A rigid-flexible coupled deformable welding gun and a control method thereof

Abstract

The present invention relates to the technical field of welding equipment, and specifically to a rigid-flexible coupling deformable welding gun and a control method thereof, comprising a driving mechanism and a rigid bending arm, a flexible bending arm, and a welding gun nozzle connected in sequence; the driving mechanism is used to drive the rigid bending arm to bend toward at least one side, and its bending angle range is 0 to 180 degrees; the driving mechanism is also used to drive the flexible bending arm to extend or extend or drive the flexible bending arm to bend toward any side, and its bending angle range is 0 to 60 degrees. The present invention improves the accuracy of weld tracking by planning the bending amount of the industrial robot arm and the rigid bending arm at different welding positions before welding, and fine-tuning the bending amount and extension amount of the flexible bending arm during welding. The rigid-flexible coupling control improves the accuracy of the position control of the welding gun end and reduces the difficulty of tracking complex welds.

Description

Technical Field

[0001] The invention relates to the technical field of welding equipment, and in particular to a rigid-flexible coupled deformable welding gun and a control method thereof. Background Art

[0002] Robot welding usually includes two steps: path planning and actual welding. The path planning step mainly generates the robot welding path program according to the preset size of the weld through teaching or offline programming. Fig.10 The parts shown are affected by factors such as the machining error of the welded workpiece, the error of the tooling, and the deformation of the workpiece. The actual weld size and shape are not completely consistent with the weld parameters preset in the path planning. The adjustable posture range of the robot in a small space is limited, and the flexibility of the traditional robot system is low, making it extremely difficult to adjust the posture online.

[0003] The Chinese invention patent with application number 2020111102184 discloses an automatic welding system based on a soft mechanical gripper, including an automatic welding device and a soft mechanical gripper device, wherein the soft mechanical gripper device includes a gripper controller, a soft support arm, a connecting component and at least four soft gripper arms. Similarly, similar technical solutions are disclosed in the Chinese invention patent with application number 2013100236912 and the Japanese patent with application number JP2006016400.

[0004] The problem with the above technical solution is that in the actual production process, robot welding is usually used for welding tasks of long straight welds, and the welding quality of complex curved welds cannot be guaranteed. The welding guns in the prior art have a low number of degrees of freedom and low flexibility, and cannot achieve precise control of the terminal posture. Therefore, when welding, for example, the inner wall of the pipeline, the reinforcement ring of the conductor rack, the inside of the vehicle cabin, etc., the end of the welding gun of the existing robot welding system cannot complete small angles and small displacements in all directions, and it is difficult to complete welding tasks in a small space. At present, manual welding is still the main method used by workers.

[0005] The Chinese invention patent with application number 2022111432164 discloses a software device for arc additive repair under spatial constraints, which includes a soft robot arm, an arc additive cladding device, a motion control system, and a frame. The welding gun shell adopts a rope-driven spring structure, and a pre-tightening method is adopted in the preparation stage. The elongation and bending of the gun body are achieved by loosening the rope. Coaxial electricity, wire, and gas pipelines are used inside the welding gun to ensure the coaxial transportation of wire and gas during the spatial curve accumulation process of the welding gun, thereby improving the quality of additive forming. The motor controls the contraction and relaxation of the drive rope to achieve multi-degree-of-freedom bending of the soft robot arm, thereby achieving highly flexible and multi-directional arc additive accumulation.

[0006] Although the above-mentioned prior art discloses a flexible welding gun, it should be noted that the components for realizing the position adjustment function are completely two springs, and a longer spring section will cause the welding gun to be unstable, thereby affecting the welding accuracy. Specifically, the spring at the head end (the end away from the welding gun nozzle) is more likely to shake due to its flexible nature, and if it shakes slightly, the tail end (the end close to the welding gun nozzle) will be displaced more. When the tail end is displaced more, the adverse effect on the welding accuracy is greater. Summary of the invention

[0007] In order to solve the problem that the welding gun end of the existing robot welding system cannot complete small angle and small displacement adjustments in all directions and is difficult to complete welding tasks in a small space, the purpose of the present invention is to provide a rigid-flexible coupled deformable welding gun and a control method thereof.

[0008] The technical solution provided by the present invention is:

[0009] In a first aspect, a rigid-flexibly coupled deformable welding gun comprises a driving mechanism and a rigid bending arm, a flexible bending arm, and a welding gun nozzle connected in sequence;

[0010] The driving mechanism is used to drive the rigid bending arm to bend toward at least one side, and the bending angle range is 0 to 180 degrees;

[0011] The driving mechanism is also used to drive the flexible bending arm to extend and retract or to drive the flexible bending arm to bend toward any side, and the bending angle range is 0 to 60 degrees.

