JP2002031581A - Air tightness testing device of piping and vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air tightness testing device of piping and a vessel capable of determining automatically with high precision and high efficiency. SOLUTION: Compressed air is supplied by an air compressor 3 into a work 1a to be tested and a pressure proof test is executed, and then a process for depressurizing the inside of the work 1a to be tested by a vacuum pump 2 is added, and the degree of vacuum in the test space kept in the depressurized state is measured by a vacuum pressure sensor 5, to thereby execute the air tightness test of the work 1a to be tested. Hereby, temperature dependency of the pressure by gas molecules in the test space is reduce, to improve determination precision of the air tightness test. A work 1b to be tested is similarly tested in parallel with a time difference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has at least one or more openings such as a heat exchanger such as a water heater using a water pipe heated from the outside by a burner and a container for storing liquid or gas. Equipment for testing whether the internal space surrounded by the structure is airtight with the external space except for the opening,
In particular, the present invention relates to an improved pipe / container airtightness test apparatus for improving the accuracy and efficiency of an airtightness test.

[0002]

2. Description of the Related Art For example, in an airtightness test of a conventional water heater pipe, a water heater pipe, which is a work to be tested, is placed in a water tank.
A pressure test of the water heater pipe was performed by pumping high-pressure air into the water heater pipe, and an airtightness test was performed by visually inspecting the presence or absence of bubbles leaking into the water tank. According to this method, the airtightness inspection and the pressure resistance test can be performed at the same time, and if there is a hole in the welded part, the defective part can be identified depending on the location of the air bubbles. In addition to the deterioration and the necessity of drying the work to be tested, the biggest problem was that it was not suitable for automatic testing.

As an airtightness test apparatus that does not use a water tank, for example, a method and an apparatus for airtightness inspection of a high-pressure gas container disclosed in JP-A-2000-2615 are known.
Helium gas and air are sealed at a predetermined pressure in a high-pressure gas container, which is a work to be tested, installed in a chamber, which is a test facility, and the chamber is evacuated. This is detected by a leak detector. According to this method, there is a problem that a sample gas as a consumable is required, a work to be tested is taken in and out of the chamber and a sealing process is required, and a defective portion cannot be specified.

To reduce the consumption of the sample gas, a high-pressure air is applied to the work (assembly) to be tested, for example, as described in Japanese Patent Application Laid-Open No. 63-66433, "pressure and airtightness inspection method". After the pressure test was performed by pumping the workpiece, the work under test (assembly) was housed in a closed casing as an inspection facility, and the work under test (assembly) was introduced into the closed casing by evacuating the inside. The intrusion of helium gas into the work under test (assembly) is detected by a gas leak detector. Even in this case, the need for the sample gas as the detection means and the closed container as the test equipment remains unchanged.

[0005] As a test apparatus which does not use a water tank or a sample gas, for example, a compressed gas is supplied to a master having no inspection object and no leak as in a "gas leak inspection method" disclosed in Japanese Patent Application Laid-Open No. 10-300244. The test object is held, and the presence or absence of air leakage of the inspection object is determined by detecting the pressure difference between the two.

[0006]

As described above, the conventional pneumatic airtightness test apparatus has the feature that it can also serve as a pressure test of the container, but the pressure in the container is gas (air) in the container. There is a problem that it is proportional to the temperature and inversely proportional to the internal volume of the container, so that accurate temperature measurement and correction calculation of the detected pressure based on the volume information are indispensable. However, for example, there is a problem that the internal temperature of the work to be tested on which the welding operation has been performed in the previous process is not uniform, and a long waiting time is required to perform accurate calculation and correction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to use a system that does not use a water tank or a material gas, and is capable of controlling the temperature of a work to be tested. An object of the present invention is to provide a highly accurate pipe / container airtightness test apparatus which is not affected. The second purpose is
An object of the present invention is to provide a pipe / container airtightness test apparatus which can improve efficiency of an airtightness test, facilitate identification of a defective portion, and realize multifunctional facilities such as a pressure resistance test as necessary. .

[0008]

According to a first aspect of the present invention, there is provided an airtightness test apparatus for piping and containers, comprising: an air compressor for feeding high-pressure air into a test space surrounded by a work under test; An air pressure sensor for measuring the internal pressure, pressure resistance determining means for performing a pressure test of the work under test by comparing a pressure measurement value by the air pressure sensor with a predetermined pressure resistance value, and a pressure reducing means for reducing the air pressure in the test space. A vacuum pump and a vacuum pressure sensor for measuring the degree of vacuum in the test space, and measuring the degree of vacuum in the test space held under reduced pressure,
An airtightness determining operation unit for performing an airtightness test of the work under test.

[0009] In a second aspect of the present invention, the pipe / vessel airtightness test apparatus further comprises a scavenging step of drying the test space with a dryer after the pressure resistance test.
Subsequently, the test space is decompressed to perform the airtightness test.

In a third aspect of the present invention, there is provided an airtightness test apparatus for piping and containers according to the first or second aspect of the present invention, wherein the workpiece to be tested has a plurality of openings. A pressurized air is supplied from one opening of the work, an air pressure sensor is provided in the other opening and the outlet thereof is closed, and in the airtight test, depressurized exhaust is performed from both openings of the work to be tested. is there.

