JPH10142021A - Thermal mass flowmeter - Google Patents
Thermal mass flowmeterInfo
- Publication number
- JPH10142021A JPH10142021A JP8302589A JP30258996A JPH10142021A JP H10142021 A JPH10142021 A JP H10142021A JP 8302589 A JP8302589 A JP 8302589A JP 30258996 A JP30258996 A JP 30258996A JP H10142021 A JPH10142021 A JP H10142021A
- Authority
- JP
- Japan
- Prior art keywords
- heat
- fluid
- generating
- thermal mass
- 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.)
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Links
Landscapes
- Measuring Volume Flow (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は熱式質量流量計に係り、
特に、流管中の質量流量をバイパスを設置すること無
く、大流量から小流量の測定に、手軽かつ廉価で使用で
きる応答性の良い挿入形熱式質量流量計に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal mass flow meter,
In particular, the present invention relates to an insert-type thermal mass flowmeter with good responsiveness that can be used easily and inexpensively for measuring a large flow rate to a small flow rate without installing a bypass for a mass flow rate in a flow tube.
【０００２】[0002]
【従来の技術】従来の熱式流量計は概略、非線形特性の
風速計、境界層流量計、又はバイパスを持った、ほぼ線
形特性の層流式細管型熱式質量流量計である。流量計の
特性は当然，線形が望ましく非線形の流量計は何等かの
方法で利用のしやすい線形に直線化しているのが現状で
ある。2. Description of the Related Art A conventional thermal flow meter is generally an anemometer, a boundary layer flow meter having a non-linear characteristic, or a laminar flow type thin tube type thermal mass flow meter having a bypass. At present, the characteristics of the flow meter are preferably linear, and the non-linear flow meter is linearized into a linear shape which can be easily used in some way.
【０００３】現在一番使用量の多い熱式質量流量計は汚
れに弱い細管形で有るが、これらは半導体製造装置、液
晶製造装置等に数多く使用されている。上記装置産業に
おいて数多く使用されている理由は、流体の接する流路
や各装置の清浄度が極端に重視されている結果、細管形
熱式質量流量計の欠点である、バイパスや検出部の一部
である、細管部の汚れ等による精度の悪化を考慮する必
要がないからである。At present, the most frequently used thermal mass flowmeters are of a thin tube type which is susceptible to dirt, and are used in many semiconductor manufacturing devices, liquid crystal manufacturing devices and the like. The reason why they are widely used in the above equipment industry is that the importance of the cleanliness of the flow paths in contact with the fluids and of each equipment is extremely high. This is because it is not necessary to consider deterioration in accuracy due to contamination of the thin tube portion, which is a portion.
【０００４】一般用途としては、これら特異な清浄度を
保つ事は技術的、経済的にも困難で、その様な必要もな
い。しかも、この様な一般的な用途に的した熱式質量流
量計は余り多くない。又存在していても、極端な非線形
で、応答速度も遅いのが実情であり、普及の少ない原因
もそこにある。For general use, it is technically and economically difficult to maintain these specific cleanliness, and there is no need to do so. Moreover, there are not so many thermal mass flow meters intended for such general use. Even if it is present, the fact is that it is extremely non-linear and the response speed is slow.
【０００５】[0005]
【発明が解決しようとする課題】流量測定は必ずしも清
浄な状態で使用されるとは限らない。大流量の測定に必
ずしも、バイパス形の熱式質量流量計は適当とは考えら
れない。しかも構造や流路の形状を複雑にして高価な商
品を作る必要もない。同一の精度で使用できるなら、廉
価で構造の簡単なものが必要である事は言うまでもな
い。従来の挿入形の熱式質量計の普及を阻む最大原因
は、応答速度、極端な非線形、高価が上げられる。SUMMARY OF THE INVENTION Flow measurement is not always used in a clean state. A thermal mass flow meter of the bypass type is not always considered suitable for measuring a large flow rate. Moreover, there is no need to make expensive products by complicating the structure and the shape of the flow path. Needless to say, if it can be used with the same precision, an inexpensive and simple structure is required. The main factors preventing the spread of the conventional insertion type thermal mass meter are the response speed, extremely non-linearity, and high cost.
【０００６】一般的には細管形熱式流量計の検出部に使
用されいて流体加熱と、その加熱された流体の移動にと
もなう温度変化を測定することにより流量計測を行って
いる。但し加熱源は流管の外におかれている。従って、
本発明にあっては、流量特性が出来る限り線形で、応答
が早い挿入形熱式質量流量計を実現する為に細管形熱式
流量計の原理とほぼ同じ、状況を直接、主流の管内で行
おうとするものである。[0006] Generally, a flow rate is measured by measuring the fluid heating and the temperature change due to the movement of the heated fluid, which is used in the detecting section of a thin tube type thermal flow meter. However, the heating source is located outside the flow tube. Therefore,
In the present invention, the flow characteristics are as linear as possible, and in order to realize an insertion-type thermal mass flowmeter with a fast response, the principle is almost the same as that of the thin-tube thermal mass flowmeter. It is what we are going to do.
【０００７】そこで、請求項１記載の発明の課題は、高
精度であると共に制作コストを低減でき、一方で、応答
速度の速い熱式質量流量計を提供する点にある。請求項
２、３、４及び５記載の発明にあっては、請求項１記載
の発明の効果に加えて、検出部の部品点数を低減するこ
とが可能な質量熱式流量計を提供する点にある。An object of the present invention is to provide a thermal mass flowmeter which has high accuracy and can reduce the production cost, and has a high response speed. According to the second, third, fourth and fifth aspects of the present invention, in addition to the effects of the first aspect of the present invention, there is provided a mass thermal type flow meter capable of reducing the number of parts of the detection unit. It is in.
