JPS6026483A - Permanent magnet rotor type synchronous motor - Google Patents

Abstract

PURPOSE:To enable to readily control the rotating direction at the starting time by controlling so that the magnetic force applied to a rotor becomes the prescribed direction after a power source is turned ON. CONSTITUTION:Before a power source is turned ON, a rotor 1 is held at the prescribed position to a stator by the magnetic forces of auxiliary poles 10a, 10b. When a power source is turned ON at a time T0, a current flowed to an armature winding 4 is controlled by initial operation control means 11 until reaching the predetermined time T1. Accordingly, the rotor 1 starts rotating in the prescribed direction. When the time T1 is elapsed, normal operation control means 14 outputs information preference to information of the means 11.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to control of the rotational direction of a permanent magnet rotor type synchronous motor with an output of several watts to several tens of watts, which is used as a drive source for household appliances such as small orange squeeze juicers. It is something.

Conventional Structure and Problems Conventionally, synchronous motors with permanent magnet rotors have been used in home-use small orange juicers and the like.

Figure 1 shows its simple configuration. In FIG. 1, 1 is a cylindrical permanent magnet rotor (hereinafter simply referred to as a rotor) magnetized with two poles in a direction perpendicular to the rotating shaft 2, 3 is a stator core (hereinafter simply referred to as a stator), and 4 is a rotor with two poles. The armature winding is wound around the rotation υ of the stator 3, 6 is the power plug, and 6 is the armature winding 4.
This is a switch that controls the current flowing to the

Insert the power plug 5 into a household outlet and switch 6
When closed, an alternating current flows through the armature winding 4 and the stator 3
Alternating magnetic flux is generated. Then, the stator end faces 3a, 3b
In VC, a magnetic field of north pole or south pole is generated alternately. Attraction or repulsion is generated between these magnetic poles and the magnetic poles magnetized on the rotor 1, and the rotor 1 begins to rotate.

FIG. 2 is an enlarged view of the vicinity of the stator end faces 3a and 3b, showing a case where the magnetic field generated at the stator end faces 3a and 3b exerts a repulsive force on the rotor 1 at the moment of starting rotation. Arbitrary four opposing points A, B, C, on the rotor 1 as shown in FIG.
Repulsive forces Fa, F, acting on D.

Fo, Fd as circumferential component Fa1FFb1 jFcl
yFcil and axial component Fa2+Fb2 +Fc2MF
d2, the repulsive force acting on points A and C creates a couple FaIFFCI' that rotates rotor 1 clockwise, and points B
The repulsive force acting on the points is a force couple Fb1. which rotates the rotor 1 counterclockwise. Fd1 is generated.

Now, if the magnitudes of the two pairs of forces (Fa1+F01) and (Fb* Fch) are equal, the torque acting on the rotor 1 becomes zero, and the rotor 1 remains stationary.

Here, by making the air gap between the rotor 1 and the stator end faces 3a, 3b uneven, and by applying a force to the rotor 1 from the outside, the balance between the two pairs of forces is maintained. Kuzusu and rotor 1 are (Fa1+Fo1)>(Fb1+Fd1)
In the case of clockwise, (Fb1+Fd1)>(Fa1
+F. , ), it starts rotating counterclockwise.

In this way, the rotational direction at the time of starting is determined by the magnitude relationship between the two pairs of couples, and as long as current continues to be supplied to the armature winding 4, the rotor 1 continues to rotate in the rotational direction at the time of starting.

Then, to turn off the switch 6 or disconnect the power plug 5,
The magnetic force acting between the rotor 1 and the rotor 1 disappears, and the rotor 1 continues to rotate due to inertia for a while, but eventually stops. However, the stopping position is not constant, and the positional relationship between the rotor 1 and the stator 3 is, for example, as shown in Fig. 3(a)t(b).
+ (a) t (varies as shown in →).

In addition, as shown in FIG.

3b, it can become either north pole or south pole at the time of starting.

Therefore, even if you try to start rotating the rotor 1 by applying current to the armature winding 4 on the next occasion, due to the magnetic relationship between the rotor 1 and stator 3 at the time of starting, the clockwise or counterclockwise rotation will occur. There was a problem in that the rotation could not be started in any direction of υ, and the direction of rotation could not be controlled.

The reason why the rotation direction of a permanent magnet rotor type synchronous motor is not determined at the time of starting is that, as mentioned above, the magnetic positional relationship between the rotor 1 and the stator 3 is not determined at the time of stopping, and also because the power supply This is because the polarity of the magnetic poles generated on the end face of the stator is not determined when the stator is turned on.

Therefore, in order to control the rotation direction of this type of synchronous motor, it is sufficient to keep the rotor at a constant position relative to the stator and to keep the magnetic poles generated on the stator end face constant when the power is turned on. .

