JPH1114421A - Heating resistor-type air-flow-rate measuring instrument - Google Patents

Heating resistor-type air-flow-rate measuring instrument

Info

Publication number
JPH1114421A
JPH1114421A JP9165612A JP16561297A JPH1114421A JP H1114421 A JPH1114421 A JP H1114421A JP 9165612 A JP9165612 A JP 9165612A JP 16561297 A JP16561297 A JP 16561297A JP H1114421 A JPH1114421 A JP H1114421A
Authority
JP
Japan
Prior art keywords
heating resistor
air passage
flow
hole
auxiliary air
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.)
Pending
Application number
JP9165612A
Other languages
Japanese (ja)
Inventor
Masayuki Ozawa
正之 小澤
Shinya Igarashi
信弥 五十嵐
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Hitachi Automotive Systems Engineering Co Ltd
Original Assignee
Hitachi Ltd
Hitachi Car Engineering Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd, Hitachi Car Engineering Co Ltd filed Critical Hitachi Ltd
Priority to JP9165612A priority Critical patent/JPH1114421A/en
Publication of JPH1114421A publication Critical patent/JPH1114421A/en
Pending legal-status Critical Current

Links

Landscapes

  • Measuring Volume Flow (AREA)

Abstract

PROBLEM TO BE SOLVED: To obtain a heating resistor-type air-flow-rate measuring instrument in which a measuring error due to the influence of a reverse flow is reduced, in which a drop in a flow velocity inside an auxiliary air passage is prevented in a forward flow and which maintains the measuring accuracy of an air flow rate by a method wherein a hole is formed between the exit and the entrance of the auxiliary air passage so as to sandwich a heating resistor. SOLUTION: The entrance part 10 of an auxiliary air passage 2 which is bypassed nearly in a U-shape via a partition wall 9 is formed. A hole 8 by which the inside of the auxiliary air passage 2 communicates is formed in the partition wall 9 between the entrance part 10 and the upstream side of a heating resistor 4. When a reverse flow is generated, reverse flow waves come in from the exit part 11 of the auxiliary air passage 2. Then, before the reverse flow waves are transmitted to the heating resistor 4 through the inside of the auxiliary air passage 2, they flow to the upstream side of the heating resistor 4 from the hole 8. As a result, the pressure on the upstream side becomes larger than the pressure on the downstream side of the heating resistor 4, and the influence of the reverse flow is reduced. In addition, in the case of a forward flow, the hole 8 makes the dead volume of the flow of the air inside the auxiliary air passage 2 communicate with a passage part other than it. As a result, the air flows to the upstream side from the downstream side of the heating resistor 4 through the hole 8, and the flow rate of the air flowing to the heating resistor 4 is increased.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、内燃機関の吸入空
気流量を測定する空気流量測定装置に係わり、特に自動
車のエンジンに吸入される空気流量を測定する発熱抵抗
体式空気流量測定装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air flow measuring device for measuring an intake air flow of an internal combustion engine, and more particularly to a heating resistor type air flow measuring device for measuring an air flow taken into an automobile engine.

【0002】[0002]

【従来の技術】従来の技術には、特開平7−113672 号公
報のように副空気通路は逆流・順流専用の通路を有し順
流専用通路に発熱抵抗体を有した空気流量測定装置があ
る。これは逆流の影響により起こる発熱抵抗体式空気流
量測定装置の測定誤差の低減を図ることを目的としたも
のである。
2. Description of the Related Art As a prior art, there is an air flow measuring device as disclosed in Japanese Patent Application Laid-Open No. Hei 7-113672, in which a sub air passage has a passage dedicated to backflow and forward flow and a heating resistor in a passage dedicated to forward flow. . This is intended to reduce the measurement error of the heating resistor type air flow measuring device caused by the influence of the backflow.

