JP3536098B2 - Leak inspection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak inspection device for inspecting whether or not a leak amount of a container is below a standard value.

[0002]

2. Description of the Related Art Today, a container is sometimes hermetically sealed in order to improve the reliability of parts and the like. In this case, the reliability cannot be improved if the container leaks even if the parts and the like are sealed in the container, and it is necessary to inspect the container for leaks.

Further, in automobiles and the like, equipment for air conditioning is mounted, and if there is a leak in these equipment, gas leakage occurs. Therefore, it is necessary to inspect whether the leak amount is within a specified value. The inventor of the present application has previously filed Japanese Patent Application Nos. 2000-47501 and 2000-
At 47503, we devised and applied for a leak inspection device that enables accurate leak inspection in a short time with a simple device configuration.

[0004]

In the above application, the inspection object in which the input / output holes and the like are sealed is housed in the chamber, and the air in the chamber is exhausted to perform the leakage inspection of the inspection object. In addition, if water or water vapor adheres to the chamber, the air or water inside the chamber may be exhausted during inspection, and the water or water vapor that has adhered to the chamber may be released as a gas, resulting in an error in the leak inspection. Therefore, the leak inspection was conducted in a state where water, water vapor, etc. did not adhere to the chamber.

However, when the leak inspection of the inspection object is completed and the lid of the chamber is opened to inspect the next inspection object, air containing water vapor flows into the chamber and adheres to the inner wall of the chamber. In addition, water vapor in the atmosphere adheres to the inner wall of the chamber even when the lid of the chamber is opened for a long time. In this way, if water or water vapor adheres to the inner wall of the chamber, the water or water vapor that adheres to the chamber during the next inspection of the inspection product will be released as a gas and added to the leakage of the inspection product. Then, an inspection error that fails is generated.

It is an object of the present invention to provide a leak inspection apparatus which eliminates the adhesion of water vapor to the inner wall of a chamber and enables a leak inspection accurately.

[0007]

Means adopted by the present invention for solving the above-mentioned problems will be described. In the first invention, the inspection in which the master chamber and the input / output holes are sealed
After exhausting air from the chamber containing the
Inspect the leak of the inspection object from the change in the differential pressure between the two.
In the leak inspection device, the
Unit time of gas released from the inspection object into the chamber
Discharge flow rate record that records the value corresponding to the discharge flow rate per hit
Section and the discharge flow rate recording section when measuring the pressure difference between the two
The gas corresponding to the recorded discharge flow rate should be
Gas releasing means for releasing to a chamber, and the master chamber
And a differential pressure gauge for measuring the differential pressure between the chamber and the chamber,
The judgment pressure recording part that records the
Part, the dry air delivery part and the lid of the chamber when opened
Dry air is sent from the dry air sending unit to the chamber.
However, at the time of inspection, the dry air should not be sent to the chamber.
Stop and empty the master chamber and the chamber
After the air is exhausted, it is sealed and the timekeeping section is used to measure the time.
The differential pressure value of the differential pressure gauge when started and timed for a predetermined time
And the judgment pressure recorded in the judgment pressure recording section
And a control unit for outputting the result of the comparison .

[0008]

[0009]

In the second aspect of the invention, a chamber for accommodating an inspection object in which the input / output holes are sealed, a pressure gauge for measuring the vacuum pressure in the chamber, a determination pressure recording section for recording the determination pressure, and a predetermined pressure measuring unit are provided. A time measuring unit for measuring time, a dry air delivery unit, and a dry air delivery unit that delivers dry air to the chamber when the lid of the chamber is opened, and stops delivery of the dry air to the chamber during inspection. , Exhausting the air in the chamber and starting the time measurement by the time measuring unit, comparing the pressure value of the pressure gauge and the judgment pressure recorded in the judgment pressure recording unit when a predetermined time is measured, And a control unit that outputs the comparison result.

In the third invention, a tank is connected to an exhaust pump for exhausting the air in the chamber, and when the vacuum pressure in the tank reaches a predetermined value, the valve is opened to exhaust the air in the chamber.

