JPS60216940A - Manufacture of print wire for dot printer and print wire - Google Patents

Abstract

PURPOSE:To manufacture a titled wire prevented from lowering the strengths of its head and underhead parts, by holding horizontally a straight wire stock having a fixed diameter, and attaching a small piece of brazing filler metal to its one end, and heating, melting, and solidifying it by cooling. CONSTITUTION:A straight wire stock 1, which is made of high-speed tool steel and is hardened and tempered and has a fixed diameter of about 0.3mm., is held at its one end in an overhanging state; a small amount of flux is coated on said one end, and further a small piece 10 of silver brazing filler metal of about 630 deg.C melting point, which is obtained by cutting a silver brazing filler metal sheet of about 1.5mm. thickness and providing a through hole of about 0.5mm. diam. to its central part, is attached to said one end through said through hole. Next, the small brazing filler metal piece 10 is heated by a burner and is cooled after melting it, to form the brazing filler metal into a spherical shape approximately symmetrical with respect to the wire stock 1; then a print wire for a dot printer, having a silver brazing filler metal layer of about 0.65mm. thickness, is obtained without causing the lowering of the hardness of wire 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming the head of a print wire for a dot printer and a wire produced by this manufacturing method.

Dot printers are formed by driving wires, (1),
(2) fixing the non-printing side end of the wire to the amatia with wax or the like, and (2) attaching an enlarged diameter part (
Hereinafter, this part will be referred to as the head, and the small length area from the head to the printing end side will be referred to as the lower neck.) A returning coil spring is provided in the lower neck, and an armature at the top of the head is used to suppress the drive. There is.

Various materials are used for these printed wires, but among these, high-speed tool copper quenched and tempered to a high degree of hardness is overall superior and is used in the largest quantity. All of these are made into printed wires by processing wires of equal diameter.

The method (2) above is called a flying method, and an example of this method is shown in FIG.

In the figure, the lower part of the neck of a head 2 formed at one end of the printed wire 1 is urged by a return coil spring 3, and the top surface of the head 2 is brought into contact with an armature 4. When the core 7 is excited by the electromagnetic coil 6, it attracts the armature 4 against the biasing force of the armature return coil spring 5.
The wire 1 is driven rightward against the biasing force of the return coil spring 3 due to the suction movement of the asture. When the excitation current is cut off, the armature 4 and the wire 1 return to their original positions by their respective spring forces.

Conventionally, the head of the print wire 10 of this flying type dot printer is formed by hot bending (Fig. 2), upsetting (Fig. 3), crushing, etc., as shown in Figs. 2 to 4. After molding (Figure A is a plan view, B is a front view) and annealing as necessary, the head is molded with synthetic resin, caulked or soldered with a soft metal sheath or ring-shaped small piece. was forming. These forming processes such as bending are performed to increase the adhesion strength between the molding material or soft metal and the wire 1.

However, in the case of high-speed tool steel wire, this forming process such as bending must be performed in a narrow temperature range and with a constant amount of processing, and annealing the core sufficiently reduces the hardness and improves toughness. It is difficult to recover. Furthermore, since this annealing is performed at a high temperature of about 800 U, the lower part of the neck, which should maintain high hardness, is likely to receive an annealing effect, resulting in a decrease in I￥fK fatigue strength.

As for the other materials, the entire wire is made highly hard so that the tip surface or the sliding part with the wire guide has wear resistance, and the shaft part has fatigue resistance. Therefore, cold forming is possible. This is not possible, and there is a decrease in hardness due to the annealing effect of heating the lower part of the neck due to hot open molding.

In addition, when using a synthetic resin mold, the elastic modulus of this mold material and the wire 1 are significantly different, and due to the difference in the amount of elastic deformation of each in the state of driving force transmission, the joint between the two will be difficult to connect at the end of the joint. Peeling was likely to proceed sequentially from the beginning.

Therefore, conventional flying type dot printers have the disadvantage that the strength of the head and its vicinity is insufficient.

The present invention provides a printed wire and a method for manufacturing the same, which prevents a decrease in strength of the head and/or lower part of the neck by forming a thick wax layer on the visible part and eliminating the bending process. The purpose is to...

The first and second inventions of the present application can be applied to a single wire by attaching a small piece of brazing filler metal to a straight wire material of constant diameter held horizontally, and melting and solidifying the brazing filler metal by heating. The melting of the addressee.

The wax is held on a braze holder made of a material that does not sag against the molten wax, and a constant diameter is placed inside the molten wax.

This method of manufacturing a print wire for a dot printer is characterized in that a straight wire material is immersed, held horizontally, and pulled up from the solder holder to obtain the thick solder layer attached to the surface thereof.

A third invention of the present application is a print wire for a dot printer, characterized in that the enlarged diameter portion has a constant diameter and a solder layer having a baseness of 0.1 m or more metallurgically bonded to the straight wire surface.

