JP2003237310A - Bias tire for aircraft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bias tire for aircraft which can suppress generation of peel-off failures and improve the durability. <P>SOLUTION: In the bias tire for aircraft, two or more tread reinforcing cloths having an organic fiber cord in a tread part is disposed so that the organic fiber cords are intersected with each other between layers so as to form a cord angle of 20 to 45° to the circumferential direction of the tire, and the distance between the organic fiber cords adjacent to the tread reinforcing cloths 2 is 2.0 to 3.0 times the cord diameter. By setting the distance between the organic fiber cords adjacent to each other to be a large value, the adhesion (the peeling resistance) between the tread and the tread reinforcing cloth is increased, any peel-off failure is effectively suppressed, and the durability of the bias tire for aircraft can be improved. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aircraft bias tire, and more particularly, to an aircraft bias tire which suppresses occurrence of a peel-off failure and has improved durability. . 2. Description of the Related Art In recent airports, in order to shorten the braking distance of an aircraft, a runway having a large number of grooves on a runway in a direction perpendicular to a traveling direction is increasing. When an aircraft lands on a grooved runway, the tire surface is caught in the runway groove, and it is easy for the tire tread surface to be traumatized.Subsequent centrifugal force during takeoff high-speed running causes the tread to start from the traumatic portion. In many cases, a failure (peel-off failure) in which the metal is peeled and partially scattered occurs. In particular, in the case of a bias tire for a high performance aircraft, as shown in FIG. 1, a half cross section in the meridian direction, two or more tread reinforcing cloths 2 are arranged inside a tread 1, and a peel-off failure is caused. As shown in the enlarged cross-sectional view of the faulty state in FIG.
And between the tread reinforcing cloths 2. Therefore, an attempt has been made to improve the durability of the tire by increasing the adhesive strength between the organic fiber cord 4 of the tread reinforcing cloth 2 and the rubber, but the effect has not been sufficient. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an aircraft bias tire which suppresses the occurrence of a peel-off failure and has improved durability. According to the present invention, two or more tread reinforcing cloths having an organic fiber cord in a tread portion are formed so as to have a cord angle of 20 to 45 ° with respect to the tire circumferential direction. A bias tire for aircraft, wherein the organic fiber cords are arranged so as to cross each other between layers, and a distance between adjacent organic fiber cords of the tread reinforcing cloth is 2.0 to 3.0 times a cord diameter. Is provided. As described above, the structure in which the distance between the adjacent organic fiber cords is increased to increase the adhesive force (peeling resistance) between the tread and the tread reinforcing cloth, thereby effectively preventing the peel-off failure. And the durability of the bias tire for aircraft can be improved. Hereinafter, the structure of the present invention will be described in detail with reference to the drawings. FIG. 1 is a half sectional view in the meridian direction showing an example of an aircraft bias tire of the present invention. The tread reinforcing cloth 2 is a reinforcing layer in which an organic fiber cord 4 (hereinafter, also simply referred to as “cord”) provided on a tread portion is covered with rubber, and two or more tread reinforcing cloths are arranged inside the tread 1 outside the carcass 3. ing. Organic fiber cord 4
Are set so as to have a cord angle of 20 to 45 ° with respect to the tire circumferential direction, and are arranged so as to cross each other between the layers of the tread reinforcing cloth 2. This cord angle is 20-4
If the angle is not 5 °, the reinforcing effect of the tread reinforcing cloth 2 is lost, and the durability of the tire is deteriorated. FIG. 2 is an enlarged cross-sectional view for explaining the state of failure. As shown in FIG. The interface peeling phenomenon between the cord 4 of the tread reinforcing cloth 2 and the rubber 2a on the upper surface thereof and the adjacent cord 4
The tearing of the rubber portion 2b therebetween occurs simultaneously. Therefore,
