JPH04250072A - Printing head for wire dot printer - Google Patents

Abstract

PURPOSE:To conduct a high-quality printing by limiting a rebound of an armature at the impact against a yoke core. CONSTITUTION:A mass body 10 having flexibility is mounted on a restoring spring 3 returning an armature 2 in the direction of abutting against a yoke core 8. The inertia force of the mass body 10 is produced after the impact of the armature against the yoke core 8. This inertia force compensates the resiliency of the armature 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head for a wire dot printer, and more particularly to a print head for a wire dot printer that is designed to limit the rebound of an armature that protrudes and supports the wire that actually performs printing. .

0002

2. Description of the Related Art FIG. 5 shows a conventional print head for a wire dot printer. Inside a partially shown hollow cylindrical housing 1, there are a plurality of armatures 2 (1) extending in the radial direction. (Only shown) are arranged in a circumferential manner, and each armature 2 is supported by one of a plurality of return springs 3 corresponding to each armature 2 and having one end fixed to the outer peripheral wall 1A of the housing 1. has been done. A center hole 1C is formed in the bottom wall 1B of the housing 1, and a guide tube 4 is vertically provided on the bottom wall 1B on the outer periphery of the center hole 1C. Moreover, inside the guide tube 4,
A plurality of guide plates 5, 5... are arranged at intervals. A wire 6 is attached to the inner end of each armature 2 by brazing or the like so as to extend downward, and each wire 6 is inserted into a small diameter hole 7 formed in each guide plate 5. Penetrating.

A yoke core 8 supported by the housing 1 is disposed above each armature 2, and the armature 2 supported by the return spring 3 is attached to the lower end of the yoke core 8. are in contact with each other. A coil 9 is wound around the yoke core 8, and by energizing the coil 9, the armature 2 in contact with the yoke core 8 is separated from the yoke core 8 by the elastic force of the return spring 3, and the armature 2 The tip of the supported wire 6 is projected to the outside of the wire 4.

According to this configuration, as described above, the coil 9 of the yoke core 8 facing the armature 2 supporting the wire 6 used for printing based on the printing information
When the yoke core 8 is energized, the armature 2 in contact with the yoke core 8 resists the elastic force of the return spring 3 and the yoke core 8
A wire 6 spaced apart from the armature 2 and supported by the armature 2
The tip of the guide tube 4 is projected outside the guide cylinder 4, and hits the paper through an ink ribbon (not shown), thereby depositing ink in dots on the paper. Then, characters and the like are formed by a collection of these dot-like inks, and printing is performed.

On the other hand, when the coil 9 is energized, the armature 2 is separated from the yoke core 8, and when the coil 9 is no longer energized, the armature 2 is rotated in the direction of contacting the yoke core 8 by the elastic force of the return spring 3. Eventually, it will collide with the yoke core 8.

[0006]

By the way, as mentioned above, when the armature 2 collides with the yoke core 8 due to the action of the return spring 3, the armature 2 performs a repulsive action (hereinafter referred to as rebound), and as a result, the wire 6 also rebounds. Will have to move again.

FIG. 6 is a graph showing the state of movement of the wire 6 as the armature 2 rebounds. The upper part of this graph is the printing pressure waveform due to the tip of the wire 6, and the lower part is the flight waveform of the tip of the wire 6.

When a certain wire 6 is used once and then not used for a while, the wire 6 has the shape shown in FIG.
As shown in FIG. 2, two flight waveforms are generated due to rebound, but since the wire 6 is not used again between these two flight waveforms, there is no adverse effect on printing.

On the other hand, if a certain wire 6 is used continuously, the coil 9 will be turned off again during the rebound of the armature 2.
However, at this time, the armature 2 is separated from the yoke core 8, as shown in the lower right part of FIG. 6, so the yoke core 8 does not apply sufficient urging force to the armature 2 Therefore, as shown in the upper part of the right side of FIG. 6, the waveform of the printing pressure due to the tip of the wire 6 during continuous operation becomes small, resulting in a problem that printing quality deteriorates.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a print head for a wire dot printer that overcomes the above-mentioned problems in the conventional printers, limits armature rebound, and prints with good quality. .

[0011]

[Means for Solving the Problems] In order to achieve the above-mentioned object, a print head for a wire dot printer according to the present invention includes an armature that is movably arranged and supports a wire, and an armature that is arranged opposite to this armature and urges the armature. A print head for a wire dot printer that has a yoke core and a return spring that returns the armature in a direction in which it comes into contact with the yoke core, characterized in that a flexible mass body is attached to the return spring.

0012

[Operation] According to the present invention configured as described above, at the moment when the armature collides with the yoke core and rebound occurs, the mass body attached to the return spring begins to bend due to inertia, and the armature attempts to rebound from the yoke core. Sometimes the mass will have an inertial force in the opposite direction to the armature. Therefore, the repulsive force of the armature and the inertial force of the mass body cancel each other out, and the rebound of the armature becomes small or does not occur.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to embodiments shown in the drawings. Note that the same reference numerals are used in the drawings to refer to the same or corresponding configurations as those of the conventional structure described above, and the explanation thereof will be omitted.

As shown in FIGS. 1 and 2, each return spring 3 extending radially inward from the outer peripheral wall 1A of the housing 1 reaches an intermediate position in the longitudinal direction of each armature 2. At the inner end of the return spring 3, there is a plate-shaped mass body 10 extending radially inward of the housing 1.
However, the flexible arm 1 is formed thin to make it easy to bend.
It is provided protrudingly through 1. In addition, these mass bodies 10
and the flexible arm 11 are integrally formed.

The mass body 10 including the flexible arm 11 has a mass that generates an inertial force sufficient to counter the repulsive force when the armature 2 collides with the yoke core 8.

The rest of the structure is the same as the conventional one described above.

Next, the operation of this embodiment having the above-described configuration will be explained.

During printing, when the coil 9 of the yoke core 8 facing the armature 2 supporting the wire 6 used for printing is energized based on the printing information, the armature 2 in contact with the yoke core 8 is energized. is separated from the yoke core 8 against the elastic force of the wire 3, and the tip of the wire 6 supported by the armature 2 is projected to the outside of the guide tube 4 and hits the paper via an ink ribbon (not shown). Then, ink is deposited in dots on the paper. Then, characters and the like are formed by a collection of these dot-like inks, and printing is performed.

On the other hand, when the coil 9 is energized, the armature 2 is separated from the yoke core 8. By stopping the energization to the coil 9, the armature 2 is brought into contact with the yoke core 8 by the elastic force of the return spring 3, as shown in FIG. 3A. It is rotated in the direction of contact and eventually collides with the yoke core 8. Then, at the moment when the armature 2 collides with the yoke core 8 and is about to rebound, as shown in FIG. When the arm 11 begins to bend due to the inertia of the flexible arm 11 and the mass body 10, and the armature 2 tries to rebound from the yoke core 8,
The mass 10 and the flexible arm 11 will have an inertial force in the opposite direction to the armature 2. That is, since the flexible arm 11 is flexible, the mass body 10 and the flexible arm 11 have an inertial force after a certain short time delay. Therefore, the repulsive force of the armature 2 and the inertial force of the mass body 10 and the flexible arm 11 are canceled out, and the rebound of the armature 2 is reduced, or
Or it will stop occurring. Therefore, even if continuous printing is performed using the same wire 6, there is no possibility that printing quality will be adversely affected.

FIG. 4 is a graph showing the state of movement of the wire 6 as the armature 2 rebounds in this embodiment.

As is clear from the graph of FIG. 4, according to this embodiment, the repulsive force of the armature 2 and the inertial force of the mass body 10 and the flexible arm 11 cancel each other out.
Almost no repulsion of armature 2 occurs. Therefore, even if the same wire 6 is used continuously, the yoke core 8 starts biasing the armature 2 while the armature 2 is in contact with the yoke core 8, and the tip of the wire 6 always The printing pressure waveform has a sufficient maximum value. As a result, printing of good quality can be performed.

Note that the present invention is not limited to the embodiments described above, and various changes can be made as necessary. For example, in the embodiment, the flexible arms forming part of the mass body are deflected to delay the generation of inertial force, but the mass body itself may be deflected.

[0023]

[Effects of the Invention] As explained above, according to the present invention, the rebound of the armature is limited and the armature is reliably energized by the yoke core, resulting in good quality printing. can be played.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of essential parts showing an embodiment of a print head for a wire dot printer according to the present invention.

[Fig. 2] Enlarged perspective view of the main parts of Fig. 1

[Fig. 3] A vertical cross-sectional view showing the operation of the embodiment shown in Fig. 1.

[Figure 4] Graph showing the effect of the embodiment in Figure 1

[Figure 5] Longitudinal cross-sectional view of main parts showing a print head for a conventional wire dot printer

[Figure 6] Graph showing the effect of the conventional example in Figure 5

[Explanation of symbols]

1 Housing 2 Armature 3 Return spring 6 Wire 8 Yoke core 9 Coil 10 Mass body 11 Flexible arm

Claims (1)

[Claims] 1. A wire dot printer comprising: an armature that is movably arranged to support a wire; a yoke core that is arranged opposite to the armature and urges the armature; and a return spring that returns the armature to a direction in which it comes into contact with the yoke core. A print head for a wire dot printer, characterized in that a flexible mass body is attached to the return spring.