JPH04369448A - Apparatus and method for inspecting leakage of fluid controller - Google Patents

Abstract

PURPOSE:To improve sensing accuracy by supplying gas for detecting liquid film formation into a sensor pipe and checking whether or not a soap liquid film is sensed by a soap film detector after existence of leakage has been decided. CONSTITUTION:A leakage inspecting apparatus comprises a sensor pipe 4, a soap film sensor 9, a ventilation controller 10, etc. Soap liquid 1 is injected into a soap liquid reservoir 7a in a case 7, its liquid level L is maintained at a predetermined position, and a distance G between the upper end of the sensor 4 and the center H' of a light signal passage of the sensor 9 is adjusted to a predetermined value. After a main valve V0, a device to be inspected V1 and a liquid film formation detecting valve V5 are closed and an atmosphere communicating valve V2 is opened, a cylinder device 3 is activated to pull up a ring body 2 which has been soaked in the soap liquid 1 and an opening 4d of the sensor tube 4 is closed by a soap film 1a. Then the atmosphere communicating valve V2 is closed and the main valve V0 is opened. If there is leakage in the device to be inspected V1, the liquid film 1a expands due to leaking gas, a light signal H is totally reflected by the liquid film 1a and incident light to a light receiving part 9b is shielded. A detection signal S is sent to a CPU device 11 where whether the device to be inspected V1 is good or detective is decided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved leak testing device and method for a fluid controller.

0002

[Background Art] In semiconductor manufacturing equipment and vacuum equipment, it is necessary to detect and measure a small amount of gas with a flow rate of about 0.01 to 0.02 cc/min, and to check for leaks in fluid controllers. There are many times. As a measurement/detection device for a small amount of gas as described above, the inventor of the present invention previously developed a device for measuring a small amount of gas as shown in FIG. 5 and published it (Japanese Patent Application No. 1-344618).

That is, the microflow gas measuring device shown in FIG. 5 includes a main body case 7 in which soap solution 1 is stored,
a detection tube 4 whose upper end opening protrudes upward from the liquid level L; a soap liquid film adhering device 8 for closing the upper end opening 4d of the detection tube 4 with a liquid film 1a of the soap liquid 1; Soap liquid film detection device 9 that detects arrival of 1a at a certain position
, a ventilation control device 10 that controls ventilation in the detection tube 4 via an atmosphere communication valve V2 and a purge valve V3, and a signal S from the soap film detection device 9, etc. to calculate the flow rate of the gas to be measured 5. It is formed from a CPU device 11 and the like.

When measuring a small amount of gas, first open the atmosphere communication valve V2 to communicate the inside of the detection tube 4 to the atmosphere, and then move the ring body 2 immersed in the soap solution 1 upward along the detection tube 4. the upper end opening 4d of the detection tube 4 to the soap liquid film 1a.
occluded by Next, the atmospheric communication valve V2 and the purge valve V3 are closed, and the valve V1 is opened, so that the gas to be measured 5 expands the soap liquid film 1a that closes the upper end opening 4d. Then, the expanded soap liquid film 1a
By reflecting the optical signal H at the sensor, the arrival of the soap liquid film 1a at a certain position is detected, and the time from the start of expansion of the soap liquid film 1a to the arrival of the soap liquid film 1a at a certain position is measured. , the flow rate of the gas to be measured 5 is calculated by the CPU device 11 from the measured time.

[0005] When performing a leak test or the like on a device to be inspected V1 such as a fluid controller, after closing the atmospheric communication valve V2, the purge valve V3, and the device to be inspected (valve) V1, open the tip of the detection tube 4. 4d, and then the gas to be measured 5 is supplied to the inlet side of the device to be tested V1. When the soap liquid film 1a expands due to the supply of the gas to be measured 5 and the measured leakage flow rate exceeds a certain value, the device to be inspected V1 is determined to be a defective product and is removed from the finished product line. Ru. Further, even if the gas to be measured 5 is supplied, if the leakage flow rate is zero or less than a specified value, the device to be inspected V1 is determined to be an acceptable product and is shipped.

[0006]

[Problems to be Solved by the Invention] The microflow rate gas measuring device shown in FIG. 5 can automatically and highly accurately measure extremely small gas flow rates, and has excellent practical utility. . However, when a valve leakage test is performed using the device, even if the measured leakage amount of the gas to be measured 5 becomes zero and the result is that there is no leak in the device to be tested V1, the Based on the results alone, the device under test V1 is 10
It cannot be determined that the product is 0% non-defective. Because,
Even if there is no expansion of the soap film 1a and, as a result, the soap film detection device 9 does not detect the soap film 1a, this is because the tip opening of the detection tube 4 is opened before the gas to be measured 5 is supplied. 4
This is because both cases include a case in which the soap liquid film 1a is not completely closed by the soap liquid film 1a, and a case in which the soap liquid film 1a is damaged during expansion.

[0007] The present invention is intended to solve the above-mentioned problems in the microflow gas measuring device developed by the inventors of the present invention. After determining the presence or absence of leakage, the liquid film formation detection gas 17a is automatically gradually supplied into the detection tube 4 through the soap liquid film formation detection mechanism 18, and the soap liquid film 1a expands to form a soap liquid film. By checking whether or not it is detected by the detection device 9 (that is, whether or not the tip opening 4d of the detection tube 4 was properly sealed in advance with the soap liquid film 1a),
The present invention provides a leakage testing device and a leakage testing method for a fluid controller that make it possible to significantly improve the accuracy of leakage testing.

[0008]

[Means for Solving the Problems] The present device invention comprises a main body case 7 in which a soap solution 1 is stored; and a detection tube 4 arranged at the upper end opening 4 of the detection tube 4.
Soap liquid film adhering device 8 for blocking d with soap liquid film 1a
and; a soap liquid film detection device 9 that detects the soap liquid film 1a expanded by the gas 5 leaking from the device to be inspected V1;
After the detection operation by the soap film detection device 9, the detection tube 4
a soap liquid film detection mechanism 18 that supplies a gas 17a for detecting liquid film formation into the inside and also supplies a purge gas 17b after a certain period of time; an atmospheric communication valve V2 that communicates the inside of the detection tube 4 with the atmosphere; A ventilation control device 10 that controls a liquid film formation detection valve V5 that supplies the liquid film formation detection gas 17a of the soap film detection mechanism 18 and a purge valve V3 that supplies purge gas; It is something. In addition, the present method invention includes opening the atmosphere communication valve V2 to communicate the inside of the detection tube 4 to the atmosphere, and then pulling up the ring body 2 immersed in the soap solution 1 with the detection tube 4 inserted therein.
The upper end opening 4d of the detection tube 4 is closed with a soap liquid film 1a, and then the atmosphere communication valve V2 is closed and the test device V1 is closed.
The soap liquid film 1a that closes the upper end opening 4d is expanded by the gas 5 leaking from the soap liquid film 1a.
The gas 5 leaking from the test device V1 is detected by the soap liquid film detection device 9 which reflects the optical signal H by the liquid film detection mechanism 18. The liquid film formation detection gas 17a is supplied to the soap liquid film 1a by the liquid film formation detection gas 17a.
By expanding the gas, it is confirmed that the soap liquid film 1a has been normally formed in advance in the case where the leaked gas 5 is not detected, and after a certain period of time, the purge gas is introduced into the detection tube 4. The basic configuration of the invention is to supply 17b.

