JP2016176868A - Leak inspection device and leak inspection method - Google Patents
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Abstract
Description
本発明は、検査対象の容器からの漏れを検査するリーク検査装置、リーク検査方法に関する。 The present invention relates to a leak inspection apparatus and a leak inspection method for inspecting leakage from a container to be inspected.
容器の密閉性を検査する場合、容器に空気等の気体を加圧導入した後、これを密閉し、その後の圧力変化を観察する方法が一般的である。 When inspecting the sealing property of a container, a method is generally employed in which a gas such as air is introduced into the container under pressure, and then the container is sealed and a subsequent pressure change is observed.
また、わずかな漏れを検出するには、高い精度で圧力変化を測定する必要があるので、圧力センサとして差圧式のものが使用される。具体的には、差圧計の一方の第１空間に検査対象の容器(ワーク)を接続し、他方の第２空間に漏れのない容器（マスタ）を接続する。そして、第１空間と第２空間の双方に同時に気体を導入して目標圧力に加圧し、その後、第１空間と第２空間をそれぞれ密閉し、両者の圧力の低下状況の違いを差圧計で検出する（特許文献１参照）。 Moreover, in order to detect a slight leak, it is necessary to measure a pressure change with high accuracy, and therefore a differential pressure type pressure sensor is used. Specifically, a container (workpiece) to be inspected is connected to one first space of the differential pressure gauge, and a container (master) having no leakage is connected to the other second space. And gas is simultaneously introduced into both the first space and the second space to pressurize to the target pressure, and then the first space and the second space are sealed, respectively, and the difference in pressure drop between the two is measured with a differential pressure gauge. It detects (refer patent document 1).
図１２は、上記の検査を行うための検査装置の構成および動作の概要を示す図である。加圧工程では、弁１０１〜弁１０３を開、排気弁１０４を閉、とした状態でエア源１００から加圧気体をワークとマスタを含む検査系に導入する。加圧の際に、検査系内に存在していた気体が略断熱圧縮されて発熱する。加圧工程の後、弁１０２、弁１０３を閉じて、ワークおよびマスタ内の圧力が安定（加圧工程で生じた熱の放熱が完了）するのを待つ（平衡工程）。検査工程では、ワーク内とマスタ内の圧力差を差圧計１０５で測定する。このとき、ワークに漏れがあると基準値を超える差圧が生じる。検査後、弁１０１を閉じ、弁１０２、１０３を開いた後、排気弁１０４を開いて検査系内の気体を外部に排気する排気工程を行う。次のワークを検査するときは、ワークを付け替えて加圧工程から再度行う。 FIG. 12 is a diagram showing an outline of the configuration and operation of an inspection apparatus for performing the above inspection. In the pressurizing step, pressurized gas is introduced from the air source 100 into the inspection system including the workpiece and the master with the valves 101 to 103 opened and the exhaust valve 104 closed. During the pressurization, the gas present in the inspection system is substantially adiabatically compressed and generates heat. After the pressurization step, the valve 102 and the valve 103 are closed, and the system waits for the pressure in the workpiece and the master to be stable (the heat radiation generated in the pressurization step is completed) (equilibrium step). In the inspection process, the pressure difference between the workpiece and the master is measured by the differential pressure gauge 105. At this time, if there is a leak in the work, a differential pressure exceeding the reference value occurs. After the inspection, the valve 101 is closed, the valves 102 and 103 are opened, and then the exhaust valve 104 is opened to exhaust the gas in the inspection system to the outside. When inspecting the next workpiece, the workpiece is replaced and the process is repeated from the pressurizing step.
上記の検査では、加圧工程、排気工程において差圧計１０５の両側が連通しているので、高い圧力で加圧しても、差圧計１０５の両側に加わる圧力差は、検査工程で生じるわずかなものである。そのため、耐圧が低いが、わずかな圧力差を検出できる高精度の差圧計を用いることができる。 In the above inspection, since both sides of the differential pressure gauge 105 communicate with each other in the pressurization process and the exhaust process, the pressure difference applied to both sides of the differential pressure gauge 105 is a slight one generated in the inspection process even if the pressure is increased with high pressure. It is. Therefore, it is possible to use a high-precision differential pressure gauge that has a low pressure resistance but can detect a slight pressure difference.
上記のようなリーク検査において、ワークやマスタに気体を加圧導入すると、該気体が断熱圧縮されて昇温し、検査後に減圧すると断熱膨張して温度低下する。このような工程において、図１３に示すように差圧計内も含む、各分岐の端部が発熱・蓄熱する。すなわち、図１２、図１３に示すように、大気開放部分(例えば交換されたワーク内大気開放部分、測定終了時に大気開放される部分等）に対して圧縮エア源１００から圧縮空気が送られると、大気圧時に室温であった大気開放部分は、圧縮エア源１００からの圧縮空気に押されて移動し、下流の片隅に追いやられて圧縮され、発熱する。図１３の例では、グレー色で示す箇所、具体的には、ワークやマスタの内部のほか、差圧計１０５の内部や閉じた排気弁１０４で行き止まりになっている箇所において発熱・蓄熱が生じる。８００ＫＰａや１０００ＫＰａのような高い圧力に加圧してリーク検査を行う場合には、上記の問題はより顕著になる。 In the leak inspection as described above, when a gas is introduced into the workpiece or the master under pressure, the gas is adiabatically compressed and the temperature rises. In such a process, as shown in FIG. 13, the end of each branch including the inside of the differential pressure gauge generates heat and stores heat. That is, as shown in FIGS. 12 and 13, when compressed air is sent from the compressed air source 100 to the atmosphere release portion (for example, the replaced workpiece atmosphere release portion, the portion released to the atmosphere at the end of measurement, etc.). The part that is open to the atmosphere at room temperature at atmospheric pressure is pushed and moved by the compressed air from the compressed air source 100, and is compressed by being driven to a downstream corner. In the example of FIG. 13, heat generation / heat storage occurs in a gray portion, specifically, in the work or master, as well as in the differential pressure gauge 105 or a place where the closed exhaust valve 104 is dead. The above problem becomes more prominent when the leak inspection is performed by applying a high pressure such as 800 KPa or 1000 KPa.
また、測定系の管路からの放熱もある。そのため、複数のワークを検査するときは、以前の検査による温度変化の影響が累積しないように、１つのワークを検査する毎に測定系の管路内の気体を入れ替える掃気が行われる。また、加圧導入する気体として、雰囲気(周囲の空気)と異なる気体を使用する場合は、初回の検査の準備においても、測定系の管路内全体がその気体に入れ替わるように掃気することが望まれる。 There is also heat dissipation from the measurement system pipeline. Therefore, when inspecting a plurality of workpieces, scavenging is performed to replace the gas in the pipe of the measurement system every time one workpiece is inspected so that the influence of temperature changes due to previous inspections does not accumulate. In addition, if a gas different from the atmosphere (ambient air) is used as the gas to be introduced under pressure, even in the preparation for the first inspection, scavenging may be performed so that the entire pipe in the measurement system is replaced with the gas. desired.
掃気は、通常、加圧気体が導入される主管路に設けた排気弁を開いて行われる。しかし、図１３に示すようにマスタ、ワーク、及び主管路から分岐して圧力計に向かう管路は、行き止まりになっているので、断熱圧縮されて昇温した気体の溜まり場になっており、ここを適切に掃気することは難しい。また、加圧導入する気体として、雰囲気(周囲の空気)と異なる気体を使用する場合、エア源１００から送られてくる気体と溜まり場にある気体とが異なる等、比較する気体同士が異なる物理常数（温湿度）を持つこととなるので、正確な検査ができない。 The scavenging is usually performed by opening an exhaust valve provided in the main pipeline into which the pressurized gas is introduced. However, as shown in FIG. 13, the pipe that branches from the master, the work, and the main pipe and goes to the pressure gauge is a dead end. It is difficult to scavenge properly. Further, when a gas different from the atmosphere (ambient air) is used as the gas to be introduced under pressure, the physical constants in which the gases to be compared are different, for example, the gas sent from the air source 100 is different from the gas in the reservoir. (Temperature and humidity), so accurate inspection is not possible.
なお、ワークが１つの入口のみを有する非貫通型であっても、マスタについては、貫通型を使用すれば、溜まり場を作らずに掃気が可能になる。しかし、ワークについては非貫通型を貫通型に変更することは当然にできないので、ワーク内の掃気は困難であった。 Even if the workpiece is a non-penetrating type having only one inlet, if the penetrating type is used for the master, scavenging can be performed without creating a reservoir. However, since the work cannot be changed from the non-penetrating type to the penetrating type, scavenging inside the work is difficult.
また、１つのワークを検査する毎に測定系の管路内を掃気し、その後、気体を加圧導入し、温度が安定するのを待ってから検査を行うと、複数のワークを検査するために長い時間を要してしまう。 In addition, every time one workpiece is inspected, the inside of the measurement system pipe is scavenged, and then, after injecting gas under pressure and waiting for the temperature to stabilize, inspecting a plurality of workpieces Takes a long time.
さらに、大きいワーク（表面積に比して体積の大きいワーク）を高い圧力で加圧して検査する場合、放熱が安定した平衡状態（漏れ検査ができる状態）に至るまでの時間（静定期間とする）が、容積の割に長時間となり、検査が、予想以上にはかどらないという問題が生じた。すなわち、加圧終了後、ワークの温度は放熱で急降下するが、ある程度下がったところで、急に温度降下が緩慢になってしまう。 Furthermore, when inspecting a large workpiece (a workpiece having a large volume compared to the surface area) with high pressure, the time required to reach a stable state of heat dissipation (a state in which leakage inspection can be performed) (a settling period) However, it took a long time for the volume, and there was a problem that the inspection did not return more than expected. That is, after the pressurization is completed, the temperature of the workpiece suddenly drops due to heat dissipation, but when the temperature drops to some extent, the temperature drop suddenly becomes slow.
また、静定期間終了直後のまさに漏れ検査を行おうとする時に圧力が乱高下してしまい、正確に検査することが難しいという問題も生じた。 In addition, the pressure fluctuated when trying to perform a leak inspection immediately after the end of the settling period, and it was difficult to perform an accurate inspection.
本発明は、上記の問題を解決しようとするものであり、検査時に加圧導入する気体と同じ気体で検査対象の容器内を掃気することのできるリーク検査方法、リーク検査装置を提供することを目的としている。 The present invention is intended to solve the above-described problem, and provides a leak inspection method and a leak inspection apparatus capable of scavenging the inside of a container to be inspected with the same gas as that introduced under pressure at the time of inspection. It is aimed.
かかる目的を達成するための本発明の要旨とするところは、次の各項の発明に存する。 The gist of the present invention for achieving the object lies in the inventions of the following items.
［１］検査対象である非貫通型の容器の入口から前記容器内に、前記容器内の奥側で終端する第１管と、前記容器内の入口側で終端する第２管を挿入した状態で前記入口を封鎖し、前記第１管と前記第２管のうちの一方の管から所定の気体を前記容器内に送り込むことで、他方の管から前記容器内の気体を排気して前記容器内を前記所定の気体で満たした後、前記他方の管を閉鎖する容器内掃気ステップと、
前記一方の管から前記所定の気体を前記容器内にさらに導入して前記容器内を加圧した後、前記一方の管を閉鎖して前記容器を含む密閉空間を形成する加圧ステップと、
前記密閉空間の圧力を圧力計で測定して前記容器に漏れがあるか否かを検査する測定ステップと、
を有する
ことを特徴とするリーク検査方法。
[1] A state in which a first tube that terminates in the inner side of the container and a second tube that terminates on the inlet side in the container are inserted into the container from the inlet of the non-penetrating container to be inspected The inlet is sealed, and a predetermined gas is sent into the container from one of the first pipe and the second pipe, so that the gas in the container is exhausted from the other pipe. A container scavenging step for closing the other pipe after filling the inside with the predetermined gas;
A pressure step of further introducing the predetermined gas from the one tube into the container to pressurize the container, and then closing the one tube to form a sealed space including the container;
A measurement step of measuring the pressure of the sealed space with a pressure gauge and checking whether or not there is a leak in the container;
A leak inspection method characterized by comprising:
上記発明および下記［８］に記載の発明では、容器の入口から該容器内に、該容器内の奥側で終端する第１管と、容器内の入口側で終端する第２管を挿入した状態で該容器の入口を封鎖し、第１管と第２管のうちの一方の管から所定の気体（検査用気体）を導入することで、容器の奥から入口、あるいはその逆に向かう気体の流れを容器内全体に発生させ、該容器内にあった気体を他方の管から排出して容器内全体を掃気する。その後、他方の管を閉鎖し、検査用気体を容器に加圧導入した後、一方の管も閉じて該容器を含む密閉空間を形成する。そして、この密閉空間の圧力変化を圧力計で測定して、容器に漏れがあるか否かを検査する。非貫通型の容器であっても、容器内全体を検査用の気体で掃気することができるので、元々容器内にあった気体が検査用気体の加圧導入によって断熱圧縮されて発熱する等の問題が解決される。 In the above invention and the invention described in [8] below, a first pipe that terminates at the back side in the container and a second pipe that terminates at the inlet side in the container are inserted into the container from the inlet of the container. In this state, the inlet of the container is sealed, and a predetermined gas (inspection gas) is introduced from one of the first pipe and the second pipe, so that the gas goes from the back of the container to the inlet or vice versa. Is generated throughout the container, and the gas in the container is discharged from the other tube to scavenge the entire container. Thereafter, the other tube is closed, and after the test gas is pressurized and introduced into the container, the other tube is also closed to form a sealed space including the container. And the pressure change of this sealed space is measured with a pressure gauge, and it is inspected whether there is a leak in the container. Even in a non-penetrating type container, the entire inside of the container can be scavenged with a gas for inspection, so that the gas originally in the container is adiabatically compressed by the introduction of pressure of the inspection gas and generates heat. The problem is solved.
［２］前記第１管を前記一方の管、前記第２管を前記他方の管とする
ことを特徴とする［１］に記載のリーク検査方法。
[2] The leak inspection method according to [1], wherein the first pipe is the one pipe and the second pipe is the other pipe.
上記発明では、第１管にて容器の奥側に導入した検査用気体が第２管のある容器の入口側に向かって流れることで、容器の内部全体が掃気される。 In the above-described invention, the entire inside of the container is scavenged by the inspection gas introduced to the back side of the container in the first pipe flowing toward the inlet side of the container having the second pipe.
［３］前記圧力計の検出口に連通した検査系空間に、気体供給源から前記所定の気体と同じ気体を導入して前記検査系空間を加圧した後、該検査系空間を密閉する検査系加圧ステップと、
前記密閉した前記検査系空間に前記密閉空間を連通させる接続ステップとをさらに備え、
前記接続ステップによって前記密閉空間と前記検査系空間が連通した状態で前記測定ステップを行う
ことを特徴とする［１］または［２］に記載のリーク検査方法。
[3] Inspection for sealing the inspection system space after introducing the same gas as the predetermined gas from a gas supply source into the inspection system space communicating with the detection port of the pressure gauge and pressurizing the inspection system space A system pressurization step;
A connection step of communicating the sealed space with the sealed inspection system space,
The leak inspection method according to [1] or [2], wherein the measurement step is performed in a state where the sealed space and the inspection system space communicate with each other through the connection step.
上記発明および下記［９］に記載の発明では、所定の気体で容器を掃気し該気体をさらに加圧導入して密閉空間を形成し、これとは別に圧力計を含む加圧済みの検査系空間を形成し、該検査系空間に密閉空間を連通させて、容器の漏れ検査が行われる。 In the above invention and the invention described in [9] below, the container is scavenged with a predetermined gas, the gas is further pressurized and introduced to form a sealed space, and a pressurized inspection system including a pressure gauge separately from this The container is inspected for leaks by forming a space and communicating the sealed space with the inspection system space.
［４］前記検査系空間を前記気体供給源から供給される気体で掃気する検査系掃気ステップをさらに有し、
前記検査系掃気ステップにて前記検査系空間を掃気してから前記検査系加圧ステップを行う
ことを特徴とする［３］に記載のリーク検査方法。
[4] An inspection system scavenging step of scavenging the inspection system space with a gas supplied from the gas supply source,
The leak inspection method according to [3], wherein the inspection system pressurization step is performed after scavenging the inspection system space in the inspection system scavenging step.
上記発明および下記［１０］に記載の発明では、検査系空間は所定の気体で掃気された後、該所定の気体で加圧される。すなわち、検査系空間、密閉空間ともに、検査用気体で掃気された後に、検査用気体が加圧導入されているので、これらを連通させた空間も検査用気体で満された空間になる。 In the above invention and the invention described in [10] below, the inspection system space is scavenged with a predetermined gas and then pressurized with the predetermined gas. That is, since both the inspection system space and the sealed space are scavenged with the inspection gas and then the inspection gas is introduced under pressure, the space in which these gases communicate with each other also becomes a space filled with the inspection gas.
［５］前記測定ステップを行った後、前記検査系空間を密閉して前記密閉空間を前記検査系空間から切り離し、次の検査対象に係る前記接続ステップを行うまで、前記検査系空間を加圧状態に維持する
ことを特徴とする［３］または［４］に記載のリーク検査方法。
[5] After performing the measurement step, the inspection system space is sealed, the sealed space is separated from the inspection system space, and the inspection system space is pressurized until the connection step relating to the next inspection object is performed. The leak inspection method according to [3] or [4], wherein the leak inspection method is maintained in a state.
上記発明では、検査系空間を加圧状態で密閉したまま、検査対象の容器を交換するので、検査系空間に大気圧から気体を加圧導入する工程が１回で済む。言い換えると、ワークＷを交換する毎に、検査系空間を減圧し、再度加圧するといった工程が不要になるので、減圧時の断熱膨張による冷却、再加圧時の断熱圧縮による発熱などの温度変化の影響を受けずに済むと共に、温度が安定するまで待つ待ち時間も不要になり、効率的で安定した検査が可能になる。 In the above invention, since the container to be inspected is replaced while the inspection system space is sealed in a pressurized state, the process of introducing gas under pressure from the atmospheric pressure into the inspection system space is only required once. In other words, each time the workpiece W is replaced, the process of depressurizing and repressurizing the inspection system space becomes unnecessary, so temperature changes such as cooling due to adiabatic expansion during decompression and heat generation due to adiabatic compression during repressurization. In addition, there is no need to wait for the temperature to stabilize, and an efficient and stable inspection becomes possible.
［６］前記測定ステップを行っている間に、他の容器に対して前記加圧ステップまでを行う
ことを特徴とする［３］乃至［５］のいずれか１つに記載のリーク検査方法。
[6] The leak inspection method according to any one of [3] to [5], wherein the process up to the pressurizing step is performed on another container while the measuring step is performed.
上記発明では、漏れを測定している間に、他の容器の掃気、加圧が行われる。これらの工程を同時並行に行うことで検査効率が向上する。 In the above-described invention, scavenging and pressurization of other containers are performed while leakage is being measured. Inspection efficiency is improved by performing these processes in parallel.
［７］前記加圧ステップを終えた容器は、所定の時間以上が経過してから、前記接続ステップに移行し、
一の容器が前記経過を待っている間に、前記経過を終えた他の一の容器に対して前記測定ステップを行う
ことを特徴とする［３］乃至［６］のいずれか１つに記載のリーク検査方法。
[7] The container that has finished the pressurizing step moves to the connecting step after a predetermined time or more has elapsed,
The measuring step is performed on another container that has finished the progress while one container is waiting for the progress. Any one of [3] to [6] Leak inspection method.
上記発明では、掃気、加圧の完了した容器は、内部の気体が容器の漏れを測定可能な安定状態になるまで待つことが望ましく、この待ち時間の間に、他の容器を掃気・加圧する工程、および、既に待ち時間の経過を終えた容器について漏れの測定を行う。これにより、複数の容器を効率的に次々と検査することができる。 In the above-described invention, it is desirable that the container that has been subjected to scavenging and pressurization waits until the internal gas reaches a stable state in which leakage of the container can be measured. During this waiting time, the other container is scavenged and pressurized. Leakage is measured for the process and the containers that have already passed the waiting time. Thereby, a some container can be test | inspected one after another efficiently.
［８］検査対象である非貫通型の容器の入口を封鎖する蓋体と、前記蓋体を貫通して前記容器内の奥で終端する第１管と、前記蓋体を貫通して前記容器内の入口側で終端する第２管を備えた蓋部と、
前記第１管と前記第２管のうちの一方の管を通じて前記容器に所定の気体を送り込む気体供給源と、
前記気体供給源と前記容器との間で前記一方の管を開閉する第１開閉弁と、
前記第１管と前記第２管のうちの他方の管を開閉する第２開閉弁と、
圧力計と、
を備え、
前記蓋部が入口に取り付けられた前記容器の中に、前記第１開閉弁および前記第２開閉弁を開いた状態で前記気体供給源から前記所定の気体を送り込むことで、前記他方の管から前記容器内の気体を排気して前記容器内を前記所定の気体で満たした後、前記第２開閉弁を閉鎖する容器内掃気ステップ、
前記気体供給源から前記一方の管を通じて前記所定の気体を前記容器内にさらに導入して前記容器内を加圧した後、前記第１開閉弁を閉鎖して前記容器を含む密閉空間を形成する加圧ステップ、
前記密閉空間の圧力を前記圧力計で測定して前記容器に漏れがあるか否かを検査する測定ステップ、
が行われる
ことを特徴とするリーク検査装置。
[8] A lid that seals the entrance of the non-penetrating container to be inspected, a first pipe that penetrates the lid and terminates in the interior of the container, and the container that penetrates the lid A lid with a second tube terminating at the inlet side of the inside;
A gas supply source for feeding a predetermined gas into the container through one of the first pipe and the second pipe;
A first on-off valve for opening and closing the one pipe between the gas supply source and the container;
A second on-off valve for opening and closing the other of the first pipe and the second pipe;
A pressure gauge,
With
By feeding the predetermined gas from the gas supply source into the container with the lid attached to the inlet in a state where the first on-off valve and the second on-off valve are opened, from the other pipe A scavenging step in the container for closing the second on-off valve after exhausting the gas in the container and filling the container with the predetermined gas;
After the predetermined gas is further introduced into the container through the one pipe from the gas supply source to pressurize the container, the first on-off valve is closed to form a sealed space including the container. Pressure step,
A measurement step of measuring whether or not the container has a leak by measuring the pressure of the sealed space with the pressure gauge;
Leak inspection device characterized in that is performed.
［９］前記気体供給源から延設された管を分岐管と主管の二手に分岐し、
前記分岐管は第１接続口に至り、
前記主管は第２接続口に至り、
前記分岐管を開閉する分岐管開閉弁と、
前記主管を開閉する主管開閉弁と、
前記第２接続口を開閉する第２接続口開閉弁と、
を備え、
前記圧力計の検出口は、前記主管開閉弁と前記第２接続口開閉弁との間の前記主管に連通しており、
前記分岐管開閉弁および前記第２接続口開閉弁を閉じた状態で前記主管開閉弁を開いて前記気体供給源から前記所定の気体を導入した後、前記主管開閉弁を閉じて前記主管開閉弁と前記第２接続口開閉弁の間に密閉された検査系空間を形成する検査系加圧ステップ、
前記第１接続口に前記一方の管を接続した後、前記主管開閉弁を閉じた状態で前記分岐管開閉弁を開いて、前記容器内掃気ステップおよび前記加圧ステップ、
が行われると共に、
前記加圧ステップの後で、前記第１開閉弁を閉じて、前記一方の管を前記第１接続口から前記第２接続口に付け替え、前記第１開閉弁および前記第２接続口開閉弁を開いて前記検査系空間と前記密閉空間を連通させた状態で前記測定ステップが行われる
ことを特徴とする［８］に記載のリーク検査装置。
[9] The pipe extending from the gas supply source is branched into two branches, a branch pipe and a main pipe,
The branch pipe reaches the first connection port,
The main pipe reaches the second connection port,
A branch pipe opening and closing valve for opening and closing the branch pipe;
A main pipe opening and closing valve for opening and closing the main pipe;
A second connection port opening / closing valve for opening and closing the second connection port;
With
The detection port of the pressure gauge communicates with the main pipe between the main pipe on-off valve and the second connection port on-off valve,
The main pipe on / off valve is opened with the branch pipe on / off valve closed and the predetermined gas is introduced from the gas supply source, and then the main pipe on / off valve is closed to close the main pipe on / off valve. And an inspection system pressurizing step for forming a sealed inspection system space between the second connection port opening and closing valve,
After the one pipe is connected to the first connection port, the branch pipe on / off valve is opened with the main pipe on / off valve closed, and the scavenging step and the pressurizing step in the container,
Is performed,
After the pressurizing step, the first on-off valve is closed, the one pipe is changed from the first connection port to the second connection port, and the first on-off valve and the second connection port on-off valve are turned on. The leak inspection apparatus according to [8], wherein the measurement step is performed in a state where the inspection system space and the sealed space are in communication with each other.
［１０］前記検査系空間を前記気体供給源から供給される気体で掃気してから前記検査系加圧ステップが行われる
ことを特徴とする［９］に記載のリーク検査装置。
[10] The leak inspection apparatus according to [9], wherein the inspection system pressurization step is performed after scavenging the inspection system space with a gas supplied from the gas supply source.
本発明に係るリーク検査方法、リーク検査装置によれば、非貫通型の容器であっても、容器内全体を検査用の気体で掃気することができるので、元々容器内にあった気体が検査用の気体の加圧導入によって断熱圧縮されて発熱する等の問題が解決される。 According to the leak inspection method and the leak inspection apparatus according to the present invention, even in a non-penetrating type container, the entire inside of the container can be scavenged with the inspection gas, so that the gas originally in the container is inspected. Problems such as heat generation due to adiabatic compression by introducing pressurized gas for use are solved.
以下、図面に基づき本発明の実施の形態を説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
図１は、本発明の実施の形態に係るリーク検査装置５の概略構成を示している。リーク検査装置５は、検査対象となる容器（ワークＷ）の漏れを検査する装置である。 FIG. 1 shows a schematic configuration of a leak inspection apparatus 5 according to an embodiment of the present invention. The leak inspection apparatus 5 is an apparatus that inspects for leakage of a container (work W) to be inspected.