[0011] Further, according to a fourth aspect of the present invention, there is provided a pipe / container airtightness test apparatus according to any one of the first to third aspects, which performs a pressure test and an airtightness test of a first workpiece to be tested. A second station for performing a pressure test and an air tightness test of the second workpiece to be tested, and an interlock means for prohibiting a temporal overlap between the pressure test and the air tightness test with each other. .

[0012] Further, in the pipe / container airtightness test apparatus according to the invention of claim 5, in the invention of any one of claims 1 to 4, the apparatus for testing a work under test determined to be defective in a pressure resistance test or an airtightness test is provided. The test space surrounded by the work under test is filled with pressurized air, and the in-line search means for detecting a defective portion by monitoring the expansion change of the test solution applied to the outer peripheral surface of the work under test is added. It is.

[0013] An airtightness test apparatus for piping and containers according to a sixth aspect of the present invention includes a vacuum pump for reducing the air pressure in a test space surrounded by a work under test, and a vacuum pump for reducing the degree of vacuum in the test space. A vacuum pressure sensor to be measured, and arithmetic means for comparing a vacuum pressure in the test space after elapse of a predetermined time after being held under reduced pressure or an increment value of the vacuum pressure with a threshold value corresponding to the volume of the test space. The airtightness of the work to be tested is determined based on the change characteristics of the vacuum pressure after the reduced pressure is maintained.

According to a seventh aspect of the present invention, in the airtightness test apparatus for piping and containers according to the sixth aspect of the present invention, the increment of the vacuum pressure is measured after a predetermined standby time after the reduced pressure is maintained. The difference between the first vacuum pressure and the second vacuum pressure measured at a time point further extended from the measurement time point of the first vacuum pressure.

According to an eighth aspect of the present invention, in the piping / container airtightness test apparatus according to the sixth or seventh aspect, the threshold value corresponding to the volume of the test space is determined by the type information of the work under test. The setting is changed by threshold setting means in proportion to the volume based on the threshold value.

Further, according to a ninth aspect of the present invention, there is provided an airtightness test apparatus for piping and containers according to any one of the first to eighth aspects, wherein the air pressure sensor for measuring compressed air pressure or the vacuum pressure sensor for measuring vacuum pressure is provided. For a test space surrounded by the provided work under test, a calibration volume of a predetermined volume is coupled, and a detection value change amount measurement unit that measures a detection value change amount of the air pressure sensor or the vacuum pressure sensor, Volume change rate calculating means for calculating the volume change rate of the test space, and comparing the detected value change amount with the volume change rate to determine whether a measurement error of the air pressure sensor or the vacuum pressure sensor exceeds a predetermined value. And an abnormality determining means for determining.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a mechanism block diagram showing Embodiment 1 of the present invention. In the drawing, reference numerals 1a and 1b denote a first work A to be tested and a second work B to be tested, respectively, and these works to be tested have right openings Pipe and Plb, which are one opening, and another opening. A certain left pipe P2a, P2b is welded and integrated, and the left and right openings communicate with each other.

Cla and C2a are first workpieces 1a to be tested.
The right and left electromagnetic chucks connected to the openings Pla and P2a are connected to a first station 8a to be described later via right and left hoses Hla and H2a as described later in FIG. It is connected. C1
b and C2b are openings Plb. of the second workpiece 1b to be tested.
Right and left electromagnetic chucks connected to P2b.
These electromagnetic chucks are connected to a second station 8b to be described later via right and left hoses Hlb and H2b as described later in FIG.

Vla and V4a are right and left decompression solenoid valves. One of the vent ports of each of these solenoid valves is connected to the vacuum pump 2, and the other is a hose via right and left filters F1a and F2a. The pipe is connected to Hla · H2a. Similarly, Vlb and V4b are right and left decompression solenoid valves. One of the vent ports of each of these solenoid valves is connected to the vacuum pump 2, and the other is a hose via right and left filters Flb and F2b. Hlb ・ H2
b is connected to a pipe.

V2a and V2b are pressurized solenoid valves. One of the vent ports of these pressurized solenoid valves is connected to the air compressor 3 via a dryer 4, and the other is connected via a right filter Fla / Flb. Right side hose Hla ・ H
1b. The dryer 4 is composed of a dehumidifying polymer filter and includes a regulator for adjusting the air pressure. V3a and V3b are open solenoid valves connected to pipes between the silencers Sa and Sb and the left filters F2a and F2b, and the solenoid valves with the reference numeral a constitute the first station 8a,
The one with the symbol b constitutes the second station 8b.

V5a and V5b are switching solenoid valves for connecting the vacuum pressure sensor 5 to the left hose H2a or H2b via the left filter F2a or F2b, and V6a and V6b.
Is a switching solenoid valve that connects the air pressure sensor 6 to the left hose H2a or H2b via the left filter F2a or F2b, and Vc is the calibration volume 7 connected to the left filter F2b.
The solenoid valve is a calibration solenoid valve connected to the left hose H2b via a line, and these solenoid valves, sensors, pumps, compressors, and the like are common equipment for the first and second stations 8a and 8b.

