JPH05256727A - Method and apparatus for inspecting leakage - Google Patents
Method and apparatus for inspecting leakageInfo
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- JPH05256727A JPH05256727A JP4089487A JP8948792A JPH05256727A JP H05256727 A JPH05256727 A JP H05256727A JP 4089487 A JP4089487 A JP 4089487A JP 8948792 A JP8948792 A JP 8948792A JP H05256727 A JPH05256727 A JP H05256727A
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- inspection
- liquid
- pressure
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は，燃料噴射ノズル，燃料
噴射ポンプのごとく，その内部に空洞部を有する被検査
体における，洩れ量を検査するための洩れ検査方法及び
その装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leakage inspection method and apparatus for inspecting the amount of leakage in an object to be inspected having a cavity inside such as a fuel injection nozzle and a fuel injection pump.
【０００２】[0002]
【従来技術】空洞部を有する被検査体における，空洞部
から外部への気体，液体の洩れを検査するために，従来
も種々の方法が提案されている。そして，その検査方法
の１つとして，被検査体の空洞部内に高圧の気体を導入
して空洞部内をテスト圧にした後，被検査体を圧力源か
ら閉鎖し，一定時間後における空洞部内の圧力変化を圧
力計などで検出し，洩れ量を測定する方法がある。2. Description of the Related Art Conventionally, various methods have been proposed for inspecting an object to be inspected having a cavity for leakage of gas or liquid from the cavity to the outside. Then, as one of the inspection methods, a high-pressure gas is introduced into the cavity of the object to be inspected to make the inside of the cavity a test pressure, the object to be inspected is closed from the pressure source, and the inside of the cavity after a certain period of time is closed. There is a method to detect the pressure change with a pressure gauge and measure the amount of leakage.
【０００３】[0003]
【解決しようとする課題】しかし，この方法は，被検査
体の空洞部の容積が大きい場合には，圧力変動が少しし
か生ぜず，洩れ量の検出精度が低い。また，上記方法に
おいて被検査体内部に入れる気体のテスト圧が高い場合
には，加圧時に断熱圧縮により気体の温度が外気温度よ
りも上昇し，その後被検査体から外気へ放熱されて被検
査体内部の気体の温度が徐々に下がり，その結果，被検
査体に洩れがなくても被検査体内部の気体に圧力変動を
生ずる。However, in this method, when the volume of the cavity of the object to be inspected is large, there is little pressure fluctuation, and the accuracy of detecting the leak amount is low. Further, in the above method, if the test pressure of the gas to be put into the object to be inspected is high, the temperature of the gas rises above the outside air temperature due to adiabatic compression during pressurization, and then the object to be inspected radiates heat to the outside air to inspect the object. The temperature of the gas inside the body gradually decreases, and as a result, pressure fluctuations occur in the gas inside the body under inspection even if there is no leakage in the body under inspection.
【０００４】また，被検査体の温度が，その周囲の気体
の温度と異なる場合，テスト圧が加圧された後に被検査
体の温度及び気体の温度が同温になるように変化するた
め，被検査体内部の気圧に圧力変動を生ずる。そのた
め，この圧力変動が洩れ量に影響を及ぼし，検出精度を
低下させる。また，これを避けるためには，被検査体内
部の気体の温度が平衡に達してから（変化しなくなって
から）洩れによる圧力変動を測定する必要があり，検査
に長時間を必要とする。Further, when the temperature of the object to be inspected is different from the temperature of the gas around it, the temperature of the object to be inspected and the temperature of the gas change after the test pressure is applied. Pressure fluctuations occur in the atmospheric pressure inside the object to be inspected. Therefore, this pressure fluctuation affects the amount of leakage and reduces the detection accuracy. Further, in order to avoid this, it is necessary to measure the pressure fluctuation due to leakage after the temperature of the gas inside the object to be inspected reaches equilibrium (after it stops changing), which requires a long time for the inspection.
【０００５】本発明は，かかる従来の問題点に鑑み，空
洞部の容積が大きい場合においても，微小な洩れ量を検
出することができ，またテスト圧の大きさや被検査体の
温度に影響されない，高精度の洩れ検査方法及びその装
置を提供しようとするものである。In view of the above conventional problems, the present invention can detect a minute leak amount even when the volume of the cavity is large, and is not affected by the magnitude of the test pressure or the temperature of the object to be inspected. , It is intended to provide a highly accurate leak inspection method and its device.
