Electric arc welding device and method for butt joint of metal wires

Abstract

The invention discloses an electric arc welding device and method for butt joint of metal wires, and the device comprises a metal wire clamp which is a copper plate engraved with a groove; the movable guide rail controls the clamp to move axially; the arc striking device and the arc extinguishing device are paired tungsten electrodes with tips and are respectively placed at the welding starting part and the welding ending part; the welding power supply is a TIG direct-current welding power supply; the magnetic field generator comprises two electrified coils which are arranged up and down; the brightness sensor is placed at the arc suppression position and judges the arc position according to the brightness change; the gas protection device is used for providing pure argon or pure helium protection; the method comprises the steps that the metal wire butt joint is cleaned and fixed to the clamp; arcing: the electric arc jumps among the welding wires under the action of a magnetic field; after the electric arc reaches the welding tail end, arc quenching is conducted, arc starting is conducted again at the arc starting end, and the welding wire is heated repeatedly; and the metal wire clamp quickly moves, so that the end parts of the molten metal wires are contacted to finish welding. The method can be used for welding multiple pairs of wires at a time, and is suitable for various materials such as iron, titanium, nickel, aluminum, copper and alloys thereof.

Description

Technical Field

[0001] The invention belongs to the technical field of welding, and in particular relates to an arc welding device and method for butting metal wires. Background Art

[0002] Metal wires are widely used in the fields of medicine, electronics, aerospace, automobiles, energy, etc., such as medical guidewires, sensor connections, cable harnesses, and micro springs. These fields have strict requirements on the accuracy, strength, and performance of metal wires. In practical applications, when a metal wire breaks, it is often necessary to repair it by welding. In addition, in order to meet complex working conditions and multi-functional requirements, it is often necessary to butt-weld metal wires of different materials, for example, combining high-strength stainless steel wire with highly conductive copper wire, or welding corrosion-resistant titanium alloy wire with medical-grade stainless steel wire, in order to take into account multiple properties.

[0003] The current welding methods for metal wires mainly include brazing, resistance welding, electron beam welding and laser welding, among which laser welding has gradually become the mainstream method in metal wire docking because of its small heat source, precise heating and firm joints. For example, patent document CN105562867A uses laser as the welding heat source, uses a clamp to continuously rotate the wire, and uses a laser spot to heat it at multiple points, and realizes the connection of nickel-titanium alloy and stainless steel metal wire by melting the solder at the end of the wire. Nevertheless, due to the inconsistency between the incident direction of the laser and the axial direction of the welding wire, the welded joint is prone to uneven heating and deformation. Although this tendency can be weakened by rotating the wire, welding deformation of the joint is often inevitable. In addition, this method also has the problems of low welding efficiency and complex process. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the main purpose of the present invention is to provide an arc welding device for butt welding of metal wires, by which arc welding of metal wires can be performed to improve the joint quality and production efficiency during butt welding of various types of metal wires.

[0005] Another object of the present invention is to provide an arc welding method for butting metal wires, so as to solve the problems of low welding efficiency and complex process in the prior art.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] An arc welding device for butting metal wires, comprising:

[0008] The wire clamp is a copper plate with grooves engraved on it, used to fix the guide wire;

[0009] The movable guide rail is a ball guide rail, a roller guide rail or a linear bearing, and is driven by a stepper motor or a servo motor to control the axial movement of the wire clamp;

[0010] The arc striking device is a pair of pointed tungsten electrodes placed at the arc starting point of the head end of the wire clamp;

[0011] The arc closure device is a pair of pointed tungsten electrodes, which are placed at the arc closure end of the wire clamp;

[0012] Welding power source, which is a DC welding power source, provides power for arc starting of welding wire;

[0013] The magnetic field generator is two enclosed charged coils placed one above the other to generate a uniform magnetic field to drive the arc movement;

[0014] A brightness sensor, located near the arc-receiving device, determines whether the arc reaches the welding position terminal according to the measured brightness, and controls the arc starting and arc extinguishing of the welding power source;

[0015] The gas protection device, including the gas cylinder and the gas blow pipe, prevents the metal wire from oxidizing during welding.

