JPH0455597B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) This invention holds each armature together with a printing wire in a rest position, and selectively releases the armature from a state in which a biasing force is accumulated in an elastic member. Based on the biasing force of the elastic member,
The present invention relates to a method of assembling a print head in which each print wire is moved to a print position.

(Prior Art) Conventionally, when assembling this type of printing head, a plurality of armatures are assembled in advance to an elastic member made of, for example, a spring piece to form an armature assembly, and the armature assembly and the nose body are assembled together. After assembling, the printing wire was inserted into the hole formed at the tip of each armature and also through the guide part of the nose body, and the armature and printing wire were fixed by brazing or laser welding.

However, in this conventional assembly method,
Since the printing wire is fixed to the armature within the head body, it is necessary to provide a gap between the tip ends of each armature in order to perform the fixing operation. On the other hand, the arrangement interval of the printing side ends of the printing wires is predetermined based on the size of the characters to be printed. As a result, the printing wire is inserted into the guide part of the nose body in a bent state, which not only increases sliding resistance and impedes high-speed printing operation, but also causes the printing head to become larger and worse. There were problems in that assembly became troublesome, the work time increased, and manufacturing costs rose.

(Object of the Invention) This invention was made to solve the above problems, and its purpose is to reduce the amount of deflection of the printing wires by narrowing the arrangement interval of each printing wire on the armature side. To provide a method for assembling a printing head, which can reduce the sliding resistance of a printing wire in a guide part of a printing head, downsize the entire printing head, and can be easily assembled and manufactured at low cost. It's about doing.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, after positioning and arranging the elastic member on the inner surface of the covering portion of the nose body, the printing wires attached in advance to each armature are inserted into the nose body. A procedure is adopted in which each armature is inserted into a guide portion of the body, and then each armature is positioned and fixed to an elastic member so as to be swingable.

(Function) Therefore, when fixing the printing wire to the armature, there is no need to perform the work within the narrow space of the printing head, which increases work efficiency and narrows the gap between the armature tips. It is possible to reduce the amount of deflection of the printing wire, thereby reducing the sliding resistance of the printing wire within the guide portion of the nose body, and it is also possible to downsize the printing head.

(Embodiment) Hereinafter, one embodiment of a print head assembled by the assembly method of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 2, the head body 3 of the printing head 2, which is movable along the printing lines on the platen 1, is formed of a magnetic material into a bottomed cylindrical shape having a circular recess 3a open toward the platen. , a flange 4 is provided on the outer periphery of the open end. The outer peripheral wall of the head body 3 including the flange 4 constitutes a rear yoke. A plurality of electromagnetic devices 5 (24 in this embodiment) are arranged in a circle on the bottom surface of the recess 3a. Each electromagnetic device 5 has cores 6 integrally formed protruding from the head body 3 at equal angular intervals.
and a coil 8 wound around the core 6 via a coil bobbin 7.

A permanent magnet 9 is bonded and fixed to the front side surface of the flange 4. This permanent magnet 9 is composed of a pair of plate-shaped divided pieces 9a, 9b which are symmetrical, and each divided piece 9a, 9b is joined and fixed at opposing ends. A front yoke 1 is attached to the front side of the permanent magnet 9 via a spacer 10 made of a magnetic material.
A plurality of slits 12 are formed in the front yoke 11 to face each electromagnetic device 5 and extend radially.

On the front side surface of the front yoke 11, an elastic member 14 is formed of a leaf spring and has a plurality of support pieces 13 extending radially opposite each of the slits 12, and a pair of spacers 15 made of a magnetic material are provided. , 16, and are joined and fixed in a sandwiched state.
A plurality of armatures 17 made of a magnetic material are swingably supported on each support piece 13 of the elastic member 14 at the base end thereof. The base end of each armature 17 is disposed within each slit 12, and the printing wire 18, which extends toward the platen 1 while being converged at the center of the head body 3, is located at the base end of the armature 17. It is attached.

