Fuel supply apparatus and internal combustion engine

• US 20050257775A1
• Filed: 05/12/2005
• Published: 11/24/2005
• Est. Priority Date: 05/24/2004
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kojima, Susumu
• Granted Patent: US 7,258,110 B2
• Time in Patent Office: Days
• US Class Current: 123/458
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 2900/0422 measuring the elapsed time
• CPC Class Codes: F01N 3/20 specially adapted for catalytic conversion F01N3/22 takes precedence; Methods of operation or control of catalytic converters
• CPC Class Codes: F02D 2041/224 Diagnosis of the fuel system
• CPC Class Codes: F02D 2250/02 Fuel evaporation in fuel rails, e.g. in common rails
• CPC Class Codes: F02D 2250/31 Control of the fuel pressure
• CPC Class Codes: F02D 41/123 the fuel injection being cut-off
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/3836 Controlling the fuel pressure
• CPC Class Codes: F02M 59/102 Mechanical drive, e.g. tappets or cams F02M45/063 takes precedence
• 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: Y02T 10/40 Engine management systems

Abstract

A fuel supply apparatus suppresses bubble generation of fuel in a delivery pipe and fuel leakage while suppressing power consumption. The fuel supply apparatus includes a fuel supply controller which is provided with a state determining unit that determines at least one of bubble generation of fuel in the delivery pipe and fuel leakage from a fuel injection valve to which fuel is supplied via the delivery pipe, and a fuel pressure controlling unit that activates a fuel feeding unit when the bubble generation is expected and activates a fuel pressure decreasing unit when the fuel leakage is expected. The fuel supply controller intermittently activates during the suspension of the operation of internal combustion engine using a timer, to adjust fuel pressure in the delivery pipe.

Claims

1. A fuel supply apparatus, comprising:

a delivery pipe that accumulates fuel to be supplied to an internal combustion engine;

a fuel feeding unit that supplies fuel to the delivery pipe;

a fuel supply controller that includes a state determining unit which determines bubble generation in the fuel in the delivery pipe, and a fuel pressure controlling unit which activates the fuel feeding unit when the bubble generation is expected; and

an activating unit that intermittently activates the fuel supply controller while operation of the internal combustion engine is under suspension, and operates even while the fuel supply controller suspends its operation.

2. A fuel supply apparatus, comprising:

a delivery pipe that accumulates fuel to be supplied to an internal combustion engine;

a fuel pressure decreasing unit that decreases a fuel pressure in the delivery pipe;

a fuel supply controller that includes a state determining unit which determines fuel leakage from a fuel injection valve to which fuel is supplied from the delivery pipe, and a fuel pressure controlling unit which activates the fuel pressure decreasing unit when the fuel leakage is expected; and

an activating unit that intermittently activates the fuel supply controller while operation of the internal combustion engine is under suspension, and operates even while the fuel supply controller is under suspension.

3. A fuel supply apparatus, comprising:

a delivery pipe that accumulates fuel to be supplied to an internal combustion engine;

a fuel pressure decreasing unit that decreases a fuel pressure in the delivery pipe;

a fuel feeding unit that supplies fuel to the delivery pipe;

a fuel supply controller that includes a state determining unit which determines at least one of bubble generation in fuel in the delivery pipe and fuel leakage from a fuel injection valve to which fuel is supplied from the delivery pipe, and a fuel pressure controlling unit which activates the fuel feeding unit when the bubble generation is expected and activates the fuel pressure decreasing unit when the fuel leakage is expected; and

an activating unit that intermittently activates the fuel supply controller while operation of the internal combustion engine is under suspension, and operates even while the fuel supply controller suspends its operation.

4. The fuel supply apparatus according to claim 3, wherein

the fuel supply controller further comprises an activation controller that determines an activation time to activate the state determining unit and the fuel pressure controlling unit at predetermined intervals,

the activating unit counts up the determined activation time, and intermittently activates the state determining unit and the fuel pressure controlling unit.

5. The fuel supply apparatus according to claim 3, wherein

the fuel pressure controlling unit activates the fuel feeding unit when fuel pressure in the delivery pipe is equal to or lower than a saturated vapor pressure of fuel in the delivery pipe, and the fuel pressure in the delivery pipe and cooling water temperature of the internal combustion engine are on a decline.

6. The fuel supply apparatus according to claim 3, wherein

the fuel pressure controlling unit determines a target fuel pressure of the delivery pipe based on temperature change of the fuel in the delivery pipe, and activates one of the fuel feeding unit and the fuel pressure decreasing unit so that the fuel pressure in the delivery pipe attain a level of the determined target fuel pressure.

7. The fuel supply apparatus according to claim 4, wherein

the activation controller determines an interval to intermittently activate the state determining unit and the fuel pressure controlling unit based on a trend of changes in the fuel pressure in the delivery pipe and in a cooling water temperature of the internal combustion engine.

