| 摘要 |
There is provided a check valve which can reduce the operation noise of a positive-pressure valve and a negative-pressure valve when they slide and which can facilitate the assemblage work of the positive-pressure valve and the negative-pressure valve. The check valve 1 includes a main-casing 10, a sub-casing 20, a positive-pressure valve 30 and a negative-pressure valve 50. The positive-pressure valve 30 has through holes 39 and a negative-pressure valve seat 36a. The negative-pressure valve 50 has leg portions 53. A cap 60 is disposed within the positive-pressure valve 30. A positive-pressure spring S1 is disposed between the positive-pressure valve 30 and the sub-casing 20, and a negative-pressure spring S2 is disposed between the positive-pressure valve 30 and the cap 60. A positive-pressure flow path R1 for releasing fuel vapor is formed between an outer circumference of the positive-pressure valve and an inner circumference of the main-casing, at further outward position than the positive-pressure spring S1. A negative-pressure flow path R2 for introducing outside air is formed between an inner circumference of the positive-pressure valve and the leg portions and an outer circumference of the cap 60 and between the through holes and the leg portions, at further outward position than the negative-pressure spring S2.
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