Control system and control method of gasoline direct injection engine

Patent metadata

Field	Value
Publication number	US-9347392-B2
Application number	US-201213712666-A
Country	US
Kind code	B2
Filing date	Dec 12, 2012
Priority date	Oct 31, 2012
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

A control system and a control method of a gasoline direct injection engine may include determining whether the engine is stopped and can improve NVH of a vehicle by keeping the fuel high-pressure pump input valve of the high-pressure pump operating for a predetermined time and preventing fuel from flowing backward to the low-pressure pump.

First claim

What is claimed is:

1. A control system of a gasoline direct injection engine, comprising:
a low-pressure pump disposed at a fuel tank;
a high-pressure pump fluid-connected to the low-pressure pump and including:
a pressure chamber having an inlet and an outlet;
a plunger reciprocated in the pressure chamber by a fuel pump cam;
a high-pressure pump input valve disposed to selectively close the inlet of the pressure chamber and stop fuel flowing inside the high-pressure pump from the low-pressure pump; and
a high-pressure pump output valve disposed to selectively open the outlet of the pressure chamber and supply the fuel in the pressure chamber to injectors from the high-pressure pump in accordance with a reciprocation of the plunger;

an actuator connected to and operating the high-pressure pump input valve to selectively open the inlet of the pressure chamber;
a high-pressure pump pressure sensor measuring an internal pressure of the high-pressure pump;
a low-pressure pump pressure sensor measuring an internal pressure of the low-pressure pump;
an ignition key sensor;
a crankshaft rotation sensor; and
a control unit receiving signals from the high-pressure pump pressure sensor, the low-pressure pump pressure sensor, the ignition key sensor, and the crankshaft rotation sensor, and controlling the injectors and the actuator,
wherein the control unit is configured to:
determine whether a key for starting the engine is turned off,
determine a stroke of the high-pressure pump when the key for starting the engine is turned off,
control the actuator to operate the high-pressure pump inlet valve that selectively blocks a fluid flow between the low-pressure pump and the high-pressure pump so as to open the inlet of the pressure chamber when the determined stroke of the high-pressure pump is an expansion stroke and a difference in internal pressures of the high-pressure pump and the low-pressure pump is a predetermined pressure or less,
determine whether an RPM of the engine is less than or equal to a predetermined RPM to finish control process of the control unit,
determine a time point of closing the high-pressure pump input valve when the determined stroke of the high-pressure pump is a compression stroke,
wherein the time point of closing the high-pressure pump input valve is maintained at a current time point of closing the high-pressure pump input valve, when the internal pressure of the high-pressure pump is a predetermined critical pressure or less, and
wherein the time point of closing the high-pressure pump input valve is delayed by a predetermined time from the current time point of closing the high-pressure pump input valve when the internal pressure of the high-pressure pump is not the predetermined critical pressure or less, and

close the high-pressure pump input valve, if the high-pressure pump input valve is opened,

wherein the determining of the stroke of the high-pressure pump is performed by measuring the internal pressure of the high-pressure pump.

2. The system of claim 1 , wherein the actuator is a solenoid.

3. The system of claim 1 , wherein a first elastic member is mounted on the high-pressure pump inlet valve to elastically bias the high-pressure pump inlet valve toward the inlet of the pressure chamber.

4. The system of claim 1 , wherein a second elastic member is mounted on the high-pressure pump outlet valve to elastically bias the high-pressure pump outlet valve toward the outlet of the pressure chamber.

5. The system of claim 1 , wherein when the RPM of the engine is equal to the predetermined RPM, the RPM of the engine is 0.

Assignees

• Hyundai Motor Co Ltd

Inventors

• Lee Heungseok
• Oh Wan Soo

Classifications

• F02D2200/0602

  Fuel pressure · CPC title

• F02D41/3082

  Control of electrical fuel pumps · CPC title

• F02M59/367

  Pump inlet valves of the check valve type being open when actuated · CPC title

• F02D41/3854

  with elements in the low pressure part, e.g. low pressure pump · CPC title

• F02D41/042 Primary

  for stopping the engine · CPC title