JPH03251096A - Dc commutatorless motor - Google Patents

Abstract

PURPOSE:To make it possible to detect an index either at the rising edge or falling edge by subjecting a position signal, produced from a signal position detecting element opposing to the magnetized band at a ternary magnetized section, to frequency division and applying a nonmagnetized pole onto a part of N pole of the magnetized band. CONSTITUTION:In an index signal generating circuit 108, a reset pulse generating circuit 104 comprising a logic circuit for extracting nonmagnetized poles one of which is applied in the N pole of a ternary magnetized section, is arranged at the output of a distributor 100 comprising a binary comparator. A signal provided from S pole of the magnetized section is subjected to 1/n frequency division through a frequency divider 105 and thus frequency divided signal is employed for creation of an index signal representing the absolute position of the rotor of a motor. Since high and low level electrical signals having mechanical angle of 180 deg. are obtained, positional accuracy is not degraded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to direct current non-commutated motors equipped with means for generating index pulse signals, such as cylinder tram motors for VTRs and spindle motors for floppy disks.
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2. Description of the Related Art Traditionally, cylinder tram motors for VTRs and motors for floppy disks each have one function: the former for detecting the rotational position of the video head of the drum.
One or two pulse signals (hereinafter abbreviated as PG multiplication signal) are required per rotation, and in the latter case, one pulse signal is used as an index pulse for the writing position of the disk.
One pulse is required per rotation.

FIG. 5 shows an example of a conventional cylinder tram motor for a VTR. A rotor magnet 12 is fixed to a rotor yoke 14, and magnetic pole pieces (hereinafter referred to as PG) are magnetized to N and S poles.
>16a called magnet.

16b is divided into 180 degrees on the outer periphery of the rotor yoke 13 and fixed in position, and a magnetic sensing element (-Hall element for boat fishing) 17 is attached to the stator board 22 facing the PG magnets h16a and 16b, and the rotor rotates. Each time, the magnetic flux is detected and a PG multiplied signal of 2 pulses per rotation is generated.

Problems to be Solved by the Invention However, in the conventional example as described above, the mounting of the PG magnet on the outer periphery of the rotor and the mounting of the magneto-sensitive element facing the rotor, etc., increases the number of parts and assembly man-hours, resulting in increased cost. Furthermore, in terms of performance, there were problems such as deterioration of the mechanical balance of the rotor, accuracy of the PC magnet mounting position, and influence of leakage magnetic flux of the PG magnet on the surrounding area.

In order to solve the above problems, the present invention utilizes this position signal and adds other special parts to a 3-phase commutatorless motor that detects 3-phase position signals with one detection element. The present invention provides a means for generating an index pulse signal without any interference.

Means for Solving the Problems In order to solve the above-mentioned problems, the DC commutatorless motor of the present invention has first and second magnets on one magnet. A rotor including a main magnetic pole of 2 parts GL, a ternary magnetized part of 3 n poles, and a multi-pole magnetized part for obtaining speed information, which are components as the second and third magnetized belts, and the rotor. The ternary magnetization section (which is the second magnetization zone)
The magnetic pole of the N pole, the second leher, the magnetic pole of the S pole, the third
one position detecting element that detects position information obtained from a non-magnetized signal); an amplifier that amplifies the output signal of the position detecting element; and an amplifier that discriminates the output signal from the amplifier. , in a three-phase motor that includes a drive circuit in which energization is switched to three-phase stator windings through a distributor that distributes and a detection signal processing circuit that generates three-phase position signals,
A part of the magnetic pole of the ternary magnetized belt facing the position detection signal is magnetized with reverse polarity or non-magnetized, and the output signal of this one position detection element is subjected to signal processing. An index signal generation circuit is constructed from a reset signal (H) from the magnetic pole and a signal obtained by frequency-dividing the position signal of one of the three phases.

Effect The present invention has the above-described configuration, and in a three-phase, one-sensor, non-commutator motor driven by one magnetic sensing element, rotation is achieved by using the rotor magnet position 1 signal output from one magnetic sensing element. An index signal of high level and low level electric signals of 1 pulse per revolution is obtained in the summer and winter with a mechanical angle of approximately 180.

EXAMPLE Hereinafter, a DC commutatorless motor according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a basic configuration diagram of a motor in an embodiment of the present invention. FIG. 1 shows a rotor yoke 2 fixed to a shaft 1, a rotor magnet 3, a stator coil 4 facing the magnet 3, a stator yoke 7, and a substrate 5. FIG. 2 is a plan view of the rotor and stator. be. 10 is a rotor magnet having 8 main magnetic poles (n-=4) magnetized, and facing the stator coil 4a.

4b and 4c are mechanically arranged at an angle of 120 degrees. A ternary magnetized band is provided on the inner circumference of the rotor magnet 3, and one Hall element 6 is disposed on the stator side facing above the magnetized band.

Further, the outer circumferential portion of the rotor magnet 3 is provided with a multi-pole magnetized portion 11 from which a speed signal can be obtained.

The ternary magnetized belt has N poles, S poles, and non-magnetized poles 3a, 3b, and 3c, and a non-magnetized pole 3C is provided on a part of the N pole 3a. Therefore, the ternary magnetized belt has 12
It consists of a pole (n=4) magnetized part, and a non-magnetized pole is formed within one of the N poles.

FIG. 3 is a circuit block diagram in the present invention.

In the figure, Z of the ternary magnetized belt is a non-magnetized pole. Hall element 6
The outputs of the Hall amplifiers 106 each have a dead band width, and the distributors 100 . Detection signal processing circuit 1
01 and the drive signal generation circuit 102 into three-phase 120-degree energized drive signals, and the drive circuit 103 composed of power transistors is turned on in accordance with the phase order, and the three-phase coil Ll.

L2. Current flows through L3 and the motor is driven.

On the other hand, the index signal generation circuit 108, which is emphasized by the present invention, is configured such that, in the output of the above-mentioned distributor 100, which is composed of a binary comparator, one is applied to one place within the N pole of the ternary magnetized part. The motor rotates from a reset pulse generation circuit 104 consisting of a logic circuit for extracting non-magnetized poles and a signal obtained by dividing the signal obtained from the S pole of the magnetized portion by 1/n using a frequency divider 105. An index signal is generated indicating the absolute position of the child.

FIG. 3 will be explained along the time chart of FIG. 4. A waveform like A is obtained from the Hall element output 6a, and an inverted waveform is obtained from the Hall element output 6b. These waveforms are input to Hall amplifier 106. This Hall amplifier 106 is provided with a dead zone in consideration of the offset of the Hall element, the main magnetic pole of the non-magnetized portion, and the leakage magnetic flux from the armature. The waveform obtained from the Hall amplifier is as shown in B, and is electrically high level.
Le.

The C and D signals are obtained by a distributor 100 which is waveform-shaped into a low level and a medium level and has a binary threshold. The detection signal processing circuit 1 is based on the two-person power of C and D.
The D-H signal can be obtained at 01, and the waveform of the electrical 120 degree energization of F, G, and H is further made to have a current value proportional to the control human power E input from the outside of the motor, and a drive signal is generated. Circuit 102. The current is switched through the drive circuit 103 to drive the motor. One index pulse signal J is composed of an index pulse generation circuit 108 consisting of two circuit blocks below the C and D signals. One is 180 degrees out of the 360 degrees mechanical angle of the rotor's rotor magnet.

It consists of a frequency divider 105 that divides the frequency of the signal in order to generate a signal of one pulse per rotation with a 180-degree low recursion, and a reset pulse generation circuit 104 that ensures the absolute position of the rise and fall of this pulse. .

In the case of the present invention, since n=4, the frequency is divided by 4, and a pulse I having a width of k shown in waveform C is extracted as the reset pulse. As described above, the index pulse signal J is obtained by the index pulse generation circuit as described above.

As explained above, according to this embodiment, by using one position detection element for position signal detection also for index detection, an index signal can be obtained once per motor rotation, and compared to the conventional method, the PG It is possible to reduce the number of magnets and corresponding magnetic sensing elements, and to reduce the number of assembly steps and costs associated therewith.

Although this embodiment has been described using a coreless planar opposed type motor, a cored circumferentially opposed type motor may also be used, and the same applies.

Effects of the Invention As described above, the present invention divides the frequency of a position signal obtained from one position detection element facing a magnetized zone of a ternary magnetization section configured as a rotor position information source. By applying an unmagnetized magnetic pole to a part of the N magnetic pole of the magnetized belt, it is possible to obtain an index pulse signal once per rotor rotation, and moreover, it is possible to obtain an index pulse signal once per rotor rotation, and moreover, it is possible to obtain an index pulse signal once per rotor rotation, and moreover, it is possible to obtain an index pulse signal once per rotor rotation. It is possible to obtain low-level electrical signals, and it is possible to perform index detection on either rising edges or falling edges without deteriorating positional accuracy, making it possible to simplify the motor and reduce costs.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a motor in an embodiment of the present invention;
3 is a circuit block diagram according to the present invention, FIG. 4 is a signal waveform diagram in the circuit, and FIG. 5 is a sectional view of a motor showing a conventional example. 1...Shirt)-12...Rotor yoke, 3...Rotor magnet, 4...Stator coil, 6...Hall element, 7... ...
...Stator yoke, 10...Main magnetic pole, 11.
...Multi-pole magnetized part.

Claims (1)

[Claims] A 3-phase stator winding and 2n poles (however, n
is a natural number of 2 or more) and a first magnetized band constituting the main magnetic pole magnetized and a first magnetized band as a rotational position information source of the rotor.
A second magnetized zone that constitutes a ternary magnetized section with 3n poles (where n is a natural number of 2 or more) consisting of a level, a second level, and a third level (an intermediate level between the first level and the second level). and a third magnetized zone constituting a multi-pole magnetized section magnetized as a speed information source of the rotor, the DC non-commutator motor having one index pulse per rotation of the rotor. As a means for generating a signal, a third magnetic pole is formed within one magnetic pole of the first level of the magnetized band of the three-value magnetized portion of the rotor, and the output of a position detection element in which the magnetic pole positions are arranged opposite to each other is also used. and generating means for frequency-dividing the second level signal and outputting high-level and low-level repetitive index pulse signals of the electric signal for each 180 degrees of mechanical angle of the rotor. Commutator motor.