Patent ID: 7484502

Claim:
An EGR coolant control system comprising: a coolant supply pipe; a coolant exhaust pipe wherein a proximate end portion of the coolant exhaust pipe is connected with a distal end portion of the coolant supply pipe; an EGR coolant supply pipe wherein a proximate end portion of the EGR coolant supply pipe is connected with the distal end portion of the coolant supply pipe and the proximate end portion of the coolant exhaust pipe in common; a coolant control plate that is pivotally disposed in a junction portion of the distal end portion of the coolant supply pipe, the proximate end portion of the coolant exhaust pipe and the proximate end portion of the EGR coolant supply pipe, and the coolant control plate controls supply of coolant to the coolant exhaust pipe or the EGR coolant supply pipe; and an actuator controlling the coolant control plate according to an engine rotation speed, wherein the actuator comprises: a body; a pressure supply pipe for supplying pressure to the body; a diaphragm disposed at and enclosing one side of the body and fluidly communicating with the pressure supply pipe; and an elastic member disposed between the body and the diaphragm, wherein both ends of the elastic member are coupled to the body and the diaphragm respectively for supporting the diaphragm.