| 摘要 |
Mass-produced fuel pumps having a stable pump efficiency comprising a circumferential groove 20 is formed within a pump body 15 and the groove 20 is divided into a first region having a constant cross-sectional area L, a second region having a cross sectional area that gradually becomes smaller toward the downstream side, and a third region having a constant cross-sectional area M. A suction hole 22 is formed within the pump body 15 and is inclined toward the rotational direction of the impeller. The suction hole 22 is communicated with the groove 20 in the first region. Even if the inclination angle of the suction hole 22 varies among mass-produced fuel pumps, the cross-sectional area L of the groove 20 is constant at the location where the suction hole 22 is communicated with the groove 20 . Therefore, variations in the amount of fuel sucked into the fuel pump can be reduced. Accordingly, pump efficiency of the mass-produced fuel pumps can be stabilized.
|
