Compression rate analyzer
First Claim
1. Apparatus for monitoring the performance of fuel injected internal combustion engines of the type having injection nozzles extending into the respective engine cylinders, said apparatus comprisingtransducer means adapted to be coupled to a selected one of said injector nozzles and capable of producing a first signal which varies substantially in accordance with the time-rate-of-change of the pressure exerted on said selected nozzle from within said cylinder,circuit means responsive to said transducer output signal for developing a second electrical signal the amplitude of which corresponds to the maximum amplitude of said transducer output signal,signal conversion means coupled to said circuit means for producing a numerically coded electrical representation of said second electrical signal,first readout means for manifesting said numerically coded electrical representation to the operator as a visual indication of the performance of said selected engine cylinder,a tachometer circuit coupled to said transducer means and adapted to produce at least one third electrical signal which varies in accordance with the primary frequency of said transducer signal, andsecond readout means driven by said tachometer circuit for manifesting to the operator a numerical value corresponding to the magnitude of said speed-related signal as an indication of engine speed.
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Abstract
A system and method for monitoring the performance and condition of various cylinder components of internal combustion engines through the provision of a transducer for detecting the time-rate-of-change of pressure within the cylinder during normal operation of the engine and a circuit for processing and quantizing the transducer signal to develop a numerical indication of pressure changes within the cylinders. The system also includes a tachometer circuit and display apparatus as well as an optional memory and processor to facilitate a comparative analysis of the various cylinders at varying speeds.
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Citations
27 Claims
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1. Apparatus for monitoring the performance of fuel injected internal combustion engines of the type having injection nozzles extending into the respective engine cylinders, said apparatus comprising
transducer means adapted to be coupled to a selected one of said injector nozzles and capable of producing a first signal which varies substantially in accordance with the time-rate-of-change of the pressure exerted on said selected nozzle from within said cylinder, circuit means responsive to said transducer output signal for developing a second electrical signal the amplitude of which corresponds to the maximum amplitude of said transducer output signal, signal conversion means coupled to said circuit means for producing a numerically coded electrical representation of said second electrical signal, first readout means for manifesting said numerically coded electrical representation to the operator as a visual indication of the performance of said selected engine cylinder, a tachometer circuit coupled to said transducer means and adapted to produce at least one third electrical signal which varies in accordance with the primary frequency of said transducer signal, and second readout means driven by said tachometer circuit for manifesting to the operator a numerical value corresponding to the magnitude of said speed-related signal as an indication of engine speed.
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4. Apparatus for monitoring the performance of internal combustion engines of the type having a plurality of cylinders and at least one receptacle extending from each of said cylinders to the exterior of said engine, said receptacle being adapted to sealingly engage a combustion-aiding device such as a fuel injection nozzle, spark plug or glow plug,
transducer means adapted to be coupled to the combustion-aiding device of at least one of said cylinders and capable of producing a signal which varies substantially in accordance with the first derivative of the pressure exerted on said combustion-aiding device from within said cylinder, first circuit means coupled to said transducer for quantizing the maximum amplitude of the transducer output signal and producing a first numerically coded electrical representation indicative of said maximum amplitude, second circuit means coupled to said transducer for measuring the primary frequency of said transducer output signal and producing a second numerically coded electrical representation indicative of engine speed, and readout means associated with said first and second circuit means for displaying a number corresponding to at least one of said first or second numerically coded electrical representations.
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10. Apparatus for monitoring the performance of internal combustion engines of the type having a plurality of cylinders and at least one receptacle extending from each of said cylinders to the exterior of said engine, said receptacle being adapted to sealingly engage a combustion-aiding device such as a fuel injection nozzle, spark plug or glow plug,
transducer means adapted to be coupled to the combustion-aiding device of at least one of said cylinders and capable of producing a signal which varies substantially in accordance with the first derivative of the pressure exerted on said combustion-aiding device from within said cylinder, first circuit means coupled to said transducer for quantizing the maximum amplitude of the transducer output signal and producing a first numerically coded electrical representation indicative of said maximum amplitude, second circuit means coupled to said transducer for measuring the primary frequency of said transducer output signal and producing a second numerically coded electrical representation indicative of engine speed, selectively controlled memory means coupled to said first and second circuit means for storing said first and second numerically coded electrical representation at selected intervals of engine speed.
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14. An instrument for monitoring the performance of the respective cylinders of an internal combustion engine from a transducer whose output signal varies substantially in accordance with the first derivative of the pressure occurring within a chosen cylinder to which the transducer is coupled, said instrument comprising
a quantizing circuit coupled to receive said transducer output signal and adapted to produce a first numerically coded signal of a value corresponding to the magnitude of said transducer output signal, a tachometer circuit coupled to receive said transducer output signal and adapted to produce a second numerically coded signal of a value corresponding to the frequency of the oscillations of said transducer output signal resulting from repetitive combustion within said chosen cylinder, and means for simultaneously monitoring said first and second numerically coded signals and manifesting the numerical magnitude of said signals.
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17. A method for monitoring the performance of an internal combustion engine comprising the steps of
attaching a piezoelectric transducer to a selected cylinder to develop a signal corresponding substantially to the first derivative of the pressure within the selected cylinder, electrically quantizing the magnitude of said transducer signal to obtain a numerical manifestation of said transducer output signal as a measure of the performance of said selected cylinder.
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24. A method for monitoring the performance of a fuel-injected internal combustion engine having an injection delivery system normally delivering fuel to each of the cylinders of said engine, said method consisting essentially of the steps of:
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attaching a piezoelectric transducer to a selected cylinder of said engine such that an output signal is developed by said transducer that varies substantially in accordance with the first derivative of the pressure within the selected cylinder, electrically quantizing the magnitude of said transducer output signal to obtain a numerical representation of said magnitude of the transducer signal, operating said engine until it achieves a stabilized normal operating temperature, running the engine to at least one preselected engine speed with the fuel system to said selected cylinder operative so as to obtain a first numerical representation of the quantized transducer signal for said preselected speed, disconnecting the fuel system for said selected cylinder, running the engine at said preselected speed with the fuel system disconnected to develop a second numerical representation of the quantized transducer signal for comparison to said first numerical representation to provide an indication of deviation between said first and second numerical representations indicating the performance of the fuel system for that selected cylinder. - View Dependent Claims (26)
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27. A method for diagnosing malfunctions within the cylinders of a diesel engine having a plurality of injection nozzles normally supplying fuel to the respective cylinders of the engine, said method consisting essentially of:
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a. bringing the engine to a stabilized operating temperature, b. inhibiting the fuel flow to a selected one of said injector nozzles, c. attaching to said selected nozzle a transducer which develops a signal corresponding substantially to the time-rate-of-change of the pressure within the selected cylinder, d. registering the magnitude of said signal at a predetermined engine speed, e. restoring fuel flow to the nozzle for said selected engine cylinder, f. repeating each of the a-e above on at least one additional cylinder to obtain a plurality of registered values corresponding to the time-rates-of-change of pressure within a plurality of cylinders measured at the same engine speed, and g. comparing said registered values to determine deviations indicative of malfunctions within one or more cylinders.
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Specification