JPH08223968A - Motor - Google Patents

Abstract

PURPOSE: To obtain position reference information for every revolution of each phase motor by differentiating the amount of the flux of one pole in a rotor from others and generating the position reference information, i.e., an index signal, for every revolution of a motor based on the amplitude of output waveform from a pole sensor subjected to level stabilization. CONSTITUTION: A plurality of poles 11a arranged circularly around the rotor 11 of a motor 1 includes one specific electrode 11b having an amount of the flux reduced as compared with other poles within such range as causing no trouble in driving the motor. An AGC circuit 24 stabilizes the output from each Hall element Hu, Hv, Hw through gain control for a sensor amplifier 21. An index circuit 3 discriminates the level of one Wi of detection outputs Ui, Vi, Wi subjected to level stabilization through the AGC circuit 24 using a predetermined threshold value Vth 1 and produces an index pulse E every time when the specific pole 11b makes a single revolution and passes one specific angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor device, and more particularly to a technique effectively applied to a motor device having an index function for generating an index signal serving as position reference information for each rotation of a polyphase brushless motor. The present invention relates to a technique effectively used for a rotary drive unit of a floppy disk drive, for example.

[0002]

2. Description of the Related Art For example, in a floppy disk drive, in order to accurately detect a read / write start reference position for a rotationally driven floppy disk,
It is necessary to generate an index signal every time the motor that drives the rotation passes one specific angular position during one rotation. Therefore, for example, a floppy disk
The drive detects the rotation of the floppy disk drive motor at one specific angular position during one rotation, and based on this detection, an index signal is generated each time the motor passes the specific angular position. (For example, see "Latest floppy disk device and know-how of its application" issued by CQ Publishing Co., Ltd. in June, 1984).

FIG. 6 shows the structure of a motor device having the above-mentioned index function, in which 1 is a multi-phase brushless motor, 11 is a rotor in which a plurality of magnetic poles 11a are arranged and formed in a circle ( Rotor), 12 is a field winding on the side of the stator (stator), 11i is a magnetized portion for index,
Hu, Hv, and Hw are Hall elements as a magnetic pole sensor for non-contact detection of the magnetic pole 11a, Hi is a Hall element as an index sensor for non-contact detection of the index magnetizing portion 11i, 2 is a motor drive / control circuit, and 32 is The comparison circuit, 4 is an index signal generation circuit, and Pi is an index signal.

Here, the motor drive / control circuit 2, the comparison circuit 32, the index signal generation circuit 4, etc. are integrally formed as one semiconductor integrated circuit device. Reference numeral 51 is an external terminal 51 of the semiconductor integrated circuit device.

The motor drive / control circuit 2 includes a sensor amplifier 21, a matrix circuit 22, an energization drive circuit 23, and an AG.
It has a C circuit 24, a capacitance element C1 for AGC time constant, and the like,
The energization control of the field winding 12 is performed based on the outputs of the Hall elements Hu, Hv, Hw forming the magnetic pole sensor.

The comparator circuit 32 outputs the detection output of the Hall signal Hi forming the index sensor to the hysteresis voltage Vh.
By performing comparison by the comparison circuit having es, the index pulse E is generated each time the index magnetizing portion 11i of the motor rotor 11 passes near the index hall element Hi. The index signal generator 4 generates and outputs an index signal Pi in which the index pulse E has a predetermined time difference td.

FIG. 7 is a waveform chart showing the generation process of the index signal Pi based on the output of the index Hall element Hi.
Is output as a pulse having a predetermined width tw after a predetermined time difference td is set after the index Hall element Hi detects the index magnetized portion 11i. The time difference td at this time is determined by the rotation angle position of the motor 1 and the index signal Pi.
This is for a correction, that is, a calibration to make the relationship with the generation timing of the constant constant, and the generation timing can be adjusted by the variable resistor Rt1 and the capacitive element C2 without moving the mounting position of the Hall element Hi. .

[0008]

However, the present inventors have clarified that the above-mentioned technique has the following problems.

That is, in the above-described motor device, FIG.
As shown in, the detection amount due to the leakage magnetic flux from the magnetic pole 11a of the rotor 11 is also superimposed on the output of the index Hall element Hi. That is, a kind of noise is superimposed. Therefore, for example, as shown in FIG. 8, when the detected output amplitude of the index Hall element Hi changes due to variations in the sensitivity of the Hall element, temperature characteristics, etc., it is possible to reliably detect only the index magnetized portion 11i. May not be possible.

Further, in the above-described motor device, in order to obtain the index signal Pi, in addition to the magnetic pole detection Hall elements Hu, Hv, Hw for performing energization control (rectification control) of the multi-phase brushless motor 1, Since the Hall element Hi is separately required, there has been a problem that the number of parts and the number of mounting steps thereof are increased, resulting in high cost.

An object of the present invention is to provide a technique for surely obtaining position reference information for each rotation of a polyphase brushless motor with a low-cost configuration.

The above and other objects and characteristics of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0013]

Of the inventions disclosed in the present application, a representative one will be briefly described below.
It is as follows.

That is, a specific magnetic pole is formed by making one of the plurality of magnetic poles formed in the rotor of the multi-phase brushless motor different from the other magnetic poles to form a specific magnetic pole, and the detection output level of the magnetic pole sensor is changed. The AGC circuit performs stabilization processing, and an index signal serving as position reference information is generated for each rotation of the motor based on the waveform amplitude of the detection output subjected to the level stabilization processing.

[0015]

According to the above-mentioned means, the position reference information for generating the index signal can be surely obtained without separately providing the index sensor and without being influenced by the sensitivity variations and temperature characteristics of the sensor. be able to.

Thus, the object of surely obtaining the position reference information for each rotation of the polyphase brushless motor with a low-cost structure is achieved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. In the drawings, the same reference numerals denote the same or corresponding parts.

FIG. 1 shows an embodiment of a motor device with index function to which the technique of the present invention is applied.

2 and 3 are waveform charts of the main part of the motor device shown in FIG.

First, in FIG. 1, 1 is a polyphase brushless motor, 11 is a rotor (rotor) in which a plurality of magnetic poles 11a are arranged and formed in a circle, and 12 is a field winding on the stator (stator) side. , Hu, Hv, Hw are Hall elements as magnetic pole sensors for non-contact detection of the magnetic pole 11a, 2 are motor drive / control circuits, 3 are index detection circuits, 4 are index signal generation circuits, E is an index pulse, and Pi is an index. It is a signal.

Here, the motor drive / control circuit 2, the comparison circuit 32, the index signal generation circuit 4, etc. are integrated and formed as one semiconductor integrated circuit device. Reference numeral 51 is an external terminal 51 of the semiconductor integrated circuit device.

One of the plurality of magnetic poles 11a arranged and formed in a circle on the rotor 11 of the motor 1 has its magnetic flux reduced with respect to the other magnetic poles within a range that does not hinder the driving of the motor. It forms a specific magnetic pole 11b.

The motor drive / control circuit 2 includes a sensor amplifier 21, a matrix circuit 22, an energization drive circuit 23, and an AG.
Having a C circuit 24, a capacitance element C1 for AGC time constant, and the like,
The energization control of the field winding, so-called rectification control, is performed based on the detection outputs of the Hall elements Hu, Hv, Hw forming the magnetic pole sensor. At this time, the AGC circuit 24 uses the sensor amplifier 2
By controlling the gain for 1, the Hall elements Hu, Hv,
Stabilize the output of Hw.

As shown in FIG. 2, the index detection circuit 3 determines a predetermined waveform amplitude of one detection output Wi among the detection outputs Ui, Vi, Wi whose levels are stabilized by the AGC circuit 24. By performing level discrimination with the value Vth1, the index pulse E is generated every time the specific magnetic pole 11b makes one rotation and passes through one specific angular position.
Is generated and output.

The index detection circuit 3 includes a buffer amplifier 31, a comparison circuit 32 for discriminating only the waveform of a specific wave height in the detection output Wi, a waveform shaping circuit 33 for square-forming all the waveforms of the detection output Wi by zero-cross detection, It is composed of a logic unit 34 which logically generates an index pulse E from the output D of the comparison circuit 32 and the output C of the waveform shaping circuit 33.

The logic unit 34 includes NAND gates G1 and G.
4, inverters G2, G3, G5, data latch circuit F
1 and logically processes the output D of the comparison circuit 32 and the output C of the waveform shaping circuit 33 to generate H when the specific magnetic pole 11 of the motor rotor 11 makes one rotation and passes through one specific angular position. The index pulse E that becomes (high level) is generated and output.

As shown in FIG. 2, the index signal generating circuit 4 generates an index signal in which the index pulse E has a predetermined time difference td. The index signal generation circuit 4 includes a differential operation amplification circuit 4
1, 42, transistors Q1 to Q4, reference voltage source V1,
Vth2, Vth3, constant current source Io, fixed resistor R3, variable resistor Rt1, capacitance elements C1 and C2, etc., and an index signal of a predetermined pulse width tw that has a predetermined time difference td with respect to the index pulse E. P
Generates and outputs i.

As shown in FIG. 3, the above-mentioned time difference td is for the purpose of correcting or calibrating the relationship between the rotational angle position of the motor 1 and the generation timing of the index signal Pi, and its magnitude is variable. It can be adjusted by the resistor Rt1 and the capacitive element C2. The pulse width tw of the index signal Pi can be set by the value of the capacitive element C3.

As described above, the specific magnetic pole 11b is formed by making the amount of magnetic flux of one magnetic pole out of the plurality of magnetic poles 11a formed on the rotor 11 of the multi-phase brushless motor 1 different from the other magnetic poles. In addition, the level of the detection output Wi of the Hall element Hw, which is a magnetic pole sensor, is set to the AGC circuit
Then, the index signal serving as the position reference information is generated for each revolution of the motor 1 based on the waveform amplitude of the detection output Wi subjected to the level stabilization process.

Thus, the position reference information for generating the index signal can be reliably obtained without separately providing an index sensor (Hall element) and without being affected by the sensitivity variation of the sensor and the temperature characteristics. be able to. In this way, the position reference information for each rotation of the multi-phase brushless motor 1 can be reliably obtained with a low-cost configuration.

FIG. 4 shows another embodiment of the index signal generating circuit 4.

In the index circuit 4 shown in the figure, the variable resistor Rt1 is replaced with a fixed resistor Rt0, and instead, the generation timing of the index signal Pi is variably set by an externally programmable delay element 43. A calibrating means is formed.

The delay element 43 is composed of resistors R11 to R14 and Zener diodes (transistors) D1 and D2, and forms an electrically programmable resistance voltage dividing circuit. Zener diodes D1 and D2 have external terminals A and
It is designed to be selectively destroyed by the energization from the outside through B. The diodes (D1, D2) destroyed by energization permanently change from the non-conducting state to the conducting state. Thus, the voltage division ratio in the resistance voltage dividing circuit, that is, the reference voltage Vth2 of the differential operational amplifier circuit 41 can be electrically programmed from the outside. Then, by this electrically programmed reference voltage Vth2,
As shown in FIG. 3, it is possible to perform correction to make the relationship between the rotational angle position of the motor 1 and the generation timing of the index signal Pi uniform.

FIG. 5 shows still another embodiment of the index signal generating circuit 4.

