JPH0116007Y2 - - Google Patents
Info
- Publication number
- JPH0116007Y2 JPH0116007Y2 JP15091982U JP15091982U JPH0116007Y2 JP H0116007 Y2 JPH0116007 Y2 JP H0116007Y2 JP 15091982 U JP15091982 U JP 15091982U JP 15091982 U JP15091982 U JP 15091982U JP H0116007 Y2 JPH0116007 Y2 JP H0116007Y2
- Authority
- JP
- Japan
- Prior art keywords
- hot wire
- lead wire
- rib
- wire
- inner cylinder
- 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
Links
Landscapes
- Measuring Volume Flow (AREA)
Description
【考案の詳細な説明】
本考案は内燃機関において吸入空気量を測定す
るために使用される熱線流量計に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot wire flowmeter used to measure the amount of intake air in an internal combustion engine.
従来この種の熱線流量計としては、例えば第１
図及び第２図に示すようなものがある。 Conventionally, this type of hot wire flowmeter has a
There are some as shown in Fig. 2 and Fig. 2.
第１図を参照し、１は吸入空気通路を構成する
熱線流量計の外筒、２は外筒１内にリブ３を介し
て配設される内筒である。ここで、内筒２及びリ
ブ３は一体で、且つ半割りに形成されており、内
筒２の中に金属製の保持リング４が収納され、こ
の保持リング４に熱線（白金線）５が保持されて
いる。詳しくは、第２図に示されるように、保持
リング４にガラス封着６により２本のリード線７
の端部と、３本のフツク８とが保持され、保持リ
ング４内にてリード線７の端部間に熱線５が架設
されている。また、熱線５は途中でフツク８に引
掛けられている。 Referring to FIG. 1, reference numeral 1 denotes an outer cylinder of a hot wire flowmeter constituting an intake air passage, and 2 an inner cylinder disposed within the outer cylinder 1 with ribs 3 interposed therebetween. Here, the inner cylinder 2 and the rib 3 are integrally formed in half, and a metal retaining ring 4 is housed in the inner cylinder 2, and a hot wire (platinum wire) 5 is attached to this retaining ring 4. Retained. Specifically, as shown in FIG. 2, two lead wires 7 are attached to the retaining ring 4 by a glass seal 6.
and three hooks 8 are held, and a hot wire 5 is installed between the ends of the lead wire 7 within the holding ring 4. Further, the hot wire 5 is hooked on a hook 8 in the middle.
熱線５と接続されるリード線７は、内筒２と保
持リング４との間に引通されるが、リード線７が
保持リング４に触れてシヨートするのを防ぐた
め、これらの間には樹脂材９が設けられる。その
後、リード線７はリブ３内を貫通し、更に外筒１
を貫通して導出され、プリント基板１０に接続さ
れる。また、外筒１の外壁に固定される放熱板１
１にハイブリツドIC１２が貼付けられており、
その端子１２ａはプリント基板１０に接続され
て、基板１０上でリード線７に接続されている。 The lead wire 7 connected to the hot wire 5 is passed between the inner cylinder 2 and the retaining ring 4, but in order to prevent the lead wire 7 from touching the retaining ring 4 and being shot, there is a gap between them. A resin material 9 is provided. After that, the lead wire 7 passes through the inside of the rib 3, and further passes through the outer cylinder 1.
It is led out through and connected to the printed circuit board 10. Also, a heat sink 1 fixed to the outer wall of the outer cylinder 1
Hybrid IC12 is attached to 1,
The terminal 12a is connected to a printed circuit board 10 and connected to a lead wire 7 on the circuit board 10.
回路的にみれば、第３図に示す如く、熱線５と
抵抗R1，R2，R3（R1は温度補償用抵抗、R2は流
量調整用抵抗、R3は基準抵抗）とによりブリツ
ジ回路が構成される。 From a circuit perspective, as shown in Figure 3, the hot wire 5 and resistors R 1 , R 2 , R 3 (R 1 is a temperature compensation resistor, R 2 is a flow rate adjustment resistor, and R 3 is a reference resistor) A bridge circuit is constructed.
