JPS5920093B2 - Leakage measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a leakage amount measuring device that measures the amount of fluid leaked from an object to be measured, such as a medical rubber glove or a gas container, when fluid is pressurized.

In general, defects such as holes and pinholes in medical rubber gloves, gas containers, etc. can cause serious problems, so strict leakage tests are required.

However, conventional leak testing of this type of object to be measured requires a long time and has extremely low work efficiency. FIG. 1 shows a conventional leakage measuring device. In the figure, a pressure source 1 is connected to a regulator 2 that sets the compressed air generated by the pressure source 1 to a predetermined pressure. The equipment storage chamber 8 of the leakage measuring device T is connected. The reference tank 9 of this leak measuring device T is connected to a position intermediate between the valves 4 and 5, so that a predetermined pressure is applied to the reference tank 9. A balance mechanism 11 having a bell cup 10 configured by inverting a bottomed container at one end is housed in the equipment storage chamber 8 of the leakage measuring device T, and a balance mechanism 11 is housed at the other end of the balance mechanism 11. A differential transformer 12 for measuring the displacement of , and a control coil 13 for setting the balance mechanism 11 at a predetermined position are provided.

The lower end opening of the bell cup 10 is located in the liquid of the liquid-sealed container 14, and the inside of this liquid-sealed bell cup 10 is connected to the reference tank 9 through a communication hole 15. An object to be measured IT is connected to an intermediate position between the pressure gauge 3 and the valve 4 via a valve 16 .

An atmospherically open pulp 18 is connected to an intermediate position between the object to be measured IT and the pulp 16, and an intermediate position between the pulps 5 and 6 is connected via the pulp 19 and a pressure switch 20. To perform measurements in such a configuration, the measurement pressure is set by the regulator 2, and
Open the pulps 4, 5, and 6 and enter the equipment storage room 8 for the leakage meter T.
The inside of the reference tank 9 and the inside of each pipeline are pressurized, and when the measured pressure is reached, each pulp 4, 5, and 6 is closed.

On the other hand, for the object to be measured IT, the pulp 16 is opened and pressurized, and when the measurement pressure is reached, the valve 16 is closed, and then the valves 19 and 6 are opened to connect the object to be measured 17 and the equipment storage chamber 8 to stabilize it. In other words, wait for the temperature that has increased due to pressurization to drop, and wait for the pressures of both to come to balance.

At this time, if there is a large leak in the object to be measured 17, the valve 19
Since the pressure in the pressure switch 20 drops rapidly at the same time as the pressure switch 20 is opened, the measurement is terminated by the operation of the pressure switch 20. When the pressure between the object to be measured 17 and the leak measuring device 7 reaches an equilibrium state, measurement is started.

That is, the initial position of the bell cup 10 is set to the differential transformer 1.
After that, the amount of displacement (inclination) of the bell cup 10 within a certain measurement time is measured by the differential transformer 12, and the amount of leakage from the object to be measured 17 is detected. At this time, if the initial position of the pel cup 10 is outside the measurement range, the valve 5 is opened and the control coil 131C is connected to the balance mechanism 1.
1, the position of the bell cup 10 is set within a measurable range, and the valve 5 is closed to start measurement. When the measurement is completed in this way, the valves 6 and 19 are closed, and the atmosphere release valve 18 is then opened to exhaust the pressure air in the object to be measured 17, and the object to be measured 17 is replaced with a new one.

After this replacement, the valves 4, 5, and 6 are opened to replenish the pressure by pressurizing the equipment storage chamber 8 of the measuring instrument 7, the reference tank 9, and the pipe line, while also pressurizing the object to be measured 17 as described above. Repeat the steps above to continue measuring. However, in such a conventional measurement method, during 1/3 of the time when replacing the object to be measured 17, the measuring instrument 7 is completely idle, resulting in wasted time. It is necessary to connect the measuring device 7 and provide a period of time for stabilization until the pressure difference between the two disappears, that is, until equilibrium is reached.

Therefore, since the measuring device 7 and the object to be measured 17 are connected during pressurization or while waiting for stability, the time during which one object to be measured 17 is connected to the measuring device r is extremely long. Measurement efficiency is very poor. Furthermore, if the amount of leakage from the object to be measured 17 is minute, accurate measurement is difficult unless the measurement time is extended to a certain extent, and from this point of view the two are connected during this waiting time. Measurement efficiency decreases. Furthermore, in conventional devices, the pressure source that pressurizes the object to be measured 17 and the measuring device 7 is the same pressure source 1, and because little attention is paid to pressure control, the measuring device 7 and the object to be measured 17, the pressure becomes unstable at the initial stage, and the waiting time for stabilization is therefore inconvenient. In addition, in the conventional measurement (standing method), the measuring object is limited to a relatively large volume17, and the pressure drop is observed using a type of pressure gauge, so the standing time is several hours or even several months. Quantitative measurements under the set pressure O were impossible because the measurement conditions such as ambient temperature were different.

