CN214443741U

CN214443741U - A magnetic field generating device and a welding gun

Info

Publication number: CN214443741U
Application number: CN202022852776.XU
Authority: CN
Inventors: 石永华; 陈金荣; 占爱文; 王劲一; 陈云可
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2020-12-02
Filing date: 2020-12-02
Publication date: 2021-10-22
Anticipated expiration: 2030-12-02

Abstract

The utility model relates to a magnetic field generating device, comprising a connecting piece, a power supply, a wiring switching device and a control device. The connecting piece is provided with a through hole for accommodating a welding torch head, and at least two peripheral iron core groups are arranged outside the connecting piece. Each peripheral iron core group includes two peripheral iron cores symmetrically arranged with the connecting piece as the center. The peripheral iron cores of at least two peripheral iron core groups are arranged in an annular array on the outer periphery of the connecting piece, and the extending direction of the peripheral iron cores communicates with the connecting piece. The extension direction of the holes is parallel, and each peripheral iron core is wound with a coil. The coil of each peripheral iron core is connected to the power supply through a wiring switching device to form a circuit. The wiring switching device is used to switch the connection mode between the coils, so that the circuit forms a horizontal For deflection magnetic field, transverse swing magnetic field, transverse rotating magnetic field or sharp angle magnetic field, the control device is respectively connected with the power supply and the wiring switching device to control the switching action of the wiring switching device and the switching of the power supply. The utility model also relates to a welding gun.

Description

Magnetic field generating device and welding gun

Technical Field

The utility model relates to the field of welding technique, especially, relate to a magnetic field generating device and a welder.

Background

The single-side welding and double-side forming is an advanced welding process method, can greatly improve the welding production efficiency and reduce the production cost, and is beneficial to the precipitation of air holes and impurities of welding seams. The single-side welding double-side forming technology is a process of welding after one side is welded, turning over a weldment, and performing back gouging treatment on the back of the weldment.

Keyhole effect argon tungsten-arc welding (also called K-TIG welding) is a novel welding method which can be used for single-side welding and double-side forming without beveling and filling welding materials. The keyhole effect is the key for realizing large-penetration welding and ensuring the quality of a welding joint by K-TIG welding. The keyhole is surrounded by liquid metal, and the inside of the keyhole is filled with gas. During welding, the keyhole penetrates through molten metal and moves along with the movement of a welding gun or a workpiece, and a molten pool moves around the edge of the keyhole to the tail of the keyhole and is solidified into a welding seam. Different from the keyhole effect in laser welding and plasma arc welding, the keyhole in the K-TIG welding process must be kept open, so that plasma jet flow is discharged through the keyhole, and the welding defects such as influencing the stability of the welding process, forming air holes and the like are avoided. Compared with the traditional TIG welding, the K-TIG welding utilizes the welding current of more than 300A to generate the welding arc with high energy density, strong penetrating power and high stiffness, thereby realizing the high-efficiency deep fusion welding of medium and thick plates and having wide application prospect. However, K-TIG welding also has some defects, and because the welding speed is high, the temperature of a molten pool is fast, molten metal does not flow sufficiently, so that the problems of undercut, hump, coarse grain of a weld structure and the like are caused.

The resultant force of arc force, surface tension and gravity on molten pool liquid metal is different when welding is carried out at different positions of all-position welding. The most significant force affecting the weld pool morphology during welding is gravity. In order to obtain good bead formation, the effect of gravity on the molten bath liquid metal needs to be overcome.

Through researches of a plurality of scholars, the magnetic field can act on the welding arc in the welding process of the external magnetic field, so that the welding arc is changed in shape and movement under the action of the external magnetic field, the distribution of heat is influenced, and the heating melting of base metal and the formation of a welding seam are further influenced. The external magnetic field can also act on the molten metal in the molten pool, and the magnetic lines of force can continuously stir the molten metal in the flowing process of the molten pool, refine the structure grains of the welding seam and improve the quality of the welding seam.

In the prior art, an excitation device is adopted to form a transverse deflection magnetic field, a transverse swinging magnetic field, a transverse rotating magnetic field, a sharp-angle magnetic field or a longitudinal magnetic field to act on a welding arc, but the existing excitation device has a complex structure, a single magnetic field type and a single function, and a magnetic field generating device which can generate various magnetic fields and has adjustable magnetic field parameters (direction, strength and frequency) is lacked.

SUMMERY OF THE UTILITY MODEL

To the technical problem who exists among the prior art, one of the purposes of the utility model is: provided is a magnetic field generating device capable of forming a plurality of magnetic fields acting on a welding arc by switching the connection mode between coils, and effectively improving the quality of a weld.

To the technical problem who exists among the prior art, the utility model discloses a second of the purpose: provided is a welding gun capable of forming a plurality of magnetic fields acting on a welding arc and effectively improving the quality of a weld.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a magnetic field generating device comprises a connecting piece, a power supply, a wiring switching device and a control device, wherein the connecting piece is provided with a through hole for accommodating the head of a welding gun, at least 2 peripheral iron core groups are arranged outside the connecting piece, each peripheral iron core group comprises 2 peripheral iron cores which are symmetrically arranged by taking the connecting piece as a center, the peripheral iron cores of at least 2 peripheral iron core groups are arranged on the periphery of the connecting piece in an annular array manner, the extending direction of the peripheral iron cores is parallel to the extending direction of the through hole of the connecting piece, each peripheral iron core is wound with a coil, the coil of each peripheral iron core is connected with the power supply through the wiring switching device to form a circuit, the wiring switching device is used for switching the connection mode between the coils, so that the circuit forms a transverse deflection magnetic field, a transverse swing magnetic field, a transverse rotation magnetic field or a sharp angle magnetic field, and the control device is respectively connected with the power supply and the wiring switching device to control the switching action of the wiring switching device and the switching of the power supply.

Further, peripheral iron core group quantity is 2, 2 peripheral iron core groups include first peripheral iron core, the second peripheral iron core, the peripheral iron core of third and the peripheral iron core of fourth, first peripheral iron core and the peripheral iron core of third use the connecting piece to set up as central symmetry, the peripheral iron core of second and the peripheral iron core of fourth use the connecting piece to set up as central symmetry, the coil includes first coil, the second coil, third coil and fourth coil, first coil twines in first peripheral iron core, the second coil twines in the peripheral iron core of second, the third coil twines in the peripheral iron core of third, the fourth coil twines in the peripheral iron core of fourth, first coil, the second coil, third coil and fourth coil pass through wiring auto-change over device and are connected with the power and form the circuit.

Further, the wiring switching device comprises a first switch, a second switch, a seventeenth switch, a nineteenth switch, a twelfth switch, a fifteenth switch, a fourth switch and a seventh switch, wherein one end of the first coil is sequentially connected with the second switch, the seventeenth switch is connected with one end of the second coil, the other end of the second coil is sequentially connected with the nineteenth switch, the twelfth switch and one end of the third coil, the other end of the third coil is sequentially connected with the fifteenth switch, the fourth switch is connected with the other end of the fourth coil, one end of the fourth coil is connected with one end of a power supply through the seventh switch, and the other end of the power supply is connected with the other end of the first coil through the first switch.

Further, the power supply is a direct current power supply or a sine alternating current power supply.

Further, the power supply comprises a first sine alternating-current power supply and a second sine alternating-current power supply, the wiring switching device comprises a first switch, a third switch, a tenth switch, a thirteenth switch, an eighteenth switch, a sixteenth switch, a ninth switch and a sixth switch, one end of the first sine alternating-current power supply is connected with the other end of the first coil through the first switch, one end of the first coil is sequentially connected with one ends of the third switch, the tenth switch and the third coil, and the other end of the third coil is sequentially connected with the thirteenth switch and the other end of the first sine alternating-current power supply; second sinusoidal alternating current power supply one end is connected with the eighteenth switch and the second coil other end in proper order, and second coil one end is connected with sixteenth switch, ninth switch and fourth coil one end in proper order, and the fourth coil other end passes through the sixth switch and is connected with the second sinusoidal alternating current power supply other end.

Further, the wiring switching device comprises a first switch, a second switch, a seventeenth switch, a nineteenth switch, a fourteenth switch, an eleventh switch, an eighth switch, a fifth switch, one end of the power supply is connected with the other end of the first coil through the first switch, one end of the first coil is sequentially connected with the second switch, the seventeenth switch and one end of a second coil, the other end of the second coil is sequentially connected with the nineteenth switch, the fourteenth switch and the other end of the third coil, one end of the third coil is sequentially connected with the eleventh switch, the eighth switch and one end of a fourth coil, and the other end of the fourth coil is connected with the other end of the power supply through the fifth switch.

Further, the wiring switching device comprises a twentieth switch, the connecting piece is a middle iron core, the through hole for accommodating the head of the welding gun is located in the middle of the middle iron core, a middle coil is wound on the outer wall of the middle iron core, and the middle coil is connected with the power supply through the twentieth switch.

Further, the peripheral iron core comprises a long iron core and a short iron core, the extending direction of the long iron core is parallel to the extending direction of the through hole of the connecting piece, one end of the long iron core is fixedly connected with one end of the short iron core, the other end of the short iron core corresponds to the through hole of the connecting piece, and the coil is wound on the long iron core.

A welding gun includes a magnetic field generating device.

In general, the utility model has the advantages as follows:

various magnetic fields such as transverse deflection magnetic fields, transverse swinging magnetic fields, transverse rotating magnetic fields, sharp-angle magnetic fields and the like which act on the welding arc can be formed by switching the connection mode among the coils, the direction, the strength and the frequency of the magnetic fields can be adjusted, and the welding quality can be effectively improved.

Drawings

Fig. 1 is a schematic perspective view of a magnetic field generator.

Fig. 2 is a schematic view of the internal structure of the magnetic field generating device.

Fig. 3 is a schematic cross-sectional view of a magnetic field generating device.

FIG. 4 is a wiring diagram of the transverse deflection magnetic field and the transverse swing magnetic field.

Fig. 5 is a schematic diagram of transverse deflection field excitation current.

Fig. 6 is a schematic diagram of transverse deflection field excitation.

Fig. 7 is a schematic diagram of a transverse swinging magnetic field excitation current.

Fig. 8 is a schematic diagram of the transverse oscillating field excitation.

Fig. 9 is a wiring diagram of a transverse rotating magnetic field.