【０００６】[0006]
【課題の解決手段】本発明は空洞部を有する被検査体
を，液体を入れた密閉可能な検査用タンク内に入れると
共に被検査体を液体中に埋没させ，かつ液体の上方には
気体容積部を残存形成しておき，検査用タンクを密閉状
態にした後上記気体容積部を減圧状態となすと共に被検
査体の上記空洞部内に加圧流体を導入し，その後上記気
体容積部の圧力変化を検出することにより，被検査体の
洩れ量を測定することを特徴とする洩れ検査方法にあ
る。According to the present invention, an object to be inspected having a hollow portion is placed in an inspectable tank for containing a liquid, the object to be inspected is immersed in the liquid, and a gas volume is provided above the liquid. Part is left formed, the inspection tank is hermetically closed, the gas volume is decompressed, and a pressurized fluid is introduced into the cavity of the object to be inspected, and then the pressure change of the gas volume is changed. In the leak inspection method, the leak amount of the object to be inspected is detected by detecting the.
【０００７】本発明において最も注目すべきことは，液
体を入れた密閉可能な検査用タンク内に被検査体を埋没
させると共に検査用タンクの上方には気体容積部を残存
形成しておくこと，検査用タンクを密閉状態となすと共
に気体容積部を減圧状態となすこと，一方被検査体の空
洞部内には加圧流体を導入しておき，減圧状態とした上
記気体容積部の圧力変化を検出することにある。What is most noticeable in the present invention is that the object to be inspected is buried in a sealable inspection tank containing a liquid, and a gas volume remains formed above the inspection tank. The inspection tank is closed and the gas volume is depressurized, while pressurized fluid is introduced into the cavity of the DUT to detect the pressure change in the depressurized gas volume. To do.
【０００８】上記被検査体としては，例えばディーゼル
エンジンに用いる燃料噴射ノズル，燃料噴射ポンプな
ど，空洞部の容積が比較的大きいものがある。勿論，本
発明は，空洞部の容積が小さい被検査体の洩れ検査方法
にも適用できる。被検査体を埋没させる液体としては，
通常は水を用いるが，軽油，ブレーキ油，洗浄油などが
ある。[0008] As the above-mentioned object to be inspected, for example, a fuel injection nozzle used in a diesel engine, a fuel injection pump, or the like, whose cavity has a relatively large volume is used. Of course, the present invention can also be applied to a leak inspection method for an object to be inspected with a small volume of the cavity. As the liquid for burying the inspection object,
Water is usually used, but light oil, brake oil, cleaning oil, etc. are available.
【０００９】気体容積部は，液体中に被検査体を埋没さ
せたときに，液体上面と検査用タンクの天井との間に形
成される気体残存部分である。この気体容積部は，洩れ
量検査に先立って減圧状態にされる。被検査体の空洞部
内には，洩れ検査用の加圧流体が導入される。加圧流体
は，通常は加圧気体を用いるが，加圧液体を用いること
もできる。気体としては，空気，窒素ガス等がある。The gas volume is a gas residual portion formed between the upper surface of the liquid and the ceiling of the inspection tank when the inspection object is immersed in the liquid. This gas volume is decompressed prior to the leak test. A pressurized fluid for leak inspection is introduced into the cavity of the device under test. A pressurized gas is usually used as the pressurized fluid, but a pressurized liquid can also be used. Examples of the gas include air and nitrogen gas.
【００１０】上記洩れ検査方法を実施するための装置と
しては，空洞部を有する被検査体を入れる密閉可能な検
査用タンクと，該検査用タンク内に密閉弁を介して液体
を導入する液体供給機と，検査用タンク内において上記
液体よりも上方に形成された気体容積部を減圧する減圧
装置と，気体容積部の圧力変化を検出する圧力測定器
と，被検査体の空洞部内に加圧流体を導入する加圧装置
とよりなることを特徴とする洩れ検査装置がある。As an apparatus for carrying out the above-mentioned leak inspection method, a sealable inspection tank for containing an object to be inspected having a cavity and a liquid supply for introducing a liquid into the inspection tank via a sealing valve Machine, a decompression device for decompressing the gas volume formed above the liquid in the inspection tank, a pressure measuring device for detecting a pressure change in the gas volume, and a pressure applied to the cavity of the inspection object. There is a leak inspection device characterized by comprising a pressurizing device for introducing a fluid.