[0009]

[Operation] By opening the atmosphere communication valve V2, the inside of the detection tube 4 is brought into communication with the atmosphere. In this state, when the ring body 2 is pulled up from inside the soap solution 1 with the detection tube 4 inserted, a soap solution film 1a is first formed between the outer wall surface of the detection tube 4 and the ring body 2, and then, The ring body 2 is the detection tube 4
When the liquid film 1a reaches the upper end opening 4d, the opening 4d is closed by the liquid film 1a. After that, the atmospheric communication valve V2 is closed, the main valve V0 is opened, and the device under test V
Apply the pressure of gas 5 to 1. At this time, if the device under test V
If there is a leak, the inside of the detection tube 4 will be pressurized by the leaked gas 5, and the soap liquid film 1a will expand. When the upper part of the expanded soap liquid film 1a reaches a certain position, the optical signal H is reflected by the liquid film 1a, and the light is blocked from entering the light receiving section 9b. As a result, arrival of the liquid film 1a at a certain position is detected. When the detection by the soap film detection device 9 is completed, the liquid film formation detection valve V of the soap film formation detection mechanism 18 is activated.
5 is opened, and the liquid film formation detection gas 17a flows into the detection tube 4.
supplied within. As a result, if there is no leak in the device to be inspected V1, the soap liquid film 1a previously formed at the tip of the detection tube 4 is expanded and detected by the detection device 9. This confirms that the soap liquid film 1a has been normally formed at the tip of the detection tube 4 in advance, and improves the reliability of the test result that there is no leakage in the test device V1. After a certain period of time has elapsed since the liquid film formation detection gas 17a was supplied, the purge valve V3 is opened, the purge gas 17b is released into the detection tube 4, and the leakage testing device is returned to the state before the start of the test.

0010

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. FIG. 1 is an explanatory diagram showing the overall configuration of the present invention, which differs from the device shown in FIG. 5 in that a soap film formation detection mechanism 18 is provided. That is, the present fluid controller leakage testing device detects the leakage of the device from the main body case 7, the detection tube 4, the soap film deposition device 8, the soap film detection device 9, the ventilation control device 10, the soap film formation detection mechanism 18, etc. The main parts are configured.

The main body case 7 is a box having a reservoir 7a for the soap solution 1 formed therein, and is provided with an air vent 7b, a soap solution replenishment port 7c, and the like. In addition, an insertion hole 7d for the detection tube 4 is bored in the center of the bottom of the main body case 7.
The detection tube 4 is inserted from below into the insertion hole 7d, and with its upper end opening 4d protruding above the soap liquid level L, the O-ring 13 is interposed to make it airtight and the fixing nut 1 is inserted.
2, it is fixed in a vertically adjustable manner.

On the side wall of the detection tube 4, there is a device to be inspected V1.
An inlet 14 for gas 5 leaked from the air and a communication port 1 to the atmosphere
5, purge gas 17b, and soap liquid film formation detection gas 17
The supply ports 16 of b are drilled respectively, and the main valve V0, the device to be inspected V1, the atmosphere communication valve V2,
It is communicated with a soap liquid film formation detection mechanism 18.

The soap film deposition device 8 includes a ring body 2 that moves up and down with the upper end of the detection tube 4 inserted therethrough;
a cylinder device 3 that drives the ring body 2 in the vertical direction;
It is formed from a cylinder control valve V4 etc. that controls the supply of working fluid to the cylinder device 3. By operating the cylinder 3 and pulling up the ring body 2 that has descended into the soap liquid 1, a soap liquid film 1a is first formed between the outer wall surface of the detection tube 4 and the ring body 2, and then the ring body 2 is pulled upward from the upper end of the detection tube 4, the liquid film 1a is attached to the upper end opening 4d of the detection tube 4, and the upper end opening 4d
is closed by a soap liquid film 1a.

The soap film detection device 9 includes an optical fiber type light emitting section 9a, a light receiving section 9b, and a fiber amplifier 9.
It is formed from c. That is, the optical signal H output from the amplifier 9c is returned to the amplifier 9c through the optical fiber 9d, the emitting section 9a, the light receiving section 9b, and the optical fiber 9e, and the soap liquid film 1a at the tip opening 4d of the detection tube 4 expands. When this enters the optical path of the optical signal H and is totally reflected by the liquid film 1a, it is detected that it has reached a predetermined position on the soap liquid film 1a.

The ventilation control device 10 includes an atmosphere communication valve V2.
, cylinder control valve V4, liquid film formation detection valve V5, etc., and the opening and closing of each valve V1 to V5 is controlled in the order described below.

