JP2000314671A - Decision method for waiting time in air leak test method and check method for computing part as well as air leak tester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decide the waiting time of a measurement in an air leak test by a simple process. SOLUTION: In a test mode, a reference container La is connected to a pressure supply line 10A, a container Lb to be inspected is connected to a pressure supply line 10B, a test pressure is given to the pressure supply lines 10A, 10B from an air pressure source 1, and a valve 12A and a valve 12B are then closed. At a point of time when a prescribed waiting time elapses after the valves are closed, the measurement of an air leak is started on the basis of differential pressure information from a pressure sensor 5. In a mode in which the waiting time is decided, a test pressure is given, the valves are closed in the same manner as in the test mode, and the piston 21 of an air cylinder 20 is moved at a set speed by a movement means 30. That is to say, a pseudo leak in a set amount per unit time is generated. Then, a change in the detection differential pressure of the pressure sensor 5 after the valves are closed is monitored, and the time in which the detection differential pressure starts to change linearly is measured. On the basis of the measured time, the waiting time is decided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining a waiting time in an air leak test method, a method for checking an arithmetic unit, and an air leak tester.

[0002]

2. Description of the Related Art For example, a differential pressure type air leak tester has a first pressure supply line leading to a leak-free reference container (master work) and a second pressure supply line leading to a container to be inspected (work to be inspected). A pressure sensor for detecting a pressure difference between the two. Then, while the test pressure is being supplied to the first and second pressure supply lines, the valves provided on the pressure supply lines are simultaneously closed, and thereafter, the container to be inspected based on the differential pressure information from the pressure sensor. The air leak is measured.

In the above-mentioned air leak test, the pressure is unstable immediately after the valve is closed and the pressure supply line is closed. This is due to the deformation of the sealing material of the valve due to the pressure and a reduction in the heat of compression. Such pressure fluctuations
Dissolved over time. Therefore, it is necessary to start the air leak measurement at a time when a predetermined waiting time has elapsed from the time when the pressure supply line is closed in order to ensure accuracy. Since the pressure fluctuation from the time when the pressure supply line is closed differs depending on the structure of the air leak tester, the test pressure, the volume of the work to be inspected, and the like, it is necessary to determine the waiting time according to these.

Conventionally, the waiting time is determined as follows. That is, in addition to the reference container, a sample of the container to be inspected having a known air leak amount, for example, a sample of the container to be inspected having an allowable limit of air leak is prepared. These reference containers and samples are connected to the first and second pressure supply lines. Then, when a waiting time for provisional determination has elapsed since the pressure supply line was closed in the test pressure application state, measurement of air leak based on the differential pressure information is started. The above operation is performed a number of times, and it is determined whether or not the data of the air leak does not vary and whether or not the air leak matches the air leak expected in the sample. In the case of a negative determination, the waiting time is lengthened, and the same data is again taken. Then, the waiting time is determined so as to obtain data that is consistent with the air leak expected in the sample without variation. Moreover,
In order to reduce the time required for the air leak test, it is necessary to determine this waiting time as short as possible.

As another conventional example, there is the following air leak tester. That is, attention is paid to the fact that the pressure fluctuation due to the deformation of the sealing material of the valve due to the pressure and the decrease in the compression heat is non-linear. More specifically, after the pressure supply line is closed, the detected differential pressure is monitored by the calculation unit, and based on the data in the area where the detected differential pressure changes linearly, a predetermined time longer than the monitoring time in the linear change area. The amount of air leak over time is estimated and calculated to shorten the test time.

[0006]

In the prior art described above, since the waiting time is provisionally determined, a large number of tests are performed, and trial and error are repeated, the operation of determining the waiting time is complicated. Further, in order to accurately determine the waiting time, it is desirable to perform the above-described test on a plurality of samples, and in this case, the work is more complicated. Further, in the conventional example described later, it is not necessary to determine the waiting time, but it is necessary to strictly check the operation unit. Although an air leak tester for diagnosing with an air cylinder and a moving means is disclosed in Japanese Patent Application Laid-Open No. 8-313384, no consideration is given here to non-linear changes and linear changes in detected pressure. .