【００１１】検査用タンク内へ液体を導入するための液
体供給機としてはポンプがある。気体容積部を減圧する
減圧装置としては，ピストンシリンダがある。圧力変化
を検出するための圧力測定器としては，例えば歪ゲージ
などを用いた各種の圧力センサがある。また，上記減圧
装置として，実施例に示すごとき，一定量の容積変化を
させることができる較正ピストンを用いる場合には，よ
り正確に，自動的に洩れ量を検出することができる。There is a pump as a liquid supply device for introducing the liquid into the inspection tank. A piston cylinder is known as a pressure reducing device for reducing the pressure of the gas volume. As a pressure measuring device for detecting a pressure change, for example, there are various pressure sensors using a strain gauge or the like. Further, when a calibration piston capable of changing the volume by a certain amount is used as the decompression device, the leak amount can be detected more accurately and automatically.
【００１２】[0012]
【作用及び効果】本発明の洩れ検査方法においては，密
閉可能な検査用タンクの液体中に被検査体を埋没させる
と共に検査用タンクの上部には，気体容積部を残存させ
ておき，その後密閉状態にした検査用タンク内の上記気
体容積部を減圧状態となし，一方被検査体の空洞部内に
は加圧流体を導入しておく。その後は，一定時間放置
し，気体容積部の圧力変化を検出する。この放置時にお
いて，もしも被検査体に洩れがある場合には，減圧状態
にある気体容積部の圧力が上昇する。洩れがなければ圧
力変化はない。そのため，上記圧力変化量と上記気体容
積部とより，洩れ量を算出することができる。In the leak inspection method of the present invention, the object to be inspected is immersed in the liquid in the sealable inspection tank, and the gas volume remains at the upper part of the inspection tank, and then sealed. The above-mentioned gas volume in the inspection tank that has been put into the state is decompressed, while pressurized fluid is introduced into the cavity of the DUT. After that, it is left for a certain period of time to detect the pressure change in the gas volume. If there is a leak in the object to be inspected during this standing, the pressure in the gas volume in the depressurized state rises. If there is no leak, there is no pressure change. Therefore, the leak amount can be calculated from the pressure change amount and the gas volume portion.
【００１３】本発明においては，洩れ量検査に当たっ
て，検査用タンクの上部に小容積の上記気体容積部を形
成させ，その所定時間当たりの圧力変化を検出してい
る。そのため，洩れ量が微小であっても上記圧力変化が
大きく表れ，洩れ量を正確に検出することができる。そ
れ故，空洞部の容積が大きい被検査体の場合にも精度良
く洩れ量を検出できる。In the present invention, in the leak amount inspection, the gas volume portion having a small volume is formed in the upper portion of the inspection tank, and the pressure change per predetermined time is detected. Therefore, even if the leak amount is minute, the above-mentioned pressure change greatly appears, and the leak amount can be accurately detected. Therefore, the leak amount can be accurately detected even in the case of an object to be inspected with a large volume of the cavity.
【００１４】また，本発明は，気体容積部を減圧状態と
した後に，その圧力変化を検出している。そのため，も
しも検査用タンクに洩れがあっても，その洩れは，被検
査体からの洩れと同様に圧力を上昇させる方向に働く。
そのため，検査用タンクに洩れがあっても，被検査体の
不良品（洩れ量大）を良品（洩れ量小）と判定すること
もない。即ち，フェイルセーフ（ｆａｉｌ ｓａｆｅ）
機能も有する。Further, according to the present invention, the pressure change is detected after the gas volume is depressurized. Therefore, even if there is a leak in the inspection tank, the leak acts in the direction of increasing the pressure, like the leak from the inspection object.
Therefore, even if there is a leak in the inspection tank, a defective product (large amount of leakage) of the inspected object is not judged to be a good product (small amount of leakage). That is, fail safe
It also has a function.
【００１５】また，被検査体を埋没させる液体は，その
熱容量が気体に比して非常に大きい。そのため，加圧に
よって被検査体内部の気体の温度が上昇したり，あるい
は検査時において被検査体と液体との間に比較的大きな
温度差があっても，液体の温度変化は少なく，液体タン
クの上方に形成した気体容積部の気体の圧力変化には殆
ど影響を与えない。The liquid for burying the object to be inspected has a very large heat capacity as compared with gas. Therefore, even if the temperature of the gas inside the object to be inspected rises due to pressurization, or there is a relatively large temperature difference between the object to be inspected and the liquid at the time of inspection, the temperature change of the liquid is small and the liquid tank Has almost no effect on the pressure change of the gas in the gas volume formed above.
