System for preheating intake air for an internal combustion engine

Claim 1

A system for preheating intake air flowing through an intake manifold of an internal combustion engine including an exhaust manifold, an oil pan, a fuel line, and a water pump adapted for directing a flow of temperature control fluid into the engine, the intake air flow being regulated by a throttle valve in a throttle body located downstream of an air cleaner on the engine, the system comprising: an exhaust heat assembly located adjacent to the exhaust manifold and adapted to receive a flow of temperature control fluid from the water pump; a heat exchanger mounted to the engine and disposed within the flow of intake air, the heat exchanger adapted for receiving a flow of heated temperature control fluid from the exhaust heat assembly and for discharging said flow of temperature control fluid into a passageway leading to the oil pan, the heat exchanger including at least one heat exchanging element for transferring heat from the temperature control fluid to the intake air; a first sensor for sensing an actual engine oil temperature and for providing a signal indicative thereof; a second sensor for sensing an actual ambient air temperature and for providing a signal indicative thereof; a control valve for regulating the flow of temperature control fluid to and from said heat exchanger, the control valve having an open state and a closed state; and an engine computer for receiving signals from the first and second sensors, producing control signals based on both of said sensor signals, and sending said control signals to said control valve to control the state of the valve, wherein said control signals are produced in accordance with a set of predetermined values which define a curve wherein said curve is a function of engine oil temperature and ambient air temperature.

Claim 2

A system for preheating intake air flowing through an intake manifold of an internal combustion engine including an exhaust manifold, an oil pan, a fuel line, and a water pump adapted for directing a flow of temperature control fluid into the engine, the intake air flow being regulated by a throttle valve in a throttle body located downstream of an air cleaner on the engine, the system comprising: an exhaust heat assembly located adjacent to the exhaust manifold and adapted to receive a flow of temperature control fluid from the water pump; a heat exchanger mounted to the engine and disposed within the flow of intake air, the heat exchanger adapted for receiving a flow of heated temperature control fluid from the exhaust heat assembly and for discharging said flow of temperature control fluid into a passageway leading to the oil pan, the heat exchanger including at least one heat exchanging element for transferring heat from the temperature control fluid to the intake air; a first sensor for sensing an actual engine oil temperature and for providing a signal indicative thereof; a second sensor for sensing an actual ambient air temperature and for providing a signal indicative thereof; a control valve for regulating the flow of temperature control fluid to and from said heat exchanger, the control valve having an open state and a closed state; and an engine computer for receiving signals from the first and second sensors, producing control signals based on both of said sensor signals, and sending said control signals to said control valve to control the state of the valve, wherein said control signals are produced in accordance with a set of predetermined values which define a curve wherein said curve is a function of engine oil temperature and ambient air temperature.

Claim 11

A method for preheating intake air flowing to an intake manifold of an internal combustion engine, the engine including an exhaust manifold, an oil pan, a water pump adapted for directing a flow of temperature control fluid into the engine, a heat exchanger adapted for receiving a flow of temperature control fluid and for transferring heat from the temperature control fluid to the intake air, and a control valve for regulating the flow of temperature control fluid to and from said heat exchanger, the method comprising the steps of: detecting the temperature of the engine oil in the engine; detecting the temperature of ambient air; comparing the detected engine oil temperature and the detected ambient air temperature to a set of predetermined temperature control values for determining a desired position of the control valve; actuating the control valve so as to place the valve in the desired position for controlling the flow of the temperature control fluid to the heat exchanger; and directing the temperature control fluid through the heat exchanger to heat the intake air.

Claim 12

A method for preheating intake air flowing to an intake manifold of an internal combustion engine, the engine including an exhaust manifold, an oil pan, a water pump adapted for directing a flow of temperature control fluid into the engine, a heat exchanger adapted for receiving a flow of temperature control fluid and for transferring heat from the temperature control fluid to the intake air, and a control valve for regulating the flow of temperature control fluid to and from said heat exchanger, the method comprising the steps of: detecting the temperature of the engine oil in the engine; detecting the temperature of ambient air; comparing the detected engine oil temperature and the detected ambient air temperature to a set of predetermined temperature control values for determining a desired position of the control valve; actuating the control valve so as to place the valve in the desired position for controlling the flow of the temperature control fluid to the heat exchanger; and directing the temperature control fluid through the heat exchanger to heat the intake air.