FIG. 2 shows the electromagnetic chucks Cla and C2 of FIG.
FIG. 3A is a mechanism diagram showing details of Clb · C2b. In the figure, reference numeral 10 denotes a right pipe Pla / Plb or a left pipe P
One end of each of these pipes is welded and fixed to the right and left sides of the first and second workpieces to be tested, and the other end forms an end face 11.

Reference numeral 12 denotes a hose representative of the right hoses Hla and Hlb and the left hoses H2a and H2b. One end of each of these hoses is fixed to a block 14 having a communication hole 13, and the other end is a first and second station. 8a and 8b (FIG. 1). 15 is an air cylinder for pressing the block 14 against the end face 11 of the pipe, 16 is an annular elastic body fixed to the end face of the block 14, 17 is a mounting plate for integrating the air cylinder 15, the block 14, and the hose 12, The end of the pipe 10 is detachably engaged with the notch 17 a of the mounting plate 17.

The hose 12 is made of, for example, a bellows-type flexible pipe made of stainless steel, which flexes flexibly but does not cause a change in internal volume. Further, the hose 12 and the pipe 10 are air-coupled through the communication hole 13, and the airtightness is maintained by the elastic body 16 being pressed against the end face 11 of the pipe.

FIG. 3 is a connection diagram showing inputs and outputs of various control devices in FIG. In the figure, reference numeral 18 denotes a controller with a built-in microprocessor and memory (not shown),
Reference numeral 19 denotes a digital switch for supplying the type information of the work to be tested to the controller 18, for example, DSP denotes a display alarm device such as a graphic display serially connected to the controller 18, and 5A and 6A denote vacuum pressure sensors 5.
And the detection signal of the air pressure sensor 6 is amplified and used as a control signal in the controller 18, or the display / warning device DSP
These amplifiers have a bias adjustment function and a gain adjustment function.

STa and STb are pressed in a predetermined control step, so that the left and right electromagnetic chucks Cla and C
Start button for driving solenoid valves VCla.VC2a and VClb.VC2b for 2a and Clb.C2b, SP
a and SPb are pressed in a predetermined control step, so that the left and right electromagnetic chucks Cla.C2a and Clb.C
Solenoid valves VCla.VC2a and VClb.VC2 for 2b
b, a stop button for disabling, Sla and Slb are limit switches for confirming the operation of the right electromagnetic chucks Cla and Clb, and S2a and S2b are left electromagnetic chucks C2a and C2
2b are operation limit switches WSa and WSb, which are limit switches for confirming that the first and second workpieces 1a and 1b are mounted on the test stand. Connected to input terminal. Further, all the solenoid valves described above are connected to the output terminal of the controller 18.

Next, an outline of the operation and operation will be described with reference to the time chart of FIG. In the figure, the vertical axis represents the atmospheric pressure in the work under test 1a or 1b (hereinafter collectively referred to as 1. The other symbols are similarly omitted by omitting the symbols a and b), and the horizontal axis is the time axis. T1 indicating the withstand voltage test process
In the period, after the work 1 to be tested is attached in advance, the solenoid valve V
When the solenoid valves 2 and V6 are opened (the other solenoid valves V1 and V3 to V5 are closed. Similarly, the solenoid valves V1 to V6 other than the designated solenoid valves are closed), the air compressor 3 → the dryer 4
→ Pressure solenoid valve V2 → Right filter F1 → Right hose H1
→ Right electromagnetic chuck C1 → Pressurized air is supplied into work under test 1 via right pipe P1, and after passing through work 1, left pipe P2 → left electromagnetic chuck C2 →
Left hose H2 → left filter F2 → switching solenoid valve V6 →
The air pressure in the test space surrounded by the work 1 to be tested reaches the air pressure sensor 6.

One atmosphere = 760 mmHg = 101.3
Respect KPa = 1.03Kg / cm ^2, the outlet air pressure dryer 4 is an example 5Kg / cm ^2, the threshold for determining the acceptability of the test workpiece 1 has a 4.5 Kg / cm ^2. If the work under test 1 has an abnormal defect, a serious air leak occurs from the work 1 and the threshold value is not reached. It does not check for airtightness.

In the period T2 indicating the scavenging process, the solenoid valve V2
V3 is opened and the dry air from the dryer 4 is pressurized solenoid valve V2 → workpiece under test 1 → open solenoid valve V3 → muffler S
The work 1 under test 1 is dehumidified by being released into the atmosphere through the air. This dehumidifying operation is a useful operation for shortening the time required for evacuation in the subsequent process and improving the accuracy of measuring the vacuum pressure. The scavenging step T
In the two periods, the atmosphere opening solenoid valve V3 is opened, and a check valve (not shown) is incorporated in the solenoid valve V3.
The high humidity atmosphere is prevented from flowing from the silencer S to the work 1 under vacuum.

In a period T3 indicating the vacuum evacuation step, the solenoid valves V1, V4 and V5 are opened, and the test space in the work 1 to be tested is depressurized by the vacuum pumps 2 from the left and right depressurizing solenoid valves V1, V4. The vacuum pressure sensor 5 operates via the valve V5. In the final stage of evacuation, the degree of vacuum in the test space is a high degree of vacuum of, for example, 0.3 Pa, but this is to prevent the measurement pressure from being affected by temperature by eliminating gas molecules. belongs to.