【００１６】更に，検査用タンク内に導入する液体量
は，どれだけであっても，被検査体が埋没する量があれ
ば良い。即ち，本発明は上記気体容積部の圧力変化を検
出するものであるから，検査用タンク内への液体の導入
量は関係ない。そのため，検査の準備も容易である。ま
た，上記検査装置においても同様の作用効果が得られ
る。したがって，本発明によれば，空洞部の容積が大き
い場合においても，微小な洩れ量を検出することがで
き，またテスト圧の大きさや被検査体の温度に影響され
ない，高精度の洩れ検査方法及び検査装置を提供するこ
とができる。Further, no matter how much liquid is introduced into the inspection tank, it is sufficient that the inspection object is buried. That is, since the present invention detects the pressure change in the gas volume portion, the amount of liquid introduced into the inspection tank is irrelevant. Therefore, preparation for inspection is easy. Further, similar effects can be obtained in the above inspection device. Therefore, according to the present invention, even if the volume of the cavity is large, a minute amount of leakage can be detected, and the leakage inspection method is highly accurate without being affected by the magnitude of the test pressure or the temperature of the inspection object. And an inspection device can be provided.
【００１７】[0017]
実施例１ 本発明の実施例にかかる洩れ検査方法及びその装置につ
き，図１〜図３を用いて説明する。まず，本例の検査装
置は，図１に示すごとく，空洞部を有する被検査体１を
入れる密閉可能な検査用タンク２と，該検査用タンク２
内に密閉弁２６１を介して液体２１を導入する液体供給
機２５と，検査用タンク２内において上記液体２１より
も上方に形成された気体容積部２２を減圧する減圧装置
３とを有する。Embodiment 1 A leak inspection method and apparatus therefor according to an embodiment of the present invention will be described with reference to FIGS. First, as shown in FIG. 1, the inspection apparatus of this example includes a sealable inspection tank 2 in which an object to be inspected 1 having a cavity is put, and the inspection tank 2
It has a liquid supply device 25 for introducing the liquid 21 via a sealing valve 261 therein, and a decompression device 3 for decompressing a gas volume 22 formed above the liquid 21 in the inspection tank 2.
【００１８】また，気体容積部２２の圧力変化を検出す
る圧力測定器４０と，被検査体１の空洞部内に加圧流体
を導入する加圧装置１３とを有する。上記液体２１は，
検査用タンク２とは別に配設した液体タンク２１０内に
貯留してある。液体２１としては水を用いる。また液体
供給機２５としては，液体ポンプを用いる。液体タンク
２１０と検査用タンク２との間には，液体導入パイプ２
５１が連結してある。Further, it has a pressure measuring device 40 for detecting a pressure change in the gas volume 22 and a pressurizing device 13 for introducing a pressurized fluid into the cavity of the device under test 1. The liquid 21 is
It is stored in a liquid tank 210 arranged separately from the inspection tank 2. Water is used as the liquid 21. A liquid pump is used as the liquid supplier 25. The liquid introduction pipe 2 is provided between the liquid tank 210 and the inspection tank 2.
51 are connected.
【００１９】一方，検査用タンク２の上部と液体タンク
２１０との間には，検査用タンク２内でオーバーフロー
した液体を液体タンク２に戻すための戻りパイプ２５２
が設けてある。上記液体導入パイプ２５１及び戻りパイ
プ２５２には，検査用タンク２内を密閉するための電磁
式密閉弁２６１，２６２が，それぞれ介設してある。上
記被検査体１には，その空洞部（図示略）に対して，加
圧装置１３との間に加圧流体導入パイプ１１が，電磁式
密閉弁１２を介して接続されている。加圧装置１３とし
ては，空気コンプレッサを用いる。On the other hand, a return pipe 252 for returning the liquid overflowing in the inspection tank 2 to the liquid tank 2 is provided between the upper portion of the inspection tank 2 and the liquid tank 210.
Is provided. The liquid introduction pipe 251 and the return pipe 252 are provided with electromagnetic sealing valves 261 and 262 for sealing the inside of the inspection tank 2, respectively. A pressurized fluid introduction pipe 11 is connected to a cavity (not shown) of the device under test 1 with a pressurizing device 13 via an electromagnetic sealing valve 12. An air compressor is used as the pressurizing device 13.
