JPH0815079A - Instrument and method for measuring pressure leakage - Google Patents

Abstract

PURPOSE:To provide a pressure leakage measuring instrument which can measure pressure leakage with high accuracy by detecting a differential pressure with a simple constitution using no master for measurement and can be manufactured at a low cost. CONSTITUTION:At the time of measuring pressure leakage with a pressure leakage measuring instrument 2, all of opening/closing valves 20, 30, and 40 are opened and a pressurized gas is introduced into an object W to be measured through pipelines 10A-10E and into a pipeline 12B through pipelines 10A and 12A. After a prescribed period of time, the supply of the pressurized gas is discontinued by closing the valve 20 and, on the other hand, the internal pressures in the object W and pipelines 10C,..., 12B are made uniform by opening the valves 3 and 40 by prescribed balancing time more. After the balancing time, the valves 30 and 40 are closed and the differential pressure between a produced closed space 12B and the object W is measured by means of a differential pressure detector 8. When no gas leakage occurs from the object W, the measured differential pressure becomes zero and, when gas leakage exists, a differential pressure equal to the leaking-out amount of the gas is detected by means of the detector 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention introduces a pressurized gas from a source of pressurized gas into an object to be measured and measures a pressure change in the object to be measured to prevent pressure leakage from the object to be measured. The present invention relates to a pressure leak measuring device and a pressure leak measuring method.

[0002]

2. Description of the Related Art In order to measure the hermeticity of a casting block for an automobile engine, a pressurized gas such as compressed air is introduced into a measured object from a pressurized gas source such as an air compressor to measure the measured object. A method is used to measure pressure leakage from the. At this time, in the method of simply measuring the change in the absolute value of the atmospheric pressure due to the pressure leak from the measured object by the pressure sensor
Due to the limitation of measurement accuracy of the pressure sensor, accurate pressure leak measurement cannot be performed. Therefore, as a device for performing highly accurate pressure leak measurement, a measurement master (hereinafter also simply referred to as “master”) having substantially the same shape as the object to be measured and having no gas leakage is prepared. There has been developed a device which is connected to a measurement object via a differential pressure detector and measures a pressure leak from the measurement object by detecting a change in the differential pressure. As a specific example of the pressure leak measuring device based on the differential pressure measurement, there is, for example, the invention of the pressure leak measuring device described in JP-A-4-221733. In the technique described in this publication, a measurement master having substantially the same shape and volume as the object to be measured and the object to be measured are connected via a differential pressure detector. Then, the pressure leakage from the measured object is measured by measuring the change over time of the differential pressure value from the time when the compressed air is introduced into the measured object and the master to reach the measured pressure.

[0003]

However, in a pressure leak measuring device using such a master, it is necessary to prepare a master having substantially the same shape and volume as the object to be measured and having no pressure leak. Generally, it is not easy to create a master having the same shape as a DUT having a complicated shape without pressure leakage, and the cost and man-hours for creating the master increase. Furthermore, in the process where a wide variety of products are produced, a new master must be prepared for each different object to be measured, and a master replacement means is also required, so the cost for pressure leak inspection is significantly high. It gets expensive. Further, since the piping becomes complicated, the number of man-hours for maintenance and maintenance of the device becomes large, and the measurement time is long because the master is replaced. On the other hand, a pressure leak measuring device has been developed that can handle multiple types of DUTs by changing the capacity of the master, but such a variable capacitance master becomes extremely expensive. , The problem of high cost is not solved. Furthermore, since pressure fluctuations occur due to temperature changes when compressed air is introduced into the DUT and the master, it is necessary to wait until the pressure stabilizes, and there is a problem that there is a limit to shortening the measurement time. there were.

Therefore, in the inventions according to claims 1 to 5 of the present application, pressure leak measurement can be performed at low cost by performing pressure leak measurement by differential pressure detection without using a master. An object is to provide a pressure leak measuring device and a pressure leak measuring method. Also,
In the invention according to claim 2, an object of the present invention is to provide a pressure leak measuring device that does not use a master and has a simple piping configuration, so that the measuring operation is easy and the device is easy to maintain. And Claim 3
According to the invention of claim 1, in a pressure leak measuring device that does not use a master, it is possible to perform accurate pressure leak measurement in a short time by speeding up the pressurization inside the object to be measured and making the pressure inside the pipe more uniform. An object of the present invention is to provide a pressure leakage measuring device that can be used. Further, in the invention according to claim 4, by making the pressure in the object to be measured equal to the pressure in the pipe, the pressure is stabilized by eliminating the movement of gas, and a more accurate pressure leak measurement can be performed in a shorter time. It is an object of the present invention to provide a leak measuring device. Further, it is an object of the invention according to claim 5 to provide a pressure leakage measuring method capable of remarkably shortening the measuring time by obtaining the measuring result in the process of stabilizing the pressure.

[0005]

Therefore, in order to solve the above-mentioned problems, in the invention according to claim 1, the differential pressure between the object to be measured into which the pressurized gas is introduced and the closed space which is independent is detected. A pressure leak measuring device for measuring pressure leak from the object to be measured, wherein the independent sealed space is formed by closing a part of the piping of the pressure leak measuring device. Created. Here, the "pressurized gas" includes various gases such as compressed air, compressed nitrogen gas, compressed oxygen gas, compressed argon gas and the like.

According to a second aspect of the present invention, in the pressure leak measuring device according to the first aspect, the pressurized gas source for introducing the pressurized gas into the object to be measured is the object to be measured. A first pipe connected to the first pipe, and both ends thereof are connected to the first pipe at a first connection part on the side closer to the pressurized gas source and a second connection part on the side closer to the DUT. A second pipe, a differential pressure detector provided on the second pipe, and a first opening / closing valve provided on the second pipe between the differential pressure detector and the first connecting portion. A pressure leak measuring device having a second on-off valve provided in the first pipe between the pressurized gas source and the second connecting portion is created.
Here, the "pressurized gas source" includes an air compressor that supplies compressed air, a gas cylinder in which various gases such as nitrogen gas and argon gas are sealed at high pressure, and the like.

Further, in the invention according to claim 3,
The pressure leak measuring device according to claim 2, wherein one end is connected to the second pipe between the first opening / closing valve and the differential pressure detector, and the other end is the object to be measured. A pressure leak measuring device having a third pipe connected to the above and a third opening / closing valve provided in the third pipe was created.

Further, in the invention according to claim 4, a pressure for measuring pressure leakage from the object to be measured is detected by detecting a differential pressure between the object to be measured into which the pressurized gas is introduced and an independent closed space. A leak measuring apparatus, wherein a primary side pipe connecting a pressurized gas source for introducing a pressurized gas to the measurement object and the measurement object, and a primary side opening / closing valve provided in the primary side pipe A pressure leak measuring device having a closed loop pipe connected to the object to be measured via a secondary pipe, and a differential pressure detector and a closed loop on-off valve provided in the closed loop pipe is created.

