JP2004012140A

JP2004012140A - Pressure detector

Info

Publication number: JP2004012140A
Application number: JP2002161796A
Authority: JP
Inventors: Kazuhiro Hamano; 浜野　和博; Hitoshi Shimomura; 下村　等
Original assignee: Saginomiya Seisakusho Inc
Current assignee: Saginomiya Seisakusho Inc
Priority date: 2002-06-03
Filing date: 2002-06-03
Publication date: 2004-01-15

Abstract

PROBLEM TO BE SOLVED: To provide a practical pressure detector in which occurrence of an improper operation caused by a pulsation or an disfunction is effectively evaded and also increasing in the number of parts or labor for assembly, or labor for piping are minimized without impairing the intrinsic pressure detecting performance of the pressure detector. SOLUTION: The pressure detector having a pressure chamber 19 detects the pressure in the pressure chamber 19. An end of a connecting tube 28 is hermetically connected with a case 13 of a main body demarcating the pressure chamber 19, and in the pipe of the connecting end part 28A of the connecting tube 28 to the case 13 of the main body, a drawn member 29 is fixed with caulking. COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
この発明は、圧力検知器に関し、特に、圧力スイッチ、圧力センサ等の圧力検知器に関するものである。
【０００２】
【従来の技術】
検知器本体ケースによって画定された受圧室を有し、受圧室の圧力を検知する圧力検知器として、受圧室の圧力に応じて開閉する電気接点を含む圧力スイッチや、受圧室の圧力を電気量に変換するピエゾ素子等による圧力・電気変換素子を含む圧力センサが知られている。
【０００３】
上述の圧力検知器は、プロセスやシステムにおける検知対象の圧力が導圧通路によって受圧室に導かれることにより、圧力の検知を行うから、検知対象の圧力が脈動成分を含むと、脈動成分の影響を受け、脈動成分に応答して誤作動することがある。
【０００４】
空調装置や冷蔵庫等の冷凍サイクル装置において、圧縮機の吐出圧異常上昇時に圧縮機を緊急停止（高圧カット）するために、圧縮機の吐出側に設けられる高圧スイッチ（圧力スイッチ）では、本来は高圧カットしない圧力値であるにも拘わらず、脈動によって瞬間的に設定値を超えた圧力が高圧スイッチに作用すると、高圧カットが作動し、システムを停止させる誤作動が生じる。また、このような圧縮機の高圧スイッチでは、液圧縮の脈動による高圧が圧力感知部に作用し、圧力スイッチの機能を損ねる原因になる。
【０００５】
受圧室に対する脈動の伝播を低減するために、管継手にオリフィス通路を形成したり、絞り部材を組み込むことが、特開昭５６−９７６９２号公報や特開平９−２５７１８６号公報に示されている。また、圧力測定装置の導圧管路に絞り部材を入れ、圧力測定装置に脈動が作用することを低減することが特開昭５６−１２９８３４号公報に示されている。
【０００６】
【発明が解決しようとする課題】
検知対象の圧力が導圧通路によって受圧室に導かれることにより、圧力の検知を行う圧力スイッチや圧力センサ等の圧力検知器において、圧力検知器本来の圧力検知性能を損ねることなく、脈動による誤作動や機能障害の発生を効果的に防止するためには、絞り部材の配置部位や絞り通路形状の選定に関して考察する必要がある。
【０００７】
しかし、このことに関して、従来のものでは、充分になされておらず、圧力検知器が脈動の影響を受けて圧力検知器が誤作動や機能障害を生じることについて、改善しなくてはならない。
【０００８】
この発明は、上述の如き問題点を解消するためになされたもので、圧力検知器本来の圧力検知性能を損ねることなく、脈動による誤作動や機能障害の発生を効果的に回避し、しかも、脈動防止のための部品点数や組付け工数、配管工数の増加を最小限に止めた実用的な圧力検知器を提供することを目的としている。
