Engine fault analysis on catalytic converter equipped autos

• US 4,175,427 A
• Filed: 08/14/1978
• Issued: 11/27/1979
• Est. Priority Date: 08/14/1978
• Status: Expired due to Term

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Beckman Instruments, Inc. (Danaher Corporation)
• Inventors: Blanke, John D.
• Primary Examiner(s): Myracle, Jerry W.
• Application Number:
  US05/933,246
• Time in Patent Office: 470 Days
• Field of Search: 73/118, 73/116, 73/23, 73/117, 73/117.3, 123/119 R, 364/431
• US Class Current: 73/114.71
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 11/007 the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus
• CPC Class Codes: F01N 2550/02 Catalytic activity of catalytic converters
• CPC Class Codes: G01M 15/102 by monitoring exhaust gases
• CPC Class Codes: G01M 15/104 using oxygen or lambda-sensors testing catalytic converters F01N3/18, F01N11/007
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An apparatus and method to isolate faults in a catalytic converter equipped internal combustion engine.

The exhaust is analyzed to determine hydrocarbon content, carbon monoxide content and oxygen content and this data is processed through an electronic circuit which accumulates information to be disclosed at the termination of testing.

Claims

1. Apparatus for isolating engine and catalytic converter problems on a catalytic converter equipped internal combustion engine having an exhaust, said engine having an idle state and an off idle state, said apparatus comprising:

analyzer means associated with the exhaust of the internal combustion engine for determining a carbon monoxide content, an oxygen content, and a hydrocarbon content of the exhaust and producing a first, second and third signal respectively proportionate thereto;

first means connected to said analyzer means for producing a first output when said first signal exceeds a first predetermined maximum and said first signal is greater than said second signal while said engine is in said idle state;

second means connected to said analyzer means for producing a second output whenever said first signal exceeds said predetermined maximum and said second signal is greater than said first signal while said engine is in said idle state;

third means connected to said analyzer means for producing a third output whenever said third signal exceeds a second predetermined maximum and said first signal is greater than said second signal while said engine is in said idle state;

fourth means connected to said analyzer means for producing a fourth output whenever said third signal exceeds said second predetermined maximum and said second signal is greater than said first signal while said engine is in said idle state;

fifth means connected to said analyzer means for producing a fifth output whenever said first signal exceeds a third predetermined maximum and said first signal is greater than said second signal while said engine is in said off idle state;

sixth means connected to said analyzer means for producing a sixth output whenever said first signal exceeds said third predetermined maximum and said second signal is greater than said first signal while said engine is in said off idle state;

seventh means connected to said analyzer means for producing a seventh output whenever said third signal exceeds a fourth predetermined maximum and said first signal is greater than said second signal while said engine is in said off idle state;

eighth means connected to said analyzer means for producing an eighth output whenever said third signal exceeds said fourth predetermined maximum and said second signal is greater than said first signal while said engine is in said off idle state; and

display means connected to first means, second means, third means, fourth means, fifth means, sixth means, seventh means and eighth means for producing information in response to said first, second, third, fourth, fifth, sixth, seventh and eighth outputs.

2. The apparatus according to claim 1 wherein said analyzer means comprises:

a CO means for determining said carbon monoxide content and producing said first signal proportionate thereto;

an O₂ means for determining said oxygen content and producing said second signal proportionate thereto; and

an HC means for determining said hydrocarbon content and producing said third signal proportionate thereto.

3. The apparatus according to claim 1 wherein said display means comprises a cathode ray tube.

4. The apparatus according to claim 1 wherein said display means comprises a series of lights.

5. An apparatus for isolating engine and catalytic converter problems on a catalytic converter equipped internal combustion engine with an exhaust, said engine having an idle state and an off-idle state, said apparatus comprising:

analyzer means associated with the exhaust of the internal combustion engine for determining a carbon monoxide content, an oxygen content, and a hydrocarbon content of the exhaust and producing a first, second, and third signal respectively proportionate thereto;

a response means connected to said analyzer means for producing a first output whenever said first signal exceeds a first predetermined maximum and said first signal is greater than said second signal, a second output when the first signal exceeds said first predetermined maximum and second signal is greater than said first signal, a third output whenever said third signal exceeds a second predetermined maximum and said first signal is greater than said second signal, and a fourth output whenever said third signal exceeds said second predetermined maximum and said second signal is greater than said first signal, while said internal combustion engine is in said idle state, and while said internal combustion engine is in said off idle state for producing a fifth output whenever said first signal exceeds a third predetermined maximum and said first signal is greater than said second signal, a sixth output whenever said first signal exceeds said third predetermined maximum and said second signal is greater than said first signal, a seventh output whenever said third signal exceeds a fourth predetermined maximum and said first signal is greater than said second signal and an eighth output whenever said third signal exceeds said fourth predetermined maximum and said second signal is greater than said first signal; and

display means connected to said response means for producing information in response to said first, second, third, fourth, fifth, sixth, seventh, and eighth outputs.