In the index circuit 4 shown in the figure, variable parameters of the delay element 43 are given by the four Zener diodes D1 to D4. Each of the diodes D1 to D4 is individually programmed to be in a conductive / non-conductive state by an externally applied current through terminals A and B, thereby enabling a finer variation correction. There is.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, the specific magnetic pole 11b is the other magnetic pole 11
A method of increasing the amount of magnetic flux with respect to a within a range that does not hinder the driving of the motor may be used. In this case, the comparison circuit 3
By appropriately selecting the threshold value Vth1 of 2, it becomes possible to directly obtain the index pulse E from the output of the comparison circuit 32.

A Hall element H as a magnetic pole sensor
u, Hv, and Hw can be replaced with other types of magnetic sensors.

In the above description, the case where the invention made by the present inventor is mainly applied to the floppy disk drive which is the field of application which is the background of the invention has been described, but the present invention is not limited to this and, for example, a motor. The present invention can be applied to all drive mechanisms having a portion that operates based on the rotational angle position of.

[0040]

The outline of the typical inventions among the inventions disclosed in the present application will be briefly described as follows.

That is, the object of surely obtaining the position reference information for each rotation of the polyphase brushless motor with a low-cost configuration is achieved.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a motor device to which the technique of the present invention is applied.

FIG. 2 is a waveform chart showing a process of generating an index signal in the device of the present invention.

FIG. 3 is a waveform chart showing a process of generating an index signal from an index pulse.

FIG. 4 is a circuit diagram showing another embodiment of the index signal generation circuit used in the device of the present invention.

FIG. 5 is a circuit diagram showing still another embodiment of the index signal generation circuit.

FIG. 6 is a block diagram showing an outline of a conventional motor device.

7 is a waveform chart showing an operation example of a main part of the motor device shown in FIG.

8 is a waveform chart showing another operation example of the main part of the motor device shown in FIG.

[Explanation of symbols]

 1 multi-phase brushless motor 11 rotor (rotor) 11a magnetic pole 11b specific magnetic pole 12 field winding Hu, Hv, Hw on the stator (stator) side Hall element as a magnetic pole sensor 2 motor drive / control circuit 3 index detection circuit 32 Comparison circuit 4 Index signal generation circuit E Index pulse Pi Index signal 51 External terminal 21 Sensor amplifier 22 Matrix circuit 23 Energization drive circuit 24 AGC circuit

Claims (6)

[Claims] 1. A multi-phase brushless motor for controlling energization of a field winding based on an output of a magnetic pole sensor for non-contact detection of a plurality of magnetic poles formed on a rotor, and one of the plurality of magnetic poles. A specific magnetic pole formed by making the amount of magnetic flux different from other magnetic poles, an AGC circuit that stabilizes the detection output level of the magnetic pole sensor, and a waveform amplitude of the detection output that is level-stabilized by this AGC circuit. A motor device comprising: an index signal generating circuit for generating an index signal serving as position reference information for each rotation of the motor. 2. An index pulse is generated every time a specific magnetic pole of the motor rotor makes one revolution and passes through one specific angular position by discriminating the level of the waveform amplitude of the detection output that has been level-stabilized by the AGC circuit. The motor device according to claim 1, further comprising: an index detection circuit for generating the index pulse; and an index signal generation circuit for generating an index signal having a predetermined time difference with respect to the index pulse. 3. The motor device according to claim 1, wherein the specific magnetic pole is reduced in magnetic flux amount with respect to the other magnetic poles in a range that does not hinder motor driving. 4. The motor device according to claim 1, wherein the specific magnetic pole is increased in the amount of magnetic flux with respect to the other magnetic poles in a range that does not hinder motor driving. 5. The motor device according to claim 1, further comprising a calibration unit that variably sets an index signal generation timing by an electrically programmable delay element. 6. A calibrating means having an electrically programmable delay element formed by using an element which is broken into a conducting state or a non-conducting state by energization, and the delay element variably sets a generation timing of an index signal. The motor device according to claim 1, wherein the motor device is formed.