Further, in the invention according to claim 5,
Introducing a pressurized gas to the object to be measured, a pressure leak measuring method for measuring pressure leakage from the object to be measured by detecting a differential pressure between an independent closed space and the object to be measured, A pressure leak measuring method for measuring the pressure leak from the object to be measured by predicting the magnitude of the differential pressure after a lapse of a predetermined time from the variation amount of the differential pressure per unit time is created.

[0010]

In the pressure leak measuring apparatus according to the first aspect of the present invention, the pressure leak from the measured object is detected by detecting the differential pressure between the measured object into which the pressurized gas is introduced and the closed space independent from the measured object. Is a device for measuring. Here, the independent closed space is formed by closing a part of the piping of the pressure leak measuring device. Therefore, unlike the measurement master in the prior art, a high degree of airtightness is ensured and a pressure-tight sealed space is easily realized. This makes it possible to detect the pressure difference between this and the enclosed space for a wide variety of objects to be measured and to perform highly accurate pressure leak measurement, and because a part of piping is used without using a master. It becomes an extremely low cost pressure leak measuring device. In this way, the pressure leak measurement apparatus can perform the pressure leak measurement at low cost by performing the pressure leak measurement by detecting the differential pressure without using the master.

Further, in the pressure leak measuring device according to the invention of claim 2, both ends of the second pipe are connected to the first pipe connecting the pressurized gas source and the object to be measured,
A bypass path for pressurized gas is provided. A differential pressure detector is provided on the second pipe, and a first opening / closing valve is provided between the differential pressure detector and the first connecting portion. Further, the first pipe is provided with a second opening / closing valve at any position between the pressurized gas source and the second connection portion. Therefore, when the first opening / closing valve is closed, an independent closed space is formed by the portion of the second pipe sandwiched between the first opening / closing valve and the differential pressure detector. On the other hand, the object to be measured is a differential pressure detector by a part of the first pipe from the object to be measured to the second connection part and a part of the second pipe from the second connection part to the differential pressure detector. It is connected to the. With such a configuration, after the pressurized gas is introduced into the DUT from the pressurized gas source through the first pipe, the first opening / closing valve and the second opening / closing valve are closed, thereby providing an independent closed space and an object to be measured. The differential pressure with the object is detected by the differential pressure detector. Therefore, it is possible to detect the differential pressure between the object to be measured and the hermetically sealed space with a high degree of hermeticity.
Moreover, since the pressure leak is detected by the differential pressure detection with the minimum necessary piping configuration, the pressure leak measuring device can be provided at an extremely low cost. In this way, the pressure leak measuring device that does not use the master is realized with a simple piping configuration, so that the pressure leak measuring device has a simple measurement operation and easy maintenance of the device.

Further, a pressure leak measuring device according to a third aspect of the present invention is different from the pressure leak measuring device according to the second aspect in that one end of the pressure leak measuring device is between the first opening / closing valve and the differential pressure detector. It has a configuration in which a third pipe connected to the second pipe and the other end of which is connected to the object to be measured, and a third opening / closing valve provided in the third pipe are added. Therefore, since the pressurized gas can be introduced from the pressurized gas source into the object to be measured through the two paths of the first pipe and the third pipe, the pressure inside the object to be measured can be quickly increased to the measurement pressure. Furthermore, since the third pipe can connect the part to be the closed space independent of the second pipe and the DUT,
The pressure difference between the two can be made small, and the pressure in the pipe stabilizes faster, so the measurement time can be shortened. When measuring the differential pressure, the third on-off valve is closed to cut off communication with the object to be measured. In this way, the pressure leak measuring apparatus can perform precise pressure leak measurement in a short time by accelerating the pressurization inside the object to be measured and making the pressure inside the pipe more uniform.

Further, in the pressure leak measuring apparatus according to the invention of claim 4, the object to be measured is connected to the pressurized gas source by the primary side pipe provided with the primary side opening / closing valve, and the object to be measured is connected to the secondary side. A closed loop pipe is connected via the pipe. Then, of the closed loop pipe, a portion sandwiched between the differential pressure detector and the closed loop on-off valve forms a closed space for measuring the differential pressure. On the other hand, the object to be measured is connected to the differential pressure detector by the part of the closed loop pipe except the part forming the closed space. With such a configuration, after the pressurized gas is introduced from the pressurized gas source to the DUT through the primary side pipe, the primary side opening / closing valve and the closed loop opening / closing valve are closed, and the differential pressure between the independent sealed space and the DUT is measured. Is detected by the differential pressure detector. Here, since the pressurized gas is introduced into the closed loop pipe through the object to be measured, the pressure in the closed space becomes equal to that of the object to be measured. Therefore, since the gas does not move and the pressure is stable, it is possible to detect the occurrence of a very small differential pressure, and it is possible to measure the pressure leak with high accuracy. Further, in combination with the fact that the object to be measured having a large volume is provided close to the pressurized gas source, the pressure can be stably measured in a short time. In this way, by making the pressure inside the object to be measured equal to the pressure inside the pipe, the pressure is stabilized by eliminating the movement of gas, and a more accurate pressure leak measurement can be performed in a shorter time. Becomes

Furthermore, in the pressure leak measuring method according to the fifth aspect of the present invention, when the differential pressure between the independent closed space and the object to be measured is detected, after a lapse of a predetermined time from the change amount of the differential pressure per unit time. The method of predicting the magnitude of the differential pressure is adopted. Therefore, it is possible to predict the pressure difference after a lapse of a predetermined time from the rate of change of the pressure difference in the process of stabilizing the pressure to determine the magnitude of pressure leakage, so that it is not necessary to wait until the pressure stabilizes, and it is possible to obtain an extremely short time. It is possible to perform pressure leak measurement. In this way, by obtaining the measurement result in the process of stabilizing the pressure, the pressure leakage measuring method can be shortened remarkably.

[0015]

【Example】

First Embodiment Next, a first embodiment embodying the present invention will be described with reference to FIGS. 1 and 2. First, the basic configuration and operation of the pressure leakage measuring device of this embodiment will be described with reference to FIG. FIG. 1A shows a pressure leak measuring device 2 of this embodiment.
FIG. 1B is a block diagram showing the basic configuration of FIG. 1B, and FIG. 1B is a chart showing the opening and closing of the on-off valve. The pressure leak measuring device 2 shown in FIG. 1 (A) is provided in the pressurized gas source 4, the piping system connecting the pressurized gas source 4 to the object W to be measured and the differential pressure detector 8, and the piping system. The on-off valves 20, 30, 40 are mainly configured. The pressurized gas source 4 is connected to the opening / closing valve 20 by a pipe 10A, and the other end of the opening / closing valve 20 is connected to the pipe 10
Connected to B. The pipe 10B branches into a pipe 10C and a pipe 12A at a branch portion 14A. Piping 10C
Is connected to the on-off valve 30, and the other end of the on-off valve 30 is connected to the pipe 10
D. The pipe 10D is branched into a pipe 10E and a pipe 12C at a branch portion 14B.
E is connected to the object to be measured W, and the pipe 12C is connected to the differential pressure detector 8
It is connected to one side of the measurement part of. On the other hand, the pipe 12A is connected to the open / close valve 40, and the other end of the open / close valve 40 is connected to the pipe 12B.
It is connected to the. The pipe 12B is connected to the other side of the measuring unit of the differential pressure detector 8. An air chamber AC is connected to the pipe 12B.

