JPH0632362Y2 - Wire dot print head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a wire dot print head used in an impact printer.

(Prior Art) Conventionally, an impact printer that drives a print wire, hits a print medium through an ink ribbon, and prints on the print medium with the force is relatively inexpensive and can be applied to various types of print media. Since it can be printed, it is used in various fields including output devices such as information processing systems.

The impact printer is classified into a plunger type, a spring charge type, and a clapper type according to the type of the wire dot print head.

Among them, in the spring charge type, an armature to which a printing wire is fixed is swingably supported by a bias leaf spring, and the armature is preliminarily attached to a core by a permanent magnet against the elastic force of the bias leaf spring. When attracting and printing, the coil wound around the core is excited to generate a magnetic flux in the direction opposite to that of the permanent magnet to release the armature. Therefore, this spring charge type wire dot print head, which has a good high-speed response, is often used.

FIG. 3 is a sectional view of a conventional wire dot print head, FIG.
FIG. 1 is a sectional view of a main part of a conventional wire dot print head.

In the figure, reference numeral 1 is a printing wire, the base of which is fixed to an armature 2, and the armature 2 is swingably supported by the tip of a leaf spring 3 for biasing. The bias leaf spring 3 is sandwiched between a hinge plate 4 and a magnetic spacer 5 and supported in a cantilever manner.

A permanent magnet 6 generates a magnetic flux that attracts the armature 2 to the surface of the core 7. A magnet yoke 8 is fixedly in contact with the permanent magnet 6, and a core yoke 9 is arranged between the magnet yoke 8 and the core 7.

On the other hand, a first armature yoke 10 and a second armature yoke 11 are adjacently fixed to the magnetic spacer 5, and a head frame 12 surrounding the print wire 1 is further provided at the end thereof.

Reference numeral 13 is a fulcrum pole that serves as a fulcrum when the bias leaf spring 3 swings, and 14 is a coil for exciting the core 7, which generates a magnetic flux in the core 7 in a direction opposite to the magnetic flux of the permanent magnet 6. . 15 is an ink ribbon, 16 is the above-mentioned printing wire 1
Is a print medium for printing by hitting through the ink ribbon 15, and is fed to the surface of the platen 20.

By the way, between the leaf spring for bias 3 and the core 7 which swingably supports the armature 2, upper and lower films, for example, upper
Lower polyester films 18 and 19 are arranged, and a metallic residual sheet 20 for protecting the upper and lower polyester films 18 and 19 is laid between them. In addition,
Reference numeral 24 is an annular polyester reinforcing material arranged around the upper and lower polyester films 18 and 19.

Here, the operation of the wire dot print head will be briefly described.

First, when the coil 14 is not exciting the core 7, the magnetic flux generated by the permanent magnet 6 causes the hinge plate 4, the bias leaf spring 3, the magnetic spacer 5, the first armature yoke 10, and the second armature yoke. 11, armature 2,
Polyester film 19, metal-resistive sheet 2
0, polyester film 18, core 7, core yoke 9,
It passes sequentially through the magnetic flux circuit consisting of the magnet yoke 8,
Due to the attraction force generated at that time, the armature 2 is attracted to the core 7 with the fulcrum pole 13 as a fulcrum against the elastic force of the bias leaf spring 3.

In this state, when the coil 14 excites the core 7, a magnetic flux in the opposite direction to the magnetic flux generated by the permanent magnet 6 is generated,
The magnetic flux of the permanent magnet 6 is canceled and the armature 2 is released. Therefore, the armature 2 and the printing wire 1 are driven to the right in the figure by the elasticity of the biasing leaf spring 3, and the tip of the printing wire 1 is the ink ribbon 15 and the printing medium.
The platen 17 is struck through 16 to print pixels on the print medium 16.

The print wire 1 after the collision starts the return operation in the left direction in the figure due to the repulsive force, but the magnetic flux of the permanent magnet 6 becomes effective by stopping the excitation of the core 7, and the armature 2 is re-energized accordingly. The core 7 is sucked, and one printing operation is completed.

By selectively driving the plurality of print wires 1 and performing the same printing operation as described above, characters and the like having a dot configuration are recorded on the print medium 16.

Here, in the above-mentioned conventional wire dot print head, the armature 2 repeats vibrations to form characters on a medium, but in order to stably generate this vibration for a long period, the core 7 and the metal Between the made-to-order resistance sheets 20 and the fulcrum pole 13 and the lower polyester film
It is necessary to apply a large amount of lubricant 22 between 18 and 19.

(Problems to be solved by the invention) However, in the wire dot print head having the above structure, the lubricant 22 enters between the bias leaf spring 3 and the upper polyester film 19 along the path shown by the arrow in FIG. Sometimes. As a result, the bias leaf spring 3
May stick to the upper polyester film 19 and cause dot loss during printing.

The present invention solves the above-mentioned problems and prints without reducing the amount of the lubricant 22 applied between the core 7 and the metal residual sheet 20 and between the fulcrum pole 13 and the lower polyester film 18. The upper polyester film of the leaf spring 3 for bias without deteriorating the magnetic characteristics of the head.
It is an object of the present invention to provide a wire dot print head that can be used stably for a long period of time without sticking to 19.

