Fuel Supply Device and Fuel Supply Method for Internal Combustion Engine

• US 20090271096A1
• Filed: 02/26/2007
• Published: 10/29/2009
• Est. Priority Date: 02/27/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Matsubara, Takuji
• Granted Patent: US 7,822,534 B2
• Time in Patent Office: Days
• US Class Current: 701/113
• CPC Class Codes: F01N 2390/04 using electropneumatic components
• CPC Class Codes: F01N 2470/08 Gas passages being formed between the walls of an outer shell and an inner chamber
• CPC Class Codes: F01N 2470/24 Concentric tubes or tubes being concentric to housing, e.g. telescopically assembled
• CPC Class Codes: F01N 2570/12 Hydrocarbons
• CPC Class Codes: F01N 3/0807 by using absorbents or adsorbents
• CPC Class Codes: F01N 3/101 Three-way catalysts
• CPC Class Codes: F02D 2041/225 Leakage detection
• CPC Class Codes: F02D 33/006 depending on engine operating conditions, e.g. start, stop or ambient conditions
• CPC Class Codes: F02D 41/3854 with elements in the low pressure part, e.g. low pressure pump
• CPC Class Codes: F02D 41/3863 by controlling the flow out of the common rail, e.g. using pressure relief valves
• CPC Class Codes: F02M 37/20 characterised by means for preventing vapour lock
• CPC Class Codes: F02M 55/025 Common rails
• CPC Class Codes: F02M 59/366 Valves being actuated electrically
• CPC Class Codes: F02M 63/0225 Fuel-injection apparatus having a common rail feeding several injectors F02M63/0003 takes precedence; Means for varying pressure in common rails; Pumps feeding common rails
• CPC Class Codes: F02M 63/025 from the common rail
• CPC Class Codes: F02M 69/465 of fuel rails
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A fuel supply device (30) for an engine (1) pressurizes the fuel drawn up from a fuel tank (31) by the low-pressure fuel pump (32) and stores it in a delivery pipe (34), and injects the fuel stored in the delivery pipe (34) from an injector (35). The fuel supply device (30) includes a return passageway (50) connecting the delivery pipe (34) and the fuel tank (31), and a relief valve (51) that is provided on the return passageway (50) and that is capable of being switched between an open state for connecting the delivery pipe (34) and the fuel tank (31) in communication and a closed state for shutting off the delivery pipe (34) and the fuel tank (31) from each other in communication. An ECU (60) switches the relief valve (51) to the open state and operates the low-pressure fuel pump (32), if a predetermined stop condition for stopping the engine (1) is satisfied.

Claims

1. A fuel supply device for an internal combustion engine in which fuel drawn up from a fuel tank by a fuel feed pump is pressurized and stored in a pressure accumulator and the fuel stored in the pressure accumulator is injected from a fuel injection valve, comprising:

a return passageway connecting the pressure accumulator and the fuel tank;

a control valve that is provided on the return passageway and that is switched between a communicating position for connecting the pressure accumulator and the fuel tank in communication and a shutting-off position for shutting off the pressure accumulator and the fuel tank from each other in communication; and

an operation control portion that switches the control valve to the communicating position and operates the fuel feed pump if a predetermined stop condition for stopping the internal combustion engine is satisfied,

wherein if the predetermined stop condition is satisfied, the operation control portion initially switches the control valve to the communicating position and operates the fuel feed pump, and then switches the control valve to the shutting-off position and operates the fuel feed pump.

3. The fuel supply device for the internal combustion engine according to claim 1, further comprising an ejection pressure change portion that changes an ejection pressure of the fuel feed pump so that the ejection pressure of the fuel feed pump when the fuel feed pump is operated with the control valve switched to the communicating position is higher than the ejection pressure of the fuel feed pump when the fuel feed pump is operated with the control valve switched to the shutting-off position.

