Multi-degree-of-freedom welding mechanical arm

Abstract

The invention relates to the technical field of welding equipment, and discloses a multi-degree-of-freedom welding mechanical arm which comprises a base, a mounting table is fixedly connected to the upper side face of the base, a horizontal rotating disc is movably embedded in the upper side face of the mounting table, and a horizontal rotating base is fixedly connected to the upper side face of the horizontal rotating disc. Driving rotating shafts are rotationally connected to the inner walls of the two sides of the horizontal rotating base, a vertical driving motor is fixedly connected to one end of each driving rotating shaft, an up-down swinging device is arranged on the other side of the horizontal rotating base, a horizontal rotating driving assembly is arranged in an inner cavity of the mounting table, and a welding arm connecting base is rotationally connected to the upper end of a vertical rotating connecting piece; according to the multi-degree-of-freedom welding mechanical arm, through multi-dimensional movement, the flexibility is improved, the welding head is accurately controlled, the working range is expanded, the welding quality and efficiency are remarkably improved, and the multi-degree-of-freedom welding mechanical arm is suitable for complex and changeable welding scenes.

Description

Technical Field

[0001] The invention relates to the technical field of welding equipment, in particular to a multi-degree-of-freedom welding robot arm. Background Art

[0002] In modern manufacturing, welding is a key link in connecting and assembling metal components. Its quality and efficiency are directly related to the overall performance and production cost of the product. With the continuous advancement of industrial technology and the increasing popularity of automated production, the requirements for welding operations are becoming higher and higher. Especially in the assembly of large components, welding of precision parts, and the manufacturing of complex structural parts, a new type of welding robot with multiple degrees of freedom that can flexibly cope with various welding scenarios is extremely important.

[0003] When faced with welding tasks for large components or precision parts, a significant technical challenge is how to efficiently and accurately complete welding operations at inflection points, depressions, corners, and other complex-shaped areas. Traditional welding manipulators, limited by their design limitations and lack of flexibility, often find it difficult to reach and effectively weld these so-called "corners and crannies". These hard-to-reach areas require not only a high degree of flexibility and multiple degrees of freedom in the welding manipulator, but also the ability to accurately control the position and angle of the welding head to ensure welding quality and the integrity of the overall structure. For this reason, the present invention proposes a multi-degree-of-freedom welding manipulator. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a multi-degree-of-freedom welding robot arm to solve the above-mentioned problems.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: A multi-degree-of-freedom welding robot arm comprises a base, wherein the bottom of the base is fixedly connected with four universal wheels, the upper side surface of the base is fixedly connected with a mounting table, the upper side surface of the mounting table is movably embedded with a horizontal turntable, the upper side surface of the horizontal turntable is fixedly connected with a horizontal rotating base, the inner walls on both sides of the horizontal rotating base are rotatably connected with a driving shaft, one end of the driving shaft extends to one side of the horizontal rotating base and is fixedly connected with a vertical driving motor, and the other side of the horizontal rotating base is provided with an up and down swinging device, the inner cavity of the mounting table is hollow, and a horizontal rotation driving assembly is provided in the inner cavity of the mounting table, a vertical rotating connecting piece is fixedly connected to the driving shaft, the upper end of the vertical rotating connecting piece is rotatably connected with a welding arm connecting seat, one side of the welding arm connecting seat is fixedly connected with a rotating driving motor, and the other side of the welding arm connecting seat is rotatably connected with a rotating connecting rod, and the end of the rotating connecting rod away from the welding arm connecting seat is provided with a port swinging assembly, and a welding head is provided on the swinging assembly.

[0006] Preferably, both ends of the vertical rotating connector are in a U shape, and symmetrical rotating holes are provided at the upper and lower ends of the vertical rotating connector.

[0007] Preferably, the welding arm connecting seat is composed of two parts. The upper end of the welding arm connecting seat is a rectangular connecting plate, and the lower end of the welding arm connecting seat is in an inverted U shape. The welding arm connecting seat is rotatably connected to the vertical rotating connector.

[0008] Preferably, the horizontal rotation driving assembly includes a horizontal rotation motor, a first bevel gear, a horizontal rotating rod, and a second bevel gear. One end of the inner wall of the bottom side of the mounting table is fixedly connected with a horizontal rotation motor, and the rotating shaft of the horizontal rotation motor is fixedly connected with a first bevel gear. The inner wall of the bottom side of the mounting table is rotatably connected with a horizontal rotating rod, and the lower end of the side surface of the horizontal rotating rod is fixedly connected with a second bevel gear. The first bevel gear and the second bevel gear are meshed, and the top of the horizontal rotating rod is fixedly connected to the center of the lower side surface of the horizontal turntable.

