JPH1194682A - Leak testing device and leak testing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to enhance productive efficiency by enhancing the operability of the leak test of a pressure sensor, facilitating automation, and enhancing the accuracy of inspection. SOLUTION: When this device LT 1 has a detection jig 1 having a first chamber R1, in which an annular projection 4 (boundary sealing part) seals the space between the junction 107 of a pressure sensor 101 (container) and a communicating hole 106 and a second chamber R2, with the junction 107 and communicating hole 106 sides of the device being located, respectively, at the first and second chamber R1, R2, a He gas feed port 7 for feeding gas for leakage detection is connected to the first chamber R1 of the detection jig 1. Further, a He detection port 17 reducing pressure and leading to a leak detector 15 detecting He gas is connected to the second chamber R2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a leak test apparatus and a leak test method for detecting a leak at a joint of a container.

[0002]

2. Description of the Related Art FIG. 2 is a cross-sectional configuration explanatory view schematically illustrating a configuration of a conventional test apparatus for performing a leak test of a pressure sensor 101.

The pressure sensor 101 is composed of a head 102
Has a cylindrical body or a threaded cylindrical body 103 integrally therewith, and a diaphragm 104 which bends under pressure at an end 103a of the body 103 so that there is no gap. Have been.

[0004] Inside the oil filling chamber 105 (upper part in the figure)
Is mounted with a chip 108 as a pressure-sensitive element. Further, an oil sealing chamber 105 for transmitting the pressure applied to the diaphragm 104 to the chip 108 is provided inside the body 103. In the oil filling chamber 105, the outer peripheral wall portion 103b of the body 103 is used in the usage mode.
Is filled with the oil flowing from the communication hole 106 provided in the oil tank. The communication hole 106 is sealed by a method such as press-fitting a steel ball (not shown) after the oil has flowed.

[0005] The joint portion 107 between the end portion 103a of the body 103 and the diaphragm 104 is welded all around by a method such as welding (laser welding or TIG welding) or brazing. The pressure sensor shown in FIG. Reference numeral 101 denotes a portion immediately after the joining of the diaphragm 104 and a joining portion 107.
Of the oil filling chamber 10
5 has no oil and the communication hole 106 is also open.

When inspecting the leak at the joint 107 of the pressure sensor 101, two jigs 201a and 201b each having a cavity formed in the shape of the pressure sensor 101 are prepared, and the pressure sensor 101 is placed inside the jigs 201a and 201b. It is performed by pinching.

The jig 201b has a port portion 202 fitted into the communication hole 106 at a position facing the communication hole 106 of the pressure sensor 101, and a periphery of the communication hole 106 of the outer peripheral wall portion 103b of the pressure sensor 101 abutting. An O-ring 203 for sealing is provided.

A port 202 is provided with a vacuum pump 205 via a valve 204 and a He gas for detecting leaking He gas.
It is connected to the leak detector 206. Note that the He leak detector 206 performs evacuation,
He gas is drawn in and detected.

The body 1 of the jigs 201a and 201b
03 is extended to the outside and the opening 207 is formed.
It has.

The inspection of the leak of the pressure sensor 101 using the jig having such a configuration is performed by the following steps.

Step 1: The pressure sensor 101 to which the diaphragm 104 is welded is set so as to be aligned with the port 202 of one of the two jigs 201b in a state where the communication hole 106 is open, and the two-piece healing is performed. Tools 201a, 201
Close b. At this time, the valve 204 is closed.

Step 2: The valve 204 is opened, and the pressure in the oil filling chamber 105 is reduced (evacuated) by the vacuum pump 205.

Step 3: When the specified degree of vacuum is reached, He
He gas is blown toward the opening 207 from the nozzle 208 connected to the gas cylinder.

Step 4: He leak detector 206
To detect He gas leakage (from the connection 107)
judge. (If there is a defective portion in the connection portion 107, the He gas leaked from the defective portion flows from the oil filling chamber 105 through the port portion 202 to the He leak detector 206. The He leak detector 206 removes the leaked He gas. The detected leakage amount (concentration) is displayed, and the operator checks the displayed leakage amount to determine whether it is OK or NG.)

Step 5: Split jigs 201a, 201
01b is opened and the pressure sensor 101 is taken out.

[0016]

However, in such a leak test apparatus, since the oil filling chamber 105 is evacuated, the communication hole 1 of the pressure sensor 101 is required.
06 needs to be aligned with the port 202 of one of the two jigs 201b in an open state.
This has reduced the workability of the operator and made the operation complicated, making automation difficult.