[0007]

According to a first aspect of the present invention, there is provided:
In the test mode, this pressure supply line is closed in a state where the test pressure is supplied to the pressure supply line leading to the work to be inspected, and when a predetermined waiting time has elapsed from the closing of the pressure supply line, the pressure supply line is connected to the pressure supply line. In the air leak test method for starting the air leak measurement of the work to be inspected based on the pressure information from the pressure sensor,
Similar to the test mode, the test pressure is applied to the pressure supply line and the pressure supply line is closed.The piston of the air cylinder connected to the pressure supply line is moved at a constant speed. A time until the detection pressure of the sensor starts to change linearly is measured, and the waiting time in the test mode is determined based on the measured time.

According to a second aspect of the present invention, in a test mode, a test pressure is supplied to a first pressure supply line leading to a master work having no leakage and a second pressure supply line leading to a work to be inspected. The pressure supply lines are closed, and when a predetermined waiting time has elapsed since the closing of the pressure supply lines, the difference between the pressure sensor connected between the first pressure supply line and the second pressure supply line is reduced. In the air leak test method for starting the air leak measurement of the work to be inspected based on the pressure information, the test pressure is applied to the first and second pressure supply lines to close the first and second pressure supply lines in the same manner as in the test mode, and , A piston of an air cylinder connected to one of the second pressure supply lines is moved at a constant speed, and the pressure supply line is closed from the time when the pressure supply line is closed. Detection differential pressure difference measuring the time until begins to change linearly, based on the measured time, and determines the waiting time in the test mode.

According to a third aspect of the present invention, in a test mode, after a pressure is supplied to a pressure supply line leading to a workpiece to be inspected while the pressure supply line is closed, an arithmetic unit connects the pressure supply line to the pressure supply line. In the air leak test method of monitoring the detected pressure by the pressure sensor, based on the data in the area where the detected pressure changes linearly, predicting and calculating the air leak amount for a predetermined time longer than the monitoring time in the linear change area The test pressure is applied to the pressure supply line, the pressure supply line is closed, the piston of the air cylinder connected to the pressure supply line is moved at a constant speed, and in this process, the amount of air leak calculated by the calculation unit is reduced by the air. Airy characterized in that it checks whether it matches the pseudo leak amount expected by the piston movement of the cylinder Computing section check method in the test method.

According to a fourth aspect of the present invention, in a test mode, a test pressure is supplied to a first pressure supply line leading to a master work having no leakage and a second pressure supply line leading to a work to be inspected. After closing these pressure supply lines, the arithmetic unit monitors the differential pressure detected by the pressure sensor connected between the first pressure supply line and the second pressure supply line, and this detected differential pressure is An air leak test method for predicting and calculating an air leak amount for a predetermined time longer than a monitoring time in the linear change area based on data in a linearly changing area, wherein the test pressure is applied to the first and second pressure supply lines. And then closes and moves the piston of the air cylinder connected to the second pressure supply line at a constant speed. Computing section check method in the air leak test methods over click amount is characterized in that checking whether matching the piston moved by a prospective pseudo leakage amount of the air cylinder.

According to a fifth aspect of the present invention, there is provided a pressure supply line communicating with a workpiece to be inspected, an air pressure source for supplying a test pressure to the pressure supply line, a valve provided on the pressure supply line, A pressure sensor connected to the supply line, and in the test mode, the valve is closed in a state where the test pressure from the air pressure source is applied to the pressure supply line. An operation control means for starting an air leak measurement of the work to be inspected based on the pressure information from the pressure sensor when a time has elapsed, and an air cylinder connected to the pressure supply line. And a moving means for moving the piston of the air cylinder in the axial direction at a constant speed. Chi-time determining mode to run the,
In this waiting time determination mode, with the test pressure applied to the pressure supply line, the valve is closed to close the pressure supply line, and the moving means is driven to move the piston of the air cylinder at a constant speed. Measuring the time from when the pressure supply line is closed until the pressure detected by the pressure sensor starts to change linearly, and based on the measured time, determines the waiting time in the test mode. .