このブリツジ回路への供給電流は、抵抗R2の
端子電圧と抵抗R3の端子電圧とに基づき差動増
幅器OP及びトランジスタTr1，Tr2を介して制御
されるようになつている。例えば、流速が増大す
ると、熱線５がより冷却されることによりその抵
抗値が減少するが、このとき抵抗R3の端子電圧
が増大して、差動増幅器OPの出力が低下し、こ
れによりトランジスタTr1，Tr2を介してブリツ
ジ回路への供給電流が増大するようになつてい
る。 The current supplied to this bridge circuit is controlled via the differential amplifier OP and the transistors Tr 1 and Tr 2 based on the terminal voltage of the resistor R 2 and the terminal voltage of the resistor R 3 . For example, when the flow velocity increases, the hot wire 5 is cooled down and its resistance value decreases, but at this time, the terminal voltage of the resistor R 3 increases and the output of the differential amplifier O P decreases. The current supplied to the bridge circuit increases via the transistors Tr 1 and Tr 2 .
こうして、流速の変化に対し、熱線５の抵抗値
を一定に保つように供給電流を変化させ、その供
給電流すなわち抵抗R3の端子電圧Ｕから流速を
読取るのである。 In this way, the supplied current is changed so as to keep the resistance value of the hot wire 5 constant in response to changes in the flow velocity, and the flow velocity is read from the supplied current, that is, the terminal voltage U of the resistor R3 .
しかしながら、このような従来の熱線流量計に
おいては、リード線７がリブ３内に密閉状態で収
納されていて、空気流による冷却が少なかつたた
め、熱線５への通電開始直後と通電開始数分後と
ではリード線７自体の電流による自己発熱で抵抗
値が大きく変化し、これに基づいて熱線５の抵抗
値すなわち熱線５への供給電流が変化してしま
い、第６図に実線で示すように、通電開始直後に
は同一流量でも流量計の出力値が変化し、安定状
態となるまでに時間がかかるという問題点があつ
た。 However, in such a conventional hot wire flowmeter, the lead wire 7 is housed in the rib 3 in a sealed state, and cooling by air flow is small, so that the lead wire 7 is not cooled immediately after the start of energization to the hot wire 5 and for several minutes after the start of energization. After that, the resistance value changes greatly due to self-heating of the lead wire 7 itself due to the current, and based on this, the resistance value of the hot wire 5, that is, the current supplied to the hot wire 5 changes, as shown by the solid line in FIG. Another problem was that the output value of the flowmeter changes immediately after the start of energization even at the same flow rate, and it takes time to reach a stable state.
本考案はこのような従来の問題点を解決するこ
とを目的としてなされたもので、リード線が貫通
するリブにリード線を露出させるための窓を設
け、リード線を冷却するようにして、温度上昇を
少なくし、通電開始後における抵抗変化を少なく
して特性の安定化時間を短縮するようにしたもの
である。 The present invention was developed with the aim of solving these conventional problems.The rib through which the lead wire passes is provided with a window to expose the lead wire, and the lead wire is cooled to reduce the temperature. This is designed to reduce the increase in resistance and reduce the change in resistance after the start of energization, thereby shortening the stabilization time of the characteristics.
以下に本考案の一実施例を第４図及び第５図に
よつて説明する。但し、この実施例において従来
例（第１図）と同一部分には同一符号を付し、異
なる部分についてのみ説明する。 An embodiment of the present invention will be described below with reference to FIGS. 4 and 5. However, in this embodiment, the same parts as in the conventional example (FIG. 1) are given the same reference numerals, and only the different parts will be explained.
この内筒２′には従来と同様に熱線５を張つた
保持リング４が収められるようになつており、熱
線５と接続されるリード線７が貫通するリブ３′
に窓１３を形成して、リード線７を露出させてあ
る。尚、この例では半割りのリブ３′の一方にの
み窓１３を形成したが、両方に形成してもよい。 This inner cylinder 2' accommodates a retaining ring 4 with a hot wire 5 stretched thereon as in the conventional case, and a rib 3' through which a lead wire 7 connected to the hot wire 5 passes.
