Hitachi, Ltd.

Hitachi Automotive Engineering Co., Ltd.

Other

Hitachi Car Engineering Co., Ltd.

Mitsukuni Tsutsui

Kaoru Uchiyama

Shinya Igarashi

Toshifumi Usui

Nobukatsu Arai

Hiroatsu Tokuda

Masayuki Kozawa

Tadao Osawa

Akira Takasago

Yoshihito Sekine

Hiroshi Hirayama

Minoru Takahashi

Chihiro Kobayashi

Yukio Kato

Takashi Yoshinari

Tadao Suzuki

Noboru Sugiura

Seiji Suda

Shotaro Naito

Kazuhiko Kawakami

Takayuki Itsuji

Tetsuo Matsukura

Toshiaki Iikubo

The thermal-type airflow meter comprises airflow meter body and measuring part Both of the frame of the housing accommodating therein the electronic circuit and the subpassage member having the heating resistor etc. positioned within a subpassage of air are arranged on the metallic base Further, the frame the subpassage member the metallic base and the cover are adhered to respectively different member more than one. The connector of the housing the frame and the subpassage member are formed in a flat shape to form the measuring module The measuring module is inserted through the insertion hole to locate the heating resistor within the main air passage and the fixing flange of the housing is fixedly attached to the airflow meter body

Thermal-type airflow meter, intake air system for an internal combustion engine, and control system for the same

A thermal-type airflow meter comprises an airflow meter body and a measuring part. Both of the frame of a housing which accommodates the electronic circuit, and a sub-passage member which has the heating resistor positioned within a sub-passage, are arranged on a metallic base. Further, the frame, the sub-passage member, the metallic base and the cover are each fixedly attached to at least two respective different members. A connector of the housing, the frame and the sub-passage member are formed in a flat shape to form the measuring module. The measuring module is inserted through an insertion hole to locate the heating resistor within the main air passage, and the fixing flange of the housing is fixedly attached to the airflow meter body.

Thermal-type airflow meter, intake air system for an internal combustion

An air flow rate measuring device for measuring intake air flow rate in an automotive engine, improved to reduce any error attributable to variation in the configurations of air cleaner and/or duct forming air passage upstream of the flow rate measuring device, thus offering high accuracy of the flow rate measurement. In one aspect of the invention, the inlet opening of a sub-air passage is disposed to contain the axis of a main air passage, while the outlet opening of the sub-air passage is disposed in the vicinity of a wall defining the main air passage. In order to cause a local reduction of the pressure of the principal of the air flow at the outlet opening, a protrusion or a flat surface which causes impediment to the flow if air in the main air passage is provided immediately upstream of the outlet opening. In another aspect, the inlet surface in which the inlet of the sub-air passage opens is stepped in the direction of flow of the air so as to enable air to be introduced into air flow rate measuring portion in the sub-air passage from different regions in the main air passage while giving a preselected order of preference to these different regions.

Air flow rate measuring device

An air flow sensor unit for an internal combustion engine control system which detects an air flow rate and outputs an optical signal corresponding to the detected air flow rate to an external equipment including a bridge circuit including a temperature sensitive resistor which detects the air flow rate and outputs a first electrical signal indicative of a voltage amplitude corresponding to the detected air flow rate; a first converting circuit which converts the first electrical signal outputted from the bridge circuit into a second electrical signal indicative of a digital value corresponding to the voltage amplitude of the first electrical signal; a second converting circuit including a laser diode, for converting the second electrical signal outputted from the first converting circuit into the optical signal having the same digital value as that of the second electrical signal; a housing for accommodating the bridge circuit, first converting circuit and second converting circuit; and an apparatus of a lens and optical fiber cable secured integrally to the housing for transmitting the optical signal outputted from the second converting circuit to an external equipment.

Physical quantity sensor arrangement

A flow rate of air flowing through an air inlet pipe is detected by a heating resistor disposed therein and converted into an electric signal. A digital processing unit carries out calculation to judge whether or not the converted signal coincides with a predetermined temperature value and to correct the converted signal so that the same is caused to coincide with the predetermined value if both the values do not coincide with each other. The corrected signal is used to keep the heating resistor at the predetermined temperature. The digital processing unit is integrated with the air inlet pipe independently of a digital processing unit for engine control.

