JPH08304317A - Control device for air cleaner - Google Patents

Abstract

PURPOSE: To prevent the erroneous operation of an air cleaner by aromatic smell without setting the detecting sensitivity of odor low. CONSTITUTION: A first odor sensor 1 has a gas sensitive part consisting of a sintered metal oxide semiconductor, which is more sensitive to aromatic smell than cigarette smell at smoking, and its output is minimized to cigarette smell and increased to aromatic smell. A second odor sensor 2 has a gas sensitive part consisting of a metal oxide semiconductor formed into thin film by vacuum evaporation, which is satisfactorily sensitive to both the cigarette smell and aromatic smell, and the output is increased to the both. On the basis of the outputs of such first and second sensors 1, 2, whether the odor is cigarette smell or aromatic smell is judged, and an air cleaner 5 is ON-OFF controlled on the basis of this judgment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an air purifier, which can be effectively used as a control device for an on-vehicle air purifier or the like.

[0002]

2. Description of the Related Art As one of the prior arts related to the present invention, there is a vehicle ventilation control device described in JP-A-61-196816. This is provided with a single gas sensor in the vehicle compartment, and it is determined whether or not the odor of smoking during smoking detected by this gas sensor is above a predetermined level for a predetermined time or longer, and above the predetermined level and above a predetermined level. When the ventilation is continued for a time or longer, the ventilation is stopped when the odor of smoking during smoking detected by the gas sensor falls below a predetermined level.

[0003]

By the way, in this type of control device, the detection sensitivity must be set low in order to prevent malfunction due to the influence of the vehicle fragrance or the like. In other words, set the detection sensitivity to a low value and do not activate it against aromatic odors, but rather activate it against cigarette odors when smoking based on the fact that cigarette odors during smoking have a relatively high concentration in the vehicle cabin. I had no choice. Since the detection sensitivity has to be set low as described above, the above-described conventional technique cannot quickly act on the cigarette odor during smoking, and the cigarette odor during smoking is not detected in the vehicle interior. Ventilation means or air purifiers will be stopped, even though they are still uncomfortable. As a result, it will always be driven manually,
The dirt of the filter of the ventilation means or the air purifier becomes large, which causes a problem that the replacement time is accelerated. If it is possible to determine whether it is an aromatic odor or a cigarette odor when smoking, it is possible to prevent malfunction due to an aromatic odor without setting the detection sensitivity low, and it is possible to improve the above-mentioned problems.

The present invention has been made based on the above point of view, and an object thereof is to provide an air purifier control device capable of preventing a malfunction due to an aromatic odor without setting a low detection sensitivity.

[0005]

According to the present invention, there is provided a gas sensitive portion made of a metal oxide semiconductor formed by sintering.
A light odor with a small odor molecule, such as an aromatic odor, is more easily adsorbed than a heavy odor with a large odor molecule, such as a cigarette odor when smoking, and is more sensitive to a light odor than a heavy odor. It has a odor sensor and a gas-sensitive part made of a metal oxide semiconductor formed by vacuum deposition to easily adsorb both heavy and light odors and is sensitive to both heavy and light odors. A good second odor sensor, and based on the outputs of the first and second odor sensors, it is determined whether the odor is a heavy odor such as a tobacco odor during smoking or a light odor such as an aromatic odor,
The above-described object is achieved by an air purifier control device having a control means for performing on / off control of the air purifier based on the determination result.

[0006]

