JPS6235857A - Electromagnetic actuator mechanism - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of Application The present invention relates to an electromagnetic actuator mechanism in which a clapper armature, i.e. a rotating armature, is attracted to a yoke upon energization of an electromagnet. , often used in printers.

B. Prior Art The present invention utilizes two known actuator mechanisms of different principles: the conventional clapper armature electromagnet;
The actuator mechanism whose principle is described in Japanese Patent Publication No. 59-44766 is suitably combined. The latter are used as high speed electromagnetically actuated ram actuators, especially in impact printers. This electromagnet essentially consists of a pair of magnetizable yoke halves of approximately symmetrical design and an energizing coil. The opposing magnetic pole ends of these yoke halves form a plurality of magnetically actuated gaps that are aligned with each other. A ram movable in the direction of the alignment of the working gaps is positioned between the magnetic working gaps. The cross section of the ram is adapted to the cross section of the working gap and is, for example, cylindrical or rectangular. The ram includes a plurality of disk-shaped or rectangular armature members made of magnetizable material, between which are arranged spacers of primarily non-magnetized material. These armature members are sized so that their volumes are as large as the volume of the working gap. In the starting position of the ram when the electromagnet is in an unenergized state, the armature member is positioned substantially outside the working gap of the electromagnet. When energizing the electromagnet.

The armature member is drawn inside the working gap and is accelerated in the process.

The problem that the C0 invention seeks to solve However, a drawback of this type of ram actuator is that it is subject to significant lateral unbalanced forces.

Conventional clapper armature type electromagnetic actuators are widely used in IBM 1403 printing equipment and others (IBM Technical Disclosure Bulletin No. 1).
6, No. 11, April 1974, page 3529, Fig. 1, as necessary), it requires a large space and has the disadvantage that the electromagnetic efficiency is only 2.3%.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an actuator mechanism that has high force, short operating time, and requires minimal space.

Means for solving problem D6 Upon energizing the electromagnet, the clapper armature 1 moves in the direction of the arrow and undergoes a rotational movement about its axis 10. The plane of movement of the clapper armature 1 is perpendicular to the plane of magnetic flux 4A of the yoke structure 4 of the electromagnet 2. When viewed from the magnetic flux plane 4A, the yoke structure has a substantially E-shaped cross section. It consists of one central leg 7, two outer legs 5, 6 and a common base 8. Magnetic pole surface 7a of central leg portion 7
is surrounded by a biasing coil 3 and faces the clapper armature 1. The free ends of the outer legs 5.6 are bent towards each other so as to form a magnetically actuated gap 9 between their pole faces 5A and 6A. The magnetic pole face 7A of the central leg 7 may be located inside or outside the working gap 9.

When electromagnet 2 is energized, clapper armature 1
is drawn into the working gap 9. At this time, since the magnetic pole surface 7A of the central leg 7 is present, the pulling force gradually becomes stronger. Approximately half of the magnetic flux crossing the clapper armature 1 passes through one of the magnetic pole faces 5A, 6A of the outer magnetic poles 5 and 6. The width C of the clapper armature 1 is preferably significantly less than the length between the pivot shaft 10 and the working gap 9, in other words more than twice the width C of the clapper armature 1. The magnetic flux passing through this actuator mechanism is represented by a group of magnetic lines of force 4B, and the local magnetic flux density at zero becomes higher as the lines of magnetic force passing therethrough become denser. Preferably, the yoke structure and the clapper armature are positioned approximately symmetrically to a plane of movement IA of the clapper armature passing through the center of the central leg 7, the moving end of which is subject to a switching or stroking movement. Can be designed to suit impact movements.

E. Embodiment FIG. 2 is an exploded perspective view of an electromagnetic actuator mechanism to which the present invention is applied to an impact printer.

This mechanism consists of five major parts. That is, a base 21 made of soft magnetic material, and an electromagnetic coil 25 inserted into the base 21. Two yoke bars 23 and 24 . fixed to the base 21 .
and a clapper armature 2 connected to the base 21
It is 2. The base 21 has a recess 21-1 and a central leg 21-1.
2, and the latter is provided with a magnetic pole face 21-3. This recess has the function of accommodating the electromagnetic coil 25. As shown in FIG. 2, the yoke bars 23 and 24 are screwed together;
It is attached to the edge of the base 21 by a welding joint or the like.

Both magnetic pole faces 23-1 and 24- of the yoke bar 23.24
An operating gap is provided between the two. One end of the clapper armature 22 itself is fixed to the inclined surface of the block 26. The protrusion 26 is disposed in a recess on the front surface of the base 21.

The recesses 21-1 and 21-4 are connected to each other so that the coil coupling portion 40 can be easily guided to the outside. The part of the clapper armature near its fixed end is the leaf spring 22-
It is formed and made by 2. That portion functions as a pivot when the clapper armature 22 is drawn into the working gap upon energization of the electromagnet. The free end of the clapper armature 22 is provided with a recess 22-4 which is operatively coupled to the printing ram 29 (shown in phantom) and moves the ram 29 in the P direction. The inner ends of the yoke bars 23.24 are provided with sloped surfaces 23-2.2 to accommodate the shape of the particular working gap.
24-2 may be provided.

FIG. 3 is a cross-sectional view taken along line A--A of FIG. 2, showing the yoke structure of the magnet and the magnetic path in the clapper armature.

In FIG. 3, the lines of magnetic force 30 are represented by thin solid lines. This magnetic flux density becomes higher as the magnetic lines of force become denser. This cross-sectional view shows the armature 2 drawn into the working gap 27.
Part 2-3 is also shown. The initial force when the armature is drawn into the working gap is primarily due to the clapper
It is a function of the attractive forces that occur between the lateral faces 22-4 and 22-5 of the armature 22-3 and the pole faces 23-1 and 24-1, where the working gap is formed. This principle of electromagnetic actuators was developed in the aforementioned Japanese Patent Publication No. 59-44.
Known as number 766.

As the clapper armature 22-3 is drawn further into the working gap, the magnetic pole face 21- of the central leg 21-2
3, the force of attraction increases gradually. Clapper
This type of attraction technique between the armature and the yoke of the electromagnet is generally known (e.g. IBM System 1
403 printing device printing hammer drive). However, the magnetic flux aspects in this known system differ from those of the mechanism according to the invention (for example in terms of drive surfaces).

The reference numbers in FIG. 3 correspond to those in FIG.

As already mentioned, the mechanism of the present invention is
It combines the advantages of the electromagnetic actuator mechanism according to No. 766 with the advantages of a conventional clapper armature system.

4A-4E are cross-sectional views similar to that of FIG. 3 of an embodiment in which the cross-sectional shapes of the clapper armature and magnetic yoke structure are different.

The magnetic field lines in the yoke and the working gap near the yoke are shown by solid lines.The higher the density of the magnetic field lines, the higher the magnetic flux density.By tilting the free ends of the yoke legs, advantages unique to the shape of the magnetic flux can be obtained. .

The example of FIG. 4A is a combination in which both the clapper armature and yoke leg ends are provided with sloped inner ends.

Advantages The asymmetrical positioning of the clapper armature during the working gap (especially at the end of acceleration) results in lower lateral forces.

The example of FIG. 4B is a combination of a T-shaped clapper armature and an outer yoke leg with a beveled inner end.

Advantages High Energy, Distance Travel In the example of Figure 4C, the clapper armature has a rectangular cross section.

Advantages Easy to manufacture, small mass of the armature In the example shown in the 4D diagram, the clapper armature has a π-shaped cross section.

Advantages Large initial acceleration In the example of Figure 4E, the clapper armature has an (inverted) U-shaped cross section.

Advantages Lower lateral forces than in the example of Figure 4D result in higher initial acceleration.

In addition, in FIG. 1, the width B of the magnetic pole surface 7A of the central leg portion 7 is
It is preferable that the distance C between the magnetic pole faces 5A and 6A of the outer legs 5 and 6 be approximately half.

F1 Effects of the invention According to the invention, there is a central leg in addition to the outer leg, so
An electromagnetic actuator mechanism is provided in which the retraction force gradually increases when the electromagnet is energized, the force is strong, the operating time is short, and the space is small.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an electromagnetic actuator mechanism of the present invention that can be used in an impact printer. FIG. 2 is an exploded view of the mechanism of FIG. 1. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. Figures 4A to 4E are similar to those in Figure 3.
FIG. 3 is a cross-sectional view showing a combination structure of an armature and a magnetic yoke having different shapes. 1...Clapper armature, 2...Electromagnet. IA...The moving surface of the clapper armature. 3... energizing coil, 4... yoke structure, 4A...
...Face of magnetic flux, 4B... Lines of magnetic force, 5.6...
outer leg. 7...Central leg, 5A, 6A, 7A...Magnetic pole surface, 8...Base, 9...Magnetic operation gap, 10
...Pivotal axis. Applicant International Business Machines Corporation Representative Patent Attorney Oka 1) Next Student (1 other person) 1- Klappa 1 Marmato Air FIG, 3

Claims (2)

[Claims] (1) An electromagnetic actuator mechanism including an electromagnet including an energizing coil and a magnetizable yoke structure and a rotating armature, the clapper armature being attracted by the yoke structure when the electromagnet is energized; The central leg has a substantially E-shaped cross section consisting of one central leg, two outer legs, and a base common to these legs, and the central leg is wound with the biasing coil. The magnetic pole faces of the outer legs face the clapper armature, and the free ends of the two outer legs are bent toward each other so that a magnetically actuated gap exists between the pole faces of the two outer legs. an electrode actuator mechanism, characterized in that the magnetic pole face of the central leg is located outside or inside the magnetic actuation gap. (2) The cross-sectional shape of the armature is rectangular, rectangular with an inclined end, T-shaped, U-shaped, or π-shaped. electromagnetic actuator mechanism.