According to a sixth aspect of the present invention, a test pressure is applied to a first pressure supply line leading to a master work, a second pressure supply line leading to a work to be inspected, and the first and second pressure supply lines. An air pressure source to be applied, valves provided on the first and second pressure supply lines, and a pressure sensor for detecting a differential pressure between the first and second pressure supply lines In the test mode, the valves provided on the first and second pressure supply lines are simultaneously closed in a state where the test pressure from the air pressure source is applied to the first and second pressure supply lines, and the first and second pressure supply lines are closed. , When a predetermined waiting time has elapsed since the closing of the second pressure supply line,
And an arithmetic control unit for starting air leak measurement of the work to be inspected based on the differential pressure information from the pressure sensor. The air leak tester further includes: a first and a second pressure supply line. An air cylinder connected thereto; and a moving means for moving a piston of the air cylinder at a constant speed in the axial direction. The arithmetic control means also executes a waiting time determination mode in addition to the test mode. In the time determination mode,
With the test pressure applied to the second pressure supply line, the valve is closed to close these pressure supply lines, and the moving means is driven to move the piston of the air cylinder at a constant speed. The time from when the line is closed to when the differential pressure detected by the pressure sensor starts to change linearly is measured, and the waiting time in the test mode is determined based on the measured time.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the present invention will be described.
This will be described with reference to the drawings. As shown in FIG. 1, the air leak tester has a main electromagnetic switching valve 2 connected to a positive pressure air pressure source 1. The downstream side of the main electromagnetic switching valve 2 is the first
Pressure supply line 10A and the second pressure supply line 10
B. The main electromagnetic switching valve 2 is a two-position, three-port electromagnetic switching valve that releases the pressure supply lines 10A and 10B to the atmosphere at the neutral position, and the test pressure of the air pressure source 1 at the offset position when the solenoid is on. Is supplied to the pressure supply lines 10A and 10B.

A reference container La (master work) is connected to the tip of the first supply line 10A via a joint 11A, and to the tip of the second pressure supply line 10B.
The inspection container Lb (work to be inspected) is connected via the joint 11B. The reference container La is
It has been confirmed that there is no leakage, and it is preferable that the container has the same shape and the same volume as the container Lb to be inspected.

The pressure supply lines 10A and 10B have:
Normally opened electromagnetic switching valves 12A and 12B are provided. In the pressure supply lines 10A and 10B, the switching valve 12
A, a pressure sensor 5 of a differential pressure detection type
Is connected. Further, the pressure supply lines 10A, 10A
One of B (second pressure supply line 10B in the present embodiment)
Is connected to an auxiliary pressure sensor 6.

An air cylinder 20 is connected to one of the pressure supply lines 10A and 10B (the second pressure supply line 10B in this embodiment). This air cylinder 2
The zero piston 21 is moved at a constant speed in the axial direction by the moving means 30.

Next, the structure of the air cylinder 20 and the moving means 30 will be described with reference to FIG. The air cylinder 20 includes a cylinder tube 22 and a piston 21 that slides inside the cylinder tube 22 while maintaining airtightness. One end of the cylinder tube 22 is connected to the second pressure supply line 10B via a joint 23 and a pipe 24.

The moving means 30 includes a pulse motor 35
And a conversion mechanism 40 for converting the rotation of the pulse motor 35 into a linear motion of the piston 21. Conversion mechanism 4
Numeral 0 has a threaded rod 42 rotatably supported by a pair of bearings 41 and extending parallel to the piston 21. One end of the threaded rod 42 is connected to the output shaft 35a of the pulse motor 35 via gears 43 and 44, so that rotation from the pulse motor 35 is transmitted. A moving member 45 is screwed to the screw rod 42. The moving member 45 is connected to an end of the piston 21 via a rod 46 and a connecting member 47. The connecting member 47
Is adapted to slide in a guide tube 48 coaxially connected to the other end of the cylinder tube 22. The guide cylinder 48 is formed with an axially extending slit 48a for accommodating the rod 46.

Further, as shown in FIG. 3, the air leak tester of this embodiment includes a display device 50 (display means) such as a CRT, a control unit 60 (operation control means), and an input device 65. The control unit 60 substantially has a control unit 61 and a calculation unit 62. The control unit 60 executes various modes according to signals from a mode switch (not shown) for commanding a test mode, a waiting time determination mode, and a diagnostic mode, and outputs signals from the pressure sensors 5 and 6. Receiving, solenoid valve 2,
12A, 12B, the pulse motor 35, and the display device 50 are controlled. The input device 65 is configured to input an allowable atmospheric pressure equivalent leakage amount per unit time.