リーク検査装置５は、圧縮された気体の供給源である気体導入部１０と、検査装置本体６とを有する。検査装置本体６は、気体導入部１０の気体吐出口１０ａに一端が接続され、他端が排気ポート３０ａにされた主管路３０を備えている。主管路３０には気体導入部１０のある上流側から順に電空レギュレータ４０、第１開閉弁４１、圧力センサ４２、第１排気弁４４、第２排気弁４５が設けてある。電空レギュレータ４０は、下流側が設定圧力を超えないように調整する機能を果たす。 The leak inspection apparatus 5 includes a gas introduction unit 10 which is a compressed gas supply source, and an inspection apparatus body 6. The inspection apparatus body 6 includes a main pipe line 30 having one end connected to the gas discharge port 10a of the gas introduction unit 10 and the other end serving as an exhaust port 30a. The main line 30 is provided with an electropneumatic regulator 40, a first on-off valve 41, a pressure sensor 42, a first exhaust valve 44, and a second exhaust valve 45 in order from the upstream side where the gas introduction unit 10 is located. The electropneumatic regulator 40 functions to adjust the downstream side so as not to exceed the set pressure.
電空レギュレータ４０と第１開閉弁４１の間の第１分岐箇所Ｂ１において主管路３０から第１分岐管３１が分岐し、第１分岐管３１の終端は、検査前のワークＷやマスタＭを接続するための準備用接続口３１ａとなっている。第１分岐管３１の途中には、第１分岐管３１を開閉する第１分岐管開閉弁４６、手動弁４７が設けてある。 The first branch pipe 31 branches from the main pipeline 30 at the first branch point B1 between the electropneumatic regulator 40 and the first on-off valve 41, and the end of the first branch pipe 31 is connected to the workpiece W and the master M before inspection. It is a connection port 31a for preparation for connection. A first branch pipe opening / closing valve 46 and a manual valve 47 for opening and closing the first branch pipe 31 are provided in the middle of the first branch pipe 31.
手動弁４７は接続口１〜３を備えている。接続口１は第１分岐管開閉弁４６に通じ、接続口２は準備用接続口３１ａに通じる。接続口３は大気に開放されている。手動弁４７は、開状態と閉状態とに手動で切り替えられる。手動弁４７は、開状態では接続口１、２を連通させ、接続口３を封鎖する。閉状態では接続口１を封鎖し、接続口２、３を連通させる。 The manual valve 47 includes connection ports 1 to 3. The connection port 1 communicates with the first branch pipe opening / closing valve 46, and the connection port 2 communicates with the preparation connection port 31a. The connection port 3 is open to the atmosphere. The manual valve 47 is manually switched between an open state and a closed state. In the open state, the manual valve 47 allows the connection ports 1 and 2 to communicate with each other and blocks the connection port 3. In the closed state, the connection port 1 is blocked and the connection ports 2 and 3 are communicated.
第１開閉弁４１と第１排気弁４４の間の第２分岐箇所Ｂ２において主管路３０から第２分岐管３２が分岐し、第２分岐管３２の終端は、検査対象のワークＷやマスタＭを接続するための検査用接続口３２ａとなっている。第２分岐管３２の途中には手動弁４８が設けてある。圧力センサ４２は、第２分岐箇所Ｂ２に設けてある。 The second branch pipe 32 branches from the main pipeline 30 at the second branch point B2 between the first on-off valve 41 and the first exhaust valve 44, and the end of the second branch pipe 32 is the workpiece W or master M to be inspected. This is an inspection connection port 32a for connecting the two. A manual valve 48 is provided in the middle of the second branch pipe 32. The pressure sensor 42 is provided at the second branch point B2.
手動弁４８は、手動弁４７と同様に接続口１〜３を備えている。手動弁４８の接続口１は第２分岐箇所Ｂ２に通じ、接続口２は検査用接続口３２ａに通じる。接続口３は大気に開放されている。手動弁４８は、開状態では接続口１、２を連通させ、接続口３を封鎖する。閉状態では接続口１を封鎖し、接続口２、３を連通させる。 As with the manual valve 47, the manual valve 48 includes connection ports 1 to 3. The connection port 1 of the manual valve 48 communicates with the second branch point B2, and the connection port 2 communicates with the inspection connection port 32a. The connection port 3 is open to the atmosphere. In the open state, the manual valve 48 allows the connection ports 1 and 2 to communicate with each other and seals the connection port 3. In the closed state, the connection port 1 is blocked and the connection ports 2 and 3 are communicated.
第１開閉弁４１と圧力センサ４２の間の第３分岐箇所Ｂ３において主管路３０から第３分岐管３３が分岐し、第３分岐管３３の終端は、差圧センサ５０の第１検出口５０ａに接続されている。第３分岐管３３には、第１検出口５０ａに向けて、第２開閉弁５２、第３開閉弁５３、貫通型の小マスタＭａがこの順に介挿されている。 The third branch pipe 33 branches from the main pipeline 30 at a third branch point B3 between the first on-off valve 41 and the pressure sensor 42, and the end of the third branch pipe 33 is the first detection port 50a of the differential pressure sensor 50. It is connected to the. In the third branch pipe 33, a second on-off valve 52, a third on-off valve 53, and a penetrating small master Ma are inserted in this order toward the first detection port 50a.
圧力センサ４２と第１排気弁４４との間の第４分岐箇所Ｂ４において主管路３０から第４分岐管３４が分岐し、第４分岐管３４の終端は、差圧センサ５０の第２検出口５０ｂに接続されている。第４分岐管３４には、第２検出口５０ｂに向けて、第４開閉弁５４、第５開閉弁５５、小マスタＭａと同一の小マスタＭｂがこの順に介挿されている。小マスタＭａ、Ｍｂの容量はワークＷに比べて十分小さい。 The fourth branch pipe 34 branches from the main pipeline 30 at the fourth branch point B4 between the pressure sensor 42 and the first exhaust valve 44, and the end of the fourth branch pipe 34 is the second detection port of the differential pressure sensor 50. 50b. In the fourth branch pipe 34, a fourth master valve Mb, which is the same as the small master Ma, is inserted in this order toward the second detection port 50b. The capacities of the small masters Ma and Mb are sufficiently smaller than the work W.
第３分岐管３３は差圧センサ５０の第１検出口５０ａの近傍に第１掃気口３３ａを備えている。また、第４分岐管３４は差圧センサ５０の第２検出口５０ｂの近傍に第２掃気口３４ａを備えている。第１掃気口３３ａと第２掃気口３４ａは、それぞれ差圧センサ５０で行き止まりになる箇所に滞留する気体を外部へ逃がすために設けてある。第１掃気口３３ａには第１掃気管３６が接続され、第２掃気口３４ａには第２掃気管３７が接続されている。第１掃気管３６と第２掃気管３７の終端同志は合流し、この合流箇所に第３掃気管３８が接続され、第３掃気管３８の終端は掃気ポート３８ａになっている。 The third branch pipe 33 includes a first scavenging port 33 a in the vicinity of the first detection port 50 a of the differential pressure sensor 50. Further, the fourth branch pipe 34 includes a second scavenging port 34 a in the vicinity of the second detection port 50 b of the differential pressure sensor 50. The 1st scavenging port 33a and the 2nd scavenging port 34a are provided in order to escape the gas which stays in the location where a dead end is each made by the differential pressure sensor 50 to the exterior. A first scavenging pipe 36 is connected to the first scavenging port 33a, and a second scavenging pipe 37 is connected to the second scavenging port 34a. The ends of the first scavenging pipe 36 and the second scavenging pipe 37 join together, and a third scavenging pipe 38 is connected to this joining location, and the end of the third scavenging pipe 38 is a scavenging port 38a.
第１掃気管３６には、第１サブ掃気弁５６が介挿されている。第２掃気管３７には、第２サブ掃気弁５７が介挿されている。第３掃気管３８には、メイン掃気弁５８が介挿されている。 A first sub scavenging valve 56 is inserted in the first scavenging pipe 36. A second sub scavenging valve 57 is inserted in the second scavenging pipe 37. A main scavenging valve 58 is inserted in the third scavenging pipe 38.
第１開閉弁４１と第１排気弁４４の間に設けられた部分は、差圧センサ５０の第１検出口５０ａ側と第２検出口５０ｂ側とが対称構造にされている。 The portion provided between the first on-off valve 41 and the first exhaust valve 44 has a symmetrical structure on the first detection port 50a side and the second detection port 50b side of the differential pressure sensor 50.
すなわち、第３分岐箇所Ｂ３から差圧センサ５０の第１検出口５０ａに至るまでの第３分岐管３３、これに介挿された第２開閉弁５２、第３開閉弁５３、小マスタＭａと、第４分岐箇所Ｂ４から差圧センサ５０の第２検出口５０ｂに至るまでの第４分岐管３４、これに介挿された第４開閉弁５４、第５開閉弁５５、小マスタＭｂとは、差圧センサ５０を中心に対称構造になっている。また、第１検出口５０ａから第１掃気口３３ａ、第１掃気管３６、第１サブ掃気弁５６を通じてメイン掃気弁５８に至る経路と、第２検出口５０ｂから第２掃気口３４ａ、第２掃気管３７、第２サブ掃気弁５７を通じてメイン掃気弁５８に至る経路も対称構造になっている。 That is, the third branch pipe 33 extending from the third branch point B3 to the first detection port 50a of the differential pressure sensor 50, the second on-off valve 52, the third on-off valve 53, and the small master Ma interposed therebetween. The fourth branch pipe 34 from the fourth branch point B4 to the second detection port 50b of the differential pressure sensor 50, the fourth on-off valve 54, the fifth on-off valve 55, and the small master Mb interposed therebetween The differential pressure sensor 50 is a symmetrical structure. Further, a path from the first detection port 50a to the main scavenging valve 58 through the first scavenging port 33a, the first scavenging tube 36, and the first sub scavenging valve 56, and the second detection port 50b to the second scavenging port 34a, second The path from the scavenging pipe 37 and the second sub scavenging valve 57 to the main scavenging valve 58 is also symmetrical.
さらに第２分岐箇所Ｂ２は第１開閉弁４１と第１排気弁４４の中央に位置している。第３分岐箇所Ｂ３から第１開閉弁４１までの主管路３０の長さと、第４分岐箇所Ｂ４から第１排気弁４４までの主管路３０の長さは同一になっている。よって、差圧センサ５０の第１検出口５０ａから第３分岐箇所Ｂ３、第２分岐箇所Ｂ２を経て検査用接続口３２ａに至る経路と、差圧センサ５０の第２検出口５０ｂから第４分岐箇所Ｂ４、第２分岐箇所Ｂ２を経て検査用接続口３２ａに至る経路は、差圧センサ５０を中心に対称構造になっている。 Further, the second branch point B <b> 2 is located at the center of the first on-off valve 41 and the first exhaust valve 44. The length of the main pipeline 30 from the third branch point B3 to the first on-off valve 41 and the length of the main pipeline 30 from the fourth branch point B4 to the first exhaust valve 44 are the same. Therefore, the path from the first detection port 50a of the differential pressure sensor 50 to the inspection connection port 32a through the third branch point B3 and the second branch point B2, and the fourth branch from the second detection port 50b of the differential pressure sensor 50. The path from the point B4 and the second branch point B2 to the inspection connection port 32a has a symmetrical structure with the differential pressure sensor 50 as the center.
このように、差圧センサ５０を中心に検査系を対称構造にすることで、差圧センサ５０の第１検出口５０ａと第２検出口５０ｂに振動や反射波が同時に到達して互いに打ち消し合うようになり、差圧センサ５０の検出値に含まれる、振動に起因したノイズが軽減される。 Thus, by making the inspection system symmetrical about the differential pressure sensor 50, vibrations and reflected waves simultaneously reach the first detection port 50a and the second detection port 50b of the differential pressure sensor 50 and cancel each other. Thus, noise caused by vibration included in the detection value of the differential pressure sensor 50 is reduced.
さらにリーク検査装置５は、恒温槽６０を備えている。差圧センサ５０、小マスタＭａ、第３開閉弁５３、小マスタＭｂ、第５開閉弁５５、および、第２開閉弁５２より差圧センサ５０の第１検出口５０ａ側の第３分岐管３３、第４開閉弁５４より差圧センサ５０の第２検出口５０ｂ側の第４分岐管３４分は恒温槽６０に収容されている。恒温槽６０は、上記の収容した部分を冷却して一定温度に維持する役割を果たす。 Furthermore, the leak inspection apparatus 5 includes a constant temperature bath 60. The third branch pipe 33 on the first detection port 50a side of the differential pressure sensor 50 from the differential pressure sensor 50, the small master Ma, the third on-off valve 53, the small master Mb, the fifth on-off valve 55, and the second on-off valve 52. The fourth branch pipe 34 on the second detection port 50 b side of the differential pressure sensor 50 from the fourth opening / closing valve 54 is accommodated in the thermostatic bath 60. The constant temperature bath 60 serves to cool the above-mentioned accommodated portion and maintain it at a constant temperature.
ワークＷやマスタＭにはそれぞれ手動４方弁７０が取り付けられ、該手動４方弁７０を介してワークＷやマスタＭは準備用接続口３１ａや検査用接続口３２ａに接続される。 A manual four-way valve 70 is attached to each of the workpiece W and the master M, and the workpiece W and the master M are connected to the preparation connection port 31a and the inspection connection port 32a via the manual four-way valve 70.
第１開閉弁４１、第１排気弁４４，第２排気弁４５、第１分岐管開閉弁４６、第２開閉弁５２、第３開閉弁５３、第４開閉弁５４、第５開閉弁５５、第１サブ掃気弁５６、第２サブ掃気弁５７、メイン掃気弁５８は、コイルの発熱を回避するために電磁弁ではなく、エアオペレート式のバルブ（スプリングリターン単動作動形）を採用している。また、第１排気弁４４、第２排気弁４５、第１サブ掃気弁５６、第２サブ掃気弁５７は、駆動時に閉じて非駆動時に開くノーマルオープン型であり、第１開閉弁４１、第１分岐管開閉弁４６、第２開閉弁５２、第３開閉弁５３、第４開閉弁５４、第５開閉弁５５、メイン掃気弁５８は、駆動時に開き非駆動時に閉じるノーマルクローズ型である。これらのバルブは内部に弁体があると共に配管取付部を持つ。従って通常の管と異なり、内部容積の割には熱容量が大きい。 A first on-off valve 41, a first exhaust valve 44, a second exhaust valve 45, a first branch pipe on-off valve 46, a second on-off valve 52, a third on-off valve 53, a fourth on-off valve 54, a fifth on-off valve 55, The first sub scavenging valve 56, the second sub scavenging valve 57, and the main scavenging valve 58 employ air operated valves (spring return single operation type) instead of electromagnetic valves in order to avoid heat generation of the coil. Yes. The first exhaust valve 44, the second exhaust valve 45, the first sub scavenging valve 56, and the second sub scavenging valve 57 are normally open types that are closed during driving and opened during non-driving. The one branch pipe opening / closing valve 46, the second opening / closing valve 52, the third opening / closing valve 53, the fourth opening / closing valve 54, the fifth opening / closing valve 55, and the main scavenging valve 58 are normally closed types that are opened when driven and closed when not driven. These valves have a valve body inside and a pipe mounting portion. Therefore, unlike ordinary tubes, the heat capacity is large for the internal volume.
圧力センサ４２は単圧式の圧力センサである。定格圧力０〜１０００ＫＰａ、測定精度（誤差）は±０．０２５％／フルスケール程度である。従って、測定レンジ１０００ＫＰａ時には２５０Ｐａ程度の誤差を含む。差圧センサ５０は定格差圧０〜５ＫＰａ（定格圧力−５〜＋５ＫＰａ）と、圧力センサ４２に比してわずかな圧力（圧力差）で壊れる（破壊圧力は定格圧力に略比例）。その代わりに、例えば２．５Ｐａ程度の誤差しかないので、わずかな差圧を判別でき、高精度で検査することができる。 The pressure sensor 42 is a single pressure type pressure sensor. The rated pressure is 0 to 1000 KPa, and the measurement accuracy (error) is about ± 0.025% / full scale. Therefore, an error of about 250 Pa is included when the measurement range is 1000 KPa. The differential pressure sensor 50 breaks with a rated differential pressure of 0 to 5 KPa (rated pressure of −5 to +5 KPa) and a slight pressure (pressure difference) compared to the pressure sensor 42 (breaking pressure is approximately proportional to the rated pressure). Instead, since there is only an error of, for example, about 2.5 Pa, a slight differential pressure can be determined and inspection can be performed with high accuracy.
図２は、恒温槽６０およびその周囲の配管状況を示している。図中、恒温槽６０は破線で示してある。恒温槽６０の中に収められた第３開閉弁５３、差圧センサ５０、第５開閉弁５５、および恒温槽６０の外側近傍に設置された第２開閉弁５２、第４開閉弁５４は略水平に配列されており、第２開閉弁５２から差圧センサ５０に至る部分の第３分岐管３３および第４開閉弁５４から差圧センサ５０に至る部分の第４分岐管３４はそれぞれ水平に配管されている。 FIG. 2 shows the thermostatic bath 60 and the surrounding piping. In the figure, the thermostat 60 is indicated by a broken line. The third on-off valve 53, the differential pressure sensor 50, the fifth on-off valve 55, and the second on-off valve 52 and the fourth on-off valve 54 installed in the vicinity of the outside of the thermostatic bath 60 are substantially omitted. The third branch pipe 33 in the portion from the second on-off valve 52 to the differential pressure sensor 50 and the fourth branch pipe 34 in the portion from the fourth on-off valve 54 to the differential pressure sensor 50 are horizontally arranged, respectively. It is piped.
主管路３０から分岐した第３分岐管３３は、上方から第２開閉弁５２に至るように配管されている。同様に主管路３０から分岐した第４分岐管３４も上方から第４開閉弁５４に至るように配管されている。なお、図２では、第３開閉弁５３と差圧センサ５０との間の第３分岐管３３が小マスタＭａの機能を果たし、第５開閉弁５５と差圧センサ５０との間の第４分岐管３４が小マスタＭｂの機能を果たす。また、第１掃気口３３ａ、第２掃気口３４ａ、およびこれらに通じる第１掃気管３６、第２掃気管３７は図示省略してある。 The third branch pipe 33 branched from the main pipeline 30 is piped so as to reach the second on-off valve 52 from above. Similarly, the fourth branch pipe 34 branched from the main pipeline 30 is also piped so as to reach the fourth on-off valve 54 from above. In FIG. 2, the third branch pipe 33 between the third on-off valve 53 and the differential pressure sensor 50 functions as a small master Ma, and the fourth branch between the fifth on-off valve 55 and the differential pressure sensor 50. The branch pipe 34 functions as the small master Mb. In addition, the first scavenging port 33a, the second scavenging port 34a, and the first scavenging tube 36 and the second scavenging tube 37 communicating therewith are not shown.
上記のように配管をレイアウトすることで、恒温槽６０によって冷却された、第２開閉弁５２から差圧センサ５０の間にある第３分岐管３３内の気体、および第４開閉弁５４から差圧センサ５０の間にある第４分岐管３４内の気体が、第２開閉弁５２や第４開閉弁５４を開いても主管路３０側へ対流して拡散しないようになっている。 By laying out the piping as described above, the gas in the third branch pipe 33 between the second on-off valve 52 and the differential pressure sensor 50 and the difference from the fourth on-off valve 54 cooled by the thermostat 60. Even if the second on-off valve 52 and the fourth on-off valve 54 are opened, the gas in the fourth branch pipe 34 between the pressure sensors 50 is not convected and diffused to the main pipe line 30 side.
さらに、検査装置本体６は、第２分岐箇所Ｂ２、第３分岐箇所Ｂ３、第４分岐箇所Ｂ４に、気体の滞留を防止する滞留防止構造を備えている。 Furthermore, the inspection apparatus main body 6 includes a stay prevention structure for preventing gas from staying at the second branch point B2, the third branch point B3, and the fourth branch point B4.
図３、図４は、滞留防止構造の一例を示している。図３は、Ｙ字型の滞留防止構造であり、図４は、Ｙ字型とノズル型を組み合わせた滞留防止構造である。滞留防止構造は、Ｙ字構造やノズル構造を用いて、慣性力を用いた慣性掃気により、分岐箇所で分岐した管路の奥深くまで掃気する機能を果たす。第２分岐箇所Ｂ２、第３分岐箇所Ｂ３、第４分岐箇所Ｂ４には、図３に示すＹ字型の滞留防止構造を使用する。 3 and 4 show an example of the stay prevention structure. FIG. 3 shows a Y-shaped retention prevention structure, and FIG. 4 shows a retention prevention structure combining a Y-shape and a nozzle type. The stay prevention structure uses a Y-shaped structure or a nozzle structure, and performs a function of scavenging deeply into the pipeline branched at the branch point by inertia scavenging using inertia force. The Y-shaped stay prevention structure shown in FIG. 3 is used for the second branch point B2, the third branch point B3, and the fourth branch point B4.
たとえば、第３分岐箇所Ｂ３の場合、第１開閉弁４１側（Ｙ字型滞留防止構造の入口側）から滞留防止構造に到来した気体は、慣性を有するので、Ｙ字構造の部分で急に向きを変えることができず、そのまま、第３分岐管３３を通じて第２開閉弁５２（Ｙ字型滞留防止構造の至行き止まり箇所側）に向かう。第２開閉弁５２が閉じている場合は、そこで行き止まりになるので、その行き止まりの部分に滞留している気体を巻き込んで向きを変え、圧力センサ４２のあるＹ字構造の出口側に向かう。このようにして、分岐管の奥深くまで掃気される。なお、第３分岐箇所Ｂ３から第２開閉弁５２までの第３分岐管３３、第４分岐箇所Ｂ４から第４開閉弁５４までの第４分岐管３４の長さは、上記の気流によって内部の気体が十分掃気されるように短くされている。 For example, in the case of the third branch point B3, the gas that has arrived at the retention prevention structure from the first on-off valve 41 side (the inlet side of the Y-shaped retention prevention structure) has inertia, and therefore suddenly stops at the Y-shaped structure. The direction cannot be changed, and the second on-off valve 52 (the Y-shaped stay prevention structure side of the dead end) is directly passed through the third branch pipe 33. When the second on-off valve 52 is closed, it becomes a dead end there, so that the gas staying in the dead end portion is entrained and changed in direction, and is directed to the outlet side of the Y-shaped structure with the pressure sensor 42. In this way, the air is scavenged deep into the branch pipe. The length of the third branch pipe 33 from the third branch point B3 to the second on-off valve 52 and the length of the fourth branch pipe 34 from the fourth branch point B4 to the fourth on-off valve 54 are determined by the above air flow. It is shortened so that the gas is sufficiently scavenged.
図４に示す滞留防止構造は、Ｙ字構造の部分については図３と同様となり、Ｙ字構造の出口の部分にノズル構造をさらに設けた構成になっている。管径を細くしたノズル型の滞留防止構造においては、Ｙ字構造の部分から到来する気体がノズルの部分で流速を増した後、行き止まり箇所に向かって吐出する。そして、その行き止まり箇所の手前の管路内に滞留している気体を巻き込んで向きを変え、出口に向かって進む。このようにして分岐管の奥深くまで掃気される。 The stay prevention structure shown in FIG. 4 is the same as that shown in FIG. 3 with respect to the Y-shaped portion, and has a structure in which a nozzle structure is further provided at the outlet portion of the Y-shaped structure. In the nozzle-type stay prevention structure with a narrow tube diameter, the gas coming from the Y-shaped portion increases the flow velocity at the nozzle portion and then discharges toward the dead end. Then, the gas staying in the pipeline before the dead end is entrained and turned, and proceeds toward the outlet. In this way, the air is scavenged deeply into the branch pipe.
図５は、気体導入部１０の構成を示す。気体導入部１０は、比熱の大きい気体を温度調整して気体吐出口１０ａから吐出する機能を果たす。ここでは、比熱の大きい気体は、加湿した空気である。気体導入部１０は、周囲から取り入れた空気を加熱するヒータ１１と、気体導入部１０に入る空気（ヒータ１１を経た空気）の温度を測る入側温度センサ１２と、ヒータ１１を経た空気を所望の湿度に加湿する加湿器１３と、加湿器１３の出側の空気の湿度を測る湿度センサ１４と、加湿器１３を経た空気を圧縮するコンプレッサ１５と、加圧され加湿された空気を除湿するエアクーラ１６およびエアドライヤ１７と、圧縮された空気を圧縮された状態で蓄えるエアタンク１８と、エアタンク１８に蓄えられている空気を加温するためのヒータ１９と、雰囲気の気圧（大気圧）を測定する気圧計２１と、リーク検査装置５（特に検査装置本体６）の周囲の雰囲気の温度と湿度を測定する温湿度センサ２２と、気体導入部１０の気体吐出口１０ａから出る気体の温度を測定する出側温度センサ２３と、目標圧力や大気圧等から、加湿器１１で加湿した後の気体（空気）の目標の湿度等を演算する演算部２４と、気体導入部１０を含めてリーク検査装置５全体の動作を制御する制御部２５を備えている。主管路３０は、気体吐出口１０ａに接続されてエアタンク１８の出口に連通する。 FIG. 5 shows the configuration of the gas introduction unit 10. The gas introduction part 10 fulfills the function of adjusting the temperature of a gas having a large specific heat and discharging it from the gas discharge port 10a. Here, the gas having a large specific heat is humidified air. The gas introduction unit 10 desires a heater 11 that heats air taken from the surroundings, an inlet temperature sensor 12 that measures the temperature of the air that enters the gas introduction unit 10 (air that has passed through the heater 11), and air that has passed through the heater 11. A humidifier 13 that humidifies the air, a humidity sensor 14 that measures the humidity of the air on the outlet side of the humidifier 13, a compressor 15 that compresses the air that has passed through the humidifier 13, and dehumidifies the pressurized and humidified air. An air cooler 16 and an air dryer 17, an air tank 18 for storing compressed air in a compressed state, a heater 19 for heating the air stored in the air tank 18, and an atmospheric pressure (atmospheric pressure) of the atmosphere are measured. A barometer 21, a temperature / humidity sensor 22 that measures the temperature and humidity of the atmosphere around the leak inspection device 5 (particularly the inspection device main body 6), and the gas discharge port 10 of the gas introduction unit 10. An outlet side temperature sensor 23 for measuring the temperature of the gas coming out of the gas, a calculation unit 24 for calculating the target humidity of the gas (air) after humidification by the humidifier 11 from the target pressure, atmospheric pressure, etc., and gas introduction The control part 25 which controls operation | movement of the leak inspection apparatus 5 whole including the part 10 is provided. The main line 30 is connected to the gas discharge port 10 a and communicates with the outlet of the air tank 18.
