In Situ Testing Of Spark Plug Patents (Class 324/393)
  • Patent number: 10644483
    Abstract: A plurality of assemblies are prepared, and a predetermined voltage is applied to a center electrode of each of the plurality of assemblies. The voltage applied to each of the plurality of center electrodes is detected by respective voltage sensors, and a differentiated value is calculated by differentiating the applied voltage, detected by each voltage sensor, with respect to time. A judgment is made as to whether or not a differentiated value change state in which an absolute value of the differentiated value becomes equal to or greater than a predetermined threshold value occurs. A judgment is made as to whether or not the occurrence of the differentiated value change state is caused by the noise, according to the voltage applied, for a specific time from the occurrence of the differentiated value change state, to the center electrode where the differentiated value change state has occurred.
    Type: Grant
    Filed: July 24, 2019
    Date of Patent: May 5, 2020
    Assignee: NGK SPARK PLUG CO., LTD.
    Inventor: Masafumi Okuda
  • Publication number: 20150054514
    Abstract: There are provided a plug built-in type optical measurement probe capable of obtaining a more accurate measurement value, and an optical measurement device provided with the same. A spark section and a light receiving section are held by a plug main body while being arranged next to each other in a protruding manner such that an end face of a holder is arranged at a position where discharge light from the spark section does not enter the field of view of the light receiving section. Accordingly, the light receiving section can be held in a manner protruding from the plug main body, and entering of the discharge light from the spark section can be restricted by the holder of the light receiving section.
    Type: Application
    Filed: August 15, 2014
    Publication date: February 26, 2015
    Applicants: SHIMADZU CORPORATION, HONDA MOTOR CO., LTD.
    Inventors: Ryoji Hiraoka, Nobuyuki Iwai, Tetsuya Nagai, Isao Azumagakito, Satoru Okada
  • Publication number: 20150042344
    Abstract: Described is a method for detecting a glow plug replacement of an engine, wherein a first value of a temperature-dependent variable is measured at a first glow plug of the engine and, simultaneously, a second value of the temperature-dependent variable is measured at a second glow plug of the engine. The first value of the temperature-dependent variable is compared with a stored reference value of the first glow plug and a glow plug replacement is detected if the difference of the first value from the reference value exceeds a threshold value. According to this disclosure, it is provided that the reference value is a value which, in an earlier measurement, was measured at the first glow plug simultaneously with the measurement of a value at the second glow plug which corresponds to the second value within a predefined tolerance.
    Type: Application
    Filed: August 5, 2014
    Publication date: February 12, 2015
    Inventors: Andreas Bleil, Michael Eberhardt, Ralf Müller, Clemens Rinkert, Dirk Wollin, Markus Pados
  • Patent number: 8860419
    Abstract: In order not to deteriorate the detection properties of an ion current that monitors a combustion state even when a smolder leak is present in an ignition plug of an internal combustion engine, an ion current detector includes an ignition plug of an internal combustion engine, an ignition coil which supplies a high voltage to the ignition plug, a controller which sends an ignition command, a bias capacitor which supplies a bias voltage to the ignition coil, an ignition capacitor which is connected to a primary side winding of the ignition coil, a DC power supply which charges the ignition capacitor and the bias capacitor, a current detecting unit which detects a current flowing through the ignition plug, an ion current detecting unit which detects an ion current from the current detected by the current detecting unit, and a Zener diode which restricts a charging voltage of the bias capacitor.
    Type: Grant
    Filed: September 7, 2011
    Date of Patent: October 14, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kimihiko Tanaya, Hiroshi Okuda
  • Patent number: 8461844
    Abstract: A self charging ion current sensing circuit is provided. The self charging ion current sensing circuit is coupled to spark generation circuitry, and utilizes the spark plug electrodes as the ion current sensing electrodes. The self charging is achieved by utilizing the spark current during an ignition event to charge an ion bias capacitor. After the ignition event, the charge voltage build up on the ion bias capacitor is used to provide an ion current across the spark plug gap. The ion current is passed through an offset stage that translates the ion current sense voltage to a voltage that can be buffered and amplified from a single power source available in automotive and vehicular applications. The output of the circuit provides tri-state information, including spark current, null current, and linear representation of ion sense current.
    Type: Grant
    Filed: October 1, 2010
    Date of Patent: June 11, 2013
    Assignee: Woodward, Inc.
    Inventor: David C. Petruska
  • Publication number: 20120286791
    Abstract: In order not to deteriorate the detection properties of an ion current that monitors a combustion state even when a smolder leak is present in an ignition plug of an internal combustion engine, an ion current detector includes an ignition plug of an internal combustion engine, an ignition coil which supplies a high voltage to the ignition plug, a controller which sends an ignition command, a bias capacitor which supplies a bias voltage to the ignition coil, an ignition capacitor which is connected to a primary side winding of the ignition coil, a DC power supply which charges the ignition capacitor and the bias capacitor, a current detecting unit which detects a current flowing through the ignition plug, an ion current detecting unit which detects an ion current from the current detected by the current detecting unit, and a Zener diode which restricts a charging voltage of the bias capacitor.