【０００８】請求項６記載の発明にあっては、請求項１
記載の発明の効果に加えて、上記ヒートパイプを加熱源
としてではなく、冷却源として使用する熱式質量流量計
を提供する点にある。以上のような課題解決のため、請
求項１記載の発明にあっては、流体の流路途中に発熱体
を配置し、流体の温度変化と流体の質量流量の関係に基
づき流量を計測する熱式質量流量計において、被測定流
体の流路の上流側と下流側において、流路中に直接配設
される、一対の発熱兼感熱抵抗体３ａ，３ｂと、これら
一対の発熱兼感熱抵抗体３ａ，３ｂは夫々、ヒートパイ
プ６ａ，６ｂに接続されていることを特徴とする。[0008] According to the sixth aspect of the present invention, a first aspect is provided.
In addition to the effects of the described invention, another object is to provide a thermal mass flowmeter that uses the heat pipe as a cooling source instead of a heating source. In order to solve the above problems, in the invention according to the first aspect, a heating element is arranged in the middle of the flow path of the fluid, and the heat is measured based on the relationship between the temperature change of the fluid and the mass flow rate of the fluid. In the mass flow meter, a pair of heat-generating and heat-sensitive resistors 3a and 3b disposed directly in the flow channel on the upstream side and the downstream side of the flow path of the fluid to be measured, and the pair of heat-generating and heat-sensitive resistors 3a and 3b are connected to the heat pipes 6a and 6b, respectively.
【０００９】また、請求項２記載の発明にあっては、検
出部の発熱体取付け部の上流側に設置された発熱兼感熱
抵抗体３ａと下流側に設置された発熱兼感熱抵抗体３ｂ
とを挾む両端の各々がヒートパイプ６ａ，６ｂで保持さ
れたことを特徴とする。また、請求項３記載の発明にあ
っては、被測定流体が周囲を流れる流路において検出部
の中心に置かれた発熱部を上記ヒートパイプヒートパイ
プ６ａ，６ｂにより外部より直接加熱することを特徴と
する。According to the second aspect of the present invention, the heat-generating and heat-sensitive resistor 3a installed on the upstream side of the heat-generating body mounting part of the detecting part and the heat-generating and heat-sensitive resistor 3b installed on the downstream side are provided.
Are held by heat pipes 6a and 6b, respectively. Further, according to the third aspect of the present invention, in the flow path around which the fluid to be measured flows, the heat generating portion located at the center of the detecting portion is directly heated from the outside by the heat pipes 6a and 6b. Features.
【００１０】また、請求項４記載の発明にあっては、被
測定流体が周囲を流れる流路において検出部の中心に置
かれた発熱部と、それを挾んだ感熱部を有し更にその両
端にヒートパイプ６ａ，６ｂを取付けたことを特徴とす
る。また、請求項５記載の発明にあっては、上記ヒート
パイプ６ａ，６ｂを冷却源として使用することを特徴と
する。According to the present invention, there is provided a heat generating portion disposed at the center of the detecting portion in the flow path around which the fluid to be measured flows, and a heat sensitive portion sandwiching the heat generating portion. The heat pipes 6a and 6b are attached to both ends. The invention according to claim 5 is characterized in that the heat pipes 6a and 6b are used as a cooling source.
【００１１】また、請求項６記載の発明にあっては、被
測定流体が周囲を流れる流路において検出部の中心から
上流側、下流側にほぼ同一寸法の点に感熱部を有し更に
その両端にヒートパイプ６ａ，６ｂを取付けたことを特
徴とする。従って、請求項１乃至６記載の発明にあって
は、外部から与えられる温度（熱量）により、流体の移
動が引き起こす熱傾斜を積極的に利用するために、従来
用いられていた挿入型の流量計にあっては開示されてい
ない、ヒートシンク部分にヒートパイプを設け、流管中
のしかも検出部に設置したことにより、流量が流れた時
そのエネルギーの変動を正確、かつ敏速に測定すること
が可能となる。In the invention according to the sixth aspect, the flow path around which the fluid to be measured flows has a heat-sensitive portion at substantially the same size upstream and downstream from the center of the detection portion. The heat pipes 6a and 6b are attached to both ends. Therefore, according to the first to sixth aspects of the present invention, the insertion type flow rate conventionally used in order to positively use the thermal gradient caused by the movement of the fluid due to the temperature (heat amount) given from the outside. The heat pipe is provided in the heat sink part, which is not disclosed in the meter, and it is installed in the flow tube and at the detection part, so that when the flow rate flows, the energy fluctuation can be measured accurately and promptly. It becomes possible.
【００１２】また、請求項１乃至６記載の発明にあって
は、前記のヒートパイプを使用したことにより、発熱部
からの熱拡散が大きくなることと同時に流管中に置かれ
た加熱源から無駄な熱放散により流体の温度を高めるこ
ともなく、時定数も小さくなり応答速度は格段に早くな
る、という効果を奏する。また、ヒートパイプが加熱
源、温度測定点の外側に設置され、共通の熱シンクに接
続される事で、検出部両端の整合が簡単に且つ正確に行
われる、という効果をも奏する。Further, in the inventions according to the first to sixth aspects, the use of the heat pipe increases the heat diffusion from the heat-generating portion, and at the same time reduces the heat source placed in the flow tube. There is an effect that the time constant is reduced and the response speed is significantly increased without increasing the temperature of the fluid due to unnecessary heat dissipation. In addition, since the heat pipe is installed outside the heating source and the temperature measurement point and connected to a common heat sink, there is an effect that alignment of both ends of the detection unit can be easily and accurately performed.
【００１３】[0013]
【発明の実施の形態】以下本発明の実施の形態を添付図
面に基づいて説明する。図１は本発明の一実施の形態に
係る熱式質量流量計の正面の断面図である。熱伝導素材
２に巻き付けられ直列に接続された発熱抵抗兼検出体３
ａ・３ｂは外筒１に覆われている。更にその両端はヒー
トパイプ６ａ，６ｂの一端に接続されいる。Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a front sectional view of a thermal mass flowmeter according to one embodiment of the present invention. Heating resistor / detector 3 wound around heat conductive material 2 and connected in series
a and 3b are covered with the outer cylinder 1. Further, both ends are connected to one ends of the heat pipes 6a and 6b.
