JPS62251156A - Assembling method for printing head - Google Patents

Abstract

PURPOSE:To reduce the pitch of printing wires and the size of a printing head, by positioning an elastic member on the inside surface of a coated part of a nose body, thereafter passing the printing wires through a guide part of the nose body, and then positioning and fixing each armature. CONSTITUTION:Recessed parts 16a, 14a of a spacer 16 and an elastic member 14 are opposed to each positioning projection 32 of a nose body 29, and the spacer 16 and the elastic member 14 are overlappingly fitted onto a coated part 27, thereby positioning the spacer 16 and the member 14. While passing each printing wire 18 fixed to each armature 17 through a guide part 28 of the nose body 29, each armature 17 is positioned on each support piece 13 of the member 14. Each support piece 13 is irradiated with electron beams or laser through each through-hole 30, thereby formly welding each armature 17 to each support piece 13. A spacer 15, a front yoke 11, a spacer 10, a permanent magnet 9 and a flange 4 are sequentially laid on the elastic member 14 while opposing each of recessed parts of them to each positioning projections 32, and these members are connected to each other, whereby a printing head can be speedily assembled.

Description

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

(Prior Art) Conventionally, when assembling this type of printing gutter, 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 portions of each armature in order to perform the fixing work. 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 print head to become larger and worse. There have been problems in that assembly becomes troublesome, takes a long time, and increases manufacturing costs.

(Object of the Invention) This invention was made to solve the above problems, and the 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. There is a method for assembling the print head that can reduce the sliding resistance of the print wire in the guide section of the print head, and also downsize the print head as a whole.Moreover, it is easy to assemble and can be manufactured at low cost. It is about providing.

(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. The armature is inserted into the guide portion of the body, and then each armature is swingably positioned and fixed to the elastic member.

(Function) Therefore, when fixing the printing wire to the armature, there is no need to perform the work within the narrow space of the print head, making it possible to increase work efficiency, and to narrow the gap between the armature tips for printing. It is possible to reduce the amount of bending of the 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, an embodiment of the 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 gutter body 3 of the print head 2, which is movable along the printing lines on the platen 1, is formed into a bottomed cylindrical shape having a circular recess 3a opened toward the platen using a magnetic material. 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 cork. 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 includes a core 6 integrally formed to project 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 left-right symmetrical plate-shaped divided pieces 9a, 9b, and each divided piece 9a, 9
b are joined and fixed at opposite ends. permanent magnet 9
A front yoke 11 is bonded and fixed to the front side surface of the front yoke 1 through a spacer 10 made of a magnetic material.
A plurality of slits 12 are formed in the electromagnetic device 1 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 plate spring and has a plurality of support pieces 13 extending radially opposite to each slot throat 12. A pair of elastic members 14 made of a magnetic material Each support piece 13 of this elastic member 14 is fixedly joined while being sandwiched between spacers 15 and 16.
A plurality of armatures 17 made of a magnetic material are each swingably supported at the base end. Each armature 17
The base end portion of the head body 3 is disposed within each of the slits 12, and a printing wire 18 is attached at its base end to the print wire 18, which extends toward the platen 1 while being converged at the center of the head body 3. ing.

That is, a plurality of protrusions 20 that protrude radially between each armature 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 between each protrusion 20. A bridge is formed. 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 protruding laterally is provided at the tip of each fixing part 22. 23
are integrally formed. Further, the armature fixing part 2
2, each protrusion 20 and each second torsion bar part 23 are integrally connected by a pair of leaf spring parts 24.

And the first. The second torsion bar parts 21 and 23, the armature fixing part 22, and the leaf spring part 24 constitute a support piece 13 for one armature 17, and each armature 17 is superimposed on each armature fixing part 22. , each armature 17 is fixed to each support piece 13.

Further, each of the spacers 15 and 16 includes the elastic member 14.
A protrusion 25 is integrally formed to overlap the protrusion 20, and each protrusion 25 holds the base end portions of a pair of leaf spring portions 24 adjacent to each other inwardly from the first torsion bar portion 21. A pair of clamping parts 26 are formed. A nose body 29 is fixedly connected to the front side surface of the spacer 16 by the covering portion 27. The nose body 29 includes a flat covering portion 27 and a substantially cylindrical guide portion 28 projecting toward the platen 1. Three through holes 30 per each armature are formed in this covering portion 27 facing each armature 17, and a plurality of guide plates 31 are provided in the guide portion 28 at predetermined intervals. Each of the printing wires 18 is movably inserted through the plurality of guide plates 31 and converged at the free end on the platen side.

As shown in FIGS. 3 and 4, four positioning protrusions 32 projecting rearward are integrally formed at the four corners of the covering portion 27. As shown in FIGS. On the other hand, the flange 4, the permanent magnet 9. Spacer 10. At the four corners of the front yoke 11, the spacers 15, 16, and the elastic member 14, there are recesses 4a, 9c, 10a, and lla having substantially the same shape that fit into the respective positioning protrusions 32.
, 15a, 16a, and 14a are formed, respectively.

