JPH1019720A - Method and apparatus for detecting abnormality of hermetic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a failure of a packing member resulting from damage, stain or the like by supplying a pressure gas to a packing groove up to a fixed pressure, holding the packing groove hermetically and monitoring a pressure change in the packing groove. SOLUTION: A packing groove 6 of a predetermined depth is formed in a container body 2 to surround an opening 3. A packing member 7 is fitted in the packing groove 6. A pressure gas feed pipe 8 communicating with a space in the packing groove 6 is connected to the packing groove 6. A first pressure detector 17 is connected to the packing groove 16, and a second pressure detector 18 is connected to a pressure gas tank 10. A first set value for a feed pressure and a second set value slightly lower than the first set value are set in the detectors 17, 18, respectively. A pressuring device 9 is driven to set the interior of the packing groove 6 at a predetermined pressure. At the same time, the packing groove 6 is separated from the pressure gas feed pipe 8. A pressure change in the packing groove 6 is monitored by the first pressure detector 17. When the pressure reaches the second set value from the first set value in a preliminarily set time, the packing member 7 is judged to be abnormal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting an abnormality in an airtight device for hermetically sealing a space between a container body and a lid in an airtight container. Here, the airtight container referred to in the present invention is also a container whose inside is pressurized,
It also includes a container whose inside is depressurized.

[0002]

2. Description of the Related Art Generally, in an airtight container, it is necessary to hermetically seal the space between the container body and the lid. For this purpose, a packing member is arranged between the container body and the lid. For example, a packing groove is formed in one of the container body and the lid, and a packing member is accommodated therein, and the packing member is pushed out of the packing groove by a pressurized gas at the time of sealing and pressed against the container body or the lid. There is a so-called extrusion packing of the type.

In this extrusion type packing, the packing member is projected from the packing groove when sealing the airtight container, and is retracted into the packing groove when releasing the sealing. When the sliding contact surface is worn and the portion is deteriorated, the airtightness between the sealing groove and the packing groove is deteriorated, and the pressure contact force to the door or the container body is reduced. If this pressure contact force is reduced, the packing member comes into contact with the lid or the container body, so that the pressure contact force is reduced, so that there is a problem that airtightness cannot be maintained. This is particularly remarkable in the case where the temperature of the closed container is high and high.
Therefore, this kind of packing member needs to be regularly inspected, and if this inspection finds a defect due to damage or dirt, it has been replaced or cleaned. by the way,
When the hermetic container is, for example, a steam sterilizer that performs a sterilization process on an object to be sterilized housed therein,
There are two states, a pressurized state higher than atmospheric pressure and a depressurized state lower than atmospheric pressure. In the case of the pressurized state, the airtight container is filled with high-temperature, high-pressure steam for sterilization.
It is dangerous that this vapor leaks out. In the case of a reduced pressure state, for example, in the drying step after the sterilization operation, at that time, the invasion of the outside air into the airtight container will contaminate the sterilized object after the sterilization.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an airtight device employing the above-mentioned push-out type packing, which is capable of detecting a defect of a packing member due to damage or dirt. A method and apparatus are provided.

[0005]

According to the present invention, a packing groove is provided in a container body or a lid at a position corresponding to the periphery of an opening of a container body of an airtight container, and the packing housed in the packing groove is provided. An airtight device for sealing a member between a container body and a lid by pressing a member toward a lid or a container body by pressurized gas from a pressurized gas supply line connected to a packing groove, wherein the packing groove After the pressurized gas is supplied from the pressurized gas supply line to a certain pressure, the communication between the packing groove and the pressurized gas supply line is interrupted to keep the packing groove airtight. The above-mentioned problem is solved by a method for detecting an abnormality of the airtight device, wherein the abnormality of the packing member is determined based on the change of the gasket.

