JPS6325054A - Printing head of wire dot printer - Google Patents

Abstract

PURPOSE:To easily position a wire with high accuracy, by providing a groove formed by two planes crossing to each other on the leading end part of an armature to hold the wire in the groove and fixing the armature and the wire by soldering. CONSTITUTION:An armature 1A has a V-shaped leading end part 18A provided with a groove formed of two crossing planes, that is, a plane containing a contact line 20a and vertical to the surface of paper and a plane containing a contact line 20b and vertical to the surface of the paper. A wire 2 is held in the groove, and the wire 2 and the armature 11A are soldered by a solder material 19. In this constitution, by pressing the wire 2 to the groove at the leading end part 18A of the armature 1A, the wire 2 can be easily positioned with high accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a print head for a wire dot printer.
In particular, the present invention relates to a print head for a wire dot printer that aims to improve print quality.

[Prior Art] A print head for a wire dot printer is known, for example, as described in Japanese Unexamined Patent Publication No. 154084/1984. The structure of the print head of the wire dot printer will be explained using one drawing.

FIG. 8 is an exploded perspective view showing an example of a print head of a wire dot printer, and FIG. 9 is a perspective view of main parts showing details of the vicinity of the armature in FIG. 8.

FIG. 10 is an enlarged top view of the tip of the armature in FIG. 9.

In Fig. 8, 3 is a leaf spring, 1 is an armature attached to this leaf spring 3, 2 is a wire fixed to the tip of this armature 1, 4 is a magnet, 5 is a coil, and 6 is a coil. , the coil 5 is attached to each of the comb-like protrusions 6a.
7 is a fixed spring, 8 is a bearing, 9 is a nose, 10 is a side yoke, 11 is a pin, and 12 is a spacer.

13 is a yoke, 14 is a rubber, 15 is a printed circuit board, 16
is the rear cover.

The operation of the wire dot printer configured in this way is that, before printing, the armature 1 with the pin 2 attached to its tip is drawn to the right by the magnetic force of the magnet 4, and the leaf spring to which the armature 1 is attached is drawn to the right. 3
There is some deflection. Then, in order to print, once the printing pattern is determined, the wire 2 to be driven is determined,
In response, a current flows through the printed circuit board 15 to the corresponding coil 5, and a magnetic force is generated in the comb-shaped protrusion 6a of the core 6 into which the coil 5 is inserted, and this magnetic force causes the magnetic force of the magnet 4 described above. is canceled, the deflection of the leaf spring 3 is also canceled, and the wire 2 is driven to the left.

Then, when the tip of the wire 2 hits the paper (not shown) through the ink ribbon (not shown),
Dots are printed on the paper, and many dots come together to form characters, lines, etc.

The details of the vicinity of the armature 1 are as shown in FIG.
An armature 1 is welded to a spring portion 17 of a leaf spring 3. As shown in FIG. 10, the wire 2 is brazed to the tip 18 of the arture 1 with a brazing material 19.

[Problems to be Solved by the Invention] The above prior art is very inconvenient because the tip 18 of the armature 1 and the wire 2 are in contact with one line along the length of the wire 2. He is in stable condition. therefore,
When joining the two, a jig is used for brazing, but it is very difficult to position the jig.

The most important requirement for armature 1 and wire 2 is to position wire 2 with high precision relative to armature 1 in order to improve printing quality.
Conventionally, sufficient consideration has not been given to this point.

The present invention improves the problems of the prior art as described above, and provides a print head for a wire dot printer with excellent print quality, which is equipped with an armature that allows wire positioning to be performed easily and with high precision. This is the purpose.

[Means for Solving the Problems] In order to solve the above problems, the print head of the wire dot printer according to the present invention has a structure in which a wire fixed to the tip of an armature attached to a leaf spring is In the print head of the wire dot printer, which is displaced by the bending of the wire and prints with the tip of the wire, a groove formed by two intersecting planes is provided at the tip of the armature, the wire is held within this groove, The armature and wire are fixed by brazing.

More specifically, the tip of the armature is V-shaped.

[By bringing the working cowire into line contact at two locations within the groove provided at the tip of the armature, the wire can be easily and precisely positioned with respect to the armature.

[Example code] Hereinafter, the present invention will be explained by examples.

1 is a perspective view showing the armature of a print head of a wire dot printer according to a first embodiment of the present invention; FIG.
The figure is an enlarged top view of the tip of the armature according to FIG. 1.

In each figure, parts given the same numbers as in FIG. 10 are the same parts. 20a and 20b are contact lines between the armature LA (described in detail later) and the wire 2, and the armature IA is connected to two intersecting planes, that is, the contact line 2
It has a V-shaped tip 18A provided with a groove formed by a plane including 0a and perpendicular to the plane of the paper, and a plane including the contact line 20b and perpendicular to the plane of the paper. The wire 2 is held in the groove, and the wire 2 and the armature IA are brazed with the brazing material 19. Since the wire 2 is configured in this manner, the wire 2 is held in the groove in the tip portion 18A of the armature IA. By simply pressing the wire 2 inward, there is an effect that the wire 2 can be positioned easily and with high precision.

Next, a method of processing the tip portion 18A will be explained.

The width t of this tip 18A is very narrow (for example, 0
．． 2mm), it is not easy to machine a high-precision groove in that part. With cutting and grinding methods, centering is difficult, making it difficult to produce highly accurate grooves. Therefore, the present inventors developed a new processing method, and the details are as follows.
This will be explained using drawings.

FIG. 3 is an enlarged cross-sectional view showing both a forging die used to carry out the method for processing the tip part according to FIG. 2 and an armature processed by the forging die.

In this FIG. 3, 24 has a wall surface 28.30,
A container capable of storing the internal armature material LA'; 23, a base on which this container 24 is placed; 25, a V-shaped tip 26; a side surface 27 of the tip;
is a punch that slides on the wall surface 28 of the container 24, and the upper side surface 29 slides on the wall surface 30 of the container 24.

In the forging die configured in this way, first, the container 2
4, hold the Armania material LA' with the tip facing upward.

When the punch 25 is inserted into the container 24 from above, it descends while being guided by the wall surface 28 of the container 24 so that the tip 26 and the armature material LA' are coaxial. Then, a predetermined pressure is applied to the upper surface of the punch 25 by a press (not shown),
The tip 26 of the punch 25 is pushed into the tip of the armature material IA', and when it reaches the bottom dead center of the press, the punch 25 stops, and the desired tip 18A is formed in the armature material IA', and the armature IA is obtained. Note that during processing, the lateral force applied to the punch 25 is supported by the wall surface 3o of the container 24, so the tip 2
There is no possibility that 6 will break.

Examples of Iso will be described below.

FIG. 4 is an enlarged top view showing the tip of the armature of the print head of the wire dot printer according to the second embodiment of the present invention.

In FIG. 4, the same parts as those in FIG. 2 are denoted by the same numbers. And IB is the 7-shaped tip 1
In this armature, the width t□ near the tip 8B is larger than the width t of the portion continuing near the tip 18B.

With this configuration, a large bonding area can be secured between the wire 2 and the tip 18B, and when using a thick wire 2 (for example, when a high-strength wire is required for high-speed printing) ) suitable for Moreover, compared to the case where the armature is made wide as a whole, it is only necessary to make it partially wide, which not only reduces material costs, but also has the advantage of being lightweight and capable of high-speed driving.

FIG. 5 is an enlarged top view showing the tip of the armature of the print head of a wire dot printer according to the third embodiment of the present invention, and FIG. 6 is used to carry out the method of processing the tip according to FIG. FIG. 2 is an enlarged cross-sectional view of essential parts showing a forging die and an armature processed by the forging die.

In each figure, the same parts are denoted by the same numbers as in FIGS. 2 and 3. And, the tip part 18C of the IC is 7
It is an armature shaped like a letter. That is, in the armature IA shown in FIG. 2, the width of the tip 18A remains constant before and after grooving, but the width of the tip 18C has increased to 7. It is shaped like a letter.

In this way, in order to form the tip 18C into a figure 7 shape, as shown in FIG. do it. Therefore, the processing force for grooving is reduced to a fraction of that when the tip is formed into a V-shape, and the stress generated in the punch 25 is also reduced proportionally, so the punch 25 has a long service life. It has the advantage of becoming

FIG. 7 is an enlarged top view showing the tip of the armature of the print head of the wire dot printer according to the fourth embodiment of the present invention.

In this armature ID, since the amount of machining of the 7-shape at the tip end 18D is made larger than that of the armature IC shown in FIG. 5, even a thick wire 2 can be used.

It goes without saying that this armature ID also allows the wire 2 to be easily and highly accurately positioned at the tip 18D of the armature ID, as in each of the embodiments described above.

[Effects of the Invention] As described in detail above, according to the present invention, there is provided a print head for a wire dot printer with excellent print quality, which is equipped with an armature that allows wire positioning to be performed easily and with high precision. be able to.

[Brief explanation of the drawing]

1 is a perspective view showing an armature of a print head of a wire dot printer according to a first embodiment of the present invention; FIG.
The figure is an enlarged top view of the tip of the armature shown in FIG. 1, and FIG. 3 shows the forging die used to carry out the method of processing the tip shown in FIG. 2, and the armature processed by this. The enlarged cross-sectional view and FIGS. 4 and 5 shown together are the second embodiment of the invention. An enlarged top view showing the tip of the armature of the print head of the wire dot printer according to the third embodiment, FIG. FIG. 7 is an enlarged sectional view of the main parts together with the armature processed by the method, and FIG. 8 is an enlarged top view showing the tip of the armature of the print head of the wire dot printer according to the fourth embodiment of the present invention. 9 is an exploded perspective view showing an example of the print head of a wire dot printer, FIG. 9 is a perspective view of main parts showing details near the armature in FIG. 8, and FIG. 10 is an enlarged view of the tip of the armature in FIG. 9. FIG. IA, IB, IC, LD...armature, 2...
Wire, 3... Leaf spring, 18A, 18B... V-shaped tip, 18C, 18D... Seven-shaped tip, 19
...brazing metal, T-work, T...width.

Claims (1)

[Claims] 1. A wire fixed to the tip of an armature attached to a leaf spring is displaced by the deflection of the leaf spring,
In the print head of the wire dot printer that prints with the tip of the wire, a groove formed by two intersecting planes is provided at the tip of the armature, the wire is held in this groove, and the armature and the wire are connected. A wire dot printer print head characterized by being fixed by brazing. 2. The print head for a wire dot printer according to claim 1, wherein the armature has a V-shaped tip. 3. The print head for a wire dot printer according to claim 2, wherein the width of the armature near the tip is larger than the width of the armature near the tip. 4. The print head for a wire dot printer according to claim 1, wherein the tip of the armature is Y-shaped.