JPH03169726A - Bias tire for high pressure - Google Patents

Abstract

PURPOSE:To reduce the width of a bead part, to reduce weight, and to improve high speed durability by a method wherein a plurality of bead cores around which a carcass ply is folded are provided, the inner sizes of the bead cores are differed from each other, and the bead cores are concentrically piled up, in order, radially outwardly. CONSTITUTION:A tire 1 is provided with a bead core 2 around which a carcass 7 extending from a tread part 5 through a side wall part 4 to a bead part 3 is folded. In this case, the bead core 2 is provided with a number of bead cores 2A-2C positioned in juxtaposition from the inside in a radial direction of the tire to the outside thereof. The bead cores 2A-2C are arranged concentrically and, in order, in a radial direction, and a gap is ensured between the adjoining bead cores. In the bead cores 2A-2C, the more the bead core is positioned radially outwardly, the more width is decreased. This constitution reduces the generation of a strain occasioned by deformation of the tire 1 through reduction of the width of the bead part 3, resulting in reduction of weight and improvement of high speed durability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-pressure bias tire that can be reduced in weight and improved in bead durability and high-speed performance. [Prior art] High-pressure bias tires, especially tires used for aircraft, are
In recent years, as aircraft have become larger and their flight speeds have increased, operating speeds and applied loads have increased. The amount is extremely large, for example, 28 to 38%, and therefore it is difficult to withstand large repeated deformations. ■ As aircraft speeds increase, the speeds associated with takeoff and landing increase, and therefore, it is difficult to withstand high-speed rotation under heavy loads and large deformations. ■ In addition to being able to withstand the taxi conditions in which a large load is applied over a relatively long period of time at low speeds when moving between the runway and the gate, it is also desirable to reduce the weight of the tires. In addition, aircraft tires are sold at 10 to 20 kg/kg in order to support large sales volume.
The tires are used at high internal pressures of about 1.5 cm", and for operational safety reasons, they are required to withstand strength more than four times the operating internal pressure. On the other hand, high-pressure bias tires used on such aircraft are required to be used in a patent application. As disclosed in Japanese Patent No. 1-98189 and schematically shown in FIG.
were arranged along the tire axial direction, and carcass e, f, g consisting of a plurality of carcass plies were wound around each bead core b%C1d, respectively.

[Problem to be solved by the invention]

However, while the tire with this structure has the excellent advantage of high lateral rigidity, the bead cores bSc and d are lined up in the width direction of the bead portion a, so the bead width W is large, and each The carcass e, f, g are each formed by a plurality of carcass blies, and these carcass e, f, g are connected to the bead portions b, c.
, d, the bead width W becomes very large. As a result, not only does the weight of the tire increase, but also the bead part a bulges out significantly compared to the sidewall part, and when the tire deforms, a large strain occurs in the bead part a, reducing the durability of the tire. There is a problem with doing this. The inventor has found that by stacking multiple bead cores concentrically and radially in order, the bead width can be narrowed and the weight of the tire can be reduced. At the same time, durability can be improved by reducing distortion occurring in the bead portion. He noticed the scales and perfected the invention. An object of the present invention is to provide a high-pressure bias tire that is lightweight, increases the durability of the bead portion, and improves high-speed performance.

[Means to solve the problem]

In the present invention, the carcass ply extending from the trend portion to the bead portion through the sidewall portion is folded back on the inner diameter surface of the plurality of bead cores, each of which has a different inner diameter, so that the bead cores are sequentially extended concentrically and outward in the radial direction. This is a high pressure bias tire.

[Effect]

Because multiple bead cores with different inner diameters are stacked one after the other in the rotational and radial direction, the width of the bead can be formed narrower than in the conventional structure in which bead cores are arranged side by side in the axial direction of the tire. Weight can be reduced. Also, by reducing the width of the bead, the difference between the bead width and the thickness of the sidewall can be reduced, and as a result, the amount of bulge in the bead can be reduced, reducing the stress generated in the bead due to tire deformation. is small and durability can be improved. Furthermore, since the bead cores overlap successively outward in the radial direction, the lateral rigidity of the tire increases during tire deformation, making it possible to omit the bead apec.