気体導入部１０は、エアタンク１８から検査装置本体６内へ目標圧力になるように気体を加圧導入したとき、検査装置本体６の配管やワークＷ内等で結露が生じない湿度、たとえば、検査装置本体６内で相対湿度が略８０〜１００％（加圧時相対湿度）となることを目標にして動作する。すなわち、検査装置本体６内の配管に導入されたときに該気体の湿度が略８０〜１００％となり、かつその温度が周囲温度とほぼ等しくなるように、湿度および温度を調整した加圧気体をエアタンク１８に蓄える。目標圧力は、たとえば、４００〜１０００ＫＰａにされる。 When the gas introduction unit 10 pressurizes and introduces gas from the air tank 18 into the inspection apparatus main body 6 so as to achieve a target pressure, the humidity at which no dew condensation occurs in the piping of the inspection apparatus main body 6 or in the workpiece W, for example, inspection It operates with the target that the relative humidity in the apparatus main body 6 is approximately 80 to 100% (relative humidity during pressurization). That is, the pressurized gas whose humidity and temperature are adjusted so that the humidity of the gas is approximately 80 to 100% and the temperature is substantially equal to the ambient temperature when introduced into the pipe in the inspection apparatus body 6. Store in the air tank 18. The target pressure is set to 400 to 1000 KPa, for example.
加湿器１３で加湿する目的は、気体導入部１０が取り入れる周囲の空気が乾燥している冬場であっても、エアドライヤ１７から出てエアタンク１８に蓄積される圧縮空気の湿度を略８０〜１００％（加圧時相対湿度）とするためである。 The purpose of humidification by the humidifier 13 is to set the humidity of the compressed air that comes out of the air dryer 17 and accumulates in the air tank 18 to about 80 to 100% even in the winter when the ambient air taken in by the gas introduction unit 10 is dry. This is because (relative humidity during pressurization).
なお、従来のエアドライヤは以下のような構造である。すなわち、コンプレッサ１５からの湿った熱い空気はエアドライヤ内の熱交換器で、該エアドライヤから出て来る湿った（除湿された）冷たい空気と熱交換されて予冷され、更に、エアクーラでフロンガスにより所定温度に冷却される。これにより空気中の水分は凝縮し、冷却除湿される。すなわち湿度１００％（加圧時相対湿度１００％）となる。その後、エアドライヤ内の熱交換器に入って来る熱い空気と熱交換（余熱）されて湿度が下げられてからエアドライヤから排出される。すなわち、エアドライヤからは乾燥した空気が供給される。 The conventional air dryer has the following structure. That is, the moist and hot air from the compressor 15 is pre-cooled by heat exchange with the moist (dehumidified) cold air coming out of the air dryer in the heat exchanger in the air dryer, and is further cooled to a predetermined temperature by the Freon gas in the air cooler. To be cooled. Thereby, moisture in the air is condensed and cooled and dehumidified. That is, the humidity is 100% (relative humidity at pressurization is 100%). After that, heat exchange (residual heat) with hot air entering the heat exchanger in the air dryer is performed to reduce the humidity, and then the air is discharged from the air dryer. That is, dry air is supplied from the air dryer.
しかし、この構造では、加圧時相対湿度を略８０〜１００％にするという気体導入部１０における加湿の目的を達成できない。そこで、気体導入部１０で用いるエアドライヤ１７は、前述した予冷、余熱を行う熱交換器を用いず（または低能力として）にエアドライヤ１７から出る空気の湿度が下げられることなく（または下げ幅をコントロールして）高湿度で出る仕組みを用いると共に、エアドライヤ１７から出る空気の温度が、気体導入部１０や検査装置本体６の周囲の空気の温度（雰囲気温度）と略同じ温度（又は所定温度低い温度）になるように温度調整する。これにより、エアドライヤ１７の下流、例えば、検査装置本体６、エアタンク１８、検査装置本体６〜エアタンク１８（またはエアドライヤ１７）間の配管等の内部で結露するのを防止している。 However, with this structure, it is not possible to achieve the purpose of humidification in the gas introduction unit 10 such that the relative humidity during pressurization is approximately 80 to 100%. Therefore, the air dryer 17 used in the gas introduction unit 10 does not use the heat exchanger that performs the pre-cooling and preheating described above (or has a low capacity) without reducing the humidity of the air from the air dryer 17 (or controlling the reduction range). The temperature of the air coming out of the air dryer 17 is substantially the same as the temperature (atmosphere temperature) of the air around the gas introduction unit 10 and the inspection apparatus body 6 (or a temperature lower by a predetermined temperature). Adjust the temperature so that. This prevents condensation on the downstream side of the air dryer 17, for example, inside the inspection apparatus body 6, the air tank 18, and the piping between the inspection apparatus body 6 to the air tank 18 (or the air dryer 17).
なお、夜間を含む略１日間の最低温度を記憶しておき、最低温度のときでも結露しない湿度とすべく、好ましくは湿度８５％（加圧時湿度）のように若干湿度を低めにしてエアドライヤ１７から出すようにしてもよい。なお、冬場に気体導入部１０に入る空気の温度と検査装置本体６等がある場所の雰囲気温度が異なる場合には、気体導入部１０に入る空気の温度とエアドライヤ１７から出る空気の温度（雰囲気温度）とは同じ温度とせずに、エアドライヤ１７から出る空気の温度は検査装置本体６等がある場所の雰囲気温度と同じ温度とすることで、前記配管等内で結露するのを防止することができる。 It should be noted that the minimum temperature for approximately one day including nighttime is stored, and the air dryer is preferably set at a slightly lower humidity, such as 85% humidity (humidity during pressurization), in order to obtain a humidity that does not condense even at the lowest temperature. You may make it start from 17. If the temperature of the air entering the gas introduction unit 10 in winter is different from the temperature of the atmosphere where the inspection apparatus body 6 is located, the temperature of the air entering the gas introduction unit 10 and the temperature of the air exiting from the air dryer 17 (atmosphere) The temperature of the air coming out of the air dryer 17 is not the same temperature as the temperature), and the temperature of the air at the place where the inspection apparatus main body 6 is located is the same as the temperature of the place where the inspection apparatus body 6 is located, thereby preventing condensation in the piping or the like. it can.
本実施の形態に示す気体導入部１０では、加湿器１３、コンプレッサ１５、エアドライヤ１７、エアタンク１８の順に接続されているが、例えば加湿器１３、コンプレッサ１５、エアタンク１８、エアドライヤ１７の順であってもかまわず、順番は問わない。 In the gas introduction unit 10 shown in the present embodiment, the humidifier 13, the compressor 15, the air dryer 17, and the air tank 18 are connected in this order. For example, the humidifier 13, the compressor 15, the air tank 18, and the air dryer 17 are in this order. It doesn't matter, the order does not matter.
なお、コンプレッサ１５で圧縮した後の空気を加湿することもできる。たとえば、エアタンク１８の中に加湿器１３を設置すれば、圧縮後の空気が加湿される。しかし、圧縮後に加湿すると、加湿方法（超音波加湿、加熱水蒸気加湿）によりエアタンク１８内の温度が変わる。例えば超音波加湿を行うとエアタン１８内の温度が下がり、加熱水蒸気加湿を行うとエアタン１８内の温度が上がる。検査装置本体６に減圧導入した際に雰囲気温度と一致するようにエアタンク１８内で気体を保温貯留しておけば、検査装置本体６に目標圧力で減圧導入した際に、結露が生じ難くなるが、圧縮後に加湿すると、検査装置本体６に減圧導入した際に結露させないようにするための温度制御も難しくなる。そのため、本実施の形態では、加湿器１３で加湿した後の空気をコンプレッサ１５で圧縮している。 The air after being compressed by the compressor 15 can be humidified. For example, if the humidifier 13 is installed in the air tank 18, the compressed air is humidified. However, when humidifying after compression, the temperature in the air tank 18 changes depending on the humidification method (ultrasonic humidification, heating steam humidification). For example, when ultrasonic humidification is performed, the temperature in the air tan 18 decreases, and when heated steam humidification is performed, the temperature in the air tan 18 increases. If the gas is kept warm in the air tank 18 so as to coincide with the atmospheric temperature when the reduced pressure is introduced into the inspection apparatus body 6, condensation is less likely to occur when the reduced pressure is introduced into the inspection apparatus body 6 at the target pressure. When humidifying after compression, it becomes difficult to control the temperature so as not to cause condensation when reduced pressure is introduced into the inspection apparatus main body 6. Therefore, in the present embodiment, the air after being humidified by the humidifier 13 is compressed by the compressor 15.
図６は、ワークＷに手動４方弁７０を取り付けた状態を示している。手動４方弁７０は、接続口１〜４を備えている。接続口１はリーク検査装置５の準備用接続口３１ａあるいは検査用接続口３２ａに接続される。接続口２には、ワークＷの内部の奥まで挿入される内挿管７１の一端が接続される。接続口３には、外郭管７２の一端が接続される。接続口４は大気に開放されている。外郭管７２の他端はワークＷの入り口に接続される。なお図示省略しているが、ワークＷの入り口を封鎖する蓋体を取り付けてあり、外郭管７２は蓋体を貫通してワークＷの入り口近くで終端して開口している。 FIG. 6 shows a state in which the manual four-way valve 70 is attached to the workpiece W. The manual four-way valve 70 includes connection ports 1 to 4. The connection port 1 is connected to the preparation connection port 31a or the inspection connection port 32a of the leak inspection apparatus 5. The connection port 2 is connected to one end of an intubation 71 that is inserted into the work W. One end of the outer tube 72 is connected to the connection port 3. The connection port 4 is open to the atmosphere. The other end of the outer tube 72 is connected to the entrance of the workpiece W. Although not shown, a lid that seals the entrance of the workpiece W is attached, and the outer tube 72 passes through the lid and terminates near the entrance of the workpiece W and opens.
内挿管７１は、外郭管７２の途中で外郭管７２の周壁を貫通して外郭管７２の中に入り、その後は、外郭管７２の中を通ってワークＷの中に挿入される。ワークＷの内部に挿入された内挿管７１はワークＷの内部の奥まで至り、先端がワークＷの内部の最奥付近で開口している。なお、内挿管７１は、外郭管７２の中を通る必要はなく、内挿管７１と外郭管７２がそれぞれ蓋体を貫通する構造としてもよい。また、外郭管７２の終端を直接、ワークＷの入り口に接続する構造とし、外郭管７２がワークＷの入り口を封鎖する蓋体の機能を兼ねるようにしてもよい。 The inner tube 71 passes through the peripheral wall of the outer tube 72 in the middle of the outer tube 72, enters the outer tube 72, and then is inserted into the workpiece W through the outer tube 72. The intubation tube 71 inserted into the work W reaches the inner part of the work W, and the tip is opened near the innermost part of the work W. The inner intubation 71 does not need to pass through the outer tube 72, and the inner tube 71 and the outer tube 72 may each have a structure that penetrates the lid. Further, the end of the outer tube 72 may be directly connected to the entrance of the work W, and the outer tube 72 may also serve as a lid that blocks the entrance of the work W.
図７は、手動４方弁７０が取り得る４つの開閉状態を示している。同図（ａ）は、接続口１と接続口２が連通し、かつ接続口３と接続口４が連通した「両開」の状態を示している。「両開」の状態で気体導入部１０から加圧導入された気体が接続口１から流入すると、該気体は接続口２から内挿管７１を通じてワークＷの内部の奥に吐出される。また外郭管７２は接続口４を経て外界に通じている。内挿管７１の先端からワークＷの内部の奥に気体が吐出されると、これに伴って、元々ワークＷの内部にあった空気が外郭管７２を通じて外界に排出される。なお、図６は、手動４方弁７０は「両開」の状態を示している。 FIG. 7 shows four open / close states that the manual four-way valve 70 can take. FIG. 2A shows a “double-open” state in which the connection port 1 and the connection port 2 communicate with each other, and the connection port 3 and the connection port 4 communicate with each other. When the gas pressurized and introduced from the gas introduction unit 10 in the “both open” state flows from the connection port 1, the gas is discharged from the connection port 2 through the inner intubation 71 into the interior of the workpiece W. Further, the outer tube 72 communicates with the outside through the connection port 4. When the gas is discharged from the distal end of the inner intubation 71 into the interior of the workpiece W, the air originally in the workpiece W is discharged to the outside through the outer tube 72. FIG. 6 shows the manual four-way valve 70 in a “double open” state.
図７（ｂ）は、接続口１と接続口２が連通し、かつ接続口３と接続口４が閉鎖された「第１開」の状態を示している。図７（ｃ）は、接続口１、接続口２、接続口３、接続口４がいずれも閉鎖された「閉」の状態を示している。図７（ｄ）は、接続口１と接続口４が連通し、かつ接続口２と接続口３が閉鎖された「第２開」の状態を示している。手動４方弁７０では各状態への切り替えは手動で行われる。 FIG. 7B shows a “first open” state in which the connection port 1 and the connection port 2 communicate with each other and the connection port 3 and the connection port 4 are closed. FIG. 7C shows a “closed” state in which the connection port 1, the connection port 2, the connection port 3, and the connection port 4 are all closed. FIG. 7D shows a “second open” state in which the connection port 1 and the connection port 4 communicate with each other and the connection port 2 and the connection port 3 are closed. In the manual four-way valve 70, switching to each state is performed manually.
次に、リーク検査装置５における検査手順について説明する。 Next, an inspection procedure in the leak inspection apparatus 5 will be described.
リーク検査装置５では、差圧センサ５０の両側の空間を一度目標圧力に加圧すると、その状態を維持したままで、マスタＭやワークＷを交換して次々と検査を進めることができる。また、断熱圧縮・膨張による温度変動を極力抑えて、短時間でかつ高い精度で検査できるようになっている。 In the leak inspection apparatus 5, once the space on both sides of the differential pressure sensor 50 is pressurized to the target pressure, the inspection can be continued one after another by exchanging the master M and the workpiece W while maintaining the state. In addition, temperature fluctuations due to adiabatic compression / expansion can be suppressed as much as possible, and inspection can be performed in a short time with high accuracy.
リーク検査装置５の検査装置本体６においては、図８に示すように、第３開閉弁５３と第１サブ掃気弁５６と差圧センサ５０の第１検出口５０ａとの間の空間を第１空間８１（図中、太線で示す）、第５開閉弁５５と第２サブ掃気弁５７と差圧センサ５０の第２検出口５０ｂとの間の空間を第２空間８２（図中、太線で示す）、第２開閉弁５２と第３開閉弁５３との間を第３空間８３（図中、太破線で示す）、第４開閉弁５４と第５開閉弁５５の間を第４空間８４（図中、太破線で示す）、第１開閉弁４１と第１排気弁４４と第２開閉弁５２と第４開閉弁５４と手動弁４８の間の空間を第５空間８５（図中、太線で示す）とする。 In the inspection apparatus main body 6 of the leak inspection apparatus 5, as shown in FIG. 8, the space between the third on-off valve 53, the first sub scavenging valve 56, and the first detection port 50a of the differential pressure sensor 50 is first. A space between the space 81 (shown by a thick line), the fifth on-off valve 55, the second sub scavenging valve 57, and the second detection port 50b of the differential pressure sensor 50 is a second space 82 (shown by a thick line). 3), a space between the second on-off valve 52 and the third on-off valve 53 is shown in a third space 83 (shown by a thick broken line in the figure), and a space between the fourth on-off valve 54 and the fifth on-off valve 55 is a fourth space 84. The space between the first on-off valve 41, the first exhaust valve 44, the second on-off valve 52, the fourth on-off valve 54, and the manual valve 48 is designated as a fifth space 85 (in the figure, indicated by a thick broken line). (Shown in bold lines).
詳細には、第１空間８１は、第３開閉弁５３と第１検出口５０ａとの間の第３分岐管３３、小マスタＭａ、第１掃気口３３ａから第１サブ掃気弁５６までの第１掃気管３６で構成される。第２空間８２は、第５開閉弁５５と第２検出口５０ｂとの間の第４分岐管３４、小マスタＭｂ、第２掃気口３４ａから第２サブ掃気弁５７までの第２掃気管３７で構成される。第３空間８３は第２開閉弁５２と第３開閉弁５３の間の第３分岐管３３で構成される。第４空間８４は第４開閉弁５４と第５開閉弁５５との間の第４分岐管３４で構成される。第５空間は、第１開閉弁４１と第１排気弁４４の間の主管路３０、第３分岐箇所Ｂ３から第２開閉弁５２までの第３分岐管３３、第４分岐箇所Ｂ４から第４開閉弁５４までの第４分岐管３４、第２分岐箇所Ｂ２から手動弁４８までの第２分岐管３２で構成される。 Specifically, the first space 81 includes the third branch pipe 33 between the third on-off valve 53 and the first detection port 50a, the small master Ma, and the first sub-scavenging valve 56 to the first sub-scavenging valve 56. 1 scavenging pipe 36 is formed. The second space 82 includes a fourth branch pipe 34 between the fifth on-off valve 55 and the second detection port 50b, a small master Mb, and a second scavenging pipe 37 from the second scavenging port 34a to the second sub scavenging valve 57. Consists of. The third space 83 is constituted by a third branch pipe 33 between the second on-off valve 52 and the third on-off valve 53. The fourth space 84 is configured by the fourth branch pipe 34 between the fourth on-off valve 54 and the fifth on-off valve 55. The fifth space includes the main pipe line 30 between the first on-off valve 41 and the first exhaust valve 44, the third branch pipe 33 from the third branch point B3 to the second on-off valve 52, and the fourth branch part B4 to the fourth. A fourth branch pipe 34 to the on-off valve 54 and a second branch pipe 32 from the second branch point B2 to the manual valve 48 are configured.
密閉した検査系空間は、連通された第１空間８１、第３空間８３、第５空間８５から構成される。 The sealed inspection system space includes a first space 81, a third space 83, and a fifth space 85 that are communicated with each other.
図９は、リーク検査装置５における検査手順を示している。まず、気体導入部１０のエアタンク１８に、加湿し圧縮し温度調整した空気を蓄える（ステップＳ２０１）。すなわち、気体導入部１０は、周囲から空気を取り入れ、この空気を加湿器１３で加湿する。そして、加湿器１３で加湿後の空気をコンプレッサ１５で目標圧力以上に圧縮し、エアクーラ１６およびエアドライヤ１７を経て、エアタンク１８に送り込み蓄える。このとき、制御部２５は、検査装置本体６内の配管に導入されたときに該気体の湿度が略８０〜１００％となり、かつその温度が周囲温度とほぼ等しくなるように、湿度および温度を調整した加圧気体がエアタンク１８に蓄えられるように温度、湿度、圧縮を制御する。 FIG. 9 shows an inspection procedure in the leak inspection apparatus 5. First, humidified, compressed, and temperature-adjusted air is stored in the air tank 18 of the gas introduction unit 10 (step S201). That is, the gas introduction unit 10 takes in air from the surroundings and humidifies the air with the humidifier 13. Then, the air after humidification by the humidifier 13 is compressed to a target pressure or more by the compressor 15, and is sent to the air tank 18 through the air cooler 16 and the air dryer 17 and stored. At this time, the control unit 25 adjusts the humidity and temperature so that the humidity of the gas becomes approximately 80 to 100% and the temperature is substantially equal to the ambient temperature when introduced into the pipe in the inspection apparatus body 6. The temperature, humidity, and compression are controlled so that the adjusted pressurized gas is stored in the air tank 18.
次に、検査装置本体６内の全体を掃気する（ステップＳ２０２）。すなわち、第１開閉弁４１を閉じ、手動弁４７、第１分岐管開閉弁４６を開いて、エアタンク１８から供給される気体で第１分岐管３１を掃気した後、第１分岐管開閉弁４６を閉じる。次に、第２開閉弁５２、第３開閉弁５３、第４開閉弁５４、第５開閉弁５５、第１サブ掃気弁５６、第２サブ掃気弁５７、メイン掃気弁５８、第１排気弁４４、第２排気弁４５、手動弁４８を開いた状態で第１開閉弁４１を開き、エアタンク１８から供給される気体を、検査装置本体６の各管路（除く第１分岐管３１）に流して掃気する。 Next, the entire inspection apparatus body 6 is scavenged (step S202). That is, the first on-off valve 41 is closed, the manual valve 47 and the first branch pipe on-off valve 46 are opened, and the first branch pipe 31 is scavenged with the gas supplied from the air tank 18. Close. Next, the second on-off valve 52, the third on-off valve 53, the fourth on-off valve 54, the fifth on-off valve 55, the first sub scavenging valve 56, the second sub scavenging valve 57, the main scavenging valve 58, the first exhaust valve 44, the second exhaust valve 45 and the manual valve 48 are opened, the first on-off valve 41 is opened, and the gas supplied from the air tank 18 is supplied to each pipe line (excluding the first branch pipe 31) of the inspection apparatus body 6. Flow and scavenge.
所定時間掃気したら、手動弁４８、第２排気弁４５、メイン掃気弁５８、第１サブ掃気弁５６、第２サブ掃気弁５７を閉じた後、第１開閉弁４１を閉じる。ここでの掃気の目的は、気体導入部１０から送られてくる気体と溜まり場（後述する熱溜まり箇所等）にある気体とを、例えば同一の気体（比較する気体同士を同じ物理常数（温湿度）を持つ気体）として、正確な検査を可能にすることである。 After scavenging for a predetermined time, the manual valve 48, the second exhaust valve 45, the main scavenging valve 58, the first sub scavenging valve 56, and the second sub scavenging valve 57 are closed, and then the first on-off valve 41 is closed. The purpose of the scavenging here is the same physical constant (temperature / humidity) for the gas sent from the gas introduction unit 10 and the gas in the reservoir (such as a heat reservoir location described later), for example, the same gas ) To enable accurate inspection.
該掃気において、第１サブ掃気弁５６、第２サブ掃気弁５７、メイン掃気弁５８を開くことで、差圧センサ５０の第１検出口５０ａの極近くの第１掃気口３３ａ、および差圧センサ５０の第２検出口５０ｂの極近くの第２掃気口３４ａが共に掃気ポート３８ａに連通する。 In the scavenging, by opening the first sub scavenging valve 56, the second sub scavenging valve 57, and the main scavenging valve 58, the first scavenging port 33a near the first detection port 50a of the differential pressure sensor 50, and the differential pressure The second scavenging port 34a very close to the second detection port 50b of the sensor 50 communicates with the scavenging port 38a.
そのため、エアタンク１８からの気体が第３分岐管３３を流れ、差圧センサ５０の第１検出口５０ａの極近くの第１掃気口３３ａから第１掃気管３６、第１サブ掃気弁５６、メイン掃気弁５８を通じて掃気ポート３８ａから大気に排出される。このとき、エアタンク１８から第３分岐管３３に入ってきた気体は、第１掃気口３３ａに直接流れ込まず、慣性により直進して、差圧センサ５０の第１検出口５０ａに到達し、差圧センサ５０内の気体をも巻き込んで、第１掃気口３３ａへ流れ込み、掃気ポート３８ａから排出される。同様に、エアタンク１８からの気体は第４分岐管３４を流れ、差圧センサ５０の第２検出口５０ｂに到達し、差圧センサ５０内の気体をも巻き込んでから、第２検出口５０ｂの極近くの第２掃気口３４ａから第２掃気管３７、第２サブ掃気弁５７、メイン掃気弁５８を通じて掃気ポート３８ａから大気に排出される。 Therefore, the gas from the air tank 18 flows through the third branch pipe 33, and the first scavenging pipe 36, the first sub scavenging valve 56, the main scavenging pipe 33 a from the first scavenging opening 33 a very close to the first detection opening 50 a of the differential pressure sensor 50. The gas is discharged from the scavenging port 38a through the scavenging valve 58 to the atmosphere. At this time, the gas that has entered the third branch pipe 33 from the air tank 18 does not flow directly into the first scavenging port 33a, but goes straight by inertia, reaches the first detection port 50a of the differential pressure sensor 50, and reaches the differential pressure. The gas in the sensor 50 is also involved, flows into the first scavenging port 33a, and is discharged from the scavenging port 38a. Similarly, the gas from the air tank 18 flows through the fourth branch pipe 34, reaches the second detection port 50b of the differential pressure sensor 50, entrains the gas in the differential pressure sensor 50, and then passes through the second detection port 50b. The air is discharged from the scavenging port 38a through the second scavenging pipe 37, the second sub scavenging valve 57, and the main scavenging valve 58 from the second scavenging port 34a that is very close to the atmosphere.
これにより、差圧センサ５０の第１検出口５０ａ、第２検出口５０ｂに至るまでの全ての管路内がエアタンク１８からの気体に置き換わって、掃気される。 As a result, all the pipes from the differential pressure sensor 50 up to the first detection port 50a and the second detection port 50b are replaced with the gas from the air tank 18 and scavenged.
なお、第１掃気口３３ａ、第２掃気口３４ａは差圧センサ５０の検出口５０ａ、５０ｂにできるだけ近くに設けることが望ましい。少なくとも、メイン掃気弁５８、第１サブ掃気弁５６、第２サブ掃気弁５７を開いて掃気する際の気体の流れ（第１掃気口３３ａや第２掃気口３４ａから第１掃気管３６、第２掃気管３７へ向かう気体の流れ）に伴って、第１掃気口３３ａから第１検出口５０ａに至る第３分岐管３３内、および第２掃気口３４ａから第２検出口５０ｂに至る第４分岐管３４内が十分掃気されるように、第１掃気口３３ａ、第２掃気口３４ａを差圧センサ５０の検出口５０ａ、５０ｂの近傍に設ける。 The first scavenging port 33a and the second scavenging port 34a are preferably provided as close as possible to the detection ports 50a and 50b of the differential pressure sensor 50. At least the main scavenging valve 58, the first sub scavenging valve 56, and the second sub scavenging valve 57 open the gas flow (from the first scavenging port 33a and the second scavenging port 34a to the first scavenging pipe 36, 4) from the first scavenging port 33a to the first detection port 50a, and from the second scavenging port 34a to the second detection port 50b. The first scavenging port 33a and the second scavenging port 34a are provided in the vicinity of the detection ports 50a and 50b of the differential pressure sensor 50 so that the inside of the branch pipe 34 is sufficiently scavenged.
掃気を終える際には、第１開閉弁４１を閉じ、排気弁４５、手動弁４８を閉じ、さらに、メイン掃気弁５８を閉じてから第１サブ掃気弁５６、第２サブ掃気弁５７閉じる。メイン掃気弁５８を閉じてから第１サブ掃気弁５６、第２サブ掃気弁５７を閉じることで差圧センサ５０の両端に大きな差圧が生じることが防止される。なお、最後に第１開閉弁４１を閉じるようにすれば、大気が管内に逆流することなく、管内がエアタンク１８からの気体で充満された状態で掃気を終えることができる。 When the scavenging is finished, the first open / close valve 41 is closed, the exhaust valve 45 and the manual valve 48 are closed, and the main scavenging valve 58 is closed, and then the first sub scavenging valve 56 and the second sub scavenging valve 57 are closed. By closing the first sub scavenging valve 56 and the second sub scavenging valve 57 after closing the main scavenging valve 58, it is possible to prevent a large differential pressure from occurring at both ends of the differential pressure sensor 50. If the first on-off valve 41 is closed at the end, the scavenging can be finished in a state where the inside of the pipe is filled with the gas from the air tank 18 without flowing back into the pipe.
次に、検査装置本体６内の全体を目標圧力に加圧した後、放置して温度が安定するまで待つ（ステップＳ２０３）。詳細には、第１サブ掃気弁５６、第２サブ掃気弁５７を閉じた後、第１開閉弁４１を開き、第１空間８１、第２空間８２、第３空間８３、第４空間８４および第５空間８５が連通した状態でエアタンク１８からの気体を検査装置本体６内に加圧導入する。実際にはエアタンク１８内の圧力が目標圧力より高いので気体は減圧されて検査装置本体６へ導入される。加圧導入が終了したら第１開閉弁４１を閉じる。目標圧力になったか否かは圧力センサ４２の検出値で確認する。 Next, after pressurizing the entire inspection apparatus main body 6 to a target pressure, it is left to wait until the temperature stabilizes (step S203). Specifically, after the first sub scavenging valve 56 and the second sub scavenging valve 57 are closed, the first on-off valve 41 is opened, and the first space 81, the second space 82, the third space 83, the fourth space 84, and The gas from the air tank 18 is pressurized and introduced into the inspection apparatus main body 6 in a state where the fifth space 85 is in communication. Actually, since the pressure in the air tank 18 is higher than the target pressure, the gas is decompressed and introduced into the inspection apparatus body 6. When the pressurization is completed, the first on-off valve 41 is closed. Whether or not the target pressure has been reached is confirmed by the detection value of the pressure sensor 42.
気体導入部１０のエアタンク１８から導入される気体は、検査装置本体６内に減圧導入されて目標圧力になったとき、ちょうど、周囲温度と同じ温度になるように調整されているので、検査装置本体６内の温度が周囲温度と一致して安定な状態になるまでの待ち時間は短くて済む。また気体導入部１０から減圧導入された気体は結露せず、かつ湿度は略８０％になる。 The gas introduced from the air tank 18 of the gas introduction unit 10 is adjusted so as to be exactly the same temperature as the ambient temperature when reduced pressure is introduced into the inspection apparatus body 6 and the target pressure is reached. The waiting time until the temperature in the main body 6 matches the ambient temperature and becomes stable is short. In addition, the gas introduced under reduced pressure from the gas introduction unit 10 does not condense, and the humidity becomes approximately 80%.
ところで、ステップＳ２０２の掃気の時間を短縮して掃気が完全でない場合には、検査装置本体６の中に残っていた気体が、行き止まりの箇所で断熱圧縮されて発熱し熱溜まりが形成される。図１０は、たとえば、リーク検査装置５の製造時の空気が検査装置本体６に残っている状態でステップＳ２０３にて加圧した場合に生じる熱溜まり箇所をグレーの塗りつぶしで示している。具体的には、主管路３０が第２排気弁４５で行き止まりになる熱溜まり箇所ｄ１、第１掃気管３６が第１サブ掃気弁５６で行き止まりになる熱溜まり箇所ｄ２、第２掃気管３７が第２サブ掃気弁５７で行き止まりになる熱溜まり箇所ｄ３、第２分岐管３２が手動弁４８で行き止まりになる熱溜まり箇所ｄ４に熱溜まりが生じる。さらに、差圧センサ５０の両側にも熱溜まりが生じる。 By the way, when the scavenging time in step S202 is shortened and the scavenging is not complete, the gas remaining in the inspection apparatus body 6 is adiabatically compressed at the dead end to generate heat and a heat pool is formed. FIG. 10 shows, for example, the heat accumulation location that is generated when the pressure in step S <b> 203 is pressurized in the state where the air at the time of manufacturing the leak inspection apparatus 5 remains in the inspection apparatus main body 6, in gray. Specifically, a heat accumulation point d1 where the main pipeline 30 stops at the second exhaust valve 45, a heat accumulation point d2 where the first scavenging tube 36 stops at the first sub-scavenging valve 56, and a second scavenging tube 37 Heat accumulation occurs at the heat accumulation point d3 where the second sub scavenging valve 57 stops and the heat accumulation point d4 where the second branch pipe 32 stops at the manual valve 48. Further, heat accumulation occurs on both sides of the differential pressure sensor 50.
そこで、ステップＳ２０３での加圧の終了直前に、あるいは、目標圧力より少し高めの圧力に加圧してから、排気弁４５、メイン掃気弁５８、第１サブ掃気弁５６、第２サブ掃気弁５７、手動弁４８を少し開いて、熱溜まり箇所ｄ１〜ｄ４、および差圧センサ５０の第１検出口５０ａや第２検出口５０ｂの部分に溜まっている気体を排出して熱を外界へ逃がすようにしている。なお、手動弁４８については、ここでは、閉じたままとしてもよい。この場合、後述するＳ２０５の掃気において、熱溜まり箇所ｄ４に溜まっている熱（気体）が排出される。 Therefore, immediately before the end of pressurization in step S203 or after pressurizing to a pressure slightly higher than the target pressure, the exhaust valve 45, the main scavenging valve 58, the first sub scavenging valve 56, and the second sub scavenging valve 57 are used. The manual valve 48 is opened a little to discharge the gas accumulated in the heat collection points d1 to d4 and the first detection port 50a and the second detection port 50b of the differential pressure sensor 50 so as to release the heat to the outside. I have to. Note that the manual valve 48 may be kept closed here. In this case, in the scavenging of S205 described later, the heat (gas) accumulated in the heat accumulation location d4 is discharged.
また、第２排気弁４５を少し開いて熱溜まり箇所ｄ１に溜まっている熱を排出したら、第１排気弁４４を閉じる。熱溜まり箇所ｄ１に溜まっていた熱で第２排気弁４５は昇温し蓄熱しているので、第１排気弁４４を閉じることで第２排気弁４５を切り離して断熱する。 Further, when the second exhaust valve 45 is slightly opened to discharge the heat accumulated in the heat accumulation location d1, the first exhaust valve 44 is closed. Since the second exhaust valve 45 is heated and stored by the heat accumulated in the heat accumulation location d1, the second exhaust valve 45 is disconnected and insulated by closing the first exhaust valve 44.
ここでの掃気は、断熱圧縮されて昇温した気体が、排気弁４５や差圧センサ５０で行き止まりになって熱溜まり箇所になった部分で周囲に熱を撒き散らしている状態を一刻も早く解消することを目的としている。 The scavenging here is as fast as possible when the gas that has been adiabatically compressed and heated up reaches the dead end by the exhaust valve 45 and the differential pressure sensor 50, and the heat is scattered around the area where heat has accumulated. The purpose is to eliminate.
ステップＳ２０３の加圧により、差圧センサ５０内が、断熱圧縮により発熱した気体で満たされるため、その後、その発熱が放熱して安定状態が形成されるまで（この時間を安定経過時間とする）待つ。 Due to the pressurization in step S203, the inside of the differential pressure sensor 50 is filled with the gas generated by adiabatic compression, and thereafter, until the generated heat is dissipated and a stable state is formed (this time is defined as a stable elapsed time). wait.
検査装置本体内が目標圧力になって安定経過時間が経過した後に、第１空間８１、第２空間８２、第３空間８３、第４空間８４、第５空間８５を分離し、それぞれを閉鎖空間にする（ステップＳ２０４）。具体的には、第３開閉弁５３、第５開閉弁５５を閉じ、さらに第２開閉弁５２、第４開閉弁５４を閉じる。このあと、第２空間８２、第４空間８４は目標圧力に維持される。 After the interior of the inspection apparatus reaches the target pressure and the stable elapsed time has elapsed, the first space 81, the second space 82, the third space 83, the fourth space 84, and the fifth space 85 are separated, and each is closed. (Step S204). Specifically, the third on-off valve 53 and the fifth on-off valve 55 are closed, and the second on-off valve 52 and the fourth on-off valve 54 are closed. Thereafter, the second space 82 and the fourth space 84 are maintained at the target pressure.
なお、前述の安定経過時間を設けない場合、あるいは設定した安定経過時間が不十分な（短い）場合には、第２空間８２を密閉・分離した後も放熱が進み、該放熱と共に第２空間８２内の圧力が下がってしまうので、第２空間８２がワークＷのリーク検査における基準にならなくなってしまう。そのため、十分な安定状態が形成されるだけの安定経過時間の経過を待ってから第２空間８２を密閉して分離する。 When the above-described stable elapsed time is not provided, or when the set stable elapsed time is insufficient (short), heat dissipation proceeds even after the second space 82 is sealed and separated, and the second space is combined with the heat dissipation. Since the pressure in 82 falls, the 2nd space 82 will no longer become the standard in the leak inspection of work W. For this reason, the second space 82 is sealed and separated after waiting for the passage of a stable elapsed time sufficient to form a sufficiently stable state.
なお、リーク検査装置５では、ワークＷやマスタＭを交換する場合に手動弁４８を閉じることで、第１空間８１、第３空間８３、第５空間８５についても、ほぼ目標圧力に維持され、これらの空間において気体の入れ替えがほとんど生じないようになっている。 In the leak inspection apparatus 5, by closing the manual valve 48 when the workpiece W or the master M is replaced, the first space 81, the third space 83, and the fifth space 85 are substantially maintained at the target pressure, Almost no gas exchange occurs in these spaces.
次に、マスタＭを準備用接続口３１ａに接続し、該マスタＭに取り付けてある手動４方弁７０を「両開」の位置にして、第１分岐管開閉弁４６、手動弁４７を開き、エアタンク１８からの気体（検査用気体：加湿され圧縮された空気）でマスタＭ内を掃気する。その後、手動４方弁７０を「第１開」の位置に変え、マスタＭ内を目標圧力まで加圧する（ステップＳ２０５）。ここでの目標圧力は、電空レギュレータ４０によって制御される圧力であり、検査時の目標圧力よりやや高くされている。 Next, the master M is connected to the preparation connection port 31a, the manual four-way valve 70 attached to the master M is set to the “both open” position, and the first branch pipe opening / closing valve 46 and the manual valve 47 are opened. The inside of the master M is scavenged with gas from the air tank 18 (inspection gas: humidified and compressed air). Thereafter, the manual four-way valve 70 is changed to the “first open” position, and the inside of the master M is pressurized to the target pressure (step S205). The target pressure here is a pressure controlled by the electropneumatic regulator 40 and is slightly higher than the target pressure at the time of inspection.
掃気時は、マスタＭに取りつけてある手動４方弁７０が「両開」の位置にあるので、エアタンク１８から導入された気体は、図６に示すように、マスタＭの内部の奥で内挿管７１の先端から吐出し、これに伴って、元々マスタＭの内部にあった空気がマスタＭの入口から外郭管７２を通じて手動４方弁７０の接続口４から外界へ排出される。 At the time of scavenging, since the manual four-way valve 70 attached to the master M is in the “double open” position, the gas introduced from the air tank 18 is in the interior of the master M as shown in FIG. The air is discharged from the distal end of the intubation 71, and accordingly, air originally in the master M is discharged from the inlet of the master M through the outer tube 72 to the outside through the connection port 4 of the manual four-way valve 70.
マスタＭ内の掃気完了後に手動４方弁７０を「第１開」の位置にすることで、その後は圧力の上昇が進み、マスタＭ内が目標圧力に至る。加圧が完了したら第１分岐管開閉弁４６を閉じる。なお、マスタＭ（後述するワークＷについても同じ）を加圧する場合の圧力は、検査装置本体内と同じ目標圧力にすることが好ましいが、任意の圧力でもよい。 By setting the manual four-way valve 70 to the “first open” position after scavenging in the master M is completed, the pressure increases thereafter, and the inside of the master M reaches the target pressure. When the pressurization is completed, the first branch pipe opening / closing valve 46 is closed. In addition, although the pressure in pressurizing the master M (same also about the workpiece | work W mentioned later) is preferable to make it the same target pressure as the inside of an inspection apparatus main body, arbitrary pressures may be sufficient.
次に、手動４方弁７０を「閉」の位置にし、マスタＭを準備用接続口３１ａから外し、検査用接続口３２ａに取り付ける（ステップＳ２０６）。手動４方弁７０を「閉」とすることで、マスタＭを含む密閉空間が形成される。 Next, the manual four-way valve 70 is set to the “closed” position, the master M is removed from the preparation connection port 31a, and attached to the inspection connection port 32a (step S206). By setting the manual four-way valve 70 to “closed”, a sealed space including the master M is formed.
次に、手動弁４８を開き、手動４方弁７０を「第２開」の位置にして、手動弁４８と手動４方弁７０との間にあった空気を外界へ排気する（ステップＳ２０７）。 Next, the manual valve 48 is opened, the manual four-way valve 70 is set to the “second open” position, and air between the manual valve 48 and the manual four-way valve 70 is exhausted to the outside (step S207).
次に、手動４方弁７０を「第１開」の位置にして、マスタＭと第５空間８５を連通させる。これにより、マスタＭを含む密閉空間と検査用空間とが連通される。その後、第１開閉弁４１を開き、圧力センサ４２の検出値に基づいて、該空間を目標圧力よりやや高い圧力に加圧する（ステップＳ２０８）。たとえば、目標圧力８００ＫＰａに対して、８００．２５ＫＰａまで（圧力センサ４２の誤差分以上まで）加圧する。圧力センサ４２は誤差が大きいので、圧力センサ４２の測定レンジ（フルスケール）１０００ＫＰａにて検出値が８００．２５ＫＰａを示していても、例えば圧力センサ４２の測定精度（誤差）が、０．０２５％／フルスケールの場合、実際には、８００．０〜８００．５ＫＰａの範囲の圧力になる。したがって、第２空間８２よりも第５空間８５は、０〜０．５ＫＰａだけ高い圧力になる。 Next, the manual four-way valve 70 is set to the “first open” position, and the master M and the fifth space 85 are communicated. Thereby, the sealed space including the master M and the inspection space are communicated. Thereafter, the first on-off valve 41 is opened, and the space is pressurized to a pressure slightly higher than the target pressure based on the detection value of the pressure sensor 42 (step S208). For example, the pressure is increased up to 800.25 KPa (up to the error of the pressure sensor 42) with respect to the target pressure of 800 KPa. Since the error of the pressure sensor 42 is large, even if the detected value indicates 800.25 KPa in the measurement range (full scale) 1000 KPa of the pressure sensor 42, for example, the measurement accuracy (error) of the pressure sensor 42 is 0.025%. / In the case of full scale, the pressure is actually in the range of 800.0-800.5 KPa. Therefore, the fifth space 85 has a pressure higher by 0 to 0.5 KPa than the second space 82.
その後、第２開閉弁５２を開いて第５空間８５と第３空間８３を連通させ、さらに第３開閉弁５３を開いて、第１空間８１、第３空間８３、第５空間８５を連通させる。そして、差圧センサ５０の検出値から、第２空間８２側と、第１空間８１側の圧力が等しくなるように、第１排気弁４４および第２排気弁４５から少しずつ排気して圧力を合わせ込む(ステップＳ２０９)。このようにすることで、圧力センサ４２の測定誤差を差圧センサ５０で校正して、第１空間８１およびこれに連通している第３空間８３、第５空間８５、マスタＭ内を正確に目標圧力（第２空間８２と同じ圧力）に調整することができる。 Thereafter, the second on-off valve 52 is opened to connect the fifth space 85 and the third space 83, and the third on-off valve 53 is further opened to connect the first space 81, the third space 83, and the fifth space 85. . Then, from the detected value of the differential pressure sensor 50, the pressure is exhausted little by little from the first exhaust valve 44 and the second exhaust valve 45 so that the pressures on the second space 82 side and the first space 81 side become equal. Align (step S209). In this way, the measurement error of the pressure sensor 42 is calibrated by the differential pressure sensor 50, and the first space 81 and the third space 83, the fifth space 85, and the master M communicating with the first space 81 are accurately detected. The target pressure (the same pressure as the second space 82) can be adjusted.
なお、第５空間８５をほぼ目標圧力に加圧してから第５空間８５を第３空間８３および第１空間８１に連通させるので、差圧センサ５０に大きな差圧が加わることが防止される。 In addition, since the fifth space 85 is almost pressurized to the target pressure and then the fifth space 85 is communicated with the third space 83 and the first space 81, a large differential pressure is prevented from being applied to the differential pressure sensor 50.
第２開閉弁５２より第３開閉弁５３側の第３分岐管３３は、恒温槽６０に収容されて一定温度に保たれているので、第３空間８３、第１空間８１、第２空間８２には一定温度に保たれた気体がある。Ｓ２０８で第２開閉弁５２を開いてから第３開閉弁５３を開いたときは、第３空間８３にあった気体が第１空間８１に流れ込む。よって、恒温槽６０にて一定温度に保たれた気体が差圧センサ５０の両側に加えられるので差圧センサ５０の温度ドリフトが発生しない。 Since the third branch pipe 33 closer to the third on-off valve 53 than the second on-off valve 52 is accommodated in the thermostatic bath 60 and maintained at a constant temperature, the third space 83, the first space 81, and the second space 82 are maintained. There is a gas kept at a constant temperature. When the third opening / closing valve 53 is opened after the second opening / closing valve 52 is opened in S 208, the gas in the third space 83 flows into the first space 81. Therefore, since the gas maintained at a constant temperature in the thermostatic bath 60 is added to both sides of the differential pressure sensor 50, the temperature drift of the differential pressure sensor 50 does not occur.
すなわち、差圧センサ５０の温度ドリフトは差圧センサ５０の周囲温度、差圧センサ５０に接触する第１空間８１、第２空間８２の温度によって左右されるが、後述の基準特性を取得する時やワークＷの検査時等において第１空間８１、第２空間８２に流出入する気体もまた第１空間８１、第２空間８２の温度と同じであるようにすれば、第１空間８１、第２空間８２の温度が変化せず、もって、差圧センサ５０の温度ドリフトの発生を防止できる（ドリフト対策）。 That is, the temperature drift of the differential pressure sensor 50 depends on the ambient temperature of the differential pressure sensor 50 and the temperatures of the first space 81 and the second space 82 that are in contact with the differential pressure sensor 50. If the gas flowing into and out of the first space 81 and the second space 82 is also the same as the temperature of the first space 81 and the second space 82 when the work W is inspected, the first space 81 and the second space 82 The temperature of the two spaces 82 does not change, so that the temperature drift of the differential pressure sensor 50 can be prevented (drift countermeasure).
ステップＳ２０８の加圧においても、各種の対策を施さなければ、行き止まりの箇所にて発熱する。具体的には、図１０に示すように、第４分岐管３４が第４開閉弁５４で行き止まりになる箇所ｄ５、第３分岐管３３が第２開閉弁５２で行き止まりになる箇所ｄ７、ワークＷの内部の奥で行き止まりになる箇所ｄ６、主管路６１が排気弁４５で行き止まりになる箇所ｄ１にて熱溜まりが発生し得る。 Even in the pressurization in step S208, heat is generated at the dead end unless various measures are taken. Specifically, as shown in FIG. 10, the point d5 where the fourth branch pipe 34 stops at the fourth on-off valve 54, the point d7 where the third branch pipe 33 stops at the second on-off valve 52, the workpiece W A heat accumulation can occur at a location d6 where the dead end is located at the back of the interior of the, and a location d1 where the main pipeline 61 becomes a dead end at the exhaust valve 45.
しかし、ステップＳ２０９にて第１排気弁４４、第２排気弁４５から排気することで熱溜まり箇所ｄ１の熱は外界へ排出される。また、熱溜まり箇所ｄ５、ｄ７についても第３分岐箇所Ｂ３、第４分岐箇所Ｂ４に設けたＹ字型の滞留防止構造により、第１排気弁４４、第２排気弁４５を開いて熱を外界に排出する際に、熱の溜まりが解消される。そして、マスタ内の奥の熱溜まり箇所ｄ６については、Ｓ２０５でマスタＭ内を同じ気体で事前に目標圧力に加圧してあるので、熱の発生はほとんどない。また、結露しない。後述するＳ２１３で事前に同じ気体で目標圧力へ加圧するワークＷをＳ２１６で加圧し、Ｓ２１７で目標圧力に合わせ込む場合も同様である。 However, by exhausting from the first exhaust valve 44 and the second exhaust valve 45 in step S209, the heat at the heat accumulation location d1 is discharged to the outside. In addition, the heat accumulation points d5 and d7 are also opened by the Y-shaped stay prevention structure provided at the third branch point B3 and the fourth branch point B4 to open the first exhaust valve 44 and the second exhaust valve 45 to transfer heat to the outside. When it is discharged, the heat accumulation is eliminated. And about the heat accumulation location d6 in the back in the master, since the inside of the master M was previously pressurized to the target pressure with the same gas in S205, almost no heat is generated. Also, there is no condensation. The same applies to the case where the workpiece W to be pressurized to the target pressure with the same gas in advance in S213 to be described later is pressurized in S216 and adjusted to the target pressure in S217.
次に、基準特性を測定する（ステップＳ２１０）。すなわち、差圧センサ５０の検出値の時間経過に伴う変化を、基準特性として測定する。また、この測定時の周囲湿度、周囲温度、周囲気圧、エアタンク１８内の気体の温度・湿度・圧力、加圧時間、加圧完了時の検査装置本体６内の気体の温度などを併せて記憶する。 Next, the reference characteristic is measured (step S210). That is, the change with time of the detection value of the differential pressure sensor 50 is measured as a reference characteristic. Further, the ambient humidity, ambient temperature, ambient pressure, the temperature / humidity / pressure of the gas in the air tank 18, the pressurization time, the temperature of the gas in the inspection apparatus main body 6 when the pressurization is completed, and the like are also stored. To do.
前述したように、加圧時に、熱溜まり箇所に熱はほとんど溜まることがなく、また、目標圧力になったときに周囲温度と一致するように温度湿度の調整された気体が気体導入部１０から減圧導入されるので、検査装置本体６内の温度が安定するまでの時間(静定時間)は短くて済む。 As described above, at the time of pressurization, almost no heat is accumulated in the heat accumulation location, and when the target pressure is reached, the gas whose temperature and humidity are adjusted so as to coincide with the ambient temperature is supplied from the gas introduction unit 10. Since the reduced pressure is introduced, the time until the temperature in the inspection apparatus main body 6 is stabilized (static time) can be short.
なお、加圧完了後、放熱（漏れ以外の要因）による圧力低下がほぼ収束するまでの所定の時間を静定時間として設定し、マスタＭについて静定時間が経過したときに差圧センサ５０が検出している圧力差の値を基準特性として取得してもよい。 A predetermined time until the pressure drop due to heat dissipation (factor other than leakage) almost converges after the pressurization is completed is set as a settling time, and when the settling time elapses for the master M, the differential pressure sensor 50 You may acquire the value of the detected pressure difference as a reference characteristic.
基準特性の測定が終了したら、第３開閉弁５３、第２開閉弁５２を閉じて第１空間８１、第３空間８３、第５空間８５を独立した空間に分離する（ステップＳ２１１）。次に、手動弁４８を「閉」位置として、マスタＭを大気開放とし、手動４方弁７０ごと、マスタＭを検査用接続口３２ａから取り外す（ステップＳ２１２）。マスタＭ内の気体は検査装置本体６の内部を通らずに手動弁４８から外界へ排出される。 When the measurement of the reference characteristics is completed, the third on-off valve 53 and the second on-off valve 52 are closed to separate the first space 81, the third space 83, and the fifth space 85 into independent spaces (step S211). Next, the manual valve 48 is set to the “closed” position, the master M is opened to the atmosphere, and the master M is removed from the inspection connection port 32a together with the manual four-way valve 70 (step S212). The gas in the master M is discharged from the manual valve 48 to the outside without passing through the inside of the inspection apparatus body 6.
マスタＭ内にあった高圧高湿度の空気を大気開放すると、断熱膨張によって急冷され、ダイヤモンドダストが舞う。マスタＭ（後述するワークＷの場合も同じ）から吐出する空気を、手動弁４８から外界へ排出することで、このダイヤモンドダストが検査装置本体６内に入らないようにしている。 When high-pressure and high-humidity air in the master M is released to the atmosphere, it is rapidly cooled by adiabatic expansion, and diamond dust flies. The diamond dust is prevented from entering the inspection apparatus main body 6 by discharging air discharged from the master M (the same applies to the workpiece W described later) from the manual valve 48 to the outside.
