JPH03124310A - Manufacture of metal wire rod - Google Patents

Abstract

PURPOSE:To prolong the life of a die and to prevent the bent and torsion of a wire rod by adding a reverse tension acting in the reverse direction to a formation drawing tension to the metal wire rod formed on a modified cross section and forming the metal wire rod with its drawing from a circular cross section to modified one. CONSTITUTION:A wire rod 1 is received by a winding drum 26 with the driving of a driving motor 27 and fed from a base metal reel 22. The wire rod 1 prior to forming is first drawn slightly by a back die 3. In this case, the back die 3 gives the wire rod reverse tension as the reaction against the drawing. The wire rod 1 drawn just as the circular cross section is further formed in the specific shaped cross section by a forming die 4 and wound on a winding drum 26. The life of the die 3 is therefore prolonged because of a reverse tension being applied on the wire rod passing through the forming die 4 and the load in the drawing direction applied on the internal face of the forming die 4 being reduced. Simultaneously the bent and torsion of the formed wire rod 1b are prevented as well.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a metal wire, and particularly to a method for manufacturing a copper wire having an irregular cross section other than a circle by drawing it using a die.

[Conventional technology]

Metal wires have various cross-sectional shapes depending on their use.

In addition to circles, there are also tapered shapes, ellipses, hexagons, squares, circles with notches, and more complex shapes. To manufacture metal wire rods with a cross section other than circular, there is a method of pultrusion molding from a metal wire rod with a circular cross section using a die with a circular inner surface of the mouth portion and a desired shape of the bearing portion.
No. 8-26455, U.S. Pat. No. 4,211.104, and the like.

Furthermore, a method of pultrusion forming a circular tube into a rectangular tube using a similar die is also known from Utility Model Publication No. 8829/1983.

[Problem to be solved by the invention]

However, when pultrusion is performed using a die like the one above,
Compared to a die with a circular bearing inner surface, the resistance during drawing is greater and the die is subjected to greater tension, resulting in a shorter die life. Furthermore, since the forces received at the bearing portion are not symmetrical, bending and twisting occur in the wire.

Therefore, an object of the present invention is to pultrude a metal wire with a circular cross section using a die with a circular inner surface of the mouth part and a desired shape of the bearing part. The aim is to extend the life of the die and prevent bending and twisting of the wire in the method of manufacturing wire (sometimes referred to as wire rod).

[Means to solve the problem]

In order to achieve the above object, the present invention provides a back die with a circular inner surface and a diameter smaller than the diameter of the wire to be formed upstream of a forming die with a circular inner surface of the mouth part and a predetermined bearing part. I tried to apply reverse tension to.

The method of the present invention consists of the following steps.

(1) The process of applying tension in the opposite direction to the drawing tension (hereinafter referred to as reverse tension) to a wire with a circular cross section using a back die whose inner surface is circular and whose diameter is smaller than the diameter of the wire to be formed (2) A wire rod that has been given reverse tension with a back die,
A process of pultrusion forming into a wire rod having a predetermined irregular cross section using a forming die with a circular inner surface of the mouth part and a predetermined irregular shape of the bearing part.The details of each process will be explained below.

(1) Process of applying reverse tension to a wire with a circular cross section using a back die whose inner surface is circular and whose diameter is smaller than the diameter of the wire to be formed. The wire to be formed (base material) with a circular cross section first passes through the back die. Then, reverse tension is applied. At this time, pultrusion is performed to make the outer diameter slightly smaller than the initial outer diameter.This pultrusion is not intended to reduce the diameter of the wire, but by passing the wire through the back die, the wire between the next die and The purpose is to provide reverse tension to. Therefore, the diameter reduction ratio may be close to 1.00 (for example, 0.93). The outer diameter of the wire rod, which is formed with a circular cross section by the back die, is of course set to a size that exactly fits the next forming die.

(2) The process of pultrusion forming the wire material pultruded with a back die using a forming die with a circular mouth part and a predetermined irregularly shaped bearing part. The wire rod is pultruded through a forming die whose inner surface of the mouth portion is circular and the bearing portion has a predetermined shape to obtain a deformed wire rod with a desired cross section.

The cross section to be molded can have various shapes depending on the application, and may be tapered, oval, hexagonal, square, circular with a notch, or even more complex shapes. A circular cross section with a notch is useful as a grooved copper wire for trolley wires and the like.

The constituent materials of the die include tungsten carbide,
Diamond, special steel, etc. can be used, but in order to extend the life of the die, it is preferable to nitride at least the surface (excluding diamond).

Although the present invention can be applied to small cross-section wire rods of various metals, it is particularly useful for manufacturing small cross-section wire rods of copper.

[Effect]

In the present invention, a wire rod with a circular cross section is drawn through a back die, and then pultruded into a wire rod with a desired cross section using a forming die with a circular inner surface of the mouth portion and a predetermined irregular shape of the bearing portion. A reverse tension is applied to the wire passing through the forming die, which reduces the load applied to the inner surface of the forming die in the drawing direction, thereby extending the life of the die. At the same time, bending and twisting of the formed wire rod is also prevented.

〔Example〕

Examples of the method of the present invention will be described below with reference to the drawings. FIG. 1 shows an apparatus for producing metal wires having irregular cross-sections outside the daily yield, using the method of the present invention.

The apparatus shown in FIG. 1 comprises a base material reel 22, a leveler 23, a die support 24, a composite die 25, a winding drum 26, a winding drum drive motor 27, and a gear box 28. The wire rod before molding is shown as 1, and the wire rod after molding is shown as 1a.

The wire rod 1 wound on the reel 22 is wound on the winding drum 2.
6, it passes through a leveler 23 and is pultruded by a composite die 25.

The formed wire 1a is wound onto a winding drum 26.

A cross section of the composite die 25 is shown in FIG. In FIG. 2, ] shows the wire before forming, and 1a shows the wire after forming.

A back die 3 and a forming die 4 are fixed to a die fixing jig 2. The cross section of the opening of the back die 3 is a circle, and the cross section along the axis of the opening is an arc.

The molding die 4 has a circular inner surface on the mouth part (right side in the figure).
The inner surface of the bearing part (left side in the figure) has a predetermined irregular shape. FIG. 3 shows an example of the molding die 4, which includes a mouth portion 3I with a circular inner surface, a bearing portion 33 with a tapered opening,
It has a funnel-shaped approach part 32 connecting between them.

The drawing method of the present invention will be explained below. When the drive motor 27 is driven, the wire 1 is taken up by the winding drum 26 and supplied from the base material reel 22. The wire rod 1 before forming is first slightly stretched by a back die 3, and at this time, the back die 3 applies tension to the wire rod as a reaction to the drawing.

The wire rod 1, which has been stretched with its circular cross section, is further formed into a predetermined cross section with a forming die 4, and then transferred to a winding drum 2.
6.

By using the composite die of the example, the life of the forming die was approximately 1.5 times longer than when the back die was omitted.

〔Effect of the invention〕

According to the present invention, in a method of pultrusion forming a metal wire having a cross section of a desired shape from a metal wire having a circular cross section using a forming die, it is possible to extend the life of the die and prevent bending or twisting of the wire. can.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the device used in one embodiment of the present invention;
The figure is a cross-sectional view of the composite die used in the embodiment of the present invention.
The figure is a perspective view of a forming die. Explanation of symbols - Wire rod 1 before forming a - Wire rod 2 after forming - Die fixing jig 3 - Back die 4 - m - Molding die 22-----Base material reel 23--Leveler 24--Dice support stand 25--Jointing die 26----- Winding drum 27----- --One-winding drum drive motor 28--
-Gearbox 1 Mouth section Approach section Bearing section

Claims (1)

[Scope of Claims] A method for manufacturing a metal wire, in which a metal wire having a circular cross section is pultruded to obtain a metal wire having an irregular cross section other than a circle, comprising: applying a forming pultrusion tension to the metal wire formed into the irregular cross section; A method for manufacturing a metal wire, comprising: applying a reverse tension that acts in the opposite direction to the above, and pultrusion forming the metal wire to which the reverse tension is applied from a circular cross section to an irregularly shaped cross section.