SUMMARY OF THE INVENTION An object of the present invention is to provide a leakage measuring device with high measurement efficiency, which requires a short measurement time even when measuring a minute leakage amount. The leak measuring device of the present invention has two isolated chambers pressurized to the same pressure by a pressure control mechanism, one of which is connected to a plurality of measurement pipes, and is connected to another pressure source in advance. This method is characterized in that the pressurized objects to be measured are successively connected by switching valves, and the leakage from the objects to be measured is detected as a pressure difference between two chambers. It is possible to preload other objects to be measured during measurement, and it can also be left standing after preloading without being connected to a measuring instrument.

In addition, since the connection between the measuring device and the object to be measured is only required for determining or displaying the amount of leakage, the measurement time is short.
Efficient measurement becomes possible. Embodiments of the present invention will be described below based on the drawings.

FIG. 2 shows a first embodiment of the invention.

A pressure control mechanism 22 is connected to the pressure source 21, and the pressure control mechanism 22 includes a regulator 23, a pressure gauge 24, a surge tank 25, a regulator 26, and a pressure gauge 27 connected in series. The leak measuring device 30 consists of two isolated chambers 31 and 33, one chamber 31 is an equipment storage chamber in which the measuring equipment described below is installed, and the other chamber 33 is
serves as a reference tank for storing compressed air. The pressure control mechanism 22 is connected to an equipment storage chamber 31 of a leak measuring device 30 via valves 28 and 29, and the valve 2
The reference tank 33 of the leak measuring device 30 is connected via a valve 32 in parallel with 8, and the equipment storage chamber 31 of this leak measuring device 30 and the reference tank 33 are connected by a valve 34, so that both chambers 31, 33 are It is possible to equalize the pressure. A balance mechanism 35 is provided in the equipment storage chamber 31, a bell cup 36 is fixed to one end of the balance mechanism 35, and a differential transformer 37 and a control coil 38 are attached to the other end.
is fixed. A recorder 40 is connected to the differential transformer 37 via an amplifier 39 so that the movement of the balance mechanism 35 can be recorded. The bell cup 36 is placed with its bottomed cylindrical body facing down, and its lower end is positioned below the liquid level of the liquid-sealed container 41. Furthermore, the inside of this liquid-sealed bell cup 36 is connected to a reference via a communication hole 42. It is communicated with the inside of the tank 33. The pressure control mechanism 22 and the valve 28
A preload line connecting to the pressure control mechanism 22, which is a pressure source for prepressing the objects to be measured 46, 47, and 48, is provided at an intermediate position between the objects to be measured and the object to be measured. Valves 43, 44, and 45 are installed on the branch pipe. Design: Gentleman ♂
32;? Atmospheric release valves 49, 50, and 51 are provided, respectively.

The object to be measured is connected to the equipment storage chamber 31 via a measurement conduit provided with valves 52, 53, and 54. The plurality of measurement pipes are combined into one pipe, and a pressure switch 55 is provided in this pipe. Well, above valve 5
Since 2, 53, and 54 are for individually connecting the objects to be measured 46, 47, and 48 to the equipment storage chamber 31, they may be replaced with one switching valve.

To perform a leakage test on such a configuration, the object to be measured 46 is first attached.

Next, since the leak measuring device 30 is not pressurized at the beginning of the measurement, the valves 32 and 34 are opened to apply compressed air from the pressure source 21 to the equipment storage chamber 31 and the reference tank 33 of the leak measuring device 30. At the same time, the valve 28 is opened to pressurize the pipeline, and at the same time, the valve 43 is opened to pressurize the first object to be measured 46. At this time, the supply pressure is accurately controlled by using multiple stages such as regulators 23 and 26 or by using a surge tank 25. In addition, this pressurization is carried out for a sufficiently long time until the temperature no longer increases or decreases due to the pressurization, and during this pressurization, the second object to be measured 47 is attached (replaced). Then, the valve 34 is closed to cut off the communication between the equipment storage chamber 31 and the reference tank 33, and the valves 28, 32, and 43 are also closed, and after this, the object to be measured 46 is left for a certain period of time to determine if there is a defect. If necessary, leakage will occur.

