JP3374897B2 - Impact type dot print head and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact type dot print head and a manufacturing method thereof, and more specifically,
The present invention relates to a positioning technique for a printing wire and a printing lever.

[0002]

2. Description of the Related Art An impact type dot print head for printing characters on a recording medium with a print wire has a plurality of print levers each having a print wire fixed to the tip thereof by brazing, and the print levers are magnetically attracted by a solenoid. It is constructed so as to be attracted to a biased core and moved in the platen direction, and there is a demand for further improvement of printing quality and stabilization and speedup of printing operation.

However, in the print head of this type, the length of the print wire fixed to the print lever is varied because the mounting position is different for each print lever, and as a result, the guide plate of the print wire is guided. The deflection state due to contact with the holes, the contact pressure, or the like changes for each print wire, and the behavior of the print wire varies and a stable print operation cannot be obtained.

Further, after the print wire is fixed to the print lever, grinding or polishing may be performed in order to make the height of the surface of the print lever located on the side opposite to the protruding side of the print wire uniform. If the rear end of the attachment sticks out beyond the surface of the print lever, it will be ground by that amount.
Due to polishing, the weight of the print wire fixed to the print lever is slightly different, which affects the behavior of the print wire in combination with the difference in the length of the print wire, and good followability and high-speed printing cannot be obtained. Such inconvenience occurs.

Further, since the mounting position of the print lever to the plunger or the like is determined by the tip of the print lever to which the print wire is brazed, the length of the print lever varies depending on the brazing state, and the print wire and the guide wire are guided. The positional relationship between the plate and the guide hole varies, the contact pressure of each printing wire changes, and a stable printing operation cannot be obtained.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to:
An object of the present invention is to provide an impact type dot print head having a simple structure and high positioning accuracy, and a manufacturing method thereof.

[0007]

That is, according to the present invention, in order to achieve such a problem , at the front end side of the print lever,
In addition, the printing wire is attached to the mounting portion of the printing wire on the circumferential surface in the longitudinal direction.
First positioning projection that joins the longitudinal end surface of the ear
The part of the print lever is formed integrally with the print lever.
Part of the longitudinal direction has a reference plane orthogonal to the longitudinal direction
So that the second positioning convex portion is integrally formed.
I chose

[0008]

[Function] The convex portion for positioning for joining with the rear end portion of the print wire is formed at the portion where the print lever is fixed to the print wire to eliminate the variation in the length and weight of the print wire among the print levers. By forming a convex portion for positioning with the plunger in a part of the longitudinal direction of the print lever, the positional relationship between the guide plate and the guide hole is made uniform to stabilize the behavior of the print wire.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 shows an example of a print head to which the present invention is applied. In the figure, reference numeral 1 is a plurality of cores provided in a convex shape on one surface of an annular magnetic plate 2, and each end surface of the core 1 is provided with a plurality of cores. Are arranged facing each other with a plunger 11 fixed to the print lever 10.

This core 1 attracts and holds each plunger 11 against the elasticity of the leaf spring 5 by the magnetic flux from the permanent magnet 3 provided on one surface of the magnetic plate 2 when not printing, and when the printing is performed, the magnetic flux is retained. By selectively energizing the electromagnetic coil 4 wound around the core 1 so as to cancel, the suction with the plunger 11 is released, and the print wire 12 fixed to the tip of the print lever 10 is noseed by the elastic force of the leaf spring 5. 6 is made to project from the front end of 6 to print.

Reference numeral 7 in the drawing denotes a guide plate fixed to the tip of the nose 6, which has a guide hole (not shown) formed therein, and a print wire 12 fixed to the tip of the print lever 10. It is configured to guide the print edge. In the figure, reference numeral 9 indicates a spacer that supports the leaf spring 5.

FIG. 2 is a diagram showing a manufacturing process of the print head in which the print lever and the print wire, which are the first characteristic part of the present invention, are positioned. First, as shown in FIG. A mounting surface 10a for fixing the circumferential surface of the print wire 12 is formed on the tip side of the print lever 10, and
In this embodiment, a positioning projection 10b joined to the longitudinal end surface 12a of the print wire 12 is provided at the end of the print wire 12 opposite to the protruding side, and the positioning projection 10b is substantially the same as the diameter of the print wire 12. It is integrally formed so as to project to the length.

Next, as shown in FIG. 2B, the circumferential surface of the printing wire 12 in the longitudinal direction is positioned on the mounting surface 10a, and the longitudinal end surface 12a of the printing wire 12 is brought into contact with the positioning projection 10b. Position it and fix it by brazing.

Finally, as shown in FIG. 2C, the print lever 10 located on the side opposite to the protruding side of the print wire 12.
In order to make the surface of the plunger 11 aligned with the surface of the plunger 11, grinding or grinding is performed so that the surface is a position not shown by the dot-dash line M in FIG. Grind.

Thus, the end surface 12 of the print wire 12 is
There is no variation that "a" sticks out from one surface of the print lever 10 or is short, and it is possible to always secure a fixed attachment position and make the lengths in the platen direction uniform.

Even when grinding or polishing is performed to align the surface of the print lever on the side opposite to the protruding side of the print wire 12, the print wire 12 is scraped off together with the ground portion of the print lever 10. It is possible to eliminate variations in the length and weight of the print wire 12 for each print lever 10, and to save the labor for grinding the hard print wire 12 and shorten the grinding time. .

