ADAPTIVE FUEL DIRECT INJECTION SYSTEM

• US 20140109875A1
• Filed: 04/17/2012
• Published: 04/24/2014
• Est. Priority Date: 05/20/2011
• Status: Active Grant

• Current Assignee: Vitesco Technologies GmbH (INA-Holding Schaeffler GmbH & Co. KG)
• Original Assignee: Continental Automotive France (Continental AG), Continental Automotive GmbH (Continental AG)
• Inventors: Lachaize, Jrme
• Granted Patent: US 9,506,440 B2
• Time in Patent Office: Days
• US Class Current: 123/456
• CPC Class Codes: F02D 41/20 Output circuits, e.g. for controlling currents in command coils
• CPC Class Codes: F02D 41/2464 Characteristics of actuators
• CPC Class Codes: F02D 41/3845 by controlling the flow into the common rail, e.g. the amount of fuel pumped
• 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

Abstract

A direct fuel injection system including a common rail and control unit, a pump, an on/off valve, controlled by the control unit, to regulate the volume of fuel sent to the pump to be fed into the common rail, the control unit including: first determination elements for determining a peak phase duration during which a command must be applied to the valve to obtain a peak current to cause a change of state of the valve; second determination elements for determining a holding ratio according to which a command must be applied to the valve, after its change of state, to maintain a holding current necessary to maintain the state of the valve; application elements for applying the command to the valve first continuously during the peak phase duration and then by pulse width modulation according to the holding ratio; and at least one recurrent and automatic adaptation element.

Claims

1. A direct fuel injection system including a common rail (4) including a control unit (1), a pump (2) and a valve (3), controlled on an on or off basis by the control unit (1), in order to regulate the volume of fuel sent to the pump (2) to be fed into the common rail (4), said control unit (1) comprising

first determination means (40) adapted to determine a first variable (a peak phase duration (27)) during which a command must be applied to the valve (3) in order to obtain a first objective variable (a peak current (38, 60)) greater than or equal to a reference value (a reference peak current (61)) necessary to cause a change of state of the valve (3),

second determination means (70) adapted to determine a second variable (a holding ratio (28)) in accordance with which a command must be applied to the valve (3), after its change of state, in order to maintain a second objective variable (a holding current (39, 90)) greater than or equal to a reference value (a reference holding current (91)) necessary to maintain said state of the valve (3),

application means adapted to apply said command to said valve (3) first continuously during said peak phase duration (27) and then by pulse width modulation in accordance with said holding ratio (28),

adaptation means (42, 72) for the first variable (27) and/or the second variable (28), these adaptation means (42, 72) being recurrent and automatic for said variable (27, 28),

characterized in that said adaptation means (42, 72) are adapted to calculate a coefficient of modulation (42, 73) and to apply it as a multiplier to the variable (27, 28) in order to correct it.

2. The system as claimed in claim 1, wherein said adaptation means (42, 72) further include calculation means (44, 74) adapted to calculate said coefficient of modulation (43, 73) in a recurrent manner as a function of its preceding value (63, 93) and the difference between the objective variable (38, 39, 60, 90) and its reference value (61, 91).

3. The system as claimed in claim 2, wherein said calculation means (44, 74) are adapted to apply the formula:

4. The system as claimed in claim 2, wherein the calculation means (44, 74) are adapted to recalculate the coefficient of modulation (43, 73) periodically.

5. The system as claimed in claim 2, wherein the calculation means (44, 74) are adapted to recalculate the coefficient of modulation (43, 73) if the variable (38, 39, 60, 90) leaves a predefined range.

6. The system as claimed in claim 3, wherein the calculation means (44, 74) are adapted to recalculate the coefficient of modulation (43, 73) periodically.

7. The system as claimed in claim 3, wherein the calculation means (44, 74) are adapted to recalculate the coefficient of modulation (43, 73) if the variable (38, 39, 60, 90) leaves a predefined range.

8. The system as claimed in claim 4, wherein the calculation means (44, 74) are adapted to recalculate the coefficient of modulation (43, 73) if the variable (38, 39, 60, 90) leaves a predefined range.