JPS5935743A - Automatic ventilation fan - Google Patents

Abstract

PURPOSE:To provide the titled fan adapted to start operating automatically upon a lowered oxygen concentration in a room, by arranging such that the ON and OFF control of motor is effected by signals outputted from an oxygen sensor detecting the oxygen concentration in the room. CONSTITUTION:Potentials (a), (b) are inputted to the input terminal of comparator 18, as an oxygen sensor 7 holds no electromotive force while an oxygen concentration remains normal (21%) in a room. Upon the oxygen concentration being lowered, the oxygen sensor 7 starts generating an electromotive force, while the potential a' at positive input terminal of comparator 18 drops lower than the potential a. At the moment when there is established a relation between potentials as a'<b, the output is lowered for actuating a relay 19. In this manner, a contact 19' is energized for rotating a fan motor 6 to start ventilating. As the oxygen concentration increases, the output from oxygen sensor disappears and the comparator 18 generates a high output power for thereby rendering the fan motor 6 inoperative again.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an automatic ventilation fan that detects the oxygen concentration in a room and automatically operates when the oxygen concentration drops below a certain value.

Conventional configurations and their problems In recent years, as the airtightness of buildings has improved, oxygen deficiency accidents have been increasing. In particular, it is extremely dangerous to use stoves, fan heaters, small instant water heaters, etc. in closed rooms, and regular ventilation is required. However, this is difficult to implement due to the complexity and forgetfulness. Recently, combustion equipment having an oxygen deficiency detection function has started to appear on the market.

This is something that alerts you when there is a lack of oxygen, something that automatically stops combustion in a trench, and something that provides ventilation. Furthermore, there are devices that operate a ventilation fan in conjunction with the use of combustion equipment, but if the ventilation fan is operated unnecessarily during heating or the like, energy will be wasted.

FIG. 7 shows a system diagram of an instantaneous water heater using this conventional ventilation fan interlocking switch system. In the figure, water flows in from an inlet 27, is heated by a heat exchanger 29 heated by a burner 28, and is supplied from a faucet 30. The gas passes through the gas cock 32 from the inlet 31 and is burned in the burner 28. Here, the switch 33 is interlocked with the gas cock 32, and when the gas cock 32 is opened, the contact becomes conductive. As a result, the ventilation fan 34 is connected to the power supply and the ventilation fan 34 is operated. When the gas cock 32 is closed, the switch 33 is opened and the ventilation fan 34 is stopped. In this case, the ventilation fan 34 always operates while the gas is burning, and it is good to use a device that is used for a short period of time, such as an instantaneous water heater, but if you use a heater or the like, if you constantly run the ventilation fan, the heating effect will decrease. There was a problem that it did not save energy. Furthermore, even if the ventilation fan is running, there is no guarantee that the oxygen deficiency will increase, and it is dangerous if the ventilation is not completely ventilated.

OBJECTS OF THE INVENTION The present invention overcomes the above-mentioned drawbacks of the prior art, and aims to provide an automatic ventilation fan that automatically operates when the oxygen concentration in the room decreases.

Structure of the Invention An integrated oxygen concentration sensor detects the indoor oxygen concentration, and a control circuit automatically operates the ventilation fan when the indoor oxygen concentration drops to suck in fresh air from outside, and the ventilation fan is still operating. The system is configured to stop the combustion equipment and issue a notification if the oxygen concentration does not increase.

With this configuration, indoor open combustion equipment such as instantaneous water heaters, stoves, fan heaters, etc. can be used safely, and in particular, when using heating equipment, there is no heat loss due to unnecessary ventilation, resulting in energy savings.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of the automatic ventilation fan of the present invention. 1 is a living room, 2 is outdoors, and 3 is an outer wall of a house or the like. Reference numeral 4 indicates a ventilation fan provided on the outer wall 3, and has a fan 6 and a motor 6 inside. An oxygen concentration sensor (hereinafter referred to as 02 sensor) detects the oxygen concentration in the room 1, 9 is a control box containing a control circuit, and a manual switch 10 is provided.

Here, the 02 sensor uses a stabilized zirconia element, and its structure and operation will be explained using FIGS. 2 and 3. Figure 2 shows a cross-sectional view of the sensor, which is made of zirconia (ZrO2,) 11 (7
) It has a structure in which the outer wall 12 and inner wall 13 are covered with porous platinum (PT). This sensor constitutes an oxygen concentration battery that generates an electromotive force according to the difference in oxygen concentration between the inside and outside of a cylinder with a bottom.

This operation will be explained with reference to FIG. The outside air of the outdoors 2 is in contact with the inside of the cylinder, and the air of the living room 1 with little oxygen is in contact with the outside of the cylinder. At this time, at the cathode of the inner wall 2, the electrode and zirconia react electrochemically, and the electrons are received and become oxygen ions, which are incorporated into a portion of the zirconia. The taken in oxygen ions move through the groups of the zirconia electrolyte, release electrons through an oxidation reaction at the anode of the outer wall 12, and return to oxygen. In other words, if there is a difference in oxygen partial pressure between the outdoor area 2 on the inside of the bottomed cylinder and the living room 1 on the outside, an electromotive force is generated in accordance with the difference. This operation is at high temperature (400-800'C)
It is performed stably. Figure 4 shows this characteristic, and the horizontal axis (
It shows the oxygen concentration in the room, and the vertical axis shows the electromotive force. When the indoor oxygen concentration and outdoor oxygen concentration are equal (21%), the electromotive force is zero. However, as the oxygen concentration in the room decreases, an electromotive force is generated, and when the oxygen concentration is around 0, an electromotive force of about 1 V is generated. Note that the zirconia sensor may be formed into a flat plate instead of a cylindrical shape with a bottom to detect the difference in oxygen concentration between the front and back surfaces.

Figure 6 shows an example of the control circuit inside the controller 9.
1 shown. DC power supply 14 and resistor 15, 16, 1
7 are connected in series, and the connection point between resistor 16 and resistor 16 is 0.
2 is connected to the positive input terminal of the comparator 18 via the sensor 7 . Let the potential of the connection point be a. The potential at the connection point between resistor 16 and resistor 17 is connected to the negative input terminal of comparator 18 . Here, the comparator 18 is a two/parator with an output from a two-person open collector in a general circuit. Comparator 18
The output of is connected to the positive potential of the DC power supply 14 via a relay 19.

Relay 19 is diode 1-'20 for absorbing coil back electromotive force.
are connected in parallel. Further, the contact 1d of the relay 19 is connected in series with the fan motor 6 connected to the AC power source 21, and the manual switch 10 is connected in parallel with the contact 19'. In addition, the AC power supply 21 is used as the heater 22 for heating the 02 sensor.
The 02 sensor 7 is always heated to a constant temperature by supplying power to the 02 sensor 7.

Next, the operation will be explained. Oxygen concentration in living room 2 is normal (21
%), the electromotive force of the 02 sensor is large as shown in FIG. Since the potentials a and b are the voltages across the resistor 16, the potential difference of the voltage drop across the resistor 16 is the potential a) b
It becomes. The positive input terminal of this comparator 18 has a higher potential than the negative input terminal, and the output becomes a NO output. Since the comparator 18 is an oven collector output, the output is
A means that the output is open and the relay 19 does not operate. Since the contact 19' is also open from the above, the fan motor 6 does not rotate.

Here, when the indoor oxygen concentration decreases, the 02 sensor 7 generates an electromotive force in the direction shown in the figure. The potential a' at the positive input terminal of the comparator 18 decreases from the potential a, and the potential a'(b
When this happens, the output becomes low and the relay 19 operates.

As a result, the contact point 19' becomes conductive, the fan motor 6 rotates, and ventilation begins. 02 if the indoor oxygen concentration increases
The output of the sensor 7 disappears, the output of the comparator 18 becomes high, and the fan motor 6 stops again. Here, the manual switch 10 can operate the fan motor 6 regardless of the operation of the relay 19.

In FIG. 1, the controller 9 may be built into the ventilation fan 4. The 02 sensor 7 may be made of something other than a zirconia element.

FIG. 6 shows a circuit diagram of another embodiment. This system is configured to automatically turn on the ventilation fan when the room becomes oxygen-deficient, and if the oxygen deficiency is not resolved even after a certain period of time has passed, a buzzer alerts the danger and at the same time stops the power supply to the combustion equipment to stop combustion. It is said that The oxygen deficiency detection axis in FIG. 6 is the same circuit as in FIG. 5, so its explanation will be omitted here.

Due to lack of oxygen, the relay 19 operates and the contact 19' drives the fan motor 6, and at the same time, the contact 19 of the relay 19
' causes the timer circuit 23 to operate and measure time. If the timer circuit 23 is not reset by opening the contact 19' within a certain period of time (approximately 10 minutes), the buzzer 24 and relay 2 are activated.
Outputs a signal to drive 5. As a result, the buzzer 24 alerts the user of danger, and at the same time, the contact 26' of the relay 25 is opened and the supply of AC power to the outlet 26 is stopped. The outlet 26 is provided in the controller 9 and supplies power to combustion equipment (not shown). The buzzer 24 may be any other notification device.

In addition to turning the power on and off using the relay 26, a solenoid or the like may be used to directly extinguish the combustor.

Effects of the Invention As described above, the automatic ventilation fan of the present invention has a built-in indoor oxygen concentration sensor and is configured to operate automatically by a control circuit, so it is suitable for indoor open combustion equipment such as instantaneous water heaters, stoves, and fan heaters. There is no fear of oxygen deficiency accidents even when using it, and it can be used for long periods of time with peace of mind. In addition, by ventilating only the necessary amount when necessary, there is no wasted ventilation, and especially when heating equipment is used, the drop in room temperature due to ventilation is minimized, resulting in energy savings.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an automatic ventilation fan in an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the structure of a zirconia oxygen concentration sensor, Fig. 3 is an explanatory diagram of its principle, and Fig. 4 is a characteristic diagram of the sensor. FIG. 5 is a circuit diagram showing an example of a control circuit, FIG. 6 is a circuit diagram showing another embodiment, and FIG. 7 is a system diagram of a conventional ventilation fan interlocking device. 5...Fan, 6...Fan motor,
7... Oxygen sensor, 9'... Control circuit, 10-... Manual switch, 11... Stabilizing zirconia element, 23... Timer circuit, 24
...Buzzer (alarm), 25°25'...
-Relay (combustion stop section). Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Figure 02 'y. Figure 7-23;

Claims (4)

[Claims] (1) A fan that exhausts indoor air outdoors, a motor that rotates the fan, and an oxygen sensor that detects the oxygen concentration in the room are provided, and a control circuit is provided that controls on/off of the motor based on the signal from the oxygen sensor. automatic ventilation fan. (2) The control circuit is provided with a timer circuit that operates in conjunction with the motor, an alarm that is operated by the timer circuit, and a combustion stop section that stops combustion of the combustion equipment. automatic ventilation fan. (3) The automatic ventilation fan according to claim 1, wherein the control circuit is provided with a manual switch that can turn the motor on and off regardless of the signal from the oxygen sensor. (4) The automatic ventilation fan according to claim 1, wherein the oxygen sensor is configured to detect the electromotive force of an oxygen concentration battery using a stabilized zirconia element.