【0003】[0003]

【発明が解決しようとする課題】上記通路構造の副空気
通路は逆流・順流専用の通路を有しているため副空気通
路構造が複雑になってしまう問題があった。また更に通
路構造の複雑化による通気抵抗の増加や曲がり部による
管路抵抗等により発熱抵抗体が検知する流速が低下して
しまう。特にアイドル付近の流速が遅くなってしまい発
熱抵抗体の検出精度が悪化してしまう問題もあった。
However, the auxiliary air passage having the above-described structure has a problem that the auxiliary air passage structure is complicated because the auxiliary air passage has a passage dedicated to the backward flow and the forward flow. Further, the flow velocity detected by the heating resistor decreases due to an increase in ventilation resistance due to a complicated passage structure, a pipe resistance due to a bent portion, and the like. In particular, there is also a problem that the flow velocity near the idle becomes slow, and the detection accuracy of the heating resistor deteriorates.

【0004】本発明は副空気通路の構造を簡単にしなが
ら、逆流の影響による測定誤差を低減し、更に副空気通
路入口から出口へ空気が流れる順流の時には、副空気通
路に設置した発熱抵抗体部の流速低下(特に発熱抵抗体
部の流速低下で問題となるエンジンのアイドル回転数付
近の流速低下)を防ぎ、計測精度を十分に維持可能とす
ることを目的とするものである。
The present invention simplifies the structure of the auxiliary air passage, reduces the measurement error due to the backflow, and furthermore, when the air flows from the inlet to the outlet of the auxiliary air passage in the forward flow, the heating resistor installed in the auxiliary air passage is provided. It is an object of the present invention to prevent a decrease in the flow velocity in the section (particularly, a decrease in the flow velocity in the vicinity of the idle speed of the engine, which is a problem due to a decrease in the flow velocity in the heating resistor section), and to sufficiently maintain the measurement accuracy.

【0005】[0005]

【課題を解決するための手段】上記課題を解決するため
に、副空気通路内に配置された発熱抵抗体を挟んだ副空
気通路の出入り口間に穴を設けた。逆流影響については
設けた穴により副空気通路出口より進入してきた逆流波
が発熱抵抗体に伝わる前に副空気通路入口側に逃がすこ
とにより低減し、また順流時では穴口の圧力差によって
設けた穴より空気を流し副空気通路内発熱抵抗体部の流
速の増加を図った。
In order to solve the above-mentioned problem, a hole is provided between the entrance and exit of the sub air passage with the heating resistor disposed in the sub air passage therebetween. The effect of backflow is reduced by allowing the backflow wave entering from the sub air passage outlet to escape to the sub air passage inlet side before being transmitted to the heating resistor by the provided hole, and the hole provided by the pressure difference at the hole at the time of forward flow More air was allowed to flow to increase the flow velocity of the heating resistor in the sub air passage.

【0006】具体的には、副空気通路内に設けられた穴
は副空気通路内に配置された発熱抵抗体に副空気通路出
口より進入した逆流波が発熱抵抗体に伝わる前に副空気
通路入口側に逃がすことができる穴、言い換えれば、副
空気通路出口から進入してくる逆流波(発熱抵抗体の下
流側より伝わってくる圧力波)を発熱抵抗体に伝わる前
に発熱抵抗体上流に伝えることで、副空気通路出口より
進入してきた逆流波を発熱抵抗体に伝わる前に発熱抵抗
体上流に伝えることにより、発熱抵抗体の上下流の圧力
を比較したときに、本来脈動の影響により(発熱抵抗体
下流の圧力)>(発熱抵抗体上流の圧力)となり、逆流
の影響を(発熱抵抗体下流の圧力)<(発熱抵抗体上流
の圧力)とすることができる。
More specifically, the hole provided in the sub air passage is provided before the backflow wave entering the heating resistor disposed in the sub air passage from the sub air passage outlet is transmitted to the heating resistor. A hole that can escape to the inlet side, in other words, a backflow wave (pressure wave transmitted from the downstream side of the heating resistor) entering from the sub air passage outlet is transmitted upstream of the heating resistor before being transmitted to the heating resistor. By transmitting the backflow wave that has entered from the auxiliary air passage outlet to the heating resistor upstream before it is transmitted to the heating resistor, by comparing the upstream and downstream pressures of the heating resistor, due to the pulsation, (Pressure downstream of the heating resistor)> (pressure upstream of the heating resistor), and the effect of the backflow can be set to (pressure downstream of the heating resistor) <(pressure upstream of the heating resistor).