[0012] In the fourth inventions, a chamber for accommodating the inspected sealing the input and output holes, etc., a pressure gauge for measuring the vacuum pressure in the chamber, and determining the pressure recording unit which records the reference pressure, A timer for measuring a predetermined time, a dry air delivery section, and a dry air delivery section that delivers dry air to the chamber when the chamber lid is open, and stops the delivery of the dry air to the chamber during inspection. Then, the air in the chamber is exhausted to a predetermined pressure, and when the predetermined pressure is reached, the exhaust is stopped and the timekeeping unit is started, and when the predetermined time is reached, the pressure value of the pressure gauge and the And a control unit for comparing the judgment pressure recorded in the judgment pressure recording unit and outputting the comparison result.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of the first embodiment of the present invention, and FIGS. 2 and 3 are operation flowcharts of the first embodiment. In FIG. 1, 1 is a master chamber,
Reference numeral 2 is a chamber for accommodating the inspection object 3, 4 is a differential pressure gauge, 5 is an exhaust pump, 6 is a regulator for adjusting the air pressure, 7 is a nozzle for discharging the air adjusted by the regulator 6 to the master chamber 1, 8 and 9 pressure gauge, 10 is dry air delivery device, V ₁ ~V ₈ is a valve.

Reference numeral 11 denotes a discharge flow rate recording section for recording the discharge flow rate discharged to the master chamber 1, and 12 denotes a regulator 6 for discharging the air at the discharge flow rate recorded in the discharge flow rate recording section 11 to the master chamber 1. Flow rate pressure conversion unit for converting the pressure to a corresponding pressure, 13 for the regulator control unit, 14 for the judgment pressure recording unit for recording the judgment pressure, 15 for the clock unit, 16 for the control unit, 17 for the interface
O) and 18 are processors (CPU) that execute processing. The inspection object 3 has an input / output hole sealed with a lid 3a,
Then, the chamber 2 is sealed by the chamber lid 2a. 2b is a packing.

First, the discharge flow rate recorded in the discharge flow rate recording unit 11 will be described. Since water, steam, oil, etc. are attached to the inspection object, when the inspection object is set to a certain vacuum pressure, water,
Water vapor, oil, etc. are vaporized and released as gas as shown in FIG. The gas discharge flow rate is large at the beginning and decreases with time as it vaporizes, and most of the gas is discharged and the gas is not discharged when the vacuum state is kept for a long time. Master chamber 1 and chamber 2 have no leaks,
In addition, the one in such an aged state is used.

The discharge flow rate recorded in the discharge flow rate recording unit 11 is a unit when the inspection object of the same type as the inspection object 3 is first housed in the chamber 2 with the input / output holes and the like sealed and the set vacuum pressure is reached. The leak amount L ₁ per hour is calculated. The obtained L ₁ includes the above-mentioned released gas amount in addition to the true leak amount.

After the vacuum state is maintained for a long time, or the vacuum state is repeated many times, the set vacuum pressure is set again in a state where the released gas can be ignored, and the leak amount L ₂ is obtained. L ₂ thus obtained is only the true leak amount. Therefore, the calculation of L ₁ -L ₂ is performed to calculate the discharge flow rate L ₃ per unit time, which is recorded in advance in the discharge flow rate recording unit 11. If the volume Q'of the master chamber 1 and the volume Q of the chamber 2 containing the inspection object 3 are not equal, (L ₁
-L ₂₎ records the Q '/ Q as release rate L _3. Alternatively, for example, it may be obtained by the method described in Japanese Patent Application No. 2000-47504.

Next, the flow pressure conversion unit 12 will be described. If the diameter of the hole of the nozzle 7 and the vacuum pressure of the master chamber 1 are determined, the relationship between the pressure regulated by the regulator 6 and the discharge flow rate per unit time discharged to the master chamber 1 can be obtained. In the flow rate pressure conversion unit 12, the pressure of the regulator corresponding to the discharge flow rate thus obtained is recorded in advance.

