Multi-axis joint structure of a spraying robot and a robot device thereof

Abstract

The present application belongs to the field of spraying technology, and is a multi-axis joint structure of a spraying robot, comprising a multi-axis flexible arm structure, which is composed of multiple unit joint bodies; the unit joint body comprises a positioning joint, a rubber connecting sleeve, a movable joint and an angle adjusting piece; the movable joint is used for active adjustment relative to the positioning joint; the angle adjusting piece is installed between the positioning joint and the movable joint; the angle adjusting piece is used for adjusting the rotation of the movable joint relative to the positioning joint; the multi-axis flexible arm structure is locally or multi-locally bent, so as to cope with workpieces with complex cavities, deep grooves, recessed curved surfaces or modeling obstructions on the periphery, complete accurate extension or reach the obstructed area for effective spraying; a robot device comprises a robot and a spraying head assembly, the robot comprises a mechanical arm, and the spraying head assembly comprises a spraying mechanical arm; the mechanical arm and the spraying mechanical arm each comprise the spraying robot multi-axis joint structure.

Description

Technical Field

[0001] This invention relates to the field of spraying technology, specifically to a multi-axis joint structure for a spraying robot and its robotic device. Background Technology

[0002] Spraying is a widely used surface treatment process in modern manufacturing, aiming to achieve purposes such as corrosion prevention, decoration, or functionalization by uniformly covering the surface of a workpiece with coating. Traditional spraying operations are mostly carried out manually, which has problems such as low efficiency, unstable quality, and great health hazards to operators. With the development of automation technology, spraying robots have emerged. Through a multi-axis joint structure, the spray head is driven to move along a predetermined trajectory, which can realize automated spraying of complex workpiece surfaces, significantly improving spraying efficiency, film thickness uniformity, and coating utilization. It has become an indispensable key equipment in industries such as automobiles, aerospace, 3C electronics, and furniture.

[0003] Currently, most existing painting robots employ multi-axis articulated robotic arm structures, with typical configurations including six-axis or seven-axis serial articulated robots. These robots utilize a series of rotary joints, including the base, upper arm, forearm, and wrist, to form an open-chain motion mechanism with multiple degrees of freedom. Each joint is typically driven by a servo motor and a precision reducer to achieve a wide range of pose adjustments for the end-effector nozzle within space. To balance the working range and motion flexibility, existing designs often set the arm length of each joint to a fixed value and employ a large joint motion radius to meet the painting requirements of workpieces of different sizes, resulting in an overall structure with a relatively long overhanging shape.

[0004] Because the arm lengths of each joint are fixed and the overall structure is relatively large, the minimum turning radius required for the robot's end effector nozzle during movement is correspondingly large. When facing workpieces with complex internal cavities, deep grooves, concave curved surfaces, or those with surrounding shapes that obstruct the view, the nozzle struggles to reach or access the obstructed areas for effective coating. Furthermore, limited by the compact design of the wrist joints and the internal pipeline layout, the existing structure has limited posture adjustment capabilities within confined spaces, often resulting in coating blind spots or uneven film thickness in certain areas. Summary of the Invention

[0005] To address the problem that existing painting robots suffer from large multi-axis joint adjustment radii and are limited by size, making it difficult for the spray nozzle to reach areas on the workpiece that are obstructed by shapes for spraying, this invention provides the following technical solution:

[0006] The painting robot has a multi-axis joint structure, including a multi-axis flexible arm structure, which is composed of multiple unit joint bodies; each unit joint body includes:

[0007] Positioning joints are used to provide support.

[0008] A movable joint is arranged side-by-side with the positioning joint; the movable joint is used for adjustment relative to the positioning joint.

[0009] An angle adjustment component is installed between the positioning joint and the movable joint; the angle adjustment component is used to adjust the rotation of the movable joint relative to the positioning joint.

[0010] A rubber connecting sleeve is fitted over the outside of the angle adjusting component; the rubber connecting sleeve connects between the positioning joint and the movable joint, and the rubber connecting sleeve is used to protect the angle adjusting component;

[0011] The angle adjustment component includes:

[0012] A hinged ball, one end of which is fixedly mounted on a movable joint; the other end of the hinged ball is hinged to a positioning joint;

[0013] The oscillating tube is fixed to the articulated ball and extends into the cavity inside the positioning joint;

[0014] A drive structure is assembled in a cavity inside the positioning joint; the drive structure is used to drive the rocker tube to rotate the movable joint synchronously.

