Patent attributes
A valve assembly including a valve element and a movable core is housed in a valve housing including a valve seat member, a magnetic cylinder, a nonmagnetic collar and a stationary core. A coil assembly is disposed on an outer periphery of the stationary core, and housed in a coil housing. The coil housing has a front end wall part which is formed such that a thickness thereof in an axial direction is larger than a thickness of its shell part in a radial direction. A magnetic path forming part is formed by the front end wall part and a rear-side cylinder part of the magnetic cylinder which is fitted to an inner peripheral surface of the front end wall part. The magnetic path forming part surrounds the movable core substantially by the entirety of its inner peripheral surface to magnetically connect the movable core and the shell part to each other. A positioning step part is formed at a rear end of the magnetic cylinder so as to support a front end of the magnetic assembly. Thus, it is possible to prevent magnetic flux saturation from occurring in the front end wall part of the coil housing, thereby improving characteristics of attraction force between the stationary core and the movable core and also stabilizing the characteristics of the attraction force.