Fig. 10 is a schematic diagram of a transverse rotating magnetic field double sinusoidal excitation current.

Fig. 11 is a schematic diagram of transverse rotating field excitation.

FIG. 12 is a diagram of a sharp magnetic field junction.

FIG. 13 is a diagram of the DC cusp magnetic field current.

FIG. 14 is a schematic view of an AC sharp field current.

FIG. 15 is a schematic diagram of a sharp angle magnetic field excitation.

Fig. 16 is a longitudinal magnetic field wiring diagram.

Fig. 17 is a schematic diagram of dc longitudinal field current.

FIG. 18 is a schematic diagram of an AC longitudinal field current.

Fig. 19 is a longitudinal magnetic field excitation schematic diagram.

FIG. 20 is a first diagram illustrating the force applied by the external transverse magnetic field.

Fig. 21 is a second force-bearing diagram of the external transverse magnetic field.

FIG. 22 is a comparison graph of the force applied before and after circumscribing a sharp magnetic field.

FIG. 23 is a diagram illustrating the force applied to a magnetic field circumscribing a sharp corner.

FIG. 24 is a first diagram illustrating the force applied by the external longitudinal magnetic field.

Fig. 25 is a second force-bearing diagram of the external longitudinal magnetic field.

Fig. 26 is a circuit diagram of a wire switching device (not including a longitudinal magnetic field).

Description of reference numerals:

10-middle iron core, 11-first peripheral iron core, 12-second peripheral iron core, 13-third peripheral iron core, 14-fourth peripheral iron core, 20-middle coil, 21-first coil, 22-second coil, 23-third coil, 24-fourth coil, 30-end cover, 40-fastening taper sleeve, 50-connecting bolt, 60-connecting screw, 70-cooling pipe, 71-water inlet, 72-water outlet, 80-shell, 90-insulating pad, 100-insulating sleeve, 110-fastening ring and 120-base metal.

Detailed Description

The present invention will be described in further detail below.

As shown in fig. 1-3, a magnetic field generating device comprises a connecting piece, a power supply, a wiring switching device and a control device, wherein the connecting piece is provided with a through hole for accommodating the head of a welding gun, at least 2 peripheral iron core groups are arranged outside the connecting piece, each peripheral iron core group comprises 2 peripheral iron cores which are symmetrically arranged by taking the connecting piece as a center, the peripheral iron cores of the at least 2 peripheral iron core groups are arranged at the periphery of the connecting piece in an annular array manner, the extending direction of the peripheral iron cores is parallel to the extending direction of the through hole of the connecting piece, each peripheral iron core is wound with a coil, the coil of each peripheral iron core is connected with the power supply through the wiring switching device to form a circuit, the wiring switching device is used for switching the connection mode among the coils so that the circuit forms a transverse deflection magnetic field, a transverse swinging magnetic field, a transverse rotating magnetic field or a sharp angle magnetic field, and the control device is respectively connected with the power supply and the wiring switching device, and controlling the switching action of the wiring switching device and the switching of the power supply.

The even number of coil annular arrays with the peripheral iron cores are arranged on the periphery of the connecting piece, different circuits can be formed by connecting different power supplies through different wiring modes, various different transverse magnetic fields can be formed on the periphery of the connecting piece, the transverse magnetic fields comprise a transverse deflection magnetic field, a transverse swing magnetic field, a transverse rotating magnetic field or a sharp-angle magnetic field, and the magnetic fields act on a welding arc of a welding gun positioned in the middle of the connecting piece during welding, and the specific steps are as follows:

under the action of transverse deflecting magnetic field, when the direct current positive polarity method is adopted for welding, the arc shape and the molten pool dynamic change correspondingly, when the magnetic field direction is vertical to the welding direction, the stress of the arc and the stress of the molten metal in the molten pool are shown in figures 20 and 21. The electric arc is subjected to a force parallel to the welding direction, so that the electric arc is deflected to one side along the welding direction, and the molten metal in the molten pool is subjected to a Lorentz force vertical to the upper surface of the base metal 120, so that the problem of electric arc blow can be solved, the electric arc trailing is inhibited, the weld structure grains are refined, the molten pool is fully fused, and the formation of a weld hump is avoided. When the magnetic field is oriented parallel to the welding direction, the arc is subjected to a force perpendicular to the welding direction, causing the arc to be deflected to one side perpendicular to the welding direction. The method can be used for welding thin plates, and welding seams with wider fusion width and shallower fusion depth (small depth-to-width ratio) can be obtained.

In the transverse swinging magnetic field, the electric arc is forced to swing left and right periodically, and the molten metal is also forced to be subjected to periodic Lorentz force, so that the molten pool can be stirred in an up-and-down oscillating mode.

In the transverse rotating magnetic field, the electric arc rotates under the action of the rotating magnetic field according to the frequency of the magnetic field, and the molten metal is periodically subjected to different Lorentz forces, so that the molten pool can be stirred in an up-and-down oscillating manner, the effect of refining weld structure grains is achieved, and the mechanical property of a weld is improved.

In the sharp-angle magnetic field, the distribution of the peripheral iron core is the same as that of magnetic columns of a transverse magnetic field, and the difference is that the winding direction, the wiring form and the type of the introduced current of the excitation coil on the magnetic columns are different. According to different excitation current types, the excitation current type can be divided into: a direct current sharp angle magnetic field and an alternating current sharp angle magnetic field.

Under the action of the DC sharp angle magnetic field, when the DC positive polarity method is adopted for welding, the arc form and the dynamic state of the molten pool can be correspondingly changed. The stress of the electric arc and the stress of molten metal in a molten pool are shown in figures 22 and 23, a self-induction magnetic field generated by the original electric arc is in a counterclockwise direction, the electric arc is in a bell-jar shape under the action of electromagnetic contraction force, the horizontal direction of the original magnetic field is strengthened after the electric arc is externally connected with a sharp-angled magnetic field, the magnetic field in the vertical direction is weakened, the electromagnetic contraction force in the horizontal direction and the electromagnetic contraction force in the vertical direction are unequal, the electric arc is compressed into an oval shape from the original round shape, and the energy density in the electric arc is increased. The welding can be carried out along the long axis or the short axis of the ellipse according to different welding requirements, and the flexibility is good. According to the left-hand rule, the molten metal in the molten pool is subjected to the Lorentz force perpendicular to the upper surface of the base material 120, and the molten pool can be supported to prevent the molten pool from collapsing.

If the external connection is an alternating current sharp-angle magnetic field, when the arc is compressed into an oval shape and performs alternate rotation motion of a long axis and a short axis, the area of a heating area can be increased, deposition efficiency is improved, and molten metal can also be subjected to different Lorentz forces periodically, so that the molten pool can be stirred in an up-and-down oscillating mode, the effect of refining weld structure grains can be achieved, and mechanical properties of a weld joint are improved.

Therefore, the utility model discloses magnetic field generating device can form the magnetic field that multiple butt welding electric arc produced different effects, can effectively improve the welding seam quality.

The number of the peripheral iron core groups is 2, 2 peripheral iron core groups include a first peripheral iron core 11, a second peripheral iron core 12, a third peripheral iron core 13 and a fourth peripheral iron core 14, the first peripheral iron core 11 and the third peripheral iron core 13 are arranged by taking a connecting piece as central symmetry, the second peripheral iron core 12 and the fourth peripheral iron core 14 are arranged by taking the connecting piece as central symmetry, the coil includes a first coil 21, a second coil 22, a third coil 23 and a fourth coil 24, the first coil 21 is wound on the first peripheral iron core 11, the second coil 22 is wound on the second peripheral iron core 12, the third coil 23 is wound on the third peripheral iron core 13, the fourth coil 24 is wound on the fourth peripheral iron core 14, and the first coil 21, the second coil 22, the third coil 23 and the fourth coil 24 are connected with a power supply through a wiring switching device to form a circuit.

The number of the peripheral iron cores is 4, so that the requirement of forming various magnetic fields can be met, and the design, the manufacture and the wiring are both more convenient.

For convenience of description, one end of the first peripheral iron core 11, the second peripheral iron core 12, the third peripheral iron core 13, and the fourth peripheral iron core 14, which faces the welding gun head in the same direction, is set as a lower end of the first peripheral iron core 11, the second peripheral iron core 12, the third peripheral iron core 13, and the fourth peripheral iron core 14, and the other end, which faces the welding gun head in the opposite direction, is set as an upper end.

The first coil 21 is spirally wound around the first peripheral core 11 with a right hand, and one end of the first coil 21 is disposed near the upper end of the first peripheral core 11, and the other end of the first coil 21 is disposed near the lower end of the first peripheral core 11.

Similarly, the second coil 22 is wound around the second peripheral core 12 in a right-hand spiral manner, and one end of the second coil 22 is set near the upper end of the second peripheral core 12, and the other end of the second coil 22 is set near the lower end of the second peripheral core 12. The third coil 23 is wound around the third peripheral core 13 in a right-handed helical manner, and one end of the third coil 23 is provided near the upper end of the third peripheral core 13, and the other end of the third coil 23 is provided near the lower end of the third peripheral core 13. The fourth coil 24 is wound around the fourth peripheral core 14 in a right-handed helical manner, and one end of the fourth coil 24 is provided near the upper end of the fourth peripheral core 14, and the other end of the fourth coil 24 is provided near the lower end of the fourth peripheral core 14.

The wiring switching device comprises a first switch, a second switch, a seventeenth switch, a nineteenth switch, a twelfth switch, a fifteenth switch, a fourth switch and a seventh switch, one end of the first coil 21 is sequentially connected with the second switch, one end of the seventeenth switch is connected with one end of the second coil 22, the other end of the second coil 22 is sequentially connected with one end of the nineteenth switch, the twelfth switch and one end of the third coil 23 are connected, the other end of the third coil 23 is sequentially connected with the fifteenth switch, the other end of the fourth switch is connected with the other end of the fourth coil 24, one end of the fourth coil 24 is connected with one end of a power supply through the seventh switch, and the other end of the power supply is connected with the other end of the first coil 21 through the first switch.

The first coil 21, the second coil 22, the third coil 23 and the fourth coil 24 are connected in sequence through the connection mode, and a transverse deflection magnetic field or a transverse swinging magnetic field is formed on the periphery of the connecting piece by the circuit.

