JP3105609B2 - Heating resistor type air flow meter - Google Patents
Heating resistor type air flow meterInfo
- Publication number
- JP3105609B2 JP3105609B2 JP03349865A JP34986591A JP3105609B2 JP 3105609 B2 JP3105609 B2 JP 3105609B2 JP 03349865 A JP03349865 A JP 03349865A JP 34986591 A JP34986591 A JP 34986591A JP 3105609 B2 JP3105609 B2 JP 3105609B2
- Authority
- JP
- Japan
- Prior art keywords
- air
- resistor
- temperature
- detection signal
- air flow
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Details Of Flowmeters (AREA)
- Measuring Volume Flow (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、空気流路中に設置した
発熱抵抗体を定温度制御するのに必要な電流により空気
流量を検出する方式の、いわゆる定温度制御型の発熱抵
抗体式空気流量計に係り、特に自動車用内燃機関の吸気
流量計測用に好適な発熱抵抗体式空気流量計に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called constant temperature control type heating resistor type air in which a flow rate of air is detected by a current necessary for controlling a heating resistor provided in an air flow path at a constant temperature. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flowmeter, and more particularly to a heating resistor type air flowmeter suitable for measuring an intake flow rate of an internal combustion engine for an automobile.
【０００２】[0002]
【従来の技術】従来から熱線式空気流量計などと呼びな
らされている発熱抵抗体式空気流量計は、例えば、特開
昭５５−４３４４７号公報に記載のように、発熱抵抗体
の外に温度補償用の抵抗体(空気温度検出抵抗体)を持
ち、これにより空気温度に対する補正が与えられるよう
になっている。一方、内燃機関、特に自動車用内燃機関
の制御に際しては、吸気温度の検出を要する場合が多
い。2. Description of the Related Art A heating resistor type air flow meter conventionally called a hot wire type air flow meter or the like is disclosed in, for example, JP-A-55-43447. A compensating resistor (air temperature detecting resistor) is provided so that a correction for the air temperature can be given. On the other hand, in controlling an internal combustion engine, especially an automobile internal combustion engine, it is often necessary to detect the intake air temperature.
【０００３】そこで、例えば、特開昭６２−２８６７１
号公報では、発熱抵抗体式空気流量計が空気温度検出抵
抗体を持っていることから、発熱抵抗体式空気流量計か
ら空気流量信号を得るのは勿論、それと共に、空気温度
信号をも出力させるようにした技術について開示してい
る。Therefore, for example, Japanese Patent Application Laid-Open No. Sho 62-28671
In the publication, since the heating resistor type air flow meter has an air temperature detecting resistor, not only the air flow signal is obtained from the heating resistor type air flow meter but also the air temperature signal is output. The disclosed technology is disclosed.
【０００４】[0004]
【発明が解決しようとする課題】上記従来技術は、空気
温度検出抵抗体が、発熱抵抗体の定温度制御のための帰
還回路を構成している点について配慮がされておらず、
このため、空気温度検出抵抗体の空気温度による抵抗値
変化を、直ちに電圧の変化として取り出し、空気温度検
出信号を得ることが出来ないという問題点があった。本
発明の目的は、空気温度検出抵抗体を使用して、空気流
量信号と同時に空気温度検出信号を簡単に出力できるよ
うにした発熱抵抗体式空気流量計を提供することにあ
る。In the above prior art, no consideration is given to the fact that the air temperature detecting resistor forms a feedback circuit for constant temperature control of the heating resistor.
For this reason, there has been a problem that a change in the resistance value of the air temperature detection resistor due to the air temperature cannot be immediately taken out as a change in voltage, and an air temperature detection signal cannot be obtained. SUMMARY OF THE INVENTION It is an object of the present invention to provide a heating resistor type air flow meter which can easily output an air temperature detection signal simultaneously with an air flow signal by using an air temperature detection resistor.
