown in FIG. As
Change the inclination direction of the cord.

In the present embodiment, the bead core 5 has a bead cord 15 substantially continuous with the carcass cord 10.
Has a continuous core portion 5A of a so-called single wind type formed by spirally winding at least one step in the circumferential direction on the upper side of the carcass ply, and as shown in FIG. A continuous transition from the position Q1 to a spiral winding forms the continuous carcass ply 11 and the continuous core portion 5A.

Here, "substantially continuous" means that the bead cord 15 and the carcass cord 10 have no break.
Or continuously in this code, or bonding a discontinuity between the bead wire 15 and the carcass cord 10, which means that continuous by connecting together by welding or the like. In a region other than the transition region Q from the meandering arrangement to the spiral winding, when the bead cord 15 is interrupted due to a lack of material in the middle of the spiral winding, and when the carcass cord 10 is interrupted in the meandering arrangement, From the vicinity of the break, a new cord can be continuously formed in a spiral winding and meandering without performing an adhesive treatment or the like. At this time, it is necessary to use the same cord as the cord before the break. When integrally connected by bonding, welding, or the like, the material, thickness, twist structure, and the like of the bead cord 15 and the carcass cord 10 may be different from each other depending on requirements.

In this embodiment, the bead core 5 is formed only of the continuous core portion 5A. The bead core 5 or the continuous core portion 5A has a sectional shape other than the flat hexagonal shape shown in FIG. 7 (A)-(F),
Various shapes such as a rectangle, a trapezoid, a parallelogram including a parallelogram, a triangle, a hexagon, and a circle can be adopted.

The carcass cord 10 and the bead cord 1
As 5, organic fiber cords such as nylon, rayon, polyester, vinylon, aromatic polyamide, wholly aromatic polyester, and high elasticity polyethylene, and metal fiber cords such as steel can be used. In order to ensure reliability and suppress rim displacement and heat generation due to the rim displacement, and furthermore, deformation of the bead base 4S, it is preferable that the initial tensile elastic modulus of the bead cord 15 be 1500 kgf / mm ² or more. The initial tensile modulus was determined by JI
It means the elastic modulus converted from the initial tensile resistance specified in SL1017.

The bead core 5 is formed of only a single-wind type or tape bead type core portion 5B using another bead code 16 that is discontinuous with the carcass cord 10, instead of the continuous core portion 5A. Alternatively, as shown in FIG. 8A, in addition to the continuous core portion 5A, a core portion 5B may be provided inside , for example, the radial direction of the continuous carcass ply 11 , that is, on the lower side . Note that the bead cords 15 and 16 can be formed of different materials from each other. For example, when the core portion 5B is formed of a conventional steel cord, the bead cords 15 and 16 are formed.
Even if a low modulus cord having an initial tensile elastic modulus of less than 1500 kgf / mm ² , such as nylon or polyester, is used, the necessary rim fitting force can be secured.

As shown in FIG. 2 and FIG. 8A, the winding portion 11B passes through the bottom surface of the continuous core portion 5A and extends outward from the continuous core portion 5A in the tire axial direction, as shown in FIGS. The protruding portion 17 that protrudes is wound radially outward, and its outer edges E1 and E2 are terminated along the outer surface of the continuous core portion 5A or the bead apex rubber 8, and as shown in FIG. Alternatively, the protruding portion 17 whose protruding direction is opposite, that is, the protruding portion 17 protruding inward in the tire axial direction from the continuous core portion 5A may be wound radially outward and terminated along the inner surface of the bead apex rubber 8 or the like.

As the winding portion 11B, as shown in FIG.
As shown in (C), it terminates on the bottom surface of the continuous core portion 5A, or as shown by a dashed line in FIG.
E2 may protrude slightly from the side surface of the continuous core portion 5A in the tire axial direction and may be terminated.

As still another example of the winding portion 11B, when the bead core 5 is constituted by the core portions 5A and 5B, the outer edges E1 and E2 of the winding portion 11B are terminated between the core portions 5A and 5B. . For details, see FIG.
As shown in the figure, the outer winding edges E1 and E2 that terminate on the bottom surface of the core portion 5A are sandwiched between the core portions 5B. Or, FIG.
As shown in (B), the protruding portion which divides the core portion 5A into a radially inner lower core portion 5A1 and an outer upper core portion 5A2, and winds up radially outward through the bottom surface of the upper core portion 5A1. The outer edges E1 and E2 of 17 are sandwiched and terminated between the upper and lower core portions 5A1 and 5A2. Alternatively, one of the core portions 5A1 and 5A2 is formed by a core portion 5B having a different code.