【００２０】次に，検査用タンク２の気体容積部２２に
対しては，測定用パイプ４１を介して，減圧装置３及び
圧力測定器４０が接続してある。減圧装置３は，シリン
ダ３２と３５とを有する。シリンダ３２は，較正ピスト
ン３１を介して，減圧室３０と背面室３２２とを有す
る。減圧室３０はパイプ３３を介して上記測定用パイプ
４１に接続してある。Next, the pressure reducing device 3 and the pressure measuring device 40 are connected to the gas volume portion 22 of the inspection tank 2 via a measuring pipe 41. The decompression device 3 has cylinders 32 and 35. The cylinder 32 has a decompression chamber 30 and a back chamber 322 via a calibration piston 31. The decompression chamber 30 is connected to the measuring pipe 41 via a pipe 33.
【００２１】また，シリンダ３５は，作動ピストン３５
０を介して第１室３５１と第２室３５２とを有する。較
正ピストン３１，作動ピストン３５０は，連結棒３７に
より一体的に連結されている。第１室３５１，第２室３
５２は，パイプ３６１，３６２切換弁３８を介して，作
動用空気源３８１に接続されている。一方，圧力測定器
４０は，増幅器４２を介して計測制御装置４５に接続さ
れている。計測制御装置は，表示部４３，記録部４４を
有する。The cylinder 35 has a working piston 35.
It has a first chamber 351 and a second chamber 352 with the space 0 in between. The calibration piston 31 and the working piston 350 are integrally connected by a connecting rod 37. First chamber 351, second chamber 3
52 is connected to an operating air source 381 via pipes 361 and 362 switching valve 38. On the other hand, the pressure measuring device 40 is connected to the measurement control device 45 via an amplifier 42. The measurement control device has a display unit 43 and a recording unit 44.
【００２２】次に，検査方法につき説明する。まず，加
圧流体導入パイプ１１を接続した被検査体１を検査用タ
ンク２内に入れる。また，検査用タンク２の蓋２０を密
閉する。次いで，密閉弁２６１，２６２を開け，液体供
給機２５より液体２１としての水を検査用タンク２内に
導入する。そして，検査用タンク２内の被検査体１が液
体２１に埋没し，検査用タンク２から液体２１がオーバ
ーフローした時点で密閉弁２６１，２６２を閉止する。Next, the inspection method will be described. First, the device under test 1 to which the pressurized fluid introduction pipe 11 is connected is put into the inspection tank 2. Further, the lid 20 of the inspection tank 2 is closed. Next, the sealing valves 261 and 262 are opened, and water as the liquid 21 is introduced into the inspection tank 2 from the liquid supply device 25. Then, when the inspection object 1 in the inspection tank 2 is submerged in the liquid 21 and the liquid 21 overflows from the inspection tank 2, the sealing valves 261 and 262 are closed.
【００２３】これにより，検査用タンク２の上部に気体
容積部２２が形成され，検査用タンク２は密閉される。
上記密閉弁２６１，２６２は，上記計測制御装置４５か
らの信号により開閉される。次に，減圧装置３を作動さ
せ，気体容積部２２を減圧状態にする。即ち，切換弁３
８を上記計測制御装置４５により作動させて，シリンダ
３５の第１室３５１側に作動加圧空気を圧入する。これ
により，作動ピストン３５０が第２室側へ押される。そ
のため，連結棒３７によってシリンダ３２の較正ピスト
ン３１が背面室３２２側へ引かれる。As a result, the gas volume 22 is formed in the upper portion of the inspection tank 2 and the inspection tank 2 is sealed.
The sealing valves 261 and 262 are opened / closed by a signal from the measurement control device 45. Next, the decompression device 3 is operated to bring the gas volume 22 into a decompressed state. That is, the switching valve 3
8 is operated by the measurement control device 45, and pressurizing operating air is injected into the first chamber 351 side of the cylinder 35. As a result, the working piston 350 is pushed toward the second chamber. Therefore, the connecting rod 37 pulls the calibration piston 31 of the cylinder 32 toward the rear chamber 322.
【００２４】ここに，重要なことは，較正ピストン３１
の後退により，減圧室３０が減圧となり，これに伴って
パイプ３３，測定用パイプ４１，気体容積部２２が減圧
となることである。また，較正ピストン３１が距離Ａだ
け後退することにより，減圧室３０内に一定の容積変化
ΔＶが与えられることである（後述の計算式参照）。こ
の状態で，較正ピストン３１は停止され，気体容積部２
２内の減圧状態が圧力測定器４０，計測制御装置４５に
より測定される。Here, it is important that the calibration piston 31
This means that the decompression chamber 30 is decompressed due to the retreat, and the pipe 33, the measurement pipe 41, and the gas volume 22 are decompressed accordingly. Further, the calibration piston 31 is retracted by the distance A, so that a constant volume change ΔV is given in the decompression chamber 30 (see the calculation formula described later). In this state, the calibration piston 31 is stopped and the gas volume 2
The depressurized state in 2 is measured by the pressure measuring device 40 and the measurement control device 45.
