JPS6327116B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for cutting metal wire, and particularly to a method suitable for cutting relatively thick stranded wire.

[Prior art]

Since a stranded wire is made by twisting together a large number of metal wires, there is a problem in that if the wire is cut in the middle, the wires at the cut ends will fall apart. For this reason, when cutting relatively thick copper stranded wires used for power cables, etc., for example, both sides of the part to be cut are bound with thin metal wires, and the gap between them is mechanically cut with a metal saw or the like. However, this method has the disadvantage that cutting is laborious and time-consuming, and even with multilayer stranded wires, binding cannot necessarily prevent the loosening of the wire at the cut end.
There is a problem in that a considerable length near the cut end must be treated as defective.

On the other hand, as a means for cutting a metal wire, there is a method of melting and cutting the metal wire by heating it with electricity. This method is
After clamping both sides of the metal wire with electrodes where the metal wire is to be cut, and heating the metal wire between the electrodes with electricity,
By separating both electrodes, the metal wire portion is torn off. However, this method has the disadvantage that the cut end is stretched into a long thin strip, which makes the post-processing of that part troublesome, and that the device becomes large because it is necessary to keep the electrodes apart from each other long.

[Purpose of the invention]

An object of the present invention is to provide a method that can easily cut a metal wire by melt cutting without stretching the cut end into a long thin wire, and in particular, in the case of stranded wire, can cut the wire without loosening the wire at the cut end. That is.

[Structure of the invention]

The method for cutting a metal wire of the present invention which achieves the above object is to clamp electrodes on both sides of the part of the metal wire to be cut, heat the part of the metal wire between the electrodes to melt it, and bring the two electrodes close to each other. The method is characterized in that the electrodes are separated from each other.

〔Example〕

1 to 3 show a method for cutting stranded wire according to an embodiment of the present invention. First, both sides of the stranded wire 1 to be cut are clamped by the fixed electrode 3 and the movable electrode 5. The fixed electrode 3 and the movable electrode 5 are upper electrodes 3A, 5A and lower electrodes 3B, 5B, respectively.
The stranded wire 1 is sandwiched between them. The fixed electrode 3 and the movable electrode 5 are connected to a power source 11 via a transformer 7 and a switch 9.

A force in the direction of arrow A is applied to the movable electrode 5 that clamps the stranded wire 1, thereby causing the stranded wire portion 1a between the electrodes to
With compressive force applied in the axial direction, the switch 9 is closed, and the twisted wire portion 1a between the electrodes is heated by electricity. At this time, the electrode spacing L is determined by the compressive force in the twisted wire portion 1a.
It is preferable to make the diameter D smaller than the diameter D of the stranded wire 1 so as not to bend the wire. When the stranded wire portion 1a softens and melts due to electrical heating, the movable electrode 5 approaches the fixed electrode 3 due to the force applied to it, so the stranded wire portion 1a between the electrodes becomes like a lump of molten metal as shown in FIG. , and its form as a stranded wire or strand is completely destroyed. In addition, the movable electrode 5
The distance at which the electrode approaches the fixed electrode 3 is regulated in advance by providing a stopper or the like. Movable electrode 5
After the wire approaches the fixed electrode 3, heating is continued, and when the twisted wire portion 1a between the electrodes has melted to an appropriate degree,
Move the movable electrode 5 in the direction of arrow B, and move the fixed electrode 3
to move away from Then, the stranded wire portion 1a, which has melted into a lump, is broken as shown in FIG.

Note that if this part is energized when the stranded wire part 1a is broken, sparks will be emitted from the broken part and it is dangerous. Therefore, the position of the movable electrode 5 or the movable block 17 that approaches and leaves is controlled by a limit switch (not shown). Upon detection, the switch 9 is opened at the latest immediately before the stranded wire portion 1a breaks, and the energization of the stranded wire portion 1a is stopped. For example, in the case of a thin wire in which the twisted wire portion 1a is sufficiently melted before the movable electrode 5 approaches the fixed electrode 3, the electrode, etc. The stranded wire portion 1a may be de-energized by detecting the position of the stranded wire portion 1a.In this case as well, if the movable electrode 5 is separated from the fixed electrode 3 while the stranded wire portion maintains the molten state, There will be no hindrance to its cutting.

After bringing the electrodes 3 and 5 close to each other while heating and melting the twisted wire portion 1a between the electrodes in this way,
When separated, the stranded wire portion 1a is once compressed in a softened and molten state, and where its strength has decreased, it is then pulled in the opposite direction, so that it breaks without being stretched much. Furthermore, since the molten end portion of the broken end portion is solidified and integrated, the wire will not fall apart or become loose even when removed from the electrode.

To give a specific example, a soft copper stranded wire with an outer diameter of 19 mm and a cross-sectional area of 250 mm ² , which is made by twisting 61 strands of wire with an outer diameter of 2.3 mm, is clamped with an electrode spacing L = 15 mm, and a voltage of 8.0 V is applied between the electrodes. When the electrodes were heated by electricity and the electrodes were brought closer to 5 mm apart, the electrodes were separated to 25 mm, and the electrodes could be easily cut. The time required from the start of energization to disconnection was 20 to 30 seconds.