In addition, the rolled end of the carcass can be sandwiched between the bead core and the bead core stacked on the outside in the radial direction, so if the carcass is sandwiched between the inner and outer bead cores, separation at the end of the carcass can be avoided. It is possible to effectively prevent this, and it is also possible to reduce the number of overlapping carcass plies, resulting in further weight reduction.

〔Example〕

An embodiment of the present invention will be explained below based on the drawings. No.l,
In FIG. 2, the high-pressure bias tire 1 has a pair of left and right bead portions 3 through which the bead core 2 passes, and a sidewall portion 4 that is continuous with the bead portions 3 and extends outward in the tire radial direction.
and a tread portion 5 connecting between the outer ends of the sidewall portion 4.
The bead core 2 includes a first bead core 2A, a second bead core 2B, and a third bead core 2C, which are arranged side by side from inside to outside in the tire radial direction. There is. The tire base 6 also includes a carcass 7 and a breaker 10 disposed inside the tread portion 5 and on the radially outer surface of the carcass 7 via tread rubber, and the carcass 7 includes a plurality of carcass ply groups. Consists of G-. Further, the first, second and third bead cores 2A, 2B, 2C
is formed by winding a high-strength cord made of organic fiber such as steel or aromatic polyamide, and connects the bead cores 2A, 2B, and 2C concentrically and radially outwardly with a first bead core 2A, Second bead core 2
B and the third bead core 2C are arranged in this order, with a gap between adjacent bead cores 2 and 2, respectively. Further, the bead cores 2A, 2B, and 2C are shaped more widely as they are located on the outer side in the radial direction. In addition, the carcass ply group G both passes from the tread portion 5 to the sidewall portion 4,
A first carcass sply group GA consisting of four carcass splices 11a located inside the tire that wrap around the inner diameter surface 9A of the l-th bead core 2A from the inside to the outside of the tire.
(shown by broken lines in Figures 1 and 3), a second carcass ply group GB (indicated by broken lines in Figs.
A third carcass ply group GC (indicated by solid lines in Figures 1 and 3) consists of four carcass plies llc.
(shown by dotted lines in FIGS. 1 and 3), and in this embodiment, two outer carcass bridles are provided on the outer surface side of the tire base 6, extending from the outer side of the first bead core 2A inward along the inner diameter surface 9A, An outer carcass ply group GD (shown by a dashed line in FIGS. 1 and 3) consisting of a lid is provided.

Further, each carcass brise lla... of the first carcass ply group GA passes through the bottom GA2 passing through the inner diameter surface 9A of the first bead core 2A, and passes through the outer surface of the first bead core 2A to the first bead core. A winding portion GA3 extending to the two-person outer diameter surface 12A is formed.

Also, each car force splice of the second carcass bly group GB
b.-- is extended to the bottom portion GB2 which passes through the inner diameter surface 9B of the second bead core 2B and sandwiches the winding portion GA3 of the first carcass ply group GA between it and the first bead core 2A. A winding portion GB3 is provided extending from the outer surface of the bead core 2B to the outer diameter surface thereof.

Further, each carcass ply llc of the third Kerr force splice group GC passes through the inner diameter surface 9c of the third bead core 2c in the same manner as the second carcass bly group GE and IaJ, and the winding of the second Kerr force splice group GB. A bottom portion GC2 that sandwiches the portion GB3 with the outer diameter surface 12B of the second bead core 2B, and a stretcher force splice that is connected to the bottom portion GC2 and extends along the outer surface and the outer diameter surface 12C of the third bead core 2c. Group GD
It is provided with a folded part GC3 which is folded inwardly and radially outwardly. Each of the Kerr force splices lla to lid includes polyvinyl alcohol fibers, polyvinylidene chloride fibers, polyvinyl chloride fibers, polyacrylonitrile fibers, polyethylene fibers, polyurethane fibers, cellulose fibers, cellulose ester fibers, Furthermore, organic fibers such as aromatic polyamide fibers can be used, especially nylon 6
Aliphatic polyamide fibers such as No. 6 can be suitably used.