In the pressure leak measuring device 2 having such a structure, the differential pressure between the measured object W into which the pressurized gas is introduced and the pipe 12B, which is an independent closed space, is measured by the differential pressure detector 8. The pressure leakage of the object to be measured W is measured. That is, as shown in FIG. 1 (B), first, all the on-off valves 20, 30, 40 are opened, and pressurized gas is introduced from the pressurized gas source 4 into the measured object W and the pipe 12B. Subsequently, only the on-off valve 20 is closed for a certain period of time to balance the atmospheric pressure inside the object to be measured W and the atmospheric pressure inside the pipe 12B. After that, the on-off valves 30 and 40 are closed,
The pipe 12 </ b> B sandwiched between the on-off valve 40 and the differential pressure detector 8 and the air chamber AC form an independent closed space. The differential pressure between the atmospheric pressure inside the closed space 12B and the air chamber AC and the atmospheric pressure inside the object to be measured W is measured by the differential pressure detector 8. Here, the pipe 12B sandwiched between the on-off valve 40 and the differential pressure detector 8
Can be regarded as an independent closed space without leakage. Further, since the atmospheric pressure in the pipe 12B and the atmospheric pressure in the object to be measured W have once reached equilibrium due to the equilibrium operation, if there is no gas leakage from the object to be measured W, the pressure difference is measured by the differential pressure detector 8. The differential pressure is zero. On the other hand, if gas leaks from the object to be measured W, the differential pressure detector 8
Therefore, the differential pressure corresponding to the gas leakage is detected. In this embodiment, since the air chamber AC is provided, the differential pressure detection sensitivity is improved.

A more specific structure of the pressure leak measuring device 2 and a measuring procedure will be described with reference to FIG. Figure 2
(A) is a piping diagram showing a specific configuration of the pressure leak measuring device 2, and FIG. 2 (B) is a chart diagram showing a procedure for pressure leak measuring. As shown in FIG. 2A, the pressure leak measuring device 2 uses an air compressor 4 as a pressurized gas source. The air compressor 4 is connected to the electromagnetic directional valve 20 by a pipe 10A via an air filter 6 that removes dust and the like in the compressed air. A pipe 10B is connected to the opposing port of the electromagnetic directional valve 20. The electromagnetic directional valve 20 has three valve chambers 24A, 24B and 24C, and when the electromagnetic solenoid 22 is inactive, the valve chamber 24C is connected to the pipe 10A by the urging force of the spring 26.
And the pipe 10B. That is, the state shown in FIG. At this time, the pipe 10A is connected to the closed port, while the pipe 10B is connected to the port communicating with the exhaust silencer 28. by this,
The compressed air remaining in the pipe 10B and subsequent pipes, the object to be measured W, and the differential pressure detector 8 is discharged from the exhaust silencer 28 into the atmosphere.

On the other hand, when the electromagnetic solenoid 22 is excited by a control signal from a control unit (not shown), the valve chambers 24A, 24B and 24C move against the biasing force of the spring 26. When the excitation force is controlled to be low, the central valve chamber 24B is connected to the pipe 10A. As a result, both the pipe 10A and the pipe 10B are connected to the closed ports, the pipe 10B and the air compressor 4 and the exhaust silencer 28 are shut off, and the pipe system after the pipe 10B is sealed. . Further, when the excitation force is controlled to be high, the valve chamber 24A is connected to the pipe 10A. As a result, the pipe 10A and the pipe 10B are connected, and compressed air is supplied from the air compressor 4 to the pipe system.

The pipe 10B is branched into a pipe 10C and a pipe 12A at a branch portion 14A, the pipe 10C is connected to the electromagnetic opening / closing valve 30, and the pipe 12A is connected to the electromagnetic opening / closing valve 40. The electromagnetic opening / closing valve 30 has two valve chambers 34A and 34B, and when the electromagnetic solenoid 32 is not operated, the valve chamber 34B in the closed state is connected to the pipe 10C by the repulsive force of the spring 36. On the other hand, the electromagnetic solenoid 3
2 is activated, the valve chambers 34A and 34B move to the spring 36.
The valve chamber 34A in the open state is connected to the pipe 10C by moving against the repulsive force of. The solenoid on-off valve 40 is also the solenoid on-off valve 3
It has the same structure as 0. The other end of the electromagnetic opening / closing valve 30 is connected to the pipe 10D, and the pipe 10D is connected to the branch portion 14
At B, a pipe 10E and a pipe 12C are branched. The pipe 10E is connected to the measured object W, and the pipe 12C is connected to the differential pressure sensor 8. Further, a pressure sensor 16A is also connected to the branch portion 14B. On the other hand, the solenoid valve 4
The other end of 0 is connected to the pipe 12B, and the pipe 12B is connected to the differential pressure sensor 8. A pressure sensor 16B and an air chamber AC are connected in the middle of the pipe 12B.

Each stage of pressure leak measurement by the pressure leak measuring device 2 having such a configuration will be described with reference to FIGS. 2 (A) and 2 (B). Here, P _m1 indicates the pressure measured by the pressure sensor 16B, pressure P _X1 indicates the pressure measured by the pressure sensor 16A, and P _W1
Indicates the pressure inside the object to be measured W. As shown in FIG. 2B, as a pressurizing operation, all of the solenoid valves 20, 30, 40 are first opened (the valve chambers 24A, 34A, 44A are connected). As a result, compressed air is introduced into the object to be measured W from the air compressor 4 through the pipes 10A, 10B, 10C, 10D and 10E, and the pipe 1
Compressed air is also introduced into 2C. At the same time, pipe 10
Compressed air is also introduced into the pipe 12B and the air chamber AC through A, 10B, and 12A. After the pressurizing operation is performed for a predetermined time T1, the electromagnetic directional valve 20 is switched to shut off the supply of compressed air from the air compressor 4. At this stage, since the solenoid on-off valves 30 and 40 are opened, the pipes 12A and 12B and the pipes 10C and 1
A sealed space including 0D, 10E and the object to be measured W is temporarily formed. By maintaining such a state for a predetermined time T2, the DUT W and the pipes 10C, ..., 12B are
The pressure inside is equalized and the pressures P _m1 and P _X1 reach equilibrium.

At this equilibrium stage, the pressure sensor 1
When the measured pressures P _X1 and P _m1 by 6A and 16B drop, it is judged that there is a large leak in the object to be measured W or the piping system, and the measurement is stopped. After the equilibrium operation is performed for a predetermined time T2, the electromagnetic on-off valves 30 and 40 are closed to form the pipe 12B and the air chamber AC as an independent closed space, and the differential pressure sensor 8 and the measured object W and the pipe 12B are used.
The differential pressure of is measured. At this detection stage, when there is air leakage from the object to be measured W, the pressure P _m1 does not change but the pressure P _X1 decreases, so that the pressure difference between the two is detected. On the other hand, when there is no air leakage from the object to be measured W, the pressure P _X1 is maintained at the same value as the pressure P _m1 , so that the differential pressure measured by the differential pressure sensor 8 becomes zero. Therefore, by analyzing the output signal from the differential pressure sensor 8 by a control unit (not shown), the presence or absence of air leakage from the object to be measured W and its magnitude can be measured. The detection operation is performed for the predetermined time T3, and the pressure leak measurement by the pressure leak measurement device 2 is completed.

