JPH0369713B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an armature mounting structure in a print head.

[Prior Art] Conventionally, an armature is attached by fitting each of a plurality of armature positioning projections provided circumferentially on an armature base into an armature positioning hole provided on the armature.

[Problems to be Solved by the Invention] When a thin and short armature positioning projection is fitted into an armature positioning hole, the armature covers the armature positioning projection and the projection is difficult to see. The problem was that it was difficult to install the armature.

SUMMARY OF THE INVENTION An object of the present invention is to provide an armature mounting structure in a print head that allows the armature to be easily mounted.

[Means for Solving the Problems] The above object is to mount an armature in a print head by fitting each of a plurality of armature positioning projections provided circumferentially on an armature base into armature positioning holes provided on the armature. In this structure, this is achieved by providing the armature base with an armature pilot guide protrusion higher than the armature positioning protrusion for guiding the outer periphery of the armature.

[Function] Rough positioning is achieved by the armature pilot guide protrusion on the armature base of the armature, and since the armature positioning hole is located near the armature positioning protrusion, the armature positioning hole can be moved very easily to the armature positioning protrusion. It can be attached to.

[Example] Hereinafter, the present invention will be explained with reference to an illustrated example. FIG. 1 shows the overall appearance of a print head for a dot printer according to the present invention. In this embodiment, the wire unit 10, the solenoid unit 20, and the armature unit 30 are positioned by means described later, respectively, and the nose 11 of the wire unit 10,
Solenoid base 21 of solenoid unit 20
The armature base 31 of the armature unit 30 is fixed together with fasteners 40.

Wire unit 10 (see FIGS. 2 and 5) A plurality of wires 12 are slidably guided in the nose 11, and have a straight tip and a circumferential rear end. Further, the plurality of wires 12 are
It is biased rearward by a wire return spring 14 disposed between the nose 11 and a wire pin 13 fixed to the rear end.

Further, the nose 11 is provided with a plurality (three in the embodiment) of nose positioning projections 11a protruding toward the solenoid unit 20 near the outer periphery. Furthermore, a nose fitting cylindrical portion 11b and a protrusion 11c are provided at the center of the nose 11.

Solenoid unit 20 (see FIGS. 2 and 6) A cylindrical core 22 is fixed to the bottom surface of a cup-shaped solenoid base 21 in a circumferential manner corresponding to the plurality of wires 12. A cylindrical solenoid bobbin 24 having flanges at both ends around which a solenoid 23 is wound is attached to each core 22, and the solenoid bobbin 24 has two solenoid terminals 24a. and the solenoid 2
The winding start portion and the winding end portion of No. 3 are each fixed to the solenoid terminal 24a.

A flexible printed board 26 is disposed on the opposite side of the solenoid base 21 from the core 22 with an insulator 25 interposed therebetween.
a coil bobbin positioning hole 21a into which a is inserted;
25a is provided, and the flexible printed board 26 is provided with a hole into which the end of the solenoid 23 is inserted. Also, solenoid base 21
A nose fitting hole 21b and a notch 21c are provided at locations corresponding to the nose fitting cylindrical portion 11b and the projection 11c of the nose 11, respectively. The solenoid terminal 24a of the solenoid bobbin 24 is inserted into the positioning hole 21a of the solenoid base 21, the coil bobbin positioning hole 25a of the insulator 25, and the hole of the flexible printed board 26, and the end of the solenoid 23 is soldered to the flexible printed board 26. It is fixed. Thereby, the solenoid bobbin 24, the solenoid base 21, the insulator 25, and the flexible printed board 26 are positioned and assembled together.

Further, the insulator 25 and the flexible printed board 26 are provided with nose positioning holes 25b and 26a, respectively, at locations corresponding to the nose positioning protrusion 11a of the nose 11, and are further provided with nose positioning holes 25b and 26a at the center, respectively, at locations corresponding to the nose positioning protrusion 11c of the nose 11. It has a large hole.

Armature unit 30 (see FIGS. 2 and 4) An armature tip guide that guides the tip side of the armature 32 provided on the center side of the armature base 32 corresponding to each of the plurality of cores 22. A protrusion 31a is provided. Furthermore, armature positioning projections 31b are provided on the outer peripheral side of the armature base 31 in correspondence with the armature 32, and armature positioning holes 32a are provided in the armature 32 to be inserted into the armature positioning projections 31b. . Further, between the armatures 32 of the armature base 31, there is an armature pilot guide protrusion 31c that guides the outer periphery of the armature 32.
is provided higher than the armature positioning projection 31b, and the armature 32 has an armature pilot guide cutout groove 32 at a portion corresponding to the armature pilot guide projection 31c.
b is provided. Further, one of the armature pilot guides 31c is provided with an armature base positioning projection 31d so as to engage with the adjacent solenoid bobbin 24.