[0016] The CPU device 11 is operated by the leaked gas 5.
The microcomputer is used to calculate the minute flow rate of the gas 5 based on the time it takes for the expanded soap film 1a to be detected by the soap film detection device 9.

The soap film formation detection mechanism 18 includes a liquid film formation detection valve V5, a speed controller 19, a delay valve (purge valve) V3, etc.
When is opened, the liquid film formation detection gas 17a whose flow rate is adjusted by the speed controller 19 is supplied to the supply hole 7g. Air 17 is also supplied to the delay valve V3,
After a certain period of time (for example, 10 seconds), the purge gas 17b
is supplied to the supply hole 7g.

Next, a leak test method for the device to be inspected V1 using the microflow measuring device shown in FIG. 1 will be explained. First, the soap solution 1 is injected into the soap solution reservoir 7a in the main body case 7, and the liquid level L is held at a predetermined position. Also, the center H' of the optical signal path between the upper end of the detection tube 4 and the soap liquid film detection device 9
The distance G between them is adjusted to a predetermined value. Furthermore, the cylinder device 3 is operated to move the ring body 2 up and down, and the outer wall surface and the upper end surface of the detection tube 4 are wetted in advance with the soap liquid film 1a.

Next, as shown in the time chart of FIG.
Close the main valve V0, close the device under test V1, close the liquid film formation detection valve V5 (therefore, close the delay valve V3), and open the atmosphere communication valve V2 to communicate the inside of the detection tube 4 with the atmosphere. . Thereafter, the cylinder device 3 is activated to lift the ring body 2 immersed in the soap solution 1 upward. As a result, the liquid film 1a formed between the ring body 2 and the detection tube 4 is attached to the tip opening 4d of the detection tube 4, and the tip opening 4d of the detection tube 4 is closed by the soap liquid film 1a. When the tip opening 4d of the detection tube 4 is blocked by the soap liquid film 1a, the atmosphere communication valve V2
is closed, the main valve V0 is opened, and at the same time, time measurement is started using the timer or CPU device 11. At this time, if there is a leak in the device to be inspected V1, the soap liquid film 1a starts to expand due to the leaked gas 5. The soap liquid film 1a expands and the upper part of the membrane surface becomes the soap liquid film detection device 9.
When reaching the vicinity of the optical path center H', the optical signal H that was incident on the light receiving section 9b from the emitting section 9a is totally reflected by the liquid film 1a, and the light entering the light receiving section 9b is blocked. As a result, the detection signal S is sent from the fiber amplifier 9c to the CPU device 11, and the time measurement that started simultaneously with the closing of the atmosphere communication valve V2 is stopped. The CPU device 11
Next, the flow rate of the leaked gas is calculated using the measured value of the time from the closing of the atmosphere communication valve V2 to the total reflection of the optical signal H by the soap liquid film 1a, and is displayed on a display (not shown). At the same time, recording and determination of the quality of the device to be inspected V1 are performed as appropriate.

On the other hand, when the detection by the soap film detection device 9 is completed, the liquid film formation detection valve V5 of the soap film formation detection mechanism 18 is opened in response to a signal from the ventilation control device 10. As a result, an appropriate amount of liquid film formation detection gas 17a is sent into the detection tube 4 through the speed controller 19, and as a result, if there is no leak in the tested device V1, the previously formed soap liquid film 1a expands. However, this is detected by the soap liquid film detection device 9. That is, by opening the liquid film formation detection valve V5 and operating the soap liquid film detection device 9,
During the leak test of the device to be inspected V1, a soap liquid film 1a was formed on the tip 4d of the detection tube 4 as specified, confirming that the leak test was carried out normally.