【０００９】
【課題を解決するための手段】
上述の目的を達成するために、この発明による圧力検知器は、受圧室を有し、前記受圧室の圧力を検知する圧力検知器であって、前記受圧室を画定する検知器本体ケースに継手管の一端が気密接続され、当該継手管は、前記検知器本体ケースに対する接続端にて前記受圧室に直接連通し、検知対象の圧力を前記受圧室に導く導圧通路をなしており、前記継手管の前記検知器本体ケースに対する接続端部の管内に絞り部材が固定装着されている。
【００１０】
この圧力検知器によれば、絞り部材が継手管の検知器本体ケースに対する接続端部の管内に固定装着され、絞り部材が継手管による導圧通路において最も受圧室に近い位置に配置されるから、絞り部材を通過した後の受圧室側の内容積が小さく、受圧室に脈動が伝わることが絞り部材によって効果的に抑制され、絞り部材による圧力検知の応答性の低下も最小限に止められる。
【００１１】
この発明による圧力検知器で用いられる絞り部材は、小径のオリフィス通路と、前記オリフィス通路より前記受圧室側に位置し前記オリフィス通路より大径の拡散通路とを有しているものであることが好ましく、受圧室に脈動が伝わることが効果的に抑制される。
【００１２】
この発明による圧力検知器では、前記受圧室はダイヤフラムにより区画されているものであってよく、前記受圧室の圧力に応じて開閉する電気接点を含む圧力スイッチ、あるいは前記受圧室の圧力を電気量に変換する圧力・電気変換素子を含む圧力センサとして構成される。
【００１３】
【発明の実施の形態】
以下に添付の図を参照してこの発明の実施の形態を詳細に説明する。
図１はこの発明による圧力検知器を圧力スイッチとして適用した一つの実施形態を示している。
【００１４】
圧力スイッチ１０は、かしめリング部材１１によって互いに結合された端子台１２と本体ケース１３とによる検出器本体ケース１４を有している。端子台１２と本体ケース１３との間には、中間ガイド部材１５、ストッパ部材１６、ダイヤフラム１７とがＯリング１８を挟んで気密に共締め状態で固定されている。
【００１５】
ダイヤフラム１７は本体ケース１３との間に受圧室１９を区画している。ダイヤフラム１７は、受圧室１９の圧力に応じて反転動作、すなわち、スナップアクションするばね性を有する金属製のものであり、受圧室１９の圧力が設定値未満である場合には、図示されているように下側に膨らんだ形状をなし、受圧室１９の圧力が設定値以上になると、この圧力によって下側に膨らんだ形状より上側に膨らんだ形状に可逆的に反転する。
【００１６】
中間ガイド部材１５は作動ピン２０を上下動可能に支持している。作動ピン２０は、下端にてダイヤフラム１７の中央部に当接し、ダイヤフラム１７の反転動作に応じて上下動する。
【００１７】
端子台１２にはＨ端子２１とＣ端子２２が取り付けられている。端子台１２は内部に電気接点室２３を画定しており、電気接点室２３には、Ｈ端子２１の内部端に固定された固定接点子２４と、Ｃ端子２２の内部端に一端を固定されたばね性を有する可動接点板２５および当該可動接点板２５の先端に取り付けられた可動接点子２６とが設けられている。
【００１８】
固定接点子２４と可動接点子２６とは上下に相対向しており、可動接点板２５の中間部に作動ピン２０の上端が当接していることにより、ダイヤフラム１７が、図示されているように、下側に膨らんだ形状をなしている状態の時には、固定接点子２４と可動接点子２６とが導通接触し、これに対し、ダイヤフラム１７が上側に膨らんだ形状をなしている状態の時には、可動接点子２６が固定接点子２４より離れる。
【００１９】
本体ケース１３には中央貫通孔２７が貫通形成されている。中央貫通孔２７には銅管等による継手管２８の一端部２８Ａが差し込まれており、この継手管２８の一端部２８Ａが溶接、ろう付け等によって本体ケース１３に気密に固着されている。継手管２８は、本体ケース１３に対する接続端（一端部２８Ａ）にて受圧室１９に直接連通しており、検知対象の圧力を受圧室１９に導く導圧通路をなしている。
【００２０】
継手管２８の本体ケース１３に対する接続端部の管内には絞り部材２９がローリングかしめ部３０によって固定装着されている。絞り部材２９は、小径のオリフィス通路３１と、オリフィス通路３１より受圧室１９側に位置しオリフィス通路３１より大径の拡散通路３２とを互いに直列に有している。
【００２１】
絞り部材２９の各部の寸法は、継手管２８の他端部２８Ｂより脈動が受圧室１９に伝わることを防止、抑制するために最適な値に設定されるものであり、継手管２８の内径が５ｍｍ程度である場合、オリフィス通路３１の内径が０．５ｍｍ、拡散通路３２の内径は１．０〜１．５ｍｍ、オリフィス通路３１の通路長が３ｍｍ、拡散通路３２の通路長が１０〜１２ｍｍ程度に設定される。
【００２２】
オリフィス通路３１の内径が０．５ｍｍ程度の極小径のドリル穴明けの場合、ドリルの強度上の問題により、オリフィス通路３１の通路長、換言すれば、ドリル工具長をさほど長くすることができず、通常のドリル穴明け加工では、ドリル工具長は３〜５ｍｍ程度が限界になる。このことに対して、絞り部材２９を継手管２８の管内に適切にかしめ固定するためには、絞り部材２９が、ある程度の軸長を有している必要があり、３〜５ｍｍの軸長では不十分である。