Then, each member 4, 9° 10 is attached to each positioning protrusion 32.
．． 11.15, 16.14 each recess 4a, 9c, 10a
, lla, 15a, 16a, 14a are fitted, each of the members 4.9, 10, 11.1 is attached to the covering portion 27.
5, 16, and 14 are stacked on top of each other in a predetermined order and are fixed together by appropriate connecting means.

In the print head configured as described above, when the coil 8 of each electromagnetic device 5 is not energized, the spacer 10 is moved by the permanent magnet 9 as shown by the two-dot chain line in FIG.
．． Front yoke 11. Armature 17. A magnetic path is formed through the core 6 and the flange 4, whereby each armature 17 is attracted to the entire end face of the core 6, each printing wire 18 is placed in a rear rest position, and the elastic member 14
Each support piece 13 is displaced rearward, each torsion bar portion 21, 23 is torsionally deformed, and each leaf spring portion 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, the armature 17 is Released from Core 6. That is, after the armature 17 is swung around the first torsion bar part 21 to the printing position, 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 printing gutter configured as described above, when assembling the armature 17 and printing wire 18 to the nose body 29, the spacer 16 and the recess 16a of the elastic member 14 are attached to each positioning protrusion 32 of the nose body 29. 14a are made to face each other and are sequentially overlapped with the covering portion 27, the respective 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, which has been fixed in advance to each armature 17 by brazing or laser welding, is attached to the nose body 29.
Each armature 17 is placed on each support piece 13 of the elastic member 14 while being inserted into the guide portion 28 of the elastic member 14, and positioned using a predetermined jig. In this state, when each support 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 is irradiated with each support piece 13 at the position shown by the circle in FIGS. 1 and 3. 17 are welded and fixed, and the assembly of each armature 17 and each printing wire 18 is completed.

Next, spacer 15. Front yoke 11° spacer 10. Each recess 15a, l of the permanent magnet 9 and flange 4
After sequentially overlapping each member on the elastic member 14 with the positioning protrusions 32 facing the respective positioning protrusions 32, the members are connected by a predetermined connecting means to complete the entire print head assembly. The attachment can be completed 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, so that the fixing work of the printing wire 18 can be performed within the narrow space of the head body 3. There is no need to perform this work, and the work can be done easily and manufacturing costs can be reduced. Further, although the arrangement interval of each printing wire 18 is predetermined at the end on the platen side,
Since the distal ends of the armatures 17 can be arranged close to each other, the entire print head can be downsized, and the amount by which each print wire 18 is bent within the 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, the through hole 30 for passing the electron beam is formed in the covering part 27 of the nose body 29, so each armature 17 can be fixed to the elastic member 14 on the nose body side, and the magnetic resistance is large. By arranging the elastic member 14 made of a leaf spring outside the magnetic path of the permanent magnet 9, the magnetic force of the permanent magnet 9 can be effectively utilized. In addition, since the irradiation direction is easily controlled and each armature 17 is fixed to the elastic member 14 by an electron beam with high energy density, even small parts such as armatures can be welded reliably with low welding heat. At the same time, the influence of welding heat on the torsion bar portion 21.23 can be almost eliminated. In addition, since each support piece 13 is integrally formed with a single handling spring, the structure can be simplified, assembly is easy, and manufacturing can be done 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 described in detail 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 print head can be miniaturized as a whole, and can be easily assembled and manufactured at low cost.

[Brief explanation of drawings]

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. 3 is a sectional view taken along the line ■-■ in Fig. 2. , FIG. 4 is a partially exploded perspective view.

Claims (1)

[Claims] 1. A plurality of armatures (17) swingably supported on the head body (3) by elastic members (14), and a printing wire (18) attached to each armature (17). , a coating part (27) that covers each of the armatures (17) and each of the printing wires (18) are housed so as to converge at their free ends, and each of the printing wires (18) is accommodated so as to converge at their free ends. ) and a nose body (29) equipped with a guide portion (28) for guiding the movement of the printing wire (1).
8), each armature (17) is held at the rest position, and the elastic member (14) is selectively released from the state where the urging force is accumulated in the elastic member (14). In a print head that moves each print wire (18) to a print position based on force, an elastic member (1) is provided on the inner surface of the covering portion (27) of the nose body (29).
4) After positioning and arranging each armature (17),
Insert the printing wire (18) attached to the guide part (28) of the nose body (29), and then
A method for assembling a print head, characterized in that the print head is swingably positioned and fixed to an elastic member (14). 2. 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). How to assemble the print head as described in . 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 for assembling a print head according to claim 1 or 2.