The armature base 31 and the armature 3
An armature spring 33 is disposed between the armature spring 33 and the armature spring 33, which causes the inner end of the armature 32 to press against the armature base 31.
is biased so as to come into contact with. Further, a residuum 34 is placed on the armature 32.

Therefore, the armature unit 30 is assembled as follows. An armature spring 33 is disposed on an armature base 31. Next, attach the inner part of armature 32 to armature base 3.
1, and the outer part of the armature 32 is inserted between the armature pilot guide projections 31c. As a result, the armature 32 is smoothly positioned, and the armature positioning hole 32a of the armature 32 is located near the armature positioning projection 31b. Therefore, by inserting the armature positioning hole 32a into the armature positioning projection 31b, the armature 32 can be positioned with high precision. As a result, armature unit 3
0 assembly is complete.

Overall assembly The entire assembly is performed as follows. First, each unit 10, 20, 30 is assembled separately in advance as described above. Then, the armature base positioning protrusion 3 of the armature base 31
The solenoid unit 20 is placed on the armature unit 30 so that the outer periphery of the solenoid bobbin 24 adjacent to the solenoid bobbin 1d is engaged. This results in
The relative positions of the core 22 and armature 32 are determined with high precision.

Next, insert the nose fitting cylindrical portion 11b and projection 11c of the nose 11 of the wire unit 10 into the nose fitting hole 21b and the notch 2 of the solenoid base 21.
Insert 1c. Thereby, the solenoid base 21 and the nose 11 can be smoothly positioned. Next, the nose positioning protrusion 11 of the nose 11
a through the nose positioning hole 26a of the flexible printed board 26 and into the nose positioning hole 25b of the insulator 25.

In this way, the nose 11 and the insulator 25
means the nose positioning protrusion 11 formed on the outer circumferential side.
Since the nose 11 and the insulator 25 are positioned by the nose positioning hole 25b and the nose positioning hole 25b, the nose 11 and the insulator 25 are positioned with high precision. Also, solenoid base 21
and insulator 25 and solenoid bobbin 24
This means that the nose 11 is precisely positioned on the solenoid base 21 because the positioning holes 21a and 25a of the solenoid base 21 and insulator 25 and the solenoid terminal 24a of the solenoid bobbin 24 are positioned accurately.

Finally, the outer periphery of the nose 11 and the outer periphery of the armature base 31 are sandwiched using the fastener 40. Thereby, each unit 10, 20, 30 is fixed together.

Operation Next, the operation will be explained. If solenoid 23 is not energized, wire return spring 1
4 and the armature spring 33, the armature 32 is moved to the armature base 31.
is in contact with. When the solenoid 23 is energized, the plunger 34 is pulled by the core 22,
The armature 32 rotates around the armature positioning protrusion 31b of the armature base 31, and comes into contact with the core 22 via the leg 34. As a result, the rear end of the wire pin 13 is pushed and the wire 12 protrudes from the front surface of the nose 11.
Hereinafter, dot printing is performed by pressing the paper against the platen via an ink ribbon (not shown). solenoid 2
When the excitation of the armature 3 is cut off, the armature 32 is rotated and restored in the opposite direction by the biasing force of the armature spring 33, and comes into contact with the armature base 31. Further, the wire 12 returns to the armature 32 by the biasing force of the wire return spring 14 so as to flow into the armature 32.

[Effects of the Invention] As is clear from the above description, according to the present invention, the armature is precisely positioned by the armature base pilot guide protrusion,
Since the armature positioning hole is located near the armature positioning protrusion, the armature positioning hole can be attached to the armature positioning protrusion very easily, and the ease of assembly is improved.

[Brief explanation of drawings]

FIG. 1 shows the appearance of one embodiment of the print head for a dot printer according to the present invention, in which a is a plan view, b is a side view, c is a rear view, and FIG. 2 is an enlarged main sectional view.
Fig. 3 is an enlarged sectional view of the solenoid terminal portion in Fig. 2, Fig. 4 is an enlarged explanatory view of the armature guide state, Fig. 5 is a rear view of the wire unit, and Fig. 6 is a rear view of the solenoid unit. . 31: Armature base, 31b: Armature positioning projection, 31c: Armature pilot guide projection, 32: Armature, 32a:
Armature positioning hole.

Claims (1)

[Claims] 1. An armature mounting structure in a print head in which a plurality of armature positioning protrusions provided circumferentially on an armature base are fitted into armature positioning holes provided on the armature, wherein the armature is attached to the armature base. An armature mounting structure in a printing head, characterized in that an armature pilot guide protrusion for guiding the outer periphery is provided higher than the armature positioning protrusion.