JP2788262B2 - Wire dot printer head - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spring-charged wire dot printer printhead, which is a component of an impact type printer used for output terminals of various computers and the like.

[Conventional technology]

A printer connected to a computer terminal device for recording information is required to be capable of high-speed printing with clear image quality, generating less noise, and operating stably without any trouble. Printers are broadly classified into impact systems and non-impact systems.

Among the impact methods, the spring-charged dot printer has features such as low power consumption, high-speed printing, and simultaneous copying (overlapping of copy paper). Although it is often used in containers, the disadvantage is that noise is generated due to the impact method.

This noise is generated from the print head, and is generated when the print wire strikes the platen and when the armature driven by the print wire is sucked into the core.

To suppress this noise, for example, Japanese Unexamined Patent Publication No. 61-69469
It is proposed to use an anti-vibration alloy having a composition of 12Cr-2Al-86Fe, which is called an amateur by Silentalloy (trade name).

FIG. 1 is a sectional view showing an example of the configuration of a spring-charged wire dot printer head. The configuration and operation of the spring-charged wire dot printer head will be described with reference to FIG.

This head forms a closed magnetic circuit composed of a core 1, a permanent magnet 2, a spacer 3, a leaf spring 4, a side magnetic plate 5, and an armature 6. When a printing operation is not performed, a print wire 7 is generated by a magnetic flux from the permanent magnet 2. The fixed amateur is arranged so as to be sucked by the core 1.

When the printing operation is performed, the signal current is applied to the demagnetizing coil 8 wound around the core to eliminate the magnetic flux of the permanent magnet 2 and eliminate the magnetic attraction between the core 1 and the armature 6. The armature 6 is actuated by the force and the print wire 7 hits the platen to perform printing.

Next, when the signal current stops, a closed magnetic path is formed again by the permanent magnet 2 and magnetically attracted to the armature 6 core 1 to complete one printing process.

Noise of the magnetic circuit portion is generated at contact points between the core 1 and the armature 6 and between the leaf spring 4 and the side magnetic plate 5.

The noise of the wire dot printer also occurs when the print wire 7 strikes the platen, but this noise is considerably smaller than the noise generated from the magnetic circuit section in the head.

Conventionally, Si steel has been used for the side magnetic plate. However, the saturation magnetic flux density of the magnetic characteristics is low, so there is a limit in increasing the printing speed, and the vibration absorbing ability is small, so that the leaf spring 4 shown in FIG. However, there are disadvantages such as generation of high noise between the side magnetic plates 5.

Since the noise of the magnetic circuit portion increases as the printing speed, that is, the drive frequency increases, it is necessary to technically solve the suppression of the noise.

[Problems to be solved by the invention]

As described above, since the spring-charged dot printer head is of the impact type, noise is inevitably generated from the magnetic circuit drive unit, and there has been a problem how to reduce and suppress this noise.

An object of the present invention is to reduce noise generated between a leaf spring and a side magnetic plate among noises generated from a magnetic circuit unit without lowering a printing speed, and to provide a quieter wire dot printer head. is there.

[Means for solving the problem]

The present invention is composed of a core having a permanent magnet and a demagnetizing coil, an armature fixed to a leaf spring, and a side magnetic plate having a groove portion, and the armature is arranged in the groove portion through a minute gap, A magnetic circuit is formed between the core and the armature, and the armature is attracted to the core.Electrical power is supplied to the degaussing coil to erase magnetic flux caused by a permanent magnet passing through the armature, so that the armature is attracted. In the spring-charged wire dot printer head that performs printing by releasing the dot wire fixed to the amateur by the return force of the released leaf spring, the side magnetic plate has 46
It is a cold-rolled material having a composition of about 50% Co, 1 to 3% V and the balance of Fe and having a thickness of 2 to 4 mm in a permender, and the groove is formed by press punching. This is a wire dot printer head.

That is, the present invention is characterized in that a permender having a thickness of 2 to 4 mm manufactured by cold rolling is used for the side magnetic plate, and the groove portion of the side magnetic plate is formed by press punching.

Permenders manufactured by cold rolling are superior in magnetic properties (especially Hc, μm) to hot rolled plates, powder sintered materials, and precision cast materials, as described later, and can be pressed above all. There is a great advantage that there is.

Fe-Co based permender has a high saturation magnetic flux density and a large magnetic permeability, is excellent in soft magnetic properties, has a large vibration absorption capacity, and is also a material excellent in vibration and soundproofing properties.
It is a material that is extremely poor in processing method, and about 2% of V is added to enable cold rolling.

However, the effect of rapid cooling was not obtained due to the mass effect for a thicker plate, and cold rolling was impossible.

However, in the application of the present invention, a sheet having a thickness of 2 to 4 mm is required to obtain a strong magnetic force. However, mass production of a cold-rolled material having this sheet thickness is very difficult for the above-described reason.

The present inventor has set a permender with a specific component of 800-1.
By rapidly cooling to 000 ° C./sec, a cold rolled material having a thickness of 2 to 4 mm was made possible, and the permender cold rolled material was successfully applied to a dot printer head.

