JPS61106058A - Ultrafine displacement linear electromagnetic actuator - Google Patents

Abstract

PURPOSE:To obtain high thrust at ultrafine displacement and to improve the responsiveness by axially aligning electromagnets in which coils are wound in the grooves of circular inner periphery, and supporting a movable member on the inner periphery. CONSTITUTION:A rod type linear electromagnetic actuator in which a permanent magnet 2 is filled inside has a stator made of two annular electromagnets 6, 8, a movable element made of a permanent magnet 2 attached with pole pieces 3 and a shaft 1, and a bracket 5. Grooves 9a, 9b are formed to produce axial N- and S-poles on the inner peripheral side of the electromagnet, and pole pieces 3a, 3b are opposed radially to the inner peripheral surfaces of the grooves 9a, 9b. Thus, when coil 6a, 6b are energized in the direction as shown, S-, N-, N-, S-poles are generated from the left on the stator, and the element is affected by the force at the left to move.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention realizes a linear electromagnetic actuator with fine displacement that is linear and has good controllability in the form of a movable magnet or a movable core. and magnetic structures that can be made larger per weight.

[Prior art and problems]

Currently, moving coil type linear electromagnetic actuators (voice coil motors) are used to drive hydraulic servo valves and laser disk lenses.

A side sectional view of this type of conventional example is shown in FIG.

This permanent magnet movable linear vibration actuator (Lin
ear 0scillation Actuator
), the negative side (stator) has one set of two coils 6 and a yoke 8.
and one central magnetic pole 7, and the secondary side (mover) is one
It is composed of two sets of magnetic pole pieces 3 and one cylindrical permanent magnet 2.

The sliding portion consists of a bearing 4 and a side plate 5, and the overall structure of this linear vibration actuator is cylindrical.

The two coils 6 are connected to opposite surfaces so that they have the same polarity, and when a current (commercial frequency) is applied, the movable element vibrates in the left-right direction.

However, although such conventional examples have good responsiveness,
Since the magnetic structure is not good, there is a drawback that the size is large in relation to the thrust.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the difficulties of the conventional examples and to provide a minute displacement linear electromagnetic actuator having a structure considered to be ideal.

[Summary of the invention]

The present invention provides means for axially arranging two electromagnets each having a coil wound therein inside a yoke having an annular shape and having a groove on its inner peripheral surface, and for mutually supplying alternating current to these two coils. a movable member formed of a magnetic material and supported so as to be freely displaceable in the axial direction through a gap between the inner circumferential surfaces of the two electromagnets; and an annular shaft. This is a minute displacement linear electromagnetic actuator equipped with a permanent magnet magnetized in the direction.

(Embodiment) FIG. 1 shows a side view in cross section of a first embodiment of the present invention.

The same reference numerals represent the same or corresponding parts in all drawings.

It is a rod-shaped linear electromagnetic actuator with a permanent magnet inside.

The stator consists of two annular pieces (yoke 8a, 8
It consists of an electromagnet (b), and the coils 6a and 6b are wound and connected so that the polarities of the magnetomotive force are in opposite directions.

The mover is magnetized in the axial direction of the ring by a permanent magnet 2 having magnetic pole pieces 3 attached thereto, and is supported on the stationary side via a suitable gap so that it can be displaced only in the axial direction.

On the inner circumferential side of the annular electromagnet, there are N and S in the axial direction.

N, 8 to produce magnetic poles of S, N or S, N, N, S
There are grooves 9a and 9b between S and N, and these 19a,
W of the mover permanent magnet 2 is radially opposed to the inner circumferential surface of the mover permanent magnet 9b.
i-pole pieces 3a, 3b are provided.

However, permanent magnet 2. The la pole pieces 3a, 3b are fixed to a shaft 1 which can freely slide in the X direction by means of a bearing 4 supported by a bracket 5.

When a current is passed through the upper side of the coil 6a, the lower side is ■, the upper side of the coil 6b is ■, and the lower side is ■, this stator will move from the left to S,
N, N, S magnetic poles are generated.

Since the magnetic poles of the permanent magnet 2 are N and S from the left, the mover moves to the left under force. This is shown in FIG.

Furthermore, if the currents in the coils 5a and 5b are reversed, a force will be applied to the right as shown in FIG.

It is obvious that the magnetic structure shown in FIG. 1 of the present invention is more rational than the magnetic structure shown in FIG. 7 (conventional example).

A side sectional view of a second embodiment of the invention is shown in FIG.

This embodiment has a structure in which the magnetic pole pieces 3a and 3b of the permanent magnet 2 are separated and used as a mover.