[0015] During spraying, the multi-axis flexible arm structure activates angle adjustment components on one or more unit joints. The angle adjustment components use a drive structure to drive the swing tube to rotate the movable joint synchronously, completing the relative rotation of the movable joint and the positioning joint. This enables the multi-axis flexible arm structure to bend locally or in multiple places, allowing the spraying robot to accurately reach or reach the obscured areas of workpieces with complex internal cavities, deep grooves, concave curved surfaces, or shapes that obstruct the surrounding area for effective spraying. This avoids situations where there are blind spots in the spraying or uneven film thickness.

[0016] A further technical solution: A positioning tube is fixed on the side of the articulated ball away from the swing tube. The positioning tube is inserted and fixed on the mounting plate. The mounting plate is installed on the movable joint by multiple bolts.

[0017] Further technical solution: The driving structure includes:

[0018] The bearing ring is rotatably mounted on the swing tube;

[0019] A rotating connector, consisting of a U-shaped plate and a rotating plate, is mounted on the bearing ring.

[0020] The electric telescopic rod is mounted on the rotating connector at one end.

[0021] A rack ring is movably fitted outside the bearing ring; the inner wall of the bearing ring is fixed to the other end of the electric telescopic rod.

[0022] Further technical solution: The positioning joint includes:

[0023] Positioning ring;

[0024] A connecting cavity is formed on one side of the positioning ring; the connecting cavity is connected to the swing tube through a flexible connecting tube.

[0025] The articulated ball is hinged to the side of the positioning ring away from the connecting cavity, and the flexible connecting tube is connected to the movable joint through the swing tube, the articulated ball, and the positioning tube.

[0026] Further technical solution: The positioning joint further includes:

[0027] The servo motor is mounted on the positioning ring;

[0028] A drive gear is mounted on the output shaft of the servo motor via a rotating shaft and a coupling; the drive gear meshes with a rack ring; the rack ring is rotatably mounted inside a positioning ring via a bearing.

[0029] The drive housing is integrally fixed on the positioning ring; the drive housing is used to hold the drive gear, and the drive gear and the drive housing are rotatably assembled.

[0030] Further technical solution: The movable joint includes two parallel fixed tubes, with the columnar center lines of the two fixed tubes on the same straight line; the movable joint also includes a telescopic arm, which is located between the two fixed tubes; multiple hydraulic telescopic rods are installed inside the telescopic arm, and the multiple hydraulic telescopic rods are arranged in a circular array inside the telescopic arm; the hydraulic telescopic rods are used to adjust the extension and retraction degree of the telescopic arm.

[0031] Further technical solution: The telescopic arm includes multiple unit telescopic tubes, each unit telescopic tube including a sleeve and an insert tube, the insert tube being movably inserted inside the sleeve; the insert tube is provided with an anti-detachment protrusion, the anti-detachment protrusion being used to prevent the insert tube from falling out of the sleeve.

[0032] Another object of the present invention is to provide a robotic device, including a robot and a spray head assembly, wherein the robot and the spray head assembly are assembled together, the robot includes a robotic arm, the robotic arm is assembled with the spray head assembly, and the spray head assembly includes a spraying robotic arm; both the robotic arm and the spraying robotic arm include the multi-axis joint structure of the spraying robot described above.

[0033] Further technical solution: The robot also includes a chassis and a top plate, with the robotic arm mounted on the top plate. Multiple pneumatic telescopic rods are mounted between the chassis and the top plate, and the multiple pneumatic telescopic rods are distributed in a ring array inside the chassis and the top plate.

[0034] Further technical solution: The spray head assembly also includes a flexible shell, which is fitted over the outside of the spraying robot arm; the spraying robot arm also includes a spray head, which is assembled at the end of the multi-axis flexible arm structure.