    Type: Application
    Filed: September 7, 2011
    Publication date: November 15, 2012
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kimihiko TANAYA, Hiroshi OKUDA
  • Patent number: 8040137
    Abstract: A device for measuring an ionization current of a spark plug of a type with a resonant structure, including a motor vehicle ignition system, the spark plug being coupled to a generator including a regulating capacitor. The generator includes a polarizer that polarizes the spark plug, connected between the generator and the spark plug, and a device that measures ionization current of the spark plug, connected between the regulating capacitor and ground.
    Type: Grant
    Filed: March 9, 2007
    Date of Patent: October 18, 2011
    Assignee: Renault S.A.S.
    Inventors: Andre Agneray, Clement Nouvel
  • Patent number: 7808250
    Abstract: There is provided a test method for detecting the presence or absence of a defect in a spark plug insulator, including a reference voltage determination process, a test area determination process, a test voltage determination process and a current detection process. In the reference voltage determination process, a reference voltage VF is determined. In the test area and voltage determined processes, test area and voltage are determined so as not to incur a flashover on the basis of a reference insulator of the same material, shape and size as the spark plug insulator when the reference insulator is placed in position between first and second test electrodes. In the current detection step, the test voltage is applied between the first and second test electrodes to detect an electric current between the first and second test electrodes.
    Type: Grant
    Filed: May 30, 2008
    Date of Patent: October 5, 2010
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Toshitaka Honda, Hirokazu Kurono, Tomoaki Kato
  • Patent number: 7746079
    Abstract: An ion current detecting apparatus includes a capacitor C that is charged as a spark plug 3 discharges, a Zener diode ZD that limits a maximum voltage of the capacitor C while charging, a detection resistor R2 through which a discharge current of the capacitor C flows, and a comparator circuit 5 that compares a current value of the detection resistor R2 with a predetermined value. A charge quantity Q of the capacitor C at discharge start is set so that, as a consequence of a discharging operation of the capacitor C, discharge duration required until the current value of the detection resistor R2 falls below the predetermined value becomes longer than time duration in which the ion current generated by fuel combustion in the engine combustion chamber lasts. The ion current detecting apparatus automatically detects degradation in an insulation resistance in the spark plug, ensuring normal operation in engine control.
    Type: Grant
    Filed: August 9, 2005
    Date of Patent: June 29, 2010
    Assignee: Diamond Electric MFG. Co., Ltd.
    Inventors: Yoshiyuki Fukumura, Mitsuhiro Izumi, Shinobu Sugisaki, Tsutomu Kusuhara
  • Publication number: 20080245144
    Abstract: A sensor structure notably for a harsh environment in a motor vehicle is disclosed. The sensor structure has a sensor body (1) having at one end an element (2) sensitive to the quantity to be measured in the harsh environment and at another end a connection circuit (3) for the latter, placed away from the harsh environment, and physically separated from one another. The sensor structure is connected by means for transmitting information by carrier current on an electrical conductor (5) of the sensor with which the sensitive element and the connection circuit are associated by wireless coupling means and between which are provided means (4) for protecting the connection circuit from the environment.
    Type: Application
    Filed: September 4, 2006
    Publication date: October 9, 2008
    Applicants: PEUGEOT CITROEN AUTOMOBILES S.A, COMMISARRIAT A L'ENERGIE ATOMIQUE
    Inventors: Bernard Bavoux, Jean-Sebastien Danel, Philippe Robert, Maxime Pauly
  • Patent number: 6943554
    Abstract: An ionic current detection apparatus for an internal combustion engine does not generate a false ionic current, and hence it does not generate a false knock component signal either, thereby avoiding an incorrect combustion determination or an incorrect knock determination. The apparatus detects an ionic current generated in spark plugs connected with secondary sides of a plurality of ignition coils, respectively, each of which generates a high ignition voltage immediately after firing of a corresponding combustion chamber. The ignition coils are arranged in such a manner that at least the directions of adjacent ignition coils do not coincide with one another. In addition, the ignition coils are fixed by a fixture, which has arrangement positions for the ignition coils predetermined according to the mounting directions thereof, in such a manner that the directions of adjacent ignition coils do not coincide with one another, the ignition coils being installed on the engine through the fixture.
    Type: Grant
    Filed: August 21, 2003
    Date of Patent: September 13, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masakazu Dohi, Yoshiyuki Sera, Yasuhiro Takahashi
  • Patent number: 6664789
    Abstract: An ignition timing device for timing an engine having a timing port and a timing mark indicative of a position of a movable member. The ignition timing device includes a sensor adapted to be secured in the timing port to provide a timing mark signal indicative of presence of the timing mark. Also, an ignition sensor is adapted to provide an ignition signal indicative of the occurrence of an ignition spark. A filter receives the ignition signal and provides a filtered ignition signal. The filter filters ignition sparks of compression strokes from ignition sparks of compression and exhaust strokes of a selected cylinder to provide the filtered ignition signal. Also, the delay element is provided that receives the filtered ignition signal and provides a delayed signal having a selected delay from the filtered ignition signal. A comparator receives the timing mark signal and the delayed signal.