As described above, in the pressure leakage measuring device 2 of the present embodiment, the presence or absence of air leakage from the object W to be measured and its magnitude can be measured with a simple structure and high accuracy. After the measurement, each solenoid valve 20, 30,
By releasing the operation of the electromagnetic solenoids 22, 32, 42 of 40, the valve chambers 24C, 34B, 44B are connected to the pipes, and the measured object W and the compressed air in the pipe system are discharged from the exhaust silencer 28. It As described above, in the pressure leak measuring device 2 of the present embodiment, the pipes 10A and 10A constituting the device are used without using the master as in the prior art.
The pressure leak measurement is performed by detecting the differential pressure between an independent closed space formed by closing a part 12B of B, 12A and 12B with an electromagnetic opening / closing valve 40. Therefore, without changing the configuration of the pressure leak measuring device 2, the pressure leak measuring device can perform the differential pressure measurement on many kinds of objects to be measured W, and can perform the pressure leak measuring at low cost.

Although this embodiment mainly corresponds to the invention of claim 2, not all of the solenoid valves 20, 30, 40 are indispensable, and either one of the solenoid valves 20, 30 may be omitted. It is possible. Although not corresponding to the second aspect of the invention, the same measurement can be performed with only the solenoid valves 20 and 30 without the solenoid valve 40. Although compressed air supplied from the air compressor 4 is used as the pressurized gas in this embodiment, other gas may be used. Further, in the present embodiment, as the opening / closing valve, the electromagnetic opening / closing (direction) valves 20, 30 and 40 that alternately connect the two valve chambers to the pipe by the electromagnetic solenoid are used. Various types of valves can be used. Further, as the differential pressure sensor 8, it is possible to use various types of differential pressure detectors including a diaphragm type and a bellows type. The configuration, shape, size, material, number, connection relationship, etc. of the other parts of the pressure leak measuring device are not limited to those in this embodiment.

Second Embodiment Next, a second embodiment embodying the present invention will be described with reference to FIGS. 3 and 4. First, the basic configuration and operation of the pressure leak measuring device of this embodiment will be described with reference to FIG. FIG. 3A shows a pressure leak measuring device 52 of this embodiment.
3B is a block diagram showing the basic configuration of FIG. 3, and FIG. 3B is a chart diagram showing opening / closing of the on-off valve. The pressure leak measuring device 52 shown in FIG. 3A has a pressurized gas source 54 and a piping system for connecting the pressurized gas source 54 to the object to be measured W and the differential pressure detector 58, as in the first embodiment. , And the on-off valves 70, 80, 90, 100 provided in the piping system. Among these, the connection relationship among the pressurized gas source 54, the measured object W, the differential pressure detector 58, and the open / close valves 70, 80, 90 is the same as that in the first embodiment. The difference from the first embodiment is that the pipes 62B, 64B and the object to be measured W which are independent closed spaces are provided.
Are connected by pipes 62C and 62D, and an on-off valve 100 is provided between the pipes 62C and 62D. The air chamber AC is preferably connected to any of the pipes 62B, 64B or 62C. When this air chamber AC is connected, the detection sensitivity is improved as in the first embodiment. The present embodiment mainly describes claim 3.
In the pressure leak measuring device 52, the pressure inside the object to be measured W reaches the measuring pressure faster due to the presence of these pipes 62C and 62D, and it becomes an object of differential pressure measurement. The pressure equilibrium between the pipe 64B and the object to be measured W is achieved in a shorter time.

In the measurement by the pressure leakage measuring device 52 having such a structure, as shown in FIG. 3B, first, all the on-off valves 70, 80, 90, 100 are opened, and the pressurized gas source 54 is used to measure the object to be measured. Pressurized gas is introduced into W and the pipes 62B, .... Subsequently, the open / close valves 70, 80, 90 are closed, and only the open / close valve 100 is opened for a certain period of time.
An equilibrium of the atmospheric pressure between the measured object W and the pipes 62B, 62C, 64B is achieved. After that, the opening / closing valve 100 is also closed, and the pipe 62 sandwiched between the opening / closing valves 90 and 100 and the differential pressure detector 8 is inserted.
B, 62C and 64B are independent closed spaces. The differential pressure between the atmospheric pressure in the closed space and the atmospheric pressure in the object to be measured W is measured by the differential pressure detector 58, and if there is a gas leak, the differential pressure corresponding to the gas leak is detected. Here, the difference from the first embodiment is that the closed spaces 62B, 62C, 64B and the object to be measured W are
This is the point where the equilibrium of the atmospheric pressures of and is performed by connecting the two with the pipe 62D. In this way, since the portion to be the closed space and the object to be measured W can be directly communicated with each other, the pressure difference between the two can be reduced and the pressure in the pipe can be stabilized more quickly.

Next, a more specific structure of the pressure leak measuring device 52 and a measuring procedure will be described with reference to FIG. FIG. 4 (A) is a piping diagram showing a specific configuration of the pressure leak measuring device 52, and FIG. 4 (B) is a chart diagram showing the procedure of pressure leak measuring. The pressure leak measuring device 52 also uses an air compressor 54 as a source of pressurized gas, and is connected to the electromagnetic directional valve 70 by a pipe 60A via an air filter 56 that removes dust and the like in the compressed air. Hereinafter, the pipes 60B, 60C, 60D, 60E,
62A, 62B, 64A, 64B, solenoid on-off valves 80, 9
The connection relationship between 0, the differential pressure sensor 58, and the object to be measured W is the same as that in the first embodiment. In addition to this, the pressure leak measuring device 52
Then, at the connecting portion 66C, the pipe 62C is connected to the pipe 62B,
It is connected to 64B. The pipe 62C is the solenoid valve 10.
0, and the other end of the electromagnetic on-off valve 100 is connected to the DUT W through a pipe 62D. Note that the pipe 62D
And the connection position of the pipe 60E to the measured object W is different. By connecting the air chamber AC to the pipe 62C,
It is preferable to improve the detection sensitivity.