(Means for Solving the Problems) To this end, the present invention is directed to an armature having a print wire fixed to its tip, a core provided to face the armature, and a fulcrum pole arranged in parallel with the core. A wire dot consisting of a biasing leaf spring that fixes the armature and is supported in a cantilever manner, and a coil that is wound around the core and that generates magnetic flux during excitation and that swings the armature with the fulcrum pole as a fulcrum. In the print head, an upper film, a metal reluctant sheet and a lower film are sequentially laminated between the bias leaf spring and the coil, and the outer peripheral edge of the metal reluctant sheet and the outer peripheral edge of the lower film are bonded together. I try to seal it.

The lower film is provided only on the portion corresponding to the fulcrum pole, and not on the portion corresponding to the core.

(Operation) According to the present invention, as described above, the upper film, the metal residual sheet and the lower film are sequentially laminated between the bias leaf spring and the coil, and the outer peripheral edge and the lower portion of the metal residual sheet are arranged. The outer peripheral edge of the film is adhered and sealed, and since the lower film is arranged only in the portion corresponding to the fulcrum pole, it is between the core and the metal rescue sheet and between the fulcrum pole and the lower polyester film. Even if the lubricant to be applied enters between the lower film metal rescue sheets, it is prevented from moving further and entering between the bias leaf spring and the upper polyester film because it is sealed at the outer peripheral edge.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention, FIG. 2 is a view showing upper and lower polyester films, FIG. 2 (A) is a plan view of an upper polyester film, and FIG. 2 (B) is The side view, FIG. 2 (C) is a plan view of the lower polyester film,
FIG. 2 (D) is a side view of the same.

In the figure, 31 is an upper polyester film provided to face the leaf spring for bias, 32 is a metal-made reluctant sheet arranged adjacent to the upper polyester film 31, and 33 is a metal-made reluctant sheet 32. A lower polyester film 34 is disposed so as to face each other, and 34 is a lubricant applied between the fulcrum 35 and the lower polyester film 33.

An adhesive 36 is attached to the outer peripheral edge of the lower polyester film 33.
Is provided, and the metal rescue sheet 32 and the lower polyester film 33 are bonded and sealed by the adhesive 36.

Even if the lubricant 34 enters between the metal rescue sheet 32 and the lower polyester film 33, the seal prevents the lubricant 34 from diffusing.

37 is an annular member for applying the adhesive 36, and serves as a reinforcing material for the lower polyester film 33. Further, 38 is an annular reinforcing material of the upper polyester film 31.

In particular, one more polyester film is laid on the portion corresponding to the fulcrum pole 35, which is particularly worn, as compared with the core 7. In the portion corresponding to the core 7, the deterioration of the magnetic properties due to the increase of the voids is remarkable, so that an unnecessary polyester film is not provided.

Lower part of the wire dot print head Polyester film 18
The conventional wire dot print head, which is simply arranged, and the lower polyester film 33 are bonded to the metal residual sheet 32, and the wire dot print head of the present invention is mounted on an actual printer under the same conditions except for the lower polyester film. Printing was performed for 1 hour a day, left for 1 day, then printed again for 1 hour and left for 1 day. However, the dot removal did not occur in the wire dot print head of the present invention.

The present invention is not limited to the above-mentioned embodiment,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described in detail above, in the wire dot print head of the present invention, the upper film, the metal residual sheet, and the lower film are sequentially laminated between the bias leaf spring and the coil. The metal peripheral sheet has an outer peripheral edge and an outer peripheral edge of the lower film adhered to each other for sealing. Since the lower film is disposed only in a portion corresponding to the fulcrum pole, the core and the metallic residual sheet are disposed. Even if the lubricant applied between the sheets and between the fulcrum pole and the lower polyester film enters between the lower film and the metal reluctant sheet, it is still sealed at the outer peripheral edge, so it will move further and the bias leaf spring It will not get in between the upper polyester films.

Therefore, it is possible to eliminate the sticking between the bias leaf spring and the upper polyester film, and to provide a highly reliable wire dot print head that does not cause dot loss.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of a wire dot print head showing an embodiment of the present invention, FIG. 2 is a view showing upper and lower polyester films, and FIG. 2 (A) is a plan view of an upper polyester film. Figure (B) is the same side view, Figure 2 (C) is a plan view of the lower polyester film, Figure 2 (D) is the same side view, and Figure 3 is a cross-sectional view of a conventional wire dot print head. FIG. 1 is a sectional view of a main part of a conventional wire dot print head. 1 ... Printing wire, 2 ... Armature, 3 ... Bias leaf spring, 4 ... Hinge plate, 5 ... Magnetic spacer, 6 ... Permanent magnet, 7, 32 ... Core, 8 ... Magnet yoke, 9 ... Core yoke, 10 ... 1st Armature yoke, 11 ... second armature yoke, 12 ... head frame, 13,35 ... fulcrum pole, 14 ... coil, 18 ... lower polyester film, 19 ... upper polyester film, 20,32 ... metal rescue sheet, 31… Upper polyester film, 33
… Lower polyester film, 34… Lubricant, 36… Adhesive.

Claims (1)

[Scope of utility model registration request] 1. An armature having a printing wire fixed to its tip, a core provided to face the armature, a fulcrum pole arranged in parallel with the core, and a cantilever type for fixing the armature. A wire dot print head comprising a supported leaf spring for bias and a coil wound around the core and generating magnetic flux when excited to swing the armature around the fulcrum pole as a fulcrum. Upper film between leaf spring and coil,
A metal-made resume sheet and a lower film are sequentially laminated and arranged, and (b) an outer peripheral edge of the metal-resistive sheet and an outer peripheral edge of the lower film are bonded and sealed, and (c) the lower film is A wire dot printing head characterized in that it is arranged only in the portion corresponding to the fulcrum pole.