[0016] Preferably, the metal wire clamp is two pairs of copper plates, each pair of copper plates consists of two pieces, an upper and a lower piece, each copper plate is engraved with a semicircular groove with a groove radius of 0.5-4mm. The two copper plates are pieced together to clamp metal wires of corresponding sizes. The number of grooves on each copper plate is 3 or more to clamp 3 pairs or more of metal wires; the grooves are arranged in a straight line with a processing accuracy of ±0.05mm to ensure precise fixation of the metal wires; each pair of copper plates is fixed to the movable guide rail by bolts to ensure stability during welding; the surface of the copper plate is plated to improve wear resistance and conductivity; the thickness of the copper plate is 2-5mm to ensure mechanical strength during welding.

[0017] Preferably, the arc striking device is a pair of pointed tungsten electrodes, and the tungsten electrodes are welding electrodes selected from thoriated tungsten, cerium tungsten, lanthanum tungsten or zirconium tungsten alloys. The diameter of the tungsten electrode is 1.0-4.0 mm, the tip is conical, the tip angle is 10°-50°, the distance between the tips of the tungsten electrodes is 0.5-1.5 mm, and the surface of the tungsten electrode is polished to improve conductivity and service life.

[0018] Preferably, the arc extinguishing device is a pair of pointed tungsten electrodes, and the tungsten electrodes are welding electrodes selected from thoriated tungsten, cerium tungsten, lanthanum tungsten or zirconium tungsten alloys. The diameter of the tungsten electrode is 1.0-4.0 mm, the tip is conical, the tip angle is 10°-50°, the distance between the tips of the tungsten electrodes is 2.0-4.0 mm, and the surface of the tungsten electrode is polished to improve conductivity and service life.

[0019] Preferably, the welding power supply is a TIG DC welding power supply with a power of 100-3000W, and arcing and arcing are performed according to the light sensor signal. The arcing method is high-voltage arcing or high-frequency high-voltage arcing. The positive pole of the power supply is connected to the left wire clamp, and the negative pole of the power supply is connected to the right wire clamp.

[0020] Preferably, the coil of the magnetic field generator is square or annular, the coil material is copper, the number of turns is 100-500 turns, and the coil size is larger than the metal wire welding area.

[0021] Preferably, the brightness sensor is a photoresistor, a photoelectric sensor or a light intensity sensor with a sensitivity of 0.1-1000 Lux and a response time of 1-10 ms, and determines whether the arc reaches the arc end by the brightness change.

[0022] Preferably, the gas protection device provides pure argon or pure helium welding protection gas, the gas flow rate is 1-10L / min, and the gas flow rate is adjusted by the flow controller.

[0023] An arc welding method for butt-jointing metal wires, using the arc welding device for butt-jointing metal wires as described above to perform arc welding for butt-jointing metal wires, comprises the following steps:

[0024] S1. Clean the butt joint of the metal wire to be welded, place two or more pairs of metal wires in a row on the metal wire clamp, keep a distance between the metal wires, and turn on the gas protection device to provide gas protection for the welding area;

[0025] S2, starting an arc at the tips of the two tungsten electrodes of the arc striking device;

[0026] S3, the magnetic field generator generates a magnetic field, and the arc jumps between the metal wire joints driven by the magnetic field, moving from the arc starting end to the arc ending end;

[0027] S4, when the arc reaches the arc-extinguishing end, the brightness sensor detects the arc brightness change and controls the welding power supply to extinguish the arc;

[0028] S5, repeating steps S2-S4, the end of the metal wire is melted into a ball under repeated heating of the arc;

[0029] S6. When the molten ball at the end of the metal wire reaches a certain size, the arc is extinguished and the metal wire clamp is quickly moved to make the molten balls on both sides contact to complete the welding.

