JP6002631B2 - Control method of brushless motor for vehicle - Google Patents

Description

  The present invention relates to a method for controlling a brushless motor mounted on a vehicle.

  A motor mounted on a vehicle, for example, a motor that rotationally drives a blower fan used in an air conditioner, is generally driven by switching the direction of current flowing in an armature coil by a switching element composed of a semiconductor element. A brushless motor that generates force is used.

  In the invention described in Patent Document 1, when the brushless motor becomes high temperature, the rotational speed is reduced to suppress the heat generation amount.

JP 2000-78880 A

  However, in the invention described in Patent Document 1, in order to reduce the rotation speed when the brushless motor becomes high temperature, the air volume is lowered, which gives an unpleasant feeling to the vehicle occupant. There was a problem.

  The present invention has been made in view of the above circumstances, and even when the brushless motor is at a high temperature, the brushless motor for a vehicle that can prevent further increase in temperature without decreasing the rotational speed of the brushless motor. It is an object to provide a control method.

  The control method for a brushless motor for a vehicle according to the present invention is to drive the brushless motor in a driving mode that rotates the brushless motor with high efficiency when it is determined that the temperature of the brushless motor is high.

  That is, according to the control method for a brushless motor for a vehicle according to the present invention, when the brushless motor mounted on the vehicle is rotated at a predetermined rotation speed or less, the brushless motor is driven in the first drive mode for rotating with low noise, and the brushless motor is controlled. In a method for controlling a brushless motor for a vehicle that is driven in a second drive mode that rotates with high efficiency when the motor is rotated at a rotational speed higher than a predetermined rotational speed, a drive control unit that performs drive control of the brushless motor. When the temperature is detected and it is determined that the temperature exceeds a predetermined temperature threshold, the brushless motor is driven in the second drive mode.

  According to the vehicular brushless motor control method configured as described above, when the vehicular brushless motor is rotated at a predetermined rotation speed or less, the vehicular brushless motor is driven in the first drive mode that rotates with low noise, When rotating at a higher rotational speed than the rotational speed, when driving in the second drive mode rotating at high efficiency, the temperature of the drive control unit of the brushless motor rises and exceeds a predetermined temperature threshold When the determination is made, the brushless motor is driven in the second drive mode in which the brushless motor is rotated with high efficiency regardless of the number of rotations thereof, so that the brushless motor is driven in the first rotation mode. However, when the temperature of the drive control unit rises, it is driven in the high-efficiency second drive mode, so that the operation can be continued without reducing the rotational speed. And since the generation | occurrence | production of a heat | fever decreases by the operating efficiency of a brushless motor rising, the further temperature rise of a drive control part can be prevented.

  Also, in the control method for a brushless motor for a vehicle according to the present invention, the brushless motor uses the voltage waveform applied to each connection point of the armature coil of the brushless motor mounted on the vehicle in the first drive mode as the sine wave. It is a drive mode for driving a motor, and the second drive mode is a drive mode for driving the brushless motor with the voltage waveform as a rectangular wave.

  According to the control method for a brushless motor for a vehicle configured in this way, the first drive mode is applied to each connection point of the armature coil of the brushless motor mounted on the vehicle as a sine wave. Since the drive mode for driving is changed, the change in the magnetic flux generated in the armature coil becomes gentle, the brushless motor can be driven with low noise, and the second drive mode has a rectangular waveform as the voltage waveform. Since the drive mode for driving the brushless motor is adopted, the period during which the effective rotational torque is generated becomes longer, the efficiency of generating the torque is improved, and the efficiency of the brushless motor is improved. The first drive mode and the second drive mode can be reliably switched by a simple method of changing the voltage waveform applied to the armature coil of the brushless motor.

  In the vehicle brushless motor control method according to the present invention, when the first drive mode switches the voltage applied to each connection point of the armature coil of the brushless motor mounted on the vehicle, A driving mode in which the brushless motor is driven by increasing the time for applying the voltage overlapping the armature coil that applied the voltage to the armature coil and the armature coil that applied the voltage after switching, When switching the voltage to be applied to each connection point of the armature coil of the brushless motor mounted on the vehicle, the driving mode is applied with the armature coil that has been applied with the voltage before switching and the voltage after the switching. And a drive mode in which the brushless motor is driven by reducing the time for applying the voltage overlapping with the armature coil. .

  According to the control method for a brushless motor for a vehicle configured as described above, when the voltage applied to each connection point of the armature coil of the brushless motor mounted on the vehicle is switched to the first drive mode, before switching. Since the armature coil that applied the voltage to the armature coil and the armature coil that applied the voltage after switching overlaps the time for applying the voltage by increasing the driving time to drive the brushless motor, the armature coil The change in the generated magnetic flux becomes gentle, and the brushless motor can be driven with low noise. The second drive mode is applied to each connection point of the armature coil of the brushless motor mounted on the vehicle. When switching the voltage, the voltage overlaps between the armature coil that applied the voltage before switching and the armature coil that applied the voltage after switching. Due to a driving mode for driving the brushless motor by reducing the time for applying, longer period resulting in effective rotational torque, thereby improving the efficiency of the brushless motor is improved efficiency of generating torque. The first drive mode and the second drive mode can be reliably switched by a simple method of changing the overlap time of the voltage waveform applied to each phase of the brushless motor.

  In the vehicular brushless motor control method according to the present invention, the switching timing of the switching element that controls the energization state of the brushless motor mounted in the vehicle is controlled by the first drive mode. A drive mode for driving the brushless motor by controlling the advance amount of the delay angle of the sensor magnet attached integrally with the rotor to the field permanent magnet attached to The second drive mode is such that the switching timing of the switching element that controls the energization state of the brushless motor mounted on the vehicle is such that the advance amount of the delay angle of the sensor magnet with respect to the field permanent magnet is increased. The driving mode is controlled to drive the brushless motor.

  According to the control method for a brushless motor for a vehicle configured as described above, the switching timing of the switching element that controls the energization state of the brushless motor mounted on the vehicle is set in the first drive mode to the rotor of the brushless motor. Generated in the armature coil because the drive mode for driving the brushless motor is controlled by reducing the advance amount of the delay angle of the sensor magnet attached to the rotor with respect to the installed field permanent magnet. The change of the magnetic flux to be performed becomes gentle, and the brushless motor can be driven with low noise. The switching timing of the switching element for controlling the energization state to the brushless motor mounted on the vehicle in the second drive mode Is controlled so that the advance amount of the delay angle of the sensor magnet with respect to the permanent magnet for the field becomes large. To, due to the driving mode for driving the brushless motor, the period resulting in effective rotational torque longer, thereby improving the efficiency of the brushless motor is improved efficiency of generating torque. The first drive mode and the second drive mode can be reliably switched by a simple method of changing the advance amount of the delay angle of the brushless motor.

  According to the control method for a brushless motor for a vehicle according to the present invention, the brushless motor is driven with high efficiency when the temperature of the drive control unit of the brushless motor mounted on the vehicle rises, so that the rotation speed of the motor is not reduced. Further, the effect that the operation can be continued while preventing further temperature rise is obtained.

(A) is a figure which shows the state of a brushless motor when a rotor rotation angle is 0 degree. (B) is a figure which shows the conduction | electrical_connection state of a switching element when a rotor rotation angle is 0 degree. (C) is a figure which shows the state of a brushless motor when a rotor rotation angle is 30 degrees. (D) is a figure which shows the conduction | electrical_connection state of a switching element when a rotor rotation angle is 30 degrees. (A) is a figure which shows the example of the voltage waveform of the sine wave shape applied to a brushless motor. (B) is a figure which shows the example of the rectangular waveform voltage waveform applied to a brushless motor. It is a figure which shows an example of the control target at the time of changing a drive voltage waveform with respect to the rotation speed of a brushless motor. It is a block diagram which shows the structure of the brushless motor control apparatus in Example 1. FIG. 3 is a flowchart illustrating a flow of operation according to the first exemplary embodiment. It is a figure which shows the conduction | electrical_connection state of a switching element when the overlap has arisen between adjacent phases, when performing the switching operation of the brushless motor shown to Fig.1 (a). It is a voltage waveform diagram which shows the overlap state of the voltage waveform applied to U phase, V phase, and W phase by overlap control. It is a figure which shows an example of the control target of overlap time with respect to the rotation speed of a brushless motor. It is a block diagram which shows the structure of the brushless motor control apparatus in Example 2. FIG. 6 is a flowchart illustrating an operation flow of the second embodiment. (A) is a figure which shows the state of a brushless motor when the delay angle is 30 degrees. (B) is a figure which shows the state of a brushless motor when the delay angle is 42 degrees. It is a figure which shows an example of the control target of the advance amount of a delay angle with respect to the rotation speed of a brushless motor. It is a block diagram which shows the structure of the brushless motor control apparatus in Example 3. FIG. (a) is a time chart of the sensor signal output from a magnetic sensor. (B) is a time chart of a gate signal for switching the MOSFET. 12 is a flowchart illustrating the operation flow of the third embodiment.

  Hereinafter, specific examples of a control method for a brushless motor for a vehicle according to the present invention will be described with reference to the drawings.

  Example 1 which is the first embodiment of the present invention will be described with reference to FIGS.

[Description of brushless motor structure]
First, the structure of the brushless motor of the present invention will be described with reference to FIGS.

  Fig.1 (a) is the bottom view which looked at the brushless motor 10 of this invention from the lower side. This brushless motor 10 is mounted on a vehicle and used to drive a fan fan of a vehicle air conditioner, and is a three-phase two-pole winding outer rotor type brushless DC motor (hereinafter simply referred to as a brushless motor). An armature coil (4a to 4f) is provided on the stator 3 on the inner peripheral side, and a main magnet (field permanent magnet) 2 is provided on the outer rotor 1.

  That is, in FIG. 1A, the stator 3 has a three-phase (U, V, W) that generates a rotating magnetic field at the outer periphery of the protrusions 3a to 3f with each protrusion (3a to 3f) as a core. Armature coils 4a to 4f are arranged. In addition, a rotor 1 having main magnets (field permanent magnets) 2 is disposed outside the stator 3 at intervals of 90 °. The sensor magnet 5 that indicates the rotational position of the rotor 1 is attached to a shaft 6 that has two pairs of N poles and S poles arranged at an equal angle with respect to the rotation center of the rotor 1 and rotates integrally with the rotor 1. Yes.

  The brushless motor 10 shown in FIG. 1A includes a rotor 1, a main magnet (field permanent magnet) 2, a sensor magnet 5, and a shaft 6 that are integrated in a rotational direction R. Rotate.

  Note that magnetic sensors (IC1 to IC3) for detecting the direction of the magnetic field generated by the sensor magnet 5 are evenly arranged on the inner peripheral side of the stator 3 at intervals of 120 °. In the magnetic sensors (IC1 to IC3), for example, there is a Hall IC that detects a magnetic field using a so-called Hall effect, in which an electromotive force is generated in a direction orthogonal to both the current and the magnetic field when a magnetic field is applied at right angles to the current. Used.

  In the brushless motor 10, the generated torque changes according to the timing of switching the current flowing through the armature coils (4 a to 4 f), that is, the positional relationship between the rotor 1 and the main magnet (field permanent magnet) 2. To do. In the first embodiment, the sensor magnet 5 indicating the rotational position of the rotor 1 is attached to the shaft 6 with a delay angle of 42 ° with respect to the main magnet 2 and further performs electrical advance control. In FIG. 1A, a region P1 indicates a coil having a short current path and a current that is twice as large as that of other armature coils (described in detail later). In addition, the region P2 is a position where the forward rotation torque is generated by the repulsive force between the armature coil 4c (4f) and the main magnet 2, and the region P3 is the reverse torque due to the repulsive force between the armature coil 4a (4d) and the main magnet 2. Indicates the location of occurrence.

  When the brushless motor 10 is in the state of FIG. 1A, each armature coil (4a to 4f) is connected to a MOSFET (switching element) (Q1 to Q6), which will be described later, as shown in FIG. 1B. Has been.

  That is, using the signal output from the magnetic sensor (IC3), the MOSFETs (Q1) and (Q5) are switched and become conductive as shown in FIG. A predetermined DC voltage is applied between the connection point Ua and the connection point Va. At this time, current flows along the two current paths from the connection point Ua toward the connection point Va. The first current path is a path from the connection point Ua through the armature coils (4c, 4f) to the connection point Va, and the second current path is from the connection point Ua to the armature coils (4b, 4e, 4a). , 4d) to the connection point Va.

[Description of operation of brushless motor]
Next, the principle of rotation of the brushless motor 10 will be briefly described with reference to FIGS.

  In the connection state of FIG. 1B, the resistance value of the first current path is half of the resistance value of the second current path. Twice as much current. The above-described region P1 (see FIG. 1A) shows the armature coils (4c, 4f) through which twice the current flows. The repulsive force is particularly strong between the armature coil (4c, 4f) and the main magnet 2 where the current value is doubled compared to the other armature coils (4a, 4b, 4d, 4e). Occurs. The repulsive force cancels the reverse torque described above, and the rotor 1 rotates in the direction of rotation R.

  FIG. 1C shows a state in which the rotor 1 is rotated 30 ° in the direction of the rotation direction R in this way. FIG. 1D shows the state of the MOSFETs (Q1 to Q6) at this time. That is, in this case, using the signal output from the magnetic sensor (IC1), the MOSFETs (Q3) and (Q5) are turned on, and a predetermined DC voltage is applied between the connection point Wa and the connection point Va. The

  In the case of FIG. 1C, a particularly strong repulsive force is generated between the armature coils (4a, 4d) and the main magnet 2 as compared with the other armature coils (4b, 4c, 4e, 4f). The rotor 1 further rotates in the direction of the rotation direction R. Thereafter, the same operation is repeated, and the brushless motor 10 continues to rotate in the direction of the rotation direction R.

  According to the structure of the brushless motor 10 shown in FIGS. 1A and 1C, the sensor magnet 5 has N and S poles arranged every 90 °, so that the magnetic sensors (IC1 to IC3). The magnetic field direction change detection signal (hereinafter simply referred to as a sensor signal) from 2 changes for two periods while the rotor 1 makes one rotation. As a result, the rotation of the rotor 1 can be controlled twice as finely as possible. Further, by arranging three magnetic sensors (IC1 to IC3) at equal intervals, the timing of the rotation of the rotor 1 can be controlled three times finely. Based on the magnetic field direction detection results from the magnetic sensors (IC1 to IC3) arranged at equal intervals, the conduction (non-conduction) of the MOSFETs (Q1 to Q6) is switched a total of 12 times while the rotor 1 rotates once, and the conduction The power supply side connection point and the ground side connection point for applying a voltage to the armature coils (4a to 4f) are sequentially switched to the armature coils (4a to 4f) by combining the MOSFETs (Q1 to Q6). Switches the direction of the flowing current. As a result, a rotating magnetic field is generated, and a driving force for rotating the rotor 1 in the rotation direction R is obtained.

[Description of brushless motor drive mode]
Next, the drive mode of the brushless motor 10 will be described with reference to FIGS.

  2A and 2B are examples of the voltage waveform e (t) applied to the armature coils (4a to 4f) of the brushless motor 10. FIG.

  Of these, FIG. 2 (a) represents a sinusoidal voltage waveform e (t), and FIG. 2 (b) represents a rectangular waveform voltage waveform e (t). When the current flowing through the armature coils (4a to 4f) of the brushless motor 10 is switched using the voltage waveform e (t) having a sine wave shape, the change in magnetic flux generated in the armature coils (4a to 4f) is moderate. Therefore, noise during phase switching can be reduced. In the first embodiment, the mode in which the brushless motor 10 is driven using the voltage waveform e (t) having a sine wave shape as described above is set as a first drive mode.

  On the other hand, if the current flowing through the armature coils (4a to 4f) of the brushless motor 10 is switched using the voltage waveform e (t) having a rectangular wave shape, the period during which effective rotational torque is generated becomes longer. Can be generated. In the first embodiment, the mode in which the brushless motor 10 is driven using the rectangular waveform voltage waveform e (t) is set as the second drive mode.

[Description of Voltage Waveform Control in Example 1]
In the first embodiment, specifically, the voltage waveform e (t) applied to the armature coils (4a to 4f) is controlled as shown in FIG. The voltage waveform e (t) applied to the armature coils (4a to 4f) is a sine wave, the first drive mode for driving the brushless motor 10 with low noise, and the voltage applied to the armature coils (4a to 4f). The waveform e (t) is a rectangular wave, and a second drive mode for driving the brushless motor 10 with high efficiency is set.

  When the temperature of the drive control unit that switches the MOSFETs (Q1 to Q6) at a predetermined timing exceeds a predetermined temperature threshold T (for example, 85 ° C.) set in advance, the brushless motor 10 is switched to the target rotational speed. Regardless of this, the second drive mode, that is, the rectangular wave is used for driving. Further, when the temperature of the drive control unit does not exceed a predetermined temperature threshold value T (for example, 85 ° C.) set in advance, when the target rotational speed of the brushless motor 10 is low (for example, 1800 rpm or less), the brushless motor 10 is turned on. When the target rotational speed of the brushless motor 10 is high (for example, more than 1800 rpm), the brushless motor 10 is driven in the second drive mode, that is, a rectangular wave. The predetermined temperature threshold value T is not limited to 85 ° C., and is set as appropriate according to the operating conditions of the brushless motor 10 and the environment where the drive control unit is placed.

[Description of Configuration of Embodiment 1]
Next, a specific configuration of the first embodiment will be described with reference to FIG.

  FIG. 4 is a block diagram illustrating the overall configuration of the brushless motor control device 100a that controls the rotation of the brushless motor 10 according to the first embodiment. That is, the brushless motor control device 100a includes a brushless motor 10, a sensor signal detection unit 12, a switching timing calculation unit 14a, a motor driving unit 20, MOSFETs (switching elements) (Q1 to Q6), and a power supply unit 22. And a drive voltage waveform generator 23, an air conditioning controller 24, a constant current circuit 26, a thermistor 28, and a temperature detector 30.

  The sensor signal detection unit 12 detects that the magnetic field direction of the sensor magnet 5 has changed based on sensor signals output from the magnetic sensors (IC1 to IC3). And the inversion signal of the sensor signal of each magnetic sensor (IC1-IC3) is produced | generated, and it inputs into the switching timing calculating part 14a as a sensor signal which consists of six types of signals with a non-inversion signal. This is because the switching timing calculation unit 14a described later operates by detecting the falling edge of the signal, so that the rising edge is converted to the falling edge and detected.

  The power supply unit 22 supplies a necessary DC voltage to the motor drive unit 20 and the MOSFETs (switching elements) (Q1 to Q6).

  The switching timing calculation unit 14a corresponds to the drive control unit described above. The switching timing calculation unit 14a is constituted by a microcomputer, and switches MOSFETs (switching elements) (Q1 to Q6) at a predetermined timing. The switching timing calculation unit 14a further includes a drive waveform determination unit 18 and a current switching timing generation unit 17a.

  The drive waveform determination unit 18 generates a voltage waveform e (t) to be applied to the armature coils (4a to 4f) of the brushless motor 10 based on the ambient temperature of the switching timing calculation unit 14a detected by the temperature detection unit 30 described later. decide. Specifically, when the ambient temperature of the switching timing calculation unit 14a configured by the microcomputer detected by the temperature detection unit 30 exceeds a predetermined temperature threshold T, the armature coils (4a to 4f) The brushless motor 10 is driven in the first drive mode with the voltage waveform e (t) applied to) as a sine waveform.

  On the other hand, when the ambient temperature of the switching timing calculation unit 14a is equal to or lower than a predetermined temperature threshold value T, the voltage waveform e (t) applied to the armature coils (4a to 4f) is a rectangular waveform, and the brushless motor 10 is Drive in the second drive mode.

  The current switching timing generation unit 17a determines the switching timing of the current to be passed through each phase (U, V, W) based on the air conditioning control signal indicating the target rotational speed of the brushless motor 10 obtained from the air conditioning control unit 24. . At this time, when the air conditioning control signal indicates a value equal to or higher than a predetermined value (for example, 1800 rpm) as the rotation speed of the brushless motor 10, the ambient temperature of the switching timing calculation unit 14a is equal to or lower than the predetermined temperature threshold T. Even so, the brushless motor 10 is driven in the second drive mode (rectangular wave). When the air conditioning control signal indicates a value smaller than a predetermined value (for example, 1800 rpm) as the rotation speed of the brushless motor 10, the ambient temperature of the switching timing calculation unit 14a exceeds the predetermined temperature threshold value T. When the brushless motor 10 is driven in the second drive mode (rectangular wave) and it is determined that the ambient temperature of the switching timing calculation unit 14a is equal to or lower than the predetermined temperature threshold T, the brushless motor 10 is moved to the first mode. It is driven in the driving mode (sine wave).

  The temperature detection unit 30 is installed in the vicinity of the switching timing calculation unit 14a and detects the temperature around the switching timing calculation unit 14a formed of a microcomputer. That is, when the temperature of the switching timing calculation unit 14a rises, the internal resistance value of the thermistor 28 installed near the switching timing calculation unit 14a and supplied with a constant current from the constant current circuit 26 changes. Since the voltage generated at both ends changes, the temperature detection unit 30 detects the temperature around the switching timing calculation unit 14a by detecting this change in voltage.

  The drive voltage waveform generator 23 generates a voltage waveform e (t) corresponding to the drive mode of the brushless motor 10. That is, when a sine wave is selected as the voltage waveform e (t), a PWM waveform is generated by pulse-modulating the sine wave with a modulation wave composed of a predetermined high frequency component. The generated PWM waveform is output as the gate signal of the MOSFET (switching element) (Q1 to Q6) at the falling timing of the six sensor signals output from the magnetic sensors (IC1 to IC3).

  On the other hand, when a rectangular wave is selected as the voltage waveform e (t), the drive voltage waveform generating unit 23 generates a rectangular wave having the current switching timing generated by the current switching timing generating unit 17c. Then, the generated rectangular wave is output as a gate signal of the MOSFET (switching element) (Q1 to Q6) at the falling timing of the six sensor signals output from the magnetic sensors (IC1 to IC3).

  The PWM waveform corresponding to the sine wave or the rectangular wave generated by the drive voltage waveform generation unit 23 in this way is input to the motor drive unit 20.

  The motor drive unit 20 generates a timing signal for generating a voltage to be applied to each phase (U, V, W) of the brushless motor 10 and gates of MOSFETs (switching elements) (Q1 to Q6) connected to the motor drive unit 20. Apply to.

  The MOSFETs (switching elements) (Q1 to Q6) intermittently connect the DC voltage supplied from the power supply unit 22 at a predetermined timing set by the timing signal, and each phase (U, V, W) is supplied to connection points (Ua, Va, Wa).

  In this way, the voltage signal supplied to the connection point (Ua, Va, Wa) of each phase (U, V, W) is applied to the armature coils (4a-4f), thereby rotating to the stator 3. A magnetic field is generated, and an attractive force and a repulsive force are generated between the rotating magnetic field and a main magnet (field permanent magnet) 2 installed on the rotor, so that the brushless motor 10 has a predetermined rotational speed. Rotate with.

[Description of Process Flow of First Embodiment]
Next, a specific processing flow of the first embodiment will be described with reference to the flowchart of FIG.

  (Step S50) The temperature detector 30 detects the ambient temperature of the switching timing calculator 14a.

  (Step 52) It is determined whether or not the detected temperature exceeds a predetermined temperature threshold value T of 85 ° C. When the temperature threshold T is exceeded, the process proceeds to step S54, and when the temperature threshold T or less, the process proceeds to step S56.

  (Step S54) The brushless motor 10 is driven in the second drive mode, that is, a rectangular wave. The target rotational speed during driving is determined by the current switching timing generation unit 17a based on the air conditioning control signal output from the air conditioning control unit 24.

  (Step S56) It is determined whether or not the target rotational speed of the brushless motor 10 is smaller than 1800 rpm. This process is performed based on the air conditioning control signal output from the air conditioning control unit 24. When the calculated target rotational speed is smaller than 1800 rpm, the process proceeds to step S58, and when the calculated target rotational speed is 1800 rpm or more, the process proceeds to step S54.

  (Step S58) The brushless motor 10 is driven in the first drive mode, that is, a sine wave.

  (Step S59) Generation of a stop command for the brushless motor 10 is detected. If there is a stop instruction, the processing of FIG. 5 is terminated, and if there is no stop instruction, the process returns to step S50.

  Next, Example 2 which is the second embodiment of the present invention will be described with reference to FIGS. 1 and 6 to 10. In the second embodiment, the first drive mode and the second drive mode are realized by a method different from the method used in the first embodiment.

[Description of Driving Mode in Embodiment 2]
The method of creating the first drive mode for driving the brushless motor 10 in a low noise rotation state and the second drive mode for driving in a high efficiency rotation state are not limited to the method described in the first embodiment. Absent.

  FIG. 6 is an explanatory diagram of overlap control performed in the second embodiment. From the state where a voltage is applied between the connection point Ua and the connection point Va shown in FIG. 1B to turn on the MOSFETs (Q1) and (Q5), the connection point Wa shown in FIG. 6 and the connection point Va, when switching to a state in which the MOSFETs (Q3) and (Q5) are turned on, the connection point Ua and the connection point Wa are both connected as shown in FIG. It is assumed that the connection is made to the power supply side and the connection point Va is connected to the ground side. At this time, the same voltage is applied to both the connection point Ua and the connection point Wa, and this state is referred to as an overlap state.

  In the overlap state, the connection point Ua and the connection point Wa are at the same potential, and no current flows between the connection point Ua and the connection point Wa. For this reason, by changing from the connection state of FIG. 1B to the connection state of FIG. 1D through the overlap state shown in FIG. 6, the change of the current flowing through the armature coils (4a to 4f) is changed. As a result, the magnetic flux generated in the armature coils (4a to 4f) changes gently. For this reason, the change of the repulsive force between the main magnet 2 of the rotor 1 and the armature coils (4a to 4f) becomes gentle, and the natural vibration sound generated by the repulsive force is reduced. On the other hand, since the period during which effective rotational torque is generated is shortened, the efficiency of torque generation is reduced.

  As shown in the timing chart of FIG. 7, this overlap state is a switching timing at the timing of switching the voltage waveform e (t) applied to each phase (U, V, W) of the armature coils (4a to 4f). This is realized by simultaneously applying a voltage to a phase to which a voltage has been applied before (either U, V, or W) and a phase to which a voltage is applied after switching timing (any of U, V, or W). be able to. At this time, the time for applying the voltage at the same time is called an overlap time δ.

[Description of Overlap Control in Example 2]
In the second embodiment, specifically, the overlap time δ is controlled as shown in FIG. That is, the first drive mode in which the overlap time δ is set long (for example, 670 μsec) and the brushless motor 10 is driven with low noise, and the brushless motor 10 in which the overlap time δ is set short (for example, 75 μsec) is highly efficient. The second drive mode for driving is set.

  When the temperature of the drive control unit that switches the MOSFETs (Q1 to Q6) at a predetermined timing exceeds a predetermined temperature threshold T (for example, 85 ° C.) set in advance, the brushless motor 10 is switched to the target rotational speed. Regardless of this, the driving is performed in the second driving mode, that is, in a state where the overlap time δ is set short. Further, when the temperature of the drive control unit does not exceed a predetermined temperature threshold value T (for example, 85 ° C.) set in advance, when the target rotational speed of the brushless motor 10 is low (for example, 1125 rpm or less), the brushless motor 10 is turned on. When the driving speed of the brushless motor 10 is high (for example, 1800 rpm or more) when the driving is performed in the first driving mode, that is, in a state where the overlap time δ is set long, the brushless motor 10 is moved to the second driving mode, that is, over Drive with the lap time δ set short. The predetermined temperature threshold value T is not limited to 85 ° C., and is set as appropriate according to the operating conditions of the brushless motor 10 and the environment where the drive control unit is placed.

  Furthermore, when the target rotational speed of the brushless motor 10 is between 1125 rpm and 1800 rpm, the overlap time δ is gradually switched according to the target rotational speed. This is because if the overlap time is changed suddenly, the rotational torque of the brushless motor 10 also changes suddenly, resulting in uneven rotation of the motor.

[Description of Configuration of Embodiment 2]
Next, a specific configuration of the second embodiment will be described with reference to FIG.

  FIG. 9 is a block diagram illustrating an overall configuration of a brushless motor control device 100b that performs rotation control of the brushless motor 10 according to the second embodiment. Since the schematic configuration of the brushless motor control device 100b is substantially the same as that of the brushless motor control device 100a (see FIG. 4) described in the first embodiment, only differences from the brushless motor control device 100a will be described here.

  The brushless motor control device 100b includes a switching timing calculation unit 14b instead of the switching timing calculation unit 14a (see FIG. 4) and the drive voltage waveform generation unit 23 (see FIG. 4) included in the brushless motor control device 100a. .

  The switching timing calculation unit 14b includes a microcomputer, and further includes an overlap time calculation unit 15b, an overlap control unit 16b, and a current switching timing generation unit 17b.

  The overlap time calculation unit 15b determines the drive mode of the brushless motor 10 based on the ambient temperature of the switching timing calculation unit 14b detected by the temperature detection unit 30, and the voltage applied to the armature coils (4a to 4f). When switching, the overlap time δ, which is the time for applying the voltage redundantly to the connection point (any one of Ua, Va, Wa) before and after switching, is calculated.

  That is, when the ambient temperature of the switching timing calculation unit 14b configured by the microcomputer detected by the temperature detection unit 30 exceeds a predetermined temperature threshold value T, it flows to the armature coils (4a to 4f). At the current switching timing, an armature coil (any one of 4a to 4f) in which a current was passed before switching (a voltage was applied), and an armature coil (a voltage applied) that passed a current after switching (a voltage was applied) 4a to 4f), the brushless motor 10 is driven in the second drive mode by reducing the time during which current is applied (voltage is applied).

  On the other hand, when the ambient temperature of the switching timing calculation unit 14b is equal to or lower than the predetermined temperature threshold T, a current is passed before switching at the switching timing of the current flowing through the armature coils (4a to 4f) (voltage The brushless motor 10 is driven by increasing the time for current to flow (apply voltage) to overlap with the armature coil that applied current (switches voltage) and the armature coil that flows current (applies voltage) after switching. Driving in the first driving mode.

  The overlap control unit 16b calculates the switching timing of the current passed through the armature coils (4a to 4f) necessary for realizing the overlap time δ calculated by the overlap time calculation unit 15b.

  Based on the current switching timing calculated by the overlap controller 16b and the air conditioning control signal indicating the target rotation speed of the brushless motor 10 obtained from the air conditioning controller 24, the current switching timing generator 17b ( The switching timing of the current passed through U, V, W) is determined. At this time, when the air conditioning control signal indicates a value larger than a predetermined value (for example, 1800 rpm) as the rotation speed of the brushless motor 10, the ambient temperature of the switching timing calculation unit 14b is equal to or lower than the predetermined temperature threshold T. Even in this case, the brushless motor 10 is driven in the second drive mode in which the overlap time δ is short. When the air conditioning control signal indicates a value equal to or lower than a predetermined value (for example, 1800 rpm) as the rotation speed of the brushless motor 10, if the ambient temperature of the switching timing calculation unit 14b exceeds the predetermined temperature threshold T When the brushless motor 10 is driven in the second drive mode in which the overlap time δ is short and it is determined that the ambient temperature of the switching timing calculation unit 14b is equal to or lower than the predetermined temperature threshold T, the brushless motor 10 is In the first drive mode, the overlap time δ is long.

[Description of Process Flow of Example 2]
Next, a specific processing flow of the second embodiment will be described with reference to the flowchart of FIG.

  (Step S60) The temperature detector 30 detects the ambient temperature of the switching timing calculator 14b.

  (Step 62) It is determined whether or not the detected temperature exceeds a predetermined temperature threshold value T of 85 ° C. When the temperature threshold T is exceeded, the process proceeds to step S70, and when the temperature threshold T or less, the process proceeds to step S64.

  (Step S64) It is determined whether or not the target rotational speed of the brushless motor 10 is 1800 rpm or more. This process is performed based on the air conditioning control signal output from the air conditioning control unit 24. When the target rotational speed is 1800 rpm or more, the process proceeds to step S70, and when the target rotational speed is less than 1800 rpm, the process proceeds to step S66.

  (Step S66) It is determined whether the target rotation speed of the brushless motor 10 is 1125 rpm or less. This process is performed based on the air conditioning control signal output from the air conditioning control unit 24. When the target rotational speed is 1125 rpm or less, the process proceeds to step S68, and when the target rotational speed is greater than 1125 rpm, the process proceeds to step S72.

  (Step S68) The current switching timing generation unit 17b generates a current switching timing signal for driving the brushless motor 10 in the first drive mode, and the motor driving unit 20 switches the MOSFETs (switching elements) (Q1 to Q6). Then, the brushless motor 10 is driven in the first drive mode.

  (Step S70) The current switching timing generator 17b generates a current switching timing signal for driving the brushless motor 10 in the second drive mode, and the motor driver 20 switches the MOSFETs (switching elements) (Q1 to Q6). Then, the brushless motor 10 is driven in the second drive mode.

  (Step S72) The current switching timing generation unit 17b generates a current switching timing signal having an overlap time δ according to the target rotational speed, and the motor driving unit 20 switches the MOSFETs (switching elements) (Q1 to Q6). Then, the brushless motor 10 is driven.

  (Step S74) Generation of a stop command for the brushless motor 10 is detected. If there is a stop instruction, the processing of FIG. 10 is terminated, and if there is no stop instruction, the process returns to step S60.

  In the second embodiment, the timing of the gate signals of the MOSFETs (Q1 to Q6) is controlled by the falling edges of the six sensor signals output from the magnetic sensors (IC1 to IC3). In this case, corresponding to the fall of each sensor signal, the timing corresponding to the next fall (equivalent to 30 ° rotation of the rotor 1) is predicted, and the gate signals of the MOSFETs (Q1 to Q6) are controlled on / off. To do. At that time, the rotation speed of the rotor 1 is calculated from the time between the falling edges of the sensor signal, and the overlap time δ for overlap control corresponding to the rotation speed is obtained. When the gate signals of the MOSFETs (Q1 to Q6) on the high side (power supply side) and the low side (ground side) are on / off controlled, overlap control is performed according to the overlap time δ. The same control can be performed using the rising edge of the sensor signal.

  Moreover, when performing overlap control, controlling the switching timing of only the output of the high-side MOSFETs (Q1 to Q3) and delaying the output off timing can provide the effect of reducing the natural vibration noise. By delaying the output switching timing of the low-side MOSFETs (Q4 to Q6), overlap control is performed at the time of switching all the currents of the armature coils (4a to 4f), and the natural vibration noise is further reduced. be able to.

  Next, Example 3 which is the 3rd Embodiment of this invention is demonstrated using FIGS. 11-15. In the third embodiment, the first drive mode and the second drive mode are realized by a method different from the method described in the first and second embodiments.

[Description of Driving Mode in Embodiment 3]
FIG. 11A is a bottom view showing the state of the brushless motor 10. The brushless motor 10 itself is exactly the same as that described in the first embodiment. However, in FIG. 11A, the sensor magnet 5 has a delay angle of 30 ° with respect to the main magnet 2 (field permanent magnet). It is attached to the shaft 6 so that it may become. In this arrangement, the generated torque is the largest and the efficiency is improved. In the third embodiment, the mode in which the brushless motor 10 is driven in the state shown in FIG.

  On the other hand, FIG. 11B is a diagram showing a state where the sensor magnet 5 of the same brushless motor 10 is attached to the shaft 6 with a delay angle of 42 °. In this arrangement, the beat sound due to resonance between the vibration frequency of the brushless motor 10 and the natural vibration frequency of the storage case storing the brushless motor is minimized. In the third embodiment, the mode in which the brushless motor 10 is driven in the state shown in FIG.

  Note that the brushless motor 10 of FIGS. 11A and 11B also rotates in the direction of the rotation direction R by switching the current flowing through the armature coils (4a to 4f). The operation principle is as described in the first embodiment.

  And the delay angle with respect to the main magnet 2 (field permanent magnet) of the sensor magnet 5 is controllable by controlling the timing which switches the electric current which flows into this armature coil (4a-4f). In other words, the brushless motor 10 is designed in the state shown in FIG. 11B (delay angle 42 °), and the timing for switching the current flowing through the armature coils (4a to 4f) is controlled, so that FIG. The state shown in a) (delay angle 30 °) can be obtained.

  Since this control is a control for advancing the delay angle from 42 ° to 30 °, it is referred to as a delay angle advance control. In this case, the advance amount d of the delay angle is 12 °.

  That is, when the rotation speed of the brushless motor 10 is small (rotation speed is low), the delay angle advance amount d is driven at 0 ° (state of FIG. 11B) (first drive mode), and the brushless motor is driven. When the number of rotations 10 is large (the rotation speed is fast), the brushless motor 10 is driven by driving the delay angle advance amount d as 12 ° (the state shown in FIG. 11A) (second drive mode). It can be driven with low noise when rotating at a low speed, and can be driven with high efficiency when the brushless motor 10 is rotating at a high speed.

  The delay angle at which the beat noise is minimized due to a mechanical error of the brushless motor 10 has a width. Therefore, with a margin, for example, it is attached at a delay angle of 44 °, and the error is controlled by the advance angle control. Make up. In this actual example 3, an advance angle control is performed in which the advance amount d of the delay angle is 8 ° (that is, the delay angle in the second drive mode is 36 °), and the drive mode 1 is switched to the drive mode 2. I will explain.

[Description of advance angle control in Embodiment 3]
In the third embodiment, specifically, the advance amount d of the delay angle is controlled as shown in FIG. That is, the first driving mode in which the delay angle advance amount d is set to 0 ° and the brushless motor 10 is driven with low noise, and the brushless motor 10 in which the delay angle advance amount d is set to 8 °. A second drive mode for driving with high efficiency is set.

  When the temperature of the drive control unit that switches the MOSFETs (Q1 to Q6) at a predetermined timing exceeds a predetermined temperature threshold T (for example, 85 ° C.) set in advance, the brushless motor 10 is switched to the target rotational speed. Regardless of this, the driving is performed in the second driving mode, that is, in a state where the advance amount d of the delay angle is set large (d = 8 °). Further, when the temperature of the drive control unit does not exceed a predetermined temperature threshold value T (for example, 85 ° C.) set in advance, when the target rotational speed of the brushless motor 10 is low (for example, 1800 rpm or less), the brushless motor 10 is turned on. When the driving speed of the brushless motor 10 is high (for example, 2500 rpm or more) when the driving speed is 1 (ie, in a state in which the advance amount d of the delay angle is set small) (d = 0 °) and the target rotational speed of the brushless motor 10 is high (eg, 2500 rpm or more) Driving is performed in the second driving mode, that is, in a state where the advance amount d of the delay angle is set large (d = 8 °). The predetermined temperature threshold value T is not limited to 85 ° C., and is set as appropriate according to the operating conditions of the brushless motor 10 and the environment where the drive control unit is placed.

  Further, when the target rotational speed of the brushless motor 10 is between 1800 rpm and 2500 rpm, the advance amount d of the delay angle is gradually switched according to the target rotational speed of the brushless motor 10. This is because if the advance amount d of the delay angle is suddenly changed, the rotational torque of the brushless motor 10 is also suddenly changed, resulting in uneven rotation of the motor.

  Note that the threshold value of the target rotational speed of the brushless motor 10 is different from the value described in the second embodiment (see FIG. 8). This threshold value depends on the characteristics of the individual brushless motors 10 and the air conditioning control. The value is set based on the specification of the unit 24 and is not limited to a specific value.

[Description of Configuration of Embodiment 3]
Next, a specific configuration of the third embodiment will be described with reference to FIGS.

  FIG. 13 is a block diagram illustrating an overall configuration of a brushless motor control device 100c that performs rotation control of the brushless motor 10 according to the third embodiment. Since the schematic configuration of the brushless motor control device 100c is substantially the same as the brushless motor control device 100a (see FIG. 4) described in the first embodiment, only differences from the brushless motor control device 100a will be described here.

  The brushless motor control device 100c includes a switching timing calculation unit 14c instead of the switching timing calculation unit 14a (see FIG. 4) and the drive voltage waveform generation unit 23 (see FIG. 4) that the brushless motor control device 100a has. .

  The switching timing calculation unit 14c is configured by a microcomputer, and further includes an advance angle calculation unit 15c, an advance angle control unit 16c, and a current switching timing generation unit 17c.

  The advance amount calculation unit 15c determines the drive mode of the brushless motor 10 based on the ambient temperature of the switching timing calculation unit 14c detected by the temperature detection unit 30. When the ambient temperature of the switching timing calculation unit 14c exceeds a predetermined temperature threshold T (for example, 85 ° C.), the brushless motor 10 is switched to the second drive mode, that is, the rotor 1 regardless of the target rotational speed. Driving is performed with the advance amount d of the delay angle of the sensor magnet 5 attached integrally with the rotor 1 with respect to the attached field permanent magnet 2 set large.

  On the other hand, when the ambient temperature of the switching timing calculation unit 14c does not exceed a predetermined temperature threshold T (for example, 85 ° C.) set in advance, the advance amount calculation unit 15c has a low target rotation speed of the brushless motor 10 ( For example, when the brushless motor 10 is driven in the first drive mode, that is, in a state in which the advance amount d of the delay angle is set small, the target rotational speed of the brushless motor 10 is high (for example, more than 1800 rpm). Sometimes, the brushless motor 10 is driven in the second drive mode, that is, in a state where the advance amount d of the delay angle is set large. The predetermined temperature threshold value T is not limited to 85 ° C., and is set as appropriate according to the operating conditions of the brushless motor 10 and the environment where the drive control unit is placed.

  The advance angle control unit 16c calculates the switching timing of the current flowing through the armature coils (4a to 4f) necessary for realizing the advance amount d of the delay angle calculated by the advance amount calculation unit 15c.

  Based on the current switching timing calculated by the advance angle control unit 16c and the air conditioning control signal indicating the target rotational speed of the brushless motor 10 obtained from the air conditioning control unit 24, the current switching timing generation unit 17c ( The switching timing of the current passed through U, V, W) is determined based on the control target shown in FIG.

  Next, a method for determining the switching timing of the current flowing through each phase (U, V, W) will be described with reference to FIGS. 14 (a) and 14 (b). 14A and 14B switch the MOSFETs (Q1 to Q6) in order to switch the sensor signal output from the magnetic sensors (IC1 to IC3) and the current flowing through the armature coils (4a to 4f). It is a time chart which shows the relationship with a gate signal.

  The sensor signals (SAH, SAL) shown in FIG. 14A indicate the sensor signal output from the magnetic sensor IC1 and its inverted signal. Similarly, sensor signals (SBH, SBL) indicate sensor signals output from the magnetic sensor IC2 and their inverted signals, respectively, and sensor signals (SCH, SCL) indicate sensor signals output from the magnetic sensor IC3, and The inverted signal is shown. With the above six signals, each time the rotor 1 rotates 30 °, the current switching timing to be passed through the armature coils (4a to 4f) can be finely controlled.

  FIG. 14B shows gate signals applied to the MOSFETs (Q1 to Q6) when the advance angle control is performed, and the gate signals (AT, BT, CT) are MOSFETs on the high side (power supply side) ( Q1 to Q3) and gate signals (AB, BB, CB) indicate gate signals for the MOSFETs (Q4 to Q6) on the low side (ground side).

  In the third embodiment, the timing of the gate signals of the MOSFETs (Q1 to Q6) is controlled by the fall of the six sensor signals (SAH, SAL, SBH, SBL, SCH, SCL). In this case, the timing corresponding to the next fall (corresponding to 30 ° rotation of the rotor 1) is predicted corresponding to the fall of each sensor signal (SAH, SAL, SBH, SBL, SCH, SCL), and the MOSFET The gate signals (Q1 to Q6) are turned on / off. At that time, the rotational speed of the rotor 1 is calculated from the time between the falling edges of the sensor signals (SAH, SAL, SBH, SBL, SCH, SCL), and the delay angle for the advance control corresponding to the rotational speed is calculated. The advance amount d is obtained. When the gate signals (AT, BT, CT, AB, BB, CB) of the MOSFETs (Q1 to Q6) are on / off controlled, the timing is controlled by performing control according to the advance amount d of the delay angle. . The same control can be performed using the rising edges of the sensor signals (SAH, SAL, SBH, SBL, SCH, SCL).

[Description of Process Flow of Embodiment 3]
Next, a specific processing flow of the third embodiment will be described with reference to the flowchart of FIG.

  (Step S80) The temperature detector 30 detects the ambient temperature of the switching timing calculator 14c.

  (Step S82) It is determined whether or not the detected temperature exceeds a predetermined temperature threshold value T of 85 ° C. When the temperature threshold T is exceeded, the process proceeds to step S90, and when the temperature threshold T or less, the process proceeds to step S84.

  (Step S84) In the advance amount calculation unit 15c, it is determined whether or not the target rotational speed of the brushless motor 10 is 2500 rpm or more. If the target rotational speed is 2500 rpm or more, the process proceeds to step S90, and otherwise, the process proceeds to step S86.

  (Step S86) In the advance amount calculation unit 15c, it is determined whether or not the target rotational speed of the brushless motor 10 is 1800 rpm or less. If the target rotational speed is 1800 rpm or less, the process proceeds to step S88. Otherwise, the process proceeds to step S92.

  (Step S88) The current switching timing generator 17b generates a current switching timing signal for setting the advance amount d of the delay angle so as to drive the brushless motor 10 in the first drive mode. The brushless motor 10 is driven in the first drive mode by switching the MOSFETs (switching elements) (Q1 to Q6).

  (Step S90) The current switching timing generation unit 17b generates a current switching timing signal that sets the advance amount d of the delay angle so as to drive the brushless motor 10 in the second drive mode. The brushless motor 10 is driven in the second drive mode by switching the MOSFETs (switching elements) (Q1 to Q6).

  (Step S92) The current switching timing generator 17b performs advance angle control according to the target rotational speed. Specifically, a current switching timing signal for setting the advance amount d of the delay angle corresponding to the target rotational speed is generated, and the motor driving unit 20 switches the MOSFETs (switching elements) (Q1 to Q6) to perform brushless. The motor 10 is driven.

  (Step S94) The generation of a stop command for the brushless motor 10 is detected. If there is a stop instruction, the processing of FIG. 15 is terminated, and if there is no stop instruction, the process returns to step S80.

  As described above, according to the control method for a vehicle brushless motor according to the first embodiment, when the vehicle brushless motor 10 is rotated at a predetermined rotation speed or less, the first drive mode is rotated with low noise. When driving in the second drive mode that rotates with high efficiency, the switching timing calculation unit 14a (drive control unit) of the brushless motor 10 is driven. When it is determined that the temperature rises and exceeds a predetermined temperature threshold value T, the brushless motor 10 is driven in the second drive mode in which the brushless motor 10 is rotated with high efficiency regardless of the number of rotations thereof. Even in the low rotation range where the motor 10 was driven in the first drive mode, the temperature of the switching timing calculation unit 14a (drive control unit) increased. Kiniwa, since they are driven by efficient second drive mode, it is possible to continue operation without reducing the speed. And since the generation | occurrence | production of a heat | fever decreases by the operating efficiency of the brushless motor 10 increasing, the further temperature rise of the switching timing calculating part 14a (drive control part) can be prevented.

  Further, according to the control method for a brushless motor for a vehicle according to the first embodiment, the first drive mode is applied to each connection point (Ua, Va, Wa) of the armature coils (4a to 4f) of the brushless motor 10. Since the voltage waveform e (t) to be driven is a sine wave and the drive mode is driven to drive the brushless motor 10, the change in magnetic flux generated in the armature coils (4a to 4f) becomes gentle, and the brushless motor 10 is driven with low noise. Since the second driving mode is a driving mode in which the brushless motor 10 is driven with the voltage waveform e (t) as a rectangular wave, the period during which the effective rotational torque is generated is lengthened, and the torque generation efficiency is increased. The efficiency of the brushless motor 10 is improved. The first drive mode and the second drive mode can be switched reliably by a simple method of changing the voltage waveform e (t) applied to the armature coils (4a to 4f) of the brushless motor 10. .

  Further, according to the control method for a brushless motor for a vehicle according to the second embodiment, the first drive mode is set such that each connection point (Ua, Va) of the armature coils (4a to 4f) of the brushless motor 10 mounted on the vehicle. , Wa) When switching the voltage applied to the armature coil (any one of 4a to 4f) to which the voltage was applied before switching, and any one of the armature coil (4a to 4f) to which the voltage is applied after switching ) And the drive mode in which the brushless motor 10 is driven by increasing the time during which the voltage is applied (overlap time δ), the change in the magnetic flux generated in the armature coils (4a to 4f) is moderate. Thus, the brushless motor 10 can be driven with low noise, and the second drive mode is set to the armature coils (4a to 4f) of the brushless motor 10 mounted on the vehicle. When switching the voltage to be applied to each connection point (Ua, Va, Wa), the armature coil (any one of 4a to 4f) to which the voltage was applied before switching, and the armature coil to which the voltage is applied after switching Since the drive mode for driving the brushless motor 10 is reduced by reducing the time (overlap time δ) during which voltage is applied redundantly (any one of 4a to 4f), the period during which effective rotational torque is generated becomes longer. Thus, the efficiency of generating the torque is improved and the efficiency of the brushless motor 10 is improved. Then, the first drive mode and the second drive mode are reliably switched by a simple method of changing the overlap time δ of the voltage waveform applied to each phase (U, V, W) of the brushless motor 10. be able to.

  Further, according to the control method for a brushless motor for a vehicle according to the third embodiment, the first drive mode is a MOSFET (Q1 to Q6) (switching element) that controls the energization state to the brushless motor 10 mounted on the vehicle. The timing advance amount d of the sensor magnet 5 attached integrally with the rotor 1 with respect to the main magnet 2 (field permanent magnet) attached to the rotor 1 of the brushless motor 10 is increased. Therefore, the change in the magnetic flux generated in the armature coils (4a to 4f) becomes gentle, and the brushless motor 10 can be driven with low noise. MOSFET (Q1 to Q6) for controlling the energization state to the brushless motor 10 mounted on the vehicle with the two drive modes Since the switching timing of the switching element is controlled so as to reduce the advance amount d of the delay angle of the sensor magnet 5 with respect to the main magnet 2 (field permanent magnet), the driving mode for driving the brushless motor 10 is set. The period during which effective rotational torque is generated becomes longer, the torque generation efficiency is improved, and the efficiency of the brushless motor 10 is improved. The first drive mode and the second drive mode can be switched reliably by a simple method of changing the advance amount d of the delay angle of the brushless motor 10.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the embodiments are only examples of the present invention, and the present invention is not limited to the configurations of the embodiments. Needless to say, design changes and the like within a range not departing from the gist of the invention are included in the present invention.

100a Brushless motor control device 1 Rotor 2 Main magnet (field permanent magnet)
4a, 4b, 4c, 4d, 4e, 4f Armature coil 5 Sensor magnet 10 Brushless motor 12 Sensor signal detection unit 14a Switching timing calculation unit 17a Current switching timing generation unit 18 Drive waveform determination unit 20 Motor drive unit 22 Power supply unit 23 Drive voltage waveform generator 24 Air conditioning controller 26 Constant current circuit 28 Thermistor 30 Temperature detectors IC1, IC2, IC3 Magnetic sensors Q1, Q2, Q3, Q4, Q5, Q6 MOSFET (switching element)
U, V, W Phase Ua, Va, Wa Connection point

Claims (4)

When rotating a brushless motor mounted on a vehicle at a predetermined rotational speed or less, when driving in a first drive mode that rotates with low noise and rotating the brushless motor at a rotational speed higher than the predetermined rotational speed In a control method of a brushless motor for a vehicle that is driven in a second drive mode that rotates with high efficiency,
The first drive mode includes an armature coil to which a voltage is applied before switching when switching a voltage applied to each connection point of an armature coil of a brushless motor mounted on the vehicle, and a voltage after switching. And an armature coil for applying the voltage to the brushless motor by increasing the time for applying the voltage redundantly,
In the second drive mode, when switching the voltage applied to each connection point of the armature coil of the brushless motor mounted on the vehicle, the armature coil to which the voltage was applied before switching, and the voltage after switching And an armature coil for applying the voltage to the brushless motor by reducing the time for applying the voltage redundantly,
When the temperature of a drive control unit that performs drive control of the brushless motor is detected and it is determined that the temperature exceeds a predetermined temperature threshold, the brushless motor generates torque from the first drive mode. It drives in said 2nd drive mode with high efficiency . The control method of the brushless motor for vehicles characterized by the above-mentioned. In the control method of the brushless motor for vehicles according to claim 1,
As the predetermined rotational speed, a second predetermined rotational speed higher than the first predetermined rotational speed is set,
When rotating the brushless motor at the first predetermined number of rotations or less, driving in the first drive mode,
When rotating the brushless motor at the second predetermined number of revolutions or more, drive in the second drive mode,
When rotating the brushless motor at a target rotational speed that is higher than the first predetermined rotational speed and lower than the second predetermined rotational speed, a voltage applied to each connection point of the armature coil of the brushless motor mounted on the vehicle When switching, the time for applying the voltage to the armature coil that has been applied with the voltage before switching and the armature coil that is to be applied with the voltage after switching is set according to the time according to the target rotational speed. Drive the brushless motor
A control method for a brushless motor for a vehicle. When rotating a brushless motor mounted on a vehicle at a predetermined rotational speed or less, when driving in a first drive mode that rotates with low noise and rotating the brushless motor at a rotational speed higher than the predetermined rotational speed In a control method of a brushless motor for a vehicle that is driven in a second drive mode that rotates with high efficiency,
In the first drive mode, the switching timing of the switching element for controlling the energization state of the brushless motor mounted on the vehicle is integrated with the rotor for the field permanent magnet attached to the rotor of the brushless motor. Is a drive mode for driving the brushless motor by controlling so that the advance amount of the delay angle of the sensor magnet attached to is small,
In the second drive mode, the switching timing of the switching element that controls the energization state of the brushless motor mounted on the vehicle increases the advance amount of the delay angle of the sensor magnet with respect to the field permanent magnet. controlled to, Ri Oh in drive mode for driving the brushless motor,
When the temperature of a drive control unit that performs drive control of the brushless motor is detected and it is determined that the temperature exceeds a predetermined temperature threshold, the brushless motor generates torque from the first drive mode. A method for controlling a brushless motor for a vehicle, wherein the driving is performed in the second driving mode with high efficiency . In the control method of the brushless motor for vehicles according to claim 3,
As the predetermined rotational speed, a second predetermined rotational speed higher than the first predetermined rotational speed is set,
When rotating the brushless motor at the first predetermined number of rotations or less, driving in the first drive mode,
When rotating the brushless motor at the second predetermined number of revolutions or more, drive in the second drive mode,
When the brushless motor is rotated at a target rotational speed that is higher than the first predetermined rotational speed and lower than the second predetermined rotational speed, switching timing of a switching element that controls the energization state of the brushless motor mounted on the vehicle The brushless motor is driven by controlling the advance amount of the delay angle of the sensor magnet with respect to the field permanent magnet to be the advance amount of the delay angle corresponding to the target rotational speed.
A control method for a brushless motor for a vehicle.