Hitachi, Ltd.

Hitachi Car Engineering Co., Ltd.

Other

Hitachi Automotive Engineering Co., Ltd.

Atsushi Kanke

Shinya Igarashi

Kenji Ohta

Izumi Watanabe

Keiji Hanzawa

Nobuyasu Kanekawa

Minoru Ohsuga

Masatoshi Hoshino

Yutaka Nishimura

Kohei Sakurai

Keiichi Mashino

Keiichi Nakada

Katsuji Marumoto

Masahiro Matsumoto

Masamichi Yamada

Masahiko Ibamoto

Mitsuru Watabe

Shigeru Oho

Chihiro Kobayashi

Kei Ueyama

Noriyoshi Urushiwara

Hisao Sonobe

Yuuji Maeda

Rintarou Minamitani

Naoyuki Takahashi

Yasuo Makie

Shouju Masumoto

Katsumi Kondo

Akira Endo

Takahiro Miki

Hiroshi Kuroda

Kunio Miyashita

Takao Sasayama

Kazuo Tahara

Takanori Shibata

Kaoru Uchiyama

Junichi Ishii

Tatsuki Inuzuka

Yasuhiro Gunji

Masato Isogai

Nobuyoshi Tsuboi

Masahiro Komachiya

Masayuki Kozawa

Akihiro Saito

Hiroshi Yoneda

Kazuhiro Kuwabara

Masahiro Takasaka

Yuichi Mori

Takashi Kadohiro

Shinji Ohyama

Sadayuki Okada

Shuuichi Kokubun

Kelji Hanzawa

Hanzawa Keiji

Thermal type flow rate meters for measuring the flow rate of intake air of an internal combustion engine of a motor vehicle or the like have encountered a problem of an increase in pulsation errors during high engine speed and high pulsation. Meanwhile, digitally recovering responses has posed a problem in which pulsation performance is liable to become worse, affected by variation in a clock or the like. The sensor is provided with means for transferring a response variation factor to the engine control unit. The engine control unit is provided with logics for automatically determining the variation factor and correcting a response. Means for detecting a backflow occurrence is provided and a parameter for a response recovery is changed before and after a backflow occurrence. The sensor is provided with a selecting means by which a sensor response can be selected and obtained and the engine control unit is provided means for allowing selection of a response.

Thermal type flow rate measurement apparatus

In regard to an output of an intake flow meter for an internal combustion engine, a pulsation error can be reduced and dispersion in correction at the time of correction of response delay (a recovering of response delay) is reduced. A digital device is used for pre-processing of a control unit for inputting a flow rate measuring signal. An output voltage of the flow sensor is converted into a digital value, the digital value is converted into a flow rate and adds a response delay. The control unit detects a degree of response delay in reference to dispersion in a clock signal so as to perform response delay recovering and reduce dispersion of the response delay.

Thermal flow meter and control system

A flow measuring device has a sensor element for outputting a nonlinear signal according to a flow rate. In the device, a first signal processing system obtains a first signal by filtering the nonlinear signal output from the sensor element, thereafter corrects a sensitivity of the filtered signal. A second signal processing system obtains a second signal by linearizing the nonlinear signal from the sensor element, thereafter filters the linearized signal and corrects a sensitivity of the filtered signal, and then non-linearizes the linearized signal with a corrected sensitivity. An amplifier amplifies a differential signal between the first and second signals. A correcting section corrects the nonlinear signal by using the amplified differential signal.

Flow measuring device

In a thermal-type airflow meter that measures an intake airflow rate in an internal combustion engine of an automobile or the like, there has been a problem that pulsation errors caused by external fluctuations under the environment including a large pulsation and reverse flow in the intake valve are difficult to be reduced. In order to solve this problem, the invention provides a flowmeter comprising a detection element that outputs a non-linear signal corresponding to a flow rate, and a regulation means that regulates an output signal of the detection element for controlling. With this construction, the regulation means executes output regulation processing that regulates irregularities of the detection element in the output signal, and inequality linearization processing that regulates an average value of the output signal after the output regulation processing by means of regulating parameters.

Flowmeter and flowmeter system

A thermal air flow rate measuring apparatus of great precision wherein sensitivity is enhanced by sensors having different output characteristics and an operating device employing a digitized signal. The sensitivity and temperature can be corrected easily depending on the flow direction of fluid. The measuring apparatus includes at least one heating resistor disposed in a gas fluid, temperature detecting resistors formed at an upstream part and a downstream part of the heating resistor in the flow direction of the fluid, a device for outputting at least two signals relating to the flow rate of the fluid, a quantizing device for quantizing the output values, and an operating device for operating the flow rate based on the quantized signals.

Thermal air flow rate measuring apparatus and its flowmeter and internal combustion engine and thermal air flow rate measuring method using it

An engine electronic control unit is inserted through a through hole provided in an intake pipe and mounted in an intake air passage in a direction substantially perpendicularly with respect to a plane of the intake pipe forming the intake air passage. This unit is then secured to the intake pipe using a fixing flange provided at a connector portion. A fixing rail is protruded inside the intake pipe and leading edges of a metal base and a metal cover of the unit are inserted into this rail, thereby securing in position an end opposite to a side of the connector portion of the unit. This realizes an engine electronic control unit offering an outstanding heat radiation performance and vibration resistance, without having to provide special heat radiating parts or without involving an increase in an intake air resistance within the intake air passage. By using such an engine electronic control unit, it is possible to provide a low-cost, compact engine air intake system.

