CN114571049A

CN114571049A - Protective welding device and welding method for appearance welding copper plate of automobile body

Info

Publication number: CN114571049A
Application number: CN202210477939.1A
Authority: CN
Inventors: 徐先进
Original assignee: Wuhan Sixian Technology Co ltd
Current assignee: Wuhan Sixian Technology Co ltd
Priority date: 2022-05-05
Filing date: 2022-05-05
Publication date: 2022-06-03

Abstract

The invention discloses a welding device and a welding method for protecting an appearance welding copper plate of an automobile body. When the welding device is used, the positioning device moves downwards, the probe is inserted into the positioning hole of the vehicle body, then the electromagnet is electrified to adsorb the vehicle body, the top of the vehicle body is aligned with the metal plates on two sides, the bottom of the leveling copper plate is attached to the vehicle body, and after welding of the spot welding pliers is completed, the vehicle body adsorption suspension adsorbs the whole vehicle body to transport a vehicle shell out of a station.

Description

Protective welding device and welding method for appearance welding copper plate of automobile body

Technical Field

The invention relates to the technical field of whole vehicle welding, in particular to a device and a method for protecting and welding a welding copper plate on the appearance of an automobile body.

Background

As automobiles change from high consumer products to popular products, the elegance of automobiles is subject to the criticism of consumers, especially the requirement of flatness of the appearance of welding spots. At present, most automobile manufacturers mainly use inner and outer decorations to shield welding spots for welding spot appearance, so that the smooth surface of the welding spots is ensured, but the structural design difficulty and the manufacturing cost of the inner and outer decorations are increased invisibly, and the technical popularization is not facilitated.

Disclosure of Invention

Therefore, the invention provides a device and a method for welding the appearance welded copper plate of an automobile body, which aim to solve the problems of difficulty and increased manufacturing cost caused by the fact that structures of inner and outer ornaments are added to shield welding spots in the prior art.

In order to achieve the above purpose, the invention provides the following technical scheme:

according to a first aspect of the present invention,

the invention discloses a protective welding device for an appearance welding copper plate of an automobile body, which comprises spot welding tongs, a positioning device, an appearance leveling structure, an automobile body adsorption suspension, a pneumatic clamp and a magnetic clamp, wherein the spot welding tongs are arranged outside the automobile body adsorption suspension, the automobile body adsorption suspension is provided with the appearance leveling structures in a threaded connection mode, the front end of the automobile body adsorption suspension is provided with the positioning device, the rear end of the automobile body adsorption suspension is provided with the pneumatic clamp, and the bottom of the automobile body adsorption suspension is provided with two magnetic clamps.

Further, outward appearance flattening structure includes bolt fastening frame, vertical spring holder, horizontal spring holder, flattening seat and flattening copper, the spiro union is pressed from both sides tightly has a plurality of bolt fastening frames on the automobile body adsorbs the suspension, arbitrary one the bottom of bolt fastening frame is fixed with vertical spring holder spiro union, vertical spring holder bottom and horizontal spring holder elastic connection, horizontal spring holder side is fixed with flattening seat spiro union, flattening seat bottom is fixed with flattening copper spiro union.

Further, the automobile body adsorbs the suspension and includes suspension, roating seat, servo pump station and sucking disc, the bolt fixing frame is fixed to be set up on the suspension, the roating seat is installed to the upper end of suspension, the lower extreme of suspension is provided with a plurality of sucking discs, and is a plurality of the sucking disc all communicates with servo pump station, servo pump station is fixed to be set up on the suspension.

Furthermore, positioner includes moving cylinder, sensor, mounting bracket and probe, servo pump station links to each other with moving cylinder, moving cylinder bottom is provided with the sensor, the sensor is connected with the probe electricity, the probe is connected with moving cylinder transmission.

Furthermore, the pneumatic clamp comprises a clamping cylinder, a piston rod, a clamping jaw, an upper pressing clamp, a lower pressing clamp and a clamp base, the probe is fixedly arranged on the upper pressing clamp, the lower pressing clamp is arranged below the upper pressing clamp, the lower pressing clamp is fixedly arranged on a suspension, the suspension is fixedly connected with the clamp base in a threaded mode, the clamping cylinder is installed on the clamp base, the piston rod is inserted into the clamping cylinder and is hinged to the clamping jaw, and the clamping jaw is movably arranged on the clamp base.

Furthermore, the magnetic suction clamp comprises an adjusting plate, limiting clamps and an electromagnet, the suspension is fixed with the limiting clamps in a threaded mode, the adjusting plate is movably arranged on the limiting clamps, and the adjusting plate is fixed with the electromagnet in a threaded mode.

