JPH05254153A - Impact dot head - Google Patents

Abstract

PURPOSE:To ensure that cost is reduced, while the capability to print data at a specified printing speed is ensured, in an impact dot head. CONSTITUTION:A core 1 is formed using high silicon steel (the content of silicon is 3 to 6wt.%) to provide a 20mum max-thick, 1m-long non-electroless nickel plated layer. Consequently, it is possible to obtain an impact dot head at high printing speed with a low frame cost.

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 an impact dot matrix printer.

[0002]

2. Description of the Related Art As a conventional technique, for example, Japanese Patent Laid-Open No. 63-63
The one described in JP-A-95954 is known. As shown in FIG. 3, the content disclosed therein is to form a non-magnetic non-magnetic layer between the armature 103 and the core 101 by forming an electroless nickel plating layer 101m having a thickness of 20 to 40 μm on the entire frame having the core 101 or the core surface. Forming layers. As a result, after the printing is completed, the influence that the return force is reduced by the residual magnetic flux during the return operation until the lever 104 returns to the standby position is reduced, the time required for one print cycle is shortened, and the impact dot head prints. It was improving the speed.

[0003]

However, as in the conventional impact dot head, the electroless nickel plating layer 10 is used.
Forming 1 m of 20 to 40 μm poses a problem of cost increase due to plating.

Therefore, the present invention has been made to solve this problem, and an object thereof is to obtain an impact dot head having a low frame cost and a high printing speed.

[0005]

In order to solve the above-mentioned problems, an impact dot head of the present invention comprises a core around which a coil is wound and an armature arranged so as to face the core. In an impact dot head in which an armature is driven by a suction force, a core is formed of high silicon steel (silicon content is 3 to 6% by weight), and the core is subjected to electroless nickel plating of 20 μm or less. .

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a three-view drawing of an impact dot head to which an embodiment of the present invention is applied. The tip of the nose 13 is provided with a wire guide 14 having a hole for linearly positioning the plurality of printing wires 6 so that they can reciprocate. A drive unit for driving the print wire 6 is provided behind the nose 13, and a radiator 15 for radiating the heat generated inside to the atmosphere is provided on the outer periphery of the drive unit. A print signal for driving the print wire 6 is input from a connector 17 soldered on the printed board 16 through a cable (not shown).

FIG. 2 is a sectional view taken along the line AA in FIG.
A frame 18 made of 5% silicon steel has a plurality of cores 1
There is an electroless nickel plating layer of 1 μm or less. Each core 1 has a coil 2 that excites magnetic attraction.
Is wound. An armature 3 made of a magnetic material faces the core 1, a lever 4 including the armature 3 is rotatably supported about a fulcrum shaft 5, and is pressed against a lever holder 8 by a return spring 7 in a standby state. The printing wire 6 is fixed to the tip of the lever 4 by brazing.

Next, the printing operation will be described with reference to FIG.

When a print signal is input to the coil 2, a magnetic attraction force is generated between the armature 3 and the core 1. Due to this magnetic attraction force, the lever 4 starts rotating while bending the return spring 7 about the fulcrum shaft 5, and the printing wire 6 collides with the platen 21 through the ink ribbon 19 and the printing paper 20 to form dots. Next, the lever 4 is the printing wire 6
Is returned to the standby position by the repulsive force received when the platen 21 collides with the platen 21 and the restoring force of the returning spring 7 that is bent, the returning process is completed, and one printing cycle is completed.

The magnetic flux excited in the above printing process is
Even after the print signal to the coil 2 is cut off, it remains in the core 1 and the armature 3 (residual magnetic flux) and gradually decreases. The amount of residual magnetic flux generated is unique to magnetic materials and decreases in the order of pure iron> low silicon steel> high silicon steel. By using silicon steel having a high silicon content as in this embodiment, it is possible to obtain the same effect of increasing the printing speed as in electroless nickel plating.

In Table 1, when the silicon content of the silicon steel is 1 to 6% by weight, the electrolessness necessary for obtaining the same printing speed as that of the core 1 in which 1% silicon steel is plated with 20 μm of electroless nickel. The nickel plating thickness obtained by experiment is shown.

[0013]

[Table 1]

As can be seen from this table, the higher the silicon content is, the thinner the electroless nickel plating can be made to be 3%.
The thickness of electroless nickel plating of silicon steel is 20 μm, which is half of the plating thickness of 1% silicon steel, and when the silicon content is 3% by weight or more, a significant cost reduction of plating can be realized.

On the other hand, when the silicon content is 6% by weight or more, the hardness becomes too high and the moldability deteriorates. Therefore, if the silicon content exceeds 6% by weight, the molding cost of the frame 18 including the core 1 increases.

FIG. 4 shows the relationship between the plating processing cost of the frame 18, the material cost + the processing cost other than plating, the total cost, and the silicon content of silicon steel. As can be seen from this figure, by using silicon steel having a silicon content of 3 to 6% by weight, a significant cost reduction of the frame 18 can be realized.

[0017]

As described above, according to the present invention, a core made of high silicon steel (silicon content 3 to 6% by weight) is used.
By providing the electroless nickel plating layer having a thickness of 0 μm or less, it is possible to reduce the cost required for plating the frame, and it is possible to obtain an impact dot head having a low frame cost and a high printing speed.

[Brief description of drawings]

FIG. 1 is a trihedral view of an impact dot head according to the present invention.

FIG. 2 is a schematic sectional view of an impact dot head of the present invention.

FIG. 3 is a sectional view showing a conventional technique.

FIG. 4 is a diagram showing the relationship between silicon content and cost.

[Explanation of symbols]

 1 Core 1m Electroless Nickel Plating Layer 2 Coil 3 Armature 4 Lever 6 Printing Wire 7 Return Spring 8 Lever Holder 13 Nose 14 Wire Guide 18 Frame 19 Ink Ribbon 20 Printing Paper 21 Platen 101 Core 101m Electroless Nickel Plating 102 Coil 103 Armature 104 Lever 105 Support shaft 106 Print wire 107 Return spring

Claims (1)

[Claims] 1. An impact dot head comprising a core around which a coil is wound and an armature arranged so as to face the core, the armature being driven by a magnetic attraction force excited by the coil. Formed from silicon steel (silicon content 3-6% by weight), 2
An impact dot head characterized by being subjected to electroless nickel plating of 0 μm or less.