JPH0443516B2 - - Google Patents

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a dot printer for forming a spherical body to increase the bonding strength between the wire and the molding material when resin molding the end of the dot wire for a dot printer. The present invention relates to a method for forming a spherical end of a dot wire for use.

<Prior art> In general, wires used for dot wires for dot printers include tungsten wires, cemented carbide wires, piano wires, stainless steel wires, and high-speed tool steel wires with an outer diameter of 0.4 mm or less. The wire is incorporated into the dot printer with one end supported by a holder or the like. For example, in a so-called flying type dot printer, since printing is performed by driving a wire by means of pushing or pulling back the holder, the holder not only easily falls off, but also uses a highly hard wire. There were problems such as many wires breaking near the holder part where stress concentration was relatively large.

Therefore, in order to reliably support the wire in the holder, it is recommended to bend one end of the wire and mold the bent part with resin to form a holder. Because the wire is bent, the wire often breaks during processing. It is also possible to integrally form a spherical body at one end of the wire by melting and cooling the same or different metal material as the wire, such as Ni-Cr powder, but in this case, when forming the spherical body, When the wire is also heated, the internal structure of the wire changes and is not only susceptible to breakage due to brittleness, but also tends to become unstable in shape.

Furthermore, in order to deal with the above-mentioned drawbacks, a wire material such as a phosphor bronze wire is wound two to three times around one end of the wire, and a spherical body is formed around the wound part using a hard brazing material, and the wire is placed inside the holder. By embedding the wire in
Although it is disclosed in No. 59-218868, the manufacturing process may become complicated due to the process of winding the wire rod and the increase in the number of parts such as the wire rod. Also, for this type of wire, inertial mass and balance are important, but
When attempting to form a spherical body using brazing filler metal, it is difficult to accurately control its position and weight.

<Problems to be Solved by the Invention> In view of the problems of the prior art, the main object of the present invention is to have high mechanical strength and high precision without complicating the manufacturing process. It is an object of the present invention to provide a method for forming a spherical end of a dot wire for a dot printer, which can form a spherical portion without changing the internal structure of the wire.

<Means for Solving the Problems> According to the present invention, such a purpose is to provide a dot wire for a dot printer that is made of a predetermined metal and has a predetermined outer diameter, and is embedded in a synthetic resin member at the end of the dot wire. A method for forming a spherical body in a part, the wire-shaped brazing material being meltable at a temperature at which the metal does not change in quality is tightly wound around the outer periphery of one end of the wire, and at a temperature at which the metal does not change in quality. This is achieved by providing a method for forming a spherical end of a dot wire for a dot printer, characterized in that the brazing material is melted by heating to solidify and form a spherical body.

<Function> If the brazing filler metal formed so that it can be wound around the wire is heated after being tightly wound around one end of the wire, a predetermined amount of the brazing filler metal can be held in a predetermined position. After placing it, a spherical body can be formed.

<Embodiments> The present invention will now be described in detail with reference to specific embodiments with reference to the accompanying drawings.

1 and 2 are sectional views of essential parts showing a first embodiment of a dot wire according to the present invention. 1st
In the figure, a dot wire wire 1 to be incorporated into a dot printer (not shown) is made of a relatively hard wire made of, for example, tungsten, cemented carbide, or high speed tool steel. A coil 2 made of a hard brazing material, such as silver solder, is wound around one end of the wire 1 with a predetermined number of turns. It is formed into a coil shape that can be rotated.

By heating the coil 2 made of a hard brazing material wound around one end of the wire 1 as described above to the melting temperature of the hard brazing material and then cooling it, a coiled brazing material is formed as shown in FIG. 2 is formed into a spherical body 3 and brazed to the wire 1. Then, the holder 4 is formed by molding a resin material so as to surround the spherical body 3 and the wire 1 in the vicinity thereof.

In the dot wire 5 formed in this way, the melting temperature of the hard solder metal is relatively low, and the internal structure of the wire 1 near the solder does not change, so there is a risk of breakage due to brittleness. There is no.

A second embodiment according to the present invention is shown in FIGS. 3 and 4. As clearly shown in FIG. 3, a coil 2 made of hard brazing material 2 is wound around one end of the wire 1 in the same way as in FIG. Since the coil 2 is formed with a sparsely wound portion 7 on the side, when the coil 2 is heated and cooled, a spherical shape is formed on the densely wound portion 6 on both sides as well shown in FIG. Body 3 is formed.
In the dot wire 5 formed in this manner, the plurality of spherical bodies 3 ensure a sufficient adhesion area between the spherical bodies 3 and the wire 1, so that the spherical bodies 3 can be made relatively small. The outer shape of the holder 4 can be made smaller.

The hard soldering material wound around one end of the wire 1 is not limited to a coil shape, but as shown in FIG. may be attached to one end of the wire 1. In this third embodiment, as clearly shown in FIG. 6, one spherical body 3 is formed and brazed in the same way as in the first embodiment, and the spherical body 3 and its vicinity are bonded together. The holder 4 is molded to surround the dot wire 5. Further, two rings 8 made of the above-mentioned hard brazing material may be attached to one end of the wire 1 at a predetermined interval, as clearly shown in FIG. 7, for example. In this fourth embodiment, as clearly shown in FIG. The dot wire 5 is formed by molding the holder 4 so as to surround the vicinity thereof.

In this embodiment, one or two spherical bodies made of a hard brazing material are formed at one end of the wire, but the number is not limited.

<Effects of the Invention> As described above, according to the present invention, by winding a predetermined amount of brazing filler metal formed so that it can be wound around a wire around one end of the wire, a spherical body of a predetermined weight can be extremely easily positioned at a predetermined position. Since the wire can be formed into a dotted wire, there is no need to process the wire, and the internal structure does not change due to high temperatures, so it is possible to supply a dot wire with high mechanical strength and a small number of parts. Furthermore, by forming a plurality of spherical bodies, the outer shape of the holder can be made smaller, so that it is possible to achieve the effect of extremely easily reducing the size and weight of the dot wire.

[Brief explanation of drawings]

1 and 2 are sectional views of essential parts showing a first embodiment of the end structure of a dot wire to which the present invention is applied. FIGS. 3 and 4 are sectional views of main parts showing the second embodiment. FIG. 5 and FIG. 6 are main part sectional views showing the third embodiment. Figures 7 and 8
The figure is a sectional view of a main part showing a fourth embodiment. 1... Wire, 2... Coil (brazing material), 3...
... Spherical body, 4 ... Holder, 5 ... Dot wire,
6...Dense part, 7...Coarse part, 8...Ring.

Claims (1)

[Scope of Claims] 1. A method for forming a spherical body in a portion embedded in a synthetic resin member at an end of a dot wire for a dot printer, which is made of a predetermined metal and has a predetermined outer diameter, wherein the metal is A linear brazing material that can be melted at a temperature that does not cause deterioration is tightly wound around the outer periphery of one end of the wire and heated at a temperature that does not cause deterioration of the metal, thereby melting the brazing material and forming a spherical body. A method for forming a spherical end of a dot wire for a dot printer, characterized by solidification.