[0030] Preferably, in step S1, the centers of the metal wires to be welded are aligned, the spacing between the metal wires is 1.5-3.0 mm, and the gas flow rate is 1-10 L / min.

[0031] Preferably, in step S2, the arc starting method is non-contact arc starting, using high-voltage arc starting or high-frequency high-voltage arc starting.

[0032] Preferably, in step S3, the direction of the magnetic field generated by the magnetic field generator is vertically downward and perpendicular to the plane of the side-by-side metal wires, and the direction of the magnetic field is controlled by adjusting the current direction of the magnetic field generator.

[0033] Preferably, in step S5, arc extinguishing and arc striking are repeated 5-10 times until the end of the metal wire melts into a ball.

[0034] Preferably, the material of the metal wire is selected from one or more of iron, titanium, nickel, aluminum, copper and alloys thereof.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) Arcing occurs between the metal wires, and the tip of the metal wire serves as the arc heating end. The heating is concentrated and the axial symmetry is good, so the deformation of the welded joint is small.

[0037] (2) Multiple pairs of metal wires are placed in a row, and the arc repeatedly jumps and heats between the wires under the drive of the magnetic field, so batch welding of multiple pairs of metal wires can be achieved, with high welding efficiency and simple operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the structure of an arc welding device for butt welding of metal wires in an embodiment;

[0039] Figure 2 Schematic diagram of the position of the metal wire in the metal wire clamp in the embodiment (side view);

[0040] Figure 3 A schematic diagram of a magnetic field driving an arc to move between metal wires in an embodiment;

[0041] Figure 4 Schematic diagram of arc motion principle driven by magnetic field in the embodiment;

[0042] Figure 5 Schematic diagram of a metal wire butt joint in an embodiment;

[0043] The reference numerals are as follows: 1. coil; 2. arc-starting electrode; 3. arc-ending electrode; 4. brightness sensor; 5. conductive copper rod; 6. wire clamp (upper); 7. wire clamp (lower); 8. guide wire; 9. movable guide rail; 10. gas cylinder; Figure 1 The arc welding device for butt welding of metal wires intuitively displays the relative positions and system layout of each unit in the device. Driven by the magnetic field, the arc moves from the arc-starting electrode at position 1 to the arc-ending electrode at position 2. DETAILED DESCRIPTION

[0044] In order to more fully understand and demonstrate the technical solutions, purposes and advantages of the present invention, the technical effects produced by the present invention are further described in detail and completely in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all. It should be pointed out that for those of ordinary skill in the art, other embodiments obtained without departing from the concept of the present invention all belong to the protection scope of the present invention.

[0045] In the following embodiments, the arc is driven to move at the end of the metal wire by a controllable magnetic field to melt the end of the metal wire, and the magnetic field is perpendicular to the paper surface. The magnetic induction intensity of the magnetic field can be adjusted according to the magnetic field source, which is a coil, and the specific magnetic induction intensity needs to be determined according to the type and diameter of the metal wire.

[0046] Figures 1 to 5 An arc welding device for butting metal wires is described exemplarily, comprising:

[0047] The wire clamp is a copper plate with grooves engraved on it, used to fix the guide wire;

[0048] The movable guide rail is a ball guide rail, a roller guide rail or a linear bearing, and is driven by a stepper motor or a servo motor to control the axial movement of the wire clamp;

[0049] The arc striking device is a pair of pointed tungsten electrodes placed at the arc starting point of the wire clamp;

[0050] The arc catching device is a pair of pointed tungsten electrodes placed at the end of the wire clamp to catch the arc;

[0051] Welding power source, which is a DC welding power source, provides power for arc starting of welding wire;

[0052] The magnetic field generator is two enclosed charged coils placed one above the other to generate a uniform magnetic field to drive the arc movement;

[0053] The brightness sensor is located near the arc-receiving device, and determines whether the arc has reached the welding position terminal according to the measured brightness, and controls the arc starting and arc extinguishing of the welding power source;

[0054] The gas protection device, including the gas cylinder and the gas blow pipe, prevents the metal wire from oxidizing during welding.

