JPH051403Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a drive device for a wire-type dot printer.

[Prior art]

In order to obtain good print quality in a wire-type dot printer, it is necessary to accurately manage and maintain the flight distance and flight speed of all drive wires. In a print head constructed of parts that are made up of parts, the rotation center support part of the armature wears out, and it is difficult to stably hold the rotation center support part of the wire drive member over a long period of time. I had a problem with the speed changing.

[Problem that the invention attempts to solve]

In the prior art, during long-term printing, the rotational center portion and the rotational center support portion of the armature are subjected to a load due to suction and a reaction force when the wire collides with the printing paper, and the armature undergoes rotational and sliding wear. Sliding wear under such stress induces unstable operation of the wire drive member as printing continues for a long time, resulting in printing defects.

Therefore, the present invention provides a simple method for wire drive members and their parts, without using special materials or structures for the armature, yoke, or their rotational center support parts, or using lubricants whose printing quality is affected by temperature. To provide a wire type impact dot head which prevents wear of a rotation center support part and provides good printing quality over a long period of time.

[Means for solving problems]

The impact dot head according to the present invention is an impact dot head that prints by attracting an armature with a dot wire at its tip using an electromagnet through a yoke member. 10~ for the thickness of these materials
It is characterized by forming a carburized and quenched layer with a hardness of Hv500 or more at a depth of 20%.

〔Example〕

The present invention attempts to improve the durability of impact dot head magnetic circuit components by applying carburizing and hardening treatment, which has conventionally been used for components other than magnetic circuit components. Conventionally, it was considered taboo to apply carburizing and quenching to the magnetic circuit components of impact dot heads, which degrades magnetic performance. By applying this treatment, it is possible to perform a hardening treatment without reducing practical printing efficiency, thereby improving the durability of the head components and contributing to significantly extending the lifespan of impact printers.

Therefore, the details of the present invention will be explained below based on illustrated embodiments.

The drawings all show one embodiment of the present invention, and the inner surface of the frame 1 is positioned on the convex shape 17a of the nose guide 17, which has an intermediate guide 14 and a tip guide 13 inside the nose 12. A shallow cylindrical core block made of magnetic material with 12 coil cores 1a formed in a ring shape is integrally fixed, and 12 slits 2a are radially arranged on top of the core block as shown in Fig. 2. The formed bottomed cylindrical yoke 2 made of magnetic material is the coil core 1a.
A disc-shaped side yoke 4 made of a magnetic material is placed at a constant distance from the top of the yoke 4, and on top of the yoke 4 is a disc-shaped side yoke 4 made of a magnetic material having twelve radial slits 4b having a shaft support mechanism 4a for the wire drive member 3. They are laminated with a wear-resistant sheet 5 interposed therebetween.

The wear-resistant sheet 5 is made so that the material portion and the shaft portion are aligned with each of these slits 2a, 4b and the horizontal groove 4a.
Twelve wire drive members 3 are placed on top, and a presser plate 6 is placed on top of them via a wear-resistant sheet 5a so as to cover them, and the whole is fixed by a fixing spring 7. There is. 5 and 5a can be the same part. In addition, the side yoke 4 is treated to have wear resistance, which is a characteristic part of the present invention. Prevents sliding wear. In this example, gas carburizing and quenching was performed to form a side yoke with a thickness of 0.6 mm.
On the other hand, it forms a carburized layer with a depth of 0.1 mm and has a hardness of Hv500 or higher. Furthermore, if the carburized layer is formed under the above conditions, the magnetic properties of the magnetic material will not be impaired.

In a printer configured in this manner, when a current is applied to one or more drive coils 8 selected by a print command signal, magnetic flux flows from the coil core 1a through the side yoke 4 and the bottomed cylindrical yoke 2. Then, the drive member 3 is attracted and guided by the two protrusions 8a protruding from the coil bobbin 8, and rotates counterclockwise in the figure without swaying, and the printed wire 9 fixed at the tip is guided by the two protrusions 8a protruding from the coil bobbin 8.
While being held by the leading edge guide 13, the ink ribbon is struck onto the recording paper via an ink ribbon (not shown).

Next, the structure of the wire driving member 3 is shown in FIG.
The wire driving member 3 has an armature 16 made of a magnetic material laminated with a lever 15 sandwiched therebetween. This armature has a hardened layer of Hv500 or higher. In this example, gas carburizing and quenching is applied to the armature plate thickness of 0.6 mm to a depth of 0.1 mm at Hv600. This hardened layer is a characteristic feature of the present invention, and prevents wear due to rotation and reciprocation with the fulcrum shaft 10 inserted at the drive rotation center of the armature without degrading the magnetic properties of the armature.

[Effect of idea]

The impact dot head according to the present invention has a carburized hardening layer with a hardness of Hv500 or more formed at a depth of 10 to 20% of the thickness of these materials on the armature and the yoke member that constitute the magnetic circuit of the impact dot head. Therefore, the wear that occurs between these members can be reduced without impairing the magnetic properties of the wire drive magnetic circuit, and the durability of the head components can be improved, contributing to a significant increase in the lifespan of impact printers.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a dot printer head showing an embodiment of the present invention. FIG. 2 is an exploded perspective view of the wire drive member, the yoke, and the wire drive member rotation support portion. FIG. 3 shows a perspective view of the wire drive member. 2...Yoke A, 3...Wire drive material, 4...
...Side yoke, 16... Armature.

Claims (1)

[Scope of Claim for Utility Model Registration] An impact dot head that prints by attracting an armature with a dot wire at its tip by an electromagnet through a yoke member, the armature and the yoke constituting a magnetic circuit of the impact dot head. Add hardness to the depth of 10 to 20% of the thickness of these materials in the member.
An impact dot head characterized by forming a carburized and hardened layer of Hv500 or more.