| 摘要 |
FIELD: tyre industry; bias tyres for wheels of trucks, buses, trailers and agricultural machines. SUBSTANCE: pneumatic tyre had tread 1, sides 3, breaker 3, layers of carcass 4, with cord threads arranged at angle of 40-65 degrees relative to meridional direction. For this purpose ends of narrow layers of carcass which do not reach level of 0.2 of tyre section height H are placed in points where load N on cord thread caused by inner pressure in remaining layers is equal to or differs from load on cord thread along equator by 10% maximum. Load is calculated by formula $$$ where P is pressure in tyre corresponding to maximum tolerable load, $$$; $$$ are radii of inflated tyre over middle layer of carcass and widest section, respectively, cm; $$$ is summary density of cord threads over equator, number of threads/cm; $$$ - is angle of cord threads in point of tyre section under consideration, degrees. Some ends of carcass narrow layers can be arranged in zones where load on cord thread caused by inner pressure is less than load on cord thread over equator by up to 30%. Ends of narrow layers of carcass in zone higher than widest point of section are arranged mainly in middle layers of carcass. EFFECT: improved performance characteristics of tyres, reduced materials usage and heating in service, increased flexibility of tyres. 1 dwg |
