초록 ▼

A method and apparatus are provided for indicating an operating characteristic of a periodically combusting internal combustion engine, such as a diesel engine, having exhaust gas issuing from one or more combustion chambers in a periodic manner through a duct. The particulate in the exhaust gas str

A method and apparatus are provided for indicating an operating characteristic of a periodically combusting internal combustion engine, such as a diesel engine, having exhaust gas issuing from one or more combustion chambers in a periodic manner through a duct. The particulate in the exhaust gas stream are electrically charged and of the same polarity, and are grouped in packets associated with the periodic combustion in the respective chambers. An electrically conductive, passive electrode, preferably annular in shape, is disposed such that most or all of the exhaust gas flows therethrough so as to electrostatically sense, principally by induced image charge, the passage of the respective packets of charged particles. The electrode is electrically isolated from the duct. Circuitry with the probe converts the sensed induced image charge to a signal containing a series of pulsating components corresponding in time with the respective particle packets and corresponding quantitatively with the charge-quantity of the respective particle packets. An indicating device responds to the pulsating signal and provides an indication of an operating characteristic of the engine. The electrode is preferably of short axial extent relative to the packet interval to enhance resolution. Structure and circuitry may be provided to minimize soot deposition and/or leakage currents across an insulator between the electrode and duct. In one instance, the indicating device may respond to the root mean square of the pulsating signal to provide a quantitative indication of the level of particulate in the exhaust gas stream. In another instance, the successive pulsations of the signal waveform may be displayed to afford evaluation of the performance of the respective combustion chambers and/or injectors.

대표청구항 ▼

Apparatus for indicating an operating characteristic of a periodically combusting internal combustion engine having duct means defining an exhaust gas path, said engine having an exhaust gas stream issuing in said path in a periodic manner from at least one combustion chamber of the engine, said exh

Apparatus for indicating an operating characteristic of a periodically combusting internal combustion engine having duct means defining an exhaust gas path, said engine having an exhaust gas stream issuing in said path in a periodic manner from at least one combustion chamber of the engine, said exhaust gas stream containing electrically-charged particles, said charge being of the same polarity on substantially all of the charged particles at a monitoring location along said path, and said periodic combustion and issuance of exhaust gas causing said charged particles to be grouped in respective periodic packets, said apparatus comprising: electrically conductive, passive electrode means inductively responsive to electrically-charged particles passing thereby, said electrode means being disposed in proximity with said exhaust gas stream at the monitoring locating in electrical isolation from said duct means for sensing, principally by the induced image charge, the passage and the charge-quantity of the respective packets of charged particles; means operatively connected to said electrode means and responsive to the sensed passage and charge-quantity of the particle packets for providing an electrical signal having a series of distinct pulsating components corresponding in time with the passage of respective one of said particle packets and corresponding quantitatively with the charge-quantity of the respective ones of said particle packets; and means responsive to at least said pulsating components of said signal for indicating an operating characteristic of the engine.