Further, the regulator control unit 13 reads out the discharge flow rate recorded in the discharge flow rate recording unit 11 and converts the pressure corresponding to the read discharge flow rate by the flow rate pressure conversion unit 12 during a leak inspection described later. The regulator 6 is controlled so that the pressure of the pressure gauge 8 becomes the pressure converted by the flow pressure converter 12.

The operation of the first embodiment will be described below with reference to FIGS. In step S1, the operator stores the inspection object 3 whose lid is sealed in the input / output hole and the like in the chamber 2 and covers the chamber 2 and seals it. Step S2
Then, the control unit 16 first initializes the valves V _{1 to} V ₈ .

That is, the valve V ₈ (hereinafter, the valve is abbreviated to V _n ) is closed to stop the delivery of the dry air delivered from the dry air delivery apparatus 10 to the chamber 2. Further, V ₃ and V ₄ are closed, and V ₁ , V ₂ , V ₅ , V ₆ and V ₇ are opened.

When the lid 2a of the chamber 2 is opened, V ₈ is opened so that the dry air is delivered from the dry air delivery device 10 into the chamber 2 as described above. However, while the lid 2a of the chamber 2 is opened and the inspection object 3 is exchanged, moisture contained in the atmosphere enters and adheres to the inner surface of the chamber 2, Moisture and other substances that adhere during inspection are released as gas, which affects the inspection results.

Therefore, when the lid 2a of the chamber 2 is opened, dry air is sent into the chamber 2 to prevent moisture from adhering to the inner surface of the chamber 2 or the like. In order to increase the dryness of the dry air delivered from the dry air delivery device 10, the delivered dry air may be heated to deliver the high temperature dry air.

In step S3, when V ₁ and V ₂ are opened in step S2, the exhaust pump 5 exhausts the air in the master chamber 1 and the chamber 2.

In step S4, the control unit 16 reads the pressure indicated by the pressure gauge 9 through the I / O 17, determines whether or not the measurement start preparation pressure is reached, and waits until the preparation pressure is reached. That is, it waits until the preparatory pressure provided until the pressure (set pressure) at the time of leak inspection is reached.

In step S5, the control unit 16 instructs to open V ₃ and V ₄ when the preparatory pressure is reached, and then close V ₅ and V ₆ . Thus, first the V ₅ and V ₆ to V ₃ and V ₄ in a state in which the opening in the open, close reason then V ₅ and V _6, is to stop the short time deflection of a differential pressure gauge 4 .

The high-sensitivity differential pressure gauge has a long vibration period, and when a large differential pressure is input first, it vibrates greatly, and it takes a long time to stop the vibration. Therefore, first type having the same pressure V ₅ and V ₆ is opened condition, then even open V ₃ and V _4, the influence due to the pressure difference becomes negligible, the V ₅ and V ₆ It is closed to start measuring the differential pressure.

By thus starting the measurement of the differential pressure in a short time, the leak amount can be accurately measured. That is, the amount of released gas largely changes with time as described with reference to FIG. Therefore, when the time until the vibration stops is significantly different, there is a difference between the discharge flow rate recorded in the discharge flow rate recording unit 11 and the amount of gas actually discharged from the inspection object, and the measurement result of the leak amount is different. Although a large error occurs, if it can be measured in a short time, it becomes the same as the recorded discharge flow rate, and the error is not included.

Next, returning to the operation, step S
In 6, the control unit 16 determines whether or not the pressure indicated by the pressure gauge 9 has reached the set pressure, and waits until it reaches the set pressure. In step S7, the control unit 16, V ₁ and V
₂ is closed to stop the exhaust, and at the same time, the timer 15 is instructed to start time counting.

In step S8, when the set time (T) has elapsed, the control unit 16 moves to step S9 and the differential pressure gauge 4
More differential pressure DP is taken in. In step S10, the control unit 1
6 determines whether the differential pressure value DP captured in step S9 is smaller than the determination pressure P recorded in the determination pressure recording unit 14.

