JPH0339467B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print head for a dot printer, and particularly to its assembly structure.

[Prior Art] Conventionally, in this type of print head, a nose member containing a print wire is attached to a yoke having an electromagnetic device, and a plurality of armatures for protruding the print wire are mounted on the yoke, and A return spring is attached to urge these armatures in the backward direction of the printing wire, and in this state, the cover member is assembled and fixed to the yoke by tightening screws or using the spring force of a leaf spring.

[Problems to be Solved by the Invention] However, in the printing head of this conventional configuration, since the printing wire and the armature are assembled to the yoke separately, it is difficult to maintain the driving directions of both in a predetermined relationship, and misalignment, etc. may occur. If so, there was a problem that the printing performance was affected.

Furthermore, when assembling the cover member and the yoke, since a plurality of armatures are placed on the yoke and are urged in the backward direction of the printing wire by return springs, the armatures must be moved against the action of the return springs. The cover member has to be assembled and fixed while being held in a predetermined position by the armature, and the assembly work is extremely complicated. There was a problem in that the wire could fall off from the wire guide, making assembly work time-consuming.

The object of the present invention is to eliminate the above-mentioned defects in the conventional technology, maintain accurate positional relationship between the printing wire and the armature, and exhibit excellent printing performance. In addition, handling the printing wire, armature, etc. as one unit facilitates assembly, eliminates the risk of the armature shifting from its designated position due to spring action, or the printing wire coming off from the wire guide, and reducing assembly time. The purpose is to provide a print head that can be assembled.

[Means for explaining the problem] The present invention includes a plurality of printing wires 21, a plurality of armatures 18 for moving the printing wires 21 in and out, and moving the armatures 18 in the backward direction of the printing wire 21. In the print head, which has a plurality of springs 22 biasing the print head and a plurality of electromagnetic devices 5 sucking the armatures 18, the print head includes a nose member 13 that supports the print wire 21 so as to be movable back and forth, and Member 13
The armature 1 is integrally molded in the shape of a flange on the base end of the armature 1 on the opposite side from the nose member 13.
8, a housing recess 17f for the spring 22, and a through hole 17d communicating with the inside of the nose member 13.
a support member 17 having a
is attached to the holding portion, and the spring 22 is attached to the accommodation recess 1.
7f, and one end of the printing wire 21 is inserted into the support member 17 through the through hole 17d.
a holding member 23 for positioning and holding the armature 18 with the printing wire 21 in the retracted position against the action of the spring 22; Means 2 for fastening to the outer periphery of 17
5, 26 and one printing wire assembly unit 2
The electromagnetic device assembly 1 comprising the plurality of electromagnetic devices 5 includes a printing wire assembly unit 2 thereof.
It is assembled with.

[Function] In this invention, the support member 17 is integrally molded in the shape of a flange at the base end of the nose member 13.
By communicating the through hole 17d with the inside of the nose member 13, the printing wire 21 extends from the position where it connects with the armature 18 into the nose member 13 through the through hole 17d, and the position of the printing wire 21 and the armature 18 is changed. The relationship can be maintained accurately and excellent printing performance can be achieved.

Further, on the integral part consisting of the nose member 13 and the support member 17, a printing wire, an armature,
By arranging the spring and pressing and tightening it with the holding member 23, it can be handled as one unit, and the armature can be easily and quickly removed without shifting from the predetermined position due to the action of the spring as in the past. It can now be assembled into the electromagnetic device assembly 1.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Now, the print head of the dot printer of this embodiment consists of an electromagnetic device assembly 1 and a print wire assembly 2.
and an assembly 3 for assembling both 1 and 2.