【０００５】[0005]
【課題を解決するための手段】上記目的は、空気通路中
に設置された温度依存性抵抗素子からなる発熱抵抗体
と、この発熱抵抗体の抵抗値を一定に制御して空気流量
検出信号を出力する定温度制御回路と、上記空気通路内
に設置された温度依存性抵抗素子からなる空気温度検出
抵抗体とを備えた発熱抵抗式空気流量計に於いて、上記
空気温度検出抵抗体に定電流を供給して、この空気温度
検出抵抗体に現れる電圧降下を空気温度検出信号として
外部に出力する空気温度検出回路と、上記空気温度検出
抵抗体に供給されている定電流値と同一の値の電流が供
給されている抵抗体と、この抵抗体の電圧降下による電
圧を基準値として、上記空気温度検出信号を上記空気流
量検出信号に乗算する乗算回路とを設け、この乗算回路
の出力により上記空気流量検出信号に対する温度補償が
与えられるようにして達成される。同じく、上記目的
は、空気通路中に設置された温度依存性抵抗素子からな
る発熱抵抗体と、この発熱抵抗体の抵抗値を一定に制御
して空気流量検出信号を出力する定温度制御回路と、上
記空気通路内に設置された温度依存性抵抗素子からなる
空気温度検出抵抗体とを備えた発熱抵抗式空気流量計に
於いて、上記空気温度検出抵抗体に定電流を供給して、
この空気温度検出抵抗体に現れる電圧降下を空気温度検
出信号として出力する空気温度検出回路と、上記空気温
度検出信号を上記定温度制御回路の制御信号に乗算し、
空気流量検出信号の温度補償を行なう乗算回路と、上記
定温度制御回路から出力される空気流量検出信号を制御
入力とする電圧制御三角波発振器と、この電圧制御三角
波発振器の出力と、上記空気温度検出信号を入力とする
比較回路とを設け、上記比較回路から、空気流量検出信
号に対応した周波数で、上記空気温度検出信号に対応し
た時比率の方形波信号を得るようにして達成つれる。 同
じく、上記目的は、空気通路中に設置された温度依存性
抵抗素子からなる発熱抵抗体と、この発熱抵抗体の抵抗
値を一定に制御して空気流量検出信号を出力する定温度
制御回路と、上記空気通路内に設置された温度依存性抵
抗素子からなる空気温度検出抵抗体とを備えた発熱抵抗
式空気流量計に於いて、上記空気温度検出抵抗体に定電
流を供給して、この空気温度検出抵抗体に現れる電圧降
下を空 気温度検出信号として外部に出力する空気温度検
出回路と、上記空気温度検出信号を上記空気温度検出回
路の制御信号に乗算し、空気流量検出信号の温度補償を
行なう第１の乗算回路と、上記空気温度検出信号を上記
空気流量検出信号に乗算する第２の乗算回路とを設け、
この第２の乗算回路から、空気温度変化によるスパン変
化分が補正された空気流量検出信号が出力されるように
して達成される。 同じく、上記目的は、空気通路中に設
置された温度依存性抵抗素子からなる発熱抵抗体と、上
記空気通路内に設置された温度依存性抵抗素子からなる
空気温度検出抵抗体とを備えた発熱抵抗式空気流量計に
於いて、シリコン基板に集積回路化され、上記発熱抵抗
体の抵抗値を一定に制御して空気流量検出信号を出力す
る定温度制御回路と、上記シリコン基板と同一のシリコ
ン基板に集積回路化され、上記空気温度検出抵抗体に定
電流を供給して、この空気温度検出抵抗体に現れる電圧
降下を空気温度検出信号として外部に出力する空気温度
検出回路と、上記空気温度検出信号を上記空気流量検出
信号に乗算する乗算回路とを設け、この乗算回路の出力
により上記空気流量検出信号に対する温度補償が与えら
れるようにして達成される。 SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problem in an air passage.
Heating element consisting of temperature-dependent resistance element installed in
And the air flow rate by controlling the resistance of this heating resistor to a constant value.
A constant temperature control circuit for outputting a detection signal;
Temperature detection consisting of temperature-dependent resistance elements installed in
In the heating resistance type air flow meter equipped with a resistor,
Supply a constant current to the air temperature detection resistor to
The voltage drop appearing on the detection resistor is used as the air temperature detection signal
An air temperature detection circuit that outputs to the outside, and the above air temperature detection
A current of the same value as the constant current value supplied to the resistor is supplied.
The voltage of the supplied resistor and the voltage drop of this resistor
Using the pressure as a reference value, the air temperature detection signal is
And a multiplying circuit for multiplying the quantity detection signal.
Temperature compensation for the air flow rate detection signal
Achieved as given . Similarly, the above purpose
Consists of a temperature-dependent resistance element installed in the air passage.
Heating resistor and control the resistance of this heating resistor to a constant value
A constant temperature control circuit that outputs an air flow rate detection signal
A temperature-dependent resistance element installed in the air passage
Heating resistance type air flow meter equipped with air temperature detecting resistor
In the above, supply a constant current to the air temperature detecting resistor,
The voltage drop that appears in this air temperature detection resistor is
An air temperature detection circuit for outputting as an output signal;
Multiplying the control signal of the constant temperature control circuit by the temperature detection signal,
A multiplying circuit for compensating the temperature of the air flow detection signal;
Controls the air flow detection signal output from the constant temperature control circuit
Voltage-controlled triangular wave oscillator as input and this voltage-controlled triangle
The output of the wave oscillator and the above air temperature detection signal are input.
A comparison circuit is provided.
Signal corresponding to the above air temperature detection signal.
This is achieved by obtaining a square wave signal having the same duty ratio. same
Eventually, the above purpose is based on the temperature dependence installed in the air passage.
Heating resistor consisting of a resistance element and the resistance of this heating resistor
Constant temperature for controlling the value to be constant and outputting the air flow detection signal
A control circuit and a temperature-dependent resistor installed in the air passage.