【００２３】
内径が１．０〜１．５ｍｍ程度で、オリフィス通路３１の内径より大きい拡散通路３２は、当該拡散通路を加工するドリルの強度確保上、オリフィス通路３１に比して軸長を長いものとすることができる。この拡散通路３２の存在によって絞り部材２９の全体の軸長を、絞り部材２９を継手管２８の管内に適切にかしめ固定するために必要な長さに設定することができる。すなわち、拡散通路３２の存在は、絞り部材２９を継手管２８の管内に適切にかしめ固定するために役立つ。
【００２４】
上述の構成による圧力スイッチ１０では、継手管２８の他端部２８Ｂが検知対象の圧力通路に接続されることにより、検知対象の圧力が絞り部材２９のオリフィス通路３１、拡散通路３２を経て受圧室１９に導かれる。絞り部材２９による絞り効果によって検知対象の圧力の脈動成分が受圧室１９に直接伝わることがなくなる。
【００２５】
絞り部材２９は継手管２８の本体ケース１３に対する接続端部２８Ａの管内に固定装着され、絞り部材２９が継手管２８による導圧通路において最も受圧室１９に近い位置に配置されるから、絞り部材２９が継手管２８の他端部２８Ｂや昼間部に設置される場合に比して、絞り部材２９を通過した後の受圧室１９側の内容積が小さく、受圧室１９に脈動が伝わることが絞り部材２９によって効果的に抑制され、絞り部材２９による圧力検知の応答性の低下も最小限に止められる。
【００２６】
また、小径のオリフィス通路３１を通過した圧力は、その後、オリフィス通路３１より大径の拡散通路３２を通り、拡散しつつ受圧室１９に伝わるから、受圧室１９に脈動が伝わることがより効果的に抑制され、受圧室１９の圧力が脈動に対して安定し、受圧室１９における脈動の影響がより一層低減される。
【００２７】
これらのことにより、圧力スイッチ１０本来の性能を損ねることなく、脈動による圧力スイッチ１０の誤作動や機能障害の発生が効果的に防止される。
【００２８】
また、絞り部材２９を継手管２８の一端部２８Ａにかしめ装着するだけでよいので、脈動防止のために生じる部品点数や組付け工数、配管工数の増加が最小限に止められる。
【００２９】
図２は圧力スイッチ１０を空調装置の高圧スイッチとして使用する使用例を示している。図２において、５０は圧縮機、５１は四方弁、５２は室外熱交換器、５３は冷媒量調節用タンク、５４は液阻止弁、５５は電動膨張弁、５６は室内熱交換器、５７はガス阻止弁を各々示している。
【００３０】
高圧スイッチとして圧力スイッチ１０は圧縮機５０の吐出配管５８の途中に継手管２８によって接続される。この場合、圧力スイッチ１０は、圧縮機５０の吐出圧力に応動し、圧縮機５０の吐出圧異常上昇時には開成して圧縮機５０の運転を緊急停止する。この緊急停止動作が高圧カットである。
【００３１】
圧力スイッチ１０は、前述した通り、継手管２８の一端部２８Ａに絞り部材２９を有するものであるから、圧力スイッチ１０本来の性能を損ねることなく、脈動による誤作動（高圧カット）、すなわち、圧縮機５０の緊急停止や、機能障害を生じることがない。
【００３２】
図３はこの発明による圧力検知器を圧力センサとして適用した一つの実施形態を示している。圧力センサ１００は、かしめリング部材１０１によって互いに結合されたコネクタハウジング１０２とキャップ部材１０３とによる検出器本体ケース１０４と、上アイレット１０５と、下アイレット１０６と、Ｏリング１０７と、ヘッダ１０８と、後述する受圧室１１４の圧力を電気量に変換する圧力・電気変換素子である感圧素子１０９と、ＦＰＣ配線基板１１０と、接続端子１１１、１１２等を有している。
【００３３】
下アイレット１０６にはダイヤフラム１１３が取り付けられており、ダイヤフラム１１３はキャップ部材１０３との間に受圧室１１４を区画している。ダイヤフラム１１３は受圧室１１４とは反対側にオイル封入室１１５を画定しており、受圧室１１４の圧力がダイヤフラム１１３によってオイル封入室１１５の封入オイルを介して感圧素子１０９に伝えられる。
【００３４】
なお、オイル封入室１１５に対するオイルの充填は下アイレット１０６に形成されたオイル注入孔１１６より行われ、オイル注入後に封止ボール１１７によってオイル注入孔１１６が閉じられる。
【００３５】
キャップ部材１０４には中央貫通孔１１８が貫通形成されている。中央貫通孔１１８には銅管等による継手管１１９の一端部１１９Ａが差し込まれており、この継手管１１９の一端部１１９Ａが溶接、ろう付け等によってキャップ部材１０４に気密に固着されている。継手管１１９は、キャップ部材１０４に対する接続端（一端部１１９Ａ）にて受圧室１１４に直接連通しており、検知対象の圧力を受圧室１１４に導く導圧通路をなしている。
【００３６】
継手管１１９のキャップ部材１０４に対する接続端部の管内には絞り部材１２０がローリングかしめ１２１によって固定装着されている。絞り部材１２０は、小径のオリフィス通路１２２と、オリフィス通路１２２より受圧室１１４側に位置しオリフィス通路１２２より大径の拡散通路１２３とを有している。
【００３７】
この場合も、絞り部材１２０の各部の寸法は、継手管１１９の他端部１１９Ｂより脈動が受圧室１１４に伝わることを防止、抑制するために最適な値に設定される。
【００３８】
