JPS63299809A - Production of fine tube packed with high density filler - Google Patents

Abstract

PURPOSE:To obtain many kinds of tubes packed with high density filler by elongating tubes containing high density filler, extending the inner filler also uniformly integrating together with the metal tube as the metal tube becomes finer and correcting the outer diameter by wire drawing. CONSTITUTION:Metal of high ductility is used for the metal tube 2 into which filler 1 is inserted before drawing. Suitable component is selected to the filler 1 according to a working object. One or more through holes 3 are provided for inserting the filler 1. The metal tube 2 is drawn by swaging. The metal tube 2 is forged by dies on both sides of the tube to reduce its diameter and to elongate its length as if its outer circumference is beaten. In this manner, a metallic wire of fine diameter packed closely and uniformly with filler is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a densely packed capillary tube that can be applied to the production of flux-filled welding wire, welding wire for heat-resistant alloys, ceramic-filled capillary tubes for use in superelectric devices, etc. It is.

[Prior Art] For example, in submerged arc welding, flux is applied to a welding area, a welding wire is inserted into the flux, and welding is performed using an arc.

Therefore, welding cannot be performed in a welding position that does not allow flux to be applied, and is unsuitable for welding the entire circumference of pipes.

Therefore, welding rods with a flux layer formed around them and welding wires with flux wrapped in a weld metal plate have come to be used.

[Problems to be Solved by the Invention] However, welding rods with a flux layer formed around them are difficult and difficult to handle because the flux layer easily peels off.
It was limited to short pieces.

In addition, in the case of flux wrapped around a welded metal plate, after the flux is wrapped around the welded metal plate, it is made into a long length by drawing process. shading tends to occur, and in some cases, it may be interrupted.

[Means for Solving the Problems] The present invention is aimed at solving the above-mentioned problems and making it possible to manufacture long thin tubes filled with fillers at a high density. A cylindrical filling having at least one hole or metal wire penetrating in the axial direction is inserted into a metal tube, and then the metal tube is stretched along with the filling, and then wire-drawn. The present invention relates to a method for producing a densely packed thin tube.

[Function] When a metal tube containing a filler is stretched, the metal tube stretches and becomes thinner, and the filler inside narrows the hole or stretches the metal wire, becoming integrated with the metal tube. It stretches evenly and thinly.

If the outer shape is modified by wire drawing, a long, densely packed thin tube can be obtained.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a metal tube 2 into which a filler l is inserted before being stretched in the manufacturing method of the present invention.
The metal tube 2 is made of a relatively highly ductile metal or alloy such as stainless steel, Inconel, or copper, and the tube diameter and length depend on the purpose of use, but for welding, the outer diameter is 10 mm, and the inner diameter is 8 mm. The length may be approximately 200mm+.

The constituent material of the filler 1 may be selected depending on the purpose of use; flux is used for general welding, and chromium, nickel, etc. are used in the flux for welding heat-resistant alloys or hard alloys.
Powders of cobalt, tungsten, etc. are added so that when melted, they form a predetermined ratio with the outer metal.

For superconductivity, superconducting ceramics such as niobium, titanium, zirconium, tin, vanadium, and gallium are used.

Before the filling l is inserted into the metal tube 2, one or more holes 3 passing through it in the axial direction are provided. The hole 3 may be formed by inserting a metal wire having the same diameter as the hole 3 and then pulling it out before or after heat treatment, or by drilling the metal wire so as to pass through the hole 3 after forming the hole 3 into a cylindrical shape. may be set. Further, instead of providing the hole 3, a malleable metal wire may be inserted in the axial direction. Here, the diameter, number, and arrangement of the holes 3 or metal wires are appropriately selected depending on the stretching ratio, and when the stretching ratio is large, the diameter may be made larger and/or the number may be increased.

The conditions for heat treatment of the filling 1 vary depending on the constituent materials, but
It is sufficient that a bisque-like sintered body can be obtained.

In this way, the filler l formed into a so-called lotus root shape may be machined to improve the outer diameter accuracy before being inserted into the metal tube 2.

An example of a method for stretching the filling material 1 after inserting it into the metal tube 2 is a method generally called swaging. That is, the outer periphery of the metal tube 2 is forged by tapping with the left and right dies, and the diameter is made thinner and the metal tube 2 is elongated. At this time, as the metal tube 2 is stretched, the filling material 1 inside is also deformed and stretched so that the holes 3 are crushed. This also applies to the case where an easily ductile metal wire is used instead of the hole 3. In this way, the hole 3 is almost completely crushed and the metal wire becomes thinner, and the outer diameter of the metal tube 2 is reduced to 1 ma+ to 0.5 mm.
It is stretched thin and densely packed with fillers until it reaches a certain level.

Since the outer diameter may not necessarily be uniform after being stretched, the shape and surface condition are made uniform by lightly drawing with a die.

Note that the manufacturing method of the present invention is not limited to the above-mentioned examples, and various changes may be made without departing from the gist of the present invention, such as annealing may be performed as necessary. Of course.

[Effects of the Invention] As described above, the method for producing a densely packed thin tube of the present invention exhibits various excellent effects as described below.

(D) Since the cylindrical filler is inserted into a metal tube and then stretched, a long, flexible, thin metal wire filled with the filler densely and uniformly can be obtained.

(■) If the filler is a flux material, a long flux-cored welding wire can be obtained, the effort of replacing the welding rod will be significantly reduced, and automatic welding will also be possible. Furthermore, since the flux can be uniformly filled, welding conditions are stable and welding defects can be prevented.

[Phase] By adding hard metal powder such as chromium or tungsten to the filler, welding materials such as super heat-resistant alloys and cemented carbide can be easily made into small diameter and long lengths, and welding materials with or without flux can be used. Regardless of the method, the effort of replacing welding rods is reduced and welding defects can be prevented.

■ If superconducting ceramics are used as a filler, a thin superconducting ceramic wire coated with metal on the outside can be obtained, making coil winding easier, and superconducting ceramics can be used in various fields. Further, the outer metal coating layer can ensure conductivity outside the temperature range where superconductivity occurs, and can prevent burnout.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing an example of a metal tube into which a filler is inserted for use in the production method of the present invention, and Figure 2 is an illustration of
It is a directional view. 1 indicates a filling, 2 indicates a metal tube, and 3 indicates a hole.

Claims (1)

[Claims] 1) Inserting a cylindrical filler having at least one hole or metal wire that penetrates in the axial direction into a metal tube, then stretching the metal tube together with the filler, and then wire-drawing the tube. A method for producing densely packed thin tubes characterized by: