JP2010116111A - Retreaded aircraft tire and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the durability of a retreaded tire by suppressing the separation of a reproduced tread from the adhesive face and the heating of a shoulder portion 16. <P>SOLUTION: Values P1/R1, P2/R2 obtained by dividing remaining rubber gages P1, P2 on perpendicular lines L1, L2 perpendicular to a carcass layer 18 through contact ends S1, S2 during applying 120%, 150% of a standard load by distances R1, R2 from a reproduced face 35 to the inner face of a base tire 34 are within a range of 0.20-0.35. Thus, the reproduced tread is pushed against a reproduced face 35 of the base tire 34 with sufficient thrust by a vulcanizing mold to actualize sufficient adhesion between the base tire 34 and the reproduced tread 24. Besides, a used tread 30 is sufficiently removed to suppress the heating of the shoulder portion 16. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

    The present invention relates to an aircraft retread tire using a base tire from which a protective layer and a tread are removed, and a method for manufacturing the same.

As a conventional aircraft retread tire and its manufacturing method, for example, those described in Patent Document 1 below are known.
JP 2008-024135 A

  In this case, the protective layer and the tread are removed from the used aircraft tire by a grinder called a rasp (buffing) so that a resurfacing surface is provided at the radially outer end, and at least the carcass layer is disposed inside. After forming the base tire, a rehabilitation tread composed of a rehabilitation protective layer and unvulcanized rubber is applied to the rehabilitation surface of the base tire, and then vulcanized to produce an aircraft rehabilitation tire.

  Here, the protective layer and the tread removal operation described above are performed using the protective layer as a guide at the central portion of the tread where the protective layer is disposed, so that the remaining rubber gauge can be easily accommodated within a desired range. However, since there is no guide for the shoulder portions located on both outer sides in the axial direction of the protective layer, it was performed based on the experience and intuition of the operator.

  As a result, if the residual rubber gauge at the shoulder portion is too thick, the weight of the retreaded tire will increase, thereby increasing the amount of heat generated at the shoulder portion and deteriorating the durability, while the residual rubber gauge at the shoulder portion is reduced. If it is too thin, the pressing force that presses the retreaded tread of the shoulder against the pedestal tire by the vulcanization mold during vulcanization will be insufficient, and this will reduce the adhesive force between the retreaded tread and the pedestal tire. There exists a subject that it becomes easy to peel.

  In particular, in recent years, with the increase in size of aircraft, tires have been required to have more load-bearing capability. Also, retreaded aircraft tires are used for high loads (at 120% standard load or 150% load) for safety reasons. Although the conventional device does not cause a fatal failure, it has not been sufficient in actual use even though it is required to exhibit a predetermined performance.

  An object of the present invention is to provide an aircraft retread tire and a method for manufacturing the same that can effectively suppress peeling from an adhesive surface and heat generation at a shoulder portion under high load.

    Such a purpose is firstly a base tire formed by removing a protective layer and a tread from a used aircraft tire, having a rehabilitation surface at a radially outer end, and at least a carcass layer disposed therein. Aircraft rehabilitation tire with rehabilitation protection layer and rehabilitation tread affixed to the rehabilitation surface of the base tire, 120% load and 150% load of standard load when mounted on regular rim and filled with standard internal pressure When the tire is loaded, the tire ground contact ends are S1, S2, the ground contact ends S1, S2 are perpendicular to the carcass layer L1, L2, and the remaining rubber gauges on the perpendicular L1, L2 are P1, P2, and the perpendicular L1, respectively. When the distance from the rehabilitated surface on the L2 to the inner surface of the base tire is R1 and R2, respectively, the residual rubber gauges P1 and P2 divided by the distances R1 and R2, respectively, P1 / R1 and P2 / R2 are both 0.20 to 0.35 In the range By the retread tires for aircraft, it can be achieved,

  Second, by removing the protective layer and the tread from the used aircraft tire, a step of forming a base tire having a rehabilitated surface at the radially outer end and at least a carcass layer disposed therein, In a method for manufacturing retreaded aircraft tires, which includes a process for attaching a retreading protective layer and a retreading tread to the retreaded surface of the tire, 120% load and 150% load of the standard load with a standard rim mounted and filled with standard internal pressure When the tire is loaded, the tire ground contact ends are S1, S2, the ground contact ends S1, S2 are perpendicular to the carcass layer L1, L2, and the remaining rubber gauges on the perpendicular L1, L2 are P1, P2, and the perpendicular L1, respectively. When the distance from the reclaimed surface on the L2 to the inner surface of the base tire is R1 and R2, respectively, the values obtained by dividing the residual rubber gauges P1 and P2 by the distances R1 and R2, respectively P1 / R1 and P2 / R2 are both 0.20 to 0.35 Within the range of The method of manufacturing so that the aircraft retread tire removing the tread can be achieved.

  In the present invention, when the tire is mounted on a regular rim and filled with the standard internal pressure, the tire ground contact ends when the standard load 120% load and 150% load are applied are S1 and S2, respectively. , L1, L2 perpendicular to the carcass layer through S2, L1, L2, the remaining rubber gauge on the perpendicular L1, L2, respectively, the distance from the rehabilitation surface on the perpendicular L1, L2 to the inner surface of the base tire R1, R2, respectively The tread is removed from the used aircraft tires so that the values P1 / R1 and P2 / R2 of the remaining rubber gauges P1 and P2 divided by the distances R1 and R2, respectively, exceed 0.20. .

  Since the residual rubber gauges P1 and P2 are made thicker in this way, when a retreaded tire is manufactured by applying a retreading protective layer and a retreading tread to the retreaded surface and vulcanizing it, the shoulder retreaded tread is added to the retreaded surface of the base tire. It is pressed with a sufficient pressing force by the sulfur mold, and the adhesion between the base tire and the retread tread can be made sufficient. As a result, even if the retreaded tire is run under a heavy load (120% load or 150% load of the standard load), the retreaded tread can be effectively prevented from peeling off from the adhesive surface. Can do.

  Further, if both the values P1 / R1 and P2 / R2 are less than 0.35, the used tread in the shoulder portion can be sufficiently removed, and an increase in the weight of the manufactured retread tire can be suppressed. Thereby, the emitted-heat amount in a shoulder part reduces and durability can be improved. As described above, when both the values P1 / R1 and P2 / R2 are within the range of 0.20 to 0.35, it is possible to effectively suppress the peeling of the tread from the adhesive surface and the heat generation at the shoulder portion under high load. As a result, the retreaded aircraft tire has improved durability and can exhibit predetermined performance even at high loads.

  Moreover, if comprised as described in Claim 2, the peeling from the adhesion surface of the tread at the time of high load and the heat_generation | fever in a shoulder part can be suppressed strongly. Further, as described in claims 3 and 4, the present invention can be suitably applied to both aircraft radial tires and bias tires.

  Here, the tire ground contact edge when 120% load or 150% load is applied is TRA (Year Book of The Tire and Rim Association Inc.) or ETRTO (Year Book of The European Tire and Rim Technical Organization). The tire is mounted on a regular rim (standard rim) to which the standard is applied, and the air pressure (standard internal pressure) corresponding to the maximum load (standard load) of the single wheel in the applicable size described in the standard is filled as the internal pressure. , The outermost tire in the axial direction (width direction) when 120% load and 150% load of the standard load (standard load is assumed to be 100% load) of a single wheel in the applicable size described in the same standard This is the ground point.

Embodiment 1 of the present invention will be described below with reference to the drawings.
In FIGS. 1 and 2, reference numeral 11 denotes a rehabilitation radial tire for an aircraft, and the rehabilitation tire 11 has a pair of bead portions 13 each having a pair of bead cores 12 embedded therein, and is substantially radially outward from the bead portions 13. Side wall portions 14 extend toward the front. Reference numeral 15 denotes a tread portion having a substantially cylindrical shape, and a pair of shoulder portions 16 are located between both axial ends of the tread portion 15 and radially outer ends of the sidewall portions 14.

  The retread tire 11 has a carcass layer 18 extending in a toroidal shape between the pair of bead cores 12 to reinforce the sidewall portion 14 and the tread portion 15. The carcass layer 18 has a radial direction (meridian direction) inside. ) And one or more, in this case, five carcass plies 19 in which a large number of carcass cords made of organic fibers are embedded.

  Of these carcass plies 19, the inner three have a turn-up ply structure in which both ends in the width direction are wound around the bead core 12 from the inner side to the outer side, and the outer two sheets are in the width direction. Both ends have a downply structure in which the periphery of the bead core 12 is wound back from the outside to the inside. In the present invention, all the carcass plies described above may have a turn-up ply structure. Here, an inner liner 22 made of air-impermeable rubber is disposed inside the carcass layer 18 located between the bead cores 12.

  A belt layer 23 for reinforcing the tread portion 15 is disposed outside the carcass layer 18 in the radial direction, and the belt layer 23 is configured by laminating a plurality of belt plies in which belt cords are embedded. . The belt cord is composed of an organic fiber cord that is inclined at a predetermined angle with respect to the tire equator E or extends substantially parallel to the tire equator E. A retread tread 24 is disposed on the outer side in the radial direction of the belt layer 23, and a plurality of main grooves 26 extending substantially parallel to the tire equator E are formed on the outer surface of the retread tread 24.

  Between the belt layer 23 and the retread tread 24, a retread protection layer 25 that is slightly narrower than the belt layer 23 is disposed in the center of the tread, and the retread protection layer 25 is substantially parallel to the tire equator E inside. Or a reinforcing cord that is inclined at a predetermined angle with respect to the tire equator E, and is composed of at least one protective ply in this case.

  Here, when the reinforcement cord is inclined with respect to the tire equator E, the inclination direction of the reinforcement cord is preferably opposite to each other between adjacent protective plies. And as an above-mentioned reinforcement cord, organic fiber cords, such as aromatic polyamide and nylon, can be used, for example. The rehabilitation protection layer 25 covers the belt layer 23 from the outside in the radial direction to protect the belt layer 23 from being cut.

  Next, the aircraft retread tire 11 as described above is manufactured, for example, as described below. That is, by using the aircraft tire for a long time, when the main groove 31 formed in the tread 30 becomes the used aircraft tire 29 that has disappeared to near the allowable limit due to wear, the used aircraft tire 29 is converted into a buff machine. After mounting, the tread 30 and the protective layer 32 (shown by a two-dot chain line in FIG. 2) are removed (buffed) by a grinder called rasp. As a result, a base tire 34 having at least a carcass layer 18 inside thereof, here a radial tire and also having a belt layer 23 is formed. The reclaimed surface 35 of vulcanized rubber (tread or cushion rubber) is exposed.

  At this time, in the shoulder portion 16 of the used aircraft tire 29, the remaining rubber gauges P1 and P2 on the vertical lines L1 and L2, the distance R1 from the rehabilitation surface 35 on the vertical lines L1 and L2 to the inner surface of the base tire 34, The base tire 34 is formed by removing the tread 30 so that the values P1 / R1 and P2 / R2 respectively divided by R2 are within the range of 0.20 to 0.35.

  Here, perpendicular lines L1 and L2 are the width of the tire when a new tire is mounted on a regular rim and filled with standard internal pressure, when 120% of the standard load and 150% of the load are applied perpendicular to the rotation axis. When the direction outermost grounding ends are S1 and S2, respectively, it is a perpendicular to the carcass layer 18 passing through these grounding ends S1 and S2, and the remaining rubber gauges P1 and P2 on the perpendiculars L1 and L2 are the perpendiculars It is the distance from the intersection M1, M2 of L1, L2 and the rehabilitation surface 35 to the intersection N1, N2 of the perpendicular line L1, L2 and the radially outer surface of the belt layer 23, and further, the distances R1, R2 are: The distances from the intersections M1 and M2 to the intersections Q1 and Q2 between the perpendicular lines L1 and L2 and the inner surface of the base tire 34.

  Then, as described above, the tread 30 is removed from the used aircraft tire 29 so that the values P1 / R1 and P2 / R2 obtained by dividing the remaining rubber gauges P1 and P2 by the distances R1 and R2, respectively, exceed 0.20. If this is done, the remaining rubber gauges P1 and P2 will become thicker. Therefore, when the retread tire 11 is manufactured by applying the retreading protective layer 25 and the retreading tread 24 to the retreading surface 35 and performing vulcanization, the retreading tread 24 of the shoulder portion 16 is The retreading surface 35 of the tire 34 is pressed with a sufficient pressing force by the vulcanization mold, and the adhesion between the base tire 34 and the retreading tread 24 can be made sufficient.

  As a result, even if the retreaded tire 11 is run under a high load of 120% or 150% of the standard load, the retreaded tread 24 may be peeled off from the adhesive surface (revitalized surface 35). It can be effectively suppressed. Moreover, if both the values P1 / R1 and P2 / R2 are less than 0.35, the used tread 30 in the shoulder portion 16 can be sufficiently removed, and an increase in the weight of the manufactured retread tire 11 can be suppressed. As a result, the amount of heat generated at the shoulder portion 16 is reduced, and the durability can be improved.

  As described above, when both the values P1 / R1 and P2 / R2 are within the range of 0.20 to 0.35, peeling from the adhesive surface of the regenerated tread 24 and heat generation at the shoulder portion 16 at high load are effectively performed. As a result, the retread tire 11 has improved durability, and can exhibit predetermined performance even at the time of high load as described above. Furthermore, if the value P1 / R1 is in the range of 0.20 to 0.23, while the value P2 / R2 is in the range of 0.23 to 0.25, as will be apparent from the test results described later, the rehabilitation tread 24 at the time of high load. Peeling from the adhesion surface and heat generation at the shoulder portion 16 can be strongly suppressed, which is preferable.

  Here, the residual rubber gauges P1 and P2 and the distances R1 and R2 described above can be obtained by cutting a cut sample from an unused retread tire 11 and measuring the cut sample. Then, based on the values of the residual rubber gauges P1 and P2 obtained in this way, the distance from the tire surface toward the belt layer 23 with a needle or the like is measured, or the target buff shape (rehabilitation surface 35) The base tire 34 having the target remaining gauges P1 and P2 can be easily formed by creating a ruler that is complementary to the outer surface shape) and buffing the ruler in contact with the tire surface. Can do.

  Next, after applying the rehabilitation protection layer 25 to the rehabilitation surface 35 of the base tire 34 formed as described above, the unvulcanized rubber ribbon is wound around the base tire 34 and the rehabilitation protection layer 25 in a spiral manner many times. The retreaded tread 24 having a predetermined cross-sectional shape is formed by pasting, and then the retreaded tread 24 for aircraft is manufactured by vulcanizing the retreaded tread 24 using a vulcanization mold.

    In the above-described embodiment, the retread tire 11 is a radial tire. However, the present invention can also be applied to an aircraft bias tire having no belt layer. In this case, the remaining rubber gauges P1 and P2 are the distances from the intersections M1 and M2 of the perpendicular lines L1 and L2 to the rehabilitation surface 35 to the intersections of the perpendicular lines L1 and L2 and the radially outer surface of the carcass layer 18 (outermost carcass ply). It becomes.

  In the above-described embodiment, the retread tread 24 is made of unvulcanized rubber. However, in the present invention, a precure tread that has been vulcanized in advance may be used as the retread tread. Furthermore, in this invention, the retreaded tread may be molded by winding an unvulcanized rubber sheet having a predetermined cross-sectional shape around the base tire and the retreading protective layer in the radial direction and joining the starting and terminal ends thereof. Moreover, the above-mentioned used aircraft tire may be a retread tire that has already been retreaded once or more.

    Next, test examples will be described. In this test, P1, P2, R1, R2, P1 / R1, and P2 / R2 were prepared as conventional tires, comparative tires, and implementation tires 1 to 4, respectively, having the values shown in Table 1 below. Here, each of these tires is a radial tire having a structure shown in FIG. 1 in which a belt layer, a protective layer, and a tread are arranged outside the carcass layer in which the carcass cord embedded therein extends in the radial direction. The size was 52 × 21.0R22 36PR.

Next, after each tire was mounted on a regular rim and filled with a standard internal pressure of 1565 kPa (227 psi), it was 1.57 m / s on the indoor drum while applying a 100% load (standard load) of 295.8 kN (66500 LBS). The acceleration was linearly accelerated from zero speed to a maximum speed of 378.2 km / h at an acceleration of ² , and the first take-off test was performed for 50 cycles as the first take-off test of one cycle until reaching the maximum speed. Next, each tire that has been subjected to the first take-off test is loaded with 295.8kN (66500LBS), which is a 100% load, at a speed of 64km / h on the indoor drum with the standard internal pressure maintained. The first taxing test for 10 minutes was performed for 10 cycles.

Next, each tire for which the above-mentioned first taxing test has been completed is loaded with 355.0 kN (79800LBS), which is 120% load, at a speed of 64 km / h on the indoor drum while maintaining the above-mentioned standard internal pressure. Two cycles of the second taxing test, running for 10 minutes, were performed. Next, each tire for which the above-mentioned second taxing test has been completed is loaded with 443.7 kN (99750LBS), which is a 150% load, with 1.57 m / s ² on the indoor drum while maintaining the above-mentioned standard internal pressure. The acceleration was linearly accelerated from zero speed to a maximum speed of 378.2 km / h, and this second take-off test was performed for one cycle, with the time until this maximum speed was reached as a second take-off test of one cycle.

  Thereafter, each tire was removed from the durability tester, and the failure state in the shoulder portion was examined. The results are shown in Table 1 with the conventional tire as an index of 100, and it was proved that all the tires had fewer failures (larger values) and better tire durability than the conventional tire and the comparative tire. .

  The present invention can be applied to the industrial field of aircraft retread tires using a base tire from which a protective layer and a tread have been removed.

It is meridian sectional drawing of the retreaded tire which shows Embodiment 1 of this invention. It is meridian sectional drawing which shows the shoulder part vicinity of a base tire.

Explanation of symbols

11 ... Rehabilitation tire for aircraft 18 ... Carcass layer
24 ... Rehabilitation tread 25 ... Rehabilitation protection layer
29… Used aircraft tires 30… Tread
32… Protective layer 34… Tire
35 ... Rehabilitation

Claims (5)

    A tire is formed by removing a protective layer and a tread from a used aircraft tire, has a retreading surface at the radially outer end, and at least a carcass layer is disposed inside, and is attached to the retreading surface of the tyre tire. Rehabilitation tires for aircraft equipped with a rehabilitation protection layer and a rehabilitation tread that are attached to the regular rim and filled with standard internal pressure. S1, S2, L1 and L2 perpendicular to the carcass layer passing through the grounding ends S1 and S2, and the remaining rubber gauges on the perpendiculars L1 and L2 from P1, P2 and the rehabilitation surface on the perpendiculars L1 and L2, respectively, to the inner surface of the base tire When the distances up to R1 and R2 are R1 and R2, respectively, the values P1 / R1 and P2 / R2 obtained by dividing the residual rubber gauges P1 and P2 by the distances R1 and R2, respectively, are in the range of 0.20 to 0.35. Aviation Use retreaded tires.     The retreaded aircraft tire according to claim 1, wherein the value P1 / R1 is in the range of 0.20 to 0.23 and P2 / R2 is in the range of 0.23 to 0.25.     The rehabilitated tire for aircraft according to claim 1, wherein when the aircraft tire is a radial tire, the remaining rubber gauges P1, P2 are distances from the rehabilitated surface to the outer surface of the belt layer.     2. The aircraft retread tire according to claim 1, wherein when the aircraft tire is a bias tire, the remaining rubber gauges P <b> 1 and P <b> 2 are distances from the retread surface to the outer surface of the carcass layer.     Removing a protective layer and a tread from a used aircraft tire to form a pedestal tire having a retread surface at the radially outer end and at least a carcass layer disposed therein; and a retread surface of the pedestal tire In a method for manufacturing retreaded aircraft tires, which includes a process for applying a retread protection layer and a retread tread to the rim, when 120% load and 150% load are applied to the standard rim and filled with standard internal pressure The tire ground contact ends pass through the ground contact ends S1 and S2, the normal lines to the carcass layer are L1 and L2, and the remaining rubber gauges on the normal lines L1 and L2 are regenerated on the normal lines P1 and P2 and the normal lines L1 and L2, respectively. When the distance from the surface to the inner surface of the base tire is R1 and R2, respectively, the values P1 / R1 and P2 / R2 obtained by dividing the remaining rubber gauges P1 and P2 by the distances R1 and R2, respectively, are within the range of 0.20 to 0.35. To be Method for producing an aircraft for retread tire characterized by removing the serial tread.

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