【００１４】ヒートパイプ６ａ，６ｂの他端は保持金具
４をへて熱シンク１３ａ，１３ｂに接続される事で一つ
のループを作っている。又、結ばれた発熱抵抗兼検出体
３ａ，３ｂの中間点に導線８が接続され、更にその発熱
抵抗兼検出体３ａ，３ｂの他端は各々導線７，９に接続
されている。これら導線は加熱源と温度検出部で構成す
るブリッジ回路の一端となっている。図６は検出部１の
上流側と下流側の温度差を検出する方法を示し、発熱抵
抗兼検出体３ａ，３ｂの各々の抵抗値をＲ１，Ｒ２とす
ると、この抵抗値は他の一対の固定抵抗Ｒ３，Ｒ４とで
ブリッジ回路を構成している。The other ends of the heat pipes 6a and 6b are connected to the heat sinks 13a and 13b via the holding fitting 4 to form one loop. A conducting wire 8 is connected to an intermediate point between the connected heating resistor and detectors 3a and 3b, and the other ends of the heating resistor and detectors 3a and 3b are connected to conductors 7 and 9, respectively. These conductors form one end of a bridge circuit composed of a heating source and a temperature detector. FIG. 6 shows a method of detecting the temperature difference between the upstream side and the downstream side of the detection unit 1. Assuming that the resistance values of the heat-generating resistors / detectors 3a and 3b are R1 and R2, these resistance values are different from each other. A bridge circuit is configured by the fixed resistors R3 and R4.
【００１５】ブリッジ回路には定電流源１８からの電流
Ｉが流れ発熱抵抗兼検出体３ａ，３ｂによって、検出部
１は流体温度よりも（設定値）一定値だけ温度が上昇し
た状態となる。上記の構成のものを組み込んだ形が図３
である。図３において、流量が零の時はブリッジがバラ
ンスして不平衡電圧は零である。流量が流れ始めると検
出部１の発熱抵抗兼検出体３ａ，３ｂで発生した熱は流
体移動に伴い、発熱抵抗兼検出体３ａ側から発熱抵抗兼
検出体３ｂ側に移動をする。 即ち、この際に、全体と
して下流側に温度の移動が起こり、その結果発熱抵抗兼
検出体３ａの温度は低下し発熱抵抗兼検出体３ｂの温度
は上昇することとなる。この温度変化によって抵抗Ｒ１
抵抗Ｒ２が変化し、結果ブリッジ回路は不平衡となり、
この不平衡電圧は作動増幅器１９の出力として取り出さ
れる。この出力は、ほぼ流速に比例している。A current I from a constant current source 18 flows through the bridge circuit, and the temperature of the detection unit 1 is raised by a fixed value (set value) from the fluid temperature by the heating resistors and detectors 3a and 3b. Figure 3 incorporates the above configuration
It is. In FIG. 3, when the flow rate is zero, the bridge is balanced and the unbalanced voltage is zero. When the flow starts to flow, the heat generated in the heat generating resistor / detector 3a, 3b of the detecting unit 1 moves from the heat generating resistor / detector 3a side to the heat generating resistor / detector 3b side as the fluid moves. That is, at this time, the temperature moves as a whole on the downstream side, and as a result, the temperature of the heating resistor / detector 3a decreases and the temperature of the heating resistor / detector 3b increases. This temperature change causes the resistance R1
The resistance R2 changes, resulting in an unbalanced bridge circuit,
This unbalanced voltage is taken out as the output of the operational amplifier 19. This output is approximately proportional to the flow velocity.
【００１６】２図に別の事例を示す。１図において、検
出体として、発熱兼感温抵抗体３ａ，３ｂを使用した
が、この方法に変えて、発熱体として単独に加熱用ヒー
トパイプ１４および加熱源として発熱部１７を接続し
た。温度計測の手段として、熱電対１２ａ，１２ｂを配
しその起電力の差を測定することで流量を測定すること
とした。FIG. 2 shows another case. In FIG. 1, the heat-generating and temperature-sensitive resistors 3a and 3b are used as the detectors. Instead of this method, the heating heat pipe 14 and the heat source 17 are individually connected as the heating elements. As a means for measuring the temperature, the thermocouples 12a and 12b are arranged, and the flow rate is measured by measuring the difference between the electromotive forces.
【００１７】この構成は、特に、検出部の部品の低減お
よび配線の低減に有効で有る。図示しないが、２図にお
ける加熱源とヒートパイプに変えて、電力による加熱源
を熱伝導素材２の中心に付設した。この場合にあって
も、効果、現象として何等変わる事なく流量の計測が可
能である。事例では、主に検出部を加熱する事で、説明
してきたが加熱源に変えて、冷却源をヒートパイプに取
り付けた場合も検出部１に熱傾斜を与える事となり、加
熱源同様、温度を測定することで流量の測定が可能とな
る。This configuration is particularly effective in reducing the number of components of the detection section and the number of wirings. Although not shown, a heat source by electric power was provided at the center of the heat conductive material 2 instead of the heat source and the heat pipe in FIG. Even in this case, the flow rate can be measured without any change as an effect or a phenomenon. In the example, the description has been made mainly by heating the detection unit. However, when the cooling unit is attached to the heat pipe instead of the heating source, the detection unit 1 is given a thermal gradient. By measuring, the flow rate can be measured.
【００１８】本旨は検出器１を挾んでその両端にヒート
パイプの取付は原則を原則としている。検出器１に取り
付けられた温度測定のための配線や加熱の為の配線の支
柱の数量、支柱の位置はいろいろ考え得る。又図中にお
いては、熱シンク１３ａ，１３ｂと分離して図示してい
るが、外部加熱装置を含めて、それらを一体の形にして
も問題はない。又検出部の構造を総て左右対称に製作出
来るため流量方向は問わない。The present invention is based on the principle that heat pipes are attached to both ends of the detector 1 with the detector 1 interposed therebetween. Various numbers and positions of the columns for the temperature measurement wiring and the wiring for heating attached to the detector 1 can be considered. Also, in the figure, the heat sinks 13a and 13b are shown separately from each other, but there is no problem if they are integrally formed, including the external heating device. Further, since the structure of the detection unit can be manufactured symmetrically in all directions, the flow direction does not matter.
