JPH042054Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a releasable print head for a wire dot printer, and more particularly to an improvement in the print head whose members are easy to manufacture and assemble.

In recent years, various wire dot printers have been developed and put into practical use as printing output devices for various computer terminals, word processors, and the like.

Wire dot printers print characters by activating a print head and forming dots with a print wire, so they can handle many types of characters and are extremely suitable and economical for applications that require copying.

In particular, as the use of the device as a terminal device such as an office computer is expanding, there is a need to improve the reliability and cost of the device.

[Conventional technology]

Hereinafter, a conventional method will be explained using a wire dot printer as an example with reference to FIGS. 1 to 3. Fig. 1 is a plan view illustrating the outline of a wire dot printer to which the present invention is applied, Fig. 2 is a side sectional view showing the print magnet section of the print head of Fig. 1, and Fig. 3 is a side sectional view of the print head of Fig. 1. FIG. 4 is a rear view of the armature shown in FIG. 3.

As shown in FIG. 1, in the wire dot printer, a platen 10 is rotatably supported on a side frame 9, and printing paper 11 is wound around the platen 10. The printing paper 11 is rotated by sprockets 12a, 12b, etc. It is sent in the direction of arrow A in the figure.

On the other hand, on the front side of the platen 10, below in the figure, a carrier 13 is slidably fitted into a guide shaft 15 provided parallel to the platen 10, and the carrier 13 is connected to a feed screw similarly provided parallel to the platen 10. It is screwed together with 16.

The feed screw 16 is connected to the motor 1 via a belt 17 etc.
9, and by the forward and reverse rotation of the motor 19, the feed screw 16 moves the carrier 13 in the direction indicated by the arrow B in the figure.
It can be moved in the C direction.

An ink ribbon cassette 20 is mounted on the carrier 13, and a part of the endless ink ribbon 20a is attached to the platen 10.
It is built-in with an exposed side, and the Carrier 13
The print head 21 is connected to the ink ribbon cassette 20.
It is mounted surrounded by.

The print head 21 usually has a plurality of print magnets 2 in order to form a print sheet with dots.
1a.

As shown in FIG. 2, the printing magnet 21a is
A coil 2 is wound around a core 1, and an armature 3 is arranged so as to come into contact with an end surface of the core 1. A holding portion 3a having a printing wire 4 fixed to the tip thereof is attached to the armature 3, and the armature 3 is elastically supported by a drive spring 6. One end of the drive spring 6 is fixed to a support member 6a.

Furthermore, the protrusion 3b of the armature 3 is fixed to one end of a support wire 6c that passes through a circular hole 6b in the center of the drive spring 6 approximately vertically, and the other end is attached to the support member 6.
It is fixed to the supporting protrusion 6d of a.

The magnetic path portions 7a and 7b sandwich the permanent magnet 8 therebetween, and are arranged so as to surround the core 1 and the armature 3 in a U-shape together with the magnetic path portions 7c and 7d and the leakage magnetic path portion 7e.

Further, side magnetic path portions 7f that engage with both sides of the armature 3 with a gap protrude from the magnetic path portion 7d.

Therefore, when the printing magnet 21a is not operating, the armature 3 is attracted to the core 1 by the magnetic force of the permanent magnet 8.

As shown in FIG. 3, the print head 21 is
A plurality of printing magnets 21a concentrate the printing wires 4 in the center, and the printing wires 4 are guided and aligned by the pin holes 5b of the pin guide 5a at the tip of the guide frame 5 protruding from the center. .

With this configuration, if current is applied to the coil 2 of the printing magnet 21a of the printing head 21 so that the NS pole of the permanent magnet 8 and the pole of the core 1 are opposite to each other, the core 1 becomes an electromagnet and the permanent magnet 8 The energy stored by the drive spring 6 causes the armature 3 to fly toward the magnetic path section 7a, that is, upward in FIG. 2.

Then, the printing wire 4 also protrudes in the direction of arrow D in the figure, and the plurality of printing heads 21a in the printing head 21
While selectively driving the print head 21, the print head 21 is moved together with the carrier 13 in the directions of arrows B and C, as shown in FIG. 1, to perform a printing operation on the print paper 11.

At this time, when the armature 3 tries to rotate around the center of impact due to the reaction when the support wire 6c prints, it receives tension, brakes the armature 3, and stabilizes the drive.

Here, the gap g between the armature 3 and the core 1 when the armature 3 is not attracted to the core 1 requires a high precision of, for example, 0.2 mm ± 0.02 mm, so as a method to obtain this precision,
In FIG. 2, the upper surface of the magnetic path section 7b and the upper surface of the core 1 are made the same surface and processed with high precision, and the lower surface of the magnetic path section 7b is similarly finished with high precision. Next, the printing wire 4 and the armature 3 with the holding part 3a attached, the drive spring 6, the support member 6a and the support wire 6c.
are connected by a method such as brazing to assemble the armature assembly 3', and the distance b between the upper surface of the support member 6a and the lower surface of the armature 3 is finished with high precision.

A magnetic path part 7c, whose both sides are finished with high precision to a predetermined dimension a, is inserted between the magnetic path parts 7b and 7d as a spacer and joined together. The upper surface of the support member 6a of the armature assembly 3' is coupled to the lower surface of the magnetic path section 7b.

Then, the gap g between armature 3 and core 1
(=a−b) is ensured with high accuracy.

[The problem that the idea aims to solve]

As explained above, according to the conventional method, armature assemblies are assembled one by one and then finished, which not only increases the cost due to the number of man-hours involved, but also causes variations due to individual processing. As a result, there is a problem that the gap g becomes non-uniform.

The object of the present invention is to provide a print head whose parts are easy to process and assemble and whose cost is low.

[Means to solve the problem]

The present invention consists of a drive member consisting of a plurality of printing magnets and permanent magnets each having a coil wound around the core, and a first yoke forming a magnetic path, and a printing wire arranged to face each core. a plurality of drive springs, each of which is fixed to the armature on a surface opposite to the surface facing the core of each armature, and whose other end is held between a supporting member and a second yoke forming a magnetic path. is integrally formed with a ring-shaped spring member, and a linear spring member having one end fixed to a protrusion provided on the side facing the core of each armature, and the other end passing through a drive spring and fixed to a support member. A driven member made of a spring, and a spacer interposed between the drive member and the driven member to define a gap between the armature and the core, and a first part that contacts the end surface of the core of the drive member and the spacer. The end faces of the yoke are the same plane, and in a neutral state where the permanent magnet does not act, the face facing the core of each armature of the driven member and the end face of the second yoke that contacts the spacer are on the same plane. In this way, the above object can be achieved.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 5 and 6. FIG. 5 is a side view showing an embodiment of the present invention, and FIG. 6 is a plan view showing the drive spring of FIG. The same reference numerals indicate the same objects throughout the figures.

FIG. 5 is a side view of the print head, which consists of a drive member, a driven member and a spacer 7i.

The drive member includes a printing magnet 21a, magnetic paths 7a and 7b (first yoke) forming a magnetic path, and a permanent magnet 8. The printing magnet 21a is
It consists of a core 1 and a coil 2 wound around the core 1.

The driven members include an armature 3 to which a printing wire is fixed, a drive spring 61, a support wire 6c,
It consists of a support member 7g, a base member 7d', and a magnetic path section 7j (second yoke) that forms a magnetic path.

As shown in FIG. 6, the drive spring 61 is made of a magnetic material, and has the same number of leaf springs 61a as the printing magnets 21a radially formed inside. The plate spring 61a is provided with a round hole 61b through which the support wire 6c passes without contacting it.

As shown in FIG. 5, a support protrusion 7h is formed on the support member 7g, one end of the support wire 6c is fixed to the lower surface of the tip of the support protrusion 7h, and the protrusion 3d of the armature 3 is fixed to the other end. ing.

