JP3644066B2 - Motor equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a technique effective when applied to a motor device, and further to a motor device having an index function for generating an index signal serving as position reference information for each rotation of a multiphase brushless motor. The present invention relates to a technique that is effective when used in a rotational drive unit of a disk drive.
[0002]
[Prior art]
For example, in a floppy disk drive, in order to accurately detect the read / write start reference position for a rotationally driven floppy disk, the rotational driving motor passes through one specific angular position during one rotation. It is necessary to generate an index signal. Therefore, for example, in the floppy disk drive, the rotation of the floppy disk drive motor is detected at one specific angular position during one rotation, and based on this detection, every time the motor passes the specific angular position, an index signal is detected. (See, for example, “Latest floppy disk device and its application know-how” issued by CQ Publishing Co., Ltd., June 1984).
[0003]
FIG. 6 shows the configuration of the motor device having the index function described above, wherein 1 is a multiphase brushless motor, 11 is a rotor (rotor) in which a plurality of magnetic poles 11a are arranged and formed in a circular shape, 12 is a field winding on the stator (stator) side, 11i is an index magnetized portion, Hu, Hv, and Hw are Hall elements as magnetic pole sensors for detecting the magnetic pole 11a in a non-contact manner, and Hi is an index magnetized portion 11i. Hall element as an index sensor for non-contact detection, 2 is a motor drive / control circuit, 32 is a comparison circuit, 4 is an index signal generation circuit, and Pi is an index signal.
[0004]
Here, the motor drive / control circuit 2, the comparison circuit 32, the index signal generation circuit 4 and the like are integrated and formed as one semiconductor integrated circuit device. Reference numeral 51 denotes an external terminal 51 of the semiconductor integrated circuit device.
[0005]
The motor drive / control circuit 2 includes a sensor amplifier 21, a matrix circuit 22, an energization drive circuit 23, an AGC circuit 24, a capacitance element C1 for AGC time constant, and the like, and includes Hall elements Hu, Hv, and Hw that form a magnetic pole sensor. The energization control of the field winding 12 is performed based on the output.
[0006]
The comparison circuit 32 compares the detection output of the Hall signal Hi forming the index sensor with a comparison circuit having a hysteresis voltage Vhes, so that the index magnetized portion 11i of the motor rotor 11 passes near the index Hall element Hi. Each time an index pulse E is generated. The index signal generation unit 4 generates and outputs an index signal Pi having a predetermined time difference td with respect to the index pulse E.
[0007]
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. The index signal Pi is detected by the index Hall element Hi by detecting the index magnetized portion 11i. Then, after a predetermined time difference td, a pulse having a predetermined width tw is output. The time difference td at this time is for correction, that is, calibration to make the relationship between the rotation angle position of the motor 1 and the generation timing of the index signal Pi constant, and the generation timing does not move the mounting position of the Hall element Hi. Both can be adjusted by the variable resistor Rt1, the capacitive element C2, or the like.
[0008]
[Problems to be solved by the invention]
However, the present inventors have revealed that the above-described technique has the following problems.
[0009]
That is, in the motor device described above, as shown in FIG. 7, the detected 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. For this reason, for example, as shown in FIG. 8, when the detection output amplitude of the Hall element for index Hi fluctuates due to variations in sensitivity of the Hall element, temperature characteristics, etc., only the index magnetized portion 11i is reliably detected. May not be possible.
[0010]
In the motor device described above, in order to obtain the index signal Pi, in addition to the magnetic pole detection Hall elements Hu, Hv, and Hw for performing energization control (rectification control) of the multiphase brushless motor 1, the index Hall element Hi. However, there is a problem that the number of parts and the number of mounting steps increase, resulting in high costs.
[0011]
An object of the present invention is to provide a technique for reliably obtaining position reference information for each rotation of a multiphase brushless motor with a low-cost configuration.
[0012]
The above and other objects and features of the present invention will be apparent from the description of this specification and the accompanying drawings.
[0013]
[Means for Solving the Problems]
Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
[0014]
That is, a specific magnetic pole is formed by making one magnetic flux amount of a plurality of magnetic poles formed on a rotor of a multiphase brushless motor different from other magnetic poles, and the detection output level of the magnetic pole sensor is set by an AGC circuit. Based on the waveform amplitude of the detection output subjected to the level stabilization process, an index signal serving as position reference information is generated for each rotation of the motor.
[0015]
[Action]
According to the above-described means, it is possible to reliably obtain position reference information for generating an index signal without separately providing an index sensor and without being affected by variations in sensor sensitivity, temperature characteristics, and the like. .
[0016]
This achieves the object of reliably obtaining the position reference information for each rotation of the multiphase brushless motor with a low-cost configuration.
[0017]
【Example】
Preferred embodiments 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.
[0018]
FIG. 1 shows an embodiment of a motor device with an index function to which the technology of the present invention is applied.
[0019]
2 and 3 show waveform charts in the main part of the motor device shown in FIG.
[0020]
First, in FIG. 1, 1 is a multiphase brushless motor, 11 is a rotor (rotor) in which a plurality of magnetic poles 11a are arranged and formed in a circle, 12 is a field winding on the stator (stator) side, Hu, Hv and Hw are Hall elements as magnetic pole sensors for detecting the magnetic pole 11a in a non-contact manner, 2 is a motor drive / control circuit, 3 is an index detection circuit, 4 is an index signal generation circuit, E is an index pulse, and Pi is an index signal. .
[0021]
Here, the motor drive / control circuit 2, the comparison circuit 32, the index signal generation circuit 4 and the like are integrated and formed as one semiconductor integrated circuit device. Reference numeral 51 denotes an external terminal 51 of the semiconductor integrated circuit device.
[0022]
One of the plurality of magnetic poles 11a arranged and formed in a circular pattern on the rotor 11 of the motor 1 is a specific magnetic pole in which the amount of magnetic flux is reduced with respect to the other magnetic poles in a range that does not hinder motor driving. 11b.
[0023]
The motor drive / control circuit 2 includes a sensor amplifier 21, a matrix circuit 22, an energization drive circuit 23, an AGC circuit 24, a capacitance element C1 for AGC time constant, and the like, and includes Hall elements Hu, Hv, and Hw that form a magnetic pole sensor. Based on the detection output, energization control of the field winding is performed, so-called rectification control. At this time, the AGC circuit 24 stabilizes the output of each Hall element Hu, Hv, Hw by gain control with respect to the sensor amplifier 21.
[0024]
As shown in FIG. 2, the index detection circuit 3 sets the waveform amplitude of one detection output Wi among the detection outputs Ui, Vi, and Wi that has been level-stabilized by the AGC circuit 24 to a predetermined threshold value Vth1. By level discrimination, the index pulse E is generated and output every time the specific magnetic pole 11b rotates once and passes through one specific angular position.
[0025]
The index detection circuit 3 includes a buffer amplifier 31, a comparison circuit 32 that discriminates only a specific wave height waveform in the detection output Wi, a waveform shaping circuit 33 that squares all waveforms of the detection output Wi by zero-cross detection, and a comparison circuit 32. And the logic unit 34 that logically generates an index pulse E from the output D of the waveform shaping circuit 33.
[0026]
The logic unit 34 includes NAND gates G1 and G4, inverters G2, G3, and G5, and a data latch circuit F1. The logic unit 34 performs logic processing on the output D of the comparison circuit 32 and the output C of the waveform shaping circuit 33, thereby obtaining a motor rotor. Each time eleven specific magnetic poles 11 make one rotation and pass one specific angular position, an index pulse E that becomes H (high level) is generated and output.
[0027]
As shown in FIG. 2, the index signal generation circuit 4 generates an index signal having a predetermined time difference td with respect to the index pulse E. The index signal generation circuit 4 includes differential operational amplifier circuits 41 and 42, transistors Q1 to Q4, reference voltage sources V1, Vth2, and Vth3, a constant current source Io, a fixed resistor R3, a variable resistor Rt1, and capacitive elements C1 and C2. An index signal Pi having a predetermined pulse width tw having a predetermined time difference td with respect to the index pulse E is generated and output.
[0028]
As shown in FIG. 3, the time difference td is for correction, that is, calibration for making the relationship between the rotation angle position of the motor 1 and the generation timing of the index signal Pi constant, and the magnitude thereof is variable resistor Rt1. And the capacitance element C2 and the like. Further, the pulse width tw of the index signal Pi can be set by the value of the capacitive element C3.
[0029]
As described above, the specific magnetic pole 11b is formed by making the amount of magnetic flux at one magnetic pole of the plurality of magnetic poles 11a formed on the rotor 11 of the multiphase brushless motor 1 different from the other magnetic poles, The level of the detection output Wi of the Hall element Hw which is a magnetic pole sensor is stabilized by the AGC circuit 24, and the position reference information for each rotation of the motor 1 based on the waveform amplitude of the detection output Wi subjected to the level stabilization processing. An index signal is generated.
[0030]
As a result, it is possible to reliably obtain position reference information for generating an index signal without separately providing an index sensor (Hall element) and without being affected by variations in sensor sensitivity, temperature characteristics, and the like. . In this way, position reference information for each rotation of the multiphase brushless motor 1 can be reliably obtained with a low-cost configuration.
[0031]
FIG. 4 shows another embodiment of the index signal generating circuit 4.
[0032]
In the index circuit 4 shown in the figure, the variable resistor Rt1 is replaced with a fixed resistor Rt0, and instead, a calibration means for variably setting the generation timing of the index signal Pi by a delay element 43 that can be electrically programmed from the outside. Is formed.