    Type: Grant
    Filed: July 9, 2002
    Date of Patent: December 16, 2003
    Inventors: Jeffrey E. Thomsen, Richard L. Clements
  • Patent number: 6642718
    Abstract: An ignition system monitoring assembly for use in a combustion engine is disclosed. The assembly includes an igniter having at least one positioning guide with at least one transmittal member being maintained in a preferred orientation by one of the positioning guides. The transmittal member is in optical communication with a corresponding target region, and optical information about the target region is conveyed to the reception member via the transmittal member. The device allows real-time observation of optical characteristics of the target region. The target region may be the spark gap between the igniter electrodes, or other predetermined locations in optical communication with the transmittal member. The reception member may send an output signal to a processing member which, in turn, may produce a response to the output signal.
    Type: Grant
    Filed: September 26, 2001
    Date of Patent: November 4, 2003
    Assignee: Siemens Westinghouse Power Corporation
    Inventor: John Samuel Brushwood
  • Publication number: 20030085709
    Abstract: A system and method are disclosed for detecting spark plug malfunction in an engine having more than one spark plug per cylinder.
    Type: Application
    Filed: November 2, 2001
    Publication date: May 8, 2003
    Applicant: Ford Global Technologies, Inc.
    Inventors: David Karl Bidner, Lynn Edward Davison, William Najib Mansur
  • Patent number: 6559647
    Abstract: The present invention related generally to a method for determining spark plug malfunction and more particularly to a method for determining spark plug malfunction in an internal combustion engine in which at least two spark plugs are disposed in each cylinder. In a dual plug configuration, a spark plug malfunction is detected by disabling one of the spark plugs during a test period in a particular cylinder. A misfire provides an indication of malfunction of the other spark plug.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: May 6, 2003
    Assignee: Ford Global Technologies, LLC
    Inventors: David Karl Bidner, Lynn Edward Davison, William Najib Mansur
  • Publication number: 20020162534
    Abstract: The invention is a strategy to detect spark plug misfires in a multiple spark plug per cylinder internal combustion engine (ICE). The present invention monitors spark plug misfires for each plug within each cylinder and initiates diagnostic fault code setting and failure mode actions such as modifying spark timing and the air/fuel ratio for the cylinder with the misfiring plug to optimize emissions and performance. The strategy modifies spark timing (such as spark retard) of a spark plug not under test but within the same cylinder of the tested spark plug and tests the tested spark plug for misfire (such as changes in crankshaft velocity or acceleration). The amount of spark retard invoked can be a calibrated value such as 30 or 50 degrees off Maximum Brake Torque (MBT) timing. The invention provides improvement over the prior art in that the strategy does not require the complete disabling of a spark plug within the same cylinder as the tested spark plug.
    Type: Application
    Filed: May 3, 2001
    Publication date: November 7, 2002
    Inventors: Arthur Joseph Varady, John Michael Kacewicz, Lynn Edward Davison
  • Patent number: 6429658
    Abstract: An ignition timing device for timing an engine having a timing port includes a sensor securable in the timing port to provide a timing mark signal. An ignition sensor is adapted to provide an ignition signal. A comparator receives the timing mark signal and the ignition signal. The comparator provides an output signal indicative of substantial simultaneous occurrence of timing mark signal and the ignition signal. An indicator receives the output signal and is operable as a function thereof.
    Type: Grant
    Filed: October 4, 1999
    Date of Patent: August 6, 2002
    Inventors: Jeffrey E. Thomsen, Richard L. Clements
  • Patent number: 6426626
    Abstract: A method and apparatus for testing spark plugs and ignition coils. An apparatus includes a power supply for supplying power to an ignition coil to generate a spark across a spark plug. A capture circuit captures an energy signal reflected from the ignition coil in response to the spark. A comparator circuit compares the captured energy signal to a predetermined signal. A method includes the steps of supplying power to an ignition coil to generate a spark across a spark plug, capturing an energy signal reflected from the ignition coil in response to the spark and comparing the captured energy signal to a predetermined signal. The predetermined signal represents one of a distinct group of reflected energy signals which indicate various defects in the coil or plug. Preferably, a match between the captured energy signal and the predetermined signal is used to indicate to the user a defective coil or plug.
    Type: Grant
    Filed: March 29, 1999
    Date of Patent: July 30, 2002
    Assignee: Progressive Tool & Industries Company
    Inventor: Steven F. Kravis
  • Patent number: 6424155
    Abstract: An inductive ignition apparatus for a combustion engine includes a measurement device for ascertaining the ionization current at the spark plug of each cylinder, and includes for each spark plug an ignition coil device which forms the ignition high voltage, operates on the transformer principle, and has a primary and a secondary winding, and through whose secondary winding the ionization current flows. A switch is provided which short-circuits the primary winding for the duration of the ionization current measurement.
