| 摘要 |
PURPOSE:To prevent the vapor lock of a fuel pump by forming an increased flow-passage part where the sectional area of a flow passage is large onto the suction-port side of a pump flow-passage and forming a vapor discharge port on the reverse side of the suction port. CONSTITUTION:A pump flow-passage 46 has a ring form which leads from a suction port 1 to a discharge port, and the sectional area of the flow passage on the side close to the suction port 1, namely the sectional area of the flow passage on the relatively low-pressure side is increased, and an increased flow- passage part 46a is formed into circular form. A stepped part 46b is formed at the position where the sectional area of the flow passage is sharply reduced. Close to the stepped part 46b, a vapor flow-out port 6 is formed close to the inner peripheral side of the flow passage, namely to the inside of an impeller 32. Since said vapor discharge port 6 communicates to the inside of the flow passage 46 and the inside of a gasoline tank as the pump outside, vapor lock of a fuel pump can be prevented.
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