JP2563263B2 - Air cleaner - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic air purifier that operates by detecting dirt on the air.

2. Description of the Related Art Conventionally, as a sensor for detecting the dirt of air in this type of air cleaner, a pair of light emitting element and light receiving element are arranged optically opposite to each other, and air for detection is sent between them to detect the air in the air. The one that applies the principle of so-called optical dust meter, which detects the change in the amount of light received by the light receiving element depending on the amount of dust, is used to amplify the output and drive the relay to control the operation. Is.

Problems to be Solved by the Invention In such a conventional configuration, dust that is white and has small particles such as cigarette smoke does not sufficiently reduce the amount of light by causing diffuse reflection of light on the particle surface, and thus the sensitivity of the sensor is reduced. It is dull, and if you try to amplify the sensor output greatly to compensate for it, the stability of the amplifier will deteriorate.Therefore, the air cleaner that applies this has low sensitivity, and it is difficult to move even if the air pollution level rises. That is, there is a problem that the stability is poor and a malfunction easily occurs.

The present invention solves such a problem, and an object of the present invention is to provide an air cleaner having a fast response speed to changes in the degree of pollution of air, good stability, and less malfunctions. Is.

Means for Solving the Problems In order to achieve the above object, the present invention provides a gas sensor in which a resistance value of an element changes depending on a gas concentration in the atmosphere, and an aging process for aging the gas sensor for a predetermined period after power-on. Means, air pollution measuring means for taking in the detection values of the gas sensor at predetermined intervals and measuring the degree of air pollution, air pollution storing means for temporarily storing the measurement value of the air pollution measuring means, and the air pollution measuring means. The operation start determination means for determining the operation start of the fan motor by comparing the measured value of the air pollution storage means with the measured value of the air pollution storage means, and the measurement of the air pollution measurement means when the operation start determination means determines that the operation does not start. First storage value updating means for updating the storage value of the air pollution storage means to the measured value only when the value decreases below a predetermined concentration, and the operation of the fan motor is started. An operating time determining means for determining a timer operating time at the start, a fan motor driving means for controlling energization of a fan motor, a measured value of the air pollution measuring means and a stored value of the air pollution storage means during timer operation. Comparing or at the end of the timer time, an operation stop judging means for judging an operation stop, and automatically updating the stored value of the air pollution storage means with the measured value of the air pollution measuring means after the operation of the fan motor is stopped. The configuration is provided with two stored value updating means.

Action With this configuration, the detection of cigarette smoke or smoke produced when food is baked is performed by detecting the reducing gas generated at the same time as the smoke with the gas sensor, and immediately after the power is turned on, the gas sensor is operated by the aging means. Wait until the air is stable, measure the gas concentration with the air pollution measuring means, store the measured value in the air pollution storage means, and use the operation start determination means to store the old gas concentration and the new gas concentration measured. The gas concentration change amount is calculated by comparing the above values, and it is determined whether the change amount is within a change that can occur on a daily basis, or whether the gas concentration has decreased or increased beyond that range. The first stored value updating means automatically updates the stored value of the old gas concentration, and when the value exceeds the range, the operating time determining means causes the fan time to change according to the increase amount. Operation is started by the drive unit, and the gas concentration change is monitored by the operation stop determination unit during the timer operation. If the operation is stopped immediately and the gas concentration does not fall below the original gas concentration, the operation is ended when the timer operation ends, and after the operation is stopped, the second stored value updating means changes the temporarily stored old measured value to the new measured value. Change automatically.

Embodiment One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of an air cleaner showing an embodiment of the present invention. In FIG. 1, 1 is an outer frame having a duct structure, 2 is an intake port thereof, and 3 is an exhaust port thereof. . The outer frame 1 is provided with a fan motor 5 inside thereof to rotate the fan 4, and an air purifying filter (hereinafter referred to as a filter) 6 is attached to the intake port 2 so that air outside the intake port 2 can be removed. Air is purified by the suction filter 6 and exhausted from the exhaust port 3. A gas sensor 7 is placed in contact with the outside air at a place where air flow due to intake and exhaust is small, and an air signal obtained by converting the gas concentration in the air is input to a control device 9 inside the panel 8. .

The control device 9 includes an aging means 10 for energizing the gas sensor 7 for a predetermined time until the resistance value of the gas sensor 7 becomes stable after the power is turned on, and thereafter, an output for inputting the gas sensor 7 at a predetermined interval to measure air. Contamination measurement means 11, air contamination storage means 12 for temporarily storing the measured results, operation start determination means 13 for determining the start of operation based on the amount of change in the gas sensor output after the lapse of time, and depending on the gas concentration. Time determining means 14 for determining when the fan motor 5 is in timer operation
From the fan motor driving means 15 for controlling the energization of the fan motor 5, and the operation stop judging means 16 for judging the stop of the operation at the end of the timer operation or when the gas concentration is equal to or less than the storage value of the air pollution storage means 12. It is configured.

Further, when the operation start determination means 13 determines that the fan motor 5 is not started, when the measurement value of the air pollution measuring means 11 is within a predetermined concentration range, the air pollution storage means 12
It is provided with a first stored value updating means 13a for changing the old measured value stored in to the new measured value.

Further, when the operation of the fan motor 5 is stopped by the judgment of the operation stop judging means 16, the second storage for changing the old measurement value stored in the air pollution storage means 12 to the new measurement value measured by the air pollution measuring means 11 Value updating means 16a and 16b are provided.

The automatic operation setting button 8a is an operation button for setting automatic operation.

FIG. 2 shows an example of a specific circuit of a main part. The controller 9 (not shown) comprises a microcomputer 18 and peripheral circuits. The microcomputer 18 shown here is a so-called one-chip microcomputer having a CPU, ROM, RAM, and an input / output unit.

The gas sensor 7 is connected to an input section of a microcomputer 18 via an A / D converter 17. As a result, the gas concentration signal from the gas sensor 7 is converted into a binary code and read by the microcomputer 18.

The automatic operation setting button 8a provided on the panel 8 is connected to the input side of the microcomputer 18.

On the other hand, the AC motor 21 is connected to the fan motor 5 and the triac 19
Of the AC power supply 21 connected to the T ₁ terminal of the triac 19 is connected to one end of the power supply of the control circuit 9 (+ V side in the figure).
When the output of 18 becomes low level and the microcomputer 18 is controlled so as to draw current from the gate terminal of the triac 19, the triac 19 is made conductive.

Therefore, when the microcomputer 18 determines that the fan motor 5 should be operated by the timer based on the gas concentration data from the gas sensor 7, the output of the microcomputer 18 is set to the low level and the fan motor control signal outputs the "on" signal. , And drives the triac 19 to supply power to the fan motor 5.

When the microcomputer 18 determines to stop the fan motor 5 based on the end of the timer operation or the gas concentration data from the gas sensor 7, the output of the microcomputer 18 is set to a high level and the fan motor control signal is "on". It is configured to output a signal, stop driving the triac 19, and stop power supply to the fan motor.

The principle of automatic operation of the air purifier will be described with reference to FIG. 3. First, after the power is turned on, the gas sensor 7 is aged for a predetermined time, and then the measured value of the degree of air pollution is stored as an initial value t _0. at a such time (or continuously) measured contamination degree t ₁ of the air, when the density difference as compared compared to the initial value t ₀ (t ₁ -t ₀₎ is equal to or greater than the limit value T _B (The Y-axis in FIG. 3 is the direction in which the lower part is the direction of increasing air pollution), the operation start determining means determines the operation start from the concentration difference (t ₁ −t ₀ ), and the timer corresponding to the gas concentration. The operation time determining means determines the time, and the timer operation of the fan motor 5 is started.

Although the operation is stopped by the operation stop determination means at the end of the timer time, if the degree of air contamination changes as shown by the solid line in FIG. 3 and the initial value t ₀ is not restored until the timer operation ends,
After the timer operation ends, the degree of air pollution is measured and stored as a new initial value.

This is to focus on the fact that the air purifier cannot remove the gas concentration in the air even if the dust is removed by the filter 2, and sets a new initial value assuming that the dust has been removed after the timer operation ends. .

Further, when the degree of air pollution changes as shown by the broken line in FIG. 3 and the value returns to the initial value t ₀ during the timer operation, the fan motor 5 is immediately stopped by the operation stop determination means and the degree of air pollution measured immediately before the stop. The value of is stored as a new initial value.

Next, the operation of the air cleaner configured as described above will be described with reference to the flowchart of FIG. However, it is assumed that the automatic operation setting button 8a is set to instruct automatic operation. After the power is turned on, the microcomputer 18 is initialized, and then the operation is started in accordance with the procedure of the program of the automatic operation stored in the built-in ROM and shown in the flowchart of FIG.

First, as the aging means 10, in the aging process of step 101, the gas sensor 7 is energized for a predetermined period (for example, 5 minutes) and waits for the performance to stabilize. Next, the gas concentration is measured as the air pollution measuring means 11 in step 102. In this measurement, in order to accurately measure the gas concentration which fluctuates in a short time, in practice, a certain period is repeated several times (for example, every 10 seconds). (3 times) and determine the value by taking the average value (however, the subsequent measurement is one measurement unless otherwise specified). A considerably dirty gas pre-installed in the program in step 103. Concentration (eg 6 sealed
It is determined whether or not the air is dirty from the beginning of the operation by comparing with (gas concentration when smoking about three cigarettes at a time in a tatami room) T _0, and when the gas concentration is high and the air is dirty, step 104 Move to a predetermined time (for example, 30 minutes)
After the operation, and when the air is not so dirty, the routine proceeds to step 105, where the initial value t ₀ is stored as T ₀ (air dirt storage means 12).

Next, as the operation start determination means 13, after a gradual time (for example, 10
(Seconds later), the gas concentration t ₁ is measured again in step 106, and compared with the previously stored concentration value T ₀ in step 107 to determine the predetermined concentration T 1.
_It is judged whether the air has been reduced by _A or more and the air has been cleaned, and if it has been cleaned, step 1 of the first stored value updating means 13a.
The process proceeds to 08, the previously stored density value T ₀ is updated to t ₁ , and the process returns to step 106.

If not cleaned in step 107, step 109
To transfer, if determines whether dirty air than the predetermined value T _B from the density value T _0, not dirty or greater than a predetermined value T _B Step 10
Return to 6 and execute step 109 again. Where T _A and
The value of T _B is a fluctuation range of gas concentration that can normally occur (for example, a value in the range of 5 to 10 ppm in terms of hydrogen gas sensitivity).

Now, if it is determined that T _B or the air in step 109 the operation start determination means 13 is dirty, then control goes to step 110 of the operating time determining means 14, further T _C or higher (T _C> T _B) air it is determined whether dirty, driving the fan motor 5 proceeds to step 111 of the fan motor driving means 15 if it stains air contaminated than the initial gas concentration t ₀ T _B or unsoiled until T _C short If it is determined that the amount of contamination is T _C or more, the process proceeds to step 112 of the fan motor driving means 15 to determine that the fan motor 5 should be operated for a long time. here,
Explaining the value of T ₀ , the fluctuation range T _B , the value of T _C incorporated in the above-mentioned program in the operation start determination means 13,
The value should be changed depending on the model of the air purifier for large halls or households, but for a household model, for example, the size of a typical Japanese house is about 6 tatami mats. As the measured value of the gas sensor converted to the normal hydrogen gas sensitivity of uncontaminated air is about 4ppm, T ₀ is assumed to be slightly contaminated air (3 cigarettes in a sealed 6 tatami room at the same time) 24ppm when sucked)
Assuming that T _B is a little dirty air (when one or two cigarettes are smoked at the same time in a sealed 6 tatami room), the fluctuation range is about 10 ppm, and T _C is a fairly dirty air (sealed. It is appropriate to set each value of about 30 ppm as the fluctuation range, assuming that 4 to 6 cigarettes are smoked at the same time in a room with 6 tatami mats.

Now, after the program reaches step 111 or 112 and the short-time or long-time timer operation is determined, the same processing is performed thereafter, so the operation stop determination means 16 during the short-time timer operation will be described as an example. . Gas concentration after gradual time (eg, 5 minutes) has passed in step 113a
measure t ₂ (this measurement is done several times and averaged),
In step 114a, it is determined whether or not the original value T ₀ or less is returned, and if it is returned, the process proceeds to step 116a and the fan motor 5
Immediately stop the operation of, the process proceeds to step 117a of the second stored value updating means 16a, the stored value T ₀ is changed to a new value t ₂ , and the process returns to step 106. If it does not return to the original value T ₀ or less in step 114a, the process proceeds to 115a, and it is determined whether or not the timer operation has ended by comparing with a counter incorporated in the microcomputer not specifically described, and if not completed, the step
Returning to 113a, when the operation is completed, the operation proceeds to step 118, the operation of the fan motor 5 is stopped, and the second stored value updating means 16b is executed.
At step 119, the gas concentration t ₃ is measured, then at step 120 the stored value T ₀ is changed to t ₃ , and step 106
Return to.

The value of the above timer time should be changed according to the application-specific model and the air flow rate, but as a short-time timer for cleaning slightly dirty air as a household model, about 30 minutes,
As a long-time timer for cleaning the considerably contaminated air, about 1 hour is the actually required processing speed. It should be noted that the timer time is not limited to two types, and a program for a larger number of types of timer time may be prepared by increasing the stain degree determination step.

According to the configuration of the above embodiment, when the air purifier is set to the automatic operation, the operation start determination means does not operate with a slight gas concentration change, and the reference gas to be compared by the stored value update means. By automatically updating the stored value of the density, malfunction can be prevented and stability can be maintained. Further, even if the operation stop determination means is in timer operation, if there is a sharp decrease in the concentration, the operation is stopped immediately, and the stored value updating means automatically updates the stored value, so that the gas concentration detection sensitivity is improved. Improved, high responsiveness to changes in air pollution, sensitive operation of air cleaner
You can stop.

EFFECTS OF THE INVENTION As is clear from the above embodiments, in the present invention, when the automatic operation is performed, the operation start determination means prevents the operation from starting with a slight gas concentration change that can occur every day, and the stored value update means allows the operation to be started. When the gas concentration falls below the specified limit, the reference gas concentration for comparison can be updated to this to prevent malfunctions, and the operation time determination means operates the fan motor at the timer time according to the gas concentration. When the gas concentration decreases and returns to the original gas concentration even during the timer operation by the operation stop determination means, the operation is stopped so that the response to air pollution is fast and the gas concentration changes according to the change in gas concentration. This is an effect that suitable operation control can be automatically performed.

[Brief description of drawings]

FIG. 1 is a block diagram of an air cleaner showing an embodiment of the present invention,
FIG. 2 is a circuit diagram of a main part of the air purifier, FIG. 3 is a gas concentration change diagram showing the principle for automatic operation determination, and FIG. 4 is a flowchart showing an example of a program for automatic operation determination. is there. 2 ... Air purification filter, 4 ... Fan, 5 ... Fan motor, 7 ... Gas sensor, 10 ... Aging means,
11 …… Air pollution measuring means, 12 …… Air pollution storage means, 13
...... Driving start determination means, 13a ...... First stored value updating means, 14 ...... Driving time determination means, 15 ...... Fan motor driving means, 16 ...... Driving stop determination means, 16a ...... Second stored value Update means, 16b ... Second stored value update means.

Claims (1)

(57) [Claims] 1. A gas sensor in which a resistance value of an element changes depending on a gas concentration in the atmosphere, an aging means for aging the gas sensor for a predetermined period after power-on, and a detection value of the gas sensor taken in at a predetermined interval. Air dirt measuring means for measuring the degree of dirt of air, air dirt storing means for temporarily storing the measured value of the air dirt measuring means, and comparison of the measured value of the air dirt measuring means with the stored value of the air dirt storing means. The operation start determination means for determining the operation start of the fan motor and the air contamination storage only when the measurement value of the air contamination measurement means decreases below a predetermined concentration when the operation start determination means determines that the operation does not start. First stored value updating means for updating the stored value of the means to the measured value, and operating time determining means for determining the timer operating time when the fan motor starts operating An operation stop is determined by comparing the measured value of the air pollution measuring means and the stored value of the air pollution storage means during the timer operation with the fan motor drive means for controlling the energization of the fan motor, or when the timer expires. An air purifier comprising: an operation stop judging means; and a second stored value updating means for automatically updating the stored value of the air dirty storage means with the measured value of the air dirty measuring means after the operation of the fan motor is stopped.