[0055] In some embodiments, the wire clamp is two pairs of copper plates, each pair of copper plates consists of two pieces, an upper and a lower piece, each copper plate is engraved with a semicircular groove with a groove radius of 0.5-4mm. The two copper plates are pieced together to clamp the metal wire of corresponding size. The number of grooves on each copper plate is 3 or more to clamp 3 pairs or more of metal wires; the grooves are arranged in a straight line with a processing accuracy of ±0.05mm to ensure precise fixation of the metal wire; each pair of copper plates is fixed to the moving guide rail by bolts to ensure stability during the welding process; the surface of the copper plate is plated to improve wear resistance and conductivity; the thickness of the copper plate is 2-5mm to ensure mechanical strength during the welding process.

[0056] In some embodiments, the arc striking device is a pair of pointed tungsten electrodes, the tungsten electrodes are welding electrodes selected from thoriated tungsten, cerium tungsten, lanthanum tungsten or zirconium tungsten alloys, the diameter of the tungsten electrodes is 1.0-4.0 mm, the tip is conical, the tip angle is 10°-50°, the distance between the tips of the tungsten electrodes is 0.5-1.5 mm, and the surface of the tungsten electrodes is polished to improve conductivity and service life.

[0057] In some embodiments, the arc extinguishing device is a pair of pointed tungsten electrodes, the tungsten electrodes are welding electrodes selected from thoriated tungsten, cerium tungsten, lanthanum tungsten or zirconium tungsten alloys, the diameter of the tungsten electrodes is 1.0-4.0 mm, the tip is conical, the tip angle is 10°-50°, the distance between the tips of the tungsten electrodes is 2.0-4.0 mm, and the surface of the tungsten electrodes is polished to improve conductivity and service life.

[0058] In some embodiments, the welding power supply is a TIG DC welding power supply with a power of 100-3000W, and arcing and arcing are performed according to the light sensor signal. The arcing method is high-voltage arcing or high-frequency high-voltage arcing. The positive pole of the power supply is connected to the left wire clamp, and the negative pole of the power supply is connected to the right wire clamp.

[0059] In some embodiments, the coil of the magnetic field generator is square or annular, the coil material is copper, the number of turns is 100-500 turns, and the coil size is larger than the metal wire welding area.

[0060] In some embodiments, the brightness sensor is a photoresistor, a photoelectric sensor or a light intensity sensor with a sensitivity of 0.1-1000 Lux and a response time of 1-10 ms. Whether the arc reaches the arc end is determined by the brightness change.

[0061] In some embodiments, the gas protection device provides pure argon or pure helium welding protection gas, and the gas flow rate is 1-10 L / min, and the gas flow rate is adjusted by a flow controller.

[0062] Example 1

[0063] In this embodiment, the metal wire to be welded is stainless steel wire 316L and 304 with a diameter of 1.0 mm, and the arc welding method is as follows:

[0064] S1. Preparation and configuration of welding equipment. First, ensure that the surface of the stainless steel wire is clean and free of oxide layer. Perform centralized surface treatment on the butt ends of the stainless steel wires 316L and 304 to be welded. Use a mixed solution of perchloric acid and acetic acid to electrically polish the butt ends of the stainless steel wires to be welded. Then, ultrasonically clean the stainless steel wires in an ethanol bath and set them aside for use. Then, refer to Figure 1 As shown, place the wire to be welded in the groove on the copper plate and align it. The groove on the copper plate helps to accurately position the wire and provides good electrical conductivity during welding, ensuring that the wire transfers charged particles quickly and effectively. The butt spacing between 316L and 304 wires is 3.0mm.