[0012] As an optional technical solution of the first aspect, the flexible bending arm includes an elastic member, and the elastic member has a resilience force;

[0013] The two ends of the elastic member are respectively connected to the rigid bending arm and the welding gun nozzle;

[0014] The driving mechanism is used to drive the elastic member to contract or bend toward any side, and the elastic member can be reset by its resilience.

[0015] Optionally, the elastic member is a coil spring;

[0016] A connecting ring is installed at one end of the coil spring away from the rigid bending arm, and the coil spring is connected to the welding gun nozzle through the connecting ring;

[0017] At least three ropes are evenly distributed on the connecting ring along the circumferential direction. The ropes are connected to a driving mechanism. The driving mechanism is used to drive the ropes to pull the connecting ring to drive the spiral spring to contract or bend.

[0018] Optionally, the rigid bending arm comprises a plurality of joints arranged at intervals, and adjacent joints are connected by spring hinges;

[0019] The driving mechanism is used to drive each joint to bend toward the same side; each joint is reset to a vertical state through the resilience of the spring hinge.

[0020] Optionally, each joint is connected to at least one rope, and the rope is connected to a driving mechanism, and the driving mechanism is used to drive the rope to pull the joint to bend.

[0021] Optionally, arc-shaped flanges are provided on adjacent end surfaces of adjacent joints, and the arc-shaped flanges are arranged correspondingly and at intervals;

[0022] The arc-shaped flange and the spring hinge are located on the opposite side of the joint bending direction.

[0023] Optionally, the driving mechanism comprises a first housing; the head end joints of the plurality of joints are connected to the first housing via a spring hinge, and the tail end joints of the plurality of joints are fixedly connected to the end of the elastic member;

[0024] A plurality of winding wheels are installed in the first housing, each winding wheel is arranged corresponding to each rope, and the rope is wound on the winding wheel;

[0025] The utility model also comprises a control assembly, which is used for driving the winding wheel to rotate forward or reversely, so as to reel in or release the rope.

[0026] Optionally, the control assembly includes a second housing connected to the first housing, a plurality of motors are installed in the second housing, and each motor is arranged corresponding to each winding wheel;

[0027] The motor is drivingly connected to the winding wheel and is used for driving the winding wheel to rotate forward or reverse.

[0028] Optionally, the control component further includes a main control panel and a controller;

[0029] Wherein, the controller and the motor are both electrically connected to the main control board.

[0030] Optionally, the coil spring, the joint, and the first housing are all provided with a coaxial central through hole, wherein the central through hole is used to allow the welding cable to pass through;

[0031] The welding cable is connected to the welding gun nozzle.

[0032] Optionally, the joint is provided with a through hole for allowing the rope to pass through;

[0033] An avoidance groove is formed between adjacent joints. For the rope located in the avoidance groove:

[0034] The ropes connected to the connecting ring are inserted into the wire feeding tube;

[0035] The rope connected to the joint is exposed in the avoidance groove adjacent to the connected joint, and is inserted into the wire feeding tube in other avoidance grooves.

[0036] In a second aspect, a control method of a rigid-flexible coupled deformable welding gun includes a welding path planning stage and a welding process control stage;

[0037] The welding path planning stage is used to generate the welding gun motion control program, which includes the following steps:

[0038] Obtain the spatial position of the target weld;

[0039] The position of the sampling point at the end of the welding gun is calculated by combining the end position of the welding gun and the spatial position of the weld;

[0040] Calculate the bending angle of each joint of the welding gun rigid bending arm based on the position of each sampling point of the welding gun;

[0041] The release length of each rope connected to the joint is calculated through the rigid bending arm section of the welding gun; the rope release length corresponding to the sampling point position of each welding path is saved to the controller, and a welding gun motion control program is generated;

[0042] The welding process control stage is used to adjust the end position of the welding gun to achieve weld tracking, including the following steps:

[0043] Execute the welding gun motion control program to make the end of the welding gun reproduce the weld trajectory position;

[0044] During welding, the center position of the welding gun end and the center position of the weld are detected in real time, and the spatial position deviation is calculated;

[0045] During welding, the release length of each rope connected to the connecting ring is adjusted according to the spatial position deviation, and the extension and bending angle of the flexible bending arm are adjusted to make the center position of the end of the welding gun correspond to the center position of the weld;

[0046] After adjusting the center position of the welding gun end, adjust the welding parameters.

