JPS6010861Y2 - wire dot head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire dot head that biases a leaf spring to release the biasing force of the leaf spring and drive a printed wire.

Conventionally, in this type of wire dot head, the armature was welded to the free end of the leaf spring by spot welding, laser welding, or the like.

However, the bending stress generated when the leaf spring is bent is concentrated in a part of the welded part as a so-called splitting force, and the material deteriorates thermally during welding, reducing the fatigue limit of the welded part to about 173. However, there was a drawback that the leaf spring was easily damaged at this welded portion.

Therefore, the present invention aims to improve the above-mentioned drawbacks of the conventional technology.The present invention has the following characteristics: S is a cylindrical magnetic housing; an armature welded to the free end of each piece; a printed wire placed near the free end of each piece; and means for biasing each piece of the leaf spring through magnetic force. However, in a wire dot head that performs dot matrix printing using the impact force of the print wire when the deflection of the leaf spring is released, the leaf spring is inserted between the fixed end of each piece of the leaf spring and the welded part of the armature. There are holes in the wire dot head to distribute the stress.

Examples will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view showing an embodiment of the wire dot head according to the present invention, in which 1 is a first yoke forming a common magnetic path, 2 is a core fixed to the upper surface of the first yoke 1, and 3 is a first yoke that forms a common magnetic path.
is a permanent magnet which also serves as a housing; 4 is a degaussing coil that is in the magnetic path of the permanent magnet 3 and cancels the magnetic field of the permanent magnet 3; 5 is a spacer with a plate thickness equal to the desired gap; and 6 is a leaf spring. , has a plurality of arms extending radially toward the center of the circle, a part of the free end of which is wider than the fixed end, and a hole 6a is formed between the fixed end and the welded part. has
A leaf spring is laminated on the spacer 5; 7 is an armature welded to the welded portion near the free end of the leaf spring 6; 8 is a printed wire welded to the tip of the armature 7; 9 is a wire of the leaf spring 6; second yoke laminated on top surface, 10
is a guide frame laminated on the second yoke 9.

The operation in the above configuration will be explained.

When the degaussing coil 4 is de-energized, the magnetic flux of the permanent magnet 3 passes through the spacer 5, the leaf spring 6, the second yoke 9, the armature 7, the core 2, and the first yoke 1, and this magnetic attraction force is generated. The armature 7 is attracted to the core 2, and the leaf spring 6 is biased.

After this, when the degaussing coil 4 is energized, the magnetic field of the permanent magnet 3 is canceled, so that the magnetic attraction force is reduced or completely eliminated.

Therefore, the armature 7 is moved away from the core 2 due to the restoring force of the leaf spring 6, and the printed wire 8 is moved away from the idle frame 1.
Protruding from 0.

Thereafter, when the demagnetizing coil 4 is deenergized again, the armature 7 is attracted to the core 2 again as described above, and the leaf spring 6 is biased.

When the leaf spring 6 is bent as shown in FIG. 2 in this way, a large bending moment is applied to the welded part 6b of the leaf spring 6 to which the armature 7 is welded. , the bending stress is distributed over the entire cross section of the weld.

Therefore, the plate spring 6 is less likely to be damaged at the welded portion.

In the above embodiment, when the magnetic circuit consisting of the core 2, the degaussing coil 4, the permanent magnet 3, the armature 7, etc. is distributed in an annular manner, the first yoke 1, the permanent magnet 3, the spacer 5, the leaf spring 6, and the second Regardless of the number of printed wires 8, it is sufficient to have one ring-shaped yoke 9.
At this time, it is desirable that the plate spring 6 has holes (including irregularly shaped holes) in its surface as shown in FIG.

Further, as shown in FIG. 4, it is desirable that the width excluding the hole 6a, 1° + 1°, be equal to the width 1 of the other parts, and by doing so, stress concentration near the hole 6a can be avoided. The leaf spring 6 is less likely to be damaged.

Note that the present invention is not limited to the above-mentioned embodiments; for example, an armature is welded to the free end of a leaf spring, a waist excitation coil is energized to attract the armature, and a printed wire fixed to the armature or the leaf spring is driven. A similar effect can be achieved in a wire dot printer in which the printed wire is returned to its original position by the restoring force of a biased leaf spring.

In order to prevent stress from concentrating on the welded portion, the shape of the hole 6a formed in the leaf spring 6 may be approximately three months as shown in FIGS. 2 and 3, or an ellipse as shown in FIG. 5A. It may be of any shape or a perfect circle as shown in the opening of Figure 5.

As explained in detail above, the present invention has holes (including irregularly shaped holes) in the free end surface of the leaf spring, which has the effect of reducing the chance of the leaf spring to which the armature is welded being cut at the welded part. Dot head failures are reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the wire dot head according to the present invention, FIGS. 2A and B are diagrams explaining the operation of the embodiment shown in FIG. 1, and FIG. 3 is a flat spring according to the present invention. FIG. 4 is a plan view showing the shape of a preferred embodiment of the leaf spring according to the present invention, and FIG. 5A is a diagram showing the shape of another embodiment of the leaf spring according to the present invention. 1...First yoke, 2...Core, 3.
... Permanent magnet, 4 ... Demagnetizing coil, 5.
...Spacer, 6...Plate spring, 6a...
...hole, 7...armature, 8...
...Printed wire, 9...Second yoke, 10
...Guide frame.

Claims (1)

[Scope of utility model registration request] A horizontal cylindrical magnetic housing, a leaf spring provided within the housing and having a plurality of arms radially in the direction of the center of the N-circular shape, an armature welded to the free end of each piece, and an armature of each piece. It has a printed wire placed near the free end and a means for biasing each piece of the leaf spring through magnetic force, and the dot matrix method is used by the striking force of the printed wire when the leaf spring is released. A wire dot head for printing, characterized in that a hole for dispersing the stress of the leaf spring is formed between the fixed end of each piece of the leaf spring and the welded part of the armature.