If the determination in step S10 is YES, the process proceeds to step S11, and if the determination is NO, the process proceeds to step S12 to output the inspection failure, and the process proceeds to step S13.

As shown in FIG. 5, V at time t = T _0
When the exhaust of the master chamber 1 and the chamber 2 is stopped by closing ₁ and V ₂ , the differential pressure value D of the differential pressure gauge 4
P is 0. In the exhausted vacuum state, the water vapor adhering to the inspection object 3 housed in the chamber 2 is vaporized and the gas is released into the chamber 2. However, since the gas corresponding to the released amount of the gas is released into the master chamber 1, the differential pressure value DP becomes 0 when the inspection object 3 has no leak.

If the inspection object 3 has a leak, the inspection object 3
Air, which is hermetically sealed at atmospheric pressure, is released into the chamber 2, and the pressure difference between the master chamber 1 and the chamber 2 increases with time as shown in FIG. Therefore, the differential pressure value DP = P corresponding to the leak amount satisfying the standard when the time T has elapsed from the time T ₀ is recorded in the determination pressure recording unit 14 in advance as the determination pressure, and when DP ≦ P, the inspection pass is determined as DP. When> P, a failure is output.

In step S13, the control unit 16
V ₃ , V ₄ and V ₇ are closed and the process proceeds to step S14,
When V ₈ is opened, dry air is flown into the chamber 2 from the dry air delivery device 10 to bring it to atmospheric pressure. In step S15, the lid of the chamber 2 is opened and the inspection object 3 is replaced. While the lid is open, dry air is sent from the dry air sending device 10 into the chamber 2.

[0035] When the replacement of the test object 3 in the step S15 is completed, the flow proceeds to step S16, the control unit 16 stops the delivery of dry air into the chamber 2 by closing the V _8, V ₅ proceeds to step S17 , V ₆ and V ₇ are opened and V ₁ and V ₂ are opened to start evacuation. Then, the process proceeds to step S3, and steps S3 to S16 are repeated.

In the embodiment, the differential pressure value DP fetched in step S9 is moved to step S10 to determine whether it is smaller than a predetermined value P, and if it is smaller, the process is moved to step S11 to pass the inspection and be larger. In the case, the inspection failure was output in step S12. However, based on the differential pressure value DP captured in step S9, the relationship between the differential pressure value obtained in advance and the leak amount measurement value, or the differential pressure value The leak amount may be calculated and output using a leak amount calculation formula.

In the embodiment, the discharge flow rate recorded in the discharge flow rate recording unit 11 is one point, but in this case, step S8
When the time T set in step 2 is small and T is large, a plurality of discharge flow rates within the time T may be recorded and the discharge flow rate may be changed with the passage of time.

In the embodiment, the discharge flow rate recorded in the discharge flow rate recording section 11 is read out and converted into the pressure by the flow rate pressure conversion section. However, the converted pressure is recorded and the recorded pressure is recorded. May be read out to adjust the pressure of the regulator 6.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a block diagram of the second embodiment of the present invention, and FIGS. 7 and 8 are operation flowcharts of the second embodiment. In FIG. 6, 2 is a chamber for accommodating the inspection object 3, 5 is an exhaust pump for exhausting the air in the chamber 2, 8 is a pressure gauge for measuring the vacuum pressure in the chamber 1, 10
Is a dry air delivery device, V ₁ , V ₂ and V ₃ are valves,
14 is a judgment pressure recording unit, 15 is a time measuring unit for measuring a predetermined time, 16 is a control unit, 17 is an interface (I / O),
A processor (CPU) 18 executes processing.

The input / output hole of the inspection object 3 is sealed with the lid 3a, housed in the chamber 2, and then the chamber 2 is sealed with the lid 2a of the chamber 2. 2b is a packing.

Before explaining the operation of the second embodiment, the principle of the second embodiment will be described with reference to FIG. When the valve V ₂ is closed, the valve V ₁ is opened, and the air in the chamber 2 is exhausted by the exhaust pump 5, the pressure in the chamber 2 lowers from atmospheric pressure with time t, as shown in FIG. .