Next, the present invention will be explained based on examples. FIGS. 5A and 5B are diagrams showing the brazing material before and after melting in the embodiment of the first invention of the present application. A straight high-speed tool copper wire material 1 with a constant diameter of 0.3 trmφ, which has been quenched and tempered, is supported with one end horizontally overhanging, and a small amount of flux is applied to this one end, and a silver solder with a thickness of 1.2 is applied. Cut the sheet into 1.5 mm and place 0.5 vu+ in the center.
A small piece of silver solder with a melting point of 630℃ with a through hole of φ,
The wire material l is passed through the small hole and attached. Next, if this small piece of solder 1o is heated with a burner to melt it and then cooled, the solder metal becomes a spherical shape with y symmetry to the wire material IK and can be fixed to the wire material (BJ. When the hardness was measured, it was found that the decrease in hardness due to the tempering effect caused by heating the wax melting pot of the wire 1 was about HV5, and was hardly a problem.

In other words, a silver solder layer with a thickness of 0.65 mm could be obtained with almost no decrease in the hardness of the wire 1. This thickness is much thicker than the silver solder layer obtained by vertically immersing the wire in a silver soldering bath and then pulling it up, and this difference in thickness is due to the following factors. can be explained.

FIG. 6A is a diagram schematically showing a process in which the wire 1 is vertically immersed in a large amount of molten solder bath and then pulled up. The molten solder adheres to the surface of the wire 10 due to its wettability, and the surface in the air is thought to form a curve 12, continuously passing through the constriction 11 from the bath liquid level 13. The force relationship at this time is: d' is the diameter of the constricted portion 11, d is the outer diameter of the adhesive layer on the outer surface of the wire 1, and T is the surface tension of the brazing material.
W=π(d-1>T is the weight of the brazing filler metal on the constriction assembly. In other words, πd'T is the weight of the brazing filler metal below the constriction and just above the bath liquid level, and (on the constriction assembly) Reduce the amount of filler metal.

perform the action of

In this way, as the wire 1 is gradually pulled up, the diameter d' of the constriction gradually decreases, and the brazing material on the constriction assembly gradually increases according to the above formula. When the wire 1 is further pulled up, when the constriction reaches a certain diameter, the core rapidly shrinks due to the circumferential surface tension, and the surface 12 separates from the liquid level 13.

During this rapid shrinkage process, the wax below the constriction cannot move upwards rapidly according to the above equation due to its viscosity and inertia, and the brazing filler metal attached to wire 1 remains on top of the constriction assembly before the rapid shrinkage. The amount is almost the same as that of

On the other hand, FIG. 6B is a schematic diagram showing that a large amount of brazing material can be attached according to the above embodiment. In the above example,
Since a fixed amount of the brazing filler metal is attached to the wire 1 in advance and then melted, the liquid level 13 as shown in FIG. 6A becomes π.
There is no effect of reducing the adhesion amount corresponding to d'T. Furthermore, the length of the line on which surface tension acts, which supports the weight of the adhered brazing filler metal, is several times larger than πd, the circumference of diameter d in Figure 6A, as shown by line 15. Therefore, it is possible to attach a large amount of brazing filler metal. If an excessively large number of brazing materials are deposited, the thickness of the brazing material layer above the wire 1 will actually decrease.

The method for attaching the brazing material 10 to the wire material 1, in addition to the above example, is to cut a ribbon-shaped or thin wire-shaped brazing material into a fixed length so as to have a constant weight, and then wind it around the wire material 1. Various methods are possible.

Next, the second invention of the present application will be explained based on drawings of embodiments. FIGS. 7A and 7B are examples of a top view and a vertical cross-sectional view, respectively, of a braze cradle used in practicing the present invention. The solder pedestal 14 has a recess 15 on its upper end surface for accommodating molten solder;
Each of the ring-shaped side walls forming this recess has a groove-shaped notch 16 for pulling the wire upward, and the surfaces of these four parts are covered with an oxidized layer of ceramic or metal that is not wettable by bath melting solder. It consists of If enough molten solder to be applied to one wire is held in this recess, this solder will have a spherical shape because it has no wettability, and after inserting the wire material 1 into the notched solder, it will be held horizontally and then pulled up. The state is the same as the state after melting of the solder in the above-mentioned embodiment, and an enlarged-diameter portion having a thick solder layer can be obtained. In this embodiment, unlike the embodiment described in the first invention, the step of attaching a small piece of brazing material to the wire 1 can be omitted, which is convenient for mass production.

This second invention is different from the conventional cast casting method. In the cast casting method, for example, when forming a hanging ear for cargo handling on a large cast product, a member consisting of a hanging ear and a handle is placed in a mold, the hanging ear is embedded in the mold, and the handle is placed in the casting space. A protruding mold is formed, and molten metal is cast into this casting space.The handle is embedded in the solidified casting material, and the ears connected to the handle are used for hanging ears after the hook is dismantled. It is a protrusion. In contrast, the second invention holds the brazing filler metal using surface tension. It would be possible to cast a thick filler layer using this cast-in casting method, but in this case a mold is required, and the casting time is exposed to high temperatures, resulting in a large decrease in hardness and cooling time. Since it is long, it may have problems such as being unsuitable for mass production.

