JPH0335813A - Coiling method for metallic wire of high melting point - Google Patents

Abstract

PURPOSE:To obviate linearizing treatment and to improve productivity of coil by using a spool with a diameter which is at least over specified times of the maximum diameter of coil when a high melting point metallic wire for working into a coil subjected to wire drawing is coiled with the spool. CONSTITUTION:A sintered material is manufactured from metals, such as W and Mo, with a normal powder metallurgy. Next, that sintered material is worked with hammering by passing through plural hammering machine and is made into a rod with prescribed diameter by narrowing successively the wire diameter. Next, after the rod is heat treated at described temperatures to remove strain, it is transferred to next wire drawing process. After the rod is coated with lubricant, such as graphite suspension and is passed through a die, the rod drawn out from the die is applied with heat treatment and is passed through the die of next stage. The rod with the desired wire diameter is obtained by repeating that process plural times. Next, coiling is performed by use of the spool with the diameter over 20 times of the diameter of coil. Thereby, even if linearizing treatment isn't applied, the high melting point metallic wire with a suitable shape characteristic to coiling with a spring machine can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for winding a high melting point metal wire, and more particularly to a method for winding a high melting point metal wire for coil processing.

(Prior Art) A film-like high melting point metal wire such as tungsten (W) wire or molybdenum (Mo) II is used for the filament of a lamp or the heating wire of a heater.

Such a coiled high melting point metal wire is usually manufactured as follows.

First, a sintered body of a high-melting point metal produced by a known powder metallurgy method is hot rolled several times to densify its structure, and then transform the uniaxial crystals into fibers. It is stretched and arranged to form a tough cotton material.

Next, this cotton material is heat-treated as necessary to remove internal distortion caused by the rolling process, and after applying a lubricant such as graphite in hot or warm conditions, the pore diameter is gradually increased from large to small. The wire is drawn through a number of dies that change in order to make it even thinner.

Then, the wire rod subjected to such wire drawing processing is wound onto a spool, and then transferred to a secondary processing step, that is, a coil processing step.

In the coil processing process, conventionally, a high melting point metal wire is wound around a core metal of a predetermined diameter made of Mo or Fe, subjected to hydrogen furnace treatment (heat treatment) to form a chain line, and then the core metal is A method of completely dissolving or semi-dissolving and extracting is being explored.

However, the method of coiling by winding high melting point metal wire around a core metal uses the core metal which is redundant for the coil itself, and there are problems such as the generation of toxic NO2 during the melting process. , there is an increasing demand for a coiling method that does not use a cored metal6.As a coiling method that does not use a cored metal, a spring machine that has been used for large coil springs such as automobile suspension springs, for example, can be used to Attempts have been made to use methods for coiling high melting point metal wires with a small curvature of about .3 to Q, 4n+m.

The principle of a spring machine is that the cotton material sent out from the spool hits an abutment tool placed in a position that blocks its direction of movement, bending it to a predetermined curvature and forming a coil. , and the curvature of the coil changes as the position of the abutting tool changes.
Further, the pitch of the coil can be adjusted by a guide groove formed in the abutting tool.

(Problems to be Solved by the Invention) However, when such a coiling method that does not use a metal core is used, the properties of the wire to be processed have a large effect on the formability when coiling the wire.

That is, when coiling is performed using a spring machine, it is preferable that the cotton material has as much straightness as possible from the viewpoint of coiling properties. However, the high melting point metal wire manufactured through the above-mentioned process has internal distortion due to the drawing angle and drawing strength from the die during the wire drawing process, or the cotton material itself has curls when wound onto a spool. Due to the nature of this, when the cut piece of 1 m long is placed on a flat surface, the diameter (curl diameter) when the cut piece naturally winds to form a loop is small, that is, the curl becomes strong.

For this reason, if a wire rod having such shape characteristics is directly coiled using a spring machine, the coiled coil will be distorted or distorted, or the pitch will not be constant, or other deformations will occur.

Conventionally, as a method for removing such deformation, a method has often been used in which a wire rod wound onto a spool is straightened to give it the desired straightness and then transferred to a spring machine.

For example, in order to coil a W wire with a wire diameter of 0.3 to 0.5+no+ using a spring machine to make a coil with a diameter of 10-1, the shape characteristic is that the curl diameter is 200o+m.
It is said that it is preferable to use the above material because it will not be deformed during coiling.