Next, the valve 52 is opened and the pressure switch 55 is used to detect whether or not there is a large leak in the object to be measured 46 .

If there is a large leak, stop the measurement and move on to the next measured object 4.
Proceed to step 7 measurement. This minimizes the pressure drop in the equipment storage chamber 31 and the reference tank 33 due to leakage of the object to be measured 46, and avoids affecting the next measurement (object to be measured 47). If there is no major leak, the valve 29 is opened to communicate the object to be measured 46 and the equipment storage chamber 31 to start measurement. Bell cup 36 via mechanism 35
Is it always held in a measurable position? Then, this state is detected by the differential transformer 37 and by the recorder 40. At the start of measurement, the holding by the control coil 38'VC is released L, the balance mechanism 35 is made free, and the displacement of the bell cup 36, that is, the inclination of the balance mechanism 35, is detected by the differential transformer 37.

At this time, the bell cup 36 is attached to the object to be measured 46 after the pressurization is completed.
It will be displaced depending on the amount of leakage from the pipe. That is,
If there is a leak in the object to be measured 46, the pressure in the equipment storage chamber 31 will decrease accordingly, but on the other hand, since the initial pressure in the reference tank 33 is maintained, pressure will increase inside and outside the liquid-sealed pel cup 36. A difference occurs, and the balance mechanism 35 is tilted by this difference. When the displacement is measured by the differential transformer 37,
Valves 52 and 29 are closed, and the measurement ends.

When this measurement is completed, the atmosphere opening valve 49 is opened to evacuate the object to be measured 46, and then the object to be measured 46 is replaced with a new object. After the valves 52 and 29 are closed, the valve 28 is opened to replenish the pressure in the pipeline, and the valves 32 and 34 are opened to pressure the equipment storage chamber 31 of the leak measuring device 30 and the reference tank 33. Replenishment will take place. At this time, the balance mechanism 35 is held at a measurable position by the control coil 38. On the other hand, during the period from the replacement of the first measured object 46 to the end of the measurement and the completion of pressure replenishment to the leak measuring device 30, pressurization and leaving are completed after the replacement of the second measured object 47 at 1fC. , valves 28, 32, 3
4 is closed, valve 53 is opened to detect a large leak, valve 29 is then opened, and measurements are made in the same manner.

Furthermore, when the measurement of the second object to be measured 47 is completed and the pressure replenishment is completed, the leaving of the third object to be measured 48 is completed, and the measurement of this third object to be measured 48 is completed. By the time the pressure replenishment is completed, the leaving of the first object to be measured 46 has been completed, so the leakage tester 30 has no idle time and the leakage test can be repeated efficiently.

FIG. 3 shows a time chart of the embodiment. According to this figure, immediately after the measurement of the first object to be measured 46 is completed, the measurement of the second object to be measured 47 is started. It can be seen that immediately after the measurement of the third object to be measured 47 is completed, the measurement of the third object to be measured 48 is started, and immediately after the third measurement is completed, the first measurement is started.

Here, measurement includes three stages; range 4 written in the measurement column in Figure 3 is the replenishment time for the pressure drop due to leakage during the previous measurement, and range 2 is the time to replenish the pressure drop due to leakage during the previous measurement. thing 46
, (47, 48) and the equipment storage chamber 31 to perform the actual measurement, and the range 3 is the time for determining the quality of the object to be measured 46 (47, 48). .
In addition, measurement 4 is carried out using the time when the device is left standing, so that the measurement time can be shortened. Furthermore, the dashed line in the measurement column for the first object to be measured 46 means the pressurization of the leak measuring device 30 at the start of the test, and the pressurization of the container to be measured 46. They are set to start at the same time.
According to the present embodiment as described above, a plurality of objects to be measured 46 to 48 are provided, and the pressure supply, etc. is connected to the leakage measuring device 30 by effectively utilizing the replacement, pressurization, and standing time of each object. Since the leak measuring device 30 can be used continuously, the test time for each of the objects to be measured 46 to 48 can be greatly shortened.

Moreover, since the pressure supplied from the pressure source 21 is highly precisely controlled via the pressure control mechanism 22 having a plurality of regulators 23 and 26 and a surge tank 25, each of the objects to be measured 46 to 48 or leakage The stabilization time of the pressure of the measuring device 30 can be shortened, and the test time can also be shortened from this point of view. Furthermore, since the valve 29 is not opened immediately when the valves 52, 53, and 54 are opened, but the valve 29 is opened after detecting the presence or absence of a large leak by the pressure switch 55, the leak measuring device 30 at the time of a large leak is opened. It is possible to prevent adverse effects on the device and to minimize the effect on the next measurement. FIG. 4 shows a second embodiment of the present invention, which differs from the first embodiment in that there are two pressure supply systems to the object to be measured.