上述の構成による圧力センサ１００では、継手管１１９の他端部１１９Ｂが検知対象の圧力通路に接続されることにより、検知対象の圧力が絞り部材１２０のオリフィス通路１２２、拡散通路１２３を経て受圧室１１４に導かれる。絞り部材１２０による絞り効果によって検知対象の圧力の脈動成分が受圧室１１４に直接伝わることがなくなる。
【００３９】
絞り部材１２０は継手管１１９の本体ケース１３に対する接続端部１１９Ａの管内に固定装着され、絞り部材１２０が継手管１１９による導圧通路において最も受圧室１１４に近い位置に配置されるから、絞り部材１２０を通過した後の受圧室１１４側の内容積が小さく、受圧室１１４に脈動が伝わることが絞り部材１２０によって効果的に抑制され、絞り部材１２０による圧力検知の応答性の低下も最小限に止められる。
【００４０】
また、小径のオリフィス通路１２２を通過した圧力は、その後、オリフィス通路１２２より大径の拡散通路１２３を通り、拡散しつつ受圧室１１４に伝わるから、受圧室１１４に脈動が伝わることがより効果的に抑制され、受圧室１９の圧力が脈動に対して安定し、受圧室１９における脈動の影響がより一層低減される。
【００４１】
これらのことにより、圧力センサ１００本来の性能を損ねることなく、脈動による圧力センサ１００の誤作動や機能障害の発生が効果的に防止される。
【００４２】
また、絞り部材１２０を継手管１１９の一端部１１９Ａにかしめ装着するだけでよいので、脈動防止のために生じる部品点数や組付け工数、配管工数の増加が最小限に止められる。
【００４３】
【発明の効果】
以上の説明から理解される如く、この発明による圧力検知器によれば、圧力検知器本来の圧力検知性能を損ねることなく、脈動による誤作動や機能障害の発生を効果的に回避でき、しかも、脈動防止のために生じる部品点数や組付け工数、配管工数の増加を最小限に止めることができる。
【図面の簡単な説明】
【図１】この発明による圧力検知器を圧力スイッチとして適用した一つの実施形態を示す断面図である。
【図２】この発明による圧力スイッチを空調装置の高圧スイッチとして使用する使用例を示する空調冷媒回路図である。
【図３】この発明による圧力検知器を圧力センサとして適用した一つの実施形態を示す断面図である。
【符号の説明】
１０　圧力スイッチ
１３　本体ケース
１７　ダイヤフラム
１９　受圧室
２０　作動ピン
２４　固定接点子
２６　可動接点子
２８　継手管
２９　絞り部材
３１　オリフィス通路
３２　拡散通路
１００　圧力センサ
１０９　感圧素子
１１３　ダイヤフラム
１１４　受圧室
１１５　オイル封入室
１１９　継手管
１２０　絞り部材
１２２　オリフィス通路
１２３　拡散通路[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pressure detector, and particularly to a pressure detector such as a pressure switch and a pressure sensor.
[0002]
[Prior art]
It has a pressure receiving chamber defined by the detector main body case, and as a pressure detector for detecting the pressure of the pressure receiving chamber, a pressure switch including an electric contact that opens and closes according to the pressure of the pressure receiving chamber, and a pressure sensor for measuring the pressure of the pressure receiving chamber. 2. Description of the Related Art There is known a pressure sensor including a pressure-electric conversion element such as a piezo element for converting the pressure into electric power.
[0003]
The pressure detector described above detects pressure by guiding the pressure of the detection target in the process or system to the pressure receiving chamber through the pressure guiding passage, so if the pressure of the detection target includes a pulsation component, the influence of the pulsation component And may malfunction in response to the pulsation component.
