JP2679047B2 - Drive mechanism of wire dot printer - Google Patents

Description

The present invention relates to a drive mechanism for a wire dot printer. (Prior Art) A direct suction type wire dot printer proposed in, for example, Japanese Utility Model Laid-Open No. 57-88558 discloses a core for forming a required gap between the armature of the print lever and the core. The end face is formed to be one step lower than each end face of the inner and outer peripheral walls.However, in this type of printer, it is difficult to polish the end face of the core correctly, and it takes a lot of man-hours and the gap is constant. It has a problem that it cannot be managed. (Problems to be Solved by the Invention) The present invention has been made in view of such a problem, and an object thereof is to easily manage a gap and to maximize energy conversion efficiency. It is to provide a new wire dot type printer drive mechanism. (Means for Solving the Problems) That is, the present invention is, as a drive mechanism of a wire type dot printer for achieving the above-mentioned problems, between inner and outer peripheral walls formed in an annular projection on a core block and between these peripheral walls. Each of the end faces of the plurality of cores arranged in an annular shape is formed so as to form the same plane, while a plate-shaped yoke that is placed on the core block to form an annular magnetic path is provided with inner and outer peripheral walls of the core block. The annular inner and outer peripheral walls, which are opposed to each other and whose end faces are flush with each other, are integrally formed to project. (Example) Then, the Example illustrated below is described. The drawings show one embodiment of the present invention. In the figure, reference numeral 1 is a frame having a nose 17 at its tip, and a core block 3 made of a magnetic material having a high magnetic permeability is positioned and fixed to an annular projection 20 and a dowel provided on the back surface of the frame 1. In the core block 3, an inner peripheral wall 5 is formed in an annular shape so as to surround the central opening 5a, and an outer peripheral wall 3d is formed in an annular shape on the outer periphery of the core block 3. Cores 4 are arranged in an annular shape, and their respective end surfaces 3c, 3a, 3b are formed as the same surface as shown in FIG. On the other hand, the first stacked on the core block 3
The yoke 6 has a plate-like shape with high magnetic permeability, and includes two inner and outer peripheral walls 8 and 6d whose end faces are flush with each other at positions corresponding to the peripheral walls 5 and 3d of the core block 3 described above. Are formed to project annularly, and the plate surface 6c of the yoke 6 and the core 4 are
These are in surface contact with the peripheral walls 5 and 3d of the core block 3 so that a required gap is formed between the end face 3b of the core block 3 and the magnetic flux and the magnetic resistance is reduced as much as possible. It is placed like this. A large number of slits 24 are radially formed from the central opening 8a in the first yoke 6, and each of these slits 24 has a thin print lever 12 having a wire 13 attached to its tip. Armature made of ferromagnetic material
11 is made to oppose the coil core 4, and is supported so as to swing around the support shaft 10 at the base end. Reference numeral 15 in the drawing denotes a second yoke for positioning and supporting the base end portion of the print lever 12 on the outer peripheral wall 6d of the first yoke 6 by means of the cross-shaped slits 7 and 25.
Is a coil wound around the core 4, 18 is a return spring for urging the printing lever 12 to the non-printing position, 21 is a wire guide mounted in the nose 17, and 14 is a substrate. Therefore, when the print lever 12 and the first and second yokes 6 and 23 are assembled in this order on the core block 3 thus constructed, the fulcrum shaft 10 of the print lever 12 is moved by the first yoke 6. Correctly positioned on the core block 3,
The armature 11 is supported so as to maintain a uniform gap between the end surface 3a of the outer peripheral wall 3d and the end surface 3b of the core 4 which is flush with the outer surface 3d, and the inner and outer peripheral walls 8, The first yoke 6 raised by 6d is
As shown in the figure, the plate surface 6c is supported so as to form a required space between the plate surface 6c and the end surface 3b of the core 4, and the magnetic flux from here is suppressed from directly flowing toward the end surface of the core 4. To be Therefore, the magnetic flux from the core 4 generated by the energization of the coil 15 is transferred from the armature 11 to the print lever 12, further to the first yoke 6 via the second yoke 23 adjacent to this side surface, and further to the core block 3. By forming an annular side magnetic path that returns from the outer peripheral wall 3d to the core 4, it is possible to further enhance the energy conversion efficiency for driving the print lever 12. (Effect) As described above, according to the present invention, the end faces of the core and the inner and outer peripheral walls are formed so as to be flush with each other. Therefore, by grinding these end faces at the same time, the gap between the armature and the core is reduced. It is possible to easily and accurately manage the gap between the print levers, make the suction force of each print lever uniform, and greatly improve the print quality. Moreover, on the plate-shaped yoke placed on the core block,
Since the ring-shaped protrusions whose end surfaces are flush with each other are formed so as to face the inner and outer peripheral walls of the core block, these protrusions form a gap between the plate surface of the yoke and the end surface of the core to prevent leakage of magnetic flux. The leakage of the magnetic flux directly flowing from the plate surface to the end surface can be eliminated to further enhance the energy conversion efficiency of this type of print head, and at the same time, the plate-shaped yoke can be provided with required strength.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of an apparatus showing an embodiment of the present invention, FIG. 2 is an exploded perspective view of the same apparatus, and FIG. FIG. 4 and FIG. 4 are views showing the flow of magnetic flux in the same apparatus. 3 ... core block, 3d ... outer peripheral wall 4 ... core, 5 ... inner peripheral wall 6 ... first yoke, 6d ... outer peripheral wall 8 ... inner peripheral wall, 11 ... armature 12 ... print lever

   ────────────────────────────────────────────────── ─── Continuation of front page    (56) References JP-A-62-73960 (JP, A)                 JP 63-176157 (JP, A)                 JP 59-218871 (JP, A)                 JP 62-101458 (JP, A)                 JP-A-60-64862 (JP, A)                 JP 62-259871 (JP, A)                 57-88558 (JP, U)                 62-191433 (JP, U)                 59-131840 (JP, U)                 Actual Development Sho 61-100538 (JP, U)

Claims (1)

(57) [Claims] In order to form an annular magnetic path, the inner and outer peripheral walls projecting annularly on the core block and the respective end surfaces of the plurality of cores annularly arranged between the peripheral walls are formed to be flush with each other. On the plate-shaped yoke mounted on the core block, an annular inner and outer peripheral wall whose end faces are flush with each other is formed integrally with the inner and outer peripheral walls of the core block. Printer drive mechanism.