JP2802293B2 - Method of manufacturing armature for print head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an armature used for a print head.

[0002]

2. Description of the Related Art An armature is provided in a print head, and the armature is magnetically driven to drive a print wire.

[0003] As an armature, a type in which a yoke portion is provided integrally with a lever portion to which a printing wire is brazed and welded is generally used.

In this type of armature, it is necessary to ensure sufficient rust prevention, brazing to a printing wire, abrasion resistance, destruction resistance, and magnetic properties in a yoke portion. A yoke member made of a soft magnetic material such as 1% silicon steel is welded with a lever member made of a high-strength material such as maraging steel, and its surface is nickel-plated, or a yoke portion and a lever portion are formed by a method such as forging. Was formed integrally with a soft magnetic material, and this was subjected to a hardening treatment such as carburizing and quenching, and its surface was subjected to nickel plating.

[0005]

However, in the former method for manufacturing an armature, not only two parts, a yoke member and a lever member, are required, but also it takes time to weld the lever member to the yoke member. However, expensive materials such as maraging steel are required, and the cost is high.

In the latter method of manufacturing an armature, sufficient hardening and destruction resistance can be ensured by a hardening treatment such as carburizing and quenching, but only a hardening treatment such as carburizing and quenching is performed. In this case, there is a problem that the magnetic characteristics are significantly reduced, sufficient magnetic characteristics cannot be obtained, and the printing ability is reduced.

An object of the present invention is to provide a method for manufacturing an armature for a print head, which can sufficiently secure the rust prevention, brazing resistance, abrasion resistance, destruction resistance and magnetic properties of an armature at a low cost. is there.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a method for manufacturing an armature for a print head, wherein a yoke portion is provided integrally with a lever portion to which a print wire is brazed and welded, wherein the yoke portion is thicker than the lever portion. The armature body formed in the meat is integrally molded with a magnetic material, and the armature body is carburized and quenched to form a carburized layer on the armature body so that the material portion remains only at the center of the yoke portion. The surface is formed by electroless nickel plating to form a plating layer on the surface of the armature body, and thereafter, the armature body is heated to temper the armature body and at the same time to age harden the plating layer.

[0009]

According to the present invention, the wear resistance and the breakage resistance of the armature are sufficiently ensured by the carburizing and quenching and tempering treatment of the armature body and the age hardening treatment of the plating layer. The magnetic properties of the armature are sufficiently ensured by the material portion remaining at the center of the yoke portion, and the rust prevention and brazing properties of the armature are sufficiently ensured by the plating layer.

[0010] Further, the armature is manufactured from a single armature body, and the tempering treatment of the armature body and the age hardening treatment of the plating layer are efficiently and simultaneously performed, so that the cost is low.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a print head to which an armature manufactured by the method according to the present invention is applied.

In this print head, an armature 2 supported swingably via a support shaft 1, a print wire 3 brazed to the end of the armature 2, and the armature 2 are attracted by electromagnetic force. Yoke 4 that swings in one direction
A return spring 5 for urging the armature 2 in the other direction;
A damper 6 is provided which comes into contact with the armature 2 when the armature 2 is swung in the other direction. And
When the armature 2 is attracted to the yoke 4 by electromagnetic force,
When the printing wire 3 performs a printing operation and the electromagnetic force of the yoke 4 is released, the armature 2 returns to the original position by the urging force of the return spring 5, and at this time, the armature 2 comes into contact with the damper 6 and the armature 2 The bounce is suppressed. In FIG. 1, reference numeral 7 denotes a base.

In the armature 2 of the print head, the thickness of the yoke portion 2a facing the yoke 4 and the print wire 3
Is compared with the thickness of the lever portion 2b to be welded by brazing, as shown in FIG.
It is formed thicker than that. The armature 2 is manufactured using an armature body 2c integrally formed of a magnetic material as a base material, and has an internal structure in which a plating layer 2d having a predetermined thickness is formed on an outer periphery as shown in detail in FIG. The carburized layer 2e is formed such that the material portion remains only in the center of the yoke 2a.

Next, a method of manufacturing the armature 2 will be described. As shown in FIG. 3A, an armature body 2c in which the yoke 2a is formed thicker than the lever 2b.
Is integrally molded with a magnetic material, and the armature body 2c is carburized and quenched to form a yoke portion 2a as shown in FIG.
Armature body 2 so that the material part remains only in the center of the body
The carburized layer 2e is formed on c.

Next, the surface of the armature body 2c is subjected to electroless nickel plating to form a plating layer 2d on the surface of the armature body 2c (see FIG. 2). Thereafter, the armature body 2c is heated to temper the armature body 2c. At the same time as the treatment, the plating layer 2d is subjected to age hardening treatment. Thus, the armature 2 is formed as shown in FIG.

