JPH06135018A - Wire dot print head and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a wire dot print head in which a first annular yoke, a permanent magnet, and a second yoke are laminated sequentially on a base plate planted with a core and then they are secured easily. CONSTITUTION:The wire dot print head comprises a clamp spring 23 having a stop part 22 provided on the outer wall of a magnetic member 21 having an end face flush with one end face of a core 13, a body 25 abutting on the other face of a base plate 3, and an arm 24 extending from an edge of the body 25 along the outer wall of the magnetic member 21 and engaging with the stop part 22 to secure the magnetic member 21 to the base plate 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure and manufacturing method of a wire dot print head used in an impact printer.

[0002]

2. Description of the Related Art Conventionally, an impact printer is provided with a print wire via an armature on a free end of a cantilevered leaf spring radially arranged toward a central portion, facing each armature. A magnetic member and a permanent magnet are laminated on one plate surface side of a base plate on which a core is erected, and an armature attracted to one end of the core by magnetic flux from the permanent magnet is applied to a coil wound around the core. Some of them use a wire dot print head which is released by printing to print.

FIG. 9 is a half sectional view showing a structure of a conventional example. A first yoke 4, a permanent magnet 5, a second yoke 6, a spacer 7, a biasing leaf spring 8 and an armature yoke 9 are provided on one plate surface side of the base plate 3. Etc. are sequentially laminated, and further the guide frame 1 is laminated on the cap 2 and the armature yoke 9 on the other plate surface side of the base plate 3 and fixed by the clamp 10. An armature 11 is provided at the free end of the cantilevered bias leaf spring 8 radially arranged toward the center, and the base of the printing wire 12 is fixed to the tip of the armature 11. Wire 1
The tip of 2 is guided by the guide 1a of the guide frame to the platen side and can be projected. An annular first yoke 4, on one plate surface side of the base plate 3,
The core 13 is erected so as to be opposed to the armature 11 so as to be built in the permanent magnet 5 and the second yoke 6, and the coil 1
A bobbin 17 having 4 wound is mounted. Coil 14
Is connected to a printed circuit board 16 fixed to the other plate surface of the base plate 3 via a board positioning space 15.

The operation will be described below. The magnetic flux of the permanent magnet 5 is changed by the second yoke 6, the spacer 7, the armature yoke 9, the armature 11, the core 13, and the base plate 3. And a magnetic circuit is formed through the first yoke 4 and back to the permanent magnet 5 by this armature 11.
Is attracted to one end surface of the core 13, strain energy is accumulated in the bias leaf spring 8, and the bias leaf spring 8 is placed in a biased state. When the coil 14 is excited to generate a magnetic flux in the direction opposite to the magnetic circuit in the biased state, the force for attracting the armature 11 decreases. Therefore, the strain energy accumulated in the bias leaf spring 8 is released, and the bias leaf spring 8 returns to cause the printing wire 12 attached to the tip of the armature 11 to protrude from the guide 1a, and an ink ribbon (not shown). And press the print medium against the platen. As a result, characters and graphic patterns can be printed.

By the way, in order to reduce the variation of the printing force at the time of hitting the medium by the printing wire 12 by keeping the amount of deflection of the bias leaf spring 8 constant, when assembling the print head, as shown in FIG. A core 13 is planted on the other plate surface of No. 3, and an annular first yoke 4, a permanent magnet 5 and a second yoke 6 are sequentially laminated on one plate surface, and their respective contact surfaces are arranged. After the core assembly is fixed by an adhesive or laser welding, one end surface of the core 13 and the second yoke 6 are formed.
And the end surface of is ground at the same time. The fixing strength at this time is about 50 kg.

[0006]

In the conventional wire dot print head, one end surface of the core and the end surface of the second yoke as a magnetic member having the end surface included in the same plane are ground at the same time. At this time, a core in which an annular first yoke, a permanent magnet and a second yoke are laminated in order on a base plate in which a core is planted and the respective contact surfaces are fixed by an adhesive or welding. It has to be carried out after the assembly, and there is a problem that a large number of man-hours are required.

According to the present invention, when one end surface of the core and the end surface of the second yoke as the magnetic member are ground simultaneously,
An annular first yoke is formed in sequence on the base plate on which the core is planted.
It is an object of the present invention to provide a wire dot printing head which can be easily fixed after stacking a magnet, a permanent magnet and a second yoke.