Unlike the electromagnetic directional valve 20 of the first embodiment, the electromagnetic directional valve 70 has two valve chambers 74A and 74B. When the electromagnetic solenoid 72 is inactive, the spring 7
The valve chamber 74B is connected to the pipe 60A and the pipe 60B by the urging force of 6. That is, the state shown in FIG. At this time, the pipe 60A is connected to the closed port, while the pipe 60B is connected to the port communicating with the exhaust silencer 78. This allows the pipe 60
The compressed air remaining in the piping after B, the object to be measured W, and the differential pressure detector 58 is discharged from the exhaust silencer 78 into the atmosphere. On the other hand, when the electromagnetic solenoid 72 is excited by a control signal from a control unit (not shown), the valve chamber 74
A and 74B move against the urging force of the spring 76,
The valve chamber 74A is connected to the pipe 60A. by this,
The pipe 60A and the pipe 60B are connected, and compressed air is supplied from the air compressor 54 to the pipe system. The structure of the electromagnetic on-off valves 80, 90, 100 is the same as that of the electromagnetic on-off valves 30, 40 of the first embodiment.

Pressure leak measuring device 52 having such a configuration
Each stage of the pressure leak measurement by the method will be described with reference to FIGS. 4 (A) and 4 (B). Here, P _m2 is the pressure measured by the pressure sensor 68B, and the pressure P _X2
Indicates the pressure measured by the pressure sensor 68A, and P
_W2 indicates the pressure inside the object to be measured W. First, the opening / closing valves 70, 80, 90, 100 are all opened (the valve chambers 74A, 84A, 94A, 104A are connected) for a predetermined time T4 as a pressurizing step, and the object to be measured is discharged from the air compressor 4. Compressed air is introduced into W and each pipe. here,
In the pressure leak measuring device 52, the pipes 60C, 60
Not only from D and 60E, but also from piping 62A, 62B and 62
Since compressed air is also supplied from C and 62D, the pressure in the object to be measured W can reach the measured pressure faster. Subsequently, the electromagnetic on-off valves 80 and 90 are closed, and the electromagnetic directional valve 70 is switched to shut off the supply of compressed air from the air compressor 54. In FIG. 4B, the electromagnetic directional valve 70 and the electromagnetic opening / closing valves 80, 90 are shown to be switched at the same time. However, in reality, they are not completely simultaneous, and the electromagnetic opening / closing valves 80, 90 are first closed. After ensuring the airtightness of the piping system, the electromagnetic directional valve 70 is switched. As a result, the DUT W and the pipes 60D, ..., 6
The pressure in 2B is equalized, and the pressure P _m2 and P _X2 reach equilibrium by the equilibrium stage of this predetermined time T5.

In the pressure leak measuring device 52,
Is the target of differential pressure measurement because there are pipes 62C and 62D.
The pressure equilibrium between the pipe 64B and the object to be measured W becomes fast.
Achieved. Note that the pressure sensor
Measured pressure P by 68A, 68B_X2, P_m2Place where
If there is a large leak in the measured object W or somewhere in the piping system,
If there is any, stop the measurement. Such equilibration stage
After that, the on-off valve 100 is closed and the pipes 62B, 62
C and 64B are independent closed spaces, and the differential pressure sensor 58
The difference between the measured object W and the pipes 62B, 62C, 64B
The pressure is measured. At the detection stage, the object to be measured W
If there is air leakage from the_m2Does not change
Against pressure P_X2Will decrease, so
appear. On the other hand, there is no air leakage from the DUT W.
If not, pressure P_X2Is the pressure P _m2Is kept at the same value as
Therefore, the differential pressure measured by the differential pressure sensor 58 becomes zero. Obedience
The output signal from the differential pressure sensor 58 is not shown in the figure.
By analyzing with the unit, the sky from the measured object W
It is possible to measure the presence or absence of air leak and its size.

After the measurement, the on-off valves 70, 80, 90,
The electromagnetic solenoids 72, ..., 102 of 100 are released from operation and the valve chambers 74B, ..., 104A are connected to the respective pipes,
The object to be measured W and the compressed air in each pipe are discharged from the exhaust silencer 28. As described above, in the pressure leak measuring device 52 of the present embodiment, the pipes 60C, 60D and 60E and the pipe 62A,
Air compressor 5 with two systems of 62B, 62C and 62D
By supplying compressed air from 4 to the object to be measured W,
The pressure in the object to be measured W can reach the measured pressure faster. In addition, a pipe 62 that becomes an independent closed space
Since B and 64B and the measured object W are connected by the pipes 62C and 62D, the pressure equilibrium between the closed spaces 62B and 64B and the measured object W is achieved in a shorter time. In this way, the pressure leak measuring device is capable of performing highly accurate pressure leak measurement in a short time.

Third Embodiment Next, a third embodiment embodying the present invention will be described with reference to FIGS. First, the basic configuration and operation of the pressure leak measuring device of this embodiment will be described with reference to FIG. FIG. 5A shows a pressure leak measuring device 112 of this embodiment.
5B is a block diagram showing the basic configuration of FIG. 5B, and FIG. 5B is a chart showing the opening and closing of the on-off valve. Similarly to the first and second embodiments, the pressure leak measuring device 112 shown in FIG. 5A also has a pressurized gas source 114, a differential pressure detector 118, a piping system and an opening / closing valve for connecting these to the object W to be measured. It is configured around 130 and 140. However, in this embodiment, the order of these connections and the configuration of the piping system are quite different from those in the first and second embodiments. In this embodiment, an independent closed space is formed by the part 124B of the pipe system formed in the closed loop shape. Further, the pipe 124 </ b> B, which is an independent closed space, is connected to the pressurized gas source 114 rearward (secondary side) of the object W to be measured. With this configuration, in the pressure leak measuring device 112 of the present embodiment, the pressure in the object to be measured W reaches the measured pressure faster, and the pressure between the pipe 124B, which is the object of differential pressure measurement, and the object to be measured W. There is no difference and pressure equilibration is achieved quickly.

Specifically, as shown in FIG. 5A, the pressurized gas source 114 includes a pipe 120A and an opening / closing valve 13.
0, connected to the object to be measured W via a pipe 120B. A pipe 122A is connected to the measured object W at a position facing the connecting portion of the pipe 120B, and a pipe 122B and a pipe 124A are branched from the pipe 122A. The pipe 122B is connected to one of the measuring units of the differential pressure detector 118, and the pipe 124A is connected to the other measuring unit of the differential pressure detector 118 via the on-off valve 140 and the pipe 124B.
In this way, the pipe 122B, the differential pressure detector 118, the pipe 124B, the on-off valve 140, and the pipe 124A form a closed-loop pipe system for differential pressure detection.
Also in this embodiment, it is preferable to connect the air chamber to the pipe 124B, and if the air chamber AC is connected, the detection sensitivity is improved.

In the measurement by the pressure leak measuring device 112 having such a configuration, as shown in FIG. 5B, first, the on-off valves 130 and 140 are both opened, and the pressurized gas source 114 is applied to the object to be measured W. Pressurized gas is introduced. The pressurized gas is
From the pipe 122A connected to the secondary side of the object to be measured W, it is further introduced into the closed loop pipes 122B, 124A, 124B. Then, the on-off valve 130 is closed, and only the on-off valve 140 is opened for a certain period of time to balance the atmospheric pressures of the object W to be measured and the closed loop pipes 122B, .... After that, the on-off valve 140 is closed and the on-off valve 140
The pipe 124B sandwiched between the differential pressure detector 118 and the differential pressure detector 118 is an independent closed space. Atmospheric pressure in this closed space and object to be measured W
The differential pressure from the internal pressure is measured by the differential pressure detector 118, and if there is a gas leak, the differential pressure corresponding to the gas leak is detected.

