JP3486089B2 - Drive control device for brushless motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for a three-phase brushless motor, and more particularly to a drive control device based on the detection output of a single position detecting element for detecting the relative position of a rotor and a stator. The present invention relates to a drive control device for a brushless motor capable of realizing three-phase 120-degree switching energization.

[0002]

2. Description of the Related Art A three-phase 120-degree switching energization method is known as a drive control method for a three-phase brushless motor. In this scheme, three magnetic sensors, typically three
The Hall element is used to detect the relative rotational position between the stator having the three-phase drive coil and the rotor having the plurality of magnetic poles, and the switching of the drive current to the drive coil of each phase is performed based on the detection result. We are in control. Generally, in order to switch the energization of the drive coil, a number of Hall elements corresponding to the number of phases of the drive coil, that is, three Hall elements are required.

[0003]

If the number of Hall elements can be reduced, there is an advantage that the motor cost can be reduced accordingly.

That is, if the number of Hall elements is reduced, the cost can be reduced accordingly, and the number of wirings between the drive IC in which the drive control circuit of the brushless motor is incorporated and the Hall element is reduced. , Wiring cost is reduced. Further, when the number of Hall elements is reduced, the number of Hall element input pins of the driving IC can be reduced, so that the IC package cost is also reduced.

In addition to this, if the number of Hall elements is reduced, the Hall bias current can be reduced, and power consumption can be reduced accordingly.

In view of the above points, an object of the present invention is to
An object of the present invention is to propose a drive control device capable of driving a three-phase brushless motor by a three-phase 120-degree energization method by using only a single position detecting element such as a Hall element.

[0007]

In order to solve the above-mentioned problems, the present invention provides a stator having a three-phase drive coil, and a rotor having a drive magnetizing portion having a plurality of magnetic poles formed therein. Position detecting means for generating three-phase first to third timing signals corresponding to the relative positional relationship between the stator and the rotor, and three-phase 120 degrees based on the first to third timing signals. The following configuration is adopted in a drive control device for a brushless motor having a signal synthesizing circuit for synthesizing switching energization signals and a drive circuit for energizing and controlling the three-phase drive coils based on the three-phase 120-degree switching energization signals. By doing so, the brushless motor can be driven by the three-phase 120-degree energization method using only a single position detecting element that detects the relative positional relationship between the stator and the rotor. It has to so that.

That is, in the drive control device for the brushless motor of the present invention, the position detecting means includes a single position detecting element and a first timing signal generating first timing signal.
Timing signal generating circuit, a rectangular wave signal generating circuit for generating a rectangular wave signal serving as a reference for generating the second and third timing signals, and for generating the second and third timing signals Second timing signal generating circuit.

The position detecting element is for generating a substantially sinusoidal position detecting signal in accordance with a change in relative position between the stator and the rotor.

The first timing signal generation circuit is for generating the first timing signal whose logic level is inverted at a zero cross point of the position detection signal.

The rectangular wave signal generation circuit is for generating the rectangular wave signal whose logical level is inverted at two points which divide the zero-cross points of the position detection signal into approximately three equal parts.

[0012] The second timing signal generation circuit outputs 12 times each for the first timing signal based on the first timing signal and the rectangular wave signal.
The second and third timing signals having a phase difference of 0 degree and 240 degrees are generated.

[0013] The position detecting element is a magnetic sensor of the Hall element or the like for generating the positive and negative pair of the position detection signal of substantially sinusoidal said detecting a change in the magnetic field of the driving magnetized portion of said rotor. Further, the first timing signal generation circuit compares the pair of positive and negative position detection signals with each other,
This is a configuration including a comparator that outputs the first timing signal whose logic level is inverted in a cycle of approximately 180 degrees .

The rectangular wave signal generation circuit includes a full-wave rectifier, a hysteresis comparator, a voltage-current converter,
And a capacitor . The full-wave rectifier is supposed to generate a full-wave rectified signal by full-wave rectifying a pair of positive and negative position detection signals, and the voltage-current converter is a logic circuit for the rectangular wave signal output from the hysteresis comparator. The charging / discharging operation of the capacitor is switched based on the level inversion . With this configuration, the comparison signal is generated by the charge / discharge operation of the capacitor, the hysteresis comparator compares the full-wave rectified signal with the comparison signal, and the rectangular wave signal is output.

Here, in order to form a comparison signal that intersects the position detection signal at two points obtained by equally dividing the zero-cross points of the sinusoidal position detection signal into three parts, the rising edge and the falling edge of the comparison signal are formed. With the same hysteresis, the ratio of the voltage rising speed to the voltage falling speed of the comparison signal defined by the charge / discharge speed of the capacitor is 2:
It should be 1.

Alternatively, the hysteresis of rising and falling of the comparison signal is set to 2: 1,
The voltage rising speed and the voltage falling speed of the comparison signal defined by the charge / discharge speed of the capacitor may be the same.

Next, the second timing signal generation circuit for generating the second and third timing signals,
A configuration including the first and second D-type flip-flops can be used. In this case, the rectangular wave signal generation circuit is provided with an inverter that generates an inverted signal of the rectangular wave signal. The first timing signal is input to the data input terminals of the first and second D-type flip-flops, and the first timing signal is input.
The rectangular wave signal may be input to the clock input terminal of the D-type flip-flop, and the inverted signal of the rectangular wave signal may be input to the clock input terminal of the second D-type flip-flop. With this configuration, the second timing signal can be obtained from the normal output terminal of the first D-type flip-flop, and the third timing signal can be obtained from the inverting output terminal of the second D-type flip-flop. You can get a signal.

Here, in order to always realize proper normal rotation start by the three-phase 120-degree switching energization method at the time of starting the motor, the first logical state is undefined at the time of starting the motor. It is necessary to set the logic state of the second timing signal generation circuit including the second flip-flop and the like to an appropriate state. To this end, the second timing signal generation circuit is set to
A reset signal generator is provided, and a set / reset pulse signal is generated from the set / reset signal generator in synchronization with rising and falling of the first timing signal. The set / reset signal may be set and reset for the first and second D-type flip-flops.

On the other hand, the distance between the zero-cross points of the detection signal is 3
In order to be able to reliably obtain the rectangular wave signal whose logical level is inverted at two equally divided points without being influenced by noise or the like, the substantially sine of the detection signal is performed as follows. The wavy signal waveform may be modified to have a steeper signal waveform.

First, a frequency generating mechanism generally attached to a brushless motor may be used. Frequency generating mechanism, which is formed on the rotor, and the signal magnetized portion provided with a 3-fold of the magnetic poles of the magnetic poles of the driving magnetized portion, wearing for the signal
It is composed of a frequency detector (FG pattern) for detecting the change of the magnetic field due to the magnetic portion . In this case, the rectangular wave signal generation circuit may generate the rectangular wave signal based on a steep and large-amplitude combined signal obtained by combining the position detection signal with the output signal of the frequency detector. do it.

Instead of using the frequency generating mechanism as described above, the rotor is provided with a magnetized portion magnetized so as to generate harmonic distortion in which the substantially sine waveform of the position detection signal becomes steep. In other words, the signal waveform of the detection signal can be steeper and have a larger amplitude than that of the substantially sine wave shape. For example, the magnetizing part may be a magnetizing pattern having a magnetic pole three times as large as that of the drive magnetizing part so that a negative third harmonic distortion is generated in the substantially sine waveform of the position detection signal. Good.

On the other hand, the present invention is a drive control device for a brushless motor which performs a 120-degree switching energization method by a signal from a single Hall element, and is a position detection signal of a substantially sine wave from a single Hall element. First to generate a first timing signal whose logic level is inverted at the zero-cross point
Timing signal generating circuit, a rectangular wave signal generating circuit for generating a rectangular wave signal whose logical level is inverted in the vicinity of positive and negative 60 degrees from a zero cross point of the position detection signal, the first timing signal generating circuit and the rectangular wave. And a drive signal generating circuit for generating a drive signal for driving the brushless motor according to the output signal of the signal generating circuit.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION A brushless motor for driving an FDD spindle to which the present invention is applied will be described below with reference to the drawings.

(Overall Configuration) FIG. 1 shows the overall configuration of a brushless motor for driving an FDD spindle of this example. The brushless motor 1 of this example is driven by a three-phase 120-degree switching energization method. The brushless motor 1 includes a stator assembly 3 fixed to the circuit board 2 side and a rotor assembly 4 rotatably supported by the stator assembly 3.

The stator assembly 3 has a cylindrical bearing 31 fixed to the circuit board 2, a stator core 32 attached to the outer periphery of the bearing 31, and a stator core 32.
3-phase drive coil L wound around a plurality of salient poles formed in
u, Lv, Lw (only the drive coil Lu is shown in the drawing). On the other hand, the rotor assembly 4 has a rotor shaft 41 rotatably supported on the bearing through a bearing surface formed on the inner peripheral surface of the bearing 31, and a cup-shaped rotor shaft 41 fixed to the rotor shaft 41. The rotor case 42 and a ring-shaped rotor magnet 43 fixed to the inner peripheral surface of the peripheral wall of the rotor case 42 are provided. The circular upper wall of the rotor case 42 has an FDD
The mounting surface 42a is provided with a drive pin 44 that can be engaged with the FDD side.

On the other hand, a single Hall element Hu is fixedly arranged as a magnetic pole sensor on the substrate portion facing the substrate-side annular end surface of the rotor magnet 43. A drive IC 5 incorporating a motor drive control circuit is mounted on the surface of the substrate.

In FIG. 2, the stator core 32, the rotor magnet 43, and the Hall element Hu are shown expanded in a plane.

(Drive Control Device) FIG. 3 is a circuit block diagram of a main part of a drive control device for driving the brushless motor 1 having the above-mentioned configuration by a three-phase 120-degree switching energization method. FIG. 4 is a timing chart showing the operation of each part of the drive control device.

Describing with reference to these figures, the drive control device 10 of the present example, the three-phase first to third timing signals (f, g, h) in accordance with the rotation of the rotor magnet 43.
And a signal for combining three-phase 120-degree switching energization signals (i, j, k and 1, m, n) based on the first to third timing signals (f to h). The three-phase drive coils Lu and L based on the combination circuit 30 and the three-phase 120-degree switching energization signals (i to n)
and a drive circuit 40 for controlling energization of v and Lw.

The position detecting means 20 is a single Hall element H.
u (position detection element), a comparator C1 as a first timing signal generation circuit that generates a first timing signal (f), and second and third timing signals (g, h) A rectangular wave signal generation circuit 21 that generates a rectangular wave signal (d, e) that serves as a reference of, and a second timing signal generation circuit 22 that generates the second and third timing signals (g, h). ing. These position detecting means 20
Each circuit will be described.

First, as is well known, the Hall element Hu has a pair of positive and negative detection signals (u +, u) having a substantially sinusoidal shape as a detection signal (a) based on the change of the magnetic pole caused by the rotation of the rotor magnet 43. -) Is output.

Further, the comparator C1 generates the first timing signal (f) based on the generation timing of the zero cross points of the detection signals (u +, u-) of the Hall element Hu. That is, a pair of positive and negative position detection signals (u +, u
-) Are compared with each other, and a first timing signal (f) whose logic level is inverted is output in a cycle of about 180 degrees.

The rectangular wave signal generation circuit 21 generates a rectangular wave signal (d, e) whose logical level is inverted at two points which divide the zero detection points of the position detection signal (u +, u-) into approximately three equal parts. Is. The rectangular wave signal generation circuit 21 of this example includes a linear amplifier A1, a full-wave rectifier Z, a hysteresis comparator H1, a voltage / current converter V / I, and a capacitor C.
x and.

Detection signal (u +, u-) of the Hall element Hu
Is input to the full-wave rectifier Z via the linear amplifier A1 and is output as a full-wave rectified signal (b) from here.
This full-wave rectified signal (b) is supplied to one input terminal of the hysteresis comparator H1.

The hysteresis comparator H1 compares the input full-wave rectified signal (b) with the comparison signal (c) generated in the capacitor Cx, and outputs the comparison result as a rectangular wave signal (d). That is, full-wave rectified signal (b)
In the case of the comparison signal (c), a high logic signal is output, and in the opposite case, a low logic signal is output.

Here, the rectangular wave signal (d) passes through the voltage / current converter V / I and the charging current I of the capacitor Cx.
c, converted into discharge current Id. That is, the charging / discharging operation of the capacitor Cx is switched based on the inversion of the logic level of the rectangular wave signal (d) output from the hysteresis comparator H1, and the discharge current Id flows when the rectangular wave signal (d) is at the high logic level. Conversely, when the logic level is low, the charging current Ic flows.

In this example, by setting the values of the charging current Ic and the discharging current Id to have a relationship of Ic = 2 · Id, the voltage increase rate (charging speed) of the comparison signal (c) is changed to the voltage drop rate. It is twice the (discharge rate). As a result, the crossing point of the full-wave rectified signal (b) and the comparison signal (c) is about 60 degrees in electrical angle from the zero-cross point a (n) of the detection signals (u +, u−) output from the Hall element. Located in.

Further, the comparison signal (c) is subjected to hysteresis by the hysteresis comparator H1, and even when the full-wave rectification signal (b) based on the Hall element output has a flat waveform, such as when the motor is started, Since the comparison signal (c) increases or decreases, the rectangular wave signal (d) can be generated. In this example, the rising and falling hysteresis of the comparison signal (c) is the same.

In this way, the rectangular wave signal generation circuit 21
Outputs a rectangular wave signal (d). In addition to this, the rectangular wave signal generation circuit 21 includes an inverter IN, from which the inverted signal (e) of the rectangular wave signal (d) is output.
Is output.

Next, the second timing signal generation circuit 22
Is based on the first timing signal (f) output from the comparator C1 and the rectangular wave signal (d) and its inverted signal (e), with respect to the first timing signal (f), Second phase 120 and 240 degrees out of phase, respectively
And a third timing signal (g, h).

In the present example, the second timing signal generation circuit 22 includes the first and second D-type flip-flops F.
1 and F2. The first timing signal (f) is input to the data input terminal D of each of the first and second D-type flip-flops F1 and F2.
The rectangular wave signal (d) is input to the clock input terminal CL of the first D-type flip-flop F1 and the inverted signal (e) of the rectangular wave signal is input to the clock input terminal CL of the second D-type flip-flop F2. ) Is entered.

As a result, the first D-type flip-flop F
The 1st non-inverted output terminal Q outputs the second timing signal (g) whose phase is delayed by 120 degrees with respect to the first timing signal (f). Further, the phase is further 12 from the inverting output terminal (Q) of the second D-type flip-flop.
The third timing signal (h) delayed by 0 degree is output.

The first to third timing signals (f to h) thus obtained are supplied to the signal synthesizing circuit 30. The signal synthesis circuit 30 synthesizes the switching energization signals (i to n) based on these signals and outputs the synthesized signals. That is, by the signal f and the inverted signal of the signal h, the signal i
Are combined, and the signal j is obtained by the signal h and the inverted signal of the signal g.
Are synthesized, and the signal k is obtained by the signal g and the inverted signal of the signal f.
Are combined, and the signal l is generated by the signal h and the inverted signal of the signal f.
Are synthesized, and the signal m is obtained by the inversion signal of the signal g and the signal h.
Are synthesized, and the signal n is synthesized by the inverted signal of the signal f and the signal g.

The switching energizing signals (i to n) synthesized by the signal synthesizing circuit 30 are output as ON / OFF control signals for the output power transistors T1 to T6 constituting the drive circuit 40. As a result, the source / sink reciprocating currents Iu, Iv, and Iw flow through the three-phase drive coils Lu, Lv, and Lw of the brushless motor 1. As a result, a continuous torque is generated and the rotor assembly 4 rotates. 4 (o), (p), (q) show induced electromotive voltages Eu, Ev, Ew generated in the three-phase drive coil and the current I.
A timing positional relationship with u, Iv, and Iw is shown.

As described above, according to the brushless motor drive controller 10 of the present embodiment, the first to third phases are shifted by 120 degrees from the detection signal (u +, u−) of the Hall element Hu. The timing signal can be obtained. Therefore, it is possible to perform 120-degree switching energization by using only one Hall element. As a result, the cost and the like can be reduced as compared with the conventional brushless motor that requires the arrangement of a plurality of Hall elements.

(First Modification) When the brushless motor 1 is started, the rotor magnet 43 is in a stationary state. Therefore, the waveform of the detection signal (u +, u-) of the Hall element Hu does not change, While it remains flat, the logic states of the two flip-flops F1 and F2 forming the second timing signal generation circuit 22 which is a logic circuit are indefinite. Therefore, unless the output of the logic circuit is set to an appropriate logic state, a negative torque is generated in the motor due to an incorrect energization logic, and it is not possible to shift to the proper forward rotation start mode.

FIG. 5 shows another example of the second timing signal generation circuit suitable for surely shifting to the normal rotation start mode when the motor is started. The second timing signal generation circuit 22A shown in FIG. 5 includes a set / reset signal generator SR in addition to the configuration of the second timing signal generation circuit 22 described above. The set / reset signal generator SR synchronizes with the rising and falling of the first timing signal (f), and the set / reset pulse signal (s,
r) to generate the set / reset signal (s, r).
Thus, the first and second D-type flip-flops F1,
This is for setting and resetting F2.

FIG. 6 shows the second timing signal generation circuit 2
Brushless motor drive controller 10 having 2A
3 is a timing chart of the operation when the motor is started. Explaining with reference to this figure, the detection signals (u +, u−) of the Hall element Hu may be flat when the motor is started. Even in this case, as described above,
The comparison signal (c) automatically repeats increasing and decreasing due to the hysteresis of the hysteresis comparator H1. Therefore, the rectangular wave signal (d) becomes a rectangular wave signal having a constant cycle even if the rotor does not rotate.

On the other hand, the first timing signal (f) is also input to the set / reset signal generator SR. When this signal is input, as described above, the set / reset signal generator SR causes the set / reset pulse signal (s,
r) is output. The set pulse signal (s) is input to the set terminals S of the flip-flops F1 and F2, forcibly switching the second timing signal (g) output from the output terminal Q of the flip-flop F1 to a high logic level,
The third timing signal (h) output from the output terminal Q of the flip-flop F2 is forcibly switched to the low logic level. Similarly, the reset pulse signal (r) is input to the reset terminals R of the flip-flops F1 and F2,
The second timing signal (g) output from the output terminal of the flip-flop F1 is forcibly switched to the low logic level, and the third timing signal (h) output from the output terminal of the flip-flop F2 is forced. Switch to high logic level. As a result, erroneous energization logic that occurs when the motor is started is corrected.

FIG. 6 (T) shows a total torque waveform generated in the motor 1. As you can see from this waveform,
The motor torque is zero in the initial period t0 at the time of starting the motor, but when the energization logic is switched by the change of the rectangular wave signal (d), a positive torque is generated and the forward rotation start of the motor is started (period t1. ). In the latter half of the period t2 thereafter, negative torque is generated, but as described above, the energization logic is forcibly corrected by the set signal (s), and in the subsequent period, the positive torque continues due to the rotation of the rotor. Will occur. Even if the motor starts reverse rotation due to the generated negative torque, it is forcibly energized by the set / reset pulse signal (s, r) generated every half cycle of the output signal (u +, u-) of the Hall element. The logic is modified so that the motor can be immediately returned to normal mode.

As described above, according to the drive control device having the circuit capable of forcibly correcting the energization logic, only one Hall element, which is two fewer than the conventional one, is used, and the three-phase one-phase circuit is used.
20-degree switching energization can be realized, and the same starting performance and driving performance as those of the conventional brushless motor can be secured.

(Second Modification) On the other hand, in order to obtain a comparison signal (c) that surely intersects at two points (around positive and negative 60 degrees) that equally divides the zero-cross points of the detection signals of the Hall element into three parts,
The substantially sinusoidal signal waveform of the detection signal may be modified to be steeper as follows.

FIG. 7 shows a first method for this purpose. In the method shown in this figure, the detection signal (FG signal) of the frequency detector used for speed control of the brushless motor 1 is used.
(X) is added to the detection signal of the Hall element.

Here, FIG. 7A is a development view showing the positional relationship among the rotor magnet 43, the Hall element Hu, the core 32 and the power generation pattern FG on a plane, and FIG. Represents the detection signal (x) of the power generation pattern FG as the frequency detector and the detection signal (u +,
7 is a block diagram showing an example of a circuit for adding to (u−);
(C) is the timing chart.

Explaining with reference to these figures, in the rotor magnet 43, in addition to the drive magnetizing portion 43a, a signal magnetizing portion (F) having three times as many magnetic poles as that of the magnetizing portion is provided.
G magnetic pole) 43b is formed. The power generation pattern FG formed on the stator side receives the magnetic field from the signal magnetizing portion 43b.

With the rotation of the rotor, the detection signals (u +, u−) of the Hall element and the FG signal (x) are generated. In the rectangular wave signal generation circuit 21A, the FG signal (x) is added to the detection signal of the Hall element after passing through the linear amplifier A1, and the FG signal (x) is passed through the full-wave rectifier Z to obtain (b ') in FIG. 7C. The full-wave rectified signal shown is obtained. The waveform of the full-wave rectified signal (b ′) in the vicinity of the positive and negative 60 degrees from the zero-cross point of the detection signal of the Hall element is more electrical than the waveform of the full-wave rectified signal (b) (see FIG. 4) in the above-described embodiment. The signal change gradient with respect to the angle (Θe) is steep. Therefore, the full-wave rectified signal (b ') is generated when the comparison signal (c') is near the positive and negative 60 degrees from the zero-cross point.
Make sure you cross against.

The rectangular wave signal generation circuit 21 shown in FIG.
A has the following characteristics in addition to the above characteristics. That is, the capacitor C for generating the comparison signal (c ')
The values of the charging current Ic and the discharging current Id of x are made equal, and the width of the rising hysteresis of the comparison signal (c ′) is doubled with respect to the falling hysteresis. Even in this case, the rectangular wave signal (d) can be obtained as in the above-described embodiment.

(Third Modification) On the other hand, FIG. 8 shows a second method for making a substantially sinusoidal signal waveform of a detection signal steeper and having a large amplitude. In the method shown in this figure, as shown in FIG.
3, a Hall element magnetizing portion 43c is formed in addition to the drive magnetizing portion 43a. The magnetized portion 43c has three times as many magnetic poles as the drive magnetized portion 43a. The configuration of the drive control device is similar to that shown in FIG.

In this case, the Hall element Hu receives a mixed magnetic field from the magnetic poles of the drive magnetized portion 43a of the rotor magnet 43 and the magnetic poles of the Hall element magnetized portion 43c, and as shown in FIG. A detection signal (u +, u−) having a waveform as shown in (a ′) of B) is generated. Since the signal change gradient is steep in the waveform in the vicinity of positive and negative 60 degrees from the zero cross point of this signal, a rectangular wave signal (d) is obtained by comparing this signal with the comparison signal (c). You can

(Other Embodiments) In each of the above examples, the Hall element is used as the sensor for detecting the rotor position, but other magnetic sensors, such as MR element, may be used. Further, a sensor of another detection form such as an optical sensor can be used.

[0061]

As described above, according to the drive control device for a brushless motor of the present invention, 120-degree switching energization of a three-phase brushless motor can be realized with only a detection signal of a single detection element. Therefore, as compared with the conventional brushless motor, the number of detection elements can be reduced,
Cost can be reduced.

Further, according to the present invention, in order to generate the second and third timing signals from the detection signal from the single detection element, a hysteresis comparator is used, and hysteresis is applied to the rising and falling edges. The comparison signal is used. Therefore, even if the detection signal of the detection element remains flat when the motor is started,
Second and third timing signals that are 120 degrees out of phase can be generated. As described above, in the present invention, since the starting circuit and the driving circuit have a common circuit configuration, it is not necessary to switch the circuit at the time of mode transition from driving to starting, and the motor can be started smoothly.

