Electric pump operating strategy
First Claim
1. A method of operating an electrically driven coolant pump for an internal combustion engine, comprising the steps of:
- measuring a coolant temperature in an engine cooling circuit of said internal combustion engine,providing a coolant pump in said engine cooling circuit driven by an electric pump motor,measuring at least electrical current to said electric pump motor and determining a speed of said electric pump motor,determining a coolant flow provided by said coolant pump from said speed of said electric pump motor,providing a coolant control valve in said engine cooling circuit, said coolant control valve defining a first section and a second section isolated from said first section, said first section receiving coolant from said internal combustion engine and directing said coolant to a radiator or to bypass said radiator and said second section receiving coolant from a turbocharger and said coolant pump and directing said coolant to an engine oil heater and a transmission oil heater,determining a negative correction if desired flow is less than said determined coolant flow by subtracting a flow correction value from a flow learn value and multiplying such result by an open loop pump flow value and providing said negative correction to said coolant control valve and said electric pump motor to reduce coolant flow and determining a positive correction if desired flow is more than said determined coolant flow by subtracting a flow correction value from a flow learn value and multiplying such result by an open loop pump flow value and providing said positive correction to said coolant control valve and said electric pump motor to increase coolant flow.
1 Assignment
0 Petitions
Accused Products
Abstract
A strategy for controlling an electric pump and control valve in an internal combustion engine cooling system compensates for backpressure variations and maintains system operation within design parameters. The method comprises the steps of measuring the coolant temperature, measuring the electrical current and voltage to the pump motor, determining the pump speed and coolant flow, determining the desired coolant flow, determining a negative correction to the flow control valve and pump if desired flow is less than present coolant flow and determining a positive correction to the flow control valve and pump if desired flow is more than present coolant flow and undertaking this correction to coolant flow. Thus, based upon inferred back pressure in the engine coolant system from the data relating to the pump energy input, proper coolant flow, heat rejection and engine operating temperature can be maintained in spite of variations in system flow restrictions and backpressure.
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Citations
12 Claims
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1. A method of operating an electrically driven coolant pump for an internal combustion engine, comprising the steps of:
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measuring a coolant temperature in an engine cooling circuit of said internal combustion engine, providing a coolant pump in said engine cooling circuit driven by an electric pump motor, measuring at least electrical current to said electric pump motor and determining a speed of said electric pump motor, determining a coolant flow provided by said coolant pump from said speed of said electric pump motor, providing a coolant control valve in said engine cooling circuit, said coolant control valve defining a first section and a second section isolated from said first section, said first section receiving coolant from said internal combustion engine and directing said coolant to a radiator or to bypass said radiator and said second section receiving coolant from a turbocharger and said coolant pump and directing said coolant to an engine oil heater and a transmission oil heater, determining a negative correction if desired flow is less than said determined coolant flow by subtracting a flow correction value from a flow learn value and multiplying such result by an open loop pump flow value and providing said negative correction to said coolant control valve and said electric pump motor to reduce coolant flow and determining a positive correction if desired flow is more than said determined coolant flow by subtracting a flow correction value from a flow learn value and multiplying such result by an open loop pump flow value and providing said positive correction to said coolant control valve and said electric pump motor to increase coolant flow. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of controlling an electrically driven coolant pump for an internal combustion engine, comprising the steps of:
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providing an electronic control module, measuring a coolant temperature in an engine cooling circuit for said internal combustion engine and providing said measurement to said electronic control module, providing a coolant pump in said engine cooling circuit driven by an electric motor, measuring electrical current and voltage to said electric pump motor and providing said electrical measurements to said electronic control module, determining a speed of said electric pump motor in said electronic control module, determining a coolant flow provided by said coolant pump from said speed of said electric pump motor, providing a coolant control valve in said engine cooling circuit, said coolant control valve defining a first section and a second section isolated from said first section, said first section receiving coolant from said internal combustion engine and directing said coolant to a radiator or to bypass said radiator and said second section receiving coolant from a turbocharger and said coolant pump and directing said coolant to an engine oil heater and a transmission oil heater, determining a negative correction signal if desired flow is less than said determined coolant flow by subtracting a flow correction value from a flow learn value and multiplying a result by an open loop pump flow value and providing said negative correction signal to said coolant control valve and said electric pump motor from said electronic control module and determining a positive correction signal if desired flow is more than said determined coolant flow by subtracting a flow correction value from a flow learn value and multiplying a result by an open loop pump flow value and providing said positive correction signal to said coolant control valve and said electric pump motor from said electronic control module. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification