Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Koji Tanimoto

Yuji Ariyoshi

Masahiro Kawai

Hiroyuki Uramachi

Naruki Suetake

Shinichiro Hidaka

Shinji Taniguchi

Tomoya Yamakawa

Kazuhiko Otsuka

Naoyuki Kishikawa

Ryuji Toyama

Shingo Hamada

Yuji Kawano

Takaki Sugino

Mikio Bessho

Akito Yokoi

Souichi Satou

Harumasa Shibata

An object is to reduce the influence of noise due to electric conduction carriers trapped between the surface of a silicon substrate and an oxide and thus achieve strain detection with a high S/N ratio. This semiconductor strain detection element includes: a silicon substrate; and a first impurity diffusion layer having a conduction type different from the silicon substrate, the first impurity diffusion layer being formed inside under a surface of the silicon substrate, wherein an amount of strain in the silicon substrate is detected on the basis of change in a resistance of the first impurity diffusion layer.

Semiconductor strain detection element with impurity diffusion layer

Provided is an intake air temperature detection apparatus mounted integrally with a flow rate measurement apparatus, the intake air temperature detection apparatus having temperature measurement precision improved by increasing thermal responsiveness of an intake air temperature detection part that is arranged in a measurement passage of the flow rate measurement apparatus and detects a temperature of intake air, which is a fluid to be measured. The intake air temperature measurement apparatus includes: the intake air temperature detection part for detecting a temperature of the intake air in the measurement passage of the flow rate measurement apparatus; and an intake air temperature detection circuit part arranged in a circuit accommodating part of the flow rate measurement apparatus, for generating a signal obtained by carrying out phase lead correction on a signal representing a result of detection by the intake air temperature detection part.

Physical amount measurement apparatus mounted integrally with flow rate measurement apparatus, and physical amount measurement method

Provided is a thermal flow sensor capable of obtaining a flow rate detection signal that differs depending on a flow direction of a fluid, with a simple configuration and at low cost. The thermal flow sensor includes: a bridge circuit () for outputting a flow rate detection signal (VM); a fluid direction detection circuit () for outputting a fluid direction detection signal (VD); and an arithmetic circuit () configured to: generate a first output signal (VQF) and a second output signal (VQR) based on the flow rate detection signal (VM) and the fluid direction detection signal (VD); and select the first output signal (VQF) when the fluid direction detection signal (VD) shows normal flow and select the second output signal (VQR) when the fluid direction detection signal (VD) shows reverse flow, to thereby output a flow rate detection signal (VOUT).

Thermal flow sensor and method of generating flow rate detection signal by the thermal flow sensor

A thermal air flow meter comprises: a bridge circuit unit that incorporates a bridge circuit including a heating resistor and supplies a current to the heating resistor so that the temperature of the resistor is always set higher by a predetermined temperature than the temperature of intake air detected by an intake-air temperature detection resistor, and outputs an output signal Vm based on the current value supplied to the heating resistor, in accordance with a flow rate of the intake air; a differential amplifier unit that amplifies a voltage dependent on difference in temperature between an upstream heating resistor and downstream heating resistor; and a subtraction processor that subtracts from the output signal Vm a constant times an output voltage Vd1 from the differential amplifier unit, and outputs a correction output signal Vout.

Thermal air flow meter

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 ().

Flow rate measuring apparatus

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.

Flow rate measuring device

A knock sensor includes: a base including an annular flange portion and a cylindrical portion, an annular piezoelectric element fitted onto the cylindrical portion, electrode portions oppositely formed on front and rear surfaces of the annular piezoelectric element, first and second terminal plates in contact with the electrode portions, an annular weight, a first insulating sheet interposed between the first terminal plate and the flange portion, a second insulating sheet interposed between the second terminal plate and the weight. The electrode portions include annular partial electrodes each having a width narrower than a radial width of the piezoelectric element. The annular partial electrode has a thickness d satisfying: L/d&#x3c;80 where L is a radial dimension of outer circumferences of the front and rear surfaces where the electrode portions are not arranged.

Knock sensor

A thermal type flow rate detector includes: a bridge circuit constructed by upstream side and downstream side temperature detecting elements for detecting a temperature of fluid flowing from the upstream side to the downstream side, and fixed resistors; and a temperature difference controlling circuit for continuously supplying an electric power to upstream side and downstream side heat generating elements so that a temperature difference between the temperature detecting elements becomes a predetermined value. The temperature difference controlling circuit includes: a differential amplifier connected to the bridge circuit; a first constant voltage power supply; a second constant voltage power supply having a lower constant voltage than that of the first constant voltage power supply; and the upstream side and downstream side heat generating elements.

Thermal type flow rate detector

A diversion passage is constructed into an inverted U shape in which an upstream diversion passage and a downstream diversion passage each having a passage direction in a direction of projection of a detector flow tube communicate by means of a curved portion. An inflow port is constructed by removing a portion of a wall of the upstream diversion passage on an upstream side in the main direction of flow, and removing a portion of first and second side walls of the upstream diversion passage facing each other in a direction perpendicular to the main direction of flow and the direction of projection of the detector flow tube. In addition, a wall surface on a downstream side of the upstream diversion passage in the main direction of flow at the inflow port is formed into a curved surface shape that is gradually displaced upstream relative to the direction of projection of the detector flow tube to constitute an air lead-in surface.

Air flow rate measuring apparatus

To provide a thermosensitive flow rate detecting in which no response lag occurs even if the flow rate change frequency is high, and no error in detection flow rate is produced even if the power source change would occur, a thermosensitive flow rate detecting device is provided which includes: a heat generating resistor provided in fluid to be measured for generating heat by electric power consumed in accordance with a flow rate of the fluid to be measured; a first temperature detecting resistor for detecting a temperature of the fluid to be measured which changes according to the flow rate; and a second temperature detecting resistor for detecting the temperature of said heat generating resistor, further including a bridge circuit provided with the first temperature detecting resistor and the second temperature detecting resistor, the heating current of the heat generating resistor being controlled such that a temperature difference between the first temperature detecting resistor and the second temperature detecting resistor is kept constant, and the flow rate within the fluid to be measured being detected by using the heating current, wherein a voltage in proportion to the heating current of the heat generating resistor is applied to the bridge circuit.

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Tokyo, Japan

Koji Tanimoto