8. The fuel supply apparatus according to claim 7, wherein

an interval to intermittently activate the state determining unit and the fuel pressure controlling unit is corrected based on an external air temperature.

9. The fuel supply apparatus according to claim 3 wherein

the fuel pressure controlling unit activates the fuel pressure decreasing unit when the fuel pressure is equal to or higher than a minimum operation pressure of the fuel pressure decreasing unit and equal to or higher than a saturated vapor pressure of the fuel in the delivery pipe, and when the fuel pressure is at a level expected to cause the fuel leakage equal to or more than a predetermined amount.

10. The fuel supply apparatus according to claim 9, wherein

an operation time of the fuel pressure decreasing unit is set from start of the operation of the fuel pressure decreasing unit up to a point where the fuel leakage is expected to be less than the predetermined amount.

11. The fuel supply apparatus according to claim 3 wherein

the fuel pressure controlling unit activates the fuel feeding unit when the fuel pressure is equal to or lower than a saturated vapor pressure determined by the temperature of the fuel, the temperature of the fuel in the delivery pipe is on a decline, and an amount of bubbles in the fuel expected from temperature changes in the fuel, a volume of the delivery pipe, and an expansion coefficient of the fuel is equal to or more than a predetermined amount.

12. The fuel supply apparatus according to claim 11, wherein

an operation time of the fuel feeding unit is from a start of the operation of the fuel feeding unit up to a point where the amount of bubbles becomes less than the predetermined amount.

13. The fuel supply apparatus according to claim 11, wherein

the fuel pressure controlling unit changes an operation condition of the fuel feeding unit when a time required for rise of the fuel pressure in the delivery pipe at start-up of the internal combustion engine is longer than a predetermined reference pressure rise time.

14. The fuel supply apparatus according to claim 3, wherein

the activating unit stops reactivation of the state determining unit and the fuel pressure controlling unit when a change in the fuel pressure in the delivery pipe is in a predetermined range after the activation of one of the fuel pressure decreasing unit and the fuel feeding unit.

15. The fuel supply apparatus according to claim 3, wherein

the activation of the state determining unit and the fuel pressure controlling unit is stopped either when a battery for operation of the internal combustion engine is removed or when voltage of the battery drops to a level equal to or lower than a predetermined value.

16. The fuel supply apparatus according to claim 3, wherein

the activation of the state determining unit and the fuel pressure controlling unit is stopped when a sum of an operation time of the fuel pressure decreasing unit and an operation time of the fuel feeding unit exceeds a predetermine time.

17. An internal combustion engine provided with a delivery pipe for accumulating fuel, comprising:

a fuel supply apparatus including

a fuel feeding unit that supplies fuel to the delivery pipe;

a fuel supply controller that includes a state determining unit which determines bubble generation in fuel in the delivery pipe, and a fuel pressure controlling unit which activates the fuel feeding unit when the bubble generation is expected; and

an activating unit that intermittently activates the fuel supply controller while operation of the internal combustion engine is under suspension, and operates even while the fuel supply controller suspends its operation, wherein

a fuel injection valve that injects fuel into a combustion chamber is attached to the delivery pipe of the fuel supply apparatus, and fuel is supplied to the fuel injection valve from the delivery pipe.

18. An internal combustion engine provided with a delivery pipe for accumulating fuel, comprising:

a fuel supply apparatus including

a fuel pressure decreasing unit that decreases a fuel pressure in the delivery pipe;

a fuel supply controller that includes a state determining unit which determines fuel leakage from a fuel injection valve to which fuel is supplied from the delivery pipe, and a fuel pressure controlling unit which activates the fuel pressure decreasing unit when the fuel leakage is expected, the fuel injection valve injecting fuel into the combustion chamber; and

an activating unit that intermittently activates the fuel supply controller while operation of the internal combustion engine is under suspension, and operates even while the fuel supply controller is under suspension.

19. An internal combustion engine provided with a delivery pipe for accumulating fuel, comprising:

a fuel supply apparatus including

a fuel pressure decreasing unit that decreases a fuel pressure in the delivery pipe;

a fuel feeding unit that supplies fuel to the delivery pipe;

a fuel supply controller that includes a state determining unit which determines at least one of bubble generation in fuel in the delivery pipe and fuel leakage from a fuel injection valve to which fuel is supplied from the delivery pipe, and a fuel pressure controlling unit which activates the fuel feeding unit when the bubble generation is expected and activates the fuel pressure decreasing unit when the fuel leakage is expected, the fuel injection valve injecting fuel into the combustion chamber; and

an activating unit that intermittently activates the fuel supply controller while operation of the internal combustion engine is under suspension, and operates even while the fuel supply controller is under suspension.