The electromagnetic device assembly 1 is constructed by arranging a plurality of electromagnetic devices 5 (24 in this embodiment) in a yoke 4 having a substantially bottomed cylindrical shape.
At the open end of d, each electromagnetic device 5 is connected, leaving the partition wall 4a.
A plurality of slits 4b corresponding to the slits 4b are formed. Each electromagnetic device 5 includes a core 6 formed integrally with the bottom wall portion 4e of the yoke 4, and a bobbin 7 attached to the core 6.
Both terminals of the coils 8 are respectively connected to a pair of connection pins 9 protruding from the bobbin 7.
The yoke 4 has a through hole 4f at the center surrounded by the core 6 of the bottom wall portion 4e. A printed circuit board 11 is fixed to the outer surface of the bottom wall portion 4e of the yoke 4 with an insulating plate 10 interposed therebetween.
is penetrated and soldered. In this state, the side surface of the printed circuit board 11 is covered with the protective rubber sheet 12.

The printing wire assembly 2 is connected to the electromagnetic device assembly 1.
The nose member 13 is made of synthetic resin and is inserted into the through hole 4f, and the support member 17 is formed in the shape of a flange at one end of the nose member 13. The nose member 13 has a hollow cylindrical shape, and there are three wire guides 1 inside the nose member 13.
4, 15, and 16 are arranged and fixed at predetermined intervals. The support member 17 has a through hole 17d in the center, and is integrally connected to one end of the nose member 13 around the through hole 17d. Through hole 17d
communicates with the inside of the nose member 13. A plurality of holding grooves 17a are formed radially on the surface of the supporting member 17 opposite to the nose member 13 (hereinafter referred to as the back surface), and the yoke is formed on the outer periphery of the supporting member 17 corresponding to each holding groove 17a. 4 slit 4
Projecting pieces 17b that fit into the respective portions 17b are provided in a protruding manner. A core 6 of the electromagnetic device 5 is provided at the bottom of each holding groove 17a.
A through hole 17e is formed to face the protrusion 17b, and a support recess 17c is formed in each protrusion 17b.

In each holding groove 17a of the support member 17, armatures 18 made of plate-like members are housed and arranged with their wide side surfaces adjacent to each other, and support protrusions 18a formed at their outer ends. It is engaged with the recess 17c and rotatably supported on the support member 17. Each armature 1
A protrusion 19 is formed at the center of one side of the electromagnetic device 8 to face the core 6 of the electromagnetic device 5 through the through hole 17e of the support member 17. Further, one end of a printing wire 21 is fixed to the inner end of each armature 18, and these printing wires 21 extend from the opening 17d of the support member 17 into the nose member 13, and each wire guide 16,
It extends to the platen 20 side through 15 and 14.

The supporting member 17 and its projecting piece 17b are inserted into the slit 4.
When the nose member 13 is fitted over the open end of the yoke 4 and brought into contact with the open end of the yoke 4, the connection part with the support member 17 is a fixed end, and the other end is connected to the electromagnetic device. It will be made to protrude to the outside through the through hole 4f of the assembly.

A spring 2 is provided in the storage recess 17f in each holding groove 17a of the support member 17 corresponding to each armature 18.
2 is provided, and each armature 18 is biased in the backward direction of the printing wire 21 by the action of the spring 22. As the electromagnetic device 5 is energized, the armature 18 is attracted and rotated toward the core 6 against the action of the spring 22, and the printing wire 21 is projected toward the platen 20.

A holding member 23 made of synthetic resin that holds the armature 18 in the holding groove 17a has a ring-shaped regulating portion 24 in its center that comes into contact with the center of the back surface of the supporting member 17, and has a ring-shaped regulating portion 24 on its outer periphery. Three locking pawls 26 are formed to protrude and engage with the engaging portions 25 of. The armature 18 comes into contact with the regulating portion 24 of the holding member 23 by the action of the spring 22, thereby regulating the retreating position. Further, 24 elastic pressing arms 27 are integrally formed on the outer periphery of the regulating portion 24 to press and hold the protrusion 18a at the outer end of each armature 18 toward the support recess 17c of the support member 17. ing.

