Exhaust Gas Composition Sensor Patents (Class 123/703)
  • Patent number: 5836155
    Abstract: A number of embodiments of feedback control systems for two-cycle, internal combustion engine management systems. Each embodiment employs an exhaust system sensor which senses the exhaust gases by drawing exhaust gases from the exhaust of the engine. In some instances this is done directly from the cylinder and in others it is done in the exhaust system. In each embodiment, the sensor is provided in an accumulator chamber so as to provide an accurate signal of instantaneous engine running conditions. The use of the accumulator chamber insures that the combustible gases will not be diluted with fresh air charge, but will be able to purge from cycle to cycle so as to provide cycle-by-cycle information. Various arrangements are provided for protecting the sensor element including serpentine flow paths, shields, the direction in which the exhaust gases are delivered, lubricant catalysts, conduit shape, sensor cooling and combinations of these features.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 17, 1998
    Assignee: Sanshin Kogyo Kabushiki Kaisha
    Inventor: Masahiko Katoh
  • Patent number: 5837114
    Abstract: An arrangement for determining the concentration of a component in a gas mixture includes a first volume in which the concentration of the component is maintained constant with respect to the influence of the coupling to the concentration in the gas mixture. The coupling acts via a diffusion resistance. The above-mentioned influence of the coupling is compensated via a controllable flow of ions of the component through a solid electrolyte between the first volume and the gas mixture. The solid electrolyte serves as the pump device. The intensity of the pump current defines a measure for the wanted concentration in the gas mixture. The above-mentioned flow is controlled as a function of the deviation of the output voltage of a Nernst cell from a desired value. The Nernst cell is between a first volume and a reference gas volume.
    Type: Grant
    Filed: January 13, 1997
    Date of Patent: November 17, 1998
    Assignee: Robert Bosch GmbH
    Inventor: Erich Junginger
  • Patent number: 5767386
    Abstract: An exhaust gas sensor has first and second sensor elements. Exhaust gas surroundings of the first sensor element are catalytically activated, so that an oxygen partial pressure which is in equilibrium will always be measured by the first sensor element, regardless of the conversion capability of a catalytic converter. The exhaust gas surroundings of the second sensor element are separate from the exhaust gas surroundings of the first sensor element, so that the exhaust gas surroundings of the second sensor element are not catalytically active. As a function of the conversion capability of the catalytic converter, the second sensor element measures either an equilibrium oxygen partial pressure or a free oxygen partial pressure, which are of different magnitudes. A malfunction of the catalytic converter is detected by comparing measurement signals of the first and second sensor elements.
    Type: Grant
    Filed: November 22, 1996
    Date of Patent: June 16, 1998
    Assignee: Siemens Aktiengesellschaft
    Inventors: Bertrand Lemire, Willibald Schuerz
  • Patent number: 5753794
    Abstract: An internal combustion engine has an engine unit with an exhaust pipe comprising an oxygen sensor an electrical resistance heater in a bridge circuit having a control resistance and two fixed resistances RA and RB. For calibration the cell is initially operated in atmospheric air with an heater power control circuit supplying variable D.C. power output, under control of a microcontroller, to the bridge to vary the temperature of the sensor. When the sensor gives an electrical output of a predetermined reference value, this is observed by the microcontroller which varies the value of the control resistance to a calibrating value RC2 at which the bridge nulls. Then the microcontroller is instructed to adopt the operating mode and in accordance with its program the microcontroller sets the resistance value of the control resistance at the control value RC1 correlated by an operating function in the program with the calibrating value RC2.
    Type: Grant
    Filed: April 24, 1996
    Date of Patent: May 19, 1998
    Assignee: British Gas plc
    Inventor: Iain John Tebbutt
  • Patent number: 5711148
    Abstract: A number of embodiments of feedback control systems for two-cycle, internal combustion engine management systems. Each embodiment employs an exhaust system sensor which senses the exhaust gases by drawing exhaust gases from the exhaust of the engine. In some instances this is done directly from the cylinder and in others it is done in the exhaust system. In each embodiment, the sensor is provided in an accumulator chamber so as to provide an accurate signal of instantaneous engine running conditions. The use of the accumulator chamber insures that the combustible gases will not be diluted with fresh air charge, but will be able to purge from cycle to cycle so as to provide cycle-by-cycle information. Various arrangements are provided for protecting the sensor including serpentine flow paths, shields, the direction in which the exhaust gases are delivered and combinations of these features.
    Type: Grant
    Filed: May 5, 1995
    Date of Patent: January 27, 1998
    Assignee: Sanshin Kogyo Kabushiki Kaisha
    Inventor: Masahiki Katoh
  • Patent number: 5704334
    Abstract: A throttle sensor senses the position of an associated throttle shaft in order to determine the position of a corresponding throttle valve. The position of the throttle sensor is positioned in the engine to reduce the girth of engine. In one embodiment, the throttle sensor lies to the side of a throttle linkage which interconnects a plurality of throttle valves. The throttle sensor and throttle linkage are arranged on a side of an intake manifold opposite a side on which fuel injectors of the engine are located. In another embodiment, the throttle sensor lies at an upper end of the intake manifold and is coupled to a common, vertically oriented throttle shaft that operates a plurality of throttle valves.
    Type: Grant
    Filed: May 31, 1996
    Date of Patent: January 6, 1998
    Assignee: Sanshin Kogyo Kabushiki Kaisha
    Inventor: Masahiko Kato
  • Patent number: 5682870
    Abstract: A number of embodiments of combustion controls for two-cycle internal combustion engines wherein a sensor chamber is provided in which a combustion condition sensor is located. The sensor chamber communicates with the combustion chamber in such a way that only combustion products can flow from the combustion chamber into the sensor chamber. Various valving and control arrangements for achieving this purpose are disclosed.
    Type: Grant
    Filed: December 28, 1995
    Date of Patent: November 4, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Yu Motoyama
  • Patent number: 5584281
    Abstract: A feedback control system for a multi-cylinder internal combustion engine that employs a combustion condition sensor that senses the condition in only one combustion chamber at the end of the combustion cycle. The power of the engine can be reduced by disabling cylinders other than that from which the combustion products are sensed.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: December 17, 1996
    Assignee: Sanshin Kogyo Kabushiki Kaisha
    Inventor: Masahiko Katoh
  • Patent number: 5561238
    Abstract: A method detects and evaluates emissions from plants, in particular from incineration or industrial plants. The absolute quantities of the pollutants are determined at preset intervals and an average over a preset measuring interval is formed therefrom. When a preset limiting average is exceeded, a check is made to determine whether this excess is due to a functional fault of the plant. If so, the plant is switched over to emergency running. If there is no functional fault, the running of the plant is restricted until the average falls again below the limiting average. The pollutant quantities determined are stored and can be utilized for determining levies.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: October 1, 1996
    Assignee: Daimler-Benz Atkiengesellschaft
    Inventors: Werner Rumez, Siegfried Sumser
  • Patent number: 5522370
    Abstract: A feedback control system for a multi-cylinder two-cycle crankcase compression internal combustion engine. The feedback control system includes a combustion condition sensor that senses the combustion conditions in only one cylinder. Upon starting, the supply of lubricant and fuel to this one cylinder are discontinued to avoid contamination of the combustion condition sensor.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: June 4, 1996
    Assignee: Sanshin Kogyo Kabushiki Kaisha
    Inventors: Masahiko Katoh, Kimihiro Nonaka, Kazuhiro Nakamura
  • Patent number: 5490490
    Abstract: An on-board gas composition sensor is disclosed for monitoring oxygen content levels in the exhaust gas of an internal combustion engine. The gas composition sensor includes a light source for generating excitation light, e.g. in the 350-525 nm wavelength range. A sensor body of porous high-temperature fluorescent inorganic oxide ceramic exposed to the exhaust gas emits an optical fluorescence signal responsive to oxygen content in the exhaust gas upon exposure to the excitation light at 400.degree.-650.degree. C. A florescence detector receives the optical fluorescence signal from the sensor means and generates an exhaust gas oxygen content output signal in response. Fiber-optic cable can be employed for transmitting excitation light to the sensor body from a remotely located light emitter. The same or a separate fiber-optic cable can transmit the optical fluorescent signal from the sensor body to the fluorescence detector also at a remote location.
    Type: Grant
    Filed: April 27, 1995
    Date of Patent: February 13, 1996
    Assignee: Ford Motor Company
    Inventors: Willes H. Weber, Bennie D. Poindexter, Jeffrey T. Remillard
  • Patent number: 5485382
    Abstract: An oxygen sensor deterioration-detecting system for an internal combustion engine having a plurality of groups of cylinders groups, an exhaust system having a plurality of exhaust passages extending, respectively, from the cylinder groups, and catalytic converters arranged in the exhaust system, and a plurality of upstream oxygen sensors arranged, respectively, in the exhaust passages at locations upstream of the catalytic converters, includes a single downstream oxygen sensor arranged in a confluent portion of the exhaust passages at a location downstream of the catalytic converters, for detecting the mixed air-fuel ratio of exhaust gases emitted from the cylinder groups.
    Type: Grant
    Filed: April 11, 1994
    Date of Patent: January 16, 1996
    Assignee: Honda Giken Kogyo K.K.
    Inventors: Yasunari Seki, Toshihiko Sato, Naoki Iida, Yoichi Iwata
  • Patent number: 5445548
    Abstract: In an outboard motor, an exhaust pipe coupled to a lower surface of a cylinder head of an engine extends downwardly through an oil case. An exhaust port, defined at a lower end of the exhaust pipe, is opened downwardly into an extension case. An exhaust gas sampling pipe, threadedly inserted into a seat surface formed on a lower surface of the extension case, extends upwardly into the exhaust pipe and has its inner end inserted into the exhaust port in the exhaust pipe. An outer end of the exhaust gas sampling pipe, extending out of the extension case, is closed by a detachable cap. Thus, it is easy to mount the exhaust gas sampling pipe for sampling an exhaust gas from the exhaust pipe for the outboard motor.
    Type: Grant
    Filed: September 15, 1994
    Date of Patent: August 29, 1995
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Koji Koishikawa, Motoyoshi Shishido
  • Patent number: 5440877
    Abstract: An alr-fuel ratio controller for-an internal-combustion engine is provided with front and rear O.sub.2 sensors respectively installed in the exhaust system on the upstream and downstream sides of an exhaust gas purifier. The controller corrects the air-fuel ratio in accordance with the result of the comparison between a detected value of the front O.sub.2 sensor and a first reference value, to thereby control the alr-fuel ratio to a desired value, and also corrects a value of a parameter related preferably to at least one of a correction amount or a correcting timing for the air-fuel ratio correction, e.g., the first reference value, in accordance with the deviation between a detected value of the rear O.sub.2 sensor and a second reference value.
    Type: Grant
    Filed: September 26, 1994
    Date of Patent: August 15, 1995
    Assignee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha
    Inventors: Hitoshi Kamura, Kazutoshi Noma, Atsuyoshi Kojima
  • Patent number: 5417058
    Abstract: A device for detecting the deterioration of a catalytic converter for an engine having two or more cylinder groups, and a catalytic converter disposed in a common exhaust passage with which exhaust passages individually connected to the respective cylinder groups are merged, wherein the air-fuel ratio of the respective cylinder groups are controlled independently based on the output of the upstream air-fuel ratio sensors disposed in the respective individual exhaust passages. Since the air-fuel ratios of the respective cylinder groups are controlled independently, the phases of the air-fuel ratio oscillations of exhaust gases flowing into the common exhaust passage from the individual exhaust passages are usually not synchronized. However, during the engine operation, the phases of the air-fuel ratio oscillations of the exhaust gases are occasionally spontaneously synchronized due to slight differences of the periods of the cycle of the air-fuel ratio feedback controls in the respective cylinder groups.
    Type: Grant
    Filed: September 20, 1993
    Date of Patent: May 23, 1995
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Yasuhiro Shimizu
  • Patent number: 5412942
    Abstract: A catalytic converter deterioration detecting system for an engine derives a low-frequency component in an output of a downstream-side oxygen sensor provided downstream of a catalytic converter. The system detects deterioration of the catalytic converter based on the low-frequency component, such as, an amplitude of the low-frequency component or a period of the low-frequency component. For higher detection accuracy, an amplitude of a high-frequency component in the output of the downstream-side oxygen sensor is additionally used for detecting deterioration of the catalytic converter. Specifically, the system determines that the catalytic converter is deteriorated when the low-frequency amplitude is smaller than a given value and the high-frequency amplitude is greater than a given value.
    Type: Grant
    Filed: August 26, 1993
    Date of Patent: May 9, 1995
    Assignee: Nippondenso Co., Ltd.
    Inventors: Yasuo Mukai, Yasuhito Takasu, Masaaki Nakayama
  • Patent number: 5404718
    Abstract: A control system which controls engine air/fuel ratio while providing a measurement of efficiency in the catalytic converter coupled to the engine exhaust. A test period is completed when counts in transitions of a feedback variable derived from an exhaust gas oxygen sensor positioned upstream of the converter have reached a preselected count for each of a plurality of inducted air flow ranges. Converter efficiency is determined during the test cycle by comparing an integration of the feedback variable, after band pass filtering and rectification, to an integration of a downstream exhaust gas oxygen sensor after its output is band pass filtered and rectified.
    Type: Grant
    Filed: September 27, 1993
    Date of Patent: April 11, 1995
    Assignee: Ford Motor Company
    Inventors: Daniel V. Orzel, Tri T. Truong, David G. Farmer
  • Patent number: 5400592
    Abstract: A catalytic diagnostic apparatus for determining whether a catalyst of an internal combustion engine has deteriorated as disclosed. Air-fuel ratio sensors are placed at the upstream and downstream sides of the catalytic converter, and the output signal from the upstream air-fuel sensor is used to control the air-fuel mixture provided to the engine via the fuel injectors, in a conventional closed loop operation. Diagnosis of the condition of the catalytic converter is performed only when selected engine operating parameters fall within a predetermined diagnostic range. When the engine is operated in the diagnostic range, the condition of the catalytic converter is analyzed by calculating a deterioration index based on a comparison of the variation of the output signals from the upstream and downstream air-fuel ratio sensors.
    Type: Grant
    Filed: February 10, 1994
    Date of Patent: March 28, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Mukaihira, Toshio Ishii, Yutaka Takaku, Akihito Numata
  • Patent number: 5398501
    Abstract: An air-fuel ratio control system for an internal combustion engine having a catalytic converter arranged in the exhaust system, a first air-fuel ratio sensor arranged upstream of the catalytic converter, and a second air-fuel ratio sensor arranged downstream of the catalytic converter, calculates an air-fuel ratio control variable, based on an output from the second air-fuel ratio sensor. An air-fuel ratio correction amount is calculated based on an output from the first air-fuel ratio sensor and the air-fuel ratio control variable. The air-fuel ratio of a mixture supplied to the engine is controlled based on the air-fuel ratio correction amount. The air-fuel ratio control variable is corrected in the rich direction such that the air-fuel ratio of the mixture supplied to the engine becomes richer, when deterioration of the catalytic converter is detected.
    Type: Grant
    Filed: October 15, 1993
    Date of Patent: March 21, 1995
    Assignee: Honda Giken Kogyo K.K. (Honda Motor Co., Ltd. in English)
    Inventors: Hiroshi Ito, Yoichi Iwata, Takizawa Tsuyoshi, Toshihiko Sato, Naoki Iida, Takayoshi Nakayama
  • Patent number: 5394691
    Abstract: An air-fuel ratio control system for an internal combustion engine having a first and second groups of cylinders and first and second catalytic converters arranged respectively in first and second exhaust systems extending from the respective cylinder groups, includes first and second upstream oxygen sensors upstream of the catalytic converters, and a single downstream oxygen sensor downstream of the catalytic converters. The air-fuel ratios of air-fuel mixtures supplied into the first and second cylinder groups are controlled by the use of first and second air-fuel ratio control amounts based on outputs from the respective first and second upstream oxygen sensors and the downstream oxygen sensor, when the engine is in a predetermined operating condition.
    Type: Grant
    Filed: February 23, 1994
    Date of Patent: March 7, 1995
    Assignee: Honda Giken Kogyo K.K.
    Inventor: Yasunari Seki
  • Patent number: 5392599
    Abstract: Engine air/fuel ratio is controlled in response to a comparison of an exhaust gas oxygen sensor output with a reference value. A correction voltage is generated which is related to a change in the midpoint between saturated output states of the sensor during a test period in which engine air/fuel operation is first forced rich and then forced lean of a preselected air/fuel ratio. The sensor output amplitude is shifted with the correction voltage to reduce variations between the reference value and the midpoint.
    Type: Grant
    Filed: January 10, 1994
    Date of Patent: February 28, 1995
    Assignee: Ford Motor Company
    Inventors: Douglas R. Hamburg, Eleftherios M. Logothetis
  • Patent number: 5392598
    Abstract: Internal combustion engine air/fuel ratio regulation in which closed-loop air/fuel ratio control responsive to a pre-converter oxygen sensor feedback signal is further regulated in accord with a feedback signal from a post-converter oxygen sensor signal operative under certain engine operating conditions to provide an average actual engine air/fuel ratio signal. A pre-converter oxygen sensor rich/lean threshold is adjusted in accord with the post-converter signal to drive or maintain such post-converter signal within a preferred range corresponding to an average engine air/fuel ratio of stoichiometry.
    Type: Grant
    Filed: October 7, 1993
    Date of Patent: February 28, 1995
    Assignee: General Motors Corporation
    Inventors: Vincent A. White, Hossein Javaherian
  • Patent number: 5392600
    Abstract: The present invention provides an improved air-fuel ratio control system which eliminates a time lag of outputs of an outlet or second oxygen sensor at a high accuracy and adequately controls the air-fuel ratio, thus efficiently reducing an exhaust of harmful gases including HC, CO, and NOx and improving the fuel consumption. When an output voltage SOX of the second oxygen sensor is within a predetermined range between a first voltage E1 and a second voltage E2 including a reference voltage E0 corresponding to a stoichiometric air-fuel ratio, an update quantity DRSR of a rich skip amount RSR is equal to zero. When the output voltage SOX is in a range between a minimum output GSOXmin and the first voltage E1, the update quantity DRSR exponentially increases with the decrease in the voltage. When the output voltage SOX is in a range between the second voltage E2 and a maximum output GSOXmax, the update quantity DRSR exponentially decreases with the increase in the voltage.
    Type: Grant
    Filed: January 28, 1994
    Date of Patent: February 28, 1995
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Toshinari Nagai
  • Patent number: 5390491
    Abstract: An ignition timing control system for an internal combustion engine which can perform fast catalyst warm-up operation and prevent stalling at the restart of the internal combustion engine at a low temperature is disclosed. This control system judges whether the engine is in the start state or not, whether the cooling water temperature is lower than the specified temperature or not, and whether the intake air temperature is higher than the preset temperature or not. When these judgments are all affirmative, the system further judges whether the time after the start has reached the control starting time or not, and then whether the engine is in the idle operation state or not. When these judgments are both affirmative, the system sets the target ignition timing retard amount and the ignition timing gradual change time according to the intake air temperature, and then actually performs the ignition timing control according to the target retard amount and gradual retard time.
    Type: Grant
    Filed: January 25, 1994
    Date of Patent: February 21, 1995
    Assignee: Nippondenso Co., Ltd.
    Inventors: Toshihiro Suzumura, Yukihiro Yamashita
  • Patent number: 5386695
    Abstract: An air-fuel ratio control system for an internal combustion engine having a catalytic converter arranged in the exhaust system, and first and second air-fuel ratio sensors arranged upstream and downstream of the catalytic converter respectively has an ECU which calculates an air-fuel ratio correction amount, based at least on an output from the first air-fuel ratio sensor, and detects deterioration of the catalytic converter, based on an output from the second air-fuel ratio sensor when the engine is in a predetermined operating condition. The ECU inhibits detection of deterioration of the catalytic converter when the air-fuel ratio correction amount falls outside a predetermined range.
    Type: Grant
    Filed: January 21, 1994
    Date of Patent: February 7, 1995
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Yoichi Iwata, Toshihiko Sato, Yasunari Seki, Tsuyoshi Takizawa, Takayoshi Nakayama
  • Patent number: 5386693
    Abstract: A control system which provides air/fuel feedback control while measuring catalytic converter efficiency. An efficiency test period is provided when the count in transitions of a signal related to an upstream exhaust gas oxygen sensor reaches a maximum count for a plurality of inducted airflow ranges. During the test period, three separate ratios indicating converter efficiency are provided. These ratios include: a ratio of downstream exhaust gas oxygen sensor total amplitude to a feedback variable derived from the upstream sensor; a ratio in frequency of transitions of the downstream sensor to frequency of the feedback variable; and a ratio of areas derived from the downstream sensor and feedback variable. When all three ratios indicate degraded converter efficiency, an overall indication is provided.
    Type: Grant
    Filed: September 27, 1993
    Date of Patent: February 7, 1995
    Assignee: Ford Motor Company
    Inventor: Daniel V. Orzel
  • Patent number: 5385016
    Abstract: A system and method of controls air/fuel ratio of an engine having exhaust manifolds from first and second cylinder banks coupled to a single catalytic converter. Fuel delivered to the cylinders of the first cylinder bank and the second cylinder bank are adjusted in response to respective first and second upstream exhaust gas oxygen sensors coupled to the first and second exhaust manifolds, and a downstream exhaust gas oxygen sensor positioned downstream of the converter. An inferred signal is read from a table having the first and second sensors as their inputs. This inferred signal is an inference of an output from a hypothetical exhaust gas oxygen sensor exposed to a hypothetical blended mixture of exhaust gases from the first and second exhaust manifolds. Converter efficiency is indicated by a ratio of a count in transitions between output states of the downstream sensor to a count in transitions between output states of the inferred signal.
    Type: Grant
    Filed: December 27, 1993
    Date of Patent: January 31, 1995
    Assignee: Ford Motor Company
    Inventors: Glenn A. Zimlich, Daniel V. Orzel, Tri T. Truong
  • Patent number: 5383333
    Abstract: A system for maintaining engine air/fuel operation within the efficiency window of a catalytic converter. Fuel delivered to the engine is adjusted in response to a step change in an output of an exhaust gas oxygen sensor positioned upstream of the converter. The step change is shifted in response to an error signal derived from a downstream emissions sensor.
    Type: Grant
    Filed: October 6, 1993
    Date of Patent: January 24, 1995
    Assignee: Ford Motor Company
    Inventors: Eleftherios M. Logothetis, Douglas R. Hamburg, Jeffrey A. Cook, Lajos Rimai
  • Patent number: 5381656
    Abstract: A control system which controls engine air/fuel ratio and provides a measurement of efficiency in the catalytic converter coupled to the engine exhaust. Fuel delivered to the engine is adjusted by a feedback variable which is generated by integrating an output of an upstream exhaust gas oxygen sensor and trimmed by the output of a downstream exhaust gas oxygen sensor. For each cycle of the feedback variable, peak amplitude of the downstream sensor output is determined and squared. Similarly, the peak amplitude of the feedback variable for each of its cycles is squared. An indicating ratio of the square of the sum of the squares derived from the downstream sensor to the square of the sum of the squares derived from the feedback variable indicates converter efficiency.
    Type: Grant
    Filed: September 27, 1993
    Date of Patent: January 17, 1995
    Assignee: Ford Motor Company
    Inventors: Daniel V. Orzel, Glenn A. Zimlich, Tri T. Truong
  • Patent number: 5381657
    Abstract: A catalyst deterioration-detecting system is provided for an internal combustion engine having an oxygen concentration sensor arranged in an exhaust system downstream of a catalyst provided therein. An electronic control unit (ECU) controls the air-fuel ratio of a mixture supplied to the engine in response to an output from the oxygen concentration sensor. The ECU detects a value of an inversion period with which the output from the oxygen concentration sensor is inverted with respect to a predetermined reference value. Operating parameter sensors detect a value of at least one operating parameter of the engine related to a flow rate of the exhaust gases in the exhaust system. The ECU determines whether the catalyst is deteriorated, based on the detected value of the inversion period and the detected value of the at least one operating parameter. The ECU corrects the value of the inversion period in dependence on the detected value of the at least one operating parameter.
    Type: Grant
    Filed: January 21, 1994
    Date of Patent: January 17, 1995
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Tsuyoshi Takizawa, Yasunari Seki, Yoichi Iwata, Toshihiko Sato, Takayoshi Nakayama
  • Patent number: 5379591
    Abstract: An air-fuel ratio control system for an internal combustion engine calculates an air-fuel ratio feedback control parameter by proportional-integral control using a proportional factor and an integral factor, based an output signal from a second air-fuel ratio sensor arranged in an exhaust passage at a location upstream of a catalytic converter. An air-fuel ratio correction amount is calculated based on the air-fuel ratio feedback control parameter and an output signal from a first air-fuel ratio sensor arranged in the exhaust passage at a location upstream of the catalytic converter. An inversion period of the output signal from the second air-fuel ratio sensor is measured, and the proportional factor is changed according to the inversion period measured.
    Type: Grant
    Filed: January 28, 1994
    Date of Patent: January 10, 1995
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Yoichi Iwata, Naoki Iida, Tsuyoshi Takizawa, Yasunari Seki, Toshihiko Sato, Takayoshi Nakayama
  • Patent number: 5379590
    Abstract: A control system for maintaining engine air/fuel operation within the efficiency window of a catalytic converter. An exhaust gas oxygen sensor having a step change between first and second output states and positioned downstream of the converter. A step change in the downstream sensor output is initialized to an initial air/fuel ratio by pumping current through one of the sensing electrodes of the downstream sensor. An emission control signal is derived from the initialized downstream sensor output to bias an air/fuel feedback loop.
    Type: Grant
    Filed: October 6, 1993
    Date of Patent: January 10, 1995
    Assignee: Ford Motor Company
    Inventors: Douglas R. Hamburg, Eleftherios M. Logothetis, Jeffrey A. Cook, Lajos Rimai
  • Patent number: 5375416
    Abstract: An air-fuel ratio sensor deterioration-detecting device for an internal combustion engine having a catalytic converter arranged in the exhaust system, and first and second air-fuel ratio sensors arranged upstream and downstream of the catalytic converter respectively has an ECU which calculates an air-fuel ratio correction amount, based on outputs from the first air-fuel ratio sensors, and detects deterioration of the first air-fuel ratio sensor, based on the output from the first air-fuel ratio sensor. The ECU inhibits detection of deterioration of the first air-fuel ratio sensor when the air-fuel ratio correction amount falls outside a predetermined range.
    Type: Grant
    Filed: January 21, 1994
    Date of Patent: December 27, 1994
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Yoichi Iwata, Toshihiko Sato, Yasunari Seki, Tsuyoshi Takizawa, Takayoshi Nakayama
  • Patent number: 5363648
    Abstract: A system for controlling an air/fuel ratio of a four-cylinder internal combustion engine. In the system, an actual air/fuel ratio, at least at upstream or downstream of a catalytic converter installed at an exhaust system of the engine, is intentionally oscillated at least either in its amplitude or cycle. A characteristic of a desired air/fuel ratio as a periodic function is established with respect to time such that the desired air/fuel ratio varies at least either at a predetermined amplitude or cycle within a predetermined period. The characteristic is sampled by a time interval determined on the basis of a time interval between TDC crank angle positions of the engine. Each cylinder's desired air/fuel ratio is then determined from the sampled data, and a fuel injection amount for each cylinder is determined from the respective cylinder's desired air/fuel ratios. Fuel is then supplied to each cylinder in response to the determined fuel injection amount.
    Type: Grant
    Filed: December 27, 1993
    Date of Patent: November 15, 1994
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Shusuke Akazaki, Yusuke Hasegawa, Yoichi Nishimura, Isao Komoriya
  • Patent number: 5363646
    Abstract: A control system which controls engine air/fuel ratio and provides a measurement of efficiency in the catalytic converter coupled to the engine exhaust. At the end of each of a plurality of test periods, one of three selected ratios of output signals generated from exhaust gas oxygen sensors positioned downstream and upstream of a catalytic converter are sampled and the weighted average of the selected ratio over a plurality of test periods is determined. When the weighted average exceeds a reference ratio, an indication of converter efficiency is provided. Such an indication is also provided when the selected ratio exceeds the weighted average by a preselected amount, such as three standard deviations, for a preselected number of times. The weighted average is reset to the selected ratio when the selected ratio exceeds the weighted average by a preselected amount.
    Type: Grant
    Filed: September 27, 1993
    Date of Patent: November 15, 1994
    Assignee: Ford Motor Company
    Inventors: Daniel V. Orzel, Glenn A. Zimlich, Tri T. Truong
  • Patent number: 5359853
    Abstract: The device according to the invention detects deterioration of a catalytic converter disposed in an exhaust passage of an internal combustion engine based on output signal response curves of the air-fuel ratio sensors disposed in the exhaust passage upstream and downstream of the catalytic converter, by determining that the catalytic converter has deteriorated when relationship of a ratio of the lengths of the output response curves of the upstream and downstream air-fuel ratio sensors and a ratio of the areas bounded by the output signal response curves and reference lines satisfies predetermined conditions during air-fuel ratio feedback control of the engine; to eliminate errors the detection during a transition of the operating condition of the engine, the device also determine a degree of transition of the operating condition of the engine, for example, by detecting number of reversals of the output signal of the upstream air-fuel ratio sensor, and corrects the value of the ratio of the areas of the outpu
    Type: Grant
    Filed: November 16, 1993
    Date of Patent: November 1, 1994
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Yasuhiro Shimizu
  • Patent number: 5359852
    Abstract: An air fuel ratio control system for an internal combustion engine having an electronic engine control module and an upstream and downstream exhaust gas oxygen sensor positioned in the engine exhaust gas stream. A first feedback loop includes the upstream EGO sensor. A second feedback loop includes a downstream EGO sensor and a trim bias signal to bias stored values provided from an air/fuel bias table. Such a biased signal is applied to an air fuel feedback controller which provides a feedback air fuel control signal to be applied to an open loop fuel controller.
    Type: Grant
    Filed: September 7, 1993
    Date of Patent: November 1, 1994
    Assignee: Ford Motor Company
    Inventors: Judith M. Curran, Thomas R. Culbertson, Douglas R. Hamburg
  • Patent number: 5355672
    Abstract: An automotive internal combustion engine is equipped with a hydrocarbon adsorber for the purpose of controlling the emissions of unburned hydrocarbons from the vehicle's tailpipe. Regeneration of the adsorber is achieved by an electronic engine controller operating an air pump and a sample pump, using information from an exhaust gas oxygen sensor.
    Type: Grant
    Filed: October 4, 1993
    Date of Patent: October 18, 1994
    Assignee: Ford Motor Company
    Inventors: Andrew A. Adamczyk, Jr., Ronald G. Hurley, James D. Pakko
  • Patent number: 5353592
    Abstract: A control system and method maintains engine air/fuel operation near stoichiometry in response to exhaust gas oxygen sensors positioned both upstream and downstream of a catalytic converter. A converter efficiency test cycle is generated during air/fuel feedback control after engine operation occurs in a plurality of airflow ranges for a period determined by a count in transitions of a feedback variable derived from the upstream sensor. Upon each transition in the downstream sensor, the measurement of inducted airflow at which such transition occurred is accumulated. At the end of the test cycle, converter efficiency is determined by an average of such airflow accumulations.
    Type: Grant
    Filed: November 26, 1993
    Date of Patent: October 11, 1994
    Assignee: Ford Motor Company
    Inventors: Glenn A. Zimlich, Daniel V. Orzel, Tri T. Truong
  • Patent number: 5340462
    Abstract: An air-fuel ratio sensor comprises an oxygen concentration cell device, an oxygen pump device, a heater for heating the oxygen concentration cell device and the oxygen pump device, a pump current cut means for stopping the supply of the pump current, first and second timers for controlling the condition of stopping the pump current, and a controller for starting the heating of the heater under the condition of stopping the pump current, to the pump device and for removing the stopping of the pump current for a predetermined time at predetermined intervals from the starting of supplying power to the heater, by means of the first timer, wherein when the pump current shows a predetermined value or higher, the pump current is stopped and the second timer is started, and when the operation of the second timer is finished, the judgment of the activation of the sensor is made, and at the same time, the stopping of the pump current is removed.
    Type: Grant
    Filed: June 9, 1993
    Date of Patent: August 23, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Hiroyoshi Suzuki
  • Patent number: 5329764
    Abstract: An air/fuel control system for internal combustion engines having three-way (NOx, CO, and HC) catalytic converters. A feedback variable is generated by subtracting the normalized output of a nitrogen oxide sensor from the normalized output of a combined HC/CO sensor. The zero crossing point of the feedback variable identifies the operating point for optimal conversion efficiency of the catalytic converter and is used to trim liquid fuel delivery for maintaining optimal conversion efficiency.
    Type: Grant
    Filed: January 11, 1993
    Date of Patent: July 19, 1994
    Assignee: Ford Motor Company
    Inventors: Douglas R. Hamburg, Jeffrey A. Cook, Eleftherios M. Logothetis
  • Patent number: 5311854
    Abstract: A two-cycle internal combustion engine configuration and control strategy in which the unburned hydrocarbon emissions in the exhaust gas are measured by a sensor in the exhaust manifold. The information from the sensor is used to control the outflow of air from a blower mixed with the fuel to vary the total volume of fuel and air to thus reduce unburned hydrocarbons in the exhaust gas.
    Type: Grant
    Filed: January 25, 1993
    Date of Patent: May 17, 1994
    Assignee: BRQT Corporation
    Inventor: Harry Cullum
  • Patent number: 5226921
    Abstract: A method for controlling the fuel-air mixture in an Otto engine having at least one cylinder, especially in an automobile engine, for the optimum use of a catalyser (18) with a probe in the hot exhaust gas stream (20) containing carbon monoxide, nitrogen oxides and hydrocarbons. The measuring signals of the probe are converted through electronic means into control signals for the mixture preparation and ignition. The oxygen content of the exhaust gas stream gas stream (20) is measured in the combustion chamber of the cylinders, beyond the outlet valve in the cylinder heads or in the single pipes (12), in the protective region of a smooth, aerodynamic deflection device (40) without a reference atmosphere with a resistive ceramic oxygen probe (24) having a heat resistance up to approximately 1300.degree. C. and an adjustment time within the millisecond range.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: July 13, 1993
    Assignee: Klaus Leistritz Engineering AG
    Inventor: Klaus Leistritz