4 to 6 show an example of an apparatus suitable for carrying out the method of the present invention, and parts corresponding to those in FIGS. 1 to 3 are given the same reference numerals. Note that electrical wiring is omitted.

The lower electrode 3B of the fixed electrode 3 is connected to the fixed block 13.
The fixing block 13 is fixed to the frame 15. Further, the lower electrode 5B of the movable electrode 5 is fixed to a movable block 17, and this movable block 17 is connected to two guide rods 19.
It is slidably supported by A and 19B. Both ends of the guide rods 19A and 19B are connected to the fixed block 1.
3 and a support member 21 erected on the frame 15
A and 21B. Further, a piston rod 25 of a slide cylinder 23 fixed to the frame 15 is connected to the movable block 17. This slide cylinder 23 moves the movable block 17 toward and away from the fixed block 13.

The upper electrode 5A of the movable electrode 5 is pivotally supported by a shaft 27 on the movable block 17 at its intermediate portion in the front-rear direction, and is rotatable about the shaft 27. Further, a spring 29 is interposed in a compressed state between the upper electrode 5A behind the shaft 27 and the movable block 17, and its repulsive force causes the upper electrode 5A and the lower electrode 5B to clamp the stranded wire 1. It's summery. Furthermore, a clamp cylinder 31 is fixed to the lower side of the movable block 17 behind the spring 29, and the piston rod 33 of this clamp cylinder 31 is connected to the rear end of the upper electrode 5A via a connecting piece 35. . This clamp cylinder 3
1, the upper electrode 5 resists the repulsive force of the spring 29.
When the rear end of A is pulled down, the upper electrode 5A and the lower electrode 5B are opened, and the stranded wire 1 can be set or removed.

The fixed electrode 3 side also has the same structure, and 37 is a clamp cylinder attached to the rear lower side of the fixed block 13.

Note that the fixed block 13 is used to insulate between the electrodes.
Either or both of the movable block 17 and the movable block 17 are made of an insulating material.

The operation of this device is as follows.

First, the clamp cylinders 31 and 37 are driven to connect the upper electrodes 3A and 5A of both electrodes 3 and 5 to the lower electrode 3.
Open B and 5B and set twisted wire 1 there. After that, when the clamp cylinders 31 and 37 are opened,
Both electrodes 3 and 5 clamp the stranded wire 1 due to the repulsive force of the spring 29 (the fixed electrode side is not shown). Next, energization to the twisted wire portion 1a between the electrodes 3 and 5 is started.
At the same time or around the same time, the slide cylinder 23 is driven forward to apply compressive force to the twisted wire portion 1a. When the twisted wire portion 1a becomes softened and melted by heating with electricity, the movable electrode 5 is moved by the force of the slide cylinder 23.
rapidly moves toward the fixed electrode. After moving a predetermined distance, the movable electrode 5 is stopped by a stopper (not shown). Thereafter, when the twisted wire portion 1a is sufficiently melted, the slide cylinder 23 is driven backward, and the movable electrode 5 is rapidly separated from the fixed electrode 3. This cuts the stranded wire portion 1a, so
After cutting, the clamp cylinders 31 and 37 are driven again to open the upper electrodes 3A and 5A and the lower electrodes 3B and 5B, and the stranded wire 1 is taken out.

Although the above embodiment describes the cutting of stranded wires, the present invention is similarly applicable to cutting a single metal wire.

〔Effect of the invention〕

As explained above, according to the present invention, the metal wire is heated with electricity, compressed after being softened and melted, and then stretched, so that the metal wire can be easily cut without being stretched into a long thin piece. In particular, the present invention is convenient for cutting stranded wires, and since the strands do not come apart or loosen after cutting, it has the advantage of reducing the number of defective parts, and it also has the advantage of significantly shortening the time required for cutting. There is.

[Brief explanation of drawings]

1 to 3 are explanatory diagrams showing one embodiment of the cutting method of the present invention, FIG. 4 is a plan view showing an example of an apparatus for carrying out the method of the present invention, and FIG. 5 is a front view of the same apparatus. , FIG. 6 is a sectional view taken along line CC in FIG. 1...Twisted wire (metal wire), 3...Fixed electrode, 5...
...Movable electrode.

Claims (1)

[Claims] 1. Clamp the metal wire on both sides of the part to be cut with electrodes, heat the metal wire between the electrodes to melt it, bring the two electrodes close together, and then close the two electrodes together. A method for cutting a metal wire, characterized by separating the wire. 2. The cutting method according to claim 1, characterized in that the electrical heating until the metal wire portion melts is performed while applying a compressive force in the axial direction to the metal wire portion. 3. The cutting method according to claim 1, wherein the metal wire is a stranded wire. 4. The cutting method according to claim 1, wherein the distance between the electrodes when the metal wire is clamped with electrodes is smaller than the diameter of the metal wire.