WO2016125456A1 - Motor control apparatus - Google Patents

Abstract

A motor control apparatus according to the present invention comprises: an inverter (33) that causes a rotational torque that promotes or prevents rotation of an output shaft of a motor; rotation angle detection unit (40, 60) that outputs rotation signals; a motor control unit (32) that controls the connection of a stator coil of the motor to a positive terminal and negative terminal of a power source respectively and that controls the generation of rotational torque; and an instruction unit (31) that instructs an increasing/decreasing direction of the rotational torque. The motor control unit enters normal mode when the increasing/decreasing direction is in a direction promoting rotation of the motor and the motor control unit enters power generation mode when the increasing/decreasing direction is in a direction preventing rotation of the motor, the motor control unit connecting the stator coil to each of the positive terminal and the negative terminal of the power source and, when in power generation mode, while the motor rotates only within a predetermined rotation angle range, the motor control unit intermittently connects the stator coil M times to the positive terminal while intermittently connecting the stator coil to the negative terminal N times.

Description

Motor control device Cross-reference of related applications

This application is based on Japanese Patent Application No. 2015-18551 filed on February 2, 2015, the contents of which are incorporated herein by reference.

The present disclosure relates to a motor control device that adjusts the phase of a camshaft with respect to a crankshaft by controlling driving of a motor mechanically coupled to each of the crankshaft and camshaft via a valve timing conversion unit. .

As shown in Patent Document 1, a valve timing adjusting device that adjusts the valve timing of an intake valve is known. This valve timing adjusting device has a rotor portion to which a motor shaft is fixed, an electric motor having a stator coil provided around the rotor portion, and a plurality of switching elements connected to the stator coil. In addition, the valve timing adjusting device includes an energization driving means for switching a switching element (selection element) to be turned on for each rotation angle range of the motor shaft, and a crankshaft and a camshaft according to the operating state of the internal combustion engine and the rotation state of the motor shaft. A phase adjustment mechanism for adjusting the relative phase.

When an electric current flows through the stator coil and a motor shaft rotates while a magnetic field is generated from the stator coil, an induced voltage is generated in the stator coil. When the target rotation direction of the motor shaft coincides with the actual rotation direction of the motor shaft, an induced voltage is generated in the opposite direction to the voltage applied to the stator coil when the switching element is turned on. As a result, a current corresponding to the difference between the applied voltage and the induced voltage flows through the switching element (selection element) in the on state. However, when the target rotation direction of the motor shaft is different from the actual rotation direction of the motor shaft, an induced voltage in the same direction is generated with respect to the voltage applied to the stator coil when the switching element is turned on. As a result, a large current corresponding to the sum of the applied voltage and the induced voltage flows through the selection element. Therefore, there is a possibility that the selection element generates excessive heat.

Therefore, the energization driving means of the valve timing adjusting device described in Patent Document 1 is such that when the target rotation direction of the motor shaft matches the actual rotation direction, for example, the rotation angle of the motor shaft is 30 ° mechanical angle (120 ° electrical angle). ) Is set to an on range in which the selection element is continuously turned on. When the target rotation direction and the actual rotation direction are different, the energization driving unit divides and sets the rotation angle range into an on range and an off range in which the selection element is continuously turned off. Thus, a voltage is applied to the stator coil in the on range, but no voltage is applied in the off range. For this reason, the time required for the current corresponding to the sum of the applied voltage and the induced voltage to flow through the selection element is shortened, and excessive heat generation of the selection element is suppressed.

Incidentally, in the valve timing adjustment device disclosed in Patent Document 1, an electric motor (motor) is mechanically connected to a crankshaft via a phase adjustment mechanism. Therefore, when the internal combustion engine is driven to burn and the crankshaft rotates, the motor shaft of the motor also rotates regardless of the generation of control torque (rotational torque) due to energization of the stator coil. Even when the crankshaft is inertially rotated by stopping the internal combustion engine, the motor shaft rotates in the same direction as the crankshaft while reducing its rotational speed. However, the rotor portion fixed to the motor shaft has a permanent magnet. Since there is a metal material such as a stator coil around the permanent magnet, a magnetic force is generated between the metal material and the permanent magnet, and this acts on the motor shaft as a brake torque that prevents the rotation of the rotor portion. If the motor shaft is inertially rotated together with the crankshaft and its rotational force is weakened so as to be stationary, there is a possibility that the rotational direction is momentarily reversed due to the brake torque and then stopped. Thus, when the rotation direction is reversed before stopping, the energization driving means determines that the target rotation direction and the actual rotation direction are different, and ends the operation. As described above, when the target rotation direction and the actual rotation direction are different, the energization driving unit divides and sets the rotation angle range into the on range and the off range. Therefore, when the rotation angle at the time when the motor is stopped is included in the ON range, the rotational torque can be generated on the motor shaft of the motor by the energization driving means at the time of restart. Therefore, by rotating the motor shaft, the phase of the cam shaft relative to the crankshaft can be adjusted to a phase suitable for restarting the internal combustion engine with the amount of compressed air in the combustion chamber constituted by the cylinder and the piston. However, when the rotation angle at the time when the motor is stopped is included in the OFF range, it is not possible to generate a rotational torque on the motor shaft by the energization driving means at the time of restart. As a result, the motor shaft cannot be rotated, and the camshaft with respect to the crankshaft cannot be adjusted to a phase suitable for restarting the internal combustion engine.

JP 2009-62837 A

An object of the present disclosure is to provide a motor control device capable of suppressing excessive heat generation of a switching element and generating rotational torque to the motor at the time of restart regardless of the rotational angle at the time when the motor is stopped. And

The motor control device according to the first aspect of the present disclosure controls the drive of a motor mechanically connected to each of the crankshaft and the camshaft via a valve timing conversion unit, so that the camshaft with respect to the crankshaft Adjust the phase. The motor includes an output shaft connected to the valve timing conversion unit, a rotor to which the output shaft is fixed, and a stator provided around the rotor, and the rotor includes a permanent magnet. The stator includes a stator coil. The motor control device generates a magnetic flux by causing a current to flow through the stator coil, and causes the rotor to generate a rotational torque that promotes or prevents the rotation of the output shaft by causing the magnetic flux to act on the permanent magnet. By opening and closing an inverter, a rotation angle detector that outputs a rotation signal that depends on the rotation angle of the motor and the rotation direction of the motor, and a plurality of switching elements that constitute the inverter based on the rotation signal. A motor control unit that controls connection between the stator coil and each of a positive terminal and a negative terminal of a power source to control a current flowing in the stator coil, and controls generation of the rotational torque; and And an instruction unit for instructing the increase / decrease direction. The motor control unit is in a normal mode when the increase / decrease direction of the rotational torque instructed by the instruction unit is a direction for promoting the rotation of the motor, and the increase / decrease direction of the rotational torque prevents the motor from rotating. In the case of, it becomes power generation mode. The motor control unit may be configured such that when M is a natural number of 1 or more and N is a natural number of 2 or more, the stator coil is connected to the positive terminal and the negative terminal of the power source regardless of the rotation angle of the motor in the normal mode. The stator coil is connected to the plus terminal while the stator coil is intermittently connected to the plus terminal M times while the motor rotates by a predetermined rotation angle range in the power generation mode. The stator coil is intermittently connected N times to the negative terminal.

According to the first aspect of the present disclosure, as described above, in the power generation mode, the motor controller is energized by intermittently connecting the stator coil to the power source while the motor rotates within a predetermined rotation angle range. . According to this, even if the motor reversely rotates momentarily due to the brake torque, and the motor control unit is temporarily switched from the normal mode to the power generation mode, the rotational torque can be generated at the time of restart. Thereby, the cam phase can be adjusted to a phase suitable for restarting the internal combustion engine. In addition, it is possible to suppress an excessive current from flowing through the plurality of switching elements. As a result, excessive heat generation of the plurality of switching elements is suppressed.

