JPH10156120A - Air cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to obtain the output of a filter exchange sign exactly correspondingly to a contamination degree by providing a fan supporting stay part where the velocity of the air flow passing a filter unit is highest with an air quantity sensor in the state parallel with the air flow. SOLUTION: This air cleaner is constituted by disposing the fan and filter unit in a main body casing. This fan comprises a multiblade impleller rotationally drive by a fan motor and a fan housing 11 covering the multiblade impeller. At this time, the fan housing 11 is composed to have four pieces of the fan motor supporting stays 11c consisting of a pair of side plates 110, 110 flat in an air flow direction and bottom plate parts 111 for connecting and integrating these plates to each other. A vent port 112 for air distribution is formed in the prescribed position in the radial direction of the bottom plate part 111 of any one stay 11c of these stays 11c.... A thermistor 50 is mounted in parallel with the air flow between the side plates 110 and 110 adjacently to the vent port 112.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purifier used for purifying indoor air.

[0002]

2. Description of the Related Art An air purifier is generally used to remove various contaminants contained in indoor air and purify indoor air.

Conventionally, an air purifier has a built-in blower and a filter unit in a casing of a predetermined shape, and purifies room air sucked from an air suction port by the blower through a filter unit. It is general that the outlet is blown into the room again.

[0004] By the way, when the air purifier having the above configuration is used for a long period of time, clogging occurs due to an increase in the amount of contaminants adsorbed on the filter unit, and the purifying action is reduced. Will come. Therefore, replace the above filter unit with a new one at the appropriate time,
It is necessary to maintain the original air purifying action, and recently, in order to inform the user of the replacement time of the filter unit, a replacement sign of the filter unit is issued by turning on a lamp or the like.

[0005]

However, the means for providing a conventional filter unit replacement sign is, for example, E ₂ P
Using a memory such as a ROM, when the cumulative operation time of the air purifier reaches the time set in advance by the manufacturer, it is automatically output, so depending on the usage environment of the air purifier, In spite of the fact that the degree of contamination of the filter unit is low and a sufficient purifying action can be maintained, a filter replacement sign will always be output after a certain operating time has elapsed, and it is possible to respond to the actual degree of contamination of the filter unit. However, the output time of the filter exchange sign was too early or too late.

[0006] Under such circumstances, the drop in the air flow rate on the downstream side of the filter unit is detected without detecting the elapse of the operation time as described above. Attempts are being made to display them according to the state.

However, in such a case, there arises a problem of how to install the airflow sensor, and there is a problem that the detected airflow varies considerably depending on the installation location and the installation form.

The present invention has been made in view of the above points, and is provided in a state where a flow rate of an air flow passing through a filter unit is highest in a blower supporting stay in a blower passage in a state parallel to the air flow. By providing an air flow sensor,
It is an object of the present invention to provide an air purifier capable of obtaining an output of a filter replacement sign corresponding to a degree of contamination.

[0009]

Means for Solving the Problems Each of the inventions of the present application is provided with the following effective problem solving means in order to achieve the above objects.

(1) The air purifier of the present invention is a blower incorporated in a casing, a blower support stay for supporting the blower, and a filter disposed on the air suction side of the blower. Unit and
An air flow sensor for detecting an air flow passing through the filter unit, wherein the air purified by the filter unit is blown out from an air outlet through an air flow path, and the air flow sensor is supported by the blower. It has a configuration provided on the stay.

The blower support stay portion is located in the middle of a blower passage between the filter unit and the blades of the blower where air is most easily circulated. Therefore, the wind sucked into the blower through the filter unit passes smoothly at the highest flow velocity.

Therefore, the air volume sensor provided in the portion detects the air volume with the highest sensitivity, and a decrease in the air volume due to the clogging of the filter unit is detected with good responsiveness.

(2) The invention of claim 2 The air purifier of the invention has the constitution of the invention of claim 1, wherein the air flow sensor is provided on the blower support stay in parallel with the air flow.

Therefore, the contact between the air flow and the air volume sensor is improved, and the detection sensitivity is further improved.

(3) The invention of claim 3 The air purifier of the invention is based on the construction of the invention of claim 1 or 2, and the blower supporting stays of the construction have, for example, a predetermined distance from each other. The air flow rate sensor is provided on a side surface of a sensor board provided between the plate members in parallel with the air flow.

The air flow sensor is generally installed with an electric circuit board or a sensor board which is a connection terminal. Therefore, although a place having high air volume detection sensitivity is preferable, it is necessary that the place is not a place where the operator touches the hand when replacing the filter unit or a place where it is not easily damaged by an impact or the like. Also, it is convenient if the sensor substrate itself can be used for mounting the sensor itself.

Therefore, as described above, the blower support stays are made of plate members provided at a predetermined interval from each other,
When the air flow sensor is mounted on the side of a sensor substrate provided between the plate members in parallel with the air flow, not only the sensor part but also the sensor substrate is hidden between the plate members, so that when the filter unit is replaced. It is hard to touch and there is no risk of damage. In addition, the airflow sensor can be mounted simply by providing the sensor substrate between the plate members, and the workability at the time of installation is improved. Further, since the sensor substrate is also parallel to the air flow, the air flow smoothly flows along the substrate surface provided with the air flow sensor, and the contact efficiency with the air flow is high.

(4) The invention of claim 4 The air purifier of the invention is based on the construction of the invention of claim 1, 2, or 3, and the air volume sensor in each of those constructions is replaced with a filter unit. This is a means for detecting a decrease in air volume for displaying the time.

Therefore, in the above structure,
According to the operation of the second or third aspect of the present invention, a decrease in air volume due to clogging of the filter unit is accurately detected with good responsiveness,
Accordingly, it is possible to appropriately issue a sign for replacing the filter unit.

(5) The invention of claim 5 The air purifier of the invention is based on the constructions of the inventions of claims 1, 2, 3 or 4, and each of the air volume sensors in each construction is formed by a thermistor. In addition, the resistance value changes with good responsiveness in accordance with the degree of cooling of the thermistor surface by the air flow, and the change in the air flow is accurately detected by the terminal voltage that changes correspondingly. Then, when it is detected that the air volume has decreased to a predetermined value or less, a sign for replacing the filter unit can be issued.

[0021]

As described above, according to the air purifiers of the present invention, the following effects can be realized.

(1) The air volume detection sensitivity of the air volume sensor is stabilized, and the responsiveness to clogging of the filter unit is improved, so that an accurate filter unit replacement sign can be provided.

(2) The air flow sensor can be effectively mounted by utilizing the empty space, and the installation work of the air flow sensor is facilitated because there is no obstacle in the installation portion.

[0024]

1 to 9 show the configuration of an air purifier according to an embodiment of the present invention.

As shown in FIGS. 1 to 3, for example, this air purifier is provided with a blower 2 in a box-shaped main body casing 1 and an air suction port of the blower 2 to remove dust, smoke and the like in the air. A filter unit 3 for adsorbing and collecting pollen, off-flavor substances and the like is provided.

The main body casing 1 comprises a synthetic resin bowl-shaped front plate 4 located on the air suction side of the blower 2,
The front plate 4 is composed of a bowl-shaped back plate 5 made of the same synthetic resin and facing the front plate 4. The front plate 4 and the back plate 5 are detachably engaged and integrated through a fan housing 11 described later. I have.

The front plate 4 of the main body casing 1 is formed such that a central portion in the vertical direction on the front side of the front plate 4 is recessed horizontally, an upper portion 6a is a horizontal surface, and a lower portion 6b is formed in the recess direction. A concave portion 6 extending to the left and right sides of the main body casing 1 having an upwardly inclined surface is formed, and a single horizontally long band-shaped air suction for sucking room air is formed in an inner deep portion of the concave portion 6. A mouth 7 is formed (see FIGS. 1 and 2). That is, the air suction port 7 is formed in a horizontally long band shape having a limited opening area, so that the air suction port 7 can be easily cleaned, and is limited to, for example, cigarette smoke. What is generated from the source can be efficiently sucked at a wide angle. The air inlet 7 has an upper part 6a on a horizontal surface, a lower part 6a.
Since b is formed in the inner part of the concave portion 6 which is an inclined surface having an upward slope in the concave direction, adhesion of dust and the like to the edge portion of the air suction port 7 is reduced, and the air suction is performed. The mouth 7 is hard to see from the outside. Reference numeral 13 denotes a pre-filter provided at the air suction port 7.

On the other hand, on one side of the upper surface of the back plate 5 of the main body casing 1 (the left rear portion in FIGS. 1 and 3), an air outlet 8 for blowing out the purified air is provided.
Are formed obliquely upward, for example.

The blower 2 includes a fan motor 9 as a driving source, a multi-blade impeller 10 driven to rotate by the fan motor 9, and a scroll-type fan housing 11 that covers the multi-blade impeller 10. The air inlet (small diameter) 11a of the fan housing 11 is directed toward the front side, and the air outlet (large diameter) 11b of the fan housing 11 is positioned above the main body casing 1. Is disposed and fixed in the main body casing 1 in a state facing the air outlet 8.

As shown in detail in FIGS. 4 to 7, the fan housing 11 has a cylindrical fan motor support frame 1 at the center.
1d, and the fan motor support frame 11d is connected to and integrated with the radially outer main body frame 11e via four fan motor support stays 11c, 11c,... Provided at 90 ° intervals in the circumferential direction. doing. Then, the rear end of the fan motor 9 is fitted into the fan motor support frame 11d, and the fastening flange 9b on the fan motor 9 side is screwed to the screw fixing portions 40, 4 on the outer periphery of the fan motor support frame 11d.
It is fixed by screwing to 0 ... In addition,
Reference numeral 9a denotes an output shaft of the fan motor 9, and 10a denotes a hub of the multi-blade impeller 10 fitted and fixed to the output shaft 9a.
The blades b, 10b,... are continuously provided on the hub 10a with a blade angle in the centrifugal direction.

By the way, 4 of the fan housing 11
The fan motor support stays 11c, 11c,... Are arranged side by side at a predetermined interval from each other, and form side plates (ribs) 110, 1 that form a pair of plate portions that are flat in the air flow direction.
10 and a bottom plate portion 111 for connecting and integrating them with each other, and has a U-shaped cross section, and is a flat surface orthogonal to the airflow of any one of the support stays 11c. At a predetermined position in the radial direction of the bottom plate portion 111, a ventilation port 112 for air circulation is formed. A sensor substrate 113 for mounting the first thermistor 50 also functioning as an air flow sensor is provided between the side plates 110 and 110 adjacent to the ventilation opening 112 and also in parallel with the air flow. The first thermistor 50 has a leg 114 on the side of the sensor board 113 on the side of the ventilation opening 112.
Is attached so as to face the ventilation port 112 via the air outlet.

Therefore, when the fan motor 9 is driven to rotate the multi-blade impeller 10, the air sucked from the air inlet 7 of the front plate 4 is first passed through the filter unit 3 to the fan housing 9. 11 enters the air suction port 11a, and from the air suction port 11a, the multi-blade impeller 10
Through the scroll passage, and is blown out from the air outlet 11b of the fan housing 11 in the direction of the air outlet 8 of the main body casing 1. At this time, the fan housing 11 passes from the air suction port 11a of the fan housing 11 through the fan motor support stay 11c.
Of the air flowing out to the air outlet 11b of
The air flow having the highest flow rate is generated by the fan motor support stay 11.
The air passes through the first thermistor 50 from the ventilation port 112 of c.

As a result, the first thermistor 50 stably detects the amount of air passing through the filter unit 3 with good responsiveness.

The filter unit 3 includes a filter cartridge 3a located on the leeward side and an activated carbon cartridge 3b located on the leeward side. The filter unit 3 is located on the air suction port 11a side (of the blower 2) of the fan housing 11. In addition, the fan housing 11 is detachably fitted to and supported by a cylindrical filter support frame 12 integrally protruding from the inside of the main body frame 11 e of the fan housing 11. A thermistor mounting member 12a is provided at a lower portion of the filter support frame 12 so as to protrude forward, and a filter unit 3 is provided at a front end of the thermistor mounting member 12a.
Is provided with a second thermistor 51 which is an airflow sensor for detecting the airflow before passing through the airbag.

Various operation keys (for example, an automatic operation key 15, a cigarette key 16 operated during a cigarette mode operation, a pollen key 17 operated during a pollen mode operation, a timer, Key 1
8. Air volume key 19 for setting air volume, operation switching key 20,
A filter reset key 21), a remote control light receiving unit 22, and various display lamps (dirt lamps 23a, 23b, and 23c serving as dirt display means for displaying the degree of dirt in indoor air), a cigarette display lamp 24 that is turned on when operating in the cigarette mode, and a pollen mode operation Pollen display lamp 25 that lights up at the time, timer lamps 26a and 26b that display the timer set time,
26c, air volume lamps 27a, 27 for displaying the set air volume
b, 27c, and an operation panel 14 having a filter exchange flap 28) for displaying a filter exchange sign is provided.
A dirt sensor (for example, a gas sensor) 30 that detects the degree of dirt of the indoor air (in other words, suction air) is provided. Reference numeral 30a denotes a suction port formed on the operation panel 14 for suctioning indoor air, and is formed in the space 31.
Is communicated with the air suction passage in the main body casing 11 through the communication port 32. Further, reference numeral 35 is
A control circuit that receives signals from the various operation keys 15 to 21, the remote control light receiving unit 22, and the dirt sensor 30, performs various calculations, and outputs control signals to the fan motor 9 and various display lamps 23 to 28 based on the results. It is a microcomputer unit provided with the above.

The dirt lamps 23a, 23b, 23c
Are sequentially turned on according to the degree of contamination of the intake air. That is, the degree of contamination of the indoor air can be displayed in a stepwise manner, and a dirt display corresponding to the degree of contamination of the indoor air can be performed. Therefore, the user can clearly know the degree of contamination of the indoor air.

On the operation panel 14, a cigarette picture display 33 imitating tobacco is provided near the cigarette display lamp 24, and a pollen picture display 34 imitating pollen is provided near the pollen display lamp 25. When the cigarette operation mode or the pollen operation mode is selected and the cigarette display lamp 24 or the pollen display lamp 25 is turned on, it is possible to display as if a cigarette is lit or as if the pollen is visible. It has become. This makes it possible to strongly impress the driving mode display for the user.

As described above, the air purifier according to the present embodiment includes the first thermistor 50 as a first airflow sensor for detecting the airflow passing through the filter unit 3 and the filter unit 3. A second airflow sensor as a second airflow sensor for detecting the airflow before passing
Are provided respectively. Then, the first thermistor 50 is connected to the filter unit 3.
The second thermistor 51 is disposed on the lee side of the filter unit 3 (see FIG. 2).

The first and second thermistors 50, 51
Constitutes a bridge-type air flow detection circuit together with fixed resistors R ₁ and R ₂ (where R ₁ = R ₂ ) as shown in FIG. 8, for example. Between the detection voltages V ₁ and V ₂ of the thermistors 50 and 51 (in other words,
The difference (V) between the first and second airflow sensors 50 and 51 (the difference between the airflow detection values) is input to the microcomputer unit 35 via the comparator 56.

The microcomputer unit 35 has built-in control means (control function) 55 for outputting a filter replacement sign signal for notifying the replacement time of the filter unit 3. Therefore, the operation of the control means 55 will be described below.

That is, the control means 55 controls the voltage change from the comparator 56 of the air volume detection circuit shown in FIG.
The change (the change in the difference between the detection values by the second two thermistors 50 and 51) V is input, and the input voltage V is the detection voltage (ie, the initial value) V ₀ when a new filter unit 3 without clogging is used. When the difference ΔV between the two becomes greater than the set value Vs when the air flow difference between the front and rear of the filter unit 3 becomes large enough to require the replacement of the filter unit 3, the filter unit is replaced. A filter replacement sign signal is output to prompt the user to turn on the filter replacement lamp 28.

The operation of the control means 55 will be described in detail with reference to the flowchart shown in FIG.

[0043] Now, the operation of the air cleaner is started, first from the air amount detection circuit in the first step S _1, the voltage of the difference between the detected value of the second thermistor 50 and 51 V
There is input, then the difference between the input voltage V and the initial value V ₀ in the second step _{S 2 (V 0 -V = ΔV} ) is calculated. Then, further the calculated values [Delta] V in the third step S ₃ is determined whether or not a higher the set value Vs is, if it is determined that YES (ΔV ≧ Vs) is 4
The process proceeds to step S _4, and turns on the filter replacement lamp 28 described above with output filter replacement sine signal. On the other hand, if in the third step S ₃ is determined NO (ΔV <Vs), a filter replacement sine signal is not output, repeating the above operation to return it to the first step S _1.

As described above, in the present embodiment, the difference between the detection values of the first and second thermistors 50 and 51 is input to the control means 55 of the microcomputer unit 35 as the input voltage V, and the input voltage V and the initial The difference from the value V ₀ is equal to or greater than the set value Vs indicating that the difference in the air volume between the front and rear of the filter unit 3 has become greater than the predetermined value due to the clogging of the filter unit 3 and the filter unit 3 needs to be replaced. It is determined whether the air purification function of the filter unit 3 has reached its limit due to clogging of the filter unit 3 based on the determination result. It is possible to obtain the output of the filter exchange signature corresponding to the above. Moreover, since the difference between the detection values of the first and second thermistors 50 and 51 provided on the fan side and the indoor side provided via the filter unit 3 is used as a parameter, the filter unit 3 is detected for dirt. Although the thermistor is inexpensive but sensitive to temperature change and easily affected by room temperature, the effect of room temperature is canceled and the filter unit 3 is surely removed.
There is an advantage that dirt can be detected.

Further, in the above configuration, the first thermistor 50 for detecting the air flow downstream of the filter unit 3 having a different air flow distribution depending on the location is provided with the fan housing 1.
One fan motor support stay 11c is provided in parallel with the air flow.

The fan motor support stay 11c is provided with the filter unit 3 and the multi-blade impeller 10 of the blower 2.
The air is located in the middle of the air passage where the air is most likely to flow straight before entering the scroll passage. Therefore, the wind sucked into the multi-blade impeller 10 of the blower 2 through the filter unit 3 smoothly passes at the highest flow velocity.

Therefore, the first thermistor 50 as an air flow sensor provided in this portion detects a stable air flow with the highest sensitivity, and the degree of decrease in the downstream air flow due to clogging of the filter unit 3 is reduced. It is detected with good responsiveness.

Further, in the above configuration, the fan motor support stay 11c is provided with a pair of side plates (plate members) 110, which are arranged side by side at predetermined intervals and are flat in the air flow direction.
110, a bottom plate 111 between the side plates 110, 110
Is formed with a ventilation port 112 for air circulation at a predetermined portion of the. Then, the first thermistor 50 is connected to the ventilation port 1.
The sensor substrate 113 is attached to a side surface of the sensor substrate 113 laid parallel to the air flow between the pair of side plates 110 near the position 12.

The thermistor 50 as an air flow sensor is generally installed with an electric circuit board or a sensor board which is a connection terminal. Therefore, although a place having high air volume detection sensitivity is preferable, it is necessary that the place should not be touched by the operator's hand when the filter unit 3 is replaced or the like and should not be easily damaged by impact or the like. Also, it is convenient if the sensor substrate itself can be used for mounting the sensor itself.

In view of the above, a pair of side plates 11 flat in the air flow direction, which are arranged side by side at predetermined intervals as described above, are provided.
In a fan motor support stay 11c provided with a pair of side plates 110 and 110, a sensor substrate 113 is installed in parallel with an air flow between the pair of side plates 110, When the first thermistor 50 is attached to the side surface of the substrate 113 and the first thermistor 50 is made to face the ventilation port 112, the sensor substrate 1 as well as the first thermistor 50 is used.
13 is also hidden between the pair of side plates 110, 110, so that it is hard to touch when replacing the filter unit 3 or the like, and there is no possibility of being damaged. In addition, the first thermistor 50, which is an air flow sensor, can be mounted simply by laying the sensor substrate 113 between the pair of side plates 110, 110, and the workability at the time of installation is improved. Further, since the sensor substrate 113 is also parallel to the airflow, the airflow smoothly flows along the surface of the sensor substrate 113 provided with the first thermistor 50, and the efficiency of contact with the airflow increases.

As a result, according to the air purifier according to the embodiment of the present invention, the following effects can be realized.

(1) The air volume detection sensitivity of the air volume sensor is stabilized, the responsiveness to clogging of the filter unit is improved, and an accurate filter unit replacement sign can be provided.

(2) The air flow sensor can be effectively installed by utilizing the empty space, and the installation work of the air flow sensor is facilitated because there is no obstacle in the installation portion.

(Modification) FIGS. 10 and 11 show a configuration of a modification of the air purifier according to the embodiment of the present invention.

In the configuration of the above embodiment, FIG.
As shown in (1), the difference V ₁ −V ₂ between the detection value of the first thermistor 50 for detecting the air volume passing through the filter unit 3 and the detection value of the second thermistor 51 for detecting the air volume not passing through the filter unit 3 is shown. = V (current value) is detected by a bridge circuit, and the difference between the detected values when a new filter unit 3 without clogging is used, V ₁ −V ₂ = V
₀ (initial value), a filter change sign signal is output when the difference V ₀ −V = ΔV becomes equal to or greater than a predetermined set value Vs indicating a clogged state requiring replacement of the filter unit 3. To cancel the effect of the change in room temperature.

On the other hand, in this modification, one of the first and second thermistors 50 and 51 for detecting the air flow is used for both the air flow detection and the room temperature detection, and the room temperature correction is added to the air flow determination value. Thus, the influence of the room temperature can be canceled with higher accuracy.

First, in FIG. 10, reference numeral 35 denotes a microcomputer unit similar to that described above, and the microcomputer unit 35 has a control function as shown in the flowchart of FIG.

The microcomputer unit 35 has first and second two input terminals P ₁ and P _2, and detects each detection voltage V ₁ of the first and second thermistors 50 and 51 shown in FIGS. , V ₂
Is entered.

In the case of the configuration of the modified example, first, at the time of measuring the air flow, the transistor Tr is turned on, and the detection voltage V ₁ of the first thermistor 50 is determined by the resistance R ₃ (thermistor heating resistance) and the resistance R _The divided voltage of the resistance value of the first thermistor 50 and the combined resistance value of each resistance value of ₁ (the resistance for measuring the room temperature) is then calculated as the detection voltage V of the second thermistor 51.
₂ is the resistance value of the resistor R ₂ (thermistor heating resistor) and the second value.
In the meantime, the transistor Tr is turned off at the time of measuring the room temperature, and the detection voltage V ₁ of the first thermistor 50 is equal to the resistance value of the resistor R ₁ . Resistance value and first thermistor 5
It is shown as a divided voltage value with a resistance value of 0.

[0060] That is, one end of a resistor R ₃ that is present only when the air volume measurement switching transistors (P
Together they are connected to a power source + B via the NP) Tr, and the other end is connected to the connection point between the resistor R ₁ and the first thermistor 50, to the base of the transistor Tr, the microcomputer unit air flow measurement command signal from the air flow measurement command signal output terminal P ₃ of 35 are supplied.

[0061] Then, when the air volume measurement, air flow measurement command signal from the air flow measurement command signal output terminal P ₃ of the microcomputer unit 35 is output, the transistor Tr is turned ON. As a result, the first thermistor 50 is in a state where the resistances R ₁ and R ₃ are connected in series with each other.

In this case, the three resistors R ₁ ,
The magnitudes of the respective resistance values of R ₂ and R ₃ are set such that R ₂ = R ₃ << R ₁ .

Therefore, when the transistor Tr is in the ON state, the heating resistance of the first thermistor 50 is a combined resistance value of the parallel resistances R ₁ and R ₃ , and the second thermistor 50
Under the same sensitivity conditions as in 1, the airflow that has passed through the filter unit 3 is detected.

The first and second thermistors 5
The detection voltages V ₁ and V ₂ of the microcomputer unit 3 are
5 is input.

On the other hand, when measuring the room temperature, the airflow measurement command signal is not supplied.
It becomes F. The first thermistor 50 has a high resistance R
₁ alone are connected in series, and the first thermistor 5 at that time is turned off when the transistor Tr is turned off.
Inputs the detection voltage V ₁ of the 0, it is controlled to apply a correction to the air volume determination value.

Next, the contents of the control will be described with reference to the flowchart of FIG.

[0067] First, when starting the operation of the air purifier 1, the transistor Tr in a first step S ₁ OFF
Then, the room temperature T (V ₁ ) detected by the first thermistor 50 in the second step S ₂ is taken in a predetermined number of times. Then, the captured room temperature data T in the third step S ₃
It is determined whether (T ₁ , T ₂ ,..., Tn) is stable.

[0068] As a result, becomes to YES, after determining the data Tn when the stable room temperature T in the fourth step S _4,
The program then proceeds to a fifth step S _5, the transistor Tr
Turn ON. Then, in the sixth step S ₆ ,
Detection voltages V ₁ and V ₂ of the second two thermistors 50 and 51
The air volume a indicated by the difference is taken in.

Next, the process proceeds to a seventh step S _7, the air volume a 'corrected to further measuring air volume after the correction in the eighth step S ₈ a' a by said determined at room temperature data Tn is, FIG. 9 It is determined whether or not it is smaller than the set airflow level α requiring replacement of the filter unit 3 as in the case of the above.

As a result, when the determination is YES, the ninth
Proceeds to step S _9, and outputs a replacement sign signal of the filter unit 3, displays a filter replacement sign.

As described above, also according to the configuration of the modified example,
As in the case of the above-described embodiment, it is possible to cancel the influence of the room temperature of the thermistor that is easily affected by the change in room temperature and to issue an appropriate sign for replacing the filter unit 3.

[Brief description of the drawings]

FIG. 1 is a front view showing a configuration of an air purifier according to an embodiment of the present invention.

FIG. 2 is a central longitudinal sectional view of the purifier.

FIG. 3 is a front view of the purifier in a partially cut-out state.

FIG. 4 is a central vertical sectional view of a fan housing part of the purifier.

FIG. 5 is a rear view of a fan housing section of the purifier.

FIG. 6 is an enlarged rear view of a main part of a fan housing part of the purifier.

FIG. 7 is an enlarged perspective view of a main part of a fan housing part of the purifier.

FIG. 8 is an electric circuit diagram showing a configuration of an air volume detection circuit of the purifier.

FIG. 9 is a flowchart showing the content of air volume detection control of the purifier.

FIG. 10 is an electric circuit diagram showing a configuration of an air volume detection circuit in a modified example of the air purifier.

FIG. 11 is a flowchart showing the content of air volume detection control of the modification.

[Explanation of symbols]

1 is a main body casing, 2 is a blower, 3 is a filter unit, 8 is an air outlet, 9 is a fan motor, 11 is a fan housing, 11a is a fan motor support frame, 11c is a fan motor support stay, 15 is an automatic operation key, 21 is a filter reset key, 23a, 23b and 23c are dirt display means (dirt lamps), 28 is a filter replacement lamp, 30 is a dirt sensor, 35 is a microcomputer unit,
0 is the first thermistor, 51 is the second thermistor, 11
0 is a side plate, 111 is a bottom plate, and 112 is a ventilation port.

Claims (5)

[Claims] 1. A blower incorporated in a casing, a blower support stay for supporting the blower, a filter unit disposed on an air suction side of the blower, and a flow rate for detecting a flow rate passing through the filter unit. It is configured to blow out air purified by the filter unit with a sensor from an air outlet through an air flow path,
An air purifier characterized in that the air flow sensor is provided on the blower support stay. 2. The air purifier according to claim 1, wherein the air flow sensor is provided in parallel with the air flow. 3. The blower support stay comprises a plate member provided at a predetermined interval from each other, and the air flow sensor is provided on a side surface of a sensor substrate provided between the plate members in parallel with an air flow. The air purifier according to claim 1, wherein the air purifier is attached. 4. The air purifier according to claim 1, wherein said air flow sensor is air flow reduction detecting means for displaying a replacement time of the filter unit. 5. The air purifier according to claim 1, wherein said air flow sensor comprises a thermistor.