JPS62155750A - Assembling method for electromagnetic apparatus - Google Patents

Abstract

PURPOSE:To miniaturize and lighten an electromagnetic apparatus by magnetizing a magnet, detachably mounting a member made of a magnetic material on the pole face side, incorporating the member and removing said member. CONSTITUTION:A plurality of radial grooves are processed to the upper end surface of a magnetized yoke 10, and windings 12 for excitation to which insulating coatings are executed are wound on the grooves. A ring-shaped magnet 5 is fixed to a back yoke 4, and pressed into an axle 3. The shaft 3 is fitted into a hole formed to the inner circumferential section of the magnetized yoke 10, and conducts centering on magnetization. Consequently, when the magnet 5 is magnetized, a plunger 14 set up to the magnetized yoke 10 is operated, an air gap is formed between the magnetized yoke 10 and the magnet 5, and a bus-yoke 20 consisting of a magnetic material is inserted. When the magnet 5 is incorporated into a motor, the axle 3 is inserted into a bearing under the state in which the sub-yoke 20 is held, and the sub-yoke 20 is removed. Accordingly, self-demagnetization on assembly can be inhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of assembling electromagnetic equipment using permanent magnets.

BACKGROUND OF THE INVENTION In recent years, electromagnetic devices and actuators equipped with permanent magnets have been increasingly used in electrical devices, and there is a strong demand for smaller size, lighter weight, and higher performance. Along with this, the number of types of permanent magnet materials with high residual magnetic flux densities has increased, and it has become possible to provide actuators that obtain extremely large outputs despite having small dimensions.

An example of its configuration will be explained with reference to FIG. FIG. 3 shows a generally well-known planar opposed motor. As shown in the figure (a shaft 3 rotatably supported by a bearing 2.2 provided on a holder 1 is equipped with a rotor magnet 5.The rotor magnet 5 is magnetized with multiple poles in the rotation direction, It is configured to be rotated by the urging of a drive coil 6 disposed on a printed circuit board 12 made of material.

Problems to be Solved by the Invention Incidentally, with the demand for thinner and lighter motors, it is desired that motors be made as small as possible, but at the same time, large outputs are also required. Therefore, while the thickness of the magnet becomes thinner, a material with a high residual magnetic flux density is used for the magnet.

Generally, materials with high residual magnetic flux density tend to have a coercive force value smaller than the residual magnetic flux density value, as shown in FIG. As shown in the figure, if the magnet's operating point is lower than the bending point of the magnet material (point A in the figure) (for example, point F), even after it has been saturated magnetized, the magnet will still It is no longer possible to provide the characteristics originally possessed, and only characteristics that conform to the operating line shown by the broken line in FIG. 5 can be obtained. The characteristics of the motor are improved as the magnetic flux density in the air gap is higher, and it is better to avoid a decrease in the residual magnetic flux density.

By the way, this phenomenon occurs, for example, in ferrite magnets when the residual magnetic flux density increases and the coercive force decreases at low temperatures, and in rare earth magnets when the coercive force decreases at high temperatures. In contrast, this phenomenon occurs even at room temperature when the thickness of the magnet is thin, and demagnetization may occur simply by removing the magnet from the magnetization yoke after magnetization.

In order to prevent this phenomenon, it is possible to incorporate the magnet into the motor in an unmagnetized state and then apply a magnetizing magnetic field from outside the motor, but in general, such a magnetization method is extremely difficult. It is necessary to apply a large magnetic field. Therefore, it is often impossible to reach a state of saturation magnetization of the magnet, or the magnetizing yoke burns out, making mass production impossible.

Therefore, in general, the occurrence of self-demagnetization at room temperature is considered unavoidable, and the current situation is to deal with it by using a material with a higher residual magnetic flux density or by increasing the size of the motor.

Means for Solving the Problems The technical means of the present invention for solving the above problems is an assembly of a magnet, a yoke for closing the magnetic path of the magnet, and an electromagnetic device arranged through a predetermined gap. After the magnet is magnetized, a member made of a magnetic material is removably attached to the side of the magnet facing the yoke, and when the yoke is attached to the magnet, the yoke is attached while maintaining a predetermined gap between the yoke and the magnet. This is achieved by replacing the magnetic material member and the magnetic material member.

action The effect of this technical means is as follows.

