Magnetventil in einer hydraulischen Bremsanlage für Kraftfahrzeuge

摘要

The object of the invention is to ensure that a solenoid valve opens reliably even when there are great drops in pressure. To this end, the solenoid valve (1) comprises an armature (5) with a plunger (27) accommodated in a longitudinally displaceable manner therein. Acting on a collar (30) of the plunger (27) is a restoring spring (36), which moves the armature (5) with the plunger (27) into a closed position of the solenoid valve, and a pressure spring (34) which acts in the opposite direction to the restoring spring (36) and is supported on the armature (5). The pressure spring (34) is pre-tensioned to a greater degree than the restoring spring (36). Drops in pressure can produce on the plunger (27) a hydraulic closing force in the opposite direction to the magnetic force effect. When the solenoid valve (1) is moved into the open position, the armature (5) therefore performs a partial stroke (h) opposite the effect of the pressure spring (34), before the armature (5), owing to the magnetic force which increases as the armature stroke (H) increases, entrains the plunger (27) by acting on the collar (30). The solenoid valve can be used in an intake line (21) between a main brake cylinder (22) and a self-priming high-pressure pump (23) of a motor vehicle hydraulic braking system.