[0035] In summary: During the spraying operation, the robot employs a hierarchical motion control strategy. First, the robotic arm and multiple pneumatic telescopic rods act as macroscopic positioning mechanisms, driving the spray head assembly to quickly reach the approximate work area near the workpiece on an overall scale. Once the spray head assembly enters the predetermined position, its built-in multi-axis flexible arm structure initiates fine-tuning of its posture. This multi-axis flexible arm structure consists of multiple unit joints connected in series, each unit joint including a positioning joint and a movable joint, which are connected by a spherical joint via a hinge ball joint. When local bending is required, the angle adjustment components on one or more joint units are activated, and the servo motor drives the gear to mesh with the rack ring, rotating the electric telescopic rod to the set position. Subsequently, the electric telescopic rod extends, utilizing its extension... The contraction motion drives the movable joint to deflect relative to the positioning joint around the articulated ball, and the swing tube moves synchronously accordingly, thereby realizing the active bending of the unit joint body. At the same time, the hydraulic telescopic rod set inside the movable joint can extend and retract to different degrees according to spatial constraints, thereby adjusting the overall arm length of the movable joint, so that the joint unit has the ability to be variable in length in the bending posture. Through the above-mentioned combined action of angle deflection and length extension, the multi-axis flexible arm can form one or more bending deformations in a local area, allowing the end nozzle to accurately extend into the interior of workpieces with complex internal cavities, deep grooves, concave curved surfaces or surrounding shapes that are obstructed, effectively reaching the obstructed areas that are difficult to cover by traditional rigid structures, avoiding the problems of spraying blind spots or uneven film thickness caused by structural interference.

[0036] The robotic arm and multiple pneumatic telescopic rods perform coarse positioning, quickly delivering the spray head assembly to a large area near the workpiece; while the multi-axis flexible arm structure is responsible for fine pose adjustment within the confined space; the two form a division of labor of "arrival first, adaptation later", avoiding the contradiction between a single long arm structure in large-scale movement and flexible local entry.

[0037] The angle adjustment component enables the active deflection of the movable joint around the hinge point, while the hydraulic telescopic rod enables the dynamic change of the arm length of the movable joint. The two work together within the same joint unit: bending changes the direction and entry angle of the nozzle, while telescopication compensates for the spatial positional shift caused by bending. The linkage between the two enables the nozzle to achieve continuous "bending and advancing" movement in narrow and tortuous channels.

[0038] The multi-axis flexible arm structure allows bending and extension movements to be initiated simultaneously or sequentially at multiple unit joints, and the deformation of each unit joint can be controlled independently. This multi-level series deformation structure enables the flexible arm to exhibit a continuous curvature change capability similar to a "bionic arm", which can fit the internal contour of complex irregular workpieces and achieve multi-point collaborative morphological adaptation.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] 1. During spraying, the multi-axis flexible arm structure activates angle adjustment components on one or more unit joints. The angle adjustment components use a drive structure to drive the swing tube to rotate the movable joint synchronously, completing the relative rotation of the movable joint and the positioning joint. This enables the multi-axis flexible arm structure to bend locally or in one or more places, allowing the spraying robot to accurately reach or reach the obscured areas of workpieces with complex internal cavities, deep grooves, concave curved surfaces, or shapes that obstruct the surrounding area for effective spraying. This avoids situations where there are blind spots in the spraying or uneven film thickness.

[0041] 2. During spraying, the telescopic arm can be extended and retracted to different degrees by the hydraulic telescopic rod. This allows for adjustment of the length of the movable joints through the extension and retraction of the telescopic arm, enabling posture adjustment in narrow spaces in conjunction with the angle adjustment components, thereby improving the uniformity and quality of spraying.

[0042] 3. Traditional multi-axis articulated robots are limited by fixed arm lengths and rigid joints. The minimum radius of motion of the end nozzle is determined by the sum of the lengths of each arm, making it difficult to enter narrow bends. This invention enables the nozzle to travel along a curved path into the obstructed area without increasing the overall turning radius through a combination of joint bending and joint extension. This achieves a leap from sweeping across a spherical surface to traversing a spatial curve, which is equivalent to expanding the robot's reachable space from a macroscopic spherical shell to the interior of an irregular cavity.

[0043] 4. Since each joint has both active bending capability and length adjustment capability, when the flexible arm enters the inner cavity of a workpiece with a complex shape, the geometry of the entire flexible arm can be dynamically matched with the direction of the inner cavity of the workpiece through the coordinated deformation of each joint. This adaptive shape not only reduces the complexity of trajectory planning, but also ensures that the nozzle and the workpiece surface always maintain the optimal spraying distance and angle, significantly improving the uniformity of the coating in hard-to-reach areas such as deep holes and grooves.