【0007】そして、順流時においては、副空気通路内
に配置されている発熱抵抗体を挟んで副空気通路内の圧
力が(発熱抵抗体下流の圧力)>(発熱抵抗体上流の圧
力)という関係になる場所に、その圧力差により空気流
量が流れでる穴を発熱抵抗体を挟んで副空気通路出入り
口間に設ける。つまり、発熱抵抗体を挟んで副空気通路
内部の構造により剥離域や空気流れのデットボリュウム
のできるところとできないところの副空気通路同士を連
通する穴を副空気通路内に設ける。
[0007] In the forward flow, the pressure in the sub air passage across the heating resistor disposed in the sub air passage is expressed as (pressure downstream of the heating resistor)> (pressure upstream of the heating resistor). A hole through which the flow rate of air flows due to the pressure difference is provided between the entrance and exit of the sub air passage at the relevant location with the heating resistor interposed therebetween. In other words, a hole is formed in the auxiliary air passage so as to allow the auxiliary air passage to communicate with the separation area and the place where the dead volume of the air flow can and cannot be formed due to the structure inside the auxiliary air passage with the heating resistor interposed therebetween.

【0008】[0008]

【発明の実施の形態】本発明の実施例を図1〜図3によ
り説明する。図1は本発明の一実施例を示す空気流量測
定装置の断面図である。
DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of an air flow measuring device showing one embodiment of the present invention.

【0009】副空気通路2の中には発熱抵抗体4及び吸
入空気温度を検出する感温抵抗体5が配置されており、
発熱抵抗体及び感温抵抗体は、支持部6を介し駆動回路
を内蔵するモジュール7と電気的に接続されている。
A heating resistor 4 and a temperature-sensitive resistor 5 for detecting the intake air temperature are arranged in the sub air passage 2.
The heat-generating resistor and the temperature-sensitive resistor are electrically connected to a module 7 having a built-in drive circuit via a support portion 6.

【0010】又、副空気通路は空気流量計の回路モジュ
ールと一体化されており、主空気通路1を形成する空気
流量計ボディ3の中に配置されている。
The sub air passage is integrated with the circuit module of the air flow meter, and is disposed in the air flow meter body 3 forming the main air passage 1.

【0011】更に、副空気通路はしきり壁9を介して、
ほぼU字形に迂回した副空気通路であり、副空気通路入
口部10と発熱抵抗体上流間の副空気通路しきり壁に、
副空気通路同士を連結する穴8が設けられている。
Further, the auxiliary air passage is formed through a partition wall 9.
A sub-air passage detouring substantially in a U-shape, and a sub-air passage partition wall between the sub-air passage inlet portion 10 and the upstream of the heating resistor,
A hole 8 connecting the sub air passages is provided.

【0012】ここで逆流が発生したとき、副空気通路出
口部11から進入してくる逆流波が、副空気通路内を通
り発熱抵抗体に伝わる前に、しきり壁に設けた穴8によ
り発熱抵抗体上流に伝えることができる。
When a backflow occurs here, before the backflow wave entering from the sub air passage outlet 11 is transmitted through the sub air passage to the heating resistor, the heat is generated by the hole 8 formed in the partition wall. Can be transmitted to the upper body.

【0013】その結果、逆流が起きたときでも発熱抵抗
体4の上下流の圧力を比較すると、(発熱抵抗体下流の
圧力)<(発熱抵抗体上流の圧力)となり、逆流の影響
を低減することができる。
As a result, even when a backflow occurs, a comparison of the upstream and downstream pressures of the heating resistor 4 shows that (pressure downstream of the heating resistor) <(pressure upstream of the heating resistor), and the effect of the backflow is reduced. be able to.

