Internal combustion engine reactor protective control system

• US 4,023,358 A
• Filed: 04/08/1974
• Issued: 05/17/1977
• Est. Priority Date: 04/18/1973
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Maurer, Helmut, Keerl, Karl Heinz
• Primary Examiner(s): Myhre, Charles J.
• Assistant Examiner(s): Argenbright, Tony M.
• Application Number:
  US05/458,777
• Time in Patent Office: 1,135 Days
• Field of Search: 60/277, 60/285, 123/198 D, 123/198 DB, 123/179 L, 123/32 EA
• US Class Current: 60/277
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 2250/04 afterburning and catalytic conversion
• CPC Class Codes: F01N 2430/02 by cutting out a part of engine cylinders
• CPC Class Codes: F01N 2430/06 by varying fuel-air ratio, e.g. by enriching fuel-air mixture
• CPC Class Codes: F01N 3/18 characterised by methods of operation; Control
• 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: F02D 41/1443 with one sensor per cylinder or group of cylinders
• CPC Class Codes: F02P 17/12 Testing characteristics of the spark, ignition voltage or current testing of sparking plugs H01T13/60
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A sensing means is provided to monitor combustion of fuel and air supplied to an internal combustion engine, for example by sensing ignition pulses, combustion pressure, or cylinder temperature. Signals, as sensed, are compared and if one of these signals is extreme with respect to an average and, at the same time, the temperature of a catalytic reactor in the exhaust system becomes excessive, supply of the combustible fuel-air mixture to the specific cylinder is interrupted. To permit starting with unequal heating of cylinders, interruption of supply of the combustible fuel-air mixture is cancelled during starting, as sensed, for example, by closing of the starting switch, or low temperature in the engine system.

Claims

1. In an internal combustion engine system in which the engine has a normal operating temperature above ambient temperature, the system having a catalytic reactor and a reactor protective system including

engine operation sensing means (26-29) located in sensing relation to at least two of the cylinders of the engine and sensing a characteristic of a combustion event in the respective cylinder to monitor combustion of fuel and air supplied thereto, and providing a combustion monitor signal upon detection of conditions indicative of failure of combustion in a respective cylinder;

and

interrupting means (16-19;

     25) controlled by said monitor signal interrupting supply of combustible mixture of air and fuel to the respective cylinder to protect the reactor against entry of uncombusted mixture thereinto,

the improvement comprising

a low-temperature sensor means (45, 23, 24;

26-29) providing an override signal to said interrupting means (16-19;

     25) to disable said interrupting means when the sensed temperature is below normal engine operating temperature level at which the exhaust gases have a predetermined temperature sufficient for detoxification in the catalytic reactor, the sensor being in temperature sensing relation with a component of the engine system and providing an output signal (41'"'"') when the temperature of the component is below said normal level, to disable said interrupting means and permit application of combustible air-fuel mixture to the engine regardless of presence of a combustion monitor signal indicative of failure of combustion.

2. In the system of claim 1, wherein the low temperature sensor means (45) is located in the exhaust system of the engine.

3. In the system of claim 1, wherein the low temperature sensor means (45) is located closely adjacent the engine (1).

4. In the system of claim 1, wherein the engine system includes a motor block component, a motor oil component, a cooling system component;

and the low-temperature sensor means (45) is located in temperature sensing relation with respect to one of said components.

5. In the system of claim 1, further comprising a threshold switch (41) having its input connected to the low-temperature sensor means (45) and providing the override signal to the interrupting means (16-19;

25) when the level of the signal provided by the low-temperature sensor means, and representative of said below normal temperature falls below the threshold level of said threshold switch.

6. In the system of claim 1, wherein the engine system includes a starter switch (42) and connecting circuit means interconnecting the starter switch (42) and said interrupting means (16-19;

25) and providing a start-override signal to the interrupting means to disable said interrupting means upon operation of said starter switch and permit application of combustible air-fuel mixture to the engine regardless of presence of a combustion monitor signal indicative of failure of combustion.

7. In the system of claim 6, wherein the connecting circuit means comprises a timing circuit (44) connected to and controlling disabling of said interrupting means (16-19;

25), said starter switch (42) being connected to said timing circuit to energize the timing circuit and thus start a timing period to disable the interrupting means during the timing period commencing upon starting of the engine.

8. In the system of claim 7, wherein the time interval of the timing means is about 15-60 seconds.