JPH06286170A - Print head for dot printer - Google Patents

Abstract

(57) [Abstract] [Purpose] In the print head, the cores around which the coils are wound are made into independent parts, respectively, so that the cores can be easily and accurately assembled to the rear yoke. [Structure] A core portion 10a and a rear yoke rear portion 10b corresponding thereto are integrally formed as a substantially U-shaped plate piece-shaped core forming member 10. In addition, the flange-shaped ring yoke 11 of the rear yoke forms a slit 11a whose inner end is open. The rear yoke rear portion 10b is fitted into the slit 11a and fixed with an adhesive.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head for a dot printer, and in particular, each of a plurality of core portions around which coils are wound is formed as an independent component integrated with a rear yoke rear portion corresponding to each core portion. Regarding

[0002]

2. Description of the Related Art Conventionally, with respect to a print head for a dot printer, a coil is wound around each of a plurality of cores arranged annularly inside a rear yoke, and an armature fixed to a leaf spring is always attached to a magnetic force of a magnet plate. The magnet is attracted to the front end surface of the core by using, or the armature is separated from the core without using a magnet plate, and when the coil is energized, the tip of the armature is moved in the platen direction, and the tip of this armature is A print head designed to print with a fixed printing wire is generally put into practical use, and various print heads of this type have been proposed.

[0003] For example, the applicant of the present application has disclosed in JP-A-62-23
In Japanese Patent No. 6758, from a platen side, a cover having a nose portion, a spring member, a front yoke, a magnet plate, a plurality of armatures fixed to the spring member, and a plurality of cores around which a coil is wound are circled. A print head having a rear yoke composed of a rear yoke integrally formed at equal intervals in the circumferential direction has been proposed. By the way, in this type of print head, the rear yoke integrated with the plurality of cores is
It is usually manufactured integrally by casting.

[0004]

As described above, the rear yoke of the print head has a complicated shape in which a plurality of cores are annularly provided on the circumferential side at equal intervals in the circumferential direction, and the rear yoke is cast. Since it is manufactured integrally with the mold, the precision of the core shape and the position where it is arranged annularly deteriorates due to the delicate solidification conditions of the molten metal poured into the mold, especially the amount of armature swing, that is, the stroke of the printing wire (protrusion). Amount) is required, so polishing of the upper end surface of the core is required, and the upper surface of the flange of the rear yoke on which the magnet plate is mounted is improved to improve the magnetic characteristics for attracting amateurs. There are problems such as the need for processing, the large amount of labor and time required for the production by casting, and the high cost.

An object of the present invention is to make a plurality of core parts into independent parts, and to provide a plurality of core parts in a rear yoke easily and accurately, and which is advantageous in terms of manufacturing and processing, and is a print head for a dot printer. Is to provide.

[0006]

According to a first aspect of the present invention, there is provided a print head for a dot printer, comprising a plurality of armatures to which one end of a printing wire is connected, and a plurality of armatures corresponding to the plurality of armatures and having coils wound around them. A core part having a plurality of core parts arranged at equal intervals in the circumferential direction and a ring-shaped flange part surrounding the plurality of core parts in the front part and each core in the rear part continuing from the front part to the rear part. In a print head for a dot printer provided with a rear yoke for supporting a portion and forming a magnetic path extending between each pair of amateurs and a core portion, each core portion and a rear yoke rear portion of the corresponding rear yokes, The flange-shaped front portion of the rear yoke is integrally formed as a ring-shaped rear ring yoke, and the inner peripheral portion of the rear ring yoke is integrally formed as a substantially U-shaped plate piece-shaped core forming member. Has a plurality of core forming members, each of which has a corresponding inner slit with an open inner end, and each core forming member has a rear ring yoke in a state in which the front end of the rear portion of the rear yoke is fitted into the corresponding fitting slit. It is fixed to.

A dot printer print head according to a second aspect of the present invention is the print head of the first aspect, wherein a ring-shaped permanent magnet and a slit with an open inner end for accommodating the armature are formed on the front side of the rear ring yoke. The ring-shaped front yoke is fixed on top of one another.

[0008]

In the print head for a dot printer according to claim 1, a plurality of core portions each corresponding to a plurality of armatures to which one end of a printing wire is connected and a coil being wound, and corresponding to this The rear yoke rear portion of the rear yoke is integrally formed as a substantially U-shaped plate piece-shaped core forming member, and the flange-shaped front portion of the rear yoke is integrally formed as a ring-shaped rear ring yoke. On the inner peripheral portion of the ring yoke, fitting slits having open inner ends corresponding to the plurality of core forming members are formed, and each core forming member fits the front end of the rear portion of the rear yoke to the corresponding fitting slit. Since it is fixed to the rear ring yoke in this state, the magnetic path extending between the core forming member that forms the armature and the core portion and the rear ring yoke is such that the armature and core of each pair are It will be respectively formed for forming members each, are dot printing by energizing the coil with print wires through the swing of the amateur.

