JP3048557B2 - Butt welding method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butt welding suitable for butt welding of a work which is likely to cause misalignment or buckling when butt like thin wires (especially stranded wires) or thin plates such as electric wires. A method and apparatus.

[0002]

2. Description of the Related Art Conventionally, in order to introduce a stranded wire into a processing machine such as a terminal attaching machine, as a method of connecting an end of a processed stranded wire and a starting end of a pre-processed stranded wire, an end of both stranded wires is used. A method in which the coating is peeled off and twisted and connected by hand or a method by soldering is used.

However, all of these methods are inefficient, and there is a problem that the operability of the original machining operation is significantly reduced particularly when the connection frequency is high.

On the other hand, as an alternative connection method, a butt welding method, that is, in a state where the end faces of both stranded wires to be connected to each other, a welding current is passed through the butt portion, and the butt portion is heated by welding heat. It is conceivable to adopt a method of melting and fusing.

According to the butt welding method, the two stranded wires can be instantaneously connected, and the efficiency of the connection work is improved.

[0006]

When the butt welding method is used, it is essential to press the butt portion in the butt direction. In the case of a particularly thin stranded wire, misalignment (misalignment) is caused by the butt pressure. ) And buckling are likely to occur, and the wire melted by the welding heat tends to spread to the outer peripheral side to easily generate large burrs, which has been a major cause of difficulty in performing the butt welding method on the electric wire.

On the other hand, as a countermeasure against this point, Japanese Patent Laid-Open No.
As described in JP-A-81-446, JP-A-8-118033, etc., the butt-welded portions of the two workpieces are butt-welded while being restrained from the surroundings by holding members such as split jigs. Techniques for suppressing the occurrence of misalignment and burrs have been proposed.

[0008] However, this method has another drawback in that it requires a separate and complicated component such as a holding member, which increases the cost.

Accordingly, the present invention provides a butt welding method and a butt welding method capable of preventing misalignment, buckling and generation of large burrs of a workpiece without adding extra parts.

[0010]

According to a first aspect of the present invention (butt welding method), the end faces of both workpieces to be welded are butt-joined, and a butt portion including the butt end faces of the two workpieces is formed. It is located between a pair of electrodes arranged at right angles to the length direction of the workpiece, and a high-frequency discharge is performed between the two electrodes to form a high-frequency electric field around the butted portion, and the butted portion is In the state of being sandwiched between the two electrodes, welding is performed while pressing in the butting direction.

According to a second aspect of the present invention, in the method of the first aspect, the two workpieces are butted in the left-right direction, and are welded in a state where the two electrodes are positioned vertically.

According to a third aspect of the present invention, in the method of the first aspect, the two workpieces are butted in a vertical direction, and the two electrodes are welded in a state where they are located on the left and right.

The invention of claim 4 (butt welding apparatus)
What is claimed is: 1. A butt-welding apparatus for butt-joining end faces of two workpieces to be welded and applying a welding current to the butt portion to perform welding. A pair of electrodes for supplying a welding current to a butt portion while being sandwiched from a direction perpendicular to the length direction, butt holding means for holding both workpieces in a butt state, and butt holding means It comprises a butt pressing means for pressing at least one of the two workpieces in the butt direction, and a high-frequency generating means for causing a high-frequency discharge between the two electrodes before applying the welding current.

According to a fifth aspect of the present invention, there is provided a butt welding apparatus for butt-joining end faces of both workpieces to be welded and applying a welding current to the butt portion to perform welding. A pair of electrodes for passing a welding current to the butt portion while sandwiching the butt portion including the end face from the direction perpendicular to the length direction of the workpiece, and butt holding means for holding both workpieces in a butt state And a butt pressing means for pressing at least one of the two workpieces in the butt direction via the butt holding means, wherein the butt holding means separately grips and fixes the two workpieces separately. A first clamp and a second clamp are provided, and one of the clamps is provided as a movable clamp so as to be movable toward and away from the other clamp, and the butting and pressing means applies the movable clamp to the other clamp. A pressure spring that presses in a direction approaching the pump, a stopper that prevents movement of the movable clamp against the spring force of the pressure spring, and a position and a movement that allow the stopper to prevent movement of the movable clamp. And a stopper driving means for moving between the positions.

According to a sixth aspect of the present invention, in the configuration of the fourth or fifth aspect, a pair of electrodes are arranged vertically so as to sandwich the butted portion of both workpieces butted from left and right from above and below. It was done.

According to a seventh aspect of the present invention, in the configuration of the fourth or fifth aspect, a pair of electrodes are arranged on the left and right sides so as to sandwich the butted portion of the two workpieces butted vertically. It was done.

According to an eighth aspect of the present invention, in any one of the fourth to seventh aspects, at least one of the electrodes is provided as a movable electrode so as to be movable in a direction in which the movable electrode comes into contact with or separates from a workpiece abutting portion. The movable electrode is sandwiched between the preparation position where a working space for setting both workpieces in a butted state between the movable electrode and the other electrode is formed, and the workpiece abutting portion is formed between the movable electrode and the other electrode. An electrode moving means for moving the electrode to and from a welding position is provided.

According to a ninth aspect of the present invention, in any one of the fourth to eighth aspects, an elastic supporting means for elastically contacting at least one electrode with a workpiece abutting portion during welding is provided. .

According to the butt welding method and apparatus described above, the butt welding portions of the two workpieces are butt-welded while being sandwiched between a pair of electrodes. Cracking and generation of large burrs can be suppressed.

That is, since both electrodes also serve as holding members for preventing misalignment, there is no need to add another holding member.

In this case, it has been experimentally confirmed that a high-frequency electric field is formed at the abutting portion by performing a high-frequency discharge between the two electrodes before the welding current flows, thereby improving the fusion effect. Was.

According to the method of the third aspect and the apparatus of the seventh aspect, since the butted portion is held by both electrodes in a state where the workpiece is abutted up and down, the spread of the melted workpiece to the outer peripheral side is increased. Thus, the occurrence of burrs can be further suppressed.

Further, according to the above method and apparatus, as compared with the case where both electrodes are arranged side by side in the longitudinal direction of the workpiece with the butt surface interposed therebetween, as is known in the known butt welding method. In the case of electric wires, the length of stripping the covering for energization can be reduced. For this reason, the waste of the wire is reduced, and the slip due to the bare wire portion can be suppressed when the length of the wire is measured.

Further, according to the configuration of claim 8, wherein at least one of the electrodes is movable as a movable electrode between a preparation position and a welding position, the workpiece is disposed while being perpendicular to the workpiece. Can be easily set at the welding position.

According to a ninth aspect of the present invention, there is provided an elastic supporting means for elastically contacting at least one of the electrodes with the workpiece abutting portion. Therefore, there is no possibility that the contact state becomes unstable due to, for example, the progress of welding and welding failure occurs.

Further, the contact pressure can be easily set to an appropriate value by selecting the spring force of the elastic support means.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings.

In this embodiment, a covered stranded wire (hereinafter simply referred to as an electric wire) is taken as an example of an object to be welded.

FIG. 1 shows an overall schematic configuration of a welding apparatus according to this embodiment.

This device includes a lower electrode 1 and an upper electrode 2 disposed above the lower electrode 1.
Above, the end faces of the core wires A1 and B1 of the electric wires A and B are butted together, and the wire butting portion including the butted end faces is sandwiched between the two electrodes 1 and 2 and pressed in the butting direction. A welding current is passed between the two electrodes 1 and 2 while the electric wire butt is fused by welding heat (resistance heat) at this time.

The electrodes 1 and 2 are made of a material that can withstand high temperatures, such as carbon, tungsten, tungaloy, and cemented carbide.

The upper electrode 2 is supported by a first lifting / lowering cylinder (air cylinder or hydraulic cylinder) 4 via a support spring (coil spring) 3 as elastic support means.
As shown in the solid line of FIG. 1 and FIG. 2B, the lower cylinder 1 is opposed to the lower electrode 1 by an interval α at which the high-frequency discharge can be performed, and the two-dot chain line in FIG.
As shown in (c), it moves up and down with respect to the welding position in contact with the wire butt portion.

The first lifting cylinder 4 is further provided with a second lifting cylinder (air cylinder or hydraulic cylinder) 5.
The first lifting cylinder 4, the supporting spring 3, and the upper electrode 2 are moved up and down at once by the second lifting cylinder 5, and the upper electrode 2 is moved to the intermediate position as shown in FIG. The lower electrode 1 is moved to a preparation position where a working space (interval β) required for setting the electric wire in a state of butt with the lower electrode 1 is formed.

Reference numeral 6 denotes a stopper for regulating the extension stroke of the second lifting cylinder 5 to stop the upper electrode 2 at the intermediate position.

On the other hand, a pair of right and left clamps 7 and 8 for separately grasping and fixing the electric wires A and B are provided.