【００２５】即ち，この減圧により気体容積部２２内
は，図２に示すごとく大気圧以下となり，その減圧量が
Ｐｃａｌとして記録される。次に，検査用タンク２内に
入れた被検査体１の空洞部内に，加圧流体導入パイプ１
１を通じて，加圧装置１３より加圧空気（例えば１０ｋ
ｇ／ｃｍ2 ）を導入する。この導入は，密閉弁１２を上
記計測制御装置４５により開閉することにより行なう。That is, due to this depressurization, the inside of the gas volume 22 becomes below atmospheric pressure as shown in FIG. 2, and the depressurized amount is recorded as Pcal. Next, the pressurized fluid introduction pipe 1 is placed in the cavity of the DUT 1 placed in the inspection tank 2.
1 through the pressurizing device 13 to pressurize air (for example, 10 k
g / cm 2 ) is introduced. This introduction is performed by opening and closing the closed valve 12 by the measurement control device 45.
【００２６】その後，この状態を維持して，一定時間に
おける洩れ量を検出する。洩れ量の検出結果は図２，図
３に示されている。図２は，被検査体に洩れがあったと
き，図３は洩れがなかった場合を示している。洩れがあ
ったときには，図２に示すごとく，上記被検査体１内へ
の加圧時を基点として，気体容積部内の圧力が一定時間
（例えば１０秒）でΔＰ圧力上昇する。Thereafter, this state is maintained and the leak amount in a fixed time is detected. The detection results of the leak amount are shown in FIGS. FIG. 2 shows the case where there is a leak in the inspection object, and FIG. 3 shows the case where there is no leak. When there is a leak, as shown in FIG. 2, the pressure in the gas volume part increases by ΔP in a certain time (for example, 10 seconds) from the time of pressurization into the device under test 1 as a base point.
【００２７】同図において，線８１は上記較正ピストン
作動までの間，線８２は較正ピストン作動時の減圧状
態，線８３は検査時の圧力変化を示している。また，図
３は，図２と同様の関係を示しているが，洩れがないの
で，加圧後も一定圧力の平行な線８３０を示している。In the figure, a line 81 indicates the pressure reduction state during the calibration piston operation, a line 82 indicates the pressure reduction state during the calibration piston operation, and a line 83 indicates the pressure change during the inspection. Further, FIG. 3 shows a relationship similar to that of FIG. 2, but since there is no leakage, parallel lines 830 having a constant pressure even after pressurization are shown.
【００２８】そこで，計測制御装置４５においては，上
記図２に示した測定結果に基づき，次式によって洩れ量
ＶL を演算する。 ＶL ＝（ΔＶ／Ｐｃａｌ）×ΔＰ×（６０／ｔ） ＶL ；洩れ量（ｃｍ3 ／分） ΔＶ；較正ピストンの容積変化（ｃｍ3 ） Ｐｃａｌ；較正ピストン動作時の圧力変化（ｍｍＨ
2 Ｏ） ΔＰ；検出時間中の圧力変化（ｍｍＨ2 Ｏ） ｔ；検出時間（秒）Therefore, in the measurement control device 45, the leakage amount V L is calculated by the following equation based on the measurement result shown in FIG. V L = (ΔV / Pcal) × ΔP × (60 / t) V L ; Leakage amount (cm 3 / min) ΔV; Volume change of calibration piston (cm 3 ) Pcal; Pressure change during operation of calibration piston (mmH)
2 O) ΔP; pressure change during detection time (mmH 2 O) t; detection time (seconds)
【００２９】上式により求められた洩れ量は，基準値と
比較され，表示器４３，記録器４４に，その合否が表
示，記録される。上記より知られるごとく，本例におい
ては，検査用タンク２の上部に小容積の気体容積部２２
を形成させ，その圧力変化ΔＰを検出している。そのた
め，洩れ量が微小であっても，圧力変化ΔＰが大きく表
われるので，洩れ量を正確に検出できる。それ故，空洞
部の容積が大きい被検査体においても，精度良く洩れ量
を検出できる。The leakage amount obtained by the above equation is compared with the reference value, and the display 43 and the recorder 44 display and record the pass / fail. As is known from the above, in this example, a small volume of gas volume 22 is provided above the inspection tank 2.
