Diagnosis of engine power and compression balance
First Claim
1. A method of diagnosing the performance of the cylinders of a multicylinder internal combustion engine, each of said cylinders having a firing interval and the intervals for all of said cylinders forming an engine cycle, said method comprising sensing the substantially instantaneous engine speed at a plurality of angularly spaced positions in the engine cycle, squaring said sensed speeds to obtain a function representing the engine kinetic energy at each of said angular positions, and for each firing interval obtaining the difference between the functions of the kinetic energy at two spaced angular positions.
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Abstract
This disclosure relates to a system for analyzing the performance of a reciprocating piston, internal combustion engine such as a diesel engine. Sensors are connected to the engine, which respond to various operating parameters, and signals representing the parameters are transmitted to computer processing equipment. A speed sensor responds to the movement of an engine part such as the teeth of the engine fly-wheel ring gear, and the processor calculates a function representing the change in the instantaneous engine kinetic energy. The kinetic energy change data are accumulated during an engine acceleration run and again during a deceleration run. The signals from an engine cycle event sensor are processed to indicate the firing intervals of the cylinders and thereby to correlate the engine acceleration and deceleration data. The changes in kinetic energy during the cylinder firing intervals are measured during engine acceleration, and the kinetic energy changes are again measured during deceleration, the two sets of measurements being at substantially the same engine speed. For each cylinder, the measurement on deceleration is subtracted from the related measurement on acceleration, to obtain the net work produced by each cylinder. A similar procedure may be followed to obtain the work done over segments of each firing interval, to thereby check the compression balance of the cylinders.
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Citations
25 Claims
- 1. A method of diagnosing the performance of the cylinders of a multicylinder internal combustion engine, each of said cylinders having a firing interval and the intervals for all of said cylinders forming an engine cycle, said method comprising sensing the substantially instantaneous engine speed at a plurality of angularly spaced positions in the engine cycle, squaring said sensed speeds to obtain a function representing the engine kinetic energy at each of said angular positions, and for each firing interval obtaining the difference between the functions of the kinetic energy at two spaced angular positions.
- 6. A method for diagnosing the performance of the cylinders of a multicylinder internal combustion engine, each of said cylinders having a firing interval and the intervals for all of said cylinders forming an engine cycle, said method comprising sensing the instantaneous engine speed and marking a regularly recurring event in the engine cycle, operating the engine and squaring said engine speed to obtain changes in a function of the kinetic energy during an engine cycle and thereby to identify each of said firing invervals, correlating said identified firing intervals with said cylinders from said event marking, squaring said engine speed during a first operating condition of the engine to obtain the change in the function of the engine kinetic energy over each of said firing intervals, squaring said engine speed during a second operating condition of the engine to obtain the change in the functions of the engine kinetic energy over each of said firing intervals, and obtaining the differences between the first mentioned and second mentioned changes.
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9. A method of diagnosing the performance of the cylinders of a multicylinder internal combustion engine, each of said cylinders having a firing interval and the intervals for all of said cylinders forming an engine cycle, said method comprising sensing the substantially instantaneous engine speed at a plurality of angularly spaced positions in the engine cycle, squaring the engine speeds to obtain the change in a function of the kinetic energy over each of said firing intervals during a first operating condition of the engine, squaring the engine speeds to obtain the change in the function of the kinetic energy over each of said firing intervals during a second operating condition of the engine, and for each of said intervals determining the difference between the function of kinetic energy.
- 10. Apparatus for diagnosing the performance of the cylinders of a multicylinder internal combustion engine, each of said cylinders having a firing interval and the intervals for all of said cylinders forming an engine cycle, comprising speed sensing means for sensing the substantially instantaneous engine speed at a plurality of angularly spaced positions in the engine cycle, and processing means responsive to said speed sensing means for squaring the engine speeds to obtain the change in a function of the kinetic energy over each of said firing intervals during a first operating condition of the engine, for squaring the engine speeds to obtain the change in the function of the kinetic energy over each of said firing intervals during a second operating condition of the engine, and for each of said intervals determining the difference between the functions of the kinetic energy.
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17. Apparatus for diagnosing the performance of the cylinders of a multicylinder internal combustion engine, each of said cylinders having a firing interval and the intervals for all of said cylinders forming an engine cycle, said apparatus comprising means for sensing the substantially instantaneous engine speed at a plurality of angularly spaced positions in the engine cycle, means for determining functions of the engine by squaring the engine speed kinetic energy at each of said angular positions, and means for obtaining the difference between the functions of kinetic energies at two spaced angular positions for each firing interval.
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18. A method for diagnosing the performance of the cylinders of a multicylinder internal combustion engine, each of said cylinders having a firing interval and the intervals for all of said cylinders forming an engine cycle, said method comprising sensing the instantaneous engine speed and marking a regularly recurring event in the engine cycle, operating the engine and processing said engine speed to obtain functions of the changes in kinetic energy during an engine cycle and thereby to identify each of said firing intervals, correlating said identified firing intervals with said cylinders from said event marking, processing said engine speed during a first operating condition of the engine to obtain the change in the function of the engine kinetic energy over each of said firing intervals by squaring said engine speeds, processing said engine speed during a second operating condition of the engine to obtain the change in the functions of the engine kinetic energy over each of said firing intervals by squaring said engine speeds, and obtaining the differences between the first mentioned and second mentioned changes.
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19. Apparatus for diagnosing the power balance of the cylinders of a multicyclinder internal combustion engine, comprising
speed sensor means responsive to the speed of the engine, cycle event sensor means responsive to an engine cycle event occurring during operation of the engine, processing means including means for determining the change in functions of the kinetic energy over each firing interval during acceleration of the engine by squaring the engine speeds, means for determining the change in the function of the kinetic energy over each of said firing intervals during deceleration of the engine by squaring the engine speeds, and means for determining the difference between the functions of the kinetic energies on acceleration and deceleration for each cylinder, and means responsive to said differences for indicating the power balance.
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23. The method of diagnosing the strengths of the cylinders of a multicylinder internal combustion engine, comprising the steps of:
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sensing the instantaneous speed of the engine, computing the changes in functions of the kinetic energy from the square of engine speeds of the engine over the firing intervals of an operating cycle during an acceleration run of the engine, computing the changes in the functions of the kinetic energy from the square of engine speeds of the engine over the firing intervals of an operating cycle during a deceleration run of the engine, and subtracting the changes during the deceleration run from the changes during the acceleration run. - View Dependent Claims (24)
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25. The method of diagnosing the strength of the cylinders of a multicylinder internal combustion engine, comprising the steps of:
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sensing the instantaneous speed of the engine, computing the changes in functions of the kinetic energy of the engine during an acceleration run for the firing intervals, computing the changes in functions of the kinetic energy of the engine during a deceleration run for the firing intervals, said computing including squaring the speed of the engine, correlating the changes in the functions during the deceleration run with the kinetic energy changes during the acceleration run, and for each firing interval substracting the change during said deceleration run from the change during the deceleration run.
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Specification