Electronic thermostat, cooling system provided with the same and control method for the same

A cooling system comprising:

• a variable water pump controlling discharging amount of coolant;
• an engine including a cylinder head and an engine block receiving the coolant from the variable water pump respectively;
• an internal housing including:
• a partition defining a head chamber fluidically-communicating with the cylinder head and a block chamber fluidically-communicating with the engine block wherein the partition is stationary;
• a head chamber hole positioned at a side of the head chamber and a block chamber hole positioned at a side of the block chamber;
• an external housing including an outlet, wherein the external housing is configured to cover the internal housing;
• a thermostat heater mounted to the partition;
• a first opening/closing portion fixed to the partition and including a first wax mounted on a first side of the thermostat heater receiving heat from the thermostat heater and selectively closing or opening the head chamber hole formed on the internal housing to selectively connect the head chamber to the outlet of the external housing;
• a second opening/closing portion fixed to the partition and including a second wax mounted on a second side of the thermostat heater and receiving heat from the thermostat heater and selectively closing or opening the block chamber hole formed on the internal housing to selectively connect the block chamber to the outlet of the external housing;
• a radiator fluidically-communicating with the outlet of the external housing;
• a first coolant temperature sensor configured for detecting a temperature of coolant flowing through the cylinder head and outputting a first signal;
• a second coolant temperature sensor configured for detecting a temperature of coolant flowing through the engine block and outputting a second signal;
• and
• a controller connected to the variable water pump and the thermostat heater, and configured for receiving vehicle operation state signals including the first and second signals of the first and second coolant temperature sensors, wherein the controller is configured for controlling operations of the variable water pump and the thermostat heater, based on the vehicle operation state signals.

A control method for a cooling system including a variable water pump controlling discharging amount of coolant, an engine including a cylinder head and an engine block receiving the coolant from the variable water pump respectively, an internal housing including a partition defining a head chamber fluidically-communicating with the cylinder head and a block chamber fluidically-communicating with the engine block wherein the partition is stationary, a head chamber hole positioned at a side of the head chamber and a block chamber hole positioned at a side of the block chamber, an external housing including an outlet, wherein the external housing is configured to cover the internal housing, a thermostat heater mounted to the partition, a first opening/closing portion fixed to the partition and including a first wax mounted on a first side of the thermostat heater and receiving heat from the thermostat heater and selectively closing or opening the head chamber hole formed on the internal housing to selectively connect the head chamber to the outlet of the external housing, and a second opening/closing portion fixed to the partition and including a second wax mounted on a second side of the thermostat heater and receiving heat from the thermostat heater and selectively closing or opening the block chamber hole formed on the internal housing to selectively connect the block chamber to the outlet of the external housing, a radiator fluidically-communicating with the outlet of the external housing, at least one heat exchange element communicating with the cylinder head and receiving coolant from the cylinder head, a vehicle operation state detecting portion including a first coolant temperature sensor configured for detecting a temperature of coolant flowing through the cylinder head and outputting a first signal, a second coolant temperature sensor configured for detecting a temperature of coolant flowing through the engine block and outputting a second signal, an accelerator pedal sensor and a vehicle speed sensor, and a controller configured for receiving vehicle operation state signals from the vehicle operation state detecting portion and configured for controlling operations of the variable water pump and the thermostat heater, based on the vehicle operation state signals, the control method including:

• determining, by the controller, when the vehicle operation state signals satisfy a predetermined cold driving condition and controlling, by the controller, operation of the variable water pump not to discharge coolant.