After-burner heated catalyst system and associated control circuit and method

• US 5,802,844 A
• Filed: 06/30/1995
• Issued: 09/08/1998
• Est. Priority Date: 06/30/1995
• Status: Expired due to Term

• Current Assignee: FCA US LLC (Stellantis NV)
• Original Assignee: Chrysler Corporation (Stellantis NV)
• Inventors: Hartwick, Larry R., Pyko, Jan S., Lee, Anson, Poublon, Mark J.
• Primary Examiner(s): LOOK, EDWARD K
• Application Number:
  US08/497,592
• Time in Patent Office: 1,166 Days
• Field of Search: 60/274, 60/284, 60/286, 60/300
• US Class Current: 60/274
• CPC Class Codes: F01N 3/2033 using a fuel burner or introducing fuel into exhaust duct
• CPC Class Codes: F01N 9/00 Electrical control of exhaust gas treating apparatus monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00; conjoint electrical control of two or more combustion engine functions F02D43/00
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An after-burner heated catalyst control system and associated control circuit for controlling operation of an after-burner heated catalyst. The control circuit has an air pump motor, a spark plug, and a fuel injector, while the catalyst is disposed within an exhaust passageway of the engine. The control circuit further includes an apparatus for controlling operation of and pulse wave modulating the air pump motor, one spark plug, and fuel injector. An RS232 interface is provided for transmitting and receiving data from and to the control circuit. In addition a method is provided for controlling a temperature of an after-burner heated catalyst and adjusting adaptively the pulse wave modulation of the air pump motor, spark plug, and fuel injector.

Claims

1. In an after-burner heated catalyst control system and an associated control circuit for controlling an after-burner heated catalyst, the after-burner heated catalyst control system having an air pump motor, a spark plug, and a fuel injector each having a signal frequency and a duty cycle, the control circuit comprising:

a device for controlling the air pump motor electrically coupled to the air pump motor, the device for controlling the air pump motor supplying electrical power to the air pump motor;

a device for controlling the spark plug electrically coupled to the spark plug, the device for controlling the spark plug supplying electrical power to the spark plug;

a device for controlling the fuel injector electrically coupled to the fuel injector, the device for controlling the fuel injector supplying electrical power to the fuel injector;

a communications interface for transmitting and receiving data communications of the control circuit; and

a microprocessing unit for individually controlling the signal frequency and the duty cycle of the air pump motor, the spark plug, and the fuel injector, the microprocessing unit being electrically coupled to the communications unit, spark plug, and the air pump motor, and having memory, a bus line, and a software program stored in the memory for executing a method for controlling operation of the after-burner heated catalyst, the method comprising the steps of;

determining the signal frequency and the duty cycle of the fuel injector and the air pump motor;

determining a temperature of the after-burner heated catalyst and a fuel injector "on" time;

pulse width modulating the fuel injector and the air pump motor if the temperature of the after-burner heated catalyst and the fuel injector "on" time are less than set limits stored in the memory of the microprocessing unit; and

disabling operation of the fuel injector if the temperature of the after-burner heated catalyst and the fuel injector "on" time are greater than set limits stored in the memory of the microprocessing unit.

2. The control circuit of claim 1 wherein the communications interface comprises an RS232 interface.

3. The control circuit of claim 2 further comprises a potentiometer for varying a voltage signal supplied to the microprocessing unit, the potentiometer electrically coupled to the microprocessing unit.

4. In an after-burner heated catalyst control system and an associated control circuit for controlling an after-burner heated catalyst, the after-burner heated catalyst control system having an air pump motor, a spark plug, and a fuel injector each having a signal frequency and a duty cycle, the control circuit comprising:

a device for controlling the air pump motor electrically coupled to the air pump motor, the device for controlling the air pump motor supplying electrical power to the air pump motor;

a device electrically coupled to the spark plug for supplying power and for controlling the spark plug;

a device for controlling the fuel injector electrically coupled to the fuel injector, the device for controlling the fuel injector supplying electrical power to the fuel injector;

a microprocessing unit for individually controlling the signal frequency and the duty cycle of the air pump motor, the spark plug, and the fuel injector, the microprocessing unit being electrically coupled to the air pump motor, the spark plug, and the fuel injector, and having memory, a bus line, and a software program stored in the memory for executing a method for controlling operation of the after-burner heated catalyst, the method comprising the steps of;

determining a flow rate of air exiting the air pump motor, the signal frequency and the duty cycle of the air pump motor;

adjusting the flow rate of air exiting the air pump motor via pulse width modulation of the air pump motor by the microprocessing unit if a spark plug "on" time is less than a set limit stored in the memory of the microprocessing unit;

disabling operation of the spark plug if the spark plug "on" time is greater than the set limit stored in the memory of the microprocessing unit;

adjusting the flow rate of air exiting the air pump motor via pulse width modulation of the air pump motor by the microprocessing unit if an air pump motor "on" time is less than a set limit stored in the memory of the microprocessing unit; and

disabling operation of the air pump motor if the air pump motor "on" time is greater than the set limit stored in the memory of the microprocessing unit.

5. The method of claim 4 wherein the communications interface comprises an RS232 interface.

6. The method of claim 5 further comprises a potentiometer for varying a voltage signal supplied to the microprocessing unit, the potentiometer electrically coupled to the microprocessing unit.

7. In an after-burner heated catalyst system and an associated method for controlling operation of an after-burner heated catalyst, the after-burner heated catalyst system having, an air pump motor, a spark plug, a fuel injector, and a microprocessing unit with memory, the air pump motor, spark plug, and fuel injector having a signal frequency and a duty cycle, the method comprising the steps of:

determining a flow rate of air exiting the air pump motor, the signal frequency, and the duty cycle of the air pump motor;

determining a temperature of the after-burner heated catalyst and a fuel injector "on" time;

adjusting adaptively pulse wave modulation of the air pump motor if the temperature of the after-burner heated catalyst and the fuel injector "on" time are less than set limits stored in the memory of the microprocessing unit;

disabling operation of the fuel injector if the temperature of the after-burner heated catalyst and the fuel injector "on" time are greater than set limits stored in the memory of the microprocessing unit;

adjusting the flow rate of air exiting the air pump motor via pulse width modulation of the air pump motor by the microprocessing unit if a spark plug "on" time is less than a set limit stored in the memory of the microprocessing unit;

disabling operation of the spark plug if the spark plug "on" time is greater than the set limit;

adjusting the flow rate of air exiting the air pump motor via pulse width modulation of the air pump motor by the microprocessing unit if an air pump motor "on" time is less than a set limit stored in the memory of the microprocessor; and

disabling operation of the air pump motor if the air pump motor "on" time is greater than the set limit.