【００１９】[0019]
【発明の効果】請求項１乃至６記載の発明にあっては、
外部から与えられる温度（熱量）により、流体の移動が
引き起こす熱傾斜を積極的に利用するために、従来用い
られていた挿入型の流量計にあっては開示されていな
い、ヒートシンク部分にヒートパイプを設け、流管中の
しかも検出部に設置したことにより、流量が流れた時そ
のエネルギーの変動を正確、かつ敏速に測定することが
可能となる。According to the first to sixth aspects of the present invention,
In order to positively utilize the thermal gradient caused by the movement of the fluid due to the temperature (heat quantity) given from the outside, a heat pipe is provided on the heat sink portion, which is not disclosed in the conventionally used insertion type flow meter. Is provided in the flow tube and at the detection section, so that when the flow rate flows, the energy fluctuation can be measured accurately and promptly.
【００２０】更に、請求項１乃至６記載の発明にあって
は、前記のヒートパイプを使用したことにより、発熱部
からの熱拡散が大きくなることと同時に流管中に置かれ
た加熱源から無駄な熱放散により流体の温度を高めるこ
ともなく、時定数も小さくなり応答速度は格段に早くな
る、という効果を奏する。また、ヒートパイプが加熱
源、温度測定点の外側に設置され、共通の熱シンクに接
続される事で、検出部両端の整合が簡単に且つ正確に行
われる、という効果をも奏する。Further, in the inventions according to the first to sixth aspects, by using the heat pipe, the heat diffusion from the heat generating portion is increased, and at the same time, the heat source placed in the flow tube is used. There is an effect that the time constant is reduced and the response speed is significantly increased without increasing the temperature of the fluid due to unnecessary heat dissipation. In addition, since the heat pipe is installed outside the heating source and the temperature measurement point and connected to a common heat sink, there is an effect that alignment of both ends of the detection unit can be easily and accurately performed.
【００２１】従って、若干の非線形ではあるものの、そ
れを補う応答速度の改善、広い測定範囲、比較的廉価な
挿入形熱式質量流量計の実現が可能になった。更に、請
求項２、３、４又は５記載の発明にあっては、請求項１
記載の発明の効果に加えて、検出部の部品点数を低減す
ることが可能となった。Therefore, it is possible to improve the response speed, which is slightly nonlinear, but to compensate for it, to realize a wide measuring range and a relatively inexpensive insertion-type thermal mass flowmeter. Further, in the invention according to claim 2, 3, 4 or 5, claim 1
In addition to the effects of the described invention, it has become possible to reduce the number of components of the detection unit.
【図１】本発明に係る熱式質量流量計の一実施の形態で
あって、検出部の構成の一例を示す図である。FIG. 1 is an embodiment of a thermal mass flow meter according to the present invention, showing an example of a configuration of a detection unit.
【図２】本発明に係る熱式質量流量計の他の実施の形態
であって、検出部の構成の一例を示す図である。FIG. 2 is a view showing another embodiment of the thermal mass flow meter according to the present invention, showing an example of a configuration of a detection unit.
【図３】本発明による検出部を流体が内部を流れる配管
に組込んだ場合を示す側面図である。FIG. 3 is a side view showing a case where the detection unit according to the present invention is incorporated in a pipe through which a fluid flows.
【図４】本発明による検出部を流体が内部を流れる配管
に組込んだ場合を示す側面図である。FIG. 4 is a side view showing a case where the detection unit according to the present invention is incorporated in a pipe through which a fluid flows.
【図５】本発明に係る熱式質量流量計の他の実施の形態
であって、検出部の構成の一例を示す図である。FIG. 5 is a view showing another embodiment of the thermal mass flow meter according to the present invention, showing an example of a configuration of a detection unit.
【図６】本発明に係る熱式質量流量計に適用される電気
回路図である。FIG. 6 is an electric circuit diagram applied to the thermal mass flow meter according to the present invention.
１ 検出部 ２ 発熱
体取付け部 ３ａ，３ｂ 発熱兼感熱抵抗体 ４ 流路
への取付部 ５ａ，５ｂ 支持柱 ６ａ，６ｂ ヒー
トパイプ ７ 発熱兼感熱抵抗体３ａの一端 ８ 発熱兼感熱抵抗体３ａと３ｂを繋いだ
中間点 ９ 発熱兼感熱抵抗体３ｂの一端 １０ 熱電対の導線 １１ 熱電対の導線 １２ａ，１２ｂ 熱電対部 １３ａ，１３ｂ 熱シンク（ヒートシンク） １４ 加熱用ヒートパイプ １５ 配管部 １６ 検出部の配管に挿入された部分と同じ
形状の物体 １７ 加熱源 １８ 定電流源 １９ 差動増幅器DESCRIPTION OF SYMBOLS 1 Detection part 2 Heating element mounting part 3a, 3b Heating and heat-sensitive resistor 4 Mounting part to a flow path 5a, 5b Support pillar 6a, 6b Heat pipe 7 One end of heat-generating and heat-sensitive resistor 3a 8 Heating and heat-sensitive resistor 3a Intermediate point connecting 3b 9 One end of heat generating and thermal resistor 3b 10 Lead wire of thermocouple 11 Conductor wire of thermocouple 12a, 12b Thermocouple portion 13a, 13b Heat sink (heat sink) 14 Heat pipe for heating 15 Pipe portion 16 Detecting portion Object having the same shape as the part inserted in the piping of the pipe 17 heating source 18 constant current source 19 differential amplifier
【手続補正書】[Procedure amendment]
【提出日】平成９年５月７日[Submission date] May 7, 1997
【手続補正２】[Procedure amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】発明の詳細な説明[Correction target item name] Detailed description of the invention
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【０００１】[0001]
【産業上の利用分野】本発明は熱式質量流量計に係り、
特に、流管中の質量流量をバイパスを設置すること無
く、大流量から小流量の測定に、手軽かつ廉価で使用で
きる応答性の良い挿入形熱式質量流量計に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal mass flow meter,
In particular, the present invention relates to an insert-type thermal mass flowmeter with good responsiveness that can be used easily and inexpensively for measuring a large flow rate to a small flow rate without installing a bypass for a mass flow rate in a flow tube.