In order to prevent the peel-off failure, the adhesive force between the tread reinforcing cloth 2 and the tread 1 so that the tread 1 does not peel off due to an external force (torque) applied to the wound portion 5 at the time of landing, and the tread 1 does not scatter due to centrifugal force during tire running. It is important to enhance (peeling resistance). That is, there is a relationship of (tread adhesive strength) = (adhesive strength between rubber and cord surface 2a) + (tearing force of rubber portion 2b between adjacent cords). In order to improve the tearing force of the rubber portion 2b, the distance L between the adjacent organic fiber cords 4 of the tread reinforcing cloth 2 has been set to be 2.0 to 3.0 times the cord diameter. As described above, by increasing the distance L between the adjacent organic fiber cords 4 as compared with the related art, the tearing force of the rubber portion 2b between the adjacent cords is improved, and the peel-off failure is effectively prevented. It can be greatly improved. For example, the distance L between the adjacent organic fiber cords 4 may be increased by reducing the number of the cords 4 of the tread reinforcing cloth 2 to be driven. This value is 2.0
If it is less than twice, the effect of the present invention will not be exhibited, and if it exceeds 3.0 times, the reinforcing effect of the tread reinforcing cloth 2 will not be exhibited, and the durability of the tire will be reduced. In FIG. 2, the distance L between the cords 4 shown for convenience is the distance between the cords 4 in a direction perpendicular to the longitudinal direction of the cords. The present invention will be further described below with reference to examples, but the scope of the present invention is not limited to these examples. An aircraft bias tire having a tire size of 49 × 1730PR having two tread reinforcing cloths 2 as shown in FIG. 1 was produced. For the tread reinforcing cloth 2, nylon 66 cord is used, the cord angle with respect to the tire circumferential direction is set to 35 °, the number of cord 4 ends, cord diameter,
The values of the distance L between adjacent cords and the (inter-cord distance / cord diameter) are as shown in Table 1. Each of the obtained tires was subjected to the following tests. Endurance test Using a scalpel, apply a length of 80 to the crown center of the tire.
mm (approximately 80% of the rib width) and a depth of 17 mm (reaching the tread reinforcing cloth layer) with a wound in the tire width direction,
A landing test in which the air pressure was set to 1.34 MPa and a drum testing machine rotating at a speed of 290 km / h landed with a load of 213.6 kN was repeated five times. With respect to the tires subjected to this test, a takeoff test in which the tires were brought into contact with a drum test machine under a load of 213.6 kN, the speed was increased to 335 km / h, and then the tires were taken off was repeated 15 times. With respect to this tire, the state of occurrence of a peel-off failure and the state of peeling of a damaged portion were observed. High-speed take-off test Using a scalpel, a length of 80
mm (approximately 80% of the rib width) and a depth of 17 mm (reaching the tread reinforcing cloth layer) with a wound in the tire width direction,
Air pressure is set to 1.34MPa, speed is 362km / h,
A take-off test was conducted in which the tire was taken off from a state in which the tire was rotated on a drum test machine under a load of 213.6 kN.
Repeated 0 times. With respect to this tire, the presence or absence of occurrence of a tread failure was observed. [0013] Adhesion test (N / 25mm)
A tangled test piece (25 m
m width), and a peeling test was performed in accordance with JIS K6256 to measure the adhesive force between the tread and the tread reinforcing cloth. [Table 1] As shown in Table 1 above, the tire of the embodiment in which the distance between the adjacent organic fiber cords of the tread reinforcing cloth is set to 2.0 to 3.0 times the cord diameter, has a tread and tread reinforcement. Excellent results were obtained in which the adhesive force between the cloths was improved and the occurrence of peel-off failure was effectively suppressed. According to the present invention, for an aircraft bias tire, two or more tread reinforcing cloths each having an organic fiber cord in a tread portion are attached to the bias tire for 20 to 4 in the tire circumferential direction.
The organic fiber cords are arranged so as to intersect with each other between the layers so as to have a cord angle of 5 °, and the distance between the adjacent organic fiber cords of the tread reinforcing cloth is set to 2.0 to 3. By setting the value to 0, it is possible to suppress the occurrence of peel-off failure and obtain an aircraft bias tire with improved durability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a meridional half sectional view of an aircraft bias tire. FIG. 2 is an enlarged cross-sectional view illustrating a failure state of the aircraft bias tire. [Description of Signs] 1 Tread 2 Tread reinforcing cloth 3 Carcass 4 Cord 5 Damaged part 2a Between cord rubbers 2b Rubber part between adjacent cords L Distance between cords

Claims (1)

Claims: 1. An organic fiber cord having an organic fiber cord in a tread portion.
More than one tread reinforcing cloth, 20 to
The organic fiber cords are arranged so as to intersect with each other between the layers so as to have a cord angle of 45 °, and the distance between the organic fiber cords adjacent to the tread reinforcing cloth is 2.0 to 3. Aircraft bias tire that is 0x.