Patent ID: 6176208
Filing Date: 2001-01-23
Classification: F01L

Abstract:
An electromagnetic valve driving apparatus comprising:a valve disposed in a valve body;a rod connected to the valve for moving the valve between a closed position and an open position thereof;a first spring biasing the rod toward the closed position of the valve;a second spring biasing the rod toward the open position of the valve;an armature connected to the rod;a first solenoid for closing the valve by attracting the armature thereto upon energization thereof;a second solenoid for opening the valve by attracting the armature thereto upon energization thereof;a first chamber formed between the armature and the second solenoid;a second chamber formed between the armature and the first solenoid; andmeans for reducing a moving speed of the valve at least at a vicinity of the closed position,wherein said means for reducing the moving speed of the valve comprises a valve position detector for generating an electrical signal representing a valve position; and a solenoid driver for selectively energizing and de-energizing the first solenoid and the second solenoid in controlled timing based on the electrical signal received from the valve position detector, andwherein to drive the valve to the closed position from the open position, the solenoid driver de-energizes the second solenoid so that the valve is moved by said first spring, then, after a first time period determined based on the electrical signal received from the valve position detector, the solenoid driver energizes the first solenoid to exert a force to attract the valve, then, after a second time period determined based on the electrical signal received from the valve position detector, when the valve is at the vicinity of the closed position, the solenoid driver temporarily discontinues energization of the first solenoid, and then, after a third time period determined based on the electrical signal received from the valve position detector, when the valve is at a position where the moving speed of the valve has become substantially zero and before said valve is in said closed position, the solenoid driver again energizes the first solenoid.