JP3901146B2 - AC power source direct-coupled brushless DC motor and electrical equipment equipped with the same - Google Patents

Description

  The present invention mainly relates to a brushless DC for driving a fan such as a pipe fan, a ceiling-embedded ventilator for exhaust and air supply, a fan, a humidifier, a dehumidifier, a refrigeration apparatus, an air conditioner, a water heater, etc. The present invention relates to a motor and an electric device equipped with the brushless DC motor.

  In recent years, there has been a strong demand for low-price, high-efficiency, and low-noise performance in fan-driven motors mounted on electrical equipment such as ventilators, and it is difficult to achieve significant increases in efficiency with induction motors. The number of brushless DC motors using permanent magnets is increasing. On the other hand, there is also a demand for an electric motor that is easy to use, such as simply rotating by connecting to an AC power source.

  Conventionally, the thing of the structure disclosed by patent documents 1-3 is known for this kind of electric motor.

  Hereinafter, the electric motor will be described with reference to FIGS.

As shown in the figure, a rectifying unit 101 that rectifies a commercial AC power source on a single printed circuit board 106, a two-phase drive coils 103 and 104 of a DC motor, and a magnet rotor 105 provided with a permanent magnet 105a, Between the motor drive coils 103 and 104 and the rectifying unit 101, a large-capacity electrolytic capacitor is arranged as a smoothing capacitor 109, and switching elements 107 and 108 for supplying current to the motor drive coils 103 and 104 only in one direction, and this switching Including the elements 107 and 108, and a control unit 102 that controls energization of the motor drive coils 103 and 104, and directly supplies the high voltage DC power source rectified by the rectification unit 101 to the motor drive coils 103 and 104. The configuration of the two-phase half-wave drive system in which the high-voltage DC power source rectified by the rectifying unit 101 is decompressed and supplied to the control unit 102 It is.
JP 2000-41370 A JP 2000-41395 A Japanese Patent Laid-Open No. 2002-10609

  According to such a conventional electric motor, since it is a two-phase half-wave drive system, in order to prevent the occurrence of dead center, countermeasures can be taken by superimposing spatial harmonic torque, or the interval between stator teeth can be changed. Even if countermeasures are taken, there is a problem that the torque ripple and torque change rate will increase, so noise and vibration will increase and noise reduction will not be possible, and the torque ripple and torque change rate will be reduced to reduce noise and vibration. Is required to do.

  In addition, since it is a half-wave drive system, the current increases and the current change with respect to the load torque also increases, so there is a problem that the range of usable load torque is narrowed, and the current can be reduced and usable. A wide range of load torque is required.

  In addition, since it is a half-wave drive system, copper loss becomes extremely large in high output areas, and there is a problem that the effect of reducing power consumption for induction motors is lost. Even so, it is required to realize low power consumption.

  In addition, since the high-voltage DC voltage obtained at the rectifying unit is used as the direct drive power supply, it is necessary to increase the capacity of the smoothing capacitor after the rectifying unit. To that end, the use of an electrolytic capacitor is indispensable. Considering the ripple current, it is necessary to further increase the capacity, and there is a problem that the circuit cannot be downsized, the stability of quality can be ensured, and the life cannot be extended.

  When the smoothing capacitor has a small capacity, the power supply ripple increases, resulting in an extremely large torque ripple, further vibration and noise, and excessive rotation unevenness. However, there is a problem that the air volume varies and a stable air flow cannot be secured, and it is required that a stable air flow can be secured after realizing miniaturization, high quality, and long life of the circuit.

  In addition, equipment with a centrifugal blower such as a sirocco fan such as a duct type ventilation device is equipped with an induction motor and used in a region where the rotational speed change from the starting torque to the maximum torque is large in its torque characteristics. Most of the equipment occupies, and when a brushless DC motor is mounted on such a blower and operated at a constant applied voltage, as shown in the torque-rotational speed characteristic comparison graph of FIG. When the maximum static pressure value is equivalent to the value when the induction motor is installed in the airflow-static pressure characteristics, the difference between the number of rotations and the number of revolutions at zero static pressure is extremely small compared to the induction motor. The air volume at zero static pressure becomes extremely large, noise and vibration increase, and there is a problem that the effect of reducing power consumption including cooling and heating energy loss is reduced. On the contrary, the air volume at zero static pressure If equal, the maximum static pressure value becomes extremely low, and there is a problem that the air volume fluctuates greatly due to changes in external pressure loss due to outside wind, etc. -Static pressure characteristics are required to be obtained.

  In addition, in electrical equipment with a built-in centrifugal blower such as a ventilator or a water heater, it is necessary to install a fan motor whose airflow does not change greatly even if static pressure such as pressure loss changes, due to the characteristics of the blower. For this purpose, it is required to obtain a torque-rotational speed characteristic in which the shaft torque increases as the rotational speed increases.

  The present invention solves such a conventional problem, can reduce torque ripple and torque change rate, suppress the generation of noise and vibration, reduce current, and can be used. Wide range of torque, low power consumption even in high output range, miniaturization of circuit, high quality, long life, suppression of uneven rotation, static pressure such as pressure loss changes It is an object of the present invention to provide a brushless DC motor directly connected to an AC power source capable of obtaining a static pressure-air flow characteristic in which the air flow does not change greatly even if it is.

  And since the speed cannot be adjusted, it can only be used in either the forced ventilation mode in the ventilation device or the constant ventilation mode with a small air volume, so there is a problem that it is difficult to install in the ventilation device, and there are two or more speeds. It is required to be able to adjust.

  The present invention solves such a conventional problem, and an object of the present invention is to provide a brushless DC motor directly connected to an AC power source capable of speed adjustment in two or more stages.

In order to achieve the above object, the AC power source direct-coupled brushless DC motor of the present invention includes a drive logic control unit for sequentially energizing the drive coil in a predetermined direction and in order based on a signal from the magnetic pole position detection unit. Based on the output of the drive logic control means, a plurality of switching elements for energizing the drive coil, and a rotation signal output means for outputting a rotation speed signal of the magnet rotor based on the signal of the magnetic pole position detection means Rectifying means for full-wave rectification of the AC power supply, low voltage DC voltage converting means for converting the high voltage obtained by the rectifying means into a low voltage DC voltage and supplying the driving coil as a driving power supply, and supplying the switching element Supply current value control means for controlling the average current to be substantially constant, and current value instruction means for indicating the average current value to be controlled to be substantially constant by the supply current value control means Comprising a, in response to an output signal of said rotation signal output means, the current value instruction means the average current value linearly or nonlinearly changing the instructing by, in accordance with the rotational speed increases, it has a large axial torque The configuration of a brushless DC motor directly connected to an AC power source characterized by the above.

  Since low voltage DC voltage is supplied to the drive coil by this means, the capacity of the smoothing capacitor used in the subsequent stage of the full-wave rectifier circuit can be kept low, so even polymer capacitors other than electrolytic capacitors, film capacitors, and ceramic capacitors can be used. It is possible to cope with it, and the circuit can be greatly reduced in size, improved in quality, extended in service life, prevented from rotating rotation, reduced in current, wide range of usable load torque and low power consumption even in high output range. Electricity can be realized, and furthermore, the torque-rotational speed characteristic that increases the shaft torque as the rotational speed increases can be obtained. Therefore, when the fan motor is used, the air volume greatly changes even if the static pressure such as pressure loss changes. A brushless DC motor and an electric device directly connected to an AC power source that can realize static pressure-air flow characteristics that are not generated are obtained.

Further, in order to achieve the above object, the AC power source directly connected brushless DC motor of the present invention is based on the magnetic flux density distribution detecting means for detecting the magnetic flux density distribution of the magnet rotor and the signal of the magnetic flux density distribution detecting means. Drive logic control means for sequentially energizing the drive coil in a predetermined direction and order, a plurality of switching elements for energizing the drive coil based on the output of the drive logic control means, and the magnetic flux density Rotation signal output means for outputting the rotation speed signal of the magnet rotor based on the signal from the distribution detection means, rectification means for full-wave rectification of the AC power supply, and high voltage obtained by this rectification means is converted into low voltage DC voltage Low voltage DC voltage conversion means for supplying the drive coil as drive power, supply current value control means for controlling the average current supplied to the switching element substantially constant, Current value indicating means for indicating an average current value controlled substantially constant by the supply current value control means, and a magnetic flux density distribution waveform detected by the magnetic flux density distribution detecting means, by rotating the magnet rotor, The magnetic flux density distribution detecting means is arranged so as to be substantially similar to the induced voltage waveform induced in the drive coil, and the drive logic control means applies a current substantially similar to the waveform detected by the magnetic flux density distribution detecting means. Current waveform control means for flowing through the drive coil, and according to the output signal of the rotation signal output means, the average current value indicated by the current value indication means is changed linearly or nonlinearly to increase the rotational speed. Accordingly, the brushless DC motor is directly connected to the AC power supply, characterized in that the shaft torque is increased .

  By this means, the induced voltage waveform and the current waveform are substantially similar, so the torque ripple and torque change rate are reduced, noise and vibration are suppressed, and the efficiency of the brushless DC motor is greatly improved. Since the range of usable load torque is widened and copper loss can be reduced, low power consumption can be realized and a low-voltage DC voltage is supplied to the drive coil. Capacitance can be kept low, so it can be used with polymer capacitors other than electrolytic capacitors, film capacitors, and ceramic capacitors, and the circuit can be greatly reduced in size, with high quality, long life, and uneven rotation. It is possible to suppress the occurrence and the shaft torque increases as the rotational speed increases. Therefore, when a fan motor is used, a brushless DC motor directly connected to an AC power source and an electric device capable of obtaining a static pressure-air flow characteristic in which the air flow does not change greatly even if the static pressure such as pressure loss changes are obtained. It is done.

Further, in order to achieve the above object, the AC power source direct-coupled brushless DC motor of the present invention is a drive logic control for sequentially energizing the drive coil in a predetermined direction and order based on the signal of the magnetic pole position detection means. , A plurality of switching elements for energizing the drive coil based on the output of the drive logic control means, and a rotation signal output for outputting a rotation speed signal of the magnet rotor based on the signal of the magnetic pole position detection means Means, rectifying means for full-wave rectification of the AC power supply, low voltage DC voltage converting means for converting the high voltage obtained by the rectifying means into a low voltage DC voltage and supplying the drive coil as a drive power supply, and the switching element Supply current value control means for controlling the supplied average current to be substantially constant, and current value indicating means for indicating the average current value to be controlled to be substantially constant by the supply current value control means A rotational speed range discriminating means for classifying and discriminating the rotational speed range of the magnet rotor based on the output signal of the rotational signal output means, and the rotational speed range detected by the rotational speed range discriminating means Accordingly, the average current value indicated by the current value indicating means is changed , and the shaft torque is increased stepwise as the rotational speed increases. It is what.

  Since low voltage DC voltage is supplied to the drive coil by this means, the capacity of the smoothing capacitor used in the subsequent stage of the full-wave rectifier circuit can be kept low, so even polymer capacitors other than electrolytic capacitors, film capacitors, and ceramic capacitors can be used. It is possible to cope with it, and the circuit can be downsized, high quality, long life and rotation unevenness can be suppressed, the current can be reduced, the range of usable load torque is wide, and the power consumption is low even in the high output range. In addition, the speed range is classified and the operation is performed at a constant current according to the range, so a constant torque constant characteristic is obtained. AC power supply direct-coupled brushless DC motor and electrical equipment capable of realizing static pressure-air flow characteristics in which the air flow does not change greatly even if the air pressure changes are obtained. It is.

Further, in order to achieve the above object, the AC power source directly connected brushless DC motor of the present invention is based on the magnetic flux density distribution detecting means for detecting the magnetic flux density distribution of the magnet rotor and the signal of the magnetic flux density distribution detecting means. Drive logic control means for sequentially energizing the drive coil in a predetermined direction and order, a plurality of switching elements for energizing the drive coil based on the output of the drive logic control means, and the magnetic flux density Rotation signal output means for outputting a rotation speed signal of the magnet rotor based on the signal of the distribution detection means, rectification means for full-wave rectification of the AC power supply, and a high voltage obtained by the rectification means is converted into a low voltage DC voltage. Low-voltage DC voltage conversion means for converting and supplying the drive coil as drive power, and supply current value control means for controlling the average current supplied to the switching element 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 a magnetic flux density distribution waveform detected by the magnetic flux density distribution detecting means are obtained by rotating the magnet rotor. The magnetic flux density distribution detecting means is arranged so as to be substantially similar to the induced voltage waveform induced in the drive coil, and the drive logic control means is a current substantially similar to the waveform detected by the magnetic flux density distribution detecting means. Current waveform control means for causing the drive coil to flow, and rotation speed range determination means for classifying and determining the rotation speed range of the magnet rotor based on the output signal of the rotation signal output means. depending on the rotational speed range is detected by means changes the average current value indicated by the current value instruction means, in accordance with the rotational speed increases, stepwise axis Is obtained by the configuration of the AC power source directly connected brushless DC motor is characterized in that a larger torque.

  By this means, the induced voltage waveform and the current waveform are substantially similar, so the torque ripple and torque change rate are reduced, noise and vibration are suppressed, and the efficiency of the brushless DC motor is greatly improved. Since the range of usable load torque is widened and copper loss can be reduced, low power consumption can be realized and a low-voltage DC voltage is supplied to the drive coil. Capacitance can be kept low, so it can be used with polymer capacitors other than electrolytic capacitors, film capacitors, and ceramic capacitors, and the circuit can be greatly reduced in size, with high quality, long life, and uneven rotation. In addition to being able to suppress the occurrence, classify the rotation speed range and operate at a constant current step by step according to the range Since a stepwise constant torque characteristic is obtained, a brushless DC motor directly connected to an AC power source that can realize a static pressure-air flow characteristic in which the air flow does not change greatly even if the static pressure changes such as pressure loss when a fan motor is used, and Electrical equipment is obtained.

  Further, in order to achieve the above object, the AC power source directly connected brushless DC motor of the present invention has a configuration of an AC power source directly connected brushless DC motor in which the permanent magnet of the magnet rotor is a polar anisotropic magnet.

  By this means, the induced voltage waveform and current waveform become approximately sine waves, so that the torque ripple and torque change rate are further reduced, and the generation of noise / vibration is further suppressed while further reducing noise and vibration. A brushless DC motor and electrical equipment directly connected to the power source can be obtained.

  Further, in order to achieve the above object, the AC power source directly connected brushless DC motor of the present invention is provided with magnetic flux density distribution waveform synthesizing means for synthesizing two phases of waveforms detected by the magnetic flux density distribution detecting means. The logic control means is configured as a drive logic control means for supplying a current substantially similar to the waveform synthesized by the magnetic flux density distribution waveform synthesis means to the drive coil. It is.

  This means that harmonic components such as third and fifth harmonics in the current waveform can be removed. Therefore, the AC power supply direct connection type that can reduce noise and vibration while suppressing the inclusion of harmonic components in the instantaneous torque. Thus, a brushless DC motor and an electric device can be obtained.

  Further, in order to achieve the above object, the AC power source direct-coupled brushless DC motor of the present invention is provided with a plurality of AC power source connecting means for connecting the AC power source, and the supply current value according to the connection location to the AC power source connecting means. An AC power supply directly connected brushless DC motor is provided, characterized in that a supply current set value changing means for changing a current value controlled substantially constant by the control means is provided.

  Since the reference set value of the current value supplied to the switching element can be changed by this means, the torque-rotational speed characteristic in which the shaft torque increases as the rotational speed increases, and the stepwise constant torque characteristic has an AC power supply connecting means. Therefore, when using a fan motor, the AC power supply direct connection type brushless DC motor that can realize the static pressure-air flow characteristics that do not change greatly even if the static pressure changes, such as pressure loss. And electrical equipment is obtained.

  Further, in order to achieve the above object, the AC power source directly connected brushless DC motor of the present invention has a low voltage DC voltage derivation terminal for deriving the low voltage DC voltage generated by the low voltage DC voltage conversion means to the outside of the brushless DC motor, and this low voltage Supply current set value input means for introducing into the brushless DC motor as a current value control signal for controlling the low voltage DC voltage obtained by reducing the low voltage DC voltage derived from the DC voltage derivation terminal to be substantially constant by the supply current value control means. And a configuration of an AC power supply direct-coupled brushless DC motor characterized in that the average current value supplied to the switching element is controlled by the magnitude of the low-voltage DC voltage introduced from the supply current set value input means It is.

  This means that torque-rotational speed characteristics that increase shaft torque and stepwise constant torque characteristics can be obtained arbitrarily as the rotational speed increases, so static pressure such as pressure loss changes when a fan motor is used. In addition, it is possible to obtain a brushless DC motor and an electric device directly connected to an AC power source that can arbitrarily realize a static pressure-air flow characteristic in which the air flow does not change greatly.

  According to the present invention, since the low-voltage DC voltage is supplied to the drive coil, the capacity of the smoothing capacitor used in the subsequent stage of the full-wave rectifier circuit can be kept low, so a polymer capacitor other than an electrolytic capacitor, a film capacitor, Ceramic capacitors can also be used, and the circuit can be significantly reduced in size, improved in quality, extended in service life, prevented from rotating unevenness, reduced in current, has a wide range of usable load torque, and has a high output range. However, low power consumption can be realized, and furthermore, the rotation speed can be increased by changing the average current value indicated by the current value indicating means linearly or nonlinearly according to the output signal of the rotation signal output means. Therefore, torque-rotational speed characteristics that increase the shaft torque can be obtained, so static pressure such as pressure loss changes when a fan motor is used. It can provide a brushless DC motor and electrical equipment of the AC power source directly coupled can realize the air volume characteristics - also static pressure air volume does not change significantly.

  Further, according to the present invention, the induced voltage waveform and the current waveform are substantially similar, so that the torque ripple and the torque change rate are reduced, noise and vibration are suppressed, and the efficiency of the brushless DC motor is greatly increased. Since the range of usable load torque is widened and copper loss can be reduced, low power consumption can be realized and low voltage DC voltage is supplied to the drive coil. Since the capacity of the smoothing capacitor used for the capacitor can be kept low, it can be used with polymer capacitors other than electrolytic capacitors, film capacitors, and ceramic capacitors, and the circuit can be greatly reduced in size, with higher quality and longer life. And the occurrence of uneven rotation, and the current value indicating means can be controlled according to the output signal of the rotation signal output means. By changing the average current value instructed linearly or non-linearly, a torque-rotational speed characteristic is obtained in which the shaft torque increases as the rotational speed increases. It is possible to provide an AC power supply directly connected brushless DC motor and an electric device capable of obtaining a static pressure-air flow characteristic in which the air flow does not change greatly even when the static pressure changes.

  Further, according to the present invention, since the low-voltage DC voltage is supplied to the drive coil, the capacity of the smoothing capacitor used in the subsequent stage of the full-wave rectifier circuit can be kept low, so that a polymer capacitor other than an electrolytic capacitor, or a film capacitor It can also be used with ceramic capacitors, and the circuit can be significantly reduced in size, increased in quality, extended in service life, prevented from rotating rotation, reduced in current, has a wide range of usable load torque, and has high output. Low power consumption can be achieved even in the range, and further, the rotation speed range is classified and the operation is performed with constant current according to the range, so that a constant torque constant characteristic can be obtained. A brushless DC motor directly connected to an AC power source and an electric device capable of realizing a static pressure-air flow characteristic in which the air flow does not change greatly even if the static pressure changes, such as pressure loss. Vessel can provide.

  Further, according to the present invention, the induced voltage waveform and the current waveform are substantially similar, so that the torque ripple and the torque change rate are reduced, noise and vibration are suppressed, and the efficiency of the brushless DC motor is greatly increased. Since the range of usable load torque is widened and copper loss can be reduced, low power consumption can be realized and low voltage DC voltage is supplied to the drive coil. Since the capacity of the smoothing capacitor used for the capacitor can be kept low, it can be used with polymer capacitors other than electrolytic capacitors, film capacitors, and ceramic capacitors, and the circuit can be greatly reduced in size, with higher quality and longer life. In addition to suppressing the generation of uneven rotation and rotation, the rotation speed range is classified, and the current is gradually increased according to the range. Because it rotates, a step-wise constant torque characteristic can be obtained. When a fan motor is used, an AC power supply directly connected brushless DC that can realize a static pressure-air volume characteristic that does not change greatly even if the static pressure changes, such as pressure loss. Motors and electrical equipment can be provided.

  In addition, according to the present invention, the induced voltage waveform and the current waveform are substantially sine waves, so that the torque ripple and the torque change rate are further reduced, and noise and vibration are further suppressed, and noise and vibration are reduced. A brushless DC motor and an electric device directly connected to an AC power source that can be realized can be provided.

  Further, according to the present invention, since harmonic components such as third harmonic and fifth harmonic in the current waveform can be removed, it is possible to reduce noise and vibration while suppressing the inclusion of harmonic components in the instantaneous torque. It is possible to provide a brushless DC motor and electrical equipment directly connected to an AC power source.

  Further, according to the present invention, since the reference set value of the current value supplied to the switching element can be changed, the torque-rotational speed characteristic in which the shaft torque increases as the rotational speed increases by the number of AC power supply connection means. In addition, since a constant torque constant characteristic can be obtained, the static air pressure-air flow characteristics can be adjusted by the number of AC power supply connection means so that the air flow does not change greatly even if the static pressure changes, such as pressure loss, when a fan motor is used. It is possible to provide an AC power supply directly connected brushless DC motor and an electric device that can be realized.

  In addition, according to the present invention, an arbitrary number of torque-rotational speed characteristics in which shaft torque increases as the rotational speed increases and stepwise constant torque characteristics can be obtained. Thus, it is possible to provide a brushless DC motor and an electric device directly connected to an AC power source that can realize an arbitrary number of air volume adjustments with respect to static pressure-air volume characteristics in which the air volume does not change greatly even when the static pressure changes.

  The invention according to claim 1 of the present invention is a drive logic control means for sequentially energizing the drive coil in a predetermined direction and order based on a signal from the magnetic pole position detection means, and an output of the drive logic control means A plurality of switching elements for energizing the drive coil, a rotation signal output means for outputting a rotation speed signal of the magnet rotor based on a signal from the magnetic pole position detection means, and full-wave rectification of the AC power supply Rectifying means, low voltage DC voltage converting means for converting the high voltage obtained by the rectifying means into low voltage DC voltage and supplying the drive coil as a drive power source, and controlling the average current supplied to the switching element to be substantially constant Supply current value control means, and current value indicating means for indicating an average current value controlled substantially constant by the supply current value control means, and an output signal of the rotation signal output means Accordingly, an AC power supply direct-connection type brushless DC motor is characterized in that the average current value indicated by the current value indicating means is changed linearly or non-linearly. By converting to a DC voltage and supplying the drive coil as a drive power supply, the smoothing capacitor after full-wave rectification has a very short period in which the voltage is insufficient (for example, if AC100V50Hz is converted to a low-voltage DC voltage 45V, 2.1). The capacity can be kept low enough to compensate for the millisecond), so it can be used with polymer capacitors other than electrolytic capacitors, film capacitors, and ceramic capacitors, and the supply current value control means keeps the current to the switching element constant. It is possible to reduce the capacity of the secondary-side smoothing capacitor. In addition, the average current value indicated by the current value indicating means is changed linearly or nonlinearly in accordance with the output signal of the rotation signal output means, so that the shaft torque increases as the rotational speed increases. A torque-rotational speed characteristic is obtained.

  According to the second aspect of the present invention, the magnetic flux density distribution detecting means for detecting the magnetic flux density distribution of the magnet rotor, and all the waves are sequentially applied to the drive coil in a predetermined direction and order based on the signal of the magnetic flux density distribution detecting means. The magnetic rotor based on a drive logic control means for energization, a plurality of switching elements for energizing the drive coil based on the output of the drive logic control means, and a signal from the magnetic flux density distribution detection means Rotation signal output means for outputting the rotation speed signal, rectification means for full-wave rectification of the AC power supply, and a low voltage that converts the high voltage obtained by this rectification means into a low-voltage DC voltage and supplies the drive coil as drive power DC voltage conversion means, supply current value control means for controlling the average current supplied to the switching element to be substantially constant, and average power to be controlled to be substantially constant by the supply current value control means A current value indicating means for indicating a value and a magnetic flux density distribution waveform detected by the magnetic flux density distribution detecting means are substantially similar to the induced voltage waveform induced in the drive coil by the rotation of the magnet rotor. The magnetic flux density distribution detection means is arranged so that the drive logic control means includes a current waveform control means for causing a current substantially similar to the waveform detected by the magnetic flux density distribution detection means to flow through the drive coil, and According to the output signal of the rotation signal output means, the average current value instructed by the current value instructing means is changed linearly or non-linearly, and the AC power source directly connected brushless DC motor is configured. Since the induced voltage waveform and the current waveform are substantially similar, the torque ripple and torque change rate are reduced, and the brushless DC motor The rate is greatly improved, and the low-voltage DC voltage conversion means converts the voltage into a low-voltage DC voltage and supplies it to the drive coil as a drive power supply, so that the smoothing capacitor after full-wave rectification has a very short period of time (for example, , If it converts AC100V50Hz to low-voltage DC voltage 45V, it can be kept low enough to compensate for the capacity of 2.1 milliseconds), so it can be handled with polymer capacitors other than electrolytic capacitors, film capacitors, and ceramic capacitors. At the same time, since the supply current value control means controls the current to the switching element to be constant, it is possible to reduce the capacity of the secondary side smoothing capacitor and also according to the output signal of the rotation signal output means. By changing the average current value indicated by the current value indicating means linearly or nonlinearly The torque-rotational speed characteristic is obtained in which the shaft torque increases as the rotational speed increases.

  The invention according to claim 3 is based on the drive logic control means for sequentially energizing the drive coil in a predetermined direction and order based on the signal of the magnetic pole position detection means, and the output of the drive logic control means. A plurality of switching elements for energizing the drive coil, a rotation signal output means for outputting a rotation speed signal of the magnet rotor based on the signal of the magnetic pole position detection means, and a rectification means for full-wave rectification of the AC power supply A low-voltage DC voltage conversion means for converting the high-voltage voltage obtained by the rectifying means into a low-voltage DC voltage and supplying the drive coil as a drive power supply; and a supply current for controlling the average current supplied to the switching element to be substantially constant Value control means and current value instruction means for instructing an average current value controlled substantially constant by the supply current value control means, and based on the output signal of the rotation signal output means A rotation speed range determination means for classifying and determining the rotation speed range of the stone rotor, and according to the rotation speed range detected by the rotation speed range determination means, an average current value indicated by the current value indicating means is determined. This is a configuration of a brushless DC motor with direct connection to an AC power source characterized in that the low-voltage DC voltage conversion means converts it to a low-voltage DC voltage and supplies it to the drive coil as a drive power source, after full-wave rectification The smoothing capacitor can be kept low enough to compensate for a very short period of time when the voltage is insufficient (for example, 2.1 milliseconds if AC100V50Hz is converted to low voltage DC voltage 45V). Capacitors, film capacitors, and ceramic capacitors can be used, and the supply current value control means switches. Since the current to the child is controlled to be constant, it is possible to reduce the capacity of the secondary-side smoothing capacitor, classify the rotation speed range, and operate at a constant current stepwise according to the range Therefore, there is an effect that a stepwise constant torque characteristic can be obtained.

  According to a fourth aspect of the present invention, based on the magnetic flux density distribution detecting means for detecting the magnetic flux density distribution of the magnet rotor and the signal from the magnetic flux density distribution detecting means, all the waves are sequentially applied to the drive coil in a predetermined direction and order. The magnetic rotor based on a drive logic control means for energization, a plurality of switching elements for energizing the drive coil based on the output of the drive logic control means, and a signal from the magnetic flux density distribution detection means Rotation signal output means for outputting the rotation speed signal, rectification means for full-wave rectification of the AC power supply, and a high voltage obtained by the rectification means is converted into a low-voltage DC voltage and supplied to the drive coil as a drive power supply. Low voltage DC voltage conversion means, supply current value control means for controlling the average current supplied to the switching element to be substantially constant, and flat voltage controlled to be substantially constant by the supply current value control means. The current value indicating means for indicating the current value and the magnetic flux density distribution waveform detected by the magnetic flux density distribution detecting means are substantially similar to the induced voltage waveform induced in the drive coil by the rotation of the magnet rotor. The magnetic flux density distribution detecting means is arranged so that the drive logic control means causes a current waveform control means to flow a current substantially similar to the waveform detected by the magnetic flux density distribution detection means to the drive coil, and the rotation A rotation speed range determining means for classifying and determining a rotation speed range of the magnet rotor based on an output signal of the signal output means, and according to the rotation speed range detected by the rotation speed range determination means, the current An AC power supply direct connection type brushless DC motor is characterized in that the average current value indicated by the value indicating means is changed, and the induced voltage waveform and current Because the shape is almost similar, the torque ripple and torque change rate are reduced, the efficiency of the brushless DC motor is greatly improved, and the low-voltage DC voltage conversion means converts it into a low-voltage DC voltage, and the drive coil as a drive power supply , The smoothing capacitor after full-wave rectification is kept low enough to compensate for a very short period in which the voltage is insufficient (for example, 2.1 milliseconds if AC100V50Hz is converted to low voltage DC voltage 45V). Therefore, polymer capacitors other than electrolytic capacitors, film capacitors, and ceramic capacitors can be used, and the supply current value control means controls the current to the switching element to be constant. It is possible to reduce the capacity of the smoothing capacitor and classify the rotation speed range. Since the operation is performed at a constant current stepwise according to the range, the stepwise constant torque characteristic is obtained.

  The invention according to claim 5 is a configuration of a brushless DC motor having an AC power supply directly connected with a permanent magnet of a magnet rotor as a polar anisotropic magnet, and an induced voltage waveform and a current waveform are substantially sine waves. Therefore, the torque ripple and the torque change rate are further reduced, and the generation of noise and vibration is further suppressed.

  The invention according to claim 6 is provided with magnetic flux density distribution waveform synthesizing means for synthesizing two phases of the waveforms detected by the magnetic flux density distribution detecting means, and the drive logic control means is provided with the magnetic flux density distribution waveform synthesizing means. This is a configuration of an AC power supply direct-coupled brushless DC motor characterized in that it is a drive logic control means for supplying a current substantially similar to the synthesized waveform to the drive coil. Harmonic components such as second harmonics can be removed.

  The invention according to claim 7 is provided with a plurality of AC power supply connection means for connecting an AC power supply, and the current value controlled substantially constant by the supply current value control means is changed according to the connection location to the AC power supply connection means. AC power supply direct connection type brushless DC motor, characterized in that the supply current set value changing means is provided, and the shaft torque increases as the rotational speed increases by the number of AC power supply connection means. Torque-rotational speed characteristics and stepwise constant torque characteristics are obtained.

  According to the eighth aspect of the present invention, the low-voltage DC voltage deriving terminal for deriving the low-voltage DC voltage generated by the low-voltage DC voltage converting means to the outside of the brushless DC motor, and the low-voltage DC voltage derived from the low-voltage DC voltage deriving terminal Supply current set value input means for introducing into the brushless DC motor is provided as a current value control signal for controlling the reduced low-voltage DC voltage to be substantially constant by the supply current value control means, and is introduced from the supply current set value input means. In this configuration, the average current value supplied to the switching element is controlled according to the magnitude of the low-voltage DC voltage. The brushless DC motor is directly connected to the AC power source, and the shaft increases as the rotational speed increases. It has an effect that an arbitrary number of torque-rotational speed characteristics that increase torque and stepwise constant torque characteristics can be obtained.

  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 1 denotes a brushless DC motor directly connected to an AC power supply, and 10 denotes a drive coil 2 via an insulator 11 formed of an insulating material on a stator core 10a having a plurality of slots. In the wound stator, the stator 10 is molded with a thermosetting resin 27 to form an outer cover, and 25 is a bracket that holds the bearing 26. Reference numeral 3 denotes a magnet rotor, which is formed by integrally orienting a plastic magnet with the shaft 24 during the injection molding, and the main magnetic pole portion is a polar anisotropic magnet 3a. A hall element 4 serves as a magnetic flux density distribution detecting means for detecting the magnetic flux density distribution of the polar anisotropic magnet 3a. The waveform detected by the hall element 4 is induced in the drive coil 2 by the polar anisotropic magnet 3a. The gap between the Hall element 4 and the polar anisotropic magnet 3a is set and arranged so as to be substantially similar to the voltage waveform. A magnetic flux density distribution waveform synthesizing unit 12 subtracts the v-phase waveform from the u-phase waveform of the Hall element 4 in order to remove the harmonic component of the current waveform supplied to the u-phase of the drive coil 2, and similarly the drive coil. For the v phase of 2, the w phase waveform is subtracted from the v phase waveform of the Hall element 4, and for the w phase of the drive coil, the u phase waveform is subtracted from the w phase waveform of the Hall element 4. Reference numeral 5 denotes drive logic control means for controlling ON / OFF of the switching element 6 so that the drive coil 2 is sequentially full-wave energized in a predetermined direction and order. The current waveform control means 7 is controlled by the magnetic flux density distribution waveform synthesis means 12. The output bias current is adjusted while performing feedback so that the switching element 6 is in a non-saturated state close to saturation so that the waveform is substantially similar to the waveform from which the harmonic components are removed. Reference numeral 15 denotes AC power connection means for connecting commercial AC power, 15a is a strong output connection terminal, 15b is a weak output connection terminal, and 15c is a common connection terminal. Reference numeral 9 is a rectifying means for full-wave rectification of the AC power supply, and 8 is a low-voltage DC voltage conversion means for converting a high-voltage voltage having ripples rectified by the full-wave rectification means 9 into a low-voltage DC voltage of 45V or less. The low-voltage DC voltage converted by the DC voltage conversion means 8 is supplied to the drive coil 2 via the switching element 6. Between the low-voltage DC voltage converting means 8 and the rectifying means 9, a polymer capacitor is used as a small-capacity smoothing capacitor 18 that compensates for a voltage of 2.1 milliseconds, which is 45 V or less when full-wave rectification is performed on AC 100 V 50 Hz. Arranged. Reference numeral 17 denotes a rotation signal output means for outputting a pulse-like waveform from the waveform detected by the magnetic flux density distribution detection means 4, 21 a current detection means for detecting a current supplied to the switching element 6, and 22 a supply current value. It is a control means. This supply current value control means 22 changes the low voltage DC voltage value so that the average current value supplied to the switching element 6 detected by the current detection means 21 is equal to the current value indicated by the current value indication means 19. By controlling the means 14, feedback control is performed while varying the voltage output from the low voltage DC voltage converting means 8. The current value indicating means 19 supplies the current supplied to the switching element 6 with respect to the reference set value in accordance with the magnitude of the voltage value after F / V converting the pulse waveform output from the rotation signal output means 17. Specify by nonlinear change (higher order proportional). At this time, considering the withstand voltage and kickback voltage of the switching element 6, an upper limit is set for the low-voltage DC voltage applied to the switching element 6, and the section is operated at a constant voltage without controlling the current even if the rotation speed increases. Is provided. Reference numeral 23 denotes an external switch, which is connected to either the strong output connection terminal 15a or the weak output connection terminal 15b. Reference numeral 13 denotes speed adjustment instruction detection means, and the external switch 23 is connected to the strong output connection terminal 15a or weak output. A configuration for detecting which one of the connection terminals 15b is connected and for changing the reference set value of the current supplied to the switching element 6 when the supply current set value changing means 20 receives the output signal of the speed adjustment instruction detecting means 13 It is. 1 except for the smoothing capacitor 18 and the coil that is one of the components constituting the low-voltage DC voltage converting means 8 and the secondary-side smoothing capacitor (not shown). The one-chip IC 16 is formed by mounting and wiring connection on an aluminum substrate. Reference numeral 28 denotes a ventilator equipped with the AC power source direct-coupled brushless DC motor 1 and a centrifugal blower 29.

  According to the brushless DC motor 1 directly connected to the AC power source according to the present invention, the current supplied to the switching element 6 by the current value indicating unit 19 according to the output signal of the rotation signal output unit 17 with respect to the reference set value. Therefore, if the rotational speed increases, the supply current also increases. Conversely, if the rotational speed decreases, the supply current decreases. As shown in FIG. As shown in FIG. 6, the torque-rotation speed characteristic of the ventilator 28 equipped with the centrifugal blower 29 has an external torque characteristic that increases the shaft torque as the rotation speed increases. Even if the pressure loss such as the wind pressure or the duct length is changed, the static pressure-air volume characteristic is obtained in which the air volume does not change greatly. Here, the amount of change in the non-linear change (proportional to the higher-order expression) may be set as appropriate from the load amount such as the fan load so as to obtain an optimum slope of the characteristic curve of the torque-rotation speed characteristic.

  Further, in the AC power source connection means 15, two places are provided such as a strong output connection terminal 15a and a weak output connection terminal 15b, and whether the speed adjustment instruction detection means 13 is connected to the strong output connection terminal 15a, or a weak output connection terminal. 15b is detected, and the current setting value changing means 20 changes the reference setting value of the current supplied to the switching element 6 based on the result. As a result, an AC power supply directly connected brushless DC motor capable of adjusting the speed by switching the connection of the AC power supply line can be obtained. Here, in the AC power supply connection means 15, if the supply current set value changing means 20 changes the reference set value according to the number of connection terminals, the speed can be adjusted by the number of connection terminals.

  Further, the high voltage having ripples rectified by the rectifying means 9 for full-wave rectification is converted into a low voltage DC voltage of 45 V or less by the low voltage DC voltage converting means 8 and supplied to the drive coil 2 as a drive power source. Since the smoothing capacitor 18 after wave rectification can be kept low enough to compensate for the very short period of 2.1 milliseconds when the voltage is insufficient, the capacitor can be reduced in size and space, and the electrolytic capacitor can be reduced. A brushless DC motor with a direct connection to an AC power source that can be used for polymer capacitors, ceramic capacitors, and film capacitors without using them, and that can be greatly reduced in size and improved in quality, such as no change in temperature characteristics. can get.

  Further, even if the capacity of the smoothing capacitor 18 is small, the current supplied to the switching element 6 by the supply current value control means 24 is controlled to be substantially constant, so that the AC power source directly connected brushless DC motor that suppresses torque ripple and rotation unevenness. Is obtained. And even if it uses for fan drive, stabilization of ventilation volume is realizable. Here, even if the secondary side smoothing capacitor used in the low-voltage DC voltage converting means 8 has a small capacity, the same effect can be obtained.

  In addition, since the driving logic control means 5 performs three-phase full-wave driving, there is no need to consider the dead point, torque ripple and torque change rate can be reduced, driving current can be reduced, and copper in a high output region can be reduced. Since the loss can be reduced, it is possible to obtain a brushless DC motor directly connected to an AC power source that suppresses the generation of noise and vibration, has a wide range of usable load torque, and can realize low power consumption even in a high output region.

  Further, the gap between the magnetic flux density distribution detecting means 4 and the magnet is set so that the waveform detected by the magnetic flux density distribution detecting means 4 is substantially similar to the induced voltage waveform induced in the drive coil 2 by the polar anisotropic magnet 3a. The current waveform control means 7 causes the induced voltage waveform and the current waveform to be substantially similar by passing a current substantially similar to the magnetic flux density distribution waveform detected by the magnetic flux density distribution detection means 4 to the drive coil 2. The torque ripple and the rate of change in torque can be further reduced, and the motor efficiency is greatly improved. Therefore, a brushless DC motor directly connected to an AC power source that achieves low noise and high efficiency can be obtained.

  Further, by making the main magnetic pole portion of the magnet rotor 3 the polar anisotropic magnet 3a, both the induced voltage waveform and the current waveform become sinusoidal waves, so that the torque ripple and the torque change rate can be further reduced. In addition, since the motor efficiency is greatly improved, it is possible to obtain a brushless DC motor directly connected to an AC power source that achieves low noise and high efficiency.

  Further, the magnetic flux density distribution waveform synthesizing unit 12 synthesizes the u-phase, v-phase, and w-phase waveforms detected by the magnetic flux density distribution detection unit 4, so that the influence of variations in the magnetic flux density distribution detection unit 4 of each phase is affected. As the magnetic flux density distribution waveform of each of the u-phase, v-phase, and w-phase is basically a waveform that is simply shifted in phase, the detected magnetic flux is obtained by subtracting and synthesizing the two phases. Since harmonic components contained in the density distribution waveform are removed, rotation irregularity can be suppressed, and torque ripple and torque change rate can be further reduced. The brushless DC motor is obtained.

  In the first embodiment, the current value indicating means 19 makes the current supplied to the switching element 6 non-linearly change (proportional to a higher order expression) with respect to the reference set value in accordance with the output signal of the rotation signal output means 17. However, it is also possible to use a linear change (primary proportionality), and the same is achieved by appropriately setting the characteristic curve of the torque-rotation speed characteristic from the load amount such as a fan load. An effect can be obtained.

  In the first embodiment, the rotation signal output means 17 outputs a pulse-like waveform and grasps the rotation speed from the frequency, but outputs a flat voltage using a resistor and a capacitor, It is good also as a structure which grasps | ascertains rotation speed from the voltage value, and does not produce a difference in the effect.

  In the first embodiment, the rotation signal output means 17 grasps the rotation speed from the magnetic flux density distribution detection means 4. However, the rotation signal output means 17 uses the switching timing of energization to the drive coil 2 or uses a magnetic pole detection element such as a Hall IC. A configuration provided separately may be used, and there is no difference in the operational effect by changing the supply current according to the rotation speed.

  In the first embodiment, the current waveform supplied to the drive coil 2 is configured to be substantially similar to the induced voltage waveform. A wide-angle energization method such as wave energization or 140 ° or 150 ° energization is also possible, and the torque-rotation speed characteristic of the motor provides a characteristic in which the shaft torque increases as the rotation speed increases, and after full-wave rectification The capacity of the smoothing capacitor is kept low, the rotation unevenness is suppressed, and the copper loss in the high output area is reduced, resulting in drastic downsizing, high quality, long life, and wide range of usable load torque. There is no difference in that a brushless DC motor directly connected to an AC power source capable of realizing low power consumption even in the output region can be obtained.

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

  In the first embodiment, the output bias current is adjusted while performing feedback so that the switching element 6 is in a non-saturated state close to saturation. However, the switching element 6 may be PWM-controlled to control the current waveform. In that case, since the loss of the switching element 6 can be reduced, the heat generation of the switching element 6 is suppressed, and a brushless DC motor directly connected to the AC power source that can further widen the range of usable load torque can be obtained.

  In the first embodiment, the low-voltage DC voltage converting means 8 converts the voltage to a low-voltage DC voltage of 45V or less. However, if the voltage is converted to a voltage of 36V or less, a capacitor that only compensates for a period of 1.7 milliseconds. The capacity can be further reduced.

(Embodiment 2)
As shown in FIGS. 7 and 8, reference numeral 34 denotes a ventilator including a centrifugal blower 35 and an AC power supply directly connected brushless DC motor 30 for rotating a sirocco fan of the centrifugal blower 35, and an AC power supply directly connected brushless. The DC motor 30 includes a rectifier 9, a small-capacity smoothing capacitor 18, a low-voltage DC voltage converter 8, a magnetic flux density distribution detector 4, a magnetic flux density distribution waveform synthesizer 12, a rotation signal output unit 17, a drive logic controller 5, The switching element 6, the current waveform control means 7, the low-voltage DC voltage value changing means 14, the current detecting means 21, the supply current value control means 22, the current value indicating means 19, and the supply current set value changing means 20 are placed on the same printed circuit board. After mounting, it is built in the brushless DC motor 30. Reference numeral 31 denotes a low-voltage DC voltage derivation terminal for deriving the low-voltage DC voltage generated by the low-voltage DC voltage conversion means 8 to the outside of the brushless DC motor 30, and the low-voltage power source derived from the low-voltage DC voltage derivation terminal 31 is external to the brushless DC motor 30. The pressure is reduced by the pressure reducing means 33 formed by a nearby resistance voltage dividing circuit or the like and converted into a supply current value indicating voltage. This supply current value indicating voltage is supplied from the supply current set value input means 32 to the brushless DC motor 30. The supply current set value changing means 20 changes the reference set value of the current supplied to the switching element 6 according to the magnitude of the supply current value indicating voltage, and the current value indicating means 19 is supplied from the rotation signal output means 17. Depending on the magnitude of the voltage value after the F / V conversion of the output pulse waveform, the current supplied to the switching element 6 is nonlinearly changed with respect to the reference set value. The configuration of the other components such as the magnet rotor 3 and the stator 10 is the same as that of the first embodiment, and the same parts are denoted by the same reference numerals for detailed description. Is omitted.

  According to the brushless DC motor 30 directly connected to the AC power source of the present invention as described above, the low voltage DC voltage deriving terminal 31 for deriving the low voltage DC voltage generated by the low voltage DC voltage converting means 8 to the outside of the brushless DC motor 30, and this Supply current set value input means 32 for introducing a low voltage DC voltage obtained by reducing the low voltage DC voltage derived from the low voltage DC voltage deriving terminal 31 into the brushless DC motor 30 is provided, and the low voltage introduced from the supply current set value input means 32 is provided. A simple pressure reducing means 33 is provided outside the brushless DC motor 30 by changing the reference set value of the current supplied to the switching element 6 by the supply current setting value changing means 20 according to the magnitude of the DC voltage. As a result, the torque-rotational speed characteristics of the motor have no characteristic that the shaft torque increases as the rotational speed increases. It can be obtained arbitrarily at the floor. Due to this characteristic, in the ventilation device 34 equipped with the centrifugal blower 35, the static air pressure-air flow characteristic in which the air volume does not change greatly even if the pressure loss such as the external air pressure or the duct length changes. Can be obtained steplessly. Here, the amount of change in the non-linear change (proportional to the higher-order expression) may be set as appropriate from the load amount such as the fan load so as to obtain an optimum slope of the characteristic curve of the torque-rotation speed characteristic.

  It should be noted that there is no difference in the operational effects in the same configuration as in the first embodiment.

  In the second embodiment, the reference set value of the current supplied to the switching element 6 is changed according to the magnitude of the low-voltage DC voltage introduced from the supply current set-value input means 32. However, the low-voltage DC voltage conversion means 8 The configuration may be changed in accordance with the ratio of the low-voltage DC voltage generated in step 1 to the low-voltage DC voltage introduced from the supply current set value input means 32, and there will be no difference in the operational effect.

  In the second embodiment, the current value indicating means 19 makes the current supplied to the switching element 6 non-linearly change (proportional to a higher order expression) with respect to the reference set value in accordance with the output signal of the rotation signal output means 17. However, it is also possible to use a linear change (primary proportionality), and the same is achieved by appropriately setting the characteristic curve of the torque-rotation speed characteristic from the load amount such as a fan load. An effect can be obtained.

(Embodiment 3)
As shown in FIGS. 9 to 12, reference numeral 41 denotes a ventilation device including a centrifugal blower 42 and an AC power supply directly connected brushless DC motor 36 for rotating a sirocco fan of the centrifugal blower 42, and an AC power supply directly connected brushless. The DC motor 36 includes a rectifier 9, a small-capacity smoothing capacitor 18, a low-voltage DC voltage converter 8, a magnetic flux density distribution detector 4, a magnetic flux density distribution waveform synthesizer 12, a rotation signal output unit 17, a drive logic controller 5, Switching element 6, current waveform control means 7, low-voltage DC voltage value change means 14, speed adjustment instruction detection means 13, current detection means 21, supply current value control means 40, supply current set value change means 39, rotation speed range determination means 37, the current value indicating means 38 is mounted on the same printed circuit board and is built in the brushless DC motor 36. The rotation speed range determination means 37 for classifying and determining the rotation speed range of the magnet rotor 3 determines the voltage range of the voltage value after the F / V conversion of the pulse waveform output from the rotation signal output means 17. The current value instructing means 38 instructs the current supplied to the switching element 6 in a stepwise manner with respect to the reference set value in accordance with the rotational speed range determined by the rotational speed range determining means 37. At this time, an upper limit is set for the low-voltage DC voltage applied to the switching element 6 in consideration of the kickback voltage from the breakdown voltage of the switching element 6, and the section is operated at a constant voltage without controlling the current even if the rotation speed increases. Is provided. 15 is an AC power supply connection means for connecting a commercial AC power supply, 15a is a strong output connection terminal, 15b is a weak output connection terminal, and 15c is a common connection terminal. The external switch 23 is connected to either the strong output connection terminal 15a or the weak output connection terminal 15b, and the speed adjustment instruction detecting means 13 is connected to the strong output connection terminal 15a or the weak output connection terminal 15b. It is configured to detect which one is connected, and the supply current set value changing means 39 changes the reference set value of the current supplied to the switching element 6 in response to the output signal of the speed adjustment instruction detecting means 13. 9 except for the smoothing capacitor 18 and the coil that is one of the components constituting the low-voltage DC voltage conversion means 8 and the secondary-side smoothing capacitor (not shown) among the electronic components surrounded by the one-dot chain line in FIG. The one-chip IC 43 is formed by mounting and wiring connection on an alumina substrate. Other configurations such as the magnet rotor 3 and the stator 10 are the same as those of the first embodiment, and the same parts are denoted by the same reference numerals and detailed description thereof is omitted.

  According to the brushless DC motor 36 directly connected to the AC power source of the present invention, the current value indicating means 38 supplies the current supplied to the switching element 6 according to the rotational speed range determined by the rotational speed range determining means 37. Since the reference setting value is changed and instructed stepwise, the supply current increases as the rotational speed increases, and conversely, the supply current decreases as the rotational speed decreases, as shown in FIG. The torque-rotation speed characteristic of the motor provides a characteristic in which the shaft torque increases stepwise as the rotation speed increases. With this characteristic, the ventilator 41 equipped with the centrifugal blower 42 is shown in FIG. As described above, the static pressure-air volume characteristic is obtained in which the air volume does not change greatly even if the pressure loss such as the external air pressure or the duct length changes. Here, the amount of change by which the current value indicating means 38 changes the current supplied to the switching element 6 in a stepwise manner with respect to the reference set value depends on the optimum characteristic curve of the torque-rotation speed characteristic from the load amount such as a fan load. What is necessary is just to set suitably so that it may become inclination. In FIG. 11, the broken line portion is a portion that is controlled with hysteresis when the rotational speed decreases and when the rotational speed increases, and the degree of hysteresis can be set appropriately so that problems such as hunting do not occur. good.

  It should be noted that there is no difference in the operational effects in the same configuration as in the first embodiment.

  Further, instead of the strong output connection terminal 15a, the weak output connection terminal 15b, and the speed adjustment instruction detection means 13, the low-voltage DC voltage generated by the low-voltage DC voltage conversion means shown in the second embodiment is derived outside the brushless DC motor. And a supply current set value input means for introducing a low voltage DC voltage obtained by reducing the low voltage DC voltage derived from the low voltage DC voltage deriving terminal into the brushless DC motor. By changing the reference set value of the current supplied to the switching element by the supply current setting value changing means according to the magnitude of the low-voltage DC voltage introduced by the means, the rotation speed is determined in the torque-rotation speed characteristics of the motor. As the torque increases, the characteristic that the shaft torque increases stepwise can be obtained arbitrarily without any step. In ventilator mounting the centrifugal blower static pressure losses including the outer wind pressure or duct length are not significantly changed air volume also vary - air volume characteristics can be obtained optionally steplessly.

  As described above, the AC power supply direct-coupled brushless DC motor according to the present invention has a torque-rotational speed characteristic in which a shaft torque increases as the rotational speed increases. Air conditioners such as ventilators, water heaters, air conditioners, air purifiers, dehumidifiers, dryers, fan filter units that are required to have no significant air flow changes even when there is a change in static pressure It is useful to install on.

The block diagram which shows the alternating current power supply direct connection type brushless DC motor in Embodiment 1 of this invention Sectional view showing the brushless DC motor Graph showing voltage waveform after rectification of brushless DC motor Three-sided view showing a ventilator equipped with the brushless DC motor Graph showing torque-rotational speed characteristics of the brushless DC motor Graph showing the static pressure-air flow characteristics of a ventilator equipped with the brushless DC motor The block diagram which shows the alternating current power supply direct connection type brushless DC motor in Embodiment 2 of this invention Three-sided view showing a ventilator equipped with the brushless DC motor The block diagram which shows the alternating current power supply direct connection type brushless DC motor in Embodiment 3 of this invention Three-sided view showing a ventilator equipped with the brushless DC motor Graph showing torque-rotational speed characteristics of the brushless DC motor Graph showing the static pressure-air flow characteristics of a ventilator equipped with the brushless DC motor Circuit diagram showing a conventional DC motor Sectional view showing the DC motor Perspective view showing the DC motor Graph comparing torque-rotational speed characteristics of DC motor and induction motor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brushless DC motor 2 Drive coil 3 Magnet rotor 4 Magnetic flux density distribution detection means 5 Drive logic control means 6 Switching element 7 Current waveform control means 8 Low voltage direct current voltage conversion means 9 Rectification means 10 Stator 10a Stator core 11 Insulator 12 Magnetic flux Density distribution waveform synthesis means 13 Speed adjustment instruction detection means 14 Low voltage DC voltage change means 15 AC power supply connection means 15a Strong output connection terminal 15b Weak output connection terminal 15c Common connection connection terminal 16 One-chip IC
DESCRIPTION OF SYMBOLS 17 Rotation signal output means 18 Smoothing capacitor 19 Current instruction means 20 Supply current set value change means 21 Current detection means 22 Supply current value control means 23 Switch 24 Shaft 25 Bracket 26 Bearing 27 Thermosetting resin 28 Ventilator 29 Centrifugal blower 30 Brushless DC motor 31 Low voltage DC voltage derivation terminal 32 Supply current set value input means 33 Depressurization means 34 Ventilation device 35 Centrifugal blower 36 Brushless DC motor 37 Rotational speed range determination means 38 Current instruction means 39 Supply current set value change means 40 Supply current Value control means 41 Ventilator 42 Centrifugal blower 43 One-chip IC

Claims (10)

A brushless DC motor that is directly connected to an AC power source, a stator in which a drive coil is wound around a stator iron core via an insulator, a magnet rotor having a permanent magnet, and a magnetic pole position of the magnet rotor are detected. Based on a signal from the magnetic pole position detection means, a drive logic control means for sequentially energizing the drive coil in a predetermined direction and order based on a signal from the magnetic pole position detection means, and an output of the drive logic control means A plurality of switching elements for energizing the drive coil, rotation signal output means for outputting a rotation speed signal of the magnet rotor based on the signal of the magnetic pole position detection means, and full-wave rectification of the AC power supply Rectifying means for converting, high voltage obtained by the rectifying means into low voltage DC voltage and supplying the driving coil as a drive power source, and supplying to the switching element Supply current value control means for controlling the average current to be substantially constant, and current value instruction means for instructing the average current value to be controlled substantially constant by the supply current value control means, the output signal of the rotation signal output means The AC power supply direct-coupled brushless DC motor is characterized in that the average torque value indicated by the current value indicating means is changed linearly or non-linearly and the shaft torque is increased as the rotational speed increases. . A brushless DC motor directly connected to an AC power source, in which a stator iron core is wound with a drive coil via an insulator, a magnet rotor having a permanent magnet, and a magnetic flux density distribution of the magnet rotor Based on the magnetic flux density distribution detecting means to be detected, a signal of the magnetic flux density distribution detecting means, a drive logic control means for sequentially energizing the drive coil in a predetermined direction and order, and a drive logic control means A plurality of switching elements for energizing the drive coil based on the output; a rotation signal output means for outputting a rotation speed signal of the magnet rotor based on a signal from the magnetic flux density distribution detection means; and the AC power supply Rectifying means for full-wave rectification, low voltage DC voltage converting means for converting the high voltage obtained by the rectifying means into a low voltage DC voltage and supplying it as a drive power to the drive coil, and the switch Supply current value control means for controlling the average current supplied to the chucking element substantially constant, current value instruction means for indicating the average current value controlled substantially constant by the supply current value control means, and the magnetic flux density distribution detection means The magnetic flux density distribution detecting means is arranged so that the magnetic flux density distribution waveform detected by the magnetic rotor is substantially similar to the induced voltage waveform induced in the drive coil as the magnet rotor rotates, and the driving logic is arranged. The control means comprises current waveform control means for causing a current substantially similar to the waveform detected by the magnetic flux density distribution detection means to flow through the drive coil, and the current value indicating means according to the output signal of the rotation signal output means average current value linearly or by non-linearly changed in accordance with rotation speed increases, exchange, characterized in that a larger axial torque indicated by Power direct connection type brushless DC motor. A brushless DC motor that is directly connected to an AC power source, a stator in which a drive coil is wound around a stator iron core via an insulator, a magnet rotor having a permanent magnet, and a magnetic pole position of the magnet rotor are detected. Based on a signal from the magnetic pole position detection means, a drive logic control means for sequentially energizing the drive coil in a predetermined direction and order based on a signal from the magnetic pole position detection means, and an output of the drive logic control means A plurality of switching elements for energizing the drive coil, rotation signal output means for outputting a rotation speed signal of the magnet rotor based on the signal of the magnetic pole position detection means, and full-wave rectification of the AC power supply Rectifying means for converting, high voltage obtained by the rectifying means into low voltage DC voltage and supplying the driving coil as a drive power source, and supplying to the switching element Supply current value control means for controlling the average current to be substantially constant, and current value instruction means for instructing the average current value to be controlled substantially constant by the supply current value control means, the output signal of the rotation signal output means And a rotational speed range discriminating means for classifying and discriminating the rotational speed range of the magnet rotor based on the rotational speed range, and instructing by the current value indicating means according to the rotational speed range detected by the rotational speed range discriminating means. A brushless DC motor directly connected to an AC power source, characterized in that the shaft torque is increased stepwise as the rotational speed increases by changing the average current value. A brushless DC motor directly connected to an AC power source, in which a stator iron core is wound with a drive coil via an insulator, a magnet rotor having a permanent magnet, and a magnetic flux density distribution of the magnet rotor Based on the magnetic flux density distribution detecting means to be detected, a signal of the magnetic flux density distribution detecting means, a drive logic control means for sequentially energizing the drive coil in a predetermined direction and order, and a drive logic control means A plurality of switching elements for energizing the drive coil based on the output; a rotation signal output means for outputting a rotation speed signal of the magnet rotor based on a signal from the magnetic flux density distribution detection means; and the AC power supply Rectifying means for full-wave rectification, low voltage DC voltage converting means for converting the high voltage obtained by the rectifying means into a low voltage DC voltage and supplying it as a drive power to the drive coil, and the switch Supply current value control means for controlling the average current supplied to the chucking element substantially constant, current value instruction means for indicating the average current value controlled substantially constant by the supply current value control means, and the magnetic flux density distribution detection means The magnetic flux density distribution detecting means is arranged so that the magnetic flux density distribution waveform detected by the magnetic rotor is substantially similar to the induced voltage waveform induced in the drive coil as the magnet rotor rotates, and the driving logic is arranged. The control means includes a current waveform control means for supplying a current substantially similar to the waveform detected by the magnetic flux density distribution detection means to the drive coil, and a rotation speed range of the magnet rotor based on an output signal of the rotation signal output means. And a rotational speed range discriminating means for classifying and discriminating between the current value indicating means and the current value indicating means. Mean change the current value, in accordance with the rotational speed increases, the AC power source directly connected brushless DC motor, characterized in that to increase the stepwise shaft torque. 5. The AC power source directly connected brushless DC motor according to claim 2, wherein the permanent magnet of the magnet rotor is a polar anisotropic magnet. 6. The AC power source direct-coupled brushless DC motor according to claim 2, further comprising magnetic flux density distribution waveform synthesizing means for synthesizing two phases of waveforms detected by the magnetic flux density distribution detecting means. The AC power source direct connection type brushless DC motor is characterized in that the drive logic control means is replaced with drive logic control means for supplying a current substantially similar to the waveform synthesized by the magnetic flux density distribution waveform synthesis means to the drive coil. A plurality of AC power supply connecting means for connecting the AC power supply, and a supply current set value changing means for changing a current value controlled substantially constant by the supply current value control means according to a connection location to the AC power supply connecting means An AC power supply direct connection type brushless DC motor according to any one of claims 1 to 6, characterized in that The low-voltage DC voltage deriving terminal for deriving the low-voltage DC voltage generated by the low-voltage DC voltage conversion means to the outside of the brushless DC motor, and the low-voltage DC voltage obtained by reducing the low-voltage DC voltage derived from the low-voltage DC voltage deriving terminal A supply current set value input means to be introduced into the brushless DC motor is provided as a control signal of a current value controlled substantially constant by the current value control means. Depending on the magnitude of the low-voltage DC voltage introduced from the supply current set value input means The AC power supply direct-coupled brushless DC motor according to claim 1, wherein an average current value supplied to the switching element is controlled. An electric device equipped with the AC power source directly connected brushless DC motor according to claim 1. The electrical device according to claim 9 is any one of a ventilator, a blower, a dehumidifier, a humidifier, an air conditioner, a water heater, and a fan filter unit.

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