US 5,507,251 AGranted

System for determining the load condition of an engine for maintaining optimum engine oil temperature

OwnerThomas J. Hollisinventor

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Abstract

A temperature control system, in a liquid cooled internal combustion engine equipped with a radiator, controls the state of a flow control valve for controlling flow of a temperature control fluid through a passageway in the engine. Sensors detect the engine oil temperature, the temperature of the temperature control fluid, and the ambient air temperature. An engine computer receives signals from the sensors, produces control signals based on the sensor signals, and sends the control signals to the flow control valve to control the state of the valve. A set of predetermined values defining a temperature control curve are utilized to determine the desired state of the valve. An optimum engine oil temperature curve is utilized to determine the temperature state and load condition of the engine. The temperature control curve is adjusted based on the temperature state and/or the load condition of the engine.

Claims32

Dependent claims

A temperature control system in a liquid cooled internal combustion engine equipped with a radiator and a water jacket, the system comprising:

a flow control valve for controlling flow of a temperature control fluid through the water jacket, the flow control valve having a first state for inhibiting said flow and a second state for allowing said flow;
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 third sensor for sensing an actual temperature control fluid temperature and for providing a signal indicative thereof;
an engine computer for receiving the actual engine oil temperature, the actual ambient air temperature and the temperature control fluid temperature, the engine computer determining a desired engine oil temperature based on ambient air temperature, the desired engine oil temperature varying as a function of the actual ambient air temperature, the engine computer comparing the actual engine oil temperature to the desired engine oil temperature for determining the temperature state of the engine, the engine computer adjusting a set of predetermined values based on the temperature state of the engine, the set of predetermined values having a temperature control fluid temperature component and an ambient air temperature component, the set of predetermined values defining a curve which determines the state of the flow control valve, the engine computer determining a desired temperature control fluid temperature by comparison of the actual ambient temperature to the adjusted set of predetermined values, the engine computer comparing the actual temperature control fluid temperature to the desired temperature control fluid temperature and controlling the actuation of the flow control valve between its first and second states depending on the comparison of the actual temperature control fluid temperature to the desired temperature control fluid temperature, the flow control valve being in the first state when the actual temperature control fluid temperature is less than the desired temperature control fluid temperature, and the flow control valve being in the second state when the actual temperature control fluid temperature is greater than the desired temperature control fluid temperature.

2 more elements

A method for controlling the state of a flow control valve in an internal combustion engine, the flow control valve controlling flow of temperature control fluid through a passageway and having a first state for inhibiting the flow of temperature control fluid through the passageway and a second state for permitting the flow of temperature control fluid through the passageway, the method comprising the steps of:

(a) measuring an actual engine oil temperature;
(b) measuring an actual ambient air temperature;
(c) measuring an actual temperature control fluid temperature;
(d) determining a desired engine oil temperature value for the actual ambient air temperature, said desired engine oil temperature value varying as a function of the ambient air temperature;
(e) comparing the actual engine oil temperature to the desired engine oil temperature value;
(f) determining a desired temperature control fluid temperature from the actual ambient air temperature, the desired temperature control fluid temperature varying as a function of the ambient air temperature;
(g) adjusting the desired temperature control fluid temperature based on the comparison of the actual engine oil temperature to the desired engine oil temperature value;
(h) comparing the actual temperature control fluid temperature to the adjusted desired temperature control fluid temperature;
and
(i) actuating the flow control valve so as to place said valve in its first state when the actual temperature control fluid temperature is less than the adjusted desired temperature control fluid temperature, and actuating the valve to place it in its second state when the actual temperature control fluid temperature is greater than the adjusted desired temperature control fluid temperature.

7 more elements

(a) measuring an actual engine oil temperature;
(b) measuring an actual ambient air temperature;
(c) measuring an actual temperature control fluid temperature;
(d) determining a desired engine oil temperature value for the actual ambient temperature, said desired engine oil temperature value varying as a function of the ambient air temperature;
(e) comparing the actual engine oil temperature to the desired engine oil temperature value;
(f) determining an adjustment factor based on the comparison of the actual engine oil temperature to the desired engine oil temperature;
(g) combining the adjustment factor with at least one temperature control fluid temperature component of a set of predetermined values having temperature control fluid temperature component and an ambient air temperature component, the combination forming an adjusted temperature control fluid temperature component;
(g) determining a desired state of the flow control valve by comparing the actual temperature control fluid temperature to the adjusted temperature control fluid temperature component and comparing the actual ambient air temperature to the ambient air temperature component of the set of predetermined values;
and
(h) actuating the valve so as to place it in the desired state.

7 more elements

Dependencies are inferred from the claim text.