In the period T4 indicating the standby / detection step, only the switching solenoid valve V5 is open, and the vacuum pressure in the test space held in vacuum is measured by the vacuum pressure sensor 5. In a few seconds (standby time) immediately after the vacuum is held, the vacuum pressure rapidly rises, and the first vacuum pressure Pa1 in FIG. 4 rises, for example, to a level of 5 to 10 Pa, but the second vacuum pressure elapses about 10 seconds further. The vacuum pressure Pa2 is Pa2 = Pa1 + (2
4) Increase to Pa level. This is due to the gas flowing out from the work under test 1 even if the airtightness is completely maintained, and the amount of gas release varies depending on the material of the work under test 1 and the volume of the test space. Note that the airtightness test period described later indicates the entirety of the period of the evacuation step T3 and the period of the standby / detection step T4.

In a period T5, which indicates the process of releasing to the atmosphere, the solenoid valve for opening to the atmosphere V3 is opened, and a check valve (not shown) is incorporated in the solenoid valve V3. Air is prevented from flowing into the work 1. Therefore, the pressurized solenoid valve V2 is temporarily opened, and the air compressor 3 → dryer 4 → pressurized solenoid valve V3 is opened.
→ Work under test 1 → Open solenoid valve V3 → Muffler S → Vacuum in work under test 1 is released by release into the atmosphere, and then pressurized solenoid valve V2 is closed, so that the inside of work under test 1 is at atmospheric pressure. To return to. T indicating the desorption process
In the six periods, all the solenoid valves V1 to V6 are in the inoperative / closed state, and the work under test 1 is replaced in a manner described later.

Next, the operation of one station will be described.
This will be described with reference to the flowchart of FIG. In the figure,
Reference numeral 20 denotes an operation start step. When the work 1 to be tested is mounted and the start button ST is pressed in a manner described later, the processing shifts to step 21. In step 21, the work detection limit switch W
The operation of the limit switches S1 and S2 for confirming the operation of the electromagnetic chuck S and the left and right electromagnetic chucks is confirmed. Then, in step 22 (interlock means), it is monitored whether or not the other station is under a pressure test. If so, the process waits in step 22. When the pressure test of the partner station is completed, the process proceeds to step 23. In step 23, the pressurizing solenoid valve V2 and the switching solenoid valve V6 for the air pressure sensor are opened, and high-pressure air is pumped into the work 1 under test. Then, the process proceeds to step 24 (withstand voltage determination means). In step 24, after waiting for a predetermined time, it is determined whether or not the detected value of the air pressure sensor 6 is equal to or higher than a predetermined threshold. If the air pressure is not sufficient, the process proceeds to step 25 (search step).

In step 25, when a test liquid such as a soap solution is applied to the surface of the work 1 to be tested, particularly a portion where airtightness is likely to occur such as a welded portion by a manual operation, bubbles are generated in the air leaking portion, and there is a problem. When the stop button SP is pressed here, the process proceeds to step 26. In step 26, the pressurized solenoid valve V2 is temporarily opened, and the open-to-atmosphere solenoid valve V3 is also opened to release the test space in the workpiece 1 to the atmosphere, and the process proceeds to step 27. In step 27, the stop button SP is pressed again to release the electromagnetic chuck C.
1. C2 is released, and the work under test 1 is replaced here. When the start button ST is pressed after attaching the new work 1 to be tested, the electromagnetic chucks C1 and C2 operate, and the process shifts to the operation start step 20 again via the end step 28.

If there is sufficient air pressure in the determination step 24 and the pressure test of the work 1 to be tested passes, the step 29
Move to (scavenging step). In step 29, the pressurized solenoid valve V2
Then, the opening electromagnetic valve V3 is operated, and the dry air passes through the test space in the work 1 under test. When the scavenging for a predetermined time is completed, the process proceeds to step 30 (interlock means). If the partner station is performing the airtight test, the process waits in step 30. If the partner station is completed with the airtight test, the process proceeds to step 31.

In step 31, the pressure reducing solenoid valves V1 and V4 are opened, the test space in the work 1 under test is evacuated by the vacuum pump 2, and after a predetermined time or when the vacuum pressure is reached, a step 32 is performed. Move to. In step 32, the evacuation is terminated, and the switching solenoid valve V5 operates to measure the vacuum pressure in the sealed test space with the vacuum pressure sensor 5, and after a predetermined time has elapsed, the process proceeds to step.

In step 34, the type information of the work 1 to be tested is read from the digital switch 19 connected to the controller 18, and the process proceeds to step 35. In step 35, the first vacuum pressure Pa1 is read and stored as the current value of the vacuum pressure sensor 5, and the process proceeds to step 36 after waiting for a predetermined time. Step 3
6, the second vacuum pressure Pa is set as the current value of the vacuum pressure sensor 5.
2 is read and stored, and the flow advances to step 37. In step 37, the increment value ΔP, which is the difference between the first and second vacuum pressures Pal and Pa2, is calculated and stored, and the process proceeds to step. Step 38
In the (threshold setting means), a threshold corresponding to the type information read in step 34 is selectively set from among thresholds corresponding to various workpieces stored in the controller 18 in advance.

