JP5806462B2

JP5806462B2 - Leak inspection apparatus and method

Info

Publication number: JP5806462B2
Application number: JP2010270065A
Authority: JP
Inventors: 佐々木　透; 透佐々木; 博信岩崎
Original assignee: Fukuda Co Ltd
Current assignee: Fukuda Co Ltd
Priority date: 2010-12-03
Filing date: 2010-12-03
Publication date: 2015-11-10
Anticipated expiration: 2030-12-03
Also published as: JP2012117997A

Description

この発明は、検査対象物からの洩れを圧力センサにて検知し、上記検査対象物の良否を検査する装置及び方法に関する。 The present invention relates to an apparatus and method for detecting leakage from an inspection object with a pressure sensor and inspecting the quality of the inspection object.

一般的に、この種の洩れ検査装置は、圧縮エア等の高圧気体源から延びる加圧路と、圧力センサとを備えている。加圧路は、基準側枝路と検査側枝路とに分岐している。基準側枝路は、基準容器（又はマスタとも言う）内の基準空間に接続されている。検査側枝路は、検査対象物内の検査空間に接続されている。圧力センサは、基準側枝路と検査側枝路との間に設けられた差圧センサにて構成されている。 In general, this type of leakage inspection apparatus includes a pressure path extending from a high-pressure gas source such as compressed air, and a pressure sensor. The pressurizing path branches into a reference side branch and an inspection side branch. The reference side branch is connected to a reference space in a reference container (also referred to as a master). The inspection side branch is connected to the inspection space in the inspection object. The pressure sensor is composed of a differential pressure sensor provided between the reference side branch and the inspection side branch.

基準側枝路と検査側枝路を互いに連通させた状態で、これら枝路に高圧気体を導入する。そして、上記基準側枝路及び検査側枝路の圧力が平衡した後、これら枝路を遮断して各々閉鎖系とする。ここで、検査対象物の密封状態に不良があったときは、検査空間からの洩れが差圧として検出される。これによって、検査対象物の良否を判定できる。 In a state where the reference side branch and the inspection side branch communicate with each other, high-pressure gas is introduced into these branches. Then, after the pressures of the reference side branch and the inspection side branch are balanced, these branches are blocked to form a closed system. Here, when there is a defect in the sealed state of the inspection object, leakage from the inspection space is detected as a differential pressure. Thereby, the quality of the inspection object can be determined.

特開２００４−０６１２０１号公報JP 2004-062011 A

上記加圧路ひいては検査空間に高圧気体を導入すると断熱圧縮により昇温し、この昇温分の放熱によっても圧力変化が起きる。そこで、従来は、放熱が収まるまで待って差圧検出を実行していた。このため、検査に時間がかかっていた。 When high-pressure gas is introduced into the pressurization path and thus into the inspection space, the temperature rises due to adiabatic compression, and the pressure changes due to the heat release of this temperature rise. Therefore, conventionally, the differential pressure detection is executed after the heat dissipation is stopped. For this reason, the inspection took time.

また、検査対象物の温度が常温又は周辺温度と異なる場合、例えば検査対象物が常温より高温の場合には、検査対象物の熱が内部の検査空間の気体に伝わり、検査空間の圧力上昇を引き起こす。そのため、洩れがあるときの検査空間の圧力低下を正しく検知するのが困難になる。 In addition, when the temperature of the inspection object is different from the normal temperature or the ambient temperature, for example, when the inspection object is higher than normal temperature, the heat of the inspection object is transferred to the gas in the internal inspection space, and the pressure in the inspection space is increased. cause. This makes it difficult to correctly detect the pressure drop in the examination space when there is a leak.

本発明の目的とするところは、高圧気体の導入に伴う断熱圧縮の影響を排除ないしは緩和した洩れ検査装置及び方法を提供することである。更に好ましくは、検査対象物の温度に拘わらず安定して検査可能な洩れ検査装置及び方法を提供することである。 An object of the present invention is to provide a leakage inspection apparatus and method that eliminates or mitigates the influence of adiabatic compression accompanying the introduction of high-pressure gas. More preferably, it is to provide a leakage inspection apparatus and method capable of stably inspecting regardless of the temperature of the inspection object.

従来の洩れ検査において、断熱圧縮による温度上昇が起きるのは、検査空間内に元から存在する気体が圧縮されるからである。本発明は、かかる知見に基づいてなされたものである。すなわち、本発明装置は、
検査対象物にて画成された検査空間と真空源とを接続する真空路と、
前記検査空間と高圧気体源とを接続する加圧路と、
前記検査空間の圧力を検出する圧力センサと、
前記真空路及び前記加圧路のうち何れか一方を選択的に開通し他方を遮断する動作と両方を遮断する動作を行なう開閉手段と、
を備え、前記開閉手段が前記真空路及び加圧路の両方を遮断している状態での前記圧力センサの検出圧力に基づいて前記検査空間の洩れを検査することを特許請求しない特徴とする。 In the conventional leak inspection, the temperature rise due to adiabatic compression occurs because the gas existing in the inspection space is compressed. The present invention has been made based on such knowledge. That is, the device of the present invention
A vacuum path connecting the inspection space defined by the inspection object and the vacuum source;
A pressurizing path connecting the inspection space and the high-pressure gas source;
A pressure sensor for detecting the pressure in the examination space;
An opening / closing means for selectively opening one of the vacuum path and the pressurizing path and blocking the other;
Wherein the switching means is characterized not to inspect the leakage of the examination space claimed on the basis of the detected pressure of the pressure sensor in a state that block both the vacuum passage and pressure passage.

開閉手段にて加圧路を遮断したうえで真空路を開通させることで、検査空間内の気体を真空路を介して真空源にて真空引きできる。このとき、検査対象の温度が常温又は周辺温度とは異なっていても、検査空間を真空状態にすることで伝熱による検出圧力への影響を小さくできる。したがって、この時点で洩れ検査を行なうことにすれば、検査対象の温度に拘わらず安定した洩れ検査を行なうことができる。このときの洩れ検査は、開閉手段にて加圧路を遮断したまま真空路を遮断して検査空間を閉鎖空間にした状態で行なう。その後、開閉手段にて真空路を遮断したまま加圧路を開通させることで、高圧気体源から高圧気体を加圧路を介して検査空間に導入する。これによって、検査空間内に元から存在する気体を排除したうえで、高圧気体を導入できる。よって、検査空間の断熱圧縮ひいては温度上昇が起きるのを回避又は抑制できる。この結果、その後の洩れ検査において、放熱による検出圧力への影響を防止又は低減できる。洩れ検査するのに放熱期間が経過するのを待つ必要がなく、検査時間を短縮できる。このときの洩れ検査は、開閉手段にて真空路を遮断したまま加圧路を遮断して検査空間を閉鎖空間にした状態で行なう。 By closing the pressurizing path with the opening / closing means and opening the vacuum path, the gas in the inspection space can be evacuated by a vacuum source through the vacuum path. At this time, even if the temperature of the inspection object is different from the normal temperature or the ambient temperature, the influence of the heat transfer on the detected pressure can be reduced by making the inspection space in a vacuum state. Therefore, if the leak inspection is performed at this time, a stable leak inspection can be performed regardless of the temperature of the inspection target. The leakage inspection at this time is performed in a state in which the inspection space is closed by blocking the vacuum path while the pressure path is blocked by the opening / closing means. After that, the high pressure gas is introduced from the high pressure gas source into the inspection space through the pressure path by opening the pressure path while the vacuum path is blocked by the opening / closing means. As a result, the high-pressure gas can be introduced after eliminating the gas originally present in the inspection space. Therefore, it is possible to avoid or suppress the adiabatic compression of the inspection space and thus the temperature rise. As a result, it is possible to prevent or reduce the influence of the heat radiation on the detected pressure in the subsequent leakage inspection. There is no need to wait for the heat dissipation period to elapse for leak inspection, and the inspection time can be shortened. The leakage inspection at this time is performed in a state in which the pressure space is blocked and the inspection space is closed while the vacuum path is blocked by the opening / closing means.

前記開閉手段が、前記加圧路を遮断した状態で前記真空路を開通させた後、前記加圧路及び前記真空路の両方を遮断し、その後、前記真空路を遮断した状態で前記加圧路を開通させ、更にその後、前記加圧路及び前記真空路の両方を遮断することが好ましい。
前記加圧路を遮断した状態で前記真空路を開通させることで、前記検査空間内の気体を真空引きできる。その後、前記加圧路及び前記真空路の両方を遮断した状態で、前記検査対象物の洩れ検査を行なってもよい。その後、前記真空路を遮断した状態で前記加圧路を開通させることで、前記検査空間内に高圧気体を導入できる。更にその後、前記加圧路及び前記真空路の両方を遮断した状態にすることで、上述したように断熱圧縮を回避又は抑制しつつ、検査対象物の洩れ検査を行なうことができる。
本発明に係る洩れ検査装置は、検査対象物にて画成された検査空間と真空源とを接続する真空路と、
前記検査空間と高圧気体源とを接続する加圧路と、
前記検査空間の圧力を検出する圧力センサと、
前記真空路及び前記加圧路のうち何れか一方を選択的に開通し他方を遮断する動作と両方を遮断する動作を行なう開閉手段と、
を備え、前記開閉手段が前記真空路及び加圧路の両方を遮断している状態での前記圧力センサの検出圧力に基づいて前記検査空間の洩れを検査し、しかも、前記開閉手段が前記加圧路を遮断した状態で前記真空路を開通させることで、前記検査空間内の気体を前記真空路を介して前記真空源にて真空引きした後、前記真空路及び前記加圧路の両方を遮断し、この遮断した状態で前記圧力センサが前記検査空間の圧力を検出することによって第１の洩れ検査を行い、その後さらに前記開閉手段が前記真空路を遮断した状態で前記加圧路を開通させることで前記高圧気体源の高圧気体を前記加圧路を介して前記検査空間内に導入した後、前記真空路及び前記加圧路の両方を遮断し、この遮断した状態で前記圧力センサが前記検査空間の圧力を検出することによって第２の洩れ検査を行なうことを特許請求する特徴とする。 The opening / closing means opens the vacuum path in a state where the pressurization path is shut off, then shuts off both the pressurization path and the vacuum path, and then pressurizes in the state where the vacuum path is shut off. It is preferable to open the passage and then shut off both the pressure passage and the vacuum passage.
The gas in the inspection space can be evacuated by opening the vacuum path with the pressurization path blocked. Thereafter, the inspection object may be inspected for leakage in a state where both the pressurization path and the vacuum path are shut off. Thereafter, the high-pressure gas can be introduced into the inspection space by opening the pressurizing passage while the vacuum passage is shut off. After that, by closing both the pressurizing path and the vacuum path, it is possible to perform a leakage inspection of the inspection object while avoiding or suppressing adiabatic compression as described above.
A leak inspection apparatus according to the present invention includes a vacuum path that connects an inspection space defined by an inspection object and a vacuum source,
A pressurizing path connecting the inspection space and the high-pressure gas source;
A pressure sensor for detecting the pressure in the examination space;
An opening / closing means for selectively opening one of the vacuum path and the pressurizing path and blocking the other;
The inspection space is inspected for leakage based on the pressure detected by the pressure sensor in a state in which the opening / closing means blocks both the vacuum path and the pressure path, and the opening / closing means By opening the vacuum path in a state where the pressure path is cut off, the gas in the inspection space is evacuated by the vacuum source through the vacuum path, and then both the vacuum path and the pressure path are opened. In the shut-off state, the pressure sensor detects the pressure in the test space to perform a first leak test, and then the opening / closing means opens the pressurizing path with the vacuum path shut off. After introducing the high-pressure gas of the high-pressure gas source into the inspection space through the pressurization path, both the vacuum path and the pressurization path are shut off, and the pressure sensor is in this shut-off state. Detect pressure in the inspection space Wherein the claimed to perform a second leakage inspection by Rukoto.

前記高圧気体源が、高圧気体を蓄えた圧力タンクを備えていてもよい。前記加圧路の開通時に前記圧力タンクの下流に連なる連通空間全体の内容積よりも、前記圧力タンクの内容積が大きいことが好ましく、十分に大きいこと（例えば２０倍〜１００倍）がより好ましい。前記連通空間は、前記圧力タンクより下流側の加圧路及び前記検査空間を含む。前記開閉手段による加圧路の開通動作によって、前記圧力タンク内の高圧気体が前記連通空間に導入される。このとき、前記高圧気体は、前記連通空間の内容積分だけ膨張し、かつ膨張に伴って圧力が低下するが、前記圧力タンクを大きくすることで膨張率を小さくでき、圧力の低下率を小さくできる。よって、高圧気体の温度低下を防止できる。この結果、検査精度を一層高めることができる。
前記高圧気体源が、高圧気体を蓄えた圧力タンクを備え、前記加圧路が、前記圧力タンクと前記検査空間とを減圧弁を介さずに接続しており、前記加圧路の開通時に前記圧力タンクの下流に連なる前記検査空間を含む連通空間全体の内容積よりも、前記圧力タンクの内容積が大きいことが好ましい。 The high-pressure gas source may include a pressure tank that stores high-pressure gas. It is preferable that the internal volume of the pressure tank is larger than the internal volume of the entire communication space connected downstream of the pressure tank when the pressure passage is opened, and it is more preferable that the internal volume is sufficiently large (for example, 20 times to 100 times). . The communication space includes a pressurizing passage downstream of the pressure tank and the inspection space. The high pressure gas in the pressure tank is introduced into the communication space by the opening operation of the pressurizing passage by the opening / closing means. At this time, the high-pressure gas expands by the content integral of the communication space, and the pressure decreases with the expansion. However, the expansion rate can be decreased by increasing the pressure tank, and the decrease rate of the pressure can be decreased. . Therefore, the temperature drop of the high pressure gas can be prevented. As a result, the inspection accuracy can be further increased.
The high-pressure gas source includes a pressure tank that stores high-pressure gas, and the pressurizing path connects the pressure tank and the inspection space without a pressure reducing valve, and when the pressurizing path is opened, It is preferable that the internal volume of the pressure tank is larger than the internal volume of the entire communication space including the inspection space connected downstream of the pressure tank.

また、本発明方法は、検査対象物を含む検査空間内を真空引きする真空引き工程と、
前記真空引きされた検査空間に高圧気体を導入する加圧工程と、
前記真空引き工程の後であって前記加圧工程の前と後のうち少なくとも前記加圧工程の後に前記検査空間の圧力を検出する検査工程と、
を備えたことを特許請求しない特徴とする。
真空引き工程によって、検査空間内に元から存在する気体を排除することができる。そのうえで、加圧工程を行なうことによって、検査空間において断熱圧縮及び温度上昇が起きるのを回避又は抑制できる。したがって、加圧工程後の検査工程において、放熱による検出圧力への影響を防止又は低減できる。放熱期間が経過するのを待つ必要がなく、検査時間を短縮できる。
また、検査空間内が真空の状態では、伝熱による検出圧力への影響が小さい。したがって、真空引き工程後かつ加圧工程前に検査工程を行なうことにすれば、検査対象の温度が常温又は周辺温度とは異なっていても、安定した洩れ検査を行なうことができる。
本発明に係る洩れ検査方法は、検査対象物にて画成された検査空間内の気体を真空引きする真空引き工程と、
前記真空引き工程の後、前記検査空間を閉鎖空間にした状態で前記検査空間の圧力を検出する第１の検査工程と、
前記第１の検査工程の後、前記真空引きされた検査空間に高圧気体を導入する加圧工程と、
前記加圧工程の後に前記検査空間を閉鎖空間にした状態で前記検査空間の圧力を検出する第２の検査工程と、
を備えたことを特許請求する特徴とする。
前記真空引き工程では、前記検査空間と基準容器の内部の基準空間とを連通させることによって、前記基準空間内の気体をも真空引きし、前記第１の検査工程では、前記基準空間と検査空間とを互いに独立した閉鎖空間にした状態でこれら空間どうし間の差圧を測定し、前記加圧工程では、前記基準空間と前記検査空間とを連通させることによって、前記基準空間へも前記高圧気体を導入し、前記第２の検査工程では、前記基準空間と検査空間とを互いに独立した閉鎖空間にした状態でこれら空間どうし間の差圧を測定することが好ましい。 Further, the method of the present invention includes a vacuuming step for evacuating the inspection space including the inspection object,
A pressurizing step for introducing a high-pressure gas into the evacuated inspection space;
An inspection step of detecting the pressure of the inspection space after the vacuuming step and before and after the pressurization step, at least after the pressurization step;
It is the feature which does not claim that it was provided.
By the evacuation process, the gas existing in the inspection space can be excluded. In addition, by performing the pressurizing step, it is possible to avoid or suppress the occurrence of adiabatic compression and temperature rise in the inspection space. Therefore, in the inspection process after the pressurizing process, the influence on the detected pressure due to heat radiation can be prevented or reduced. There is no need to wait for the heat dissipation period to elapse, and the inspection time can be shortened.
Further, when the inspection space is in a vacuum state, the influence of the heat transfer on the detected pressure is small. Therefore, if the inspection process is performed after the evacuation process and before the pressurization process, a stable leak inspection can be performed even if the temperature of the inspection object is different from the normal temperature or the ambient temperature.
A leakage inspection method according to the present invention includes a vacuuming step of evacuating a gas in an inspection space defined by an inspection object,
After the evacuation step, a first inspection step of detecting the pressure of the inspection space in a state where the inspection space is a closed space;
After the first inspection step, a pressurizing step for introducing a high-pressure gas into the evacuated inspection space;
A second inspection step of detecting the pressure of the inspection space in a state where the inspection space is a closed space after the pressing step;
It is characterized by having provided.
In the evacuation step, the gas in the reference space is also evacuated by communicating the inspection space and a reference space inside the reference container. In the first inspection step, the reference space and the inspection space are evacuated. In the closed space independent of each other, the differential pressure between these spaces is measured, and in the pressurizing step, the reference space and the inspection space are communicated with each other, whereby the high-pressure gas is also introduced into the reference space. In the second inspection step, it is preferable that the differential pressure between these spaces is measured in a state where the reference space and the inspection space are closed spaces independent from each other.

本発明によれば、検査空間を予め真空にしておくことによって、検査空間への高圧気体の導入時に断熱圧縮及びそれに伴う温度上昇が起きるのを回避又は抑制でき、温度上昇後の放熱による検出圧力への影響を防止又は低減できる。 According to the present invention, by preliminarily inspecting the inspection space, it is possible to avoid or suppress the occurrence of adiabatic compression and the accompanying temperature increase when the high-pressure gas is introduced into the inspection space. Can be prevented or reduced.

本発明の第１実施形態に係る洩れ検査装置の概略構成を示す回路図である。1 is a circuit diagram showing a schematic configuration of a leak inspection apparatus according to a first embodiment of the present invention. 本発明の第２実施形態に係る洩れ検査装置の概略構成を示す回路図である。It is a circuit diagram which shows schematic structure of the leak inspection apparatus which concerns on 2nd Embodiment of this invention. 上記洩れ検査装置の回路構成の変形例を示す回路図である。It is a circuit diagram which shows the modification of the circuit structure of the said leak test | inspection apparatus. 上記洩れ検査装置の回路構成の変形例を示す回路図である。It is a circuit diagram which shows the modification of the circuit structure of the said leak test | inspection apparatus.

以下、本発明の実施形態を図面にしたがって説明する。
図１は、本発明の第１実施形態の洩れ検査装置１を示したものである。洩れ検査装置１の検査対象物６は、特に限定がなく、例えばエンジンのシリンダブロック、燃料タンク等である。検査対象６は内部空間を有している。この内部空間が検査空間６ａになっている。検査対象物６によって検査空間６ａが画成されている。詳細な図示は省略するが、検査空間６ａの開口部は冶具等によって閉塞されており、これによって、検査空間６ａが密封されている。検査対象物６がカプセル内に収容されており、このカプセルの内周と検査対象物６の外周との間の空間が検査空間６ａを構成していてもよい。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a leak inspection apparatus 1 according to a first embodiment of the present invention. The inspection object 6 of the leak inspection apparatus 1 is not particularly limited, and is, for example, an engine cylinder block, a fuel tank, or the like. The inspection object 6 has an internal space. This internal space is the inspection space 6a. An inspection space 6 a is defined by the inspection object 6. Although detailed illustration is omitted, the opening of the inspection space 6a is closed with a jig or the like, and the inspection space 6a is thereby sealed. The inspection object 6 is accommodated in the capsule, and the space between the inner periphery of the capsule and the outer periphery of the inspection object 6 may constitute the inspection space 6a.

洩れ検査装置１は、圧力センサ１０と、真空路２０と、加圧路３０と、開閉手段４０を備えている。真空路２０及び加圧路３０は、ブロック内に形成されていてもよく、配管によって形成されていてもよい。 The leak inspection apparatus 1 includes a pressure sensor 10, a vacuum path 20, a pressure path 30, and an opening / closing means 40. The vacuum path 20 and the pressurization path 30 may be formed in the block or may be formed by piping.

真空路２０は、幹路２１と、二つの枝路２２，２３を有している。幹路２１の基端コネクタ２１ａに真空ポンプ等の真空源２が接続されている。幹路２１には圧力計２４が設けられている。幹路２１の先端から基準側枝路２２と検査側枝路２３が分岐されている。基準側枝路２２には常閉の電磁開閉弁４１が設けられている。基準側枝路２２の先端が冶具（図示省略）を介して基準容器５内の基準空間５ａに連なっている。 The vacuum path 20 has a main path 21 and two branch paths 22 and 23. A vacuum source 2 such as a vacuum pump is connected to the base end connector 21 a of the trunk path 21. A pressure gauge 24 is provided on the main path 21. A reference side branch 22 and an inspection side branch 23 are branched from the front end of the trunk path 21. The reference side branch 22 is provided with a normally closed electromagnetic switching valve 41. The tip of the reference side branch 22 is connected to the reference space 5a in the reference container 5 via a jig (not shown).

検査側枝路２３には、常閉の電磁開閉弁４２が設けられている。検査側枝路２３の先端が冶具（図示省略）を介して検査対象物６の内部の検査空間６ａに連なっている。 The inspection side branch 23 is provided with a normally closed electromagnetic switching valve 42. The tip of the inspection side branch 23 is connected to the inspection space 6a inside the inspection object 6 via a jig (not shown).

加圧路３０は、幹路３１と、二つの枝路３２，３３を有している。幹路３１の基端コネクタ３１ａにエアコンプレッサ等の高圧気体源３が接続されている。幹路３１には、レギュレータ３４（減圧弁）と、圧力計３５と、方向制御弁４６が上流側（高圧気体源３の側）から順次設けられている。方向制御弁４６は、二位置三方型電磁弁にて構成され、オフ（第１位置）のとき、該方向制御弁４６より上流側の幹路３１を閉止し、かつ該方向制御弁４６より下流側の幹路３１を大気に開放する。方向制御弁４６がオン（第２位置）のとき、幹路３１が開通する。 The pressurizing path 30 has a main path 31 and two branch paths 32 and 33. A high-pressure gas source 3 such as an air compressor is connected to the proximal end connector 31 a of the trunk path 31. In the main path 31, a regulator 34 (pressure reducing valve), a pressure gauge 35, and a direction control valve 46 are sequentially provided from the upstream side (the high-pressure gas source 3 side). The directional control valve 46 is constituted by a two-position three-way solenoid valve. When the directional control valve 46 is off (first position), the directional control valve 46 closes the trunk path 31 upstream from the directional control valve 46 and is downstream from the directional control valve 46. The side main road 31 is opened to the atmosphere. When the direction control valve 46 is on (second position), the trunk path 31 is opened.

幹路３１の下流端から基準側枝路３２と検査側枝路３３が分岐されている。基準側枝路３２には常開の電磁開閉弁４３が設けられている。基準側枝路３２の下流端が治具（図示省略）を介して基準空間５ａに連なっている。検査側枝路３３には、常開の電磁開閉弁４４が設けられている。検査側枝路３３の下流端が治具（図示省略）を介して検査対象物６の内部の検査空間６ａに連なっている。 A reference side branch 32 and an inspection side branch 33 are branched from the downstream end of the main road 31. The reference side branch 32 is provided with a normally open electromagnetic opening / closing valve 43. The downstream end of the reference side branch 32 is connected to the reference space 5a via a jig (not shown). The inspection side branch 33 is provided with a normally open electromagnetic opening / closing valve 44. The downstream end of the inspection side branch 33 is connected to the inspection space 6a inside the inspection object 6 via a jig (not shown).

加圧路３０の枝路３２，３３どうし間に圧力センサ１０が設けられている。圧力センサ１０は、ダイヤフラム１１と、基準側センサ室１２と、検査側センサ室１３を有するダイヤフラム式差圧センサにて構成されている。ダイヤフラム１１によって２つの室１２，１３が仕切られている。センサ室１２のポートにセンサ路１４が連なっている。センサ路１４は、基準側枝路３２における開閉弁４３と基準容器５との間の路部分３２ｃに接続されている。センサ室１３のポートにセンサ路１５が連なっている。センサ路１５は、検査側枝路３３における開閉弁４４と検査対象物６との間の路部分３３ｃに接続されている。ダイヤフラム１１が二つのセンサ室１２，１３の圧力差に応じて変位する。差圧センサ１０は、この変位を電圧に変換し出力する。これによって、実質的に検査空間６ａの圧力が検出される。 The pressure sensor 10 is provided between the branch paths 32 and 33 of the pressurizing path 30. The pressure sensor 10 is constituted by a diaphragm type differential pressure sensor having a diaphragm 11, a reference side sensor chamber 12, and an inspection side sensor chamber 13. The two chambers 12 and 13 are partitioned by the diaphragm 11. A sensor path 14 is connected to the port of the sensor chamber 12. The sensor path 14 is connected to a path portion 32 c between the on-off valve 43 and the reference container 5 in the reference side branch path 32. A sensor path 15 is connected to a port of the sensor chamber 13. The sensor path 15 is connected to a path portion 33 c between the on-off valve 44 and the inspection object 6 in the inspection side branch 33. The diaphragm 11 is displaced according to the pressure difference between the two sensor chambers 12 and 13. The differential pressure sensor 10 converts this displacement into a voltage and outputs it. Thereby, the pressure in the examination space 6a is substantially detected.

４つの開閉弁４１〜４４及び方向制御弁４６によって開閉手段４０が構成されている。開閉手段４０は、真空路２０及び加圧路３０のうち何れか一方を選択的に開通し他方を遮断する動作と、真空路２０及び加圧路３０の両方を遮断する動作とを行なう。常閉の開閉弁４１，４２がオフのとき、該開閉弁４１，４２が閉止され、真空路２０が遮断状態になる。開閉弁４１，４２をオンにすると、該開閉弁４１，４２が開き、真空路２０が開通状態になる。真空路２０が開通することで、真空源２と、基準空間５ａ及び検査空間６ａとが、真空路２０を介して連通する。常開の開閉弁４３，４４がオンのとき、該開閉弁４３，４４が閉止され、加圧路３０が遮断状態になる。方向制御弁４６がオン（第２位置）で、かつ開閉弁４３，４４がオフのとき、開閉弁４３，４４が開き、加圧路３０が開通状態になる。加圧路３０が開通することで、高圧気体源３と、基準空間５ａ及び検査空間６ａとが、加圧路３０を介して連通する。 The opening / closing means 40 is constituted by the four opening / closing valves 41 to 44 and the direction control valve 46. The opening / closing means 40 performs an operation of selectively opening one of the vacuum path 20 and the pressurization path 30 and blocking the other, and an operation of blocking both the vacuum path 20 and the pressurization path 30. When the normally closed on-off valves 41, 42 are off, the on-off valves 41, 42 are closed, and the vacuum path 20 is cut off. When the on-off valves 41 and 42 are turned on, the on-off valves 41 and 42 are opened and the vacuum path 20 is opened. By opening the vacuum path 20, the vacuum source 2 communicates with the reference space 5 a and the inspection space 6 a via the vacuum path 20. When the normally open on-off valves 43 and 44 are on, the on-off valves 43 and 44 are closed, and the pressurizing path 30 is cut off. When the direction control valve 46 is on (second position) and the on / off valves 43 and 44 are off, the on / off valves 43 and 44 are opened, and the pressurizing passage 30 is opened. When the pressurization path 30 is opened, the high-pressure gas source 3 communicates with the reference space 5a and the inspection space 6a via the pressurization path 30.

開閉手段４０は、開閉弁４１，４２を開けて真空路２０を開通させるときは、予め開閉弁４３，４４を閉じて加圧路３０を遮断しておく。方向制御弁４６をオン（第２位置）にし、かつ開閉弁４３，４４を開けて加圧路３０を開通させるときは、予め開閉弁４１，４２を閉じて真空路２０を遮断しておく。 When the opening / closing means 40 opens the opening / closing valves 41, 42 to open the vacuum path 20, the opening / closing means 43 previously closes the opening / closing valves 43, 44 to block the pressurization path 30. When the direction control valve 46 is turned on (second position) and the on-off valves 43 and 44 are opened to open the pressurizing path 30, the on-off valves 41 and 42 are closed in advance to shut off the vacuum path 20.

４つの開閉弁４１〜４４を共に閉じると、真空路２０及び加圧路３０の両方が遮断される。このとき、基準空間５ａと検査空間６ａが互いに独立した閉鎖空間になる。詳細には、基準空間５ａ、基準側枝路２２における開閉弁４１と基準容器５との間の路部分２２ｃ、基準側枝路３２における開閉弁４３と基準容器５との間の路部分３２ｃ、センサ路１４、及びセンサ室１２からなる基準側の空間部７が、１つの閉鎖空間になる。検査空間６ａ、検査側枝路２３における開閉弁４２と検査対象物６との間の路部分２３ｃ、検査側枝路３３における開閉弁４４と検査対象物６との間の路部分３３ｃ、センサ路１５、及びセンサ室１３からなる検査側の空間部８が、もう１つの閉鎖空間になる。 When the four on-off valves 41 to 44 are closed together, both the vacuum path 20 and the pressurization path 30 are blocked. At this time, the reference space 5a and the inspection space 6a are closed spaces independent of each other. Specifically, the reference space 5a, the path portion 22c between the on-off valve 41 and the reference container 5 in the reference side branch 22, the path portion 32c between the on-off valve 43 and the reference container 5 in the reference side branch 32, and the sensor path 14 and the reference-side space portion 7 made up of the sensor chamber 12 becomes one closed space. Inspection space 6a, a path portion 23c between the on-off valve 42 and the inspection object 6 in the inspection-side branch 23, a path portion 33c between the on-off valve 44 and the inspection object 6 in the inspection-side branch 33, the sensor path 15, The space 8 on the inspection side made up of the sensor chamber 13 becomes another closed space.

洩れ検査装置１によって検査対象物６の洩れ検査を行なう方法を説明する。
まず、検査空間６ａ内を真空引きする（真空引き工程）。好ましくは、真空引き工程後に検査空間６ａの圧力を検出する（第１の検査工程）。次に、検査空間６ａに圧縮空気等の高圧気体を導入する（加圧工程）。更にその後、検査空間６ａの圧力を検出する（第２の検査工程）。以下、詳述する。 A method for performing a leakage inspection of the inspection object 6 by the leakage inspection apparatus 1 will be described.
First, the inspection space 6a is evacuated (evacuation step). Preferably, the pressure in the inspection space 6a is detected after the evacuation step (first inspection step). Next, high-pressure gas such as compressed air is introduced into the inspection space 6a (pressurization process). Thereafter, the pressure in the inspection space 6a is detected (second inspection step). Details will be described below.

［真空引き工程］
開閉弁４３，４４をオンとして閉止状態とし、加圧路３０を遮断する。次いで、開閉弁４１，４２をオンとして開状態にし、真空路２０を開通させて、真空源２によって基準空間５ａ及び検査空間６ａ内のガスを真空引きする。圧力計２４によって基準空間５ａ及び検査空間６ａの内部が真空状態になったことを確認後、開閉弁４１，４２をオフとして閉止状態とし、真空路２０を遮断する。これによって、基準側の空間部７ひいては基準空間５ａと、検査側の空間部８ひいては検査空間６ａとが、互いに独立した閉鎖空間になる。このとき、空間部７，８内に存在していた気体は真空引き工程によって殆どが排除され、空間部７，８が真空状態になっている。 [Vacuum drawing process]
The on-off valves 43 and 44 are turned on to close the pressurizing passage 30. Next, the on-off valves 41 and 42 are turned on to open the vacuum path 20, and the vacuum source 2 evacuates the gas in the reference space 5 a and the inspection space 6 a. After confirming that the inside of the reference space 5a and the inspection space 6a is in a vacuum state by the pressure gauge 24, the on-off valves 41 and 42 are turned off to be closed, and the vacuum path 20 is shut off. Thus, the reference-side space portion 7 and thus the reference space 5a and the inspection-side space portion 8 and thus the inspection space 6a become closed spaces independent of each other. At this time, most of the gas existing in the space portions 7 and 8 is eliminated by the evacuation process, and the space portions 7 and 8 are in a vacuum state.

［第１の検査工程］
ここで、差圧センサ１０の検出差圧を読み取る。検査対象物６が良品であれば、検査空間６ａからの洩れが無く、基準空間５ａと検査空間６ａとの間（基準側空間部７と検査側空間部８との間）に差圧が発生しない。検査対象物６に欠損等があれば、そこから洩れが起きる。すなわち、外気が欠損部から検査空間６ａ内に流入する。したがって、検査空間６ａの真空度が低下し、基準空間５ａと検査空間６ａとの間に差圧が発生する。この差圧を差圧センサ１０で検知する。これによって、検査空間６ａの洩れの有無を判定でき、ひいては検査対象物６の良否を判定できる。検査対象物６の温度が常温と異なっていても、検査空間６ａ内が真空状態であるため伝熱による検出圧力への影響が小さい。したがって、検査対象物６の温度が常温又は周辺温度とは異なっていても、検査対象物６の温度に拘わらず安定した洩れ検査を行なうことができる。
第１の検査工程の洩れ判定に利用できる圧力差は、大気圧と真空との差である。大気圧以上の圧力差により判定を行わなければならない場合には、引き続き以下の処理を行う。 [First inspection process]
Here, the detected differential pressure of the differential pressure sensor 10 is read. If the inspection object 6 is a non-defective product, there is no leakage from the inspection space 6a, and a differential pressure is generated between the reference space 5a and the inspection space 6a (between the reference-side space portion 7 and the inspection-side space portion 8). do not do. If there is a defect or the like in the inspection object 6, leakage will occur from there. That is, outside air flows into the examination space 6a from the defect portion. Accordingly, the degree of vacuum in the inspection space 6a is reduced, and a differential pressure is generated between the reference space 5a and the inspection space 6a. This differential pressure is detected by the differential pressure sensor 10. Thereby, the presence or absence of leakage of the inspection space 6a can be determined, and consequently the quality of the inspection object 6 can be determined. Even if the temperature of the inspection object 6 is different from the normal temperature, since the inspection space 6a is in a vacuum state, the influence of the heat transfer on the detected pressure is small. Therefore, even if the temperature of the inspection object 6 is different from the normal temperature or the ambient temperature, a stable leak inspection can be performed regardless of the temperature of the inspection object 6.
The pressure difference that can be used for leakage determination in the first inspection process is the difference between atmospheric pressure and vacuum. If the determination must be made based on a pressure difference equal to or greater than the atmospheric pressure, the following processing is continued.

［加圧工程］
方向制御弁４６をオンにし、かつ開閉弁４３，４４をオフにして、加圧路３０を開通させる。開閉弁４１，４２はオフのままにして、真空路２０の遮断状態を維持する。これにより、高圧気体源３からの高圧気体が、レギュレータ３４で試験圧力になり、更に基準側枝路３２を通って基準側空間部７ひいては基準容器５に導入されるとともに、検査側枝路３３を通って検査側空間部８ひいては検査対象物６に導入される。これによって、基準側の空間部７ひいては基準空間５ａの内部圧力、及び検査側の空間部８ひいては検査空間６ａの内部圧力が急速に立ち上がって試験圧力に達する。このとき、空間部７，８には気体が殆ど存在しないところへ高圧気体が導入されるから、空間部７，８内で断熱圧縮が起きるのを回避でき、断熱圧縮による温度上昇を防止できる。また、高圧気体源３からの高圧気体は空間部７，８への充填によって膨張するが、これに伴う圧力低下及び温度低下は僅かである。
上記開閉弁４３，４４の開操作後、空間部７，８の内部圧力が安定するまで所定時間待った後、開閉弁４３，４４をオンにして閉じる。これによって、基準側空間部７と検査側空間部８とが互いに独立した閉鎖空間になる。 [Pressure process]
The direction control valve 46 is turned on and the on-off valves 43 and 44 are turned off to open the pressurizing path 30. The on-off valves 41 and 42 are kept off to maintain the vacuum path 20 in the shut-off state. As a result, the high-pressure gas from the high-pressure gas source 3 becomes a test pressure by the regulator 34, and is further introduced into the reference-side space 7 and the reference container 5 through the reference-side branch 32 and through the inspection-side branch 33. Then, the inspection side space 8 is introduced into the inspection object 6. As a result, the reference-side space 7 and thus the internal pressure of the reference space 5a and the inspection-side space 8 and thus the internal pressure of the inspection space 6a rise rapidly and reach the test pressure. At this time, since the high-pressure gas is introduced into the space portions 7 and 8 where there is almost no gas, it is possible to avoid adiabatic compression in the space portions 7 and 8 and to prevent an increase in temperature due to the adiabatic compression. Moreover, although the high pressure gas from the high pressure gas source 3 expand | swells by filling to the space parts 7 and 8, the pressure fall and temperature fall accompanying this are slight.
After the opening operation of the on-off valves 43, 44, after waiting for a predetermined time until the internal pressure of the space portions 7, 8 is stabilized, the on-off valves 43, 44 are turned on and closed. As a result, the reference-side space portion 7 and the inspection-side space portion 8 become a closed space independent of each other.