Further, according to the present invention, a packing groove is provided in either the container body or the lid at a position corresponding to the periphery of the opening of the container body of the airtight container, and the packing member housed in the packing groove is provided with a packing groove. In a hermetic device that seals between the container body and the lid by pressing against the lid or the container body with the pressurized gas from the pressurized gas supply line connected to the And a pressure detector connected downstream of the on-off valve of the pressurized gas supply line, and the on-off valve and the pressure detector are opened by opening the on-off valve and a packing groove is formed from the pressurized gas supply line. A function of closing the on-off valve after supplying the pressurized gas into the inside, a function of monitoring the pressure in the packing groove after closing the on-off valve, and judging an abnormality of the packing member based on the change in the pressure; and , Size The abnormality detecting device of a hermetic device configuration connected to a control device having a function of outputting the result, is to solve the above problems.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is applied to an airtight device employing the above-mentioned so-called push-out type packing, and detects a defect of a packing member due to damage or dirt. This airtight container includes one that pressurizes the inside and one that reduces the pressure. The extrusion-type packing has a structure in which a packing groove is formed at a peripheral edge of an opening of a container body constituting a closed container, or a corresponding portion of a lid that closes the opening, and a packing member is accommodated in the packing groove. By supplying a pressurized gas from a pressurized gas supply means into the packing groove, a packing member protrudes from the packing groove, and is pressed against an opposing lid, or a container body, so that the airtight container is closed. Keep tightly closed.

In the method for detecting an abnormality of the sealing device according to the present invention, the time for replacement, cleaning, and inspection of the push-out packing is appropriately determined. In the present invention, after the pressurized gas is supplied from the pressurized gas supply line into the packing groove to a certain pressure, the communication between the packing groove and the pressurized gas supply line is cut off to keep the packing groove airtight,
The change in the pressure in the packing groove is monitored, and the abnormality of the packing member is determined based on the change in the pressure. The supply of the pressurized gas into the packing groove is performed to a certain pressure. The pressure at this time is preferably the supply pressure during normal operation, but is not limited to this pressure. After supplying the pressurized gas into the packing groove, shutting off the communication with the pressurized gas supply line and keeping the packing groove airtight means that the pressurized gas from the pressurized gas supply line into the packing groove is To prevent the backflow of the pressurized gas from the packing groove to the pressurized gas supply line, and to keep the gas from flowing in and out of the packing groove. This pressurized gas is
Generally, pressurized air is used.
Considering the case of leakage into the container body, change as appropriate according to environmental pollution and the contents inside the sealed container. That is, by supplying the pressurized air to the predetermined pressure in the packing groove and maintaining this state, if a gap is formed between the packing groove and the packing member, the pressurized air leaks from here,
The pressure in the packing groove decreases with time. Therefore, after the communication between the pressurized gas supply line and the packing groove is cut off, deterioration of the packing member is determined by determining how fast the pressure in the packing groove is reduced. Further, in the present invention, if the pressure in the packing groove falls within a preset time and drops by a predetermined pressure or more, it is determined that the packing member is abnormal. In making this determination, the pressure in the packing groove is measured at the time when a preset set time has elapsed, and when the pressure value is compared with the set pressure, the pressure in the packing groove is reduced by a predetermined set pressure or more. This includes the case where the time at the time when the measurement is performed is measured and the elapsed time is compared with the set time to make a determination. Further, the abnormality may be determined by measuring a rate of change of the pressure in the packing groove.

