JPH0660754B2 - Automatic operation devices such as ventilation fans - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an automatic operation device such as a ventilating fan that senses dirt on air and automatically operates a fan motor.

[Technical background of the invention]

Conventionally, this type of automatic operation device uses a sensor made of a metal oxide semiconductor as a means for detecting dirt in the air, and in this sensor, redox gas is caused by a reducing gas (for example, carbon monoxide) in the air. When a reaction occurs and the electric resistance value of the sensor changes, the dirt of the air is detected. Here, referring to FIG. 5, the conventional structure will be described. The electrical resistance value of the sensor a is the signal voltage generation circuit b.
Is converted into a voltage (detection signal) at, and this voltage is compared with the reference voltage (reference signal) from the reference voltage generation circuit d in the voltage comparison circuit c, and when the voltage from the sensor a exceeds the reference voltage. The motor control circuit e is operated to drive the fan motor f. Therefore, the electric resistance value of the sensor a changes not only due to the dirt of the air but also due to the temperature and humidity of the air, so it is necessary to adjust the reference voltage according to the season. Therefore, conventionally, a voltage adjusting switch g is attached to the reference voltage generating circuit d, and the reference voltage generated by the reference voltage generating circuit d is adjusted by operating the voltage adjusting switch g.

Other conventional techniques include, for example, JP-A-58-99.
There is one described in Japanese Patent No. 630. This device measures the clean air level M ₁ with a gas sensor 3 minutes after the power switch is turned on and stores the measured value M ₁ in the RAM. After that, the air pollution level M ₂ is measured at regular intervals, and the measured value M ₂ is compared with the stored value M ₁ to obtain M ₁
It is determined whether or not ≧ M ₂ . Here, M ₁ ≧ M ₂
If so, it is determined that the air has been polluted more than when M ₁ was measured, (M ₁ −M ₂ ) / M ₁ is calculated, and the calculated value is the pollution degree M manually set by the user. Compared to ₀ ,
If (M ₁ −M ₂ ) / M ₁ ≧ M ₀ , the ventilation damper is opened to ventilate the air, but (M ₁ −M ₂ ) / M ₁ <M ₀
If so, do not open the ventilation damper because the air pollution level is within the set value.

On the other hand, when the air is gradually cleaned after the power switch is turned on (that is, when M ₁ <M ₂ ), the stored value M ₁ is sequentially replaced with new data. As a result, the stored value M ₁ is gradually corrected in the direction of air cleaning.

[Problems of background technology]

However, in the former configuration, the reference voltage must be adjusted by operating the voltage adjustment switch g one by one according to the season,
It's really troublesome. Moreover, it is easy to forget to operate such a voltage adjusting switch g, and when the operation is forgotten, the fan motor f is operated even if the air is not contaminated, or conversely, the fan motor f is operated even if it is contaminated. It causes problems such as not being performed.

On the other hand, in the latter configuration, the value M ₁ measured 3 minutes after the power switch is turned on is stored, and thereafter, the value M ₂ measured at regular time intervals is compared with the stored value M ₁ to determine whether the pollution is determined, if greeted in a direction gradually cleaning the air, but the stored value M ₁ is rewritten to new data, the air from these updates stored value M _1, the power switch oN state immediately after Is performed only when the cleaning is performed (that is, the stored value M ₁ is updated in the increasing direction).
Therefore, it is impossible to appropriately increase or decrease the stored value M ₁ according to environmental changes such as temperature and humidity (season). That is, as described above, even if the air pollution level does not change, the output level of the sensor fluctuates up and down due to environmental changes such as seasons. Therefore, in order to perform optimal control that follows environmental changes, Therefore, it is necessary to update the stored value M ₁ not only in one direction (air cleaning direction) but also in the opposite direction. However, the latter configuration cannot automatically perform control according to such environmental changes. Therefore, with the latter conventional configuration that cannot perform such control, it is impossible to perform optimal control that follows environmental changes, and again, the user must adjust the set value according to environmental changes. It is necessary and troublesome.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and therefore an object thereof is to eliminate the need for an adjusting operation according to environmental changes such as seasons and to automatically operate a fan motor, such as a ventilation fan. To provide a driving device.

[Outline of Invention]

In order to achieve the above object, the present invention compares a detection signal from a sensor sensitive to air pollution with a reference signal, and operates a fan motor when the air becomes dirty. A storage means is provided for storing while updating the plurality of detection signals sampled by the sensor at short time intervals, and the latest data stored in the storage means is different from the old data by a predetermined amount or more while the fan motor is stopped. Sometimes a reference signal is set from the old data and the reference signal setting data corresponding to the old data, and a control means is provided for deleting the set reference signal after the operation of the fan motor is stopped. It is composed.