[0044] 5. In traditional solutions, to meet the needs of large-area spraying, the overall structure of the robot is often designed to be quite large, but this becomes an obstacle to entering complex workpieces. The present invention uses a configuration decomposition of a rigid upper arm composed of a robotic arm and multiple pneumatic telescopic rods for coarse positioning and a flexible lower arm composed of a multi-axis flexible arm structure for fine adaptation. This allows the equipment to maintain a large working range as a whole, while having miniaturized and flexible entry capabilities in certain areas. This resolves the long-standing design contradiction between large-area coverage and entry into narrow spaces, and achieves full-coverage spraying from macroscopic surfaces to microscopic cavities in one go without increasing the number of devices or workpiece repositioning. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of the robot device of the present invention;

[0046] Figure 2 This is a schematic diagram of the spray head assembly of the present invention;

[0047] Figure 3 for Figure 2 A sectional view;

[0048] Figure 4 for Figure 3 A schematic diagram of the structure of the spraying robot arm;

[0049] Figure 5 This is a schematic diagram of the multi-axis joint structure of the spraying robot of the present invention;

[0050] Figure 6 for Figure 5 A schematic diagram of the structure of the middle unit joint;

[0051] Figure 7 for Figure 6 A schematic diagram of the structure of the middle unit joint after the rubber connecting sleeve has been removed;

[0052] Figure 8 for Figure 7 Schematic diagram of the mid-positioning joint;

[0053] Figure 9 for Figure 7 A schematic diagram of the assembly structure of the movable joint and multi-axis flexible arm;

[0054] Figure 10 for Figure 9 A schematic diagram of a multi-axis flexible arm structure.

[0055] In the diagram: 100-Robot, 110-Chassis, 120-Pneumatic telescopic rod, 130-Top plate, 140-Mechanical arm; 200-Spray head assembly, 210-Flexible shell, 220-Spraying robotic arm, 230-Spray head, 240-Multi-axis flexible arm structure, 250-Unit joint body, 251-Positioning joint, 252-Rubber connecting sleeve, 253-Moving joint, 254-Angle adjustment component, 2511-Servo motor, 2512-Drive shell, 2513-Positioning ring, 2514-Connecting cavity, 2531-Telescopic arm, 2532-Fixed tube, 2541-Mounting plate, 2542-Hinge ball, 2543-Positioning tube, 2544-Swing tube, 2545-Rack ring, 2546-Bearing ring, 2547-Flexible connecting tube, 2548-Rotating connecting component, 2549-Electric telescopic rod. Detailed Implementation

[0056] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. In the description of the present invention, unless otherwise stated, "a plurality of" means two or more.

[0057] In embodiments of the present invention, such as Figures 5-7 As shown: The multi-axis joint structure of the painting robot includes a multi-axis flexible arm structure 240, which is composed of multiple unit joint bodies 250; each unit joint body 250 includes:

[0058] Positioning joint 251 is used to provide support force;

[0059] The movable joint 253 is arranged side by side with the positioning joint 251; the movable joint 253 is used to adjust its movement relative to the positioning joint 251.

[0060] An angle adjustment component 254 is installed between the positioning joint 251 and the movable joint 253; the angle adjustment component 254 is used to adjust the rotation of the movable joint 253 relative to the positioning joint 251.

[0061] A rubber connecting sleeve 252 is fitted over the angle adjusting member 254; the rubber connecting sleeve 252 is connected between the positioning joint 251 and the movable joint 253, and the rubber connecting sleeve 252 is used to protect the angle adjusting member 254.

[0062] During spraying, the multi-axis flexible arm structure 240 adjusts the rotational position of the movable joint 253 relative to the positioning joint 251 through angle adjustment components 254 on one or more unit joints 250. This allows the multi-axis flexible arm structure 240 to bend locally or in one or more places, enabling the spraying robot to accurately reach or reach the obscured areas for effective spraying of workpieces with complex internal cavities, deep grooves, concave curved surfaces, or shapes that obstruct the surrounding area. This avoids the occurrence of blind spots or uneven film thickness in some areas.

[0063] Among them, such as Figure 9 and Figure 10 As shown: Angle adjusting component 254 includes:

[0064] The hinge ball 2542 is fixedly mounted on the movable joint 253 at one end; the other end of the hinge ball 2542 is hinged to the positioning joint 251.

[0065] The swing tube 2544 is fixed to the hinge ball 2542 and extends into the cavity inside the positioning joint 251;

[0066] The drive structure is assembled in the cavity inside the positioning joint 251; the drive structure is used to drive the rocker tube 2544 to drive the movable joint 253 to rotate synchronously.