However, according to the conventional method, the wire diameter is 0.3 to 0.51.
In the case of am+ WII, it is customary to wind it onto a spool with a diameter of 100 to 150 n+m, and in this case, it is customary to have a shape characteristic of a curl diameter of 100 to 150 iu+. Therefore, the cotton material wound on the spool has 10
It was necessary to perform heat treatment while applying a reverse tension of about kg/+u+2, and to perform a straightening process such that the curl diameter became 200 mm+ or more.

Therefore, there is a problem in the productivity of the coil, and it has been desired to simplify the manufacturing process.

Therefore, the present invention provides a high melting point metal wire that can provide a high melting point metal wire having shape characteristics suitable for coiling with a spring machine without performing a straightening process, thereby contributing to improving the productivity of coils. The purpose is to provide a method for winding wire.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present inventors conducted intensive research and found that the size of the curl diameter mainly depends on the size of the spool diameter among the above factors. Focusing on the fact that it depends on
The present invention has now been completed.

Namely, 1. The method for winding high-melting metal wire of the present invention [1] is a method for winding a drawn high-melting point metal wire for coil processing onto a spool, in which the diameter is at least 20 times or more the maximum diameter of the trocoil. In this case, the high melting point metal refers to W and Mo.

In the present invention, first, a sintered body is manufactured from the above-mentioned metal by a commonly used powder metallurgy method.Then, this sintered body is passed through a plurality of rolling machines to be rolled, and the wire diameter is successively reduced. Then, the wire is heat-treated at a predetermined temperature to remove the strain accumulated in the wire, and then transferred to the next wire drawing process.

In the wire drawing process, graphite is added to the transferred wire! ! A lubricant such as a slurry is applied to provide lubricity, but at this time, a metal oxide layer has already been formed on the surface of the wire from the processing process prior to this wire drawing process, so graphite The suspension will deposit on the metal oxide layer.

The wire rod coated with lubricant is passed through a die, the wire rod extracted from the die is subjected to heat treatment, and then passed through the next die. By repeating this process multiple times, the wire rod with the desired wire diameter is obtained. .

Next, the obtained wire is wound onto a spool, and the present invention is characterized in that a spool having a diameter 20 times or more of the maximum diameter of the final product coil is used.

The reason for specifying this is because the curl diameter largely depends on the diameter of the spool on which the drawn wire is wound, and the larger the spool diameter, the larger the curl diameter. be.

If you use a spool that is less than 20 times the maximum diameter of the coil,
The wire has strong curls and cannot be made into a shape suitable for coiling.

It goes without saying that the spool diameter has an upper limit within a common sense range from the standpoint of storage, transportation, etc.

(Example) Hereinafter, the present invention will be explained in more detail based on Examples.

EXAMPLE A W sintered body was manufactured using a powder metallurgy method. This sintered body was subjected to rolling processing using a commonly used rolling machine to obtain a wire rod having a wire diameter of 3 mm.

Next, this wire was passed through a lubricant coating device, and graphite was coated on its surface. After that, the wire is drawn through a 15-stage die, and the final wire diameter is 0.4t+uoφ.
The W wire was wound onto a spool with a diameter of 300 mm. This W wire was pulled out from the spool, the 1m cut piece was placed on a flat surface, and the curl diameter was measured, which was 220m-
Met.

After that, coil this W wire with a spring machine,
Diameter 10a+m, pitch 1mm, length 15011I1
1 coil was manufactured. The results of investigating the number of deformed parts of this coil are shown in the table. However, the number of deformed locations here refers to the number of locations where the pitch width deviates from the design standard value per 1 km of coil length.

It refers to the sum of the number of places where the coil shape is distorted or twisted.

Comparative Example A coil was manufactured in the same manner as in the example except that the spool diameter was 100 m5+. W# the result! It is shown in the table together with the curl diameter.

[Effects of the Invention] According to the present invention, it is possible to supply a high melting point metal wire having shape characteristics suitable for coiling with a spring machine without performing straightening treatment, and therefore, it is possible to provide a high melting point metal wire having shape characteristics suitable for coiling with a spring machine. It is a great contribution.

Claims (1)

[Claims] A method for winding a drawn high-melting point metal wire for coil processing into a spool, the method comprising using a spool having a diameter at least 20 times or more the maximum diameter of the coil. .