As described above, since the core forming member integrally forming each core portion and the rear portion of the rear yoke corresponding thereto and the rear ring yoke integrally formed with the flange-shaped front portion of the rear yoke constitute the rear yoke. , A plate-shaped core forming member or a flange-shaped or plate-shaped rear ring yoke,
For example, it can be easily manufactured by punching, etc. Moreover, the positional accuracy of each core part with respect to the rear ring yoke is improved by simply attaching a plurality of core forming members to the rear ring yoke, and the upper surface of the rear ring yoke and the core part Since it is not necessary to polish the end faces, the rear yoke can be manufactured easily and efficiently.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a 24-pin print head used in a wire dot type printer. As shown in FIG. 1, the carriage 25
The print head 1 mounted above has a head frame 2 having a nose portion 2a, a thin plate-like leaf spring 4, a front yoke 5 for forming a magnetic path M, a plate-like magnet 8 and a rear yoke from the platen 24 side. The rear yoke 9 will be described first.

As shown in FIGS. 2 to 4, the rear yoke 9 is composed of a rear yoke portion 10b of the core forming member 10 and a rear ring yoke 11. The core forming member 10 will be described. As shown in FIGS. 2 and 4, the core forming member 10 is formed by punching from a magnetic material plate material, and has a wide core portion 10 around which the coil 18 is wound.
The rear yoke portion 10b corresponding to the rear portion of the rear yoke of the rear yoke 9 is a plate piece having a substantially U-shape in side view. However, the core portion 10a is tapered.

As shown in FIG. 2, the rear ring yoke 11 corresponds to a ring-shaped flange portion in the front portion of the rear yoke 9 that surrounds the 24 core portions 10a, and is composed of a magnetic material plate and a substantially ring shape. And 24 fitting slits 11a with open inner ends corresponding to the 24 core forming members 10, respectively, are formed in the inner peripheral portion by punching at equal intervals in the circumferential direction. There is. However,
Two rear ring yokes 11 are stacked and fixed to form a flange portion. Here, the width of the fitting slit 11a is slightly larger than the thickness of the upper end portion of the rear yoke portion 10b. Reference numeral 11b is a pin hole into which a positioning pin (not shown) is fitted.

Next, as shown in FIG. 2, the rear yoke portion 10 of the core forming member 10 is made by using a jig (not shown).
With the upper surface of b and the upper surface of the rear ring yoke 11 aligned and the core forming member 10 positioned, the upper end of the rear yoke portion 10b is sufficiently fitted into the corresponding fitting slit 11a and fixed with an adhesive. To do. And FIG. 3 and FIG.
As shown in FIG. 5, all 24 core forming members 10 are assembled to the rear ring yoke 11. Here, since the rear ring yoke 11 is stamped from the plate material, the polishing process of the upper surface on which the magneto 8 is placed is not necessary, and the core forming member 10 is stamped from the plate material, so the core portion 1
Similarly, no polishing step is required for the upper end surface of 0a.
Further, all of the core forming members 10 are assembled to the rear ring yoke 11 at a predetermined height position, and the core portions 10a have a predetermined pitch with respect to the rear ring yoke 11 and have no inclination. It is provided with high positional accuracy.

By the way, as shown in FIG. 1, a coil bobbin 19 around which a coil 18 is wound is fitted on each of the 24 core portions 10a. The end of the coil 18 is connected to the printed board 21 via the connector 20. A plate-shaped and substantially ring-shaped magnet 8 is joined and fixed to the front side of the rear ring yoke 11, and a ring yoke 7 made of a magnetic material is joined and fixed to the front side of the magnet 8 and is attached to the front side of the ring yoke 7. Is joined and fixed to a ring-shaped front yoke 5 having a slit having an open inner end for accommodating an armature 12 via a film-shaped radial sheet 6 having abrasion resistance and heat resistance. . A leaf spring 4 and a spacer 3 made of a magnetic material are joined and fixed to the front side of the front yoke 5, and a head frame 2 having a nose portion 2a is joined and fixed to the front side of the spacer 3.

Here, the amateur 12 provided on the front side of the core portion 10a corresponding to each of the plurality of core portions 10a.
The outer ends thereof are elastically supported by the leaf springs 4, respectively, and the base end of the printing wire 13 is fixed to the inner end thereof. The printing wire 13 extends in the vicinity of the platen 24 while passing through the four guide members 14 to 17 and converging in the nose portion 2a. Reference numeral 26 is a heat sink provided on the rear yoke 9.