【0014】しきり壁に設けた穴8は、(副空気通路出
口から発熱抵抗体までの距離)>(副空気通路からしき
り壁の穴を通り発熱抵抗体までの距離)とする位置にす
ることが望ましい。
The hole 8 provided in the partition wall should be located at a position where (distance from the sub air passage outlet to the heating resistor)> (distance from the sub air passage to the heating resistor through the hole in the partition wall). Is desirable.

【0015】そしてまた、しきり壁に設けた穴8は順流
のとき副空気通路2内の空気流れのデットボリュウム
と、そうではないところの副空気通路同士を連通する穴
を設けている。従ってその穴の両口で生じる圧力差によ
り、発熱抵抗下流の副空気通路から発熱抵抗体上流の副
空気通路へその穴を通って空気が流れる。その結果、発
熱抵抗体へ流れる空気流量の増加を図ることができる。
The hole 8 provided in the partition wall is provided with a hole for communicating the dead volume of the air flow in the sub air passage 2 at the time of the forward flow and the sub air passage at the other portion. Therefore, air flows through the hole from the sub-air passage downstream of the heating resistor to the sub-air passage upstream of the heating resistor due to the pressure difference generated at both ends of the hole. As a result, the flow rate of air flowing to the heating resistor can be increased.

【0016】図2は本発明の他の一実施例を示す空気流
量測定装置の断面図である。本構造は、しきり壁9に設
けている穴8が副空気通路入口部10に向かって角度を
持っている。
FIG. 2 is a sectional view of an air flow measuring device showing another embodiment of the present invention. In this structure, the hole 8 provided in the partition wall 9 has an angle toward the sub air passage entrance 10.

【0017】本構造にすることにより、逆流が発生した
ときに副空気通路入口部10に逆流波を伝えることがで
き、その逆流波を副空気通路入口部より副空気通路外に
伝えられる。これによって副空気通路出口部11より進
入してきた逆流波が、副空気通路内に設置された発熱抵
抗体4に伝わらず副空気通路入口部から副空気通路2外
に伝えることができ、逆流影響を低減することができ
る。また順流時は図1で示した実施例と同じ作用効果が
得られ、発熱抵抗体へ流れる空気流量の増加が図れる。
According to this structure, when a backflow occurs, a backflow wave can be transmitted to the sub air passage inlet 10, and the backflow wave is transmitted from the sub air passage inlet to the outside of the sub air passage. Thus, the backflow wave entering from the sub air passage outlet 11 can be transmitted to the outside of the sub air passage 2 from the sub air passage entrance without being transmitted to the heating resistor 4 installed in the sub air passage. Can be reduced. Further, at the time of forward flow, the same operation and effect as those of the embodiment shown in FIG. 1 are obtained, and the flow rate of air flowing to the heating resistor can be increased.

【0018】図3は本発明の他の一実施例を示す空気流
量測定装置の断面図である。本通路構造は、逆流発生時
には図1で示した実施例と同様の作用効果が得られると
ころに穴8を設け逆流の影響を低減し、さらに順流時に
おいては副空気通路内の曲がり部12により発生した剥
離域に穴8の片方の口を設置し、図1で示した実施例と
同様の作用効果が得られ、発熱抵抗体4へ流れる空気流
量の増加を図る部分に、発熱抵抗体を挟んで副空気通路
同士を連通する穴を設けている。
FIG. 3 is a sectional view of an air flow measuring device showing another embodiment of the present invention. This passage structure reduces the influence of the backflow by providing a hole 8 where the same effect as that of the embodiment shown in FIG. 1 is obtained when a backflow occurs, and furthermore, by the bent portion 12 in the sub air passage during the forward flow. One opening of the hole 8 is provided in the generated peeling area, and the same operation and effect as those of the embodiment shown in FIG. 1 can be obtained. A hole is provided to connect the sub air passages to each other.