If there is no leak in the inspection object 3 housed in the chamber 2, the pressure in the chamber 2 decreases with time as shown by A, but if the inspection object 3 has a leak, the inspection object 3 does not leak. The air inside leaks and is released into the chamber 2, and as indicated by B, the pressure drop with time is less than that when there is no leak.

The second invention is an application of this principle, in which an inspection object whose allowable leak amount is known in advance is housed in a chamber and the time-pressure relationship shown in FIG. 9 is obtained. Next, a predetermined time T (T = T ₂ −T ₁ ,
T _1: open time, T _2: measurement time) and reads the pressure P ₂ in the measurement time T _2, counting the predetermined time T read unit 1
5, and the pressure P ₂ is recorded in the judgment pressure recording unit 14.

When the pressure in the chamber 2 is lowered, water and the like attached to the outer surface of the inspection object 3 housed in the chamber 2 are released as a gas, and the released gas also leaks. The judgment pressure applied to the judgment pressure recording unit 14
To record.

Next, referring to FIGS. 7 and 8, the second
The operation of this embodiment will be described. In step S21, the operator puts the sealed inspection object 3 in the chamber 2 by covering the input / output hole and the like, and covers the chamber 2 with the cover 2a.

In step S22, when the operator turns on an operation switch (not shown) and inputs the start of inspection, the control unit 16 closes the valve V ₂ through the I / O 17 and sends the dry air into the chamber 2. Stop the valve V
_{When 1} is opened, the exhaust pump 5 starts exhausting the air in the chamber 2.

In step S23, when the control unit 16 starts the exhaust of the chamber 2, the control unit 16 instructs the time measuring unit 15 to start measuring the time. In step S24, the control unit 16 waits until the timing unit 15 outputs the timing completion signal for the predetermined time T '.

In step S25, the control unit 16 once opens the valve V ₃ of the pressure gauge 8 and then closes it again. In step S26, the control unit 16 waits until the timing unit 15 outputs a timing completion signal for a predetermined time T ″.

In step S27, the control unit 16 opens the valve V ₃ . The reason for opening / closing the valve V ₃ in steps S24 to S27 will be described later. In step S28, the control unit 16 waits until the timing unit 15 outputs a timing completion signal for a predetermined time T.

In step S29, the control section 16 controls the I / O.
Taking in the pressure value P output from the pressure gauge 8 via O17,
In step S30, it is determined whether the taken pressure value P is lower than the judgment pressure P ₂ recorded in the judgment pressure recording unit 14. In step S30, the pressure value P is the judgment pressure P.
If lower than ₂ , move to step S31 and pass the inspection.
If it is higher, the process proceeds to step S32, the inspection failure is output, and the process proceeds to step S33.

In step S33, the control unit 16 closes the valves V ₁ and V ₃ to stop the exhaust and opens the valve V ₂ to open the chamber 2 from the dry air delivery device 10.
Deliver dry air into it.

In step S34, the operator selects the chamber 2
The lid 2a is opened to take out the inspection object 3, and the process proceeds to step S21 to start the inspection of the next inspection object. Thus, when the lid 2a of the chamber 2 is open, the dry air delivery device 10
Since more dry air is sent into the chamber 2, moisture does not adhere to the chamber 2 and gas is not released,
Erroneous judgment of inspection can be eliminated.

Next, steps S25, S27 and S
The reason for opening and closing the valve V ₃ at 33 will be described. When the inspection is completed and the valve V ₂ is opened in step S33 described above, the pressure in the chamber 2 is rapidly changed from the exhaust pressure to the atmospheric pressure. Therefore, the pressure gauge 8 for measuring the pressure in the chamber 2 is damaged.

Therefore, before opening the valve V ₂ , the valve V ₃ is closed to keep the pressure of the pressure gauge 8 at the exhaust pressure at the end of the inspection, and the opening of the valve V ₃ starts the inspection of the next inspection object 3. Then, open it when it is close to the time to make the judgment of the leak inspection.

