JPH0462751B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a device for controlling the oxygen concentration in inspired air in a circulation type respirator.

[Conventional technology]

When a fire breaks out in an underground mall, factory, building, construction site, tunnel, ship, etc., and there is smoke, toxic gas, or a lack of oxygen, go inside and carry out rescue and firefighting operations. Conventionally, compressed air (oxygen)-emitting respirators have been widely used. However, this type sucks in air (oxygen) stored in a high-pressure container and releases the sucked air directly to the outside, which is uneconomical, so it has the disadvantage that its usage time is limited to a short time. Circulating respirators solve this problem. Rather than discarding exhaled air outside, a cleaning agent is passed through it to absorb and remove carbon dioxide from the exhaled air. This absorption and removal reduces the pressure within the system, causing the oxygen supply valve to close. The structure (circulation system) that automatically opens the container and automatically replenishes the insufficient amount of oxygen from the high-pressure oxygen container into the remaining air and rebreathes it (circulation system) enables long-term use. This is what I did.

[Problem to be solved by the invention]

By the way, the oxygen concentration in the air is normally about 21%, and when this drops below 18%, it is said that oxygen deficiency or oxygen deficiency occurs. However, because conventional circulation respirators do not have a function to maintain a constant oxygen concentration, the oxygen concentration in the inhaled air can drop to around 15%, leaving workers constantly worried about oxygen depletion. I had to work by feeling it. Therefore, regulating the lower limit of oxygen concentration is extremely important from the viewpoint of ensuring safety in use.

On the other hand, if the oxygen concentration becomes too high, there is no danger to human life, but in a circulating respirator that can only store a certain amount of oxygen, oxygen is wasted, so the duration of the hyperbaric oxygen container is shortened. I was supposed to do it. Therefore, it is important to regulate the upper limit of the oxygen concentration from the viewpoint of extending the duration of the high-pressure hydrogen container.

This invention was made in view of the above points,
In circulation type respirators, which automatically open the oxygen supply valve and automatically replenish oxygen from a high-pressure oxygen container when the pressure in the system decreases, when the oxygen concentration in the inspired air decreases, oxygen is forced into the circulatory system. It is an object of the present invention to provide an oxygen concentration control device for a circulation type respirator that increases the oxygen concentration by flowing into the passageway, prevents oxygen deficiency, and improves the safety of use.

Furthermore, in addition to regulating the lower limit of oxygen concentration, when the oxygen concentration in the intake air increases,
Provides an oxygen concentration control device for a circulation type respirator that prevents wasteful consumption of oxygen and extends the usage time of a high-pressure oxygen container by prohibiting the supply of oxygen and regulating the oxygen concentration in the intake air within a predetermined range. This is what I am trying to do.

[Means to solve the problem]

The invention described in claim 1 includes a circulation system path that leads from the face piece through an exhalation path to a cleaning can containing a cleaning agent, and returns to the face piece from an outlet of the cleaning can through an intake path, and a high-pressure oxygen The container is connected to the intake passage through an oxygen supply valve, and when the pressure in the intake passage drops below a predetermined value, the oxygen supply valve automatically opens to supply oxygen from the high-pressure oxygen container to the intake passage. an oxygen supply system path for supplying oxygen, and an air intake path that is arranged in the air intake path and selectively controls the inflow of intake air from the air intake path to the face piece due to the intake operation of the face piece, and the state that does not restrict the inflow of air intake. an operable intake air regulating means; an oxygen concentration detector that detects the oxygen concentration in the intake passage; and when the oxygen concentration detected by the oxygen concentration detector is lower than a preset oxygen concentration lower limit value, the intake air an intake regulation control means for operating the regulating means to regulate the inflow of the intake air, and operating the intake regulation means for not regulating the inflow of the intake air when the oxygen concentration is higher than the lower limit value; The outlet of the supply system path is connected to a portion of the air intake path where the pressure decreases due to the air intake operation at the face piece when the air intake regulating means is in a state of regulating the inflow of the air intake. It is something to do.