The support wire 6c passes through a circular hole 61b in the center of the drive spring 61. The ring portion of the drive spring 61 is joined to the lower surface of the ring-shaped support member 7g, and the upper surface of the armature 3 is joined to the lower surface of the leaf spring 61a. There is a magnetic path part 7j on the upper surface of the magnetic path part 7b, which is finished on the same surface as the upper surface of the core 1, with a spacer 7i made of a magnetic material whose upper and lower surfaces are finished with high precision, and a magnetic path part 7j with a drive spring 61 in between. The upper surface of the support member 7g is joined to the lower surface of the base member 7d'.

Further, side magnetic path portions 7k extend from the magnetic path portion 7j to both sides of the armature 3. Therefore, the magnetic path section 7
b, 7j act as a magnetic path and drive spring 6
It has the function of 1 supporting member.

Therefore, in order to assemble the armature 3 so that there is a gap g between the lower surface of the armature 3 and the upper surface of the core 1, the upper and lower surfaces of the spacer 7i are finished to a predetermined thickness (=g), and the magnetic path section 7j and the armature 3 are By assembling the lower surfaces with the same surface finish, the gap g can be obtained with high accuracy.

When processing the lower surface of the armature 3, the ring-shaped support member 7g, the magnetic path section 7j, and the plurality of armatures 3 are attached to the drive spring 61, but the support protrusion 7h to which the support wire 6c is fixed is Since it is not on the processing side, it is easy to process.

Therefore, unlike the conventional method, there is no need to carefully process each piece one by one, and a plurality of pieces can be assembled radially and then processed at once.

In this way, the gap g between the lower surface of the armature 3 of the plurality of printing magnets 21a and the upper surface of the core 1 can be set with high accuracy, and furthermore, plane finishing and assembly are easy and costs can be reduced.

[Effect of idea]

As explained above, according to the present invention, a plurality of armatures can be assembled radially on a ring-shaped leaf spring member, and the end face of the yoke that contacts the spacer in a neutral state where no permanent magnet acts. Also, the surfaces facing the core of each armature can be easily processed to be the same surface, and the gap between the armature and the core can be easily set, so individual processing can be omitted.
Furthermore, not only is assembly easier and costs can be improved, but also the gap is made uniform, which has the effect of improving reliability in obtaining stable printing operations.

[Brief explanation of the drawing]

FIG. 1 is a plan view illustrating the outline of a wire dot printer to which the present invention is applied, and FIG. 2 is a side view showing the printing magnet section of the print head of FIG. 1.
Figure 3 is a side view showing the print head in Figure 1;
The figure is a rear view showing the armature section in Figure 3, and Figure 5.
The figure is a side view showing an embodiment of the present invention, and FIG. 6 is a plan view showing the drive spring of FIG. 5. In the figure, 1 is the core, 3 is the armature, 3
b, 3d are protrusions, 4 is printing wire, 6, 61
is a drive spring, 6a, 7g are support members, 6b, 61
b is a round hole, 6c is a support wire, 6d, 7h are support protrusions, 7a to 7d, 7j are magnetic path sections, 7e is a leakage magnetic path section, 7f, 7k are side magnetic path sections, 7i is a spacer, 7d' 8 is a base member, 8 is a permanent magnet, 21 is a printing head, 21a is a printing magnet, and 61a is a leaf spring.

Claims (1)

[Claims for Utility Model Registration] A drive member consisting of a plurality of printed magnets each having a coil wound around the core, a permanent magnet, and a first yoke forming a magnetic path, and arranged to face each core. a plurality of armatures fixed to the armature on the surface opposite to the surface facing the core of each armature, the other end of which is sandwiched between a supporting member and a second yoke forming a magnetic path; a ring-shaped spring member integrally formed with a plurality of drive springs, one end of which is fixed to a protrusion provided on the side facing the core of each armature, and the other end of which extends through the drive spring and extends through the support member; a spacer interposed between the drive member and the driven member to define a gap between the armature and the core; The end face and the end face of the first yoke that contact the spacer are on the same plane,
A printing head characterized in that in a neutral state in which the permanent magnet does not act, a surface of the driven member facing the core of each armature and an end surface of the second yoke that contacts the spacer are on the same plane.