Hitachi, Ltd.

Hitachi Car Engineering Co., Ltd.

Other

Hitachi Automotive Systems, Ltd.

Akira Takasago

Hiroyuki Abe

Shinya Igarashi

Masayuki Kozawa

Kaoru Uchiyama

Hiromu Kikawa

Mitsukuni Tsutsui

Akio Yasukawa

Naoki Saito

Noboru Tokuyasu

Izumi Watanabe

Chihiro Kobayashi

Yukio Kato

Tomoaki Saito

Tadashi Isono

Masayuki Satou

Provided is a thermal flowmeter that can achieve both measurement accuracy and antifouling performance with a simple and space-saving passage structure. In the thermal flowmeter of the invention, a housing is disposed in a main passage through which a gas to be measured flows, and the gas to be measured is taken from the main passage into an auxiliary passage provided in a housing, and a flow rate detection unit disposed in the auxiliary passage measures a flow rate of the gas to be measured. The auxiliary passage includes an inlet opening that opens to be inclined with respect to the main flow direction of the gas to be measured flowing through the main passage, and an inclined passage that extends in a direction inclined with respect to the main flow direction of the gas to be measured flowing from the inlet opening through the main passage.

Thermal flowmeter

The present invention improves reliability of an in-vehicle electronic device against corrosive gases. A trapping agent that has trap performances (adsorptive performance, suction performance, absorption performance, chemical reactivity, etc.) that are higher than that of water vapor with respect to corrosive gases other than water vapor is held within a connector having a terminal that is insert-molded in a case housing an electronic circuit. Here, the trapping agent may be held in a counterpart connector of the connector integrally formed in the case.

In-vehicle electronic device

A heating resistor type flow measuring device comprising a housing having a support part provided between a frame body and a connector and connected to the mounting part of a fluid passage, a flow rate detection element held on the frame body side of the housing, and an electronic circuit held on the housing and connected electrically to the flow rate detection element and the connector, wherein the electronic circuit is held on the frame body side of the housing and positioned in the fluid passage, a member with the rigidity higher than the material of the main structural member of the housing is formed integrally with the support part, the housing is fixed to the fluid passage through the member with high rigidity. A metal plate is inserted into the support part so as to increase rigidity. Further, a distance is provided between the support part and a metal plate forming a route for conducting the heat transferred to the metal base fixing an electronic circuit substrate by a plastic mold so as to form a structure obstructing a heat transfer, or a clearance is provided in a portion spaced by the plastic mold between the support part and the metal base so as to form a structure obstructing a heat transfer.

Heating resistor type flow measuring device housing structure having projection and recess for preventing mis-installation

Heating resistor type flow measuring device

In a gas-flow measuring instrument for measuring a gas flow in an intake gas passage for sucking gas, an abnormal output, deterioration per hour, stain, and breakage of a flow measuring element caused by fluid and foreign materials contained in intake gas are reduced. A gas-flow measuring instrument disposed in an intake gas passage for sucking gas for measuring a gas flow includes a bypass passage for bringing gas flowing along the intake gas passage, a bypass passage inlet opened to the upstream side of a main stream direction of gas in the intake gas passage, and a flow measuring element disposed in the bypass passage.

Gas-flow measuring instrument

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

A measuring element for an air flow rate measuring apparatus has upstream and downstream heating resistors and first and second temperature compensating resistors paired with the upstream and downstream heating resistors, respectively. The resistors are mounted on an electrically insulated substrate positioned within an air flow. A substantial part of resistor film of the temperature compensating resistor paired with the upstream heating resistor is positioned upstream on the insulated substrate relative to the resistor film of the compensating resistor paired with the downstream heating resistor.

Air flow measuring element and air flow measuring apparatus therewith

A highly accurate, low-cost and easy-to-handle heating resistor type flow meter has a main air flow passage body forming a main air flow passage for allowing air flowing therethrough. A measuring module has a heating resistor for measuring a flow rate of the air inserted inside the main air flow passage body: The measuring module comprises the heating resistor inside an auxiliary air flow passage body forming an L-shaped auxiliary air flow passage having an inlet opening portion opening in a direction perpendicular to a main flow line of the air and an outlet opening portion opening in a direction parallel to the main flow line. The main air flow passage body comprises an orifice on a periphery of the inner side wall positioned in an upstream side of the air flow passage body. Both of the inlet opening portion and the outlet opening portion are arranged within a flow flux zone formed by extending the air flow from a top edge of the orifice in a direction parallel to the main flow line.

Growing community of inventors

Hitachinaka, Japan

Akira Takasago