Furthermore, the invention described in claim 2 is as follows:
In addition to the invention set forth in item 1 above, an oxygen supply system opening/closing means disposed in the oxygen supply system and capable of selectively operating the oxygen supply system between an open state and a closed state; When the oxygen concentration detected by the oxygen concentration detection means is higher than a preset oxygen concentration upper limit value, the oxygen supply system opening/closing means is operated in the closing direction, and when it is lower than the oxygen concentration upper limit value, the oxygen supply system The oxygen supply system line opening/closing control means is provided to operate the line opening/closing means in the opening direction.

[Effect]

According to the invention described in claim 1,
When the pressure in the intake passage decreases due to the absorption of carbon dioxide by the cleaning agent, the oxygen supply valve automatically opens to allow oxygen to flow into the circulation system. An intake regulating means is installed to regulate the inflow of intake air from the intake passage to the facepiece due to the intake operation, and when the oxygen concentration in the intake air falls below a predetermined lower limit value, the intake regulating means By operating the pump in a state where it is regulated, the pressure in the circulation system path is forcibly lowered with the intake operation, and the oxygen supply valve is opened to force oxygen to flow into the circulation system path. ing.

According to this, the lower limit value of the oxygen concentration in the intake air is regulated, so safety in use can be ensured. Furthermore, by using both pressure control and oxygen concentration control, the atmosphere within the circulation system can be maintained optimally. In addition, the existing oxygen supply system, which automatically opens the oxygen supply valve and automatically replenishes oxygen from a high-pressure oxygen container when the pressure in the intake passage decreases, can be used to control replenishment when the concentration decreases. As a result, there is no need to separately install an oxygen supply line equipped with a solenoid valve, etc. for replenishment control when the concentration drops from the existing oxygen supply line for pressure control, and the configuration of the oxygen supply line can be simplified as before. A configuration is sufficient.

Further, according to the invention set forth in claim 2, an oxygen supply system opening/closing means is disposed in the oxygen supply system separately from the intake air regulating means of the invention set forth in claim 1, Since the oxygen supply system opening/closing means is closed when the oxygen concentration in the intake air exceeds a predetermined upper limit, the pressure drop in the intake passage is no longer transmitted to the oxygen supply valve. will not open, and the rise in oxygen concentration will be suppressed.
Therefore, since the oxygen concentration in the intake air is regulated within a predetermined range, safety in use is ensured, wasteful consumption of oxygen is prevented, and the duration of the high-pressure oxygen container can be extended.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, a case will be described in which both the lower limit and upper limit of oxygen concentration are regulated.

In FIG. 1, a facepiece 1 covers the nostrils and mouth of the face. The exhaled air discharged from the facepiece 1 is passed through an exhalation pipe 3 that has a built-in exhalation valve 2 that opens only when exhaling.
It flows into the clean can 7 through the . The portion from this face piece 1 to the inlet of the cleaning can 7 corresponds to the exhalation pipe.

In the cleaning can, carbon dioxide gas in exhaled air is removed by the cleaning agent 6 filled inside. Cleanliness 7
The air exiting the air is returned to the facepiece 1 from the can 13 containing the breathing bag 18 through the intake pipe 5 and the intake valve 4, which opens only when inhaling. The portion from the outlet of the cleaning can 7 to the face piece 1 corresponds to an air intake path. Further, the entire path from the facepiece 1 through the exhalation path, the cleaning canister 7, and the intake path and returning to the facepiece 1 corresponds to the circulatory system path.

An opening 17 is formed in the upper surface of the can body 13, and an opening 19 of a respiratory organ 18 is connected to this opening 17. The respiratory system 18 is made of a flexible, airtight material such as synthetic resin, and suppresses pressure fluctuations in the circulation system by introducing and expelling outside air and expanding and contracting in response to breathing. It is.

A high-pressure oxygen container 10 containing high-pressure oxygen is connected to a can body 13 via an oxygen supply valve 11 consisting of an automatic pressure reducing valve, and when oxygen is consumed, the can body
When the pressure inside the can body 13 decreases, the oxygen supply valve 11 opens and oxygen is supplied into the can body 13. Oxygen supply valve 11 from this high pressure oxygen container 10
The part that passes through and reaches the can body 13 is the oxygen supply line 30
corresponds to

A remaining fuel gauge 9 is attached to the high-pressure oxygen container 10. In addition, if the pressure in the circulation system becomes abnormally high due to a large amount of oxygen supplied, the wearer will feel pressured, so in order to remove air from the system, the facepiece 1 is kept under a constant pressure. Automatic exhaust valve 8 that operates as above
is installed.

