SYSTEM FOR ANALYZING ENGINE PERFORMANCE

• US 3,777,559 A
• Filed: 04/21/1972
• Issued: 12/11/1973
• Est. Priority Date: 04/21/1972
• Status: Expired due to Term

• Current Assignee: Northrop Corporation (Northrop Grumman Corporation)
• Original Assignee: Clarence L. Almich, John D. Shore, Lyle V. Rennick, Ronald B. Weiss, William L. Mitchael
• Inventors: Rennick, Lyle V., Mitchael, William L., Almich, Clarence L., Shore, John D., Weiss, Ronald B.
• Primary Examiner(s): Myracle, Jerry W.
• Application Number:
  US05/246,142
• Time in Patent Office: 599 Days
• Field of Search: 73/116,117.3
• US Class Current: 73/114.28
• CPC Class Codes: F02P 17/02 Checking or adjusting ignition timing
• CPC Class Codes: G01M 15/05 by combined monitoring of two or more different engine parameters

Abstract

A first counter is driven by pulses from a signal generator. A second counter is driven by the output of the signal generator divider by a factor in accordance with the number of cylinders in the engine under test. The output of the second counter is shifted to a register in response to a pulse which is phase synchronized with a predetermined point in the rotation cycle of the engine. The output of the register and the output of the first counter are compared for coincidence, a coincidence signal being generated which corresponds to a predetermined point in the cycle of each of the engine cylinders. These coincidence signals are used to generate window signals which provide gating signals to sensor circuits. The sensor circuits receive the outputs of sensors which provide electrical signals in accordance with various engine parameters. The outputs of the sensor circuits are gated to an indicator by the window signals so that the sensed parameters can be observed at predetermined identifiable portions of each engine rotation cycle.

Claims

1. In a system for determining the performance of an internal combustion engine having a plurality of cylinders, said system including means for sensing various engine operating parameters, the improvement comprising means for indicating the values of said parameters during a precisely defined portion of the engine operating cycle, comprising:

means for generating a reference pulse signal indicative of a predetermined point in each operating cycle of the engine, means for generating a train of pulses, a first counter means for counting the output of said pulse train generating means, divider means for Dividing the output of said pulse train generating means by a factor corresponding to the number of cylinders in said engine, second counter means for counting the output of said divider means, register means for receiving the output count of said second counter means, the output of said reference signal generating means being fed to said second counter means and said register means to provide a reset signal therefor, comparator means receiving the outputs of said first counter means and said register means for generating an output signal when the output of said register means corresponds to the output of said first counter means, the output of said comparator means corresponding to the operating cycle of each of the engine cylinders, window generator means for generating window signals in response to the output of said comparator means, sensor circuit means for receiving the outputs of said sensing means and generating a signal in accordance therewith, said sensor circuit means including a gating circuit, and indicator means for receiving the outputs of said sensor circuit means and providing an indication thereof, the window signals being fed to the gating circuit of said sensor circuit means to gate the outputs thereof to said indicator means at preselected portions of the rotation cycle of said engine.

2. The system of claim 1 wherein said window generator means includes means for adjusting the width and position of the window.

3. The system of claim 1 wherein said sensor circuit means comprises means for providing a reference voltage and means for comparing the sensing means output with said reference voltage, said voltage being indicative of the tolerance limits of the engine parameter being measured, a signal being provided from said sensor circuit means to said indicator means whenever the sensing means outputs are not within said tolerance limits.

4. The system of claim 1 wherein said window generator means includes a plurality of window generators each for generating a window signal at one of said preselected portions of the rotation cycle of the engine, and further including window selector means for selecting various window outputs of said window generators for use in gating the sensor circuit means.

5. The system of claim 4 and further including a counter responsive to the output of said comparator means for providing a count corresponding to a predetermined point in the operating cycle of each of the cylinders of the engine, the output of said counter being fed to said window selector means for use in gating the window signals to said sensor cirucit means.

6. The system of claim 1 wherein said means for generating a train of pulses comprises a voltage controlled oscillator and a rate integrator for generating a voltage for controlling said voltage controlled oscillator, said rate integrator operating in response to said reference pulse signal, whereby the frequency of the output of said voltage controlled oscillator is in accordance with the rotation speed of the engine.

7. A system for providing signals indicative of the operating condition of an internal combustion engine having a plurality of cylinders during preselected portions of the operating cycle of said engine comprising:

means for generating a reference pulse signal synchronized with a predetermined point of said cycle, means for generating a train of clock pulses, divider means for dividing said train of pulses by a factor corresponding to the number of cylinders in said engine, first counter means for counting the output of said divider means, a register for registering the count in said first counter in response to the output of said reference pulse signal generating means, second counter means for counting the pulses in said clock pulse train, means for delaying said reference pulse, the output of said delaying means being fed to said first counter means to reset said first counter means, comparator Means for comparing the output of said second counter with the output of said register and for generating a pulse output when these outputs correspond, window generator means responsive to the pulse output of said comparator means for generating a window signal in a predetermined phase relationship with said last mentioned pulse output, sensor means for sensing an operating parameter of the engine, sensor circuit means for generating an output signal in accordance with the sensor means output, said sensor circuit means including a gating circuit, said window signal being fed to the gating circuit of said sensor circuit means to gate said output signal, and indicator means for indicating said output signal.

8. The system of claim 7 wherein said window generator means includes means for adjusting the position and width of the window.

9. The system of claim 7 wherein said means for generating a train of clock pulses comprises a voltage controlled oscillator and a rate integrator connected to said oscillator for generating a voltage for controlling said oscillator, said rate integrator operating in response to said reference pulse signal.

10. The system of claim 7 wherein said sensor circuit means comprises means for providing a reference voltage indicative of the tolerance limits of the parameter sensed by said sensor means and means for comparing the sensor means output with said reference voltage, a signal being provided to said indicator means whenever the sensor means outputs are not within said tolerance limits.