11 is a non-magnetic body that supports the permanent magnet 2 on the stator, and 12 is a non-magnetic body that separates the magnetic pole pieces 3a and 3b.

Although the support structure becomes somewhat complicated, the mass of the mover (separated magnetic pole pieces 3a, 3b) can be reduced, resulting in improved responsiveness.

As a third embodiment of the present invention, although not shown, it is conceivable to cut inductor teeth on the opposing surfaces of the gap between the m1 stone and the permanent magnet.

In this embodiment, although the stroke is small, a large thrust can be obtained.

FIG. 5 is a side view showing a cross section of the upper half of the fourth embodiment of the present invention.

This embodiment is of a rod type and has a structure in which the permanent magnet 2 is moved to the stator side.

The permanent magnet 2 is moved to the stator side, inserted between the yokes 8a and 8b forming the electromagnet core, and fixed to the sides of both.The shaft is a movable core 10 made of a magnetic material, and the inner circumference of the electromagnet is placed with a gap in between. Inductor tooth protrusions 10a and 10b are formed on the outer periphery of the movable core 10 facing each other.

By applying alternating current to the coils 5a and 5b, the movable core 10 generates minute vibrations in the X direction.

A side sectional view of the upper half of the fifth embodiment of the present invention is shown in FIG.

This embodiment is also of the rod type, and the permanent magnet 2 is disposed on the stator side, and the inductor teeth 10a, 1 of the movable core 10 are
0b are extended to the full depth of the grooves of the yokes 8a and 8b of the respective electromagnets to protrude.

In particular, it has the advantage of being a small displacement, high thrust type.

〔Effect of the invention〕

Thus, according to the present invention, the following special effects can be obtained, which greatly contributes to the relevant field industrially.

a) By using rare earth as a permanent magnet and constricting the magnetic flux, the magnetic flux density in the gap can be made extremely high.

Since there is enough space for the coil, a large ampere turn can be taken, so B11 (here, B is the magnetic flux density,
When calculated using 1 as the effective conductor length and i as the current, it can produce 10 times more force than a voice coil motor with the same dimensions.

b) It is promising as a vibration actuator for near compressors. In particular, the movable core type has a small inertia and can be used up to high frequencies.

C) It has a relatively wide linear range from several millimeters to more than ten millimeters, is compact considering its thrust, and has good controllability, so it can be used for servo valves, proportional valves, minute displacement position control, current-force and current- It can be applied as a displacement transducer.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of the first embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams of its operation, FIG. 4 is a side sectional view of the second embodiment of the present invention, and FIG. 5 , FIG. 6 shows the fourth aspect of the present invention. FIG. 7 is a side sectional view of the upper half of the fifth embodiment, and FIG. 7 is a side sectional view of the conventional example. 1... Axis, 2... Permanent magnet, 3.3a, 3b...
Magnetic pole piece, 4... Bearing, 5... Bracket (side root),
6゜5a, 6b...Coil, 7...Central magnetic pole, 8
...Yoke, 8a, F3b...Circular yoke, 9a, 9
b,...Groove, 10...Movable core, 10a, 10b.
...Inductor tooth (protrusion), 11.12...Nonmagnetic material. Figure 2 Figure 3 Chicken Figure 6 Figure 7

Claims (1)

[Scope of Claims] 1. A stator having two sets of excitation cores, each of which has both ends bent in the axial direction and faces each other with a constant gap, each core forming a magnetic path. two excitation windings that are wound around the stator and reversibly generate magnetic flux in opposite directions, and the two sets of excitation iron cores that are movably supported in a linear direction with a constant gap from the stator. A micro-displacement linear electromagnetic actuator characterized by comprising a permanent magnet with a magnetic path configured in series with the permanent magnet, and torque in a linear direction is obtained from the permanent magnet. 2. The stator described in item 1 above, and the same two excitation windings,
A permanent magnet fixed in a linear direction with a certain gap between the two exciting iron cores, and a mover made of a magnetic material placed in the gap formed by the two exciting iron cores and the permanent magnet,
This micro-displacement linear electromagnetic actuator is characterized by obtaining torque in a linear direction from this mover. 3. In the stator described in item 1, a permanent magnet is connected in series between the two excitation cores, and a permanent magnet is wound around each of the excitation cores to reversibly generate magnetic flux in opposite directions. The motor is equipped with two excitation windings, a movable element made of a magnetic material that has a fixed air gap with the stator, and is movably supported in a linear direction, so that torque in the linear direction is obtained from the movable element. A micro-displacement linear electromagnetic actuator featuring: 4. A minute displacement linear electromagnetic actuator characterized in that the movable member according to item 3 above is provided with two teeth.