At the opening 19 of the breathing bag 18, an intake regulating valve 20, which is a solenoid valve for opening and closing the breathing bag 18, is disposed. This intake regulating valve 20 constitutes an intake regulating means in combination with the can body 13 and the breathing bag 18, and by regulating the inflow of intake air from the intake passage to the facepiece 1 due to the intake action of the wearer, The oxygen supply valve 11 is operated by lowering the pressure of the intake air, and the oxygen supply valve 11 is forced to supply oxygen, thereby regulating the decrease in the oxygen concentration in the intake air.

That is, according to the intake passage structure shown in FIG. 1, the amount of intake air flowing from the intake passage into the face piece 1 due to the intake operation in the face piece 1 is equal to the decrease in the volume of the intake passage inside the can body 13 due to the expansion of the breathing bag 18. This is the total amount newly supplied from clean can 6, but can body 1
3. The intake regulating means by the breathing bag 18 and the intake regulating valve 20 function to regulate the inflow of intake air by blocking the former of these, that is, the inflow due to the reduction in the volume of the intake passage in the can body 13. That is, when the intake regulating valve 20 is closed, no outside air is introduced into the breathing bag 18 even if the wearer performs an inhalation operation, so the breathing bag 18 does not expand and the volume of the intake passage inside the can body 13 decreases. do not. Therefore, the inflow of intake air is only the amount newly supplied from the cleaning can 6. At this time, the supply of intake air from the clean can 6 does not immediately follow the intake operation due to the resistance when passing through the inside of the clean can 6, so the pressure in the intake passage temporarily decreases. As a result, the oxygen supply valve 11 opens and oxygen is forcibly supplied into the can body 13 from the oxygen supply line 30.

On the other hand, when the intake regulating valve 20 is opened, when the wearer performs an inhalation operation, outside air is introduced into the breathing bag 18 and the breathing bag 18 expands, and the volume of the intake passage inside the can body 13 decreases accordingly. Therefore, the inflow of intake air is not obstructed due to the reduction in the volume of the intake passage in the can body 13, so the inflow of intake air is no longer restricted, and the pressure drop in the intake passage due to the intake operation is alleviated, resulting in forced oxygen supply. will no longer be carried out.

In order to realize the forced oxygen supply operation through the intake operation as described above, the outlet of the oxygen supply line 30 is closed when the intake regulation valve 20 is closed (that is, when the inflow of intake air is regulated). It is connected to the part of the intake passage (that is, the can body 13 in this embodiment) where the pressure decreases due to the intake operation.

An oxygen supply system opening/closing valve 21 composed of a solenoid valve is disposed in the oxygen supply system 30 to open and close the oxygen supply system 30 . This oxygen supply system opening/closing valve 21 regulates an increase in oxygen concentration in intake air. That is, when this is closed, the pressure drop in the intake passage is no longer transmitted to the oxygen supply valve 11, so the oxygen supply valve 11 is no longer opened. Therefore, oxygen is no longer supplied, and as oxygen is consumed, the oxygen concentration in exhaled breath gradually decreases.

The oxygen concentration detector 22 detects the oxygen concentration in the intake air. The comparator 23 and the driver 24 correspond to first concentration control valve control means. That is, the comparator 23 compares a preset oxygen concentration lower limit value D _nio (for example, 20%) with the detected oxygen concentration value D, and determines that D>
When D _nio, keep the intake regulation valve 20 open,
<D _nio , the intake regulating valve 2 is activated via the driver 24.
0 and close it to regulate the decrease in oxygen concentration.