Heating resistor with air temperature detecting resistor consisting of resistance element
In the air flow meter, a constant voltage is applied to the air temperature detection resistor.
Current to reduce the voltage drop that appears on this air temperature sensing resistor.
Air temperature detection to be output to the outside under a air temperature detection signal
Output circuit and the air temperature detection signal to the air temperature detection circuit.
Multiplies the control signal of the road to compensate the temperature of the airflow detection signal.
A first multiplying circuit for performing the operation,
A second multiplier circuit for multiplying the air flow rate detection signal;
From the second multiplication circuit, the span change due to the air temperature change is obtained.
So that the air flow rate detection signal with corrected component is output
Is achieved. Similarly, the above purpose is
Heating element consisting of a temperature-dependent resistance element
A temperature-dependent resistance element installed in the air passage
Heating resistance type air flow meter equipped with air temperature detecting resistor
In the integrated circuit on the silicon substrate
Outputs the air flow detection signal by controlling the body resistance to a constant value
Constant temperature control circuit and the same silicon as the silicon substrate
Integrated on the circuit board and set as the air temperature detection resistor.
The voltage that appears on this air temperature sensing resistor by supplying current
Air temperature that outputs the drop as an air temperature detection signal to the outside
The detection circuit and the air temperature detection signal detect the air flow rate.
And a multiplying circuit for multiplying the signal.
Provides temperature compensation for the above airflow detection signal.
Is achieved in such a way.
【０００６】[0006]
【作用】空気温度検出抵抗体は空気通路中に設置されて
いるので、その抵抗値は空気温度の変化に応じて変化す
る。しかして、この空気温度検出抵抗体は定電流駆動さ
れているので、その電圧降下が直接空気温度を表わす信
号となる。そして、この電圧降下は、乗算回路により定
温度制御回路の入力に乗算されるので、空気流量信号に
対する温度補償が得られ、結局、空気流量信号と空気温
度信号の両方を出力として得ることが出来る。Since the air temperature detecting resistor is installed in the air passage, its resistance value changes according to the change of the air temperature. Since the air temperature detecting resistor is driven by a constant current, the voltage drop is a signal directly indicating the air temperature. Then, since this voltage drop is multiplied by the input of the constant temperature control circuit by the multiplication circuit, temperature compensation for the air flow rate signal is obtained, and as a result, both the air flow rate signal and the air temperature signal can be obtained as outputs. .
【０００７】[0007]
【実施例】以下、本発明による発熱抵抗体式空気流量計
について、図示の実施例により詳細に説明する。図１
は、本発明を自動車用のエンジンの給気流量検出用に適
用した場合の一実施例で、本発明の如き定温度制御型の
発熱抵抗体式空気流量計では、例えばエンジンの吸気通
路などの空気通路中に設置された温度依存性の抵抗素子
からなる発熱抵抗体１と、同じく空気通路中に設置され
た温度依存性の抵抗素子からなる空気温度検出抵抗体２
と、上記発熱抵抗体１に直列に接続した電流検出用の抵
抗３と、定温度制御回路１０とを備え、空気流の速度に
応じて冷却されている発熱抵抗体１を一定の抵抗値、す
なわち、一定の温度となるように定温度制御回路１０か
ら電流を供給し、この定温度制御に要した電流を電流検
出用の抵抗３により電圧として検出し、これにより空気
流量信号ＶQを得るようになっている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A heating resistor type air flow meter according to the present invention will be described below in detail with reference to the illustrated embodiment. FIG.
Is an embodiment in which the present invention is applied to the detection of an air supply flow rate of an automobile engine. In a constant temperature control type heating resistor type air flow meter according to the present invention, for example, air in an intake passage of an engine or the like is used. A heating resistor 1 made of a temperature-dependent resistance element installed in a passage, and an air temperature detection resistor 2 also made of a temperature-dependent resistance element installed in an air passage.
And a current detecting resistor 3 connected in series to the heating resistor 1 and a constant temperature control circuit 10. The heating resistor 1, which is cooled in accordance with the speed of the air flow, has a constant resistance value. that is, to supply current from the constant temperature control circuit 10 so that a constant temperature, the current required for a constant temperature control is detected by the resistor 3 for detecting current as a voltage, thereby obtaining an air flow rate signal V Q It has become.
【０００８】空気温度検出抵抗体２は空気温度の変化に
伴いその抵抗値が変化し、定温度制御回路１０に対して
空気温度を表わす信号を帰還させる働きをし、定温度制
御回路１０の制御目標温度を変化させ、空気温度変化に
よる空気流量信号ＶQの変化を補正する。The resistance value of the air temperature detecting resistor 2 changes with the change of the air temperature, and serves to feed back a signal representing the air temperature to the constant temperature control circuit 10. changing the target temperature, to compensate for changes in the air flow signal V Q due to air temperature changes.
【０００９】２０は空気温度検出回路で、定電流源２６
を備え、これにより空気温度検出抵抗体２と、空気温度
特性を調整する為の抵抗７の直列回路に一定値の電流を
供給することにより、空気温度検出抵抗体２の抵抗変化
を直接、電圧として検出し、空気温度検出信号ＶTとし
て取出したあと、さらに演算増幅器１７でゼロ点とスパ
ン(感度)を調整した空気温度検出信号Ｖ0Tを出力させる
ようになっている。なお、ここで、ゼロ点は抵抗２７と
２８の抵抗値で、そしてスパンは抵抗２９と３１の抵抗
値により、それぞれ調整することができる。Reference numeral 20 denotes an air temperature detecting circuit, which is a constant current source 26.
By supplying a constant current to the series circuit of the air temperature detecting resistor 2 and the resistor 7 for adjusting the air temperature characteristic, the resistance change of the air temperature detecting resistor 2 can be directly applied to the voltage. It is detected as, after taken out as air temperature detection signal V T, so that the further output air temperature detection signal V 0T adjusted for zero and span (sensitivity) in the operational amplifier 17. Here, the zero point can be adjusted by the resistance values of the resistors 27 and 28, and the span can be adjusted by the resistance values of the resistors 29 and 31.
【００１０】こうして空気温度検出回路２０で検出され
た空気温度検出信号ＶTは定温度制御回路１０内の乗算
回路３０に入力し、電流検出用の抵抗３から得られる空
気流量信号ＶQに乗算した上で演算増幅器３２を介して
電流制御用のトランジスタ１３のベースに供給し、これ
により、発熱抵抗体１に供給される加熱電流が空気温度
検出信号ＶTにより補正されるようにするのである。こ
のとき、抵抗１１と１２の抵抗値により流量応答性の調
整を行なう。[0010] Thus air temperature detection signal V T detected by the air temperature detecting circuit 20 is input to the multiplier circuit 30 of the constant temperature control circuit 10, multiplying the air flow signal V Q obtained from the resistor 3 for detecting a current is supplied to the base of transistor 13 for current control through the operational amplifier 32 on and in which the heating current supplied to heat-generating resistor 1 is to to be corrected by the air temperature detecting signal V T . At this time, the flow response is adjusted by the resistance values of the resistors 11 and 12.
【００１１】従って、この図１の実施例によれば、空気
流量計から、温度補正された正確な空気流量信号ＶQが
得られると共に、これとは独立に空気温度検出信号Ｖ0T
を簡単に得ることが出来、自動車用エンジンに適用し
て、給気温度などを考慮した制御を、別に給気温度セン
サを設けることなく、容易に行なうことができる。な
お、この図１の実施例で、ＶBはバッテリ電圧、ＶREFは
安定化されたセンサ動作用の電源電圧である。Therefore, according to the embodiment of FIG. 1, an accurate air flow signal V Q with temperature correction can be obtained from the air flow meter, and the air temperature detection signal V 0T independently of this.
Can be easily obtained, and control in consideration of the supply air temperature and the like applied to an automobile engine can be easily performed without providing a separate supply air temperature sensor. In the embodiment of FIG. 1, V B is a battery voltage, and V REF is a stabilized power supply voltage for sensor operation.
【００１２】次に、本発明の別の一実施例について、図
２を用いて説明する。この図２の実施例は、図２の実施
例における乗算回路３０を具体的に構成したもので、演
算増幅器３２の入力となる乗算回路３０の出力をＺ、演
算増幅器１５の入力をＸ1、演算増幅器１６の入力を
Ｘ2、そして演算増幅器１４の入力をＹとしたとき、こ
れらに対して、 Ｚ∝(Ｘ1×Ｘ2)／Ｙ が成立するように構成したもので、この結果、定電流駆
動された空気温度検出抵抗体２の電圧Ｘ2の変化に従
い、発熱抵抗体１の設定温度が変化し、これにより空気
温度補正が得られるようにしたものである。Next, another embodiment of the present invention will be described with reference to FIG. In the embodiment of FIG. 2, the multiplication circuit 30 in the embodiment of FIG. 2 is specifically configured. The output of the multiplication circuit 30 which is an input of the operational amplifier 32 is Z, the input of the operational amplifier 15 is X 1 , When the input of the operational amplifier 16 is X 2 and the input of the operational amplifier 14 is Y, the configuration is such that Z∝ (X 1 × X 2 ) / Y is established. according variation of the voltage X 2 of the constant current driving air temperature detecting resistors 2, the set temperature of the heating resistor 1 changes, thereby is obtained as the air temperature correction is obtained.