That is, a plurality of protrusions 20 that protrude radially between the armatures 17 are integrally formed on the outer peripheral annular portion of the elastic member 14, and a first torsion bar portion 21 is integrally formed as a bridge between each of the protrusions 20. has been done. An armature fixing part 22 extending radially inward is integrally formed in the center of each first torsion bar part 21, and a pair of second torsion bar parts 23 projecting laterally at the tip of each fixing part 22.
are integrally formed. Further, on both sides of the armature fixing portion 22, each protrusion 20 and each second
The torsion bar portion 23 is integrally connected by a pair of leaf spring portions 24.

The first and second torsion bar parts 21 and 2
3. The armature fixing part 22 and the leaf spring part 24 constitute a support piece 13 for one armature 17, and in a state where each armature 17 is superimposed on each armature fixing part 22, each armature 17 is attached to each support piece 13. It is fixed to piece 13.

Further, each of the spacers 15 and 16 is integrally formed with a protrusion 25 that protrudes so as to overlap with the protrusion 20 of the elastic member 14, and each protrusion 25 has a pair of protrusions that are adjacent to each other inwardly from the first torsion bar portion 21. A pair of clamping parts 26 are formed to clamp the base end portions of the leaf spring parts 24. The spacer 1
A flat plate-like covering part 27 and a platen 1 are provided on the front side of the platen 6.
A nose body 29 including a substantially cylindrical guide portion 28 protruding toward the nose body 29 is bonded and fixed at its covering portion 27 . This covering portion 27 has three through holes 30 for each armature.
A plurality of guide plates 31 are installed at predetermined intervals in the guide portion 28, and each of the printing wires 18 is movably inserted through the plurality of guide plates 31. and are converged at the free end on the platen side.

As shown in FIGS. 3 and 4, the covering portion 2
Four positioning protrusions 32 projecting rearward are integrally formed at the four corners of 7. On the other hand, at the four corners of the flange 4, permanent magnet 9, spacer 10, front yoke 11, spacers 15, 16, and elastic member 14, there are recesses 4a, 9c, 10a of substantially the same shape that fit into the respective positioning protrusions 32. 11a, 15
a, 16a, and 14a are formed, respectively.
Then, each member 4,
Each recess 4 of 9, 10, 11, 15, 16, 14
a, 9c, 10a, 11a, 15a, 16a, 1
4a is fitted, the members 4, 9, 10, 11, 15, 16, and 14 are stacked on the covering portion 27 in a predetermined order, and are fixed together by appropriate connecting means.

In the print head configured as above,
When the coil 8 of each electromagnetic device 5 is not energized, the permanent magnet 9 creates a magnetic path passing through the spacer 10, front yoke 11, armature 17, core 6, and flange 4, as shown by the two-dot chain line in FIG. is formed, whereby each armature 17 is attracted to the entire end surface of the core 6, and each printing wire 18
is placed in the rear rest position, and the elastic member 14
Each support piece 13 is displaced rearward, each torsion bar part 21, 23 is torsionally deformed, and each leaf spring part 24 is bendingly deformed to accumulate biasing force.

In this state, when the coil 8 of each electromagnetic device 5 is selectively energized and the core 6 is temporarily excited so as to cancel the magnetic path, each of the parts 21, 23, 2
The armature 17 is released from the core 6 by the urging force of 4. That is, the first torsion bar section 21
After the armature 17 is swung to the printing position about , it is swung back to the printing position based on the magnetic force of the permanent magnet 9 and held at the rest position. Due to the reciprocating movement of the print wire 18 in conjunction with the reciprocating swing of the armature 17, dots are formed on the print paper (none of which is shown) on the platen 1 via the print ribbon between the print head 2 and the platen 1. .

In the print head configured as above,
The armature 17 and the printing wire 1 are attached to the nose body 29.
8, the spacer 16 and the recesses 16a, 14a of the elastic member 14 are made to face each of the positioning protrusions 32 of the nose body 29, and if they are sequentially overlapped with the covering part 27, each of the positioning protrusions 32 are fitted into the respective recesses 16a, 14a, and the spacer 16 and the elastic member 14 are positioned.

Next, each printing wire 18 is fixed in advance to each armature 17 by brazing or laser welding.
while inserting it into the guide part 28 of the nose body 29,
Each armature 17 is connected to each support piece 13 of the elastic member 14.
and position it using a predetermined jig. In this state, when each supporting piece 13 is irradiated with an electron beam or a laser from the outside of the covering part 27 through each through hole 30, each armature 17 are welded and fixed, each armature 17 and each printing wire 1
The assembly of step 8 is completed.