Further, the comparator 25 and the driver 26 correspond to second concentration control valve control means. That is, the comparator 25 compares a preset oxygen concentration upper limit D _nax (for example, 30%) with the oxygen concentration output value D, and determines that D<
When D _nax , the oxygen supply system opening/closing valve 21 is kept open, and when D>D _nax , the oxygen supply system opening/closing valve 21 is driven via the driver 26 and closed to regulate the increase in oxygen concentration. . As a result, the oxygen concentration in the intake air is controlled within a range of 20 to 30%, and it is possible to prevent oxygen deficiency due to a decrease in oxygen concentration and wasteful consumption of oxygen due to an increase in oxygen concentration.

In the above embodiment, the present invention is applied to a circulation type respirator in which the breathing bag 18 is housed in the can body 13, but as shown in FIG. In the case of a configuration in which the air passes through the inside and reaches the breathing tube 5, an intake regulating valve 20' composed of a solenoid valve for regulating the decrease in the oxygen concentration can be disposed at the outlet of the cleaning canister 7, for example.

That is, according to the intake passage structure shown in FIG. 2, the amount of intake air that flows from the intake passage into the facepiece 1 due to the intake operation is equal to the decrease in the volume of the intake passage due to the contraction of the breathing bag 18', and the amount of fresh air from the cleaning can 7. This is the total amount supplied, but the intake regulating valve 20' has the following amount:
It functions to restrict the inflow of intake air by blocking the newly supplied air from the purifier 7. That is, when the intake air regulating valve 20' is closed, no new intake air will flow in from the clean can 7 even if the wearer performs an intake operation. Therefore, as the pressure in the intake passage gradually decreases, the oxygen supply valve 11 opens and oxygen is forcibly supplied from the oxygen supply system passage 30 into the intake passage.

Furthermore, when the intake regulating valve 20' is opened, new intake air is supplied from the clean can 7 when the wearer performs an intake operation, so the pressure drop in the intake passage due to the intake operation is alleviated, and forced oxygen supply is performed. It will no longer be done. Therefore, in the case of Fig. 2, the intake regulating valve 2
0' alone constitutes the intake regulating means.

In order to realize the forced oxygen supply operation through the intake operation as described above, the outlet of the oxygen supply line 30 is closed when the intake regulation valve 20' is closed (that is, when the inflow of intake air is regulated). It is connected to a portion of the intake passage where the pressure decreases due to the intake operation (that is, in this embodiment, a position closer to the face piece 1 than the intake regulating valve 20').

〔Effect of the invention〕

As explained above, according to the invention recited in claim 1, when the pressure in the intake passage decreases due to absorption of carbon dioxide gas by the cleaning agent, the oxygen supply valve is automatically opened to supply oxygen. In a circulation type respirator that allows air to flow into the circulation system, an intake regulating means is provided in the intake passage to restrict the inflow of air from the intake passage to the facepiece due to the intake action of the facepiece, and oxygen in the intake air is When the concentration falls below a predetermined lower limit value, the intake air regulating means is operated to restrict the inflow of intake air, thereby forcibly reducing the pressure in the circulation system path with the intake operation. Since the oxygen supply valve is opened to force oxygen to flow into the circulation system, the lower limit of the oxygen concentration in the intake air is regulated and safety in use can be ensured. Furthermore, by using both pressure control and oxygen concentration control, the atmosphere within the circulation system can be maintained optimally. In addition, the existing oxygen supply system, which automatically opens the oxygen supply valve and automatically replenishes oxygen from a high-pressure oxygen container when the pressure in the intake passage decreases, can be used to control replenishment when the concentration decreases. As a result, there is no need to separately install an oxygen supply line equipped with a solenoid valve, etc. for replenishment control when the concentration drops from the existing oxygen supply line for pressure control, and the configuration of the oxygen supply line can be simplified as before. A configuration is sufficient.