The magnetic field lines of the magneto 8 cause the ring yoke 7, the front yoke 5, the armature 12, the core portion 10a, the rear yoke portion 10b, and the rear ring yoke 1.
1, the closed loop magnetic path M is formed for each core portion 10a. Therefore, the armature 12 is always attracted to the upper surface of the core portion 10a against the spring force of the leaf spring 4 by the magnetic force line of the magneto 8, and the tip of the printing wire 13 is separated from the platen 24 at a non-printing position. Held in. That is, the leaf spring 4 is deformed by the rotation of the armature 12 and the biasing force is accumulated.

On the other hand, when the coil 18 is energized,
A magnetic field is generated in the core portion 10a around which the energized coil 18 is wound so as to cancel the magnetic path M, the attraction force of the armature 12 is canceled, and at the same time, the armature 12 is caused by the spring force of the leaf spring 4. Is swung in the direction away from the core portion 10a, the tip of the printing wire 13 fixed to the armature 12 collides with the platen 24, and dots are printed on the printing paper P via the ink ribbon R. Is printed. By the way, when the coil 18 is de-energized for a minute time, the armature 12 is again attracted to the upper surface of the core part 10a by the reaction force of the collision between the printing wire 13 and the platen 24 of the armature 12 and the magnetic force of the magnet 8. To be done.

In this way, the core forming member 10 in which each core portion 10a and the rear portion of the rear yoke 9 corresponding thereto are integrally formed is attached to the rear ring yoke 11 in which the flange-shaped front portion of the rear yoke 9 is integrally formed. Since the rear yoke 9 is manufactured, the magnetic path M extending from the armature 12, the core forming member 10 having the core portion 10a and the rear ring yoke 11 is formed, and the function as the rear yoke 9 is provided. The ring yoke 11 can be easily manufactured by punching or the like, and the positional accuracy of each core portion 10a with respect to the rear ring yoke 11 can be improved by simply attaching the plurality of core forming members 10 to the rear ring yoke 11. 11 upper surface and core portion 10a
Since it is not necessary to polish the upper end surface of the rear yoke 9,
Can be manufactured easily and in a short time, and the manufacturing cost can be reduced.

It should be noted that, without using the magnet 8, a print head constituted so that the armature 12 is projected toward the platen 24 by the magnetic force from the core portion 10a, or the printing wire 13 other than 24, for example, 36 It is needless to say that the present invention can be applied to a print head provided with 48 lines.

[0020]

As described above, according to the print head for a dot printer of claim 1, the core forming member integrally forming each core portion and the rear portion of the rear yoke corresponding thereto is provided with the flange-shaped front portion of the rear yoke. Since the rear yoke is manufactured by attaching it to the rear ring yoke where the part is integrally formed,
A magnetic path extending between the core forming member that forms the armature and the core portion and the rear ring yoke is formed to have a function as a rear yoke, and the core forming member and the rear ring yoke can be easily manufactured, for example, by punching and the like. By simply attaching a plurality of core forming members to the rear ring yoke, the positional accuracy of each core portion with respect to the rear ring yoke is improved, and it is not necessary to polish the upper surface of the rear ring yoke and the upper end surface of the core portion. The core portion and the rear yoke can be easily and inexpensively manufactured, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a main part of a print head for a dot printer.

FIG. 2 is an exploded perspective view of a rear ring yoke and a core forming member.

FIG. 3 is a front view of a rear yoke.

FIG. 4 is a rear view of a rear yoke.

[Explanation of symbols]

 1 Print Head 2 Side Frame 5 Front Yoke 8 Magnet 9 Rear Yoke 10 Core Forming Member 10a Core 10b Rear Yoke 11 Rear Ring Yoke 11a Fitting Slit 12 Mature 13 Printing Wire

Claims (2)

[Claims] 1. A plurality of armatures to which one end of a printing wire is connected, and a plurality of core portions corresponding to the plurality of armatures and each having a coil wound around them are arranged at equal intervals in the circumferential direction. Having a plurality of core parts and a ring-shaped flange part surrounding the plurality of core parts in the front part, and supporting each core part in the rear part continuing from the front part to the rear part, extending over each pair of amateur and core part In a print head for a dot printer including a rear yoke for forming a magnetic path, each core portion and a rear yoke rear portion of the rear yokes corresponding to the core portion serve as a substantially U-shaped plate piece-shaped core forming member. The flange-shaped front portion of the rear yoke is integrally formed as a ring-shaped rear ring yoke, and the inner peripheral portion of the rear ring yoke corresponds to a plurality of core forming members, respectively. Dots characterized in that a fitting slit having an open inner end is formed, and each core forming member is fixed to the rear ring yoke with the front end of the rear portion of the rear yoke fitted into the corresponding fitting slit. Print head for printer. 2. A ring-shaped permanent magnet and a ring-shaped front yoke having an open inner end slit for accommodating the armature are fixed in an overlapping manner on the front side of the rear ring yoke. The print head for a dot printer according to claim 1.