The operation of the air leak tester having the above configuration in the test mode by the control unit 60 will be described. When the electromagnetic switching valve 2 is turned on with the reference container La and the container Lb to be inspected attached to the pressure supply lines 10A, 10B, the test pressure is increased.
Via 10B, it supplies to reference container La and container Lb to be inspected. Then, after the supply pressure is stabilized, the electromagnetic switching valves 12A and 12B are simultaneously turned on and closed to make the pressure supply lines 10A and 10B closed systems independent of each other.

The control unit 60 starts air leak measurement when a predetermined waiting time has elapsed since the pressure supply lines 10A and 10B were closed. During this waiting time, a pressure fluctuation unrelated to the air leak, that is, a pressure fluctuation due to a decrease in heat of compression, deformation of the sealing material of the electromagnetic switching valves 12A and 12B, and the like occur. . However, as a result of this pressure fluctuation, even if there is no air leak, the pressure supply lines 10A, 10A
Since a differential pressure may occur in B, the zero point correction is performed so that the output voltage of the pressure sensor 5 at this time indicates zero differential pressure.

Then, a differential pressure detected by the pressure sensor 5 (a change in the differential pressure during the measurement time) when a predetermined measurement time has elapsed from the zero point correction time (measurement start time) is read, and an air leak is measured. If the detected differential pressure remains zero, it can be seen that there is no air leak in the container Lb to be inspected. If the inspected container Lb has a defect exceeding the allowable limit,
An air leak occurs and the detected differential pressure increases. In this case, a buzzer sounds to notify that the container Lb to be inspected is a rejected product.

The quality judgment in this embodiment will be described in more detail. An atmospheric pressure conversion air leak amount is calculated from the detected differential pressure and the test pressure detected by the auxiliary pressure sensor 6, and the atmospheric pressure conversion air leak amount is calculated per unit time of an allowable limit input from the input device 65. The air quality is compared with a threshold value (corresponding to the permissible value of the detected differential pressure) obtained by multiplying the air-equivalent air leak amount by the measurement time. As described above, since the measurement of the air leak is performed after waiting for a predetermined time from the closing of the pressure supply lines 10A and 10B, accurate measurement can be performed, and the quality of the container Lb to be inspected can be accurately determined.

Finally, the electromagnetic switching valves 2, 12A and 12B are simultaneously turned off and the reference container La and the container Lb to be inspected are released to the atmosphere, thereby completing the test mode. Thereafter, the container Lb to be inspected is detached from the joint 11B, a new container Lb to be inspected is attached, and the test is performed again.

The waiting time in the test mode is determined as follows. The container Lb to be inspected, which has been confirmed to have no leakage, is connected to the pressure supply line 10B, and the reference container La is connected to the pressure supply line 10A. In this state, when the switch for the waiting time determination mode is turned on, the control unit 60 starts execution of the waiting time determination mode, turns on the solenoid valve 2 in the same manner as in the test mode, and turns on the pressure supply lines 10A and 10B. Is supplied with the test pressure.

After the pressure supply lines 10A and 10B are stabilized at the test pressure, the control unit 60 turns on the electromagnetic switching valves 12A and 12B to turn on the pressure supply lines 10A and 10B.
B is closed and the pulse motor 3
5 is driven to move the piston 21 of the air cylinder 20 at a constant speed, thereby increasing the volume of the air cylinder 20 at a constant speed. That is, the pulse motor 35 rotates at a constant speed, and the rotation of the pulse motor 35 is
When the screw bar 42 and the moving member 45 are screwed together, the moving member 45 linearly moves, and the linear movement of the moving member 45 is transmitted to the piston 21 via the rod 46 and the connecting member 47.

The moving speed S of the piston 21 is determined by the following equation so that the pseudo leak from the air cylinder 20 becomes the allowable limit air leak amount Vx per unit time by the input device 65. S = {Vx · P ′ / Pt} / A where S is the moving speed of the piston 21, P ′ is the atmospheric pressure,
Pt is a test pressure detected by the pressure sensor 6, and A is a cross-sectional area of the piston 21.