In the abnormality detecting device for a sealing device according to the present invention, an on-off valve is connected in the middle of the pressurized gas supply line, and a pressure detector is connected between the on-off valve and the packing groove. A valve and a pressure detector are connected to a control device. The on-off valve shuts off the communication between the packing groove and the pressurized gas supply line, and is an electromagnetic valve or an electric valve. The pressure detector is connected after the on-off valve in the supply pipe of the pressurized gas, and this on-off valve is connected to a position where a change in pressure in the packing groove can be detected even after the on-off valve is closed. The pressure detector includes a pressure switch that detects a change in pressure in a stepwise manner, and a well-known pressure sensor that continuously detects the change. The control device has a function of closing the on-off valve after releasing the on-off valve and supplying pressurized air from the pressurized gas supply line into the packing groove. After closing the on-off valve, the pressure in the packing groove is reduced. It has a function of monitoring and judging that the packing member is abnormal based on a change in the pressure in the packing groove, and a function of outputting a judgment result. The function of judging the abnormality is that, after the closing of the on-off valve, the pressure in the packing groove is within a preset time, and when the pressure is reduced by a predetermined pressure or more, the packing member It is determined to be abnormal. The control device is preferably configured using a storage device storing the above processing procedure as a program and an arithmetic processing device such as a microcomputer that executes the program. If used, a sequencer combining a relay circuit, a timer circuit and the like may be used.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. In the following specific examples, a case where the present invention is applied to a sterilizer as an example of a closed container will be described. This steam sterilizer is an airtight container whose inside is pressurized and decompressed. FIG. 1 is a flowchart for explaining a method for detecting an abnormality in an airtight device according to the present invention and a processing procedure in the device, and FIG. 2 is a diagram to which an abnormality detecting method and an apparatus for an airtight device according to the present invention are applied. It is explanatory drawing which shows the example of a structure of a closed container.

In FIG. 2, a lid 4 that covers an opening 3 is attached to a container body 2 of an airtight container 1. A support member 5 for holding the lid 4 in the closed position around the opening 3 is attached to the container body 2. The lid 4 is attached to the container body 2
The opening and closing of the opening 3 is slidable along the support member 5 with respect to the opening 3 (the sliding direction is a direction perpendicular to the paper surface of FIG. 2). An annular packing groove 6 having a predetermined depth is formed in the container body 2 so as to surround the opening 3, and a packing member 7 also having an annular shape is fitted into the packing groove 6. A pressurized gas supply pipe 8 is connected to the packing groove 6 so as to communicate with a space in the packing groove 6 set by the depth and the thickness of the packing member 7. A pressurizing device 9 for pressurizing gas (air in this embodiment) is connected to the pressurized gas supply line 8 at the upstream end. The pressurized gas supply line 8 has a pressurized gas tank 10, a pressurized air opening / closing valve 11, a first
The check valve 12 is connected.

In the pressurized air supply line 8, a first groove for the packing groove 6 is provided between the packing groove 6 and the first check valve 12.
The upstream end of the exhaust line 13 is connected. The first exhaust line 13 includes a second on-off valve 14, a second check valve 15
Are connected in this order, and the downstream end is connected to the vacuum pump 16. The vacuum pump 16 is also used for evacuating the inside of the sealed container 1 as described later. The vacuum pump 16 is connected to the container main body 2 by a second exhaust line 30 that is separate from the first exhaust line 13. And this second
A third opening / closing valve 31 is connected to the exhaust line 30 in the middle of the exhaust line 30 to switch between suction in the packing groove 6 and suction in the sealed container 1.

In the packing groove 6, the first pressure detector 1 is provided.
7 and the pressurized gas tank 10 has a second
The pressure detector 18 is connected. The first pressure detector 1
7 is for monitoring the pressure in the packing groove 6,
The first pressure detector 17 may be connected to any of the pipes communicating with the packing groove 6. In this embodiment, the first pressure detector 17 is directly connected to the packing groove 6. Here, the first and second pressure detectors 17 and 18 are:
In this embodiment, a pressure switch is used. The pressure switch switches to an ON state when the pressure increases and reaches a first set value, and switches to an OFF state when the pressure decreases and reaches a second set value lower than the set value. The difference between the value and the second set value is generally called a differential. The switching between the ON and OFF states of the first and second pressure detectors 17 and 18 can be extracted as a pressure detection signal. In this embodiment, the same first set value and second set value are set in the first and second pressure detectors 17 and 18, and the set values are set as follows. That is, the first set value is the supply pressure of the pressurizing device 16 or the supply pressure of pressurized air that can reliably press the packing member 7 against the lid 4 in order to maintain airtightness.
Or a pressure slightly higher than that. On the other hand, the second set value is a pressure slightly lower than the first set value. In this embodiment, as described later, one of the determination factors is a case where the pressure of the pressurized air in the packing groove 6 has decreased by a predetermined value or more within a predetermined time, and the first set value and the second set value By setting the set value as described above, the pressure drop in the packing groove corresponds to the differential.