Furthermore, according to the present invention, based on the detection signal of the single detection element, the zero crossing point of the detection signal is used for the security.
A reset signal is generated. Therefore, the set / reset signal can be used to instantaneously correct an erroneous energization logic, thereby avoiding the occurrence of reverse rotation or step out.

[Brief description of drawings]

1A and 1B are a schematic plan view and a schematic half sectional view showing a mechanical structure of an FDD spindle motor to which the present invention is applied.

FIG. 2 is a development view showing a positional relationship between magnetic poles of a rotor magnet, a core, and Hall elements in the motor of FIG.

FIG. 3 is a schematic block diagram showing a main part of a control system of the drive control device for the motor shown in FIG.

FIG. 4 is a timing chart showing an operation of the drive control device of FIG.

5 is a schematic block diagram showing another example of the second timing signal generation circuit of the drive control device in FIG.

FIG. 6 is a flowchart showing the operation of the drive control device equipped with the second timing signal generation circuit of FIG. 5 when the motor is started.

FIG. 7 is a view showing a modified example of the present invention, (A) is a development view showing the positional relationship among the magnetic poles of the rotor magnet, the core, the power generation pattern, and the Hall elements, and (B) is a drive control device. 2 is a block diagram showing a circuit configuration of a changed portion of FIG. 5, and FIG. 6C is a timing chart showing its operation.

8A and 8B are diagrams showing another modification of the present invention, FIG. 8A is a development view showing a positional relationship among a rotor magnet, a core, and a Hall element, and FIG. 8B is a timing chart showing an operation.

[Explanation of symbols]

1 brushless motor 2 circuit board 3 Stator assembly 32 cores 4 rotor assembly 43 rotor magnet 43a Magnetizing part for driving 43b Signal magnetizing section 43c Magnetizing part for Hall element Lu, Lv, Lw drive coil 10 Drive control device 20 Position detection means 21, 21A rectangular wave signal generation circuit 22, 22A Second timing signal generation circuit 30 signal synthesizer 40 drive circuit Hu Hall element C1 comparator (first timing signal generation circuit) Z full wave rectifier H1 hysteresis comparator V / I voltage-current converter Cx capacitor F1, F2 D-type flip-flop SR set / reset signal generator u +, u- Hall element detection signal b Full wave rectified signal c Comparison signal d Square wave signal e Inversion signal f, g, h first to third timing signals i to n switching energization signal

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02P 6/14

Claims (9)

