JP2000166208A - Driver of outer-rotor multipole brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise the reliability by materializing the positional constitution of an IC for detecting the position of a rotor, and a driver for supplying each coil of a stator with drive power by simple constitution. SOLUTION: For this driver, hole IC's (H1-H6), which detect the position of a permanent magnet 11 by grasping the magnetic flux of the permanent magnet 12, are supported outside in the direction of rotation axis against the coil 9 wound on the salient pole 3c of a stator 3, and also six pieces of IC's are arranged by 60 deg. in electric angle at the center in circumferential direction of specified salient poles (3cu, 3cv, and 3cw), and the signal output of the hole IC's (H1-H6) is reflected directly on the switching of the polarity of the drive current to be applied to the coil 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for an outer rotor type multi-pole brushless electric motor.

[0002]

2. Description of the Related Art As a conventional brushless motor, three stators are arranged so as to have a phase difference of 120 degrees from each other.
2. Description of the Related Art It is known that a rotor includes a permanent magnet having two magnetic poles in which N and S poles are alternately magnetized in the circumferential direction as a rotor. In addition, a brushless motor having an inverter circuit including a transistor for detecting the number of rotations of the motor and the position of the rotor using three ball ICs and supplying drive power to each coil is also known. It is. The detection output in this case is a control circuit which generates a pulse signal for turning on / off the transistor of the inverter circuit so as to make the rotation speed of the motor match the rotation speed of the electric motor based on the detection output and a predetermined rotation speed, thereby performing a constant rotation. Have gained.

[0003]

In the conventional driving device, the output of the Hall IC which detects the position of the rotor of the brushless motor is an electrical angle whose output signal width is determined by the configuration of the stator and the rotor. Because it is different from 180 degrees, it is necessary to process the output signal digitally or analogly in the control device and supply drive power to each coil,
The circuit configuration is complicated, which has been a constraint for achieving high reliability.

The present invention has been made in view of such circumstances, and has a brushless electric motor of a multi-pole outer rotor type, a position configuration of a Hall IC for detecting the position of the rotor, and
It is an object of the present invention to provide a drive device for an outer rotor type multi-pole brushless electric motor which realizes a drive device that supplies drive power to each coil of a stator with a simple configuration and achieves high reliability.

[0005]

According to the present invention, a plurality of coils are wound around a plurality of salient poles provided on the outer periphery of a stator core via a bobbin, and air is supplied to the salient poles. In a drive device for driving an outer rotor type multi-pole brushless motor in which a bottomed cylindrical rotor in which a plurality of permanent magnets opposed to each other with a gap fixed to an inner periphery of a side wall are rotatably supported coaxially, the magnetic flux of the permanent magnets is reduced. The Hall IC for capturing and detecting the position of the permanent magnet is supported on the outer side in the rotation axis direction with respect to the coil wound around the salient pole of the stator, and the electrical angle is 60 degrees relative to the circumferential center of the salient pole. Six pieces are arranged at intervals, and technical means for directly reflecting the signal output of the Hall IC to the polarity switching of the drive current applied to the coil is adopted.

According to the present invention having such means,
The Hall IC detects the position of the permanent magnet by capturing the magnetic flux of the permanent magnet of the rotor, outputs a rising signal of a rectangular wave as a position detection signal, and switches the timing of this signal directly to the coil of the stator to energize. The rotor is rotated because the current is reflected and supplied.

In addition, since the Hall IC is arranged in a region where the permanent magnet has a high magnetic flux density, the Hall IC is hardly affected by the magnetic flux generated by the coil of the stator, and its output signal is stable and operates reliably.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

FIGS. 1 to 4 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of an outer rotor type multi-pole brushless electric motor, and FIG. 2 is a view taken along the line AA of FIG. FIG. 3 is a plan view of a main part of the stator and the rotor, FIG. 3 is a configuration diagram of a drive circuit, and FIG. 4 is a control signal system diagram of the drive circuit.

First, in FIG. 1, the outer rotor type multi-pole brushless electric motor 1 is composed of a rotor 2, a stator 3 and the like, and the stator 3 is connected to a boss 5 connected to the engine body 4 as described later. The crankshaft 6 of the engine is disposed so as to pass through the stator 3 coaxially. At the end of the crankshaft 6,
Rotor 2 formed in bowl shape so as to cover stator 3
Are coaxially fastened to the stator 3 via a gap.

The stator 3 is connected to a boss portion 5 connected to the engine body 4 by a plurality of bolts 7, for example, four bolts 7. The crankshaft 6 of the engine is arranged so as to penetrate the stator 3 coaxially, and And a stator core 3a composed of a plurality of core plates formed in a substantially T shape on the outer periphery of a core base 3b formed in a ring shape. The plurality of salient poles 3c are provided at equal intervals and protrude from each other.

The plurality of core plates constituting the stator core 3a are partially covered with a synthetic resin bobbin 8 after being caulked between both ends in the laminating direction.
The stator core 3a is formed by maintaining the mutual lamination state, and the bobbin 8 is configured such that the distal end portion of each salient pole 3c and a part of the inner peripheral surface of the core base portion 3b are exposed, and the stator core 3a is positioned at both axial ends. It is formed to cover over.

In such a stator core 3a, each salient pole 3c has a U-phase, a V-phase,
A total of 24 coils 9 each having eight phases and W phases and eight coils 9 for each phase
Are wound, and each coil 9 is connected in three phases.

The rotor 2 is a crankshaft in which a hub 10 is fixed with a rivet 11 to a center hole at the bottom of a rotor yoke 2 a formed in a bottomed cylindrical shape, a so-called bowl shape, and the hub 10 is rotatably supported by the engine body 4. 6, a plurality of, for example, 27 permanent magnets 12 coaxially surrounding the stator 3 so as to form a slight air gap with the stator 3 on the inner periphery of the side wall of the rotor yoke 2a.
The poles and the S poles are fixed in a state of being alternately magnetized in the circumferential direction.

A support member 13 is fixedly held between the stator 3 and the engine body 4 by bolts 7. The support member 13 converts the rotational position of the magnetic pole of the permanent magnet 12 into an electric signal. Six Hall ICs (H) to be output are placed in the circumferential direction of the rotating shaft, and are located near the permanent magnet 12 and at positions axially outside the coil 9 wound around the salient poles 3c of the stator 3. Be placed.

Referring to FIG. 2 as well, six Hall ICs (H1 to H6) are arranged at specific successively adjacent salient poles 3, and are provided with a U-phase coil wound thereon. Pole 3c
The circumferential edges of the salient pole 3cv around which the u and V phase coils are wound and the salient pole 3cv around which the W phase coil is wound are Hall ICs.
(H), and is arranged so as not to contact the open end of the rotor yoke 2 a and the permanent magnet 12. In other words, the Hall ICs adjacent to each other around the rotation axis
(Eg, H2 and H3) are arranged at a phase difference of 60 degrees at the electrical angle α.

In order to facilitate the drive control described later, a salient pole 3cu wound with a U-phase coil, a salient pole 3cv wound with a V-phase coil, and a salient pole wound with a W-phase coil. 3
When the rotation direction of the rotor 2 is clockwise as shown in FIG. 3, the hall IC (H2) is provided at the inner edge (left side) and the hall IC (H3) is provided at the outer edge (right side) of the salient pole 3cu. ) Are arranged, and hereinafter, salient poles 3c
Hall IC (H4) on the in-edge (left), Hall IC (H5) on the out-edge (right), Hall IC (H6) on the in-edge (left) of salient pole 3cw, and Hall IC (H1) on the out-edge (right) ). further,
Each phase coil is wound so that each salient pole is excited to the N pole when a current is applied.

The salient pole 3cu, salient pole 3cv, salient pole 3c
The relationship between the circumferential edge of w and the centers of the Hall ICs (H1 to H6) is such that all Hall ICs (H1 to H6) have an angle in which the armature reaction is canceled in the direction opposite to the rotation direction of the rotor 2.
May be moved by the same angle.

FIG. 3 is a diagram showing the configuration of the drive circuit. Each salient pole 3 of the stator 3 of the outer rotor type multi-pole brushless electric motor 1 is shown in FIG.
FIG. 3 mainly shows a U-phase connection U, a V-phase connection V, a W-phase connection W in which the U-phase, V-phase, and W-phase coils 9 wound around c are connected in three phases, and a drive circuit unit 15. is there. The plus sides of the three cascaded IGBT elements 14U, 14V, and 14W are connected to each other and to the DC input plus terminal 16P, and the minus sides are also connected to each other and the DC minus input terminal 16P.
N. In addition, DC input plus terminal 16P
And a capacitor 17 is connected between the DC negative input terminal 16N.

Cascaded IGBT element 14U
The emitter terminal of the upper-side IGBT (Up) and the collector terminal of the lower-side IGBT (Un) are connected, and this connection point becomes the output terminal, and is connected to the outer rotor type multi-pole brushless motor 1 as the U-phase connection U. I have. Similarly, the IGBT elements 14V and 14W are also
V-phase connection V and W-phase connection W are connected. Note that each I
Although the connection of the base terminal that controls the GBT is omitted in FIG. 3, it will be described later in detail with reference to FIG.