The pressurizing device 9, the on-off valve for pressurized air 11,
Second on-off valve 14, vacuum pump 16, first pressure detector 1
7. The second pressure detector 18 is connected to the control device 20 of the present invention. The control device 20 includes a storage device 21 storing a processing procedure for detecting an abnormality of the packing member 7 as a program, an arithmetic processing device 22 including a microcomputer or the like for executing the program,
The pressurizing device 9, the on-off valve for pressurized air 11, the second on-off valve 1
4, control signal of vacuum pump 16 and first pressure detector 1
And an input / output device 23 for inputting / outputting a pressure detection signal from the second pressure detector 18. An alarm device (not shown) is connected to the input / output device 23, and an operation signal of the alarm device is output based on an alarm signal output when the arithmetic processing unit 22 determines that there is an abnormality. I do.

Further, the storage device 21 of the control device 20 stores the following program which is executed prior to detecting an abnormality of the packing member 7 (see FIG. 1). That is, from the initial state (step S1) in which the pressurizing device 9 is stopped (step S1), the packing groove 6 and the pressurized gas tank 10 are opened by opening the on-off valve 11 for pressurized air and the second on-off valve 14 (step S2). Through the first exhaust line 13 to make the pressure in the pressurized air tank 10 equal to that of the atmosphere. At this time, when the vacuum pump 16 in the first exhaust line 1 is stopped, it is assumed that the intake port and the exhaust port are in communication with the atmosphere. Next, the on-off valve 11 for pressurized air is closed, and the pressurizing device 9 is started (step S3).
Thus, it is detected whether or not the pressure detection signal of the second pressure detector 18 has changed (step S4). And
The on-off valve for pressurized air 11 is opened and the second on-off valve 14 is closed for a short time (step S5), and it is detected whether or not the pressure detection signal of the first pressure detector 17 has changed (step S6). In this embodiment, if the pressure in each of the pressure detectors 17 and 18 rises above the first set value, an ON-state signal is output, and if it is below that, an OFF-state signal is output. After the above procedure, if the output signals of the first and second pressure detectors 17 and 18 change in the judgment A of step S7, the pressurizing device 9, the on-off valve 11 for the pressurized air, Step S1, in which the first and second pressure detectors 17 and 18 are determined to be normal, and the abnormality of the packing member 7 is detected.
Move to 10. On the other hand, the first and second pressure detectors 17 and 1
8 does not change, the pressurizing device 9
Is judged to be defective or the open / close valve for pressurized air 11 is defective, and an alarm signal is output to enter a standby state (step S8). On the other hand, if the output signal of any one of the pressure detectors 17 and 18 has changed, it is determined that the pressure detector does not change, and an alarm signal is output to enter a standby state (step S).
8), when only the output signal of the first pressure detector 17 changes, the second pressure detector 18 is determined to be defective, and stored so that an alarm signal is output after the end of all the operations of the sterilizer ( Step S9), and proceed to the next step S10. That is, the above processing procedure is for judging whether or not other devices are normal before detecting the abnormality of the packing member 7.