As another example of the winding portion 11B, as shown in FIG. 10 (A), a protruding portion 17 which protrudes from the core portion 5A in the tire axial direction is wound radially outward, and its outer edge E1, E2 is sandwiched between the core portion 5A and the bead apex rubber 8 and terminated,
Alternatively, as shown in FIG. 10 (B), the wire passes through the core portion 5A and the bead apex rubber 8 and is sandwiched and terminated between the carcass main portion 11A and the bead apex rubber 8.

Among the various structures of the winding portion 11B, the one that terminates by sandwiching the outer edges E1 and E2 can more reliably prevent the cord loose and blow-through at the outer edges E1 and E2.

The belt layer 9 is formed as a layer of a continuous belt ply 12 in which the belt-shaped body 20 is continuously circulated at an angle of 0 to 30 degrees with respect to the tire equator C. As shown in FIG. 11, the belt-like body 20 has a small length of a substantially rectangular cross section formed by rubberizing one or more belt cords 21 arranged in parallel, in this example, three belt cords 21 with rubber 22. The width Wo is preferably 5 to 15 mm. As the belt cord 21, an organic fiber such as nylon, polyester, or aromatic polyamide, or a steel cord is used. In particular, an aromatic polyamide fiber has substantially the same strength as steel and is rich in flexibility. This can be suitably adopted.

In the present embodiment, the continuous belt ply 12
As shown in FIGS. 12 and 13, using one strip 20,
The belt-like body 20 is inclined at an angle θ in the range of 5 to 30 degrees with respect to the tire equator C, and in the width direction at the positions of left and right turn points V1 and V2 contacting both side edges Y1 and Y2 of the belt layer 9. In other words, by alternately folding in the shape of a letter on the same plane, a zigzag shape is formed, and the tire is turned many times in the circumferential direction of the tire, thereby being formed jointless.

As shown exaggeratedly in FIG. 14, the belt-shaped body 20 returns to a position S2 adjacent to its starting end point S1 when it makes a round in the tire circumferential direction, that is, the band-shaped body 20 The tire is turned while the turning width T is shifted in the circumferential direction of the tire. In this example, the belt-shaped body 20 is formed such that a product TN of the folding width T and the number of times of folding N at one side edge Y1 (Y2) is defined as a circumferential length of the belt layer 7.
Therefore, by making N rounds using the method described above,
A two-layer continuous belt ply 1 having a cross structure in which the side edges 20a of adjacent strips 20 are substantially butted against each other, and the direction of the angle θ of the strips 20 is reversed in the inner and outer layers.
2 and 12 are formed.

Here, as shown in FIG. 13, the strip 20 has an opening angle β centered on the tire axis I sandwiching one of the side edges Y1 (Y2) between the turning points adjacent to each other in the circumferential direction.
Is turned around as in this example, the opening angle β
Subtracted the folded width of the band 20 from 360 °,
That is, the value is slightly less than 360 °. Therefore, when the belt layer 9 has a circumferential development length of 3000 mm and a belt width of 300 mm, the cord angle θ of the belt layer 9 is 5 mm.
°. Further, as shown in FIG. 15, when the belt-like body 20 is folded at an opening angle β of about 180 ° under the same size condition, the cord angle θ can be set in a range of about 15 to 18 °.

The continuous belt ply 12 may be arranged such that adjacent side edges 20a are slightly overlapped or slightly spaced apart from each other, or a plurality of belts having the same width or different widths may be provided. May be formed by simultaneously or sequentially rotating. The belt-like body 20 has a side edge Y
In addition to extending linearly between 1, Y2, it may be formed by a curve such as a sine curve.

As described above, the pneumatic tire 1 has the jointless continuous carcass ply 11 and the continuous belt ply 12 in both the carcass 7 and the belt layer 9.
By eliminating the joint itself that previously caused partial disproportionate rigidity and reduced weight balance, the uniformity of the tires can be dramatically increased and the lateral flow of the vehicle , Vibration, noise and the like can be improved.

Further, each of the continuous carcass ply 11 and the continuous belt ply 12 uses a common member such as a cord and a topping rubber at the time of manufacturing a tire, and determines a cord interval, a cord angle, a ply width and the like suitable for the type of the tire. Since they are sequentially formed on the former, the conventional ply forming materials required for various types of tires, which are necessary for each type of tire, become unnecessary. Equipment and space used for the operation can be reduced, and labor and cost reduction in tire production can be greatly promoted.

