JPS6212615Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a print wire driving device such as a wire dot printer that selectively drives a print wire to collide with a print paper to print a dot pattern on the print paper.

There are two ways to drive this type of printed wire: the so-called normally open type in which the coil is energized and the printed wire is driven when the armature is attracted to the core, and the other is the so-called normally open type in which the printed wire is driven when the armature is attracted to the core by a permanent magnet. There is a so-called normally closed type in which the printed wire is driven when the magnetic force is offset by energization and restored by spring force, but the latter type is considered advantageous because it is easy to increase speed and consumes less power.

Figure 1 shows a conventional printed wire drive device of the latter type, and Figure 2 shows its main parts. This is what was disclosed.

In the following description, when "upper" or "lower" is used, the distinction between upper and lower in the drawings is used as a reference. In the figure, 1 is a yoke (part of the core), 2 is a permanent magnet, 3 is a core, 4 is a coil, and 5
6 is an armature, 6 is a printed wire, and 7 is a leaf spring, and the figure shows the point at which the armature 5 has been restored by the force of the spring. The leaf spring 7 has its base end 7a fixed to the yoke 1. Then, two parallel slits 8, 8 are formed from the base end 7a to the tip 7b.
The bent portion 7c, which is cut toward the slits 8 and 8, is bent downward to form a cut and raised portion 7d.
is formed. An end portion 7e of the cut and raised portion 7d is fixed to a protruding portion 1b that is a part of the yoke 1. The armature 5 is fixed on the back surface of the flexible portion 7c of the leaf spring 7. These portions 7a, 7c, and 7e are fixed by welding, brazing, or the like.
When the coil 4 is not energized, an attractive force is always generated on the tip end surface 3a of the core 3 by the permanent magnet 2 and attracts the armature 5, but when the coil 4 is energized to cancel the magnetic force, The armature 5 is separated from the distal end surface 3a of the core 3 by the spring force of the leaf spring 7, rotates around point p in the figure, and connects the printed wire 6 attached to the armature 5.
is driven to perform dot printing. By the way, as shown in the bottom view of FIG. 3, this print wire drive device is assembled in a radial circular arrangement as a print head, and miniaturizing this print head will increase the spacing speed and increase the printer speed. This is in demand due to the miniaturization of In order to meet this demand, it is necessary to downsize the print wire drive device itself. When accommodating as many as 24 print wire drives in one print head as shown in FIG. 3, it is also necessary to reduce its width (perpendicular to the plane of the paper in FIG. 1). However, in the case of such a conventional print wire drive device, if the entire device is made proportionally smaller, the amount of displacement of the print wire 6 becomes smaller and it no longer moves within the range necessary for original dot printing. In addition, if the width of the yoke 1 or the core 3 is made narrower, the spring constant becomes smaller and a predetermined response speed cannot be obtained. If the thickness is increased, there is a problem in that fatigue at the bent portion 7f becomes severe, leading to a breakage accident.

This invention was made by focusing on these problems, and uses a second leaf spring made of a relatively thin spring material different from the leaf spring at the cut-and-raised portion of the leaf spring, and furthermore, The purpose is to solve the above problems by improving the relative positional relationship of the armature, core, yoke, etc.

This invention will be explained below based on the drawings. It should be noted that portions similar to those of the prior art are denoted by the same reference numerals in the drawings, and redundant explanation will be omitted.

4 to 6 are diagrams showing an embodiment of this invention. The first leaf spring 17 includes a pair of leaf spring parts 17p having a generally U-shaped overall plane that communicate with each other via a communication part 17j at the tip end 17b, and has grooves 18, 18 in the leaf spring parts 17p. The lip-shaped flexible portion 17 protrudes from the communication portion 17j with a length equal to or less than the leaf spring portion 17p while being held in place.
c, and its base end 17a, that is, the plate spring portion 1
The base end 17a of 7p is horizontally fixed to the upper end 11a of the yoke 11 (a part of the core 13), and the armature 15 is joined and supported from its non-suction surface by this flexible portion 17c. Here, the "non-suction surface" means:
This term refers to the "face" opposite the "face" on which the armature 15 is attracted by the core 13.
On the other hand, the upper part 19a of the second leaf spring 19 is fixed to the base end 15a of the armature 15, and the lower part 19b of the second leaf spring 19 is fixed to the protruding part 11b of the yoke 11.
The whole is fixed at right angles to the first leaf spring 17. The thickness of the second leaf spring 19 is preferably about 1/5 to 1/2 of the thickness of the first leaf spring 17. Furthermore, methods such as welding or brazing can be used for fixing. When the coil 14 is not energized, the armature 15 is attracted to the upper end 13a of the core 13 by the permanent magnet 12, and the first leaf spring 17 is bent to maintain the state shown in FIG. The second leaf spring 19 is positioned together with the first leaf spring 17 so as to maintain a straight shape in this state, and is fixed as described above. When the coil 14 is energized to offset the attractive force of the permanent magnet 12, the first leaf spring 17 is restored as shown in FIG. Here, the armature 15 has its upper surface
It is supported by the lip-shaped flexible portion 17c of the leaf spring 17, and its base end 15a is connected to the second leaf spring 1.
9, as shown in FIG.
is rotated counterclockwise around p' near the base end 15a. At this time, the second leaf spring 1
As shown in FIG. 6, the entire armature 9 is tilted clockwise, and its upper part 19a is rotated counterclockwise to hold the base end 15a of the armature 15. The force acting on the leaf spring 19 is mainly a tensile force, and since the leaf spring 19 is thin, the "spring force" does not contribute much. In this way, the armature 15 has its base end 1
5a as the center of rotation, the distance l ₁ ' between the rotation center p' and the core tip surface 13a is smaller than the conventional distance l ₁ [FIG. 1], and therefore the core 13 and the printed wire 16 spacing l ₂ and armature 1
5 and the core 13 as before, the amount of displacement of the printed wire 16 will be larger than before. In other words, this means that the entire device can be made smaller in size to obtain the same amount of light. Furthermore, due to the relationship between the leaf spring portion 17p and the lip-shaped bending portion 17c as described above, the fulcrum for the bending deformation of the conventional one is only near the point p shown in FIG. The fulcrums for the deflection deformation occur at two locations, indicated by H ₁ and H ₂ in FIG. 5, and the deflection stress is further dispersed throughout the first leaf spring 17.
The life of the first leaf spring 17 will be further extended.

As explained above, according to the present invention, the second
Since the center of rotation of the armature is regulated by the leaf spring, the amount of displacement of the print wire can be expanded, which means that the entire device can be made smaller, and the print head in which this print wire drive device is integrated can be made smaller. , the non-suction surface of the armature is supported by a lip-shaped flexible portion, and when the first leaf spring is activated,
By making the lip-shaped bending part tilt with respect to the leaf spring part and creating two supporting points for bending deformation, the stress caused by the bending deformation of the first leaf spring can be more generally dispersed. Therefore, the life of the first leaf spring can be extended.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional print wire drive device, Fig. 2 is an enlarged perspective view of its main parts, Fig. 3 is a bottom view when a large number of print wire drive devices are arranged, and Fig. 4 is a print wire drive device of the present invention. An enlarged perspective view of the main part of the wire drive device, and FIGS. 5 and 6 are explanatory diagrams of its operation. 1, 11... Yoke (part of the core) 2, 12...
... Permanent magnet, 3, 13 ... Core, 4, 14 ... Coil, 5, 15 ... Armature, 6 ... Printed wire, 7 ... Leaf spring, 8, 18 ... Groove, 17
...First leaf spring, 19...Second leaf spring.

Claims (1)

[Claims for Utility Model Registration] A first leaf spring is fixed to the upper end of the side wall of the yoke, which is integrally formed with the core and forms a substantially U-shaped side surface together with the core, so as to be substantially parallel to the upper surfaces of the core and the yoke; The first leaf spring connects and supports the non-suction surface of the armature, and the lower part of the second leaf spring, which is disposed perpendicularly to the first leaf spring, protrudes from the side wall of the yoke. In a printed wire drive device in which the base end of the armature is fixed to and supported by the upper part of the second leaf spring, the first leaf spring communicates with the distal end of the armature through a communicating part. A pair of leaf spring parts whose overall planes form a substantially U-shape, and in a state where the leaf spring parts are sandwiched, the length from the communicating part is shorter than the length size of the leaf spring parts in the proximal end direction of the leaf spring parts. 1. A printed wire drive device comprising: a lip-shaped flexible portion projecting from the first plate spring; and a non-suction surface of an armature is joined and supported by at least the flexible portion of the first leaf spring.