[0021] The liquid film formation detection valve V5 is opened for about 1 hour.
After about 0 seconds, delay valve V3 (purge valve V
3) is automatically opened for a short time, the purge gas 7b is released, and the soap solution adhering to the inner wall surface of the tip opening 4d of the detection tube 4 is removed. Note that if the purge operation is not performed, the dripping soap solution will adhere to the inner wall surface of the upper end opening 4d of the detection tube 4 due to the tearing of the liquid film.
Soap liquid film 1a formed in opening 4d by ring body 2
The film thickness may change, or a liquid film 1a may be formed again due to the adhering soap solution, resulting in measurement errors and measurement troubles. When the operation of the purge valve V3 is completed, the ring body 2 is lowered into the soap solution 1 by the cylinder control valve V4, and the main valve V0 is closed and the atmosphere communication valve V2 is opened to perform one leak test. Complete.

FIG. 3 shows another embodiment of the soap film detection mechanism 18, in which a timer delay circuit 20 is used to open the liquid film formation detection valve V5 and the purge valve V3 after a certain time delay. It was designed to do so. That is, the timer delay circuit 20 is activated by a signal from the ventilation control device 10, and first, the liquid film formation detection valve V5 is opened, and the soap liquid film detection gas 17 is passed through the speed controller 19b.
a is released. Next, after a certain period of time, purge valve V3
A release signal is applied to the purge gas 17b, and the purge gas 17b is released into the detection tube 4 through the speed controller 19a.

Although the timer delay circuit 20 may be any type of circuit, FIG. 4 shows an example of the timer delay circuit 20 used in the present invention. That is,
When the input from the ventilation control device 10 is applied to the input terminal 21, the transistor Tr3 is turned on,
At the same time, transistor Tr1 also turns on,
Liquid film formation detection valve V5 is opened. Also, at the same time as transistor Tr3 turns on, capacitor C and resistor R
The time constant circuit (integrator circuit) consisting of
Then, purge valve V3 is opened.

Effects of the Invention In the present invention, the soap liquid film 1a formed at the tip opening 4d of the detection tube 4 is expanded by the leaked fluid 5 introduced into the detection tube 4, and the expanded soap liquid film 1a is expanded into a soap liquid film 1a. The liquid film detection device 9 detects leakage from the test device V1, and after the soap film detection device 9 completes the detection operation, the soap film formation detection mechanism 18 injects liquid into the detection tube 4. Film formation detection gas 17a
The soap liquid film 1a previously formed on the tip of the detection tube 4
The purge gas 17b is expanded and detected, and the purge gas 17b is discharged into the detection tube 4 after a certain period of time has elapsed. As a result, in the present invention, the soap liquid film detection device 9 detects the leaked gas 5 during the leak test of the device to be inspected V1.
In the case where the expansion of the soap liquid film 1a is not detected due to
Inspection errors caused by the soap liquid film 1a not being formed properly, i.e. "If the soap liquid film 1a is not formed properly or if the soap liquid film ruptures during expansion, it is determined that there is no leakage." This eliminates all inspection errors such as "The leak test was carried out" and greatly improves the reliability of leak tests. Further, in the present invention, the soap liquid film 1a formed at the tip opening 4d of the detection tube 4 is expanded toward the atmosphere, and the optical signal H is totally reflected by the expanded soap liquid film 1a. It is configured to detect that the soap liquid film 1a has reached a certain position. As a result, the soap liquid film 1a is not affected by the condition of the inner wall surface of the detection tube 4 unlike the conventional leak test device, and is always expanded under constant external conditions. Arrival at a certain position is detected extremely accurately, greatly improving detection accuracy. Further, by pulling the ring body 2 immersed in the soap solution 1 upward with the detection tube 4 inserted therein, the upper end opening 4d of the detection tube 4 is closed by the liquid film 1a. The upper end opening 4d of the detection tube 4 can be closed with a liquid film extremely reliably, and there are no problems such as breakage of the liquid film as in the case of conventional leak testing devices. Furthermore,
The inside of the detection tube 4 blocked by the liquid film 1a is communicated with the atmosphere through the atmosphere communication valve V2, and the expansion of the soap liquid film 1a before the start of detection is completely prevented.
In addition to improving inspection accuracy, the inspection itself can be performed smoothly and with high efficiency. As mentioned above, the present invention has excellent practical utility.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a leak testing device for a fluid controller according to the present invention.

