JP6598870B2 - Electric motor, blower and air conditioner - Google Patents

Description

  The present invention relates to an electric motor including a substrate on which circuit components are mounted, and a blower and an air conditioner including the electric motor.

  As an electric motor that drives a blower mounted on an indoor unit or an outdoor unit of an air conditioner, Patent Document 1 listed below includes a stator iron core, a Hall IC, an inverter IC, and a control means for PWM control of the inverter IC. A configuration is disclosed in which a drive circuit board on which a certain microcomputer is mounted is integrally formed using a thermosetting mold resin.

  In Patent Document 1, the optimum phase advance angle characteristic information corresponding to the number of revolutions of the motor is held as a table, and the motor is controlled based on the optimum phase advance angle characteristic information stored in the table. Realizes low noise motor control. Here, the optimum phase advance angle (also referred to as “optimum advance angle”) is the advance angle of the phase angle that maximizes the driving efficiency of the motor. Here, the “phase angle” refers to a voltage induced in the stator winding (hereinafter referred to as “induced voltage”) and a voltage applied to the stator winding by the inverter IC (hereinafter referred to as “applied voltage”). The positive lead angle is when the applied voltage is ahead of the induced voltage.

JP 2014-230363 A

  When the electric motor is controlled with the optimum phase advance angle, the operating efficiency of the electric motor is maximized or the noise of the electric motor is minimized. However, when an electric motor is used for an air conditioner, there is a request from a user who wants to quickly perform rapid cooling or rapid heating while maximizing the efficiency of the electric motor or suppressing noise. It is desired as a product to respond. In order to rapidly perform rapid cooling or rapid heating, it is necessary to improve the performance in a high rotation range.

  In order to increase the performance of the motor, the motor speed is increased. However, as the speed increases, the current flowing through the motor increases and the temperature of the power IC becomes very high. It is necessary to dissipate heat. However, since the microcomputer has a non-volatile memory and is vulnerable to heat, the power IC and the drive circuit board on which the microcomputer is mounted cannot be molded, and the performance of the power IC may be deteriorated by heat generation.

  Alternatively, a method of mounting the power IC on a board other than the driving circuit board on which the microcomputer is mounted can be considered, but the motor becomes larger and the cost increases, and the driving circuit board and the microcomputer on which the power IC is mounted As a result, the wiring connecting the circuit board and the circuit board becomes longer, and noise is likely to be placed on the wiring, which may adversely affect the motor.

  The present invention has been made in view of the above, and while suppressing the increase in size and cost of equipment, avoids noise and thermal effects, and can improve the performance in a high rotation range, It aims at obtaining a blower and an air conditioner.

  In order to solve the above-described problems and achieve the object, an electric motor according to the present invention includes a stator, a rotor disposed inside the stator, a magnetic pole position sensor, a driving element, and a control element, and a mold. And a drive circuit board sealed integrally with the stator with resin. The magnetic pole position sensor detects the rotational position of the rotor, the drive element applies a drive voltage to the stator winding, and the control element performs PWM control of the drive element. Further, the control element has a second advance angle larger than a first advance value that is an advance value at which the operation efficiency of the motor becomes maximum when the rotation speed of the motor becomes equal to or higher than the first rotation speed. Output the value.

  According to the present invention, it is possible to avoid noise and thermal influence while suppressing increase in size and cost of the device when enhancing performance in a high rotation range.

Side sectional view of the electric motor according to the present embodiment External view showing an air conditioner equipped with the electric motor according to the present embodiment The top view which shows typically the circuit components arrange | positioned at the drive circuit board of this Embodiment The top view which shows typically the circuit components arrange | positioned at the drive circuit board of this Embodiment Partial sectional view of a portion where a power IC is mounted on the drive circuit board of the present embodiment The block diagram which shows the electrical connection relation of the drive circuit component of this Embodiment The circuit diagram which shows the internal structure of the power IC of this Embodiment The block diagram which shows the structure of the advance angle calculation part of this Embodiment The circuit diagram which shows an example of the circuit structure which embodies the advance voltage signal generation part of this Embodiment Graph showing the relationship between motor torque and rotation speed according to advance angle A graph representing the first optimum advance characteristic at which the driving efficiency of the motor is maximized and the second optimum advance characteristic at which the noise of the motor is minimized in relation to the rotational speed of the motor. A graph comparing the optimum advance angle characteristic according to the rotation speed of the motor and the discrete advance angle control curve representing the relationship between the rotation speed and the advance angle of the motor and the present embodiment. Partial enlarged view of the optimum advance angle characteristic and advance angle control curve shown in FIG.

With reference to the accompanying drawings, illustrating the motor according to the embodiment of the present invention, a blower and an air conditioner in details. In addition, this invention is not limited by embodiment shown below.

Embodiment.
FIG. 1 is a side sectional view of the electric motor according to the present embodiment. FIG. 2 is a diagram showing an air conditioner equipped with the electric motor according to the present embodiment.

  The air conditioner 300 shown in FIG. 2 includes an indoor unit 300a and an outdoor unit 300b connected to the indoor unit 300a. An indoor unit fan (not shown) is mounted on the indoor unit 300a, and an outdoor unit fan 310 is mounted on the outdoor unit 300b. An electric motor 100 shown in FIG. 1 is used as a drive source for these fans. In addition, in FIG. 2, although the air conditioner was illustrated as an application example of the electric motor which concerns on this Embodiment, it is not limited to an air conditioner, For example, it can also be used as an electric motor of an air blower.

  Next, the configuration of the electric motor 100 according to the present embodiment will be described. As shown in FIG. 1, the electric motor 100 includes a mold stator 1, a rotor assembly 18, and a bracket 25 as main components. As the electric motor 100, a brushless DC motor driven by an inverter is exemplified.

  A shaft 10 serving as a rotation shaft of the electric motor 100 passes through the central portion of the rotor assembly portion 18. A load of the electric motor 100 is mounted on the shaft 10 of the electric motor 100. In the air conditioner shown in FIG. 2, an indoor unit fan or an outdoor unit fan 310 is mounted as a load.

  The mold stator 1 is formed in a cylindrical shape centered on a shaft 10 and includes a stator assembly part 3 and a mold resin part 2 filled with a mold resin.

  The stator assembly portion 3 is a portion in which the stator 5, the drive circuit board 4, and the connector 6 are integrally formed among the constituent elements of the electric motor 100. The drive circuit board 4 of the present embodiment is not mounted with a microcomputer, and can be integrally molded together with the stator 5 by the mold resin portion 2. That is, the drive circuit board 4 is integrally sealed with the stator with a mold resin. However, since the drive circuit board 4 and the like have a weak structure, low pressure molding is desirable. As the mold resin used for the mold resin portion 2 for integrally molding the drive circuit board 4 and the stator 5, unsaturated polyester is used. A thermosetting resin such as a resin is preferred.

  The mold resin portion 2 constitutes an outer shell of the electric motor 100 and constitutes a housing 19 on the side surface of the mold stator 1. The housing 19 surrounds and supports the outer ring of the load side bearing 16.

  An opening provided in the mold resin portion 2 on the side (hereinafter referred to as “load side” in FIG. 1) opposite to the side on which a load such as a fan is mounted (hereinafter referred to as “load side”). A mortar-shaped recess 26 formed so as to accommodate the rotor assembly 18 from the portion 29 into the mold stator 1 is provided. In addition, the opening part 29 is a part in which the bracket 25 is provided in FIG. The bracket 25 is manufactured by, for example, pressing a conductive metal.

  The stator 5 includes a winding 7, a stator core 8, and an insulator 9, and the stator core 8 is formed by punching an electromagnetic steel sheet having a thickness of about 0.1 to 0.7 mm into a band shape, caulking, welding, and It is laminated and manufactured by bonding. The strip-shaped stator core 8 includes a plurality of teeth (not shown), and an insulator 9 is applied to the teeth. The insulator 9 is formed integrally or separately with the stator core 8 by using a thermoplastic resin such as PBT (polybutylene terephthalate). Concentrated windings 7 are wound around the teeth to which the insulator 9 is applied. When a plurality of concentrated windings 7 are connected, for example, a three-phase single Y-connection winding is formed. However, distributed winding may be used.

  The rotor assembly portion 18 is a portion where the rotor 15, the load side bearing 16 and the anti-load side bearing 17 are combined among the components of the electric motor 100.

  The rotor 15 is disposed to face the stator core 8 and is provided around the shaft 10, an annular rotor insulating portion 12 provided on the outer peripheral portion of the shaft 10, and the outer peripheral side of the rotor insulating portion 12. The rotor magnet 13 is a permanent magnet, and the position detection magnet 11 is provided between the rotor magnet 13 and the drive circuit board 4 in the axial direction of the shaft 10.

  The rotor 15 is rotatable about the shaft 10, obtains rotational force by a rotating magnetic field from the stator core 8, transmits torque to the shaft 10, and receives a load directly or indirectly connected to the shaft 10. To drive.

  The rotor insulating portion 12 is provided to insulate the shaft 10 and the rotor magnet 13 and insulate the shaft 10 and the stator core 8 from each other. The rotor magnet 13, the shaft 10 and the position detection magnet 11 are integrally formed by a rotor insulating portion 12 injected by a vertical molding machine. A thermoplastic resin is used for the rotor insulating portion 12. Examples of the thermoplastic resin include PBT (polybutylene terephthalate) and PPS (polyphenylene sulfide), but those obtained by blending a glass filler with these PBT or PPS are also suitable. The rotor insulating unit 12 constitutes a dielectric layer.

  As the rotor magnet 13, a resin magnet, a rare earth magnet, or a sintered ferrite magnet formed by mixing a thermoplastic material with a magnetic material is used. As the rare earth magnet, neodymium or samarium iron is exemplified.

  In the axial direction of the shaft 10, a load side bearing 16 is attached to the load side (left side in FIG. 1) of the shaft 10, and an antiload side bearing 17 is attached to the antiload side (right side in FIG. 1). The shaft 10 is rotatably supported by the load side bearing 16 and the anti-load side bearing 17.

  The load-side bearing 16 is, for example, a ball bearing, and includes an inner ring 16a that rotates integrally with the shaft 10, an outer ring 16b that is fitted on the inner peripheral surface of the housing 19, and a plurality of rollers disposed between the inner and outer rings. The moving body 16c includes a lubricating oil (not shown) for rolling the rolling element 16c for lubrication, and a seal plate (not shown) for enclosing the lubricating oil. The inner ring 16a, the outer ring 16b, the rolling elements 16c and the seal plate are generally made of a conductive metal such as iron. The seal plate is fixed to the outer ring and rotates together with the outer ring. The seal plate is electrically connected to the outer ring, but is not in contact with the inner ring.

  The anti-load side bearing 17 is configured similarly to the load side bearing 16. The components of the anti-load side bearing 17 are the same as or equivalent to the components of the load side bearing 16, and detailed description thereof is omitted.

  When the rotor assembly 18 is inserted into the recess 26 from the opening of the mold stator 1, the load-side bearing 16 attached to the shaft 10 is incorporated into the housing 19. One end of the shaft 10 on the load side bearing 16 side passes through the housing 19, and the above-described fan or the like is attached to the shaft 10. On the other hand, an anti-load side bearing 17 is attached to the other end of the shaft 10, and when the bracket 25 is press-fitted into the inner peripheral portion of the mold resin portion 2 and fitted so as to close the opening 29, An anti-load side bearing 17 is incorporated inside.

  The drive circuit board 4 is formed with a through hole 8 a that penetrates the shaft 10 and the load side bearing 16. The drive circuit board 4 is held by the insulator 9. The drive circuit board 4 is disposed between the load-side bearing 16 and the winding 7 in the axial direction of the shaft 10 and is disposed perpendicular to the axial direction. Here, the term “perpendicular” does not need to be 90 degrees with respect to the axial direction of the shaft 10 and may be deviated from 90 degrees.

  Next, circuit components (hereinafter referred to as “drive circuit components” as necessary) mounted on the drive circuit board 4 will be described with reference to FIGS. 3 to 7. FIG. 3 is a plan view when the circuit components arranged on the drive circuit board 4 shown in FIG. 1 are viewed from the anti-load side, and FIG. 4 is a plan view when the same drive circuit board 4 is viewed from the load side. FIG. FIG. 5 is a partial cross-sectional view of a portion of the drive circuit board 4 where the power IC 22 is mounted. FIG. 6 is a block diagram showing the electrical connection relationship of the drive circuit components. FIG. 7 is a circuit diagram showing an internal configuration of the power IC 22.

As shown in FIG. 3, the Hall IC 21, the power IC 22, and the control IC 23 are mounted on the anti-load side of the drive circuit board 4, that is, the stator side. The Hall IC 21 is a magnetic pole position sensor for detecting the rotational position of the rotor 15, and a Hall element or the like is representative. The power IC 22 is a drive element that applies a drive voltage to the winding 7 of the stator 5, and is mounted on the drive circuit board 4 via a heat radiation pattern 32 as shown in FIG. 5. The control IC 23 is a control element that generates a PWM signal for performing pulse width modulation (PWM) control of the power IC 22 based on detection information of the Hall IC 21. The control IC 23 is an analog IC such as an ASSP (Application Specific Standard Product) that does not incorporate a nonvolatile memory, and has a wider process rule than the microcomputer and is more resistant to heat than the microcomputer. Further, the control IC 23 can be formed integrally with the power IC 22 and configured as a drive IC.

  On the other hand, the heat generated in the power IC 22 is radiated to the load side of the drive circuit board 4, that is, the surface opposite to the mounting surface of the power IC 22, that is, the non-mounting surface side of the power IC 22, as shown in FIG. A heat radiation pattern 32 is provided. The power IC 22 may be mounted on the drive circuit board 4 via a heat transfer plate 30 as shown in FIG. According to the structure of FIG. 5, the power IC 22 is connected to the heat radiation pattern 32 through the heat transfer plate 30 formed of a metal having high thermal conductivity and the through hole 34 into which the metal having high thermal conductivity is injected. It becomes a structure. With this structure, the heat generated in the power IC 22 is not only radiated to the mounting surface side of the power IC 22, that is, the anti-load side of the drive circuit board 4, but is also radiated to the load side of the drive circuit board 4. It is possible to effectively dissipate heat and enhance the heat dissipating ability. In addition, although copper or silver etc. are illustrated as a metal with high heat conductivity, it cannot be overemphasized that metals other than copper or silver may be used. Moreover, as long as it has a characteristic with high heat conductivity, you may use things other than a metal.

  The Hall IC 21, power IC 22 and control IC 23 mounted on the drive circuit board 4 are connected as shown in FIG. 6 to drive the motor. More specifically, a magnetic pole position signal that is a signal including position information of the rotor 15 detected by the Hall IC 21 (hereinafter referred to as “rotor position information” or simply “position information”) is input to the control IC 23. . The control IC 23 is also given a rotational speed command (rotational speed command) for commanding the rotational speed of the rotor 15. The control IC 23 generates a PWM signal for controlling the power IC 22 based on the rotor position information from the Hall IC 21 and an external rotational speed command, and applies the PWM signal to the power IC 22. The control IC 23 is provided with an advance angle calculation unit 200. The advance angle calculation unit 200 generates a rotation speed signal including information on the rotation speed of the electric motor 100 and outputs the rotation speed signal to the outside, and calculates an optimum phase advance angle and a phase advance angle with improved performance in a high rotation range. Part. Details of the advance angle calculation unit 200 will be described later.

  The power IC 22 includes an inverter circuit 114 and an arm drive circuit 116 as shown in FIG. The inverter circuit 114 is configured by bridge-connecting three pairs of upper and lower arm switching elements 114 a to 114 f that drive the three-phase winding 7 (see FIG. 1) in the electric motor 100. The connection point between the switching elements of the upper and lower arms is drawn out as an AC terminal and connected to the stator. On the other hand, the connection point between the upper arms and the connection point between the lower arms are drawn out as a DC terminal and connected to the rectifier circuit 112. The rectifier circuit 112 converts the AC voltage of the commercial power supply 110 into a DC voltage and applies it to the inverter circuit 114. The control IC 23 generates a PWM signal for PWM driving the switching elements 114 a to 114 f of the upper and lower arms and outputs the PWM signal to the arm driving circuit 116. The arm drive circuit 116 is provided with an upper arm drive circuit 116a for driving the upper arm switching elements 114a to 114c and a lower arm drive circuit 116b for driving the lower arm switching elements 114d to 114f. The upper arm drive circuit 116a and the lower arm drive circuit 116b drive the switching element to be driven based on the PWM signal. When the switching elements 114a to 114f are driven, the DC voltage from the rectifier circuit 112 is converted into an AC voltage having a variable frequency. The converted AC voltage is applied to the winding 7 via a winding terminal 24 (see FIG. 1) that electrically connects the drive circuit board 4 and the winding 7 to drive the electric motor.

  FIG. 8 is a block diagram illustrating a configuration of the advance angle calculation unit 200. As shown in FIG. 8, the advance angle calculation unit 200 is generated by a rotation speed signal generation unit 202 that generates a rotation speed signal including information on the rotation speed of the electric motor 100 based on the Hall signal, and a rotation speed signal generation unit 202 generates the rotation angle signal. An advance voltage signal generation unit 204 that generates a voltage signal that represents advance angle information based on the rotation speed signal, and an analog signal generated by the advance angle voltage signal generation unit 204 represents the advance angle information. And an AD conversion unit 206 for converting into a digital signal.

  Here, the Hall signal output from the Hall IC is a digital signal, but is converted into an analog signal by the rotation speed signal generation unit 202. That is, the rotation speed signal generation unit 202 also has a DA conversion function for converting a digital signal into an analog signal. As described above, the rotation speed signal generated by the rotation speed signal generation unit 202 is output to the outside of the advance angle calculation unit 200 for other control.

  The advance angle voltage signal generation unit 204 is a circuit that generates information including the voltage value having a magnitude proportional to the information included in the rotation speed signal, that is, the rotation speed of the motor. The amplitude of the voltage signal generated by the advance voltage signal generation unit 204 represents the advance angle. For this reason, the AD converter 206 AD converts the voltage signal to output a digital signal representing the advance angle. As will be described later, the advance angle of the applied voltage applied to the electric motor 100 is discretely controlled by a digital signal.

  FIG. 9 is a circuit diagram illustrating an example of a circuit configuration that embodies the rotation speed signal generation unit 202 and the advance angle voltage signal generation unit 204. In FIG. 9, the first circuit block 202 a is a circuit example that embodies the rotation speed signal generation unit 202, and the second circuit block 204 a and the third circuit block 204 b are circuits that embody the advance voltage signal generation unit 204. It is an example.

  The first circuit block 202a includes a comparator 250, a changeover switch 252, capacitor elements 254 and 256, and a resistance element 258. The first circuit block 202a takes charge of the function of converting the hall signal into the rotation speed signal. Further, the second circuit block 204 a is configured to include an operational amplifier 260.

The changeover switch 252 is a one-circuit, two-contact switch, and has a base point b, a first changeover contact u1, and a second changeover contact u2. The hall signal is input to the capacitor element 256 via the capacitor element 254 and the first switching contact u1 of the changeover switch 252, and is also input to the plus terminal of the comparator 250 via the capacitor element 254. With this configuration, the voltage divided by the capacitor elements 254 and 256 is applied to the plus terminal of the comparator 250. The reference voltage V _ref is input to the negative terminal of the comparator 250, and the comparator 250 compares the magnitude relationship between the _divided voltage of the Hall signal and the reference voltage V _ref .

When the divided voltage of the hall signal is larger than the reference voltage V _ref , the comparator 250 controls the changeover switch 252 so that the first changeover contact u1 and the base point b are electrically connected, and the hall signal is divided. When the voltage is equal to or lower than the reference voltage V _ref , the comparator 250 controls the changeover switch 252 so that the second changeover contact u2 and the base point b are electrically connected.

  In the changeover switch 252, when the first changeover contact u1 and the base point b are electrically connected, a voltage pulse based on the Hall signal is applied to the capacitor element 256, and the voltage (charge) during the period in which the voltage pulse is generated is generated. The capacitor element 256 is charged (stored). On the other hand, when the second switching contact u2 and the base point b are electrically connected, the capacitor element 256 and the resistor element 258 are electrically connected, and the voltage stored in the capacitor element 256 passes through the resistor element 258. Discharged. The speed of discharge depends on a time constant τ that is the product of the capacitance value of the capacitor element 256 and the resistance value of the resistance element 258. If the time constant τ is large, the discharge speed is slow, and if the time constant τ is small, the discharge speed is fast.

  In this manner, the capacitor element 256 is charged with a voltage corresponding to the frequency at which the voltage pulse of the Hall signal appears, that is, the period of the Hall signal. If the motor speed is faster, the voltage pulse repetition period will be shorter, so the stored voltage will be larger, and if the motor speed is slower, the voltage pulse repetition period will be longer. Becomes smaller.

  The divided voltage of the Hall signal stored in the capacitor element 256 is applied to the plus terminal of the operational amplifier 260 of the second circuit block 204a. The output terminal of the operational amplifier 260 is returned to the negative terminal of the operational amplifier 260, and the second circuit block 204a constitutes a buffer circuit. The second circuit block 204a constituting the buffer circuit operates so that the operation of the first circuit block 202a and the operation of the third circuit block 204b do not interfere with each other, that is, are not affected by the mutual operations. It becomes possible to do.

  The output of the operational amplifier 260 of the second circuit block 204a is input to the third circuit block 204b. The third circuit block 204b includes an operational amplifier 262, resistance elements 264 and 266, and a feedback circuit 268 in which a resistance element 268a and a capacitor element 268b are connected in parallel. The third circuit block 204b generates a voltage signal for performing advance angle control to be described later.

  The voltage stored in the capacitor element 256, which is the output of the operational amplifier 260 of the second circuit block 204a, is applied to the negative terminal of the operational amplifier 262 through the resistive element 264, and the resistive element 266 is connected to the positive terminal of the operational amplifier 262. A GND potential (zero potential) is applied. The third circuit block 204b to which the feedback circuit 268 is connected constitutes an integrating circuit as a whole circuit, and the voltage when the rotation speed of the motor is high, that is, when the rotation speed of the motor is high, becomes larger than the conventional one. Such a voltage signal is generated. Further details of the third circuit block 204b will be described later.

  Here, the advance angle will be described in detail. When a voltage having a sine wave waveform is applied to the stator windings, the phase of the winding current changes depending on the number of rotations of the motor and the size of the load, resulting in a reduction in torque and a reduction in efficiency. For this reason, it is necessary to adjust the phase of the voltage applied to the winding in accordance with the change in the phase of the winding current, and the phase is used to maximize the torque by matching the phase difference between the induced voltage of the motor and the winding current. The control of is important. In order to drive the electric motor with high efficiency or minimum noise driving, it is necessary to advance the phase of the applied voltage to advance the phase of the winding current and to adjust the phase difference between the induced voltage and the winding current. The phase advance angle of the applied voltage at this time is an advance angle.

FIG. 10 is a graph showing the relationship between the torque of the electric motor and the rotational speed according to the advance angle. 10 that the rotational speed at which the motor has output torque T1 in the case of advance A, the rotation speed R _A, if the advance B, and the rotational speed R _B higher than the rotational speed R _A It is shown. Here, there is a relationship of advance angle A <advance angle B between advance angle A and advance angle B. That is, under a constant torque condition, it means that the rotation speed increases as the phase angle difference between the applied voltage and the induced voltage increases.

  FIG. 11 shows the optimum advance angle at which the driving efficiency of the motor is maximized as the first optimum advance angle, the optimum advance angle at which the noise of the motor is minimized as the second optimum advance angle, and the first optimum advance angle. The characteristic and the second optimum advance angle characteristic are shown in a graph showing the relationship between the rotation speed and the advance angle of the electric motor. As shown in FIG. 11, the first optimum advance angle and the second optimum advance angle have a characteristic that the advance angle becomes larger as the rotational speed of the electric motor increases.

  FIG. 12 is a graph comparing the optimum advance angle characteristic according to the rotation speed of the motor and a discrete advance angle control curve representing the relationship between the rotation speed and the advance angle of the motor and the present embodiment. 12 (a) also shows the advance angle control curve according to the prior art, and FIG. 12 (b) also shows the advance angle control curve according to the present embodiment. Since the relationship between the first optimum advance angle and the advance angle control curve and the relationship between the second optimum advance angle characteristic and the advance angle control curve are the same, the first optimum angle is shown in FIGS. The advance angle and the second optimum advance angle are not distinguished from each other and will be referred to as the optimum advance angle.

  In FIG. 12 (a) and FIG. 12 (b), a curved line K1 indicated by a thin line represents the optimum advance angle. In FIGS. 12A and 12B, curves L1 and L2 indicated by bold lines are advance values set according to the number of revolutions when the motor is controlled. In the control calculation of the present embodiment, since it is assumed that discrete control by the control IC is performed, the control value for the advance angle control is stepped. Note that the value on the advance control curve shown in FIG. 12B is calculated by the advance calculation unit 200 (see FIGS. 6 and 8).

  When FIG. 12A is compared with FIG. 12B, the following is clear. In the following description, a range where the rotational speed of the electric motor is from 1200 rpm to 1500 rpm is referred to as a middle rotational range, and a rotational speed of the electric motor of 1500 rpm or higher is referred to as a high rotational range. In addition, these divisions are for convenience, and the range of the middle rotation range and the high rotation range is not limited to these numerical values.

(I) In the middle rotation region and the high rotation region, the conventional curve L1 changes so as to overlap the optimal advance curve K1, but the curve (hereinafter referred to as “the present application curve”) L2 of the present embodiment is optimal. It is a value that is larger than the advance angle on the advance angle K1, that is, an advance angle that increases the advance than the advance angle on the optimum advance curve K1.
(Ii) In the present curve L2, the difference between the advance angle used in the control and the advance angle on the optimum advance curve K1 is larger in the high rotation range than in the middle rotation range.

  13 is a partially enlarged view of the optimum advance angle characteristic and advance angle control curve shown in FIG. 12, FIG. 13 (a) is an enlarged view of a broken line portion M1 shown in FIG. 12 (a), and FIG. ) Is an enlarged view of a broken line portion M2 shown in FIG.

  13 (a) and 13 (b), Δθ is a change in advance angle that occurs during discrete one-step advance control, that is, an LSB (Least Significant Bit) of the AD converter 206 shown in FIG. ) Advancing change width in 1-bit advance control. Δθ1 is a phase difference between the advance angle on the conventional curve L1 and the advance angle on the optimum advance angle K1 at the same rotation speed, and Δθ2 is the optimum advance angle on the curve L2 of the present application at the same rotation speed. It is a phase difference between the advance angle on the advance angle K1. As shown in FIGS. 13A and 13B, there is a relationship of “Δθ1 <Δθ <Δθ2” among these Δθ, Δθ1, and Δθ2.

  Increasing the phase difference between the value on the advance angle control curve and the optimum advance angle, that is, increasing the advance angle of the advance angle control is equivalent to increasing the rotational speed. For this reason, as shown also in the graph of FIG. 10, since the rotation speed when torque is made the same can be made higher than before, the performance of the electric motor can be improved and rapid air conditioning control can be performed quickly. Note that the degree of advance of the advance angle control can be changed by adjusting the time constant that is the product of the resistance value of the resistance element 258 and the capacitance value of the capacitor element 256 in the first circuit block 202a. Since the microcomputer is not equipped with heat-sensitive microcomputers, the degree of advance of the advance angle control can be adjusted without worrying about heat generation of the microcomputer.

  The voltage stored in the capacitor element 256, which is the output of the operational amplifier 260 of the second circuit block 204a, is applied to the negative terminal of the operational amplifier 262 through the resistive element 264, and the resistive element 266 is connected to the positive terminal of the operational amplifier 262. A GND potential (zero potential) is applied. The third circuit block 204b to which the feedback circuit 268 is connected constitutes an integrating circuit as a whole circuit, and the voltage when the rotation speed of the motor is high, that is, when the rotation speed of the motor is high, becomes larger than the conventional one. Such a voltage signal is generated. Further, this control can be realized by changing only the configuration of the control IC 23 as can be understood from the block diagrams of FIGS. 6 and 8 and the circuit diagram of FIG. Further, as can be understood from the block diagram of FIG. 8, this can be realized without modifying the AD conversion unit 206.

  In the configuration of FIG. 9, the feedback circuit 268 in which the resistance element 268a and the capacitor element 268b are connected in parallel is used as an internal component of the control IC 23. However, the feedback circuit 268 may be connected to the control IC 23 from the outside. If the circuit element is external to the control IC 23, the resistance value of the resistance element 268a and the capacitance value of the capacitor element 268b can be changed, so that the specification of the load driven by the motor, the use of the device in which the motor is mounted, The effect that the advance angle control according to the installation environment becomes possible is obtained.

  As described above, according to the electric motor according to the present embodiment, when the rotational speed of the motor is equal to or higher than the rotational speed in the rotational range where the performance is to be improved, that is, equal to or higher than the first rotational speed. Since the second advance value larger than the first advance value, which is the optimum advance value that maximizes the driving efficiency of the motor or minimizes the noise of the motor, is generated, the motor is driven. It is possible to improve the performance. Since the control IC is mounted on the drive circuit board, the drive circuit board can be molded together with the stator, and thermal influence can be avoided.

  Further, according to the electric motor according to the present embodiment, a microcomputer is not mounted on the drive circuit board, a heat-resistant control IC is mounted instead of the microcomputer, and molding with the power IC causes heat generation from the power IC. Since heat can be radiated to the outside through the mold resin and the temperature rise of the power IC can be reduced, it is possible to improve the performance of the motor to the desired region without worrying about the influence of heat generation by enhancing the performance of the motor. It becomes possible.

  Further, according to the electric motor according to the present embodiment, since the control IC and the power IC are mounted on the same surface of the drive circuit board, it is possible to avoid an increase in the size of the electric motor and to reduce the cost. Since the wiring connecting the control IC is short, it is difficult for noise to ride on the wiring, and the influence of noise on the motor can be avoided. Therefore, according to the electric motor according to the present embodiment, it is possible to increase the performance of the electric motor to a desired performance while avoiding the thermal influence while suppressing the increase in size and cost of the device.

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. The part can be omitted or changed.

  DESCRIPTION OF SYMBOLS 1 Mold stator, 2 Mold resin part, 3 Stator assembly part, 4 Drive circuit board, 5 Stator, 6 Connector, 7 Winding, 8a Through-hole, 8 Stator iron core, 9 Insulator, 10 Shaft, 11 Position detection Magnet, 12 Rotor insulation, 13 Rotor magnet, 15 Rotor, 16 Load side bearing, 16a Inner ring, 16b Outer ring, 16c Rolling element, 17 Anti-load side bearing, 18 Rotor assembly, 19 Housing, 21 Hole IC (magnetic pole position sensor), 22 power IC (drive element), 23 control IC (control element), 24 winding terminal, 25 bracket, 26 recess, 29 opening, 30 heat transfer plate, 32 heat dissipation pattern, 34 through hole , 100 electric motor, 110 commercial power supply, 112 rectifier circuit, 114 inverter circuit, 114a to 114f switching element , 116 arm driving circuit, 116a upper arm driving circuit, 116b lower arm driving circuit, 200 advance angle calculation unit, 202 rotation speed signal generation unit, 202a first circuit block, 204 advance angle voltage signal generation unit, 204a second Circuit block, 204b third circuit block, 206 AD converter, 250 comparator, 252 changeover switch (b base point, u1 first changeover contact, u2 second changeover contact), 254, 256, 268b capacitor element, 258, 264, 266, 268a Resistance element, 260, 262 operational amplifier, 268 feedback circuit, 300 air conditioner, 300a indoor unit, 300b outdoor unit, 310 fan.

Claims (7)

A stator,
A rotor disposed inside the stator;
A magnetic circuit position sensor, a drive element and a control element are mounted, and a drive circuit board is integrally sealed with the stator with a mold resin, and
The magnetic pole position sensor detects the rotational position of the rotor, the drive element applies a drive voltage to the winding of the stator, the control element performs PWM control of the drive element,
The control element has a second advance angle larger than a first advance value, which is an advance value at which the operation efficiency of the motor becomes maximum when the rotation speed of the motor becomes equal to or higher than the first rotation speed. Output the value,
It said second advance value is Ri Na greatly depending on the increase in the rotational speed detected by the magnetic pole position sensor,
An electric motor in which a difference value between the second advance value and the first advance value is larger than a change range of the advance angle generated in discrete one-step advance control . A stator,
A rotor disposed inside the stator;
A magnetic circuit position sensor, a drive element and a control element are mounted, and a drive circuit board is integrally sealed with the stator with a mold resin, and
The magnetic pole position sensor detects the rotational position of the rotor, the drive element applies a drive voltage to the winding of the stator, the control element performs PWM control of the drive element,
The control element has a second value larger than a first advance value that is an advance value that minimizes the noise of the motor at each rotation speed when the rotation speed of the motor is equal to or higher than the first rotation speed. and output the advance value,
An electric motor in which a difference value between the second advance value and the first advance value is larger than a change range of the advance angle generated in discrete one-step advance control . A resistance element and a capacitor element are provided outside the control element,
The electric motor according to claim 1 or 2 for adjusting the lead angle of the advance angle control by adjusting the time constant is the product of the capacitance value of the resistance value and the capacitor element of the resistive element. The control element is
A rotational speed signal generating unit that generates a rotational speed signal including information on the rotational speed of the electric motor based on a signal from the magnetic pole position sensor;
An advance voltage signal generator for generating a voltage signal representing information on the advance angle based on the rotation speed signal;
An AD converter that converts the voltage signal, which is an analog signal generated by the advance voltage signal generator, into a digital signal that represents advance information;
The electric motor according to any one of claims 1 to 3 , further comprising: The drive element is mounted on the drive circuit board via a heat transfer plate, and a heat dissipation pattern is provided on the non-mounting surface side of the drive element in the drive circuit board. The heat transfer plate and the heat dissipation pattern are made of metal. The electric motor according to any one of claims 1 to 4 , wherein the electric motor is connected through a through hole into which is injected. A blower equipped with the electric motor according to any one of claims 1 to 5 . An air conditioner equipped with the electric motor according to any one of claims 1 to 5 .

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