Control circuit module, intake air passage body, engine electronic control device, and engine air intake system provided with the same

An engine electronic control unit is inserted through a through hole provided in an intake pipe and mounted in an intake air passage in a direction substantially perpendicularly with respect to a plane of the intake pipe forming the intake air passage. This unit is then secured to the intake pipe using a fixing flange provided at a connector portion. A fixing rail is protruded inside the intake pipe and leading edges of a metal base and a metal cover of the unit are inserted into this rail, thereby securing in position an end opposite to a side of the connector portion of the unit.

An air flow meter which can decrease the error due to the backflow. Throttle valvewhich opens and shuts the air intake passage is installed in the air intake passage of the internal combustion engine. The first sensor partis installed in the air intake passage in the upstream of throttle valveFurther, the second sensor partis installed in the air intake passage in the downstream of throttle valvePulsation compensating meanscorrects the pulsation of the air flow rate signal detected by the first sensor part by using the output signals of the first and the second sensor partsbased on each cylinder of the internal combustion engine.

Air flow meter

To offer a mass airflow measuring apparatus in which the effect of the adhesion onto the heating resistor caused while the engine is off is reduced and the measuring accuracy is improved. The apparatus measures the mass airflow of the air sucked into the internal combustion engine, using the heating resistorThe power control circuitmaintains the heating resistortemperature equal to or higher than the temperature during the operation of the internal combustion engine after the internal combustion engine has stopped and until the temperature of the internal combustion engine and its apparatuses installed in the suction system has lowered below the generation temperature of volatile gas such as oil vapor. The power control circuitusing the temperature sensing resistorthat detects the temperature of the air sucked into the combustion engine, detects the air temperature and maintains the heating resistortemperature, based on the temperature measured, equal to or higher than the temperature during the operation of the internal combustion engine even after the internal combustion engine has stopped.

Mass airflow measuring apparatus

A hot-wire type air flow meter for an internal combustion engine has an exothermic resistor film provided on a thin portion formed on a silicon substrate and a control circuit for controlling a voltage to be applied to the resistor film or a current to be supplied. The resistor film is arranged in a suction pipe of the internal combustion engine and heat is emitted to an air through the resistor film. In the case where a liquid droplet is deposited onto the resistor film, the control circuit controls the applied voltage to a value smaller than a voltage which is applied to the resistor film at the time of measuring a maximum specified measuring range or controls the supply current to a value smaller than a current flowing in the resistor film at the time of measuring the maximum specified measuring range.

Hot-wire type air flow meter for internal combustion engine

To offer a mass airflow measuring apparatus in which the effect of the adhesion onto the heating resistor caused while the engine is off is reduced and the measuring accuracy is improved. The apparatus measures the mass airflow of the air sucked into the internal combustion engine, using the heating resistor The power control circuit maintains the heating resistor temperature equal to or higher than the temperature during the operation of the internal combustion engine after the internal combustion engine has stopped and until the temperature of the internal combustion engine and its apparatuses installed in the suction system has lowered below the generation temperature of volatile gas such as oil vapor. The power control circuit using the temperature sensing resistor that detects the temperature of the air sucked into the combustion engine, detects the air temperature and maintains the heating resistor temperature, based on the temperature measured, equal to or higher than the temperature during the operation of the internal combustion engine even after the internal combustion engine has stopped.

To correct properly the error of the thermal resistor type air flow measuring apparatus caused by the pulsation in the intake pipe in detecting the air flow of the internal combustion engine, a thermal resistor is placed in a passage inside the auxiliary air passage into which the reverse flow hardly flows directly and the error caused by the reverse flow is prevented. The existence of the reverse flow is judged by the ratio of the amplitude to the mean value using the maximum value, the minimum value and the mean value of the forward air flow waveform, and the error caused by the increase of the forward air flow is corrected.

Thermal resistor type air flow measuring apparatus

By employing command value signals for controlling the opening timing of an exhaust valve or an intake valve and means for measuring flow rates of an intake air of a flow direction which flows through an intake manifold of an internal combustion engine, an air flow rate corresponding to the command value signal is measured. A valve mechanism includes the intake valve and the exhaust valve for each cylinder of the internal combustion engine and is controlled by a valve control means for controlling the valve mechanism. A failure diagnosis of an operating status of the valve mechanism can be performed.

Apparatus of diagnosing an internal combustion engine and a method of diagnosing of an internal combustion engine

An air flow measuring apparatus, is of a type converting digital values Vadc having a non-linearity characteristic to a flow rate in air flow rate conversion processing. The apparatus, is provided with voltage output conversion processing, uses a QV map formed on a PROM, and is formed so as to obtain a voltage output signal Vout having a property equivalent to a signal Vin outputted from a sensor circuit by converting a smoothed signal Qaf into a voltage value having a non-linearity characteristic.

Air flow measuring apparatus

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Hitachi, Japan

Atsushi Kanke