JP2012149546A - Blower, and electrical apparatus mounting the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blower that obtains high-accuracy air flow/static pressure characteristics having extremely little variation of air flow even if static pressure, such as pressure loss, is varied, in addition that increase a blast volume according to variation of humidity when the humidity is high.SOLUTION: A magnetic pole of a magnet rotor 3 is formed of a polyamide 6 resin, which has many amide groups in the same molecular length, and therefore a water molecule forming a hydrogen bond with the amide groups makes the surrounding water molecules come near within a region having much higher humidity to form a hydrogen bonding between the water molecules and swell. Accordingly, the outer diameter of the magnetic pole of the magnet rotor 3 is increased, an air gap 18 is decreased, and then an induced voltage induced by a drive coil 2 is increased. In addition, if a current supplied to the drive coil 2 is the same, shaft torque is increased by the amount of increased induced voltage. As a result, the air flow/static pressure characteristics are obtained in which ventilation air flow is increased at high humidity compared with that at normal humidity.

Description

  The present invention mainly relates to a ventilator for exhaust and air supply such as a range hood and a ceiling-embedded type, and a blower mounted on a humidifier, a dehumidifier, a refrigeration apparatus, an air conditioner, a water heater, a fan filter unit, etc. Further, the present invention relates to an electric device equipped with the blower.

  In recent years, in air blowers installed in electrical equipment such as ventilators, pressure loss due to duct piping configuration, outside air pressure, pressure loss due to clogging of filters, etc., after lowering price, increasing efficiency and reducing noise There is a need for an air blower with good controllability that allows ventilation with an optimal air volume according to the situation of the room without being affected by changes.

  Conventionally, the thing of the structure disclosed by patent document 1 is known for this kind of air blower.

  Hereinafter, the blower will be described with reference to FIG.

  As shown in the figure, the blower 110 has a built-in centrifugal blower 110 a, and the centrifugal blower 110 a is driven by a brushless DC motor 111. The DC voltage control means 108 is a step-down chopper circuit that converts a high voltage including ripple after full-wave rectification of a commercial AC power supply into a DC voltage of 45 V or less. The supply current value control means 122 is connected to the current detection means 119. The output voltage of the DC voltage control means 108 is controlled by controlling the DC voltage value changing means 114 so that the average current value to the inverter circuit 106 detected in this way becomes equal to the current value indicated by the current value indicating means 120. Feedback control while changing The air volume control unit 132 has a configuration of the blower 110 that changes the current supplied to the inverter circuit 106 with respect to the reference set value according to the output voltage of the DC voltage control unit 108 and instructs the current value instruction unit 120.

Japanese Patent Application Laid-Open No. 2007-100574

  According to such a conventional blower, from the viewpoint of realizing a comfortable indoor air quality, the amount of blown air is controlled even when the humidity is high, even when the humidity is high, according to the humidity of the room. When installed in a ventilator that is required to increase, there is a problem that the air flow rate when the humidity is low and the air flow rate when the humidity is high cannot be changed, and it is special without increasing the required circuit space. It is required that specification adjustments such as air flow-static pressure characteristics and a plurality of air flow settings can be easily made without using a simple sensor or a microcomputer, and the air flow rate can be controlled according to changes in humidity.

  The present invention solves such a conventional problem, and simplifies specification adjustment, circuit miniaturization, high quality, and the amount of change in air volume is extremely small even when static pressure changes such as pressure loss. An object of the present invention is to provide a blower capable of increasing the amount of air flow when the humidity is high in accordance with a change in humidity after realizing an accurate air volume-static pressure characteristic.

  In order to achieve this object, the present invention is composed of a magnet rotor that is rotatably arranged through an air gap around a stator around which a drive coil is wound. Centrifugal blower equipped with a brushless DC motor formed by a plastic magnet that swells by bonding, an inverter circuit composed of an upper stage and a lower stage, each bridge-connected by a plurality of switching elements, and a DC voltage applied to the inverter circuit PWM control of the upper or lower stage of the switching element, drive logic control means for sequentially energizing the drive coil of the brushless DC motor in a predetermined direction and order, and PWM control of the switching element Duty instruction voltage generating means for indicating an ON / OFF duty instruction voltage Supply current value control means for changing the ON / OFF duty of the PWM control of the switching element by changing the output of the duty instruction voltage generation means to control the average current supplied to the inverter circuit to be substantially constant. A current value indicating means for indicating an average current value controlled substantially constant by the supply current value control means, and the current value indicating means according to the voltage value of the DC voltage generated by the duty indicating voltage generating means. The correlation instruction means for instructing the correlation with the average current value instructed by the current value instructing means is arranged, and the correlation instruction means is in response to the reference current value instructed by the reference current value instructing means. An average current value indicated by the current value indicating means is determined by changing linearly or nonlinearly, and the magnet of the magnet rotor has a reference humidity. By become remote and high humidity, by swelling with moisture, the are those air gap has a blowing device which is characterized by smaller, thereby is to achieve the intended purpose.

  According to the present invention, it is constituted by a magnet rotor that is rotatably arranged through an air gap on a stator around which a drive coil is wound, and the magnet of this magnet rotor is a plastic magnet that swells by hydrogen bonding. A centrifugal blower equipped with a brushless DC motor to be formed, an inverter circuit composed of an upper stage and a lower stage, each bridge-connected with a plurality of switching elements, and a DC voltage applied to the inverter circuit to the upper or lower stage of the switching elements And a drive logic control means for sequentially energizing the drive coil of the brushless DC motor in a predetermined direction and order, and an instruction for instructing an ON / OFF duty when the switching element is PWM controlled. Duty instruction voltage generating means for generating a voltage and the duty instruction voltage generating means Supply current value control means for controlling the average current supplied to the inverter circuit by changing the ON / OFF duty of PWM control of the switching element by changing the output of the means, and the supply current value control Current value indicating means for indicating an average current value controlled substantially constant by the means, and the current value indicating means according to the voltage value of the DC voltage generated by the duty indicating voltage generating means. Correlation indicating means for instructing the correlation with the average current value specified by is provided, and the correlation indicating means changes linearly or nonlinearly with respect to the reference current value specified by the reference current value indicating means. And determining an average current value to be instructed by the current value indicating means, and the magnet of the magnet rotor has a humidity higher than a reference humidity, thereby absorbing moisture. Therefore, the rotation speed-torque characteristic of the brushless DC motor in which the shaft torque increases further as the rotation speed increases due to the configuration of the air blower characterized in that the air gap is reduced by swelling. When the humidity is higher than the reference humidity, the air gap is reduced by swelling due to moisture absorption, and the induced voltage induced in the drive coil is increased, so that the shaft torque at the same rotational speed is increased. Without using a special sensor such as a computer or a humidity sensor, it is possible to provide an effect that it is possible to provide an air blower and an electrical device that can realize an increase in air volume in constant air volume control.

The block diagram which shows the structure of the ventilator which incorporated the air blower in Embodiment 1 of this invention. Sectional drawing which shows an example of the brushless DC motor mounted in the air blower The graph which shows an example of the duty instruction | indication voltage-current characteristic of the brushless DC motor mounted in the air blower The graph which shows an example of the rotation speed-torque characteristic of the brushless DC motor mounted in the air blower The graph which shows an example of the air volume-static pressure characteristic of the ventilator which incorporated the air blower Three-sided view showing a ventilator with a built-in air blower The block diagram which shows the structure of the ventilation apparatus which incorporated the air blower in Embodiment 2 of this invention. Block diagram showing a conventional blower

  The air blower according to claim 1 of the present invention is configured by a magnet rotor that is rotatably arranged through an air gap on a stator around which a drive coil is wound, and the magnet of the magnet rotor is bonded by hydrogen bonding. Centrifugal blower equipped with a brushless DC motor formed by a swelled plastic magnet, an inverter circuit composed of an upper stage and a lower stage, each bridge-connected by a plurality of switching elements, and a DC voltage applied to the inverter circuit PWM control of the upper or lower stage of the switching element, and drive logic control means for sequentially energizing the drive coil of the brushless DC motor in a predetermined direction and order, and ON / OFF when the switching element is PWM-controlled. Duty instruction voltage generating means for indicating an OFF duty instruction voltage, and A supply current value control means for controlling the average current supplied to the inverter circuit by changing the ON / OFF duty of the PWM control of the switching element by changing the output of the battery instruction voltage generating means; and Current value indicating means for indicating an average current value controlled substantially constant by the supply current value controlling means, and the current value indicating means includes a current value indicating means according to the voltage value of the DC voltage generated by the duty indicating voltage generating means, Correlation indicating means for indicating the correlation with the average current value specified by the current value indicating means is provided, and the correlation indicating means is linear with respect to the reference current value specified by the reference current value indicating means. An average current value indicated by the current value indicating means is determined in a non-linear manner, and the magnet of the magnet rotor has a humidity higher than a reference humidity. By becoming has by swelling with moisture, the configuration of a blower, wherein the air gap is reduced. As a result, the rotational speed-torque characteristics of the brushless DC motor, in which the shaft torque increases further as the rotational speed increases, become higher than the reference humidity, and swells due to moisture absorption, thereby reducing the air gap. Because the induced voltage induced in the drive coil increases, the shaft torque at the same rotation speed increases, so the air volume increases in constant air volume control without using a special sensor such as a microcomputer or humidity sensor. There is an effect that it is possible to provide a blower capable of realizing the above.

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

(Embodiment 1)
As shown in FIGS. 1 to 6, reference numeral 10 denotes an air blower including a centrifugal blower 10 a on which a brushless DC motor 11 is mounted, and is connected to an external power source. Reference numeral 1 denotes a ventilator incorporating a blower 10. Dirty room air generated by smoke or cooking sucked by the blower 10 passes through the wall of the building via the discharge port of the ventilator 1 and the duct 23 and is discharged to the outside. The magnetic pole portion 3a of the magnet rotor 3 of the brushless DC motor 11 is formed by orienting a plastic magnet having polyamide 6 resin having a small number of methylene groups per amide group as a main binder and an elastomer as an auxiliary binder at the time of injection molding. An air gap 18 is formed between the magnet rotor 3 and the stator 19 around which the drive coil 2 is wound. The outer cover of the brushless DC motor 11 is molded with a filler such as calcium carbonate, aluminum hydroxide or wollastonite, and a resin such as unsaturated polyester containing glass fiber. The brushless DC motor 11 includes a Hall element 4 serving as a magnetic pole position detecting means for detecting a magnetic pole position and a magnetic flux density distribution of the magnet rotor 3, an upper switching element Q1, Q3, Q5 and a lower switching element Q2. A DC voltage, which is an external power source supplied based on the output of the Hall element 4 and the inverter circuit 6 in which Q4 and Q6 are bridge-connected, is applied to the drive coil 2 so that full-wave energization is sequentially performed in a predetermined direction and order. Drive logic control means 5 for controlling ON / OFF of the switching elements Q1 to Q6, PWM control means 12 for PWM control of the lower switching elements Q2, Q4, Q6, and each phase current waveform of the drive coil 2 is the Hall element 4 Current that adjusts the ON / OFF duty of the lower switching elements Q2, Q4, Q6 so that the output waveform is substantially similar to It incorporates a shape control means 7. Here, since the magnetic pole portion 3a of the magnet rotor 3 is a polar anisotropic magnet, the induced voltage induced in the drive coil 2 has a substantially sinusoidal waveform, and the detection waveform of the hall element 4 also has a substantially sinusoidal waveform. It becomes the waveform. Since the current waveform control means 7 controls each phase current waveform of the drive coil 2 to be substantially sinusoidal, the current supplied to the inverter circuit 6 has no non-energized section, and the current waveform changes sharply. And the generation of ripples is suppressed. Further, outside the brushless DC motor 11, current detection means 15 for detecting the current supplied to the inverter circuit 6, and the DC voltage supplied from the external power source are reduced to set the ON / OFF duty of the PWM control means 12. A duty instruction voltage generating means 14 for indicating, a reference current value indicating means 16 for setting a reference current value to be supplied to the inverter circuit 6 when a DC voltage generated by the duty instruction voltage generating means 14 is a predetermined voltage, and a correlation The duty instruction voltage generation means 14 is set so that the average current value supplied to the instruction means 13 and the inverter circuit 6 detected by the current detection means 15 is equal to the current value indicated by the current value instruction means 9. Supply current value control for feedback control while varying the ON / OFF duty of the PWM control means 12 by controlling The stage 17, an air volume instruction unit 20 that instructs a plurality of operating air volumes of the blower 10, a reference current value instruction change unit 21, and a correlation change unit 22 are arranged, and the correlation instruction unit 13 generates a duty instruction voltage. According to the magnitude of the voltage value output from the duty instruction voltage generating means 14 by feeding back the change in the output voltage so that the output voltage-current characteristics of the means 14 become the characteristics shown in FIG. 6 is instructed to the current value indicating means 9 by linearly changing (proportional) the current supplied to the reference current value. At this time, an upper limit is set for the ON / OFF duty in consideration of the withstand voltage of the inverter circuit 6 and the kickback voltage, and a section for operating at a constant ON / OFF duty without controlling the current is provided. Correlation indicating means 13 determines a change amount to be changed with respect to the reference current value instructed by reference current value indicating means 16 according to the magnitude of the resistance value of connected resistor R1, and reference current value indicating means 16 is The reference current value supplied to the inverter circuit 6 when the DC voltage generated by the duty instruction voltage generation means 14 is a predetermined voltage is determined according to the magnitude of the resistance value of the resistor R2 to be connected. The air volume instruction means 20 controls the torque characteristic changing means 24 so that the reference current value instruction changing means 21 changes the resistance value of the resistor R2 connected to the reference current value indicating means 16 and the correlation changing means 22 In this configuration, the resistance value of the resistor R1 connected to the correlation instruction means 13 is changed.

  According to the air blower 10 of the present invention, the current supplied to the inverter circuit 6 with respect to the reference current value by the correlation instruction unit 13 according to the magnitude of the voltage value output from the duty instruction voltage generation unit 14 is determined. Since the current value indicating means 9 is instructed linearly, the supply current increases as the rotational speed increases. Conversely, the supply current decreases as the rotational speed decreases. Therefore, as shown in FIG. 4, the rotational speed-torque characteristic of the brushless DC motor 11 is obtained such that the shaft torque increases as the rotational speed increases. With this characteristic, the ventilation apparatus 1 equipped with the blower 10 can obtain an air volume-static pressure characteristic in which the air volume does not change greatly even if the pressure loss such as the external air pressure and the duct length changes as shown in FIG. The polyamide 6 resin forming the magnetic pole part of the magnet rotor 3 has many amide groups at the same molecular length, and water molecules that are hydrogen-bonded to the amide groups attract surrounding water molecules in a higher humidity region. It will swell by forming hydrogen bonds of molecules-water molecules. Therefore, the outer diameter of the magnetic pole part of the magnet rotor 3 is increased, the air gap 18 is decreased, and the induced voltage induced in the drive coil 2 is increased. Therefore, if the current supplied to the drive coil 2 is the same, the shaft torque becomes higher as the induced voltage becomes higher. Therefore, the air volume-static pressure characteristic shown in FIG. 5 is the reference humidity (normal humidity). On the other hand, an air volume-static pressure characteristic in which the ventilation air volume increases at high humidity can be obtained.

  Further, the amount of change to be changed with respect to the reference current value instructed by the reference current value instruction means 16 is determined by the magnitude of the resistance value of the resistor R1 connected to the correlation instruction means 13. Therefore, it is possible to change the degree of increase in shaft torque as the rotational speed increases in the rotational speed-torque characteristics of the brushless DC motor 11. That is, specification adjustment for responding to changes in the in-machine resistance of the ventilator 1, specification adjustment for responding to load changes by changing the blade diameter of the centrifugal fan 10a, changing the number of blades, changing blade specifications, The air volume-static pressure characteristics of the blower 10 can be adjusted. Therefore, the man-hour required for the specification adjustment can be greatly reduced, and the brushless DC motor 11 and the main control circuit can be standardized.

  Further, the reference current value supplied to the inverter circuit 6 at a predetermined voltage of the DC voltage generated by the duty instruction voltage generation means 14 is determined by the magnitude of the resistance value of the resistor R2 connected to the reference current value instruction means 16. . Therefore, the specification adjustment for the change of the in-machine resistance of the ventilator 1 and the adjustment of the air volume in the air volume-static pressure characteristics of the ventilator 1 can be performed, and the man-hour required for the specification adjustment can be greatly reduced. The brushless DC motor and main control circuit can be standardized.

  Further, since the resistance value of the resistor R2 connected to the reference current value instruction unit 16 is changed depending on the instruction state of the air volume instruction unit 20, the air volume adjustment according to the air volume instruction of the air volume instruction unit 20 can be easily performed. Accordingly, since it is possible to adjust only the resistance R2 according to the required air volume required for the room where the ventilation device 1 is installed, the man-hours required for specification adjustment can be greatly reduced, and the brushless DC motor and the main control circuit can be reduced. Can be standardized.

  Further, the correlation changing unit 22 changes the resistance value of the resistor R1 connected to the correlation instructing unit 13 according to the instruction state of the air volume instructing unit 20, so that the air blower 10 is in accordance with the required air volume-static pressure characteristics. Easy airflow characteristics. Accordingly, since it is possible to adjust only the resistance R1 according to the required air volume required in the room where the ventilation device 1 is installed, the man-hours required for specification adjustment can be greatly reduced, and the brushless DC motor and the main control circuit can be reduced. Can be standardized.

  Further, since the drive logic control means 5 supplies the drive coil 2 with a current without a non-energized section, the current ripple supplied to the inverter circuit is greatly reduced, and the current detection precision by the current detection means 15 is increased. Therefore, the air blower 10 and the ventilator 1 that realize high accuracy of the air volume accuracy and low vibration by reducing the torque ripple of the motor can be realized.

  The gap between the Hall element 4 and the magnet is set and arranged so that the waveform detected by the Hall element 4 is substantially similar to the induced voltage waveform induced in the drive coil 2 by the polar anisotropic magnet. Then, the current waveform control means 7 supplies a current substantially similar to the magnetic flux density distribution waveform detected by the Hall element 4 to the drive coil 2. In this way, the induced voltage waveform and the current waveform are substantially similar, so that the torque ripple and torque change rate can be further reduced, and the motor efficiency is greatly improved, resulting in low noise and high efficiency. The blower 10 and the ventilator 1 thus obtained are obtained.

  Moreover, since the induced voltage waveform and the current waveform are both sine waves by making the magnetic pole portion of the magnet rotor 3 a polar anisotropic magnet, the torque ripple and the torque change rate can be further reduced, Since the motor efficiency is also greatly improved, it is possible to obtain the blower 10 and the ventilator 1 that achieve noise reduction and high efficiency.

  In the first embodiment, the correlation instruction means 13 linearly changes the current supplied to the inverter circuit 6 with respect to the reference set value in accordance with the magnitude of the voltage value output from the duty instruction voltage generation means 14. It was set as the structure to instruct | indicate. However, a non-linear change (higher-order proportionality) may be adopted, and the same effect can be obtained by appropriately setting the characteristic curve of the rotational speed-torque characteristic from the load amount such as a fan load. be able to.

  Further, in the first embodiment, the current waveform supplied to the drive coil 2 is configured to be substantially similar to the induced voltage waveform, but depending on the use, the required air volume accuracy and the noise level of the product, A 120-degree rectangular wave energization, a wide-angle energization system such as 140-degree and 150-degree energization, and a sinusoidal drive system using two-phase modulation may be used. There is no difference in obtaining the characteristic of increasing.

  In the first embodiment, the Hall element 4 is used as the magnetic flux density distribution detecting means. However, a sensorless system that determines the energization phase for the magnet rotor by detecting the induced voltage or current induced in the non-energized phase. A system or a system using magnetic pole position detection means for detecting the magnetic pole position of the magnet rotor by judging the N pole and S pole of a magnet such as a Hall IC may be used, and there is no difference in the operation effect.

  In the first embodiment, a DC voltage is input to the ventilator 1 from an external power source. However, after a commercial AC voltage is input and rectified and smoothed, a predetermined DC voltage is generated and then driven. It is good also as a structure supplied to the coil 2, and does not produce a difference in the effect.

  Moreover, in this Embodiment 1, although it was set as the structure which applies the direct current voltage from the external power supply supplied to the ventilation apparatus 1 to the drive coil 2, it is good also as a structure applied to the drive coil 2 via a buck-boost converter. , No difference in its effects.

  In the first embodiment, the torque characteristic changing unit 24 changes the resistance value of the resistor R2 connected to the reference current value indicating unit 16 by the reference current value indicating changing unit 21 according to the instruction state of the air volume indicating unit 20. At the same time, the correlation change means 22 is configured to change and control the resistance value of the resistor R1 connected to the correlation instruction means 13. However, only the reference current value instruction change means 21 or the correlation change means 22 is controlled. It is good also as a structure to perform, and does not produce a difference in the effect.

(Embodiment 2)
As shown in FIG. 7, reference numeral 25 denotes an AC power supply connection means for connecting a commercial AC power supply, which comprises a strong output connection terminal 25a, a weak output connection terminal 25b, and a common connection terminal 25c. A number is attached and detailed explanation is omitted. An external switch 26 is connected to either the strong output connection terminal 25a or the weak output connection terminal 25b. Then, the input commercial AC power is rectified and smoothed by the rectifying means 27 and the smoothing means 28. A predetermined DC voltage generated by the DC voltage converting means 8 formed by a step-down chopper circuit is applied to the inverter circuit 6. 29 is an air volume instruction means, which detects whether the external switch 26 is connected to the strong output connection terminal 25a or the weak output connection terminal 25b, and the torque characteristic changing means 24 outputs the output signal of the air volume instruction means 29. In response, a signal is sent to the reference current value instruction changing means 21 and the correlation changing means 22. Other configurations of the brushless DC motor 11, the inverter circuit 6, the drive logic control unit 5, the current detection unit 15, the reference current value instruction unit 16, the correlation instruction unit 13, and the like constituting the other blower device 10 are the same as those in the first embodiment. It is.

  According to the air blower 10 of the present invention as described above, in the AC power supply connection means 25, two places are provided, such as the strong output connection terminal 25a and the weak output connection terminal 25b, and the air volume instruction means 29 is connected to the strong output connection terminal 25a. It is detected whether it is connected to the weak output connection terminal 25b. Based on the result, the air volume instruction means 29 instructs the torque characteristic changing means 24 to control the reference current value instruction changing means 21 to change the resistance value of the resistor R2 connected to the reference current value indicating means 16. And since the reference | standard setting value of the electric current supplied to the inverter circuit 6 is changed, since two steps of air volume are obtained, the air blower which can adjust the speed by switching connection of an AC power supply line is obtained. Here, in the AC power source connecting means 25, if the torque characteristic changing means 24 changes the reference set value according to the instruction of the air volume indicating means 29 according to the number of connecting terminals, the number of connecting terminals is equal to that at normal humidity. When the humidity is high, an air volume-static pressure characteristic in which the ventilation air volume increases is obtained.

  Further, since the air volume instruction means 29 controls the correlation changing means 22 to change the resistance value of the resistor R1 connected to the correlation instruction means 13, the air volume-static pressure characteristic can be easily changed by switching the connection of the AC power supply line. An air blower that can be used is obtained. Here, in the AC power supply connecting means 25, if the torque characteristic changing means 24 changes the correlation according to the instruction of the air volume indicating means 29 according to the number of connecting terminals, the number of connecting terminals is equal to that at normal humidity. When the humidity is high, an air flow-static pressure characteristic in which the ventilation air flow increases is obtained.

  In addition, there is no difference in the operational effect in the same configuration as the configuration shown in the first and second embodiments.

  The torque characteristic changing unit 24 changes the resistance value of the resistor R2 connected to the reference current value indicating unit 16 by the reference current value indicating changing unit 21 and the correlation changing unit 22 by the instruction of the air volume indicating unit 29. Although the configuration is such that the resistance value of the resistor R1 connected to the correlation instruction means 13 is changed and controlled, only the reference current value instruction change means 21 or the correlation change means 22 may be controlled. There is no difference in effect.

  As described above, the air blower according to the present invention can obtain a constant air volume regardless of the static pressure in the air volume-static pressure characteristics without being affected by pressure loss, and the air volume even in a sudden static pressure change. Because it can reduce the amount of change in air, it has a built-in air blower, and even if there is a change in static pressure, air conditioners such as ventilators, water heaters, air conditioners, etc. Use in air cleaners, dehumidifiers, dryers, fan filter units, cooling units, etc. is useful.

DESCRIPTION OF SYMBOLS 1 Ventilator 2 Drive coil 3 Magnet rotor 3a Magnetic pole part 4 Hall element 5 Drive logic control means 6 Inverter circuit 7 Current waveform control means 8 DC voltage conversion means 9 Current value instruction means 10 Blower 10a Centrifugal blower 11 Brushless DC motor 12 PWM control means 13 Correlation instruction means 14 Duty instruction voltage generation means 15 Current detection means 16 Reference current value instruction means 17 Supply current value control means 18 Air gap 19 Stator 20 Air volume instruction means 21 Reference current value instruction change means 22 Correlation Relation changing means 23 Duct 24 Torque characteristic changing means 25 AC power supply connecting means 25a Strong output connecting terminal 25b Weak output connecting terminal 25c Common connecting terminal 26 External switch 27 Rectifying means 28 Smoothing means 29 Air flow indicating means Q1 Upper stage switching element Q2 Lower stage Switching element Q3 upper stage switching elements Q4 lower stage switching element Q5 upper stage switching element Q6 lower stage switching element

Claims (6)

A brushless DC motor is composed of a magnet rotor that is rotatably arranged through an air gap around a stator around which a drive coil is wound, and a magnet of this magnet rotor is formed by a plastic magnet that swells by hydrogen bonding. The mounted centrifugal blower, the upper stage and the lower stage, each of which is an inverter circuit bridge-connected by a plurality of switching elements, and the DC voltage applied to the inverter circuit is PWM controlled on the upper stage or the lower stage of the switching element, A drive logic control means for sequentially energizing the drive coil of the brushless DC motor in a predetermined direction and in order, and a duty instruction voltage for indicating an ON / OFF duty when PWM controlling the switching element Generating means and the output of the duty instruction voltage generating means. By changing the ON / OFF duty of the PWM control of the switching element, the supply current value control means for controlling the average current supplied to the inverter circuit to be substantially constant, and the supply current value control means substantially constant A current value indicating means for indicating an average current value to be controlled, and an average current indicated by the current value indicating means according to the voltage value of the DC voltage generated by the duty indicating voltage generating means; Correlation indicating means for instructing the correlation with the value is arranged, and the correlation indicating means changes the current value linearly or nonlinearly with respect to the reference current value specified by the reference current value indicating means. An average current value to be instructed by the instructing means is determined, and the magnet of the magnet rotor swells due to moisture absorption by becoming higher than a reference humidity. And, the blower, characterized in that the air gap is reduced. An air volume instruction means for instructing a plurality of operating air volumes, and a torque characteristic changing means for controlling the reference current value instruction changing means are provided for performing a constant operation at each air volume instructed by the air volume instruction means. The blower according to claim 1. The blower according to claim 2, wherein the torque characteristic changing means controls the correlation changing means in accordance with an instruction from the air volume instruction means. A plurality of AC power supply connection means for connecting an AC power supply is provided, and the air volume instructed by the airflow instruction means is changed according to the connection location to the AC power supply connection means. The blower described in 1. The electric equipment carrying the air blower in any one of Claims 1-4. 6. The electric device according to claim 5, wherein the electric device is any one of a ventilator, a dehumidifier, a humidifier, an air conditioner, a water heater, a fan filter unit, and a cooling unit.

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