JPH0533666B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. INDUSTRIAL APPLICATION The present invention relates to an electromagnetic actuator mechanism in which a clapper armature, or a rotating armature, is attracted to a yoke upon energization of an electromagnet. The actuator mechanism of the present invention
Often used in printers.

B. Prior Art The present invention preferably combines two known actuator mechanisms with different principles, namely, the electromagnet of the conventional Clatspa armature and the actuator mechanism whose principle is described in Japanese Patent Publication No. 44766/1983. . 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 aligned with one another. A ram movable in the direction of the alignment of the working gap is positioned between the magnetically working gap. The cross section of the ram is made to match the cross section of the working gap and is, for example, cylindrical or rectangular. The ram includes a plurality of disc-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 volume is comparable to the volume of the working gap. In the starting position of the ram when the electromagnet is in its unenergized state, the armature member is substantially in the working gear of the electromagnet.
Positioned externally. When the electromagnet is energized, the armature member is pulled inside the working gap,
It is accelerated in the process.

C. Problems to be Solved by the Invention However, a drawback of this type of ram actuator is that it is subject to significant lateral unbalanced forces.

Conventional Clatspa armature type electromagnetic actuators are widely used in IBM 1403 printing equipment, etc. (IBM Technical Disclosure Bulletin Vol. 16, No. 11, April 1974, No.
(Please refer to Figure 1 on page 3529 if necessary), it requires a large space and has the drawbacks of having an electromagnetic efficiency of only 2.3%.

The purpose of the present invention is to have strong force, short operating time,
The object is to provide a good actuator mechanism that takes up minimal space.

D Means for Solving the Problem When the electromagnet is energized, the Clatspa armature 1 moves in the direction D of the arrow and undergoes a rotational movement about its axis 10. The plane of movement of the Klapper 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 an energizing coil 3 and faces the clamp 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 surface 7A of the central leg 7 may be located inside or outside the working gap 9.

When the electromagnet 2 is energized, the clamp 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. Pole face 5 of outer magnetic poles 5 and 6
On one side of A and 6A, Clatupa armature 1 is installed.
Approximately half of the magnetic flux passing through passes through. The width C of the clamp armature 1 is considerably less than the length between the pivot shaft 10 and the working gear 9. In other words, it is preferable that the width is more than twice the width C of the Clatspa armature 1. The magnetic flux passing through this actuator mechanism is represented by a group of magnetic field lines 4B. The local magnetic flux density becomes higher as the magnetic field lines passing through it become denser. Preferably, the yoke structure and the clasp armature are positioned substantially symmetrically to a plane of movement 1A of the clasp armature passing through the center of the central leg 7. The moving end of this Clatsupa armature can perform switch movements, stroke movements,
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. namely, a base 21 of soft magnetic material, an electromagnetic coil 25 inserted into the base 21, two yoke bars 23 and 24 fixed to the base 21, and a clamp armature 22 connected to the base 21. base 2
1 has a recess 21-1 and a central leg 21-2, the latter of which 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, yoke bars 23 and 24 are attached to the edges of base 21 by threaded connections, welded joints, or the like. An operating gap is provided between the pole faces 23-1 and 24-1 of the yoke bars 23, 24. One end of the clamp armature 22 itself is fixed to the inclined surface of the block 26.
The block 26 is disposed in a recess in the front view 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. A portion of the Clatspa armature near its fixed end is formed by a leaf spring 22-2.
That portion functions as a pivot when the clapper armature 22 is pulled into the working gear upon energization of the electromagnet. Clatupa armature 22
The free end of is provided with a recess 22-4 which is operatively connected to the printing ram 29 (shown in broken lines) and moves the ram 29 in the P direction. The inner ends of the yoke bars 23, 24 may be provided with ramps 23-2, 24-2 to suit the shape of the particular working gap.

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 also shows the portion of armature 22-3 drawn into working gear 27. The forces initially developed when the armature is drawn into the working gap are primarily between the lateral faces 22-4 and 22-5 of the clamp armature 22-3 and the pole faces 23-1 and 24-1 (where The working gap is a function of the attractive force that occurs at the working gap. This principle of an electromagnetic actuator is known from the aforementioned Japanese Patent Publication No. 59-44766.

As it is further drawn into the working gear of the Clatpa armature 22-3, the central leg 21-2
The attractive force gradually increases due to the magnetic pole face 21-3. This type of attraction technique between a clamp armature and an electromagnetic yoke is generally known (eg, the printing hammer drive of the IBM System 1403 printing machine). 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. 44766 with those of the conventional Clatspa armature system.

4A to 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 operating gap near the yoke are shown by solid lines. The higher the density of magnetic lines of force, the higher the magnetic flux density. By tilting the free ends of the legs of the yoke, specific advantages with respect to magnetic flux are obtained.

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

Advantages The asymmetrical positioning of the clamp armature during the working gear (particularly at the end of acceleration) results in lower lateral forces.

The example shown in FIG. 4B is a combination of a T-shaped clasp armature and an outer yoke leg with a sloped inner end.

Advantages: Large energy, small travel distance. In the example of FIG. 4C, the Klapper armature has a rectangular cross section.

Advantages Easy to manufacture, small mass of armature In the example of FIG. 4D, the Clatspa armature has a π-shaped cross section.

Advantages: Large initial acceleration In the example of Figure 4E, the Clatspa 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 FIG. 1, it is preferable that the width B of the magnetic pole surface 7A of the central leg portion 7 is approximately half the distance C between the magnetic pole surfaces 5A and 6A of the outer leg portions 5 and 6.

F Effects of the Invention The electromagnetic actuator of the present invention has a specific arrangement of the center leg and the outer leg with respect to the armature, so that the armature is strongly attracted to the armature by the edge effect between the center leg and the armature. The closer they get, the more strongly they attract each other, and when they work together, a powerful attraction is obtained. Furthermore, since the operating time is short, high-speed repetitive operations are possible. In addition, with only two outer legs, the lateral attracting force was difficult to balance with each other due to manufacturing errors, but in the present invention, the attracting force of the central magnetic pole increases while the armature moves. It has a remarkable effect of reducing it. Furthermore, since the armature moves in a direction that intersects the E-shaped cross section of the yoke structure, a larger edge effect (magnetic flux density concentrates and produces a larger magnetic force) can be obtained than when the armature moves in other directions.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the 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.
FIGS. 4A to 4E are cross-sectional views showing a combination structure of a clamp armature and a magnetic yoke of different shapes, similar to FIG. 3. DESCRIPTION OF SYMBOLS 1...Clatsupa armature, 2...Electromagnet, 1A...Moving surface of Clatupa armature, 3...Biasing 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... Magnetically actuated gap, 10
...Pivotal axis.

Claims (1)

[Scope of Claims] 1. An electromagnet including an energizing coil and a magnetizable yoke structure, and an elongated clamp armature rotatable about a pivoting part, and when the electromagnet is energized, the yoke is In the electromagnetic actuator mechanism for attracting the armature to the structure, the yoke structure has a rectangular parallelepiped shape as a whole, and each extends in the longitudinal direction so that a cross section perpendicular to the longitudinal direction has a substantially E-shape.
It has one central leg, two outer legs, and a base common to these legs, the biasing coil is wound around the center leg, and the biasing coil is wound around the two outer legs. the free ends being bent in opposite directions to form a longitudinally extending magnetically actuated gap between the pole faces at their ends, with the ends of said central leg extending outwardly or inwardly from said magnetically actuated gap; positioning a magnetic pole face such that upon energization of the electromagnet, the armature is drawn into the magnetically actuated gap, and magnetic flux generated from the central leg flows laterally through the armature to the pole face of the outer leg; The armature is disposed substantially parallel to and in the vicinity of the magnetically actuated gap and the magnetic pole surface of the central leg, and the length of the armature is such that the magnetic pole surface of the central leg attracts the armature more strongly as the magnetic pole surface of the central leg increases. is sufficiently longer than the length of the magnetically actuated gear, and the length of the armature is at least twice its width. 2. The electromagnetic actuator mechanism according to claim 1, wherein the armature has a rectangular cross-sectional shape, a rectangular shape with an inclined end, a T-shape, a U-shape, or a π-shape. .