Process for finding an additional quantity of fuel to be injected during reinjection in an internal combustion engine

• US 5,839,409 A
• Filed: 10/06/1997
• Issued: 11/24/1998
• Est. Priority Date: 02/06/1996
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Denz, Helmut, Kloos, Alfred, Pfitz, Manfred, Bottcher, Klaus
• Primary Examiner(s): ARGENBRIGHT, TONY MICHAEL
• Application Number:
  US08/930,889
• Time in Patent Office: 414 Days
• Field of Search: 123/325, 123/326, 123/481, 123/492, 123/493
• US Class Current: 123/326
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/047 Taking into account fuel evaporation or wall wetting; special correction after fuel cut-off F02D41/126
• CPC Class Codes: F02D 41/126 transitional corrections at the end of the cut-off period

Abstract

A method for determining an additional injected quantity upon reactivation of an internal combustion engine by multiplying a load-dependent wall-film quantity by a correction factor. The correction factor is modulated up during the coasting deactivation time until reactivation with a first time constant. The correction factor is modulated back down during reactivation with a second time constant.

Claims

1. A method for determining an additional quantity of fuel to be injected upon a reactivation of at least one suppressed cylinder of an internal combustion engine, comprising the steps of:

determining a load-dependent wall-film quantity at a time of activation;

modulating a correction factor, the correction factor being modulated up, during a coasting deactivation time until the reactivation, with a first time constant, and being modulated down during the reactivation with a second time constant; and

multiplying the load-dependent wall-film quantity by the correction factor to determine the additional quantity of fuel.

2. The method according to claim 1, wherein the first and second time constants are load-dependent.

3. The method according to claim 1, wherein the first and second time constants are engine speed dependent.

4. The method according to claim 1, wherein the additional quantity of fuel is set to a value of 0 if a coasting deactivation occurs during a downward modulation of the correction factor.

5. The method according to claim 1, wherein the load-dependent wall-film quantity is determined from a characteristic curve.