【0019】[0019]

【発明の効果】本発明は、逆流が発生したときの逆流影
響を低減し、さらに順流時においても副空気通路内の流
速の増加が図ることができるため、発熱式空気流量測定
装置の計測精度向上を図ることができる。
According to the present invention, the influence of backflow when backflow occurs is reduced, and the flow velocity in the sub air passage can be increased even during forward flow. Improvement can be achieved.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明の一実施例である空気流量測定装置の断
面図。
FIG. 1 is a sectional view of an air flow measuring device according to an embodiment of the present invention.

【図2】本発明の一実施例である空気流量測定装置の断
面図。
FIG. 2 is a sectional view of an air flow measuring device according to one embodiment of the present invention.

【図3】本発明の一実施例である空気流量測定装置の断
面図。
FIG. 3 is a sectional view of an air flow measuring device according to an embodiment of the present invention.

【符号の説明】[Explanation of symbols]

1…主空気通路、2…副空気通路、3…空気流量計ボデ
ィ、4…発熱抵抗体、5…感温抵抗体、6…支持部、7
…モジュール、8…穴、9…副空気通路しきり壁、10
…副空気通路入口部、11…副空気通出口部、12…副
空気通路内の曲がり部。
DESCRIPTION OF SYMBOLS 1 ... Main air passage, 2 ... Sub air passage, 3 ... Air flow meter body, 4 ... Heating resistor, 5 ... Temperature sensitive resistor, 6 ... Support part, 7
... Module, 8 ... Hole, 9 ... Sub air passage partition wall, 10
... Sub air passage inlet, 11 ... Sub air passage outlet, 12 ... Bend in the sub air passage.

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】内燃機関の吸入空気流量を測定するため
に、内部に吸入空気への放熱量を基に空気流量を測定す
る発熱抵抗体を備えた副空気通路を、前記吸気管路の主
空気通路に配置した発熱抵抗体式空気流量測定装置にお
いて、前記副空気通路は発熱抵抗体下流で1つ以上の曲
がりを有し、更に曲がりにより発生する副空気通路内の
剥離部域に曲がり部前後の副空気通路を連結する穴を前
記発熱抵抗体上流に設けたことを特徴とする発熱抵抗体
式空気流量測定装置。
1. An auxiliary air passage provided with a heating resistor for measuring an air flow rate based on a heat release amount to intake air in order to measure an intake air flow rate of an internal combustion engine. In the heating resistor type air flow measuring device disposed in the air passage, the sub air passage has one or more bends downstream of the heating resistor, and further includes a bend at a separation portion area in the sub air passage generated by the bend. A heating resistor type air flow measuring device, wherein a hole for connecting the auxiliary air passage is provided upstream of the heating resistor.
【請求項2】前記副空気通路は、少なくとも折り返され
る2つ以上の曲がりを有し、更に曲がりにより起こる副
空気通路内の流れのデットボリュウム域に曲がり部前後
の副空気通路を連結する穴を前記発熱抵抗体上流に設け
たことを特徴とする発熱抵抗体式空気流量測定装置。
2. The auxiliary air passage has at least two bends that are turned back, and further has a hole connecting the auxiliary air passage before and after the bend to a dead volume region of a flow in the auxiliary air passage caused by the bend. A heating resistor type air flow measuring device provided upstream of the heating resistor.
【請求項3】請求項2において、前記副空気通路を連通
する穴は副空気通入口に向かって穴があいている発熱抵
抗体式空気流量測定装置。
3. A heating resistor type air flow measuring device according to claim 2, wherein a hole communicating with the auxiliary air passage is opened toward the auxiliary air passage inlet.
【請求項4】少なくとも空気流量検出のための発熱抵抗
体,温度補償のための感温抵抗体及びこれらを駆動する
回路、更にこれらを保持するためのハウジング部材を設
け、副空気通路と一体化した請求項1〜3のいずれかに
記載の発熱抵抗体式空気流量測定装置。
4. At least a heating resistor for detecting an air flow rate, a temperature-sensitive resistor for temperature compensation, a circuit for driving them, and a housing member for holding them are provided, and are integrated with a sub air passage. A heating resistor type air flow measuring device according to any one of claims 1 to 3.
JP9165612A 1997-06-23 1997-06-23 Heating resistor-type air-flow-rate measuring instrument Pending JPH1114421A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9165612A JPH1114421A (en) 1997-06-23 1997-06-23 Heating resistor-type air-flow-rate measuring instrument