Further, unlike the conventional cut ply, the continuous carcass ply 11 and the continuous belt ply 12 have the cord cut ends removed from both side edges of the ply, so that the continuous carcass ply 11 and the continuous belt ply 12 have excellent adhesion to the tire rubber and suppress ply end peeling. Durability can be improved. In particular, the continuous carcass ply 1 having the above configuration
1, as shown in FIGS. 16A and 16B, a load for compressing the rubber G1 inside the U-shape against the tensile force TA acting on the carcass cord 10 due to the filling internal pressure or the like, Also, since the load pulling the inner rubber G1 opposes the compressive force TB acting by the bead deformation,
The stress between the U-shaped tip and the outer rubber G2 can be reduced, and since this stress itself is dispersed by the U-shape, the bead durability can be improved.

Further, when the bead core 5 is formed only by the continuous core portion 5A, the conventional front member for forming the bead core and the forming process thereof are not necessary, which can promote labor saving and the like, and reduce the strength due to stress concentration. Since the cut end of the bead cord is eliminated from the bead portion 4, the bead durability can be further improved.

Further, since the continuous belt ply 12 having the above-described structure has a cord angle θ of 5 to 30 degrees which is close to that of the conventional cut ply, it is possible to provide the belt layer with appropriate elasticity while maintaining the advantage of the jointlessness. And maintain running performance.

In addition, as shown in FIG. 17, the continuous belt ply 12 may be formed such that the belt-shaped body 20 is bent in the shape of a rectangle while being bent in the thickness direction at the positions of the folding points V1 and V2. it can.

The continuous belt ply 12 may be formed by winding the belt-like body 20 from, for example, one side edge Y1 to the other side edge Y2 in a helical manner without being folded in a V-shape. The code angle θ ranges from 0 to 5 degrees. When the spiral is used, it is preferable to use a hybrid cord in which a high modulus fiber and a low modulus fiber are twisted as the belt cord 21 in order to impart elasticity to the belt layer 9.

Further, in the pneumatic tire 1 of the present invention, in order to prevent frictional damage to the rim, a chafer comprising a ply of an organic fiber cord covering the bead portion 4 from the bottom surface to the outer surface, and the tire. In order to improve ride comfort and lateral groove rigidity, the bead section 4 to the side wall section 3
Members that can be used in various tires, such as bead fillers made of plies of organic fiber cords, steel cords and the like disposed on the lower part, and a conventional cut belt ply can be additionally used for the belt layer 7. However, in order to maximize the effect of improving the uniformity and the effect of labor saving in tire manufacturing, the carcass 7, the belt layer 9, and the bead core 5 are respectively composed of the continuous carcass ply 11, the continuous belt ply, and the like. It is most preferable to form only the base 12 and the continuous core 5A.

[0044]

EXAMPLES A heavy-duty radial tire having a tire size of 11R22.5 and having the structure shown in FIG. 1 was prototyped according to the specifications shown in Table 1, and the bead durability (bead damage), bead heat generation, and bead base of the sample tire were measured. Deformability, tire weight, and high-speed durability were tested and compared.

The test conditions are as follows. 1) Bead heat generation: A test tire was sized 22.5 × 8.
Attached to 25 15 ° deep bottom rim, filling internal pressure 8.00ks
c, running on the drum under the conditions of a load of 9000 kg and a speed of 20 km / h, measuring the surface temperature of the bead portion at every running distance of 1000 km, and averaging the average value of the conventional product 1 by 10
It was indicated by an index of 0. The smaller the numerical value, the lower the heat generation and the better.

2) Bead durability (bead damage): The tire running 5000 km on the drum under the above conditions was disassembled, and the presence or absence of ply loose was examined. In Table 1, ○ indicates that ply loose did not occur, △ indicates that loose occurred at the end of the winding portion of the carcass ply, and × indicates that carcass separation occurred. .

3) Deformability of the bead base: As shown by a dashed line in FIG. 2, the deformation height ha of the floating deformation of the toe portion t of the bead base of the tire after traveling 5,000 km on the drum under the above conditions was measured. And before running 100 tires
It was indicated by an index. The larger the value, the smaller the deformation and the better.

4) Tire weight: The weight of each sample tire was indicated by an index with the conventional product being 100. The smaller the value, the lighter and better.

5) High-speed durability: a test tire having a size of 2
Mounted on a 2.5 × 8.25 15 ° deep bottom rim, run continuously on the drum under the conditions of a filling internal pressure of 8.00 ksc, a load of 4500 kg (150% load), and a speed of 120 km / h for 2 hours, and run The surface temperature of the subsequent tread portion was measured, and the average value was indicated by an index with the conventional product 1 being 100.
The smaller the value, the lower the heat generation and the better. After running, the tires were disassembled and checked for damage such as cord loose at the belt end.

