Method for operating an internal combustion engine and device for the openloop and closed-loop control of an internal combustion engine, injection system, and internal combustion engine

Patent metadata

Field	Value
Publication number	US-2016298570-A1
Application number	US-201415028565-A
Country	US
Kind code	A1
Filing date	Aug 21, 2014
Priority date	Oct 11, 2013
Publication date	Oct 13, 2016
Grant date	—

Abstract

A method for operating an internal combustion engine having a motor with cylinder and an injection system having a common rail and injectors for the cylinders. Each injector has an accumulator for holding fuel from the common rail. A multiple injection of fuel is performed during each working cycle of a cylinder, including injecting a first amount in a first injection and injecting a second amount in a second injection, and determining fuel pressure for the common rail and/or the accumulator. A fuel injection amount parameter is determined for the first injection; an individual accumulator pressure and/or a common rail pressure is determined for the second injection; and a fuel injection amount parameter is determined for the second injection. The individual accumulator pressure and/or the common rail pressure are/is considered for determining the injection amount parameter of the fuel for the second injection.

First claim

1 - 17 . (canceled)

18 . A method for operating an internal combustion engine having a motor with a number of cylinders and an injection system having a common rail and a number of injectors assigned to the cylinders, wherein an injector is assigned an individual accumulator that holds fuel from the common rail available for the injector, wherein the method comprises the steps of:
injecting fuel by an injector into a cylinder, wherein a multiple injection is performed during each working cycle of a cylinder, having the steps: injecting a first injection quantity of fuel in a first, preceding injection and injecting a second injection quantity of fuel in a second, subsequent injection, and determining a fuel pressure for the common rail and/or the individual accumulator, determining an injection quantity parameter for the first, preceding injection; determining an individual-accumulator pressure and/or a common rail pressure for the second, subsequent injection, and determining an injection quantity parameter for the second, subsequent injection, by selecting and taking into consideration the individual-accumulator pressure and/or the common rail pressure in order to determine the injection quantity parameter for the second, subsequent injection.

19 . The method as claimed in claim 18 , including determining the injection quantity parameter for the first, preceding injection and/or the second, subsequent injection with adaptation of an energization duration and/or a start of energization.

20 . The method as claimed in claim 19 , including carrying out the determination of the injection quantity parameter with formation of at least one characteristic map value in each case of the energization duration and/or of a start of energization and/or with specification of a corrective value of a predefined standard value in each case of the energization duration and/or of a start of energization of the injector.

21 . The method as claimed in claim 18 , including determining the injection quantity parameter for the second, subsequent injection in a manner dependent on a threshold value formed in order to indicate an adaptation-relevant deviation of the individual-accumulator pressure from the common-rail pressure.

22 . The method as claimed in claim 21 , wherein the deviation is a difference between an individual-accumulator pressure and a common rail pressure for the second injection.

23 . The method as claimed in claim 18 , comprising the further steps of:
determining an injection interval duration between the first injection and the second injection, and determining an individual-accumulator pressure in order to determine the injection quantity parameter for the second, subsequent injection.

24 . The method as claimed in claim 23 , wherein the determination of the individual-accumulator pressure is performed at least in a manner dependent on the injection quantity parameter for the first, preceding injection and on the injection interval duration.

25 . The method as claimed in claim 18 , wherein the injection quantity parameter is an injection quantity itself in the case of the first injection, and/or the injection quantity parameter comprises an injection duration and/or a start of injection in the case of the second injection.

26 . The method as claimed in claim 25 , herein the injection quantity parameter is a setpoint and/or an, actual value of the injection quantity.

27 . The method as claimed in claim 23 , wherein the injection interval duration is determined from an injection end of the first, preceding injection and a start of injection of the second, subsequent injection.

28 . The method as claimed in claim 18 , wherein the individual-accumulator pressure for the second, subsequent injection is determined analytically and/or by interpolation of a pressure profile of the individual-accumulator pressure from a characteristic map.

29 . The method as claimed in claim 23 , wherein in the event that
the injection quantity of the first, preceding injection lies above an injection quantity threshold value and/or the injection interval duration lies below an injection interval threshold value, the individual-accumulator pressure rather than the common rail pressure is predefined for the determination of the injection quantity of the fuel for the second, subsequent injection, and/or in the event that the first injection quantity lies below an injection quantity threshold value and/or the injection interval duration lies above an injection interval threshold value the common rail pressure rather than the individual-accumulator pressure is predefined for the determination of the injection quantity of the fuel for the second, subsequent injection.

30 . The method as claimed in claim 18 , including forming a learning characteristic map as an injector-specific learning characteristic map, and/or configuring a control characteristic map for a setpoint injector, wherein the injection quantity is that of a setpoint injector that is corrected by a value obtained by selecting and taking into consideration the individual-accumulator pressure and/or the common rail pressure for the second, subsequent injection.

31 . The method as claimed in claim 30 , including recording the individual-accumulator pressure in a learning characteristic map that is generated by an appraisal algorithm, wherein the appraisal algorithm generates an output value that is input into the learning characteristic map via a weighting and/or evaluation process.

32 . The method as claimed in claim 30 , including recording the individual-accumulator pressure in a learning characteristic map that is based on a control algorithm, wherein the control algorithm generates an output value that is input into a control characteristic map.

33 . A device for controlling and/or regulating an internal combustion engine, comprising: a motor regulator; and an injection processor module designed for carrying out a method as claimed in claim 18 , wherein the motor regulator has a control characteristic r tap and the injection processor module has a learning characteristic map.

23 . An injection system, comprising: a common rail for an internal combustion engine having a motor with a number of cylinders, and a number of injectors assigned to the cylinders, wherein an injector is assigned an individual accumulator designed for holding fuel from the common rail available for injection into the cylinder; and a device according to claim 33 for controlling and/or regulating the internal combustion engine.

35 . An internal combustion engine, comprising: a motor that has a number of cylinders; and an injection system according to claim 34 having a common rail and having a number of injectors.

Assignees

• Mtu Friedrichshafen Gmbh

Inventors

• Gölz Markus
• Gerbeth Robby
• Mlicki Frank
• Walder Michael
• Engler Carsten
• Mehr Andreas
• Wolf Christian

Classifications

• F02D41/402 Primary

  Multiple injections · CPC title

• F02D41/3809

  Common rail control systems (common rail apparatus F02M55/025, F02M63/0225) · CPC title

• F02D2250/04

  Fuel pressure pulsation in common rails · CPC title

• F02D2200/0602

  Fuel pressure · CPC title

• Y02T10/40

  Engine management systems · CPC title