Is formed, and the pressure change ΔP is detected. Therefore, even if the amount of leak is small, the pressure change ΔP is large, so that the amount of leak can be accurately detected. Therefore, the leak amount can be accurately detected even in the object to be inspected with a large volume of the cavity.
【００３０】また，気体容積部２２を減圧とした後に圧
力変化を検出するので，もしも検査用タンク２に洩れが
あっても，その洩れは気体容積部２２の圧力を上昇する
方向に働く。そのため，洩れ量の大きい被検査体１を，
洩れのない良品と判別してしまうことがなく，フェイル
セーフ機能も有する。また，本例においては，上記シリ
ンダ３２内に較正ピストン３１を設けて減圧するので，
較正ピストン３１の移動量Ａより上記容積変化（ΔＶ）
を容易に測定することができる。Further, since the pressure change is detected after the gas volume 22 is depressurized, even if there is a leak in the inspection tank 2, the leak acts in the direction of increasing the pressure in the gas volume 22. Therefore, the inspection object 1 with a large leak amount
It also has a fail-safe function so that it is not judged as a good product without leakage. Further, in this example, since the calibration piston 31 is provided in the cylinder 32 to reduce the pressure,
The volume change (ΔV) from the movement amount A of the calibration piston 31
Can be easily measured.
【００３１】また，被検査体１を埋没する液体２１は，
水であり，空気に比して熱容量が非常に大きい。そのた
め，液体２１と被検査体１との温度差が大きくても，圧
力変化に影響を与えない。また，検査は気体容積部２２
の圧力変化を検出するものであるから，検査用タンク２
内の液体２１は，被検査体１を埋没させる量であれば良
く，その量は測定毎に同じとする必要はない。それ故，
検査準備も容易である。なお，本例では，容積変化ΔＶ
を較正ピストン３１により行ったが，この容積変化は上
記較正ピストン以外でも，例えばボルトネジ方式によっ
ても行うことができる。The liquid 21 for burying the inspection object 1 is
It is water and has a much larger heat capacity than air. Therefore, even if the temperature difference between the liquid 21 and the device under test 1 is large, it does not affect the pressure change. In addition, the inspection is performed in the gas volume 22
Because it detects the pressure change of the
The amount of the liquid 21 in the liquid may be any amount as long as it can immerse the device under test 1, and the amount need not be the same for each measurement. Therefore,
Inspection preparation is also easy. In this example, the volume change ΔV
Although the calibration piston 31 is used, the volume change can be performed by other than the calibration piston, for example, by a bolt screw method.
【００３２】実施例２ 上記実施例１の検査装置を用いた，具体的測定例につき
示す。 検査用タンクの容積；．．．３６００ｃｍ3 気体容積部；．．．７ｃｍ3 較正ピストンの気体容積部変化；ΔＶ＝０．０２７ｃｍ
3 較正ピストン動作時の圧力変化；Ｐｃａｌ＝２６ｍｍＨ
2 Ｏ 検出時間中の圧力変化；ΔＰ＝５ｍｍＨ2 Ｏ 検出時間；ｔ＝１０秒Example 2 A specific measurement example using the inspection apparatus of Example 1 will be described. Inspection tank volume ;. ． ． 3600 cm 3 gas volume; ． ． Gas volume change of 7 cm 3 calibration piston; ΔV = 0.027 cm
3 Pressure change during calibration piston operation; Pcal = 26mmH
Pressure change during 2 O detection time; ΔP = 5 mmH 2 O detection time; t = 10 seconds
【００３３】上記測定値を前記の式により算出すると洩
れ量ＶL （ｃｍ3 ／分）は次のようになる。 ＶL ＝（ΔＶ／Ｐｃａｌ）×ΔＰ×（６０／ｔ） ＝（０．０２７／２６）×５×（６０／１０） ＝０．０３１（ｃｍ3 ／分）When the measured value is calculated by the above equation, the leak amount V L (cm 3 / min) is as follows. V L = (ΔV / Pcal) × ΔP × (60 / t) = (0.027 / 26) × 5 × (60/10) = 0.031 (cm 3 / min)
【図１】実施例１における検査装置の全体説明図。FIG. 1 is an overall explanatory diagram of an inspection device according to a first embodiment.