Next, a more specific structure of the pressure leak measuring device 112 and a measuring procedure will be described with reference to FIG. FIG. 6 (A) is a piping diagram showing a specific configuration of the pressure leak measuring device 112, and FIG. 6 (B) is a chart diagram showing a procedure of pressure leak measuring. Also in the pressure leak measuring device 112, the air compressor 114 is used as a pressurized gas source, and an air filter 116 for removing dust and the like in the compressed air is attached to the pipe 126A. Plumbing 126
A is branched into a pipe 126B and a pipe 126C,
The pipe 126B is connected to one input port of the electromagnetic directional valve 170 via the pressure regulator 150. A pressure gauge 156 for measuring the pressure by the pressure regulator 150 is attached to the pipe 126B,
The pressure by the pressure regulator 150 is adjusted by the adjusting screw 152. The pipe 126C is connected to the other input port of the electromagnetic directional valve 170 via the pressure boosting regulator 160. The booster regulator 160 is adjusted so that the pressure of the supplied compressed air is higher than that of the pressure regulator 150. A pressure gauge 162 for measuring the pressure by the pressure boosting regulator 160 is attached to the pipe 126C.

Piping 1 is provided at the output port of the electromagnetic directional valve 170.
26D is connected to the object to be measured W through the electromagnetic directional valve 180, the pipe 120A, the electromagnetic opening / closing valve 130, and the pipe 120B. Piping 1 of the object to be measured W
A pipe 122A is connected to a position facing the connecting portion of 20B, and a closed loop pipe system including a pipe 122B and below is connected to the pipe 122A. Note that the pipe 122A
A pressure detection sensor 164 is attached midway. The closed loop piping system includes a pipe 122B connected to one side of the differential pressure sensor 118, a pipe 124B connected to the other side of the differential pressure sensor 118, and a pipe 122B from the pipe 124B via an electromagnetic opening / closing valve 140 and an electromagnetic directional valve 190. It is constituted by a pipe 124AI connected to. The air chamber AC may be connected to the pipe 124B. The structure of the electromagnetic directional valves 170, 180 and 190 is the same as that of the electromagnetic directional valve 20 and the like described above.
The structure of 40 is the same as that of the solenoid on-off valve 30 and the like.

Pressure leak measuring device 11 having such a configuration
Each step of pressure leak measurement according to No. 2 will be described with reference to FIGS. 6 (A) and 6 (B). Note that P _m3 represents the atmospheric pressure in the pipe 124B, and the pressure P _X3 is the pressure sensor 1.
P _W3 indicates the atmospheric pressure measured by 64, and P _W3 indicates the atmospheric pressure inside the object to be measured W. As shown in FIG. 6B, first, the pressurizing operation for a predetermined time T7 is executed. First, as pre-pressurization, the electromagnetic directional valves 170 and 180 are operated for a predetermined time ΔT7.
Is the excited state of the electromagnetic solenoids 172, 182 (valve chamber 17
4A and 184A are connected). As a result, the pipe 126B is closed, and the pipe 126C is connected to the pipe 1
It communicates with 26D. Further, the electromagnetic directional valve 180 is opened. On the other hand, the electromagnetic on-off valves 130 and 140 and the electromagnetic directional valve 190 are in the open state because the electromagnetic solenoids are not excited.

Therefore, the compressed air supplied from the air compressor 114 is adjusted to a high pressure by the pressure boosting regulator 160 and supplied into the object to be measured W through the pipes 120A and 120B. Then, it is further introduced into the closed loop piping system below the piping 122B via the piping 122A. After the elapse of the predetermined time ΔT7, the electromagnetic directional valve 170 is switched, the pipe 126C is closed, and the pipe 126B communicates with the pipe 126D. As a result, the compressed air, which has been adjusted to the measurement pressure by the pressure regulator 150, is supplied to the object to be measured W and the piping system. In this way, when compressed air having a pressure higher than the measurement pressure is supplied first, and then compressed air having a measurement pressure is supplied, the compressed air is introduced into the object W to be measured. It is possible to minimize pressure fluctuations due to temperature changes and the like. Further, the compressed air is supplied to the closed loop piping system below the piping 122B through the object to be measured W, so that the pressure difference between the two is eliminated.

After the pressurizing operation is performed for the time T7, the equilibrium operation is performed. That is, the electromagnetic directional valve 180
Also, the electromagnetic on-off valve 130 is switched to shut off the supply of compressed air from the air compressor 114. Although FIG. 6B shows that the solenoid valves 180 and 130 are switched at the same time, in actuality, switching of the solenoid on-off valve 180 is slightly delayed to prevent compressed air from escaping. Done. On the other hand, the electromagnetic opening / closing valve 140 and the electromagnetic directional valve 190 are left in the open state, and the communication between the DUT W and the closed loop piping system is maintained. By maintaining this state (zero equilibrium state) for a predetermined time ΔT8, the measured object W
And the pressure in the closed loop piping system is more equalized and stabilized. After such a zero balance operation, the solenoid on-off valve 140 and the solenoid directional valve 190 are switched, and the valve chamber 144A and the valve chamber 19 are switched.
4A is connected to the pipe. Also at this time, the electromagnetic on-off valve 140 is first closed, and then the electromagnetic directional valve 190 is switched. As a result, the communication between the pipe 124AI and the pipe 124B is cut off, and the pipe 124B sandwiched between the electromagnetic opening / closing valve 140 and the differential pressure sensor 118 becomes an independent closed space. Along with this, the air in the pipe sandwiched between the electromagnetic on-off valve 140 and the electromagnetic directional valve 190 is the exhaust silencer 1 of the electromagnetic directional valve 190.
Emitted from 98 into the atmosphere.

A predetermined time from this valve operation (= T8-ΔT
8) After the lapse of time, the differential pressure detecting step is started. The reason for providing such a waiting time (T8−ΔT8) is to eliminate a minute differential pressure that is temporarily generated when the electromagnetic switching valve 140 and the electromagnetic directional valve 190 are switched. In the differential pressure detection stage,
The measured value (output voltage) of the differential pressure sensor 118 after the elapse of the predetermined detection time T9 is input to a control unit (not shown). Then, with the output voltage of the differential pressure sensor 118 at the time of switching from the equilibrium stage to the detection stage as a reference, the pressure leakage amount is calculated and output from a previously calculated formula. After the measurement is completed, as shown in FIG. 6B, the electromagnetic solenoids of the electromagnetic opening / closing valves 130 and 140 and the electromagnetic directional valve 190 are deenergized to be in the communication state, and the measured object W
And the compressed air in each pipe is discharged from the exhaust silencer 186 of the electromagnetic directional valve 180.

