SOLENOID VALVE FOR VARIABLE VALVE TIMING CONTROL DEVICES, AND VARIABLE VALVE TIMING CONTROL SYSTEM

摘要

A solenoid valve 30 includes a spool 41 moving within a valve housing 40 in a direction of an axis thereof to adjust a fed or discarded amount of a working fluid flowing via ports 43 to 47 formed in the valve housing 40 according to an amount of the movement, and including lands 41a, 41b, 41c, and 41d and recessed portions 41e, 41f, and 41 g for connecting the lands with one another, and a solenoid unit 50 containing a moving member of a magnetic circuit for driving the spool 41. In edge portions 41b′ and 41e of the lands 41b and 41c or in hole edge portions of the valve housing corresponding to the edge portions 41b′ and 41c′, notch portions 60 or taper grooves 61, or penetrating holes 62 for adjusting the amount of the working fluid which is close to a central current value are formed.