[0009] Preferably, the up-and-down swinging device includes a third bevel gear, a swinging driving motor, and a fourth bevel gear. One end of the driving rotating shaft far away from the vertical driving motor extends to one side of the horizontal rotating base and is fixedly connected with a rotating sleeve. One end of the rotating sleeve far away from the vertical driving motor is fixedly connected with a third bevel gear. The upper side surface of the horizontal turntable is fixedly connected with a swinging driving motor, and the rotating shaft of the swinging driving motor is fixedly connected with a fourth bevel gear. The fourth bevel gear and the third bevel gear are meshed.

[0010] Preferably, the up-and-down swinging device further includes a swinging connecting arm, a connecting rod, a pulling connecting rod, and a connecting plate. Swinging connecting arms are rotatably connected to the side surface of the driving rotating shaft corresponding to both ends of the vertical rotating connector. One ends of the two swinging connecting arms far away from the driving rotating shaft are rotatably connected with a connecting rod, and the two ends of the connecting rod are rotatably connected with pulling connecting rods. The swinging connecting arm close to the swinging driving motor is fixedly connected with the rotating sleeve. The upper ends of the two pulling connecting rods are both hinged with a connecting plate, and the two connecting plates are both fixedly connected to the two ends of the side surface of the lower end of the welding arm connecting seat.

[0011] Preferably, the port swinging assembly includes a U-shaped connecting short plate, a U-shaped connecting long plate, and a head adjusting motor. One end of the rotating connecting rod far away from the welding arm connecting seat is fixedly connected with a U-shaped connecting short plate. The inner walls on both sides of the U-shaped connecting short plate are rotatably connected with a U-shaped connecting long plate. One side of the U-shaped connecting short plate is fixedly connected with a head adjusting motor, and the rotating shaft of the head adjusting motor is fixedly connected with the rotating shaft of the U-shaped connecting short plate and the U-shaped connecting long plate.

[0012] Preferably, a welding torch is fixedly connected to the inner wall of the side of the U-shaped connecting long plate far away from the U-shaped connecting short plate, and a welding head is fixedly connected to the welding torch.

[0013] Compared with the prior art, the present invention provides a multi-degree-of-freedom welding robot arm, which has the following beneficial effects: This multi-degree-of-freedom welding robot arm integrates multiple movement modes such as horizontal, vertical and swinging, providing flexibility and versatility for welding operations, allowing the robot arm to easily cope with various complex and changeable welding scenarios. Whether it is the assembly of large components or the welding of precision parts, it can achieve efficient and accurate operations, thereby greatly improving the production efficiency and processing quality of welding operations.

[0014] This multi-degree-of-freedom welding robot arm addresses the limitations of traditional welding robots when welding in areas with complex shapes. The device uses a multi-degree-of-freedom design, including horizontal rotation, vertical rotation, and up and down swinging, etc., which greatly improves the flexibility and accessibility of the robot arm. This enables the robot arm to easily reach and weld inflection points, depressions, corners and other hard-to-reach areas in large components or precision parts, effectively solving the welding problems mentioned in the background technology and improving the comprehensiveness and completeness of welding operations.

[0015] Through the precise control of the swing drive motor, the multi-degree-of-freedom welding robot arm can swing up and down over a wide range in the vertical plane, thereby easily covering a wider welding area, improving the flexibility of the welding operation, and enabling the robot arm to handle a wider variety of welding tasks.

[0016] This multi-degree-of-freedom welding robot arm achieves fine adjustment of the welding head position and angle through a precise control system. The introduction of the end adjustment motor enables the welding gun and welding head to be flexibly adjusted according to the specific position and direction of the weld, ensuring that the welding head always maintains the best alignment with the weld, thereby greatly improving the accuracy and quality of welding.

[0017] The multi-degree-of-freedom welding robot arm can move and rotate in a large range in three-dimensional space through the coordinated work of the horizontal rotation motor, the vertical drive motor and the swing drive motor, effectively expanding the working range of the welding operation, which enables the robot arm to complete more welding tasks in a shorter time and significantly improves production efficiency. At the same time, the multi-degree-of-freedom design also reduces the need for manual intervention and transposition, further improving the overall efficiency of the automated production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a schematic diagram of the inner cavity structure of the mounting platform in the present invention; Figure 3 The structure of the up and down swing device in the present invention is shown in FIG. Figure 1 ; Figure 4 The structure of the up and down swing device in the present invention is shown in FIG. Figure 2 ; Figure 5 It is a schematic diagram of the structure of the pulling connecting rod and the connecting rod in the present invention; Figure 6 It is a schematic diagram of the structure of the vertical rotating connecting member in the present invention; Figure 7 It is a schematic diagram of the structure of the rotary drive motor in the present invention; Figure 8 This is a schematic diagram of the structure of the welding arm connecting seat in the present invention; Fig. 9 It is a schematic diagram of the structure of the port swing assembly in the present invention.

[0019] In the figure: 1. base; 2. universal wheel; 3. mounting table; 4. horizontal turntable; 5. horizontal rotating base; 6. driving shaft; 7. vertical driving motor; 8. up and down swinging device; 9. vertical rotating connecting piece; 10. welding arm connecting seat; 11. rotating driving motor; 12. rotating connecting rod; 13. horizontal rotating motor; 14. first bevel gear; 15. horizontal rotating rod; 16. second bevel gear; 17. third bevel gear; 18. swing driving motor; 19. fourth bevel gear; 20. swing connecting arm; 21. connecting rod; 22. pulling connecting rod; 23. connecting plate; 24. U-shaped connecting short plate; 25. U-shaped connecting long plate; 26. end adjustment motor; 27. welding gun; 28. welding head. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] See also Figure 1-9, A multi-degree-of-freedom welding robotic arm, comprising a base 1. Four universal wheels 2 are fixedly connected to the bottom of the base 1. An installation platform 3 is fixedly connected to the upper side of the base 1. A horizontal turntable 4 is movably embedded in the upper side of the installation platform 3. A horizontal rotation base 5 is fixedly connected to the upper side of the horizontal turntable 4. Driving rotating shafts 6 are rotatably connected to the inner walls on both sides of the horizontal rotation base 5. One end of the driving rotating shaft 6 extends to one side of the horizontal rotation base 5 and is fixedly connected to a vertical driving motor 7. An up-and-down swing device 8 is arranged on the other side of the horizontal rotation base 5. The inner cavity of the installation platform 3 is hollow. A horizontal rotation driving assembly is arranged in the inner cavity of the installation platform 3. A vertical rotation connecting piece 9 is fixedly connected to the driving rotating shaft 6. The upper end of the vertical rotation connecting piece 9 is rotatably connected to a welding arm connecting seat 10. A rotation driving motor 11 is fixedly connected to one side of the welding arm connecting seat 10. A rotation connecting rod 12 is rotatably connected to the other side of the welding arm connecting seat 10. A port swing assembly is arranged at one end of the rotation connecting rod 12 away from the welding arm connecting seat 10. A welding head 28 is arranged on the swing assembly.

[0022] Further, both ends of the vertical rotation connecting piece 9 are in a C shape, and symmetrically arranged rotation holes are opened at the upper and lower ends of the vertical rotation connecting piece 9. Its function is to provide a stable structural basis for the rotational connection with the welding arm connecting seat 10. Through the rotation holes, the accuracy and flexibility of the connection can be ensured, making the rotation of the welding arm connecting seat 10 on the vertical rotation connecting piece 9 smoother, effectively reducing the friction and jamming caused by unreasonable connection structures, ensuring the accuracy and stability of the robotic arm during vertical movement, thereby controlling the position of the welding head 28 more precisely and improving the welding quality.

[0023] Further, the welding arm connecting seat 10 is composed of two parts. The upper end of the welding arm connecting seat 10 is a rectangular connecting plate, and the lower end of the welding arm connecting seat 10 is in an inverted U shape. The welding arm connecting seat 10 is rotatably connected to the vertical rotation connecting piece 9. The lower end of the welding arm connecting seat 10 is in an inverted U shape, and the welding arm connecting seat 10 is rotatably connected to the vertical rotation connecting piece 9. The rectangular connecting plate provides a stable installation plane for components such as the rotation driving motor 11, ensuring that it will not be displaced or shaken due to uneven force during the working process.

