JPH0443330Y2 - - Google Patents

Description

[Detailed description of the invention] [Summary] In a printing head where an armature fixed to an arm holding a wire is attracted to or released from a core through a plurality of stacked sheets, the thickness of each sheet is determined. By forming the sheets differently and stacking them so that the thicker sheets are located on the armature side, the wear rate of the sheets is reduced and the life of the print head is extended.

[Industrial application field]

The present invention relates to a print head for wire dot printing, and more particularly to a print head designed to reduce the wear rate of a sheet inserted between an armature and a core.

Print heads used in wire dot printers are constructed in such a way that the wire is ejected by attracting or releasing an armature from the core.

For example, in the case of a release type, as shown in the block diagram of the printing head in FIG. 3, the arm 2 is supported by an armature 3 and a block 8 fixed to the tip of a leaf spring 7 formed by cantilever support. The wire 4 is fixed to the block 8, and the core 1 has a permanent magnet 11 at one end and a coil 10 at the other end.

Further, a gap S between the armature 3 and the core 1 is formed so that a plurality of sheets 9 can be inserted therein.

Therefore, the armature 3 is normally attracted to the core 1 through the sheet 9 by the permanent magnet, but when a current is passed through the coil 10, it is reversely excited, and the armature 3 is attracted to the elastic force of the leaf spring 7. The wire 4 is moved in the direction of the arrow A by the force and protrudes in the direction of the arrow A.

Dot printing is performed by the protrusion of the wire 4.

The seat 9 inserted into the gap S between the armature 3 and the core 1 is
This design is designed to prevent wear and noise caused by contact with other parts.

However, as the number of printing processes increases, the sheet 9 will naturally be worn out, and the gap between the armature 3 and the core 1 will widen, which will adversely affect the drive of the wire.

Therefore, it is desired that the wear rate of the sheet 9 be as low as possible.

[Conventional technology]

Conventionally, the configuration was as shown in the conventional explanatory diagram of FIG. 4.

A plurality of sheets 9 were inserted into a gap S between an armature 3 fixed to a leaf spring 7 and a block 8, and a core 1 provided with a coil 10.

This sheet 9 is made of polyimide material and is formed to buffer the contact between the armature 3 and the core 1, thereby preventing wear and noise.

In order to prevent such wear and noise, it is effective to increase the thickness t1 of the sheet 9, but there is a limit to increasing the thickness due to the limitation of the gap S.

Therefore, the sheet 9 generally has a thickness t1
It was used by stacking three layers of 25 μm thick layers.

[Problem that the invention attempts to solve]

However, in such a configuration, the sheet 9 on the side that the armature 3 comes into contact with is more abraded than the other sheets 9, and tearing occurs due to the abrasion.

Therefore, there was a problem in that the gap S widened, adversely affecting the driving of the wire, and further increasing the noise.

[Means for solving problems]

The above problem has been solved by the present invention, as shown in the principle explanatory diagram of Fig. 1, which includes a core 1 around which a coil is wound, and an arm 2 made of a plate spring that faces the core and is attracted to and released from the core. The armature 3 is cantilever-supported and holds the printing wire 4, and the sheet set 12 is provided between the core and the armature. The present invention is solved by a print head characterized in that the sheets 6 on the armature side of the print head are constructed so as to be superimposed on each other so as to be movable relative to each other.

[Effect]

That is, the gap S is provided by overlapping first and second sheets having different thicknesses t1 and t2, and when overlapping, the thicker second sheet is positioned on the side that contacts the armature. It is.

Therefore, the second
By increasing the thickness of the sheet, the elastic force of the material increases, reducing the wear rate and preventing damage.

〔Example〕

The present invention will be explained in detail below with reference to FIG.
FIG. 2 is an explanatory diagram of an embodiment according to the present invention.
The same reference numerals indicate the same objects throughout the figures.

As shown in FIG. 2, first and second sheets are placed in a gap S between an armature 3 provided on an arm 2 formed by a leaf spring 7 and a block 8, and a core 1 provided with a coil 10. 5 and 6 are simply inserted overlapping each other so that they can be moved relative to each other.

Further, the first and second sheets 5 and 6 are made of polymide, which is the same material as described above, and have thicknesses t1 and t2, respectively, with t2 being larger, and furthermore, when overlapping, the second sheet The seat 6 is formed so as to be located on the abutting side of the armature 3.

For example, if the thickness t1 of the first sheet 5 is 25 μm, which is equivalent to the conventional thickness, the thickness t2 of the second sheet 6 is approximately twice that, 50 μm.

That is, in the printing head targeted by the present invention, the armature is supported cantilevered by a leaf spring, and is attracted to the core.
However, in this case, the leaf spring swings while being bent like a whip, so the armature slides when it collides with the core. This sliding occurs between the armature and the seat and causes wear of the seat, but in this invention, the two sheets are simply overlapped so that they can move relative to each other, so even if there is sliding on the armature, there will be no misalignment. Since the misalignment mainly occurs between the sheets and between the armature and the sheet, the wear of the seat is reduced, and since the sheet on the sliding armature side is thicker than the sheet on the core side, the wear is further reduced. In addition, by providing the thick second sheet 6 in this way, the elastic force obtained by overlapping each sheet can be further increased, and the amateur 3
It is possible to enhance the buffering effect of the repulsive force caused by the contact between the two.

Therefore, the frictional force caused by the armature 3 is reduced, and the friction coefficient can be reduced.

Furthermore, when inserting the first and second sheets into a gap S of a predetermined value that allows insertion of the conventional 25 μm x 3 sheets 9, one each of the first and second sheets 5 and 6 should be used. The total length is 25 μm + 50 μm, which allows for sufficient insertion.

By stacking the first and second sheets 5 and 6 with different thicknesses t1 and t2 in this way, the wear rate is reduced compared to the conventional stacking of three sheets 9 with the same thickness t1. be able to.

Incidentally, if four sheets 9 can be inserted as the gap S, it is natural to insert the thin first sheet 5 into two.
It is sufficient to insert one thick second sheet located on the side of the armature 3, and even in this case, the same effect as described above can be obtained.

[Effect of idea]

As explained above, according to the present invention, by inserting a thick sheet on the armature side, the cushioning effect due to the contact of the armature can be enhanced and the wear rate of the sheet can be reduced.

Therefore, the sheet is not damaged as in the past, its lifespan is extended, and furthermore, noise generation is prevented, and the practical effects are the first.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the principle of the present invention, FIG. 2 is an explanatory diagram of an embodiment of the present invention, FIG. 3 is a configuration diagram of a print head, and FIG. 4 is an explanatory diagram of a conventional printer. In the figure, 1 is a core, 2 is an arm, 3 is an armature, 4 is a wire, 5 is a first sheet, 6 is a second sheet, and 12 is a sheet set.

Claims (1)

[Scope of utility model registration request] A core 1 around which a coil is wound, an armature 3 that faces the core and is cantilevered by an arm 2 made of a leaf spring so as to be attracted to and released from the core, and holds a printing wire 4; It consists of a sheet set 12 provided between the core and the armature,
A printing head characterized in that the sheet set 12 is constituted by a core-side sheet 5 and an armature-side sheet 6 having a larger thickness stacked on each other so as to be able to move relative to each other.