[0050]

[Table 1]

[0051]

Since the pneumatic tire of the present invention is constructed as described above, the joint itself is eliminated from the tire to improve the uniformity, and conventionally, it has been necessary for each type of tire. It is possible to reduce the work of preparing and storing various kinds of ply forming materials, the facilities and the like related to each of these works, and achieve labor saving and cost reduction in tire production.

[Brief description of the drawings]

FIG. 1 is a sectional view of a tire showing one embodiment of the present invention.

FIG. 2 is an enlarged partial sectional view showing the bead portion.

FIG. 3 is a perspective view showing a carcass structure together with a bead core.

FIG. 4 is a schematic diagram illustrating an example of a meandering arrangement of carcass cords.

FIG. 5 is a schematic diagram illustrating another example of a meandering arrangement of carcass cords.

FIG. 6 is a schematic diagram showing still another example of a meandering arrangement of carcass cords.

FIGS. 7A to 7F are schematic cross-sectional views showing an example of a cross-sectional shape of a bead core.

FIGS. 8A to 8C are schematic cross-sectional views showing an example of a bead structure that can be used in the present application.

FIGS. 9A and 9B are schematic cross-sectional views showing another example of a bead structure that can be used in the present application.

FIGS. 10A and 10B are schematic sectional views showing still another example of a bead structure that can be used in the present application.

FIG. 11 is a perspective view showing an example of a belt-like body.

FIG. 12 is a developed plan view showing an example of a belt structure.

FIG. 13 is a perspective view showing an example of the orbit of the band.

FIG. 14 is a schematic plan view showing exaggerated folding of the strip.

FIG. 15 is a plan view showing another example of the orbit of the band.

16A and 16B are schematic cross-sectional views illustrating the operation of the carcass cord of the present application.

FIG. 17 is a perspective view showing another example of folding back of the belt-shaped body.

FIG. 18 is a partial perspective view showing the structure of a carcass and a belt layer of a conventional tire.

FIG. 19 is a plan view illustrating a ply forming material used for a conventional carcass and belt layer.

[Explanation of symbols]

 Reference Signs List 2 tread portion 3 sidewall portion 4 bead portion 5 bead core 6 tire body 7 carcass 9 belt layer 10, 10A, 10B, 10C carcass cord 11 continuous carcass ply 12 continuous belt ply 20 belt 21 belt cord C tire equator θ belt cord Angle Li, Ri Turn point of carcass cord

Continuation of the front page (56) References JP-A-55-39398 (JP, A) JP-A-62-50207 (JP, A) JP-A-5-193306 (JP, A) JP-A-5-270211 (JP) , A) JP-A-9-155991 (JP, A) JP-A-3-167012 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60C 9/02-9/08 B60C 9/20-9/22 B60C 15/04 B29D 30/38-30/48

Claims (3)

(57) [Claims] 1. A pneumatic tire comprising a carcass passing through a tire body from a tread portion to a bead portion having a bead core through sidewall portions on both sides of the tire , wherein the carcass passes through the tire body and forms a bead core. while
Along the toroidal main part and the lower surface of the bead core.
And the carcass is in a state where the main part and the winding part are unfolded.
, A large number of which are arranged at equal intervals in the circumferential direction on one outer edge
And the other outer edge at equal intervals in the circumferential direction
The turn points on both sides with the number turn points are alternately turned
While moving the point in the circumferential direction, and at least
In a substantially parallel manner without intersecting each other
One or more formed by a meandering arrangement of folded cascodes
Including the folded carcass ply above, the belt layer is formed by continuously aligning one or a plurality of belt cords in parallel and rubberized a belt-like body at an angle of 0 to 30 degrees with respect to the tire equator. consists continuous belt ply obtained by circulating, yet the bead core is substantially said carcass cord
Pass the continuous bead cord over the carcass cord
A continuous core portion wound in the circumferential direction, or the carcass
A non-continuous bead code is placed on the carcass code.
A pneumatic tire having a core portion wound in a circumferential direction through a side . 2. The continuous belt ply, wherein the belt-like body
2. The pneumatic tire according to claim 1, wherein the belt layer is formed by inclining at an angle of 5 to 30 degrees with respect to the equator of the tire and turning around at a turning point of both side edges of the belt layer. tire. 3. The pneumatic tire according to claim 1, wherein the bead core has a continuous core portion formed by winding a bead cord substantially continuous with the carcass cord in a circumferential direction.