[0065] S2. Arc striking process. Turn on the protective gas control switch to keep the wire welding area in pure argon protective atmosphere. Start the welding power supply. Figure 3 As shown, two tungsten electrodes are used for discharge arc initiation at position 1, and the specific parameters are as follows: welding current 5A, tungsten electrode material is cerium tungsten, tungsten electrode diameter is 2.0mm, and tip angle is 30°. In this method, the arc is stably formed between the two arc initiation electrodes through discharge at the tungsten electrode tip. At this time, the welding power supply provides a suitable current to stabilize the arc, and the tungsten electrode is connected to the copper plate through a copper rod to ensure that it is synchronously charged with the guide wire.

[0066] S3, the magnetic field drives the arc to move and heat the welding wire. This step is the core of this welding method, and the specific operation is as follows:

[0067] Configuration of magnetic field source: A magnetic field with adjustable strength is generated by a coil. The direction of the magnetic field is usually perpendicular to the direction of the paper, vertically downward, to control the arc to move from the arc striking end at position 1 to the arc closing end at position 2.

[0068] Effect of magnetic field on arc: refer to Figure 3 As shown in the figure, the arc moves in a fixed direction under the action of the magnetic field. In this method, the magnetic field drives the arc to jump between the wire joints to ensure uniform heating of the welding area and avoid the arc being concentrated at a specific position. When the arc reaches position 2, the brightness sensor detects the arc on the arc-receiving electrode, the welding power supply is cut off, and the arc moves in one direction once. Then, the arc continues to ignite from position 1, and then moves to position 2 driven by the magnetic field, and this cycle is repeated 8 times.

[0069] S4. Formation and docking of the wire ball head. With the action of the magnetic field, the arc moves unidirectionally between the wires, and the metal in the wire joint area begins to melt, forming a ball head under the action of surface tension. The guide rail controls the wire clamps on both sides to dock toward the center, and the two ends of the wire collide with each other and gradually fuse. After the welding area cools down, the metal of the welding joint has been firmly combined; the wire welding is completed, the joint has no obvious defects, and the welding quality is stable.

[0070] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An arc welding device for butting metal wires, characterized in that: include: The wire clamp is a copper plate with grooves engraved on it, used to fix the guide wire; The movable guide rail is a ball guide rail, a roller guide rail or a linear bearing, and is driven by a stepper motor or a servo motor to control the axial movement of the wire clamp; The arc striking device is a pair of pointed tungsten electrodes placed at the arc starting point of the head end of the wire clamp; The arc closure device is a pair of pointed tungsten electrodes, which are placed at the arc closure end of the wire clamp; Welding power source, which is a DC welding power source, is used to provide power for arc starting of welding wire; The magnetic field generator is two enclosed charged coils placed one above the other, used to generate a uniform magnetic field to drive the arc movement; A brightness sensor, located near the arc-receiving device, determines whether the arc reaches the welding position terminal according to the measured brightness, and controls the arc starting and arc extinguishing of the welding power source; Gas protection device, including gas cylinder and gas blow pipe, is used to prevent oxidation of metal wire during welding.

2. The arc welding device for butt welding of metal wires according to claim 1, characterized in that: The metal wire clamp is two pairs of copper plates, each pair of copper plates consists of two pieces, one above the other. Each copper plate is engraved with a semicircular groove with a radius of 0.5-4mm. The two copper plates are pieced together to clamp metal wires of corresponding sizes. The number of grooves on each copper plate is 3 or more to clamp 3 or more pairs of metal wires. The grooves are arranged in a straight line with a processing accuracy of ±0.05mm. Each pair of copper plates is fixed to the movable guide rail by bolts. The surface of the copper plate is plated. The thickness of the copper plate is 2-5mm.

3. The arc welding device for butt welding of metal wires according to claim 1, characterized in that: The arc striking device is a pair of pointed tungsten electrodes, which are welding electrodes selected from thoriated tungsten, cerium tungsten, lanthanum tungsten or zirconium tungsten alloy. The diameter of the tungsten electrode is 1.0-4.0 mm, the tip is conical, the tip angle is 10°-50°, the distance between the tips of the tungsten electrodes is 0.5-1.5 mm, and the surface of the tungsten electrode is polished.

4. The arc welding device for butt welding of metal wires according to claim 1, characterized in that: The arc closure device is a pair of pointed tungsten electrodes, which are welding electrodes selected from thoriated tungsten, cerium tungsten, lanthanum tungsten or zirconium tungsten alloys. The diameter of the tungsten electrode is 1.0-4.0 mm, the tip is conical, the tip angle is 10°-50°, the distance between the tips of the tungsten electrodes is 2.0-4.0 mm, and the surface of the tungsten electrode is polished.

5. The arc welding device for butt welding of metal wires according to claim 1, characterized in that: The welding power supply is a TIG DC welding power supply with a power of 100-3000W. Arcing and arcing are performed according to the light sensor signal. The arcing method is high-voltage arcing or high-frequency high-voltage arcing. The positive pole of the power supply is connected to the left wire clamp, and the negative pole of the power supply is connected to the right wire clamp.

6. The arc welding device for butt welding of metal wires according to claim 1, characterized in that: The coil of the magnetic field generator is square or ring-shaped, the coil material is copper, the number of turns is 100-500 turns, and the coil size is larger than the metal wire welding area.

7. The arc welding device for butt welding of metal wires according to claim 1, characterized in that: The brightness sensor is a photoresistor, a photoelectric sensor or a light intensity sensor with a sensitivity of 0.1-1000 Lux and a response time of 1-10 ms. It determines whether the arc reaches the arc end by the change in brightness.

8. The arc welding device for butt welding of metal wires according to claim 1, characterized in that: The gas protection device provides pure argon or pure helium welding protection gas, and the gas flow rate is 1-10L / min, and the gas flow rate is adjusted by the flow controller.

9. An arc welding method for butting metal wires, characterized in that: Using the arc welding device for butt welding of metal wires as claimed in any one of claims 1 to 8 to perform arc welding of butt welding of metal wires comprises the following steps: S1. Clean the butt joint of the metal wire to be welded, place two or more pairs of metal wires in a row on the metal wire clamp, keep a distance between the metal wires, and turn on the gas protection device to provide gas protection for the welding area; S2, starting an arc at the tips of the two tungsten electrodes of the arc striking device; S3, the magnetic field generator generates a magnetic field, and the arc jumps between the metal wire joints driven by the magnetic field, moving from the arc starting end to the arc ending end; S4, when the arc reaches the arc-extinguishing end, the brightness sensor detects the arc brightness change and controls the welding power supply to extinguish the arc; S5, repeating steps S2-S4, the end of the metal wire is melted into a ball under repeated heating of the arc; S6. When the molten ball at the end of the metal wire reaches a certain size, the arc is extinguished, and the metal wire clamp is quickly moved to make the molten balls on both sides contact to complete the welding.

10. The arc welding method for butt welding of metal wires according to claim 9, characterized in that: In step S1, the centers of the metal wires to be welded are aligned, the spacing between the metal wires is 1.5-3.0 mm, and the gas flow rate is 1-10 L / min; And / or in step S2, the arc starting method is non-contact arc starting, using high-voltage arc starting or high-frequency high-voltage arc starting; And / or in step S3, the direction of the magnetic field generated by the magnetic field generator is vertically downward, perpendicular to the plane of the parallel metal wires, and the direction of the magnetic field is controlled by adjusting the current direction of the magnetic field generator; and / or in step S5, arc extinguishing and arc striking are repeated 5-10 times until the end of the metal wire melts into a ball; And / or the material of the metal wire is selected from one or more of iron, titanium, nickel, aluminum, copper and alloys thereof.

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