[0004]
In a refrigeration cycle device such as an air conditioner or a refrigerator, a high-pressure switch (pressure switch) provided on the discharge side of the compressor for originally stopping the compressor (high-pressure cut) when the discharge pressure of the compressor rises abnormally is originally If the pressure instantaneously exceeds the set value due to the pulsation and acts on the high-pressure switch despite the pressure value that does not cause the high-pressure cut, the high-pressure cut is activated, and a malfunction that stops the system occurs. Further, in such a high-pressure switch of the compressor, the high pressure due to the pulsation of the liquid compression acts on the pressure sensing unit, which causes the function of the pressure switch to be impaired.
[0005]
JP-A-56-97692 and JP-A-9-257186 disclose that an orifice passage is formed in a pipe joint and a throttle member is incorporated to reduce the propagation of pulsation to the pressure receiving chamber. . Japanese Patent Application Laid-Open No. 56-129834 discloses that a restricting member is inserted into a pressure guiding pipe of a pressure measuring device to reduce pulsation acting on the pressure measuring device.
[0006]
[Problems to be solved by the invention]
Since the pressure to be detected is guided to the pressure receiving chamber by the pressure guiding passage, the pressure detector, such as a pressure switch or a pressure sensor for detecting the pressure, does not impair the original pressure detection performance of the pressure detector and generates an error due to pulsation. In order to effectively prevent the occurrence of operation or functional failure, it is necessary to consider the arrangement of the throttle member and the selection of the shape of the throttle passage.
[0007]
However, in this regard, in the related art, this has not been sufficiently performed, and it has to be improved that the pressure detector is affected by pulsation and causes malfunction or malfunction of the pressure detector.
[0008]
The present invention has been made in order to solve the above-described problems, and effectively avoids the occurrence of malfunction or functional failure due to pulsation without impairing the original pressure detection performance of the pressure detector, and It is an object of the present invention to provide a practical pressure detector in which an increase in the number of parts, assembly steps, and piping steps for preventing pulsation is minimized.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a pressure detector according to the present invention has a pressure receiving chamber, and is a pressure detector for detecting the pressure of the pressure receiving chamber, wherein the pressure detector is connected to a detector main body case defining the pressure receiving chamber. One end of the pipe is airtightly connected, the joint pipe communicates directly with the pressure receiving chamber at a connection end to the detector main body case, and forms a pressure guiding passage that guides a pressure to be detected to the pressure receiving chamber. A throttle member is fixedly mounted in a pipe at a connection end of the joint pipe to the detector main body case.
[0010]
According to this pressure detector, the throttle member is fixedly mounted in the pipe at the connection end of the joint pipe with respect to the detector main body case, and the throttle member is arranged at a position closest to the pressure receiving chamber in the pressure guiding passage formed by the joint pipe. Since the internal volume of the pressure receiving chamber after passing through the throttle member is small, the transmission of pulsation to the pressure receiving chamber is effectively suppressed by the throttle member, and a decrease in responsiveness of pressure detection by the throttle member is also minimized. .
[0011]
The throttle member used in the pressure detector according to the present invention may have a small-diameter orifice passage, and a diffusion passage that is located closer to the pressure receiving chamber than the orifice passage and has a larger diameter than the orifice passage. Preferably, transmission of pulsation to the pressure receiving chamber is effectively suppressed.
[0012]
In the pressure detector according to the present invention, the pressure receiving chamber may be partitioned by a diaphragm, and a pressure switch including an electric contact that opens and closes according to the pressure of the pressure receiving chamber, or a pressure switch that measures the pressure of the pressure receiving chamber. It is configured as a pressure sensor including a pressure / electric conversion element for converting the pressure into electric power.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows an embodiment in which the pressure detector according to the present invention is applied as a pressure switch.
[0014]
The pressure switch 10 has a detector main body case 14 including a terminal block 12 and a main body case 13 which are connected to each other by a caulking ring member 11. An intermediate guide member 15, a stopper member 16, and a diaphragm 17 are airtightly fixed between the terminal block 12 and the main body case 13 with an O-ring 18 interposed therebetween.
[0015]
The diaphragm 17 defines a pressure receiving chamber 19 between the diaphragm 17 and the main body case 13. The diaphragm 17 is made of metal having a reversible operation, that is, a snap action, in accordance with the pressure of the pressure receiving chamber 19, and is illustrated when the pressure of the pressure receiving chamber 19 is less than a set value. When the pressure in the pressure receiving chamber 19 becomes equal to or more than a set value, the pressure in the pressure receiving chamber 19 is reversibly inverted to a shape bulging upward from the shape bulging downward.