仮に、マスタＭを大気開放する際に、検査装置本体６の第２排気弁４５から排気すると、減圧で発生したダイヤモンドダストは、圧力センサ４２に衝突して溜まってしまう。すなわち、ワークＷやマスタＭを大気開放する際に排気弁４５を開くと、マスタＭ（検査時はワークＷ）内の気体は第２分岐管３２、主管路３０を通って検査装置本体６から排出されるが、減圧によって生成されたダイヤモンドダストは、慣性力で直進し、圧力センサ４２に向かい、主管路３０の方向へは行かない。 If the master M is vented from the second exhaust valve 45 of the inspection apparatus body 6 when the master M is released to the atmosphere, diamond dust generated by the reduced pressure collides with the pressure sensor 42 and accumulates. That is, when the exhaust valve 45 is opened when the work W or the master M is opened to the atmosphere, the gas in the master M (work W at the time of inspection) passes from the inspection apparatus body 6 through the second branch pipe 32 and the main pipeline 30. Although it is discharged, the diamond dust generated by the reduced pressure travels straight by the inertial force, goes to the pressure sensor 42, and does not go in the direction of the main pipeline 30.
このダイヤモンドダストは、周囲湿度が低いので（たとえば、４２０KPaに加圧されている時の相対湿度１００％は、大気開放下では相対湿度１５．１５％なので）、すぐに蒸発するが、それと共に周囲湿度が上昇する。そのため、次の加圧前に第５空間８５を掃気しなければ、次の加圧により管内で結露が発生してしまう。本実施の形態に係るリーク検査装置５では、マスタＭやワークＷを大気開放する際に手動弁４８から外界へ気体を逃がすので、上記の問題は生じない。 Since this diamond dust has a low ambient humidity (for example, 100% relative humidity when pressurized to 420 KPa is 15.15% relative to the atmosphere), it evaporates quickly, but with it Humidity increases. Therefore, if the fifth space 85 is not scavenged before the next pressurization, dew condensation occurs in the pipe by the next pressurization. In the leak inspection apparatus 5 according to the present embodiment, when the master M or the workpiece W is released to the atmosphere, the gas is released from the manual valve 48 to the outside, so the above problem does not occur.
次に、ワークＷを準備用接続口３１ａに接続し、マスタＭの時と同様に掃気した後、目標圧力に加圧する（ステップＳ２１３）。すなわち、ワークＷに取り付けてある手動４方弁７０を「両開」の位置にして、第１分岐管開閉弁４６、手動弁４７を開き、エアタンク１８からの気体（検査用気体：加湿され圧縮された空気）でワークＷ内を掃気する。その後、手動４方弁７０を「第１開」の位置に変え、ワークＷ内を目標圧力まで加圧する。 Next, the work W is connected to the preparation connection port 31a, and after scavenging as in the case of the master M, the pressure is increased to the target pressure (step S213). That is, the manual four-way valve 70 attached to the workpiece W is set to the “double open” position, the first branch pipe opening / closing valve 46 and the manual valve 47 are opened, and the gas from the air tank 18 (inspection gas: humidified and compressed) The inside of the workpiece W is scavenged with air). Thereafter, the manual four-way valve 70 is changed to the “first open” position, and the inside of the workpiece W is pressurized to the target pressure.
次に、ワークＷの手動４方弁７０を「閉」位置にしてワークＷを準備用接続口３１ａから取り外し、検査用接続口３２ａに取り付ける（ステップＳ２１４）。手動４方弁７０を「閉」とすることで、ワークＷを含む密閉空間が形成される。 Next, the manual four-way valve 70 of the workpiece W is set to the “closed” position, and the workpiece W is detached from the preparation connection port 31a and attached to the inspection connection port 32a (step S214). By setting the manual four-way valve 70 to “closed”, a sealed space including the workpiece W is formed.
なお、ワークＷについては、目標圧力に加圧する作業を次々に行い、準備用接続口３１ａから取り外したものを、内部の気体の温度が周囲温度に一致するまで保管場所にてしばらく放置し、その後、検査用接続口３２ａに接続する。こうすれば、別のワークＷを検査している間に、保管場所にて温度の安定を図ることができる。また、ワークＷを検査用接続口３２ａに接続して検査している間に別のワークＷを準備用接続口３１ａに接続して掃気及び目標圧力へ加圧することを行うこともできる。 In addition, about the workpiece | work W, the operation | work which pressurizes to a target pressure is performed one after another, and the thing removed from the connection port 31a for preparation is left for a while in a storage place until the internal gas temperature corresponds to ambient temperature, and then And connected to the inspection connection port 32a. By so doing, it is possible to stabilize the temperature at the storage location while inspecting another workpiece W. Further, while the work W is connected to the inspection connection port 32a and being inspected, another work W can be connected to the preparation connection port 31a to pressurize to the scavenging and target pressure.
次に、手動弁４８を開き、ワークＷの手動４方弁７０を「第２開」の位置にして、手動弁４８と手動４方弁７０との間にあった空気を外界へ排気(パージ)する（ステップＳ２１５）。 Next, the manual valve 48 is opened, the manual four-way valve 70 of the workpiece W is set to the “second open” position, and the air between the manual valve 48 and the manual four-way valve 70 is exhausted (purged) to the outside. (Step S215).
次に、手動４方弁７０を「第１開」の位置にして、ワークＷと第５空間８５を連通させる。ワークＷを含む密閉空間と検査用空間とが連通される。その後、マスタＭの場合と同様に、第１開閉弁４１を開き、圧力センサ４２の検出値に基づいて、該空間を目標圧力よりやや高い圧力に加圧する（ステップＳ２１６）。次に、第２開閉弁５２を開いて第５空間８５と第３空間８３を連通させ、さらに第３開閉弁５３を開いて、第１空間８１、第３空間８３、第５空間８５を連通させる。そして、差圧センサ５０の検出値から、第２空間８２側と、第１空間８１側の圧力が等しくなるように、第１排気弁４４および第２排気弁４５から少しずつ排気して圧力を合わせ込む(ステップＳ２１７)。このようにすることで、圧力センサ４２の測定誤差を差圧センサ５０で校正して、第１空間８１およびこれに連通している第３空間８３、第５空間８５、ワークＷ内を正確に目標圧力（第２空間８２と同じ圧力）に調整することができる。 Next, the manual four-way valve 70 is set to the “first open” position, and the workpiece W and the fifth space 85 are communicated. The sealed space including the workpiece W is communicated with the inspection space. Thereafter, as in the case of the master M, the first on-off valve 41 is opened, and the space is pressurized to a pressure slightly higher than the target pressure based on the detection value of the pressure sensor 42 (step S216). Next, the second on-off valve 52 is opened to connect the fifth space 85 and the third space 83, and the third on-off valve 53 is opened to connect the first space 81, the third space 83, and the fifth space 85. Let Then, from the detected value of the differential pressure sensor 50, the pressure is exhausted little by little from the first exhaust valve 44 and the second exhaust valve 45 so that the pressures on the second space 82 side and the first space 81 side become equal. Align (step S217). By doing so, the measurement error of the pressure sensor 42 is calibrated by the differential pressure sensor 50, and the first space 81 and the third space 83, the fifth space 85, and the work W communicating with the first space 81 are accurately measured. The target pressure (the same pressure as the second space 82) can be adjusted.
なお、第５空間８５をほぼ目標圧力に加圧してから第５空間８５と第３空間８３、第１空間８１を連通させるので、差圧センサ５０に大きな差圧が加わることが防止される。 Since the fifth space 85, the third space 83, and the first space 81 are communicated after the fifth space 85 is almost pressurized to the target pressure, it is possible to prevent a large differential pressure from being applied to the differential pressure sensor 50.
ここでも、ステップＳ２０８、２０９で説明したと同様に、合わせ込み時の排気やＹ字型構造、恒温槽６０の存在により、差圧センサ５０の温度ドリフトおよび熱溜まりの発生が防止される。また、ワークＷ内はＳ２１３にて同じ気体で事前に充填されているので、発熱や結露は生じない。 Here, as described in steps S208 and S209, the temperature drift of the differential pressure sensor 50 and the occurrence of heat accumulation are prevented by the exhaust at the time of fitting, the Y-shaped structure, and the presence of the thermostat 60. Moreover, since the inside of the workpiece W is pre-filled with the same gas in S213, heat generation and condensation do not occur.
次に、ワークＷの漏れを検査する（ステップＳ２１８）。すなわち、差圧センサ５０の検出値の時間経過に伴う変化を測定し、この測定結果と、先に測定した基準特性を比較することで、ワークＷの漏れの有無を判定する。ワークＷに漏れがなければ、測定結果は基準特性と一致あるいはほぼ一致する。ワークＷから空気が漏れている場合は、基準特性との差が大きくなる。たとえば、所定時間経過時点の検出値と基準特性の値との差が許容値を超える場合はワークＷに漏れがあると判定する。 Next, the workpiece W is inspected for leakage (step S218). That is, the change with time of the detection value of the differential pressure sensor 50 is measured, and the presence of leakage of the workpiece W is determined by comparing the measurement result with the previously measured reference characteristic. If there is no leakage in the workpiece W, the measurement result matches or substantially matches the reference characteristic. When air leaks from the workpiece W, the difference from the reference characteristic becomes large. For example, when the difference between the detected value at the time when a predetermined time has elapsed and the value of the reference characteristic exceeds an allowable value, it is determined that the workpiece W has a leak.
なお、マスタＭについて静定時間が経過したときの圧力差の値を基準特性として取得している場合には、ワークＷの検査においても静定時間経過時の圧力差を計測し、この値と基準特性としての静定時間経過後の圧力差とを比較し、その差が所定の閾値未満ならばワークＷは漏れなし（検査合格）と判定し、閾値以上ならば漏れあり（検査不合格）と判定するようにしてもよい。 In addition, when the value of the pressure difference when the settling time has elapsed for the master M is acquired as the reference characteristic, the pressure difference when the settling time has elapsed is also measured in the inspection of the workpiece W. The pressure difference after the settling time elapses as a reference characteristic is compared. If the difference is less than a predetermined threshold value, the workpiece W is judged as having no leakage (inspection pass), and if it is above the threshold value, there is leakage (inspection failure). May be determined.
前述したように、加圧時に熱溜まり箇所に熱がほとんど溜まることがなく、また、目標圧力になったときに周囲温度と一致し結露せずに湿度略８０％になるように温度・湿度が調整された気体が気体導入部１０から導入されるので、検査装置本体６内の温度が安定するまでの時間(静定時間)は短くて済む。また、結露しない。ステップＳ２０５〜Ｓ２０９と、Ｓ２１３〜Ｓ２１７は同じ動作であり、基準特定の測定時と検査時とで条件を同一にすることができる。 As described above, almost no heat is accumulated in the heat accumulation area during pressurization, and when the target pressure is reached, the temperature / humidity is adjusted so that the humidity is approximately 80% with the ambient temperature and no condensation. Since the adjusted gas is introduced from the gas introduction unit 10, the time until the temperature in the inspection apparatus main body 6 is stabilized (static time) can be short. Also, there is no condensation. Steps S <b> 205 to S <b> 209 and S <b> 213 to S <b> 217 are the same operation, and the conditions can be made the same at the time of reference specific measurement and at the time of inspection.
検査が終了したら、第３開閉弁５３、第２開閉弁５２を閉じて、第１空間８１、第３空間８３、第５空間８５を分離する（ステップＳ２１９）。次に、手動弁４８を「閉」位置として、ワークＷを大気開放とし、手動４方弁７０ごとワークＷを検査用接続口３２ａから取り外す（ステップＳ２２０）。ワークＷ内の気体は検査装置本体６の内部を通らずに手動弁４８を介して外界へ排出される。 When the inspection is completed, the third on-off valve 53 and the second on-off valve 52 are closed, and the first space 81, the third space 83, and the fifth space 85 are separated (step S219). Next, the manual valve 48 is set to the “closed” position, the workpiece W is opened to the atmosphere, and the workpiece W is removed from the inspection connection port 32a together with the manual four-way valve 70 (step S220). The gas in the workpiece W is discharged to the outside through the manual valve 48 without passing through the inside of the inspection apparatus main body 6.
次のワークＷを続けて検査する場合は（ステップＳ２２１;Ｎｏ）、ステップＳ２１３へ移行して作業を継続する。検査終了ならば（ステップＳ２２１;Ｙｅｓ）、本処理を終了する。 When the next workpiece W is continuously inspected (step S221; No), the process proceeds to step S213 and the operation is continued. If the inspection is finished (step S221; Yes), this process is finished.
なお、図１０の手順は、作業員が行う、あるいは一部（ワークＷの取り付け、取り外しなど）は作業員の手を借り、その他は制御基板が制御して実行する。 The procedure of FIG. 10 is performed by a worker, or a part (attachment / detachment of the workpiece W, etc.) is assisted by the worker, and the other is controlled and executed by the control board.
このように、リーク検査装置５では、マスタＭやワークＷを交換する場合にも、差圧センサ５０の両側の第１空間８１と第２空間８２はほぼ同じ圧力に維持されるので、差圧センサ５０の両側に大きな差圧が加わることがなく、高精度の差圧センサ５０を用いて、高圧下での検査を行うことができる。 As described above, in the leak inspection apparatus 5, the first space 81 and the second space 82 on both sides of the differential pressure sensor 50 are maintained at substantially the same pressure even when the master M and the workpiece W are replaced. A large differential pressure is not applied to both sides of the sensor 50, and a high-precision differential pressure sensor 50 can be used to perform inspection under high pressure.
また、第１空間８１、第２空間８２、第３空間８３、第４空間８４、第５空間８５は、マスタＭからワークＷへの交換やワークＷを次のワークＷに交換する際にも、ほぼ目標圧力に加圧された状態が維持されると共に、空間内の気体がほとんど入れ替わることがない。このため、気体の加圧導入や減圧開放時に生じる熱（断熱圧縮による発熱、断熱膨張による冷却と冷却された加湿空気の配管内結露、音速以下の空気通過による摩擦熱、音速以上の空気通過による衝撃波による加熱など）の影響をリーク検査装置５はほとんど受けることがなく、同じ条件で短時間のうちに複数のワークＷを検査することができる。 The first space 81, the second space 82, the third space 83, the fourth space 84, and the fifth space 85 are also used when the master M is replaced with the workpiece W or when the workpiece W is replaced with the next workpiece W. The state in which the pressure is almost increased to the target pressure is maintained, and the gas in the space is hardly changed. For this reason, heat generated when gas is introduced or released under reduced pressure (heat generation due to adiabatic compression, condensation due to adiabatic expansion, condensation in the piping of cooled humidified air, frictional heat due to passage of air below the speed of sound, passage of air above the speed of sound) The leak inspection apparatus 5 hardly receives the influence of heating by shock waves or the like, and can inspect a plurality of workpieces W in a short time under the same conditions.
また、検査装置本体６の配管やワークＷ、マスタＭは、それらの中に元々あった気体を、気体導入部１０で物理常数を調整した検査用気体で掃気した後、該検査用気体を加圧導入するので、元の気体が断熱圧縮されて発熱し、行き止まり箇所に熱が溜まることが防止・低減される。 In addition, the piping of the inspection apparatus main body 6, the workpiece W, and the master M scavenge the gas originally in them with the inspection gas whose physical constant is adjusted by the gas introduction unit 10, and then add the inspection gas. Since the pressure is introduced, the original gas is adiabatically compressed and generates heat, and heat is prevented and reduced from accumulating at the dead end.
特に、従来は掃気が困難であった非貫通型のワークＷやマスタＭの内部についても、内挿管７１、外郭管７２および手動４方弁７０を使用することで掃気が可能になった。ワークＷやマスタＭの内部を、検査用気体で事前に置換することで、ワークＷやマスタＭ内に元々あった気体が断熱圧縮されることによる発熱等を防止することができる。 In particular, it is possible to scavenge the inside of the non-penetrating workpiece W and the master M, which has conventionally been difficult to scavenge, by using the inner intubation tube 71, the outer tube 72, and the manual four-way valve 70. By replacing the inside of the workpiece W or the master M with the gas for inspection in advance, heat generated by the adiabatic compression of the gas originally in the workpiece W or the master M can be prevented.
また、各熱溜まり箇所ｄ１〜ｄ５、ｄ７についても、加圧時にそれらの箇所に溜まる熱い気体を、加圧終了の直前等に弁を少し開く制御、および滞留防止構造によって外部へ逃がして排熱している。差圧センサ５０の第１検出口５０ａ、第２検出口５０ｂでの熱溜まりについては、検出口５０ａ、５０ｂの極近傍に弁で開閉可能な第１掃気口３３ａ、第２掃気口３４ａを設け、加圧終了の直前等に該弁を開いて熱を外部へ逃がしている。また、恒温槽６０を設けることで、Ｓ２０９、Ｓ２１７の圧力の合わせ込みにおいても、差圧センサ５０の第１検出口５０ａに接する気体を一定温度に維持している。 In addition, for each of the heat accumulation points d1 to d5, d7, the hot gas accumulated in these points at the time of pressurization is released to the outside by a control that opens the valve a little before the end of pressurization and the stay prevention structure to exhaust heat. ing. For heat accumulation at the first detection port 50a and the second detection port 50b of the differential pressure sensor 50, a first scavenging port 33a and a second scavenging port 34a that can be opened and closed by a valve are provided in the immediate vicinity of the detection ports 50a and 50b. The valve is opened just before the end of pressurization to release heat to the outside. Further, by providing the constant temperature bath 60, the gas in contact with the first detection port 50a of the differential pressure sensor 50 is maintained at a constant temperature even when the pressures in S209 and S217 are adjusted.
このように、リーク検査装置５では、検査系、マスタＭやワークＷの内部を十分掃気すること、加圧時に各熱溜まり箇所ｄ１〜ｄ５、ｄ７に生じる熱を外部へ排出すること、恒温槽６０によって差圧センサ５０の両検出口に接する気体を一定温度に保つこと、ワークＷ交換時に検査系空間を閉鎖状態に維持すること等により、気体の加圧導入や減圧開放時に生じる熱（断熱圧縮による発熱、断熱膨張による冷却と冷却された加湿空気の配管内結露、音速以下の空気通過による摩擦熱、音速以上の空気通過による衝撃波による加熱など）の影響をほとんど受けずに、同じ条件で短時間のうちに複数のワークＷを検査することができる。 As described above, in the leak inspection apparatus 5, the inside of the inspection system, the master M and the workpiece W is sufficiently scavenged, the heat generated in the heat accumulation points d1 to d5 and d7 at the time of pressurization is discharged to the outside, and the thermostatic chamber 60 keeps the gas in contact with both detection ports of the differential pressure sensor 50 at a constant temperature, and maintains the inspection system space in a closed state when the workpiece W is exchanged. Under the same conditions without being affected by heat generated by compression, condensation due to adiabatic expansion and dew condensation in the piping of cooled humid air, frictional heat due to passage of air below the sonic velocity, heating by shock waves due to passage of air above the sonic velocity) A plurality of workpieces W can be inspected in a short time.
さらに、比熱（組成、湿度）をコントロールした検査用気体を気体導入部１０で生成して使用するので、圧力をかけた時に断熱圧縮で発生する熱量や減圧時に断熱膨張で放熱される熱量を空気線図等から事前に求めることができる。これを利用して本実施の形態に係るリーク検査装置５では、エアタンク１８から検査装置本体６へ気体を減圧導入したときに目標圧力となり、かつ周囲温度とほぼ同じ温度で結露しない状態が形成されるように制御し、静定時間の短縮等を図っている。 Further, since a test gas with controlled specific heat (composition, humidity) is generated and used in the gas introduction unit 10, the amount of heat generated by adiabatic compression when pressure is applied and the amount of heat released by adiabatic expansion during decompression are air. It can be obtained in advance from a diagram or the like. Using this, in the leak inspection apparatus 5 according to the present embodiment, a state is formed in which a target pressure is obtained when gas is introduced from the air tank 18 to the inspection apparatus body 6 under reduced pressure, and no condensation occurs at substantially the same temperature as the ambient temperature. In order to shorten the settling time, etc.
また、マスタＭやワークＷ内の気体を、手動弁４８から外部に排出するので、該気体が主管路３０等の検査装置本体６内をほとんど通らなくて済む。これにより、断熱膨張による冷却と冷却による加湿空気の配管内結露等を防ぐことができる。なお、ステップＳ２１９にて、第３開閉弁５３、第２開閉弁５２を閉じて、第１空間８１、第３空間８３、第５空間８５を分離した後に、ステップＳ２２０の手動弁４８を「閉」位置としていたが、その前に、手動４方弁７０を「第１開」の位置から「閉」の位置とした後に手動弁４８を「閉」位置とすることで手動弁４８と手動４方弁７０との間にあった空気を大気開放とし、手動４方弁７０ごとワークＷを検査用接続口３２ａから取り外した後に手動４方弁７０を「第１開」の位置とすることでワークＷを大気開放としても良い（ステップＳ２２０）。このようにすると検査装置の使用時間が短くなり、検査回数を増やすことができる。また、断熱膨張による冷却の影響を検査装置がより受け難くなる。さらに、準備用接続口３１ａは、熱的影響を受けないように検査装置本体６と別体にして、ステップ２１３等の加圧を行うようにすれば、ワークＷを加圧する際の断熱圧縮による熱の影響を検査装置本体６がより受け難くなる。 Further, since the gas in the master M and the work W is discharged to the outside from the manual valve 48, the gas hardly passes through the inspection apparatus main body 6 such as the main pipeline 30. As a result, it is possible to prevent cooling due to adiabatic expansion and condensation in the piping of humidified air due to cooling. In step S219, the third open / close valve 53 and the second open / close valve 52 are closed to separate the first space 81, the third space 83, and the fifth space 85, and then the manual valve 48 in step S220 is closed. The manual valve 48 and the manual 4 are moved to the “closed” position after the manual four-way valve 70 is moved from the “first open” position to the “closed” position. The air between the two-way valve 70 is opened to the atmosphere, and after the workpiece W is removed from the inspection connection port 32a together with the manual four-way valve 70, the manual four-way valve 70 is set to the “first open” position. May be opened to the atmosphere (step S220). In this way, the use time of the inspection apparatus is shortened, and the number of inspections can be increased. In addition, the inspection apparatus is less susceptible to the influence of cooling due to adiabatic expansion. Furthermore, if the connection port 31a for preparation is separated from the inspection apparatus main body 6 so as not to be affected by heat and pressurization such as step 213 is performed, adiabatic compression at the time of pressurizing the workpiece W is performed. The inspection apparatus body 6 is less susceptible to the influence of heat.
ところで、天候によって、加湿器１３に入る空気の温度や湿度、気圧が相違する。そこで、天候に左右されずに、毎日の検査を同じ条件で行うために、制御部２５は、加湿器１３で加湿しコンプレッサ１５で圧縮してエアタンク１８に蓄える空気が、一定密度（kg/m3）、一定比熱KJ(/kg・K)、一定熱伝導度W/(M・K)になるように加湿器１３、コンプレッサ１５、エアクーラ１６、エアドライヤ１７、ヒータ１９等を制御する。 By the way, the temperature, humidity, and atmospheric pressure of the air entering the humidifier 13 differ depending on the weather. Therefore, in order to perform daily inspections under the same conditions regardless of the weather, the control unit 25 has a constant density (kg / m) of air that is humidified by the humidifier 13 and compressed by the compressor 15 and stored in the air tank 18. 3 ) The humidifier 13, the compressor 15, the air cooler 16, the air dryer 17, the heater 19, and the like are controlled so as to have a constant specific heat KJ (/ kg · K) and a constant thermal conductivity W / (M · K).
なお、空気の比熱Ｃは以下の式によって求められる。
Ｃ＝（Ｃpa・ｔ＋（γ＋Ｃpv・ｔ）ｘ）／ｔ
Ｃpa：乾き空気の定圧比熱［1.006KJ/(kg/K)］
Ｃpv：水蒸気の定圧比熱［1.805KJ/(kg/K)］
γ：１気圧、０℃の水の蒸発潜熱［2500KJ/kg］
ｔ：湿り空気の温度［℃］
ｘ：絶対湿度[kg/kg(DA)]
In addition, the specific heat C of air is calculated | required by the following formula | equation.
C = (Cpa · t + (γ + Cpv · t) x) / t
Cpa: Constant pressure specific heat of dry air [1.006KJ / (kg / K)]
Cpv: Constant pressure specific heat of water vapor [1.805KJ / (kg / K)]
γ: latent heat of vaporization of water at 1 atm and 0 ° C [2500KJ / kg]
t: Temperature of humid air [° C]
x: Absolute humidity [kg / kg (DA)]
空気の比熱は、空気中に含まれる水分量（絶対湿度）に大きく左右されるので、空気に含ませることのできる水分量を多くするために、特に冬場においては、空気を加温して加湿することが有効になる。 The specific heat of air greatly depends on the amount of moisture (absolute humidity) contained in the air. Therefore, in order to increase the amount of moisture that can be contained in the air, the air is heated and humidified, especially in winter. To be effective.
たとえば、周囲から取り入れた空気を気体導入部１０に設けたヒータ１１で昇温してから加湿器１３で加湿する。加温しても（さらにコンプレッサ１５で圧縮されて発熱しても）エアタンク１８に貯留している間に放熱して雰囲気温度に近づく。すると、検査時に、主管路３０等に導かれた時に、電空レギュレータ４０で減圧されるので、断熱膨張によりさらに冷却される。そこで、主管路３０などの各管路（第１空間８１から第５空間８５を構成する管路）を断熱材で保温したり、エアタンク１８内にヒータ１９を入れて保温したりするとよい。 For example, the air taken in from the surroundings is heated by the heater 11 provided in the gas introduction unit 10 and then humidified by the humidifier 13. Even if it is heated (further compressed by the compressor 15 to generate heat), it is dissipated while it is stored in the air tank 18 and approaches the ambient temperature. Then, since the pressure is reduced by the electropneumatic regulator 40 when guided to the main pipeline 30 or the like at the time of inspection, it is further cooled by adiabatic expansion. In view of this, it is preferable to keep each pipe line such as the main pipe line 30 (the pipe lines constituting the first space 81 to the fifth space 85) with a heat insulating material, or to put the heater 19 in the air tank 18 to keep the temperature.
