| 摘要 |
PROBLEM TO BE SOLVED: To provide a diaphragm type fuel pump of a compact size having stable performance. SOLUTION: In a pump body 16, a recessed part 41 extending from the outside of the pump body 16 toward the inside in the direction right-angled to a diaphragm 22 is formed in a position contacting a fuel delivery chamber 34. Further a return passage 42 having one side communicating with a fuel intake chamber 32 and the other side communicating with the recessed part 41 is formed in the pump body 16. The inside of the recessed part 41 is provided with a pressure regulating mechanism 43, and the pressure regulating mechanism 43 is kept from dislocating from the inside of recessed part 41 by a cap 44. The pressure regulating mechanism 43 is disposed on the inside from the diameter D of a pump chamber 26. Thus, the pressure regulating mechanism which has been projected outward heretofore is not projected outward so as to be reduced to a compact size. A valve seat 46 is formed on the cap 44 formed separately from the pump body 16 to facilitate machining for the valve seat 46. |