[0067] Therefore, existing painting robots suffer from problems such as large multi-axis joint adjustment radii and limited size, making it difficult for the spray nozzle to reach areas on the workpiece that are obstructed by shape for painting. This application can achieve the following:

[0068] During spraying, the multi-axis flexible arm structure 240 activates one or more angle adjustment components 254 on one or more unit joints 250. The angle adjustment component 254 uses a drive structure to drive the swing tube 2544 to drive the movable joint 253 to rotate synchronously, completing the relative rotation of the movable joint 253 and the positioning joint 251. This enables the multi-axis flexible arm structure 240 to bend locally or in one or more places, so that the spraying robot can accurately reach or reach the obscured area for effective spraying when dealing with workpieces with complex internal cavities, deep grooves, concave curved surfaces or shapes that are obstructed around them. This avoids situations where there are blind spots in the spraying or uneven film thickness in some areas.

[0069] In embodiments of the present invention, such as Figure 9 and Figure 10 As shown: The hinge ball 2542 is fixed with a positioning tube 2543 on the side away from the swing tube 2544. The positioning tube 2543 is inserted and fixed on the mounting plate 2541. The mounting plate 2541 is installed on the movable joint 253 by multiple bolts.

[0070] Further: such as Figure 10As shown: The driving structure includes:

[0071] Bearing ring 2546 is rotatably sleeved on rocker tube 2544;

[0072] A rotating connector 2548, which is composed of a U-shaped plate and a rotating plate, is mounted on the bearing ring 2546.

[0073] The electric telescopic rod 2549 is mounted on the rotating connector 2548 at one end;

[0074] The rack ring 2545 is movably sleeved on the outside of the bearing ring 2546; the inner wall of the bearing ring 2546 is fixed to the other end of the electric telescopic rod 2549.

[0075] It should be noted that the electric telescopic pole 2549 and its power supply wiring method are existing technologies. Their detailed structure can be found in existing literature and journals, and they can also be purchased directly on the market, or components can be purchased on the market to assemble them, etc.; they are not what this invention is intended to protect, and will not be described in detail here.

[0076] like Figure 7 and Figure 8 As shown: The positioning joint 251 includes:

[0077] Positioning ring 2513;

[0078] A connecting cavity 2514 is formed on one side of the positioning ring 2513; the connecting cavity 2514 is connected to the swing tube 2544 through a flexible connecting tube 2547.

[0079] Among them, the hinge ball 2542 is hinged to the side of the positioning ring 2513 away from the connecting cavity 2514, and the flexible connecting tube 2547 is connected to the movable joint 253 through the swing tube 2544, the hinge ball 2542 and the positioning tube 2543.

[0080] like Figures 7-10 As shown: The positioning joint 251 further includes:

[0081] Servo motor 2511 is mounted on positioning ring 2513;

[0082] A drive gear is mounted on the output shaft of the servo motor 2511 via a rotating shaft and a coupling; the drive gear meshes with a rack ring 2545; the rack ring 2545 is rotatably mounted inside the positioning ring 2513 via a bearing.

[0083] The drive housing 2512 is integrally fixed on the positioning ring 2513; the drive housing 2512 is used to hold the drive gear, and the drive gear is rotatably assembled with the drive housing 2512.

[0084] It should be noted that the servo motor 2511 and its power supply wiring method are existing technologies. Their detailed structure can be found in existing literature and journals, and they can also be purchased directly on the market, or components can be purchased on the market to assemble them, etc. They are not what this invention is meant to protect, and will not be described in detail here.

[0085] Therefore, during spraying, the multi-axis flexible arm structure 240 activates one or more angle adjustment components 254 on one or more unit joints 250. The angle adjustment component 254 activates the servo motor 2511, which transmits power to the drive gear. The drive gear then transmits power to the rack ring 2545 of the drive structure. The rack ring 2545 drives the electric telescopic rod 2549 to rotate to a certain position. After the electric telescopic rod 2549 is activated, it extends and retracts to move the joints. 253 rotates around the hinge ball 2542 relative to the positioning joint 251, and the drive structure drives the swing tube 2544 to drive the movable joint 253 to rotate synchronously. The movable joint 253 and the positioning joint 251 rotate relative to each other, realizing the local or multiple local bending of the multi-axis flexible arm structure 240. This allows the painting robot to deal with workpieces with complex internal cavities, deep grooves, concave curved surfaces or shapes that are obstructed by the surrounding shape, and to accurately reach or reach the obstructed area for effective painting. This avoids the occurrence of blind spots or uneven film thickness in some areas.