The excess He gas blown is discharged to the periphery of the jig. If no special He gas removing operation is performed, He gas will be used when the next pressure sensor is inspected.
This may lead to erroneous detection of gas and lower the inspection accuracy.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to improve workability of a leak test of a pressure sensor, facilitate automation, and improve inspection accuracy. Accordingly, it is an object of the present invention to provide a leak test apparatus and a leak test method that can improve production efficiency.

[0019]

In order to achieve the above object, according to the present invention, a leak at a joint between a container having a communication hole with the outside and a lid member closing an opening of the container is detected. A leak test apparatus, wherein a boundary seal portion is provided between a joint portion of the container and a communication hole, and a first seal portion is located on the joint portion side.
And a detection jig having a second chamber for positioning the communication hole side, gas supply means for supplying a gas for leak detection to the first chamber, and a pressure in the second chamber. It is characterized by comprising pressure reducing means for reducing the pressure and gas detecting means for detecting the gas leaking into the second chamber.

Further, an exhaust path for releasing the pressure of the first chamber, scavenging means for discharging the gas retained in the first chamber from the exhaust path, and increasing the pressure of the second chamber It is also preferable to provide an intake means for causing the air to flow.

Further, a transfer means for accommodating the container provided with the joint to be tested in the detection jig and allowing the container to be taken out after the leak test, the gas supply means, the pressure reduction means, and the gas detection means Control means for controlling the operation of the exhaust path, the scavenging means, the suction means, and the transfer means, so that a leak test of a plurality of containers can be continuously performed.

Preferably, the gas for detecting the leak is He gas.

In the leak test method, a leak test method for detecting a leak at a joint between a container having a communication hole with the outside and a lid member closing an opening of the container is provided. A container provided with a joint to be tested is provided in a detection jig having a first chamber for locating the joint and a second chamber for locating the communication hole, with a boundary seal between the hole and the boundary seal. After the gas is contained and the pressure in the second chamber is reduced by the pressure lowering means, He gas for leak detection is supplied to the first chamber by the gas supply means, and the second chamber is supplied by the gas detecting means. A leak test method characterized by detecting He gas leaking into a chamber.

Further, when He gas is supplied to the first chamber for leak detection by the gas supply means, an increase in the pressure of the first chamber is suppressed by an exhaust path. It is also preferable that the He gas retained in the first chamber is exhausted from the exhaust path, and the negative pressure in the second chamber is eliminated by suction means connected to the second chamber. .

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in FIG. The pressure sensor 101 described with reference to FIG. 2 in the section of the related art is used as a container having a joint to be tested according to this embodiment. There is no change in the configuration and operation of the pressure sensor 101, and the same components are denoted by the same reference numerals and description thereof will be omitted.

The leak test apparatus LT1 has a main characteristic configuration in the detection jig 1 that houses the pressure sensor 101. The configuration of the detection jig 1 will be described below.

A detection jig 1 has a columnar leak test chamber 2 capable of housing the body 103 of the pressure sensor 101.
Is formed so that the opening 2 a is located on the upper end surface of the detection jig 1. The diameter of the leak inspection chamber 2 is larger than the body 103 of the pressure sensor 101 and the head 10
2 is smaller than the diameter of the head unit 102.
Is positioned in the insertion direction (vertical direction in the figure) by contacting the lower end of the opening 2a around the opening 2a.

In the insertion direction of the leak inspection chamber 2, the O-ring 3 that is in close contact with the outer periphery of the body 103 of the pressure sensor 101 is held and inserted between the joint 107 of the pressure sensor 101 and the communication hole 106. Pressure sensor 1
An annular projection 4 as a boundary seal portion for performing positioning in the radial direction (left-right direction in the figure) of No. 01 projects inward.

An annular groove 4a is formed on the inner peripheral end face of the annular projection 4, and the O-ring 3 is held therein. Also,
An annular groove 5 is formed around the opening 2a of the leak inspection chamber 2, and an O-ring 6 is held.

Therefore, when the pressure sensor 101 is inserted into the leak test chamber 2 of the detection jig 1, the leak test chamber 2
A first chamber R1 in which independent joining portions 107 are located by the annular protrusion 4 and the O-ring 3;
6 is divided into a second chamber R2. The first chamber R1 contains He as a gas for leak detection.
An He gas supply port 7 serving as a gas supply means for supplying gas and an exhaust port 8 serving as an exhaust means for releasing the pressure of the first chamber R1 are provided.

The He gas supply port 7 is connected to a gas supply path 10 from a He gas supply source 9. Further, a compressed air supply path 12 from a compressed air supply source 11 functioning as a scavenging means is connected in the middle of the gas supply path 10.

In the second chamber R2, a He leak detector integrally provided with a vacuum pump 13 as a pressure reducing means for reducing the pressure in the chamber (vacuum evacuation) and a He gas detector 14 as a means for detecting He gas. A He detection port 17 connected to a He detection path 16 from the second chamber R;
2 is provided with an air introduction port 19 from the atmosphere path 18 as an intake means for introducing the atmosphere.

Reference numerals 20, 21, 22, and 23 denote solenoid valves for controlling the flow of each path, and are operated by a sequence controller as control means (not shown).

Numeral 30 denotes a pick-up arm as a transfer means capable of automatically and continuously performing a leak test on the plurality of pressure sensors 101. Arrows A1, A
It can move in two directions.

The concave portion 31a of the gripper portion 31 is fitted into the head portion 102 to generate a negative pressure so as to be capable of sucking and transferring the pressure.
1 are sequentially inserted into the leak inspection chamber 2 of the detection jig 1,
It is also possible to automate the leak test by removing the sample after the inspection and transferring it to the subsequent process.

If it is necessary to press the pressure sensor 101 during leak detection, the gripper 31 is moved to 31 '.
By stopping and pressing at the position, the close contact of the O-ring 6 can be enhanced, and the sealing performance of the second chamber R2 can be enhanced.

The leak test of the pressure sensor 101 by the leak test apparatus LT1 having such a configuration is performed by the following steps.

Step 1: The pressure sensor 101 is inserted into the leak inspection chamber 2 of the detection jig 1 by the pickup arm 30 and pressed against the detection jig 1 at a predetermined pressure (at this time, the solenoid valves 20, 21, 22, 23) Are all closed.).

Step 2: Open the solenoid valve 22 to evacuate the second chamber R2 (simultaneously with the communication hole 1).
From 06, the oil filling chamber 105 is also evacuated).

Step 3: When the specified degree of vacuum is reached, the solenoid valve 20 is opened and He gas is supplied to the first chamber R1.
, And then the solenoid valve 20 is closed.

Step 4: The He leak detector 15 detects and determines He gas leak (from the connecting portion 107). (If there is a defective portion in the connection portion 107, He gas leaked from the defective portion flows from the oil filling chamber 105 through the He detection port 17 and flows into the He leak detector 15. The He leak detector 15 detects the leaked He gas. And sends a detection signal of the leakage amount (concentration) to a remote meter (not shown), which displays the leakage amount of He gas detected by the He leak detector 15 and
By setting the reference value, OK / NG
Is automatically determined).

Step 5: When the judgment is completed, the solenoid valve 22 is closed.

Step 6: After the solenoid valve 22 is closed in step 5, the solenoid valve 21 is opened, and the compressed air supply source 11
The compressed air flows into the first chamber R1 via the e gas supply port 7, and the retained He gas is separated from the exhaust port 8 to the outside (a predetermined distance from the detection jig 1 that does not affect the inspection accuracy). Scavenge to). When the scavenging is completed, the solenoid valve 21 is closed.

In this step 6, the solenoid valve 23 as an intake means is opened simultaneously with the scavenging of the first chamber R1, the second chamber R2 is returned to the atmospheric pressure from the vacuum state, and the solenoid valve 23 is closed.

Step 7: The pressure sensor 101 is pulled out of the leak test chamber 2 by the pickup arm 30 and moved to a predetermined position.

In this embodiment, the pressure sensor 10
Although the description has been made assuming that the movement operation of 1 and the insertion operation into the detection jig 1 are performed by the pickup arm 30 (automatic machine), the operation can be performed manually by an operator instead of the pickup arm 30.

Pressure sensor 1 by leak tester LT1
As a characteristic action and effect in the leak test 01, first, a region of the body 103 of the pressure sensor 101 closer to the communication hole 106 than the portion where the O-ring 3 is in close contact is exposed to the second chamber R2. Therefore, regardless of the position of the communication hole 106 in any direction, the oil sealing chamber 105 can be evacuated through the communication hole 106, and the rotational direction of the pressure sensor 101 does not need to be aligned. The workability of the operator can be improved, or automation can be easily performed, and the production efficiency can be improved.

Second, when the He gas is blown into the first chamber R1 by a predetermined amount through the exhaust port 8 provided in the first chamber R1, the pressure in the first chamber R1 is prevented from becoming too high. Is done. Oil filling chamber 10 of diaphragm 104
Since the side 5 is evacuated, it may be deformed when pressure from the first chamber R1 is applied too much, and this can be prevented.

