Procedure to operate a fuel system of an internal combustion engine

• US 20080004786A1
• Filed: 06/28/2007
• Published: 01/03/2008
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Matischok, Marcel, Posselt, Andreas, Lorenz, Marko
• Granted Patent: US 7,481,202 B2
• Time in Patent Office: Days
• US Class Current: 701/101
• CPC Class Codes: F02D 1/02 not restricted to adjustment of injection timing, e.g. varying amount of fuel delivered
• CPC Class Codes: F02D 2041/225 Leakage detection
• CPC Class Codes: F02D 2200/0606 Fuel temperature
• 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 41/0235 in relation with the state of the exhaust gas treating apparatus control of exhaust gas treating apparatus per se F01N
• CPC Class Codes: F02D 41/0255 to accelerate the warming-up of the exhaust gas treating apparatus at engine start
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: F02D 41/064 at cold start F02D41/067 takes precedence
• CPC Class Codes: F02D 41/3082 Control of electrical fuel pumps
• CPC Class Codes: F02D 41/3845 by controlling the flow into the common rail, e.g. the amount of fuel pumped
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

In the operation of a fuel system (10) of an internal combustion engine (12), the fuel is compressed by a fuel pump (20) and travels by way of at least one fuel injection device (24) into at least one combustion chamber (36) of the internal combustion engine (12). It is proposed that at least periodically during a phase immediately when starting or just after starting the internal combustion engine (12), the fuel pump (20) is actuated corresponding to an increased set point pressure. An increase in the set point pressure, however, is blocked if at least one blocking condition is met.

Claims

1. Procedure to operate a fuel system (10) of an internal combustion engine (12), in which the fuel is compressed by a fuel pump (20) and travels by way of at least one fuel injection device (24) into at least one combustion chamber (36) of the internal combustion engine (12) is thereby characterized;

in that at least periodically during a phase immediately when starting or just after starting the internal combustion engine (12), the fuel pump (20) is actuated corresponding to an increased set point pressure (pincr); and

in that an increase of the set point pressure (pincr) is, however, blocked, if at least one blocking condition is met (B2=false).

2. Procedure according to claim 1 is thereby characterized, in that the blocking condition is met if a degree (wist) to which a catalytic converter assembly (42) of the internal combustion engine (12) is heated up at least achieves a threshold state (G1).

3. Procedure according to one of the claims 1 or 2 is thereby characterized, in that the blocking condition is met if the set point pressure (psol) has already at least once been increased within the existing operating cycle (B1=true).

4. Procedure according to one of the preceding claims is thereby characterized, in that the blocking condition is met, if a variable (tfuel), which characterizes an actual temperature of the fuel system (10), especially of the fuel pump (20) or of a fuel filter (18), achieves or exceeds a threshold value (G2).

5. Procedure according to one of the preceding claims is thereby characterized, in that the blocking condition is met if a time (TN), which has elapsed since starting (B3) the internal combustion engine (12), achieves or exceeds a threshold value (TL).

6. Procedure according to one of the preceding claims is thereby characterized, in that the blocking condition is met if a release of the air bag was requested (B4 true) in a motor vehicle, in which the fuel system (10) is installed.

7. Procedure according to one of the preceding claims is thereby characterized, in that the blocking condition is met if at least one certain error (C1, C2) was detected in the fuel system (10).

8. Procedure according to one of the preceding claims is thereby characterized, in that the increased set point pressure (pincr) is a function of a set point output rate (v) and an actual supply voltage (u) of the fuel pump (20).

9. Procedure according to one of the preceding claims is thereby characterized, in that the normal set point pressure (pnorm) is a function of a rotational speed of the crankshaft (54) of the internal combustion engine (10) and of a relative filling of the cylinder(s) with air (r1);

and in that the increased set point pressure (pincr) is dependent on a variable (tfuel), which characterizes an actual fuel temperature, in such a way that the set point (pincr) is more dramatically increased at a higher fuel temperature (tfuel) than at a lower fuel temperature (tfuel).

10. Computer program is thereby characterized, in that it is programmed for use in one procedure according to one of the preceding claims.

11. Electrical storage medium for an open-loop and/or closed-loop control device (44) of a fuel system (10) of an internal combustion engine (12) is thereby characterized, in that a computer program for use in a procedure of claims 1 to 9 is stored on it.

12. Open-loop and/or closed-loop control device (44) for a fuel system (10) of an internal combustion engine (12) is thereby characterized, in that it is programmed for use in a procedure according to one of the claims 1 to 9.