With this configuration, even if the sensor output fluctuates (drifts) due to environmental changes (changes in temperature, humidity, etc.), the detection characteristics will be automatically corrected following the environmental changes. Therefore, it is possible to accurately determine the air pollution without being affected by the environmental change.

Example of Invention

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. First, in FIG. 1 showing the overall circuit configuration,
Reference numeral 1 is an AC power supply for general household use, 2 is a motor control circuit composed of, for example, a bidirectional thyristor, 3 is a fan motor, and 4 is a sensor composed of, for example, a metal oxide semiconductor, and its electric resistance value is a reducing gas in the air. It varies depending on the amount (for example, carbon monoxide). 5 is a signal voltage generating circuit for converting the electric resistance of the sensor 4 into a voltage, 6 is an A / D converting circuit for converting the output voltage of the signal voltage generating circuit 5 into a detection signal V of a digital value, 7 is a CPU as a control means, Reference numeral 8 is a RAM serving as a storage means for storing the detection signal V, and 9 is a ROM, in which a control program for executing the processing procedure shown in the flowchart of FIG. 2 and a reference signal setting data α described later are stored. It is stored in advance. Thus, the detection signal (hereinafter referred to as the normal level signal V _A ) from the sensor 4 in the clean air changes as shown by the solid line in FIG. 3 due to the temperature change, and the air causes the fan motor 3 to operate. The detection signal when it is dirty to the extent that it should be started (hereinafter referred to as the operation start level signal V _A ′) changes as shown by the alternate long and short dash line. Therefore, in this embodiment, the difference between the driving start level signal V _A ′ and the normal level signal V _A is selected as the value of the data α, and the reference signal (driving start level which is compared with the detection signal V from the sensor 4 in actual use is selected. (Equal to V _A ′) is set based on the detection signal stored in the RAM 8.
That is, the reference signal is set by adding the data α corresponding to the detection signal to the detection signal stored in the RAM 8. The set value of such a reference signal is automatically changed without discriminating in any of the upper and lower directions by following an environmental change as described later. Incidentally, 10 is a DC circuit.

Next, the operation of the above configuration will be described. Now, it is assumed that the AC power supply 1 is turned on with the air being clean. Then, the electric resistance value of the sensor 4 according to the degree of contamination of the air is converted into a voltage by the signal voltage generation circuit 5, and this voltage is further converted into a detection signal V by the A / D conversion circuit 6, and the CPU 7
Entered in. Thus, the detection signal V input to the CPU 7
Are processed according to the control program stored in the ROM 9. Hereinafter, description will be given based on FIG. 2 showing a flowchart of this control program. That is, the CPU 7
The detection signal V from the sensor 4 is sampled for a fixed short time, for example, every 1 minute (step N1), and stored in the RAM 8 as data (step N2). Data of the detection signal V is sequentially stored in the RAM 8, and when the number of stored data exceeds 20, for example (step N3), R
The oldest data among the data stored in the AM8 is discarded and the new data of the detection signal V is stored in the RAM8 (step N4). When the fan motor 3 is stopped (step N5), it is determined whether or not the detection signal V newly input to the CPU 7 has changed more than a predetermined value as compared with the oldest data stored in the RAM 8. A judgment is made (step N6). In this case, while the air is clean (before t _{1 in} FIG. 4 showing the time change of the detection signal V), the detection signal V
Does not change much with respect to the stored data, the process proceeds to step N7, and in step N7, a reference signal V ₁ described later is generated.
The presence or absence of the setting of is determined. Here, the reference signal V is still
_{Since 1} is not set, the process returns to step N1. Then, at time t ₁ , for example, when smoking is started and the air becomes dirty, the sensor 4 senses and the value of the detection signal V starts to rise rapidly, and the determination result in step N 6 is “YES”. Therefore, the process proceeds to step N8, and it is determined whether or not the reference signal V ₁ is set in step N8. In this case, it is determined to be "NO", the process proceeds to step N9, and the oldest data V ₀ stored in the RAM 8 (that is, the detection signal V at time t ₀ 20 minutes before time t ₁ ).
And the reference signal V ₁ from the data α stored in the ROM 9
And the stop signal V ₂ are set according to the following equation.

V ₁ = V ₀ + α, V ₂ = V ₀ + α / 2 Here, as the data α, one corresponding to the oldest data V ₀ is selected as shown in FIG. The reference signal V ₁ and the stop signal V ₂ thus set are stored in the RAM 8. After this, the detection signal V input to the CPU 7 becomes "V
≧ V ₁ ”(step N10), it is determined to be“ NO ”before time t ₂ (see FIG. 4),
Return to step N1. When the detection signal V exceeds the reference signal V ₁ (time t ₂ ) as a result of the increase in the air pollution in the room (time t ₂ ), it is determined to be “YES” in step N10 and the fan motor 3 is controlled by the motor. The circuit 2 is operated (step N11), and the ventilation operation is executed accordingly. During the operation of the fan motor 3, it is determined to be "NO" in step N5, and then the detection signal V is "V≤V" in step N12.
₂ "is determined. While the indoor air is much contaminated and the detection signal V is larger than the stop signal V ₂ , step N1
When it is determined to be "NO" in 2, the process returns to step N1 and the fan motor 3 is continuously operated. When the air pollution is reduced by the execution of the ventilation operation and the detection signal V becomes lower than the stop signal V ₂ (time t ₃ ), step N1
In 2 the judgment is "YES" and the operation of the fan motor 3 is stopped (step N13). When the air is cleaned in this way, the detection signal V does not change at a low level. Therefore, after steps N6 and N7, it is determined whether or not a certain time has elapsed after the fan motor 3 was stopped. (Step N14) Until the fixed time elapses, the reference signal V ₁ and the stop signal V ₂ are stored in the RAM 8 and are erased after the fixed time elapses (step N15). By thus storing the reference signal V ₁ and the stop signal V ₂ in the RAM 8 for a certain period of time even after the fan motor 3 is stopped, the fan motor 3 is immediately restarted when the air becomes dirty again immediately after the fan motor 3 stops. I am able to drive.

According to the above-mentioned embodiment, the detection signal V from the sensor 4 is stored in the RAM 8 at every elapse of a fixed time, and the reference signal V is stored by the stored data of the detection signal V and the reference signal setting data α stored in the ROM 9. _Since I set it to ₁ ,
Even if the temperature and humidity of the air change due to environmental changes such as seasonal changes, the optimum reference signal V ₁ at that time can be set based on the detection signal V stored in the RAM 8. Thereafter, the reference signal V ₁ and the detection signal V ₁ can be set. By comparing with V, the fan motor 3 can be operated when the air becomes dirty. Therefore, unlike the conventional configuration, the operation of adjusting the reference signal V ₁ according to changes in temperature and humidity is completely unnecessary, and the operation of the fan motor 3 is completely automated.

The present invention is not limited to the above-described embodiment, and for example, when the detection signal becomes equal to or higher than the reference signal, the fan motor may be operated by a timer for a certain period of time. The time and the number of stored times can be changed as appropriate. Further, the automatic operation device of the present invention is not limited to the ventilation fan, and is widely applied to equipment such as other blowers, air purifiers, etc. that cleans air by physical or chemical means by ventilating or circulating indoor air. it can.

〔The invention's effect〕

As is apparent from the above description, the present invention is provided with a storage unit that stores while updating a plurality of detection signals sampled by the sensor at short time intervals, and the latest data stored in the storage unit while the fan motor is stopped. Is set to be more than a predetermined value from the old data, a reference signal is set from the old data and the reference signal setting data corresponding to the old data, and the set reference signal is set after the operation of the fan motor is stopped. Since the control means for erasing the
Even if the temperature and humidity of the air change due to environmental changes such as seasonal changes, the excellent effect that the fan motor operation can be completely automated by eliminating the need for adjustment operations according to the temperature and humidity changes. Play.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention.
FIG. 1 is an overall block diagram, FIG. 2 is a flow chart of a control program, FIG. 3 is a temperature change diagram of a detection signal, and FIG. 4 is a time change diagram of a detection signal during one use,
FIG. 5 is a block diagram of a conventional structure. In the drawing, 3 is a fan motor, 4 is a sensor, and 7 is a CPU.
(Control means), 8 is a RAM (storage means), and 9 is a ROM.

Claims (1)

[Claims] Claims: 1. A sensor for detecting a contamination of air and comparing a detection signal from a reference signal with a reference signal to drive a fan motor when the air is contaminated. A storage means for storing the plurality of detection signals while updating is provided, and when the latest data stored in the storage means is different from the old data by a predetermined amount or more while the fan motor is stopped, the old data and the old data are stored. An automatic ventilation fan, etc., characterized by having a control means for setting a reference signal from the reference signal setting data corresponding to the data and for deleting the set reference signal after the operation of the fan motor is stopped. Driving device.