Method for rapid catalyst heating

• US 6,568,177 B1
• Filed: 06/04/2002
• Issued: 05/27/2003
• 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
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): TRAN, BINH Q
• Application Number:
  US10/064,019
• Time in Patent Office: 357 Days
• Field of Search: 602/74, 602/76, 602/85, 602/89, 602/90, 602/84, 123/443, 123/406.23, 123/406.44, 123/481, 123/198.F
• US Class Current: 60/285
• CPC Class Codes: F02D 2200/0804 Estimation of the temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 2250/18 Control of the engine output torque
• CPC Class Codes: F02D 31/002 controlling air supply
• CPC Class Codes: F02D 31/003 for idle speed control
• CPC Class Codes: F02D 41/003 Adding fuel vapours, e.g. drawn from engine fuel reservoir
• CPC Class Codes: F02D 41/0082 per groups or banks F02D41/0087 takes precedence
• 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: F02P 5/1506 with particular means during starting
• CPC Class Codes: F02P 5/1512 with particular means concerning an individual cylinder
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

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 having at least first and second groups of cylinders, the engine coupled to an emission control device, comprising:

providing a request to increase temperature of the emission control device;

in response to said request;

operating the first group of cylinders to induct air with substantially no injected fuel;

operating the second group of cylinders to combust a rich air-fuel mixture; and

adjusting at least airflow entering at least the second group to adjust engine output.

2. The method recited in claim 1 wherein said engine output is engine torque.

3. The method recited in claim 1 wherein said engine output is engine power.

4. The method recited in claim 1 wherein said engine output is engine speed.

5. The method recited in claim 1 wherein said rich air-fuel mixture and said air mix to form a substantially stoichiometric mixture.

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

providing a request to increase temperature of the emission control device;

in response to said request;

operating the first group of cylinders with substantially no injected fuel;

operating the second group of cylinders to combust a rich air-fuel ratio;

adjusting at least airflow entering at least the second group to adjust engine output;

determining a desired mixture air-fuel ratio; and

adjusting at least injected fuel entering the first group of cylinder based on said desired mixture air-fuel ratio.

7. The method recited in claim 6 wherein said desired air-fuel ratio is near stoichiometry.