The power supply is a direct current power supply or a sine alternating current power supply.

When the power supply is a direct current power supply, as shown in fig. 5, the current type is direct current, the winding direction and the wiring form of the exciting coil are shown in fig. 4, the circuit forms a transverse deflection magnetic field, and the excitation principle of the transverse deflection magnetic field is shown in fig. 6.

When the power supply is a sine alternating current power supply, as shown in fig. 7, the current type is sine alternating current, the swinging direction and frequency of the magnetic field change with the period of the exciting current, the winding direction and the wiring form of the exciting coil are shown in fig. 4, the circuit forms a transverse swinging magnetic field, and the excitation principle of the transverse swinging magnetic field is shown in fig. 8.

The power supply comprises a first sine alternating-current power supply and a second sine alternating-current power supply, the wiring switching device comprises a first switch, a third switch, a tenth switch, a thirteenth switch, an eighteenth switch, a sixteenth switch, a ninth switch and a sixth switch, one end of the first sine alternating-current power supply is connected with the other end of the first coil 21 through the first switch, one end of the first coil 21 is sequentially connected with one ends of the third switch, the tenth switch and the third coil 23, and the other end of the third coil 23 is sequentially connected with the thirteenth switch and the other end of the first sine alternating-current power supply; one end of the second sine alternating-current power supply is sequentially connected with the eighteenth switch and the other end of the second coil 22, one end of the second coil 22 is sequentially connected with the sixteenth switch, the ninth switch and one end of the fourth coil 24, and the other end of the fourth coil 24 is connected with the other end of the second sine alternating-current power supply through the sixth switch.

The first coil 21, the second coil 22, the third coil 23 and the fourth coil 24 are connected in sequence by the connection mode, and the circuit forms a transverse rotating magnetic field on the periphery of the connecting piece. The current type is double sine alternating current, the phase difference between the first sine alternating current power supply and the second sine alternating current power supply is 90 degrees, the winding direction and the wiring form of the exciting coil are shown in fig. 9, a rotating transverse magnetic field can be superposed on the horizontal plane of the magnetic head, the rotating direction and the frequency of the magnetic field change along with the period of the exciting current, and fig. 10 shows the process of generating the transverse rotating magnetic field in one period.

The wiring switching device comprises a first switch, a second switch, a seventeenth switch, a nineteenth switch, a fourteenth switch, an eleventh switch, an eighth switch and a fifth switch, wherein one end of a power supply is connected with the other end of the first coil 21 through the first switch, one end of the first coil 21 is sequentially connected with the second switch, the seventeenth switch and one end of a second coil 22, the other end of the second coil 22 is sequentially connected with the nineteenth switch, the fourteenth switch and the other end of a third coil 23, one end of the third coil 23 is sequentially connected with one end of the eleventh switch, the eighth switch and one end of a fourth coil 24, and the other end of the fourth coil 24 is connected with the other end of the power supply through the fifth switch.

The first coil 21, the second coil 22, the third coil 23 and the fourth coil 24 are connected in sequence through the connection mode, and the circuit forms a sharp-angle magnetic field on the periphery of the connecting piece. The power supply is a direct current power supply or a sine alternating current power supply.

Fig. 15 shows a principle diagram of dc sharp-angle magnetic field excitation, the winding direction and connection form of the excitation coil are shown in fig. 12, and as shown in fig. 13, when dc current is applied, a magnetic field with opposite homopolarity and adjacent heteropolarity is generated between the magnetic heads, and the magnetic induction lines of the magnetic field are sparse inside and dense outside.

Fig. 15 shows an excitation schematic diagram of an ac sharp-angle magnetic field, where the winding direction and the connection form of the excitation coil are shown in fig. 12, and as shown in fig. 14, when a sinusoidal ac current is applied, a rotating magnetic field with opposite poles and adjacent opposite poles is generated between the magnetic heads, the rotating direction and frequency change with the excitation current period, and the magnetic induction lines of the rotating magnetic field are sparse inside and dense outside.

The wiring switching device comprises a twentieth switch, the connecting piece is a middle iron core 10, a through hole for accommodating the head of the welding gun is located in the middle of the middle iron core 10, a middle coil 20 is wound on the outer wall of the middle iron core 10, and the middle coil 20 is connected with the power supply through the twentieth switch.

The current is introduced into the middle coil 20 to generate a magnetic field, and the direction of the magnetic line of the magnetic field is parallel to the axial direction of the electric arc. The power supply may be a dc power supply or a sinusoidal ac power supply. Fig. 19 shows a longitudinal magnetic field excitation schematic diagram. According to different excitation current types, the excitation current type can be divided into: a direct current longitudinal magnetic field and an alternating current longitudinal magnetic field.

The winding direction and the wiring form of the direct-current longitudinal magnetic field excitation coil are shown in fig. 16, and as shown in fig. 17, direct current is introduced to generate an electromagnetic field parallel to the axial direction of the arc;

the winding direction and the wiring form of the alternating longitudinal magnetic field excitation coil are shown in fig. 16, and a sinusoidal alternating current is introduced into the alternating longitudinal magnetic field excitation coil as shown in fig. 18, so that an electromagnetic field which is parallel to the axial direction of the arc and has a direction which changes along with the period of the excitation current can be generated.

Under the action of the DC longitudinal magnetic field, when the DC positive polarity method is adopted for welding, the arc form and the molten pool dynamic state can be correspondingly changed. As shown in fig. 24 and 25, under the action of the longitudinal magnetic field, the charged particles q in the arc receive the lorentz force F, the lorentz force F provides a centripetal force, and the charged particles q change from the original central radiation motion state to a circular spiral motion from top to bottom. The larger the Lorentz force F is, the smaller the circumferential radius r is, the more obvious the compression effect on the arc is, the energy density in the arc is increased, and the arc welding machine can be used for thick plate welding. According to the left-hand rule, the lorentz force perpendicular to the current direction and the magnetic field direction is applied to the molten metal in the molten pool, so that the molten metal in the molten pool is deviated to one side along the welding direction, and the influence of gravity on the weld formation can be counteracted during transverse welding. In fig. 24, q represents a charged particle in an arc, F represents a lorentz force to which the charged particle q is subjected, and r represents a circumferential radius of a circumferential spiral motion of the charged particle q.

In the ac longitudinal magnetic field, the charged particles of the arc are periodically oscillated by the force, and the molten metal is also subjected to the periodic lorentz force, so that the molten pool can be agitated by oscillating left and right in the welding direction.

The peripheral iron core comprises a long iron core and a short iron core, the extending direction of the long iron core is parallel to the extending direction of the through hole of the connecting piece, one end of the long iron core is fixedly connected with one end of the short iron core, the other end of the short iron core corresponds to the through hole of the connecting piece, and the coil is wound on the long iron core.

The short iron core has the function of magnetic conduction, so that the magnetic induction lines around the electric arc are denser, the magnetic field intensity is higher, and the acting force on the welding electric arc is greatly enhanced.

As shown in fig. 1, 2, and 3, in the present embodiment, the long iron core and the short iron core are integrally formed into an L-shaped silicon steel core. The middle iron core 10 is a cylindrical silicon steel iron core. The coils are all enameled wires. The enameled wires are respectively wound on the cylindrical silicon steel core and the L-shaped silicon steel core.

The magnetic field generating device mainly comprises a cylindrical silicon steel core, an L-shaped silicon steel core, an enameled wire, an end cover 30, a fastening taper sleeve 40, a connecting bolt 50, a connecting screw 60, a cooling pipe 70, a water inlet 71, a water outlet 72, a shell 80, an insulating pad 90, an insulating sleeve 100 and a fastening ring 110.

The cylindrical silicon steel core and the L-shaped silicon steel core are determined according to the working environment and the practicability, and the iron core with high Curie temperature is selected for use because the temperature of the electric arc is higher. The iron core is used for providing a magnetic loop, enhancing and guiding magnetic flux, so that the magnetic field intensity of the whole magnetic circuit reaches the maximum, and magnetic leakage loss is avoided.

The L-shaped silicon steel core is formed by stacking cold-rolled silicon steel sheets with the thickness of 0.35mm, and the cross section area is 10mm x 10 mm.

An insulating pad 90 is arranged between the cylindrical silicon steel core and the end cover 30 and is fixed below the end cover 30 through a connecting screw 60.

Be equipped with fastening taper sleeve 40 between cylinder silicon steel iron core and the welder, fastening taper sleeve 40 can imbed between end cover 30 and the welder, and the surface gradient of the hole of fastening taper sleeve 40 and end cover 30 is unanimous, can make its more firm connection through connecting bolt 50.

The fastening cone 40 is designed into an opening shape, which can effectively prevent the fastening cone from deforming when the end cover 30 is fixedly connected with the welding gun.

The number of the L-shaped silicon steel cores is 4, the L-shaped silicon steel cores are fixed below the end cover 30 through the connecting screws 60, and annular through holes are formed in the L-shaped silicon steel cores, so that the positions of the L-shaped silicon steel cores can be adjusted up and down. The four L-shaped silicon steel cores are uniformly distributed on the same circumference, the enameled wires on the L-shaped silicon steel cores are connected with current to generate four electromagnetic fields, the four electromagnetic fields can be superposed into transverse magnetic fields in different forms by changing the type of the current and the wiring form of the excitation coil, and the magnetic lines of the magnetic fields are perpendicular to the axis of the electric arc. According to different coil wiring forms and excitation current types, the transverse magnetic field can be divided into: a transverse deflection magnetic field, a transverse swinging magnetic field and a transverse rotating magnetic field.

A cooling pipe 70 is arranged between the cylindrical silicon steel iron core and the L-shaped silicon steel iron core, the cooling pipe 70 is a copper pipe and has good heat conductivity, and the cooling pipe 70 is spirally wound between the cylindrical silicon steel iron column and the L-shaped silicon steel iron core from bottom to top.

The water inlet 71 and the water outlet 72 are used for feeding cooling liquid into and guiding the cooling liquid out of the magnetic field generating device from bottom to top, so that heat generated by the enameled wire and radiation heat from electric arc can be taken away more efficiently, and cooling is realized.

The bottom of the shell 80 is provided with four through holes, and the L-shaped silicon steel core can penetrate through the shell 80 to form an electromagnetic field at the bottom of the shell.