[Function] The first odor sensor is more sensitive to light odors such as aromatic odors than heavy odors such as cigarette odors during smoking. Small,
If the odor is aromatic, the output will be large. The second odor sensor is
Since it has good sensitivity to both heavy odors such as cigarette odors during smoking and light odors such as aromatic odors, the output is large regardless of whether it is a cigarette odor during smoking or an aromatic odor. Become. Therefore, if it is a cigarette odor during smoking, the output of the first odor sensor is small and the output of the second odor sensor is large, and if it is an aromatic odor, the output of the first odor sensor and the output of the second odor sensor. Since both of them increase, it is possible to determine whether the odor is a heavy odor such as a cigarette odor during smoking or a light odor such as an aromatic odor. For example, if the ratio S _B / S _A of the output S _A of the first odor sensor and the output S _B of the second odor sensor is taken,
In the case of heavy odor such as cigarette odor during smoking, the output S _A of the first odor sensor becomes small, so the output ratio S _B / S _A becomes large, and in the case of light odor such as aromatic odor. The output S _A of the first odor sensor is large, and the output ratio S _B / S _A is small. Based on such discrimination, by driving the air purifier in case of heavy odor such as cigarette odor during smoking, light odor such as aromatic odor can be generated without setting detection sensitivity low. Malfunction is prevented.

[0007]

FIG. 1 is a block diagram showing an embodiment of the present invention,
2 is a perspective view showing the first odor sensor in the configuration of FIG. 1, and FIG. 3 is a perspective view showing the second odor sensor in the configuration of FIG.

In FIG. 1, 1 is a first odor sensor, 2 is
Is a second odor sensor, 3 is a control unit, and 4 is an air purifier.

As shown in FIG. 2, the first odor sensor 1 includes a gas sensing portion 7 composed of a platinum wire coil 5 and a metal oxide semiconductor 6 formed on the coil portion of the platinum wire coil 5 by sintering.
And have. Although the metal oxide semiconductor 6 is shown as a spherical body in order to illustrate the coil portion of the platinum wire coil 5 inside, the metal oxide semiconductor 6 is a substantially spherical shape that covers the coil portion of the platinum wire coil 5. The coil portion of the platinum wire coil 5 functions as a heater that heats the metal oxide semiconductor 6 in order to enhance the sensitivity and responsiveness of the metal oxide semiconductor 6. The metal oxide semiconductor 6 includes SnO ₂ series, ZnO series, TiO ₂ series, F
In a metal oxide semiconductor formed by sintering such as e ₂ O ₃ , the resistance value decreases due to the adsorption of odorous molecules. From an electrical point of view, the platinum wire coil 5 and the metal oxide semiconductor 6 are considered to form a parallel circuit with the resistance of the platinum wire coil 5 and the resistance of the metal oxide semiconductor 6. Therefore, when the resistance value of the metal oxide semiconductor 6 decreases due to the adsorption of odor molecules, the combined resistance of the platinum wire coil 5 and the metal oxide semiconductor 6 decreases. The first odor sensor 1 gives such a change in the combined resistance to the control unit 3 as a voltage output S _A. First
The odor sensor 1 is porous because the metal oxide semiconductor 6 is formed by sintering. Therefore, large and small holes are mixed on the surface of the metal oxide semiconductor 6, and it is difficult for heavy odors having a large odor molecule such as cigarette odor and dark odor during smoking to enter into the small holes. Light odors with small odor molecules such as aromatic odors and alcohol odors, which are difficult to be adsorbed and have high volatility, are easy to adsorb because they easily enter small and large holes. Therefore, the first odor sensor 1 is more sensitive to a light odor such as an aromatic odor than a heavy odor such as a cigarette odor during smoking, and outputs the output S if a cigarette odor during smoking.
_{When A} is small, the output S _A is large when the smell is aromatic.

