JPH02186232A - Method and apparatus for inspecting leakage of sealed container - Google Patents

Abstract

PURPOSE:To enable inspection of a leakage quickly and with a high reliability by a method wherein a piston is moved by a fixed value within a cylinder to pressurize or depressurize the outside of an object to be inspected and after this condition is kept for a fixed time length, the piston is put back to the original position to measure the current pressure of the outside of the object to be inspected. CONSTITUTION:A lid 101 part of an object 100 to be inspected is inserted into an inspection pocket 10 and with an O ring 11 pressed on a flange 105, a chamber 10a is formed within the pocket 10. A piston 14 is pulled up to the upper end of a cylinder to depressurize the chamber 10a and after this condition is held for a fixed time length (normally for about 1-5sec.), the piston 14 is returned to the lower end thereof. An opening-closing valve 17 is opened to measure a pressure within the chamber 10a with a sensor 19. When the pressure of the chamber 10a exceeds an atmospheric pressure as reference beyond a fixed range, an object to be inspected is judged with a leakage judging circuit 20 to be a defective product because of a leakage. This enables inspection of a leakage quickly with a high reliability.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention involves filling a glass bottle or a plastic bottle with foods, beverages, etc. This invention relates to a leakage inspection method for containers sealed by heat sealing and their packaging.

[Conventional technology]

If the sealed state is impaired due to a defect in one or all of the sealed containers, or due to poor fitting or adhesion between the two, the contents may deteriorate or rot. Therefore, products with poor sealing properties must be inspected and reliably removed as defective products.

Conventional 2 As a leakage test method for such a sealed container, 711. Methods of non-contact measurement using mechanical or optical methods and methods of measuring changes in the natural frequency of the top surface of the lid using the frequency of the sound generated by the impact are known.

However, these conventional methods assume that the pressure inside the container is different from the pressure in the outside world, and as in aseptic filling, which is being researched recently, the contents are filled at room temperature and there is a pressure difference between the inside and outside of the container. If this does not occur, the pressure inside the container will not change even if the sealing performance is poor, so such a container could not be used as a test object.

As a leak test method when there is no difference between the internal pressure of the test object and the pressure in the outside world, it has traditionally been used to test for leaks in unfilled empty cans, plastic containers, gas fittings, piping parts, or automobile parts. There is a method that is used.

In this method, leakage is determined by pressurizing or depressurizing the outside of the object, holding it for a certain period of time, and then measuring pressure fluctuations caused by poor sealing. However, even though it is called a sealing failure, there is usually only an extremely narrow gap, and the amount of pressure fluctuation due to a sealing failure is often extremely small compared to the external pressurizing force (reducing pressure). ) The amount of pressure fluctuation was smaller than the variation in pressure, and there were cases where sealing failure could not be detected.

Conventionally, therefore, a master 506 serving as a reference is prepared as shown in FIG. 5, and the differential pressure between this master 506 and a test object 507 is measured to detect a sealing failure.

That is, a branch pipe 501 is connected to a two-pressure supply pump 500, and on-off valves 502, 503 and an airtight connection A304.
505 to the respective branch paths 501a, 50
A master 506 and a subject 507 are connected to the tip of the lb, and a differential pressure gauge 508 is connected between each branch path 501a and 501b. As the master 506, a reference container with the same -8 plants as the subject 507, another subject, or the like is used.

In the inspection method, first, the master 506 and the subject 507 are connected to the branch paths 501a and 507 with the on-off valves 502 and 503 closed.
Connect 01b and open the on-off valves 502 and 503,
Compressed air is supplied to both the master 506 and the subject 507, and when the respective pressures reach equilibrium, the on-off valve 50
Close 2°503. After holding the pressure for a certain period of time, the measured value of the differential pressure gauge 508 is read. At this time, the subject 507
If it is a normal crystal with no leakage, no differential pressure will occur, but if there is leakage, the pressure on the test object 5Q7 side will decrease by that much, so a differential pressure will occur and it will be judged as a defective product.

Note that, instead of supplying pressure to the master 506 and the subject 507, a method has also been used in which the pressure is similarly determined by vacuum suctioning each of them.

[Issues to be solved Wi] In order to obtain high reliability in the conventional leakage inspection method described above (Fig. 5), after supplying compressed air, the master 50
6 and the pressure inside the subject 507 must be brought into equilibrium, and for this purpose, it is necessary to provide a sufficiently long compressed air supply time. In particular, when using the inspection device shown in FIG. 5, compressed air is supplied to the master 506 and the test object 507 through separate on-off valves 502 and 503, so the air resistance of both is not necessarily the same. Furthermore, the eight plants of master 506 and test subject 507 are not identical due to variations in the products, and as a result, it takes a long time to reach equilibrium, which is contrary to the demand for rapid testing.

Further, in order to automate and make the inspection continuous, the inspection device shown in FIG. 5 may be used by being incorporated into a rotating mechanism in a bridge filling production line or the like. That is, in addition to providing a full valve in each of the areas indicated by broken lines A-A and B-B in the same figure, airtight connections A304 and 505 are incorporated into the rotating mechanism, so that the containers that are continuously sent can be handled one after another. On the other hand, the pressure supply [500, differential pressure gauge 50
By installing the components such as 8 outside the rotating mechanism,
Master 506 and subject 50 sequentially through the slide valve
7 is connected to a pressure supply source 500, a differential pressure gauge 508, etc., and is configured so that a leakage test can be performed.

However, due to the structure of the sliding valve, if too much pressure is passed through it, leakage will occur in the sliding portion. Therefore, with the conventional method of measuring differential pressure by equilibrating in a high pressure state, leakage occurs from the slide valve during measurement, leading to incorrect judgments. There was a risk that the product would be judged to be defective (leaking container) due to pressure build-up.

In order to prevent such false detection, it is necessary to increase the airtightness by adding an on-off valve between the slide valve and the airtight connectors 504 and 505, but this increases the pipe resistance. For compressed air supply.

It took a long time to equilibrate, making it impossible to speed up the test.

Furthermore, since the sealed container serving as the test object mainly contains food, drinks, etc., the compressed air to be supplied is required to be hygienically clean. However, general compressed air supply pumps often have condensate mixed with wood and oil collected inside them, and sometimes this condensate is supplied together with compressed air, contaminating the surface of the subject 507. .

On the other hand, if the master 506 and the subject 507 are vacuum-suctioned, the above problem will not occur.
7 is a semi-rigid plastic bottle, and if there is an extremely large leak in the bottle or container, most of the air that was present in the head space inside the place will be sucked out, and as a result, the inside of the place will be greatly depressurized, and the atmospheric pressure will drop. There was a risk that the bottle would become soaked and the inspection device would suck in the contents, causing a malfunction.

The method of the present invention was developed in order to solve the above-mentioned problems, and it is possible to quickly and reliably test for leaks in sealed containers, and it also provides high reliability even when the test is automated and continuous. The purpose of the present invention is to provide a leakage testing method for a sealed container that can maintain the integrity of the container.

In addition, the device of the present invention can quickly and reliably perform leakage tests on sealed containers, and can support automated dead weight continuous testing while maintaining high reliability. To provide a leakage testing method for a sealed container that does not have the risk of contaminating a test subject with drainage from a water pump, and also prevents the inconvenience of sucking out the contents of the test subject by vacuum suction.

[! ! [Means for Solving the Problem] In order to achieve the above object, the leakage testing method for a sealed container according to the method of the present invention generates a pressure difference between the outside of the specimen and the inside of the specimen by pressurizing or depressurizing the outside of the specimen. , a method for inspecting leaks in a sealed container by detecting pressure changes outside the specimen due to poor sealing, in which the outside of the specimen is pressurized or depressurized by moving a piston a certain amount within a cylinder; After maintaining the state for a certain period of time for 11 seconds, the piston is returned to its original position.

This is a method for determining leakage by measuring the pressure outside the subject at this time.

In addition, the leak testing device for a sealed container related to an unexploded F11 device has an inspection pocket that airtightly accommodates all or part of the subject, a cylinder that communicates with this pocket, and a cylinder that moves within this cylinder and moves into the inspection pocket. The test pocket includes a piston that pressurizes or depressurizes the inside of the test pocket, and two pressure sensors that measure the pressure inside the test pocket.

[Examples] Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a front cross-sectional view showing the structure of a first embodiment of the present invention *a. In this embodiment, a plastic bottle 100 with a volume of 1 to 2 liters is filled with fruit juice N, etc. as a test object. A case will be described in which a lid 101 sealed with an aluminum screw lid 101 having a diameter of 38 mm is used, and leakage caused by a defect in either the seed opening 102 or the liner 103 provided on the inner surface of the lid is inspected. Note that the head space 104 of the bottle 100 is approximately 70 cc.

In FIG. 1, reference numeral 10 denotes a cup-shaped inspection pocket, which has a rubber O-ring 11 on the inner surface of its open end, and covers the lid iox of the subject.