Each of the clamps 7 and 8 comprises a lower clamp body 9 whose position is fixed, and an upper clamp body 11 urged downward by a pressing spring 10.

When the electric wires A and B are set at the welding position, the upper clamp body 11 is pushed up by, for example, a manual operation as shown by a two-dot chain line in FIG. The upper clamp body 11 is pushed downward by the spring force of 10 to close the clamps 7 and 8 (grasp and fix the wires A and B).

The clamps 7 and 8 are both movable clamps and upper and lower clamp bodies 9 and 11 are integrally provided so as to be movable in the length direction of the electric wire. That is, pressure is applied in the direction in which the electric wires are butted.

Reference numerals 13 and 13 denote spring receivers which receive a spring reaction force of the pressure spring 12.

Further, L-shaped arms 14, 14 are provided downward on the lower clamp bodies 9, 9, and rollers 15, 15 are provided at the lower ends of the arms 14, 14, respectively.
A conical wedge 16 is provided as a stopper that enters between the rollers 15, 15.
5,15, both clamps 7,8 via arms 14,14
Is prevented from moving.

The wedge 16 is a wedge drive cylinder (air cylinder or hydraulic cylinder) as stopper moving means.
By means of 17, the stopper 15 is configured to move between a stopper position where it enters between the rollers 15 and 15 and a release position where it is disengaged downward from between the rollers 15 and 15 and allows the clamps 7 and 8 to move. ing.

Reference numeral 18 denotes a wedge stopper for stopping the wedge 16 at the stopper position.

The upper electrode 2 is elastically brought into contact with the electric wire butt at a welding pressure indicated by a two-dot chain line in FIG. However, as the welding progresses, the contact is lowered slightly within the range of the spring force to secure the contact state. 19
Is a stopper for regulating the lower limit position of the upper electrode 2 at the welding position.

FIG. 3 shows a circuit for disconnecting the electrodes 1 and 2.

The control circuit 20 includes a timer circuit and a relay circuit (not shown). When the relay contact 21 is closed, the electrodes 1 and 2 are connected to a high-frequency power source (high-frequency generation means) 22 to perform high-frequency discharge. When the relay contact 22 is closed, the electrodes 1 and 2 are connected to the welding power source 24 and a welding current flows.

The control circuit 20 includes the first and second
A predetermined sequence control is performed by operating each solenoid valve (not shown) provided between the lift cylinders 4 and 5 and the wedge drive cylinder 17 and the pressure source.

The operation of this device will be described with reference to the time chart of FIG.

As preparation work before welding, both clamps 7 and
8 is opened as shown by a two-dot chain line in FIG. 1, and the upper electrode 2 is raised to the preparation position in FIG.
The ends of the core wires A1 and B1 are butted on the lower electrode 1 by peeling off the coating of the end of B to be welded.

In this state, the operation is started by closing the clamps 7, 8 to grip and fix the electric wires A, B, and then pressing the operation switch.

First, the first lifting cylinder 5 is extended to lower the upper electrode 2 to the intermediate position shown by the solid line in FIG. 1 and FIG. 2 (b), and high-frequency discharge is performed at this position for a predetermined time. As a result, a high-frequency electric field is formed around the wire butt portion.

Almost simultaneously with the start of the discharge, the wedge drive cylinder 17 is contracted and the wedge 16 is pulled out from between the rollers 15, 15. B is pressed in the butting direction.

After the start of the butt press operation, the second lifting cylinder 4 is driven to lower the upper electrode 2 to the welding position, and the electric wire butt portion is sandwiched between the lower electrode 1 and the lower electrode 1 (FIG. 4). The upper electrode is pressurized), and welding energization is started.

As a result, a welding current flows between the two electrodes 1 and 2 through the butted portions of the electric wires, and the butted portions of the two electric wires A and B are fused by welding heat generated at this time.

In this case, this wire butt portion is sandwiched between the two electrodes 1 and 2 to prevent misalignment and buckling and also prevent the melted wire from flowing out and spreading to the outer peripheral side. You. For this reason, the butt portion is welded in a good condition in which the butt portion is straight and strong and almost no burrs appear.

Also, during this welding, the upper electrode 2 elastically contacts the wire butt portion by the spring force of the support spring 3, whereby both electrodes 1 and 2 surely come into contact with the butt portion with an appropriate pressure. Therefore, for example, there is no possibility that the contact state becomes unstable due to the progress of welding and welding failure occurs.

Further, it has been experimentally confirmed that a good fusion result can be obtained by forming a high-frequency electric field immediately before the welding.

After the welding power is supplied, the wedge cylinder 17 is extended by the extension operation of the wedge cylinder 17 so that the wedge 16 enters the gap between the rollers 15 and 15 to stop the butting and pressurizing operation. (At the same time, the upper electrode 2 is raised from the welding position to the intermediate position, and further to the preparation position.

In this state, the welded electric wires A and B are taken out, the operation is completed, and the next electric wire set is performed.

Other Embodiments (1) In the first embodiment, the first and second lifting cylinders 4 and 5 are used as means for moving the upper electrode 2 up and down, but a motor and a gear mechanism are used instead. Combinations and the like can be used.

(2) A concave portion for receiving the melted wire may be provided on the upper surface of the lower electrode 1.

(3) In the above embodiment, both clamps 7,
Although the movable clamp 8 is configured to be moved in the electric wire butting direction, only one of the clamps 7 and 8 may be configured as a movable clamp.

(4) As the butt pressing means, in the above embodiment, the pressing spring 12, the arm 14, the roller 15, the wedge 1
6. Although the wedge drive cylinder 17 is provided, the movable clamp may be directly pushed and pulled by a cylinder (air cylinder or hydraulic cylinder) instead.

(5) In the above embodiment, the support spring (coil spring) 3 is used as the elastic support means for elastically supporting the upper electrode 2, but rubber may be used instead of the support spring 3.

Instead of using the elastic supporting means, an equivalent action may be obtained by adjusting the pressing force of the first lifting / lowering cylinder 4, for example.

(6) In the above embodiment, high-frequency discharge is performed between the electrodes 1 and 2 immediately before welding, but this high-frequency discharge may be performed as needed.

(7) In the above embodiment, the two electrodes 1 and 2 are arranged vertically, but the horizontal direction (front and rear) perpendicular to the electric wires A and B is used.
May be arranged.

Further, as shown in FIG. 5, the electric wires A and B may be butted up and down, and this butted portion may be sandwiched between the left and right electrodes 1 and 2. In this case, the other configuration and the welding operation / procedure may be the same as those of the first embodiment.

In this case, the same operation and effect as in the first embodiment can be obtained. In addition, since the wires A and B are butted up and down, the wire melted at the time of welding is less likely to spread to the outer peripheral side, and the occurrence of burrs is reduced accordingly.

(8) In the above embodiment, the covered stranded wire is to be welded. However, the present invention can be applied not only to a covered single wire, a bare wire, but also to a flat (band-shaped) electric wire without being limited to a round wire. Further, the present invention can be widely applied not only to electric wires but also to various workpieces in which misalignment and buckling are likely to occur, such as various wires and thin plates.

[0070]

As described above, according to the present invention, butt welding is performed with the butt portion of both workpieces sandwiched between a pair of electrodes. Buckling and generation of large burrs can be suppressed.

That is, it is possible to obtain a good welding result with no eccentricity or buckling and without burrs without separately providing a holding member.

In this case, it has been experimentally confirmed that a high-frequency electric field is formed at the abutting portion by performing a high-frequency discharge between the two electrodes before the welding current is supplied, thereby enhancing the fusion effect. Was.

According to the method of the third aspect and the apparatus of the seventh aspect, since the abutting portion is held by both electrodes while the workpiece is abutted up and down, the spread of the melted workpiece toward the outer peripheral side is increased. Thus, the occurrence of burrs can be further suppressed.

Further, according to the above method and apparatus, as compared with the case where both electrodes are arranged side by side in the longitudinal direction of the workpiece with the butt surface interposed therebetween, as is known in the known butt welding method. In the case of electric wires, the length of stripping the covering for energization can be reduced. For this reason, the waste of the wire is reduced, and the slip due to the bare wire portion can be suppressed when the length of the wire is measured.

Further, according to the constitution of claim 8, wherein at least one of the electrodes is movable as a movable electrode between the preparation position and the welding position, the work piece is arranged at right angles to the work piece. Can be easily set at the welding position.

According to the ninth aspect of the present invention, there is provided the elastic support means for elastically contacting at least one of the electrodes with the workpiece abutting portion. Therefore, there is no possibility that the contact state becomes unstable due to, for example, the progress of welding and welding failure occurs.

Further, the contact pressure can be easily set to an appropriate value by selecting the spring force of the elastic support means.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram of a welding device according to an embodiment of the present invention.