上記の保温は、電空レギュレータ４０で減圧冷却した温度が雰囲気温度となるように、減圧後の湿度、エアタンク１８内圧力、目標圧力等からエアタンク１３内の貯留温度を求めて制御する。このように、管路を断熱材で保温したり、エアタンク１８内にヒータ１９を入れて保温したりすることで、減圧した際に結露し難くなるので、加湿器１３で加湿後の空気の絶対湿度を高めることができる。 The above-described heat retention is controlled by obtaining the storage temperature in the air tank 13 from the reduced pressure, the pressure in the air tank 18, the target pressure, and the like so that the temperature cooled by the electropneumatic regulator 40 becomes the ambient temperature. In this way, it is difficult to condense when the pressure is reduced by keeping the pipe line with a heat insulating material or keeping the heater 19 in the air tank 18, so that the air after humidification by the humidifier 13 becomes absolute. Humidity can be increased.
ここで、エアタンク１８内に蓄える空気の湿度、温度を目標値に調整する際に気体導入部１０が行う制御や演算について説明する。 Here, the control and calculation performed by the gas introduction unit 10 when adjusting the humidity and temperature of the air stored in the air tank 18 to the target values will be described.
気体導入部１０の演算部２４は、空気の湿度を演算する第１演算、エアタンク１８内の加圧された空気の貯留温度を演算する第２演算、検査装置本体６内の目標圧力に対してエアタンク１８内の圧力をどの程度高くしておくかを表す係数の値を決定する第３演算等を行う。係数は、エアタンク１８内に蓄えられる空気圧力／目標圧力 で表される。 The calculation unit 24 of the gas introduction unit 10 performs a first calculation for calculating the humidity of the air, a second calculation for calculating a storage temperature of the pressurized air in the air tank 18, and a target pressure in the inspection apparatus body 6. A third calculation or the like is performed to determine a coefficient value indicating how much the pressure in the air tank 18 is kept high. The coefficient is expressed as air pressure / target pressure stored in the air tank 18.
空気の湿度を演算する第１演算は次のように行なう。 The first calculation for calculating the humidity of the air is performed as follows.
大気圧をＰ１、検査での目標圧力をＰ２、気体導入部１０に取り入れる空気の温度をＴ１、エアタンク１８の出口での気体の温度をＴ２、大気圧Ｐ１かつ温度Ｔ１での飽和水蒸気量をＶ１、大気圧Ｐ１かつ温度Ｔ２での飽和水蒸気量をＶ２とし、エアタンク内での気体を湿度１００％とする場合、
加圧前の大気圧下の空気に必要な湿度Ｈ１は、
Ｈ１＝Ｖ２×圧縮比÷Ｖ１×１００＝Ｖ２×（Ｐ１／（（Ｐ１＋Ｐ２）×係数））÷Ｖ１×１００
として求まる。
The atmospheric pressure is P1, the target pressure in the inspection is P2, the temperature of the air introduced into the gas introduction unit 10 is T1, the temperature of the gas at the outlet of the air tank 18 is T2, and the saturated water vapor amount at the atmospheric pressure P1 and the temperature T1 is V1. When the saturated water vapor amount at atmospheric pressure P1 and temperature T2 is V2, and the gas in the air tank is 100% humidity,
Humidity H1 required for air under atmospheric pressure before pressurization is
H1 = V2 × compression ratio ÷ V1 × 100 = V2 × (P1 / ((P1 + P2) × coefficient)) ÷ V1 × 100
It is obtained as
必要な湿度Ｈ１が、大気圧下の加湿前の空気の湿度Ｈ２より高ければ、（Ｈ１−Ｈ２）だけ加湿器１３で加湿する必要があり、Ｈ１がＨ２以下であれば、加湿器１３で加湿する必要はない。 If the required humidity H1 is higher than the humidity H2 of the air before humidification under atmospheric pressure, it is necessary to humidify only by (H1-H2) with the humidifier 13, and if H1 is equal to or less than H2, the humidifier 13 humidifies. do not have to.
＜演算例１＞
たとえば、大気圧１００ＫＰａ、目標圧力９００ＫＰａ、目標加圧時相対湿度１００％、係数１．３、気体導入部１０に取り入れる空気の温度Ｔ１が３０℃、エアタンク１８の出口で気体の温度Ｔ２が３０℃の時について、必要な湿度Ｈ１を求める。
<Calculation Example 1>
For example, the atmospheric pressure is 100 KPa, the target pressure is 900 KPa, the target pressurization relative humidity is 100%, the coefficient is 1.3, the temperature T1 of the air introduced into the gas introduction unit 10 is 30 ° C., and the temperature T 2 of the gas at the outlet of the air tank 18 is 30 ° C. For this time, the required humidity H1 is obtained.
この場合の圧縮比は、
圧縮比＝１／１３（＝大気圧１００ＫＰａ／（（大気圧１００ＫＰａ＋９００ＫＰａ目標圧力）×係数１．３）） となる。
The compression ratio in this case is
Compression ratio = 1/13 (= atmospheric pressure 100 KPa / ((atmospheric pressure 100 KPa + 900 KPa target pressure) × factor 1.3)).
雰囲気温度Ｔ１が３０℃のとき、検査装置本体６に供給される圧縮空気の温度（エアタンク１８の出口での気体の温度）Ｔ２も、周囲温度と同じ３０℃にすべきである。大気圧下かつ３０℃での飽和水蒸気量Ｖ２は３０．４（g/m3）なので、気体導入部１０から吐出する空気中の（湿度１００％時の）水分量Ｋは、
水分量Ｋ＝Ｖ２×圧縮比＝３０．４（g/m3）×（１／１３）＝２．３３８（g/m3）となる。
When the atmospheric temperature T1 is 30 ° C., the temperature of the compressed air supplied to the inspection apparatus body 6 (the temperature of the gas at the outlet of the air tank 18) T2 should also be 30 ° C., which is the same as the ambient temperature. Since the saturated water vapor amount V2 under atmospheric pressure and 30 ° C. is 30.4 (g / m 3 ), the water amount K (at 100% humidity) in the air discharged from the gas inlet 10 is
Water content K = V2 × compression ratio = 30.4 (g / m 3 ) × (1/13) = 2.338 (g / m 3 ).
加湿器１３の入口温度Ｔ１が３０℃ならば、加湿器１３の入側の空気の飽和水蒸気量Ｖ１はＶ２と同じ３０．４（g/m3）である。よって大気圧下かつ３０℃での必要な湿度Ｈ１は、
Ｈ１＝Ｖ２×圧縮比÷Ｖ１×１００＝Ｋ÷Ｖ１×１００＝２．３３８／３０．４×１００＝７．７％となる。
If the inlet temperature T1 of the humidifier 13 is 30 ° C., the saturated water vapor amount V1 of the air on the inlet side of the humidifier 13 is 30.4 (g / m 3), which is the same as V2. Therefore, the required humidity H1 at atmospheric pressure and 30 ° C. is
H1 = V2 × compression ratio ÷ V1 × 100 = K ÷ V1 × 100 = 2.338 / 30.4 × 100 = 7.7%.
したがって、加湿器１３の入口湿度が約７．７％以下ならば加湿を行って約７．７％以上としてエアドライヤ１７（コンプレッサ１５）に送り込む（７．７％は大気圧時湿度）。例えば夏期では、気温が高く（例えば３０℃）湿度も高い（例えば６５％RH）。このような時期において雰囲気の湿度を測定する温湿度センサ２２の出力が例えば６５％RHを出力していた場合には、目標圧力から求める必要湿度Ｈ１（上記演算例１）が約７．７％なので、この差（７．７−６５．０）がマイナスの場合には加湿不要として、加湿器１３を動かす（加湿する）ことは行わない。 Therefore, if the humidity at the inlet of the humidifier 13 is about 7.7% or less, humidification is performed and the air is fed to the air dryer 17 (compressor 15) as about 7.7% or more (7.7% is humidity at atmospheric pressure). For example, in summer, the temperature is high (eg, 30 ° C.) and the humidity is high (eg, 65% RH). When the output of the temperature / humidity sensor 22 for measuring the humidity of the atmosphere at this time is, for example, 65% RH, the required humidity H1 (calculation example 1) obtained from the target pressure is about 7.7%. Therefore, when this difference (7.7-65.0) is negative, the humidifier 13 is not moved (humidified) without humidification.
なお、検査装置本体６が置かれている場所の雰囲気温度と気体導入部１０に入る空気の温度とが異なる場合には下記のように演算を行う。 In addition, when the atmospheric temperature of the place where the test | inspection apparatus main body 6 is placed differs from the temperature of the air which enters the gas introduction part 10, it calculates as follows.
＜演算例２＞
目標加圧時相対湿度１００％、目標圧力４２０ＫＰａ、大気圧１０３ＫＰａ、気体導入部１０に入る空気の温度１０℃、検査装置本体の周囲の雰囲気温度が２５℃の場合、
大気圧下、１０℃での飽和水蒸気量は９．４（g/m3）、
大気圧下、２５℃での飽和水蒸気量は２３．０（g/m3）、
圧縮比＝１０３／（（４２０＋１０３）×１．３）＝０．１５１から
Ｈ１＝Ｖ２×圧縮比÷Ｖ１×１００＝２３．０×０．１５１÷９．４×１００＝３７．１％ となる。
<Calculation Example 2>
When the target pressure is 100% relative humidity, the target pressure is 420 KPa, the atmospheric pressure is 103 KPa, the temperature of the air entering the gas introduction unit 10 is 10 ° C., and the ambient temperature around the inspection apparatus body is 25 ° C.
The saturated water vapor amount at 10 ° C. under atmospheric pressure is 9.4 (g / m 3 ),
The saturated water vapor amount at 25 ° C. under atmospheric pressure is 23.0 (g / m 3 ),
From compression ratio = 103 / ((420 + 103) × 1.3) = 0.151, H1 = V2 × compression ratio ÷ V1 × 100 = 23.0 × 0.151 ÷ 9.4 × 100 = 37.1% .
雰囲気温度が仮に１０℃であれば、Ｈ１＝１５．１％であるが、雰囲気温度が２５℃なので３７．１％以上としてエアドライヤ１７（コンプレッサ１５に送り込む。 If the atmospheric temperature is 10 ° C., H1 = 15.1%. However, since the atmospheric temperature is 25 ° C., the air temperature is set to 37.1% or more, and the air dryer 17 (feeds to the compressor 15).
例えば冬期では、気温が低く（例えば10℃）湿度も低い（例えば12％RH／25℃）。このような時期において雰囲気の湿度を測定する温湿度センサ２２の出力が例えば１２％RH／２５℃を出力していた場合には、目標圧力から求める必要湿度Ｈ１（上記演算例２）が約３７．１％となるので、この差がプラスの場合（０＜（３７．１％−１２．０％））には加湿必要として、加湿器１３を大気圧時湿度において３７．１％となるように動かして加湿する。 For example, in winter, the temperature is low (eg, 10 ° C.) and the humidity is low (eg, 12% RH / 25 ° C.). When the output of the temperature / humidity sensor 22 for measuring the humidity of the atmosphere at this time is, for example, 12% RH / 25 ° C., the required humidity H1 (the above calculation example 2) obtained from the target pressure is about 37. Therefore, if this difference is positive (0 <(37.1% -12.0%)), it is necessary to humidify the humidifier 13 so that the humidity at atmospheric pressure is 37.1%. Move to to humidify.
すなわち、この加湿によって、例えば春〜秋期に至る期間（例えば演算例１の場合）と、乾燥した冬場の期間（例えば演算例２の場合）とで、加圧時の湿度に差が生じないように、すなわち、検査条件に差が生じないようにしている。 That is, this humidification does not cause a difference in humidity during pressurization between, for example, a period from spring to autumn (for example, in the case of Calculation Example 1) and a dry winter period (for example, in the case of Calculation Example 2). In other words, no difference occurs in the inspection conditions.
次に、エアタンク１８内の加圧された空気の貯留温度を演算する第２演算について説明する。エアタンク１８内の加圧された空気の貯留温度は下記のようにして求める。 Next, the 2nd calculation which calculates the storage temperature of the pressurized air in the air tank 18 is demonstrated. The storage temperature of the pressurized air in the air tank 18 is obtained as follows.
例えば、大気圧１００ＫＰａ、目標圧力９００ＫＰａ、係数１．３の場合、エアタンク内の圧力は１２００ＫＰａ（＝（（大気圧１００ＫＰａ＋９００ＫＰａ目標圧力）×係数１．３）−大気圧１００ＫＰａ）であるが、この空気が検査装置本体６に充填されると９００ＫＰａ（目標圧力）となる。 For example, when the atmospheric pressure is 100 KPa, the target pressure is 900 KPa, and the coefficient is 1.3, the pressure in the air tank is 1200 KPa (= ((atmospheric pressure 100 KPa + 900 KPa target pressure) × factor 1.3) −atmospheric pressure 100 KPa). Becomes 900 KPa (target pressure) when the inspection apparatus body 6 is filled.
すなわち、減圧充填されるので、エアタンク内にある時に比して充填されると温度が下がる（検査装置本体６は断熱構造ではないが、断熱圧縮時の発熱と逆の現象（断熱膨張）で温度が下がる）。検査装置本体６内に空気を加圧導入して目標圧力である９００ＫＰａになったときの検査装置本体６内の空気の温度が周囲温度と略同じになれば、加圧導入直後に、温度の安定した状態にすることができる。そこで、該状態にすべく係数１．３に基づき（正確には大気圧、湿度等も考慮に入れて）、周囲温度に比して所定温度高めた温度でエアタンク１３内に空気を蓄える。 That is, since it is filled under reduced pressure, the temperature drops when it is filled as compared to when it is in the air tank (the inspection device body 6 is not a heat insulating structure, but the temperature is a phenomenon reverse to heat generation during adiabatic compression (adiabatic expansion)) ). If the temperature of the air in the inspection apparatus main body 6 when the air is pressurized and introduced into the inspection apparatus main body 6 and reaches the target pressure of 900 KPa becomes substantially the same as the ambient temperature, It can be in a stable state. Therefore, air is stored in the air tank 13 at a temperature that is higher than the ambient temperature by a predetermined temperature based on the coefficient 1.3 (accurately taking into account atmospheric pressure, humidity, and the like) to achieve this state.
この時、所定温度高めた温度を下記理由に基づいてやや低めとしても良い。詳述すると、図９に示すＳ２０３、Ｓ２０８、Ｓ２１６等の加圧時と、Ｓ２０９、Ｓ２１２、Ｓ２１７、Ｓ２２０等の減圧時において、空気と検査装置本体６内の配管との摩擦によって熱が発生する（摩擦発熱）。この摩擦発熱の大きさはマッハ数（空気の速度）によって左右される（断熱圧縮の温度は圧力の0.3乗に比例するが、マッハ１を超えると衝撃波が発生し、圧力に比例する別の温度上昇現象が発生するのでマッハ１未満としている）。 At this time, the temperature increased by a predetermined temperature may be slightly lowered based on the following reason. More specifically, heat is generated by friction between air and piping in the inspection apparatus main body 6 during pressurization such as S203, S208, and S216 shown in FIG. 9 and during decompression such as S209, S212, S217, and S220. (Friction heat generation). The magnitude of this frictional heat generation depends on the Mach number (the speed of air) (the temperature of adiabatic compression is proportional to the 0.3th power of the pressure, but if Mach 1 is exceeded, a shock wave is generated and another temperature proportional to the pressure. As the rising phenomenon occurs, it is set to less than Mach 1).
ところで、掃気によってある程度の熱は除去できるものの、掃気時間を短くしようとすればするほど摩擦発熱の熱が残ってしまう（発熱の絶対量が多くなる為）。そこで、摩擦発熱のうちの掃気で除去しきれなかった蓄熱分を、加圧時に周囲温度より少し低い温度の空気をエアタンク１８から導入して相殺する。 By the way, although a certain amount of heat can be removed by scavenging, the heat of frictional heat remains as the scavenging time is shortened (because the absolute amount of heat generation increases). Therefore, the heat stored in the frictional heat that cannot be removed by scavenging is offset by introducing air at a temperature slightly lower than the ambient temperature from the air tank 18 during pressurization.
これにより、加圧後の静定時間中の放熱は、検査装置本体６内の空気温度と周囲温度との差がほぼない状態からスタートする僅かな放熱となるので、掃気の短時間化を図ることができる。このように、エアタンク１８内の加圧された空気の貯留温度は、周囲温度に比して所定温度高めた温度ではなく、摩擦発熱を相殺するためにやや低めとしても良い。 As a result, the heat release during the settling time after pressurization is a slight heat release starting from a state in which there is almost no difference between the air temperature in the inspection apparatus main body 6 and the ambient temperature, thereby shortening the scavenging time. be able to. As described above, the storage temperature of the pressurized air in the air tank 18 is not a temperature increased by a predetermined temperature compared to the ambient temperature, and may be slightly lower in order to offset the frictional heat generation.
次に、目標圧力に対してエアタンク１８内の圧力をどの程度高くすべきかを示す係数の値を決定する第３演算について説明する。係数は固定でなくても良い。 Next, the third calculation for determining the value of the coefficient indicating how much the pressure in the air tank 18 should be higher than the target pressure will be described. The coefficient may not be fixed.
たとえば、大気圧１００ＫＰａ、目標圧力８００ＫＰａ（加圧時相対湿度８０％）、係数１．３の場合、エアタンク１８内の圧力は１０７０ＫＰａ（＝（（大気圧１００ＫＰａ＋目標圧力８００ＫＰａ）×係数１．３）−大気圧１００ＫＰａ）にされる。１０７０ＫＰａのエアタンク１８内の湿度を１００％（加圧時相対湿度）とすると、８００ＫＰａに減圧したときの湿度は、以下に示すように７７％になる。 For example, when the atmospheric pressure is 100 KPa, the target pressure is 800 KPa (relative humidity at pressurization is 80%), and the coefficient is 1.3, the pressure in the air tank 18 is 1070 KPa (= ((atmospheric pressure 100 KPa + target pressure 800 KPa) × factor 1.3) -Atmospheric pressure 100 KPa). Assuming that the humidity in the 1070 KPa air tank 18 is 100% (relative humidity during pressurization), the humidity when reduced to 800 KPa is 77% as shown below.
エアタンク内の圧力が１０７０ＫＰａ時の圧縮比は、圧縮比＝大気圧／（（大気圧＋目標圧力）×１．３）＝１００／（（１００＋８００）×１．３）＝１／１１．７であり、目標圧力における圧縮比は、圧縮比＝大気圧／（大気圧＋目標圧力）＝１００／（１００＋８００）＝１／９、である。したがって、
圧縮比１／１１．７：湿度１００％＝圧縮比１／９：７７％、
なので、８００ＫＰａに減圧したときの湿度は７７％になる。
The compression ratio when the pressure in the air tank is 1070 KPa is compression ratio = atmospheric pressure / ((atmospheric pressure + target pressure) × 1.3) = 100 / ((100 + 800) × 1.3) = 1 / 11.7. The compression ratio at the target pressure is compression ratio = atmospheric pressure / (atmospheric pressure + target pressure) = 100 / (100 + 800) = 1/9. Therefore,
Compression ratio 1 / 11.7: Humidity 100% = Compression ratio 1/9: 77%
Therefore, the humidity when the pressure is reduced to 800 KPa is 77%.
このように、係数１．３の場合には目標圧力８００ＫＰａとすると検査装置本体６に導入したときの気体の湿度は７７％となり、希望の８０％にならない。そこで、第３演算では、係数を、たとえば、１．３から１．２５に変更する。すなわち、目標圧力８００ＫＰａに対してエアタンク１８内の圧力を１０７０ＫＰａから１０２５ＫＰａに落とす。こうすると、加圧時間が長くなって検査時間が延びるものの、目標圧力８００ＫＰａ時の湿度を略８０％以上（加圧時相対湿度）にすることができ、検査装置本体６に送りこむ気体の比熱を大きくして、温度による影響を少なくできる。 Thus, in the case of the coefficient 1.3, if the target pressure is 800 KPa, the humidity of the gas when introduced into the inspection apparatus main body 6 is 77%, not the desired 80%. Therefore, in the third calculation, the coefficient is changed from 1.3 to 1.25, for example. That is, the pressure in the air tank 18 is reduced from 1070 KPa to 1025 KPa with respect to the target pressure 800 KPa. In this way, although the pressurization time is extended and the inspection time is extended, the humidity at the target pressure of 800 KPa can be made approximately 80% or more (relative humidity at the time of pressurization), and the specific heat of the gas sent to the inspection apparatus main body 6 can be reduced. The effect of temperature can be reduced by increasing it.
なお、エアタンク１８の容量Ｖと、エアタンク１８内の圧力Ｐ１と、必要吐出圧力Ｐ２と、使用空気量（必要空気量−吐出空気量）（ｍ３）と、使用時間ｔ（分）との間には以下の関係がある。
Ｖ＝Ｑ×ｔ÷（（Ｐ１−Ｐ２）×１０）
Note that the volume V of the air tank 18, the pressure P1 within air tank 18, required discharge pressure P2, the working air rate - between the (required air volume air delivery) (m 3), and using the time t (min) Have the following relationship:
V = Q × t ÷ ((P1-P2) × 10)
ここで、検査圧力の切換えがある場合について説明する。 Here, the case where the inspection pressure is switched will be described.
まず、検査準備として、第１空間８１〜第５空間８５を目標圧力に加圧した後、冷やして、安定な状態にする（図９のＳ２０１〜Ｓ２０３）。前回の検査が演算例１に示すような目標圧力（９００ＫＰａ）であり、今回の検査が演算例２に示すような目標圧力（４２０ＫＰａ）であるような場合には、以下のような方法でリーク検査装置５の検査装置本体６内の掃気を行う。 First, as an inspection preparation, the first space 81 to the fifth space 85 are pressurized to a target pressure and then cooled to a stable state (S201 to S203 in FIG. 9). When the previous test is the target pressure (900 KPa) as shown in Calculation Example 1 and the current test is the target pressure (420 KPa) as shown in Calculation Example 2, the following method is used to leak The scavenging in the inspection apparatus body 6 of the inspection apparatus 5 is performed.
すなわち、前回の検査は目標圧力９００ＫＰａ（雰囲気温度30℃）であり、気体導入部１０に蓄える気体は、圧力が１２００ＫＰａ（＝((100+900)×1.3)-100）で湿度は１００％（加圧時湿度）なので、これを絶対湿度に換算すると２．３(＝30.4×1/13)（g/m3）となる。 That is, in the previous inspection, the target pressure is 900 KPa (atmosphere temperature 30 ° C.), and the gas stored in the gas introduction unit 10 has a pressure of 1200 KPa (= ((100 + 900) × 1.3) -100) and a humidity of 100% ( (Humidity during pressurization), so when converted to absolute humidity, it becomes 2.3 (= 30.4 × 1/13) (g / m 3 ).
今回の検査が目標圧力４２０ＫＰａ（雰囲気温度25℃）の場合、絶対湿度は３．５(＝23.0×1/13)（g/m3）となり、前回の検査状態を放置したまま今回の検査を行うと、第１空間８１、第２空間８２内に残っている空気の湿度（例えば絶対湿度２．３g/m3）と、今回検査に用いる空気の湿度（例えば絶対湿度３．５g/m3）とが異なることとなり、検査毎に少しずつ空間内の空気が今回の検査の空気と入れ替わる第１空間８１と、まったく入れ替わらない第２空間８２内の空気の湿度（比熱）が異なることとなり、測定毎に誤差が生じてくる。 If the current inspection is at a target pressure of 420 KPa (atmosphere temperature 25 ° C), the absolute humidity will be 3.5 (= 23.0 × 1/13) (g / m 3 ). As a result, the humidity of the air remaining in the first space 81 and the second space 82 (for example, absolute humidity 2.3 g / m 3 ) and the humidity of the air used for this inspection (for example, absolute humidity 3.5 g / m 3). ), And the humidity (specific heat) of the air in the first space 81 where the air in the space is replaced little by little for each inspection and the air in the second space 82 where the air is not replaced at all is different for each inspection. An error occurs for each measurement.
そこで検査条件が異なる場合には、事前に第１空間８１、第２空間８２（さらに第３空間８３〜第５空間８５）内の空気を入れ替える。さらに初回の検査前にもこの掃気を行う。なぜならば、第１空間８１から第５空間８５内の空気はリーク検査装置５の検査装置本体６が組立てられた時の空気で満たされているためである。 Therefore, when the inspection conditions are different, the air in the first space 81 and the second space 82 (further, the third space 83 to the fifth space 85) is replaced in advance. This scavenging is also performed before the first examination. This is because the air in the first space 81 to the fifth space 85 is filled with air when the inspection device body 6 of the leak inspection device 5 is assembled.
このような掃気を行うことで、第１空間８１、第２空間８２（さらに第３空間８３から第５空間８５）内の空気が同一となり、同一の物理常数（検査用気体の調湿を行って、同一温度、同一圧力の元で、同一の比熱）を持った空気での比較を行うことができる。 By performing such scavenging, the air in the first space 81 and the second space 82 (further, from the third space 83 to the fifth space 85) becomes the same, and the same physical constant (the humidity of the test gas is adjusted). Thus, a comparison can be made with air having the same specific heat) under the same temperature and pressure.
次に、熱溜まり箇所の発熱を掃気で解消する点について、より詳しく説明する。 Next, the point of eliminating the heat generation at the heat accumulation location by scavenging will be described in more detail.
例えば、大気圧１００ＫＰａ、目標圧力８００ＫＰａ、係数１．２５の場合、エアタンク１８内には、気体が１０２５ＫＰａ（＝（（大気圧１００ＫＰａ＋８００ＫＰａ目標圧力）×係数１．２５）−大気圧１００ＫＰａ）で蓄えられる。この時のエアタンク１８内湿度が略１００％であれば、気体導入部１０からリーク検査装置５の検査装置本体６に減圧導入されると湿度は略８０％（加圧時相対湿度）となる。 For example, when the atmospheric pressure is 100 KPa, the target pressure is 800 KPa, and the coefficient is 1.25, the gas is stored in the air tank 18 at 1025 KPa (= ((atmospheric pressure 100 KPa + 800 KPa target pressure) × coefficient 1.25) −atmospheric pressure 100 KPa). . If the humidity in the air tank 18 at this time is approximately 100%, when the reduced pressure is introduced from the gas introduction unit 10 to the inspection apparatus body 6 of the leak inspection apparatus 5, the humidity becomes approximately 80% (relative humidity during pressurization).