In the following step 39, the increment value of the vacuum pressure stored in the step 37 is compared with the threshold value set in the step 38. If the increment value is equal to or smaller than the threshold value, the airtightness test has passed. Then, the process proceeds to step 26 described above. Step 39
If the air-tightness test fails in step, the process proceeds to step 40, but a series of steps from step 34 to step 39 constitutes the calculating means 33.

In step 40, when the stop button SP is pressed for confirmation, the pressurizing solenoid valve V2 and the opening solenoid valve V3 are operated to open the test space to the atmosphere. Move to. In step 41, if the partner station is in the withstand voltage test, the operation waits. If the withstand station test is completed, the process proceeds to step. Step 4
2, the pressurized solenoid valve V2 and the switching solenoid valve V for the air pressure sensor
6 is released, and high-pressure air is pressure-fed into the workpiece 1 to be tested, and the process proceeds to the step 25 described above.

Next, a calibration operation for confirming the accuracy of the air pressure sensor 6 and the vacuum pressure sensor 5 will be described with reference to the flowchart of FIG. In the figure, reference numeral 50 denotes an operation start step, in which the work 1 to be tested is mounted and a check button ST
Pressing c moves to step 51. In step 51, the operations of the work detection limit switch WS and the left and right electromagnetic chuck operation confirmation limit switches S1 and S2 are confirmed.
Subsequently, in step 52, it is monitored whether or not the other station is in the withstand voltage test. If the other station is in the withstand voltage test, the process stands by in step 52.

When the pressure test of the partner station is completed, the process proceeds to step 53. In step 53, the pressurizing solenoid valve V2 and the switching solenoid valve V6 for the air pressure sensor are opened, and high-pressure air is fed into the work 1 under test. Step 54 in that state
Move to. In step 54, after waiting for a predetermined time, it is determined whether or not the detection value of the air pressure sensor 6 is equal to or more than a predetermined threshold value. If the air pressure is not sufficient, the process proceeds to step 55.

At step 55, an abnormal alarm is displayed. At this point, if the stop button SP is pressed, the process proceeds to step 56.
In step 56, the pressurizing solenoid valve V2 is temporarily opened, and the open-to-atmosphere solenoid valve V3 is also opened to release the test space in the work 1 under test to the atmosphere. In step 57, the electromagnetic chucks C1 and C2 are opened by pressing the stop button SP again. At this point, the workpiece 1 to be tested is removed, and the process proceeds to the end step 58.

If there is sufficient air pressure in the judgment step 54 and the pressure test of the work 1 under test passes, a step 59 is executed.
Move to. In step 59, the type information of the work 1 to be tested is read from the digital switch 19 connected to the controller 18, and the process proceeds to step 60. In step 60 (volume change rate calculating means), the ratio of the volume V of the test space of the work 1 under test to the volume ΔV of the calibration volume 7 is ΔV /
(V + △ V) is calculated and the process proceeds to step 61.

In step 61, the calibration electromagnetic valve Vc is opened, the calibration volume 7 is connected to the test space, and the flow advances to step 62 (detection value change amount measuring means). In step 62, △ P / (P−Pc) is calculated as the ratio of the current value P of the air pressure sensor 6 before step 61 and the decrease amount 現在 P of the current value after step 61, and the process proceeds to step 63 (abnormality determination means). Transition. Here, Pc is the initial air pressure (1 atm) in the calibration volume 7.

In step 63, the volume change rate ΔV / (V + ΔV) calculated in step 60 and the pressure change rate ΔP / (P−Pc) calculated in step 62 are compared. It is determined that the air pressure sensor 6 is abnormal, and
Then, the process proceeds to step 64 if the air pressure sensor 6 is normal. The validity of the comparison is proved by the following equation.

{P = P− (PV + Pc △ V) / (V + △)
V) = (P-Pc) △ V / (V + △ V) ∴ △ P / (P-Pc) = △ V / (V + △ V)

In step 64, the pressurizing solenoid valve V2 and the opening solenoid valve V3 operate to allow dry air to pass through the test space in the work 1 under test. When the scavenging for a predetermined time is completed, the process proceeds to step 65. In step 65, the pressurizing solenoid valve V2 and the calibration solenoid valve Vc are also closed.

Subsequently, in step 66, when the calibration volume 7 having a volume suitable for the calibration check of the vacuum pressure sensor 5 is replaced and the start button ST is pressed, the process proceeds to step 67. Step 6
In step 7, if the partner station is in the airtight test, step 67
When the airtight test of the partner station is completed, the process proceeds to step 68. In step 68, the pressure reducing solenoid valve V1 · V
4 is opened, the test space in the work 1 to be tested is evacuated by the vacuum pump 2, and the process proceeds to step 69 after a predetermined time or when the vacuum pressure is reached. Step 69
Then, the vacuum evacuation is completed, and the switching solenoid valve V5 operates to measure the vacuum pressure in the closed test space with the vacuum pressure sensor 5, and after a predetermined time has elapsed, the process proceeds to step 70. Step 7
If the value is 0, the airtightness test is performed in the above-described manner. If the test is not acceptable, the process proceeds to step 55, and if the test is successful, the process proceeds to step 71 (volume change rate calculating means).