Next, spacer 15, front yoke 1
1. After sequentially overlapping each member on the elastic member 14 with the recesses 15a, 11a, 10a, 9c, and 4a of the spacer 10, permanent magnet 9, and flange 4 facing each positioning protrusion 32, By connecting each member using a predetermined connecting means, the entire printing head can be assembled in a short time.

In this embodiment, each printing wire 18 can be inserted into the nose body 29 after each printing wire 18 is fixed to each armature 17.
There is no need to perform the fixing work in step 8, and the work can be done easily, reducing manufacturing costs. Further, although the arrangement interval of each printing wire 18 is predetermined at the end on the platen side,
Since the distal ends of each armature 17 can be placed close to each other, the entire print head can be made smaller and the amount by which each print wire 18 is bent within guide portion 28 can be reduced. Therefore, the sliding resistance against the printing wire 18 is reduced, and smooth printing operation can be performed at high speed.

Furthermore, in this embodiment, since the through hole 30 for passing the electron beam is formed in the covering part 27 of the nose body 29, each armature 17 can be fixed to the elastic member 14 on the nose body side, and a plate with high magnetic resistance can be fixed to the elastic member 14. By arranging the elastic member 14 made of a spring outside the magnetic path formed by the permanent magnet 9, the magnetic force of the permanent magnet 9 can be effectively utilized. In addition, the irradiation direction can be easily controlled, and each armature 17 is fixed to the elastic member 14 using an electron beam with high energy density, so even small parts such as armatures can be reliably welded by reducing the welding point. Welding can be performed, and the influence of welding heat on the torsion bar parts 21 and 23 can be almost eliminated. In addition, since each support piece 13 is integrally formed with a single plate spring, the structure can be simplified, and
It is easy to assemble and can be manufactured at low cost.

Note that the present invention is not limited to the above-mentioned embodiments, and the configuration of each part can be arbitrarily changed without departing from the spirit of the present invention.

(Effects of the Invention) As detailed above, the present invention narrows the arrangement interval of each printing wire on the armature side to reduce the amount of deflection of the printing wire and reduces the sliding resistance of the printing wire within the guide section of the nose body. In addition, the printing head can be miniaturized as a whole, and has excellent effects in that it can be easily assembled and manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a main part of a print head embodying the present invention, FIG. 2 is a partially cutaway side view of the print head, and FIG.
The line sectional view and FIG. 4 are partially exploded perspective views. In the figure, 3 is the head body, 13 is a support piece,
14 is an elastic member, 17 is an armature, 18 is a printing wire, 27 is a covering portion, 28 is a guide portion, 29 is a nose body, and 30 is a through hole.

Claims (1)

[Scope of Claims] 1. A plurality of armatures 17 swingably supported by the head main body 3 by elastic members 14, a printing wire 18 attached to each armature 17, and a covering portion covering each armature 17. 27 and a nose body 29 that accommodates each of the printing wires 18 so as to converge at the free end thereof and includes a guide portion 28 that guides the movement of each printing wire 18 as the armature 17 swings; The printing wire 18
At the same time, each printing wire 18 is printed based on the biasing force of the elastic member 14 by selectively releasing the armature 17 from a state in which each armature 17 is held at the rest position and a biasing force is accumulated in the elastic member 14. In the print head that is moved to the desired position, an elastic member 14 is attached to the inner surface of the covering portion 27 of the nose body 29.
After positioning and arranging, the printing wire 18 attached to each armature 17 in advance is inserted into the guide part 28 of the nose body 29, and then each armature 17 is positioned and fixed to the elastic member 14 so as to be swingable. How to assemble the print head. 2. The printing head assembly according to claim 1, wherein each of the armatures 17 is fixed on the nose body 29 side by an electron beam or laser passing through a through hole 30 formed in the covering part 27. Method. 3. The elastic member 14 is a leaf spring having a support piece 13 facing each armature 17, and each armature 17 is fixed to overlap the support piece 13. A method of assembling a print head according to any one of paragraphs 2 to 3.