When the piston 21 is moved at a constant speed as described above, the volume of the air cylinder 20 increases linearly (increases at a constant speed), and accordingly, the differential pressure detected by the pressure sensor 5 also increases linearly. It should change. By the way, in the waiting time determination mode, similarly to the test mode, pressure fluctuations occur due to a decrease in heat of compression and deformation of the sealing material of the electromagnetic switching valves 12A and 12B, and therefore, as shown in FIG. Disturbed. Then, after the pressure fluctuation is eliminated, the detected differential pressure changes linearly in response to only the pseudo leak from the air cylinder 20.

In FIG. 4, the symbol t0 indicates the electromagnetic switching valve 12
A and 12B indicate a closing time point, and a symbol t1 indicates a time point at which the detected differential pressure starts to change linearly. The control unit 60
A built-in timer measures the time Δt from the closing time t0 to the start time t1 of the linear change. The measurement time Δt is a minimum time required for performing an accurate air leak measurement. The control unit 60 calculates the measurement time Δ
The waiting time in the test mode is t or a time obtained by adding a predetermined margin time to the time t. At this time, it is also checked whether or not the linear change in the differential pressure corresponds to the atmospheric pressure-converted air leak amount per unit time of the permissible limit, and the waiting time is finally determined.

As described above, by utilizing a certain amount of pseudo leakage per unit time by the air cylinder 20,
The waiting time in the test mode can be accurately determined by a simple process. In addition, at the time of the pseudo leakage of the air cylinder 20, a change in the differential pressure corresponding to FIG. 4 may be displayed on the display device 50, and the tester may visually determine the change and determine the waiting time.

Next, the diagnostic mode will be briefly described. This diagnostic mode is performed periodically, for example, about once every three months. The container Lb to be inspected which has been confirmed to have no leakage is connected to the pressure supply line 10B, and the reference container L
a to the pressure supply line 10A. In this state, when the switch for the diagnostic mode is turned on, the control unit 60 starts the execution of the diagnostic mode, turns on the solenoid valve 2 as in the test mode, and turns on the pressure supply lines 10A, 1A.
After the test pressure is supplied to the solenoid-operated switching valves 12A,
Close 12B.

Next, as in the waiting time determination mode,
The air cylinder 20 is driven to generate a pseudo leak so that an allowable atmospheric pressure equivalent air leak amount per unit time is obtained. Then, similarly to the test mode, the zero point is corrected when the waiting time has elapsed, and then the differential pressure after the predetermined measuring time has elapsed is detected. Whether or not the system includes the pressure sensor 5 is diagnosed by checking whether or not it is not. In this diagnostic mode, a change in the differential pressure may be displayed on the display device 50 to check whether or not a linear change corresponding to the pseudo leak has occurred.

Next, a second embodiment of the present invention will be described. In this embodiment, there is no setting of the waiting time. In the test mode, similarly to the above, after the test pressure is supplied to the reference container La and the container Lb to be inspected via the pressure supply lines 10A and 10B, the electromagnetic switching valves 12A and 12B are supplied.
B are simultaneously turned on and closed, and the pressure supply lines 10A, 10A
B is a closed system independent of each other. The control unit 6
0 reads the differential pressure detected by the pressure sensor 5 after the pressure supply lines 10A and 10B are closed. As described above, the detected differential pressure changes non-linearly at first, and then changes linearly according to the degree of the scratch on the container Lb to be inspected. Is also a linear change area).

The control unit 60 monitors the detected differential pressure, ignores the data in the non-linear region, and calculates the air leak amount using the data after the start of the linear change.
At this time, by using data of a relatively short monitoring time (for example, 2 seconds) after the start of the linear change, an air leak amount is calculated for a predetermined time (for example, 10 seconds) longer than the monitoring time. The estimated air leak amount is determined by the first
It is preferable that the air leak amount be converted into the atmospheric pressure as in the embodiment, but the air leak amount may be the test pressure. The pass / fail judgment using the air leak amount calculated and calculated is the same as in the first embodiment.

As described above, the arithmetic unit 6 of the control unit 60
2 performs a prediction operation, and therefore requires a strict performance check. Therefore, the same diagnostic mode as in the first embodiment is executed. That is, the container Lb to be inspected, which is confirmed to have no leakage, is connected to the pressure supply line 10B, the reference container La is connected to the pressure supply line 10A, and the electromagnetic valve 2 is turned on to connect the pressure supply lines 10A, 10B. After supplying the test pressure, the electromagnetic switching valves 12A and 12B are closed.