Next, a concrete measurement result by the pressure leak measuring device 112 will be described with reference to FIG. Figure 7
[Fig. 4] is a graph showing changes in pressure and differential pressure in measurement by the pressure leak measuring device 112 of the present embodiment. Figure 6
(A) is the pressure measured by the pressure sensor 164, and the differential pressure is the differential pressure measured by the differential pressure sensor 118. In addition,
This differential pressure is positive when the pressure on the measured object W side is high and low on the sealed pipe side, and negative when the pressure is opposite. As shown in FIG. 7, since compressed air adjusted to a pressure higher than the measured pressure is supplied in the pre-pressurization step described above, the measured value of the pressure sensor 164 once exceeds the measured pressure. After the pre-pressurization is completed, compressed air adjusted to the measurement pressure is supplied, so that the pressure value drops to the measurement pressure and stabilizes. In the process of this preliminary pressurization, since the pipe line resistance is slightly different between the pipe 122B side of the closed loop pipe and the pipe 124B side through the two solenoid valves 190, 140, the differential pressure sensor 118 makes a difference as shown in FIG. The pressure is detected. Therefore, by using this phenomenon, the length of each closed loop pipe can be changed so that the absolute value of the detected differential pressure becomes large,
The detection sensitivity in the following detection steps can be improved by inserting a throttle valve or the like if necessary. If a pressure fluctuation of a predetermined value or more occurs in the preliminary pressurization stage, it is determined that the object to be measured has an abnormality such as a hole, and the measurement is interrupted for inspection.

In the subsequent equilibrium stage and detection stage, when there is no pressure leak from the object to be measured W, the measurement value of the pressure sensor 164 is maintained at a stable constant pressure in the pressurization stage as shown by the solid line. Be done. Here, at the end of the zero equilibrium stage, as shown in FIG.
Since 0 is switched at the same time, a differential pressure as shown in FIG. 7 temporarily occurs. This differential pressure is so small that it disappears at the end of the equilibration stage. On the other hand, when there is a pressure leak, the pressure does not become a constant value as indicated by the broken line, and the pressure continues to drop. Therefore, the differential pressure sensor 1
The measured values of 18 also maintain zero as indicated by the solid line when there is no pressure leak, and do not become constant as indicated by the broken line when there is pressure leak, and the absolute value of the differential pressure is Continue to increase. Therefore, in the control unit not shown,
By comparing the measured value (output voltage) of the differential pressure sensor 118 after the elapse of the predetermined detection time T9 with the output voltage at the end of the equilibrium stage, the presence or absence of air leakage from the object to be measured W and its magnitude are calculated. be able to.

As described above, in the pressure leak measuring device 112 of this embodiment, the closed loop piping system, which is a closed space, is connected to the secondary side of the object to be measured W with respect to the air compressor 114. The pressures in the object to be measured W and the system in the closed loop pipe can be equalized. Therefore, the movement of air between the object to be measured W and the pipe does not occur, and the pressure is stable, so that highly accurate measurement is possible and the measurement can be performed in a short time.

Fourth Embodiment Next, a fourth embodiment embodying the present invention will be described with reference to FIGS. 8 and 9. First, the basic configuration of the pressure leak measuring device of the present embodiment and the measurement procedure will be described with reference to FIG. As shown in FIG. 8 (A), the pressure leak measuring device 202 of this embodiment is the same as that of the third embodiment of FIG. 6 (A).
This is almost the same as the pressure leak measuring device 112. The measurement procedure is also the same as in Example 3, as shown in FIG. However, the pressure leak measuring device 202
In addition to the control unit (not shown) similar to the first to third embodiments, the arithmetic processing unit 210 is provided as a control unit that receives the output signal (output voltage) from the differential pressure detector 118.
This arithmetic processing unit 210 processes the output signal from the differential pressure detector 118 to obtain the change in the differential pressure per unit time, and predicts the value of the differential pressure at the end of the inspection stage from this rate of change. There is. That is, unlike Examples 1 to 3, it is not necessary to wait until a predetermined inspection time at which the measured value of the differential pressure becomes stable to some extent, and the calculation processing is performed in the initial stage of the inspection to predict the result, so that the measurement is performed in an extremely short time. Can be completed.

Specific measurement results by the pressure leak measuring device 202 of this embodiment will be described with reference to FIG.
FIG. 9 is a graph showing changes in pressure and differential pressure in measurement by the pressure leak measuring device 202 of this embodiment. As shown in FIG. 9, also in the measurement by the pressure leak measuring device 202, the changes with time of the pressure and the differential pressure from the pressurizing stage to the equilibrium stage are similar to those of the third embodiment of FIG. 7. In the present embodiment as well, similar to the case of the third embodiment shown in FIG. 7, a temporary differential pressure is generated after switching the solenoid valves 140 and 190 after zero equilibrium. After the zero equilibrium of time ΔT11, depending on the presence or absence of pressure leak from the object to be measured W,
As shown in FIG. 9, different differential pressure changes are shown. That is, when there is no pressure leak from the object to be measured W, as shown by the solid line, it stabilizes at a constant value after the predetermined equilibrium time T11. On the other hand, when there is a pressure leak, the absolute value of the differential pressure continues to increase without being a constant value as indicated by the broken line. In addition, when there is a minute pressure leak, it becomes an intermediate curve between these, as indicated by the alternate long and short dash line.

Here, the pressure leak measuring device 11 according to the third embodiment is used.
In 2, unless the predetermined detection time T9 has elapsed,
It was not possible to determine the magnitude of these pressure leaks. On the other hand, the pressure leak measuring device 202 of the present embodiment
Then, in the process in which the pressure immediately after zero equilibrium stabilizes, the output voltage from the differential pressure sensor 118 is processed by the arithmetic processing unit 210 to calculate the amount of change in the differential pressure per unit time. From the rate of change of the differential pressure, the value of the differential pressure after the elapse of the detection time T12 is predicted by calculation. That is, according to the pressure leak measuring device 202, the presence or absence and the magnitude of the pressure leak can be obtained in the equilibrium stage. Therefore, it is not necessary to wait for the detection time T12 to elapse, and the measurement time can be significantly shortened. In FIG. 9, the equilibrium stage (particularly the stage after zero equilibrium) is shown in an enlarged manner in order to clearly show the difference between the case with pressure leak and the case without pressure leak. Therefore, the ratio of the lengths of the steps shown on the horizontal axis of FIG. 9 does not always correspond to the actual length of the measurement time.

The arithmetic processing section 210 is provided with compensating means for compensating for the influence of the work temperature and the influence of the work volume. For example, if the workpiece is extremely hot,
The gas filled in the work is heated by the heat of the work, and the gas pressure in the work increases during the measurement. On the other hand, the temperature of the closed pipe section is equal to room temperature, and the pressure is not affected by the temperature. Therefore, even if there is no gas leakage from the workpiece, if the temperature of the workpiece is extremely high, the pressure on the workpiece side increases and the detected differential pressure increases to the plus side (changes to the upper right side in FIG. 9). To). Also in this case,
The value obtained by subtracting the pressure on the sealed piping side from the pressure on the work side is the differential pressure, and the differential pressure is positive when the former is the latter or higher.
Changes in the detected differential pressure due to heating (changes to the negative side) and changes due to heating (changes to the positive side)
Will be added. Therefore, the work temperature compensating means inputs the temperature of the work, and if it is high, corrects the detected differential pressure to the negative side to cancel the change due to heating. This correction amount is corrected more as the work temperature increases.

