Other

Hitachi, Ltd.

Hitachi Car Engineering Co., Ltd.

Yasuo Makie

Shinya Igarashi

Hiroshi Hirayama

Atsushi Kanke

Kenji Ohta

Takayuki Itsuji

Chihiro Kobayashi

Takashi Kadohiro

Takayuji Itsuji

An air flow sensor for an internal combustion engine is disclosed. An air flow rate measurement meter, a pressure gauge, electronically controlled throttle body, and the microcomputer, etc. are integrated as one body, and the correction of the air flow rate, the control, and the fault diagnosis, etc. are done in the integrated microcomputer. The air flow sensor outputs an air flow rate signal in which the error is deleted to suppress the discharge of the harmful exhaust gas from the internal combustion engine, carries out the self-diagnosis of the breakdown of the air flow sensor or the electronically controlled throttle body to prevent the accident beforehand, and controls to obtain the best intake air amount.

Air flow measuring device formed integrally with electronically controlled throttle body

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

In flow detection by a thermal-type flow measuring instrument, a flow rate valve with reduced measurement error due to temperature variation can be obtained even under environment where a fluid temperature and a circuit temperature are different. A measurement error due to temperature variation of the fluid of the thermal-type flow measuring instrument can be corrected on the basis of a temperature of the fluid by adjusting the measurement error to be constant ratio irrespective of the flow rate. On the other hand, a temperature characteristic of the circuit is adjusted to be substantially zero %.

Thermal type flow measuring instrument and temperature-error correcting apparatus thereof

Growing community of inventors

Ibaraki, Japan

Yasuo Makie