FIG. 4 is a system diagram showing the flow of control signals for each IGBT (Up, Un, Vp, Vn, Wp, Wn) from each Hall IC (H1 to H6). Each IGBT (U
Since the driving circuits for p, Un, Vp, Vn, Wp, Wn) are common, the connection relationship of the Hall IC (H1) will be described as a representative. The Hall IC (H1) is supplied with V + from a stabilizing power supply (not shown), and is connected to the resistor 18 to the Hall IC (H1).
At the output terminal (H1), the signal output is turned ON in response to the permanent magnet 12 having the S pole. This signal is input to the photocoupler 22 via the NOR logic element 19, the NAND logic element 20, and the resistor 21 without the timing being manipulated.
The power is transmitted to the base terminal of the BT (Up) and driven. IG
When driving the BT (Up), a power supply 23 that is electrically insulated is applied to the photocoupler 22 and
Output of the IGBT (Up) via the resistor 24
Connected between emitter terminals. IGBT (Up)
A resistor 25 and a Zener diode 26 are connected in parallel between the base and emitter terminals for stabilizing the operation.

A signal obtained by inverting the output of the Hall IC (H4) by the NOT logic element 27 is applied to the input side of the NOR logic element 19, and an interlock configuration prevents a ground fault accident of each phase. Further, a resistor 29 is connected in series to the output side, and a capacitor 29 is connected to a connection point between the resistor 28 and the NAND logic element 20 to prevent malfunction due to noise. Note that the NOT logic element 27, the resistor 2
8. The capacitor 29 is not indispensable for the configuration of control, but is an additional circuit.

Also, it has been described that the output of the NOR logic element 19 is added as one input of the NAND logic element 20, but the other input is much higher than the maximum frequency of the signal of the Hall IC (H). Chopper control can be performed by adding a PWM signal having a frequency. In this case, a voltage limiting function can be added.

Next, the operation of this embodiment will be described. The Hall IC (H1)
The position of the permanent magnet 12 is detected by capturing the magnetic flux of the pole, and a rising signal of a rectangular wave is output as the position detection signal.
The signal is directly transmitted to the base terminal of the IGBT (Up) via the AND logic element 20 and the photocoupler 22 and driven. Similarly, the IGBTs (Wn, Vp, Un, Wp, Vn) are sequentially driven on the basis of signals from the Hall ICs (H2 to H6), and supply a drive current for switching and energizing the coil 9 of the stator 3 so that the rotor 2 Rotates. In addition, since the Hall IC (H) is arranged in the region of high magnetic flux density by the permanent magnet 12, the coil 9 of the stator 3
Is less susceptible to the magnetic flux created by the device, and its output signal is stable and reliable.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

[0026]

As described above, according to the present invention, the Hall IC for detecting the position of the permanent magnet by capturing the magnetic flux of the permanent magnet is disposed outside the coil wound around the salient pole of the stator in the rotation axis direction. In addition to the support, the six salient poles are arranged at an electrical angle of 60 degrees with respect to the center in the circumferential direction, and the signal output of the Hall IC is directly reflected on the polarity switching of the drive current applied to the coil. A drive device for supplying drive power to each coil can be realized with a simple configuration, and a drive device for an outer rotor type multi-pole brushless motor that achieves high reliability can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an outer rotor type multi-pole brushless electric motor of the present invention.

FIG. 2 is a plan view of a main part of a stator and a rotor as viewed from the direction of arrows AA in FIG. 1;

FIG. 3 is a configuration diagram of a drive circuit of the present invention.

FIG. 4 is a control signal system diagram of FIG. 3;

[Explanation of symbols]

 2 ... rotor 3 ... stator 3a ... stator core 3c ... salient pole 8 ... bobbin 9 ... coil 12 ... permanent magnet H ... Hall IC

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H019 AA00 BB01 BB05 BB12 BB20 BB24 CC04 CC08 DD01 EE01 EE14 FF01 5H611 AA01 BB08 PP05 QQ03 RR02 TT01 TT02 UA04 5H621 BB07 BB10 GA01 GA04 GB08 HH14

Claims (1)

[Claims] 1. A plurality of coils are wound around a plurality of salient poles provided on the outer periphery of a stator core via bobbins, and a plurality of permanent magnets opposed to the salient poles via an air gap are fixed to an inner periphery of a side wall. In the drive device for driving the outer rotor type multi-pole brushless motor in which the bottomed cylindrical rotor is rotatably supported coaxially, a Hall IC that captures the magnetic flux of the permanent magnet and detects the position of the permanent magnet, The coil wound around the salient poles of the stator is supported on the outer side in the rotation axis direction, and six coils are arranged at an electrical angle of 60 degrees with respect to the circumferential center of the salient poles. A driving device for an outer rotor type multi-pole brushless electric motor, wherein a signal output is directly reflected on a polarity change of a driving current applied to the coil.