前述したようにＳ２０３での発熱は、加圧の終了直前に排気弁４５等を少し開いて熱溜まり箇所ｄ１〜ｄ４に溜まっている気体を外界へ排出する制御およびＹ字型の滞留防止構造により解消され、Ｓ２０８やＳ２１６での発熱は、排気弁４５等を開いて熱溜まり箇所ｄ１、ｄ２、ｄ５、ｄ７に溜まっている熱を外界へ排出する圧力合わせ込み制御およびＹ字型の滞留防止構造により、解消される。 As described above, the heat generation in S203 is caused by the control of discharging the gas accumulated in the heat accumulation points d1 to d4 to the outside by slightly opening the exhaust valve 45 and the like immediately before the pressurization and the Y-shaped retention prevention structure. The heat generation in S208 and S216 is canceled, and the pressure adjustment control and the Y-shaped retention prevention structure that opens the exhaust valve 45 etc. and discharges the heat accumulated in the heat accumulation locations d1, d2, d5, d7 to the outside It is solved by.
ところが、マスタＭやワークＷ内の発熱箇所ｄ６の熱は、上記の制御や滞留防止構造では解消されない。リーク検査装置５では、ワークＷやマスタＭ内を気体導入部１０から導入される気体で事前に掃気することで発熱箇所ｄ６の発熱を防止している。もしも、これを行わない場合には以下のようなになる。 However, the heat of the heat generation point d6 in the master M or the workpiece W is not eliminated by the above-described control or stay prevention structure. In the leak inspection apparatus 5, the work W and the master M are scavenged in advance with the gas introduced from the gas introduction unit 10, thereby preventing the heat generation point d <b> 6 from generating heat. If you do not do this, it will look like this:
たとえば、大気圧１００ＫＰａ、目標圧力８００ＫＰａ、雰囲気温度が３０℃、雰囲気湿度６５％RH、係数（第三演算により）１．３→１．２５、エアタンク１８内湿度略１００％（加圧時相対湿度）、リーク検査装置５の検査装置本体６へ送られる空気の湿度が略８０％（加圧時相対湿度）の時（温度は第二演算により雰囲気温度）、エアタンク１８から導入されてワークＷに向けて送られる加圧空気は雰囲気温度と同じ３０℃（目標圧力８００ＫＰａ加圧時温度）で、湿度略８０％（目標圧力８００ＫＰａ加圧時湿度）である。 For example, the atmospheric pressure is 100 KPa, the target pressure is 800 KPa, the atmospheric temperature is 30 ° C., the atmospheric humidity is 65% RH, the coefficient (according to the third calculation) is 1.3 → 1.25, the humidity in the air tank is approximately 100% (relative humidity at pressurization) ) When the humidity of the air sent to the inspection apparatus main body 6 of the leak inspection apparatus 5 is approximately 80% (relative humidity during pressurization) (temperature is the ambient temperature by the second calculation), the air is introduced from the air tank 18 to the workpiece W. The pressurized air sent toward is 30 ° C. (temperature when the target pressure is 800 KPa), which is the same as the ambient temperature, and the humidity is approximately 80% (humidity when the target pressure is 800 KPa).
しかし、事前の掃気を行わない場合には、元々ワークＷ内にあった空気が、雰囲気温度と同じ３０℃（大気圧時温度）、雰囲気湿度６５％（大気圧時相対湿度）で満たされている場合が多い。ワークＷ内の空気は加圧により発熱（図１０の発熱箇所ｄ６）し、この熱は対流してワークＷ（タンク）内上方に移動するが、時間と共に雰囲気温度に近づく（図１１参照）。雰囲気温度（３０℃）に近づいた（例えば＋０〜＋１０℃以内程度）ところでリーク検査が終了するが、この時ワークＷ（タンク）内では以下のような現象が予想される。 However, if no prior scavenging is performed, the air originally in the work W is filled with the same atmospheric temperature as 30 ° C. (atmospheric pressure) and atmospheric humidity of 65% (atmospheric relative humidity). There are many cases. The air in the work W generates heat by heating (heat generation point d6 in FIG. 10), and this heat convects and moves upward in the work W (tank), but approaches the ambient temperature with time (see FIG. 11). The leak inspection ends when the ambient temperature approaches 30 ° C. (for example, within about +0 to + 10 ° C.). At this time, the following phenomenon is expected in the workpiece W (tank).
すなわち、大気圧時相対湿度６５％のワークＷ内にあった空気は、加圧後に体積は１／９（＝−１００ＫＰａ／（８００ＫＰａ＋１００ＫＰａ））になり、これによって湿度は５８５％（＝６５％×９ 目標圧力８００ＫＰａ加圧時湿度at３０℃）となる。すなわち、図１１にあるように時間と共に放熱すると、タンク内では水蒸気（気体）が水（液体）に変化し、それと共に潜熱を放熱する。すなわち、ワークＷの漏れ検査を判別終了するまでの静定時間が潜熱放熱により延びる。さらに、タンク内表面を部分的にうっすら水膜が覆った状態となる。 That is, the air in the workpiece W having a relative humidity of 65% at atmospheric pressure has a volume of 1/9 (= −100 KPa / (800 KPa + 100 KPa)) after pressurization, whereby the humidity is 585% (= 65% × 9 Target pressure 800 KPa pressurization humidity at 30 ° C.). That is, as shown in FIG. 11, when heat is released with time, water vapor (gas) changes to water (liquid) in the tank, and latent heat is released with it. In other words, the settling time until the work W leakage inspection is completed is extended by latent heat radiation. Furthermore, a water film partially covers the inner surface of the tank.
ところで、検査時と実際の使用時とでワークＷの中に入れるものが同じ気体であれば、検査時の判定基準となる漏れ気体量と、実際に使用する際に許される気体の漏れ許容量とに同じ基準値を用いることができる。しかし、内部に液体を入れて使用する容器（例えば電気温水器で使用するようなステンレス製温水貯湯タンク（オールステンレス）、瞬間湯沸器で使用するような銅製熱交換器（銅製フィンと銅管）など）をワークＷとする場合には、実際の使用時に許される液体の漏れ許容値を気体の漏れ量に換算して、検査時用漏れ許容値（気体）を設定しなければならない。 By the way, if the gas to be put into the workpiece W is the same during inspection and during actual use, the amount of leaked gas that is a criterion for inspection and the allowable amount of gas allowed during actual use The same reference value can be used for. However, containers that use liquids inside (for example, stainless steel hot water storage tanks (all stainless steel) used in electric water heaters, copper heat exchangers (copper fins and copper tubes used in instant water heaters), etc. ), Etc.) is the workpiece W, the allowable leakage value of liquid allowed in actual use must be converted into the amount of gas leakage, and the inspection allowable leakage value (gas) must be set.
この換算に当たっては粘性係数の差を用いて換算する。ところが、ワークＷ（タンク）で漏れを生じている部分に水滴（水膜）が付着しているならば漏れ検査基準は、液体の漏れ量を用いなくてはならない。しかし、前述したように、検査において、タンク内表面を部分的にうっすら水膜が覆った状態になる場合、漏れを生じている部分に水滴（水膜）が付着していかどうかが判らない（漏れ塞ぎ現象）。 In this conversion, conversion is performed using the difference in viscosity coefficient. However, if water droplets (water film) are attached to the part where leakage occurs in the workpiece W (tank), the leakage inspection standard must use the amount of liquid leakage. However, as described above, in the inspection, when the water film partially covers the inner surface of the tank, it is not known whether water droplets (water film) are attached to the leaking part ( Leak plugging phenomenon).
さらに、結露→放熱妨害→滴下→放熱復活のサイクルを経ていると思われる圧力変化の揺らぎが、静定期間終了後のまさに漏れ検査を行おうとする時（リーク検査終了間際）に発生しており、正確に検査することが難しい（圧力揺らぎ現象）。 In addition, the fluctuation of pressure change that seems to have gone through the cycle of condensation-> heat radiation disturbance-> dripping-> heat radiation recovery occurs when trying to perform a leak test after the end of the static period (immediately after the leak test). It is difficult to inspect accurately (pressure fluctuation phenomenon).
そこで、本実施の形態に係るリーク検査装置５の検査装置本体６では、上記したワークＷ内結露を防止すべく、電空レギュレータ４０の下流側を２手に分岐し、検査前に大気圧時相対湿度６５％（at３０℃）のワークＷ内にあった空気を、８００ＫＰａ時相対湿度８０％（at３０℃）＝大気圧時相対湿度８．９％（at３０℃）の空気で置換しておくことで、上記の問題を解決している。 Therefore, in the inspection apparatus body 6 of the leak inspection apparatus 5 according to the present embodiment, the downstream side of the electropneumatic regulator 40 is branched into two hands in order to prevent the above-described dew condensation in the workpiece W, and at atmospheric pressure before the inspection. Replace the air in the workpiece W with a relative humidity of 65% (at 30 ° C) with air at a relative humidity of 80% (at 30 ° C) at 800 KPa = 8.9% (at 30 ° C) relative humidity at atmospheric pressure. This solves the above problem.
さらにワークＷには、手動４方弁７０が取り付けられており、気体導入部１０から送り込んだ空気と雰囲気空気（例えば相対湿度６５％（at３０℃））とが混ざらないようにしている。この時、ワークＷ内に閉じ込めた空気の圧力は、大気圧であろうと、負圧であろうと、目標圧力であろうとかまわない。 Further, a manual four-way valve 70 is attached to the workpiece W so that air sent from the gas introduction unit 10 and ambient air (for example, relative humidity 65% (at 30 ° C.)) are not mixed. At this time, the pressure of the air confined in the workpiece W may be an atmospheric pressure, a negative pressure, or a target pressure.
ところで、ワークＷに取りつけられた手動４方弁７０のワークＷでない側（接続口１側）は大気（例えば相対湿度６５％（at３０℃））で満たされており、さらに検査装置本体６の検査用接続口３２ａの部分も大気で満たされており、図９のステップＳ２１４でのワークＷの取りつけにあたって、手動弁４８と手動４方弁７０との間も大気圧時相対湿度６５％（at３０℃）の大気が封印されてしまう。 By the way, the non-work W side (connection port 1 side) of the manual four-way valve 70 attached to the work W is filled with the atmosphere (for example, relative humidity 65% (at 30 ° C.)), and further the inspection of the inspection apparatus main body 6 is performed. The portion of the connection port 32a is also filled with the atmosphere. When the work W is attached in step S214 in FIG. 9, the relative humidity at atmospheric pressure is 65% (at 30 ° C.) between the manual valve 48 and the manual four-way valve 70. ) Will be sealed.
そこでステップＳ２１５（マスタＭの場合はＳ２０７）にて、手動４方弁７０を一時的に「第２開」としてパージを行って、調湿されていない空気がワークＷ内に流れ込むことを防止している。これにより、第１空間８１〜第５空間８５内の空気だけではなく、ワークＷ内、手動弁４８と手動４方弁７０の間の空気も同一となり、同一の物理常数を持った空気での比較（漏れ検査）を行うことができる。 Therefore, in step S215 (S207 in the case of the master M), the manual four-way valve 70 is temporarily set to “second open” and purged to prevent unconditioned air from flowing into the workpiece W. ing. As a result, not only the air in the first space 81 to the fifth space 85 but also the air in the work W and between the manual valve 48 and the manual four-way valve 70 are the same, and the air with the same physical constant is used. Comparison (leakage inspection) can be performed.
ところで、気体導入部１０から送られる気体以外の気体（例えば雰囲気）が、ワークＷやワークＷに取りつけられた手動４方弁７０と手動弁４８との間の配管等の中に入っているが故に（気体導入部１０から送られる気体と同一の物理常数を持っていない空気がワークＷや配管に満たされているが故に）、加圧時に結露が発生し、漏れ塞ぎ現象等の不具合が発生するが、リーク検査装置５では、慣性掃気を可能とする構造（滞留防止構造）と、排気弁４５等を開いて目標圧力に合わせ込む等の制御（「発熱箇所の掃気解消」を含む）等により、これを解消している。 By the way, although gas (for example, atmosphere) other than the gas sent from the gas introduction part 10 is contained in piping etc. between the manual four-way valve 70 and the manual valve 48 attached to the workpiece W or the workpiece W. Therefore, because the work W and piping are filled with air that does not have the same physical constant as the gas sent from the gas introduction unit 10, condensation occurs during pressurization, causing problems such as leakage blockage. However, in the leak inspection apparatus 5, a structure that enables inertia scavenging (residence prevention structure), control such as opening the exhaust valve 45 and the like to match the target pressure (including “scavenging elimination of heat generation points”), etc. This has been solved.
例えば、リーク検査装置５の検査装置本体６が組立てられた（製造された）時に、分岐管端部に残っていた内部空気が除去され、また例えば、リーク検査装置５の検査装置本体６と気体導入部１０が接続された時の、検査装置本体６〜気体導入部１０間の配管内気体（雰囲気）が掃気される。 For example, when the inspection apparatus main body 6 of the leak inspection apparatus 5 is assembled (manufactured), the internal air remaining at the end of the branch pipe is removed, and for example, the inspection apparatus main body 6 of the leak inspection apparatus 5 and the gas The gas (atmosphere) in the pipe between the inspection apparatus main body 6 and the gas introduction unit 10 when the introduction unit 10 is connected is scavenged.
ところで、結露を防止するのならば、例えば、リーク検査装置５の組立てにあたって、湿度が「０」のような環境で組立てれば良い。しかしそれでは気体導入部１０から送られる気体の物理常数と異なる空気でリーク検査が行われることとなり、物理常数を同じとした空気条件下での比較ができず、無意味である。 By the way, in order to prevent condensation, for example, when assembling the leak inspection apparatus 5, it may be assembled in an environment where the humidity is “0”. However, in that case, the leak inspection is performed with air different from the physical constant of the gas sent from the gas introduction unit 10, and the comparison under the air condition with the same physical constant cannot be performed, which is meaningless.
本発明に係るリーク検査装置５では、冬場であっても加湿することで、温度の影響を受け難い比熱の大きい気体で検査するという特徴を有している。このことは特に乾燥地帯（エジプト、モロッコ等）での検査にあたっては、通年して加湿した空気で検査できるので特に有効である。 The leak inspection apparatus 5 according to the present invention has a feature of performing inspection with a gas having a large specific heat that is not easily affected by temperature by humidifying even in winter. This is particularly effective when testing in dry areas (Egypt, Morocco, etc.) because it can be tested with humidified air throughout the year.
次にリーク検査を行うワークＷの製造方法について述べる。本実施の形態に係るリーク検査装置５が検査対象とするものは、内部に液体を入れて使用する容器（例えば電気温水器で使用するようなステンレス製温水貯湯タンク（オールステンレス）、瞬間湯沸器で使用するような銅製熱交換器（銅製フィンと銅管））であり、溶接によって作られる（又は射出成型によるプラスチック製温水貯湯タンクでも良い）。 Next, a method for manufacturing the workpiece W for leak inspection will be described. The leak inspection apparatus 5 according to the present embodiment is to be inspected for a container to be used with liquid inside (for example, a stainless hot water hot water storage tank (all stainless steel) used in an electric water heater, Copper heat exchangers (copper fins and copper tubes) as used in the oven, and made by welding (or plastic hot water storage tanks by injection molding).
内部に気体を入れて使用する容器としてのワークＷをリーク検査するならば、許される漏れ許容値として気体の漏れ量を簡単に設定できる。すなわち、検査時と実際の使用時とでワークＷの中に入れるものが同じ気体であれば、検査時の判定基準となる漏れ気体量と、実際に使用する際に許される気体の漏れ許容量とに同じ基準値を用いることができる。しかし、液体を入れて用いるワークの検査に気体を用いる場合には、実際の使用時に許される液体の漏れ許容値を気体の漏れ量に換算して、検査時用漏れ許容値（気体）を設定しなければならない。 If the workpiece W as a container to be used with gas inside is subjected to a leak inspection, the amount of gas leakage can be easily set as an allowable leakage allowable value. In other words, if the gas to be put into the workpiece W is the same during inspection and during actual use, the amount of leakage gas used as a criterion for inspection and the allowable amount of gas allowed during actual use The same reference value can be used for. However, when gas is used for inspection of workpieces that contain liquid, the allowable leakage value of liquid allowed during actual use is converted into the amount of gas leakage, and the allowable leakage value (gas) for inspection is set. Must.
この換算に当たっては動粘性係数の差を用いて換算する。本発明での検査対象の容器としてのワークＷは、製造して、リーク検査合格後に機器に組み込まれる。例えば瞬間湯沸器の場合には出荷検査で（内部に組み込まれたワークＷを含めて）水を通水するが、ステンレス製温水貯湯タンクがワークＷのような場合には機器に組み込まれて施工現場に運び込まれてから初めて、ワークＷを組み込んだ製品に通水される。すなわち、ワークＷは容器に加工される部品（例えばステンレス板、銅板、銅管等部品）段階から容器形状となってリーク検査に至るまでの間は、一度も通水されることなく、水で洗浄されることもない。 In this conversion, conversion is performed using the difference in the kinematic viscosity coefficient. The workpiece W as a container to be inspected in the present invention is manufactured and incorporated into an apparatus after passing the leak inspection. For example, in the case of an instantaneous water heater, water is passed through the shipping inspection (including the work W incorporated inside), but when the stainless hot water hot water storage tank is like the work W, it is built into the equipment. Only after being transported to the construction site is water passed through the product incorporating the workpiece W. In other words, the workpiece W is made of water without being passed through from the part processed into a container (for example, a stainless steel plate, a copper plate, a copper pipe, etc.) to the shape of the container until leak inspection. It is not washed.
ところで、ワークＷと同じはずのマスタＭを元に基準特性（ステップＳ２１０）を取得し、複数のワークＷのリーク検査を行うが、マスタＭを含めた複数のワークＷ（以下ワークＷ等）間の製造誤差によりそれぞれの重さが微妙に異なり、リーク検査に影響を与える（外乱）。本実施の形態で用いているワークＷ等の重量差は、部品に用いている母材と異なる（比熱が異なる）物、たとえば内部の水等によって重量が異なるわけではないので（ワークＷ等と比熱が異なる外乱物の混入がないので、「比熱が異なる外乱物の除去」は不要なので）、重量の差は母材重量の差である。そこで、マスタＭとの重量差を補正するために、母材と同一材質で作った補正部品を、ワークＷ内に入れたり検査用接続口３２ａに接続する部品内に取り付けたりすることで重量差を補正する（ワークＷ等と「同一比熱補正部品を用いた外乱防止」）。 By the way, the reference characteristic (step S210) is acquired based on the master M that should be the same as the workpiece W, and a plurality of workpieces W are inspected for leaks. Between the workpieces W including the master M (hereinafter referred to as workpieces W, etc.) Depending on the manufacturing error, each weight is slightly different and affects the leak inspection (disturbance). The difference in weight of the workpiece W or the like used in the present embodiment is different from the base material used in the parts (differing in specific heat), for example, the weight does not differ depending on the internal water or the like (with the workpiece W or the like). Since there is no mixing of disturbances with different specific heats, “removal of disturbances with different specific heats is unnecessary”), the difference in weight is the difference in the weight of the base material. Therefore, in order to correct the weight difference with the master M, a correction part made of the same material as the base material is put in the work W or in a part connected to the inspection connection port 32a, so that the weight difference is obtained. (“Disturbance prevention using the same specific heat correction component” with the workpiece W etc.).
もちろん、検査用接続口３２ａに接続する部品や検査用接続口３２ａに接続する場所以外の開口部を塞ぐ補機類の材質と重量も、複数のワークＷ等間で差がないように同一部材を用いると共に同じ重量物を用いることで熱容量を合わせる（「接続口に接続する部品や補機類による外乱防止」）。 Of course, the same material is used so that there is no difference in the materials and weights of the parts connected to the inspection connection port 32a and the auxiliary equipment that closes the opening other than the location connected to the inspection connection port 32a. The heat capacity is adjusted by using the same heavy object ("Preventing disturbance caused by parts and accessories connected to the connection port").
このような各種外乱の防止を行った後、均温化作業に入る。すなわち、ワークＷ等間で温度が異なると、その保有熱量によりリーク検査に影響を与えるのでそれを除去する（「保有熱量合わせ込みによる外乱防止」）。上述のような外乱防止は、ステップＳ２０１〜ステップＳ２０４のように、基準特性や検査の前日までに行うとよい。 After preventing such various disturbances, the temperature equalizing operation is started. That is, if the temperature differs between the workpieces W and the like, the leakage inspection is affected by the amount of retained heat, so that it is removed (“disturbance prevention by adjusting the amount of retained heat”). The above-described disturbance prevention is preferably performed by the day before the reference characteristic or inspection, as in steps S201 to S204.
ところで断熱圧縮による発熱は、検査にあたってリーク検査装置５の検査装置本体６に導入される気体と異なる気体（例えば前回検査して放熱しきって温度が異なる気体や、ワークＷが作られた際に一緒に閉じ込められた湿度・温度が違う気体等）が残っているからなのであるから、例えば検査に先立ちリーク検査装置５の検査装置本体６内の気体、ワークＷ内気体、マスタＭ内気体、差圧センサ５０内気体等、検査装置本体内のすべてを真空吸引してしまえば、断熱圧縮による発熱問題は一気に解消される。発熱の根源である気体を無くしてしまうのであるから理想的である（ただし、真空吸引に起因する減圧冷却が静定する静定時間が代わりに必要となる）。 By the way, the heat generated by the adiabatic compression is different from the gas introduced into the inspection apparatus body 6 of the leak inspection apparatus 5 in the inspection (for example, when the work W is made, or the gas having a different temperature after the previous inspection is dissipated). For example, the gas in the inspection device body 6 of the leak inspection device 5, the gas in the workpiece W, the gas in the master M, the differential pressure, etc., before the inspection. If all of the inside of the inspection apparatus main body such as the gas in the sensor 50 is vacuumed, the heat generation problem due to adiabatic compression is solved at once. It is ideal because it eliminates the gas that is the source of heat generation (however, a settling time is required instead to settle the reduced pressure cooling due to vacuum suction).
ところが真空吸引しても発熱の根源である気体を完全に無くすことはできない。なぜならば、気体のない空間（絶対真空）をだれ一人つくれた者がいないからである。このことはＪＩＳの定義で、真空とは「大気圧より低い圧力の気体で満たされている特定の空間の状態」となっていることからも判る。すなわち、真空にしても気体が残存するので断熱圧縮による発熱は回避できない。 However, even if vacuum suction is used, the gas that is the source of heat generation cannot be completely eliminated. Because no one has created a space without gas (absolute vacuum). This is the definition of JIS, and it can be understood from the fact that the vacuum is “a state of a specific space filled with a gas having a pressure lower than the atmospheric pressure”. In other words, since the gas remains even in a vacuum, heat generation due to adiabatic compression cannot be avoided.
本発明では、負圧吸引で真空を作り、そこに気体導入部１０からの検査用気体を流し込むことで、新旧気体の置換をはかるのではなく、気体導入部１０から検査用気体を流し込み、加圧掃気で新旧気体の置換を行った。これにより、コンプレッサ１５のほかに真空ポンプを設ける必要がない。 In the present invention, a vacuum is created by negative pressure suction, and the inspection gas from the gas introduction unit 10 is poured into the vacuum, so that the old and new gases are not replaced, but the inspection gas is introduced from the gas introduction unit 10 and added. The old and new gases were replaced by pressure scavenging. Thereby, it is not necessary to provide a vacuum pump in addition to the compressor 15.
さらに付言すれば、真空吸引の方式では、以下のような方法を取り得る。すなわち、真空吸引によって減圧冷却が起き、この時所定量の気体を残して加圧すれば残った気体の断熱圧縮で発熱がおきる。そこで、この減圧冷却量と断熱圧縮発熱量が等量になった時点で吸引から加圧に切り替えれば、熱が相殺され、たとえ完全に吸引（絶対真空）を作ることができなくとも目的（測定時間の短縮化）を達することができる。 In addition, in the vacuum suction method, the following method can be taken. That is, the vacuum suction is caused by vacuum suction, and at this time, if pressure is applied while leaving a predetermined amount of gas, heat is generated by adiabatic compression of the remaining gas. Therefore, if switching from suction to pressurization when the reduced pressure cooling amount and the adiabatic compression heat generation amount are equal, the heat is offset and even if the suction (absolute vacuum) cannot be made completely, the purpose (measurement) Time reduction).
ところが、吸引が足りずに加圧したり、逆に吸引しすぎてから加圧したりする場合には、熱が相殺できずに測定毎の誤差が生じる。これに対して、加圧掃気による新旧気体の置換では、所定時間以上の掃気であれば良く、測定毎の誤差を簡単に収束させることができる。 However, when the pressure is applied without sufficient suction, or when the pressure is applied after excessive suction, the heat cannot be offset and an error occurs for each measurement. On the other hand, in the replacement of old and new gases by pressurized scavenging, it is sufficient if the scavenging is performed for a predetermined time or longer, and the error for each measurement can be easily converged.
次に、液体の漏れ許容値を気体の漏れ量に換算する換算計算式等について説明する。 Next, a conversion calculation formula for converting the liquid leakage allowable value into the gas leakage amount will be described.
＜粘性係数を用いた換算計算式＞
細孔から漏れる流量は粘性係数を用いて計算することができる。
<Conversion formula using viscosity coefficient>
The flow rate leaking from the pores can be calculated using the viscosity coefficient.