(Operation)

The present invention is directed to a permender cold-rolled material that not only has a high saturation magnetic flux density and a large magnetic permeability, and has excellent soft magnetic properties, but also has a large vibration absorption capacity and excellent vibration and soundproof properties. With this configuration, the noise level of the head can be reduced and high-speed printing can be performed.

The reasons for limiting the composition range of permender applied to the present invention are described below.

As a result of the experiment, the saturation magnetic flux density B of the permender was Co = 30.
~ 54%, the magnetic permeability μ becomes maximum at Co = 49%,
If it is less than 46% and exceeds 52%, the magnetic permeability μ sharply decreases, so Co was limited to 46 to 52%.

V is added for improving cold workability. However, if V is less than 1%, there is no effect of improving cold workability, and if V exceeds 3%, the saturation magnetic flux density B is too low and the characteristic of permender is lost, so V is 1%. Limited to ~ 3%.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to examples and drawings.

In the spring-charged dot printer head of FIG. 1, the magnetic flux of the permanent magnet 2 passes through the spacer 3, the leaf spring 4, the side magnetic plate 5, the armature 6, and the core 1 to form a magnetic circuit. Is turned on and off alternately, so that the armature 6 moves up and down in the side magnetic plate 5 to perform a printing operation. In this example, a 2.6 mm-thick permender manufactured by cold rolling was machined by press punching to produce a side magnetic plate, which was incorporated into a head.

As shown in FIG. 2, the side magnetic plate 5 has a shape in which comb teeth are radially arranged, and an armature 6 is arranged with a gap 9 inside the comb teeth.

The amateur 6 moves up and down by the suction force of the core 1 and the return force of the leaf spring 4.

In order to allow the amateur 6 to operate stably at high speed and perform high-speed printing, it is necessary to minimize the gap 9 between the side magnetic plate 5 and the amateur 6 so that they do not interfere with each other, and to reduce dimensional variations. The groove width 10 of the side magnetic plate 5 is required to be formed with high precision. From this point, it is convenient to press-cut a cold-rolled permender because a high-precision dimension can be obtained.

Table 1 shows the magnetic properties of the side plate made of the cold rolled permender material of the present invention and the magnetic properties of the conventional material.

In this table, the magnetic properties of Permender are shown for magnetically annealed products in 850 ° C for 3 hours in hydrogen and furnace-cooled.However, approximately the same magnetic properties can be obtained in vacuum and furnace-cooled at 850 ° C for 3 hours. confirmed.

From Table 1, the saturation magnetic flux density B ₂₅ of 3% Si steel is around 16,000, but the permender is much larger at 22,000 (G), and the magnetic properties of the side plate made of permender are cold-rolled. goods are precision casting, as compared to the powder sinter coercive force Hc is low, large saturation magnetic flux density B _25, maximum permeability μ
It can be seen that since m is large, the soft magnetic characteristics are excellent, and this is most advantageous for increasing the speed of the printer head.

Although the groove width 10 of the side magnetic plate in FIG. 2 needs to be processed with high precision as described above, the side magnetic plate obtained by pressing and punching using a rolled material is a precision cast product, a powder sintered product. It was also found that there was no variation compared to that of the above, and it was easy to process with high precision.

Press stamping can be performed at lower cost and with higher precision than cold machining of cold rolled material.

Next, using the material for the side magnetic plate shown in Table 1, the permender rolled material is formed into a side magnetic plate by press punching, and incorporated into a spring-charged dot printer head shown in FIG. 1 to perform a printing test. Was. Table 2 shows the results.

The printer head using the cold-rolled material of the present invention for the side magnetic plate can increase the driving frequency of the head from 2.4 kHz to 3.0 kHz and reduce the noise level as compared with the conventional case using 3% Si. From about 60dB to less than 55dB, a remarkable effect could be obtained.

[Effects of the Invention] As described above, according to the present invention, the printing speed of a spring-charged wire dot printer head can be increased, and noise generated during operation can be reduced, and its industrial value is extremely large. is there.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a spring-charged wire dot printer head according to the present invention, and FIG. 2 is a plan view of a side magnetic plate. 1: core, 2: permanent magnet, 3: spacer, 4: leaf spring, 5: side magnetic plate, 6: amateur, 7: printed wire, 8: degaussing coil,
9: gap, 10: groove width.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-146648 (JP, A) JP-A-62-44555 (JP, A) JP-A-62-37909 (JP, A) 43702 (JP, B1) (58) Field surveyed (Int. Cl. ⁶ , DB name) B41J 2/23-2/25 B41J 2/26-2/295 H01F 1/12-1/38

Claims (1)

(57) [Claims] 1. An armature having a permanent magnet and a demagnetizing coil, an armature fixed to a leaf spring, and a side magnetic plate having a groove portion, wherein the armature is disposed in the groove portion with a small gap therebetween. A magnetic circuit is formed between the core and the armature, and the armature is attracted to the core, energizing the degaussing coil, eliminating magnetic flux by a permanent magnet passing through the armature, and attracting the armature. Is released and the dot wire fixed to the amateur is projected by the return force of the leaf spring to perform printing.In the spring-charged wire dot printer head, the side magnetic plate is
It is a cold-rolled material having a thickness of 2 to 4 mm of a permender consisting of 46 to 52% Co, 1 to 3% V, the balance Fe and impurities, and the groove portion is formed by press punching. Wire dot printer head.