Abstract: A solenoid valve includes a movable core, a magnetic opposed portion opposed to the movable core, a nonmagnetic cylindrical portion, a first magnetic cylindrical portion axially close to the movable core, and a second magnetic cylindrical portion located radially outside of the magnetic opposed portion. The nonmagnetic cylindrical portion surrounds radially outside of a gap between the magnetic opposed portion and the movable core. A coil is provided radially outside of the nonmagnetic cylindrical portion. A thickness t of the nonmagnetic cylindrical portion, a cross-sectional area S1 of the magnetic opposed portion, and a total cross-sectional area S2 of both the magnetic opposed portion and the second magnetic cylindrical portion having the thickness t satisfy the relationships of t?0.6 mm and 0.55?(S1/S2).

Abstract: A solenoid valve includes a movable core, a magnetic opposed portion opposed to the movable core, a nonmagnetic cylindrical portion, a first magnetic cylindrical portion axially close to the movable core, and a second magnetic cylindrical portion located radially outside of the magnetic opposed portion. The nonmagnetic cylindrical portion surrounds radially outside of a gap between the magnetic opposed portion and the movable core. A coil is provided radially outside of the nonmagnetic cylindrical portion. A thickness t of the nonmagnetic cylindrical portion, a cross-sectional area S1 of the magnetic opposed portion, and a total cross-sectional area S2 of both the magnetic opposed portion and the second magnetic cylindrical portion having the thickness t satisfy the relationships of t?0.6 mm and 0.55?(S1/S2).

Abstract: A fuel pump mounted in the fuel tank for the motor cycle comprises a motor and a pump driven by the motor for increasing a pressure of the sucked fuel. The motor is a brushless motor and has a stator core, coils and a rotor. An electrical energization for the coils wound around the stator core is controlled in response to a rotating position of the rotor, thereby the rotor is rotated. The rotor has a shaft, a rotating core and a permanent magnet, and the rotor is rotatably mounted at the inner circumference of the stator core. The permanent magnet is mounted at the outer circumference of the rotating core and magnetically energized so as to form magnetic poles different alternatively in a rotating direction at the outer circumferential surface facing the stator core.