[0008]

In order to achieve the above object, in a wire dot printing head of the present invention, a magnetic member having an end face included in the same plane as one end face of a core and a base plate are provided. It is provided with a sandwiching means for sandwiching the space.

[0009]

In the wire dot printing head constructed as described above, the magnetic member and the permanent magnet are laminated on one plate surface side of the base plate on which the core is erected, and included in the same plane as one end surface of the core. The magnetic member having the end face to be held and the base plate are clamped and fixed by the pinching means, and then one end face of the core and the end face of the magnetic member are ground at the same time.

Therefore, according to the present invention, when the one end surface of the core and the end surface of the magnetic member are simultaneously ground, the magnetic member and the like are laminated on one plate surface side of the base plate on which the core is erected. , It can be fixed easily.

[0011]

Embodiments of the present invention will be described with reference to the drawings. Elements common to the drawings are given the same reference numerals. First Embodiment FIG. 1 is a half cross-sectional view showing a structure of a first embodiment including a broken portion. This embodiment is different from the conventional example in the structure of the core assembly. That is, in the core assembly 20, after the core 13 is planted on the plate surface of the base plate 3, the annular first yoke 4 and the permanent magnet 5 are provided on one plate surface side of the base plate 3. , And the second yoke 21 are stacked to house the core 13, and the main body 25 of the clamp spring 23 is brought into contact with the other plate surface of the base plate 3 so as to be flush with one end surface of the core 13. Second yoke 2 having an end face included in
The arm 24 of the clamp spring 23 is hooked and fixed to the claw 22 provided on the outer wall of 1.

FIG. 2 is a side view of the clamp spring. The clamp spring 23 of the present embodiment is in the shape of a hook having three arms, and the arm 24 standing on the edge portion 26 of the annular body 25 is provided on the outer wall of the second yoke 21. Nail 2
A hole 27 for hooking on 2 is provided. An edge portion 26 sandwiched between the arm 24 and the arm 24 is bent toward the arm side by bending. That is, as shown in FIG. 1, the main body 25 of the clamp spring 23 is attached to the base plate 3 on which the core 13 is erected.
The hole 27 of the arm 24 is hooked on the claw 22 provided on the outer wall of the second yoke 21. As a result, the bent portion that is in contact with the other plate surface side becomes a hinge, and the first yoke 4, the permanent magnet 5, and the second yoke 21 that are laminated by the pulling force are the base plate 3 It is pressed against one of the plate surfaces and fixed. At this time, the tip of the arm 24 is located at a position having a margin δ that is equal to or larger than the polishing allowance from one end surface of the core 13. The fixed strength per arm is 20 kg.
There is a degree, and the total fixing strength is 60 kg. Since the core assembly fixed by adhesion or laser welding described in the prior art has a fixed strength of about 50 kg, it does not move during the grinding process. Then, the armature yoke and the cap are further laminated and fixed with a clamp. The operation of the wire dot print head is the same as in the prior art, and will not be described.

Second Embodiment FIG. 3 is a half cross-sectional view showing a structure of a second embodiment including a broken portion. This embodiment differs from the first embodiment in the engaging portion between the clamp spring 31 and the second yoke 32.
That is, the claw 34 is attached to the arm 33 of the clamp spring 31.
And a recess 35 is provided in the outer wall of the second yoke 32. The operation is similar to that of the first embodiment.
The operation of the wire dot print head is similar to that of the first embodiment.

Third Embodiment FIG. 4 is a partial perspective view showing the structure of the third embodiment, and FIG.
FIG. 5 is a sectional view taken along the line AA of FIG. This embodiment is different from the first and second embodiments in that a core 4 built in a magnetic member is used.
1. A tongue extending portion 42 extending from the other end portion of the magnetic head toward the outer wall of the magnetic member is provided, and as shown in FIG.
The point is that the tongue extending portion 42 is received and sandwiched by the tongue extending portion 42, and is sandwiched by the first yoke 4 as a magnetic member. In this embodiment, the tongue extension of the core is sandwiched between the base plate and the first yoke as the magnetic member. However, the positions of the first yoke and the permanent magnet are exchanged. It may be sandwiched between a permanent magnet and a base plate. Further, the clamp spring and the second yoke are based on the first embodiment, but may be based on the second embodiment. According to the third embodiment, since it is not necessary to weld the core to the base plate, the number of steps is further reduced as compared with the first and second embodiments.

Fourth Embodiment FIG. 6 is a plan view of an essential part according to the fourth embodiment, and FIG. 7 is a plan view.
It is a BB cross-section arrow line view of. In the core assembly 50 of this embodiment, the heat sink 5 is used instead of the clamp spring.
The reference numeral 1 is for sandwiching the base plate 52, the first and second yokes 4 and 54 as magnetic members, and the permanent magnet 5. That is, as shown in FIG. 7, a groove 56 having a width C is provided along the U-shaped notch 54 inside the heat sink 51 having the U-shaped notch 54, and the base plate 52 is formed. The first yoke 4 and the permanent magnet 5 are sandwiched between the second yoke 53 and the second yoke 53 to measure the width C, and then fitted in the direction of arrow D as shown in FIG. . Then, the heat sink 51 and the base plate 52 are welded at a plurality of points. In this embodiment, a groove having a width C is provided along the U-shaped cutout portion of the heat sink. However, instead of the groove, a convex portion 61 is provided on one side as shown in FIG. 8 to form a base plate. 52,
After fitting the first yoke 4, the permanent magnet 5, and the second yoke 53, the convex portion 61 may be welded. The shape of the base plate may be as shown in the third embodiment.

[0016]

Since the present invention is configured as described above, it has the following effects. By providing the sandwiching means for sandwiching between the magnetic member having the end surface included in the same plane as the one end surface of the core and the base plate,
When simultaneously grinding the one end surface of the core and the end surface of the magnetic member having the end surface included in the same plane, the magnetic member and the permanent magnet can be laminated in order on the base plate in which the core is planted and then easily fixed. . Therefore, the number of steps can be greatly reduced compared to fixing the contact surface between the magnetic member and the permanent magnet with an adhesive or welding.

[Brief description of drawings]

FIG. 1 is a half sectional view showing the structure of a first embodiment.

FIG. 2 is a side view of a clamp spring.

FIG. 3 is a half sectional view showing the structure of the second embodiment.

FIG. 4 is a half sectional view showing a structure of a third embodiment.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is a plan view of a main part according to a fourth embodiment.

7 is a cross-sectional view taken along the line BB of FIG.

FIG. 8 is a perspective view of a main part showing a modified example of the fourth embodiment.

FIG. 9 is a half sectional view showing a structure of a conventional example.

FIG. 10 is a partial perspective view showing a welded portion.

[Explanation of symbols]

 20, 30, 40, 50 Core assembly 23, 31 Clamp spring 24, 33 Arm 42 Tongue extension 51, 60 Heat sink

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Toshiyuki Asaka 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (6)

[Claims] 1. A bear in which a print wire is provided via an armature at a free end of a cantilevered leaf spring radially arranged toward a central portion, and a core is erected so as to face each armature. A magnetic member and a permanent magnet are laminated on one plate surface side of the plate, and the magnetic flux generated by the permanent magnet is attracted to one end of the core.
In a wire dot print head for printing by releasing a mature coil by energizing a coil wound around a core, a magnetic member having an end face included in the same plane as one end face of the core and a base plate are sandwiched. A wire dot print head, characterized in that it is provided with a holding means. 2. The holding means is a locking portion provided on an outer wall of a magnetic member having an end surface included in the same plane as one end surface of the core,
And a main body that abuts on the other plate surface of the base plate, extends from the edge of the main body along the outer wall of the magnetic member, and engages with the locking portion to place the magnetic member in the base plate. The wire dot print head according to claim 1, further comprising a clamp spring including a fixing arm. 3. The wire dot print head according to claim 2, wherein the clamp spring has an annular main body, and the tip of the arm is provided with a margin greater than a polishing allowance from one end surface of the core. 4. The sandwiching means is a heat sink provided with a fitting groove along a U-shaped cutout portion, and a magnetic member and an armature having an end face included in the same face as one end face of the core. The wire dot print head according to claim 1, wherein the gap is fitted in the fitting groove. 5. The core is provided with a tongue extending portion extending from the other end toward the outer wall of the magnetic member, and is sandwiched between the base plate and the magnetic member or the permanent magnet. 3,
Alternatively, the wire dot print head according to item 4. 6. A method of manufacturing a wire dot print head in which a core is provided on a base plate, a base plate, a permanent magnet and a magnetic member are laminated and sandwiched by a sandwiching means, and then the magnetic member and the core. A method for manufacturing a wire dot print head, which comprises grinding one end surface of the wire.