Furthermore, the spot welding pliers comprise a transmission device, a mechanical arm connecting frame, an anode welding head, a pliers body and a cathode welding head, wherein the upper end of the leveling copper plate abuts against the anode welding head, the anode welding head is in transmission connection with the transmission device, the transmission device is fixedly arranged at the end part of the mechanical arm connecting frame, the mechanical arm connecting frame is in threaded connection with one end of the pliers body, and the cathode welding head is arranged at the other end of the pliers body.

Furthermore, the transmission device comprises a motor, a lead screw, a telescopic pipe and a water passing pipe, the mechanical arm connecting frame is fixedly connected with the motor in a threaded mode, the motor is coaxially connected with the lead screw in a transmission mode, the lead screw is inserted into the telescopic pipe and is in threaded transmission connection with the telescopic pipe, the telescopic pipe is communicated with the water passing pipe, and the water passing pipe is communicated with the anode welding head.

According to a second aspect of the present invention,

the invention discloses a welding method, which comprises the above protective welding device for the appearance welding copper plate of an automobile body, and comprises the following steps;

firstly, the moving cylinder drives the probe to move downwards, so that the probe is inserted into the positioning hole of the vehicle body, then the electromagnet is electrified to adsorb the vehicle body, the top of the vehicle body is aligned with the metal plates on two sides, and meanwhile, the bottom of the leveling copper plate is attached to the vehicle body.

Further, the motor drives the lead screw to rotate, the telescopic pipe drives the anode welding head to move downwards to abut against the top of the leveling copper plate, the water pipe leads cooling liquid to the anode welding head, the anode welding head and the cathode welding head are aligned to clamp welding spots of the automobile body, and after welding is completed, the sucker adsorbs the whole automobile body.

The invention has the following advantages:

this technical scheme adopts the mode of spot welding, utilize the principle that resistance circular telegram generates heat, weld in the short time, it is showing and has improved efficiency, simultaneously in the welding, utilize the flattening copper to cover the automobile body surface and exert pressure on the copper, produce the nugget in welding process, and under the pressure effect, prevent that the automobile body outside from producing the side weld, splash and welding problems such as indentation is too dark, and effectively reduce the thermal stress that the welding produced, utilize copper and automobile body surface laminating, thereby showing the pleasing to the eye roughness that has improved weldment solder joint, solved among the prior art because the structure that increases inside and outside shields the solder joint and lead to the degree of difficulty and make this improvement problem.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.

The structures, ratios, sizes, and the like shown in the present specification are only used for matching with the contents disclosed in the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions that the present invention can be implemented, so that the present invention has no technical significance, and any structural modifications, changes in the ratio relationship, or adjustments of the sizes, without affecting the effects and the achievable by the present invention, should still fall within the range that the technical contents disclosed in the present invention can cover.

FIG. 1 is a perspective view of a welding copper plate arc welding device for the appearance of an automobile body according to the present invention;

FIG. 2 is a perspective view of a vehicle body absorption suspension of the device for protecting and welding the appearance of the vehicle body by the copper plate for welding;

FIG. 3 is a perspective view of a magnetic clamp of the device for protecting and welding the appearance of the welded copper plate of the automobile body;

FIG. 4 is a perspective view of a spot welding clamp of the device for protecting and welding the appearance of the welded copper plate of the automobile body provided by the invention;

FIG. 5 is a perspective view of a pneumatic clamp of the device for protecting and welding the appearance of the welded copper plate of the automobile body provided by the invention;

FIG. 6 is a perspective view of a positioning device of the welding copper plate arc welding device for the appearance of the automobile body according to the present invention;

FIG. 7 is a perspective view of an appearance leveling structure of the device for the protective welding of the appearance welded copper plate of the automobile body according to the present invention;

FIG. 8 is a perspective view of a transmission device of the welding copper plate arc welding device for the appearance of the automobile body according to the present invention;

in the figure: 1, spot welding tongs; 11 a transmission device; a 111 motor; 112 lead screw; 113 telescoping tubes; 114 a water pipe; 12 a mechanical arm connecting frame; 13 an anodic bonding head; 14 a clamp body; 15 cathode welding head; 2, a positioning device; 21 moving the cylinder; 22 a sensor; 23, mounting frames; 24 a probe; 3, leveling structure of appearance; 31 a bolt fixing frame; 32 vertical spring seats; 33 a transverse spring seat; 34 leveling seat; 35 leveling the copper plate; 4, absorbing the suspension on the vehicle body; 41 a suspension; 42 a rotary base; 43 servo pump station; 44 a suction cup; 5, pneumatic clamping; 51 a clamping cylinder; 52 a piston rod; 53 clamping jaws; 54 pressing tongs on the surface; 55 pressing down the pliers; 56 a clamp base; 6, magnetically attracting the clamp; 61 adjusting plate; 62, limiting pliers; 63 an electromagnet.

Detailed Description

The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The embodiment 1 of the invention discloses an automobile body appearance welding copper plate protective welding device which comprises spot welding tongs 1, a positioning device 2, an appearance leveling structure 3, an automobile body adsorption suspension 4, a pneumatic clamp 5 and a magnetic clamp 6, wherein the spot welding tongs 1 are arranged on the outer side of the automobile body adsorption suspension 4, the spot welding tongs 1 are used for welding the connection part of an automobile body in a resistance welding mode, and the spot welding tongs 1 are installed on a mechanical arm, so that the spot welding tongs 1 can move in six degrees of freedom. A plurality of appearance leveling structures 3 are installed on the vehicle body adsorption suspension 4 in a threaded mode, and the appearance leveling structures 3 can guarantee that the surface of a vehicle body does not deform in the welding process. The front end of the vehicle body adsorption suspension 4 is provided with a positioning device 2 so as to complete positioning of the top of the whole vehicle body and complete process operation. The rear end of the vehicle body adsorption suspension frame 4 is provided with a pneumatic clamp 5, two magnetic clamps 6 are installed at the bottom of the vehicle body adsorption suspension frame 4, and the pneumatic clamp 5 can clamp the top of the vehicle body after the positioning is completed, so that the vehicle body adsorption suspension frame 4 moves to the next station to be welded.

According to an embodiment of the present disclosure, the appearance leveling structure 3 includes a bolt fixing frame 31, a vertical spring seat 32, a horizontal spring seat 33, a leveling seat 34, and a leveling copper plate 35, and the vehicle body adsorption suspension 4 is screwed and clamped with a plurality of bolt fixing frames 31, as shown in fig. 7, the bolt fixing frame 31 can be adjusted in position on the suspension 41 to adapt to vehicle bodies of different models. The bottom of arbitrary one bolt fastening frame 31 is fixed with vertical spring holder 32 spiro union, vertical spring holder 32 bottom and horizontal spring holder 33 elastic connection, inhale the clamp 6 when magnetism and adsorb the roof part after, pneumatic clamp 5 can loosen, because horizontal spring holder 33 side is fixed with flattening seat 34 spiro union, flattening seat 34 bottom is fixed with flattening copper 35 spiro union, consequently, can make flattening copper 35 fully laminate together with the welding part of automobile body, thereby make flattening copper 35 play the effect of protection automobile body appearance, furthermore, because the appearance of automobile body forms for the different cambered surface combinations of camber, the flattening copper 35 that needs a plurality of different shapes covers on the solder joint completely, consequently, the shape diverse bottom a plurality of flattening copper 35, thereby realize its technical objective.

According to a specific embodiment of the present disclosure, the vehicle body adsorption suspension 4 includes a suspension 41, a rotary seat 42, a servo pump station 43 and suction cups 44, the bolt fixing frame 31 is fixedly disposed on the suspension 41, the rotary seat 42 is mounted at the upper end of the suspension 41, the rotary seat 42 is connected to a crown block for loading the suspension 41, as shown in fig. 2, the lower end of the suspension 41 is provided with a plurality of suction cups 44, the suction cups 44 are all communicated with the servo pump station 43, the servo pump station 43 is fixedly disposed on the suspension 41, after welding is completed, the servo pump station 43 adsorbs the whole vehicle body on the suction cups 44 through the suction cups 44, so as to increase suction force to prevent the vehicle body from falling off, and thereby drive the whole vehicle body to leave a welding production line.

According to a specific embodiment of the present disclosure, the positioning device 2 includes a moving cylinder 21, a sensor 22, a mounting frame 23 and a probe 24, a servo pump station 43 is connected to the moving cylinder 21 to control the moving cylinder 21 to move in a telescopic manner, and then drive the probe 24 to move up and down, the sensor 22 is disposed at the bottom of the moving cylinder 21, the sensor 22 is electrically connected to the probe 24, and the probe 24 is in transmission connection with the moving cylinder 21, as shown in fig. 2. The positioning devices 2 mounted on the suspensions 41 are provided in two sets in total, and when the probe 24 is moved down, the probe 24 is directly inserted into a positioning hole in the top of the vehicle body (the positioning hole is a screw hole for mounting the vehicle body and other components), thereby restricting the degree of freedom of rotation of the vehicle body in the vertical direction.

According to an embodiment of the present disclosure, the pneumatic clamp 5 includes a clamping cylinder 51, a piston rod 52, a clamping jaw 53, an upper pressing jaw 54, a lower pressing jaw 55 and a clamp base 56, the probe 24 is fixedly disposed on the upper pressing jaw 54, the lower pressing jaw 55 is disposed below the upper pressing jaw 54, the lower pressing jaw 55 is fixedly disposed on the suspension 41, when the probe 24 is directly inserted into the top of the vehicle body for positioning, the clamping cylinder 51 is controlled by the servo pump station 43 to contract, so that the piston rod 52 drives the lower pressing jaw 55 to move up to clamp the end of the vehicle body, the suspension 41 is fixedly screwed with the clamp base 56, the clamping cylinder 51 is mounted on the clamp base 56, the piston rod 52 is inserted into the clamping cylinder 51, the piston rod 52 is hinged with the clamping jaw 53, the clamping jaw 53 is movably disposed on the clamp base 56, and the lateral rotational freedom of the vehicle body can be maintained after the lower pressing jaw 55 moves up to clamp the vehicle body.

According to a specific embodiment of the invention, the magnetic suction clamp 6 comprises an adjusting plate 61, a limiting clamp 62 and an electromagnet 63, the suspension 41 is screwed and fixed with the limiting clamp 62, the limiting clamp 62 is movably provided with the adjusting plate 61, as shown in fig. 3, the adjusting plate 61 is provided with two through grooves, the adjusting plate 61 is screwed and fixed with the electromagnet 63, therefore, the relative position of the limiting clamp 62 and the electromagnet 63 can be adjusted through the two through grooves, the electromagnet 63 can be adsorbed on the top of the vehicle body after the electromagnet 63 is electrified, and simultaneously the limiting clamp 62 is driven to abut against the edge of the vehicle body, so as to limit the forward rotational freedom degree of the vehicle body, therefore, the problem of the rotation of the vehicle body can be prevented through the magnetic suction clamp 6, the pneumatic clamp 5 and the positioning device 2, the vehicle body can integrally move along with the suspension 41, so as to remarkably improve the welding precision, and simultaneously, the leveling copper plate 35 is attached to the vehicle body, the problem of deformation of the welding position is avoided.

According to one embodiment of the invention, the spot welding tongs 1 comprises a transmission device 11, a mechanical arm connecting frame 12, an anode welding head 13, a tongs body 14 and a cathode welding head 15, wherein the upper end of a leveling copper plate 35 abuts against the anode welding head 13, the anode welding head 13 is in transmission connection with the transmission device 11, the transmission device 11 is fixedly arranged at the end part of the mechanical arm connecting frame 12, the anode welding head 13 can be driven to move up and down through the transmission device 11, and pressure is formed on the leveling copper plate 35 to compress a welding point to prevent the part from being heated and deformed. The arm is connected with arm link 12 transmission, arm link 12 is fixed with 14 one end spiro union of pincers body, can freely control position and the gesture of pincers body 14 from this, pincers body 14 other end is provided with negative pole soldered connection 15, when welding, the heavy current passes through positive pole soldered connection 13 in proper order, flattening copper 35, automobile body solder joint and negative pole soldered connection 15, because the position resistance of automobile body solder joint is the highest, consequently produce a large amount of heats with this to melt the automobile body and form the nugget at the position of automobile body solder joint, realize the welding of automobile body, this welding mode is the thermal resistance welding under the pressure effect, need not solder bonding and the operating time is short, therefore, the cost is low, and keep the automobile body appearance unchangeable through flattening copper 35, compare prior art. The welding spot is not required to be shielded by adding the inner and outer decorations, and the mass production is facilitated.

