JPH09233884A - Sensorless and commutatorless dc motor drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving equipment which, regardless of the stop position of a rotor, can always start up accurately and rapidly a sensorless and commutatorless DC motor wherein induced voltage signals from armature windings are processed by a rotor position signal generating circuit and then a rotor position signal is obtained and then driving current is supplied to the armature windings of respective phases U, V, W, being reversed every other one cycle, six times, and thereby the rotor is driven. SOLUTION: At the time of start-up, a start-up signal generating circuit 17 generates a start-up signal which reverses a rotor every other one cycle, six times, and then fixes the rotor to a stop phase for a specified period of time and then rotates the rotor in the forward direction. The signal is supplied to an armature winding driving circuit 10. When the rotational speed of the rotor increases enough to induce sufficient voltage in armature windings 6, a switching circuit 13 is switched and normal operation is started by a positional signal from a rotor position signal generating circuit 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensorless commutator DC motor drive device used in a spindle motor or the like incorporated in a disk drive device used for information recording, and more particularly to improvement of its starting method. Is.

[0002]

2. Description of the Related Art Generally, a non-commutator DC motor has been adopted as a spindle motor incorporated in a disk drive used for recording information. The position signal detection method for controlling the number of rotations of the spindle motor has hitherto been mainly supported by sensing with a hall element. However, as motors have become smaller and cheaper,
In recent years, a sensorless method has been used in which a position signal is detected by an induced voltage generated by an interaction between a stator winding of a motor and a rotor without using a Hall element.
However, in this sensorless method, the position signal cannot be detected when the rotational speed of the rotor is zero, that is, no induced voltage is generated at the time of startup, and it is difficult to generate a commutation signal. Therefore, it is necessary to start excitation from a specific phase only at the time of starting, and then commutate the forward sequence one after another to forcefully start.

FIG. 7 is a plan view showing an example of a sensorless commutatorless DC motor used as a spindle motor, FIG. 8 is a plan view of a disk drive hub mounted on this spindle motor, and FIG. 9 is this sensorless commutator. FIG. 10 is a block diagram showing the configuration of a drive device for a DC motor, FIG. 10 is a circuit diagram showing an armature winding drive circuit for this motor, and FIG. 11 is a time chart for explaining the operation of this motor drive device.

In the figure, 1 is a spindle motor, 2 is a rotor composed of 16 pairs of NS magnetic poles, 3 is a rotary shaft, 4 is a drive pin, 5 is a 24 slot stator, and 6 is wound around this stator 5. Armature winding composed of U, V, and W phases, 7 a disk drive hub, 8 chucking holes, 9 positioning holes for fitting the drive pins 4, 10 armature winding drive circuit, 11
Is a rotor position signal generation circuit, 12 is a hexadecimal counter, 13
Is a switching circuit, 14 is a start signal generation circuit, 15 is a hexadecimal counter, and 16 is a timer which outputs a pulse signal to the hexadecimal counter 14 and the switching circuit 13 at a predetermined timing according to an input clock signal.

Vcc is a direct current power source, Gnd is a ground terminal, Tr ₁ ,
Tr ₂ and Tr ₃ are P channel MOS transistors (hereinafter P
MOS), Tr ₄ , Tr ₅ , Tr ₆ are N-channel MO
S transistor (hereinafter referred to as NMOS), Nr ₁ , Nr ₂ ,
Nr ₃ , Nr ₄ , Nr ₅ and Nr ₆ are NOR elements, Ad ₁ , Ad ₂ and A
d ₃ , Ad ₄ , Ad ₅ , and Ad ₆ are AND elements, Iv ₁ , Iv ₂ , and I
v ₃ , Iv ₄ , Iv ₅ , and Iv ₆ are inverter elements, and a, b, and c are any one of a high level value H and a low level value 6
Each bit value of the base number, T _uw , T _vw , T _vu , T _wu , T _wv , T _uv
Is a commutation signal which is an output signal of the AND elements Ad _{1 to} Ad ₆ , and S
c _u , Sc _v , and Sc _w are source signals for driving the current inflow, Sk _u and S
k _v and Sk _w are current outflow driving sink signals.

Next, the operation will be described. First, the operation of the spindle motor 1 during steady rotation will be described. While the rotor 2 of the motor 1 is rotating, the phase voltages shown in FIG. 11 are induced in the U-, V-, and W-phases of the armature winding 6 of the three-phase Y-connection of the stator 5, and the difference between these phase voltages. , That is, the interphase voltage U−
Position signals P _uw , P _wv , W, W-V, V-U are taken in by the rotor position signal generation circuit 11, amplified and sliced.
P _vu is output to the hexadecimal counter 12. Hexadecimal counter 1
2 is counted up at each of the rising and falling edges of the input position signals P _uw , P _wv and P _vu to obtain hexadecimal signals a, b and c, which are sent to the armature winding drive circuit 10 via the switching circuit 13. Is applied.

In the armature winding drive circuit 10, the hexadecimal signal a,
b and c are applied to each AND element Ad _{1 to} Ad ₆ directly or via the inverter elements Iv ₁ , Iv ₂ and Iv ₃ to generate a commutation signal T _uw.
~ T _uv is output to the NOR elements Nr _{1 to} Nr ₆ and the NOR elements Nr _{1 to} Nr ₆ are output.
L-level source signals Sc _u , Sc _v , and Sc _w from r ₁ , Nr ₂ , and Nr ₃ to PMOS Tr ₁ , Tr ₂ , and Tr ₃ are transferred to NOR elements Nr ₄ and Nr.
H-level sync signal S from r ₅ , Nr ₆ to NMOS Nr ₄ , Nr ₅ , Nr ₆ via inverter elements Iv ₄ , Iv ₅ , Iv _6.
applied to k _u , Sk _v , and Sk _w to form PMOS Tr ₁ , Tr ₂ , T
The r ₃ and the NMOSs Nr ₄ , Nr ₅ and Nr ₆ are sequentially commutated, and the current from the DC power supply Vcc flows into each phase of the armature winding 6 and flows out to the ground terminal Gnd.

The following table shows the hexadecimal signal, commutation signal and U in each commutation sequence (1) (2) (3) (4) (5) (6) for each 1/6 cycle in one AC cycle. The relationship between V and W phase currents is shown.

[Table 1]

As shown in this table, the drive current to the armature winding 6 of the motor 1 commutates from the sequence (1) to (6) and is regularly switched in 6 ways.
Rotates by an angle θ = π / 8 shown in FIG. Therefore, 16 cycles, that is, 96 total commutations are required for one rotation of the rotor 2.

Since the motor of this type cannot be self-started, the timer 1 of the start signal generating circuit 14 is started at the time of start.
6, a pulse is output to the hexadecimal counter 12 in response to a clock signal from the outside to start counting, and hexadecimal signals a, b and c are applied to the armature winding drive circuit 10 via the switching circuit 13. It As a result, the armature winding drive circuit 1
0 causes the armature winding 6 to sequence (1) → (2) → (3) →
The commutation is switched in the order of (4) → (5) → (6), and the rotor 2 is forcibly started to rotate in the forward direction. Then, when the rotation speed of the rotor 2 increases and a sufficient induced voltage is obtained in the armature winding 6, the switching circuit 13 is switched and the rotor position signal generating circuit 11 and the hexadecimal counter 12 perform a steady rotation operation. to go into.

[0011]

In the conventional sensorless commutatorless DC motor driving apparatus as described above, the magnetic pole position of the rotor 2 and the excitation start phase winding position of the stator armature winding 6 at the time of start-up. Depending on the relative position between and, it may not be possible to obtain an appropriate normal rotation force, or a force may be applied in the reverse direction, and it takes a long time for the rotation to be corrected in the positive direction and to stabilize. There was a problem.

When such a sensorless commutatorless DC motor is used for a spindle motor of a disk drive, the rotor 2 is always driven in the forward direction (clockwise direction indicated by the arrow). As shown in FIG. 5, when stopped, the drive pin 4 fixed to the rotor 2 is in contact with the edge of the positioning hole 9 of the disk drive hub 7 on the rotation direction side. When the motor 1 is started in this state, a load such as head stiction of the disk drive hub 7 is directly applied to the motor 1 at the time of starting, and a driving force exceeding this is required of the motor 1 so that it is difficult to start and it takes time from the start to the normal rotation. There was also the problem of this.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a sensorless commutatorless DC motor drive device that can be started quickly and reliably.

[0014]

A non-commutator DC motor drive device according to the present invention generates a start signal for rotating a rotor in a reverse direction for a predetermined phase, fixing the rotor in a stop phase for a predetermined time, and then rotating the rotor forward. And supplied to the armature winding drive circuit.

Further, after the rotor is fixed to a predetermined phase, a start signal for causing two commutations to successively and normally rotate in 6 cycles in one cycle is generated and supplied to the armature winding drive circuit. It was done like this.

Further, after fixing the rotor to a predetermined phase, a start signal for normal rotation is generated from the phase in which two commutations have advanced in one cycle of six commutations and is supplied to the armature winding drive circuit. It is a thing.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of this embodiment, FIG. 2 is a time chart for explaining the operation of this embodiment, and FIG. 3 is a plan view of a disk drive hub mounted on a motor in this embodiment. FIG. 4 and FIG. 4 are diagrams showing the torque of the motor in this embodiment. 7 and 10 are also applied to this embodiment.

In the figure, 3 is a rotary shaft, 4 is a drive pin,
6 is an armature winding composed of U, V, and W phases wound around the stator 5, 7 is a disk drive hub, 8 is a chucking hole, and 9
Is a positioning hole into which the drive pin 4 is fitted, 10 is an armature winding drive circuit, 11 is a rotor position signal generation circuit, 12 is a hexadecimal counter, 13 is a switching circuit, and 15 is a hexadecimal counter. 8 and the same as the conventional example shown in FIG. 17
Is a start signal generation circuit, and 18 is a countdown (reverse rotation) and countup (forward rotation) clock pulse CLp to the hexadecimal counter 14 and a switching signal to the switching circuit 13 at a predetermined timing according to the input start signal and the clock signal. This is a forward / reverse clock control circuit.

Next, the operation will be described. In the start-up mode at the time of start-up, the switching circuit 13 is switched to the start-up mode in response to the start signal to the forward / reverse clock control circuit 18 of the start-up signal generation circuit 17, and the countdown clock pulse CLp is output to the hexadecimal counter 15. It As a result, the countdown hexadecimal signals a, b, and c from the hexadecimal counter 15 are applied to the armature winding drive circuit 10 via the switching circuit 13. As a result, the armature winding driving circuit 10 causes the armature winding 6 to perform the sequence (6) → (5).
The commutation is switched in the order of → (4) → (3) → (2) → (1), and the rotor 2 is forcibly rotated in the reverse direction by 6 commutations, that is, one cycle. From this reverse rotation cout region, the phase fixed region of a certain time T ₀ is entered, the clock pulse CLp is not applied, the commutation is stopped in the sequence (1), and only the U phase and the W phase of the armature winding 6 have current. As a result, the N pole of the rotor 2 vibrates and stops at a position where the N pole of the rotor 2 is closest to the U-phase stator pole and the S pole is closest to the W-phase stator pole. In this way, the stop is reliably stopped at the phase position determined by the last commutation sequence in the reverse rotation count period.

After the phase is fixed to one phase until the vibration is subsided in this phase-fixed region, the normal rotation count region is entered, and the forward / reverse clock control circuit 18 counts up the clock pulse CLp for normal rotation in two pulses at short intervals. It is output to the decimal counter 15. Thereby, the count-up hexadecimal signals a, b, and c from the hexadecimal counter 15 are applied to the armature winding drive circuit 10 via the switching circuit 13, and the armature winding drive circuit 1
0 causes armature winding 6 to go from sequence (1) to (2), (3)
The commutation is performed and the rotor 2 rapidly starts rotating in the forward direction. When the rotation speed of the rotor 2 increases and a sufficient induced voltage is obtained in the armature winding 6, the switching circuit 13 is switched by the switching signal from the forward / reverse clock control circuit 18 to generate the rotor position signal. The rotation operation in the steady mode by the circuit 11 and the hexadecimal counter 12 is started.

Timing of switching to this steady mode,
That is, the phase fixing region and the forward rotation counting region time can be set from the inertia of the rotor 2, the torque constant of the motor, and the like. At this time, when the mechanical vibration of the rotor 2 is settled by fixing the one phase, the maximum is 10 when there is no load when the rotor inertia is 35 gcm / sec ² and the torque constant is 240 gcm / A.
It should be 0 ms.

Since the rotor 2 rotates in the reverse direction and stops at the predetermined phase position in this manner, at the time when the normal rotation is started, the drive pin 4 fixed to the rotor 2 is the disk as shown in FIG. Since the drive hub 7 is located at a position not engaged with and separated from the end of the positioning hole 9 on the rotation direction side of the drive hub 7, the load at the start of rotation of the rotor 2 is lightly and quickly activated, and the drive pin after activation is started. Four
Drives the disk drive hub 7 in rotation by overcoming a load such as head stiction by an impact force that strikes an edge of the positioning hole 9 on the rotation direction side.

Further, as shown in FIG. 4, at the position where the rotor 2 is stopped in the commutation sequence (1), the commutation sequence (2)
It is considered that the torque is increased during the decrease, and a stronger start is promoted by applying the increasing torque as in the commutation sequence (3). Therefore, sequence as fast as possible
In order to commutate to (3), two clock pulses CLp are applied to the hexadecimal counter 15 at short intervals.

Embodiment 2 FIG. In the first embodiment, two clock pulses CLp after phase fixing are applied to the hexadecimal counter 15 to make two rotations flow. However, in order to generate a stronger torque, two commutations two from the beginning are commutated. You may make it start from a sequence. FIG. 5 is a time chart for explaining the operation of the second embodiment in this case, and FIG. 6 is a diagram showing the motor torque in the present embodiment.

As is clear from the figure, the commutation sequence
After phase-fixing in (1), 6 in the second commutation sequence (3)
The clock pulse CLp is applied so that the progressive signals a, b, and c are output from the hexadecimal counter 15, and the rotation of the rotor 2 is started in the commutation sequence (3) in which stronger torque is generated. And at the timing when the acceleration of the rotor 2 becomes maximum,
It is switched to the next commutation sequence (4) and further accelerated. By switching the commutation sequence in this manner, the normal mode is switched to the normal mode in the state of the rotor 2 which is faster in the normal rotation count region.

[0026]

As described above, the sensorless commutatorless DC motor drive device according to the present invention provides a start signal for rotating the rotor in the reverse direction for a predetermined phase, fixing it in the stationary phase for a predetermined time, and then rotating it forward. Since it is generated and supplied to the armature winding drive circuit, the rotor is surely started to rotate in the forward direction, and when it is used as a spindle motor to drive the disk drive hub, it is fixed to the rotor. The drive pin can utilize the impact force that hits the edge of the positioning hole of the disk drive hub, and there is an effect that the disk drive hub can be rotationally driven by overcoming the load such as head stiction.

Further, after the rotor is fixed to a predetermined phase, a start signal for making two normal commutations in one cycle and six normal commutations is generated and supplied to the armature winding drive circuit. Therefore, there is an effect that a strong torque can be quickly applied to the rotor at the time of starting the normal rotation of the rotor, and the startup can be performed surely and quickly.

Further, after the rotor is fixed to a predetermined phase, a starting signal for normal rotation is generated from the phase which has advanced two commutations of six commutations in one cycle, and is supplied to the armature winding drive circuit. Therefore, the maximum torque can be immediately applied at the start of the normal rotation of the rotor, and the start-up can be performed reliably and quickly.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a time chart for explaining the operation of the first embodiment.

FIG. 3 is a plan view of the disk drive hub mounted on the motor according to the first embodiment.

FIG. 4 is a diagram showing a torque of the motor in the first embodiment.

FIG. 5 is a time chart for explaining the operation of the second embodiment.

FIG. 6 is a diagram showing torque of a motor according to the second embodiment.

FIG. 7 is a plan view showing an example of a sensorless commutatorless DC motor.

FIG. 8 is a plan view of a disk drive hub of a conventional disk drive device.

FIG. 9 is a block diagram showing a configuration of a conventional sensorless commutatorless DC motor driving device.

FIG. 10 is a circuit diagram showing an armature winding drive circuit of a sensorless commutatorless DC motor.

FIG. 11 is a time chart for explaining a steady operation of the sensorless commutatorless DC motor driving device.

[Explanation of symbols]

1 spindle motor, 2 rotors, 5 stators, 6
Armature winding, 10 Armature winding drive circuit, 11 Rotor position signal generation circuit, 17 Start signal generation circuit.

Claims (3)

[Claims] 1. A rotor having magnetic poles, a stator having a plurality of phases of armature windings, and a rotor position signal generation circuit for processing an induced voltage signal from the armature windings to generate a rotor position signal. , An armature winding drive circuit for switching and supplying a drive current to each of the phase armature windings in accordance with a rotor position signal from this circuit, and the rotor position in the armature winding drive circuit when the motor is started. In the sensorless non-commutator DC motor drive device having a start signal generation circuit that generates a start signal applied instead of the signal, the start signal generation circuit causes the rotor to rotate in the reverse direction for a predetermined phase and then for a predetermined time. A sensorless commutatorless DC motor drive device configured to supply a start signal to the armature winding drive circuit so that the armature winding drive circuit is fixed to a stop phase and then rotated normally. 2. A rotor having magnetic poles, a stator having three-phase armature windings, and a rotor position signal generating circuit for processing an induced voltage signal from the armature windings to generate a rotor position signal. , An armature winding drive circuit that causes a drive current to flow through the armature windings of each phase six revolutions in one cycle according to a rotor position signal from this circuit, and to the armature winding drive circuit when the motor is started. In a sensorless non-commutator DC motor drive device including a start signal generation circuit that generates a start signal applied instead of the rotor position signal, the start signal generation circuit is a rear speed that fixes the rotor in a predetermined phase. A sensorless commutatorless DC motor drive device characterized in that a starting signal is supplied to the armature winding drive circuit so that the armature winding drive circuit is normally and normally commutated twice. 3. A rotor having magnetic poles, a stator having three-phase armature windings, and a rotor position signal generating circuit for processing an induced voltage signal from the armature windings to generate a rotor position signal. , An armature winding drive circuit that causes a drive current to flow through the armature windings of each phase six revolutions in one cycle according to a rotor position signal from this circuit, and to the armature winding drive circuit when the motor is started. In a sensorless non-commutator DC motor drive device including a start signal generation circuit that generates a start signal that is applied instead of the rotor position signal, the start signal generation circuit fixes the rotor to a predetermined phase and then A sensorless commutatorless DC motor drive device configured to supply a start signal to the armature winding drive circuit so as to perform normal rotation from a phase in which commutation has advanced.