【０００２】[0002]
【従来の技術】従来の熱式流量計は概略、非線形特性の
風速計、境界層流量計、又はバイパスを持った、ほぼ線
形特性の層流式細管型熱式質量流量計である。流量計の
特性は当然，線形が望ましく非線形の流量計は何等かの
方法で利用のしやすい線形に直線化しているのが現状で
ある。2. Description of the Related Art A conventional thermal flow meter is generally an anemometer, a boundary layer flow meter having a non-linear characteristic, or a laminar flow type thin tube type thermal mass flow meter having a bypass. At present, the characteristics of the flow meter are preferably linear, and the non-linear flow meter is linearized into a linear shape which can be easily used in some way.
【０００３】現在一番使用量の多い熱式質量流量計は汚
れに弱い細管形で有るが、これらは半導体製造装置、液
晶製造装置等に数多く使用されている。上記装置産業に
おいて数多く使用されている理由は、流体の接する流路
や各装置の清浄度が極端に重視されている結果、細管形
熱式質量流量計の欠点である、バイパスや検出部の一部
である、細管部の汚れ等による精度の悪化を考慮する必
要がないからである。At present, the most frequently used thermal mass flowmeters are of a thin tube type which is susceptible to dirt, and are used in many semiconductor manufacturing devices, liquid crystal manufacturing devices and the like. The reason why they are widely used in the above equipment industry is that the importance of the cleanliness of the flow paths in contact with the fluids and of each equipment is extremely high. This is because it is not necessary to consider deterioration in accuracy due to contamination of the thin tube portion, which is a portion.
【０００４】一般用途としては、これら特異な清浄度を
保つ事は技術的、経済的にも困難で、その様な必要もな
い。しかも、この様な一般的な用途に的した熱式質量流
量計は余り多くない。又存在していても、極端な非線形
で、応答速度も遅いのが実情であり、普及の少ない原因
もそこにある。For general use, it is technically and economically difficult to maintain these specific cleanliness, and there is no need to do so. Moreover, there are not so many thermal mass flow meters intended for such general use. Even if it is present, the fact is that it is extremely non-linear and the response speed is slow.
【０００５】[0005]
【発明が解決しようとする課題】流量測定は必ずしも清
浄な状態で使用されるとは限らない。大流量の測定に必
ずしも、バイパス形の熱式質量流量計は適当とは考えら
れない。しかも構造や流路の形状を複雑にして高価な商
品を作る必要もない。同一の精度で使用できるなら、廉
価で構造の簡単なものが必要である事は言うまでもな
い。従来の挿入形の熱式流量計の普及を阻む最大原因
は、応答速度、極端な非線形、高価が上げられる。SUMMARY OF THE INVENTION Flow measurement is not always used in a clean state. A thermal mass flow meter of the bypass type is not always considered suitable for measuring a large flow rate. Moreover, there is no need to make expensive products by complicating the structure and the shape of the flow path. Needless to say, if it can be used with the same precision, an inexpensive and simple structure is required. The main factors preventing the spread of the conventional insertion type thermal flow meter are response speed, extremely non-linearity, and high cost.
【０００６】一般的には細管形熱式流量計の検出部に使
用されていて流体加熱と、その加熱された流体の移動に
ともなう温度変化を測定することにより流量計測を行っ
ている。但し加熱源は流管の外におかれている。従っ
て、本発明にあっては、流量特性が出来る限り線形で、
応答が早い挿入形熱式質量流量計を実現する為に細管形
熱式流量計の原理とほぼ同じ、状況を直接、主流の管内
で行おうとするものである。[0006] In general, doing a flow body heating has been used in the detection portion of the capillary-type thermal flow meter, the flow rate measurement by measuring the temperature change due to movement of the heated fluid. However, the heating source is located outside the flow tube. Therefore, in the present invention, the flow characteristic is as linear as possible,
In order to realize an insert-type thermal mass flowmeter with fast response, the principle is the same as the principle of the thin-tube thermal flowmeter, and the situation is to be performed directly in the mainstream pipe.
【０００７】そこで、請求項１記載の発明の課題は、高
精度であると共に制作コストを低減でき、一方で、応答
速度の速い熱式質量流量計を提供する点にある。請求項
２、３、４及び５記載の発明にあっては、請求項１記載
の発明の効果に加えて、検出部の部品点数を低減するこ
とが可能な質量熱式流量計を提供する点にある。An object of the present invention is to provide a thermal mass flowmeter which has high accuracy and can reduce the production cost, and has a high response speed. According to the second, third, fourth and fifth aspects of the present invention, in addition to the effects of the first aspect of the present invention, there is provided a mass thermal type flow meter capable of reducing the number of parts of the detection unit. It is in.
【０００８】請求項６記載の発明にあっては、請求項１
記載の発明の効果に加えて、上記ヒートパイプを加熱源
としてではなく、冷却源として使用する熱式質量流量計
を提供する点にある。以上のような課題解決のため、請
求項１記載の発明にあっては、流体の流路途中に発熱体
を配置し、流体の温度変化と流体の質量流量の関係に基
づき流量を計測する熱式質量流量計において、被測定流
体の流路の上流側と下流側において、流路中に直接配設
される、一対の発熱兼感熱抵抗体３ａ，３ｂと、これら
一対の発熱兼感熱抵抗体３ａ，３ｂは夫々、ヒートパイ
プ６ａ，６ｂに接続されていることを特徴とする。[0008] According to the sixth aspect of the present invention, a first aspect is provided.