According to one embodiment of the present disclosure, the transmission device 11 includes a motor 111, a lead screw 112, a telescopic tube 113 and a water pipe 114, the robot arm connecting frame 12 is screwed and fixed to the motor 111, the motor 111 is coaxially connected to the lead screw 112 in a transmission manner, the lead screw 112 is inserted into the telescopic tube 113, the lead screw 112 is in a threaded transmission connection with the telescopic tube 113, the telescopic tube 113 is communicated with the water pipe 114, and the water pipe 114 is communicated with the anode welding head 13, as shown in fig. 8, when the motor 111 rotates, the lead screw 112 is driven to rotate together, the inner wall of the telescopic tube 113 and the lead screw 112 form a screw pair, the outer wall of the telescopic tube 113 is provided with a chute to move along the axis, therefore, when the lead screw 112 rotates, the telescopic tube 113, the water pipe 114 and the anode welding head 13 are connected to each other, so as to drive the anode welding head 13 to perform a telescopic motion, and then press and level the copper plate 35, and the water pipe 114 is used for introducing a cooling liquid, further, a similar water pipe 114 is also provided on the cathode welding head 15, so that the anode welding head 13 and the cathode welding head 15 can be prevented from being deformed due to the temperature rise during the welding process, and the welding spot can be rapidly cooled, condensed and formed.

Example 2

The embodiment 2 of the invention provides a welding method, which comprises the above-mentioned device for protecting and welding the appearance of the automobile body with the welded copper plate, and comprises the following steps;

the moving cylinder 21 drives the probe 24 to move downwards, so that the probe 24 is inserted into the positioning hole of the vehicle body, then the electromagnet 63 is electrified to adsorb the vehicle body, the limiting pliers 62 are abutted to the edge of the vehicle body, the top of the vehicle body is aligned with the metal plates on two sides, and meanwhile, the bottom of the leveling copper plate 35 is attached to the vehicle body.

According to a specific embodiment of the present invention, the motor 111 drives the screw 112 to rotate, the telescopic tube 113 drives the anode welding head 13 to move down to abut against the top of the leveling copper plate 35, the water pipe 114 feeds cooling liquid to the anode welding head 13, the anode welding head 13 and the cathode welding head 15 are aligned to clamp the welding point of the vehicle body, after the welding is completed, the suction cup 44 adsorbs the whole vehicle body, and after the vehicle body leaves the station, the suction cup 44, the electromagnet 63, the moving cylinder 21 and the clamping cylinder 51 are all released.

The using process of the invention is as follows:

firstly, the moving cylinder 21 is driven, the probe 24 is inserted into a positioning hole of a vehicle body, after the sensor 22 senses feedback information of the probe 24, the electromagnet 63 is electrified to magnetically attract the top of the vehicle body, meanwhile, the limiting clamp 62 is abutted against the edge of the vehicle body, meanwhile, the clamping cylinder 51 is started to drive the lower pressing clamp 55 to be folded with the upper pressing clamp 54, so that the top of the vehicle body is clamped, then, parts on two sides of the vehicle body are aligned with the top of the vehicle body, the mechanical arm drives the mechanical arm connecting frame 12 to weld the vehicle body, the anode welding head 13 is driven by the transmission device 11 to press and flatten the copper plate 35, and the electricity is conducted, so that current passes through the vehicle body, a large amount of heat is formed on the vehicle body in a short time, a nugget is formed, meanwhile, cooling liquid passes through the anode welding head 13 and the cathode welding head 15, so that welding spots are rapidly cooled and shaped, and finally, the suction disc 44 adsorbs the welded vehicle body and leaves a station.

Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, it is intended that all such modifications and alterations be included within the scope of this invention as defined in the appended claims.

Claims

1. The utility model provides an automobile body outward appearance welding copper shielded welding device, its characterized in that inhales clamp (6) including spot welding pincers (1), positioner (2), outward appearance flattening structure (3), automobile body absorption suspension (4), pneumatic clamp (5) and magnetism, a plurality of spot welding pincers (1) are arranged and are adsorbed suspension (4) the outside at the automobile body, a plurality of outward appearance flattening structures (3) are installed to the spiro union on the automobile body absorption suspension (4), automobile body absorption suspension (4) front end is provided with positioner (2), automobile body absorption suspension (4) rear end is provided with pneumatic clamp (5), clamp (6) are inhaled to two magnetism installed to automobile body absorption suspension (4) bottom.

2. The automotive body appearance welding copper plate protection welding device is characterized in that the appearance leveling structure (3) comprises a bolt fixing frame (31), a vertical spring seat (32), a transverse spring seat (33), a leveling seat (34) and a leveling copper plate (35), a plurality of bolt fixing frames (31) are screwed and clamped on the automotive body adsorption suspension (4), the bottom end of any one of the bolt fixing frames (31) is screwed and fixed with the vertical spring seat (32), the bottom end of the vertical spring seat (32) is elastically connected with the transverse spring seat (33), the side face of the transverse spring seat (33) is screwed and fixed with the leveling seat (34), and the bottom of the leveling seat (34) is screwed and fixed with the leveling copper plate (35).