Third, after the end of the leak inspection, He gas staying in the first chamber R1 can be scavenged,
He gas is prevented from remaining in the leak inspection chamber 2. Therefore, the detection accuracy of He gas can be improved,
The probability of erroneous determination is reduced and reliability is improved.

Fourth, it is possible to automate all the steps of the leak inspection.

[0051]

According to the leak test apparatus and the leak test method of the present invention described above, it is not necessary to position the container having the joint to be tested in the rotational direction, and it is not necessary to mount the container on the detection jig. The mounting workability is improved and automation is facilitated, so that production efficiency can be improved.

It is possible to prevent the container (diaphragm) from being damaged when He gas is blown.

He gas remaining on the detection jig is eliminated, and the probability of erroneous determination by the gas detection means is reduced to improve reliability.

Further, it is possible to automate all the steps of the leak inspection.

[Brief description of the drawings]

FIG. 1 is a sectional configuration explanatory view of a main part of a leak test apparatus according to an embodiment.

FIG. 2 is a cross-sectional configuration explanatory view of a main part of a leak test apparatus according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Detection jig 2 Leak test room 2a Opening 3,6 O-ring 4 Annular protrusion (boundary seal part) 4a Annular concave groove 5 Annular groove 7 He gas supply port (gas supply means) 8 Exhaust port (exhaust means) 9 He gas supply source 10 Gas supply path 11 Compressed air supply source (scavenging means) 12 Compressed air supply path 13 Vacuum pump (pressure reducing means) 14 He gas detection unit (gas detection means) 15 He leak detector 16 He detection path 17 He Detection port 18 Atmospheric path (intake means) 19 Atmospheric introduction port 20, 21, 22 Solenoid valve 23 Solenoid valve (intake means) 30 Pickup arm (transfer means) 31 Gripper 31a Recess 101 Pressure sensor (container) 102 Head 103 Body 103a End 103b Outer peripheral wall 104 Diaphragm (lid) 105 Oil filling chamber 106 Communication hole 107 Joint 108 Chip (pressure-sensitive element) LT1 Leak tester R1 First chamber R2 Second chamber

Claims (6)

[Claims] 1. A leak test apparatus for detecting a leak at a joint between a container having a communication hole with the outside and a lid member closing an opening of the container, wherein a leak test device is provided between the joint of the container and the communication hole. Is the boundary seal part,
A detection jig having a first chamber for locating the joint portion side and a second chamber for locating the communication hole side; gas supply means for supplying a gas for leak detection to the first chamber; A leak test apparatus comprising: a pressure reducing unit configured to reduce a pressure in the second chamber; and a gas detecting unit configured to detect the gas leaking into the second chamber. 2. An exhaust path for releasing the pressure of the first chamber, scavenging means for discharging the gas retained in the first chamber from the exhaust path, and increasing a pressure of the second chamber. The leak test apparatus according to claim 1, further comprising: an intake unit configured to perform the suction. 3. A container provided with a joint to be tested,
A transfer unit that is housed in the detection jig and that can be taken out after a leak test; and controls the operation of the gas supply unit, the pressure reduction unit, the gas detection unit, the exhaust path, the scavenging unit, the suction unit, and the transfer unit. The leak test apparatus according to claim 1 or 2, further comprising a control unit, wherein a leak test of a plurality of containers can be continuously performed. 4. The leak test apparatus according to claim 1, wherein the gas for detecting the leak is He gas. 5. A leak test method for detecting a leak at a junction between a container having a communication hole with the outside and a lid member closing an opening of the container, wherein a leak test is performed between the junction of the container and the communication hole. Is the boundary seal part,
A container having a joint to be tested is accommodated in a detection jig having a first chamber for locating the joint side and a second chamber for locating the communication hole side, and the second unit is pressed by a pressure reducing means. After reducing the pressure of the chamber, He gas is supplied to the first chamber by gas supply means for leak detection, and He gas leaking to the second chamber is detected by gas detection means. And the leak test method. 6. When a gas supply means supplies He gas to the first chamber for leak detection, a pressure increase in the first chamber is suppressed by an exhaust path, and after a leak test, the scavenging means suppresses the pressure rise in the first chamber. Discharging the He gas retained in the first chamber from the exhaust path;
6. The leak test method according to claim 5, wherein a negative pressure in the second chamber is eliminated by an intake unit connected to the second chamber.