In other words, after the magnet is magnetized as described above, a member made of magnetic material is removably attached to the magnetic pole side of the magnet, and after it is incorporated into an electromagnetic device such as a motor, this member made of magnetic material is removed, thereby reducing the residual magnetic flux density. Even if the material has a relatively small coercive force, the operating point before the magnet is incorporated into an electromagnetic device such as a motor is above the bending point on the B-H characteristic diagram, so it is difficult to at least attach the magnet. Self-demagnetization does not occur when the magnet is removed from the magnetic yoke, making it possible to fully utilize the characteristics of the magnet, making it possible to make electrical equipment such as motors smaller and lighter.

EXAMPLE Hereinafter, an example of the present invention will be explained based on the drawings. 1st
Figures (al to d) are explanatory diagrams of a method for assembling a motor in one embodiment of the present invention.

In FIG. 1(a), a magnetizing yoke 1o is made of a magnetic material, and a plurality of radial grooves are machined on its upper end surface.
Furthermore, an excitation winding 12 coated with insulation is wound around the groove.

The ring-shaped magnet 5 is fixed to a hack yoke 4 made of a magnetic material by adhesive or the like, and the back yoke 4 is press-fitted into the shaft 3.

Here, the shaft 3 fits into a hole provided in the inner circumference of the magnetizing yoke 10, and performs centering during magnetization. After the magnet 5 is centered on the magnetizing yoke 10, a current is applied to the excitation winding 12, and the magnet 5 is saturated.

When the magnet 5 is magnetized, the plunger 1 attached to the magnetizing yoke 10 as shown in FIG.
4 operates to push up the end face of the shaft 3, and the magnetizing yoke lO
A gap is created between the magnet 5 and the magnet 5.

Here, the sub-yoke 2o made of magnetic material is attached to the magnetized yoke 1.
Insert it into the gap between 0 and magnet 5. sub yoke 2
0 has a disk shape as shown in FIG. 2, and has a slit cut therein.

Next, as shown in FIG. 1(C), when incorporating the magnet 5 into the motor, the magnet 5 is attached to the bearing supported by the holder 1 on the shaft 3 while holding the sub-yoke 20 integrally. 2. Insert the sub yoke 20 into the 2" section and then remove the sub yoke 20. Note that the printed circuit board 7 on which the drive coil 6 is disposed is made of a magnetic material.

Next, the operation of this embodiment will be explained. After magnetizing the magnet 5 with the magnetizing yoke 10, by creating a slight gap between the magnetic pole surface of the magnet 5 and the magnetizing yoke 10, and inserting the sub-yoke 20 made of a magnetic material into this gap,
The operating point at the stage before the magnet throat 5 is incorporated into the motor is higher than the bending point (point A) in FIG.
For example, it will be located at point (3) in the figure. In this state, self-demagnetization does not occur at room temperature.

Note that if the magnet 5 is removed from the magnetizing yoke 10 without attaching the sub-yoke 20, the operating point of the magnet 5 will be located at point F in Figure 5 if the thickness of the magnet 5 is significantly thinner than the diameter. This results in self-demagnetization at room temperature.

Thereafter, the magnet 5 is incorporated into the motor while being held integrally with the sub-yoke 20, and the sub-yoke 20 is removed from the magnetic pole surface of the magnet 5 for the first time. Here, if the printed circuit board 7 is made of a non-magnetic material, the magnet 5 will self-demagnetize at room temperature, but in this embodiment, the printed circuit board 7 is made of a magnetic material, so the operating point of the magnet 5 is In FIG. 5, for example, since it is located at point E, self-demagnetization does not occur.

By assembling the magnet 5 to the motor in the manner described above, it is possible to suppress self-demagnetization even when the magnet 5 is thin, and it is possible to fully bring out the characteristics possessed by the magnet material. This makes it possible to set the motor dimensions to a minimum.

In this embodiment, the sub-yoke 20 is in direct contact with the magnetic pole surface of the magnet 5 in order to prevent self-demagnetization at room temperature. , sub yoke 2
0 and the magnet 5 may be reduced.

Next, other embodiments of the present invention will be described based on the drawings. FIGS. 3(a) to 3(d) are explanatory diagrams of the method of assembling the motor in this embodiment. This embodiment deals with a circumferentially opposed type motor.

In FIG. 3 [a], the magnetizing yoke 30 is made of a magnetic material, and has a plurality of vertical grooves formed on its inner circumferential surface, and an excitation winding 32 coated with insulation is placed in the grooves. It's wrapped.

The ring-shaped magnet 25 is fixed to the bank yoke 24 made of a magnetic material by adhesive or the like.
4 is press-fitted into the shaft 23.

Here, the shaft 23 fits into a hole provided in the inner circumference of the magnetizing yoke 30 to perform centering during magnetization.

After the magnet 25 is centered on the magnetizing yoke 30, a current is applied to the excitation winding 32 and the magnet 25 is saturated magnetized.

After the magnet 25 is magnetized, the magnet 25 is pushed up as shown in FIG. 3(b). Here, the magnet 25 is inserted into the sub-yoke 40 with the sub-yoke 40 made of a magnetic material placed on the magnetizing yoke 30.

Next, as shown in FIG. 3(C), when incorporating the magnet throat 25 into the motor, the magnet 25 is attached to the sub yoke 4.
0 is held integrally, the shaft 23 is inserted into the bearing 22, 22' supported by the holder 21 made of magnetic material, and then the sub-yoke 40 is removed.

By assembling the magnet 25 to the motor in the manner described above, self-demagnetization of the magnet 25 is prevented. This means that even if the thickness of the magnet 25 is very small compared to the diameter of the magnet 25, by attaching the sub-yoke 40 to the magnet 25, the operating point of the magnet 25 can be changed to the bending point (point A) as shown in FIG. ) (for example, point D).

Therefore, even when the thickness of the magnet 25 is thin, self-demagnetization can be suppressed to the minimum level, and the characteristics possessed by the magnet material can be fully brought out. This makes it possible to set the motor dimensions to a minimum.

Although the above embodiments have been described with respect to motors, it is obvious that the present invention is not limited to motors and can be applied to all kinds of electromagnetic devices using permanent magnets.

Effects of the Invention The present invention provides a method for assembling an electromagnetic device in which a magnet and a cork for closing the magnetic path of the magnet are arranged through a predetermined gap. A member made of magnetic material is detachably attached to the magnet, and when the yoke is attached to the magnet, the yoke and the member made of magnetic material are replaced while maintaining a predetermined gap between the yoke and the magnet. This makes it possible to make full use of its own characteristics and make it smaller and lighter.

[Brief explanation of drawings]

Figures 1+a) to (C) are sectional views showing a motor assembly method in an embodiment of the present invention, Figure 2 is a perspective view of a sub-yoke in an embodiment of the present invention, and Figures 3(a) to (C1 are FIG. 4 is a sectional view showing a method of assembling a motor in another embodiment of the present invention, FIG. 4 is a sectional view of a motor in a conventional example, and FIG. 5 is a characteristic diagram of the magneto-node material. .23...axis, 4.24...throat
Tsukuyoke, 5.25...Magnet, 20.
40... Keb yoke, 10.30... Magnetizing yoke. Name of agent Patent attorney Toshio Nakao Number A1 3-1
i Yu (Phantom 70--Ichiban Magnetic Yoke 12-
Excitation M8 braze 1-m-holder 2.2'--Ichiura 1 receiver 3-Ichinoki 6-Top I force coil 7---Printed circuit board 2o---Sub yoke (C) 7-Holder 2 z'---'4d receiver 3-

Claims (1)

[Claims] In the assembly of an electromagnetic device comprising a yoke made of a magnetic material and a permanent magnet arranged through a predetermined gap, after the permanent magnet is magnetized, a member made of a magnetic material is placed on the side of the permanent magnet facing the yoke, The yoke is detachably attached integrally to the permanent magnet, and when the yoke is attached to the permanent magnet, the yoke and the magnetic material are maintained while maintaining a gap substantially equal to the predetermined gap between the yoke and the permanent magnet. A method for assembling electromagnetic equipment characterized by replacing parts.