Next, the air cylinder 20 is driven to generate a pseudo leak so as to obtain an allowable air leak amount per unit time of an allowable limit. In this process, the calculation unit 62 predicts and calculates the atmospheric pressure-converted air leak amount for a predetermined time in the same manner as in the test mode. If the calculation unit 62 is normal, this calculation result should match the atmospheric pressure converted air leak amount obtained by multiplying the atmospheric pressure converted air leak amount per unit time by the driving of the air cylinder 20 by a predetermined time. Thus, the pressure sensor 5 and the calculation unit 62
Can be checked.

The present invention is not limited to the above embodiment, and various modes are possible. For example, in the first embodiment, the first
Even when the air cylinder 20 is connected to the pressure supply line 10A, the same operation and effect as described above can be obtained. In the pressure supply lines 10A and 10B of the first and second embodiments, a normally open manual switching valve may be provided downstream of the electromagnetic switching valves 12A and 12B. In this case, in the waiting time determination mode and the diagnosis mode, the manual switching valve is closed, and the connection of the reference container and the container to be inspected is omitted. In the first and second embodiments,
The air leak tester need not be a differential pressure type. in this case,
The pressure supply line 10A is omitted, and the pressure sensor 5 detects the pressure of the pressure supply line 10B. The test pressure may be a negative pressure. In this case, the piston 21
The air cylinder 20 is moved in a direction to reduce the volume. In the first embodiment, in the waiting time determination mode, the atmospheric pressure-converted air leak amount is calculated from the detected pressure and the detected differential pressure of the pressure sensor, and the calculated value is monitored. Until the calculated value starts to change linearly. May be measured. This is substantially the same as measuring the time until the detected pressure and the detected differential pressure start to change linearly.

[0038]

As described above, according to the first, second, fifth and sixth aspects of the present invention, the piston of the air cylinder is moved at a constant speed, and the air cylinder and its connection relationship are moved. In the state where the volume of the closed system including the pressure supply line in the above is changed at a constant speed, the time until the pressure or the differential pressure detected by the pressure sensor starts to change linearly is measured, and based on this measurement time, Since the waiting time in each mode is determined, the waiting time determining operation can be completed by a very simple process. According to the third and fourth aspects of the present invention, it is possible to easily and strictly check a calculation unit that predicts and calculates an air leak amount.

[Brief description of the drawings]

FIG. 1 is an overall view of an air leak tester according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an air cylinder and moving means incorporated in the air leak tester.

FIG. 3 is a block diagram of a control system of the air leak tester.

FIG. 4 is a diagram showing a change in a detected differential pressure in a waiting time determination mode executed by the air leak tester.

[Explanation of symbols]

 Reference Signs List 1 air pressure source 5 pressure sensor 10A first pressure supply line 10B second pressure supply line 12A, 12B electromagnetic switching valve (valve) 20 air cylinder 21 piston 30 moving means 60 control unit (computation control means) 62 computing section La Reference container (master work) Lb Container to be inspected (work to be inspected)

Claims (6)

