JP2001211685A - Brushless motor and brushless motor drive device - Google Patents

Abstract

(57) [Problem] To provide a brushless motor capable of simplifying the configuration of energization control means and easily replacing a brushed DC motor. SOLUTION: A diode bridge 30 is provided between power supply lines 33, 34 and a power supply terminal of a driving IC 31, and the power supply lines 33, 34 are connected to respective power supply terminals of Hall elements 32u to 32w. The driving IC 31 includes Hall elements 32u to 32
It has a control circuit 35 for generating energization signals Sup to Swn based on the signal voltage from w, and a drive circuit 36 for energizing the windings 24u to 24w in accordance with the energization signals Sup to Swn. By controlling the polarity of the DC voltage between the power supply lines 33 and 34, the normal / reverse operation can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forward / reverse rotatable brushless motor provided with a position detecting means and an energization control means, and a drive device for a forward / reverse rotatable brushless motor.

[0002]

2. Description of the Related Art Brushless motors are highly efficient and operable up to a high-speed range, have no sliding parts, have a long life and are highly reliable. Therefore, brushless DC motors have been used in various fields where DC motors with brushes have been used. Widely used. In order to drive the brushless motor, position detection means for detecting the rotational position of the rotor and energization control means for energizing a predetermined winding based on the detected rotational position are required.

FIG. 5 shows an electrical configuration of a brushless motor driving device provided with these position detecting means and energization controlling means. In FIG. 5, the drive IC 1 as the power supply control means and the Hall elements 2u, 2v and 2w as the position detection means are both connected to a positive power supply line 3 and a negative power supply line 4 from an external controller (not shown). And is operated by a DC voltage of a constant polarity provided through In this case, if the external controller is connected to the opposite polarity, the driving IC 1 may be destroyed.
Inside 1, a protection diode (not shown) is provided in series with the positive power supply line 3 or the negative power supply line 4.

The Hall elements 2u, 2v, 2w output a signal voltage corresponding to the rotor rotation position of the brushless motor 7, and the driving IC 1 is output from these Hall elements 2u, 2v, 2w. The control circuit 5 includes a control circuit 5 that generates an energization signal based on the signal voltage, and a drive circuit 6 that performs a switching operation according to the energization signal to energize the windings 7u, 7v, and 7w.

[0005]

A rotation direction command signal Sd is externally applied to the driving IC 1 via a signal line 8, and the energization signal generation unit 9 in the control circuit 5 generates the rotation direction command signal Sd. , And the brushless motor 7 is driven forward and backward. However, this configuration requires a forward / reverse switching circuit 9b in addition to the energization signal generation circuit 9a, which complicates the configuration of the control circuit 5.

Further, in addition to the positive power supply line 3 and the negative power supply line 4, another signal line 8 is required. If, for example, the signal line 8 is routed for a long time, noise may be mixed and the driving IC 1 may malfunction, so that it is necessary to separately provide a noise filter or the like (not shown), and the configuration of the control circuit 5 is further complicated. Become

Further, the brush DC motor conventionally used is designed to perform a forward / reverse rotation operation by switching the voltage polarity of an external controller between positive and negative, so that the brushless DC motor and the brushless motor 7 are connected to each other. Simple replacement is not possible. Therefore, when the brush DC motor is replaced with the brushless motor 7, it is necessary to change the configuration of an interface unit (not shown) in the external controller for instructing the motor to perform the forward / reverse rotation operation.

[0008] Such a situation is not limited to the case where the driving IC 1 and the brushless motor 7 are separately installed, and the driving IC 1 is housed in one housing together with the hall elements 2u, 2v, 2w, the rotor, the stator and the like. The same applies to the brushless motor having the configuration described above.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to enable forward and reverse rotation, simplify the configuration of the power supply control means as compared with the conventional configuration, and place the DC control device with a brushed DC motor. An object of the present invention is to provide a brushless motor and a brushless motor driving device that can be easily replaced.

[0010]

According to a first aspect of the present invention, there is provided a brushless motor which operates by receiving a DC voltage from a rotor, a stator having a winding, and an external device. Position detecting means for outputting a position signal corresponding to the rotational position of the rotor with a polarity corresponding to the polarity of the DC voltage; and energizing control for the winding based on the position signal output from the position detecting means. And a voltage polarity stabilizing means for converting the DC voltage supplied from the outside into a constant polarity and outputting the converted voltage to the energizing control means. It is characterized by the following.

According to this configuration, when a DC voltage is applied from the outside, the DC voltage converted to a fixed polarity by the voltage polarity stabilizing means is supplied to the energization control means regardless of the polarity of the DC voltage. Is done. Thus, the energization control means can operate irrespective of the DC voltage polarity. On the other hand, an external DC voltage having the same polarity is applied to the position detecting means, and the position detecting means outputs a position signal corresponding to the rotational position of the rotor with a polarity corresponding to the DC voltage polarity.

When the polarity of the position signal is inverted, the energization signal corresponding to the rotational position of the rotor is electrically shifted by 180 degrees, so that the direction of the generated torque is reversed. That is, the rotation of the rotor can be inverted by inverting the polarity of the DC voltage from the outside, and the rotation direction command signal and the forward / reverse switching circuit are not required. As a result, the configuration of the energization control unit is simplified, and a malfunction caused by noise mixing in the rotation direction command signal is also eliminated. In addition, replacement with a DC motor with a brush is facilitated, and a change in a controller that controls the brushless motor in forward and reverse rotations at the time of replacement can be reduced.

In this case, the voltage polarity fixing means is preferably a diode bridge circuit.
According to this configuration, the positive or negative DC voltage applied from the outside is converted to a DC voltage of a constant polarity while substantially maintaining the voltage amplitude.

Preferably, the position detecting means is a Hall element. The Hall element uses the Hall effect to output a voltage corresponding to the magnetic flux density of the magnetic field generated by the magnet disposed on the rotor, so that the rotor position is always accurately detected regardless of whether the rotor is stopped or rotating. be able to.

In each of the above cases, it is preferable that the rotor, the stator, the position detecting means, the energizing control means and the voltage polarity stabilizing means are housed in a single housing. According to this configuration, ease of use is improved, and replacement with a brushed DC motor is further facilitated.

According to another aspect of the present invention, there is provided a semiconductor device comprising:
The driving device for a brushless motor described in (1) is characterized by comprising the above-described position detecting means, energization controlling means, and voltage polarity stabilizing means. According to this configuration, the rotation of the rotor can be inverted by inverting the polarity of the external DC voltage, and the rotation direction command signal and the forward / reverse switching circuit are not required as described above.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 2 is a perspective view of the brushless motor, and shows an internal structure by partially breaking the motor. In FIG. 2, the housing of the brushless motor 21 is composed of a frame 22 which is a so-called bottomed cylindrical container having a right end closed, and an end plate 23 for closing a left end opening thereof. Accommodates a stator 25 around which windings 24u, 24v, and 24w are wound, a rotor 26 provided with permanent magnets, and a substrate 27 on which various components described below are attached.

One end of the rotating shaft 28 of the rotor 26 is
, And the other end of the rotating shaft 28 is supported by a bearing (not shown) provided at a right end closing portion of the frame 22 to the outside of the housing. And protrude.

A wiring pattern is formed on the substrate 27. On the back surface thereof, that is, the surface facing the stator 25 and the rotor 26, a diode bridge 30 formed into an IC corresponding to a voltage polarity stabilizing unit, a driving IC 31 corresponding to a conduction control unit, a Hall element 32u corresponding to a position detecting unit,
32v, 32w (only 32u is shown) and the like are attached. Then, two power supply lines 33 and 34 are drawn out from the substrate 27 through the end plate 23 to the outside.

FIG. 1 shows an electrical configuration of the brushless motor 21. In FIG. 1, a power supply line 33,
34 is connected to the input terminal of the diode bridge 30 composed of the diodes 30a to 30d, and the positive and negative output terminals of the diode bridge 30 are connected to the positive and negative power supply terminals of the driving IC 31, respectively. I have. Further, the power supply lines 33 and 34 are provided with Hall elements 32u, 32v,
32w is connected to each power supply terminal.

The driving IC 31 comprises Hall elements 32u, 3
A control circuit 35 generates an energization signal based on signal voltages (corresponding to position signals) output from the 2v and 32w, and a drive circuit 36 energizes the windings 24u, 24v and 24w according to the energization signal. are doing. The control circuit 35 includes a hall amplifier 37 and a conduction signal generation circuit 3.
And 8.

The hall amplifier 37 includes a hall element 32u,
By amplifying the signal voltages output from 32v and 32w and comparing them with a predetermined threshold value, position detection signals Hu, Hv and Hw having a high level or a low level (FIG. 3,
4 (see FIG. 4). Then, the energization signal generation circuit 38 performs a logical operation based on the position detection signals Hu, Hv, Hw, and generates energization signals Sup, Svp, Swp,
Sun, Svn, and Swn are generated. For example, the energization signal Sup includes a position detection signal Hu and a position detection signal H.
The energization signal Sun is generated by a logical AND operation of the inverted signal of the position detection signal Hu and the position detection signal Hv.
Is generated by a logical AND operation with

The drive circuit 36 supplies the energization signals Sup to Swn
, For example, transistors 36a to 36f, and transistors 36a to 36f
A return diode (not shown) connected in anti-parallel to 36f is formed in the form of a three-phase bridge. The U-phase, V-phase, and W-phase output terminals of the drive circuit 36 are connected to the terminals of the windings 24u, 24v, and 24w, respectively.

Next, the operation of this embodiment will be further described with reference to FIGS. The power lines 33 and 34 have a positive polarity (the power line 33 is positive and the power line 34 is negative) or a negative polarity (the power line 33 is negative and the power line 34 is Side). The diode bridge 30 receives this external DC voltage as input, converts the polarity into a DC voltage having a fixed polarity, that is, a positive side on the cathode side of the diode 30a and a negative side on the anode side of the diode 30c, and supplies the DC voltage to the power supply terminal of the driving IC 31. In the driving IC 31, the voltage having the fixed polarity is an operating voltage for the control circuit 35 and the drive circuit 36.

The Hall elements 32u, 32v, and 32w are elements utilizing the Hall effect. When a magnetic field is applied in a state where a current is applied to the elements, a signal voltage corresponding to the magnetic flux density is generated between both side surfaces of the elements. Then, when the direction of the magnetic field or the direction of the current is reversed, the polarity of the output signal voltage is reversed.

The external DC voltage is applied to the Hall elements 32u, 32u
v and 32w are directly applied to the Hall element 32 when the polarity of the external DC voltage is reversed.
The directions of the currents flowing through u, 32v, and 32w are reversed. As a result, the signal voltages output from the Hall elements 32u, 32v, and 32w are also inverted.

That is, the energization signal generation circuit 38 outputs the position detection signals Hu and H regardless of the polarity of the external DC voltage.
v, Hw, a predetermined logical operation is performed, and the energization signal S
up to Swn are generated. On the other hand, the position detection signal Hu,
The phases of Hv and Hw with respect to the rotational position of the rotor 26 change by 180 degrees when the polarity of the external DC voltage is reversed.

FIG. 3 shows the position detection signal H when a positive external DC voltage is applied to the brushless motor 21.
u, Hv, Hw and energization signals Sup, Sun, Svp, Svn, S
6 is a timing chart showing wp and Swn. In this case, a forward torque is generated by the voltage output from the drive circuit 36, and the rotor 26 rotates forward.

On the other hand, FIG.
3 is a timing chart when a negative external direct-current voltage is applied to No. 1; Compared to the case shown in FIG.
The correspondence between the position detection signals Hu to Hw and the energization signals Sup to Swn is the same, but the phases of the position detection signals Hu to Hw with respect to the rotational position of the rotor 26 are different by 180 degrees.
Therefore, in this case, a reverse torque is generated by the voltage output from the drive circuit 36, and the rotor 26 rotates in the reverse direction.

As described above, according to the present embodiment, the diode bridge 30 is provided between the input terminal of the external DC voltage and the power supply terminal of the driving IC 31, and the driving IC 31 is connected regardless of the polarity of the external DC voltage. The Hall elements 32u, 32
v, 32 w, two power lines 3
By controlling the polarity of the external DC voltage applied via the third and the third, the forward / reverse operation of the rotor 26 becomes possible.

This eliminates the need for a signal line for instructing the rotation direction, which is required in the conventional configuration (see FIG. 5), and simplifies the configuration of the control circuit 35. In addition, malfunction of the driving IC 31 due to noise in the signal line is also eliminated. Further, replacement with a brushed DC motor is facilitated, and at the time of replacement, there is little change in the interface unit on the controller side that commands forward and reverse rotation operation.

The brushless motor 21 is easy to use and has a brush since the motor unit including the stator 25 and the rotor 26 and the drive unit including the diode bridge 30 and the drive IC 31 are housed in the same housing. Replacement with a DC motor is easier.

The present invention is not limited to the embodiment described above and shown in the drawings. For example, the motor unit and the driving unit (corresponding to the driving device in the present invention) are housed in separate housings. You may do it. Further, the brushless motor 21 is not limited to three phases, but may be two phases or four or more phases.

[0034]

The brushless motor and the brushless motor driving device according to the present invention operate by receiving a DC voltage supplied from the outside and operate at the same time according to the polarity of the DC voltage with a position signal corresponding to the rotational position of the rotor. Position detecting means for outputting, energizing control means for performing energization control based on the position signal, and voltage for converting a DC voltage supplied from the outside to a constant polarity and outputting the converted voltage to the energization control means Since the apparatus has the polarity stabilizing means, it is possible to perform a forward / reverse operation according to the polarity of the DC voltage supplied from the outside. This eliminates the need for a signal line for giving a rotation direction command, and simplifies the configuration of the power supply control means. Also, replacement with a brushed DC motor is facilitated.

[Brief description of the drawings]

FIG. 1 is an electrical configuration diagram of a brushless motor according to an embodiment of the present invention.

FIG. 2 is a perspective view of a brushless motor shown partially broken away.

FIG. 3 is a diagram illustrating position detection signals Hu to Hw and energization signals Sup to S in a case where a positive DC voltage is applied and the motor rotates forward.
wn timing chart

FIG. 4 is a diagram showing position detection signals Hu to Hw and energization signals Sup to Sw in a case where a DC voltage of a negative polarity is applied and the rotation is reversed.
wn timing chart

FIG. 5 is a diagram corresponding to FIG. 1 showing a conventional technique.

[Explanation of symbols]

21 is a brushless motor, 24u / 24v / 24w is a winding, 25 is a stator, 26 is a rotor, 30 is a diode bridge (voltage polarity stabilizing means), and 31 is a driving IC.
(Electrification control means) and 32u, 32v, 32w are Hall elements (position detection means).

Claims (5)

[Claims] A stator having windings, a stator having windings, and a DC signal supplied from the outside to operate and output a position signal corresponding to the rotational position of the rotor with a polarity corresponding to the polarity of the DC voltage. A position detection unit that performs the energization control on the winding based on the position signal output from the position detection unit; anda DC voltage supplied from the outside is converted into a constant polarity. A brushless motor comprising: a voltage polarity stabilizing unit that outputs the converted voltage to the energization control unit. 2. The brushless motor according to claim 1, wherein said voltage polarity fixing means is a diode bridge circuit. 3. The brushless motor according to claim 1, wherein the position detecting means is a Hall element. 4. The brushless motor according to claim 1, wherein the rotor, the stator, the position detecting means, the energizing control means, and the voltage polarity stabilizing means are housed in one housing. . 5. A position detecting means which operates by receiving a DC voltage from the outside and outputs a position signal corresponding to the rotor rotation position of the brushless motor with a polarity corresponding to the polarity of the DC voltage. Energization control means for performing energization control on the windings of the brushless motor based on the position signal output from the means, and converting the DC voltage supplied from the outside to a fixed polarity, and converting the converted voltage to A drive device for a brushless motor, comprising: a voltage polarity stabilizing unit that outputs to the energization control unit.