The motor control device according to the second aspect of the present disclosure controls the drive of a motor mechanically connected to each of the crankshaft and the camshaft via a valve timing conversion unit, so that the camshaft with respect to the crankshaft Adjust the phase. The motor includes an output shaft connected to the valve timing conversion unit, a rotor to which the output shaft is fixed, and a stator provided around the rotor, and the rotor includes a permanent magnet. The stator includes a stator coil. The motor control device generates a magnetic flux by causing a current to flow through the stator coil, and causes the rotor to generate a rotational torque that promotes or prevents the rotation of the output shaft by causing the magnetic flux to act on the permanent magnet. By opening and closing an inverter, a rotation angle detector that outputs a rotation signal that depends on the rotation angle of the motor and the rotation direction of the motor, and a plurality of switching elements that constitute the inverter based on the rotation signal. A motor control unit that controls connection between the stator coil and each of a positive terminal and a negative terminal of a power source to control a current flowing in the stator coil, and controls generation of the rotational torque; and And an instruction unit for instructing the increase / decrease direction. The motor control unit is in a normal mode when the increase / decrease direction of the rotational torque instructed by the instruction unit is a direction for promoting the rotation of the motor, and the increase / decrease direction of the rotational torque prevents the motor from rotating. In the case of, it becomes power generation mode. The motor control unit connects the stator coil to each of the plus terminal and the minus terminal regardless of the rotation angle of the motor in the normal mode, where N is a natural number of 2 or more, and in the power generation mode. After connecting the stator coil to the minus terminal intermittently N times while the motor rotates by a predetermined rotation angle range while connecting the stator coil to the plus terminal regardless of the rotation angle of the motor. The stator coil and the minus terminal are continuously disconnected from each other for at least one time corresponding to the time when the minus terminal is intermittently connected N times.

The motor control device according to the second aspect of the present disclosure has the same effects as the first aspect of the present disclosure.

The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing
FIG. 1 is a block diagram illustrating a schematic configuration of the motor control device according to the first embodiment. FIG. 2 is a cross-sectional view showing a schematic configuration of the motor, FIG. 3 is a cross-sectional view for explaining the arrangement of the rotation angle sensor. FIG. 4 is a circuit diagram showing a schematic configuration of the inverter and the stator coil. FIG. 5 is a timing chart showing the relationship between the sensor signal and the control signal. FIG. 6 is a chart showing the relationship between the sensor signal and the rotation angle. FIG. 7 is a chart showing the relationship between the rotation angle and the control signal in normal control. FIG. 8 is a schematic diagram showing current flowing through the inverter and the stator coil in normal control. FIG. 9 is a chart showing the relationship between the rotation angle and the control signal in power generation control. FIG. 10 is a timing chart showing control signals input to the upper and lower switches to be controlled in the power generation control. FIG. 11 is a schematic diagram showing a current flowing through the inverter and the stator coil in the power generation control. FIG. 12 is a graph schematically showing the brake torque, FIG. 13 is a cross-sectional view of the motor showing the positional relationship between the rotation angle sensor and the stator coil, FIG. 14 is a chart showing the positional relationship between the rotation angle sensor and the permanent magnet with respect to the rotation angle of the rotor, FIG. 15 is a timing chart for explaining that it becomes impossible to restart as a result of mode switching by brake torque. FIG. 16 is a timing chart for explaining that restarting is possible even when mode switching by brake torque is performed. FIG. 17 is a block diagram showing a schematic configuration of the pre-driver, FIG. 18 is a timing chart for explaining the PWM drive signal. FIG. 19 is a flowchart showing the determination process of the control determination unit, FIG. 20 is a timing chart for explaining the count number and the switch-off signal. FIG. 21 is a flowchart for explaining signal processing of the power generation control unit. FIG. 22 is a timing chart for explaining a modified example of the power generation control, and FIG. 23 is a timing chart for explaining a modified example of the power generation control.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
(First embodiment)
The motor control device according to this embodiment will be described with reference to FIGS. In addition to the motor control device 100, FIG. 1 illustrates a motor 200, an internal combustion engine 300, a valve timing conversion unit 310, a cam angle sensor 340, and a crank angle sensor 350. 2, 3, 13, and 14, an electrical angle, which will be described later, is shown in parentheses, and the rotation angle sensor 60 is hatched. In FIG. 14, reference numerals are omitted to avoid complication, and one N pole of a permanent magnet 212 described later is hatched to clarify the rotation state. Finally, in order to indicate that the control signal input to the upper switch to be controlled is not simply at the Hi level in the power generation control of FIGS. 5 and 16, a part of the control signal is hatched.

The motor control device 100 controls the phase difference between the camshaft 320 and the crankshaft 330 of the internal combustion engine 300 (hereinafter referred to as cam phase) by controlling the rotation of the motor 200. As shown in FIG. 1, the motor control device 100 is electrically connected to the motor 200 via three stator wires 97 to 99, and the motor 200 is mechanically connected to the internal combustion engine 300 via a valve timing conversion unit 310. ing. In the following, the motor 200, the valve timing conversion unit 310, and the internal combustion engine 300 will be described first, and then the motor control device 100 will be described in detail.

2, the motor 200 includes a rotor 210 fixed to the output shaft, and a stator 220 provided around the rotor 210. The rotor 210 has a cylindrical iron core 211 and a permanent magnet 212 embedded in the iron core 211. In the present embodiment, the N poles and S poles of the permanent magnet 212 are embedded at equal intervals around the axis of the iron core 211 so that the N poles and S poles are alternately adjacent to each other, and the adjacent interval between the adjacent N poles and S poles is 45 °. It has become. As a result, the magnetic flux generated by the plurality of permanent magnets 212 periodically changes every time the rotor 210 rotates 90 °, and the electrical angle is 360 ° with respect to the mechanical angle of 90 °. A magnetic flux generated from the permanent magnet 212 is detected by a rotation angle sensor 60 described later.

In contrast, the stator 220 includes a cylindrical case 221, salient poles 222 provided on the inner peripheral surface of the case 221, and a stator coil 223 wound around the salient poles 222. Twelve salient poles 222 are provided at equal intervals on the inner peripheral surface of the case 221, and the shortest adjacent interval between the two salient poles 222 is 30 ° around the axis of the rotor 210. As shown in FIG. 4, the stator coil 223 includes a U-phase stator coil 224, a V-phase stator coil 225, and a W-phase stator coil 226. The U-phase stator coil 224, the V-phase stator coil 225, and the W-phase stator coil 226 are wound around the 12 salient poles 222 so as to be adjacent to each other in order, and each of the four salient poles has an adjacent interval of 90 ° It is wound around 222. The three stator coils 224 to 226 are Y-connected as shown in FIG. 4, and are connected to the midpoints of the two switches of the corresponding inverter 33, respectively. As will be described in detail later, for example, when the switches 34 and 37 shown in FIG. 4 are turned on, the stator coils 224 and 225 are connected to the positive terminal and the negative terminal of the power source, and current flows through the stator coils 224 and 225. Magnetic flux is generated from the stator coils 224 and 225 by this current flow, and this magnetic flux acts on the permanent magnet 212 of the rotor 210 to generate rotational torque in the rotor 210. As a result, the output shaft of the motor 200 rotates independently.

The output shaft of the motor 200 described above is connected to the camshaft 320 via the valve timing conversion unit 310. The valve timing conversion unit 310 is connected to the crankshaft 330 via a chain. When the crankshaft 330 starts to rotate by driving the internal combustion engine 300, the camshaft 320 and the output shaft of the motor 200 together with the valve timing conversion unit 310 also start to rotate. This rotation causes the cam lobe provided on the cam journal of the camshaft 320 to rotate. The intake valve and the exhaust valve move up and down with respect to the combustion chamber by the rotation of the cam lobe, the intake valve intakes the combustion chamber, and the exhaust valve exhausts the combustion chamber.

When the internal combustion engine 300 is a four-cycle engine, for example, the cam lobe of the camshaft 320 corresponding to the intake valve or the exhaust valve rotates once when the crankshaft 330 rotates twice. Normally, the phases of the intake valve and the exhaust valve are shifted by approximately 180 ° when converted by the rotation angle of the camshaft 320. This phase difference can be adjusted by controlling the cam phase described above by the motor control device 100, the motor 200, and the valve timing conversion unit 310.

Although not shown, the valve timing converter 310 transmits the rotational torque of the crankshaft 330 transmitted through the above-described chain to the camshaft 320, and the planetary gear that rotates the camshaft 320 relative to the crankshaft 330. It has a mechanism. The valve timing conversion unit 310 includes an annular ring gear to which the above-described chain is connected, and a disk-shaped pinion gear and a valve gear provided in the ring gear. The ring gear is connected to the crankshaft 330 via a chain, and the valve gear is connected to the camshaft 320. The pinion gear is connected to the output shaft of the motor 200. Teeth are formed on the inner surface of the ring gear, and teeth are formed on the outer surfaces of the pinion gear and the valve gear. The teeth of the inner surface of the ring gear and the teeth of the pinion gear mesh with each other, and the teeth of the pinion gear and the teeth of the valve gear mesh with each other. Therefore, when the crankshaft 330 rotates, the rotational torque is transmitted to the ring gear through the chain, and thereby the ring gear rotates. Then, the pinion gear revolves around the valve gear, thereby rotating the valve gear. As a result, the camshaft 320 rotates together with the crankshaft 330.

When maintaining the phase difference (or cam phase) between the camshaft 320 and the crankshaft 330, the motor control device 100 causes the valve gear and the ring gear to revolve around the valve gear without causing the motor 200 to rotate the pinion gear. Rotate at the same speed. However, when the cam phase is advanced or retarded, the motor control device 100 revolves around the valve gear while rotating the pinion gear by the motor 200, thereby rotating the valve gear relative to the ring gear. When the output shaft of the motor 200 revolves faster than the crankshaft 330, the cam phase is advanced, and when the output shaft revolves later than the crankshaft 330, the cam phase is retarded. When the cam phase reaches the target phase due to advance or retard, the output shaft of the motor 200 is revolved at the same speed as the ring gear. As a result, the adjusted cam phase is maintained. By the cam phase control by the motor 200, the intake timing and the exhaust timing are adjusted.

As shown in FIG. 1, the motor 200 is provided with a rotation angle sensor 60, and the internal combustion engine 300 is provided with a cam angle sensor 340 and a crank angle sensor 350. A detection signal indicating the rotation state of the motor 200 is detected by the rotation angle sensor 60, and the rotation angle of the camshaft 320 and the rotation angle of the crankshaft 330 are detected by the cam angle sensor 340 and the crank angle sensor 350. The motor control device 100 calculates the rotation angle of the motor 200 based on the detection signal, and calculates the rotation speed of the internal combustion engine 300 based on the rotation angle of the camshaft 320 and the rotation angle of the crankshaft 330. The motor control device 100 controls the motor 200 based on the calculated rotation speed of the internal combustion engine 300 and the rotation angle of the motor 200. By doing so, the motor control device 100 performs cam phase control.

Note that in order to perform cam phase control, the target phase described above must be calculated. The target phase is determined based on various sensor signals indicating the running state of the vehicle, such as an accelerator opening sensor that indicates the accelerator depression amount of the user and an air flow meter that measures the intake air amount of the internal combustion engine 300. It is calculated by. Hereinafter, the motor control device 100 will be described in detail.

As shown in FIG. 1, the motor control device 100 includes an electronic control device 10, a driver 20, and a rotation angle sensor 60. The electronic control device 10 outputs an instruction signal including the target rotation speed (or rotation speed) of the motor 200 to the driver 20, and the driver 20 performs a motor operation based on the instruction signal and the detection signal of the rotation angle sensor 60. 200 is controlled. The rotation angle sensor 60 generates a detection signal corresponding to the rotation of the motor 200 and outputs the detection signal to the driver 20. The electronic control unit 10 and the driver 20 are electrically connected via four signal lines 90 to 93, and the driver 20 and the rotation angle sensor 60 are electrically connected via three sensor lines 94 to 96. Yes.

The electronic control unit 10 sets the target number of rotations of the motor 200 based on the various sensor signals indicating the traveling state of the vehicle, the number of rotations of the internal combustion engine 300, and the rotation angle signal and the rotation direction signal output from the driver 20. Is to determine. The electronic control unit 10 calculates a cam phase as a target that matches the traveling state of the vehicle based on the various sensor signals. Next, the electronic control unit 10 calculates the rotation speed of the motor 200 for setting the target cam phase, and outputs an instruction signal including this rotation speed to the driver 20. The electronic control unit 10 always sets the number of revolutions included in the instruction signal to a finite value, and when the internal combustion engine 300 stops combustion driving, instructs the driver 20 to stop generating the rotational torque together with the finite number of revolutions. Is included in the instruction signal.

As shown in FIG. 1, the driver 20 includes a motor control unit 30, a sensor signal processing unit 40, and a state determination unit 50. The motor control unit 30 controls the rotation of the motor 200 based on the instruction signal input from the electronic control device 10, the rotation angle signal input from the sensor signal processing unit 40, and the sensor signal. The motor control unit 30 rotates the rotor 210 by flowing a rotation current for rotating the output shaft of the motor 200 through the three-phase stator coils 224 to 226 of the motor 200. The sensor signal processing unit 40 generates a digital sensor signal, a rotation angle signal, and a rotation direction signal based on an analog detection signal input from the rotation angle sensor 60. The state determination unit 50 generates a state determination signal described later. The state determination unit 50 receives the sensor signal, the rotation angle signal, the rotation direction signal, the instruction signal, and the rotation current. Although not shown, the motor control device 100 includes a current sensor for detecting the rotation current, and a detection signal of the current sensor is input to the state determination unit 50.

When the instruction signal is input from the electronic control device 10, the motor control unit 30 causes the rotation current to flow so that the rotation speed of the output shaft matches the rotation speed included in the instruction signal. As a result, the motor control unit 30 advances, retards, or maintains the cam phase. However, as described above, when the combustion drive of the internal combustion engine 300 is stopped and the instruction signal includes an instruction to stop the generation of rotational torque, the motor control unit 30 does not flow the rotation current through the three-phase stator coils 224 to 226. In this case, the output shaft of the motor 200 is driven by the crankshaft 330 and the camshaft 320 to rotate. The planetary gear mechanism has a stopper for stopping the cam phase at the slowest most retarded angle and the most advanced advance angle. As described above, when the output shaft of the motor 200 rotates with the crankshaft 330, the cam phase becomes the most retarded angle.

As shown in FIG. 1, the motor control unit 30 includes a rotation control processing unit 31, a pre-driver 32, and an inverter 33. The rotation control processing unit 31 determines the increase / decrease direction of the rotational torque based on the target rotation speed (target rotation speed) included in the instruction signal and the current rotation speed (current rotation speed) detected from the rotation angle signal described later. calculate. When the target rotational speed is higher than the current rotational speed, the rotational control processing unit 31 determines to increase the rotational torque in the direction in which the rotation of the motor 200 is promoted. On the other hand, when the target rotation speed is lower than the current rotation speed, the rotation control processing unit 31 determines to decrease the rotation torque in the increasing / decreasing direction so that the rotation of the motor 200 is prevented. Further, the rotation control processing unit 31 is based on the target number of rotations and the current number of rotations, and the time during which each of the lower switches 35, 37, and 39 to be described later is turned on while the motor 200 rotates 60 degrees in electrical angle (or Duty ratio) is also calculated. The rotation control processing unit 31 outputs control information including the increase / decrease direction of the rotational torque and the duty ratio to the pre-driver 32. The rotation control processing unit 31 corresponds to an instruction unit.

The pre-driver 32 controls the inverter 33 based on the control information input from the rotation control processing unit 31 and the rotation angle signal and sensor signal input from the sensor signal processing unit 40. The pre-driver 32 detects the current rotation direction (or actual rotation direction) of the rotor 210 based on a sensor signal described later, and the actual rotation direction and the increase / decrease direction (or torque direction) of the rotation torque included in the control information. And compare. The pre-driver 32 is in the normal mode when both the actual rotation direction and the torque direction are coincident (in the direction of promoting rotation), and is in the power generation mode when they are different (or in the direction of preventing rotation). . The pre-driver 32 promotes the rotation of the output shaft and increases the rotation speed by controlling the drive of the inverter 33 so that a rotational torque along the rotation direction of the output shaft is generated in the normal mode. Further, the pre-driver 32 controls the drive of the inverter 33 so as to generate a rotation torque opposite to the rotation direction of the output shaft in the power generation mode, thereby preventing the rotation of the output shaft and slowing down the rotation speed. The pre-driver 32 controls the acceleration and deceleration of the rotational speed of the output shaft by the duty ratio included in the control information. The configuration of the pre-driver 32 and the control (normal control and power generation control) of the inverter 33 in the normal mode and the power generation mode will be described in detail later. The rotation direction detection by the pre-driver 32 is performed based on FIG. 6 in the same manner as the sensor signal processing unit 40 as described later. The pre-driver 32 stores the relationship between the sensor signal and the rotation direction shown in FIG.

As described above, since the instruction signal always includes a finite number of rotations, the rotation control processing unit 31 always outputs the torque direction to the pre-driver 32. Therefore, the pre-driver 32 is always in the normal mode or the power generation mode. In particular, when the combustion drive of the internal combustion engine 300 is finished and the instruction signal includes an instruction to stop the generation of rotational torque, the direction of the torque coincides with the direction in which the rotor 210 rotates inertially with the crankshaft 330. Therefore, in this case, the pre-driver 32 is in the normal mode. The pre-driver 32 corresponds to a motor control unit.

As shown in FIG. 4, the inverter 33 has switches 34 to 39 corresponding to the stator coils 224 to 226, respectively. In this embodiment, each of the switches 34 to 39 is an N-channel MOSFET and corresponds to a switching element. The U-phase switches 34 and 35, the V- phase switches 36 and 37, and the W- phase switches 38 and 39 are connected in series from the plus terminal to the minus terminal of the power source, and the two switches that form these pairs are connected in parallel. Yes. One end of the U-phase stator coil 224 is connected to the midpoint of the U-phase switches 34 and 35, and one end of the V-phase stator coil 225 is connected to the midpoint of the V- phase switches 36 and 37. One end of a W-phase stator coil 226 is connected to the midpoint. The other ends of the stator coils 224 to 226 are connected to each other, and the stator coils 224 to 226 are Y-connected.

The sensor signal processing unit 40 binarizes the detection signal corresponding to the rotation angle of the output shaft output from the rotation angle sensor 60 to generate a digital sensor signal, and based on this sensor signal, the rotation angle signal and A rotation direction signal is generated. As shown in FIG. 2, the rotation angle sensor 60 has three Hall elements 61 to 63 as sensor elements, and these three Hall elements 61 to 63 are located above the permanent magnet 212 of the rotor 210. As described above, the magnetic flux generated by the permanent magnet 212 changes periodically every time the rotor 210 rotates 90 ° in mechanical angle (360 ° in electrical angle). Therefore, when the rotor 210 rotates 90 ° in mechanical angle, the direction of the magnetic flux passing through each of the three Hall elements 61 to 63 is reversed. As shown in FIGS. 2 and 3, the three Hall elements 61 to 63 are provided around the axis of the rotor 210 at a mechanical angle of 30 °. As a result, the magnetic flux of the permanent magnet 212 that passes through the three Hall elements 61 to 63 is shifted by 120 ° in terms of electrical angle, and the phases of the detection signals output from the three Hall elements 61 to 63 are also shifted by 120 °. The three detection signals are binarized by the sensor signal processing unit 40, and the pulsed U-phase sensor signal, V-phase sensor signal, and W-phase sensor signal shown in FIG. 5 are generated. The rotation angles shown in FIGS. 5 to 7, 9, and 10 correspond to the electrical angles described above, and in the following, the rotation angles are expressed in electrical angles unless otherwise specified. The sensor signal corresponds to a rotation signal, and the sensor signal processing unit 40 and the rotation angle sensor 60 constitute a rotation angle detection unit.

The above three sensor signals have the same waveform, and when the rotor 210 rotates 180 °, the voltage level changes from the Hi level to the Lo level, or from the Lo level to the Hi level. The three sensor signals are out of phase with each other by 120 °. As described above, as shown in FIGS. 5 and 6, the voltage level of any one of the U-phase sensor signal, the V-phase sensor signal, and the W-phase sensor signal changes every time the rotation angle of the rotor 210 advances by 60 °.

The rotation angle signal described above is a pulse signal in which the voltage level changes for a predetermined time and returns to the original every time at least one of the three sensor signals changes. In the present embodiment, the voltage level of the rotation angle signal changes from the Hi level to the Lo level every time the voltage level of the sensor signal changes from the Hi level to the Lo level, or from the Lo level to the Hi level. Then, after a predetermined time, the voltage level returns from the Lo level to the Hi level. In other words, the pulse included in the rotation angle signal falls every time the output shaft rotates 60 °. Therefore, by detecting the falling edge of the pulse of the rotation angle signal, it is possible to detect that the motor 200 has rotated 60 °. For this reason, the rotation speed (or rotation speed) of the motor 200 can be detected by detecting the number of pulses (the number of falling edges) of the rotation angle signal per unit time.

The above rotation direction signal is a pulse signal whose voltage level is fixed at the Hi level or the Lo level according to the voltage level change pattern of the three sensor signals. In order to determine the voltage level of the rotation direction signal, the sensor signal processing unit 40 must detect the rotation direction of the motor 200. The rotation direction of the motor 200 is detected based on the chart shown in FIG. The sensor signal processing unit 40 stores a correspondence relationship between the change patterns of the three sensor signals with respect to the rotation angle of the motor 200 shown in FIG. As shown in FIGS. 5 and 6, the sensor signal processing unit 40 determines how the voltage levels of the three sensor signals have changed in the process in which the time advances from t1 to t7 (process in which the time advances from period T1 to T6). judge. For example, as shown in FIG. 6, when the voltage levels of the U-phase sensor signal, the V-phase sensor signal, and the W-phase sensor signal are Hi, Lo, and Hi in the period T1, the time advances and changes to Hi, Lo, and Lo in the period T2. In this case, the sensor signal processing unit 40 determines that the motor 200 is rotating forward. In contrast, when the voltage levels of the U-phase sensor signal, the V-phase sensor signal, and the W-phase sensor signal are Hi, Lo, and Hi in the period T1, the time advances and changes to Lo, Lo, and Hi in the period T2. The sensor signal processing unit 40 determines that the motor 200 is rotating in reverse. In this way, the sensor signal processing unit 40 causes the motor 200 to rotate forward when the combination of the voltage levels of the three sensor signals shown in FIG. 6 changes from left to right as indicated by the solid line arrows as time elapses. It is determined that On the other hand, the sensor signal processing unit 40 reverses the motor 200 when the combination of the voltage levels of the three sensor signals shown in FIG. 6 changes from right to left as indicated by the dashed arrows with the passage of time. It is determined that The sensor signal processing unit 40 determines the voltage level of the rotation direction signal based on the determination result.

The state determination unit 50 generates a state determination signal whose duty ratio changes according to the rotation state of the motor 200. The state determination unit 50 according to the present embodiment generates a state determination signal having a first duty ratio when the voltage levels of the three sensor signals are changing. In contrast, when the voltage level of each of the three sensor signals becomes constant, the state determination unit 50 generates a state determination signal having a second duty ratio different from the first duty ratio. In the present embodiment, the first duty ratio is 80% and the second duty ratio is 90%. The first duty ratio indicates that the motor 200 is in a rotating state, and the second duty ratio indicates that the motor 200 is in a stopped state. This state determination signal is input to the electronic control device 10. Based on the duty ratio of the state determination signal, the electronic control unit 10 determines whether the motor 200 is in a rotating state or a stopped state.

The state determination unit 50 according to the present embodiment performs another determination in addition to the rotation state of the motor 200. That is, the state determination unit 50 also determines the state of the sensor signal, the state of the motor control unit 30, and the state of the instruction signal line 90. For example, the voltage level of the W-phase sensor signal may be constant even though the voltage levels of the U-phase sensor signal and the V-phase sensor signal have changed. In this case, the state determination unit 50 causes a power fault or a ground fault in the third Hall element 63 that generates the W-phase sensor signal, or in the third sensor line 96 that connects the third Hall element 63 and the sensor signal processing unit 40. And a state determination signal having a third duty ratio (for example, 40%) is generated. For example, when at least one voltage level of the rotational current supplied to the three-phase stator coils 224 to 226 via the stator wires 97 to 99 becomes constant, the state determination unit 50 causes an abnormality in the motor control unit 30. Alternatively, it is determined that at least one of the stator wires 97 to 99 has a power fault or a ground fault. In this case, the state determination unit 50 generates a state determination signal having a fourth duty ratio (for example, 60%). Furthermore, for example, when the voltage level of the instruction signal line 90 becomes constant, the state determination unit 50 determines that a power fault or a ground fault has occurred in the instruction signal line 90, and a fifth duty ratio (for example, 100%) The state determination signal is generated. Based on the duty ratio of the state determination signal, the electronic control unit 10 determines not only the rotation state of the motor 200 but also the state of the sensor signal, the state of the motor control unit 30, and the state of the instruction signal line 90.

Next, normal control will be described. In the normal control, the pre-driver 32 makes the direction in which the rotor 210 rotates (or the actual rotation direction) the same as the direction of the rotational torque generated in the rotor 210 by the inverter 33 (torque direction). In this control, as indicated by symbol Hi in FIG. 7, when the rotation angle of the rotor 210 is 0 ° -120 °, the U-phase upper switch 34 connected to the positive terminal side of the power supply is in the ON state, and at 120 ° -240 ° The upper phase switch 36 is turned on. Then, the W-phase upper switch 38 is turned on at 240 ° -360 °. Further, as indicated by the symbol P in FIG. 7, the V-phase lower switch 37 connected to the negative terminal side of the power source is intermittently turned on when the rotation angle of the rotor 210 is 300 ° -60 °, and W The phase lower stage switch 39 is intermittently turned on. Then, the U-phase lower switch 35 is intermittently turned on at 180 ° -300 °. In this way, the pre-driver 32 sequentially turns on the upper switches 34, 36, 38 connected to the positive terminal side of the power source while the motor 200 rotates 360 °, and the lower switch connected to the negative terminal side of the power source. 35, 37, and 39 are sequentially turned on sequentially. By doing so, two of the three stator coils 224 to 226 are connected in series to the positive terminal and the negative terminal of the power source, and a rotating current flows through the stator coil. As a result, rotational torque is generated in the rotor 210, and the output shaft of the motor 200 rotates.

For example, when the rotation angle of the motor 200 is 0 ° -60 ° and the switches 34 and 37 are turned on, the stator coils 224 and 225 are connected in series to the positive terminal and the negative terminal of the power source via the switches 34 and 37. . Accordingly, a current based on the power supply voltage flows from the positive terminal to the negative terminal of the power supply as shown by the solid line arrow in FIG. At this time, since the actual rotation direction and the torque direction of the motor 200 are the same, a counter electromotive force in the direction opposite to the power supply voltage is generated in the stator coils 224 and 225. Accordingly, in this case, a current based on the back electromotive force flowing from the minus terminal to the plus terminal of the power source flows as indicated by a broken line arrow in FIG. At this time, since the flow directions of the two currents flowing through the switches 34 and 37 are opposite to each other, an excessive current does not flow through each of the switches 34 and 37, and excessive heat is not generated. The flow rate of the rotating current increases depending on the ON time of each of the lower switches 35, 37, and 39. Therefore, as the ON time of each of the lower switches 35, 37, 39 becomes longer, the rotational torque increases and the acceleration of the motor 200 increases.

Next, power generation control will be described. The pre-driver 32 makes the actual rotation direction and the torque direction of the rotor 210 different in the power generation control. In this case, as indicated by the symbol Ph in FIG. 9, the upper switches 34, 36, 38 connected to the positive terminal side of the power supply are turned on intermittently. More specifically, if N is a natural number of 2 or more, the upper switches 34 and 36 to be controlled are controlled every time the lower switches 37 and 39 to be controlled are intermittently turned on N times as shown in FIG. The state is changed from the on state to the off state or from the off state to the on state. In this embodiment, N is 3, and the pre-driver 32 changes the voltage level of the control signal input to the upper switch to be controlled from the Hi level to the Lo level each time three pulses are input to the lower switch to be controlled. Change from Lo level to Hi level. As shown in FIG. 9, the upper switch that is not controlled is in an off state, and the upper switch that is to be controlled is intermittently changed to an on state while the motor 200 rotates 120 °. The number M of times the upper switch to be controlled is intermittently turned on while the motor 200 rotates 120 ° is determined by the number of rotations of the motor 200. For example, in FIG. 10, since the lower switches 37 and 38 to be controlled are intermittently turned on 4N + 1 times while the motor 200 rotates 120 °, the U-phase upper end switch 34 to be controlled is intermittently turned on three times. It has become. Depending on the number of rotations of the motor 200, the upper switch to be controlled may be turned on once while the motor 200 rotates 120 °. In this case, the upper switch to be controlled is once in the on state and in the off state. Therefore, the number M of times the upper switch to be controlled is intermittently turned on is 1 or more.

When all the three upper switches 34, 36, and 38 are in the OFF state, the rotating current based on the power supply voltage does not flow through the stator coils 224 to 226, and the rotating torque based on the rotating current is not generated in the rotor 210. However, as described above, the upper switch to be controlled is intermittently turned on, but always turned on. When the upper switch is turned on, the lower switch to be controlled is turned on N times intermittently. Therefore, a rotating current based on the power supply voltage flows in the stator coils 224 to 226, and a rotating torque based on the rotating current is generated in the rotor 210.

The reason why no current flows through the stator coils 224 to 226 as described above is as follows. For example, when the rotation angle of the motor 200 is 0 ° -60 ° and the switches 34 and 37 are turned on, the stator coils 224 and 225 are connected in series to the positive terminal and the negative terminal of the power source via the switches 34 and 37. . Therefore, a current based on the power supply voltage flows from the positive terminal to the negative terminal of the power supply as shown by the solid arrow in FIG. At this time, since the actual rotation direction of the motor 200 is different from the torque direction, a counter electromotive force is generated in the U-phase stator coil 224 in the same direction as the power supply voltage. Therefore, in this case, a current based on the back electromotive force that flows from the U-phase upper switch 34 to the W-phase upper switch 38 via the stator coils 224 and 226 flows as indicated by a broken line arrow in FIG. At this time, since the flow directions of the two currents flowing through the U-phase upper switch 34 are the same, an excessive current flows through the U-phase upper switch 34, which may cause excessive heat generation. Such excessive heat generation may occur in the upper switches 36 and 38 as well.

In this way, in the power generation control in which the actual rotation direction and the torque direction of the motor 200 are different, there is a possibility that the upper switches 34, 36, and 38 generate excessive heat. Therefore, as described above, the upper switch to be controlled is intermittently turned on, and a time during which no current flows is provided in each of the upper switches 34, 36, and 38. Thereby, excessive heat generation of the upper switches 34, 36, 38 is suppressed.

Unlike this configuration, in order to suppress excessive heat generation of the upper switches 34, 36, 38, all upper stages in a specific angle range such as 60 ° -120 °, 180 ° -240 °, 300 ° -360 °, etc. When the switches 34, 36, and 38 are turned off, the following problems may occur. As shown in FIG. 2, the rotor 210 has a plurality of permanent magnets 212, and a stator coil 223 wound around the salient pole 222 is provided around the permanent magnets 212. When no rotating current flows through the stator coil 223, no rotating torque is generated in the rotor 210 due to the rotating current. However, a magnetic force is generated between the permanent magnet 212 and the stator coil 223 described above, and this acts on the rotor 210 as a brake torque that prevents the rotation of the rotor 210. The brake torque generated due to the permanent magnet 212 varies as shown in FIG. The brake torque becomes zero when the stator coil 223 (the salient pole 222) and the N pole or S pole of the permanent magnet 212 face each other. However, when the rotor 210 rotates and thereby the N-pole or S-pole and the salient pole 222 are separated from the opposed positions, a brake torque is generated that prevents the rotation. Note that torque that promotes rotation of the rotor 210 is also generated due to the magnetic force. However, since the torque in a direction that prevents the rotation of the rotor 210 is a problem, this torque is mainly discussed in the present embodiment.

As shown in FIG. 13, the third Hall element 63 located in the middle of the three Hall elements 61 to 63 deviates by 7.5 ° in mechanical angle (30 ° in electrical angle) from the salient pole 222 closest to itself. Are arranged as follows. Accordingly, as shown in the column (a) of FIG. 14, the first Hall element 61 is located between the N pole and the S pole in a state where the four N poles of the permanent magnet 212 are opposed to the salient pole 222. The output level of the 1 hall element 61 changes from the Hi level to the Lo level, or from the Lo level to the Hi level. 14B, when the rotor 210 rotates 60 °, the four south poles of the permanent magnet 212 face the salient pole 222, and the third hall element 63 is located between the north and south poles. Position and change its output level. Similarly, as shown in the columns (c) to (f) of FIG. 14, every time the rotor 210 rotates 60 degrees, the four north or south poles of the permanent magnet 212 face the salient pole 222, and three holes One of the elements 61 to 63 is located between the N pole and the S pole, and its output level changes. As described above, when the rotor 210 is rotated by 60 °, 120 °, 180 °, 240 °, 300 °, 360 ° (0 °), the N pole or S pole of the permanent magnet 212 faces the salient pole 222, and the brake torque Becomes zero. At these six rotation angles, the output level of one of the three Hall elements 61 to 63 is inverted.

As described above, the output shaft of the motor 200 is rotated by the crankshaft 330 and rotates. However, when the combustion drive in the internal combustion engine 300 ends, the rotation of the output shaft of the motor 200 as well as the crankshaft 330 weakens. If the rotation becomes weak enough to stop, the rotor 210 may stop so that the N pole or the S pole faces the salient pole 222 after the rotation direction is reversed momentarily due to the brake torque. At this time, for example, as shown in FIG. 15, when the output level of the third Hall element 63 is reversed and then returned to the original level, it is determined that the rotor 210 is reversely rotated by the sensor signal processing unit 40 and the pre-driver 32. . Then, the pre-driver 32 determines that the actual rotation direction of the motor 200 is different from the torque direction, and switches from the normal mode to the power generation mode. Then, the operation ends. In the case of the above-described modification, the pre-driver 32 does not pass a rotating current through the stator coils 224 to 226 in a specific angle range such as 60 ° -120 °, 180 ° -240 °, 300 ° -360 ° in the power generation mode. For example, as shown in FIG. 15, when the motor 200 stops within a range of a rotation angle of 180 ° -240 °, the pre-driver 32 outputs a control signal corresponding to this angle range to the switches 34 to 39 at the time of restart. At this time, since all the upper switches 34, 36, and 38 located on the positive terminal side of the power supply are controlled to be in an OFF state, no rotating current flows through the stator coils 224 to 226. As a result, no rotational torque is generated in the rotor 210, and the rotor 210 cannot be rotated.

In contrast, the pre-driver 32 according to the present embodiment, as described above, outputs the voltage level of the control signal input to the upper switch to be controlled every time three pulses are output to the lower switch to be controlled in the power generation mode. Change. Therefore, as shown at time t8 in FIG. 16, a rotational current flows through the stator coils 224 to 226 at the time of restarting, whereby the rotor 210 is rotated.

Next, a schematic configuration of the pre-driver 32 will be described with reference to FIG. The pre-driver 32 includes a reference signal generation unit 70, a PWM drive signal generation unit 71, a control determination unit 72, a power generation control unit 73, a memory 74, and a switch drive circuit 75. The reference signal generation unit 70 determines the pulse period of the control signal input to the lower switches 35, 37, 39, and the PWM drive signal generation unit 71 sets the pulse width of the control signal input to the lower switches 35, 37, 39 ( Alternatively, the duty ratio is determined. As shown in FIG. 18, the reference signal generation unit 70 generates a triangular wave having a constant period as a reference signal, and outputs this triangular wave to the PWM drive signal generation unit 71. Control information of the rotation control processing unit 31 is input to the PWM drive signal generation unit 71 together with the above-described triangular wave. This control information includes a duty ratio based on the target rotational speed and the current rotational speed, which is a signal whose voltage level depends on the target rotational speed and the current rotational speed as shown by a straight line in FIG. Hereinafter, it is indicated as a duty signal). The PWM drive signal generation unit 71 compares the duty signal and the triangular wave, and generates a PWM drive signal that becomes Hi level when the former has a higher voltage level than the latter, and becomes Lo level when the other is opposite. The pulse period of this PWM drive signal is determined by a triangular wave, but the pulse width is determined by a duty signal. When the difference between the target rotational speed and the current rotational speed is large, the voltage level of the duty signal increases and the pulse width of the PWM drive signal becomes long. On the other hand, when the difference between the target rotational speed and the current rotational speed is small, the voltage level of the duty signal is lowered and the pulse width of the PWM drive signal is shortened. The switch drive circuit 75 performs on / off control of the lower switches 35, 37, and 39 based on the pulse width and pulse period of the PWM drive signal, and the on-time depends on the pulse width of the PWM drive signal. That is, when the pulse width of the PWM drive signal is increased, the ON time of the lower switches 35, 37, 39 is increased, and when the pulse width of the PWM drive signal is decreased, the ON time of the lower switches 35, 37, 39 is decreased.

The control determination unit 72 determines whether the operation mode of the power generation control unit 73 is the normal mode or the power generation mode. The control determination unit 72 determines the operation mode according to the flowchart shown in FIG. First, in step S10, the control determination unit 72 reads the control information input from the rotation control processing unit 31, and the rotation angle signal and sensor signal input from the sensor signal processing unit 40. Then, the control determination unit 72 proceeds to step S20.

In step S20, the control determination unit 72 determines the rotation direction of the rotor 210 based on the read sensor signal and the relationship shown in FIG. Then, the control determination unit 72 proceeds to step S30.

In step S30, the control determination unit 72 detects the current rotation speed of the motor 200 based on the read rotation angle signal, and determines whether the current rotation speed is higher than a stored threshold value. That is, the control determination unit 72 determines whether or not the rotation speed (or rotation speed) of the rotor 210 is fast enough to perform power generation control. If it is determined that the rotational speed is higher than the threshold value, the control determination unit 72 proceeds to step S40, and if it is determined that the rotational speed is equal to or less than the threshold value, the control determination unit 72 proceeds to step S50.

Note that when the rotor 210 stops after momentarily rotating in the reverse direction due to brake torque, the signal switching occurs instantaneously, so the control determination unit 72 determines that the rotation speed is sufficiently higher than the above-described threshold value. . Therefore, when the rotor 210 rotates in reverse due to the brake torque, the control determination unit 72 proceeds to step S50.

In step S40, the control determination unit 72 determines to set the operation mode to the normal mode, and outputs a mode signal including the information to the power generation control unit 73. Then, the operation ends. The mode signal of the present embodiment is set to Lo level in the normal mode and Hi level in the power generation mode.

When going back in the flow and determining that the rotational speed is higher than the threshold value in step S30 and proceeding to step S50, the control determination unit 72 determines whether or not the rotational direction of the rotor 210 is different from the torque direction. If it is determined that the rotation direction and the torque direction are the same, the control determination unit 72 proceeds to step S40 and sets the voltage level of the mode signal to the Lo level. In contrast, if it is determined that the rotation direction and the torque direction are different, the control determination unit 72 proceeds to step S60.

In step S60, the control determination unit 72 determines that the operation mode is set to the power generation mode, and sets the voltage level of the mode signal to the Hi level. Then, the operation ends.

The power generation control unit 73 determines the on / off state of the switch of the inverter 33 to be controlled. The power generation control unit 73 receives the triangular wave and the mode signal as the reference signal described above. As shown in FIG. 20, the power generation control unit 73 has a comparison signal having a constant voltage level, and compares the comparison signal with a reference signal to generate a switch signal with a duty ratio of 50%. The pulse period of this switch signal is the same as the pulse period of the PWM drive signal, and is the same as the interval at which the lower switches 35, 37 and 39 are intermittently turned on. The power generation control unit 73 counts the falling edge of the switch signal and stores the count number in the memory 74. Then, when the count number is counted up to N (for example, 3), the power generation control unit 73 resets the count number and returns it to zero. The power generation control unit 73 resets the count number and rewrites the flag that determines the voltage level of the switch-off signal stored in the memory 74 from 0 to 1 or from 1 to 0. The power generation control unit 73 enters the normal mode when the voltage level of the mode signal is the Lo level, and sets the output signal (for example, the switch-off signal) to the Lo level regardless of the flag. However, when the voltage level of the mode signal is the Hi level, the power generation control unit 73 enters the power generation mode and changes the voltage level of the switch-off signal according to the flag. That is, the power generation control unit sets the switch-off signal to Hi level when the flag is 1 in the power generation mode, and sets the switch-off signal to Lo level when the flag is 0.

The switch drive circuit 75 generates a control signal to be output to the switches 34 to 39 based on the sensor signal, the switch-off signal, and the PWM drive signal. The switch drive circuit 75 stores the relationship between the sensor signal and the rotation angle shown in FIG. 6, and the relationship between the sensor signal and the control signal shown in FIG. The switch drive circuit 75 calculates the rotation angle based on the relationship shown in FIG. 6 and the sensor signal, and specifies the switch of the inverter 33 to be controlled based on the relationship shown in FIG. 7 and the calculated rotation angle. Then, the switch drive circuit 75 outputs a pulsed control signal to the lower switch that is the control target based on the PWM drive signal. The switch drive circuit 75 outputs a control signal to the upper switch to be controlled based on the relationship shown in FIG. 7 and the switch-off signal. When the switch-off signal is at the Lo level, the switch drive circuit 75 outputs a Hi-level control signal to the upper switch to be controlled and turns it on. As described above, when the power generation control unit 73 is in the normal mode, the switch-off signal is always at the Lo level. Therefore, the switch drive circuit 75 outputs a Hi level control signal to the upper switch to be controlled, as indicated by the symbol Hi in FIG. In contrast, when the power generation control unit 73 is in the power generation mode, the switch-off signal changes between the Hi level and the Lo level. When the switch-off signal is at the Hi level, the switch drive circuit 75 outputs a Lo-level control signal to the upper switch to be controlled to turn it off. Therefore, as indicated by symbol Ph in FIG. 10, the switch drive circuit 75 changes the voltage level of the control signal output to the upper switch to be controlled from the Hi level to the Lo level or the Lo level each time the voltage level of the switch-off signal is switched. Switch to Hi level.

Next, the signal processing of the power generation control unit 73 will be described in detail based on FIG. First, in step S110, the power generation control unit 73 determines whether or not the mode signal is at the Hi level. If it is determined that the mode signal is not at the Hi level, the power generation control unit 73 enters the normal mode and proceeds to step S120. On the other hand, when it is determined that the mode signal is at the Hi level, the power generation control unit 73 enters the power generation mode and proceeds to step S130.

When proceeding to step S120, the power generation control unit 73 resets the count number stored in the memory 74, and proceeds to step S140.

In step S140, the power generation control unit 73 sets the switch-off signal flag stored in the memory 74 to 0 and sets the switch-off signal to Lo level. While the power generation control unit 73 in the normal mode repeats the above steps S110, S120, and S140, the switch drive circuit 75 controls the switches 34 to 39 to open and close based on the relationship shown in FIG.

When the flow goes back a little and it is determined in step S110 that the mode signal is Hi level and the process proceeds to step S130, the power generation control unit 73 acquires the count number stored in the memory 74. Then, the power generation control unit 73 proceeds to step S150.

In step S150, the power generation control unit 73 acquires the switch-off signal flag stored in the memory 74 and confirms the switch-off signal state. Then, the power generation control unit 73 proceeds to step S160.

When the process proceeds to step S160, the power generation control unit 73 determines whether or not the count number acquired in step S130 is N (for example, 3) or more. If it is determined that the count number is smaller than N, the power generation control unit 73 proceeds to step S170. On the other hand, if it is determined that the count number is N or more, the power generation control unit 73 proceeds to step S180.

In step S170, the power generation control unit 73 increases (or increments) the count number by 1 and stores it in the memory 74. Then, the power generation control unit 73 proceeds to step S220.

In step S180, the power generation control unit 73 determines whether the switch-off signal flag acquired in step S150 is 1, and the switch-off signal is at the Hi level. If it is determined that the switch-off signal is not at the Hi level, the power generation control unit 73 proceeds to step S190. On the other hand, if it is determined that the switch-off signal is at the Hi level, the power generation control unit 73 proceeds to step S200.

In step S190, the power generation control unit 73 sets the switch-off signal flag to 1 and stores it in the memory 74. Then, the power generation control unit 73 sets the voltage level of the switch-off signal to the Hi level, and proceeds to step S210.

In step S200, the power generation control unit 73 sets the switch-off signal flag to 0 and stores it in the memory 74. Then, the power generation control unit 73 sets the voltage level of the switch-off signal to the Lo level, and proceeds to step S210.

When proceeding to step S210, the power generation control unit 73 resets the count number stored in the memory 74, and proceeds to step S220.

In step S220, the power generation control unit 73 determines whether the switch-off signal flag is 1, and the switch-off signal is at the Hi level. If it is determined that the switch-off signal is not at the Hi level, the power generation control unit 73 proceeds to step S230. On the other hand, if it is determined that the switch-off signal is at the Hi level, the power generation control unit 73 proceeds to step S240.

In step S230, the power generation control unit 73 sets the switch-off signal to Lo level. Then, the operation ends.

In step S240, the power generation control unit 73 sets the switch-off signal to the Hi level. Then, the operation ends. While the above-described steps S110, S130, and S150 to S240 are repeated by the power generation control unit 73 in the power generation mode, the switch drive circuit 75 sets the switches 34 to 39 in FIG. 9 according to the relationship shown in FIG. Open / close control is performed so as to satisfy the relationship shown.

The normal mode power generation control unit 73 sequentially repeats steps S110, S120, and S140 of FIG. 21 to fix the voltage level of the switch-off signal at the Lo level. On the other hand, the power generation control unit 73 in the power generation mode sequentially repeats steps S110, S130, and S150 to S240 in FIG. 21 to change the voltage level of the switch-off signal.

When the power generation control unit 73 immediately after switching from the normal mode to the power generation mode proceeds to step S130 for the first time, the count number stored in the memory 74 is zero. When the process proceeds to step S150, the flag of the switch-off signal stored in the memory 74 is 0, and the voltage level of the switch-off signal is Lo level. Therefore, when the process proceeds to step S160, since the count number is zero, the power generation control unit 73 proceeds to step S170 and increments the number of switches. When the power generation control unit 73 proceeds to step S220, the switch-off signal is Lo level, so the process proceeds to step S230 and outputs a Lo-level switch-off signal. After repeating this process N times (for example, 3 times) and then proceeding to step S160 again, the power generation control unit 73 proceeds to step S180 because the number of switches is N or more. At this time, since the switch-off signal is at the Lo level, the power generation control unit 73 proceeds to step S190, sets the switch-off signal flag to 1, and sets the switch-off signal to the Hi level. As a result, for example, as shown in FIG. 10, the voltage level of the control signal input to the U-phase upper switch 34 to be controlled is changed from the Hi level to the Lo level.

Thereafter, when the process proceeds to step S210, the power generation control unit 73 resets the number of switches. When the power generation control unit 73 proceeds to step S220, since the switch-off signal is at the Hi level, the power generation control unit 73 proceeds to step S240 and outputs a Hi-level switch-off signal. If the power generation control unit 73 thereafter proceeds to step S130 again, the count number stored in the memory 74 is zero. When the process proceeds to step S150, the flag of the switch-off signal stored in the memory 74 is 1, and the voltage level of the switch-off signal is Hi level. Therefore, when the process proceeds to step S160, since the count number is zero, the power generation control unit 73 proceeds to step S170 and increments the number of switches. When the power generation control unit 73 proceeds to step S220, since the switch-off signal is at the Hi level, the power generation control unit 73 proceeds to step S240 and outputs a Hi-level switch-off signal. After repeating this process N times (three times) and then proceeding to step S160 again, the power generation control unit 73 proceeds to step S180 because the number of switches is N or more. At this time, since the switch-off signal is at the Hi level, the power generation control unit 73 proceeds to step S200, sets the switch-off signal flag to 0, and sets the switch-off signal to the Lo level. As a result, for example, as shown in FIG. 10, the voltage level of the control signal input to the U-phase upper switch 34 to be controlled is changed from the Lo level to the Hi level.

Next, functions and effects of the motor control device 100 according to the present embodiment will be described. As described above, in the power generation mode, the pre-driver 32 is energized by intermittently connecting the stator coil 223 to the power source while the motor 200 rotates by a predetermined rotation angle range. According to this, even when the motor 200 reversely rotates momentarily due to the brake torque and the pre-driver 32 is temporarily switched from the normal mode to the power generation mode, the rotational torque can be generated at the time of restart. As a result, the cam phase can be adjusted to a phase suitable for restarting the internal combustion engine 300.

As described above, the pre-driver 32 intermittently energizes the stator coil 223 while the motor 200 rotates by a predetermined rotation angle range in the power generation mode. According to this, it is possible to suppress an excessive current flow through the upper switches 34, 36, and 38, and it is possible to suppress excessive heat generation of the upper switches 34, 36, and 38.

More specifically, the pre-driver 32 is connected to the positive terminal while intermittently connecting the stator coil 223 and the positive terminal of the power source M times while the motor 200 rotates by a predetermined rotation angle range in the power generation mode. When connected, the negative terminal is connected N times intermittently. Therefore, the upper switches 34, 36, and 38 are excessive compared to the configuration in which the negative terminal is intermittently connected N times while the stator coil and the positive terminal are always connected while the motor rotates by a predetermined rotation angle range. Current flow is suppressed. As a result, excessive heat generation of the upper switches 34, 36, 38 is suppressed.

The preferred embodiments of the present disclosure have been described above. However, the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure.

(First modification)
As shown in FIG. 10, in the present embodiment, an example in which the lower switch as the control target is intermittently controlled to the OFF state N times even when the upper switch as the control target is in the off state is shown. However, unlike this, as indicated by a broken line in FIG. 22, when the upper switch as the control target is in the OFF state, the lower switch as the control target may be controlled to be in the OFF state. In this case, since the switching frequency of the lower switch is reduced, heat generation of the inverter 33 is suppressed. When performing such control, the switch drive circuit 75 controls all of the switches 34 to 39 to be in an OFF state when a Hi level switch-off signal is input.

(Second modification)
In this embodiment, the example which controls the upper stage switch of a control object to an ON state intermittently was shown. However, unlike this, as shown in FIG. 23, the upper switch as the control target may be always on. In this case, the lower switch to be controlled is repeatedly turned on and continuously turned off sequentially. In this case, since the number of switching times of the upper switch is reduced as compared with the first modified example, heat generation of the inverter 33 is suppressed. When such control is performed, the switch drive circuit 75 always controls the upper switch to be controlled to be in an on state depending on the voltage level of the switch-off signal. The switch drive circuit 75 controls the lower switches 35, 37, and 39 to be in an OFF state when a Hi level switch-off signal is input.

(Other variations)
In the present embodiment, an example in which the pre-driver 32 detects the rotation direction of the motor 200 based on the sensor signal is shown. However, a configuration in which the rotation direction of the motor 200 detected by the sensor signal processing unit 40 is input to the pre-driver 32 may be employed.

In the present embodiment, the rotation angle sensor 60 has a Hall element as a sensor element. However, any sensor element can be used as long as it is a magnetoelectric conversion element that converts a magnetic signal into an electric signal. In addition, although three examples are shown as the number of sensor elements, the number of sensor elements need not be three or more.

In the present embodiment, an example in which the driver 20 includes the state determination unit 50 is shown. However, the driver 20 may not have the state determination unit 50.

In the present embodiment, an example is shown in which the rotation angle signal is a pulse signal in which the voltage level changes for a predetermined time each time at least one of the three sensor signals changes. However, the rotation angle signal is not limited to the above example, and may be a signal whose voltage level fluctuates according to the change frequency of the voltage levels of the three sensor signals. In the case of this modification, the sensor signal processing unit 40 stores the relationship of the voltage level corresponding to the change frequency of the voltage level of the three sensor signals, and after detecting the change frequency of the voltage level of the sensor signal, A voltage level signal based on the relationship is output as a rotation angle signal. Each of the electronic control device 10, the rotation control processing unit 31, and the pre-driver 32 stores the relationship of the rotation speed corresponding to the voltage level of the rotation angle signal, and this relationship and the voltage of the input rotation angle signal. The number of revolutions is detected based on the level.

Although not particularly mentioned in the present embodiment, the motor control device 100 having the above function is suitable for a vehicle that performs idling stop. In the case of a vehicle that performs idling stop, it is required to restart in a short time after stopping the engine. At this time, for example, when the operation mode of the pre-driver 32 is forcibly set to the normal mode once after the engine is stopped, the processing takes time. Therefore, there is a possibility that the engine cannot be restarted in a short time. On the other hand, as shown in the present embodiment, the motor control device 100 can generate the rotational torque by the pre-driver 32 without depending on the stop of the motor 200 due to the brake torque. Thus, unlike the above-described comparative configuration, the cam phase can be adjusted to a phase suitable for restarting the internal combustion engine 300 in a short time, whereby the engine can be restarted in a short time.

Here, the flowchart described in this application or the process of the flowchart is configured by a plurality of sections (or referred to as steps), and each section is expressed as S10, for example. Further, each section can be divided into a plurality of subsections, while a plurality of sections can be combined into one section. Further, each section configured in this manner can be referred to as a device, module, or means.

Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims (4)

1. The camshaft phase relative to the crankshaft is controlled by controlling the driving of the motor (200) mechanically connected to the crankshaft (330) and the camshaft (320) via the valve timing converter (310). A motor control device for adjusting
   The motor includes an output shaft coupled to the valve timing conversion unit, a rotor (210) to which the output shaft is fixed, and a stator (220) provided around the rotor, and the rotor Comprises a permanent magnet (212), the stator comprises a stator coil (223-226),
   An inverter (33) for generating a rotating torque in the rotor that promotes or prevents rotation of the output shaft by causing a current to flow through the stator coil to generate a magnetic flux and causing the magnetic flux to act on the permanent magnet;
   A rotation angle detector (40, 60) for outputting a rotation signal depending on the rotation angle of the motor and the rotation direction of the motor;
   Based on the rotation signal, a plurality of switching elements (34 to 39) constituting the inverter are controlled to be opened and closed to control connection between the stator coil and each of the positive terminal and the negative terminal of the power source and flow to the stator coil. A motor control unit (32) for controlling current and controlling generation of the rotational torque;
   An instruction unit (31) for instructing the motor control unit to increase or decrease the rotational torque,
   The motor control unit is in a normal mode when the increase / decrease direction of the rotational torque instructed by the instruction unit is a direction for promoting the rotation of the motor, and the increase / decrease direction of the rotational torque prevents the motor from rotating. In the case of
   The motor controller is
   When M is a natural number of 1 or more and N is a natural number of 2 or more,
   In the normal mode, the stator coil is connected to the positive terminal and the negative terminal of the power source regardless of the rotation angle of the motor,
   The stator coil is connected to the positive terminal M times intermittently while the stator coil is intermittently connected to the positive terminal while the motor rotates in a predetermined rotation angle range in the power generation mode. A motor control device that connects the coil to the negative terminal intermittently N times.
2. The motor control device according to claim 1, wherein the motor control unit disconnects the stator coil and the minus terminal when the stator coil is not connected to the plus terminal in the power generation mode.
3. The camshaft phase relative to the crankshaft is controlled by controlling the driving of the motor (200) mechanically connected to the crankshaft (330) and the camshaft (320) via the valve timing converter (310). A motor control device for adjusting
   The motor includes an output shaft coupled to the valve timing conversion unit, a rotor (210) to which the output shaft is fixed, and a stator (220) provided around the rotor, and the rotor Comprises a permanent magnet (212), the stator comprises a stator coil (223-226),
   An inverter (33) for generating a rotating torque in the rotor that promotes or prevents rotation of the output shaft by causing a current to flow through the stator coil to generate a magnetic flux and causing the magnetic flux to act on the permanent magnet;
   A rotation angle detector (40, 60) for outputting a rotation signal depending on the rotation angle of the motor and the rotation direction of the motor;
   Based on the rotation signal, a plurality of switching elements (34 to 39) constituting the inverter are controlled to be opened and closed to control connection between the stator coil and each of the positive terminal and the negative terminal of the power source and flow to the stator coil A motor control unit (32) for controlling current and controlling generation of the rotational torque;
   An instruction unit (31) for instructing the motor control unit to increase or decrease the rotational torque,
   The motor control unit is in a normal mode when the increase / decrease direction of the rotational torque instructed by the instruction unit is a direction for promoting the rotation of the motor, and the increase / decrease direction of the rotational torque prevents the motor from rotating. In the case of
   The motor controller is
   When N is a natural number of 2 or more,
   In the normal mode, the stator coil is connected to each of the plus terminal and the minus terminal regardless of the rotation angle of the motor,
   While the stator coil is connected to the plus terminal regardless of the rotation angle of the motor in the power generation mode, the stator coil is intermittently connected to the minus terminal while the motor rotates by a predetermined rotation angle range. A motor control device that performs at least one time that the stator coil and the minus terminal are continuously disconnected from each other for an amount of time that the minus terminal is intermittently connected N times after being connected once.
4. The motor control device according to any one of claims 1 to 3, wherein a phase of the camshaft with respect to the crankshaft of the internal combustion engine (300) that performs idling stop is adjusted by controlling driving of the motor.

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