FIGS. 2A, 2B, and 2C are views showing a state in which an upper electrode, which is a movable electrode, is set to a preparation position, an intermediate position, and a welding position in the apparatus.

FIG. 3 is a configuration diagram of an electric circuit that performs electrode power cutoff control in the device.

FIG. 4 is a time chart showing a movement of an upper electrode, a state of energization to the electrode, and the like during operation of the apparatus.

FIG. 5 is a partial schematic configuration diagram of a welding device according to another embodiment of the present invention.

[Explanation of symbols]

 A, B Wires as workpieces 1 Lower electrode 2 Upper electrode (movable electrode) 3 Support spring as elastic support means 4 First lifting cylinder 5 as electrode moving means 5 Second lifting cylinder 7, 8 Clamp as wire rod holding means DESCRIPTION OF SYMBOLS 12 Pressing spring which comprises butt pressing means 14 Same arm 15 Same roller 16 Same wedge (stopper) 17 Wedge drive cylinder (stopper driving means) 20 High frequency power supply for performing high frequency discharge 21 Welding power supply 19 High frequency discharge Control circuit for controlling welding current

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-B 54-15860 (JP, B1) JP-B 49-12472 (JP, B1) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B23K 11/00-11/36

Claims (9)

(57) [Claims] An end face of both workpieces to be welded is butt-joined, and a butt portion including a butt end face of the two workpieces is sandwiched between a pair of electrodes arranged at right angles to a length direction of the workpiece. And apply high-frequency discharge between these two electrodes.
A high-frequency electric field is formed around the joint
A butt welding method, wherein the butt portion is sandwiched between the two electrodes while welding is performed while pressing in the butt direction. 2. The butt welding method according to claim 1, wherein the two workpieces are butted in the left-right direction, and the two electrodes are welded in a state where the two electrodes are positioned vertically. 3. The butt welding method according to claim 1, wherein the two workpieces are butted in a vertical direction, and welding is performed in a state where both electrodes are located on the left and right. 4. The end faces of both workpieces to be welded are butted together.
And a welding current is applied to this
A butt welding apparatus, wherein the butt end faces of the two workpieces are
Hold the butted part in the direction perpendicular to the length of the workpiece.
A pair of electrodes that allow welding current to flow
Butt holding to hold the pole and both workpieces in butt condition
Means and a small amount of both workpieces through the butt holding means.
Butt pressing means for pressing at least one in the butting direction
High-frequency discharge between both electrodes before applying the welding current
A butt welding device comprising: a high-frequency generating means . 5. A butt-welding apparatus for butt-joining end faces of two workpieces to be welded and applying a welding current to the butt portion for welding, the butt-welding apparatus including the butt end faces of the two workpieces. A pair of electrodes for applying a welding current to the butt portion while the portion is sandwiched from a direction perpendicular to the length direction of the workpiece, butt holding means for holding both workpieces in a butt state, and this butt Butting pressurizing means for pressing at least one of the two workpieces in the butting direction via the holding means, wherein the two workpieces are used as the butting and holding means.
First and second clamps which are separately gripped and fixed are provided.
One of these clamps is used as a movable clamp
It is movable in a direction approaching and moving away from to clamp,
The butting and pressurizing means clamps the movable clamp to the other clamp.
A pressure spring that presses in the direction approaching the lamp and this pressure
A switch that prevents the movable clamp from moving against the spring force of the spring
Use the topper and this stopper to prevent the movable clamp from moving.
Move between the stop position and the position that allows movement.
A butt welding device comprising a topper driving means . 6. A structure according to claim 4 , wherein a pair of electrodes are arranged vertically and sandwich a butted portion of both workpieces which are butted left and right from above and below.
The butt welding device as described. 7. A pair of electrodes are disposed on the left and right, claim 4 or 5, characterized in that it is configured to interleave the butt portions of both workpieces are butted vertically from the left and right
The butt welding device as described. 8. The butt welding apparatus according to claim 4 , wherein at least one electrode is provided as a movable electrode so as to be movable in a direction of coming and going with respect to a workpiece butt portion, and The movable electrode is sandwiched between the preparation position where a working space for setting both workpieces in a butted state between the movable electrode and the other electrode is formed, and the workpiece abutting portion is formed between the movable electrode and the other electrode. A butt welding apparatus comprising an electrode moving means for moving the electrode to and from a welding position. 9. The butt welding apparatus according to claim 4, further comprising an elastic supporting means for elastically bringing at least one electrode into contact with the workpiece butt portion during welding. Butt welding equipment.