6. The apparatus according to claim 5 wherein said analyzer means comprises:

first means for determining said carbon monoxide content and producing said first signal proportionate thereto;

second means for determining oxygen content and producing said second signal proportionate thereto; and

third means for determining said hydrocarbon content and producing said third signal proportionate thereto.

7. The apparatus according to claim 6 wherein said response means comprises a programmable microprocessor.

8. The apparatus according to claim 7 wherein said display means comprises a cathode ray tube.

9. The apparatus according to claim 7 wherein said display means comprises a series of lights.

10. In combination:

a catalytic converter equipped internal combustion engine having an exhaust;

analyzer means associated with the exhaust of the internal combustion engine for determining a carbon monoxide content, and oxygen content, and a hydrocarbon content of the exhaust and producing a first, second, and third signal respectively proportionate thereto;

a response means connected to said analyzer means for producing a first output whenever said first signal exceeds a first predetermined maximum and said first signal is greater than said second signal, a second output when the first signal exceeds said first predetermined maximum and second signal is greater than said first signal, a third output whenever said third signal exceeds a second predetermined maximum and said first signal is greater than said second signal, and a fourth output whenever said third signal exceeds said second predetermined maximum and said second signal is greater than said first signal, while said internal combustion engine is in said idle state, and while said internal combustion engine is in said off idle state for producing a fifth output whenever said first signal exceeds a third predetermined maximum and said first signal is greater than said second signal, a sixth output whenever said first signal exceeds said third predetermined maximum and said second signal is greater than said first signal, a seventh output whenever said third signal exceeds a fourth predetermined maximum and said first signal is greater than said second signal and an eighth output whenever said third signal exceeds said fourth predetermined maximum and said second signal is greater than said first signal; and

display means connected to said response means for producing information in response to said first, second, third, fourth, fifth, sixth, seventh, and eighth outputs.

11. A method for isolating engine and catalytic converter problems on a catalytic converter equipped internal combustion engine including the steps of:

operating the internal combustion engine at an idle speed;

sensing the carbon monoxide emissions in the exhaust of said internal combustion engine and producing a first output when said carbon monoxide emissions exceed a first predetermined maximum and said carbon monoxide emissions exceed oxygen emissions while producing a second output if said oxygen emissions exceed said carbon monoxide emissions;

sensing the hydrocarbon emissions in the exhaust of said internal combustion engine and producing a third output if said hydrocarbon emissions are greater than a second predetermined maximum and said carbon monoxide emissions are greater than said oxygen emissions while producing a fourth output when said oxygen emissions are greater than said carbon monoxide emissions;

operating the internal combustion engine at an off-idle speed;

sensing the carbon monoxide emission in the exhaust of said internal combustion engine and producing a fifth output when said carbon monoxide emissions are greater than a third predetermined maximum and said carbon monoxide emissions are greater than said oxygen emissions while producing a sixth output when said oxygen emissions are greater than said carbon monoxide emissions; and

sensing said hydrocarbon emissions in the exhaust of said internal combustion engine and producing a seventh output when said hydrocarbon emissions exceed a fourth predetermined maximum and said carbon monoxide emissions are greater than said oxygen emissions while producing an eighth output when said oxygen emissions are greater than said carbon monoxide emissions.

12. An apparatus for isolating problems in a catalytic converter equipped internal combustion engine having an idle state and an off idle state, said engine including a carburetor and exhaust, said apparatus comprising:

analyzer means for sensing carbon monoxide emissions, oxygen emissions and hydrocarbon emissions in said exhaust;

first means for producing a first response whenever said carburetor is out of balance as indicated by one of high carbon monoxide emissions while said engine is in said idle state or high hydrocarbon emissions with carbon monoxide emissions are greater than oxygen emissions while said engine is in said idle state;

second means for producing a second response whenever said carburetor needs to be overhauled as indicated by one of high carbon monoxide emissions while said engine is in said off idle state or high hydrocarbon emissions with carbon monoxide emissions greater than oxygen emissions while said engine is in said off idle state;

third means for producing a third response whenever said engine needs a tune up as indicated by high hydrocarbon emissions; and

fourth means for producing a fourth response whenever the catalytic converter needs to be replaced as indicated by one of high carbon monoxide emissions with oxygen emissions greater than carbon monoxide emissions or high hydrocarbon emissions with oxygen emissions greater than carbon monoxide emissions.