[0033]
The delay element 43 includes resistors R11 to R14 and Zener diodes (transistors) D1 and D2, and forms an electrically programmable resistance voltage dividing circuit. The Zener diodes D1 and D2 are selectively destroyed by external energization performed via the external terminals A and B. The diodes (D1, D2) destroyed by the energization change permanently from the non-conductive state to the conductive state. Thereby, the voltage dividing ratio in the resistor voltage dividing circuit, that is, the reference voltage Vth2 of the differential operational amplifier circuit 41 can be electrically programmed from the outside. Then, with this electrically programmed reference voltage Vth2, as shown in FIG. 3, it is possible to perform correction so that the relationship between the rotation angle position of the motor 1 and the generation timing of the index signal Pi is made uniform.
[0034]
FIG. 5 shows still another embodiment of the index signal generating circuit 4.
[0035]
In the index circuit 4 shown in the figure, the variable parameter of the delay element 43 is given by 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 being energized from the outside via the terminals A and B, respectively, thereby enabling finer variation correction. It is.
[0036]
The invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. Not too long.
[0037]
For example, the specific magnetic pole 11b may be of a type in which the amount of magnetic flux is increased with respect to the other magnetic pole 11a in a range that does not hinder the driving of the motor. In this case, the index pulse E can be obtained directly from the output of the comparison circuit 32 by appropriately selecting the threshold value Vth1 of the comparison circuit 32.
[0038]
Further, the Hall elements Hu, Hv, Hw as magnetic pole sensors can be replaced with other types of magnetic sensors.
[0039]
In the above description, the case where the invention made by the present inventor is applied to a floppy disk drive, which is a field of use behind the invention, has been described. However, the present invention is not limited to this. The present invention can be applied to all drive mechanisms having a portion that operates based on a position.
[0040]
【The invention's effect】
The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
[0041]
That is, the object of reliably obtaining position reference information for each rotation of the multiphase brushless motor with a low-cost configuration is achieved.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing an embodiment of a motor device to which the technology of the present invention is applied. FIG. 2 is a waveform chart showing a generation process of an index signal in the device of the present invention. FIG. 4 is a circuit diagram showing another embodiment of the index signal generating circuit used in the apparatus of the present invention. FIG. 5 is a circuit diagram showing still another embodiment of the index signal generating circuit. 6 is a block diagram showing an outline of a conventional motor device. FIG. 7 is a waveform chart showing an operation example of the main part of the motor device shown in FIG. 6. FIG. 8 is another waveform chart in the main part of the motor device shown in FIG. Chart showing an example of operation [Explanation of symbols]
1 Multiphase brushless motor 11 Rotor
11a Magnetic pole 11b Specific magnetic pole 12 Field windings Hu, Hv, Hw on the stator (stator) side Hall element 2 as a magnetic pole sensor 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 (1)

A multiphase brushless motor that controls energization of the field winding based on the output of a magnetic pole sensor that detects a plurality of magnetic poles formed on the rotor in a non-contact manner;
A specific magnetic pole formed by making one of the magnetic poles different from the other magnetic poles ,
An AGC circuit for stabilizing the detection output level of the magnetic pole sensor;
An index signal generation circuit that generates an index signal serving as position reference information for each rotation of the motor based on the waveform amplitude of the detection output level-stabilized by the AGC circuit ;
Index detection that generates an index pulse each time a specific magnetic pole of the motor rotor makes one rotation and passes one specific angular position by level discrimination of the waveform amplitude of the detection output level-stabilized by the AGC circuit Circuit,
An index signal generation circuit for generating an index signal having a predetermined time difference with respect to the index pulse;
Calibration means for variably setting the generation timing of the index signal by an electrically programmable delay element;
With
The specific magnetic pole is reduced or increased in the range where the amount of magnetic flux does not interfere with motor drive relative to other magnetic poles.
The delay element is
First and second terminals;
A first Zener diode connected between the first terminal and a ground voltage source;
A second Zener diode connected between the second terminal and a ground voltage source;
A third Zener diode connected between the first terminal and a reference voltage source of the index signal generation circuit;
A fourth Zener diode connected between the second terminal and the reference voltage source of the index signal generation circuit;
A first resistor connected in parallel to the reference voltage source of the index signal generation circuit and the third and fourth Zener diodes;
A second resistor connected between the first resistor and a ground voltage source;
A third resistor connected between the first resistor and the first terminal;
A fourth resistor connected between the first resistor and the second terminal;
A resistive voltage divider circuit comprising:
The first to fourth Zener diodes are configured to be selectively broken into a conductive or non-conductive state by being energized from the outside through the first and second terminals,
By destroying the first to fourth Zener diodes arbitrarily selected by energization, the reference voltage of the differential operational amplifier circuit constituting the index signal generation circuit, which is the voltage dividing ratio in the resistance voltage dividing circuit, is arbitrarily set. And a correction for making the relationship between the rotation angle position of the motor rotor and the generation timing of the index signal constant by a reference voltage of the differential operational amplifier circuit .

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