In other words, there are valves 43, 44, 45 and O that supply or cut off pressure from the pressure source 21 to each of the objects to be measured 46, 47, 48, respectively. A pressure control mechanism 59 separate from the pressure control mechanism 22 is connected through valves 56, 57, and 58, and this pressure control mechanism 59 is connected to a pressure source 60 separate from the pressure source 21. It is. Further, the pressure control mechanism 59 includes a τ regulator 61 and a pressure gauge 62. Here, the same components as those in the previous embodiment are designated by the same reference numerals, and the explanation thereof will be omitted. In this embodiment configured in this way, each of the objects to be measured 46, 47
When installing (replacing) , 48, first
, 58 are opened, each of the objects to be measured 46, 47, 48 is preloaded to approximately the measurement pressure from the pressure source 60 via the pressure control mechanism 59,
Next, the valves 43, 44, and 45 are opened to supply a pressure precisely controlled by the pressure control mechanism 22 from the pressure source 21 to set the measurement pressure, and the other operations are the same as in the first embodiment. It is exactly the same.

According to the present embodiment as described above, the pressure applied to the objects to be measured 46, 47, and 48 is duplicated in addition to that in the first embodiment (third embodiment).
(see figure) can effectively prevent increases in test time caused by pressure fluctuations that occur during testing.

Furthermore, since the pressure is formally applied after pre-pressurizing, the pressure does not change suddenly, and temperature fluctuations due to sudden changes in pressure during pressurization can be reduced. Although the type of each valve was not mentioned in each of the above embodiments, these valves may be of a manual type or an automatic type.

However, if each valve is composed of an electromagnetic valve, and these electromagnetic valves are connected to a timer to operate according to a preset program, the work can be done very efficiently.
Further, in each of the above embodiments, the leak measuring device was described as a Pel cup type, but the present invention is not limited to this. A differential pressure type diaphragm may also be used, and in this case, both sides of the diaphragm ( Since the measurement can be started by keeping the reference tank and the pipe line at the same pressure, there is no need to control the bell cup position as in the previous embodiment. Further, in the second embodiment, the pressure sources were provided separately, but if the pressure sources have a large capacity, they may be the same pressure source. However, the pressure control mechanism needs to be separate. In addition, in each of the above examples,
Although the case in which there are three objects to be measured has been described, the present invention is not limited to this, and it is sufficient if there are two or more objects to be measured. As described above, according to the present invention, there is an effect that it is possible to provide a leakage amount measuring device that requires a short measurement time.

[Brief explanation of the drawing]

1 is a system diagram of a conventional leakage measuring device, FIG. 2 is a system diagram showing a first embodiment of a leakage measuring device according to the present invention, FIG. 3 is a timing chart of the embodiment of FIG. 2, and FIG. The figure is a system diagram showing a second embodiment of the present invention. 21... Pressure source, 22... Pressure control mechanism, 23, 2
6. Lugiurator, 25. Surge tank, 30.
... Leakage measuring device, 31... Equipment storage room, 33... Reference tank, 35... Balance mechanism, 36... Bell cup, 37... Differential transformer, 45, 44, 45... Valve, 46, 47, 48...Object to be measured, 56, 57,
58...Pulp'. 59...pressure control mechanism, 60...
...Pressure source.

Claims (1)

[Claims] 1. Leakage measurement that captures leakage from an object to be measured connected to one of two isolated chambers pressurized to the same pressure by a pressure control mechanism as a pressure difference between the two chambers. In the device,
a plurality of measurement pipes to which objects to be measured are connected; a switching valve that selects one of the pipes to communicate with the one chamber; a pressure source that prepresses the object to be measured; and the object to be measured. and a prepressure supply conduit connecting the pressure source, the leak measurement method is characterized in that it is configured to prepressurize another object to be measured while measuring the leakage of the object to be measured, and then sequentially switch the communication to one chamber. Device. 2. The leak measuring device according to claim 1, wherein the pressure source is configured to use the pressure control mechanism in combination. 3. The pressure source includes the pressure control mechanism and a low pressure source that supplies a pressure lower than the pressure supplied by the pressure control mechanism, and is configured to be able to switch between the two. A leakage measuring device according to claim 1.