CONTROL FOR AN ENGINE SYSTEM

• US 3,768,259 A
• Filed: 07/06/1971
• Issued: 10/30/1973
• Est. Priority Date: 07/06/1971
• Status: Expired due to Term

• Current Assignee: David H. Spielberg, Karl J. Youtsey, Robert D. Carnahan
• Original Assignee: David H. Spielberg, Karl J. Youtsey, Robert D. Carnahan
• Inventors: Carnahan, Robert D., Youtsey, Karl J., Spielberg, David H.
• Primary Examiner(s): Hart, Douglas
• Application Number:
  US05/159,936
• Time in Patent Office: 847 Days
• Field of Search: 60/274,276,289,285 204/195S,1T
• US Class Current: 60/276
• CPC Class Codes: F01N 13/008 Mounting or arrangement of exhaust sensors in or on exhaust apparatus sensor arrangements for engine control F02D41/1439
• CPC Class Codes: F01N 2430/06 by varying fuel-air ratio, e.g. by enriching fuel-air mixture
• CPC Class Codes: F01N 3/20 specially adapted for catalytic conversion F01N3/22 takes precedence; Methods of operation or control of catalytic converters
• CPC Class Codes: F01N 3/22 Control of additional air supply only, e.g. using by-passes or variable air pump drives
• CPC Class Codes: F01N 3/222 using electric valves only
• CPC Class Codes: F02D 2700/09 Other ways of controlling
• CPC Class Codes: F02D 41/1476 Biasing of the sensor
• CPC Class Codes: F02D 9/00 Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
• CPC Class Codes: G01N 27/4065 Circuit arrangements specially adapted therefor
• CPC Class Codes: G01N 27/407 for investigating or analysing gases G01N27/411 takes precedence
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A control system for an engine system which utilizes solid oxygen-ion electrolyte oxygen sensing means to generate an electrical signal responsive to the oxygen content of exhaust gases of the engine which in turn is used to control regulating means to vary the character of the exhaust gases issuing from the engine. In a preferred embodiment, the oxygen sensing means is disposed upstream from a catalytic reactor and this establishes means to control the nature of the gases entering such reactor in order to maximize the effect of said reactor. Specifically, the oxygen-ion electrolyte oxygen sensing means may comprise a first and second electrode means connected to the regulating means and spaced by a stabilized solid oxygen sensitive electrolyte, such as zirconia stabilized with calcia, with the first electrode means being in communication with the exhaust gases and the second electrode means being in communication with a reference gas such as atmospheric air.

Claims

2. The engine system of claim 1 wherein said solid electrolyte comprises stabilized zirconia.

3. The engine system of claim 1 wherein said oxygen sensing means includes temperature compensating means connected to said electrode means for compensating for thermal variations of electrical activity of said electrolyte.

4. The engine system of claim 3 wherein said temperature compensating means comprises a thermopile placed in bucking series with said electrodes.

5. The engine system of claim 1 wherein said engine system includes a catalytic reactor for treating said exhaust gases, said oxygen sensing means being mounted in said exhaust path downstream from said catalytic converter.

6. An oxygen sensing device for generating an electrical voltage signal in response to the concentration of oxygen in the exhaust gases in an exhaust conduit of an internal combustion engine when said gases are at a temperature of at least about 700* F, said sensing device comprising a tubular, hollow conductive body;

means for mounting one end of said tubular body in an opening in the exhaust conduit of said internal combustion engine so that its sides are in the path of the exhaust gases following substituted so that the length of the portion of the body which extends into the exhaust path is less than one half the inside width of the exhaust path where the body is mounted, a wafer of oxygen sensitive, stabilized solid electrolyte;

means for sealing said wafer in the said one end of said tubular body, said wafer being sufficiently dense to prevent the passage of gases therethrough;

first and second electrode means affixed to the inner and outer surfaceS, respectively, of said wafer;

said first and second electrode means having lead ends attached thereto, said lead means being accessible at the end of said oxygen sensing device which is remote from said wafer;

said wafer being mounted in said tubular body so as to be adapted to be exposed in an exhaust conduit to a flow of exhuast gases to be sensed across its outer surface;

said inner surface of said wafer being adapted to be exposed to an oxygen containing reference gas contained in an open chamber inside said hollow tubular body, said open chamber being defined on its sides by said hollow tubular body, said open chamber having a volume greater than the displacement volume of the solid electrolyte wafer, said wafer being adapted to be heated during use to a temperature of at least about 700*) F, solely by the heat of the exhaust gases being sensed;

the difference in oxygen partial pressures to which the inner and outer surfaces of said wafer are exposed when heated causing an electrical voltage to be developed between said electrodes.

7. The oxygen sensing device of claim 6 wherein said electrolyte is stabilized zirconia.

8. The oxygen sensing device of claim 6 wherein said oxygen sensing means includes temperature compensating means for compensating for variations in the voltage generated between said electrodes due to variations in the temperature of the exhaust gases.

9. The oxygen sensing device of claim 8 wherein said temperature compensation means comprises a thermally activated voltage generating means for generating a bucking voltage.

10. The oxygen sensing device of claim 9 wherein said bucking voltage is produced by a thermopile placed in bucking series with said electrodes.