The assembly body 3 is an assembly member 2 made of a plate spring material.
8 and a metal lid body 29 attached to the outer surface of the assembly member 28. Three elastic legs 30 are formed protruding from the outer periphery of the assembly member 28, and the protrusions 29a on the lid body 29 engage with the inner surface of their bases, thereby connecting the assembly member 28 and the lid body 29. are combined. In addition, each leg 30 has a locking portion 30a formed at its tip that is approximately horizontally T-shaped, and engages with a stepped engagement portion 31 provided on the outer periphery of the yoke 4 of the electromagnetic device assembly 1. When engaged, the printing wire assembly unit 2 is clamped and held between the electromagnetic device assembly 1. The center portion 32 of the assembly member 28 presses the holding member 23 so as to come into contact with the back surface of the support member 17 .

Now, in this embodiment, as described above, the armature 18 to which the printing wire 21 is connected and the spring 22 are respectively assembled on the integral part consisting of the nose member 13 and the support member 17, and each armature 18 is operated by the action of the spring 22. The holding member 2 is mounted on the supporting member 17 so as to be positioned and held in a predetermined position against the
3 constitutes one printing wire assembly unit 2.

Therefore, a plurality of printing wires 21, armatures 18, and springs 22 can be handled as one unit, and handling and parts management can be easily performed. Further, during assembly, there is no fear that the armature 18 will shift from a predetermined position on the support member 17 due to the action of the spring 22, or that the printing wire 21 will come off from the wire guides 14, 15, 16 in the nose member 13, and the printing wire The assembly unit 2 can be easily assembled to the electromagnetic device assembly 1.

Further, since the electromagnetic device assembly 1 can be removed from the printing wire assembly unit 2 without disassembling the printing wire assembly unit 2, if the coil 8 of the electromagnetic device 5 is broken, it can be repaired very easily.

[Effects of the Invention] As described in detail above, in this invention, the support member is integrally molded in the shape of a flange at the base end of the nose member, and the through hole of the support member is communicated with the inside of the nose member, so that printing is possible. The wire 21 extends into the nose member 13 from the position where it is connected to the armature 18 through the through hole 17d, so that the positional relationship between the printing wire 21 and the armature 18 can be maintained accurately, and excellent printing performance can be exhibited.

Further, on the integral part consisting of the nose member 13 and the support member 17, a printing wire, an armature,
By arranging the spring and pressing and tightening it with the holding member 23, it can be handled as a single unit, and unlike the conventional case, the armature does not shift from the predetermined position due to the action of the spring, or the printing wire separates from the wire guide. This provides an excellent effect in that the unit can be assembled into the electromagnetic device assembly easily and in a short time without any fear of damage.

Furthermore, since the electromagnetic device assembly can be removed from the printing wire assembly unit without disassembling the printing wire assembly unit, if the electromagnetic device 5 has a failure such as a disconnection, it can be repaired very easily. There is also.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a print head embodying the invention, FIG. 2 is a sectional view taken along line A--A in FIG. 1, and FIG. 3 is a partially exploded perspective view. In the figure, 1 is an electromagnetic device assembly, 2 is a printing wire assembly unit, 3 is an assembled body, 13 is a nose member, 1
7 is a support member, 18 is an armature, 21 is a printing wire, 22 is a spring, and 23 is a holding member.

Claims (1)

[Claims] 1. A plurality of printing wires 21, a plurality of armatures 18 for causing the printing wires 21 to project, and a plurality of armatures 18 for urging the armatures 18 in the backward direction of the printing wires 21. A printing head having a spring 22 and a plurality of electromagnetic devices 5 for attracting each of the armatures 18, the nose member 13 supporting the printing wire 21 so as to be movable back and forth, and the base end portion of the nose member 13. The retaining portion of the armature 18 and the spring 22 are integrally molded into a flange shape on the surface opposite to the nose member 13.
a holding member 17 having an accommodation recess 17f and a through hole 17d communicating with the inside of the nose member 13; the armature 18 is disposed in the holding part, the spring 22 is disposed in the accommodation recess 17f, and the printing wire One end of the through hole 1
7d through the support member 17 and connected to the armature 18; a holding member 23 for positioning and holding the armature 18 against the action of the spring 22 in the retracted position of the printing wire 21; means 25 and 26 for fastening the member 23 to the outer periphery of the support member 17; A printing head characterized in that a wire assembly unit 2 is assembled.