JPH0415495Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a wire dot print head in a serial dot printer.

[Conventional technology]

Japanese Utility Model Application No. 59-157827 discloses a means for fixing a leaf spring in a spring charge type wire dot printing head in which a printing wire is fixed to one end of an armature and a leaf spring is fixed to the other end.

As shown in the main part perspective view of FIG. 3, this is a spacer yoke 4 in which a circular recess 2 provided in a leaf spring 1 is superimposed on an armature yoke 3 by laser welding or the like.
Compared to the method of fixing with screws, it has advantages such as fewer parts and improved mounting accuracy.

In the drawings, 5 is an armature, 6 is a printing wire, and 7 is a welding nugget.

[Problem that the invention attempts to solve]

However, according to the above technique, as shown in FIG. 4 of the A-A line in FIG. The leaf spring 1 is deformed by this force, and a gap 8 is created.

Furthermore, due to the influence of this deformation, Fig. 3B-B
As shown in the cross-sectional view of FIG. 5, which is a view taken along the line, gaps 9 and 10 are also created near the fixed end of the leaf spring 1, which increases the variation in the leaf spring constant and amount of deflection, resulting in variation in printing force. There was a problem of poor manufacturing yield.

[Means for solving problems]

The present invention is characterized in that the welded portion of the leaf spring with the spacer yoke is connected through a hinge so that the welded portion is independent of the leaf spring, and a groove is formed around the connected portion. do.

[Effect]

With the above configuration, when the leaf spring is welded to the spacer yoke, the deformation of the leaf spring due to contraction due to cooling after heating is absorbed at the hinge part, so that the deformation of the leaf spring is eliminated and the leaf spring and the spacer yoke are welded together. It is possible to assemble them in close contact with each other without forming any gaps between them, and even if there is a gap between the leaf spring and spacer yoke, they can be easily brought into close contact with each other by bending the hinge. This makes it possible to suppress variations in spring constant and deflection amount, making it possible to easily suppress variations in impact force.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of the main parts, and FIG. 2 is a sectional view taken along the line CC in FIG. 1. In the figure, 3 is an armature yoke, 4 is a spacer yoke, 5 is an armature,
Reference numeral 6 denotes a printing wire attached to the tip of this armature, which is similar to the conventional example described above.

Reference numeral 11 designates a leaf spring, the above-mentioned armature 5 is attached to the tip of the leaf spring, and the welded part 1 at the rear end of the leaf spring 11 is attached.
For example, a groove 13 is formed around the groove 13 at a substantially right angle.
The welded portion 12 is connected to the leaf spring 11 by a hinge 14 at one location.

Furthermore, as shown in FIG. 2, the plate thickness t of this welded portion 12 is made smaller than the plate thickness T of the main body of the leaf spring 11, and even if the bulge of the weld nugget 7 during welding is added, the plate thickness T
It is designed not to exceed.

According to the above configuration, the welded portion 12 of the leaf spring 11
When laser welding the leaf spring 11 to the spacer yoke 4, the leaf spring 11
However, since the groove 13 is provided, the leaf spring 11 is only affected by the hinge 14.
When assembled as a wire dot printing head, the leaf spring 11 is attached to the welded part 1 so that the hinge 14 can be easily bent when the leaf spring 11 is pressed by a mating member (not shown).
The mating member and the spacer yoke 4 can be brought into close contact with each other in the vicinity of the two points, preventing the occurrence of gaps, and making it possible to suppress variations in the spring constant and deflection amount, thereby creating a stable impact force. can be obtained easily.

Note that in the above embodiment, the thickness t of the welded portion is made smaller than the thickness T of the leaf spring to take into account the effect of the buildup of the weld nugget during welding, but both thicknesses are made the same and a mating member (not shown) is used. A relief recess for the weld nugget may be provided in the weld nugget.

Further, the shape of the groove described above is not limited to a right angle, but may be circular or any other shape as long as it is formed so that the hinge can be easily bent.

[Effect of idea]

According to the present invention described in detail above, the welded portion of the leaf spring with the spacer yoke is connected through a hinge so that the welded portion is as independent as possible from the leaf spring body, and a groove is formed around the connected portion. By forming this structure, the deformation of the leaf spring due to contraction during welding can be absorbed by the hinge, and even if a gap occurs between the leaf spring and the spacer yoke, the hinge can be bent. Since the leaf springs can be easily attached to each other, it is possible to assemble the leaf springs in close contact with the mating member, and by suppressing variations in the spring constant and deflection of the leaf springs, it is easy to reduce variations in the impact force of the printing wire. It has an effect that can be suppressed.

In addition, it is possible to manufacture with a larger tolerance for the gap between the leaf spring and the spacer yoke, which is caused by variations in the flatness of the leaf spring itself and variations in the setting when setting the leaf spring in the welding jig. Yield is dramatically improved, and wire dot printing heads with high precision can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of essential parts showing an embodiment of the present invention;
2 is a sectional view taken along the line C-C in FIG. 1, FIG. 3 is a perspective view of main parts of the conventional example, and FIG.
FIG. 5 is a perspective view taken along line BB in FIG. 3. 4... Spacer yoke, 5... Armature,
6... Printing wire, 11... Leaf spring, 12... Welded part, 13... Groove, 14... Hinge.

Claims (1)

[Scope of Claim for Utility Model Registration] A spring charge type wire dot printing head in which a printing wire is fixed to one end of an armature, a leaf spring is fixed to the other end, and this leaf spring is fixed to a spacer yoke by welding. Wire dot printing characterized in that a groove is formed around the welded part with the spacer yoke so that the welded part is independent from the leaf spring body, and the leaf spring body and the welded part are connected by a hinge. Head.