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: July 23, 2002
    Assignee: Robert Bosch GmbH
    Inventors: Lothar Puettmann, Walter Gollin, Bernhard Eisele, Markus Ketterer, Hubert Bischof
  • Patent number: 6396278
    Abstract: A hand-held ignition voltage tester for detecting voltage on a spark plug wire in an ignition system, such as a distributorless ignition system. The tester includes a housing, positive and negative power cables and a capacitive probe for capacitively coupling to the spark plug wire. The capacitive probe generates a voltage signal which is representative of the voltage on the spark plug wire. A plurality of voltage level indicators are mounted to the housing to form a bar graph, with each indicator corresponding to a selected voltage level. A measurement circuit is coupled to the power cables and the capacitive probe for activating the voltage level indicators in response to the voltage signal.
    Type: Grant
    Filed: September 10, 1998
    Date of Patent: May 28, 2002
    Inventor: Surender K. Makhija
  • Patent number: 6396277
    Abstract: An apparatus for measuring ignition charge signals produced by coils of coil-on-plug devices of an internal combustion engine. A signal detector comprises an insulating substrate having a first conductive planar layer on a first side and a second conductive planar layer on a second side. The first layer is coupled to a signal wire and the second layer is coupled to a ground wire. When the signal detector is held in close proximity to the coil of the coil-on-plug, ignition signals generated by the coil and passing to the plug are detected. The detected signals may be coupled to a signal analyzer for display and analysis. The amplitude of the signal that is output by the signal detector may be adjusted to different coils having different output signal strengths by modifying the ratio of the surface areas of the first layer and the second layer.
    Type: Grant
    Filed: October 1, 1999
    Date of Patent: May 28, 2002
    Assignee: Snap-On Technologies, Inc.
    Inventors: Chee K. Fong, Robert R. Bryant, James M. Normile, Kenneth A. McQueeney, Timothy J. Spencer
  • Patent number: 6281682
    Abstract: An ignition secondary sensor is provided which is disposed in a high voltage path between an ignition coil and a spark plug for use with a detecting circuit for detecting ignition current and ion current flowing through a spark plug. The sensor comprises an ignition path connected in series with the high voltage path and having a pair of reverse current preventing diodes and a detection path connected to a spark plug side end portion of the ignition path and having a pair of current detecting diodes. A path portion of the detection path on the side of the current detecting diodes opposite to the ignition path and a path portion of the ignition path connecting between the reverse current preventing diodes are capacitively coupled. The detecting circuit is connected to the sensor for detecting the ignition current (ignition timing) on the basis of current flowing into the sensor therefrom and the ion current (combustion timing) on the basis of current flowing from the sensor thereinto.
    Type: Grant
    Filed: May 27, 1999
    Date of Patent: August 28, 2001
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Hiroyuki Kameda, Yoshihiro Matsubara
  • Patent number: 6249123
    Abstract: The present invention is an assembly line testing apparatus and method for automatically determining whether a size of a gap, within at least one component of an article of manufacture, is within an acceptable range, during assembly of the article of manufacture. The present invention uses a microcontroller to control the operation of the assembly line testing apparatus of the present invention such that the size of the gap may be checked in a flexible and reliable manner by repeating the cycle of checking for the size of the gap. The present invention may be used to particular advantage for checking that the size of a spark plug gap within a vehicle engine is within an acceptable range during assembly of the vehicle engine.
    Type: Grant
    Filed: April 20, 1999
    Date of Patent: June 19, 2001
    Assignee: Honda of America, Mfg., Inc.
    Inventor: Brent C. Rankin
  • Patent number: 6236213
    Abstract: Method and apparatus for inspecting a spark plug as installed in an engine, for an abnormal size of a discharge gap and cracking of porcelain, based on a shape parameter value Sn (=Vn/Tn) calculated from a voltage parameter value Vn which is an average of primary voltage V1 during a period of substantially inductive discharge, and a time parameter value Tn indicative of the period of the substantially inductive discharge. The inspection for the abnormal discharge gap size is effected with the engine held at rest, while the inspection for the porcelain cracking is effected with the engine controlled by a motor so as to increase air pressure within the cylinder bore, contrary to conventional system wherein the inspection is effected during operation of the engine by combustion of an air-fuel mixture.
    Type: Grant
    Filed: April 8, 1999
    Date of Patent: May 22, 2001
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Naoyuki Maruta, Nobuaki Suzuki
  • Patent number: 6134947
    Abstract: A load sensor for measuring engine cylinder pressure and vehicle seat occupant weight in a nonintrusive manner that is easily adaptable to existing vehicle components and occupancy support structures. The sensor of the invention provides a toroidal-shaped ferromagnetic steel core that defines a hollow space within which an excitation coil and a detection coil are wound. For engine cylinder pressure sensing, this toroidal sensor is placed on a spark plug, much in the nature of a washer, and is clamped between the spark plug and the spark plug seat in the chamber. For seat occupant weight sensing, the sensor is placed under a seat leg around a fastening bolt, again much in the nature of a washer, and is clamped between the bolt and the floor of the vehicle. Changes in the load or force produced by the cylinder pressure or the occupant weight, alters the stress in the steel core of the sensor. These stress changes in turn induce changes in the magnetic properties of the steel core.