粘性係数（μ Pa・s）20℃時 水のμ＝0.0010050Pa・s 空気のμ＝0.0000181Pa・s、細孔の直径 0.1mm（＝0.0001m）、細孔の長さ 1mm（＝0.001m）、大気圧（雰囲気の気圧）101300Pa Abs、細孔入口圧（目標圧力）300kPa G（＝401300Pa Abs）、細孔出口圧（雰囲気の圧力）0kPa G（＝101300Pa Abs）の時の水の漏れ量は、
ΔＰ（以下、水ΔＰとする）＝[細孔入口圧]−[細孔出口圧]（Pa Abs）＝300000（Pa Abs）
とすると、
[水の漏れ量]＝π×[細孔の直径]4×[水ΔＰ]／（128×[水のμ]×[細孔の長さ]）
＝3.14×0.0001[m]４×（300000[Pa Abs]）／（128×0.0010050[Pa・s]×0.001[m]
＝0.00000073[m3/s]＝0.73[ml/s]、となる。
Viscosity (μ Pa · s) at 20 ° C Water μ = 0.0010050 Pa · s Air μ = 0.0000181 Pa · s, pore diameter 0.1 mm (= 0.0001 m), pore length 1 mm (= 0.001 m ), Atmospheric pressure (atmospheric pressure) 101300Pa Abs, pore inlet pressure (target pressure) 300kPa G (= 401300Pa Abs), pore outlet pressure (atmospheric pressure) 0kPa G (= 101300Pa Abs) The amount is
ΔP (hereinafter referred to as water ΔP) = [pore inlet pressure] − [pore outlet pressure] (Pa Abs) = 300000 (Pa Abs)
Then,
[Water leakage amount] = π × [pore diameter] 4 × [water ΔP] / (128 × [water μ] × [pore length])
= 3.14 x 0.0001 [m] 4 x (300000 [Pa Abs]) / (128 x 0.0010050 [Pa · s] x 0.001 [m]
= 0.00000073 [m3 / s] = 0.73 [ml / s].
これに対し空気の漏れ量は、水が非圧縮性流体であるのに対し、空気は圧縮性流体であるので差圧（以下、空気ΔＰとする）は下記のように表される。 On the other hand, the amount of air leakage is expressed as follows, since water is an incompressible fluid, whereas air is a compressible fluid, and hence the differential pressure (hereinafter referred to as air ΔP).
空気ΔＰ＝（[細孔入口圧]2-[細孔出口圧]2)／（2×[細孔入口圧]）
＝744225（Pa Abs）
[空気の漏れ量]＝π×[細孔の直径]4×[空気ΔＰ]／（128×[空気のμ]×[細孔の長さ]）
＝3.14×0.0001[m]4×（744225[Pa Abs]）／（128×0.0000181[Pa・s]×0.001[m]
＝0.00010087[m3/s]＝100.87[ml/s]、となる。
Air ΔP = ([pore inlet pressure] 2- [pore outlet pressure] 2 ) / (2 × [pore inlet pressure])
= 744225 (Pa Abs)
[Air leakage amount] = π × [pore diameter] 4 × [air ΔP] / (128 × [μ of air] × [length of pore])
= 3.14 × 0.0001 [m] 4 × (744225 [Pa Abs]) / (128 × 0.0000181 [Pa · s] × 0.001 [m]
= 0.00010087 [m3 / s] = 100.87 [ml / s].
[水の漏れ量]を基に、リーク検査装置からの[空気の漏れ量]を換算する為の換算係数（[水の細孔入口圧]＝[空気の細孔入口圧]とした場合に）は、
[空気の漏れ量]＝[水の漏れ量]×[換算係数]
[換算係数]＝[空気の漏れ量]／[水の漏れ量]
＝（[細孔入口圧]2-[細孔出口圧]2)×[水のμ]／（2×[細孔入口圧]×[空気のμ]×（[細孔入口圧]−[細孔出口圧]））
＝137.7（＝100.87／0.73） となる。
Based on the [Water Leakage], a conversion factor ([Water pore inlet pressure] = [Air pore inlet pressure]) to convert [Air leak amount] from the leak inspection device )
[Air leakage] = [Water leakage] x [Conversion factor]
[Conversion factor] = [Air leakage] / [Water leakage]
= ([Pore inlet pressure] 2- [pore outlet pressure] 2 ) × [μ of water] / (2 × [pore inlet pressure] × [μ of air] × ([pore inlet pressure] − [ Pore outlet pressure]))
= 137.7 (= 100.87 / 0.73)
たとえば、70℃の温水を300[kPa G]で蓄えるタンクの許容温水漏れ量が10[ml/h]の時で検査時の周囲温度（＝リーク検査装置に満たされる気体温度）が20℃の時に200[kPa G]で検査する場合（[水の細孔入口圧]＝[空気の細孔入口圧]とならない場合）には、[20℃空気のμ]＝0.0000181Pa・s、[70℃の温水のμ]＝0.0004Pa・s、大気圧（雰囲気の気圧）101300Pa Absとすると、
[換算係数]＝[空気の漏れ量]／[水の漏れ量]は、
[空気の漏れ量]＝π×[細孔の直径]4×[空気ΔＰ]／（128×[空気のμ]×[細孔の長さ]）
[水の漏れ量]＝π×[細孔の直径]4×[水ΔＰ]／（128×[水のμ]×[細孔の長さ]） なので、
[換算係数]＝（[空気ΔＰ]×[水のμ]）／（[空気のμ]×[水ΔＰ]）
で表される。計算すると、
[換算係数]＝29.28（＝292.8／10） となり、
許容気体漏れ量（[空気の漏れ量]）＝292.8[ml/h] として求められる。
For example, when the allowable hot water leakage of a tank that stores hot water of 70 ° C at 300 [kPa G] is 10 [ml / h], the ambient temperature during inspection (= the gas temperature that fills the leak inspection device) is 20 ° C Sometimes when testing at 200 [kPa G] (when [pore inlet pressure of water] = [air inlet pressure of air]), [20 ° C. air μ] = 0.0000181 Pa · s, [70 ℃ hot water μ] = 0.0004Pa · s, atmospheric pressure (atmospheric pressure) 101300Pa Abs,
[Conversion factor] = [Air leakage] / [Water leakage]
[Air leakage amount] = π × [pore diameter] 4 × [air ΔP] / (128 × [μ of air] × [length of pore])
[Water leakage amount] = π × [pore diameter] 4 × [water ΔP] / (128 × [water μ] × [pore length])
[Conversion factor] = ([Air ΔP] × [Water μ]) / ([Air μ] × [Water ΔP])
It is represented by When calculating
[Conversion factor] = 29.28 (= 292.8 / 10)
Allowable gas leakage ([air leakage]) = 292.8 [ml / h].
但し、圧力センサには誤差があるので、その分を考慮に入れて換算係数を修正して、許容気体漏れ量を設定する必要がある。ここでは、
Ａ：高耐圧（片耐圧が例えば１０００ＫＰａ以上）で、誤差２５０Ｐａ、測定精度（誤差）０．０２５％／フルスケールの第２圧力センサ２４を用いる場合
Ｂ：高耐圧（片耐圧が例えば１０００ＫＰａ以上）で、わずかな差圧を判別できる（誤差２．５Ｐａ、測定精度（誤差）０．０００２５％／フルスケール）差圧センサを用いる場合
を比較して説明する。
However, since there is an error in the pressure sensor, it is necessary to set the allowable gas leakage amount by correcting the conversion factor in consideration of the error. here,
A: High breakdown voltage (single breakdown voltage is 1000 KPa or more, for example), error 250 Pa, measurement accuracy (error) 0.025% / full scale second pressure sensor 24 is used B: high breakdown voltage (single breakdown voltage is 1000 KPa or more, for example) A case where a differential pressure sensor that can discriminate a slight differential pressure (error 2.5 Pa, measurement accuracy (error) 0.00025% / full scale) is used will be compared and described.
Ａの差圧センサを用いる場合、目標圧力８００ＫＰａに対して、８００．２５ＫＰａまで加圧しても誤差があるので、本当の圧力は８００．０〜８００．５ＫＰａの範囲の圧力であることしか判らない（誤差２５０Ｐａ）。漏れ量はＢと同程度に測れるが、加圧する目標圧力に対する誤差があるので、前述の換算係数の演算で用いる細孔入口圧が変わり、Ｂに対してある程度厳しい漏れ判定基準を用いなければならない。 When the differential pressure sensor of A is used, there is an error even if the pressure is increased up to 800.25 KPa with respect to the target pressure of 800 KPa. Therefore, it can be understood that the real pressure is a pressure in the range of 800.0 to 800.5 KPa. (Error 250 Pa). Although the amount of leakage can be measured to the same extent as B, there is an error with respect to the target pressure to be pressurized, so the pore inlet pressure used in the above calculation of the conversion coefficient changes, and a somewhat strict leakage criterion for B must be used. .
すなわち、Ａの場合、
空気ΔＰ＝([901550±250 Pa Abs]２-［101300 Pa Abs］２)／(2×[901300±250 Pa Abs])
[換算係数]＝[空気ΔＰ]×［水のμ］／[空気のμ]×[水ΔＰ]で表される。計算すると、
[換算係数]＝(([901550-250 Pa Abs]２-［101300 Pa Abs］２)／(2×[901300-250 Pa Abs])×［水のμ］／[空気のμ]×[水ΔＰ]、となる。
That is, in the case of A,
Air ΔP = ([901550 ± 250 Pa Abs] 2 − [101300 Pa Abs] 2 ) / (2 × [901300 ± 250 Pa Abs])
[Conversion factor] = [Air ΔP] × [Water μ] / [Air μ] × [Water ΔP]. When calculating
[Conversion factor] = (([901550-250 Pa Abs] 2- [101300 Pa Abs] 2 ) / (2 x [901300-250 Pa Abs]) x [mu of water] / [mu of air] x [water ΔP].
Ｂの差圧センサを用いる場合、目標圧力８００ＫＰａに対して、８００．２５ＫＰａまで加圧すると、本当の圧力は８００．２４７５〜８００．２５２５ＫＰの範囲にある。したがって、Ｂの場合、
空気ΔＰ＝([901550±2.5 Pa Abs]２-［101300 Pa Abs］２)／(2×[901300±2.5 Pa Abs])
[換算係数]＝[空気ΔＰ]×［水のμ］／[空気のμ]×[水ΔＰ]で表され、計算すると、
[換算係数]＝(([901550-2.5 Pa Abs]２-［101300 Pa Abs］２)／(2×[901300-2.5 Pa Abs])×［水のμ］／[空気のμ]×[水ΔＰ]、となる。
When the differential pressure sensor of B is used, if the pressure is increased to 800.25 KPa with respect to the target pressure of 800 KPa, the real pressure is in the range of 800.2475 to 800.2525 KP. Therefore, for B,
Air ΔP = ([901550 ± 2.5 Pa Abs] 2 − [101300 Pa Abs] 2 ) / (2 × [901300 ± 2.5 Pa Abs])
[Conversion factor] = [Air ΔP] × [Water μ] / [Air μ] × [Water ΔP]
[Conversion factor] = (([901550-2.5 Pa Abs] 2- [101300 Pa Abs] 2 ) / (2 × [901300-2.5 Pa Abs]) × [water μ] / [air μ] × [water ΔP].
したがって、Ｂに対してＡの方を厳しい判定基準にすることで、同等の測定（判定）が可能になる。 Therefore, equivalent measurement (determination) is possible by using A as a stricter determination criterion than B.
以上、本発明の実施の形態を図面によって説明してきたが、具体的な構成は実施の形態に示したものに限られるものではなく、本発明の要旨を逸脱しない範囲における変更や追加があっても本発明に含まれる。 The embodiment of the present invention has been described with reference to the drawings. However, the specific configuration is not limited to that shown in the embodiment, and there are changes and additions within the scope of the present invention. Are also included in the present invention.
実施の形態では、比熱の大きい気体を、加湿した空気としたが、雰囲気より比熱の大きい気体は、たとえば、エチレン、メタン、ヘリウム等の単体、あるいはこれを空気に混ぜたものであってもよい。また、加圧導入する気体は、雰囲気より比熱の大きい気体に限定されず、任意の気体でよく、周囲の空気であっても構わない。 In the embodiment, the gas having a large specific heat is humidified air, but the gas having a specific heat larger than that of the atmosphere may be, for example, a single substance such as ethylene, methane, or helium, or a mixture of this with air. . Moreover, the gas to be introduced under pressure is not limited to a gas having a specific heat larger than that of the atmosphere, and may be an arbitrary gas or ambient air.
実施の形態では、電空レギュレータ４０の下流で配管を二手に分けて準備用接続口３１ａを設けたが、ワークＷやマスタＭ内を掃気して事前に検査用気体で満たす作業は、別途の場所で行われてもよい。ただし、完全に物理常数が同一の検査用気体を用いるには、本実施の形態で示したように、気体導入部１０から配管を二手に分けて気体を供給することが望ましい。 In the embodiment, the piping is divided into two at the downstream of the electropneumatic regulator 40 and the preparation connection port 31a is provided. However, the work of scavenging the work W or the master M and filling it with the inspection gas in advance is performed separately. It may be done at the place. However, in order to use a test gas having the same physical constant, it is desirable to supply the gas from the gas introduction unit 10 in two separate ways as shown in the present embodiment.
本発明に係るリーク検査装置の構成は、実施の形態に例示したものに限定されない。例えば、差圧センサ５０の両側の熱溜まりを解消するために第１掃気口３３ａ、第２掃気口３４ａを設けたが、Ｙ字型の滞留防止構造等で対応してもかまわない。 The configuration of the leak inspection apparatus according to the present invention is not limited to that illustrated in the embodiment. For example, although the first scavenging port 33a and the second scavenging port 34a are provided in order to eliminate heat accumulation on both sides of the differential pressure sensor 50, a Y-shaped retention preventing structure or the like may be used.
実施の形態では、内挿管７１をワークＷの最も奥側で終端させて開口させ、外郭管７２はワークＷの入口近くで終端して開口させ、ワークＷの奥から入口側へ向かう気体の流れを起こして掃気するようにしたが、この流れは逆にされてもよい。すなわち、ワークＷ内の入口近くで終端する管から検査用気体をワークＷ内に導入し、ワークＷ内の奥で終端する管を通じてワークＷ内の気体を外部に排出するようにしてもよい。 In the embodiment, the inner tube 71 is terminated and opened at the innermost side of the workpiece W, the outer tube 72 is terminated and opened near the inlet of the workpiece W, and the gas flow from the inner side of the workpiece W toward the inlet side is opened. However, this flow may be reversed. That is, the inspection gas may be introduced into the work W from a pipe that terminates near the entrance in the work W, and the gas in the work W may be discharged to the outside through a pipe that terminates in the back of the work W.
５…リーク検査装置
６…検査装置本体
１０…気体導入部
１０ａ…気体吐出口
１１…ヒータ
１２…入側温度センサ
１３…加湿器
１４…湿度センサ
１５…コンプレッサ
１６…エアクーラ
１７…エアドライヤ
１８…エアタンク
１９…ヒータ
２１…気圧計
２２…温湿度センサ
２３…出側温度センサ
２４…演算部
２５…制御部
３０…主管路
３０ａ…排気ポート
３１…第１分岐管
３１ａ…準備用接続口
３２…第２分岐管
３２ａ…検査用接続口
３３…第３分岐管
３３ａ…第１掃気口
３４…第４分岐管
３４ａ…第２掃気口
３６…第１掃気管
３７…第２掃気管
３８…第３掃気管
３８ａ…掃気ポート
４０…電空レギュレータ
４１…第１開閉弁
４２…圧力センサ
４４…第１排気弁
４５…第２排気弁
４６…第１分岐管開閉弁
４７…手動弁
４８…手動弁
５０…差圧センサ
５０ａ…第１検出口
５０ｂ…第２検出口
５２…第２開閉弁
５３…第３開閉弁
５４…第４開閉弁
５５…第５開閉弁
５６…第１サブ掃気弁
５７…第２サブ掃気弁
５８…メイン掃気弁
６０…恒温槽
７０…手動４方弁
７１…内挿管
７２…外郭管
８１…第１空間
８２…第２空間
８３…第３空間
８４…第４空間
８５…第５空間
Ｂ１…第１分岐箇所
Ｂ２…第２分岐箇所
Ｂ３…第３分岐箇所
Ｂ４…第４分岐箇所
ｄ１…熱溜まり箇所
ｄ２…熱溜まり箇所
ｄ３…熱溜まり箇所
ｄ４…熱溜まり箇所
ｄ５…熱溜まり箇所
ｄ６…熱溜まり箇所
ｄ７…熱溜まり箇所
Ｍ…マスタ
Ｍａ…小マスタ
Ｍｂ…小マスタ
Ｗ…ワーク
DESCRIPTION OF SYMBOLS 5 ... Leak inspection apparatus 6 ... Inspection apparatus main body 10 ... Gas introduction part 10a ... Gas discharge port 11 ... Heater 12 ... Incoming temperature sensor 13 ... Humidifier 14 ... Humidity sensor 15 ... Compressor 16 ... Air cooler 17 ... Air dryer 18 ... Air tank 19 ... Heater 21 ... Barometer 22 ... Temperature / humidity sensor 23 ... Exit side temperature sensor 24 ... Calculation unit 25 ... Control unit 30 ... Main pipeline 30a ... Exhaust port 31 ... First branch pipe 31a ... Preparation connection port 32 ... Second branch Pipe 32a ... Inspection port 33 ... Third branch pipe 33a ... First scavenging port 34 ... Fourth branch pipe 34a ... Second scavenging port 36 ... First scavenging pipe 37 ... Second scavenging pipe 38 ... Third scavenging pipe 38a ... scavenging port 40 ... electro-pneumatic regulator 41 ... first on-off valve 42 ... pressure sensor 44 ... first exhaust valve 45 ... second exhaust valve 46 ... first branch pipe on-off valve 47 ... manual valve 4 ... manual valve 50 ... differential pressure sensor 50a ... first detection port 50b ... second detection port 52 ... second on-off valve 53 ... third on-off valve 54 ... fourth on-off valve 55 ... fifth on-off valve 56 ... first sub scavenging Valve 57 ... Second sub scavenging valve 58 ... Main scavenging valve 60 ... Thermostatic chamber 70 ... Manual four-way valve 71 ... Inner tube 72 ... Outer tube 81 ... First space 82 ... Second space 83 ... Third space 84 ... Fourth Space 85 ... Fifth space B1 ... First branch point B2 ... Second branch point B3 ... Third branch point B4 ... Fourth branch point d1 ... Heat accumulation point d2 ... Heat accumulation point d3 ... Heat accumulation point d4 ... Heat accumulation point d5 ... Heat accumulation location d6 ... Heat accumulation location d7 ... Heat accumulation location M ... Master Ma ... Small master Mb ... Small master W ... Workpiece
Claims (10)
前記一方の管から前記所定の気体を前記容器内にさらに導入して前記容器内を加圧した後、前記一方の管を閉鎖して前記容器を含む密閉空間を形成する加圧ステップと、
前記密閉空間の圧力を圧力計で測定して前記容器に漏れがあるか否かを検査する測定ステップと、
を有する
ことを特徴とするリーク検査方法。 The inlet in a state in which a first pipe that terminates on the back side in the container and a second pipe that terminates on the inlet side in the container are inserted into the container from the inlet of the non-penetrating container to be inspected. And by sending a predetermined gas from one of the first pipe and the second pipe into the container, the gas in the container is exhausted from the other pipe and the inside of the container is An in-vessel scavenging step of closing the other tube after filling with a predetermined gas;
A pressure step of further introducing the predetermined gas from the one tube into the container to pressurize the container, and then closing the one tube to form a sealed space including the container;
A measurement step of measuring the pressure of the sealed space with a pressure gauge and checking whether or not there is a leak in the container;
A leak inspection method characterized by comprising:
ことを特徴とする請求項１に記載のリーク検査方法。 The leak inspection method according to claim 1, wherein the first tube is the one tube, and the second tube is the other tube.
前記密閉した前記検査系空間に前記密閉空間を連通させる接続ステップとをさらに備え、
前記接続ステップによって前記密閉空間と前記検査系空間が連通した状態で前記測定ステップを行う
ことを特徴とする請求項１または２に記載のリーク検査方法。 A test system pressurization that seals the test system space after introducing the same gas as the predetermined gas from a gas supply source into the test system space communicating with the detection port of the pressure gauge. Steps,
A connection step of communicating the sealed space with the sealed inspection system space,
The leak inspection method according to claim 1 or 2, wherein the measurement step is performed in a state where the sealed space and the inspection system space communicate with each other by the connection step.
前記検査系掃気ステップにて前記検査系空間を掃気してから前記検査系加圧ステップを行う
ことを特徴とする請求項３に記載のリーク検査方法。 An inspection system scavenging step of scavenging the inspection system space with a gas supplied from the gas supply source;
The leak inspection method according to claim 3, wherein the inspection system pressurizing step is performed after the inspection system space is scavenged in the inspection system scavenging step.
ことを特徴とする請求項３または４に記載のリーク検査方法。 After performing the measurement step, the inspection system space is sealed, the sealed space is separated from the inspection system space, and the inspection system space is maintained in a pressurized state until the connection step relating to a next inspection target is performed. The leak inspection method according to claim 3 or 4, wherein:
ことを特徴とする請求項３乃至５のいずれか１つに記載のリーク検査方法。 The leak inspection method according to any one of claims 3 to 5, wherein the pressure step is performed on another container while the measurement step is performed.
一の容器が前記経過を待っている間に、前記経過を終えた他の一の容器に対して前記測定ステップを行う
ことを特徴とする請求項３乃至６のいずれか１つに記載のリーク検査方法。 The container after the pressurizing step is shifted to the connecting step after a predetermined time or more has elapsed,
The leak according to any one of claims 3 to 6, wherein, while one container is waiting for the progress, the measuring step is performed on the other container that has finished the progress. Inspection method.
前記第１管と前記第２管のうちの一方の管を通じて前記容器に所定の気体を送り込む気体供給源と、
前記気体供給源と前記容器との間で前記一方の管を開閉する第１開閉弁と、
前記第１管と前記第２管のうちの他方の管を開閉する第２開閉弁と、
圧力計と、
を備え、
前記蓋部が入口に取り付けられた前記容器の中に、前記第１開閉弁および前記第２開閉弁を開いた状態で前記気体供給源から前記所定の気体を送り込むことで、前記他方の管から前記容器内の気体を排気して前記容器内を前記所定の気体で満たした後、前記第２開閉弁を閉鎖する容器内掃気ステップ、
前記気体供給源から前記一方の管を通じて前記所定の気体を前記容器内にさらに導入して前記容器内を加圧した後、前記第１開閉弁を閉鎖して前記容器を含む密閉空間を形成する加圧ステップ、
前記密閉空間の圧力を前記圧力計で測定して前記容器に漏れがあるか否かを検査する測定ステップ、
が行われる
ことを特徴とするリーク検査装置。 A lid that seals the inlet of the non-penetrating container to be inspected, a first pipe that penetrates the lid and terminates in the interior of the container, and an inlet in the container that penetrates the lid A lid with a second tube terminating at the side;
A gas supply source for feeding a predetermined gas into the container through one of the first pipe and the second pipe;
A first on-off valve for opening and closing the one pipe between the gas supply source and the container;
A second on-off valve for opening and closing the other of the first pipe and the second pipe;
A pressure gauge,
With
By feeding the predetermined gas from the gas supply source into the container with the lid attached to the inlet in a state where the first on-off valve and the second on-off valve are opened, from the other pipe A scavenging step in the container for closing the second on-off valve after exhausting the gas in the container and filling the container with the predetermined gas;
After the predetermined gas is further introduced into the container through the one pipe from the gas supply source to pressurize the container, the first on-off valve is closed to form a sealed space including the container. Pressure step,
A measurement step of measuring whether or not the container has a leak by measuring the pressure of the sealed space with the pressure gauge;
Leak inspection device characterized in that is performed.
前記分岐管は第１接続口に至り、
前記主管は第２接続口に至り、
前記分岐管を開閉する分岐管開閉弁と、
前記主管を開閉する主管開閉弁と、
前記第２接続口を開閉する第２接続口開閉弁と、
を備え、
前記圧力計の検出口は、前記主管開閉弁と前記第２接続口開閉弁との間の前記主管に連通しており、
前記分岐管開閉弁および前記第２接続口開閉弁を閉じた状態で前記主管開閉弁を開いて前記気体供給源から前記所定の気体を導入した後、前記主管開閉弁を閉じて前記主管開閉弁と前記第２接続口開閉弁の間に密閉された検査系空間を形成する検査系加圧ステップ、
前記第１接続口に前記一方の管を接続した後、前記主管開閉弁を閉じた状態で前記分岐管開閉弁を開いて、前記容器内掃気ステップおよび前記加圧ステップ、
が行われると共に、
前記加圧ステップの後で、前記第１開閉弁を閉じて、前記一方の管を前記第１接続口から前記第２接続口に付け替え、前記第１開閉弁および前記第２接続口開閉弁を開いて前記検査系空間と前記密閉空間を連通させた状態で前記測定ステップが行われる
ことを特徴とする請求項８に記載のリーク検査装置。 Branching the pipe extended from the gas supply source into two branches, a branch pipe and a main pipe,
The branch pipe reaches the first connection port,
The main pipe reaches the second connection port,
A branch pipe opening and closing valve for opening and closing the branch pipe;
A main pipe opening and closing valve for opening and closing the main pipe;
A second connection port opening / closing valve for opening and closing the second connection port;
With
The detection port of the pressure gauge communicates with the main pipe between the main pipe on-off valve and the second connection port on-off valve,
The main pipe on / off valve is opened with the branch pipe on / off valve closed and the predetermined gas is introduced from the gas supply source, and then the main pipe on / off valve is closed to close the main pipe on / off valve. And an inspection system pressurizing step for forming a sealed inspection system space between the second connection port opening and closing valve,
After the one pipe is connected to the first connection port, the branch pipe on / off valve is opened with the main pipe on / off valve closed, and the scavenging step and the pressurizing step in the container,
Is performed,
After the pressurizing step, the first on-off valve is closed, the one pipe is changed from the first connection port to the second connection port, and the first on-off valve and the second connection port on-off valve are turned on. The leak inspection apparatus according to claim 8, wherein the measurement step is performed in a state where the inspection system space and the sealed space are communicated with each other.
ことを特徴とする請求項９に記載のリーク検査装置。 The leak inspection apparatus according to claim 9, wherein the inspection system pressurization step is performed after scavenging the inspection system space with a gas supplied from the gas supply source.
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