On the other hand, if the temperature of the work is not so high, when the work is filled with the gas, the gas is adiabatically compressed and heated, and the work is cooled. Therefore, the gas is cooled during the measurement, and the pressure becomes lower. At this time, if the work volume is larger than the sealed pipe volume, the gas in the work is cooled more quickly. For this reason, even if gas leakage from the work does not actually occur, if the work volume is large and the sealed pipe volume is small, the pressure on the work side decreases and a differential pressure to the negative side occurs. This differential pressure is directed to the lower right in FIG. Therefore, the volume-based compensating means inputs the work volume, and if it is large, corrects the detected differential pressure to the positive side and corrects it so as to correspond to the differential pressure caused by the leak. The correction amount at this time is corrected more as the work is larger. The compensation by the work temperature and the work volume is applied to both the method for detecting the differential pressure itself in the third embodiment and the method for detecting the rate of change of the differential pressure in the fourth embodiment.

[0048]

According to the first aspect of the present invention, the pressure leak from the object to be measured is measured by detecting the differential pressure between the object to be measured and the closed space formed by closing a part of the pipe. To create a pressure leak measuring device that
It is possible to perform highly accurate pressure leak measurement by differential pressure detection with a simple configuration that does not use a measurement master. As a result, it becomes a practical pressure leak measuring device capable of performing highly accurate pressure leak measurement at low cost.

Further, in the invention according to claim 2, since the pressure leak measuring device which does not use the measuring master is realized with the minimum piping configuration, the pressure measuring operation is simple and the device maintenance is easy. It becomes a leak measuring device. As a result, it becomes a practical pressure leak measuring device capable of highly accurate pressure leak measurement with low device cost and running cost.

Further, in the invention according to claim 3,
In order to create a pressure leak measuring device that adds a third pipe that serves as a second path for introducing pressurized gas to the measured object and also serves to connect the closed space and the measured object, As the pressurization of is accelerated, the pressure in the pipe becomes more uniform. As a result, it becomes a practical pressure leak measuring device capable of performing accurate pressure leak measurement in a short time.

Further, in the invention according to claim 4, since the pressure leak measuring device in which the pipe serving as the closed space is connected to the secondary side of the object to be measured is connected to the pressurized gas source, the inside of the object to be measured is created. The pressures in the pipes are equalized, and highly accurate measurement is possible, and the measurement can be performed in a short time. As a result, it becomes a very practical pressure leak measuring device capable of performing more accurate pressure leak measurement in a shorter time.

Further, in the invention according to claim 5,
A pressure leak measurement method was created that predicts the magnitude of the differential pressure after a lapse of a predetermined time from the amount of change in the differential pressure per unit time, so the measurement result can be obtained in the process of stable pressure, and the pressure stabilizes. You don't have to wait until. As a result, it becomes a very practical pressure leak measuring method capable of significantly shortening the measuring time.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration and operation of a pressure leak measuring device and a pressure leak measuring method according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a specific configuration and a measurement procedure of Example 1 of the pressure leak measuring device and the pressure leak measuring method.

FIG. 3 is a diagram showing a basic configuration and an operation of Example 2 of a pressure leak measuring device and a pressure leak measuring method.

FIG. 4 is a diagram showing a specific configuration and a measurement procedure of Example 2 of the pressure leak measuring device and the pressure leak measuring method.

FIG. 5 is a diagram showing the basic configuration and operation of Example 3 of the pressure leak measuring device and the pressure leak measuring method.

FIG. 6 is a diagram showing a specific configuration and a measurement procedure of Example 3 of the pressure leak measuring device and the pressure leak measuring method.

FIG. 7 is a diagram showing a measurement result in Example 3 of a pressure leak measuring device and a pressure leak measuring method.

FIG. 8 is a diagram showing a specific configuration and a measurement procedure of Example 4 of the pressure leak measuring device and the pressure leak measuring method.

FIG. 9 is a diagram showing a measurement result in Example 4 of the pressure leak measuring device and the pressure leak measuring method.

[Explanation of symbols]

2, 52, 112, 202 Pressure leak measuring device 4, 54, 114 Pressurized gas source 8, 58, 118 Differential pressure detector 10A to 10E, 60C to 60E First pipe 12A to 12C, 62A, 62B, 64B, 64A 2nd piping 12B, 62B, 62C, 64B, 124B Independent closed space 14A 1st connection part 14B 2nd connection part 20 (30), 70 (80) 2nd on-off valve 40, 90 1st on-off valve 62C, 62D Third piping 100 Third opening / closing valve 120A, 120B Primary side piping 122A Secondary side piping 122B, 124B, 124A Closed loop piping 130 Primary side opening / closing valve 140 Closed loop opening / closing valve W Measured object

Claims (5)

[Claims] 1. A pressure leak measuring device for measuring a pressure leak from an object to be measured by detecting a differential pressure between the object to be measured into which a pressurized gas is introduced and an independent closed space, the pressure leakage measuring device comprising: A pressure leak measuring device, wherein the closed space is formed by closing a part of piping of the pressure leak measuring device. 2. The pressure leak measuring device according to claim 1, further comprising a first pipe connecting a pressurized gas source for introducing a pressurized gas to the object to be measured with the object to be measured. A second pipe whose both ends are respectively connected to the first pipe at a first connection part on the side close to the pressurized gas source and a second connection part on the side close to the object to be measured; A differential pressure detector provided in the pipe, a first opening / closing valve provided in the second pipe between the differential pressure detector and the first connecting portion, the pressurized gas source and the A pressure leak measuring device, comprising: a second opening / closing valve provided in the first pipe between the second connecting part and the second connecting part. 3. The pressure leak measuring device according to claim 2, wherein one end is connected to the second pipe between the first on-off valve and the differential pressure detector, and the other end is connected. A pressure leak measuring device having a third pipe connected to the object to be measured, and a third opening / closing valve provided in the third pipe. 4. A pressure leak measuring device for measuring a pressure leak from an object to be measured by detecting a differential pressure between the object to be measured into which pressurized gas is introduced and an independent closed space, A primary side pipe that connects a pressurized gas source for introducing a pressurized gas to the measurement object with the measurement target object, a primary side opening / closing valve provided in the primary side piping, and a secondary side for the measurement target object A pressure leak measuring device comprising: a closed loop pipe connected via a pipe; and a differential pressure detector and a closed loop opening / closing valve provided in the closed loop pipe. 5. A pressure leak measuring method for measuring pressure leak from an object to be measured by introducing a pressurized gas to the object to be measured and detecting a differential pressure between an independent closed space and the object to be measured. A pressure leak measuring method for measuring pressure leak from the object to be measured by predicting a magnitude of the differential pressure after a lapse of a predetermined time from a variation amount of the differential pressure per unit time.