JPH04320828A - Repairing method for pneumatic radial tire for aircraft and tire thereof - Google Patents

Abstract

PURPOSE:To maintain performance of a tire for a long period of time by removing a tread rubber in a damaged region as deep as the vicinity just above a belt to place repairing material thereon and fixing the tread rubber thereon. CONSTITUTION:At first, a tread rubber in the region containing a damaged belt is cut out as deep as the vicinity just above a belt 5 by means of a grinder, etc., and if there is a foreign matter in the damaged region of the belt 5, it is removed and, preferably, raw rubber is injected into said region, following which a repairing material 6 is placed all over the surface of the damaged region. And then a cut protector and tread rubber are put thereon and vulcanized and formed. By covering the damaged region of the belt 5 with the material 6 in this manner, even when excessive load is applied thereto, strain in said region of the belt 5 can be reduced, thereby effectively preventing separation therefrom.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic radial tire for aircraft, and is an object of the present invention to simply and reliably repair a damaged portion of a tread reinforcing belt of the tire.

0002

[Prior Art] In this type of tire, which is subject to excessive loads, when the reinforcing belt of the tread is cut or otherwise damaged, the entire length of the damaged belt is torn off, leaving a healthy portion. Previously, a method was used to retread a tire by attaching a new belt to the old tire, but with this method, the same procedure was followed even if the belt had only a small area of damage, which required a lot of time and effort to retread the tire. There was a disadvantage. For this reason,
Recently, in the case of localized damage that does not seriously affect tire performance, partial repairs have been carried out, such as cleaning the damaged area with unleaded gasoline and simply filling it with rubber. It was nothing more than

0003

[Problems to be Solved by the Invention] However, in the above-mentioned partial repair method, it is not possible to obtain sufficient strength in the repaired part, and the damaged part is damaged by repeated application of particularly large impacts during takeoff and landing. Because the rubber layer and cord separate at the starting point, the usable life of the tire is shorter than that of tires retreaded using conventional methods, and the current situation is that we have no choice but to rely on conventional methods. An object of the present invention is to provide a new repair method that can maintain the performance of the tire for a long period of time even if the repair is only a partial repair when repairing damage to the belt of a pneumatic radial tire for aircraft, and to provide a new repair method that can maintain the performance of the tire for a long period of time. This is where I try to suggest tires.

0004

[Means for Solving the Problems] The present invention provides a carcass consisting of a radially arranged rubber-coated organic fiber cord layer spanning a pair of bead cores in a toroidal shape, and To repair a belt in a pneumatic radial tire for aircraft, which is equipped with a tread reinforcing belt in which multiple layers of rubber-coated organic fiber cords are laminated and arranged in a cord arrangement that forms an angle of 0° to 30° with respect to the equator of the tire. In doing so, the tread rubber in the area including the damaged belt is first removed to the area directly above the belt, at least one repair material is placed in that area, and then the tread rubber is installed. A method of repairing a pneumatic radial aircraft tire, and the present invention also provides a carcass consisting of a radially arranged rubber-coated organic fiber cord layer spanning a pair of bead cores in a toroidal shape, 0°～30
In an aircraft pneumatic radial tire equipped with a belt in which a plurality of rubber-coated organic fiber cord layers are laminated in a cord arrangement forming an angle of A pneumatic radial tire for aircraft, characterized in that it includes at least one repair material that reduces shear strain between the belts caused by. In this invention, the above-mentioned repair material has a cord arrangement that is equal to or intersects with the cord arrangement of the belt directly below the repair material, and the cord angle of the belt with respect to the equator of the tire is α, (α+10°) to (α−2
A rubber-coated organic fiber cord layer with a cord angle of 0°) is advantageously suitable.

Now, FIG. 1 shows a cross section of an aircraft radial tire repaired according to the method according to the present invention. In the figure, number 1 is the tire body, 2 is the tread, 3 is the bead core, and 4 is the tire between the pair of bead cores 3. A carcass consisting of a radially arranged rubber-coated organic fiber cord layer spanning a toroidal shape, 5 a cord arrangement forming an angle of 0 to 30 degrees with respect to the tire equator on the outside of the carcass 4 in the tire radial direction. A belt consisting of multiple layers of rubber-coated organic fiber cord layers arranged in a laminated manner (in this example, there are 12 layers of 5a to 5L, of which 5e is shown as having a cord arrangement parallel to the tire equator), 6 is a damaged belt. The repair material 6 shown in the example is placed on the surface of a belt that has suffered C.This repair material 6 reduces the difference in rigidity between the damaged part and the healthy part, and also reduces damage such as cuts on the belt. This reduces the shear strain (see arrow in Figure 4) caused by Further, 7 is a cut protector. FIG. 2 shows the main parts of the belt in FIG. 1 above, and each belt 5a to
The 5l code shall take an angle as shown in the figure with respect to the tire's equator, with R pointing upward to the right and L pointing upward to the left.

