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US 11,480,144 B2Granted
Fuel supply system
AssigneeDenso Corporation
InventorMakoto Asai
Life of this patent
Estimating the term…
Abstract
A fuel supply system includes an electronic control unit that outputs a target fuel pressure for controlling a low-pressure pump and an engine status, and a fuel pump controller (FPC) that generates a drive signal for driving the low-pressure pump based on the target fuel pressure. The FPC is configured to obtain an actual fuel pressure, to set a duty ratio and to perform a feedback control for the actual fuel pressure to follow the target fuel pressure, and to set a lower limit guard value based on the engine status. The lower limit guard setter sets a duty ratio of 0% as the lower limit guard value when the engine status indicates a stop of the engine.
Claims14
A fuel supply system comprising:
- a controller configured to output
- (i) information on a target fuel pressure for controlling a fuel pump, the fuel pump configured to pump fuel in a fuel tank toward an internal combustion engine and,
- (ii) information on an operation state of the internal combustion engine;
- and
- a driver configured to generate a drive signal for driving the fuel pump based on the target fuel pressure, a supply of electric power to the driver enabled by turning ON a relay, the driver including:
- an obtainer configured to obtain information of an actual fuel pressure representing a pressure of the fuel discharged from the fuel pump;
- a duty ratio setter configured to set a duty ratio of the drive signal and to perform a feedback control for the actual fuel pressure to follow the target fuel pressure;
- and
- a lower limit guard setter configured to set a lower limit guard value based on the operation state for limiting a lower limit value of the duty ratio and to keep the relay ON, wherein
- the lower limit guard setter is further configured to set, a preset duty ratio at which the drive of the fuel pump is stopped as the lower limit guard value when the operation state of the internal combustion engine indicates a stop of the engine when a vehicle ignition switch is ON, wherein the preset duty ratio at which the drive of the fuel pump is stopped as the lower limit guard value is a zero duty ratio, and
- the driver further includes a target corrector configured to correct the target fuel pressure to have a higher pressure value when the internal combustion engine is stopped.
8 more elements
A fuel supply system for use in a vehicle, the fuel supply system comprising:
- a fuel pump configured to pump fuel in a fuel tank toward an internal combustion engine;
- an electronic control unit configured to output target fuel pressure information for controlling the fuel pump and information regarding an operation state of the engine;
- and
- a fuel pump controller configured to generate a drive signal for driving the fuel pump based on the target fuel pressure, the fuel pump controller configured to:
- obtain an actual fuel pressure of the fuel discharged from the fuel pump;
- set a duty ratio of the drive signal;
- perform a feedback control on the actual fuel pressure to match the actual fuel pressure to the target fuel pressure;
- and
- set a lower limit value for the duty ratio based on the operation state of the engine and to keep a relay that supplies electric power to the fuel pump controller ON, wherein
- the fuel pump controller is further configured to set a preset duty ratio as the lower limit value for stopping the fuel pump when the operation state of the engine indicates the engine is stopped and a vehicle ignition switch is ON, wherein the preset duty ratio at which the drive of the fuel pump is stopped as the lower limit guard value is a zero duty ratio, and
- the fuel pump controller is further configured to correct the target fuel pressure to have a higher pressure value when the internal combustion engine is stopped.
8 more elements
A fuel supply system controller comprising:
- a processor;
- and
- a non-transitory computer-readable storage medium,
- wherein the controller is configured to:
- obtain an actual fuel pressure,
- determine that an engine status is STOP,
- perform a correction process for a target fuel pressure to generate a corrected target fuel pressure,
- set a lower limit guard value and to keep a relay that supplies electric power to a fuel pump controller ON, and
- perform control of a duty ratio for a fuel pump based at least partially on the corrected target fuel pressure and/or the set lower limit guard value.
6 more elements
A fuel supply system controller comprising:
- a processor;
- and
- a non-transitory computer-readable storage medium,
- wherein the controller is configured to:
- obtain an actual fuel pressure,
- determine that an engine status is STOP,
- perform a correction process for a target fuel pressure to generate a corrected target fuel pressure,
- set a lower limit guard value, and
- perform control of a duty ratio for a fuel pump based at least partially on the corrected target fuel pressure and/or the set lower limit guard value,
- wherein the correction process includes:
- determine whether an elapsed time from a beginning of the STOP engine status is within a preset time,
- upon a determination that the elapsed time is within the preset time, raise the target fuel pressure, and
- upon a determination that the elapsed time is NOT within the preset time, maintain the target fuel pressure.
10 more elements
A driver of a fuel supply system to generate a drive signal for driving a fuel pump based on a target fuel pressure, a supply of electric power to the driver enabled by turning ON a relay, the driver comprising:
- an obtainer configured to obtain information of an actual fuel pressure representing a pressure of a fuel discharged from the fuel pump;
- a duty ratio setter configured to set a duty ratio of the drive signal and to perform a feedback control for the actual fuel pressure to follow the target fuel pressure;
- a lower limit guard setter configured to set a lower limit guard value based on an operation state of an internal combustion engine for limiting a lower limit value of the duty ratio and to keep the relay ON, wherein
- the lower limit guard setter is further configured to set a preset duty ratio at which the drive of the fuel pump is stopped as the lower limit guard value when the operation state of the internal combustion engine indicates a stop of the engine when a vehicle ignition switch is ON, wherein the preset duty ratio at which the drive of the fuel pump is stopped as the lower limit guard value is a zero duty ratio;
- and
- a target corrector configured to correct the target fuel pressure to have a higher pressure value when the internal combustion engine is stopped.
3 more elements
Dependencies are inferred from the claim text.