【００１３】なお、抵抗３３と３４は、発熱抵抗体１に
印加される電圧を分圧して演算増幅器３２の他方の入力
に与える働きをするものであり、ＶCCはセンサ動作用の
電源電圧で、電源電圧ＶREFよりは高い電圧で、且つ、
それよりは安定化度の低い電圧である。[0013] Incidentally, the resistor 33 and 34, which serve to provide a voltage applied to the heating resistor 1 divides the other input of the operational amplifier 32, V CC is the supply voltage for the sensor operation A voltage higher than the power supply voltage V REF , and
A voltage with a lower degree of stabilization than that.
【００１４】この実施例によれば、定電流駆動すること
により、空気温度検出抵抗体２の電圧を空気温度検出信
号ＶTとして出力すると共に、空気流量信号ＶQの空気温
度変化に対する補正を行なうことがでると共に、空気温
度検出回路２０をカレントミラー回路Ｃで構成したの
で、乗算回路３０の入力Ｘ2と、その動作の基準となる
電圧(基準電圧)Ｙとが等しく設定され、従って、空気温
度検出抵抗体２を流れる電流の誤差が、定温度制御回路
１０の特性に影響を与えないので、高い精度が得られる
という効果がある。ところで、この実施例では、ゼロ点
とスパンが調整された空気温度検出信号Ｖ0Tを出力する
回路は省略してあるが、勿論、これを含めて構成しても
よいことは言うまでもない。According to this embodiment, by constant current driving, the voltage of the air temperature detecting resistors 2 and outputs as air temperature detection signal V T, performs correction for air temperature change of the air flow signal V Q In addition, since the air temperature detection circuit 20 is constituted by the current mirror circuit C, the input X 2 of the multiplication circuit 30 and the voltage (reference voltage) Y serving as a reference for the operation are set to be equal. Since the error of the current flowing through the temperature detection resistor 2 does not affect the characteristics of the constant temperature control circuit 10, there is an effect that high accuracy can be obtained. By the way, in this embodiment, the circuit for outputting the air temperature detection signal V 0T in which the zero point and the span are adjusted is omitted, but it goes without saying that the circuit may be configured to include this.
【００１５】更に、本発明の別の一実施例を、図３を用
いて説明する。この図３の実施例は、電源電圧ＶREFを
抵抗３７、３８で分割した電圧を入力とする演算増幅器
３６と、トランジスタ３５とにより定電流源を構成し、
これにより空気温度検出抵抗体２を定電流駆動するよう
にし、このとき、乗算回路３０に入力される空気温度検
出抵抗体２の電圧Ｘと、空気温度検出抵抗体２の電流を
検出した電圧Ｙとが同じ電流によって得られるように構
成したもので、これにより空気温度検出抵抗体２のバイ
アス電流のばらつきによる定温度制御回路１０の特性の
ばらつきが抑えられ、更に検出精度を向上させることが
できる。なお、このトランジスタ３５のコレクタをトラ
ンジスタ１３のエミッタに接続したのは、バッテリ電圧
ＶBよりも低い電圧でトランジスタ３５を動作させるた
めであり、特に意味は無い。Further, another embodiment of the present invention will be described with reference to FIG. In the embodiment of FIG. 3, a constant current source is constituted by an operational amplifier 36 having a voltage obtained by dividing a power supply voltage V REF by resistors 37 and 38 as an input, and a transistor 35,
As a result, the air temperature detection resistor 2 is driven at a constant current. At this time, the voltage X of the air temperature detection resistor 2 input to the multiplication circuit 30 and the voltage Y obtained by detecting the current of the air temperature detection resistor 2 are input. Are obtained by the same current, whereby variations in the characteristics of the constant temperature control circuit 10 due to variations in the bias current of the air temperature detection resistor 2 can be suppressed, and the detection accuracy can be further improved. . The reason was connected to the collector of the transistor 35 to the emitter of the transistor 13 is to operate the transistor 35 at a voltage lower than the battery voltage V B, it is not particularly meant.
【００１６】本発明の更に別の一実施例を、図４を用い
て説明する。この図４の実施例は、図１の実施例に電圧
制御三角波発振回路４０と比較器４１を付加し、電圧制
御三角波発振回路４０に空気流量信号ＶQを供給して周
波数変調した三角波信号に変換し、さらに、この三角波
信号を比較器４１を用いて空気温度検出信号Ｖotと比較
し、方形波信号に変換するようにしたものであり、この
結果、比較器４１の出力信号ｆは、その周波数が空気流
量信号ＶQの電圧値を表わし、その時比率(デューティ
比)が空気温度検出信号Ｖotの電圧値を表わす方形波信
号となる。Another embodiment of the present invention will be described with reference to FIG. Embodiment of the FIG. 4 adds the comparator 41 and the voltage control triangular wave oscillation circuit 40 in the embodiment of FIG. 1, by supplying the air flow rate signal V Q to the voltage-controlled triangular wave oscillator 40 to the triangular wave signal frequency modulated After that, the triangular wave signal is compared with the air temperature detection signal Vot using the comparator 41, and is converted into a square wave signal. As a result, the output signal f of the comparator 41 is frequency represents the voltage value of the air flow signal V Q, then the ratio (duty ratio) of square wave signal representing the voltage value of the air temperature detection signal Vot.