In the control device 20, the packing member 7
A processing procedure for detecting an abnormality of the device will be described with reference to FIG. After confirming that other devices such as the pressurizing device 9, the on-off valve for pressurized air 11, the first pressure detector 17, and the second pressure detector 18 are normal by the above-described processing procedure, the pressurizing device 9 is operated to close the on-off valve 11 for pressurized air (step S10). In this state, since the second on-off valve 14 is in the closed state in step S5, the packing groove 6 is in a state of being isolated from the first exhaust line 13. Therefore, after the pressurized air is supplied to the packing groove 6 to a predetermined pressure, the pressurized air on-off valve 11 is closed to be isolated from the pressurized air supply pipe 8. Thereafter, the change in the pressure in the packing groove 6 is monitored by the first pressure detector 17, and the time until the pressure reaches the second set value from the first set value is measured (step S11). In the next judgment B in step S12, when the pressure in the packing groove 6 reaches the second set value within the preset set time T0, that is, when the pressure in the packing groove It is determined that there is no abnormality, otherwise, it is determined that there is no abnormality in the packing member 7, and the process proceeds to the next step S14. When the abnormality of the packing member 7 is detected, an alarm signal to that effect is output to the input / output device 23 to activate the alarm device (step S13). Here, the control device 20
Monitors the change time until the voltage drops to the second set value based on the output signal of the first pressure detector 17, and judges an abnormality in step S12 based on the change time. By appropriately adjusting the required time at this time, the degree of malfunction of the packing member 7 can be detected. That is, the required time is defined as T01, T02 (0 <T01 <
T02), and if the required time to change to the second set value is shorter than the shorter required time T01,
A warning such as "replacement of packing" is output assuming that the packing member 7 is severely deteriorated. If the longer required time T02 is shorter than the shorter required time T02, the packing member 7 is contaminated. And outputs a warning such as "cleaning". If the required time is T02 or more, it is determined that the packing member 7 is normal. Then, the next step S1
2, the pressurized air on-off valve 11 is opened, and the pressurized air supply pipe 8 and the packing groove 6 are communicated with each other, whereby the hermetic sealing between the container body 2 and the lid 4 is performed.

After that, the procedure shifts to the actual sterilization operation, but before that, failures and malfunctions of other components such as the vacuum pump 16 are determined. Further, before moving on to the sterilization operation, it is preferable to determine whether or not the hermetically sealed container 1 is kept airtight, including the state of tight contact between the packing member 7 and the lid 4. That is, in the sterilization operation, there is an operation of vacuum suction as described later, and by using this operation, the second on-off valve 13 is closed,
With the third on-off valve 31 opened, the vacuum pump 16
To detect whether the inside of the sealed container 1 reaches a predetermined negative pressure state, further close the third on-off valve 31 and stop the vacuum pump 16 to detect a change in the pressure in the sealed container 1. By doing. Here, when the inside of the sealed container 1 reaches a predetermined negative pressure state within a certain time, the third on-off valve 31 is closed, and if there is no change in the pressure after the vacuum pump 16 is stopped, it is determined that everything is normal, If there is a change in the pressure, it means that the airtight container 1 is leaking, and there is an abnormality in the close contact state between the packing member 7 and the lid 4 or the third on-off valve 31 and other valves (not shown). However, it is determined that a malfunction has occurred in the on-off valve such as the steam supply valve. On the other hand, closed container 1
If the inside does not reach the predetermined negative pressure state within a certain time,
If the change in pressure after stopping the vacuum pump 16 is less than or equal to a predetermined value, the third on-off valve 31 is closed, it is determined that there is an abnormality such as a decrease in the capacity of the vacuum pump 16. It is determined that there is an abnormality in the close contact state between the packing member 7 and the lid 4 or that a failure has occurred in the third on-off valve 31 and other valves.

In the sterilization operation, first, the air in the sealed container 1 is eliminated by performing vacuum suction or the like, and the inside is replaced with steam. Thereafter, the object to be sterilized in the closed container 1 is sterilized by maintaining the inside of the closed container 1 in a high-temperature and high-pressure steam atmosphere. After a lapse of a predetermined time, steam is discharged from the closed container 1 and clean air filtered by a filter is introduced into the closed container 1, thereby completing a series of sterilization processes. Thereafter, the on-off valve for pressurized air 11 is closed, the second on-off valve 14 is opened, and the vacuum pump 16 is opened.
Activate By this operation, the inside of the packing groove 6 is decompressed, the packing member 7 is drawn into the packing groove 6, and the sealed state between the container body 2 and the lid 4 is released.
Then, the lid 4 is opened and the object to be sterilized in the container body 2 is taken out.