Purpose of the Invention The present invention has been made in consideration of these conventional problems, and provides a method for controlling the rotational direction at the time of starting without impairing other characteristics of the electric motor and without losing the original advantage of simple structure. The present invention provides a permanent magnet rotor type synchronous motor that can be used as a drive source for devices such as small orange juicers.

Structure of the Invention In order to achieve the above object, the permanent magnet rotor type synchronous motor of the present invention includes a stator having a magnetic pole part, an armature winding that excites this stator, and a rotatable motor between the magnetic pole parts. The rotor is supported on a shaft and has permanent magnet poles, and while the power is not turned on or after the power is turned off, the magnetic field of the auxiliary magnetic poles with permanent magnet poles located near the rotor and the rotor's The rotor is stationary at a fixed position with a balanced magnetic field, and there is an initial operation control means for controlling the polarity of the magnetic field generated in the stator when the stator starts rotating when the power is turned on, and a means for controlling the magnetic field to continue rotating. A steady-state operation control means that detects the polarity of the magnetic field, and a time-measuring means for measuring the elapsed time after the power is turned on to provide a timing for the start of the operation of the steady-state operation control means, so that the direction of rotation of the rotor is always constant. In order to maintain a constant magnetic force, the magnetic force applied to the rotor is in a fixed direction for a fixed period of time after the power is turned on.

Description of examples FIG. 5 shows a block diagram 2 of an embodiment of the present invention.

In FIG. 6, parts having the same functions as those in FIG. 1 are given the same reference numerals, and their explanations are omitted here.

In FIG. 6, auxiliary magnetic poles 10a and 10b are N-pole or S-pole permanent magnet poles with different polarities, and both are arranged near the rotor 1. 11 is the armature winding 4 by twisting the magnetic poles generated on the stator end faces 3a and 3b.
This is an initial operation control means that controls the direction of the current flowing through the circuit. That is, the initial operation control means 11 controls the direction in which the rotor 1 starts rotating when the power is turned on. give. Reference numeral 14 denotes steady-state operation control means for causing the rotor 1 to rotate continuously.

That is, the steady-state operation control means 14 generates information or instructions for canceling the information of the initial operation control means 11 in order to cause the rotor 1 to rotate continuously after the rotation direction of the rotor 1 becomes constant by the initial operation control means 11. In other words, it gives priority information to the information of the initial operation control means 11.

Further, 12 is a power-on detection means for detecting that the power has been turned on, and 13 is a time measuring means for measuring the elapsed time after the power is turned on and giving the operation start time of the steady operation control means 14. 16 is the power-on detection means 12;
This is a DC voltage generating means that supplies a DC voltage kLj to the time measuring means 13 and the steady-state operation control means 14.

The operation of the above configuration will be explained with reference to FIG. FIG. 6 is a timing chart showing the operating state of each part in FIG.

First, before time T0 when the power is turned on, the rotor 1 is kept at a constant position with respect to the stator by the magnetic force of the auxiliary magnetic poles 10a and 10b.

Here, when the power is turned on at time T0, the power-on detection means 12 detects that the power is turned on and outputs information to the time measurement means 13. Then, the time measuring means 13 starts measuring the time after the power is turned on, but since it does not output information to the steady operation control means 14 until the predetermined time T1 is reached, the initial operation control means 11 controls the υ current. The direction of flow is determined.

That is, time T. During -T1, since the current flowing through the armature winding 4 is controlled, only a certain number of magnetic poles are generated in the stator 3. If the polarity of this magnetic pole is selected to be the same as the polarity of the magnetic pole of the rotor 1 near the end face of the stator, a repulsive force will be generated between the two, and the rotor 1 will receive magnetic force only in a certain direction. Start rotating.

Next, when the power is turned on and a certain period of time T1 has elapsed, the time measurement means 13 outputs information to the steady-state operation control means 14, and the steady-state operation control means 14 outputs information that has priority over the information from the initial operation control means 11. do.

Then, the control of the current flowing through the armature winding 4 is canceled and the same operating state as described in FIG. 1 is reached, so that the rotor 1 continues to rotate in a fixed direction until the power is turned off.

That is, between times 11 and 120, the power supply current flows through the armature winding 4 without being controlled, so the magnetic poles generated in the stator 3 alternately change, and the rotor 1 is at time T. -T1
The rotation continues in the rotation direction determined within the specified rotation direction.

Then, after time T2, it is time T. As before, the rotor 1 is kept in a fixed position by the magnetic force of the auxiliary magnetic poles 10a, 10b.