[0086] In embodiments of the present invention, such as Figure 9 As shown: The movable joint 253 includes two parallel fixed tubes 2532, and the columnar center lines of the two fixed tubes 2532 are on the same straight line;

[0087] The movable joint 253 also includes a telescopic arm 2531, which is located between two fixed tubes 2532. Multiple hydraulic telescopic rods are installed inside the telescopic arm 2531, and the multiple hydraulic telescopic rods are distributed in a circular array inside the telescopic arm 2531. The hydraulic telescopic rods are used to adjust the extension and retraction of the telescopic arm 2531.

[0088] Therefore, during spraying, the telescopic arm 2531 can be extended or retracted to different degrees by the hydraulic telescopic rod. This allows for adjustment of the length of the movable joint 253 through the extension or retraction of the telescopic arm 2531, enabling posture adjustment in narrow spaces in conjunction with the angle adjustment component 254, thereby improving the uniformity and quality of spraying.

[0089] like Figure 9 As shown: The telescopic arm 2531 includes multiple unit telescopic tubes, each unit telescopic tube including a sleeve and an insert tube, the insert tube being movably inserted inside the sleeve; the insert tube is provided with an anti-detachment protrusion, the anti-detachment protrusion being used to prevent the insert tube from falling out of the sleeve.

[0090] In this embodiment of the invention, a robotic device is provided, including a robot 100 and a spray head assembly 200. The robot 100 and the spray head assembly 200 are assembled together. The robot 100 includes a robotic arm 140, which is assembled with the spray head assembly 200. The spray head assembly 200 includes a spraying robotic arm 220. Both the robotic arm 140 and the spraying robotic arm 220 include the aforementioned multi-axis joint structure of the spraying robot.

[0091] Further technical solutions: such as Figure 1 As shown: The robot 100 also includes a chassis 110 and a top plate 130. The robotic arm 140 is mounted on the top plate 130. A plurality of pneumatic telescopic rods 120 are mounted between the chassis 110 and the top plate 130. The plurality of pneumatic telescopic rods 120 are distributed in a ring array inside the chassis 110 and the top plate 130.

[0092] Further technical solutions: such as Figures 1-3 As shown: The spray head assembly 200 also includes a flexible housing 210, which is sleeved on the outside of the spraying robot arm 220; the spraying robot arm 220 also includes a spray head 230, which is assembled at the end of the multi-axis flexible arm structure 240.

[0093] The robotic arm 140 and multiple pneumatic telescopic rods 120 are used to adjust the spray head assembly 200 as a whole. After the spray head assembly 200 enters the approximate position, the spray head assembly 200 uses the movable joint 253 and the positioning joint 251 to enable the spray head 230 to accurately reach or reach the obscured area for effective spraying of workpieces with complex internal cavities, deep grooves, concave curved surfaces or shapes that obstruct the surrounding area; thus avoiding blind spots or uneven film thickness in some areas.

[0094] In summary: During the spraying operation, the robot device employs a graded motion control strategy. First, the robotic arm 140 and multiple pneumatic telescopic rods 120 act as macroscopic positioning mechanisms, driving the spray head assembly 200 to quickly reach the approximate work area near the workpiece on an overall scale. Once the spray head assembly 200 enters the predetermined position, its built-in multi-axis flexible arm structure 240 initiates fine-tuning of its posture. This multi-axis flexible arm structure 240 is composed of multiple unit joints 250 connected in series. Each unit joint 250 includes a positioning joint 251 and a movable joint 253, which are connected by a spherical joint via a hinge ball 2542. When local bending is required, the angle adjustment component 254 on one or more joint units is activated. The servo motor 2511 drives the gear to mesh with the rack ring 2545, causing the electric telescopic rod 2549 to rotate to the set position. The rear electric telescopic rod 2549 extends, and its telescopic motion drives the movable joint 253 to deflect relative to the positioning joint 251 around the hinge ball 2542. The swing tube 2544 moves synchronously, thereby realizing the active bending of the unit joint body 250. At the same time, the hydraulic telescopic rod set inside the movable joint 253 can extend and retract to different degrees according to spatial constraints, thereby adjusting the overall arm length of the movable joint, so that the joint unit has the ability to be variable in length in the bending posture. Through the above-mentioned combined action of angle deflection and length extension, the multi-axis flexible arm can form one or more bending deformations in a local area, so that the end nozzle can accurately extend into the interior of the workpiece with complex internal cavity, deep groove, concave curved surface or surrounding shape obstruction, effectively reaching the obstructed area that is difficult to cover by traditional rigid structures, avoiding the problem of spraying blind spots or uneven film thickness caused by structural interference.

