JPH0722602B2 - Self-diagnosis mechanism in oxygen generator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a self-diagnosis mechanism in an oxygen generator mounted on an aircraft.

(Prior Art) Oxygen Generator (OBOGS ON BOARD OXY
GEN GENERATING SYSTEM) is known.

This type of oxygen generator normally uses the generated gas from a concentrator that uses air (hereinafter referred to as engine bleed air) obtained by extracting a part of the compressed air generated by the engine, and there is a failure in the concentrator series. Sometimes, a backup oxygen device is used.

It is necessary to easily diagnose whether the operation of the switching mechanism of the backup oxygen device or the oxygen concentration monitor for detecting the oxygen deficiency of the concentrator system is reliably performed by these devices.

Various studies were conducted on the self-diagnosis mechanism shown in FIG.

FIG. 3A shows a normal monitoring state of the self-diagnosis mechanism. In this state, part of the gas produced by the concentrator 99 is taken in through the inlet 11 of the cylinder 30 and the orifice 19
It is led to the oxygen sensor 20 via.

In this state, the output of the oxygen sensor 20 monitors the oxygen content of the output of the concentrator 99 (see FIG. 2) in the normal operating state. As the oxygen sensor 20, a polarographic sensor in which the resistance value between the electrodes changes according to the oxygen concentration is used. FIG. 6B shows a self-diagnosis state.

When the test button is pushed, the piston rod 13 is pushed and the cylinder 30
Since the valves 31 and 32 inside are opened, the gas produced by the concentrator 99 flows leftward. Then, the air in the cabin flows through the oxygen sensor 20.

Since the air in the cabin usually has a lower oxygen concentration than the gas produced by the concentrator, the oxygen sensor detects the state and generates a signal.

By confirming the generation of this signal or the operation of other parts based on this signal, the operation of the oxygen sensor and the diagnosis of the signal generation thereof are made.

(Problems to be Solved) In the self-diagnosis mechanism described above, the oxygen sensor 20 is in the atmosphere of the generated gas of the concentrator 99 until the test button 17 is pressed, and the air in the cabin is sucked by operating the test button 17.

Therefore, the response speed varies depending on the pressure of the concentrator-generated gas. In addition, the response speed is generally not fast. The produced gas of the concentrator 99, which further contains abundant oxygen, is released into the cabin and serves to increase the oxygen concentration of the air in the vicinity thereof. Then, there is a possibility that this air will go around and enter the oxygen sensor 20.

An object of the present invention is to provide a self-diagnosis mechanism in an oxygen generator capable of surely and quickly confirming the operation by positively utilizing engine bleeding.

(Means for Solving the Problems) In order to achieve the above-mentioned object, a self-diagnosis mechanism in an oxygen generator according to the present invention is generally used in an oxygen generator that monitors the oxygen concentration of a concentrator-generated gas to generate control information. Is provided with a switching valve for connecting the extracted pressure gas to the oxygen sensor connected to the generated gas of the concentrator at the time of diagnosis, and operates the switching valve at the time of diagnosis to connect the extracted pressure gas to the oxygen sensor. When the alarm signal is output in response to the extracted pressure gas whose oxygen concentration is lower than that of the gas produced by the concentrator, it is determined that the operation of the device is normal.

(Example) Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a self-diagnosis mechanism in an oxygen generator according to the present invention.

FIG. 2 is a block diagram of an oxygen supply system mounted on an aircraft to which the present invention is applied.

The air (hereinafter referred to as engine bleed air) obtained by extracting a part of the pressurized air generated by starting the engine is connected to a concentrator 99 that generates air containing abundant oxygen.

Output air from the concentrator 99 and oxygen from the backup oxygen system 98 are connected to the front seat regulator 100.

The backup oxygen system 98 is usually formed by an oxygen cylinder, and is automatically or selectively used by the backup oxygen switching unit 104 of the front seat regulator 100 when the concentrator 99 and its series have some inconvenience. Is.

The front seat regulator 100 is provided with a concentration controller 101 for controlling the oxygen concentration from the concentrator 99 and an oxygen concentration monitor 102 for measuring the oxygen concentration.

The mode selector 103 is an operation mode that does not use the backup oxygen (backup off), a mode that automatically selects and uses the backup oxygen and air from the concentrator (automatic or kemal mode), and a mode that uses only the backup oxygen system 98. Manually set the three modes of (backup on).

The backup oxygen switching unit 104 forms a valve state by a signal from the mode selector 103. Breathing regulator 10
5 is a mask 120 for air from the backup oxygen switching unit 104
It is a regulator that adjusts to a pressure suitable for supplying to.

The output of the backup oxygen switching unit 104 is branched to the rear seat regulator 110.

The rear seat regulator 110 is provided with a shut-off valve 111 and a breathing regulator 112 having the same structure as the breathing regulator 105 described above.

The shut-off valve 111 is a valve that is opened and closed manually, and another mask 121 is connected to the breathing regulator 112.

The self-diagnosis mechanism shown in FIG. 1 is provided in the oxygen concentration monitor 102 shown in FIG.
Monitoring the oxygen concentration in the air from 9.

As described above, the concentrator 99 is a device that generates high-concentration oxygen gas for human breathing from compressed air (bleed air).

A part of the oxygen gas generated by the concentrator 99 is guided to the oxygen concentration monitor 102 as a sampling gas.

The density controller 101 receives the signal from the monitor 102,
The oxygen concentration of the produced gas is controlled within a certain range higher than the atmospheric oxygen concentration.

If the oxygen concentration of the produced gas drops abnormally due to a failure of the concentrator 99, a backup oxygen system
98 receives the signal from the monitor 102 and sends a signal to the oxygen switching unit 104 to switch the flow path so as to supply the gas from the backup oxygen system 98 to the pilot.

The self-diagnosis mechanism is for determining whether or not the functions of the monitor 102 and the backup oxygen switching unit 104 are normal among these functions by the button operation by the user and the display of the result. A cylinder 10 of the self-diagnosis mechanism is provided with a concentrator generated gas inlet 11 and an engine bleed pressure air inlet 12.

Pistons 14, 15, 16 are provided on the piston rod 13, and an O-ring is attached to each piston.

In the normal case of operating the concentrator 99, when the test button 17 is not pressed [Fig. 1 (A)], the monitor 10
The oxygen gas concentrated in the concentrator 99 is supplied to the oxygen sensor 20 in 2 as a sampling gas.

The concentrated oxygen gas from the concentrator 99 enters from the concentrator generated gas inlet 11 of the diagnostic mechanism and enters the piston 14.
It enters a room partitioned by an O-ring between 15 and flows to an oxygen sensor 20 through an orifice 19 at the outlet.

While operating the concentrator 99, press the test button 17
When you press [Fig. 1 (B)], the piston moves and the bleed air connected to the engine bleed pressure air inlet 12 enters the room partitioned by the O-ring between the pistons 15 and 16 and exits. It flows to the oxygen sensor 20 through the orifice 19. Since the oxygen concentration of the bleed air of the engine is about 21%, which is the same as that of the atmosphere, the oxygen sensor outputs a low oxygen concentration signal, and the backup oxygen switching unit 104 that receives this outputs the backup oxygen instead of the gas generated by the concentrator 99. The flow path is switched to supply gas to the pilot.

The backup oxygen switching unit 104 notifies that the backup oxygen supply has been switched by lighting a backup start confirmation lamp.

After the pilot confirms that the lamp is on, press the test button
When the hand is released from 17, the reaction force of the spring 18 causes the flow path of the sampling gas to automatically return to the state before the button is pressed, and the backup starting state is also canceled.

When performing self-diagnosis in this way, the oxygen sensor is positively supplied to the oxygen sensor 20 by bleeding the engine.
The gas (concentrated oxygen gas) of the concentrator 99 remaining on the head of 20 can be discharged at a time corresponding to the piping volume of the sampling gas flow path and the sampling flow rate.

The sampling flow rate is limited to a substantially constant value by the orifice 19.

The time from when the test button 17 is pressed until the backup oxygen is supplied is the sum of the time required for the concentrated oxygen gas to be discharged from the sampling channel and the response speed of the oxygen sensor.

Therefore, by appropriately adjusting the flow rate of the orifice 19, the inspection time can be stabilized in a preferable short time.

(Effects of the Invention) As described in detail above, in the oxygen generator having the self-diagnosis function according to the present invention, in the oxygen generator that monitors the oxygen concentration of the concentrator-generated gas to generate control information, the oxygen sensor is usually A switching valve for connecting the generated gas of the concentrator and connecting the extracted pressure gas during diagnosis is provided, and self-diagnosis is performed by the operation of the oxygen sensor during diagnosis.

In the self-diagnosis mechanism of FIG. 3 shown as a reference, the time until the backup oxygen starts up was about 9 to 20 seconds, which was a large variation.

In the apparatus of the above embodiment, this time is about 7 to 10 seconds, and the confirmation time can be shortened.

The device according to the present invention can shorten the confirmation time and stabilize the self-diagnosis mechanism during a busy pre-flight inspection, and is very effective in reducing the labor of the pilot.

[Brief description of drawings]

FIG. 1 is a sectional view of a self-diagnosis mechanism in an oxygen generator according to the present invention. FIG. 2 is a block diagram showing the overall configuration of the oxygen generator. FIG. 3 is a cross-sectional view showing a self-diagnosis mechanism (reference example) before improvement. 10 …… Cylinder 11 …… Concentrator Generated gas inlet 12 …… Engine bleed pressure Air inlet 13 …… Piston rod 14,15,16 …… Piston 17 …… Test button 18 …… Spring 19 …… Orifice 20 …… Oxygen sensor 30 …… Cylinder 31,32 …… Valve 33 …… Piston 98 …… Backup oxygen system 99 …… Concentrator 100 …… Front seat regulator 101 …… Concentration controller 102 …… Oxygen concentration monitor 103 …… Mode selector 104 …… Backup Oxygen switching unit 105 …… Breathing regulator 110 …… Rear seat regulator 111 …… Shut-off valve 112 …… Breathing regulator 120,121 …… Mask

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiji Furuno 1-6-1 Sakaemachi, Tachikawa-shi, Tokyo No. 1045, Government Office No. 1045 (72) Hiroshi Kawai, 1 Kawasaki-cho, Kakamigahara-shi, Gifu Kawasaki Heavy Industries, Ltd. Gifu Factory (72) Inventor Susumu Ohara 1-35-1 Izumihonmachi, Komae-shi, Tokyo Inside Tokyo Aircraft Instrument Co., Ltd.

Claims (1)

[Claims] 1. An oxygen generator for monitoring the oxygen concentration of a concentrator-produced gas to generate control information. A switching valve for connecting a bleed pressure gas to a oxygen sensor normally connected to the concentrator-produced gas during diagnosis. When the switching valve is operated at the time of diagnosis to connect the extracted pressure gas to the oxygen sensor, and the oxygen sensor outputs an alarm signal in response to the extracted pressure gas having a lower oxygen concentration than the gas produced by the concentrator. Is a self-diagnosis mechanism in an oxygen generator, which is configured to determine that the operation of the device is normal.