In step 71, the ratio of the volume V of the test space of the work 1 under test to the volume of the calibration volume 7 {V}
Calculate V / (V + 演算 V) and go to step 72. Step 7
In step 2, the calibration electromagnetic valve Vc is opened, the calibration volume 7 is connected to the test space, and the process proceeds to step 73 (detection value change amount measuring means). In step 73, ΔP / (Pc−P) is calculated as the ratio between the current value P of the vacuum pressure sensor 5 before step 72 and the increment ΔP of the current value after step 72, and step 74 (abnormality determination means) Move to. Here, Pc is the initial air pressure (1 atm) in the calibration volume 7.

In step 74, the volume change rate ΔV / (V + ΔV) calculated in step 71 is compared with the pressure change rate ΔP / (Pc−P) calculated in step 73. It is determined that the vacuum pressure sensor 5 is abnormal, and
Then, if the vacuum pressure sensor 5 is normal, the process proceeds to step 56. The validity of the comparison is proved by the following equation.

ΔP = (PV + Pc △ V) / (V + △ V)
-P = (Pc-P) △ V / (V + △ V) ∴ △ P / (Pc-P) = △ V / (V + △ V)

Since the calibration volume 7 is connected to the test space on the second station 8b side in FIG.
Although the calibration check operation is performed using the second station 8b, the calibration volume may be connected to both stations. The reason why the volume of the calibration volume 7 is changed between the time of the calibration check of the air pressure sensor 6 and the time of the calibration check of the vacuum pressure sensor 5 is as follows. Although the accuracy of the calibration check is improved by increasing the volume of the calibration volume 7 as much as possible, the vacuum pressure sensor 5 is capable of measuring, for example, 0.01 to 100 Pa in order to increase the measurement accuracy. If the calibration volume 7 is too large, it will exceed the measurement range of 100 Pa. Therefore, the calibration volume has a large volume within a range not exceeding the measurement range.

The air pressure sensor 6 and the vacuum pressure sensor 5 for which an abnormality has been determined must be separately removed and correctly calibrated using a calibration standard. If you set it quite strictly,
Short-term continuous use is possible as a real application.

Embodiment 2 In the first embodiment, the case where the first and second stations are operated in parallel to reduce the line tact time has been described. However, a single station may be used in view of the balance with other processes of the production line. Can be. Further, in the case of a product that does not require a pressure test, a pressure test step can be omitted, or a system in which the air conditioner 3 and the pressurized solenoid valve V2 are excluded can be constructed.

Further, when it is more convenient to perform the abnormal processing of the product completely on a separate line, the search step of applying the test liquid and checking for the presence or absence of bubbles may be omitted. In addition, when there is only one opening in the work under test, pressurization, decompression, etc. can all be performed using one opening,
If there are three or more openings, it is preferable to use a pair of openings located at remote positions as much as possible and close the middle opening to test.

Embodiment 3 Further, in the first embodiment, as the means for calculating the airtightness, the means for comparing the increment value of the vacuum pressure with the threshold value has been mainly described, but the air pressure after the evacuation for the normal work measured in advance is mainly described. Various deformation methods are conceivable for the judging means, such as judging pass / fail by pattern matching between the ascending characteristics and the ascending characteristics of the workpiece to be tested, and judging pass / fail by elapse of time from evacuation to a predetermined vacuum pressure. The point is that when the degree of vacuum is increased, the temperature dependence of the pressure caused by gas molecules is eliminated and accurate measurement is possible, but on the other hand, a small amount of gas component springs out of the material body of the work under test, and the amount Is increased in proportion to the internal volume, and a determination should be made in consideration of this.
Also, it has been described that the determination threshold is selectively set based on the product type information from data measured and stored in advance.
If the product groups have the same material and similar shape, the amount of gas generated from the material body of the work under test will be proportional to the volume of the test space. It is also possible to use the internal volume information.

Further, in the evacuation step T3 (FIG. 4), if sufficient depressurization cannot be performed even after a predetermined time has elapsed, a step of judging poor airtightness at this point is added, and the required depressurization time is reduced. It is possible to perform processing such as making it proportional to the volume of the test space or conversely increasing the target vacuum degree in the final stage of evacuation in proportion to the volume of the test space while keeping the decompression time constant. As a result, although the pressure resistance test has passed, it is possible to find in advance a poor airtightness worse than the airtightness detected in the standby / detection step T4, thereby improving efficiency.