A window 13 is formed in the window 13 to expose the lead wire 7. In this example, the window 13 is formed only on one side of the half-split rib 3', but it may be formed on both sides.
かかる構成によれば、リード線７や窓１３を介
して被測定空気流に直接触れるようになり、これ
によりリード線７は冷却され、温度上昇が少なく
なる。このため、第６図に破線で示すように、通
電開始前と通電開始後とでの抵抗変化が小さくな
り、特性の安定化時間が早まる。 According to this configuration, the lead wire 7 comes into direct contact with the airflow to be measured via the window 13, thereby cooling the lead wire 7 and reducing the temperature rise. Therefore, as shown by the broken line in FIG. 6, the change in resistance between before and after the start of energization becomes smaller, and the stabilization time of the characteristics becomes faster.
以上説明したように本考案によれば、内筒のリ
ブの部分に窓を設けて、リード線を露出させるよ
うにしたため、空気流によりリード線を冷却し
て、その自己発熱を抑えることができ、これによ
り通電開始後の特性安定化の時間を短縮できると
いう効果が得られる。 As explained above, according to the present invention, a window is provided in the rib part of the inner cylinder to expose the lead wire, so the lead wire can be cooled by airflow and its self-heating can be suppressed. This has the effect of shortening the time for stabilizing the characteristics after the start of energization.
第１図は従来例を示す熱線流量計の断面図、第
２図は同上要部の拡大断面図、第３図は熱線流量
計の回路図、第４図は本考案の一実施例を示す熱
線流量計の要部断面図、第５図は同上の側面図、
第６図は従来及び本考案における通電開始後の出
力特性の変化の様子を示す線図である。
１……外筒、２，２′……内筒、３，３′……リ
ブ、４……保持リング、５……熱線、７……リー
ド線、１０……プリント基板。
Fig. 1 is a sectional view of a conventional hot wire flowmeter, Fig. 2 is an enlarged sectional view of the main parts of the same, Fig. 3 is a circuit diagram of the hot wire flowmeter, and Fig. 4 is an embodiment of the present invention. A sectional view of the main parts of the hot wire flowmeter, Figure 5 is a side view of the same as above,
FIG. 6 is a diagram showing how the output characteristics change after the start of energization in the conventional and the present invention. 1... Outer cylinder, 2, 2'... Inner cylinder, 3, 3'... Rib, 4... Retaining ring, 5... Hot wire, 7... Lead wire, 10... Printed circuit board.
Claims (1)
内筒を配設し、この内筒内に収納される保持リン
グに熱線を保持させ、この熱線をリブ内を貫通す
るリード線により外筒外の電気回路と接続してな
る内燃機関の吸入空気量測定用熱線流量計におい
て、前記リブに前記リード線を露出させる窓を形
成したことを特徴とする内燃機関の吸入空気量測
定用熱線流量計。 An inner cylinder is disposed through a rib inside the outer cylinder that constitutes the intake air passage, a retaining ring housed in the inner cylinder holds a hot wire, and a lead wire passing through the rib connects the hot wire to the outer cylinder. A hot wire flowmeter for measuring the amount of intake air of an internal combustion engine connected to an external electric circuit, characterized in that a window is formed in the rib to expose the lead wire. Total.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15091982U JPS5956525U (en) | 1982-10-06 | 1982-10-06 | Hot wire flow meter for measuring intake air amount of internal combustion engines |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15091982U JPS5956525U (en) | 1982-10-06 | 1982-10-06 | Hot wire flow meter for measuring intake air amount of internal combustion engines |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5956525U JPS5956525U (en) | 1984-04-13 |
| JPH0116007Y2 true JPH0116007Y2 (en) | 1989-05-12 |
Family
ID=30334592
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15091982U Granted JPS5956525U (en) | 1982-10-06 | 1982-10-06 | Hot wire flow meter for measuring intake air amount of internal combustion engines |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5956525U (en) |
-
1982
- 1982-10-06 JP JP15091982U patent/JPS5956525U/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5956525U (en) | 1984-04-13 |
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