FIG. 10 shows a pressure gauge 8 by opening and closing the valve V ₃ .
Shows the pressure of. In FIG. 10, the dotted line shows the pressure in the chamber 2, and the times T ₁ , T ₂ and T are as described in FIG. When the valve V ₁ is opened at time T ₁ and the exhaust of the air in the chamber 2 is started (step S22), the pressure decreases as shown by the dotted line.

The pressure in the chamber 2 approaches the pressure of the pressure gauge 8.
Based time T₃Then, the valve V ₃Open the pressure gauge
The pressure of 8 is made the same as the pressure in the chamber 2, and the valve V₃
Is closed (step S25). Further time passes,
Interval T₂Just before time T_FourThen valve V₃Open
(Step S27), the leak inspection is dealt with.

Time T (= T₂-T₁) Together with the time
T '(= T₃-T₁) And T ″ (T _Four-T₁) In advance
It is recorded, and in step S24, the recorded time T '
It is determined whether or not the time has passed, and in step S26,
It is determined whether or not the time T ″ recorded has elapsed.
It

In addition, between T, T'and T ", as shown in FIG.
As shown by 0, there is a relationship of T ′ <T ″ <T, and these values are obtained in advance by experiments.

In the embodiment, steps S24 and S2
Although the time T '5 was closed again with the valve V ₃ is opened, step S delete the steps S24 and S25
26 and S27, the valve V ₃ may be opened when the time T ″ has elapsed.

Next, referring to FIG. 11 and FIG.
A third embodiment of the present invention will be described. FIG. 11 is a block diagram of the third embodiment, and FIG. 12 is an operation flowchart of the third embodiment. In the configuration of the third embodiment, as shown in FIG. 11, a tank 19, a pressure gauge 9 and a valve V ₄ are added to the exhaust pump 5 of the configuration of the second embodiment described in FIG.

In the second embodiment, the pressure in the chamber decreases, a difference from the pressure in the inspection object occurs, and the air in the inspection object leaks into the chamber, as described with reference to FIG. In addition, there is a pressure difference between the case with a leak and the case without a leak. Therefore, in order to perform the inspection in a short time, the pressure in the chamber may be lowered in a short time.

In the third embodiment, the valve V ₁ is closed and V ₄ is opened to evacuate the tank 19 in advance by the exhaust pump, and as shown in FIG. 13, the valve V ₁ is opened at time t = T.
_When opened at ₁ , the pressure in the chamber drops sharply from atmospheric pressure to P ₃ . Therefore, compared with the second embodiment, in the third embodiment, the pressure in the chamber is higher than the atmospheric pressure by a pressure P ₃
It is possible to shorten the time until it is lowered.

In the third embodiment, the pressure in the chamber becomes P ₃ every time when the valve V ₁ is opened.
The pressure of the tank 19 before opening the valve V ₁ is measured by the pressure gauge 9 and adjusted to a predetermined pressure.

The operation of the third embodiment will be described below with reference to FIG. In the third embodiment, steps S21 and S of FIGS. 7 and 8 described in the second embodiment are performed.
12, step S40 shown in FIG. 12 is inserted, step S22 is inserted between step S22 and step S23, and step S33 ′ is executed instead of step S33.

That is, in step S40, the control unit 1
6 closes the valve V ₁ and opens V ₄ to exhaust the air in the tank 19, and when the pressure value of the pressure gauge 9 reaches a predetermined value, moves to step S22, closes the valve V ₂ and closes the valve V ₁ And the air in the chamber 2 is exhausted.

When the exhaust in step S22 ends, the step
Move to step S41 and immediately valve V _FourClose the tank 1
Eliminate exhaust from 9. In addition, in step S33 ',
Rub V₁And V₃Closed and valve V₂Open
The dry air is sent into the chamber 2 and the valve V_FourOpen
Then, the exhaust of the air in the tank 19 is started.

Next, referring to FIG. 14, the fourth embodiment of the present invention will be described.
An example will be described. The configuration of the fourth embodiment is the same as the configuration of the second embodiment described with reference to FIG. In the fourth embodiment, the structure shown in FIG. 6 is used, and a leak inspection is performed by a vacuum leaving method.

That is, as shown in FIG. 15, the exhaust of the air in the chamber 2 is started from the time T ₁ , and the exhaust is stopped at the time T ₅ when the pressure in the chamber 2 reaches a predetermined pressure P _0. .

When exhaust is stopped, if there is no leak, A
The pressure P ₀ at the time of exhaust stop is maintained as shown by
If the inspection object 3 has a leak, the air in the inspection object 3 leaks and is released into the chamber 2, so that the pressure in the chamber 2 increases with time as shown by B.

Therefore, if the pressure P in the chamber 2 at the time T ₆ after the elapse of the predetermined time T from the time T ₅ at which the predetermined pressure P ₀ is reached is smaller than the predetermined value P _{2, the} inspection is passed.
Therefore, the judgment pressure recording unit 14 stores the judgment pressure P _{2 in} advance.
Record.

FIG. 14 shows an operation flowchart of the fourth embodiment. Step S28 of the second embodiment described with reference to FIGS. 7 and 8 is deleted, and steps S50 to S29 are executed between steps S27 and S29. S52 is inserted, and the other points are the same as described in the second embodiment.

[0072] At step S50, the control unit 16, the pressure value of the pressure gauge 8, it is determined whether it is a predetermined value P _0, waits until the predetermined value P _0. In step S51, when it is determined that the predetermined value P ₀ is reached, the control unit 16 closes the valve V ₁ to stop the exhaust and starts the time counting of the time counting unit 15, and proceeds to step S52 to move to the time counting unit 15 It is determined whether or not the time measured by T is timed, and the process waits until T time is measured.

When it is determined in step S52 that the time T has elapsed, the process proceeds to step S29, the pressure value of the pressure gauge 8 is taken in, and steps S30 to S30 described in the second embodiment are performed.
S34 and S21 to S27 are executed.

[0074]

As described above, according to the present invention, the following effects can be obtained. The sealed test object is stored in the chamber, the value corresponding to the discharge flow rate of the gas discharged from the test object is recorded in advance, and the gas corresponding to the discharge flow rate recorded during the differential pressure measurement is discharged to the master chamber. Therefore, the change in pressure due to the gas released from the test object is canceled by the differential pressure measurement value and is not detected, and when the chamber lid is open, dry air is sent into the chamber. Therefore, moisture or the like is not attached to the chamber, and the accuracy at the time of inspection can be improved.

The sealed test object is housed in the chamber, the air in the chamber is exhausted, the pressure value in the chamber after a lapse of a predetermined time is compared with the pre-recorded judgment pressure, and the success or failure of the test is output. By doing so, it is possible to perform a leak test in a short time with a simple device configuration, and since dry air is sent into the chamber when the lid of the chamber is opened, moisture etc. can be stored in the chamber. It is not attached, and the accuracy at the time of inspection can be improved.

The sealed test object is housed in the chamber, the air in the chamber is evacuated, the evacuation is stopped when the predetermined pressure is reached, the time measurement is started, and the pressure value in the chamber after the lapse of the predetermined time. Since it is configured to output the pass / fail of the inspection by comparing with the determination pressure recorded in advance, it is possible to perform the leak inspection in a short time with a simple device configuration,
Further, since the dry air is sent into the chamber when the lid of the chamber is opened, moisture or the like is not attached to the chamber, and the accuracy of inspection can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is an operation flowchart of the first embodiment.

FIG. 3 is an operation flowchart of the first embodiment.

FIG. 4 is a diagram for explaining an amount of released gas with respect to time.

FIG. 5 is a diagram for explaining a differential pressure value with respect to time.

FIG. 6 is a configuration diagram of a second embodiment of the present invention.

FIG. 7 is an operation flowchart of the second embodiment.

FIG. 8 is an operation flowchart of the second embodiment.

FIG. 9 is a diagram for explaining the principle of the second embodiment.