    Type: Grant
    Filed: September 12, 1997
    Date of Patent: October 24, 2000
    Assignee: Southwest Research Institute
    Inventor: Hegeon Kwun
  • Patent number: 6091244
    Abstract: The invention is directed to a method of detecting combustion misfires of an internal combustion engine wherein an ion current is generated during the operation of the engine. The ion current signal is detected over a pregiven time interval starting with the discharge of a spark plug. The ion current signal is integrated over time with a weighting function to obtain a weighted integrated signal and the weighting function is adapted to previously detected ion current signals. The maximum of the weighted integrated signal is compared to a threshold value (s.sub.-- io) dependent upon engine rpm (nmot) and load (rl). A fault signal is outputted when the threshold value (s.sub.-- io) is not exceeded. The invention is also directed to an arrangement for detecting the combustion misfires.
    Type: Grant
    Filed: June 23, 1998
    Date of Patent: July 18, 2000
    Assignee: Robert Bosch GmbH
    Inventor: Juergen Rottler
  • Patent number: 6064211
    Abstract: A tester for testing the spark plugs, distributor system, and wires used on combustion engines. The tester includes a housing that has an opening therethrough adapted and dimensioned for receiving a spark plug therethrough. The housing has at least one open face. A grounding rod is inserted through the aperture of the housing. The grounding rod is adapted for abutting a spark plug. A grounding wire is electrically connected to the grounding rod, which is adapted for coupling to a ground.
    Type: Grant
    Filed: March 11, 1999
    Date of Patent: May 16, 2000
    Inventor: Michael F. Spooner
  • Patent number: 6043660
    Abstract: A circuit arrangement measures an ion current generated in the combustion chamber of an internal combustion engine during an iron current flow phase following an ignition phase. A voltage drop across a feedback resistor (R.sub.1) connected in parallel to an inverting amplifier is measured since the voltage drop is proportional to the ion current resistance. The amplifier is connected with its inverting input to a low voltage end of a secondary winding of an ignition transformer or coil. The high voltage end of the secondary winding is connected through a spark gap of a spark plug to ground, whereby the spark plug functions as an ion current sensor during the ion current flow phase. Negative voltage peaks flowing during an ignition phase and the ignition current flowing during the ignition phase are diverted through respective first and second circuit branches. The first branch has a first semiconductor diode (D.sub.
    Type: Grant
    Filed: February 18, 1997
    Date of Patent: March 28, 2000
    Assignees: DaimlerChrysler AG, Volkswagen AG
    Inventors: Ulrich Bahr, Michael Daetz
  • Patent number: 5933009
    Abstract: An engine analyzing device for an internal combustion engine including a spark generator and means for testing the voltage of the sparks generated for a diagnosis of engine performance, the testing of the sparks generated relating to analysis of the spark voltage wave form from the breakdown voltage, the collapsing field voltage and the duration of the spark pulse or some combination of these.
    Type: Grant
    Filed: May 30, 1996
    Date of Patent: August 3, 1999
    Inventor: William M. Kayser
  • Patent number: 5914604
    Abstract: An ion current in the combustion chamber of an internal combustion engine is measured by using the spark plug as an ion current sensor. The ignition circuit arrangement has an ignition coil or transformer with a primary winding forming a primary circuit and a secondary winding forming a secondary circuit in which the spark plug is connected. A measuring voltage is applied to the secondary circuit by circuit components forming a measuring circuit for measuring the ion current. The measuring circuit provides a measuring voltage at a value that is lower than the battery voltage of the ignition system or corresponds to the battery voltage at most. A rectifying element is connected to the secondary circuit which feeds the secondary or ignition current into the battery circuit of the ignition system while an ion current caused to flow by the measuring voltage applied to the secondary circuit is measured between sparking times when no ignition current is flowing.
    Type: Grant
    Filed: February 18, 1997
    Date of Patent: June 22, 1999
    Assignees: Daimler-Benz Aktiengesellschaft, Volkswagen AG
    Inventors: Ulrich Bahr, Michael Daetz
  • Patent number: 5841283
    Abstract: A discriminator circuit for detecting an event spark plug in a distributorless ignition system. The voltage waveform during event and waste cycles of the ignition system is conditioned and applied to a pair of comparators which compare the voltage waveform with different voltage reference levels. Both comparators switch states to a logical high level upon the firing of the event spark plug. The first comparator switches back to a low logical state after the end of the burn time in the event cycle. The second comparator remains in a high logic state following the burn time in the event cycle due to the negative voltage remaining on the spark cable, but switches back to a low logical state after the firing of the event spark plug in the waste cycle when the voltage on the spark plug cable goes positive. A delay element connected to the output of the first comparator holds the output of the first comparator at the high logical for a predetermined time period that is longer than the burn time in the event cycle.
    Type: Grant
    Filed: August 12, 1997
    Date of Patent: November 24, 1998
    Assignee: Fluke Corporation
    Inventor: Hendrikus Franciscus Bonifatius Bloemen
  • Patent number: 5834939
    Abstract: A hand-held ignition voltage tester for detecting voltage on a spark plug wire in an ignition system, such as a distributorless ignition system. The tester includes a housing, positive and negative power cables and a capacitive probe for capacitively coupling to the spark plug wire. The capacitive probe generates a voltage signal which is representative of the voltage on the spark plug wire. A plurality of voltage level indicators are mounted to the housing to form a bar graph, with each indicator corresponding to a selected voltage level. A measurement circuit is coupled to the power cables and the capacitive probe for activating the voltage level indicators in response to the voltage signal.