[0024] Furthermore, the horizontal rotation driving assembly includes a horizontal rotation motor 13, a first bevel gear 14, a horizontal rotation rod 15 and a second bevel gear 16. The horizontal rotation motor 13 is fixedly connected to one end of the bottom inner wall of the mounting platform 3, and the first bevel gear 14 is fixedly connected to the rotating shaft of the horizontal rotation motor 13. The bottom inner wall of the mounting platform 3 is rotatably connected to the horizontal rotation rod 15, and the lower end of the side of the horizontal rotation rod 15 is fixedly connected to the second bevel gear 16. The first bevel gear 14 and the second bevel gear 16 are meshed, and the top of the horizontal rotation rod 15 is fixedly connected to the axis of the lower side of the horizontal turntable 4. The horizontal rotation motor 13 serves as a power source for horizontal rotation. The torque output by the horizontal rotation motor 13 is decelerated, increased in torque and converted in direction by the gear transmission system composed of the first bevel gear 14 and the second bevel gear 16, and then smoothly transmitted to the horizontal rotation rod 15. This gear transmission method has high transmission efficiency and accuracy, and can accurately control the horizontal turntable 4. The rotation angle and speed meet the requirements for fast and precise adjustment of the horizontal position of the robot arm in different welding processes. For example, when welding different parts of a large workpiece, the welding head 28 can be quickly moved to a specified horizontal position, thereby improving the overall efficiency of the welding operation.

[0025] Furthermore, the up and down swinging device 8 includes a third bevel gear 17, a swinging drive motor 18 and a fourth bevel gear 19. The end of the driving shaft 6 away from the vertical drive motor 7 extends to one side of the horizontal rotating base 5 and is fixedly connected to the rotating sleeve. The end of the rotating sleeve away from the vertical drive motor 7 is fixedly connected to the third bevel gear 17. The upper side surface of the horizontal turntable 4 is fixedly connected to the swinging drive motor 18. The fourth bevel gear 19 is fixedly connected to the rotating shaft of the swinging drive motor 18. The fourth bevel gear 19 and the third bevel gear 17 are meshed. The swinging drive motor 18 serves as a power provider for the up and down swinging. Through the meshing transmission of the fourth bevel gear 19 and the third bevel gear 17, the power is transmitted to the rotating sleeve and the swing connecting arm 20 connected thereto, so as to achieve precise control of the swing amplitude and speed of the swing connecting arm 20, thereby precisely controlling the up and down swinging angles of the welding arm connecting seat 10 and the welding assembly thereon, so that when welding workpieces with complex curved surfaces or welds of different heights, the welding head 28 can be made to Better fit the weld to ensure uniformity and quality of welding.

[0026] Furthermore, the up and down swing device 8 also includes a swing arm 20, a connecting rod 21, a pulling link 22 and a connecting plate 23. The two ends of the corresponding vertical rotating connecting member 9 on the side of the driving shaft 6 are rotatably connected with the swing arm 20, and the two ends of the two swing arms 20 away from the driving shaft 6 are rotatably connected with the connecting rod 21. The two ends of the connecting rod 21 are rotatably connected with the pulling link 22. The swing arm 20 near one end of the swing driving motor 18 is fixedly connected to the rotating sleeve, and the upper ends of the two pulling links 22 are hinged with connecting plates 23, and the two connecting plates 23 are fixedly connected to the two ends of the side of the lower end of the welding arm connecting seat 10.

[0027] Furthermore, the port swing assembly includes a U-shaped connecting short plate 24, a U-shaped connecting long plate 25 and an end adjustment motor 26. The end of the rotating connecting rod 12 away from the welding arm connecting seat 10 is fixedly connected to the U-shaped connecting short plate 24. The inner walls on both sides of the U-shaped connecting short plate 24 are rotatably connected to the U-shaped connecting long plate 25. One side of the U-shaped connecting short plate 24 is fixedly connected to the end adjustment motor 26. The rotating shaft of the end adjustment motor 26 is fixedly connected to the rotating shafts of the U-shaped connecting short plate 24 and the U-shaped connecting long plate 25. The structure composed of the U-shaped connecting short plate 24 and the U-shaped connecting long plate 25 provides a stable installation platform for the welding gun 27, and the fixed connection between the rotating shaft of the end adjustment motor 26 and the rotating shaft can achieve precise angle control of the U-shaped connecting long plate 25. When welding welds of different shapes and angles, the end adjustment motor 26 can quickly and accurately adjust the angle of the welding gun 27 and the welding head 28 thereon according to preset welding parameters or real-time welding requirements, ensuring that the welding head 28 can always contact the weld at the optimal welding angle, thereby improving the welding quality and the weld forming effect.

[0028] Furthermore, a welding gun 27 is fixedly connected to the inner wall of one side of the U-shaped connecting long plate 25 away from the U-shaped connecting short plate 24 , and a welding head 28 is fixedly connected to the welding gun 27 .