3. The automotive body appearance welding copper plate arc-welding device according to claim 2 is characterized in that the automotive body adsorption suspension (4) comprises a suspension (41), a rotary seat (42), a servo pump station (43) and suckers (44), the bolt fixing frame (31) is fixedly arranged on the suspension (41), the rotary seat (42) is installed at the upper end of the suspension (41), a plurality of suckers (44) are arranged at the lower end of the suspension (41), the suckers (44) are communicated with the servo pump station (43), and the servo pump station (43) is fixedly arranged on the suspension (41).

4. The automotive body appearance welding copper plate arc welding device according to claim 3 is characterized in that the positioning device (2) comprises a moving cylinder (21), a sensor (22), a mounting frame (23) and a probe (24), the servo pump station (43) is connected with the moving cylinder (21), the sensor (22) is arranged at the bottom of the moving cylinder (21), the sensor (22) is electrically connected with the probe (24), and the probe (24) is in transmission connection with the moving cylinder (21).

5. The automotive body appearance welding copper plate protection welding device according to claim 4 is characterized in that the pneumatic clamp (5) comprises a clamping cylinder (51), a piston rod (52), a clamping jaw (53), an upper pressing clamp (54), a lower pressing clamp (55) and a clamp base (56), the probe (24) is fixedly arranged on the upper pressing clamp (54), the lower pressing clamp (55) is arranged below the upper pressing clamp (54), the lower pressing clamp (55) is fixedly arranged on the suspension bracket (41), the suspension bracket (41) is fixedly connected with the clamp base (56) in a threaded mode, the clamping cylinder (51) is installed on the clamp base (56), the piston rod (52) is inserted into the clamping cylinder (51), the piston rod (52) is hinged to the clamping jaw (53), and the clamping jaw (53) is movably arranged on the clamp base (56).

6. The automotive body appearance welded copper plate arc welding device according to claim 3, characterized in that the magnetic suction clamp (6) comprises an adjusting plate (61), a limiting clamp (62) and an electromagnet (63), the suspension (41) and the limiting clamp (62) are fixed in a threaded manner, the adjusting plate (61) is movably arranged on the limiting clamp (62), and the adjusting plate (61) and the electromagnet (63) are fixed in a threaded manner.

7. The automotive body appearance welding copper plate protection welding device is characterized in that the spot welding tongs (1) comprise a transmission device (11), a mechanical arm connecting frame (12), an anode welding head (13), a tongs body (14) and a cathode welding head (15), the upper end of the leveling copper plate (35) is abutted against the anode welding head (13), the anode welding head (13) is in transmission connection with the transmission device (11), the transmission device (11) is fixedly arranged at the end part of the mechanical arm connecting frame (12), the mechanical arm connecting frame (12) is in threaded connection with one end of the tongs body (14), and the cathode welding head (15) is arranged at the other end of the tongs body (14).

8. The welding copper plate protection device for the appearance of the automobile body according to claim 7 is characterized in that the transmission device (11) comprises a motor (111), a lead screw (112), a telescopic pipe (113) and a water passing pipe (114), the mechanical arm connecting frame (12) is fixedly connected with the motor (111) in a threaded mode, the motor (111) is in coaxial transmission connection with the lead screw (112), the lead screw (112) is inserted into the telescopic pipe (113), the lead screw (112) is in threaded transmission connection with the telescopic pipe (113), the telescopic pipe (113) is communicated with the water passing pipe (114), and the water passing pipe (114) is communicated with the anode welding head (13).

9. A welding method comprising the automotive body appearance welded copper plate shielded welding device according to claim 8, characterized by comprising the steps of;

firstly, a moving cylinder (21) drives a probe (24) to move downwards, so that the probe (24) is inserted into a positioning hole of an automobile body, then an electromagnet (63) is electrified to adsorb the automobile body, so that the top of the automobile body is aligned with metal plates on two sides, and meanwhile, the bottom of a leveling copper plate (35) is attached to the automobile body;

the motor (111) drives the lead screw (112) to rotate, the telescopic pipe (113) drives the anode welding head (13) to move downwards to abut against the top of the leveling copper plate (35), the water pipe (114) introduces cooling liquid to the anode welding head (13), the anode welding head (13) and the cathode welding head (15) are opposite to each other to clamp welding spots of the automobile body, and after welding is completed, the sucker (44) adsorbs the whole automobile body.