[0095] The robotic arm 140 and multiple pneumatic telescopic rods 120 perform coarse positioning, quickly delivering the spray head assembly 200 to a large area near the workpiece; while the multi-axis flexible arm structure 240 is responsible for fine posture adjustment within the confined space; the two form a division of labor of "arrival first, adaptation later", avoiding the contradiction between a single long arm structure in large-scale movement and flexible local entry.

[0096] The angle adjustment component 254 enables the active deflection of the movable joint 253 around the hinge point, while the hydraulic telescopic rod enables the dynamic change of the arm length of the movable joint. The two work together within the same joint unit: bending changes the direction and entry angle of the nozzle 230, while telescopication compensates for the spatial positional shift caused by bending. The linkage between the two enables the nozzle to achieve continuous "bending and advancing" movement in narrow and tortuous channels.

[0097] The multi-axis flexible arm structure 240 allows bending and extension movements to be initiated simultaneously or sequentially at multiple unit joints 250, and the deformation of each unit joint 250 can be controlled independently. This multi-level series deformation structure enables the flexible arm to exhibit a continuous curvature change capability similar to a "bionic arm", which can fit the internal contour of complex irregular workpieces and achieve multi-point collaborative morphological adaptation.

[0098] Traditional multi-axis articulated robots are limited by fixed arm lengths and rigid joints. The minimum radius of motion of the end nozzle is determined by the sum of the lengths of each arm, making it difficult to enter narrow bends. This invention, through the combined motion of joint bending and joint extension, enables the nozzle 230 to travel along a curved path into the obstructed area without increasing the overall turning radius. This achieves a leap from sweeping across a spherical surface to traversing a spatial curve, which is equivalent to expanding the robot's reachable space from a macroscopic spherical shell to the interior of an irregular cavity.

[0099] Since each joint 250 has both active bending capability and length adjustment capability, when the flexible arm enters the inner cavity of a workpiece with a complex shape, the geometry of the entire flexible arm can be dynamically matched with the direction of the inner cavity of the workpiece through the coordinated deformation of each joint. This adaptive shape not only reduces the complexity of trajectory planning, but also ensures that the nozzle 230 and the workpiece surface always maintain the optimal spraying distance and angle, significantly improving the uniformity of the coating in hard-to-reach areas such as deep holes and grooves.

[0100] In traditional solutions, to meet the needs of large-area spraying, the overall structure of the robot is often designed to be quite large, which becomes an obstacle to entering complex workpieces. The present invention uses a configuration decomposition of a rigid upper arm consisting of a robotic arm 140 and multiple pneumatic telescopic rods 120 for coarse positioning and a flexible lower arm consisting of a multi-axis flexible arm structure 240 for fine adaptation. This allows the equipment to maintain a large working range as a whole, while having miniaturized and flexible entry capabilities in certain areas. It resolves the long-standing design contradiction between large-area coverage and entry into narrow spaces, and achieves full-coverage spraying from macroscopic surfaces to microscopic cavities in one go without increasing the number of devices or workpiece repositioning.

[0101] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0102] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A multi-axis joint structure for a painting robot, comprising a multi-axis flexible arm structure (240), said multi-axis flexible arm structure being composed of multiple unit joint bodies (250); characterized in that, The unit joint body (250) includes: Positioning joint (251) is used to provide support force; The movable joint (253) is arranged side by side with the positioning joint (251); the movable joint (253) is used for adjustment relative to the positioning joint (251); An angle adjustment component (254) is installed between the positioning joint (251) and the movable joint (253); the angle adjustment component (254) is used to adjust the rotation of the movable joint (253) relative to the positioning joint (251); A rubber connecting sleeve (252) is fitted over the outside of the angle adjusting member (254); the rubber connecting sleeve (252) is connected between the positioning joint (251) and the movable joint (253), and the rubber connecting sleeve (252) is used to protect the angle adjusting member (254); The angle adjustment component (254) includes: A hinge ball (2542) is fixedly mounted on a movable joint (253) at one end; the other end of the hinge ball (2542) is hinged to a positioning joint (251). The swing tube (2544) is fixed to the articulated ball (2542) and extends into the cavity inside the positioning joint (251); The drive structure is assembled in the cavity inside the positioning joint (251); the drive structure is used to drive the rocker tube (2544) to drive the movable joint (253) to rotate synchronously.

