Method for operating an electric fuel pump
AssigneeRobert Bosch GmbH
InventorsJoerg Kuempel, Klaus Joos
Life of this patent
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Abstract
A method is described for operating an electric fuel pump constituting a low-pressure pump in a fuel supply system for an internal combustion engine, having a high-pressure reservoir and a high-pressure pump, of a motor vehicle. The electric fuel pump is operated at least temporarily, during a time period during which the internal combustion engine is switched off during operation of the motor vehicle, with a minimum value for a control application variable for the electric fuel pump.
Claims13
A method for operating an electric fuel pump constituting a low-pressure pump in a fuel supply system for an internal combustion engine of a motor vehicle, the fuel supply system including a high-pressure reservoir and a high-pressure pump, the method comprising:
- ascertaining a minimum value for a control application variable for the electric fuel pump, the minimum value being a value for the control application variable at which the electric fuel pump draws in fuel but does not convey any fuel toward the high-pressure pump;
- and
- operating the electric fuel pump at least temporarily, during a time period during which the internal combustion engine is switched off during operation of the motor vehicle, with the ascertained minimum value for the control application variable for the electric fuel pump;
- wherein the method further comprises determining a value for the control application variable at which zero delivery by the electric pump occurs, wherein the minimum value for the control application variable is ascertained in the ascertaining step using the value for the control application variable at which the zero delivery by the electric pump occurs;
- wherein the fuel supply system further includes at least one suction jet pump, and wherein the minimum value for the control application variable is also ascertained based on a characteristic curve of the at least one suction jet pump.
A computation unit configured to operate an electric fuel pump constituting a low-pressure pump in a fuel supply system for an internal combustion engine of a motor vehicle, the fuel supply system including a high-pressure reservoir and a high-pressure pump, the computation unit configured to:
- ascertain a minimum value for a control application variable for the electric fuel pump, the minimum value being a value for the control application variable at which the electric fuel pump draws in fuel but does not convey any fuel toward the high-pressure pump;
- and
- operate the electric fuel pump at least temporarily, during a time period during which the internal combustion engine is switched off during operation of the motor vehicle, with the ascertained minimum value for the control application variable for the electric fuel pump;
- wherein the computation unit is further configured to:
- determine a value for the control application variable at which zero delivery by the electric pump occurs, wherein the minimum value for the control application variable is ascertained in the ascertaining step using the value for the control application variable at which the zero delivery by the electric pump occurs;
- wherein the fuel supply system further includes at least one suction jet pump, and wherein the minimum value for the control application variable is also ascertained based on a characteristic curve of the at least one suction jet pump.
A non-transitory machine-readable memory medium that stores a computer program for operating an electric fuel pump constituting a low-pressure pump in a fuel supply system for an internal combustion engine of a motor vehicle, the fuel supply system including a high-pressure reservoir and a high-pressure pump, the computer program, when executed by a computation unit, causing the computation unit to perform the following steps:
- ascertaining a minimum value for a control application variable for the electric fuel pump, the minimum value being a value for the control application variable at which the electric fuel pump draws in fuel but does not convey any fuel toward the high-pressure pump;
- and
- operating the electric fuel pump at least temporarily, during a time period during which the internal combustion engine is switched off during operation of the motor vehicle, with the ascertained minimum value for the control application variable for the electric fuel pump;
- wherein the computer program, when executed by the computation unit, causes the computation unit to perform the following addition step:
- determining a value for the control application variable at which zero delivery by the electric pump occurs, wherein the minimum value for the control application variable is ascertained in the ascertaining step using the value for the control application variable at which the zero delivery by the electric pump occurs;
- wherein the fuel supply system further includes at least one suction jet pump, and wherein the minimum value for the control application variable is also ascertained based on a characteristic curve of the at least one suction jet pump.
Dependencies are inferred from the claim text.