Mitsubishi Electric Corporation

Shinichiro Hidaka

Masahiro Kawai

Yuji Ariyoshi

Naoyuki Kishikawa

Naoki Morinaga

Hiroyuki Uramachi

Kazuhiko Otsuka

Koji Tanimoto

Kenji Nakajima

Kazuto Akagi

Takayuki Gamahara

The internal-combustion-engine control apparatus has an intake-air-temperature correction control apparatus including a first-order advance compensation means that calculates an advance-compensation amount for an intake-air temperature detection signal, a time constant determination means that calculates a time constant of the first-order advance compensation means, and a first-order delay compensation means that receives a calculation value of the first-order advance compensation means; the time constant determination means includes a time constant setting means that sets a time constant, based on an intake-air flow rate detection signal, an upper-limit-value setting means that sets an upper limit value of the time constant calculated by the time constant determination means, and a minimum value selection means that selects and outputs a minimum value of a time constant set by the time constant setting means and the upper limit value set by the upper-limit-value setting means.

Internal-combustion-engine control apparatus

A flow rate detector includes a detection circuit, which is configured to output as an analog signal a voltage in accordance with a flow rate of air flowing through an intake pipe, and a conversion circuit, which is configured to convert the analog signal input from the detection circuit to a digital signal based on an analog-to-digital conversion characteristic to output the digital signal. The analog signal that corresponds to a forward flow direction and is input to the conversion circuit is set to have a value larger than an input voltage range in which a missing code may occur in the analog-to-digital conversion characteristic.

Flow rate detector

This signal processing unit includes: a comparison signal output unit which outputs a comparison signal on a negative side that corresponds to a negative side portion, of a second amplitude-increased signal, which is on the negative side with respect to the comparison threshold TH; an averaging processing unit which outputs an average signal obtained by averaging the comparison signal; a coefficient multiplication processing unit which outputs a coefficient-multiplied signal obtained by multiplying the average signal by an adjustment coefficient set in advance; and a signal correction processing unit which outputs, as a flow rate signal, a value obtained by correcting a first amplitude-increased signal so as to be decreased by use of the coefficient-multiplied signal, wherein the comparison threshold TH is set on the basis of an output characteristic of a sensor measured in advance with respect to at least a forward flow direction of an intake air.

Thermal air flow meter with adjustment of pulsation correction function

An environment sensor arranged in a measuring chamber disposed in a circuit board receiving portion does not affect a flow of air through a bypass passage, and thus does not affect detection accuracy of a flow rate detection element arranged in the bypass passage. A recessed portion is disposed in a side surface of a base parallel to a flow direction A of intake air passing through a main passage and a communication port of the measuring chamber is disposed in the recessed portion, and thus the measuring chamber is unlikely to be infiltrated by fouling substances, water droplets, and the like contained in the intake air. The communication port has a small length dimension L, and thus an environment parameter of the intake air is likely to propagate to the measuring chamber and high levels of detection response, detection accuracy, and reliability are ensured for the environment sensor.

Flow rate measurement device

There is provided a thermal-type airflow meter that reduces the number of output signals of the sensor circuit and that can suppress the accuracy of flow rate detection from being deteriorated because due to a nonlinear sensor output characteristic and a response delay in the output signal, the output signal shifts toward the positive side or the negative side. A thermal-type airflow meter outputs one or both of a positive-side comparison signal that is at the positive side of a comparison threshold value and a negative-side comparison signal that is at the negative side of the comparison threshold value, outputs a coefficient multiplication signal obtained by multiplying an average signal acquired by averaging the comparison signal by an adjustment coefficient, and outputs, as a flow rate signal, a value obtained by applying the coefficient multiplication signal to increase correction or decrease correction of the amplitude increase signal.

Thermal-type airflow meter

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

A flow rate measuring apparatus includes: a flow rate detecting device placed in an intake passage; a detection circuit for outputting an analog signal varying depending on the flow rate; a conversion circuit for converting the analog signal to a digital signal; a temperature detecting device for detecting an ambient temperature; and a correction circuit for primarily correcting the digital signal using a gain and/or an offset (correction coefficient) that can set the temperature coefficient in any appropriate way. The gain and/or the offset vary depending on the temperature coefficient set in any appropriate way and the ambient temperature detected by the temperature detecting device. Also, a plurality of the gains and/or the offsets are set depending on the flow rate, allowing the temperature characteristic error in flow rate measurement to be reduced.

Flow rate measuring apparatus

An environment sensor is mounted on a second surface of a circuit board that does not have a wire bonding pad, and is arranged in a measuring chamber that is disposed in a circuit board receiving portion. The measuring chamber has a communication port for communication with a main passage. According to this configuration, process addition attributable to integration between a flow rate measurement device and the environment sensor is not required. The environment sensor does not affect air flow in a bypass passage, and thus detection accuracy of a flow rate detection element that is arranged in the bypass passage does not decline.

In a flow sensor, an upstream heating element and a downstream heating element are disposed, respectively, upstream and downstream in a flow direction of a fluid so as to undergo mutual thermal interference. By controlling heating currents flown through the respective heating elements, an average temperature control portion maintains an average temperature of the two heating elements at a temperature predetermined degrees higher than a temperature of the fluid detected by a fluid temperature detection portion while a voltage ratio control portion performs control so that a temperature difference or a ratio of applied voltages between the two heating elements takes a predetermined value. A detection signal corresponding to a flow direction of the fluid is obtained from a state of the control on the heating currents and whether a flow direction of the fluid is forward or backward is determined.

Flow sensor and control system of internal combustion engine

A thermal flow sensor for vehicles includes a bridge circuit unit having a heating resistor whose resistance value changes according to temperature, a resistance thermometer, detecting a temperature of a fluid, whose resistance value changes according to temperature, and an integrated circuit unit controlling the bridge circuit unit and outputting a signal of detected fluid flow rate. A drive power source for the bridge circuit unit is supplied from a battery, and a drive power source for the integrated circuit unit is supplied from a constant voltage source stabilized by a fuel injection control device.

Thermal flow sensor having a power source for driving a bridge circuit and an integrated circuit

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.

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Tokyo, Japan

Shinichiro Hidaka