Therefore, the wear resistance and destruction resistance of the armature 2 are sufficiently ensured by the carburizing and quenching and tempering treatment of the armature body 2c and the age hardening treatment of the plating layer 2d, and the center of the yoke portion 2a during the carburizing and quenching treatment. The magnetic properties of the armature 2 are sufficiently ensured by the material portion remaining in the portion, and the rust prevention property of the armature 2 and the brazing property with the printing wire 3 are sufficiently ensured by the plating layer 2d, and the performance of the print head is improved. It becomes possible.

Further, since the armature 2 is manufactured from a single armature body 2c, and the tempering treatment of the armature body 2c and the age hardening treatment of the plating layer 2c are performed simultaneously and efficiently, the cost is reduced, and the print head is reduced. Costs can be reduced.

As the magnetic material, a soft magnetic material such as pure iron 1% silicon steel can be applied, and as the electroless nickel plating, Ni (P) plating or Ni (B) plating can be applied. It is.

Next, an experimental example will be described. 1% pure iron
A ring for magnetic measurement having a thickness of 1.5 mm is formed from a rolled material made of silicon steel, and the ring (as a rolled material), the surface of which is simply plated with Ni (P),
The ring is magnetically annealed at a temperature of 850 ° C., and then Ni (P) plated on its surface. The ring is carburized and quenched to a thickness of 100 μm.
(P) Plated and then tempered at a temperature of 300 ° C. The ring is carburized and quenched to a thickness of 200
The coercive force, the maximum magnetic permeability, and the magnetic flux density were measured for those which were subjected to Ni (P) plating on their surfaces and then tempered at a temperature of 400 ° C.

As a result, as shown in Table 1 below, carburizing and quenching were performed at a layer thickness of 100 μm, and then Ni (P)
Plated and then tempered at a temperature of 300 ° C. or carburized and quenched with a layer thickness of 200 μm,
Next, the surface is plated with Ni (P),
In the case of tempering at 00 ° C, the temperature is 850 ° C.
The magnetic properties are slightly inferior to those obtained by magnetic annealing with Ni (P) plating on the surface after that, but those without heat treatment (rolled material, Ni (P) plating on the surface) It was found that the magnetic properties were superior to those of the above. This is because Ni (P) plating is applied to the surface after carburizing and quenching, and then tempering is performed. In this case, a material portion remains in the center during carburizing and quenching, and this material portion remains after plating. This is because the tempering treatment results in a structure state equivalent to that obtained by magnetic annealing.

[0021]

[Table 1]

In Table 1, B ₂₅ is the magnetic field strength 250
3 shows the magnetic flux density at e (1990 A / m).

Further, the armature body 2c according to the present embodiment integrally formed of pure iron 1% silicon steel is used, the thickness of the lever portion 2b is set to 0.2 mm (200 μm), and the thickness of the armature body 2c is adjusted. Carburizing and quenching at 100 μm to form a carburized layer 2e on the armature body 2c so that the material portion remains only at the center of the yoke portion 2a, and then the surface of the armature body 2c is plated with Ni (P) to make the armature body A plating layer 2e was formed on the surface of 2c, and thereafter, the armature body 2c was tempered at a temperature of 300 ° C., and the hardness of the carburized layer 2e and the plating layer 2d was measured.

As a result, the hardness of the carburized layer 2e is Hv 70
It was about 0, and the hardness of the plating layer 2c was Hv900 or more.

[0025]

As described above, according to the method of manufacturing an armature for a print head according to the present invention, an armature body having a yoke portion formed thicker than a lever portion is integrally formed of a magnetic material, and the armature body is formed. To form a carburized layer on the armature so that the material remains only in the center of the yoke, then electroless nickel plating the surface of the armature to form a plating layer on the surface of the armature After forming, the armature body is heated and the armature body is tempered and the plating layer is age-hardened at the same time.
Abrasion resistance, destruction resistance, and magnetic properties can be ensured at low cost and sufficiently, and there is an excellent effect that the cost and performance of the print head can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a print head to which an armature manufactured by a method according to the present invention is applied.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view corresponding to FIG. 2 showing a step of manufacturing the armature.

[Explanation of symbols]

 2 Armature 2a Yoke 2b Lever 2c Armature 2d Plating layer 2e Carburized layer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 2/235 B41J 2/275-2/28

Claims (1)

(57) [Claims] 1. A method for manufacturing an armature for a print head, wherein a yoke portion is provided integrally with a lever portion to which a printing wire is brazed and welded, wherein the yoke portion is formed thicker than the lever portion. Is formed integrally with a magnetic material, and the armature body is carburized and quenched to form a carburized layer on the armature body so that a material portion remains only at the center of the yoke portion. Then, the surface of the armature body is formed. An electroless nickel plating process is performed to form a plating layer on the surface of the armature body. Thereafter, the armature body is heated to temper the armature body, and at the same time, the plating layer is age-hardened. A method for manufacturing an armature for a print head.