Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Denki K.k.

Mitsubishi Materials Corporation

Mitsubishi Denki Kabushiki Kiasha

Yutaka Ohashi

Wataru Fukui

Naoki Hiraoka

Mitsuru Koiwa

Koichi Okamura

Shigemi Murata

Noriaki Hayashi

Izuru Shinjo

Hideki Umemoto

Hiroshi Sakanoue

Mituru Koiwa

Masahiro Kawai

Masahiro Yokotani

Tomoya Yamakawa

Akira Yamashita

Yasuyoshi Hatazawa

Yasuhiro Takahashi

Takeshi Shimizu

Nobuyuki Sawazaki

Hisanori Nobe

Shingo Morita

Haruyuki Matsuo

Toshio Iwata

Kenichi Ono

Kazuhiko Tsutsumi

Yukio Yasuda

Katsuaki Yasui

Masayuki Ikeuchi

Masami Matsumura

Yuichi Sakai

Tohru Kohno

Masaaki Chiba

Hideki Maruhashi

Hidetoshi Miyaji

Takafumi Narishige

Tsutomu Morishita

Shu Sasaki

Noriaki Murahashi

Toshihiko Goto

Toshi Sasaki

A thermo-sensitive flow rate sensor that comprises a plate-like substrate, a part of which is removed so that a space is provided therein, a diaphragm portion formed like a thin layer above the space in such a manner as to be integral with the plate-like substrate, and a heating element constituted by a thermo-sensitive electrically resistant film formed on the diaphragm. Plural holes penetrating the diaphragm portion are bored in an outer peripheral portion of the heating element. Each of the plurality of holes is shaped in such a way as to have obtuse corner portions or to have substantially no corner portions. The thermo-sensitive flow rate sensor measures the flow rate of a fluid, which is to be measured, according to an amount of heat transferred to the fluid from a part heated by energizing the heating element.

Thermo-sensitive flow rate sensor

A method of manufacturing a rotation sensor is provided. In the method, an insert conductor having a predetermined shape and having at least a connector terminal and a conversion device terminal is provided. The insert conductor is insert-molded in a resin base such that at least the connector terminal and the conversion device terminal of the insert conductor remain exposed from the resin base. A resin connector part is molded such that the resin connector part encircles the connector terminal. Also, a magnetoelectric conversion device is connected to the conversion device terminal of the insert conductor, and positioning parts are provided at a tip of the resin base. In addition, the magnetoelectric conversion device is sandwiched between the positioning parts to securely hold the magnetoelectric conversion device, and a press fit part is formed at the tip of the resin base. Also, an output terminal of the magnetoelectric conversion device is pressed against the conversion device terminal of the insert conductor with the press fit part.

Manufacturing method of a rotation sensor

A misfire detecting apparatus for an internal combustion engine detects only an ion current due to combustion of an air/fuel mixture regardless of a leakage current when combustion: takes place normally. The apparatus includes circuitry for detecting an ion current generated within the engine cylinder immediately after combustion, circuitry for detecting a leakage current occurring between electrodes of a spark plug , a first waveform shaper for shaping the ion current into a pulse signal indicating a combustion or misfire event by comparing the pulse signal with a first threshold value for deciding the ion current, the first threshold value being set on the basis of a level of the ion current upon rising thereof, the ion current being superposed on the leakage current, a second waveform shaper for shaping the ion current as detected into a pulse signal through comparison with a second fixed threshold value which is fixed at a value smaller than the first threshold value, and a selector for selectively outputting as the combustion pulse signal either a shaped pulse signal outputted from the first waveform shaper upon detection of occurrence of the leakage current or a shaped pulse signal outputted from the second waveform shaper when no leakage current is detected.

Misfire detecting apparatus for internal combustion engine

A torque sensing unit, sensor unit, and method for manufacturing the torque sensing unit. The torque sensing unit includes a first shaft and a second shaft rotatably arranged in a coaxial fashion, and a torsion bar for allowing a rotational displacement in response to a torque between the first shaft and the second shaft. Magnetic elements are used in conjunction with the shafts for sensing a reluctance which is changed in compliance with rotational phase differences between the magnetic elements. A sensor module is prepared in which the magnetic elements are temporarily fixed to have a predetermined neutral rotational phase difference. This temporary fixture is released after the first shaft , the second shaft , the torsion bar , and the sensor module have been assembled.

Torque sensing unit manufacturing method, sensor module, and torque sensing unit

A combustion state detecting apparatus for an internal combustion engine which can ensure adequate thermal insulation between a transformer and a bias circuit and which can be manufactured in a miniaturized structure. The apparatus includes a transformer ( ) having a primary winding ( ) and a secondary winding ( ) which are so electromagnetically coupled mutually that upon interruption of a current flowing through the primary winding, a high voltage is induced at a high-potential end of the secondary winding, a switch ( ) for controllably interrupting the current flowing through the primary winding, a spark plug ( ) for generating a spark discharge in response to application of the high voltage at the high-potential end of the secondary winding, a bias circuit ( ) for applying to a low-potential end of the secondary winding a voltage of plus polarity for detecting ions produced when the spark discharge occurs at the spark plug, and an outer packaging case ( ) for accommodating therein the transformer, the switch and the bias circuit, wherein the bias circuit is disposed within the outer packaging case at a location adjacent to the switch remote from the transformer, and wherein the outer packaging case is filled with a moldable resin ( ).

Combustion state detecting apparatus for internal combustion engine

The invention provides a magnetic object motion sensor which can operate with high accuracy not only when a magnetic object moves at high speeds but also even when it moves at low speeds, which can be produced with a greater production tolerance and a greater dimensional tolerance. The magnetic object motion sensor includes: magnetoelectric transducer elements disposed opposite protrusions of a moving magnetic object; a magnet for generating bias magnetic flux toward the magnetoelectric transducer elements; unbalanced bias producing means for producing imbalance in the magnetic field sensitivity between the magnetoelectric transducer elements; a differential amplifier for amplifying in a differential fashion the electric signals output by the magnetoelectric transducer elements; a waveform shaping circuit for converting the differential signal output by the differential amplifier to a pulse signal corresponding to the edges of the magnetic material protrusion; the unbalanced bias producing means producing a difference in the amplitude of the magnetic flux density between that applied to one element of the pair of magnetoelectric transducer elements and that applied to the other element so that the difference in the electric signal level corresponding to the difference in the amplitude of the magnetic flux density becomes greater than the hysteresis of the waveform shaping circuit, thereby, in effect, introducing imbalance in the sensitivity between the magnetoelectric transducer elements.

Rotating magnetic object motion sensor with unbalanced bias

To obtain a knock detection apparatus for an internal combustion engine which may obtain a good knock pulse S/N even if an ionic current generation amount is changed by the change of a kind of fuel or plugs, a vibratory component superimposed on an ionic current generated by combustion of fuel is extracted and shaped in waveform into a pulse waveform by comparison with a threshold value, the number of the pulses in the pulse waveform is calculated by a calculation unit, and a control of an ignition timing is performed on the basis of an output result of the calculation unit. The knock detection apparatus for an internal combustion engine comprises an integration circuit for integrating (charging) the vibratory component superimposed on the ionic current and a discharge circuit for discharging a predetermined amount of charge from the integrated charge. The threshold value is self-adjusted by a balance of charge/discharge between the integration circuit and the discharge circuit.

Knock detection apparatus for an internal combustion engine

A knock suppression control apparatus for an internal combustion engine which can avoid erroneous knock detection and hence the erroneous knock suppression control, to thereby ensure knock suppression control with high reliability. The knock suppression control apparatus includes an ion current detecting means (,) for detecting an ion current (i) flowing by way of a spark plug (,) upon combustion of an air-fuel mixture charged in the cylinder, a filter means (,A) for extracting a knock signal (Kj) from an output signal (Ei) of the ion current detecting means (,), a knock decision means (,) for deciding occurrence of a knock event in the engine on the basis of the knock signal (Kj), a control quantity correcting means (,) for correcting a control quantity for the internal combustion engine so as to suppress the knock event on the basis of result (H) of decision made by the knock decision means (,), an integrating means (,A) for arithmetically determining an integral value (Km; Em) which corresponds to an output level of the ion current (Ei), a comparison level setting means (,A) for setting a predetermined comparison reference level (MR) for the integral value (Km; Em), and a correcting quantity arithmetic means (,A) for outputting a correcting signal (M,; M,) for correcting parameters relevant to the knock decision means (,) or alternatively relevant to the control quantity correcting means (,) on the basis of result of the comparison between the integral value (Km; Em) and the comparison reference level (MR).

Knock suppression control apparatus for internal combustion engine

A device for controlling knocking of an internal combustion engine featuring improved reliability by preventing signals of the knocking level from being erroneously detected as those of the noise level. The device detects an ionic current flowing through a spark plug, counts a signal of the knocking level from the ionic current, establishes an average knocking level from the signals of the knocking level and determines a background level from the average knocking level. A comparator judges the knocking state by comparing the signal of the knocking level with the background level. The device calculates the control quantity of the engine based on the operation conditions and the result of judgement of knocking. The device further judges a transient state and decreases the average knocking level depending upon a transience judgment signal in order to maintain a background level in a transient state at an optimum value.