FIG. 3 is a diagram showing a manufacturing process of a print head in which a print lever and a plunger, which are the second characteristic part of the present invention, are positioned. First, as shown in FIG. A mounting surface 10a for fixing the circumferential surface of the print wire 12 in the longitudinal direction is formed on the tip side of the lever 10, and
In this embodiment, a first positioning projection 10b joined to the longitudinal end surface 12a of the print wire 12 is provided at the end of the print wire 12 opposite to the protruding side thereof. It is integrally formed so as to project to substantially the same length as.

A second positioning projection 10d having a reference surface 10c orthogonal to the longitudinal direction is integrally formed on a part of the printing lever 10 in the longitudinal direction.

Next, as shown in FIG. 3B, the longitudinal circumferential surface of the print wire 12 is positioned on the mounting surface 10a, and the longitudinal end surface 12a of the print wire 12 is positioned at the first positioning projection 10b. It is positioned by abutting against and fixed by brazing.

Next, as shown in FIG. 3C, with the print wire 12 fixed, the reference surface 10c of the second positioning convex portion 10d formed on the print lever 10 is fixed to the jig 2.
After abutting against the wall surface of the recessed portion 20a of 0 to secure the specified length L, it is fixed to the plunger 11. The jig 20 is a jig prepared in advance in order to define the mounting length of the print lever 10 in the longitudinal direction.

Finally, as shown in FIG. 3D, the print lever 10 located on the side opposite to the protruding side of the print wire 12.
In order to align the surface of the plunger 11 with the surface of the plunger 11, at least the position shown by the alternate long and short dash line M in FIG. Second positioning protrusion 10d
Grind or polish. In this case, if it is not necessary to grind the first positioning protrusion 10b of the printing wire 12, only a part of the second positioning protrusion 10d with the plunger 11 may be ground. .

As described above, the length of the print lever 10 is kept constant, the positional relationship between the print wire 12 and the guide hole of the guide plate 7 is made constant, and the deflection state and the contact pressure of the print wire 12 due to contact or the like are caused. By making uniform, the behavior of the entire print head is stabilized, and good followability and high-speed printing are possible.

In the above embodiment, the case where the first positioning convex portion of the print wire is formed at the tip end of the print lever has been described, but the formation position of the convex portion such as the central portion is changed. It is clear that this makes it possible to adjust the mounting position of the end face of the print wire.

Further, in the above-described embodiment, the case where the print lever is attached to the plunger has been described, but it is clear that the same effect can be obtained even when the print lever is directly attached to the leaf spring without using the plunger.

[0025]

As described above, according to the present invention, the positioning end is joined to the longitudinal end surface of the printing wire at the tip end side of the printing lever and at the mounting portion with the longitudinal circumferential surface of the printing wire. Since the protrusion is integrally formed, positioning can be performed accurately by abutting the rear end of the print wire to the protrusion, eliminating variations in the length and weight of the print wire for each print lever, and Not only can the behavior be stabilized, but even when grinding or polishing is performed to align the height of the print lever surface on the side opposite to the protruding side of the print wire, the labor of grinding a hard print wire is required. Can be omitted, and the grinding time can be shortened.

Further, since the positioning projection having the reference plane orthogonal to the longitudinal direction is integrally formed on a part of the longitudinal direction of the printing lever to which the printing wire is fixed, the length of the printing lever is constant. The print wire position accuracy is improved, the print wire deflection and contact pressure due to contact with the guide hole of the guide plate are made uniform, and the behavior of the print head as a whole is stabilized, resulting in good followability. And enables high-speed printing.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a print head to which the present invention is applied.

2A to 2C are views showing a manufacturing process of a print head in which a print lever and a print wire are positioned, showing an embodiment of the present invention.

3A to 3D are views showing a manufacturing process of a print head in which a print lever and a plunger are positioned, showing another embodiment of the present invention.

[Explanation of symbols]

10 Print lever 10a Mounting surface 10b First convex portion for positioning 10c Reference plane 10d Second convex portion for positioning 11 Plunger 12 printing wire

Claims (3)

(57) [Claims] 1. A first positioning projection that integrally joins with the longitudinal end surface of the printing wire is integrally projected at the tip side of the printing lever and at the mounting portion with the circumferential surface of the printing wire. An impact-type dot print head characterized in that a second positioning projection having a reference surface orthogonal to the longitudinal direction is integrally formed with a part of the printing lever in the longitudinal direction. . 2. A step of protrudingly forming a positioning convex portion that is joined to a longitudinal end surface of the print wire at a mounting portion that fixes the longitudinal peripheral surface of the print wire on the tip side of the print lever. Fixing the longitudinal circumferential surface of the print wire to the attachment portion and fixing the longitudinal end surface of the print wire to the positioning projection, and locating the print wire on the opposite side to the projecting side. A method of manufacturing an impact type dot print head, comprising the step of grinding the surface of the print lever. 3. A first positioning projection that joins with the longitudinal end surface of the print wire is formed on the mounting portion that secures the longitudinal circumferential surface of the print wire on the tip side of the print lever. A step of projecting a second positioning convex portion having a reference surface orthogonal to the longitudinal direction on a part of the longitudinal direction of the print lever; Fixing the surface and fixing the longitudinal end surface of the print wire to the first positioning projection, and fixing the reference surface of the second positioning projection formed on the print lever. A step of abutting against the wall surface of the concave portion of the tool and fixing it to the holding member, and grinding at least a part of the second positioning convex portion of the surface of the print lever located on the side opposite to the protruding side of the print wire. And the impact formula consisting of Manufacturing method of Tsu door print head.