【図２】実施例１において被検査体に洩れがあるときの
圧力変化を示す線図。FIG. 2 is a diagram showing a pressure change when there is a leak in the object to be inspected in Example 1.
【図３】実施例１において被検査体に洩れがないときの
圧力変化を示す線図。FIG. 3 is a diagrammatic view showing a pressure change when there is no leakage in the object to be inspected in Example 1.
１．．．被検査体， １３．．．加圧装置， ２．．．検査用タンク， ２１．．．液体， ２２．．．気体容積部， ２５．．．液体供給機， ３．．．減圧装置， ３１．．．較正ピストン， ３０．．．減圧室， ４０．．．圧力測定器， 1. ． ． Inspection object, 13. ． ． Pressurizing device, 2. ． ． Inspection tank, 21. ． ． Liquid, 22. ． ． Gas volume, 25. ． ． Liquid feeder, 3. ． ． Decompression device, 31. ． ． Calibration piston, 30. ． ． Decompression chamber, 40. ． ． Pressure gauge,
Claims (2)
た密閉可能な検査用タンク内に入れると共に被検査体を
液体中に埋没させ，かつ液体の上方には気体容積部を残
存形成しておき，検査用タンクを密閉状態にした後上記
気体容積部を減圧状態となすと共に被検査体の上記空洞
部内に加圧流体を導入し，その後上記気体容積部の圧力
変化を検出することにより，被検査体の洩れ量を測定す
ることを特徴とする洩れ検査方法。1. An object to be inspected having a hollow portion is placed in a sealable inspection tank containing a liquid, the object to be inspected is immersed in the liquid, and a gas volume remains above the liquid. Then, after the inspection tank is hermetically closed, the gas volume is depressurized and a pressurized fluid is introduced into the cavity of the object to be inspected, and then the pressure change in the gas volume is detected. A leak inspection method characterized by measuring the amount of leak of an object to be inspected.
能な検査用タンクと，該検査用タンク内に密閉弁を介し
て液体を導入する液体供給機と，検査用タンク内におい
て上記液体よりも上方に形成された気体容積部を減圧す
る減圧装置と，気体容積部の圧力変化を検出する圧力測
定器と，被検査体の空洞部内に加圧流体を導入する加圧
装置とよりなることを特徴とする洩れ検査装置。2. An inspectable tank for accommodating an object to be inspected having a cavity, a liquid feeder for introducing a liquid into the inspecting tank via a sealing valve, and Also, a decompression device for decompressing the gas volume formed above, a pressure measuring device for detecting a pressure change in the gas volume, and a pressure device for introducing a pressurized fluid into the cavity of the DUT. Leak inspection device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4089487A JP2601098B2 (en) | 1992-03-13 | 1992-03-13 | Leakage inspection method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4089487A JP2601098B2 (en) | 1992-03-13 | 1992-03-13 | Leakage inspection method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05256727A true JPH05256727A (en) | 1993-10-05 |
| JP2601098B2 JP2601098B2 (en) | 1997-04-16 |
Family
ID=13972106
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4089487A Expired - Fee Related JP2601098B2 (en) | 1992-03-13 | 1992-03-13 | Leakage inspection method and device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2601098B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07218379A (en) * | 1994-01-31 | 1995-08-18 | Nippondenso Co Ltd | Method and apparatus for inspecting leakage |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5256590A (en) * | 1975-11-04 | 1977-05-10 | Sharp Corp | Leak detector |
| JPS6061636U (en) * | 1983-10-04 | 1985-04-30 | 株式会社神崎高級工機製作所 | Oil leak detection device for transmission case |
| JPH03245031A (en) * | 1990-02-23 | 1991-10-31 | Fujitsu Ltd | Waterproof test method |
-
1992
- 1992-03-13 JP JP4089487A patent/JP2601098B2/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5256590A (en) * | 1975-11-04 | 1977-05-10 | Sharp Corp | Leak detector |
| JPS6061636U (en) * | 1983-10-04 | 1985-04-30 | 株式会社神崎高級工機製作所 | Oil leak detection device for transmission case |
| JPH03245031A (en) * | 1990-02-23 | 1991-10-31 | Fujitsu Ltd | Waterproof test method |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07218379A (en) * | 1994-01-31 | 1995-08-18 | Nippondenso Co Ltd | Method and apparatus for inspecting leakage |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2601098B2 (en) | 1997-04-16 |
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