［第２の検査工程］
続いて、差圧センサ１０の検出差圧を読み取る。基準容器５と検査対象物６の温度等が同一条件で、かつ検査対象物６が良品で洩れがなければ、基準空間５ａと検査空間６ａとの間に差圧が発生せず、差圧センサ１０の検出差圧はゼロである。検査対象物６に欠損等があってそこから洩れがあれば、検査空間６ａ内の圧力が基準空間５ａの圧力より低下し、差圧が発生する。この差圧を差圧センサ１０にて検知することによって、検査空間６ａの洩れの有無を判定でき、ひいては検査対象物６の良否を判定できる。前述した通り、真空引き工程を行なったうえで加圧工程を行なうことで、断熱圧縮による温度上昇を防止できるから、安定した洩れ検査を行なうことができる。温度上昇後の放熱期間が経過するのを待つ必要がなく、検査に要する時間を短縮できる。
真空下での第１の検査工程と加圧下での第２の検査工程の両方の検査結果を考慮することによって、洩れ検査の精度を高めることができる。 [Second inspection process]
Subsequently, the detected differential pressure of the differential pressure sensor 10 is read. If the temperature of the reference container 5 and the inspection object 6 are the same, and the inspection object 6 is a good product and does not leak, no differential pressure is generated between the reference space 5a and the inspection space 6a, and the differential pressure sensor The detected differential pressure of 10 is zero. If there is a defect or the like in the inspection object 6 and there is leakage from the inspection object 6, the pressure in the inspection space 6 a falls below the pressure in the reference space 5 a and a differential pressure is generated. By detecting this differential pressure with the differential pressure sensor 10, it is possible to determine the presence or absence of leakage in the inspection space 6 a, and thus the quality of the inspection object 6 can be determined. As described above, by performing the evacuation process and then performing the pressurization process, temperature rise due to adiabatic compression can be prevented, so that a stable leak test can be performed. There is no need to wait for the heat dissipation period after the temperature to rise, and the time required for inspection can be shortened.
By considering the inspection results of both the first inspection step under vacuum and the second inspection step under pressure, the accuracy of the leak inspection can be increased.

次に、本発明の他の実施形態を説明する。以下の実施形態において既述の形態と重複する部分に関しては図面に同一符号を付して説明を省略する。 Next, another embodiment of the present invention will be described. In the following embodiments, the same reference numerals are attached to the drawings for the same parts as those already described, and the description thereof is omitted.

図２は、本発明の第２実施形態を示したものである。この実施形態の洩れ検査装置１Ｘは、高圧気体源として大容積の圧力タンク３９を更に備えている。圧力タンク３９は、幹路３１におけるレギュレータ３４と方向制御弁４６の間の部分に介在されている。圧力タンク３９に圧力計３５が設けられている。高圧気体源３からの高圧気体が圧力タンク３９に導入され、圧力タンク３９内に畜圧されている。方向制御弁４６がオフの時の圧力タンク３９の内圧は、レギュレータ３４の二次圧すなわち試験圧力と等しい。 FIG. 2 shows a second embodiment of the present invention. The leak test apparatus 1X of this embodiment further includes a large-capacity pressure tank 39 as a high-pressure gas source. The pressure tank 39 is interposed between the regulator 34 and the directional control valve 46 in the main path 31. A pressure gauge 35 is provided in the pressure tank 39. High-pressure gas from the high-pressure gas source 3 is introduced into the pressure tank 39 and stored in the pressure tank 39. The internal pressure of the pressure tank 39 when the directional control valve 46 is off is equal to the secondary pressure of the regulator 34, that is, the test pressure.

圧力タンク３９の内容積は、加圧工程時に当該タンク３９の下流側に連なる連通空間９全体の内容積よりも大きく、好ましくは連通空間９全体の内容積よりも十分に大きい。ここで、上記連通空間９は、圧力タンク３９より下流の加圧路３０（枝路３２，３３を含む）、基準空間５ａ、検査空間６ａ、路部分２２ｃ，２３ｃ、センサ路１４，１５、及びセンサ室１２，１３を含む。連通空間９の内容積の大半は、基準空間５ａ及び検査空間６ａにて占められている。圧力タンク３９の内容積は、連通空間９の内容積の好ましくは２０〜１００倍程度である。圧力タンク３９の内容積は、加圧工程時の圧力低下を小さくする観点からは大きければ大きいほど好ましいが、実用面を考慮して内容積の上限を設定する。 The internal volume of the pressure tank 39 is larger than the entire internal volume of the communication space 9 connected to the downstream side of the tank 39 during the pressurizing step, and preferably sufficiently larger than the internal volume of the entire communication space 9. Here, the communication space 9 includes a pressure passage 30 (including branch passages 32 and 33) downstream from the pressure tank 39, a reference space 5a, an inspection space 6a, passage portions 22c and 23c, sensor passages 14 and 15, and Sensor chambers 12 and 13 are included. Most of the internal volume of the communication space 9 is occupied by the reference space 5a and the inspection space 6a. The internal volume of the pressure tank 39 is preferably about 20 to 100 times the internal volume of the communication space 9. The inner volume of the pressure tank 39 is preferably as large as possible from the viewpoint of reducing the pressure drop during the pressurizing step, but the upper limit of the inner volume is set in consideration of practical use.

加圧工程においては、方向制御弁４６をオンにし、開閉弁４３，４４をオフにして加圧路３０を開通させることで、圧力タンク３９内の高圧気体を連通空間９に導入する。このとき、高圧気体は、連通空間９の内容積分だけ膨張し、かつ膨張に伴って圧力が低下するが、圧力タンク３９の内容積を大きくすることで膨張率を小さくでき、圧力の低下率を小さくできる。圧力タンク３９の内容積を連通空間９の内容積の２０倍〜１００倍程度にすることで、定温変化と仮定すれば、圧力低下を１％〜５％程度に収めることができる。これによって、高圧気体の温度低下を防止できる。この結果、検査精度を一層高めることができる。 In the pressurization step, the directional control valve 46 is turned on, the on-off valves 43 and 44 are turned off, and the pressurization path 30 is opened, whereby the high-pressure gas in the pressure tank 39 is introduced into the communication space 9. At this time, the high-pressure gas expands by the content integral of the communication space 9 and the pressure decreases with the expansion. However, the expansion rate can be decreased by increasing the internal volume of the pressure tank 39, and the pressure decrease rate can be reduced. Can be small. By making the internal volume of the pressure tank 39 about 20 to 100 times the internal volume of the communication space 9, assuming a constant temperature change, the pressure drop can be reduced to about 1% to 5%. This can prevent a temperature drop of the high-pressure gas. As a result, the inspection accuracy can be further increased.

洩れ検査装置１，１Ｘの回路は適宜改変できる。
図３に示すように、真空路２０と加圧路３０の路部分２２ｃ，３２ｃどうしが直接連なり、これに基準側接続路７ｃを介して基準容器５が接続されていてもよい。真空路２０と加圧路３０の路部分２３ｃ，３３ｃどうしが直接連なり、これに検査側接続路８ｃを介して検査対象物６が接続されていてもよい。 The circuit of the leakage inspection apparatus 1, 1X can be modified as appropriate.
As shown in FIG. 3, the passage portions 22c and 32c of the vacuum passage 20 and the pressurization passage 30 may be directly connected to each other, and the reference container 5 may be connected to the passage portions 22c via a reference-side connection passage 7c. The passage portions 23c and 33c of the vacuum passage 20 and the pressurization passage 30 may be directly connected to each other, and the inspection object 6 may be connected to the passage portions via the inspection-side connection passage 8c.