[0058]

As described above, according to the first aspect of the present invention, an air compressor for pumping high-pressure air into a test space surrounded by a work under test and a pressure in the test space are measured. An air pressure sensor, pressure resistance determining means for performing a pressure resistance test on the work under test by comparing a pressure measurement value obtained by the air pressure sensor with a predetermined pressure resistance value, a vacuum pump for reducing the air pressure in the test space, and the test A vacuum pressure sensor for measuring the degree of vacuum in the space; and an airtightness determining operation means for measuring the degree of vacuum in the test space held under reduced pressure and performing an airtightness test on the work under test. The test and the hermeticity test are performed in separate processes.The hermeticity test measures the vacuum pressure from which the gas has been removed, thereby reducing the temperature dependence of the pressure caused by the gas molecules and improving the accuracy of the hermeticity test. There is an effect that can contribute to the improvement of efficiency and accuracy although requiring a separate step than by detecting air leakage to perform airtightness test in the process.

According to the second aspect of the present invention, a scavenging step of drying the test space with a dryer after the pressure resistance test is provided, and then the test space is depressurized to perform the airtightness test. While reducing the time required for depressurization required to achieve pressure and improving efficiency,
There is an effect that the temperature dependency of the pressure due to the residual moisture can be reduced and the accuracy of the airtight test can be further improved.

According to the third aspect of the present invention, the work under test has a plurality of openings, and in the pressure test, pressurized air is supplied from one of the openings of the work under test and the other is opened. A part of the work is provided with an air pressure sensor, the outlet of which is closed, and in the airtight test, depressurized exhaust is performed from both openings of the work to be tested. In addition to improving the planning efficiency, if abnormal clogging or the like occurs inside the work under test, even if compressed air is supplied from one opening, the air pressure of the air pressure sensor provided in the other opening Does not rise, the clogging abnormality can be determined, and the communication between the openings can be confirmed.

According to the fourth aspect of the present invention, the first station for performing the pressure test and the airtight test of the first workpiece to be tested, and the second station for performing the pressure test and the airtight test of the second workpiece to be tested. And the interlock means for prohibiting overlapping of the mutual pressure test and the airtight test in time, so that the first and second stations are operated in parallel to shorten the overall test time. Can reduce the waiting time for workers, and can share the vacuum pressure sensor and air pressure sensor for both stations, reducing equipment costs. Therefore, there is an effect that a small and inexpensive device can be used since no pressurization or decompression is performed.

According to the fifth aspect of the present invention, the work under test determined to be defective in the pressure test or the airtight test is filled with pressurized air in the test space surrounded by the work under test. An in-line search means has been added to detect the failure by monitoring the change in the expansion of the test solution applied to the outer peripheral surface of the workpiece. After specifying the location, the defective workpiece can be repaired and repaired while performing the test by replacing the workpiece with another workpiece to be tested, so that there is an effect that the inline processing can be performed without deteriorating the operation efficiency.

According to the invention of claim 6, a vacuum pump for reducing the air pressure in the test space surrounded by the work under test, a vacuum pressure sensor for measuring the degree of vacuum in the test space, and Computing means for comparing a vacuum pressure in the test space after a predetermined period of time has elapsed since the pressure was held and the increment value of the vacuum pressure with a threshold value corresponding to the volume of the test space, Since the air density of the work under test is determined based on the change characteristics of the vacuum pressure, the temperature dependence of the pressure caused by the gas molecules is reduced in determining the air density of the work under test after the vacuum pressure change characteristics after maintaining the reduced pressure. Therefore, the degree of vacuum can be sufficiently increased, and the accuracy can be further improved by taking into account the gas component that springs out of the material body of the work under test.

According to the seventh aspect of the present invention, the increment value of the vacuum pressure is determined based on the first vacuum pressure measured after a predetermined standby time after the pressure is maintained and the first vacuum pressure. Since it is the difference from the second vacuum pressure measured at the time point further extended from the measurement time point of the measurement, when determining the airtightness of the work to be tested based on the change characteristics of the vacuum pressure after holding the reduced pressure, evacuation is performed. And the pressure fluctuations caused by the opening and closing of the solenoid valve, there is an effect that the influence can be eliminated and the determination accuracy can be further improved.

According to the invention of claim 8, the threshold value corresponding to the volume of the test space is set and changed by the threshold value setting means proportional to the volume based on the type information of the work under test. In addition, it is possible to provide an airtight test apparatus that can cope with various types of workpieces to be tested, and it is possible to ensure high determination accuracy.

Further, according to the ninth aspect of the present invention, a predetermined volume is calibrated with respect to a test space surrounded by a work under test provided with an air pressure sensor for measuring compressed air pressure or a vacuum pressure sensor for measuring vacuum pressure. Detecting volume change means for measuring a change in the detected value of the air pressure sensor or the vacuum pressure sensor, a volume change rate calculating means for calculating a volume change rate of the test space, and Abnormality judgment means for judging whether the measurement error of the air pressure sensor or the vacuum pressure sensor exceeds a predetermined value by comparing the value change amount and the volume change rate is provided, so that part of the test equipment is effectively used. As a part of the test process, the accuracy of the air pressure sensor and vacuum pressure sensor can be self-checked to maintain high-quality test accuracy, and the air pressure sensor and vacuum pressure sensor can be calibrated using a reference prototype. Operation with confidence by extending the regular calibration period, there is an effect that can continue to be.

[Brief description of the drawings]

FIG. 1 is a mechanism block diagram showing Embodiment 1 of the present invention.