In the above, the case where the present invention is applied to a steam sterilizer as an example of the airtight container has been described. However, the present invention is also applicable to airtight containers other than such a steam sterilizer. Further, the present invention can be similarly applied to an airtight container such as a vacuum cooler that mainly reduces the pressure inside.
Further, the embodiment described above shows an example in which the lid 4 is slid and opened and closed as shown in FIG. 2, and the present invention is applied to an airtight container other than such a sliding type. It goes without saying that the same can be applied to an airtight container having a lid, for example, a lid attached via a hinge.

[0020]

As described above, according to the present invention, the malfunction of the packing member can be automatically determined. In particular, the check of the airtightness between the packing member and the packing groove has conventionally been performed by taking the packing member out of the packing groove, but in the present invention, the check of the airtightness can be automatically determined, so that The labor savings are significant. Further, conventionally, there has been a problem that the number of times of starting and stopping the pressurizing device is increased due to the occurrence of a defect in the packing member. However, according to the present invention, since the defect can be detected in advance, the pressurizing device A countermeasure can be taken before the number of times of starting / stopping increases.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a method for detecting an abnormality in an airtight device according to the present invention and a processing procedure in the device.

FIG. 2 is an explanatory diagram showing an example of a method for detecting an abnormality in an airtight device according to the present invention and a closed container to which the device is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Airtight container 2 Container main body 3 Opening 4 Lid 6 Packing groove 7 Packing member 8 Pressurizing means 11 1st on-off valve (on-off valve) 17 1st pressure detector (pressure detector) 20 Controller

Claims (4)

[Claims] 1. A packing groove 6 is provided in a position corresponding to the periphery of an opening 3 of a container body 2 of an airtight container 1 in one of a container body 2 and a lid 4, and a packing member housed in the packing groove 6. 7 is pressed against the lid 4 or the container main body 2 by pressurized gas from a pressurized gas supply line 8 connected to the packing groove 6, thereby sealing the container main body 2 and the lid 4. In the apparatus, after a pressurized gas is supplied to the packing groove 6 from the pressurized gas supply line 8 to a predetermined pressure, the communication between the packing groove 6 and the pressurized gas supply line 8 is cut off to seal the packing groove 6. Wherein the abnormality of the packing member 7 is determined based on a change in the pressure in the packing groove 6 thereafter. 2. After a pressurized gas is supplied to the packing groove 6 from the pressurized gas supply line 8 to a predetermined pressure, the communication between the packing groove 6 and the pressurized gas supply line 8 is cut off to remove the gas. Is kept airtight, and the subsequent change in the pressure in the packing groove 6 is monitored. When the pressure in the packing groove 6 falls within a preset set time and drops by a predetermined set pressure or more. 2. The method according to claim 1, wherein it is determined that the packing member is abnormal. 3. A packing groove 6 is provided in one of the container body 2 and the lid 4 at a position corresponding to the periphery of the opening 3 of the container body 2 of the airtight container 1, and a packing member housed in the packing groove 6. 7 is pressed against the lid 4 or the container main body 2 by pressurized gas from a pressurized gas supply line 8 connected to the packing groove 6, thereby sealing the container main body 2 and the lid 4. In the apparatus, the pressurized gas supply line 8
And a pressure detector 17 connected downstream of the on-off valve 11 of the pressurized gas supply line 8.
A function of opening and closing the on-off valve 11 and the pressure detector 17 to supply the pressurized gas from the pressurized gas supply line 8 into the packing groove 6 and then closing the on-off valve 11; After the on-off valve 11 is closed, it is connected to the control device 20 having a function of monitoring the pressure in the packing groove 6 and judging an abnormality of the packing member 7 based on a change in the pressure, and a function of outputting a judgment result. An abnormality detection device for an airtight device. 4. In the control device 20, the abnormality of the packing member 7 is defined as a case where the pressure in the packing groove 6 falls within a preset time and falls by a predetermined pressure or more. The abnormality detection device for an airtight device according to claim 3, wherein: