Exhaust heat recovery device

An exhaust heat recovery device configured so that exhaust gas passes therethrough, the device comprising:

• a bypass pipe installed in the device and bypassing exhaust gas introduced from an exhaust pipe at an upstream side to be discharged;
• a coolant housing installed in the device to surround the bypass pipe and including a coolant inlet port and a coolant outlet port through which coolant passes;
• an oil flow pipe including an oil inlet port and an oil outlet port through which oil passes and installed in the coolant housing such that heat exchange between coolant and oil is made;
• and
• a plurality of exhaust flow pipes installed in the coolant housing to penetrate the interior of the coolant housing such that the exhaust gas fed into the device is heat-exchanged with the coolant and oil,
• wherein a valve device controls the flow of the exhaust gas passing through the interior of the bypass pipe in connection with the temperature of the coolant supplied to the coolant housing or the temperature of the oil supplied to the oil flow pipe, and
• wherein the plurality of exhaust flow pipes are arranged parallel to the oil flow pipe which is parallel to the bypass pipe,
• wherein the oil flow pipe includes a heat transfer medium filled within an internal space thereof so that oil passes therethrough to increase heat transfer performance, and the exhaust flow pipes include an inner exhaust flow pipe arranged inside the oil flow pipe and an outer exhaust flow pipe arranged outside the oil flow pipe,
• wherein the rotating plate is integrally connected to a top of a drive shaft and includes a projection pushed by a spindle of a thermostat to rotate when the spindle moves forward, and
• wherein the drive shaft includes a spring member for rotating a flow control valve via an elastic force in order to be maintained in a closed state and the flow control valve is a flap valve rotating together with the drive shaft to be opened when an exhaust pressure above a predetermined level is applied in the bypass pipe.