Device for controlling the knocking of an internal combustion engine

A combustion state detecting apparatus for an internal combustion engine is imparted with facility for determining discriminatively the causes for non-occurrence of combustion. The apparatus includes a spark plug (,) for generating a spark discharge upon application of a high voltage generated by an ignition coil (,) in response to an ignition signal (X,) to thereby fire an air-fuel mixture within a cylinder of the internal combustion engine, an ion current detecting means (,A) for detecting as ion current detection signals (X,; X,) an ion current corresponding to an amount of ions produced within the cylinder immediately after combustion of the air-fuel mixture, a signal detecting means (,A;,B;,) for comparing the ion current detection signal (X,) outputted from the ion current detecting means (,A) with a first reference voltage (Vth,) to thereby output a first decision signal (X,) while comparing the ion current detection signal (X,) with a second reference voltage (Vth,) to thereby output a second decision signal (X,) while invalidating output of the second decision signal (X,) during a predetermine time period from a time point at which the comparison of the ion current detection signal (X,) with the second reference voltage (Vth,) is started, and an estimating logic unit (,) for estimating a cause for nongeneration of a combustion signal on the basis of output statuses of the first decision signal (X,) and the second decision signal (X,).

There is provided a combustion state detecting device for an internal combustion engine even in the case where disconnection of a secondary current path or misfire in an ignition plug occurs. A voltage developed at the secondary winding low voltage side is suppressed so that the high voltage can be prevented from being leaked. The combustion state detecting device for an internal combustion engine includes a capacitor,for charging a positive bias voltage necessary for detecting ions generated when an ignition plug,discharges upon application of the ignition high voltage, a resistor,disposed between the low voltage side of the secondary winding and the capacitor for suppressing the drop of the bias voltage, ion current detecting means,for detecting a discharge current from the capacitor as an ion current flowing through the ignition plug, an ECU,for detecting a combustion state in the ignition plug on the basis of a detection value of the ion current detecting means, and a Zener diode,for suppressing a voltage developed when a path in which the ion current flows is disconnected.

Combustion state detecting device for an internal combustion engine

A combustion state detecting device for an internal combustion engine is obtained which is capable of preventing noises from being superimposed on an ion current, and surely obtaining a desired peak value of the ion current. The combustion state detecting device for the internal combustion engine includes an ignition coil which develops an ignition high voltage, an ignition plug to which the ignition high voltage is applied through a high-voltage path connected to a plurality of output terminals of the ignition coil, bias means for charging a bias voltage necessary for detecting ions which are discharged and generated from the ignition plug, discharge current limiting means for discharging the bias voltage, ion current detecting means for detecting the discharge of the bias voltage as an ion current that flows through the ignition plug, and an ECU for detecting a combustion state in the ignition plug on the basis of a detection value of the ion current, wherein the discharge current limiting means is disposed between an ignition current path formed by discharging the ions from the ignition plug and the bias means.

A combustion state detecting device for an internal combustion engine enables diverse combustion state detection by obtaining a plurality of currents analogous to an ion current. The combustion state detecting device includes a bias circuit,that applies an ion current detection voltage to an ignition plug,disposed in a cylinder of the internal combustion engine, an ion current signal distributor circuit,made up of a current mirror circuit for detecting the ion current on the basis of a voltage from the bias circuit, and current-voltage converter circuits,and,, to thereby produce a plurality of currents analogous to the ion current by the ion current signal distributor circuit.

For a purpose of improving detecting performance toward knocking in small and middle intensity which must be detected as a top priority to conduct regulation of ignition timing, a device is provided to vary an output gain of an alternating component included in an ion current in accordance with ion current quantity. An ion current detector to detect the ion current to be generated surrounding an ignition plug just after mixed gas inside a cylinder has been ignited with a spark discharge having occurred at the ignition plug due to a voltage generated by an ignition coil, comprises a bias voltage generating part to generate a high voltage for an ion current detection to be applied to the ignition plug via the ignition coil, an ion current-to-voltage conversion part to convert an ion current having flowed between electrodes of the ignition plug by the high voltage into a voltage, and a knock signal generator to extract and amplify a frequency band resembling knocks on the basis of voltage conversion effect.

Ion current detector

To obtain a combustion state detecting device in which a detection range is optimized to thereby make it possible to improve the S/N ratio, thereby making it possible to enhance the accuracy in detection of the combustion state of the internal combustion engine, in particular, the accuracy in knock detection. The combustion state detecting device for an internal combustion engine includes an ignition plug 4 which discharges by application of the ignition high voltage to fire a fuel-air mixture within a cylinder of an internal combustion engine, a bias circuit,for applying a bias voltage to the ignition plug, a current detector circuit,for detecting an ion current corresponding to the quantity of ions which are generated within the cylinder in which the fuel-air mixture is being burned as an ion current detection signal, knock signal processing means,to,for producing a knock decision signal representative of a knock occurrence state of the internal combustion engine on the basis of the ion current detection signal, and an ECU,for detecting the combustion state in the ignition plug on the basis of the ion current detection signal and the knock decision signal. The knock signal processing means sets a detection period of the knock decision signal on the basis of an integral value of the ion current detection signal.

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Tokyo, Japan

Yutaka Ohashi