Also, the first, second and third carcass ply groups OA, GB, G
In this embodiment, each carcass code of C is the tire equator C.
Tilt within a range of 20 to 50 degrees, preferably 30 to 45 degrees. Moreover, the cord angles of the carcass cords of the first to third carcass ply groups GA-GC arranged from the inside to the outside of the tire are sequentially decreased. For example, the cord angle of the first carcass ply group GA is
25 to 50 degrees, preferably 30 to 45 degrees, and for the second and third carcass ply groups GBSGC, 1 to 5 degrees, preferably 2 degrees, compared to the cord angle of the first carcass ply group GA. The code angle is sequentially reduced in angle steps of approximately 100 degrees. That is, when the cord angle of the first carcass ply group GA is 40 degrees as described above, the cord angle of the second inner carcass ply group GC is set to about 36 degrees. Moreover,
In each Kerr force spline 11a=11c in each carcass ply group GA-GC, each Kerr force squawd is arranged to cross each other.

By decreasing the cord angle from the inside to the outside in this manner, the stiffness of the ply increases from the inside to the outside and a desired predetermined inflated shape can be obtained. Therefore, the slope of the Kerr force code of the outer Kerr force spry group GD is set to be even smaller, for example, about 34 degrees.

Therefore, in the present application, (1) By arranging a plurality of bead cores 2 in the tire radial direction, the bead width WB can be greatly reduced without reducing tire rigidity. (2) Since the cross-sectional shape and cross-sectional area of each bead core 2A, 2B, and 2C can be set arbitrarily, a shape with less distortion caused by tire deformation can be freely selected, increasing the strength of the bead portion and improving durability and high-speed running performance. Improvements can be made easily. Incidentally, the ratio WBH/WB of the bead width WB of the bead portion 3 to the width WBH of the radially outer end portion of the bead portion 3 is 0. 5
Distortion is lowest in the range of ~0.8.

(3) Furthermore, the number of carcass plies can be significantly reduced, especially in the carcass ply group located on the inside, and together with the reduction in tire thickness, the tire weight can be reduced.

(4) The winding portions of each carcass bridle lla1lb of the first carcass sply group GA, second carcass sply group...
, can be sandwiched between the third bead cores 2B and 2C, so that peeling from the ends of the carcass bridle can be effectively prevented. (5) In addition, since the bead cores 2- are overlapped in the tire radial direction, the overlapping bead cores increase the bending ability of the bead part, making it possible to omit the bead apex for maintaining the rigidity of the bead part. By doing so, it is possible to further reduce the weight of the tire.

〔Effect of the invention〕

As mentioned above, the high-pressure bias tire of the present invention has a plurality of bead cores with different inner diameters for folding Kerr force splies on their inner diameter surfaces, so that the bead cores are rotated and stacked sequentially on the outside in the radial direction, so that the bead width can be increased. It can be made smaller, reducing distortion caused by tire deformation, improving high-speed performance and durability, and reducing weight.

[Brief explanation of the drawing]

The first picture is a right half sectional view of a tire showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an enlarged view of the bead portion, and FIG. 3 is a cross-sectional view showing a conventional technique. 2, 2A, 2B, 2C - bead core, 3... bead part, 4... sidewall part, 5... trend part, 9, 9A, 9B, 9C - inner diameter surface, 11, lla, llb, llc - carcass ply.

Claims (1)

[Claims] 1. A high-pressure bias tire in which the carcass ply extending from the tread part through the sidewall part to the bead part is folded back on the inner diameter surface of a plurality of bead cores, each having a different inner diameter, so that the bead cores are sequentially stacked concentrically and outward in the radial direction. .