The housing 80 is connected to the end cap 30 by a connecting screw 60, and an insulating pad 90 is provided between the housing 80 and the end cap 30.

An insulating sleeve 100 is arranged between the shell 80 and the cylindrical silicon steel core, and the insulating sleeve 100 is sleeved on the cylindrical silicon steel core, so that the cylindrical silicon steel core is kept in non-contact with the shell 80, and the magnetic leakage phenomenon is effectively avoided.

Also be equipped with insulating cover 100 between shell 80 and the L shape silicon steel core, insulating cover 100 covers on the L shape silicon steel core, makes L shape silicon steel core and shell 80 keep contactless, not only can prevent L shape silicon steel core and shell 80 contact, has effectively avoided the magnetic leakage phenomenon, but also can prevent that L shape silicon steel core from swinging in welding process, guarantees the stability in magnetic field.

The end cap 30 and the housing 80 are made of aluminum alloy material, and the connection screw 60 is made of stainless steel material and has no magnetism.

The insulating sleeve 100 and the insulating pad 90 are both high-strength and high-temperature-resistant insulating plastics. The welding gun is a K-TIG special welding gun.

The control device is an STM32 singlechip, the wiring switching device comprises 20 switches (triacs), and the control ends of the switches are controlled by an STM32 singlechip, so that the circuit can be controlled to be switched on and off, the switching among different magnetic fields is realized, and a circuit diagram is shown in fig. 26. The structure of the three-terminal bidirectional silicon controlled switch is that 2 thyristors are connected in parallel in reverse direction, different from the thyristor, the three-terminal bidirectional silicon controlled switch can control the current in any direction, and the maximum characteristic is that the three-terminal bidirectional silicon controlled switch can control the AC current in two directions.

Conduction conditions of control ends of switches with different magnetic fields:

transverse deflection magnetic field, transverse swinging magnetic field: the first switch PA1, the second switch PA2, the seventeenth switch PA17, the nineteenth switch PA19, the twelfth switch PA12, the fifteenth switch PA15, the fourth switch PA4 and the seventh switch PA7 are switched on, and if a direct-current power supply is connected to the input end ab, a transverse deflection magnetic field is generated; if a sine alternating current power supply is connected between the input end ab, a transverse swinging magnetic field is generated;

transverse rotating magnetic field: the first switch PA1, the third switch PA3, the tenth switch PA10, the thirteenth switch PA13, the eighteenth switch PA18, the sixteenth switch PA16, the ninth switch PA9 and the sixth switch PA6 are conducted, a first sinusoidal alternating-current power supply and a second sinusoidal alternating-current power supply are respectively connected between input ends ab and cd, and the phase difference between the first sinusoidal alternating-current power supply and the second sinusoidal alternating-current power supply is 90 degrees;

sharp-angle magnetic field: the first switch PA1, the second switch PA2, the seventeenth switch PA17, the nineteenth switch PA19, the fourteenth switch PA14, the eleventh switch PA11, the eighth switch PA8 and the fifth switch PA5 are switched on, and if a direct-current power supply is connected to the input end ab, a direct-current sharp-corner magnetic field is generated; if a sine alternating current power supply is connected between the input end ab, an alternating current sharp-corner magnetic field is generated;

longitudinal magnetic field: the twentieth switch PA20 is conducted, and if the input end ef is connected with a direct-current power supply, a direct-current longitudinal magnetic field is generated; if a sinusoidal AC power supply is connected to the input end ef, an AC longitudinal magnetic field is generated.

By controlling the conduction of different triacs, the superposition of different types of magnetic fields and extremely compound magnetic fields can be realized.

A liquid cooling system: the magnetism of enameled wire and silicon steel iron core is greatly influenced by high temperature, and the liquid cooling system can effectively reduce the temperature of working environment and improve the stability of magnetic field, thereby improving the stability of welding arc and greatly improving the working efficiency of welding. In the welding process, the bottom of the magnetic field generating device is influenced by the heat radiation generated by the welding arc and the coil at the same time, particularly the heat radiation of the welding arc, so that the temperature rise is most obvious. The cooling liquid flows into the bottom of the magnetic field generating device from the water inlet 71, spirally flows from top to bottom, and finally flows out from the water outlet 72, so that the temperature of the magnetic field generating device can be better reduced. Meanwhile, the flow of the cooling liquid should be increased along with the increase of the welding current, so that the cooling effect is more favorably ensured, and the stability of the magnetic field is ensured.

An excitation system: an excitation power supply used by the magnetic field generating device is connected with the enameled wire, and can adopt two excitation modes of direct current and alternating current, and the magnetic field intensity is adjustable in the direct current mode; in an alternating current mode; the magnetic field intensity and the frequency are adjustable. The magnet exciting coil adopts an enameled wire with the diameter of 1mm, the maximum rated current can reach 5A, and the enameled wire can continuously work in the environment of 220 ℃. Under the condition of 500 turns of coil and 5A current, a magnetic field of up to 100mT can be generated.

To sum up, the utility model discloses magnetic field generating device can produce that multiple magnetic field and magnetic field parameter (direction, intensity and frequency) are adjustable, can effectively improve the welding seam quality.

A welding gun comprises a magnetic field generating device, and can form various magnetic fields which act on welding arcs, so that the quality of welding seams is effectively improved.

