JPS5935954A - Head for dot printer - Google Patents

Abstract

PURPOSE:To provide the titled head easy to fit in, easy to handle, provented from cracking of a permanent magnet and capable of effectively utilizing a magnetic flux, by providing a chip form permanent magnet between a core and a yoke in place of a conventional annulr permanent magnet. CONSTITUTION:The titled head for dot printer is constituted by fitting the chip form permanent magnet between the core 4 and the yoke 2. A plurality of demagnetizing core parts are projectingly provided on a surface on one side of the periphery of a central hole 4a provided in the core 4, and a demagnetizing coil 5 is wound. The permanent magnet 3 and the annular yoke 2 are sequentially placed and fixed on the side on which the demagnetizing core parts are projectingly provided on the core. The armature 1 such that a part in proximity to the inner end part is brought into contact with an end face of the demagnetizing core part is fitted to the yoke 2 so that it can be oscillated with one end thereof as a fulcrum, is energized in such a direction that the inner end part is spaced apart from the demagnetizing core part, and a printing wire 6 extended in the energizing direction is fixed, thereby constituting the titled head.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to printing-\rad for dot printers.

An example of a conventional head for this type of dot printer is shown in the first example.
．． This will be explained using Figure 2. FIG. 1 is a front view with the right half in section, and FIG. 2 is an enlarged sectional view of the main part of FIG.

In the figure, the core 4 is made of a disc-shaped magnetic material having a hole 4a in the center and a step 4b on the outer periphery.
A number of degaussing cores 4C corresponding to the number of dots in the print matrix are protruded from the upper surface of the periphery, and a degaussing coil 5 is wound around each demagnetizing core 4C. The yoke 2 is an annular member made of a magnetic material, and an annular permanent magnet 3 is interposed between the yoke 2 and the stepped portion 4N of the core 4 in the vertical direction of the figure. equipped. Further, on the upper surface of the yoke 2, the same number of rod-shaped armatures 1 as the degaussing cores 4c are swingably mounted on the outer ends of the armatures 1 as fulcrums. has been done.

The lower part near the inner end of this armature 1 is still in contact with the upper end of the front I self-erasing core 4C, and the tJ niblint wire 6 is fixed above. In FIG. 1, a cover 8 has a bearing portion 8a for accommodating a large number of printed wires 6, and surrounds the armature 1 with a gap that does not hinder the operation of the armature 1.

In the above structure, the degaussing coil 5 is not energized when not in operation and printing is not performed, and as shown in FIG. 2, the vicinity of the inner end of the armature 1 is attracted to the upper end of the demagnetizing core 4C. The magnetic flux of permanent magnet 3 is yoke 2, armature 14?
and a magnetic circuit passing through the core 4, and the vicinity of the inner end of the armature 1 is maintained in a state where it is attracted to the upper end of the degaussing core 4c.

When printing (during operation), the degaussing coil 5 is wound around the degaussing core 4C that attracts the vicinity of the tip of the armature 1.
A current is applied to the magnet in the opposite direction to the magnetic field to cancel the magnetic field of the permanent magnet 3, and the restoring force of the leaf spring 7 moves the armature 1 clockwise as shown by the chain line in FIG. The print wire 6 solidified near the section is driven in the direction of the arrow.

However, when the above conventional dot printer head incorporates the annular permanent magnet 3, the annular permanent magnet 3
The three members, the annular yoke 2 and the disk-shaped core 4, must be exactly overlapped, and this overlapping work is very time-consuming and difficult to manufacture the head. Unfortunately, it is very difficult to make a thin annular permanent magnet to make the head smaller, and the thinner it gets, the more likely it is to break, and there are many problems with miniaturizing the head. be.

The object of the present invention is to provide a dot printer head that is easy to manufacture and miniaturize, while eliminating the drawbacks of the prior art.

The dot printer head of the present invention is characterized in that a chip-shaped permanent magnet is mounted between the core and the yoke.

An embodiment of the present invention will be described below with reference to FIG.

FIG. 3 is an enlarged sectional view of the main part.

In FIG. 3, reference numeral 3 denotes a plurality of chip-shaped permanent magnets, and 7 are respectively fitted into four parts 2a provided on the yoke 2 and four parts 4d provided on the core 4, and between the yoke 2 and the core 4. It is embalmed. When printing, it operates in the same way as the conventional one. Because of the above structure, compared to the conventional one in which a circular permanent magnet is mounted between the yoke 2 and the core 4, Three magnets can be easily stacked on top of each other, and since the trench permanent magnet 3 is miniaturized in the form of a chip, it is difficult to break and is easy to handle.

In this embodiment, since chip-shaped permanent magnets 3 are fitted into the recesses Za and 4d provided in the yoke 2 and the core 4, the permanent magnets 3 are inserted between the yoke 2 and the core 4. It is stably mounted and effectively secured without moving or being damaged even when subjected to some kind of impact. In addition, as mentioned above, when a current is passed through the degaussing coil to generate a back electromotive force and the armature 1 is released from the degaussing core 4c, the reverse magnetic field is generated by avoiding the part of the permanent magnet 3 because the permanent magnet 3 has a large magnetic resistance. This occurs through the bypass section from the yoke 2 to the core 4, and in this case, if the recesses 2a and 4d are provided, the effect as a bypass section is effective. However, it is not necessary that the recessed portions 2a14d be present on both sides, and it is possible to have only one side, or there is no particular difference in the function and effect of making the permanent magnet 3 into a chip shape even if both are not present.

As described in detail above, the present invention makes the permanent magnet in the form of a chip, which facilitates the assembly work and ease of handling, prevents cracking of the permanent magnet, reduces the defective rate, and furthermore, the magnetic flux It has a number of effects, including the ability to make effective use of.

[Brief explanation of drawings]

Fig. 1 is a partial sectional view showing an example of a conventional dot printer head, Fig. 2 is an enlarged sectional view of the main part of Fig. FIG. 1: armature, 2: yoke, 2a: recess of yoke,
3: Permanent magnet, 4: Core, 4a = hole in the center of the core, 4
c: Demagnetizing core, 4d: Recessed portion of core, 5: Demagnetizing coil, 6
: Printed wire, 7: Leaf spring agent Patent attorney Takashi Honma 7 Figure 1゛■ )゛・ / 4.2 ac 4 4b 4 (24C4 Figure 3

Claims (1)

[Claims] 1. A disc-shaped core having a hole in the center has a plurality of degaussing core parts protruding from one surface around the hole, and a degaussing coil is wound around each of the degaussing core parts. A permanent magnet and an annular yoke are sequentially polymerized and fixed to the side where the demagnetizing core part is protruded,
An armature whose inner end portions are in contact with the end faces of the demagnetizing core portion is attached to the yoke so as to be swingable about one end of the armature as a fulcrum, and the inner end portions are biased in a direction away from the demagnetizing core portion. In the print head of a dot printer in which a print wire extending in the biased direction is fixed near the inner end, a plurality of chip-shaped permanent magnets are fully installed between the core and the yoke. Dot printer head. 2. The dot printer head according to claim 1, wherein a plurality of disk-shaped permanent magnets are installed between the core and the yoke. 3. Claim 1, characterized in that a plurality of polygonal flat permanent magnets are installed between the core and the yoke.
The dot printer head 04 according to Claims 1 to 3, characterized in that at least one of the core and the yoke is provided with four parts into which permanent magnets can be fitted. Dot printer head.