2. The multi-axis joint structure of the painting robot according to claim 1, characterized in that, The hinge ball (2542) is fixed with a positioning tube (2543) on the side away from the swing tube (2544). The positioning tube (2543) is inserted and fixed on the mounting plate (2541). The mounting plate (2541) is installed on the movable joint (253) by multiple bolts.

3. The multi-axis joint structure of the painting robot according to claim 2, characterized in that, The driving structure includes: The bearing ring (2546) is rotatably mounted on the swing tube (2544); A rotating connector (2548), which is composed of a U-shaped plate and a rotating plate, is mounted on the bearing ring (2546); An electric telescopic rod (2549) is mounted at one end on the rotating connector (2548); The rack ring (2545) is movably sleeved on the outside of the bearing ring (2546); the inner wall of the bearing ring (2546) is fixed to the other end of the electric telescopic rod (2549).

4. The multi-axis joint structure of the painting robot according to claim 3, characterized in that, The positioning joint (251) includes: Positioning ring (2513); A connecting cavity (2514) is formed on one side of the positioning ring (2513); the connecting cavity (2514) is connected to the swing tube (2544) through a flexible connecting tube (2547); Among them, the articulated ball (2542) is articulated on the side of the positioning ring (2513) away from the connecting cavity (2514), and the flexible connecting tube (2547) is connected to the movable joint (253) through the swing tube (2544), the articulated ball (2542) and the positioning tube (2543).

5. The multi-axis joint structure of the painting robot according to claim 4, characterized in that, The positioning joint (251) also includes: A servo motor (2511) is mounted on a positioning ring (2513); The drive gear is mounted on the output shaft of the servo motor (2511) via a rotating shaft and a coupling; the drive gear meshes with the rack ring (2545); the rack ring (2545) is rotatably mounted inside the positioning ring (2513) via a bearing; The drive housing (2512) is integrally fixed on the positioning ring (2513); the drive housing (2512) is used to hold the drive gear, and the drive gear is rotatably assembled with the drive housing (2512).

6. The multi-axis joint structure of the painting robot according to claim 1, characterized in that, The movable joint (253) includes two parallel fixed tubes (2532), and the columnar center lines of the two fixed tubes (2532) are on the same straight line; The movable joint (253) also includes a telescopic arm (2531), which is located between two fixed tubes (2532). Multiple hydraulic telescopic rods are installed inside the telescopic arm (2531), and the multiple hydraulic telescopic rods are arranged in a circular array inside the telescopic arm (2531). The hydraulic telescopic rods are used to adjust the extension and retraction of the telescopic arm (2531).

7. The multi-axis joint structure of the painting robot according to claim 6, characterized in that, The telescopic arm (2531) includes multiple unit telescopic tubes, each unit telescopic tube including a sleeve and an insert tube, the insert tube being movably inserted inside the sleeve; the insert tube is provided with an anti-detachment protrusion, the anti-detachment protrusion being used to prevent the insert tube from falling out of the sleeve.

8. A robotic device, characterized in that, The system includes a robot (100) and a spray head assembly (200), which are assembled together. The robot (100) includes a robotic arm (140), which is assembled with the spray head assembly (200). The spray head assembly (200) includes a spraying robotic arm (220). Both the robotic arm (140) and the spraying robotic arm (220) include the multi-axis joint structure of the spraying robot as described in any one of claims 1-7.

9. The robot device according to claim 8, characterized in that, The robot (100) also includes a chassis (110) and a top plate (130). The robotic arm (140) is mounted on the top plate (130). Multiple pneumatic telescopic rods (120) are mounted between the chassis (110) and the top plate (130). The multiple pneumatic telescopic rods (120) are arranged in a ring array inside the chassis (110) and the top plate (130).

10. The robot device according to claim 8, characterized in that, The spray head assembly (200) also includes a flexible housing (210) which is fitted over the outside of the spraying robot arm (220); the spraying robot arm (220) also includes a nozzle (230) which is mounted on the end of the multi-axis flexible arm structure (240).

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