As shown in FIG. 3, the second odor sensor 2 includes an alumina substrate 8, a gas sensitive portion 10 made of a metal oxide semiconductor 9 formed on the upper surface of the alumina substrate 8 by vacuum deposition, and a metal. An electrode portion 13 formed by combining a pair of comb-teeth-shaped platinum thin-film electrodes 11 and 12 on the oxide semiconductor 9 in a comb shape in a non-contact state.
And a platinum thin film heater 14 which is formed on the lower surface of the alumina substrate 8 and heats the metal oxide semiconductor 9 in order to enhance the sensitivity and responsiveness of the metal oxide semiconductor 9. The metal oxide semiconductor 9 includes SnO ₂ series, ZnO series, TiO ₂ series,
It is a metal oxide semiconductor formed into a thin film by vacuum vapor deposition of Fe ₂ O ₃ system or the like, and its resistance value decreases due to adsorption of odor molecules. Power supply terminals 15, 16 and output terminals 17, 18 are provided on the pair of platinum thin film electrodes 11, 12 constituting the electrode part 3, and the platinum thin film heater 14 is supplied with power supply terminals 19, 2.
0 is provided. The second odor sensor 2 gives the resistance change of the metal oxide semiconductor 9 to the control unit 3 as a voltage output S _B. Since the metal oxide semiconductor 9 is formed into a thin film by vacuum vapor deposition, the second odor sensor 2 has a uniform particle size on its surface, and is easily adsorbed regardless of the size of odor molecules. Therefore, the second odor sensor 2 has a heavy odor with a large odor molecule such as a cigarette odor and a dark odor during smoking, and a light odor with a small odor molecule such as a volatile aromatic odor and an alcohol odor. The sensitivity to both odors is good, and the output S _B is large regardless of whether it is a cigarette odor or an aromatic odor when smoking.

FIG. 4, FIG. 5 and FIG.
A diagram showing an output S _A and a second output S the experimental results showing the _B odor sensor 2 odor sensor 1, FIG. 4 is an output of the first odor sensor 1 against tobacco odor during smoking S _A and the second
The odor sensor 2 indicates output S _B, Figure 5 shows the output S _A and a second output S _B of the odor sensor 2 of the first odor sensor 1 for lemon odor used in the fragrance, 6
Is the output S _A of the first odor sensor 1 and the output S of the second odor sensor 2 with respect to the musk odor used for the fragrance.
_B is shown. In these figures, the vertical axis represents the first output S _B of the output S _A and the second odor sensor 2 odor sensor 1, the horizontal axis represents time (minutes). As shown in FIG. 4, the output S _{A of} the first odor sensor 1 is 16.1 mV with respect to the cigarette odor during smoking after 10 minutes.
Then, the output S _{B of} the second odor sensor 2 becomes 259.4 mV, and for the lemon odor, as shown in FIG.
The output S _{A of} the first odor sensor 1 is 56.1 mV, and the second
The output S _B of the odor sensor 2 becomes 238.6 mV, and as for the musk odor, as shown in FIG. 6, the output S _{A of} the first odor sensor 1 is 43.7 mV and the second S The output S _B of the odor sensor 2 became 219.5 mV. In this experiment, the metal oxide semiconductors 6 and 9 of the first and second odor sensors 1 and 2 were both made of SnO ₂ system.
As is clear from these experimental results, the first odor sensor 1 has a small output for a cigarette odor during smoking and a large output for an aromatic odor.
Has a large output for both cigarette odor and aromatic odor during smoking.

[0012] Control unit 3 has a first output S _A of the odor sensor 1 and the second output S _B of the odor sensor 2
Is input, the ratio S _B / S _A between the output S _A and the output S _B is calculated, and if the ratio S _B / S _A is larger than a predetermined value, it is recognized that the odor is a tobacco odor during smoking. Then, the air purifier 4 is driven, and if the ratio S _B / S _A is smaller than a predetermined value, the air purifier 4 is stopped because it is recognized that it is not a cigarette odor during smoking.

[0013]

[Table 1] Table 1 is the experiment results showing the ratio S _B / S _A of the first output S _B of the output S _A second odor sensor 2 odor sensor 1 to various aromatic odor and smoke when the cigarette odor . As is clear from Table 1, in the case of aromatic odor, the highest ratio S _B / S _A is 5.6, which is higher than the ratio S _B / S _A = 16.1 in the case of smoking tobacco odor. Will be a much smaller value. In this example, the above-mentioned predetermined value is set to 6 based on such an experimental result.

