Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Hiroyuki Uramachi

Tomoya Yamakawa

Fumiyoshi Yonezawa

Masahiro Kawai

Yuji Ariyoshi

Shingo Hamada

Koji Tanimoto

Takeharu Oshima

Satoru Kotoh

Naoyuki Kishikawa

Naruki Suetake

Shinichiro Hidaka

Kazuto Akagi

Akira Takashima

Masao Kikuchi

Yasuo Tada

Hiroshi Sakanoue

Ryuji Tohyama

Ryouichi Sasahara

Hidehito Yamauchi

Souichi Satou

A flow rate measuring device includes: a bypass passage; a flow rate detecting element; and a flow rate measuring circuit. The bypass passage includes: an inflow port; an outflow port; and a plurality of bent portions. The plurality of bent portions include first to third bent portions for forming U-shapes, and a fourth bent portion for bending the bypass passage bent at the third bent portion so as to be parallel to a mainstream flowing direction. The flow rate detecting element is arranged inside the bypass passage in a part after bending at the fourth bent portion. A route connecting the inflow port and the flow rate detecting element as a straight line is blocked by an inner wall surface of the bypass passage on an outer peripheral side, which is formed between the first bent portion and the second bent portion.

Flow rate measuring device

Dust with various particle diameters entering a bypass passage, particularly, relatively large dust with a particle diameter of 100 to 200 &#x3bc;m or so, is reliably caused to collide with a first step-shaped part, a second step-shaped part and a plate-like member to be sufficiently decelerated and reach a flow rate detecting device with low collision energy. This can prevent the flow rate detecting device from being damaged by collision of dust. Furthermore, the placement position of the plate-like member is optimized to suppress air turbulence at a flow rate detecting part, which achieves a good balance between flow rate detection accuracy and dust tolerance.

Flow rate measuring apparatus

An electronic circuit storage case includes a housing made of resin and having a case portion storing an electronic circuit board and a connector portion extending in a direction perpendicular to a board attachment surface of the case portion and incorporating a connector. Interior and exterior opening holes communicate at bottoms via a communication hole. A ventilating hole continuing from the interior of the case portion to the exterior of the connector portion is provided in a solid portion of the housing. The interior opening hole and the communication hole are bent in an L shape and provided to a primary resin mold part forming the housing. The exterior opening hole is provided to a secondary resin mold part of the housing enclosing the primary resin mold part and forming the connector and case portions so as to communicate with one end of the L-shaped communication hole substantially perpendicularly.

Electronic circuit storage case and manufacturing method thereof

Provided is a flow rate measuring apparatus which prevents a reduction in flow-rate detection accuracy through reducing stress applied to a flow rate detection element. The flow rate measuring apparatus includes a support member () provided with a stepped portion () formed between a region facing a circuit board () and a region facing a detection portion of a flow rate detection element (), in which the support member () includes a groove portion () provided on a side opposite to an insertion hole () with respect to the region facing the detection portion, for reducing stress applied to the flow rate detection element ().

Flow rate measuring apparatus having stress reducing means

Provided is a flow rate measuring apparatus which suppresses deformation of a base main body due to vibration of a pipe so as to be able to reduce occurrence of disconnection of wires due to the vibration of the pipe. The flow rate measuring apparatus includes a bonding portion () corresponding to a deformation suppression portion provided between an inner wall surface () of a flange () of a base () and an outer circumferential wall surface () of a cover () covering a circuit board (), which is opposed to the inner wall surface (), for connecting the flange () and the cover () to suppress the deformation of a base main body () of the base () due to vibration of an intake pipe ().

Although flow detection accuracy deterioration due to a subject fluid inflow into a gap between a sensor device and an engaging portion is prevented by an underflow inhibitor, the underflow inhibitor overflow to a sensor device surface results in the subject fluid turbulence, causing a flow element output fluctuation risk. One solution is a configuration comprising a sensor device made of a planar semiconductor material with a heating element and an intake air temperature detection element formed thereon, a support member containing an engaging portion the sensor device is engaged to, which is placed at a passage the subject fluid circulates and underflow inhibitor being filled into a void between the sensor device and the support member to prevent the subject fluid from flowing into the void, and a pooling portion being placed to prevent the under flow inhibitor from overflowing out of the void.

Flow sensor device having a gap formed between a sensor device and an engaging portion and a pooling portion formed in the gap

An inflow port and an outflow port of a bypass passage have openings on a front surface near a projecting end and on a bottom surface, respectively, of a bypass passage forming member. A recess portion is disposed on the front surface of the bypass passage forming member on a circuit housing portion side of the inflow port so as to extend at a predetermined depth over an entire region in a longitudinal direction of a short side of a rectangular cross section of the bypass passage forming member.

