Patent ID: 6044808
Filing Date: 2000-04-04
Classification: F01P,F16N

Abstract:
A temperature control system in a liquid cooled internal combustion engine comprising:an electronically assisted thermostat for controlling flow of a temperature control fluid through the engine, the electronically assisted thermostat having a first state for inhibiting said flow and a second state for allowing said flow, the electronically assisted thermostat includinga housing,a valve member reciprocatable within the housing between the first state and the second state,a return spring for biasing the valve member into the second state, a wax pellet attached to the valve member and having a solid state and a liquid state, the wax pellet maintaining the valve member in its first state when the wax pellet is in its solid state, and the wax pellet allowing the return spring to bias the valve member into its second state when the wax pellet is in its liquid state, anda heating element mounted within the housing and adapted to transfer heat to wax pellet, the heating element adapted to receive an electrical transmission for producing heating of the heating element;a first sensor for sensing a temperature indicative of the temperature control fluid temperature and for providing a temperature control fluid temperature signal indicative thereof; a second sensor for sensing the temperature of the ambient air and for providing an ambient air temperature signal indicative thereof;a third sensor for sensing the temperature of the engine oil and for providing an engine oil temperature signal indicative thereof;an engine computer for receiving the temperature control fluid temperature signal, the ambient air temperature signal, and the engine oil temperature signal the engine computer comparing the engine oil and ambient air temperature signals to a set of engine oil temperature limits, the engine oil temperature limits varying with ambient air temperature, the engine computer comparing the engine oil temperature signal to the engine oil temperature limit associated with the ambient air temperature signal the engine computer determining the desired state for the thermostat based on the comparison, the engine computer comparing the temperature control fluid temperature signal to a threshold temperature value to determine the actual state of the thermostat the thermostat being in its first state when the temperature control fluid temperature signal is less than the threshold temperature value and the thermostat being in its second state when the temperature control fluid temperature signal is greater than the threshold temperature value, the engine computer sending an output signal when the engine oil temperature signal exceeds the engine oil limit and the thermostat is in the first state; andwherein the signal from the engine computer controls the electrical transmission to the heating element.