[0016]
The intermediate guide member 15 supports the operating pin 20 so as to be vertically movable. The operating pin 20 abuts on the center of the diaphragm 17 at the lower end, and moves up and down in accordance with the inversion operation of the diaphragm 17.
[0017]
An H terminal 21 and a C terminal 22 are attached to the terminal block 12. The terminal block 12 defines an electric contact chamber 23 therein. The electric contact chamber 23 has a fixed contact 24 fixed to the inner end of the H terminal 21 and one end fixed to the inner end of the C terminal 22. A movable contact plate 25 having a spring property and a movable contact 26 attached to the tip of the movable contact plate 25 are provided.
[0018]
The fixed contact 24 and the movable contact 26 are vertically opposed to each other, and the upper end of the operating pin 20 is in contact with an intermediate portion of the movable contact plate 25, so that the diaphragm 17 is moved as shown in the drawing. In the state in which the fixed contact 24 and the movable contact 26 are in conductive contact with each other in the state in which the diaphragm 17 is bulging downward, while the state in which the diaphragm 17 is in the state bulging upward, The movable contact 26 is separated from the fixed contact 24.
[0019]
A central through hole 27 is formed through the main body case 13. One end 28A of a joint pipe 28 made of a copper pipe or the like is inserted into the central through hole 27, and one end 28A of the joint pipe 28 is hermetically fixed to the main body case 13 by welding, brazing, or the like. The joint pipe 28 is in direct communication with the pressure receiving chamber 19 at a connection end (one end portion 28 A) to the main body case 13, and forms a pressure guiding passage for guiding the pressure to be detected to the pressure receiving chamber 19.
[0020]
A throttle member 29 is fixedly mounted by a rolling caulking portion 30 in the connection end of the joint tube 28 with respect to the main body case 13. The throttle member 29 has a small-diameter orifice passage 31 and a diffusion passage 32 located on the pressure receiving chamber 19 side of the orifice passage 31 and having a larger diameter than the orifice passage 31 in series with each other.
[0021]
The size of each part of the throttle member 29 is set to an optimal value to prevent or suppress pulsation from being transmitted to the pressure receiving chamber 19 from the other end 28B of the joint pipe 28. When the diameter is about 5 mm, the inner diameter of the orifice passage 31 is 0.5 mm, the inner diameter of the diffusion passage 32 is 1.0 to 1.5 mm, the length of the orifice passage 31 is 3 mm, and the length of the diffusion passage 32 is 10 to 12 mm. Is set to
[0022]
In the case of drilling an extremely small diameter hole having an inner diameter of the orifice passage 31 of about 0.5 mm, the passage length of the orifice passage 31, in other words, the length of the drill tool cannot be increased significantly due to a problem in the strength of the drill. In ordinary drilling, the length of the drill tool is limited to about 3 to 5 mm. On the other hand, in order to appropriately caulk and fix the restricting member 29 in the pipe of the joint pipe 28, the restricting member 29 needs to have a certain axial length, and when the axial length is 3 to 5 mm, Not enough.
[0023]
The diffusion passage 32 having an inner diameter of about 1.0 to 1.5 mm and larger than the inner diameter of the orifice passage 31 has a longer axial length than the orifice passage 31 in order to secure the strength of a drill for processing the diffusion passage. be able to. Due to the presence of the diffusion passage 32, the entire axial length of the throttle member 29 can be set to a length necessary for appropriately caulking and fixing the throttle member 29 in the joint pipe 28. That is, the presence of the diffusion passage 32 helps to appropriately caulk and fix the throttle member 29 in the pipe of the joint pipe 28.
[0024]
In the pressure switch 10 having the above-described configuration, the other end portion 28B of the joint pipe 28 is connected to the pressure passage to be detected, so that the pressure to be detected passes through the orifice passage 31 and the diffusion passage 32 of the throttle member 29 and the pressure receiving chamber. It is led to 19. The pulsating component of the pressure to be detected is not directly transmitted to the pressure receiving chamber 19 due to the restricting effect of the restricting member 29.
[0025]
The throttle member 29 is fixedly mounted in the connection end 28A of the joint pipe 28 with respect to the main body case 13, and the throttle member 29 is disposed at a position closest to the pressure receiving chamber 19 in the pressure guiding passage formed by the joint pipe 28. Compared to the case where the pipe 29 is installed at the other end 28B of the joint pipe 28 or in the daytime, the internal volume of the pressure receiving chamber 19 after passing through the throttle member 29 is smaller, and pulsation may be transmitted to the pressure receiving chamber 19. The throttle member 29 is effectively suppressed, and a decrease in the responsiveness of pressure detection by the throttle member 29 is also minimized.
