Method for controlling an engine to obtain rapid catalyst heating

• US 7,032,572 B2
• Filed: 06/04/2002
• Issued: 04/25/2006
• Est. Priority Date: 06/04/2002
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Surnilla, Gopichandra, Bidner, David Karl
• Primary Examiner(s): HUYNH, HAI H
• Application Number:
  US10/064,016
• Publication Number:
  US 20030221671A1
• Time in Patent Office: 1,421 Days
• Field of Search: 123/329, 123/406.53, 123/406.72, 123/406.47, 123/443, 123/481, 701/113, 602/74, 602/84, 602/85
• US Class Current: 123/406.47
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 13/011 having two or more purifying devices arranged in parallel
• CPC Class Codes: F01N 13/107 More than one exhaust manifold or exhaust collector
• CPC Class Codes: F01N 2430/02 by cutting out a part of engine cylinders
• CPC Class Codes: F01N 3/0814 combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
• CPC Class Codes: F01N 3/0842 Nitrogen oxides
• CPC Class Codes: F01N 3/2006 Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F02D 2200/0402 the parameter being determined by using a model of the engine intake or its components
• CPC Class Codes: F02D 2200/0404 Throttle position
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 41/0032 Controlling the purging of the canister as a function of the engine operating conditions
• CPC Class Codes: F02D 41/0035 to achieve a special effect, e.g. to warm up the catalyst
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/0245 by increasing temperature of the exhaust gas leaving the engine
• CPC Class Codes: F02D 41/1443 with one sensor per cylinder or group of cylinders
• CPC Class Codes: F02D 41/1456 with sensor output signal being linear or quasi-linear with the concentration of oxygen
• CPC Class Codes: F02D 41/2461 by learning a value and then controlling another value
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A method is disclosed for controlling operation of an engine coupled to an exhaust treatment catalyst. Under predetermined conditions, the method operates an engine with a first group of cylinders combusting a lean air/fuel mixture and a second group of cylinders pumping air only (i.e., without fuel injection). In addition, the engine control method also provides the following features in combination with the above-described split air/lean mode: idle speed control, sensor diagnostics, air/fuel ratio control, adaptive learning, fuel vapor purging, catalyst temperature estimation, default operation, and exhaust gas and emission control device temperature control. In addition, the engine control method also changes to combusting in all cylinders under preselected operating conditions such as fuel vapor purging, manifold vacuum control, and purging of stored oxidants in an emission control device.

Claims

1. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:

starting the engine by firing cylinders from both cylinder groups; and

then operating the first group of cylinders at a first ignition timing and rich of stoichiometry; and

operating the second group of cylinders at a second ignition timing more retarded than said first group and lean of stoichiometry.

2. The method recited in claim 1 wherein said first ignition timing is retarded from a maximum torque ignition timing.

3. The method recited in claim 1 wherein said second ignition timing is retarded more than 10 degrees from said first ignition timing.

4. The method recited in claim 1 wherein said operation is carried out during engine idle speed control.

5. A method for controlling an engine have at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:

starting the engine by firing cylinders from both cylinder groups; and

then transitioning to;

operating the first group of cylinders at a first ignition timing; and

operating the second group of cylinders at a second ignition timing more retarded than said first group;

and then transitioning to;

operating the first group at said first ignition timing and rich of stoichiometry; and

operating the second group at said second ignition timing and lean of stoichiometry.

6. The method recited in claim 5 wherein said first ignition timing is retarded from a maximum torque timing.