JPS6339074Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a printing head for a dot printer in which printing is performed by electromagnetically driving an armature having a printing wire.

In this type of print head, the gap length between the armature and the core of the electromagnet that attracts or releases the armature must be maintained at a precise value in order to maintain a constant impact force on the print wire. There is. For this reason, conventionally, the above-mentioned value has been secured by using high-precision parts or by performing troublesome adjustment work. Therefore, it takes time and effort to manufacture, which is one of the reasons for preventing cost reduction.

Purpose of the invention The purpose of this invention is to provide a print head that can solve the above problems.

Embodiment Hereinafter, an embodiment embodying this invention will be described based on the drawings.A magnetic ring 1 made of soft iron disposed on the rear side of the printing head has a large number of protruding pieces 2 extending toward the center. A core part 3 extending forward is formed at the front end of the protruding piece 2, and a thin connecting part 4 which is deformable in the direction in which the core extends is formed at the base of the proximal end. has been done. That is, the connecting portion 4 has flexibility so that the core portion 3 can be displaced. A coil 5 is wound around each core portion 3.

An annular permanent magnet 6 is fixed to the front surface of the magnetic ring 1, and an annular armature support member 7 made of a magnetic material is further fixed to the front surface thereof. A front cover 8 made of a magnetic material is fixed to the front surface of the support member 7 so as to form the front surface of the printing head, and a nose body 9 is fixed to the center thereof. At all times, a magnetic path is formed by the permanent magnet 6 that passes through the magnetic ring 1, the protruding piece 2, the front cover 8, and the armature support member 7, and when the coil 5 is energized, the magnetic path is formed. A canceling magnetic flux is created. The magnetic ring 1, the armature support member 7, and the front cover 8 constitute a yoke portion 10 for the magnetic path.
The yoke portion 10 and the core portion 3 are connected by the connection portion 4.

A leaf spring 11 is fixed at its base end between the armature support member 7 and the front cover 8 so as to correspond to each of the core parts 3, respectively. At the tip of each leaf spring 11, an armature 12 made of a magnetic material is fixed at its base end. When the coil 5 is energized and the magnetic path caused by the permanent magnet 6 is canceled, the biasing force of the leaf spring 11 causes the arrow P to move.
The core portion 3 is released and moved in the direction so as to be separated from the distal end surface of the core portion 3. A printing wire 13 is fixed to the tip of the armature 12 and extends forward through a through hole 14 formed in the nose body 9.
Each time the armature 12 is separated from the core portion 3, it projects forward of the nose body 9 to perform impact printing. Therefore, this print head is of the open type.

An annular adjusting fixing plate 15 is fixed to the rear surface of the magnetic ring 1 so as to be located on the opposite side of the core part 3 with respect to the connecting part 4, and the adjusting fixing plate 15 is attached to each of the protrusions. It integrally has protrusions 16 corresponding to the pieces 2, respectively. Adjustment screws 18 are screwed into the screw holes 17 provided through each of the protruding portions 16, and their tips abut against the rear surface of the core portion 3. Then, by advancing each adjustment screw 18 and fixing it in an arbitrary installation state with a nut 19, the connecting portion 4 is forcibly deformed, and the position of the core portion 3 is moved in a direction approaching the armature 12. be adjusted.

Therefore, by assembling each armature 12 so that the gap length between each armature 12 and the core part 3 becomes large, and moving the adjustment screw 18 forward by an appropriate amount, the core part 3 is moved forward and the armature 12 and The gap length between the core portion 3 and the core portion 3 can be set to a predetermined value. This results in
The impact force of each printing wire 13 can be made constant. In this way, each armature 1
Since the gap length between the core part 2 and the core part 3 can be easily and freely adjusted, parts such as the armature 12 that are not highly accurate and have large tolerances can be used, which simplifies manufacturing and reduces costs. It is possible.

In the embodiments described above, this invention was embodied in a release-type printing head, but it may also be embodied in a suction-type printing head that performs printing by suctioning the armature.

Effects of the invention As exemplified in the embodiments above, this invention is configured so that the position of the core part can be changed in the armature direction by forcibly deforming the connecting part by changing the mounting state of the adjustment screw. As a result, the impact force of the printing wire can be easily adjusted, resulting in an excellent effect of reducing costs. Moreover, even if the position of the core part is changed, since the core part and the yoke part are integrally formed through the connecting part, there is no magnetic loss and an efficient impact operation can be realized.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of a printing head embodying this invention, and FIG. 2 is a rear view thereof. Core part 3, connection part 4, coil 5, yoke part 1
0, armature 12, printing wire 13, adjustment fixing plate 15, adjustment screw 18.

Claims (1)

[Claims for Utility Model Registration] Armature 12 having a printing wire 13 at its tip
a yoke part 10 for rotatably supporting the armature; a core part 3 around which a coil 5 is wound to attract or release the armature 12;
and a connecting part 4 connecting the core part 3 are integrally molded from a magnetic material, and the connecting part 4 has flexibility so that the core part 3 can be displaced. On the other hand, an adjustment fixing plate 15 disposed on the opposite side of the core part 3, and an adjustment screw 18 attached to the adjustment fixing plate 15 so that its tip can come into contact with a part of the connecting part 4. A printing head for a dot printer, characterized in that the connecting portion 4 is forcibly deformed by changing the mounting state of the adjusting screw 18, and the position of the core portion 3 is adjusted in the direction of the armature 12.