JP2014059116A - Air cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air cleaner which compensates capture performance degraded from an arrival performance of an initial blow air current and enables a user to continue to use the air cleaner without degrading the capture performance even when a filter is clogged by using a simple circuit constitution and a simple calculation.SOLUTION: A control device 16 can detects an electric current value of a DC motor 15 by means of an electric current value detection means 32. With respect to an electric current value of a DC motor 15 obtained when being operated at a rotation number according to design by using a clogged filter 12, such a configuration as to perform a control by increasing the rotation number introduced in consideration of the electric current obtained when being operated with the initial performance from the rotation number according to the design is provided. Thereby, an air cleaner which compensates the initial blow quantity even in such a state that the filter is clogged by using a low-cost sensor and a simple, low-cost circuit configuration and a simple calculation without providing special detection means can be obtained.

Description

  The present invention relates to an air purifier used in a general home or office.

  Conventionally, this type of air purifier is known in which the louver angle is changed and dust is collected efficiently by the flow of blown airflow (see, for example, Patent Document 1). In the air purifier configured as described above, the airflow of the wind blown by tilting the louver angle toward the front side of the main body can reach far away from the room where the air is to be purified, and can clean a wide range of air. it can.

  In such a conventional air purifier, the filter is clogged as the dirt generated in the room is removed. In order to have it cleaned and replaced, clogging of the filter is detected by various methods and notified to the user. As the method, generally, the operation time is integrated, a special sensor as in Patent Document 2 is provided to detect clogging of the filter, or a decrease in air volume is detected as a torque decrease as in Patent Document 3. Various ideas have been devised.

  On the other hand, in an air purifier designed to clean a wide range with the reach distance of the blown airflow as described above, the blown air volume decreases due to clogging of the filter, rather than the collection effect due to clogging of the filter. Since the degradation of performance due to the shortened reach distance of the blown airflow becomes a problem, there has been an effort to make the air volume constant by performing a complicated calculation from the current of the motor as in Patent Document 4.

  In recent years, air cleaners equipped with a DC motor capable of rotating speed control that allows energy-saving and fine air volume setting have been developed.

Japanese Patent No. 4983531 JP-A-63-274422 Japanese Patent No. 2667743 Japanese Patent No. 3738685

  However, just informing the user of clogging of the filter as in the case of conventional air purifiers, the ability to reach the initial blown airflow is reduced by the reduction of the blowout air volume until the user cleans and replaces the filter. The further reduced collection performance cannot be improved, and the user continues to use the air purifier while the collection performance is reduced. In order to keep the blowing air volume to be reduced constant, it is necessary to increase the voltage applied to the motor with an expensive circuit or to make the air volume constant by complicated calculation.

  Therefore, the present invention solves such a conventional problem, and it is possible to reduce the initial blowing air volume until the user cleans and replaces the filter with a simple and inexpensive circuit and simple calculation. An object is to provide an air purifier that can compensate.

  In order to achieve this object, the air purifier of the present invention has been cleaned with a suction port for sucking indoor air, a filter for cleaning the air sucked from the suction port, and a fan for ventilating the filter. An air purifier comprising an air outlet for blowing air, a brushless DC motor for driving the fan, and a control device for driving the DC motor, wherein the control device receives a DC motor from a rotational speed output signal of the DC motor. A rotational speed input calculating means for calculating the rotational speed of the motor, a rotational speed instruction signal output means for calculating a rotational speed instruction signal from the target rotational speed and the rotational speed input value and outputting the rotational speed instruction signal to the DC motor, and a current flowing through the DC motor Value detecting means, and the control device increases the predetermined rotational speed from the design rotational speed according to the difference between the detected value obtained from the current value detecting means and the design value, and indicates the rotational speed. No. it is those that have an air cleaner, characterized in that for compensating the air volume which is reduced by outputting from the output means, thereby it is intended to achieve the intended purpose.

  According to the present invention, the current value detecting means detects the amount of air blown by the DC motor, so that an inexpensive sensor is used without providing a special detecting means, and the circuit structure is simple and inexpensive. In addition, it is possible to obtain an effect that it is possible to provide an air purifier that compensates for the initial air flow rate even when the filter is clogged with simple calculation.

Structure diagram of the air cleaner according to the first embodiment of the present invention. The figure which shows the flow of the blowing wind of the air cleaner of Embodiment 1 of this invention. 1 is a block diagram of a control device according to a first embodiment of the present invention. Airflow characteristic diagram of fan motor according to Embodiment 1 of the present invention Airflow characteristic diagram of fan motor according to Embodiment 1 of the present invention Airflow characteristic diagram of fan motor according to Embodiment 1 of the present invention The figure which shows the rotation speed memorize | stored in memory of the microcomputer of Embodiment 2 of this invention The block diagram of the control apparatus of Embodiment 2 of this invention The figure which shows the rotation speed memorize | stored in the memory of the microcomputer of Embodiment 3 of this invention ((a) The figure which shows the relationship between the electric current at the ambient temperature of 25 degreeC, and a rotation speed, (b) When the ambient temperature is 35 degreeC Figure showing the relationship between the current and the rotational speed of

  According to the first aspect of the present invention, there is provided a suction port for sucking in indoor air, a filter for purifying air sucked from the suction port, a fan for passing air through the filter, and a blower outlet for blowing out the purified air. An air cleaner comprising a brushless DC motor for driving the fan and a control device for driving the DC motor, wherein the control device calculates a rotation speed of the DC motor from a rotation speed output signal of the DC motor. A number input calculation means, a rotation speed instruction signal output means for calculating a target rotation speed and the rotation speed input value and outputting a rotation speed instruction signal to the DC motor, and a current value detection means for flowing through the DC motor, The control device raises a predetermined rotational speed from the design rotational speed according to the difference between the detected value obtained from the current value detecting means and the design value, and outputs the predetermined rotational speed from the rotational speed instruction signal output means. Is the air cleaner, wherein the compensating air volume. As a result, there is an effect that the initial air volume can be compensated by an inexpensive and simple calculation.

  According to a second aspect of the present invention, in the air cleaner according to the first aspect, the value of the rotational speed that is increased from the design rotational speed in accordance with a difference between the detected value obtained from the current value detecting means and the designed value. Is calculated from a table derived from the design, and it is possible to compensate for the initial air flow more accurately by taking into account the change in the current value due to the increase in the static pressure of the filter. Play.

  According to a third aspect of the present invention, in the air cleaner according to the second aspect, the control device is provided with an ambient temperature detecting means, and a plurality of tables derived from the design are provided for each temperature condition. This is an air purifier, and has an effect that the initial air volume can be compensated with higher accuracy in consideration of the change in the current value of the DC motor due to the ambient temperature.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a structural diagram of an air cleaner. As shown in FIG. 1, the main body 10 of the air purifier has a suction port 11 that sucks in indoor air, a filter 12 that cleans the air sucked from the suction port 11, and a fan 13 that ventilates the filter 12. A blower outlet 14 for blowing out the air, a brushless DC motor 15 for driving the fan 13, and a controller 16 for driving the DC motor 15 are provided. The air cleaner generally includes a panel operation unit 17 controlled by the control device 16, and the user can set the fan air volume such as weak, weak, medium, strong, and turbo by panel operation. Moreover, the fan air volume may be determined by a sensor or the like by setting automatic operation. Once the fan airflow is determined, the control device 16 is generally configured such that the fan rotates at a fixed number of revolutions designed for each fan airflow, as in the case of an AC fan.

  FIG. 2 is a diagram showing the flow of blown air when the air cleaner of FIG. 1 is installed in a room 20 to be cleaned. By depressing the louver 18 provided at the air outlet 14 of the air cleaner forward, the effect of purifying the air by reaching the corner of the room 20 is enhanced. Immediately after the filter 12 is new or replaced / cleaned, even if the filter 12 reaches the corner of the room 20 like the blown airflow 21 with the predetermined fan airflow, if the filter 12 becomes clogged with dust, the blown airflow 22 As a result, the reach distance decreases and the cleaning performance deteriorates.

  FIG. 3 is a block diagram of the control device of the air cleaner. Here, a recent DC motor 15 has a built-in semiconductor element capable of driving a brushless DC motor, and is configured to rotate at a predetermined number of revolutions simply by applying a DC power source and a revolution number instruction signal. The rotation speed instruction signal is generally a low-voltage DC voltage signal, and a pulse width modulation (PWM) signal (the duty ratio of the pulse signal represents the rotation speed instruction) or the like is used. When a low-voltage DC voltage signal is used, there are means such as using a D / A conversion circuit of a microcomputer or charging a capacitor charge circuit with a PWM output circuit of the microcomputer. Similarly, the DC motor 15 has a built-in signal output circuit that represents the rotational speed, and is configured such that the controller can control the rotational speed. As this rotational speed output signal, a DC voltage signal having a low voltage is generally used, and a configuration in which a necessary number of Hall elements or the like are incorporated and a pulse signal is output in accordance with the rotation of the motor is used.

  The control device 16 creates a DC power source for driving the DC motor 15 by rectifying from the AC power source and a low-voltage DC power source for driving the control device 16.

  When operating the air cleaner, the control device 16 first outputs a rotation speed instruction signal that can activate the DC motor 15 to the rotation speed instruction signal output means 30. After the rotation of the DC motor, the rotation speed signal output from the DC motor 15 is input to the rotation speed input calculation means 31 to calculate the rotation speed of the DC motor. The control device 16 compares the calculated rotational speed with a predetermined target rotational speed that is determined in advance corresponding to the set fan air volume, and increases or decreases the rotational speed instruction signal so that they coincide with each other. By outputting to the output means 30, the DC motor 15 can be controlled to rotate stably at a predetermined rotational speed.

  Further, the current value detection means 32 can detect the current consumption of the DC power supply when the DC motor 15 is operated. As the current value detection means, a method of measuring the voltage across the shunt resistor is generally used.

  FIG. 4 shows an air flow characteristic diagram of the fan motor when the air purifier is operated with a set fan air flow.

  The air volume-static pressure characteristic 70 is a PQ characteristic when the fan is operated at a predetermined rotational speed N70 determined by design corresponding to the set fan air volume, and the filter 12 is new or just after replacement / cleaning. The load is indicated by a resistance characteristic 80.

  The air cleaner blows out the air volume Q1 determined by the intersection X1 of these two characteristics as the blown air volume 21. The current value of the DC motor at that time is represented by A1. Here, assuming that the load when the air cleaner is operated for a long time and the filter 12 is clogged to almost the limit of use is represented by the resistance characteristic 81, the air volume at that time decreases to Q2 corresponding to the intersection X2. The cleaning performance of the air cleaner is deteriorated up to the blowout air volume 22. The current consumption value of the DC motor 15 at this time decreases to A2 because the work amount of the fan decreases. A characteristic in which the current value A1 and the current value A2 are connected by a straight line is assumed to be an airflow-current characteristic 90.

  Next, the operation of the air volume compensation control of the control device 16 will be described with reference to FIGS. FIG. 5 shows an air flow characteristic diagram of the fan motor when the air cleaner is operated with a set fan air flow and then with the rotation speed changed.

  When the filter is clogged to the use limit at a predetermined rotation speed N70 determined by design and the target rotation speed is increased by a predetermined value from the state where the filter is at the intersection X2, the air volume-static pressure characteristic of the rotation speed N71 is obtained. Accordingly, the air volume increases to Q3 according to the intersection point X3, and the initial air volume can be compensated by the increase in the air volume. At this time, the current of the DC motor 15 increases, but cannot be increased beyond the upper limit value on the control device 16 or the circuit of the DC motor 15, and the rotation speed N71 is a limit that can compensate for the air volume.

  The operation of the initial air volume compensation control according to the first embodiment of the present invention will be described using FIG. 6 while following the above operation principle. FIG. 6 shows an air flow characteristic diagram of the fan motor when the air cleaner is operated with a set fan air flow and is operated with the rotation speed changed.

Assuming that the load when the filter 12 is not clogged up to the use limit shown in FIG. 5 is the resistance characteristic 82, when operating at a predetermined rotational speed N70 determined by design, the air flow decreases to the air volume Q4 determined at the intersection X4. doing. Assuming that the current value of the DC motor 15 at this time is A4, it is practical even if the maximum amount of rotation (N71-N70) determined in FIG. Air volume compensation control with sufficient effect can be realized. That is,
(A1-A2): (N71-N70) = (A1-A4): (N72-N70)
The desired number of rotations can be obtained with a simple calculation by calculating N72 from the above relationship. It is desirable to provide this primary expression for each set fan air volume.

  In order to realize the initial air volume compensation control, which is a feature of the present invention, it is necessary to grasp the air volume reduced due to the current filter clogging. As an example of the method, the operation of the air cleaner is started. Immediately after that, the initial air flow compensation control may be performed after first operating at the design speed and detecting the current value at that time.

  When the air purifier is used continuously, it is periodically returned to the designed number of rotations to grasp the clogged state of the filter, and then the initial air volume compensation control is performed again. When such an example is complicated, it is also effective to operate by increasing the rotational speed from a certain point where filter clogging is expected to a point where the current value does not exceed A3.

(Embodiment 2)
In this embodiment, since FIGS. 1 to 6 described in the first embodiment are the same, description thereof is omitted.

  FIG. 7 is a diagram showing the number of rotations stored in the memory of the microcomputer according to the second embodiment of the present invention, and FIG. 7 will be described.

  In the first embodiment, the increase amount of the current value of the DC motor 15 is approximated by a linear expression. However, when the filter 12 is clogged, the current value is due to the clogging of the filter 12 in addition to the power for conveying the blowing air. The static pressure increases, and the current corresponding to the pressure loss also increases. For this reason, in order to accurately obtain the rotational speed for compensating the initial air volume, a plurality of clogging amounts of the filter 12 are set at the designed rotational speed, and the relationship between the rotational speed, current, and air volume is measured. Design conditions may be stored in a microcomputer memory as a table.

  FIG. 7 shows a state in which the number of revolutions (N1, N2, N3 in the figure) to be increased to compensate the initial air volume from the fan air volume (weak, medium, strong in the figure) with respect to the current value is derived from the above measurement results. Represents.

  After detecting the current A4 corresponding to the intersection point X4 in FIG. 6, the rotational speed to be increased is determined by collating with the table of FIG. 7, thereby obtaining the intersection point X5 with high accuracy and obtaining the air volume Q5 that compensates the initial air volume. be able to.

(Embodiment 3)
Since this embodiment is the same except for FIG. 3 in FIGS. 1 to 6 described in the first embodiment, FIGS. 8 and 9 instead of FIG. 3 will be described. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 8 is a block diagram of the control device. In the first and second embodiments, the air volume is estimated from the value of the current flowing through the DC motor 15, but the current consumption value of the DC motor is greatly influenced by the ambient temperature because it is determined by the winding resistance of the DC motor. For this reason, the influence of the ambient temperature may not be negligible in order to obtain the compensation air volume with high accuracy.

  For this reason, in FIG. 8, the ambient temperature input means 33 is added to the control device 16. The ambient temperature can generally be easily obtained with a thermistor, and in an air purifier, the position of the thermistor is not a problem because it is almost the same whether it is in the air passage or in the main body other than the air passage.

  FIG. 9 is a design table in which a plurality of temperature conditions are set for the design table obtained by measurement in the second embodiment and the relationship between the rotational speed, current, and air volume is measured for each temperature condition. . FIG. 9A is a table measured at room temperature (25 ° C.) and is the same as FIG. FIG. 9B is a table measured in an ambient temperature region (for example, 35 ° C.) where the current consumption value of the DC motor changes greatly. By providing a rotation speed table for each ambient temperature region as shown in FIG. 9, in this embodiment, it is possible to obtain an air volume Q5 in which the initial air volume is accurately compensated under any use conditions.

  The air cleaner according to the present invention can supply an air volume close to the initial air volume even when the filter is clogged, and thus can be applied to an air conditioner including a filter and a DC motor, and is useful for home appliances in general.

DESCRIPTION OF SYMBOLS 10 Main body 11 Suction port 12 Filter 13 Fan 14 Air outlet 15 DC motor 16 Controller 30 Rotation speed instruction signal output means 31 Rotation speed input calculation means 32 Current value detection means 33 Ambient temperature input means

Claims (3)

A suction port for sucking in indoor air, a filter for purifying the air sucked from the suction port, a fan for passing air through the filter, a blow-out port for blowing the purified air, a brushless DC motor for driving the fan, and the DC An air cleaner comprising a control device for driving a motor, the control device comprising: a rotational speed input computing means for computing the rotational speed of the DC motor from a rotational speed output signal of the DC motor; a target rotational speed; Rotational speed instruction signal output means for calculating a rotational speed instruction signal from the rotational speed input value and outputting a rotational speed instruction signal to the DC motor; and current value detection means for flowing through the DC motor; and the control device includes: A predetermined rotation speed is increased from the design rotation speed according to the difference between the obtained detection value and the design value, and output from the rotation speed instruction signal output means to compensate for the reduced air volume. Air cleaner to be. 2. The air purifier according to claim 1, wherein a value of a rotational speed that is increased from a design rotational speed in accordance with a difference between a detected value obtained from the current value detecting means and a design value is calculated from a table derived from design. Machine. The air cleaner according to claim 2, wherein the control device includes an ambient temperature detecting means, and a plurality of tables derived from the design are provided for each temperature condition.

Images