FIG. 2 is a mechanism diagram showing details of an electromagnetic chuck in FIG. 1;

FIG. 3 is a connection diagram showing input and output of various control devices in FIG. 1;

FIG. 4 is a time chart for explaining the operation of the first embodiment of the present invention;

FIG. 5 is a flowchart for explaining an operation of the first embodiment of the present invention;

FIG. 6 is a flowchart for explaining a calibration operation according to the first embodiment of the present invention;

[Explanation of symbols]

1a first work A under test, 1b second work B under test, 2 vacuum pump, 3 air compressor,
4 Dryer, 5 Vacuum pressure sensor, 6 Air pressure sensor, 7 Calibration volume, 8a First station, 8b Second station, Pla / Plb
Right pipe (one opening part), P2a / P2b Left pipe (the other opening), 22, 30, 41 Interlock means, 24 Withstand pressure determination means, 25 Search step, 29 Scavenging step, 33 calculation means, 38 Threshold value setting means, 60, 71 Volume change rate calculating means, 6
2, 73 Detected value change amount measuring means, 63, 74 Abnormality judging means.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noriyuki Nishio 2-6-1, Otemachi, Chiyoda-ku, Tokyo Within Mitsubishi Electric Engineering Co., Ltd. (72) Inventor Kenichi Ogura 9 Futami-cho Minami-Futami, Akashi-shi, Hyogo Prefecture 1 Taisei Corporation (72) Inventor Minami Kadomoto 9-1 Minami Futami-machi, Akashi-shi, Hyogo Prefecture Inside Taisei Corporation (72) Hideki Takano 9-1 Minami-Futami, Futami-cho, Akashi-shi, Hyogo (72) Inventor Yasuhisa Ishihara 9-1 Futami-cho Minami-Futami, Akashi-shi, Hyogo F-term (reference) 2G067 AA11 AA44 BB11 DD02

Claims (9)

[Claims] An air compressor for pumping high-pressure air into a test space surrounded by a work under test, an air pressure sensor for measuring a pressure in the test space, a pressure measurement value by the air pressure sensor and a predetermined pressure resistance Pressure determination means for performing a pressure test of the workpiece under test by comparing the values, a vacuum pump for reducing the air pressure in the test space, a vacuum pressure sensor for measuring the degree of vacuum in the test space, An airtightness test device for pipes and containers, comprising: an airtightness determining operation means for measuring the degree of vacuum in the held test space and performing an airtightness test on the work under test. 2. The piping / container according to claim 1, wherein a scavenging step of drying the test space with a dryer after the pressure resistance test is provided, and then the test space is depressurized to perform the airtightness test. Airtight test equipment. 3. The work under test has a plurality of openings, and when performing a pressure test, pressurized air is supplied from one opening of the work under test, and an air pressure sensor is provided at the other opening. The piping / container airtightness test apparatus according to claim 1 or 2, wherein the outlet is closed, and in the airtightness test, reduced pressure exhaust is performed from both openings of the work under test. 4. A first station for performing a pressure test and an airtight test of a first workpiece to be tested, a second station for performing a pressure test and an airtight test of a second workpiece to be tested, and a mutual pressure test. The pipe / container airtightness test apparatus according to any one of claims 1 to 3, further comprising an interlock means for prohibiting the airtightness test from overlapping in time. 5. A test solution in which a test space determined to be defective in a pressure resistance test or an airtightness test is filled with pressurized air in a test space surrounded by the work to be tested and applied to an outer peripheral surface of the work to be tested. 5. The airtightness test apparatus for piping and containers according to claim 1, further comprising an in-line search means for detecting a defective portion by monitoring a change in expansion of the pipe. 6. A vacuum pump for reducing air pressure in a test space surrounded by a workpiece to be tested, a vacuum pressure sensor for measuring a degree of vacuum in the test space, and a predetermined time has elapsed since the reduced pressure was maintained. Computing means for comparing the vacuum pressure in the test space or the incremental value of the vacuum pressure with a threshold value corresponding to the volume of the test space. An airtightness test device for piping and containers, characterized in that the airtightness of a pipe is determined. 7. The increment value of the vacuum pressure is a first vacuum pressure measured after a predetermined waiting time after being maintained under reduced pressure, and further extended from a time point of measurement of the first vacuum pressure. 7. The pipe / container airtightness test apparatus according to claim 6, wherein the difference is a difference from a second vacuum pressure measured at a time point. 8. The apparatus according to claim 6, wherein the threshold value corresponding to the volume of the test space is set and changed by threshold value setting means proportional to the volume based on the type information of the workpiece under test. Item 8. An airtightness test device for piping and containers according to Item 7. 9. A calibration volume having a predetermined volume is connected to a test space surrounded by a test object provided with an air pressure sensor for measuring compressed air pressure or a vacuum pressure sensor for measuring vacuum pressure, and A detection value change amount measuring means for measuring a detection value change amount of the sensor or the vacuum pressure sensor, a volume change rate calculating means for calculating a volume change rate of the test space, and comparing the detected value change amount and the volume change rate. The piping according to any one of claims 1 to 8, further comprising abnormality determination means for determining whether a measurement error of the air pressure sensor or the vacuum pressure sensor exceeds a predetermined value. -Container airtightness test equipment.