In addition to the effects of the described invention, another object is to provide a thermal mass flowmeter that uses the heat pipe as a cooling source instead of a heating source. In order to solve the above problems, in the invention according to the first aspect, a heating element is arranged in the middle of the flow path of the fluid, and the heat is measured based on the relationship between the temperature change of the fluid and the mass flow rate of the fluid. In the mass flow meter, a pair of heat-generating and heat-sensitive resistors 3a and 3b disposed directly in the flow channel on the upstream side and the downstream side of the flow path of the fluid to be measured, and the pair of heat-generating and heat-sensitive resistors 3a and 3b are connected to the heat pipes 6a and 6b, respectively.
【０００９】また、請求項２記載の発明にあっては、検
出部の発熱体取付け部の上流側に設置された発熱兼感熱
抵抗体３ａと下流側に設置された発熱兼感熱抵抗体３ｂ
とを挾む両端の各々がヒートパイプ６ａ，６ｂで保持さ
れたことを特徴とする。また、請求項３記載の発明にあ
っては、被測定流体が周囲を流れる流路において検出部
の中心に置かれた発熱部を上記ヒートパイプヒートパイ
プ６ａ，６ｂにより外部より直接加熱することを特徴と
する。According to the second aspect of the present invention, the heat-generating and heat-sensitive resistor 3a installed on the upstream side of the heat-generating body mounting part of the detecting part and the heat-generating and heat-sensitive resistor 3b installed on the downstream side are provided.
Are held by heat pipes 6a and 6b, respectively. Further, according to the third aspect of the present invention, in the flow path around which the fluid to be measured flows, the heat generating portion located at the center of the detecting portion is directly heated from the outside by the heat pipes 6a and 6b. Features.
【００１０】また、請求項４記載の発明にあっては、被
測定流体が周囲を流れる流路において検出部の中心に置
かれた発熱部と、それを挾んだ感熱部を有し更にその両
端にヒートパイプ６ａ，６ｂを取付けたことを特徴とす
る。また、請求項５記載の発明にあっては、被測定流体
が周囲を流れる流路において検出部の中心から上流側、
下流側にほぼ同一寸法の点に感熱部を有し更にその両端
にヒートパイプ６ａ，６ｂを取付けたことを特徴とす
る。According to the present invention, there is provided a heat generating portion disposed at the center of the detecting portion in the flow path around which the fluid to be measured flows, and a heat sensitive portion sandwiching the heat generating portion. The heat pipes 6a and 6b are attached to both ends. Further, in the invention according to claim 5 , in the flow path around which the fluid to be measured flows, an upstream side from the center of the detection unit,
On the downstream side, a heat-sensitive portion is provided at a point having substantially the same dimension, and heat pipes 6a and 6b are attached to both ends thereof.
【００１１】また、請求項６記載の発明にあっては、上
記ヒートパイプ６ａ，６ｂを冷却源として使用すること
を特徴とする。従って、請求項１乃至６記載の発明にあ
っては、外部から与えられる温度（熱量）により、流体
の移動が引き起こす熱傾斜を積極的に利用するために、
従来用いられていた挿入型の流量計にあっては開示され
ていない、ヒートシンク部分にヒートパイプを設け、流
管中のしかも検出部に設置したことにより、流量が流れ
た時そのエネルギーの変動を正確、かつ敏速に測定する
ことが可能となる。The invention according to claim 6 is characterized in that the heat pipes 6a and 6b are used as a cooling source. Therefore, in the inventions according to claims 1 to 6, in order to positively use the thermal gradient caused by the movement of the fluid due to the temperature (heat amount) given from the outside,
It is not disclosed in the insertion type flow meter that has been used conventionally.A heat pipe is provided in the heat sink part, and it is installed in the detection part in the flow tube, so that when the flow rate flows, the energy fluctuation is reduced. It is possible to measure accurately and promptly.
【００１２】また、請求項１乃至６記載の発明にあって
は、前記のヒートパイプを使用したことにより、発熱部
からの熱移動が大きくなることと同時に流管中に置かれ
た加熱源から無駄な熱放散により流体の温度を高めるこ
ともなく、時定数も小さくなり応答速度は格段に早くな
る、という効果を奏する。また、ヒートパイプが加熱
源、温度測定点の外側に設置され、共通の熱シンクに接
続される事で、検出部両端の整合が簡単に且つ正確に行
われる、という効果をも奏する。According to the present invention, the use of the heat pipe increases the heat transfer from the heat- generating portion and simultaneously reduces the heat transfer from the heating source placed in the flow tube. There is an effect that the time constant is reduced and the response speed is significantly increased without increasing the temperature of the fluid due to unnecessary heat dissipation. In addition, since the heat pipe is installed outside the heating source and the temperature measurement point and connected to a common heat sink, there is an effect that alignment of both ends of the detection unit can be easily and accurately performed.
【００１３】[0013]
【発明の実施の形態】以下本発明の実施の形態を添付図
面に基づいて説明する。図１は本発明の一実施の形態に
係る熱式質量流量計の正面の断面図である。熱伝導素材
２に巻き付けられ直列に接続された発熱抵抗兼検出体３
ａ・３ｂは外筒１に覆われている。更にその両端はヒー
トパイプ６ａ，６ｂの一端に接続されいる。Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a front sectional view of a thermal mass flowmeter according to one embodiment of the present invention. Heating resistor / detector 3 wound around heat conductive material 2 and connected in series
a and 3b are covered with the outer cylinder 1. Further, both ends are connected to one ends of the heat pipes 6a and 6b.
【００１４】ヒートパイプ６ａ，６ｂの他端は保持金具
４をへて熱シンク１３ａ，１３ｂに接続される事で一つ
のループを作っている。又、結ばれた発熱抵抗兼検出体
３ａ，３ｂの中間点に導線８が接続され、更にその発熱
抵抗兼検出体３ａ，３ｂの他端は各々導線７，９に接続
されている。これら導線は加熱源と温度検出部で構成す
るブリッジ回路の一端となっている。図６は検出部１の
上流側と下流側の温度差を検出する方法を示し、発熱抵
抗兼検出体３ａ，３ｂの各々の抵抗値をＲ１，Ｒ２とす
ると、この抵抗値は他の一対の固定抵抗Ｒ３，Ｒ４とで
ブリッジ回路を構成している。The other ends of the heat pipes 6a and 6b are connected to the heat sinks 13a and 13b via the holding fitting 4 to form one loop. A conducting wire 8 is connected to an intermediate point between the connected heating resistor and detectors 3a and 3b, and the other ends of the heating resistor and detectors 3a and 3b are connected to conductors 7 and 9, respectively. These conductors form one end of a bridge circuit composed of a heating source and a temperature detector. FIG. 6 shows a method of detecting the temperature difference between the upstream side and the downstream side of the detection unit 1. Assuming that the resistance values of the heat-generating resistors / detectors 3a and 3b are R1 and R2, these resistance values are different from each other. A bridge circuit is configured by the fixed resistors R3 and R4.
【００１５】ブリッジ回路には定電流源１８からの電流
Ｉが流れ発熱抵抗兼検出体３ａ，３ｂによって、検出部
１は流体温度よりも（設定値）一定値だけ温度が上昇し
た状態となる。上記の構成のものを組み込んだ形が図３
である。図３において、流量が零の時はブリッジがバラ
ンスして不平衡電圧は零である。流量が流れ始めると検
出部１の発熱抵抗兼検出体３ａ，３ｂで発生した熱は流
体移動に伴い、発熱抵抗兼検出体３ａ側から発熱抵抗兼
検出体３ｂ側に移動をする。即ち、この際に、全体とし
て下流側に温度の移動が起こり、その結果発熱抵抗兼検
出体３ａの温度は低下し発熱抵抗兼検出体３ｂの温度は
上昇することとなる。この温度変化によって抵抗Ｒ１抵
抗Ｒ２が変化し、結果ブリッジ回路は不平衡となり、こ
の不平衡電圧は作動増幅器１９の出力として取り出され
る。この出力は、ほぼ流速に比例している。A current I from the constant current source 18 flows through the bridge circuit, and the temperature of the detection unit 1 is raised by a fixed value (set value) from the fluid temperature by the heating resistors and detectors 3a and 3b. Figure 3 incorporates the above configuration
It is. In FIG. 3, when the flow rate is zero, the bridge is balanced and the unbalanced voltage is zero. When the flow starts to flow, the heat generated in the heat generating resistor / detector 3a, 3b of the detecting unit 1 moves from the heat generating resistor / detector 3a side to the heat generating resistor / detector 3b side as the fluid moves. That is, at this time, the temperature moves as a whole on the downstream side, and as a result, the temperature of the heating resistor / detector 3a decreases and the temperature of the heating resistor / detector 3b increases. This temperature change causes the resistance R1 and the resistance R2 to change, resulting in an unbalanced bridge circuit, and this unbalanced voltage is taken out as the output of the operational amplifier 19. This output is approximately proportional to the flow velocity.
【００１６】２図に別の事例を示す。１図において、検
出体として、発熱兼感温抵抗体３ａ，３ｂを使用した
が、この方法に変えて、発熱体として単独に加熱用ヒー
トパイプ１４および加熱源として発熱部１７を接続し
た。温度計測の手段として、熱電対１２ａ，１２ｂを配
しその起電力の差を測定することで流量を測定すること
とした。FIG. 2 shows another case. In FIG. 1, the heat-generating and temperature-sensitive resistors 3a and 3b are used as the detectors. Instead of this method, the heating heat pipe 14 and the heat source 17 are individually connected as the heating elements. As a means for measuring the temperature, the thermocouples 12a and 12b are arranged, and the flow rate is measured by measuring the difference between the electromotive forces.
【００１７】この構成は、特に、検出部の部品の低減お
よび配線の低減に有効で有る。図示しないが、２図にお
ける加熱源とヒートパイプに変えて、電力による加熱源
を熱伝導素材２の中心に付設した。この場合にあって
も、効果、現象として何等変わる事なく流量の計測が可
能である。事例では、主に検出部を加熱する事で、説明
してきたが加熱源に変えて、冷却源をヒートパイプに取
り付けた場合も検出部１に熱傾斜を与える事となり、加
熱源同様、温度を測定することで流量の測定が可能とな
る。This configuration is particularly effective in reducing the number of components of the detection section and the number of wirings. Although not shown, a heat source by electric power was provided at the center of the heat conductive material 2 instead of the heat source and the heat pipe in FIG. Even in this case, the flow rate can be measured without any change as an effect or a phenomenon. In the example, the description has been made mainly by heating the detection unit. However, when the cooling unit is attached to the heat pipe instead of the heating source, the detection unit 1 is given a thermal gradient. By measuring, the flow rate can be measured.
【００１８】本旨は検出器１を挾んでその両端にヒート
パイプの取付を原則としている。検出器１に取り付けら
れた温度測定のための配線や加熱の為の配線の支柱の数
量、支柱の位置はいろいろ考え得る。又図中において
は、熱シンク１３ａ，１３ｂと分離して図示している
が、外部加熱装置を含めて、それらを一体の形にしても
問題はない。又検出部の構造を総て左右対称に製作出来
るため流量方向は問わない。The gist of the invention is to attach heat pipes to both ends of the detector 1 in principle. Various numbers and positions of the columns for the temperature measurement wiring and the wiring for heating attached to the detector 1 can be considered. Also, in the figure, the heat sinks 13a and 13b are shown separately from each other, but there is no problem if they are integrally formed, including the external heating device. Further, since the structure of the detection unit can be manufactured symmetrically in all directions, the flow direction does not matter.
【００１９】[0019]
【発明の効果】請求項１乃至６記載の発明にあっては、
外部から与えられる温度（熱量）により、流体の移動が
引き起こす熱傾斜を積極的に利用するために、従来用い
られていた挿入型の流量計にあっては開示されていな
い、ヒートシンク部分にヒートパイプを設け、流管中の
しかも検出部に設置したことにより、流量が流れた時そ
のエネルギーの変動を正確、かつ敏速に測定することが
可能となる。According to the first to sixth aspects of the present invention,
In order to positively utilize the thermal gradient caused by the movement of the fluid due to the temperature (heat quantity) given from the outside, a heat pipe is provided on the heat sink portion, which is not disclosed in the conventionally used insertion type flow meter. Is provided in the flow tube and at the detection section, so that when the flow rate flows, the energy fluctuation can be measured accurately and promptly.
