Electromagnetic valve for vehicle automatic gearbox - operated by pivoted flap closing magnetic circuit

摘要

An electromagnet has a magnetic circuit completed by two end plates and an arm pivotally attached to one plate to engage a contact on the other plate. The arm has connected to its mid point an operating shaft for a spool valve normally held in an on position by a first spring acting directly on the valve and a second spring acting on the arm for completing a hydraulic circuit. The valve lifts under pressure from a pump completing the magnetic circuit and disconnecting the pump. The valve is held closed magnetically until the pressure falls and spring forces open the valve. Moving parts have low inertia.