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: November 10, 1998
    Inventor: Surender K. Makhija
  • Patent number: 5828217
    Abstract: A misfire detecting device for an internal combustion engine having a double-ended or single-ended distributorless ignition system is provided. The device comprises a first capacitor connected to a secondary winding side of a spark plug and in parallel to the spark plug, the first capacitor being charged by a voltage produced at a secondary winding side of an ignition coil and thereafter applying a voltage to the spark plug when a voltage at the secondary winding side drops, a second capacitor connected in series with the first capacitor and having a capacitance larger than that of the first capacitor to divide a voltage across the first capacitor, and a misfire detecting unit connected to a junction between the first capacitor and the second capacitor to detect a misfire on the basis of a decay characteristic of a divided voltage produced at the second capacitor.
    Type: Grant
    Filed: December 4, 1995
    Date of Patent: October 27, 1998
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Hiroshi Inagaki, Kanehisa Kitsukawa
  • Patent number: 5754051
    Abstract: A misfire detecting device for an ignition system, comprises high voltage applying means for applying a pulsed high voltage to each spark plug of an engine after completion of firing of the spark plug, voltage restricting means for restricting a peak of the pulsed high voltage to a highest possible value that does not cause firing of the spark plug, voltage detecting means for detecting a plug voltage across a center electrode-to-outer electrode of the spark plug after reducing the same, and misfire detecting means for detecting a misfire at each cylinder on the basis of a decay characteristic of a detection voltage which is caused by application of the pulsed high voltage.
    Type: Grant
    Filed: November 22, 1996
    Date of Patent: May 19, 1998
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Shigeru Miyata, Noriaki Kondo
  • Patent number: 5751147
    Abstract: A preignition detecting method which prevents preignition (PI) from being misjudged as having occurred when an ignition plug is fouling. It is determined whether or not the ignition plug fouls in accordance with a voltage, developed across a detecting resistor which is fetched into a microcomputer 18 at a relatively early timing after an ignition command signal is outputted from an ignition device. Further it is determined whether or not preignition occurs in accordance with another voltage fetched at a relatively late timing after the ignition command signal is outputted. When it is determined that the ignition plug is fouling, it is inhibited to fetch the another voltage at a relatively late timing to prevent a misjudgment that preignition occurs due to a leakage current from being caused though preignition does not actually occur.
    Type: Grant
    Filed: May 28, 1997
    Date of Patent: May 12, 1998
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Koichi Nakata, Kazuhisa Mogi, Youichi Kurebayashi
  • Patent number: 5747677
    Abstract: An apparatus for detecting pressure in an engine cylinder comprises a cylinder pressure sensor inserted between an ignition plug screwed into an engine cylinder head and a bearing surface on which the ignition plug is mounted. The sensor outputs a detection signal depending upon a change in the sensor load corresponding to a change in the pressure in the cylinder, to detect the pressure in the cylinder based on a detection signal from the cylinder pressure sensor. The detection signal from the cylinder pressure sensor is invalidated for only a predetermined period based on an ignition signal that controls the ignition of the ignition plug so that the S/N ratio in the sensor output will not be deteriorated by the ignition noise.
    Type: Grant
    Filed: December 16, 1996
    Date of Patent: May 5, 1998
    Assignee: Unisia Jecs Corporation
    Inventors: Naoki Tomisawa, Kenichi Mori
  • Patent number: 5672972
    Abstract: An apparatus is provided for monitoring ignition in individual cylinders of a multi-cylinder engine of the type having an ignition system which includes a separate transformer for each cylinder. Each transformer has primary and secondary coils. The secondary coil is connected in series with a spark gap in an associated one of the cylinders. The ignition system further includes selector switches for receiving cylinder select signals and responsively connecting respective transformer primary coils. The current flows through the primary coil resulting in a voltage potential across an associated spark gap which normally increases to a magnitude sufficient to cause a spark across the spark gap. A first circuit receives the cylinder select signals, senses time delay between the reception of a cylinder select signal and sparking in a respective cylinder and responsively produces a delay signal indicative of the sensed time delay.
    Type: Grant
    Filed: November 9, 1992
    Date of Patent: September 30, 1997
    Assignee: Caterpillar Inc.
    Inventors: Steven R. McCoy, Horst Scheel
  • Patent number: 5652381
    Abstract: An ignition system test instrument used on spark ignited engines includes a housing having a spark chamber. A sleeve with an open and a closed end is slidably mounted over the housing. A compression chamber is formed between the sleeve closed end and the housing. An air passage connecting the spark and compression chambers extends through the housing. The sleeve can be moved relative to the housing, from a lower to an upper position to compress the air in the compression chamber and the spark chamber. A pair of electrodes is mounted to the housing and extend into the spark chamber to form a spark gap. The electrodes are connected in circuit to an engine ignition voltage source. With the spark gap under pressure, the engine can be turned over and the arc (if any) between the electrodes can be observed. A pressure gauge is carried by the housing for sensing and indicating the air pressure in the spark chamber.