FIG. 10 is a diagram for explaining the operation of the valve V ₃ .

FIG. 11 is a configuration diagram of a third embodiment of the present invention.

FIG. 12 is an operation flowchart of the third embodiment.

FIG. 13 is a diagram for explaining the principle of the third embodiment.

FIG. 14 is an operation flowchart of the fourth embodiment.

FIG. 15 is a diagram for explaining the principle of the fourth embodiment.

[Explanation of symbols]

1 Master Chamber 2 Chamber 3 Specimen 4 Differential Pressure Meter 5 Exhaust Pump 6 Regulator 7 Nozzle 8, 9 Pressure Gauge 10 Dry Air Delivery Device V _{1 to} V ₈ Valve 11 Discharge Flow Recorder 12 Flow Pressure Converter 13 Regulator Control 14 Judgment Pressure recording unit 15 Timing unit 16 Control unit 17 Interface (I / O) 18 Processor (CPU) 19 Tank

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP 10-293076 (JP, A) JP 10-293075 (JP, A) JP 58-34337 (JP, A) JP 50- 66288 (JP, A) JP 2001-235386 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 3/32 G01M 3/26

Claims (4)

(57) [Claims] 1. A leak test for inspecting a leak of an inspection object by evacuating air in a chamber accommodating an inspection object in which a master chamber and an input / output hole and the like are housed, and sealing the inspection object, and checking the leakage of the inspection object based on a change in pressure difference between the two In the apparatus, a discharge flow rate recording unit that records a value corresponding to the discharge flow rate of the gas discharged into the chamber from the inspection object at the exhaust pressure at the time of inspection, and the differential pressure between the two A gas discharging means for discharging a gas corresponding to the discharge flow rate recorded in the discharge flow rate recording section to the master chamber, a differential pressure gauge for measuring a differential pressure between the master chamber and the chamber, and a judgment recording the judgment pressure. A pressure recording unit, a time measuring unit for measuring a predetermined time, a dry air delivery unit, and a dry air delivery unit delivering dry air to the chamber when the lid of the chamber is opened, for inspection. Stops the delivery of the dry air to the chamber, exhausts the air in the master chamber and the chamber, and then seals and starts the time measurement by the time measuring unit, and when the time is measured for a predetermined time, the differential pressure gauge. And a control unit which compares the differential pressure value of 1. with the determination pressure recorded in the determination pressure recording unit and outputs the comparison result. 2. A chamber for accommodating an inspection object in which an input / output hole and the like are sealed, a pressure gauge for measuring a vacuum pressure in the chamber, a determination pressure recording section for recording a determination pressure, and a timing for timing a predetermined time. A dry air delivery part, the dry air delivery part delivers dry air to the chamber when the lid of the chamber is opened, and stops the delivery of the dry air to the chamber at the time of inspection, The air is exhausted and at the same time the timekeeping section is started, and when the time is measured for a predetermined time, the pressure value of the pressure gauge is compared with the judgment pressure recorded in the judgment pressure recording section, and the comparison result is output. A leak inspection device comprising: a control unit. 3. A tank is connected to an exhaust pump for exhausting air in the chamber, and a valve is opened to exhaust the air in the chamber when the vacuum pressure of the tank reaches a predetermined value. leak testing device according to claim 2 Symbol mounting to. 4. A chamber for accommodating an object to be inspected, in which an input / output hole is sealed, a pressure gauge for measuring a vacuum pressure in the chamber, a determination pressure recording section for recording a determination pressure, and a timing for timing a predetermined time. A dry air delivery part, the dry air delivery part delivers dry air to the chamber when the lid of the chamber is opened, and stops the delivery of the dry air to the chamber at the time of inspection, The air is exhausted to a predetermined pressure, and when the predetermined pressure is reached, the exhaust is stopped and the time counting section is started, and when the predetermined time is measured, the pressure value of the pressure gauge and the judgment pressure recording section are recorded. A leak inspection apparatus, comprising: a control unit that compares the determined determination pressure and outputs the comparison result.