[0029] Working principle: First, the base 1 of the robot arm can be flexibly moved through four universal wheels 2 to ensure that the robot arm can easily reach any position in the working area. The mounting platform 3 fixed on the base 1 serves as the supporting platform of the entire robot arm. Its internal hollow design accommodates the horizontal rotation drive component to provide power for the horizontal rotation of the robot arm. When the horizontal rotation motor 13 is started, its shaft drives the first bevel gear 14 to rotate, and then engages with the second bevel gear 16 to drive the horizontal rotation rod 15 to rotate in the mounting platform 3. The top of the horizontal rotation rod 15 is fixedly connected to the axis of the lower side of the horizontal turntable 4. Therefore, the horizontal turntable 4 can rotate with the horizontal rotation rod 15 to realize 360-degree free rotation of the robot arm on the horizontal plane. In the horizontal rotation base 5 fixed on the upper side of the horizontal turntable 4, the driving shaft 6 is connected through the rotation at both ends, and is respectively connected to the vertical drive motor 7 and the vertical rotation connector 9.

[0030] When the vertical drive motor 7 is started, the entire upper structure (including the vertical rotation connector 9, the welding arm connection seat 10, etc.) is driven to rotate in the vertical direction through the driving shaft 6, thereby increasing the degree of freedom of the robot arm in the vertical plane. Specifically, the driving shaft 6 drives the vertical rotation connector 9 to rotate together, and the vertical rotation connector 9 serves as the supporting structure of the welding arm connection seat 10, and its rotational motion is directly transmitted to the welding arm connection seat 10. The welding arm connection seat 10 is not only fixed with a rotation drive motor 11, but also connected to the port swing assembly through a rotating connecting rod 12. Therefore, when the welding arm connection seat 10 rotates, the entire welding arm (including the rotation drive motor 11, the rotating connecting rod 12, the port swing assembly and the final welding head 28) will rotate in the vertical plane accordingly.

[0031] When the swing drive motor 18 is started, its rotating shaft drives the third bevel gear 17 to rotate and meshes with the fourth bevel gear 19 fixed on the rotating sleeve, thereby driving the rotating sleeve and the swing connecting arm 20 connected thereto to swing. The swing connecting arm 20 is connected to the connecting plate 23 through the connecting rod 21 and the pulling connecting rod 22, thereby driving the welding arm connecting seat 10 and the welding assembly thereon to swing up and down in the vertical plane, further expanding the working range of the robot arm. Specifically, with the rotation of the rotating shaft of the swing drive motor 18, the third bevel gear 17 also starts to rotate and meshes closely with the fourth bevel gear 19 fixed on the rotating sleeve. The rotating sleeve starts to rotate under the drive of the fourth bevel gear 19, and drives the swing connecting arm 20 closely connected thereto to swing together. The swinging motion of the swing connecting arm 20 is further transmitted to the connecting plate 23 through the connecting rod 21 and the pulling connecting rod 22. Driven by the swing connecting arm 20, the connecting plate 23 drives the welding arm connecting seat 10 and the welding assembly thereon to swing up and down in the vertical plane.

[0032] When the end adjustment motor 26 is started, its rotating shaft drives the U-shaped connecting long plate 25 to rotate in the U-shaped connecting short plate 24, thereby adjusting the angle of the welding gun 27 and the welding head 28 thereon to ensure that the welding head can accurately align with the weld to achieve precise welding.

[0033] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-degree-of-freedom welding robot arm, comprising a base (1), characterized in that: Four universal wheels (2) are fixedly connected to the bottom of the base (1). An installation platform (3) is fixedly connected to the upper side surface of the base (1). A horizontal turntable (4) is movably embedded in the upper side surface of the installation platform (3). A horizontal rotation base (5) is fixedly connected to the upper side surface of the horizontal turntable (4). Driving rotating shafts (6) are rotatably connected to the inner walls on both sides of the horizontal rotation base (5). One end of the driving rotating shaft (6) extends to one side of the horizontal rotation base (5) and is fixedly connected to a vertical driving motor (7). An up-and-down swing device (8) is arranged on the other side of the horizontal rotation base (5). The inner cavity of the installation platform (3) is hollow. A horizontal rotation driving component is arranged in the inner cavity of the installation platform (3). A vertical rotation connecting piece (9) is fixedly connected to the driving rotating shaft (6). The upper end of the vertical rotation connecting piece (9) is rotatably connected to a welding arm connecting seat (10). A rotation driving motor (11) is fixedly connected to one side of the welding arm connecting seat (10). A rotation connecting rod (12) is rotatably connected to the other side of the welding arm connecting seat (10). A port swing component is arranged at the end of the rotation connecting rod (12) far away from the welding arm connecting seat (10). A welding head (28) is arranged on the swing component.