The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be equivalent replacement modes, and all are included in the scope of the present invention.

Claims

1. A magnetic field generating device characterized by: comprises a connecting piece, a power supply, a wiring switching device and a control device, wherein the connecting piece is provided with a through hole for accommodating the head part of a welding gun, at least 2 peripheral iron core groups are arranged outside the connecting piece, each peripheral iron core group comprises 2 peripheral iron cores which are symmetrically arranged by taking the connecting piece as a center, the peripheral iron cores of at least 2 peripheral iron core groups are arranged at the periphery of the connecting piece in an annular array manner, the extending direction of the peripheral iron cores is parallel to the extending direction of the through hole of the connecting piece, each peripheral iron core is wound with a coil, the coil of each peripheral iron core is connected with the power supply through the wiring switching device to form a circuit, the wiring switching device is used for switching the connection mode between the coils, so that the circuit forms a transverse deflection magnetic field, a transverse swing magnetic field, a transverse rotation magnetic field or a sharp angle magnetic field, and the control device is respectively connected with the power supply and the wiring switching device to control the switching action of the wiring switching device and the switching of the power supply.

2. A magnetic field generating device according to claim 1, wherein: peripheral iron core group quantity is 2, 2 peripheral iron core groups include first peripheral iron core, the second peripheral iron core, the peripheral iron core of third and the peripheral iron core of fourth, first peripheral iron core uses the connecting piece to set up as central symmetry with the peripheral iron core of third, the peripheral iron core of second uses the connecting piece to set up as central symmetry with the peripheral iron core of fourth, the coil includes first coil, the second coil, third coil and fourth coil, first coil twines in first peripheral iron core, the second coil twines in the peripheral iron core of second, the third coil twines in the peripheral iron core of third, the fourth coil twines in the peripheral iron core of fourth, first coil, the second coil, third coil and fourth coil pass through wiring switching device and are connected with the power and form the circuit.

3. A magnetic field generating device according to claim 2, wherein: the wiring switching device comprises a first switch, a second switch, a seventeenth switch, a nineteenth switch, a twelfth switch, a fifteenth switch, a fourth switch and a seventh switch, wherein the first coil one end is sequentially connected with the second switch, the seventeenth switch and the second coil one end are connected, the second coil other end is sequentially connected with the nineteenth switch, the twelfth switch and the third coil one end are connected, the third coil other end is sequentially connected with the fifteenth switch, the fourth switch and the fourth coil other end are connected, the fourth coil one end is connected with one end of a power supply through the seventh switch, and the other end of the power supply is connected with the other end of the first coil through the first switch.

4. A magnetic field generating device according to claim 3, wherein: the power supply is a direct current power supply or a sine alternating current power supply.

5. A magnetic field generating device according to claim 2, wherein: the power supply comprises a first sine alternating-current power supply and a second sine alternating-current power supply, the wiring switching device comprises a first switch, a third switch, a tenth switch, a thirteenth switch, an eighteenth switch, a sixteenth switch, a ninth switch and a sixth switch, one end of the first sine alternating-current power supply is connected with the other end of the first coil through the first switch, one end of the first coil is sequentially connected with one ends of the third switch, the tenth switch and the third coil, and the other end of the third coil is sequentially connected with the other ends of the thirteenth switch and the first sine alternating-current power supply; second sinusoidal alternating current power supply one end is connected with the eighteenth switch and the second coil other end in proper order, and second coil one end is connected with sixteenth switch, ninth switch and fourth coil one end in proper order, and the fourth coil other end passes through the sixth switch and is connected with the second sinusoidal alternating current power supply other end.

6. A magnetic field generating device according to claim 2, wherein: the wiring switching device comprises a first switch, a second switch, a seventeenth switch, a nineteenth switch, a fourteenth switch, an eleventh switch, an eighth switch, a fifth switch, one end of a power supply is connected with the other end of the first coil through the first switch, one end of the first coil is sequentially connected with the second switch, the seventeenth switch and one end of a second coil, the other end of the second coil is sequentially connected with the nineteenth switch, the fourteenth switch and the other end of the third coil, one end of the third coil is sequentially connected with the eleventh switch, one end of the eighth switch is connected with one end of a fourth coil, and the other end of the fourth coil is connected with the other end of the power supply through the fifth switch.

7. A magnetic field generating device according to claim 1, wherein: the wiring switching device comprises a twentieth switch, the connecting piece is a middle iron core, the through hole for accommodating the head of the welding gun is located in the middle of the middle iron core, a middle coil is wound on the outer wall of the middle iron core, and the middle coil is connected with the power supply through the twentieth switch.

8. A magnetic field generating device according to claim 6 or 7, wherein: the power supply is a direct current power supply or a sine alternating current power supply.

9. A magnetic field generating device according to claim 1, wherein: the peripheral iron core comprises a long iron core and a short iron core, the extending direction of the long iron core is parallel to the extending direction of the through hole of the connecting piece, one end of the long iron core is fixedly connected with one end of the short iron core, the other end of the short iron core corresponds to the through hole of the connecting piece, and the coil is wound on the long iron core.

10. A welding gun, characterized by: comprising a magnetic field generating device according to any of claims 1-9.