No r! By elastically pressing one O-ring into contact with the flange 105 provided at the f section, a small volume chamber 10a can be formed inside.

Reference numeral 12 denotes a piston device, in which a piston 14 is slidable in the axial direction inside the cylinder 13, and as the piston 14 slides, air is absorbed from the opening 13a. Here, piston installation! The amount of air absorbed by the bottle 12 is approximately the same as the volume of the head space 104 present in the bottle 100 of the subject. With this setting, there is no possibility that the contents inside the bottle 100 will leak out due to suction.

Although the piston 14 can be driven by one manual operation, it is generally driven automatically by a drive atMj of a cam mechanism or the like.

The opening 13a of the cylinder 13 communicates with the opening 10b of the inspection pocket 10 via a conduit 15, and the pressure inside the chamber 10a of the inspection pocket 10 can be increased or decreased by sliding the piston device 4. It's a monkey.

Further, the pipe line 15 is branched in the middle, and the branched pipe line 16 is connected to a pressure sensor 19 via an on-off valve 17 and a slip valve 18. The pressure sensor 19 is connected to the pipe line 15
Various known pressure sensors can be used to detect the internal pressure. Furthermore, a leakage determination circuit 20 is provided at the output end of the pressure sensor 19, and based on the measurement results of the pressure sensor 19, the presence or absence of pressure change is checked to automatically determine leakage. Note that the sliding valve 18 has a pair of connecting members 18a, 1
8b, the sliding surfaces of which are in pressure contact with each other by the pressing springs 21, 21, and one of the in members 18a slides in the left-right direction in the drawing. In addition, this ttc connecting member 1
81L is provided with an open hole 22. For example, after pressure detection, the connecting member 18a is slid to open the open hole 22.
The structure is such that the pressure sensor 19 is opened to atmospheric pressure and reset by communicating the pressure sensor 19 with the pressure sensor 19 .

Next, an embodiment of a method for inspecting leakage of a sealed container using the above-mentioned inspection device will be described.

First, the piston 14 in the cylinder 13 is pushed to the lower end, and the MIO of the subject is closed while the on-off valve 17 is closed.
1 part is inserted into the inspection pocket 10, and by further pressing 100 from below, the O-ring 11 is brought into pressure contact with the flange 105 of the subject, forming a sealed chamber 10a in the inspection pocket 10. Step 1).

Next, the piston 14 is pulled up to the upper end of the cylinder 13 by a drive mechanism (not shown) (step 2), thereby reducing the pressure inside the chamber 10a.
The total volume of the range from the branch point to the on-off valve 17 is 25c.
Assuming that the joint end increase amount in the cylinder 13 is 75 cc at c, the pressure in the chamber t<10 a is reduced to about 57 cmHH in gauge pressure.

Maintain this reduced pressure state for a certain period of time (Step 3) Item 1
If there is a leak due to a defect in the 02 or the liner 103, the air that was in the head space 104 inside the bottle 100 will leak out to the chamber 10a during this holding time, and the pressure value in the reduced pressure state will drop. . Note that the retention time is usually 1~
About 5 seconds is sufficient.

After a certain holding time has elapsed, the piston 14 is returned to the lower end (Step 4). By this operation, the reduced pressure state created by the lifting operation of the piston 14 is eliminated. Therefore, the inside of the chamber 10a should normally be at atmospheric pressure, but if there is a leak as described above, the pressure value that has changed due to the leakage remains as is, and becomes higher than the atmospheric pressure by that pressure value.

Then, the on-off valve 17 is opened, the pressure inside the chamber 10a is guided to the pressure sensor 19 via the slip valve 18, and the pressure value is measured (step 5).The measurement result is sent to the leakage determination circuit 20, If the pressure at 10a is within a certain range with respect to atmospheric pressure, the test object is determined to be normal, and if it exceeds the certain range, it is determined to be a defective product with leakage.

Here, the pressure applied to the slide valve 18 is only the residual pressure generated by the leakage, which is minuscule by several tens of minutes compared to the conventional technology, and almost no leakage occurs, even if *a small leakage occurs. Even if there is an error, the resulting error only causes the output of the pressure sensor 19 to decrease to some extent.

The on-off valve 17 used in this embodiment is not involved in the suction operation for inspection, so it basically does not affect the sensitivity.
Furthermore, a decrease in sensitivity due to leakage from the slide valve 18 begins to occur when there is an extremely large defect in the bottle or lid and the residual pressure in the chamber loa is sufficiently large. In such a case.