2. A multi-degree-of-freedom welding robot according to claim 1, characterized in that: Both ends of the vertical rotation connecting piece (9) are in a U shape, and symmetrically arranged rotation holes are formed at the upper and lower ends of the vertical rotation connecting piece (9).

3. The multi-degree-of-freedom welding robot arm according to claim 1, characterized in that: The welding arm connecting seat (10) is composed of two parts. The upper end of the welding arm connecting seat (10) is a rectangular connecting plate, and the lower end of the welding arm connecting seat (10) is in an inverted U shape. The welding arm connecting seat (10) is rotatably connected to the vertical rotation connecting piece (9).

4. The multi-degree-of-freedom welding robot arm according to claim 1, characterized in that: The horizontal rotation driving component includes a horizontal rotation motor (13), a first bevel gear (14), a horizontal rotating rod (15), and a second bevel gear (16). A horizontal rotation motor (13) is fixedly connected to one end of the bottom inner wall of the installation platform (3). A first bevel gear (14) is fixedly connected to the rotating shaft of the horizontal rotation motor (13). A horizontal rotating rod (15) is rotatably connected to the bottom inner wall of the installation platform (3). A second bevel gear (16) is fixedly connected to the lower side of the horizontal rotating rod (15). The first bevel gear (14) and the second bevel gear (16) are meshed. The top of the horizontal rotating rod (15) is fixedly connected to the center of the lower side surface of the horizontal turntable (4).

5. The multi-degree-of-freedom welding robot arm according to claim 1, characterized in that: The up-and-down swing device (8) includes a third bevel gear (17), a swing driving motor (18), and a fourth bevel gear (19). One end of the driving rotating shaft (6) far away from the vertical driving motor (7) extends to one side of the horizontal rotation base (5) and is fixedly connected to a rotating sleeve. A third bevel gear (17) is fixedly connected to the end of the rotating sleeve far away from the vertical driving motor (7). A swing driving motor (18) is fixedly connected to the upper side surface of the horizontal turntable (4). A fourth bevel gear (19) is fixedly connected to the rotating shaft of the swing driving motor (18). The fourth bevel gear (19) and the third bevel gear (17) are meshed.

6. A multi-degree-of-freedom welding robot according to claim 5, characterized in that: The up-and-down swing device (8) further comprises a swing connecting arm (20), a connecting rod (21), a pulling connecting rod (22) and a connecting plate (23). Both ends of the corresponding vertical rotating connecting member (9) on the side surface of the driving shaft (6) are rotatably connected to the swing connecting arms (20). The ends of the two swing connecting arms (20) away from the driving shaft (6) are rotatably connected to the connecting rod (21). Both ends of the connecting rod (21) are rotatably connected to the pulling connecting rods (22). The swing connecting arm (20) at one end close to the swing driving motor (18) is fixedly connected to the rotating sleeve. The upper ends of the two pulling connecting rods (22) are hingedly connected to the connecting plates (23). The two connecting plates (23) are fixedly connected to the two ends of the side surface of the lower end of the welding arm connecting seat (10).

7. The multi-degree-of-freedom welding robot arm according to claim 1, characterized in that: The port swing assembly comprises a U-shaped connecting short plate (24), a U-shaped connecting long plate (25) and an end adjustment motor (26); one end of the rotating connecting rod (12) away from the welding arm connecting seat (10) is fixedly connected to the U-shaped connecting short plate (24); the inner walls on both sides of the U-shaped connecting short plate (24) are rotatably connected to the U-shaped connecting long plate (25); one side of the U-shaped connecting short plate (24) is fixedly connected to the end adjustment motor (26); and the rotating shaft of the end adjustment motor (26) is fixedly connected to the rotating shafts of the U-shaped connecting short plate (24) and the U-shaped connecting long plate (25).

8. The multi-degree-of-freedom welding robot arm according to claim 7, characterized in that: A welding gun (27) is fixedly connected to the inner wall of the U-shaped connecting long plate (25) on a side away from the U-shaped connecting short plate (24), and a welding head (28) is fixedly connected to the welding gun (27).

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