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9165612A JPH1114421A (en) 1997-06-23 1997-06-23 Heating resistor-type air-flow-rate measuring instrument

Publications (1)

Publication Number Publication Date
JPH1114421A true JPH1114421A (en) 1999-01-22

Family

ID=15815678

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9165612A Pending JPH1114421A (en) 1997-06-23 1997-06-23 Heating resistor-type air-flow-rate measuring instrument

Country Status (1)

Country Link
JP (1) JPH1114421A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002066936A1 (en) * 2001-02-21 2002-08-29 Hitachi, Ltd. Flowmeter with resistor heater
JP2008233111A (en) * 2008-07-04 2008-10-02 Hitachi Ltd Heat generation resistor type flow measurement device
JP2013032923A (en) * 2011-08-01 2013-02-14 Hitachi Automotive Systems Ltd Air flow rate measuring device
DE102021203214B3 (en) 2021-03-30 2022-04-28 Vitesco Technologies GmbH Air mass sensor and motor vehicle
US11391610B2 (en) 2018-08-08 2022-07-19 Denso Corporation Flow rate measurement device

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002066936A1 (en) * 2001-02-21 2002-08-29 Hitachi, Ltd. Flowmeter with resistor heater
US7201046B2 (en) 2001-02-21 2007-04-10 Hitachi, Ltd. Flowmeter with resistor heater
JP2008233111A (en) * 2008-07-04 2008-10-02 Hitachi Ltd Heat generation resistor type flow measurement device
JP2013032923A (en) * 2011-08-01 2013-02-14 Hitachi Automotive Systems Ltd Air flow rate measuring device
US11391610B2 (en) 2018-08-08 2022-07-19 Denso Corporation Flow rate measurement device
DE102021203214B3 (en) 2021-03-30 2022-04-28 Vitesco Technologies GmbH Air mass sensor and motor vehicle
WO2022207334A1 (en) * 2021-03-30 2022-10-06 Vitesco Technologies GmbH Air mass sensor and motor vehicle

Similar Documents

Publication Publication Date Title
JP3310167B2 (en) Gas flow measurement device
EP1160546B1 (en) Fluid flow meter unit having thermal flow sensor
JP4979262B2 (en) Flow measuring device
EP0708315B1 (en) Thermal-type air flow measuring instrument
US6220090B1 (en) Air flow meter
JPH11118559A (en) Air flow rate measuring apparatus
JPH0988658A (en) Air fuel measuring device
JP3709385B2 (en) Gas flow measuring device for internal combustion engine
JPH1114421A (en) Heating resistor-type air-flow-rate measuring instrument
JP2005315718A (en) Air flow rate measuring instrument
JP2003315126A (en) Air flow meter
JP3386982B2 (en) Heating resistor type air flow measurement device
JPH1164059A (en) Air flow rate measuring instrument and internal combustion engine controller
WO2002103301A1 (en) Heating resistor flow rate measuring instrument
JP3383237B2 (en) Air flow meter
JPH08285651A (en) Air flow rate measuring device
JP3378833B2 (en) Heating resistor type air flow measurement device
JPH09210749A (en) Heating element type air flow measuring apparatus
JPH09329473A (en) Gas flow measuring device
JP2000002573A (en) Gas flow rate measuring apparatus
JP2007121221A (en) Fluid flow detector
JP2001059759A (en) Exothermic resistance type flow rate measuring apparatus
JP2000314646A (en) Heating resistance-type flow-rate measuring apparatus
JPH1114420A (en) Heating resistor-type air-flow-rate measuring instrument
JPH08327422A (en) Measuring apparatus of air flow rate