【００１７】従って、この図４の実施例によれば、一本
の信号線を用いて空気流量と空気温度の二種類の情報を
送ることができるので、エンジン制御ユニットの入出力
端子の数を少なくすることが出来る。Therefore, according to the embodiment shown in FIG. 4, two types of information, that is, the air flow rate and the air temperature, can be transmitted using one signal line, so that the number of input / output terminals of the engine control unit is reduced. Can be reduced.
【００１８】本発明の別の一実施例を、更に図５を用い
て説明する。この図５の実施例は、図１の実施例に第２
の乗算回路４３を追加し、定温度制御回路１０で検出し
た空気流量検出信号ＶQ に、さらに空気温度検出信号Ｖ
t を掛け合わせるように構成したものであり、従って、
この実施例によれば、空気流量電圧信号ＶQ の空気温度
変化によるスパン変化分を補正した空気流量検出信号Ｖ
Q'を得ることが出来、さらに精度の良い空気流量の検出
が可能になる。Another embodiment of the present invention will be described with reference to FIG. Embodiment of the FIG. 5, the second to the embodiment of FIG. 1
Add the multiplication circuit 43, the air flow detecting signal V Q detected by the constant temperature control circuit 10, further air temperature detection signal V
t are multiplied, so that
According to this embodiment, air flow detecting signal V obtained by correcting the span change due to air temperature variation of the air flow rate voltage signal V Q
Q ′ can be obtained, and the air flow rate can be detected with higher accuracy.
【００１９】ところで、このような発熱抵抗体式空気流
量計では、その制御回路が集積回路化されているのが通
例である。そこで、上記実施例においても、その定温度
制御回路１０の集積回路化に際して、空気温度検出回路
２０も含めて１チップ集積回路化するのが望ましい。By the way, in such a heating resistor type air flow meter, the control circuit is usually integrated into an integrated circuit. Therefore, also in the above embodiment, when the constant temperature control circuit 10 is formed into an integrated circuit, it is desirable to form a one-chip integrated circuit including the air temperature detection circuit 20.
【００２０】[0020]
【発明の効果】本発明によれば、発熱抵抗体式空気流量
計が持つ空気温度検出抵抗体を利用して、通常の如く、
温度補償された空気流量が得られるだけでなく、これと
は独立に空気温度検出信号が得られるので、空気温度セ
ンサを新たに設けることなく、空気流量計から空気流量
信号と同時に空気温度検出信号を得られるという効果が
ある。According to the present invention, by utilizing the air temperature detecting resistor of the heating resistor type air flow meter,
In addition to obtaining the temperature-compensated air flow rate, the air temperature detection signal can be obtained independently of this.Therefore, without installing a new air temperature sensor, the air flow rate signal can be output from the air flow meter at the same time as the air temperature detection signal. There is an effect that can be obtained.
【００２１】そして、この結果、空気温度信号をエンジ
ン制御システムに使用することにより、空気温度の急変
時に於ける空燃比の補正、点火進角制御に於ける空気温
度特性の補正、電子制御スロットルシステムの加速度補
正などを行なうことができ、さらには、タ−ボチャ−ジ
ャ−等の過給装置の下流側に於ける吸気温度の変化を検
出することができ、自動車用燃料制御システムの高精度
化に寄与する効果が有る。As a result, by using the air temperature signal for the engine control system, correction of the air-fuel ratio when the air temperature changes rapidly, correction of the air temperature characteristic in the ignition advance control, and electronic control throttle system Acceleration, etc., and furthermore, it is possible to detect a change in the intake air temperature downstream of a supercharging device such as a turbocharger or the like, thereby improving the accuracy of an automobile fuel control system. Has the effect of contributing to
【００２２】さらに、本発明によれば、空気流量信号と
空気温度検出信号を１個の出力端子から同時に出力する
ことができるので、配線及びエンジン制御ユニットの入
力端子を増やさずに空気流量信号に加えて空気温度検出
信号を伝送する事ができる効果が有る。Further, according to the present invention, the air flow rate signal and the air temperature detection signal can be output simultaneously from one output terminal, so that the air flow rate signal can be output without increasing the number of wirings and the input terminals of the engine control unit. In addition, there is an effect that the air temperature detection signal can be transmitted.
【図１】本発明による発熱抵抗体式空気流量計の一実施
例を示す回路図である。FIG. 1 is a circuit diagram showing one embodiment of a heating resistor type air flow meter according to the present invention.
【図２】本発明の別の一実施例を示す回路図である。FIG. 2 is a circuit diagram showing another embodiment of the present invention.
【図３】本発明の別の一実施例を示す回路図である。FIG. 3 is a circuit diagram showing another embodiment of the present invention.
