JPH0440930Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an electromagnetic core for a low-noise dot impact printer that incorporates a vibration damping device.

[Prior Art] As shown in FIGS. 1 and 2, the pole core 2 of a conventional dot impact printer is constructed by laminating electric iron plates of the same shape.

Although FIGS. 1 and 2 are for a line printer, the same applies to a serial printer.

In the figure, 8-1 and 8-2 are the printing paper and ink ribbon in contact with the platen 7, and 1 is the printing paper 8.
- a hammer for impacting 1; 3 a coil for applying a reverse magnetic field current to release Hana 1 attracted to the pole core 2; 4 a permanent magnet;
5 is an iron plate yoke.

[Problem that the invention attempts to solve]

Now, in Figures 1 and 2, the hammer spring 1
-1 is attracted to the pole core 2, an impact force F acts in the direction of the arrow, and the tooth portion 2-1 and the yoke portion 2-2 of the pole core 2 vibrate in a mode as shown in FIG.

In this case, since the conventional pole core 2 is constructed by laminating electric iron plates of the same shape, each electric iron plate moves in the same direction and with the same phase, so that no friction or shear occurs between the iron plates.

Therefore, as shown in Figure 3a, the impact vibration when struck by the hammer 1 has a large amplitude and its duration is long, so the pole core impact sound, which is the main component of the sound of the dot impact printer, is loud. There are drawbacks.

In order to reduce this noise, conventional methods have been used to surround the enclosure with a soundproof enclosure lined with sound-absorbing material, but the power of the sound source is relatively large compared to the adsorption and sound-insulating power of the enclosure, which limits the sound reduction ability. .

Therefore, the present invention attempts to provide a low-noise electromagnetic core with a vibration damping structure.

[Means for solving problems]

The present invention was developed to solve the above problems, and has a structure that reduces the sound of the pole core at the sound source stage. This is a vibration damping structure that generates friction and shear between laminated electric iron plates to reduce printer noise at the sound source stage.

That is, in the present invention, the shape of the teeth or yoke of each laminated iron plate is not the same, but is different from that of the adjacent iron plate, so that they move in opposite directions when struck.

[Effect]

As the laminated steel plates move in the opposite direction to the adjacent steel plates during impact, friction and shear occur, creating damping properties within the pole core, and as shown in Figure 3b, the vibrations of the tooth and yoke parts are quickly attenuated. , the pole core impact sound is reduced.

〔Example〕

Hereinafter, two or three embodiments in which the present invention is applied to an electromagnetic core for a line printer will be described.

Embodiment (1) Fig. 4 shows the first embodiment of the present invention, in which one side a of the tooth portion 2-1 of the electric iron plate 2 is cut diagonally and the tooth width is cut from the tooth tip to the tooth root. The structure is such that the electric iron plates 2 are alternately inverted and stacked.

According to this structure, when the hammer spring 1-1 moves in the direction of the arrow and is attracted to the pole core 2, the teeth 2-1 of each iron plate are bent and deformed in opposite directions as shown by the arrows, and the upper and lower iron plates Friction and shear occur between the pole cores and damping properties occur within the pole core, as shown in Figure 3b.
As shown in , the vibration of the teeth is rapidly attenuated and the impact sound is reduced.

In this embodiment, one side of the tooth portion 2-1 is cut obliquely so that the tip of the tooth portion moves in the direction of the arrow when struck, but the tooth portion 2-1 may also be shaped like a dogleg or an arch. You can get something that has the same effect.

Embodiment (2) Fig. 5 shows a second embodiment of the present invention, in which an integral number of notches b are provided in the yoke portion 2-2 of the iron plate 2, and the notches are stacked by alternately inverting the iron plates 2. b overlaps the protrusion c formed by the notch.

In this case, the amount of elongation or contraction of the upper and lower steel plates in response to the force F transmitted through the teeth during hammer spring impact is different, which causes friction and shear between the steel plates, so the vibration damping properties within the pole core are insufficient. As shown in FIG. 3, a rapid vibration damping is observed, and the pole core impact noise is reduced.

Embodiment (3) FIG. 6 shows a third embodiment of the present invention, in which the structure of the tooth portion 2-1 is the same as that of the embodiment shown in FIG. 4, and the structure of the yoke portion 2-2 is as follows. The structure is based on the embodiment shown in FIG.

According to this structure, the vibration damping performance is the same as that of embodiment (1). It is even better than (2), and the pole core impact noise is reduced.

[Effect of idea]

According to the present invention, the pole core impact sound, which is the main component of dot impact printer sound, can be reduced at a low cost at the sound source stage without significantly deteriorating the magnetic properties.

[Brief explanation of the drawing]

Figure 1 is a side view of a conventional dot impact type line printer, Figure 2 is a perspective view of the pole core of the conventional line printer shown in Figure 1, and Figure 3 is a diagram showing the case of using the conventional structure and the present invention. Explanatory diagram showing the difference in vibration waveform when using the product, Figure 4~
FIG. 6 is a perspective view of an embodiment of the present invention. 2... Pole core, 2-1... Teeth, 2-2...
...York Department.

Claims (1)

[Claims for Utility Model Registration] (1) The shape of the teeth or yoke of the laminated electric iron plate is so formed that the movement or expansion/contraction direction when struck by a hammer is opposite to that of the adjacent laminated electric iron plate. Electromagnetic core for dot impact printers. (2) Claim No. 1 for utility model registration, which is characterized in that one side of the teeth of the laminated electric iron plate is cut obliquely.
An electromagnetic core for a dot impact printer as described in . (3) An electromagnetic core for a dot impact printer according to claim 1 of the utility model registration, characterized in that a notch is provided in the yoke portion of the laminated electric iron plate.