4. The fuel supply device for the internal combustion engine according to claim 1, further comprising a pressure detection portion that detects a pressure in the pressure accumulator,

wherein the operation control portion controls an operation of the control valve based on the pressure detected by the pressure detection portion, if the predetermined stop condition is satisfied.

5. The fuel supply device for the internal combustion engine according to claim 4, wherein;

the operation control portion switches the control valve to the communicating position if the predetermined stop condition is satisfied and the pressure detected by the pressure detection portion is higher than a predetermined criterion pressure that is set taking into account a startup characteristic of the internal combustion engine; and

the operation control portion switches the control valve to the shutting-off position if the predetermined stop condition is satisfied and the pressure detected by the pressure detection portion is less than or equal to the predetermined criterion pressure.

6. The fuel supply device for the internal combustion engine according to claim 1, wherein if a predetermined startup condition for starting up the internal combustion engine is satisfied, the operation control portion provides a fuel circulation period during which the control valve is switched to the communicating position and the fuel feed pump is operated, within a period from satisfaction of the predetermined startup condition until fuel is injected from the fuel injection valve.

7. The fuel supply device for the internal combustion engine according to claim 1, wherein the operation control portion provides a delayed startup mode that prevents inflow of hydrocarbon to an exhaust catalyst of the internal combustion engine which is in a catalytically inactive state if the predetermined startup condition for starting up the internal combustion engine is satisfied.

8. The fuel supply device for the internal combustion engine according to claim 1, wherein the predetermined stop condition is set based on at least one of a speed of a vehicle in which the internal combustion engine is mounted, an idle operation time of the internal combustion engine, and an on/off state of the an ignition switch of the vehicle.

2. (canceled)

9. A fuel supply method for an internal combustion engine in which fuel drawn up from a fuel tank by a fuel feed pump is pressurized and stored in a pressure accumulator and the fuel stored in the pressure accumulator is injected from a fuel injection valve, comprising:

connecting the pressure accumulator and the fuel tank to each other in communication if a predetermined stop condition for stopping the internal combustion engine is satisfied; and

shutting off the pressure accumulator and the fuel tank from each other in communication if the predetermined stop condition is not satisfied;

wherein if the predetermined stop condition is satisfied, initially the pressure accumulator and the fuel tank are connected in communication and the fuel feed pump is operated, and then the pressure accumulator and the fuel tank are shut off from each other in communication and the fuel feed pump is operated.

11. The fuel supply method for the internal combustion engine according to claim 9, further comprising changing an ejection pressure of the fuel feed pump so that the ejection pressure of the fuel feed pump when the fuel feed pump is operated with the pressure accumulator and the fuel tank connected to each other in communication is higher than the ejection pressure of the fuel feed pump when the fuel feed pump is operated with the pressure accumulator and the fuel tank shut off from each other in communication.

12. The fuel supply method for the internal combustion engine according to claim 9, further comprising:

detecting a pressure in the pressure accumulator; and

controlling connection and shutting-off of communication between the pressure accumulator and the fuel tank if the predetermined stop condition is satisfied.

13. The fuel supply method for the internal combustion engine according to claim 12, further comprising connecting the pressure accumulator and the fuel tank in communication if the predetermined stop condition is satisfied and the pressure detected by the pressure detection portion is higher than a predetermined criterion pressure that is set taking into account a startup characteristic of the internal combustion engine, and shutting off the pressure accumulator and the fuel tank from each other in communication if the predetermined stop condition is satisfied and the pressure detected by the pressure detection portion is less than or equal to the predetermined criterion pressure.

14. The fuel supply method for the internal combustion engine according to claim 9, wherein if a predetermined startup condition for starting up the internal combustion engine is satisfied, a fuel circulation period during which the pressure accumulator and the fuel tank are connected in communication and the fuel feed pump is operated is set within a period from satisfaction of the predetermined startup condition until fuel is injected from the fuel injection valve.

10. (canceled)

15-16. -16. (canceled)