    Type: Grant
    Filed: March 11, 1996
    Date of Patent: July 29, 1997
    Inventor: Richard W. Fuchs
  • Patent number: 5644491
    Abstract: An engine monitor includes, in a self-contained preferably sealed unit, a spark sensor, inductively and capacitively coupled through the case to a spark pick up wire, a timer, and a running time detector, responsive to inputs from the spark pick up to provide total running time, job time, and service time metering. Preferably, storage means are included for storing maximum RPM and spark mode data, that is, data indicating the number of firings per RPM for the particular engine, as well as a preset service interval and one or more auxiliary timers.
    Type: Grant
    Filed: January 31, 1994
    Date of Patent: July 1, 1997
    Assignee: SenDEC Corporation
    Inventors: Kenton W. Fiske, Edward G. Reehil, Herbert F. Ley, David L. Sestito
  • Patent number: 5581188
    Abstract: A misfire detecting device for an ignition system, comprises high voltage applying device for applying a pulsed high voltage to each spark plug of an engine after completion of firing of the spark plug, voltage restricting device for restricting a peak of the pulsed high voltage to a highest possible value that does not cause firing of the spark plug, voltage detecting component for detecting a plug voltage across a center electrode-to-outer electrode of the spark plug after reducing the same, and misfire detecting device for detecting a misfire at each cylinder on the basis of a decay characteristic of a detection voltage which is caused by application of the pulsed high voltage.
    Type: Grant
    Filed: January 26, 1995
    Date of Patent: December 3, 1996
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Shigeru Miyata, Noriaki Kondo
  • Patent number: 5554930
    Abstract: In a spark plug voltage probe device which detects a voltage applied to a spark plug installed in an internal combustion engine so as to analyze a burning condition in the internal combustion engine on the basis of the voltage applied to the spark plug, a rubber clamper (9) is secured to the internal combustion engine, and having a groove (92) in which a spark cable (60) is located so as to form a static capacity between the rubber clamper (9) and the spark plug cable (60). An electrical conductor (93) is embedded in the rubber clamper (9) along the groove (92) while the electrical conductor (93) is connected to a microcomputer by way of an output cable (64) so as to analyze a spark plug voltage waveform. A condenser (42) is connected to a common point (A) between the electrical conductor (93) and the microcomputer so as to reduce the spark plug voltage according to a capacity of the condenser (42).
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: September 10, 1996
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Shigeru Miyata, Hideji Yoshida, Yoshihiro Matsubara, Yasuo Ito, Takashi Suzuki
  • Patent number: 5543716
    Abstract: In a sparkplug voltage probe device in use for an internal combustion engine, an insulator base is attached to the internal combustion engine, an upper surface of the insulator base having a plurality of grooves in which the sparkplug cables are placed. An insulator sheet is embedded in the insulator base. An electrode layer is provided on an upper surface of the insulator base along the grooves to form a static capacity between the electrode layer and the sparkplug cables when the voltage is applied across the spark plugs. On a lower surface of the insulator sheet an electrical shield layer is provided connected to the internal combustion engine by a ground wire. A lead wire electrically connects the electrode plate to a microcomputer so as to analyze the engine burning condition based on the static capacity between the electrode plate and the sparkplug cables.
    Type: Grant
    Filed: June 20, 1994
    Date of Patent: August 6, 1996
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Shigeru Miyata, Yoshitaka Yamada, Hideji Yoshida, Yoshihiro Matsubara, Yasuo Ito
  • Patent number: 5534781
    Abstract: An ionization current sensing circuit providing a way to detect the combustion event in a spark ignited engine cylinder. The presence of an output signal from the proposed circuit indicates that a flame exists and that combustion has occurred in the cylinder. This signal is drastically changed if combustion is absent, the circuit providing viable engine misfire detection. The ionization current sensing circuit comprising a power source for providing voltage directly to the primary winding of the ignition coil, an integrator for integrating a spark plug ionization current and thereby providing a voltage output in proportion to the integral of the ionization current, and an ionization current sensing module for sensing a spark plug ionization current, the ionization means connected between the secondary winding of the ignition coil and the integrator means.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: July 9, 1996
    Assignee: Chrysler Corporation
    Inventors: Anscn Lee, Jan S. Pyko
  • Patent number: 5523691
    Abstract: A device for diagnosing the state of health of an ignition system is provided, where the system includes at least one spark producing channel comprising an exciter, output circuit and igniter plug. The device provides a diagnosis of the state of health for both the exciter and igniter plug by monitoring the high energy pulses at the output of the exciter. By monitoring the ignition system at an intermediate point in the system such as the output of the exciter, the sensor and electronics of the device may be completely contained within the electronic environment of the exciter, thereby avoiding any need for attaching sensors at the output of the system adjacent to the igniter plug in order to diagnose the plug's state of health. As an alternative to the device being built into the ignition system, it can be incorporated into automatic test equipment that produces high energy pulses for delivery to an igniter plug to be tested.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: June 4, 1996
    Assignee: Unison Industries Limited Partnership
    Inventor: John R. Frus
  • Patent number: 5521509
    Abstract: In a device of estimating heat resistivity for a spark plug, an ignition spark control circuit is provided to discontinue ignition spark across electrodes of a spark plug at a predetermined intervals. A counter circuit is provided to count the times of the ignition spark suppressed by the ignition spark control circuit. A self-ignition detection circuit is provided to detect the self-ignition from the spark plug when the ignition spark is suppressed by the ignition spark control circuit. A self-ignition counter circuit is provided to count the numbers of the self-ignition detected by the self-ignition detection circuit. A calculation circuit is provided to calculate occurrences rate of the self-ignition from the spark plug on the basis of the suppressing numbers of the ignition spark counted by the counter circuit and the detecting numbers of the self-ignition counted by self-ignition counter circuit.