Further, according to the invention set forth in claim 2, an oxygen supply system opening/closing means is disposed in the oxygen supply system separately from the intake air regulating means of the invention set forth in claim 1. Since the oxygen supply system opening/closing means is closed when the oxygen concentration in the intake air exceeds a predetermined upper limit, the pressure drop in the intake passage is no longer transmitted to the oxygen supply valve. will not open, and the rise in oxygen concentration will be suppressed.
Therefore, since the oxygen concentration in the intake air is regulated within a predetermined range, safety in use is ensured, wasteful consumption of oxygen is prevented, and the duration of the high-pressure oxygen container can be extended.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the invention, and FIG. 2 is a diagram showing another embodiment of the invention. 1... Face piece, 2... Exhalation valve, 3... Exhalation pipe, 4... Intake valve, 5... Intake pipe, 6... Cleaning agent, 7... Cleaning can, 8
...Automatic exhaust valve, 9...Remaining amount gauge, 10...High pressure oxygen container, 11...Oxygen supply valve, 13...Can body, 18,1
8'... Breathing bag, 20... Can body 13 and breathing bag 18
An intake regulation valve, 20', which constitutes an intake regulation means in combination with the intake regulation valve, 21...
Oxygen supply system path opening/closing valve, 30...Oxygen supply system path.

Claims (1)

[Scope of Claims] 1. A circulatory system path that leads from the facepiece through an exhalation path to a cleaning can containing a cleaning agent, and returns to the facepiece from an outlet of the cleaning can through an intake path, and an oxygen supply valve from a high-pressure oxygen container. an oxygen supply system that is connected to the intake passage through the intake passage, and that the oxygen supply valve automatically opens when the pressure in the intake passage falls below a predetermined value to supply oxygen from the high-pressure oxygen container to the intake passage; and an intake regulating means disposed in the intake passage and capable of selectively operating between a state of regulating the inflow of intake air from the intake passage to the face piece due to the intake operation of the face piece and a state of not regulating the inflow of intake air. an oxygen concentration detector that detects the oxygen concentration in the intake passage; and when the oxygen concentration detected by the oxygen concentration detector is lower than a preset oxygen concentration lower limit value, the intake air regulating means is configured to control the intake air. an intake air regulation control means for operating the intake air regulation means to regulate the inflow of intake air, and operating the intake air regulation means for not regulating the inflow of the intake air when the oxygen concentration is higher than the lower limit value, the outlet of the oxygen supply system , wherein the intake air regulating means is connected to a portion of the intake passage where the pressure decreases due to the intake action of the face piece when the intake air regulating means is in a state of regulating the inflow of intake air. Oxygen concentration control device. 2. A circulatory system path from the facepiece through an exhalation path to a cleaning canister containing a cleaning agent, and returning from the cleaning canister outlet to the facepiece through an intake path, and a high-pressure oxygen container to the intake path through an oxygen supply valve. an oxygen supply system line that is connected to the intake passage, and the oxygen supply valve automatically opens when the pressure in the intake passage falls below a predetermined value to supply oxygen from the high-pressure oxygen container to the intake passage; an intake regulating means that is arranged and can be selectively operated to regulate the inflow of intake air from the intake path to the facepiece due to the intake operation at the facepiece and to the state that does not regulate the inflow of intake air; and the oxygen supply system. an oxygen supply system opening/closing means disposed in the air passageway and capable of selectively operating the oxygen supply system passage in an open state and a closed state; an oxygen concentration detector for detecting the oxygen concentration in the intake passage; When the oxygen concentration detected by the oxygen concentration detector is lower than a preset oxygen concentration lower limit value, the intake air regulating means is operated to restrict the inflow of intake air, and when it is higher than the oxygen concentration lower limit value, the intake air regulating means is operated to regulate the inflow of intake air. an intake regulation control means for operating an intake regulation means in a state where the inflow of intake air is not regulated; and when the oxygen concentration detected by the oxygen concentration detection means is higher than a preset oxygen concentration upper limit value, the oxygen supply system path is opened or closed. and an oxygen supply system opening/closing control means for operating the oxygen supply system opening/closing means in the direction of closing the oxygen supply system, and opening the oxygen supply system passage opening/closing means when the oxygen concentration is lower than the upper limit value, the outlet of the oxygen supply system including: Oxygen in a circulation type breathing apparatus, characterized in that the intake air regulating means is connected to a portion of the intake passage where the pressure decreases due to the intake action of the facepiece when the intake air regulating means is in a state of regulating the inflow of intake air. Concentration control device.