(57) [Claims] 1. A stator provided with a three-phase drive coil,
A rotor provided with a drive magnetizing portion having a plurality of magnetic poles formed therein; and a position detecting means for generating three-phase first to third timing signals according to a relative positional relationship between the stator and the rotor, A signal synthesizing circuit for synthesizing three-phase 120-degree switching energization signals based on the first to third timing signals, and a drive for energizing and controlling the three-phase drive coils based on the three-phase 120-degree switching energization signals A drive control device for a brushless motor having a circuit, wherein the position detecting means includes a single position detecting element, and the first position detecting element.
A first timing signal generating circuit for generating the timing signal, a rectangular wave signal generating circuit for generating a rectangular wave signal serving as a reference for generating the second and third timing signals, and the second and third timing signal generating circuits. A second timing signal generating circuit for generating a timing signal of No. 3, and the position detecting element is provided in the drive magnetizing part of the rotor.
Detects changes in the magnetic field and outputs the detection signal in a substantially sinusoidal shape.
A Hall element for force, said first timing signal generating circuit is for generating said first timing signal logic level is inverted at the zero-crossing point of the position detection signal, positive and negative pair of position
The position detection signals are compared with each other, and the logical level is approximately 180 degrees.
Ratio for outputting the first timing signal with inverted bell
Includes較器, the rectangular-wave signal generating circuit is for generating the rectangular wave signal logic level is inverted at approximately three equal to 2 points between zero-crossing points of the position detection signal, full wave A rectifier,
Hysteresis comparator, voltage-current converter,
And a voltage comparator , wherein the voltage-current converter includes the hysteresis comparator.
Based on the inversion of the logic level of the signal output from
This is to switch the charging / discharging operation of the capacitor , and the comparison signal is generated by the charging / discharging operation of the capacitor.
The hysteresis comparator is used to adjust the full wave.
Current signal is compared with the comparison signal to obtain the rectangular wave signal.
And the second timing signal generation circuit outputs 120 degrees and 24 degrees with respect to the first timing signal based on the first timing signal and the rectangular wave signal, respectively.
A drive control device for a brushless motor, characterized in that it generates the second and third timing signals that are out of phase by 0 degrees. 2. The rising edge of the comparison signal according to claim 1.
The hysteresis of rising and falling is the same,
The comparison signal specified by the charge / discharge speed of the capacitor.
The ratio of the voltage rising speed to the voltage falling speed is 2: 1
A drive control device for a brushless motor, characterized in that 3. The rising edge of the comparison signal according to claim 1.
The hysteresis of rising and falling is 2: 1
The comparison specified by the charge and discharge speed of the capacitor
The signal voltage rising speed and voltage falling speed are the same
A drive control device for a brushless motor. 4. The rectangular wave signal generation circuit according to claim 1.
Is an inverter that generates an inverted signal of the rectangular wave signal.
And the second timing signal generation circuit includes first and second timing signal generation circuits.
Of includes a D-type flip-flop, the first and second D-type flip-flop
The first timing signal is input to the data input terminal
The clock input of the first D-type flip-flop
The rectangular wave signal is input to the terminal, and the second D-type signal is input.
The rectangular wave signal is applied to the clock input terminal of the lip flop.
The inverted signal of is input to the normal output terminal of the first D-type flip-flop.
The second timing signal is output, and the second D-type
From the inverting output terminal of the flip-flop, the third tie
Brushless model characterized by outputting a minging signal
Drive control device. 5. The method according to any one of claims 1 to 4.
In the above, the second timing signal generation circuit is
And a set / reset signal generator, wherein the set / reset signal generator is the first timer.
Set in synchronization with the rising and falling edges of the
A reset pulse signal is generated, and the rectangular wave signal is generated by the set / reset signal.
Characterized in that the circuit is set and reset
Brushless motor drive controller. 6. The method according to any one of claims 1 to 5.
In addition, the signal magnetizing portion formed on the rotor
And a frequency detector formed on the stator.
It has a frequency generating mechanism, and the signal magnetizing unit is
For signals with magnetic poles three times as large as the magnetic poles of the magnetizing portion for driving
A magnetizing unit, wherein the frequency detector is the signal magnetizing unit
The rectangular wave signal generation circuit detects the change in the magnetic field due to
Based on the composite signal that is the composite of the output signals of the wave number detector,
A brushless model characterized by generating a rectangular wave signal
Drive control device. 7. The method according to any one of claims 1 to 5.
In the above, the rotor further includes an abbreviation for the position detection signal.
Magnetized to generate harmonic distortion that makes the sine waveform steep
Brushless having a magnetized part
Motor drive control device. 8. The magnetizing portion according to claim 7,
It is characterized by having three times as many magnetic poles as the dynamic magnetizing part.
Drive controller for brushless motor. 9. A signal from a single Hall element is used for 12
Driving a brushless motor that uses the 0-degree switching energization method
A dynamic control device for detecting the position detection signal of a substantially sinusoidal wave from a single Hall element.
The first timing signal at which the logic level is inverted at the cross point
Timing signal generating circuit for generating a signal, and in the vicinity of positive and negative 60 degrees from the zero cross point of the position detection signal.
Square wave signal that generates a square wave signal with inverted logic level
Generating circuit, the first timing signal generating circuit, and the rectangular wave signal
Drives the brushless motor with the output signal of the generation circuit
Drive signal generating circuit for generating a drive signal for
And a drive control device for a brushless motor.