FIG. 7 shows a circuit diagram of an embodiment of the present invention based on the block diagram of FIG. 5. The operation of this circuit is the same as the operation explained above, but a slightly supplementary explanation will be given.

In FIG. 7, 20 is a three-terminal regulator that generates a constant DC voltage, and 21a and 21b are operational amplifiers, both of which are used as buffers. 22 is a photocoupler, 23 is a triac, and 24 is a diode for half-wave control of the direction of the current flowing through the armature winding 4.

For example, let us assume that the rotor 1 always rotates clockwise, and the rotor 1 and the auxiliary magnetic pole 10a when the power is not turned on.

The relationship between the magnetic poles of 1ob is shown in FIG.

It is assumed that the polarity of the magnetic pole generated at point 3b is given in FIG. 8(b).

For example, the auxiliary magnetic pole 10a is closer to the stator end face 3a, the auxiliary magnetic pole 10b is closer to the stator end face 3b, and the auxiliary magnetic pole 10a is closer to the stator end face 3b.

and 10b are arranged in a straight line, the rotor 1, stator 3, and auxiliary magnetic pole 10a before power is turned on.

10b maintains equilibrium in the state shown in FIG. 8 (-).

Immediately after the power is turned on, the eighth
A magnetic pole with the polarity shown in Figure (b) is generated. Then, as shown in FIG. 9, at point E, the rotor 1 experiences a repulsive force F with the stator end face 3a. 1 and the auxiliary magnetic pole 10a, F, 2 (
7) At point G, the resultant force F8 is the resultant force F of the repulsive force F91 with the stator end face 3b and the attractive force F92 with the compensating magnetic pole 10b.
9 acts, the rotor 1 starts rotating clockwise.

Although two auxiliary magnetic poles were used in this embodiment, one or three or more auxiliary magnetic poles may be used.

Alternatively, a pair of permanent magnets may be used as auxiliary magnetic poles.

Further, in this embodiment, the output of the steady operation control means 14 is configured to have priority over the output of the initial operation control means 11.
Each output may be selected.

Effects of the Invention As is clear from the description of the above embodiments, according to the present invention,
This type of synchronous motor not only makes it possible to easily control the direction of rotation at startup without sacrificing the characteristics of a permanent magnet rotor type synchronous motor, nor does it lose the original advantage of a simple structure. It has an excellent advantage in that it can solve the problem of difficulty in starting rotation, which is a drawback of electric motors.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a conventional permanent magnet rotor type synchronous motor.
Figure 2 is an enlarged sectional view of the same essential parts, Figure 3 is a diagram of the magnetic positional relationship between the rotor and the stator, Figure 4 is a diagram of the magnetic relationship between the stator and the rotor, and Figure 5 is a diagram showing the magnetic relationship between the rotor and the rotor. A block diagram of the embodiment, FIG. 6 is a timing chart showing the operation of each part in FIG. 6, FIG. 7 is a circuit diagram of an embodiment of the present invention based on the block diagram of FIG. 6, and FIG. (a) is a diagram of the relationship between the magnetic fields of the rotor and the auxiliary magnetic poles when the power is not turned on to explain the circuit operation in Figure 7, and Figure 8 (b) is a diagram of the relationship between the magnetic fields generated at the diodes and the stator end face. The relationship diagram, FIG. 9, is an enlarged view of the vicinity of the rotor at the time of starting rotation. 1... Permanent magnet rotor, 3... Stator core, 4... Armature winding, 10a, 10b...
... Auxiliary magnetic pole, 11 ... Initial operation control means, 12 ... Power-on detection means, 13 ...
・Time measurement means (monostable multi-node (ibrator), 14
. . . Steady operation control means, 16 . . . DC voltage generation means. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 (α) (b2 Figure 4

Claims (1)

[Claims] (1) It has a stator having magnetic pole parts, an armature winding that excites the stator, and a rotor rotatably supported between the magnetic pole parts and having permanent magnet poles, and the power source is Before the power is turned on or after the power is turned off, the magnetic positional relationship between the rotor and the stator is maintained constant by auxiliary magnetic poles having permanent magnet poles, so that the rotor moves in a fixed direction after the power is turned on. Until the rotation starts, the rotation start direction of the rotor is controlled to be constant by the initial operation control means that forces the direction in which the power supply current flows, and after that, the rotation is continuously performed by the steady operation control means. Permanent magnet rotor type synchronous motor. ('4) The output information of the initial operation control means and the output information of the steady operation control means are used as the input information for the rotor operation control, so that the output information of the steady operation control means cancels the output information of the initial operation control means. A permanent magnet rotor type synchronous motor according to claim (1) configured as follows. A permanent magnet rotor type synchronous motor according to claim (1), which uses a time measuring means.