Since the product is already far above the defective determination level, and if it is determined as a defective product, the purpose of the present invention can be fully achieved, so the occurrence of an error is not a problem.

After the discrimination has been completed, the specimen is removed from the inspection pocket 10 and transported to a defective product removal device by a transport device (not shown).

Then, a specimen determined to be a defective product is removed from the transport line, and a normal product is transported to a subsequent process such as a boxing process.

After the series of determination operations are completed, close the on-off valve 17 again,
By sliding one connecting member 18a of the slide valve 18, the pressure sensor 19 is communicated with the open hole 22 and reset, in preparation for the next measurement (step 6).

FIG. 2 is a diagram showing the effect in each step described above, that is, the relationship between the movement of the piston and the pressure state in the chamber 10a. The vertical axis in FIG. The horizontal axis represents time. Note that the pressure takes a positive value in the direction of pressure reduction, with atmospheric pressure being 0.

In the drawings, the numbers in circles indicate the operation time of each step described above. In addition, the solid line a indicates the movement of the piston 14 (
(The suction operation is shown upward), the broken line indicates the pressure inside the chamber 10a when the test object is a normal product with no leakage, and the dotted line C shows the pressure inside the chamber loa when the test object has a slight leakage.
- The dashed line d shows the pressure inside the chamber 10a when there is a large amount of leakage in the object.

First, the chamber 10 when the test object is a normal product with no leakage.
The internal pressure (a) (broken line b) lags slightly behind the movement of the piston 14, but follows closely and is reduced.

Then it returns to atmospheric pressure. This delay is due to conduit resistance.

Next, the chamber 10a when there is a slight leakage in the subject
The internal pressure (dotted line C) slightly decreases during step 3 due to reduced pressure, and the amount of the decrease appears in step 5 as a difference P1 from the atmospheric pressure.

Also, if there is a large amount of leakage in the specimen, the chamber loa
The internal pressure (-dotted chain line d) is rapidly reduced due to the suction operation of the piston 14 in step 2, but during this time the air in the 57-d space 104 leaks into the chamber 10a, so the product may not be normal or not. The system will stop at a lower reduced pressure than when there is only a small amount of leakage. Then, during step 3, air leaks out from the head space 104, and finally the pressure is reduced to P2. When the piston 14 performs a compression operation from this reduced pressure state (step 4), air returns to the head space 104 again, so that at the time of step 5, P? A residual pressure P3 of a smaller value (absolute value) is generated.

As mentioned above, if there is a leak in the subject, step 5
Since the pressure Pl or P3 remains in the chamber loa at the time of pressure measurement, leakage can be detected by detecting this residual pressure.

Next, an experimental example conducted by the present invention will be described.

A sealed container consisting of the above-mentioned plastic bottle 100 and lid 101 is used as a reference sample, and Mlo
The center of the top surface of 1 was cut out, and a 0.2 mm thick stainless steel plate with a round hole of 50 microns in diameter formed by electron beam processing was attached to that part.

Naturally occurring leakage routes and shapes are extremely diverse, and it is difficult to quantitatively express the relationship between them and the deterioration of the contents due to the invasion of bacteria. In such cases, it is empirically known that changes in the contents due to the ingress of bacteria are negligible, so if leakage can be reliably detected using the above reference sample, sufficient reliability can be obtained for practical use. can.

The amount of air leaking from the 50 micron diameter round hole formed in the above reference sample was measured by underwater M exchange, and the result was 0.4 cc per second when the pressure acting on the round hole was 50 cmHg. Calculating that this leaked air accumulates in a chamber with a volume of 25 cc and the pressure increases, it is 16 g per second.
/cm2.

The pressure sensor has the highest sensitivity and maximum measurement m of end face diaphragm type commercial products whose internal volume can be ignored.
200 g/cm7, pressure resistance 400 g/c
m' and its 10% 20g/c
m2 was set as the pass/fail discrimination level. In this case, the holding time required in step 3 is 1.25 seconds, so the holding time was set to 1.5 seconds with some margin.

The electrical signal oil pressure of the pressure sensor was set to a maximum value of 10 volts using a dedicated amplifier, and the discrimination level was set to 1.0 volts. After converting it into an electrical signal, we used ordinary electrical signal processing techniques to obtain the discrimination results.

This discrimination result showed that there was a leak in the subject.

Next, the leak testing device for sealed containers according to the present invention was installed in a line for filling contents into sealed containers.

Example of a case where continuous leakage inspection can be performed (
Embodiment 2) will be explained based on FIG. 3 and FIG. 4.

FIG. 3 is an enlarged cross-sectional front view of the leak testing device alone, and FIG. 4 is a conceptual diagram showing the overall configuration of the device. Note that the same parts as in FIG. 1 shown above are given the same reference numerals.

In the drawing, 200 is a base of the device, and this base 2
The rotary table 2 is centered around a support 201 fixed perpendicular to 00.
02 is provided, and an inspection head 203 and an inspection table 204 are attached as a pair on the outer periphery of this rotary table 202 at regular intervals.

The inspection pad 203 is a combination of the piston fitting ff112 and the inspection pocket 1O described in the previous embodiment. Further, the upper end of the piston rod 14a of the piston assembly M12 is engaged with an upper cam mechanism 205, and the piston 14 is moved up and down according to the shape of the cam. The examination table 204 is used to place the bottle 100 of the object to be examined, and its lower end engages with a lower cam mechanism 206 fixed to the base 200 and is driven up and down. 207 is a pressure spring that urges the examination table 204 upward.

Further, the one-turn table 202 includes pipe lines 15 and 16 communicating with the chamber loa in the inspection head 2.03, and on-off valves 17. A connecting member 18a of the slide valve 1B is provided corresponding to each inspection head 203, respectively.

On the other hand, on the support plate 208 fixed to the support shaft 201.

A connecting member 18b of the slide valve 18 and a pressure sensor 19 are provided.

Inspection mentioned above! The i position operates in a first-order manner.

As shown in FIG. 4, the bottles 100 are fed in a line from the direction of the arrow by a conveyor 301, and transported in the direction of arrow i by a known introduction mechanism using a timing screw 302 and an infeed wheel 303. It is supplied to the inspection table 204 in an accurately positioned state. The examination table 204 is supplied with a bottle 100 of a subject when it is in the lowered position by a lower cam mechanism 206 .

As the rotation table 202 rotates, the examination table 204 rises by one position, and as a result, the lid 101 portion of the subject is inserted into the examination pocket (10), and the flange 105 is moved upward by the action of the pressing spring 207. It is pressed against the ring 11 to form a chamber 10a.

At this time, the piston 14 is at the lower end within the cylinder 13. Then, when the subject is attached, the upper cam mechanism 205
The piston 14 is pulled up and the inspection pocket 1
Reduce the pressure inside 0. after that.

While the rotating table 202 rotates about 5/6 times in the direction of arrow j, the reduced pressure state is maintained as it is. If the test subject has a defective seed opening 102, a defective lid 101, or a defective fit,
During the holding interval, air in the headspace 104 leaks into the chamber loa.

After passing the holding section, the piston 14 moves to the upper cam mechanism 20
5 to push it down to its original position. This results in
The reduced pressure state previously created by the lifting action of the piston 14 disappears, and only the pressure due to the air leaking from the bottle remains in the chamber 10a as residual pressure.

The on-off valve 17 is provided with an on-off push button 17a, while the support column 201 is provided with a protrusion 209. and,
The opening/closing valve 17, which was in operation during the above operation, opens when the opening/closing push button 17a is pushed by the protrusion 209. As a result, the residual pressure in the chamber 10a is guided to the pressure sensor 19 via the slide valve 18. Its value is measured.

The electrical output of the pressure sensor 9 is inputted to a voltage discrimination device via a dedicated amplifier (not shown), and if the voltage exceeds a preset voltage value, it is discriminated as a defective product. This discrimination signal is sent to a defective product discharging device 304 that separates the bottles discharged from the rotary table 202 into non-defective products and defective products.

When the inspection is completed, the inspection table 204 moves to the lower cam mechanism 206.
is pushed down again, and the enlarged stitch 102 portion is removed from the inspection blank 10. This is the inspection pocket) 10
Since the pressure inside is O or a slight positive pressure, the bottle 100
It will come off naturally due to its own weight, and no forced operation is necessary.

The bottle 1oo removed from the inspection pocket 10 is carried by the outlet star wheel 305 as shown by arrow k and transferred onto the conveyor 301, and at the same time, if it is a defective product, it is removed by the defective product removal device 304 to the defective product conveyor 30.
8, and the process of one inspection head 203 is completed.

A similar process is performed one after another at high speed and continuously for a large number of inspection rods 203 placed on the rotary table 202. The discharged good products and defective products are each marked with arrow 1.
．． It is carried out in the direction m to complete the entire inspection process.

The number of inspection rods 203 to be attached to the turntable 202 is determined by the product of the number of inspection rods 203 required per minute and the holding time per head required to obtain the necessary sensitivity, the vertical movement of the piston 14, and the number of inspection rods 203 required for inspection per minute. Calculated taking into account the space required for supply and discharge.

For example, if a processing capacity of 500 lines per minute is required, a 10% margin is set at 550 lines, and the number of RADs 203 required for inspection on the rotary table 202 is determined.

The number of operations per second is 9.16668, and the holding time of one head is 1.5 seconds, so the number of heads required is the product of both, which is 13.75, and one head is required for each up and down operation of the piston 14. In addition, it becomes 75 pieces of 15°. This is followed by infeed and outleft star wheels 303.
305 must be installed, and that space is the turntable 2.
Since it takes 1/8 rotation of 02, the total number of inspection rads 203 placed around the 1-turn table 202 is 15.75×615=18.9.

However, since this is the number of heads, it is assumed to be an integer of 19. However, for reasons of design and manufacturing, 20 pieces may be arranged at a convenient angle of 18 degrees per head.

Note that the rotating table 202 of the apparatus of this embodiment is rotated once in 2.2 seconds by a drive mechanism (not shown) via a bell 210.

Note that the present invention is not limited to the embodiments described above.

For example, in the above-described embodiment, the piston was operated in the direction of suction, but it may be operated in the direction of pressurizing the inside of the inspection pocket.

In addition, the objects to be tested include materials other than those covered in the examples.
Of course, sealed containers of various sizes and shapes can be used.

Furthermore, when using the device of the present invention alone.

The measurement sensor may be reset by other means without using the measurement sensor reset structure using a slide valve as shown in FIG.

Effects of the Invention J According to the method and apparatus for testing leakage of a sealed container of the present invention, the following effects can be obtained.

■ In the conventional inspection method using differential pressure between the master and the object, it took a long time for the pressure between the two to reach an equilibrium state; however, the method and device of the present invention eliminates this problem. Since a long equilibration time is not required, testing can be performed more quickly.

■ There is no risk of leakage in the slip valve when testing is automated and continuous; that is, according to the method and device of the present invention, the pressure that acts on the slip valve is only a small amount of air pressure leaking from the test object. Therefore, the load is not large enough to cause S deviation, and therefore high reliability can be obtained even when the inspection is automated and continuous.

Q) According to the method and device of the present invention, the pressure acting on the pressure sensor is only a small amount of air pressure leaked from the subject, so the withstand pressure of the pressure sensor may be small, and therefore a highly sensitive pressure sensor can be obtained. High sensitivity can be achieved by using

- Since the apparatus of the present invention does not use a pump for supplying compressed air, there is no need to worry about contamination of the subject by drain discharged from the pump.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view showing the structure of the first embodiment of the unreleased #J device, Fig. 2 is a pressure change diagram showing the operation of the embodiment according to the present invention, and Figs. 3 and 4 are the invention of the present invention. This is a diagram showing the configuration of a second embodiment of the device in which the inspection is made continuous. Figure 3 is an enlarged cross-sectional front view of the leak testing device alone, and Figure 4 is the overall configuration of the device. Conceptual Diagram FIG. 5 is a conceptual diagram showing a conventional example. lO: Inspection pocket 12: Piston device 14: Piston 17: Open/close valve 19; Pressure sensor 100: Test bottle 104: Head space 201: Support column 20 203: Inspection head 20 10a: Chamber 13 Niji cylinder 15.16: Pipe line 18 :Slip valve 20:Leakage determination circuit 101:Test lid 2:Rotary table 4:Inspection table

Claims (2)

[Claims] (1) Inspect for leaks in sealed containers by creating a pressure difference between the outside of the test object and the inside of the test object by pressurizing or depressurizing it, and detecting pressure changes outside the test object due to poor sealing. In this method, the outside of the subject is pressurized or depressurized by moving a piston a certain amount within a cylinder, and after this state is maintained for a certain period of time, the piston is returned to its original position, and the outside of the subject at this time is A leakage inspection method for sealed containers characterized by determining leakage by measuring pressure. (2) A test pocket that airtightly accommodates all or part of the subject, a cylinder communicating with the pocket, a piston that moves within the cylinder to pressurize or depressurize the test pocket, and the test pocket. A leakage testing device for a sealed container, comprising a pressure sensor that measures the pressure inside.