Flow rate measuring apparatus including a recess for changing air flow direction

The flow rate measuring apparatus includes a connector portion, a main body portion, a bypass passage, a flow rate sensing element having a flow rate detection portion, a control circuit, a pair of metal terminals having end portions connected to a connector, embedded portions molded integrally with a resin portion constituting the main body portion, and exposed portions exposed in the main passage, which are connected to each other in a cascade manner, and a fluid temperature sensing element having a temperature sensing portion. The fluid temperature sensing element is arranged at a position apart from an outer wall surface of a side face of the bypass passage, and the temperature sensing portion is arranged at the center between the pair of metal terminals that are exposed in the main passage by the same length or between extension lines thereof.

In a flow rate measuring device including a bypass channel having at least one bending portion and at least one channel portions, a detecting element is disposed in the bypass channel to detect the flow rate of measurement target fluid, a ratio L/H of a width H of the channel portion in which the detecting element is disposed, and a distance L from the bending portion at the upstream side of the detecting element to the upstream end portion of the detecting portion is set in range from 0 to 0.7, and a ratio D/H of a distance D from the wall surface of the base side of the detecting element to the center of the detecting portion of the surface of the detecting element and the width H of the channel portion is set in the range from 0.22 to 0.33.

A flow rate measuring apparatus can reduce flow rate detection errors resulting from a temperature difference between an inside and an outside of piping. A base has a base main body which is formed at its base end with a connector protruding to the outside of the piping, and a flange which is formed on the base main body and is fitted into an insertion hole in the piping. A plate made of PBT resin is arranged on the base, and a flow rate detection element is formed on the plate so as to be exposed therefrom. A circuit board is arranged at a side of the plate opposite to the connector. A housing has a fluid passage groove that cooperates with the plate to form a measuring passage in which the flow rate detection element is disposed, and an enclosure portion enclosing the circuit board. A cover closes the enclosure portion.

Flow rate measuring apparatus having a resin plate for supporting a flow rate detecting element and a circuit board

A measuring passage includes: an inflow aperture opening onto a vicinity of an end portion of a surface of a main body portion that is perpendicular to a direction of flow of a main flow of a measured fluid so as to be facing upstream; and an outflow aperture opening onto an end surface of the main body portion in a direction of projection. A first passage extends from the inflow aperture in the direction of flow of the main flow to a first bend portion, a second passage extends from the first bend portion so as to be perpendicular to the direction of flow of the main flow toward the circuit housing portion to a second bend portion, a third passage extends from the second bend portion in the direction of flow of the main flow to a third bend portion, a fourth passage extends from the third bend portion in a direction that is perpendicular to the direction of flow of the main flow in a direction away from the circuit housing portion, and a fifth passage extends from the fourth bend portion in a reverse direction to the direction of flow A of the main flow and is connected to the outflow aperture.

A metal plate is supported by a base, and is disposed inside a main passage so as to be generally parallel to a direction of flow of a fluid being measured through the main passage, and a circuit board and a flow rate detecting element are disposed so as to be positioned generally in a common plane with a front surface of the metal plate. A circuit housing portion formed integrally on the base is disposed on the front surface of the metal plate so as to surround the circuit board, an electrical connection portion between the circuit board and the flow rate detecting element, and an electrical connection portion between the circuit board and a connector portion. A measuring passage groove forming portion formed integrally on the base is disposed on the front surface of the metal plate, and functions together with the metal plate to constitute a measuring passage. In addition, the circuit housing portion is charged with a sealing gel, and a cover is mounted so as to cover the circuit housing portion.

Measuring apparatus for measuring flow rate of a fluid

An air flow rate measuring device serves to measure a flow rate of air flowing through a main passage inside an intake pipe of an engine. A base has its one end directed axially of the main passage toward an upstream side of air flowing therein, and its other end directed toward a downstream side thereof, with a bent groove being formed in the base. A circuit module includes a support substrate and a detection element installed one surface of the support substrate for detecting the flow rate of air, the module being joined to the base in a face-to-face relation with respect to each other to form an auxiliary passage in cooperation with the groove. The detection element on the one surface of the support substrate is exposed to air in the auxiliary passage, and the other surface of the support substrate is exposed to air in the main passage.

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Tokyo, Japan

Hiroyuki Uramachi