【００２０】更に、請求項１乃至６記載の発明にあって
は、前記のヒートパイプを使用したことにより、発熱部
からの熱拡散が大きくなることと同時に流管中に置かれ
た加熱源から無駄な熱放散により流体の温度を高めるこ
ともなく、時定数も小さくなり応答速度は格段に早くな
る、という効果を奏する。また、ヒートパイプが加熱
源、温度測定点の外側に設置され、共通の熱シンクに接
続される事で、検出部両端の整合が簡単に且つ正確に行
われる、という効果をも奏する。Further, in the inventions according to the first to sixth aspects, by using the heat pipe, the heat diffusion from the heat generating portion is increased, and at the same time, the heat source placed in the flow tube is used. There is an effect that the time constant is reduced and the response speed is significantly increased without increasing the temperature of the fluid due to unnecessary heat dissipation. In addition, since the heat pipe is installed outside the heating source and the temperature measurement point and connected to a common heat sink, there is an effect that alignment of both ends of the detection unit can be easily and accurately performed.
【００２１】従って、若干の非線形ではあるものの、そ
れを補う応答速度の改善、広い測定範囲、比較的廉価な
挿入形熱式質量流量計の実現が可能になった。更に、請
求項２、３、４又は５記載の発明にあっては、請求項１
記載の発明の効果に加えて、検出部の部品点数を低減す
ることが可能となった。Therefore, it is possible to improve the response speed, which is slightly nonlinear, but to compensate for it, to realize a wide measuring range and a relatively inexpensive insertion-type thermal mass flowmeter. Further, in the invention according to claim 2, 3, 4 or 5, claim 1
In addition to the effects of the described invention, it has become possible to reduce the number of components of the detection unit.
【手続補正３】[Procedure amendment 3]
【補正対象書類名】図面[Document name to be amended] Drawing
【補正対象項目名】図２[Correction target item name] Figure 2
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【図２】 FIG. 2
【手続補正４】[Procedure amendment 4]
【補正対象書類名】図面[Document name to be amended] Drawing
【補正対象項目名】図５[Correction target item name] Fig. 5
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【図５】 FIG. 5
【手続補正５】[Procedure amendment 5]
【補正対象書類名】図面[Document name to be amended] Drawing
【補正対象項目名】図６[Correction target item name] Fig. 6
【補正方法】削除[Correction method] Deleted
Claims (6)
の温度変化と流体の質量流量の関係に基づき流量を計測
する熱式質量流量計において、 被測定流体の流路の上流側と下流側において、流路中に
直接配設される、一対の発熱兼感熱抵抗体と、これら一
対の発熱兼感熱抵抗体は夫々、ヒートパイプに接続され
ていることを特徴とする熱式質量流量計。1. A thermal mass flowmeter which arranges a heating element in the middle of a flow path of a fluid and measures a flow rate based on a relationship between a temperature change of the fluid and a mass flow rate of the fluid, wherein an upstream side of a flow path of the fluid to be measured is provided. And a pair of heat-generating and heat-sensitive resistors disposed directly in the flow path on the downstream side, and the pair of heat-generating and heat-sensitive resistors, each being connected to a heat pipe. Flowmeter.
された発熱兼感熱抵抗体と下流側に設置された発熱兼感
熱抵抗体とを挾む両端の各々がヒートパイプで保持され
たことを特徴とする請求項１記載の熱式質量流量計。2. Both ends sandwiching a heat-generating and heat-sensitive resistor provided on the upstream side of the heat-generating body mounting part of the detecting part and a heat-generating and heat-sensitive resistor provided on the downstream side are held by heat pipes. The thermal mass flow meter according to claim 1, wherein:
検出部の中心に置かれた発熱部を上記ヒートパイプによ
り外部より直接加熱することを特徴とする請求項１記載
の熱式質量流量計。3. The thermal mass flowmeter according to claim 1, wherein a heat generating portion located at the center of the detecting portion in the flow path around which the fluid to be measured flows is directly heated from the outside by the heat pipe. .
検出部の中心に置かれた発熱部と、それを挾んだ感熱部
を有し更にその両端にヒートパイプを取付けたことを特
徴とする請求項１記載の熱式質量流量計。4. A flow path around which a fluid to be measured flows, a heat generating portion located at the center of the detecting portion, a heat sensitive portion sandwiching the heat generating portion, and heat pipes attached to both ends. The thermal mass flowmeter according to claim 1.
検出部の中心から上流側、下流側にほぼ同一寸法の点に
感熱部を有し更にその両端にヒートパイプを取付けたこ
とを特徴とする熱式質量流量計。5. A flow path around which a fluid to be measured flows, a heat-sensitive portion is provided at substantially the same size upstream and downstream from the center of the detection portion, and heat pipes are attached to both ends thereof. Thermal mass flow meter.
ることを特徴とする熱式質量流量計。6. A thermal mass flowmeter using the heat pipe as a cooling source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8302589A JPH10142021A (en) | 1996-11-14 | 1996-11-14 | Thermal mass flowmeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8302589A JPH10142021A (en) | 1996-11-14 | 1996-11-14 | Thermal mass flowmeter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10142021A true JPH10142021A (en) | 1998-05-29 |
Family
ID=17910801
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8302589A Pending JPH10142021A (en) | 1996-11-14 | 1996-11-14 | Thermal mass flowmeter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10142021A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7117736B2 (en) | 2000-10-17 | 2006-10-10 | Yamatake Corporation | Flow sensor |
-
1996
- 1996-11-14 JP JP8302589A patent/JPH10142021A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7117736B2 (en) | 2000-10-17 | 2006-10-10 | Yamatake Corporation | Flow sensor |
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