FIG. 7 is a flowchart of the control unit 3 shown in FIG. 1. The operation of the configuration shown in FIG. 1 will be described with reference to FIG. The control unit 3 starts with step 3
A first output S _A and a second output S _B of the odor sensor 2 odor sensor 1 uptake at 0,31, the next step 32
Then, the ratio S _B / S _A of both outputs is calculated. Next, at step 33, it is judged if the calculated output ratio S _B / S _A is larger than 6. If the ratio S _B / S _A is greater than 6, it is determined that the smell is a cigarette odor when smoking, the process proceeds from step 33 to step 34, the air purifier 4 is operated, and the process returns to step 30. If the ratio S _B / S _A is less than 6, then
When it is determined that the cigarette does not smell like smoking, the process proceeds from step 33 to step 35, the air purifier 4 is stopped, and the process returns to step 30. With such a configuration, the output ratio S _B / S _A becomes equal to or less than the predetermined value in the case of an aromatic odor, so that the air purifier 4 does not malfunction. Also, as mentioned above,
The output ratio S _B / S _A for the aromatic odor is much smaller than the output ratio S _B / S _A for the tobacco odor during smoking, so the predetermined value for discrimination can be set low, and The detection sensitivity to the tobacco odor of can be increased.

FIG. 8 is another flowchart of the control unit 3 of FIG. 1, which is applied instead of the flowchart of FIG. The operation of the configuration of FIG. 1 will be described with reference to FIG. The control unit 3 starts with step 40,
41 captures the first output S _A and a second output S _B of the odor sensor 2 odor sensor 1, the next step 42,
The ratio S _B / S _A of both outputs is calculated. Then step 4
At 3, it is determined whether the calculated output ratio S _B / S _A is larger than 6. If the output ratio S _B / S _A is smaller than 6, it is determined that the smoke odor is not smoking, and the process returns to step 40 after the air purifier 4 is stopped in step 44. If the output ratio S _B / S _A is larger than 6, it is determined that the smell is a cigarette odor when smoking, and the routine proceeds from step 43 to step 45. In step 45, the output S _{B of} the second odor sensor 2
Is determined to be equal to or higher than a predetermined concentration. This predetermined concentration is experimentally determined based on whether or not the cigarette odor during smoking remains uncomfortable. If the output S _B of the second odor sensor is equal to or higher than the predetermined concentration, the operation process of the air purifier 4 in step 46 is performed, and the process returns to step 45, and the output S _B of the second odor sensor is equal to or higher than the predetermined concentration. Then, after the stop processing of the air purifier 4 in step 47, step 4
Return to 0. According to such a configuration, when it is determined that the cigarette odor during smoking is determined, the air purifier 4 is driven until the cigarette odor during smoking becomes a predetermined concentration or less. By setting the predetermined concentration to a level that does not cause discomfort due to a cigarette odor, the air purifier 4 may stop even though the cigarette odor during smoking remains uncomfortable. To be prevented.

In the embodiment described above, the first odor sensor 1
Of the output S _A of the second odor sensor 2 to the output S _{B of} the second odor sensor 2 S _B
Based on / S _A , it is determined whether the odor is a heavy odor such as a cigarette odor during smoking or a light odor such as an aromatic odor, and the air purifier is controlled to be turned on and off based on the determination result. the first output S _a and lighter odor or discrimination such as heavy odor or fragrance odor such as tobacco odor during smoking based on differentially between the second output S _B of the odor sensor 2 odor sensor 1 It is also possible to
With this, the air purifier may be on / off controlled.

[0017]

As described above, according to the present invention, a heavy odor having a large odor molecule such as a cigarette odor during smoking, which has a gas sensitive portion made of a metal oxide semiconductor formed by sintering, is provided. Also, a light odor with a small odor molecule such as an aromatic odor is more easily adsorbed, and the first odor sensor has better sensitivity to a light odor than a heavy odor, and a metal oxide semiconductor formed into a thin film by vacuum deposition. A second odor sensor having a gas-sensing part consisting of, which easily adsorbs both heavy odors and light odors, and has good sensitivity to both heavy odors and light odors.
Based on the output of the second odor sensor, it is determined whether the odor is a heavy odor such as a cigarette odor during smoking or a light odor such as an aromatic odor, and on / off control of the air purifier is performed based on this determination result. Since this is done, it is possible to prevent malfunction of the air purifier due to aroma odor without lowering the detection sensitivity.

Further, the output of the first odor sensor and the second
Based on the comparison between the output ratio of the odor sensor and a predetermined value, it is determined whether the odor is a heavy odor such as a cigarette odor during smoking or a light odor such as an aromatic odor. Since the air purifier is driven while such a heavy odor is determined, it is possible to prevent malfunction of the air purifier due to aroma odor without setting the detection sensitivity low.

Also, the output of the first odor sensor and the second
Based on the comparison between the output ratio of the odor sensor and a predetermined value, it is determined whether the odor is a heavy odor such as a cigarette odor during smoking or a light odor such as an aromatic odor. When such a heavy odor is determined, the air purifier is driven until the output of the second odor sensor falls below a predetermined concentration, so the aromatic odor can be set without lowering the detection sensitivity. It is possible to prevent malfunction of the air purifier due to.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a first odor sensor in the configuration of FIG.

FIG. 3 is a perspective view showing a second odor sensor in the configuration of FIG.

FIG. 4 is an output S of the first odor sensor for odor.
A diagram showing experimental results showing the output S _B of the _A and the second odor sensor shows an output S _A and a second output S _B of the odor sensor of the first odor sensor for smoking when the tobacco odor.

FIG. 5 is an output S of the first odor sensor for odors.
FIG. 6 is a diagram showing the experimental results showing the outputs S _B of _A and the second odor sensor, showing the outputs S _A of the first odor sensor and the outputs S _B of the second odor sensor with respect to the lemon odor used in the aromatic agent. Shows.

FIG. 6 is an output S of the first odor sensor for odor.
_It is a figure which shows the experimental result which shows the output S _B of _A and a 2nd odor sensor, and shows the output S _A of the 1st odor sensor and the output S _B of the 2nd odor sensor with respect to the musk odor used for the aromatic agent. Shows.

FIG. 7 is a flowchart of the control unit of FIG.

8 is another flowchart of the control unit of FIG. 1, which is applied instead of the flowchart of FIG. 7.

[Explanation of symbols]

 1 First Odor Sensor 2 Second Odor Sensor 3 Control Unit 4 Air Purifier 5 Platinum Wire Coil 6 Metal Oxide Semiconductor 7 Gas Sensing Part 8 Alumina Substrate 9 Metal Oxide Semiconductor 10 Gas Sensing Part 13 Electrode Part 14 Platinum Thin Film heater

Claims (3)

[Claims] 1. A light substance having a gas sensitive portion made of a sintered metal oxide semiconductor and having a small odor molecule such as an aromatic odor rather than a heavy odor having a large odor molecule such as a cigarette odor during smoking. It has a first odor sensor that is more easily adsorbed by odors and is more sensitive to light odors than heavy odors, and has a gas sensitive part made of a metal oxide semiconductor formed by vacuum deposition to form a heavy odor. A second odor sensor that easily adsorbs both odors and light odors and has good sensitivity to both heavy odors and light odors, and odors are smoked based on the outputs of the first and second odor sensors An air purifier control device having a control means for discriminating between a heavy odor such as a cigarette odor at a time and a light odor such as an aroma odor, and controlling on / off of the air purifier based on the discrimination result. 2. The heavy odor such as a tobacco odor when smoking is odor based on a comparison between a ratio between the output of the first odor sensor and the output of the second odor sensor and a predetermined value. The air purifier control device according to claim 1, wherein the air purifier is driven while determining whether the smell is a light odor such as an aromatic odor and the odor is determined to be a heavy odor such as a cigarette odor during smoking. . 3. The heavy odor such as a cigarette odor when smoking is odor based on a comparison between a ratio between the output of the first odor sensor and the output of the second odor sensor and a predetermined value. Or a light odor such as an aromatic odor, and when the odor is determined to be a heavy odor such as a cigarette odor during smoking, until the output of the second odor sensor falls below a predetermined concentration. The controller for an air purifier according to claim 1, which drives the air purifier.