| 摘要 |
PROBLEM TO BE SOLVED: To provide a pumping tube capable of preventing fracture of rubber between an outer surface side reinforcement cord layer and an inner surface side reinforcement cord layer and preventing fatigue of reinforcement cord. SOLUTION: The reinforcement cord 8 is arranged by providing the outer surface side reinforcement code layer 6 and an inner surface side reinforcement cord layer 7 between an outer surface rubber 4 and an inner surface rubber 5. Cord interval a1 of the outer surface side reinforcement cord layer 6 is set smaller than cord interval a2 of the inner surface side reinforcement cord layer 7. Total cross section area of the reinforcement cord 8 arranged in a unit width of the outer surface side reinforcement code layer 6 gets larger than that of the inner surface side reinforcement code 7. Elongation of the reinforcement cord 8 in the outer surface side reinforcement cord layer 6 in which tension per unit width gets roughly equal to elongation in the inner surface side reinforcement layer 7. Fracture of rubber 9 between both layers can be prevented by preventing twist of the pumping tube 1. COPYRIGHT: (C)2007,JPO&INPIT |