図４に示すように、差圧センサ１０が、加圧路３０に代えて、真空路２０の基準側枝路２２と検査側枝路２３の間に設けられていてもよい。この差圧センサ１０のセンサ路１４は、基準側枝路２２における開閉弁４１と基準容器５との間の路部分２２ｃに接続されている。センサ路１５は、検査側枝路２３における開閉弁４２と検査対象物６との間の路部分２３ｃに接続されている。 As shown in FIG. 4, the differential pressure sensor 10 may be provided between the reference side branch 22 and the inspection side branch 23 of the vacuum path 20 instead of the pressurization path 30. The sensor path 14 of the differential pressure sensor 10 is connected to a path portion 22 c between the on-off valve 41 and the reference container 5 in the reference side branch 22. The sensor path 15 is connected to a path portion 23 c between the on-off valve 42 and the inspection object 6 in the inspection side branch 23.

本発明は、上記実施形態に限定されず、発明の要旨を変更しない限りにおいて種々の改変をなすことができる。
真空引き工程後かつ加圧工程前の第１検査工程を省略してもよい。圧力センサ１０は、真空路２０と加圧路３０のうち少なくとも加圧路３０の圧力を検出するものであればよい。
或いは、真空引き工程後かつ加圧工程前の第１検査工程だけで検査対象６を十分に洩れ判定可能な場合は、その後の加圧工程及び第２検査工程を省略してもよい。 The present invention is not limited to the above-described embodiment, and various modifications can be made without changing the gist of the invention.
The first inspection step after the evacuation step and before the pressurization step may be omitted. The pressure sensor 10 may be any sensor that detects at least the pressure of the pressure path 30 out of the vacuum path 20 and the pressure path 30.
Alternatively, when it is possible to determine whether the inspection object 6 can be sufficiently leaked only by the first inspection process after the evacuation process and before the pressurization process, the subsequent pressurization process and the second inspection process may be omitted.

本発明は、例えば密封ワークの良否判定を行なう検査装置及び検査方法に適用可能である。 The present invention can be applied to, for example, an inspection apparatus and an inspection method for determining whether a sealed workpiece is good or bad.

１，１Ｘ洩れ検査装置
２真空源
３高圧気体源
５基準容器
５ａ基準空間
６検査対象物
６ａ検査空間
７基準側空間部
７ｃ基準側接続路
８検査側空間部
８ｃ検査側接続路
９連通空間
１０差圧センサ（圧力センサ）
１１ダイヤフラム
１２基準側センサ室
１３検査側センサ室
１４基準側センサ路
１５検査側センサ路
２０真空路
２１真空幹路
２１ａ基端コネクタ
２２基準側枝路
２２ｃ路部分
２３検査側枝路
２３ｃ路部分
２４圧力計
３０加圧路
３１加圧幹路
３１ａ基端コネクタ
３２基準側枝路
３２ｃ路部分
３３検査側枝路
３３ｃ路部分
３４レギュレータ（減圧弁）
３５圧力計
４６方向制御弁
３９圧力タンク
４０開閉手段
４１真空基準側開閉弁
４２真空検査側開閉弁
４３加圧基準側開閉弁
４４加圧検査側開閉弁 1,1X Leakage inspection device 2 Vacuum source 3 High pressure gas source 5 Reference container 5a Reference space 6 Inspection object 6a Inspection space 7 Reference side space 7c Reference side connection 8 Inspection side space 8c Inspection side connection 9 Communication space 10 Differential pressure sensor (pressure sensor)
11 Diaphragm 12 Reference side sensor chamber 13 Inspection side sensor chamber 14 Reference side sensor passage 15 Inspection side sensor passage 20 Vacuum passage 21 Vacuum trunk passage 21a Base connector 22 Reference side branch 22c Road portion 23 Inspection side branch 23c Road portion 24 Pressure gauge 30 Pressurizing path 31 Pressurizing trunk path 31a Base end connector 32 Reference side branch path 32c Road section 33 Inspection side branch path 33c Road section 34 Regulator (pressure reducing valve)
35 Pressure gauge 46 Direction control valve 39 Pressure tank 40 Opening / closing means 41 Vacuum reference side opening / closing valve 42 Vacuum inspection side opening / closing valve 43 Pressure reference side opening / closing valve 44 Pressure inspection side opening / closing valve

Claims

A vacuum path connecting the inspection space defined by the inspection object and the vacuum source;
A pressurizing path connecting the inspection space and the high-pressure gas source;
A pressure sensor for detecting the pressure in the examination space;
An opening / closing means for selectively opening one of the vacuum path and the pressurizing path and blocking the other;
The inspection space is inspected for leakage based on the pressure detected by the pressure sensor in a state in which the opening / closing means blocks both the vacuum path and the pressure path, and the opening / closing means By opening the vacuum path in a state where the pressure path is cut off, the gas in the inspection space is evacuated by the vacuum source through the vacuum path, and then both the vacuum path and the pressure path are opened. In this blocked state, the pressure sensor detects the pressure in the inspection space to perform a first leakage inspection, and then the opening and closing means keeps the vacuum path closed and the inspection space is opened. After introducing the high-pressure gas of the high-pressure gas source into the inspection space through the pressurization path by opening the pressurization path without releasing the atmosphere , both the vacuum path and the pressurization path are shut off. And cut off this State by the pressure sensor leakage inspection apparatus and carrying out the second leakage test by detecting the pressure of the examination space.

The high-pressure gas source includes a pressure tank that stores high-pressure gas, and the pressurizing path connects the pressure tank and the inspection space without a pressure reducing valve, and when the pressurizing path is opened, The leak inspection apparatus according to claim 1, wherein an internal volume of the pressure tank is larger than an internal volume of an entire communication space including the inspection space connected downstream of the pressure tank.

A evacuation step for evacuating the gas in the inspection space defined by the inspection object;
After the evacuation step, a first inspection step of detecting the pressure of the inspection space in a state where the inspection space is a closed space;
After the first inspection step, a pressurizing step for introducing a high-pressure gas into the inspection space without releasing the evacuated inspection space to the atmosphere ;
A second inspection step of detecting the pressure of the inspection space in a state where the inspection space is a closed space after the pressing step;
A leakage inspection method characterized by comprising:

In the evacuation step, the gas in the reference space is also evacuated by communicating the inspection space and a reference space inside the reference container. In the first inspection step, the reference space and the inspection space are evacuated. In the closed space independent of each other, the differential pressure between these spaces is measured, and in the pressurizing step, the reference space and the inspection space are communicated with each other, whereby the high-pressure gas is also introduced into the reference space. 4, and in the second inspection step, the differential pressure between the spaces is measured in a state where the reference space and the inspection space are closed spaces independent from each other. Leakage inspection method.