    Type: Grant
    Filed: March 20, 1995
    Date of Patent: May 28, 1996
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Masahiro Ishikawa, Yoshihiro Matsubara
  • Patent number: 5510715
    Abstract: An apparatus for determining the ignition characteristic of combustion in an internal combustion engine having an ignition coil including an ionic current computing circuit which analyzes ionic current enabled as a result of combustion. Ionic current flow is facilitated by establishing a voltage potential across the gap of a spark plug the instant after an ignition spark across the gap has occurred. The flow of ionic current enabled by the combustion process is provided to an ionic current computing circuit effecting the creation of a signal reflecting the flow of ionic current. The output signal from the computing circuit is integrated to determine the quality (length and magnitude of ionic current flow. This quality of flow is compared against predetermined high and low values for the integrated value and the ignition characteristic or state of combustion, ie, whether a spark and/or complete combustion has occurred, of the cylinder can be understood.
    Type: Grant
    Filed: February 2, 1993
    Date of Patent: April 23, 1996
    Assignee: Diamond Electric Mfg. Co., Ltd.
    Inventor: Manabu Takeuchi
  • Patent number: 5492007
    Abstract: A method for detecting misfire in a cylinder of an internal combustion engine through the ignition system of the engine. The present invention first predicts a time-to-fire measurement for an interrogating spark, then measures the actual time-to-fire measurement of the interrogating spark and then compares the predicted measurement and the actual measurement to determine whether misfire has occurred.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: February 20, 1996
    Assignee: Chrysler Corporation
    Inventors: Gardiner A. Noble, Carl R. Morganti
  • Patent number: 5491417
    Abstract: In a sparkplug voltage probe device, an insulator base is attached to the internal combustion engine, an upper surface of the insulator base having a plurality of grooves in which the corresponding cables are placed. An electrode plate is embedded in the insulator base along the grooves to form a static capacity between the electrode plate and an array of all the cables in the grooves, both of the longitudinal sides of the electrode plate being curled around the outermost cables respectively to compensate shortage of static capacitance so as to form a capacitance adjusting function in order to substantially even a distribution of the static capacity between the electrode plate and the array of all the cables in a direction perpendicular to a length of the electrode plate. A lead wire is provided to electrically connect the electrode plate to a microcomputer.
    Type: Grant
    Filed: June 20, 1994
    Date of Patent: February 13, 1996
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Shigeru Miyata, Yoshitaka Yamada, Hideji Yoshida, Yoshihiro Matsubara, Yasuo Ito
  • Patent number: 5491416
    Abstract: Spark gap measuring and monitoring method and device, for providing, during operation, a signal indicative of the intended performance of the spark gap (1), in particular a spark plug of a combustion engine. The device includes an electrical detecting element which is coupled inductively to a connecting lead (4) of the spark gap (1), for example a toroidal coil (8), which detecting element is connected to a processing circuit (9-11) for the purpose of converting the electrical signal produced by the detecting element into a measuring signal indicative of the spark gap (1) performance, for example the spacing (d) between the electrodes (2, 3). Measurement results obtained from an initial measurement can be established as reference data by means of memory elements and circuit elements. The measuring signal is then analyzed by means of an analyzing circuit (14) as a function of the reference data.
    Type: Grant
    Filed: January 13, 1994
    Date of Patent: February 13, 1996
    Assignee: Deltec Fuel Systems B.V.
    Inventors: Jacob Klimstra, Abraham De Voogd
  • Patent number: 5483818
    Abstract: A method and a circuit are provided for detecting low level ionic currents. An ionization detection voltage is applied to a spark plug and a resulting output voltage signal is sent to a threshold device. The output voltage signal is developed by a low offset operational amplifier. First and second serially connected Zener diodes carry current in a normal diode direction when a spark event occurs and carry current in their Zener breakdown mode upon recovery from the spark event. A second operational amplifier and its associated feedback circuit generate a guard voltage which is applied to the junction of the two Zener diodes. The guard voltage is regulated to track the input voltage to the circuit at the cathode of the first diode. Because the guard voltage is essentially the same as the input voltage, there is no leakage current flow through the first diode.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: January 16, 1996
    Assignee: Ford Motor Company
    Inventors: Arnold W. Brandt, Thomas E. Jones, III, Robert B. Bucciarelli