Next, the third invention of the present application will be explained. The printed wire of the present invention has on its surface, as described in the embodiment of the first invention.
It has a brazing layer with a thickness of 0.1so+ or more that is metallurgically bonded and has excellent adhesion strength to the wire without impairing the mechanical strength of the wire. The outer diameter of this brazing layer is, for example, 0.3
0.5 m or more for +mφ wire 1 in 10.3 m
．． 7 times or more, increasing the bonding area with the synthetic resin and increasing the bonding strength. Generally, soldering has good workability and can be subjected to plastic processing such as cutting and knurling very easily, and by forming the surface into irregularities, the bonding strength with the synthetic resin can be further increased. Therefore, it is necessary to provide this wax layer.

By this, the purpose of conventional forming such as bending can be achieved. Furthermore, when molding the surface of this brazing layer with synthetic resin, the elastic modulus of the brazing material is intermediate between that of the wire and the molding material, so peeling of the bonding surface occurs due to the difference in elastic modulus at each bonding interface. .

separation is suppressed. Of course, the solder side surface can also be caulked and joined with a soft metal. FIG. 8 is an example showing a cross section of the head of the printed wire of the present invention, which is molded with synthetic resin.

Further, since the print wire of the present invention has a thick solder layer, the solder layer can be left in a solidified state or the upper and lower end surfaces can be flattened by grinding or cutting to form the head.

Conventionally, there has been a proposal for a printed wire in which a tubular sheath with one end sealed or both ends open is inserted into the outer diameter of the wire material, and this is joined with solder to form the head, but this method of applying the brazing material has been proposed. This is a soldering method in which both surfaces to be joined are joined with a solder layer interposed between them, and is different from the method of applying a solder according to the third invention of the present application. Moreover, the brazing layer in this proposal is substantially extremely thin in order to maintain the concentricity between the wire and the sheath material, and is not thicker than 0.1 wn as in the third invention of the present application.

As described above, the invention of the present application is based on the discovery of a method for obtaining a thick solder layer, and is a manufacturing method and a printed wire particularly suitable for manufacturing a printed wire with excellent fatigue strength.

[Brief explanation of the drawing]

FIG. 1 is an example of a cross-sectional view of a print head of a flying dot printer, and FIGS. 2 to 4 are examples of a wire forming method. Figures 5 and 7 are diagrams showing embodiments of the first and second inventions of the present application, respectively, and Figures 6A and B are diagrams in which the wire is immersed in a wax bath and pulled vertically, respectively. FIG. 3 is a diagram illustrating that a large amount of brazing material adheres to a wire held horizontally. FIG. 8 shows an embodiment of the third invention of the present application. Agent Patent Attorney Harumada Takaishi /ffi A Figure 6B Figure 7ffi Name of invention 8th place for manufacturing method of print wire for dot printer and correction of print wire (sog + l': Representative of Ritsu Metal Co., Ltd. Furukawa Kenoyo Osamu Hitoshi 2 1-: Location Higashi ≦ c Tokyo Chiyo I 11-ku Marunouchi λ 1-ro 1-2 C: - Amendment L The detailed description of the invention column in the specification is amended as follows. (Correct ``formation'' and ``format'' on page 2 of the specification, line 12. (2) Line 16 of page 2 of the specification: ``Write as the lower part of the neck.''!
Add rYJ below. (3) On page 9, line 15 of the specification, "notch" is corrected to "notch."

Claims (1)

[Claims] 1. A method for manufacturing a print wire for a dot printer in which a diameter enlarged portion is formed in a part of the length, which includes attaching a small piece of brazing material to a straight wire material with a constant diameter held horizontally; A method for producing a print wire for a dot printer, comprising the steps of heating, melting, and cooling the solder piece to obtain a thicker solder layer. 2. In a method for manufacturing a print wire for a dot printer in which a diameter enlarged portion is formed in a part of the wire in the length direction, one of the wires is
An amount of molten solder to be applied to the book is held on a solder pedestal made of a material that is not wettable by this molten solder, and a straight wire material of a constant diameter is dipped into this molten solder and held horizontally. The solder is pulled up from the solder pedestal and attached to its surface.
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A method for manufacturing a print wire for a dot printer, comprising the step of obtaining a wax layer having a large thickness. 3. In a print wire for dot printers that has an enlarged diameter part formed in a part of its length, the enlarged diameter part has a constant diameter and a thickness of 0.1 m metallurgically bonded to the straight wire surface.
A print wire for a dot printer characterized by having a wax layer of + or more.