【図４】本発明の別の一実施例を示す回路図である。FIG. 4 is a circuit diagram showing another embodiment of the present invention.
【図５】本発明の別の一実施例を示す回路図である。FIG. 5 is a circuit diagram showing another embodiment of the present invention.
１ 発熱抵抗体 ２ 空気温度検出抵抗体 １０ 定温度制御回路 ２０ 空気温度検出回路 ３０、５１ 乗算回路 ４０ 電圧制御三角波発振回路 ４１ 比較器 DESCRIPTION OF SYMBOLS 1 Heating resistor 2 Air temperature detection resistor 10 Constant temperature control circuit 20 Air temperature detection circuit 30, 51 Multiplication circuit 40 Voltage control triangular wave oscillation circuit 41 Comparator
Claims (4)
素子からなる発熱抵抗体と、この発熱抵抗体の抵抗値を
一定に制御して空気流量検出信号を出力する定温度制御
回路と、上記空気通路内に設置された温度依存性抵抗素
子からなる空気温度検出抵抗体とを備えた発熱抵抗式空
気流量計に於いて、 上記空気温度検出抵抗体に定電流を供給して、この空気
温度検出抵抗体に現れる電圧降下を空気温度検出信号と
して外部に出力する空気温度検出回路と、上記空気温度検出抵抗体に供給されている定電流値と同
一の値の電流が供給されている抵抗体と、 この抵抗体の電圧降下による電圧を基準値として、 上記
空気温度検出信号を上記空気流量検出信号に乗算する乗
算回路とを設け、 この乗算回路の出力により上記空気流量検出信号に対す
る温度補償が与えられるように構成したことを特徴とす
る発熱抵抗式空気流量計。1. A heating resistor comprising a temperature-dependent resistance element installed in an air passage, a constant temperature control circuit for controlling the resistance of the heating resistor to a constant value and outputting an air flow detection signal, In a heating resistance type air flow meter including an air temperature detection resistor comprising a temperature-dependent resistance element installed in the air passage, a constant current is supplied to the air temperature detection resistor , An air temperature detection circuit that outputs a voltage drop appearing at the temperature detection resistor to the outside as an air temperature detection signal, and a constant current value supplied to the air temperature detection resistor.
A resistor to which a current of one value is supplied, and a multiplier circuit for multiplying the air flow rate detection signal by the air temperature detection signal by using a voltage due to a voltage drop of the resistor as a reference value; Wherein the temperature of the air flow rate detection signal is compensated by the output of the air flow meter.
素子からなる発熱抵抗体と、この発熱抵抗体の抵抗値を
一定に制御して空気流量検出信号を出力する定温度制御
回路と、上記空気通路内に設置された温度依存性抵抗素
子からなる空気温度検出抵抗体とを備えた発熱抵抗式空
気流量計に於いて、上記空気温度検出抵抗体に定電流を供給して、この空気
温度検出抵抗体に現れる電圧降下を空気温度検出信号と
して出力する空気温度検出回路と、 上記空気温度検出信号を上記定温度制御回路の制御信号
に乗算し、空気流量検出信号の温度補償を行なう乗算回
路と、 上記定温度制御回路から出力される空気流量検出信号を
制御入力とする電圧制御三角波発振器と、 この電圧制御三角波発振器の出力と、上記空気温度検出
信号を入力とする比較回路とを設け、 上記 比較回路から、空気流量検出信号に対応した周波数
で、上記空気温度検出信号に対応した時比率の方形波信
号を得るように構成したことを特徴とする発熱抵抗式空
気流量計。2. A temperature-dependent resistor installed in an air passage.
The heating resistor consisting of the element and the resistance value of this heating resistor
Constant temperature control to output air flow detection signal by controlling to constant
A circuit and a temperature-dependent resistive element installed in the air passage.
Heating resistance type air with air temperature detecting resistor
In the air flow meter, a constant current is supplied to the air temperature detecting resistor to
The voltage drop appearing on the temperature detection resistor is used as the air temperature detection signal.
An air temperature detection circuit that outputs the air temperature detection signal and a control signal of the constant temperature control circuit.
Multiplied to perform temperature compensation of the air flow detection signal
Path and the air flow rate detection signal output from the constant temperature control circuit.
A voltage controlled triangular wave oscillator to a control input, and an output of the voltage controlled triangular wave oscillator, the air temperature detected
It provided a comparison circuit which receives the signal from the comparison circuit, and characterized in that at a frequency corresponding to the air flow rate detection signal, and configured to obtain a square wave signal of duty ratio corresponding to the air temperature detection signal Heating resistance type air flow meter.
素子からなる発熱抵 抗体と、この発熱抵抗体の抵抗値を
一定に制御して空気流量検出信号を出力する定温度制御
回路と、上記空気通路内に設置された温度依存性抵抗素
子からなる空気温度検出抵抗体とを備えた発熱抵抗式空
気流量計に於いて、上記空気温度検出抵抗体に定電流を供給して、この空気
温度検出抵抗体に現れる電圧降下を空気温度検出信号と
して外部に出力する空気温度検出回路と、 上記空気温度検出信号を上記空気温度検出回路の制御信
号に乗算し、空気流量検出信号の温度補償を行なう第１
の乗算回路と、 上記空気温度検出信号を上記空気流量検出信号に乗算す
る第２の 乗算回路とを設け、 この第２の乗算回路から、空気温度変化によるスパン変
化分が補正された空気流量検出信号が出力されるように
構成したことを特徴とする発熱抵抗式空気流量計。3. A temperature-dependent resistor installed in an air passage.
A heating resistor antibody consisting element, the resistance value of the heating resistor
Constant temperature control to output air flow detection signal by controlling to constant
A circuit and a temperature-dependent resistive element installed in the air passage.
Heating resistance type air with air temperature detecting resistor
In the air flow meter, a constant current is supplied to the air temperature detecting resistor to
The voltage drop appearing on the temperature detection resistor is used as the air temperature detection signal.
An air temperature detection circuit which outputs the air temperature detection signal to the outside, and outputs the air temperature detection signal to a control signal of the air temperature detection circuit.
No. 1 which multiplies the signal and performs temperature compensation of the air flow detection signal.
Multiplying the air flow rate detection signal by the air temperature detection signal.
A second multiplying circuit, from which the span change due to the air temperature change is provided.
An exothermic resistance type air flow meter characterized in that an air flow rate detection signal in which a component is corrected is output .
素子からなる発熱抵抗体と、上記空気通路内に設置され
た温度依存性抵抗素子からなる空気温度検出抵抗体とを
備えた発熱抵抗式空気流量計に於いて、シリコン基板に集積回路化され、上記発熱抵抗体の抵抗
値を一定に制御して空気流量検出信号を出力する定温度
制御回路と、 上記シリコン基板と同一のシリコン基板に集積回路化さ
れ、上記空気温度検出抵抗体に定電流を供給して、この
空気温度検出抵抗体に現れる電圧降下を空気温度検出信
号として外部に出力する空気温度検出回路と、 上記空気温度検出信号を上記空気流量検出信号に乗算す
る乗算回路とを設け、 この乗算回路の出力により上記空気流量検出信号に対す
る温度補償が与えられるように構成した ことを特徴とす
る発熱抵抗式空気流量計。4. A temperature-dependent resistor installed in an air passage.
A heating resistor consisting of an element and installed in the air passage
Air temperature detection resistor consisting of a temperature-dependent resistance element
In the heating resistance type air flow meter equipped , the integrated circuit on the silicon substrate and the resistance of the heating resistor
Constant temperature for controlling the value to be constant and outputting the air flow detection signal
Control circuit and integrated circuit on the same silicon substrate as above
Supply a constant current to the air temperature detection resistor,
The voltage drop that appears in the air temperature detection resistor is
And an air temperature detecting circuit for outputting to the outside, the air temperature detection signal to the multiplication to the air flow detecting signal as No.
And a multiplying circuit for detecting the air flow rate detection signal based on the output of the multiplying circuit.
A heating resistance type air flowmeter characterized in that the temperature compensation is provided .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03349865A JP3105609B2 (en) | 1991-12-10 | 1991-12-10 | Heating resistor type air flow meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03349865A JP3105609B2 (en) | 1991-12-10 | 1991-12-10 | Heating resistor type air flow meter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05164583A JPH05164583A (en) | 1993-06-29 |
| JP3105609B2 true JP3105609B2 (en) | 2000-11-06 |
Family
ID=18406645
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03349865A Expired - Lifetime JP3105609B2 (en) | 1991-12-10 | 1991-12-10 | Heating resistor type air flow meter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3105609B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010520459A (en) * | 2007-03-01 | 2010-06-10 | アドバンスト・エナジー・インダストリーズ・インコーポレイテッド | Method and apparatus for measuring the temperature of a gas in a mass flow controller |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3493116B2 (en) | 1996-05-24 | 2004-02-03 | 株式会社リコー | Flow measurement device and flow measurement method |
| JP2003240620A (en) | 2002-02-20 | 2003-08-27 | Hitachi Ltd | Gas flow measuring device |
| JP3817497B2 (en) | 2002-06-10 | 2006-09-06 | 株式会社日立製作所 | Thermal flow meter |
| JP6201901B2 (en) | 2014-06-04 | 2017-09-27 | 株式会社デンソー | Air flow measurement device |
-
1991
- 1991-12-10 JP JP03349865A patent/JP3105609B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010520459A (en) * | 2007-03-01 | 2010-06-10 | アドバンスト・エナジー・インダストリーズ・インコーポレイテッド | Method and apparatus for measuring the temperature of a gas in a mass flow controller |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05164583A (en) | 1993-06-29 |
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