[0026]
Further, the pressure that has passed through the small-diameter orifice passage 31 is then transmitted to the pressure receiving chamber 19 while diffusing through the diffusion passage 32 having a larger diameter than the orifice passage 31, so that it is more effective that pulsation is transmitted to the pressure receiving chamber 19. The pressure in the pressure receiving chamber 19 is stabilized against pulsation, and the influence of the pulsation in the pressure receiving chamber 19 is further reduced.
[0027]
As a result, erroneous operation or malfunction of the pressure switch 10 due to pulsation can be effectively prevented without impairing the original performance of the pressure switch 10.
[0028]
Further, since it is only necessary to caulk the throttle member 29 to the one end 28A of the joint pipe 28, the increase in the number of parts, the number of assembling steps, and the number of piping steps caused for preventing pulsation can be minimized.
[0029]
FIG. 2 shows an example in which the pressure switch 10 is used as a high-pressure switch of an air conditioner. 2, 50 is a compressor, 51 is a four-way valve, 52 is an outdoor heat exchanger, 53 is a refrigerant amount adjusting tank, 54 is a liquid blocking valve, 55 is an electric expansion valve, 56 is an indoor heat exchanger, and 57 is an indoor heat exchanger. Each shows a gas check valve.
[0030]
The pressure switch 10 as a high-pressure switch is connected to the discharge pipe 58 of the compressor 50 in the middle of the joint pipe 28. In this case, the pressure switch 10 responds to the discharge pressure of the compressor 50 and is opened when the discharge pressure of the compressor 50 rises abnormally to stop the operation of the compressor 50 urgently. This emergency stop operation is a high pressure cut.
[0031]
As described above, since the pressure switch 10 has the throttle member 29 at one end 28A of the joint pipe 28, a malfunction due to pulsation (high-pressure cut), that is, compression, without impairing the original performance of the pressure switch 10 There is no emergency stop of the machine 50 or functional failure.
[0032]
FIG. 3 shows one embodiment in which the pressure detector according to the present invention is applied as a pressure sensor. The pressure sensor 100 includes a detector main body case 104 including a connector housing 102 and a cap member 103 joined together by a caulking ring member 101, an upper eyelet 105, a lower eyelet 106, an O-ring 107, a header 108, A pressure-sensitive element 109, which is a pressure-electric conversion element for converting the pressure in the pressure receiving chamber 114 into an electric quantity, an FPC wiring board 110, connection terminals 111 and 112, and the like.
[0033]
A diaphragm 113 is attached to the lower eyelet 106, and the diaphragm 113 partitions a pressure receiving chamber 114 between the lower eyelet 106 and the cap member 103. The diaphragm 113 defines an oil filling chamber 115 on the opposite side to the pressure receiving chamber 114, and the pressure of the pressure receiving chamber 114 is transmitted to the pressure-sensitive element 109 by the diaphragm 113 via the oil filled in the oil filling chamber 115.
[0034]
The oil filling chamber 115 is filled with oil through an oil injection hole 116 formed in the lower eyelet 106. After the oil is injected, the oil injection hole 116 is closed by the sealing ball 117.
[0035]
A central through hole 118 is formed through the cap member 104. One end 119A of a joint pipe 119 made of a copper pipe or the like is inserted into the central through hole 118, and one end 119A of the joint pipe 119 is air-tightly fixed to the cap member 104 by welding, brazing, or the like. The joint pipe 119 communicates directly with the pressure receiving chamber 114 at a connection end (one end portion 119A) to the cap member 104, and forms a pressure guiding passage for guiding the pressure to be detected to the pressure receiving chamber 114.
[0036]
A restricting member 120 is fixedly mounted by a rolling caulking 121 in the connection end of the joint pipe 119 with respect to the cap member 104. The throttle member 120 has a small-diameter orifice passage 122 and a diffusion passage 123 which is located closer to the pressure receiving chamber 114 than the orifice passage 122 and has a larger diameter than the orifice passage 122.
[0037]
Also in this case, the dimensions of each part of the throttle member 120 are set to optimal values for preventing and suppressing pulsation from being transmitted to the pressure receiving chamber 114 from the other end 119B of the joint pipe 119.
[0038]
In the pressure sensor 100 having the above-described configuration, the other end portion 119B of the joint pipe 119 is connected to the pressure passage to be detected, so that the pressure to be detected passes through the orifice passage 122 and the diffusion passage 123 of the throttle member 120, and the pressure receiving chamber. It is led to 114. The pulsating component of the pressure to be detected is not directly transmitted to the pressure receiving chamber 114 due to the restricting effect of the restricting member 120.
[0039]
The throttle member 120 is fixedly mounted in the connection end 119 A of the joint pipe 119 with respect to the main body case 13, and the throttle member 120 is disposed at a position closest to the pressure receiving chamber 114 in the pressure guiding passage formed by the joint pipe 119. Since the internal volume of the pressure receiving chamber 114 after passing through the pressure receiving chamber 120 is small, the transmission of pulsation to the pressure receiving chamber 114 is effectively suppressed by the throttle member 120, and the reduction in the responsiveness of pressure detection by the throttle member 120 is minimized. Can be stopped.
[0040]
In addition, the pressure that has passed through the small-diameter orifice passage 122 is transmitted to the pressure receiving chamber 114 while diffusing through the diffusion passage 123 having a larger diameter than the orifice passage 122, so that the pulsation is more effectively transmitted to the pressure receiving chamber 114. The pressure in the pressure receiving chamber 19 is stabilized against pulsation, and the influence of the pulsation in the pressure receiving chamber 19 is further reduced.
[0041]
As a result, malfunction of the pressure sensor 100 due to pulsation and occurrence of a functional failure are effectively prevented without impairing the original performance of the pressure sensor 100.
[0042]
Further, since it is only necessary to caulk the throttle member 120 to the one end 119A of the joint pipe 119, the increase in the number of parts, the number of assembling steps, and the number of piping steps caused for preventing pulsation can be minimized.
[0043]
【The invention's effect】
As can be understood from the above description, according to the pressure detector according to the present invention, it is possible to effectively avoid the occurrence of malfunction or functional failure due to pulsation without impairing the original pressure detection performance of the pressure detector, and The increase in the number of parts, the number of assembling steps, and the number of piping steps caused for preventing pulsation can be minimized.
[Brief description of the drawings]
FIG. 1 is a sectional view showing one embodiment in which a pressure detector according to the present invention is applied as a pressure switch.
FIG. 2 is an air conditioning refrigerant circuit diagram showing a usage example in which the pressure switch according to the present invention is used as a high pressure switch of an air conditioner.
FIG. 3 is a cross-sectional view showing one embodiment in which the pressure detector according to the present invention is applied as a pressure sensor.
[Explanation of symbols]
Reference Signs List 10 pressure switch 13 main body case 17 diaphragm 19 pressure receiving chamber 20 operating pin 24 fixed contact 26 movable contact 28 joint pipe 29 throttle member 31 orifice passage 32 diffusion passage 100 pressure sensor 109 pressure sensitive element 113 diaphragm 114 pressure receiving chamber 115 oil filling chamber 119 joint pipe 120 throttle member 122 orifice passage 123 diffusion passage

Claims

受圧室を有し、前記受圧室の圧力を検知する圧力検知器であって、
前記受圧室を画定する検知器本体ケースに継手管の一端が気密接続され、当該継手管は、前記検知器本体ケースに対する接続端にて前記受圧室に直接連通し、検知対象の圧力を前記受圧室に導く導圧通路をなしており、
前記継手管の前記検知器本体ケースに対する接続端部の管内に絞り部材が固定装着されていることを特徴とする圧力検知器。A pressure detector having a pressure receiving chamber and detecting the pressure of the pressure receiving chamber,
One end of a joint pipe is airtightly connected to a detector main body case that defines the pressure receiving chamber, and the joint pipe communicates directly with the pressure receiving chamber at a connection end to the detector main body case, and receives the pressure of the detection target by the pressure receiving pressure. It forms a pressure guiding passage leading to the chamber,
A pressure detector, wherein a throttle member is fixedly mounted in a pipe at a connection end of the joint pipe to the detector body case.

前記絞り部材は、小径のオリフィス通路と、前記オリフィス通路より前記受圧室側に位置し前記オリフィス通路より大径の拡散通路とを有していることを特徴とする請求項１記載の圧力検知器。2. The pressure detector according to claim 1, wherein the throttle member has a small-diameter orifice passage, and a diffusion passage located closer to the pressure receiving chamber than the orifice passage and larger in diameter than the orifice passage. .

前記受圧室はダイヤフラムにより区画されていることを特徴とする請求項１または２記載の圧力検知器。The pressure detector according to claim 1, wherein the pressure receiving chamber is partitioned by a diaphragm.

前記受圧室の圧力に応じて開閉する電気接点を含む圧力スイッチである請求項１〜３の何れか１項記載の圧力検知器。The pressure sensor according to any one of claims 1 to 3, wherein the pressure sensor is a pressure switch including an electric contact that opens and closes according to the pressure of the pressure receiving chamber.

前記受圧室の圧力を電気量に変換する圧力・電気変換素子を含む圧力センサである１〜３の何れか１項記載の圧力検知器。The pressure detector according to any one of claims 1 to 3, which is a pressure sensor including a pressure-electric conversion element that converts a pressure in the pressure receiving chamber into an electric quantity.