[Claims] In a test mode, when a test pressure is supplied to a pressure supply line communicating with a workpiece to be inspected, the pressure supply line is closed, and when a predetermined waiting time elapses after the pressure supply line is closed, the pressure is reduced. In the air leak test method for starting the air leak measurement of the work to be inspected based on pressure information from a pressure sensor connected to a supply line, the test pressure is applied to the pressure supply line and closed in the same manner as in the test mode. The piston of the air cylinder connected to the pressure supply line is moved at a constant speed, and the time from when the pressure supply line is closed until the pressure detected by the pressure sensor starts to change linearly is measured. And determining the waiting time in the test mode based on the air leak test method. The waiting time determined how. 2. In a test mode, when a test pressure is supplied to a first pressure supply line leading to a master work having no leakage and a second pressure supply line leading to a work to be inspected, these pressure supply lines are closed. When a predetermined waiting time has elapsed since the closing of the pressure supply line, the above-mentioned pressure-sensitive object is detected based on differential pressure information from a pressure sensor connected between the first pressure supply line and the second pressure supply line. In the air leak test method for starting an air leak measurement of an inspection work, the test pressure is applied to the first and second pressure supply lines to close them in the same manner as in the test mode, and the first and second pressure supply lines are closed.
The piston of the air cylinder connected to one of the pressure supply lines is moved at a constant speed, and the time from when the pressure supply line is closed to when the differential pressure detected by the pressure sensor starts to change linearly is measured. Determining the waiting time in the test mode based on the measured time. 3. In a test mode, after the pressure supply line is closed while a test pressure is being supplied to a pressure supply line communicating with a workpiece to be inspected, detection by a pressure sensor connected to the pressure supply line is performed by a calculation unit. An air leak test method for monitoring pressure and predicting and calculating an air leak amount for a predetermined time longer than a monitoring time in the linear change area based on data in an area where the detected pressure changes linearly. Close by applying test pressure,
The piston of the air cylinder connected to the pressure supply line is moved at a constant speed. In this process, it is determined whether or not the amount of air leak calculated by the calculation unit matches the pseudo leak amount expected by the piston movement of the air cylinder. A method of checking an arithmetic unit in an air leak test method, characterized in that: 4. In a test mode, these pressure supply lines are closed while a test pressure is supplied to a first pressure supply line leading to a master work having no leakage and a second pressure supply line leading to a work to be inspected. Thereafter, the arithmetic unit monitors the differential pressure detected by the pressure sensor connected between the first pressure supply line and the second pressure supply line, and monitors the differential pressure in an area where the detected differential pressure changes linearly. An air leak test method for predicting and calculating an air leak amount for a predetermined time longer than the monitoring time in the linear change region based on the data, wherein the test pressure is applied to the first and second pressure supply lines, and the first and second pressure supply lines are closed. The piston of the air cylinder connected to the second pressure supply line is moved at a constant speed. Computing section check method in the air leak test method characterized by checking whether matching the expected pseudo leak amount by the piston movement of Sunda. 5. A pressure supply line communicating with a workpiece to be inspected, an air pressure source for supplying a test pressure to the pressure supply line, a valve provided on the pressure supply line, and a pressure connected to the pressure supply line. In the test mode, the sensor is closed in a state where the test pressure from the air pressure source is applied to the pressure supply line, and when a predetermined waiting time elapses after the pressure supply line is closed due to the valve closing, And an arithmetic control means for starting air leak measurement of the work to be inspected based on pressure information from a pressure sensor. An air leak tester comprising: an air cylinder connected to the pressure supply line; and a piston of the air cylinder. Moving means for moving at a constant speed in the axial direction, wherein the arithmetic control means includes a waiting time determination mode in addition to the test mode. In the waiting time determination mode, in the state where the test pressure is applied to the pressure supply line, the valve is closed to close the pressure supply line, and the moving means is driven to drive the piston of the air cylinder. Move at a constant speed, measure the time from when the pressure supply line is closed to when the detected pressure of the pressure sensor starts to change linearly, and determine the waiting time in the test mode based on this measured time. An air leak tester characterized in that: 6. A first pressure supply line communicating with a master work, a second pressure supply line communicating with a work to be inspected, an air pressure source for applying a test pressure to the first and second pressure supply lines, A valve provided on each of the first and second pressure supply lines; a pressure sensor for detecting a pressure difference between the first and second pressure supply lines; With the test pressure from the air pressure source applied to the first and second pressure supply lines, the valves provided on the pressure supply lines are simultaneously closed, and the first and second pressure supply lines associated with the closing of these valves are provided. An air leak tester comprising: an arithmetic control unit that starts measuring an air leak of the work to be inspected based on differential pressure information from the pressure sensor when a predetermined waiting time has elapsed since the closing of the air leak tester. An air cylinder connected to one of the first and second pressure supply lines; and a moving unit that moves a piston of the air cylinder at a constant speed in the axial direction. In addition to the test mode, a wait time determination mode is also executed. In the wait time determination mode, the valve is closed by applying the test pressure to the first and second pressure supply lines and closing these valves. The line is closed, the moving means is driven to move the piston of the air cylinder at a constant speed, and the time from when the pressure supply line is closed to when the differential pressure detected by the pressure sensor starts to change linearly is measured. , Based on this measurement time,
An air leak tester for determining a waiting time in the test mode.