Heating resistor type air flow meter with separate/processing unit

An air flow measuring system has a unit for measuring an air flow rate and outputting an air flow rate indicative signal, a unit for measuring an air temperature for outputting an air temperature indicative signal, and a mixing unit for converting the air flow rate indicative signal and the air temperature indicative signal by superimposing them so that the converted signal may be transmitted through a single signal transmission path.

Method and system for measuring air flow rate

An exothermic resistor type air flow detector according to the invention is compact and requires no special radiation structure. A control circuit comprised of a transistor T and a differential amplifier are formed with an exothermal resistor Rh on an insulated substrate 2, which is placed in an air passage in which air current is to be measured.

Air flow detector for engine control unit

An air flow meter has a body forming a main passage defining an intake air passage of an internal combustion engine. An auxiliary passage within the main passage has a longitudinal passage in the axial direction and at least one transverse passage in the radial direction of the main passage. The auxiliary passage is defined by a member having a radially directed portion connected to an internal wall of the main passage. A hollow space is provided in the radially directed portion to render the wall thickness of the radially directed portion substantially uniform. Additionally, the hollow space is separated from the longitudinal passage by an auxiliary member which, in a preferred embodiment, surrounds a heat sensitive resistor.

Air flow meter

Hot-wire air flow meter

The present invention whose object is to provide a hot wire type of flow meter capable of accurately detecting a flow rate under various conditions required for satisfying a desire for low fuel consumption of an engine system and space saving in an engine room, the present invention being characterized in a hot wire type of air flow meter including a main flow passage forming an air intake flow passage of an internal combustion engine, a hot wire element measuring intake air, and a bypass having the hot wire element therein and disposed in the main flow passage, the hot wire type of air flow meter comprising: a flow passage forming the bypass, and formed in the axial direction of the main flow passage; and a flow passage forming the bypass and formed in the radial direction of the main flow passage, the flow passage having a structure designed in such a manner that the upper stream portion of an outlet portion thereof projects over the lower stream portion of the same.

Hot wire type of air flow meter and internal combustion engine using the

A compact hot-wire type air flow meter for an internal combustion engine with a high measuring accuracy is provided with a primary flow path forming an intake air passage and an auxiliary flow path incorporating therein a hot-wire element for measuring the intake air. The auxiliary flow path is defined by a flow path in an axial direction of the primary flow path and a flow path in a radial direction of the primary flow path.

Hot-wire type air flow meter and an internal combustion engine with the

The air flow rate detecting resistance element 1A or the temperature sensing resistance element 1B comprises a dielectric substrate 5A or 5B, a thin film type conductor 6A or 6B as a resistance element forming conductor, and a thin film type conductor 7A or 7B as a shield electrode element forming conductor. The resistance element conductor 6A or 6B and the shield electrode element conductor 7or 7B are formed by evaporation on the dielectric substrate 5A or 5B. The shield electrode element conductor 7A or 7B is provided in the vicinity of the resistance element conductor 6A or 6B an electrostatic capacity is formed therebetween. The shield electrode element conductor 7A or 7B is maintained at the lowest potential such as ground or a common potential. The guidance of high frequency radio waves to the resistance element 1A or 1B can be effectively prevented, so that the radio interference resistance of the hot film type air flow meter can be improved.

Hot film type air flow meter

A hot-wire flow rate measuring apparatus includes a first thermo-sensitive resistive element disposed in the flow path of fluid under measurement, resistor unit connected in series to the first sensing element, a second thermo-sensitive resistive element for temperature compensation disposed in the flow path of the fluid, a control circuit adapted to supply a current to the serial connection of the first sensing element and the resistor unit in response to the difference between the voltage produced by the first sensing element and the voltage produced by the second sensing element, and an output circuit for producing a voltage representative of the fluid flow rate in response to the terminal voltage of the resistor. The apparatus is further provided with a current circuit which controls the ouptut characteristics of the output circuit by supplying a compensation current proportionate to the terminal voltage of the resistor to a portion of the serial connection.

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Ibaraki, Japan

Mitsukuni Tsutsui