As shown in FIGS. 3 and 4, in a cut C that extends Wmm in the width direction of the tread, tmm along the equator S of the tire, and reaches the belt 5h, in order to repair such a tire, the first step is to repair the damage. Using a grinder, etc., remove 5 liters of tread rubber from the area including the affected belt.
Next, if any foreign matter has entered the torn part of the belt 5, remove it, and more preferably inject raw rubber into the torn part, and then cover at least the entire cut C. A repair material 6 of the same size is placed on the surface thereof. Here, when injecting the raw rubber, the part may be cut away. Then, a cut protector and tread rubber are placed thereon and vulcanization molding is performed.

[0007]

[Function] In this invention, since the repair material 6 is arranged to cover the damaged part of the belt 5, in addition to the load supporting the aircraft body, there is no possibility that an excessive load will be applied during takeoff and landing. Even if the belt 5 is damaged, the strain in the damaged portion can be alleviated, and separation from that portion can be effectively suppressed.

[0008] In this invention, the repair material 6 is made of a rubber-coated organic fiber cord layer with a cord arrangement that is equal to or intersects with the cord arrangement of the belt immediately below it, but the angle of the cords is different from that of the repair material. Based on the belt 5l directly under the tire 6, approximately 20 degrees toward the tire's equator, orthogonal to it (tire's rotation axis)
It can be shifted as appropriate within a range of about 10°. By arranging the repair material 6 so as to satisfy the above range, it is possible to restore the stiffness of the belt 5 in the tire equator direction that has been reduced due to damage, and to alleviate the strain in the damaged portion of the belt 5.

[0009] In the present invention, when the belt is damaged over several belts, fewer belts are torn off than the number of damaged belts, and the repair material 6 is applied to that area, preferably with the cord arrangement intersecting above and below. Arrange multiple sheets in a stacked manner.

0010

[Example] Size 4 damaged as shown in Fig. 4 in the central region of the tread width along the circumference of the tire, 40 mm in the width direction of the tread, and reaching the depth of belt 5d.
Aircraft radial tire of 6×17R20 with the structure shown in Figure 1 above (belt cord material: nylon 66, cord type: 1890D/3, number of tires:
37 tires/5cm), and this tire has a width of 120
Repair material with a length of 120 mm and a thickness of 1.30 mm.
(Cord material: Nylon 66, Cord type: 1890D/
3.Number of nails: 37/5cm, cord angle: L16° to the tire's equator A comparative study was conducted. A comparative study of tire performance was conducted at a speed of 40 miles/h and a load of 25,000 kg.
One step was running for 8 minutes and stopping for 37 minutes under an internal pressure of 15.6 kg/cm2, and this step was repeated 50 times (target for completion) in a drum durability test. As a result, tires repaired in accordance with the present invention were able to withstand 50 repetitions of the test, while tires simply injected with raw rubber showed separation at the damaged area after 5 repetitions.

[0011]

Thus, according to the present invention, the performance of the tire can be maintained for a long period of time even when damage to the belt portion of an aircraft pneumatic tire used under severe conditions is locally repaired.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a pneumatic aircraft tire.

FIG. 2 is a diagram showing a belt structure.

FIG. 3 is a diagram showing the state of damage to a tire.

FIG. 4 is a diagram showing a cross section of the belt.

[Explanation of symbols]

1 Tire body 2 Tread 3 Bead core 4 Carcass 5 Belt 6 Repair material This specification has been compiled based on the original draft received, but where information is considered to be missing, leave it blank and fill in the details. I am planning to receive it. Also, if there are any other points that you think should be included in the statement, please add them as well.

Claims (3)

[Claims] Claim 1: A carcass consisting of a radially arranged rubber-coated organic fiber cord layer spanning between a pair of bead cores in a toroidal shape, and a radially outer side of the carcass that is 0 with respect to the equator of the tire. When repairing damage to the belt of an aircraft pneumatic radial tire equipped with a tread reinforcing belt made of multiple layers of rubber-coated organic fiber cords arranged in a cord arrangement forming an angle of 30° to 30°, the first step is to repair the damage. A pneumatic radial tire for an aircraft, characterized in that the tread rubber in the area including the received belt is removed to the area directly above the belt, at least one repair material is placed in that area, and then the tread rubber is installed. How to repair. 2. A carcass consisting of a radially arranged rubber-coated organic fiber cord layer spanning between a pair of bead cores in a toroidal shape, and a carcass that extends from 0° to 3° with respect to the equator of the tire.
In a pneumatic radial tire for aircraft equipped with a belt in which a plurality of rubber-coated organic fiber cord layers are stacked and arranged in a cord arrangement forming an angle of 0°, the surface of the damaged belt is A pneumatic radial tire for aircraft, comprising at least one repair material that reduces shear strain between the belts. 3. The repair material has a cord arrangement that is parallel to or intersects with the cord arrangement of the belt immediately below the repair material, and the cord angle of the belt with respect to the equator of the tire is set to α.
The tire according to claim 2, comprising a rubber-coated organic fiber cord layer having a cord angle of (α+10°) to (α−20°).