FIG. 2 is an explanatory diagram showing the operating state of each device in a leak test using the leak test device of the present invention.

FIG. 3 shows another embodiment of the soap film formation detection mechanism used in the present invention.

4 shows an example of a timer delay circuit used in the soap film formation detection mechanism of FIG. 3. FIG.

FIG. 5 is an explanatory diagram of the previously developed microflow gas measuring device.

[Explanation of symbols]

1 is a soap liquid, 1a is a soap liquid film, 2 is a ring body, 3 is a cylinder device, 4 is a detection tube, 4d is an upper end opening, 5 is a leak body from the device to be inspected, 7 is a main body case, 8 is soap A liquid film adhesion device, 9 a soap liquid film detection device, 10 a ventilation control device, 1
1 is a CPU device, 17 is a fluid source, 17a is a liquid film formation detection gas, 17b is a purge gas, 18 is a soap liquid film formation detection mechanism, H is an optical signal, H' is the center of the optical signal path, and G is a distance, V0 is the main valve, V1 is the device under test, V2 is the atmospheric communication valve, V3 is the purge valve, V4 is the cylinder control valve, V
5 is a liquid film formation detection valve.

Claims (5)

[Claims] Claim 1: A main body case (7) in which soap solution (1) is stored; an upper end opening (4) into the main body case (7);
d) a detection tube (4) arranged to protrude above the liquid level (L) of the soap solution (1); a soap film adhering device (8) that is blocked; a soap film detection device (9) that detects the soap film (1a) expanded by the gas (5) leaking from the device to be inspected (V1); After the detection operation by the liquid film detection device (9), soap liquid film formation detection is performed by supplying liquid film formation detection gas (17a) into the detection tube (4) and supplying purge gas (17b) after a certain period of time has passed. a mechanism (18); an atmosphere communication valve (V2) that communicates the interior of the detection tube (4) with the atmosphere; and a gas (17a) for supplying liquid film formation detection to the soap liquid film formation detection mechanism (18). Ventilation control device (10) that controls a liquid film formation detection valve (V5) and a purge valve (V3) that supplies purge gas
A leakage inspection device for a fluid controller formed from and; 2. The soap liquid film deposition device (8) is connected to a detection tube (
4) is inserted through the ring body (2) and arranged to be movable in the vertical direction; the ring body (2) is moved between the soap solution (1) and the upper part of the detection tube (4). The leak testing device for a fluid controller according to claim 1, comprising a cylinder device (3). 3. A soap liquid film detection device (9) is installed in a light signal (H) emitting part (9a) and a light receiving part (9), which are arranged facing each other.
The leakage testing device for a fluid controller according to claim 1, comprising: (b) and an optical fiber amplifier (9c). 4. The soap film detection mechanism (18) is connected to a liquid film formation detection valve (V) that controls the liquid film formation detection fluid (17a).
5) and purge gas (17b) connected in parallel to this
2. The leak testing device for a fluid controller according to claim 1, further comprising a delay valve (V3) for controlling the flow rate. 5. A ring body immersed in soap solution (1) with the detection tube (4) inserted after opening the atmosphere communication valve (V2) and communicating the inside of the detection tube (4) with the atmosphere. (2) upward, the upper end opening (4d) of the detection tube (4) is closed with the soap liquid film (1a), and then the atmospheric communication valve (
V2) is closed and the gas (5) leaked from the inspection device (V1) expands the soap liquid film (1a) that closes the upper end opening (4d), and the expanded soap liquid film (1a) generates an optical signal ( The gas (5) leaking from the device to be inspected (V1) is detected by the soap liquid film detection device (9) designed to reflect H), and when the leak detection is completed, the liquid film detection mechanism (18 ) into the detection tube (4), and by expanding the soap liquid film (1a) with the liquid film formation detection gas (17a), the leaked gas ( 5) If the detection tube (4) is not detected, confirm that the soap liquid film (1a) has been normally formed in advance, and after a certain period of time have passed, check the detection tube (4).
) A leakage testing method for a fluid controller in which a purge gas (17b) is supplied into the fluid controller.