[0047] As an optional technical solution of the second aspect, when calculating the bending angles of each joint of the rigid bending arm of the welding gun based on the positions of each sampling point of the welding gun, first, the ropes connected to the connecting ring are contracted to the same length at the same time to contract the elastic part so that the bending angle of the flexible bending arm is 0; then, the release lengths of the ropes connected to the joints are adjusted to make each joint bend.

[0048] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0049] The rigid-flexible coupling deformable welding gun of the present invention can work in a narrow space by setting a rigid bending arm and a flexible bending arm, wherein the rigid bending arm can achieve obstacle avoidance and large-angle bending, and the rigid bending arm is relatively rigid and will not shake easily during welding, while the flexible bending arm can provide small-angle deflection and extension. By planning the bending amount of the industrial robot arm and the rigid bending arm at different welding positions before welding, and fine-tuning the bending amount and extension amount of the flexible bending arm during welding, the weld tracking accuracy is improved, and the rigid-flexible coupling control improves the accuracy of the welding gun end posture control and reduces the difficulty of tracking complex welds. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A three-dimensional diagram of a welding gun in one embodiment of the present application;

[0051] Figure 2 This is a schematic diagram of a rigid bending arm structure in one embodiment of the present application;

[0052] Figure 3 This is a schematic diagram of the flexible bending arm structure in one embodiment of the present application;

[0053] Figure 4 This is a schematic diagram of the driving mechanism structure in one embodiment of the present application;

[0054] Figure 5 This is a schematic diagram of the control component structure in one embodiment of the present application;

[0055] Figure 6 This is a flow chart of a motion control method in one embodiment of the present application;

[0056] Figure 7 This is a schematic diagram of a rigid bending arm bending in one embodiment of the present application;

[0057] Figure 8 This is a schematic diagram of a welding gun connected to an industrial robot arm in one embodiment of the present application;

[0058] Fig. 9 This is a schematic diagram of a welding gun welding in one embodiment of the present application;

[0059] Fig.10 Schematic diagram of the target part in the embodiment.

[0060] Explanation of the symbols in the schematic diagram:

[0061] Welding gun nozzle 1, flexible bending arm 2, rigid bending arm 3, rope 4, control component 5, driving mechanism 6, welding cable 7, pipeline 8, reinforcement ring 9, industrial robot arm 10;

[0062] Elastic member 201, connecting ring 202;

[0063] Joint 301, fixing point 3011, arc flange 3012, avoidance groove 3013, spring hinge 302, connecting plate 303;

[0064] Wire feeding tube 401;

[0065] Motor 501, second annular side plate 502, controller 503, main control board 504, motor power supply 505, end cover 506, circular cable hole 5061, flange hole 5062;

[0066] Winding wheel 601 , first platform 602 , second platform 603 , first annular side plate 604 , L-shaped angle piece 605 , gear fixing plate 606 , gear shaft 607 , bevel gear set 608 , cable fixing plate 609 , pulley frame 610 , pulley 611 . DETAILED DESCRIPTION

[0067] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments.

[0068] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of implementation. The change or adjustment of their relative relationship should also be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0069] In one embodiment, the present invention provides a rigid-flexible coupled deformable welding gun, such as Figure 1 , 7 As shown, the welding gun includes a driving mechanism 6 and a rigid bending arm 3, a flexible bending arm 2, and a welding gun nozzle 1 connected in sequence. The driving mechanism 6 can drive the rigid bending arm 3 to bend and the flexible bending arm 2 to extend and bend.

[0070] Specifically, the driving mechanism 6 can drive the rigid bending arm 3 to bend toward at least one side, and the bending angle range is 0 to 180 degrees, for example, 0 to 120 degrees. When the rigid bending arm 3 is in a straight state, its bending angle is 0 degrees; when the rigid bending arm 3 is bent to the end face axis of the two ends is parallel, its bending angle is 180 degrees. Before welding, the bending angle of the rigid bending arm 3 is adjusted according to the target weld position. At this time, the bending of the rigid bending arm 3 will make the position adjustment of the welding gun nozzle 1 larger. After the bending angle of the rigid bending arm 3 is adjusted according to the target weld position, the rigid bending arm 3 will not be adjusted again during welding, and because the rigid bending arm 3 is relatively rigid and will not shake easily, the position of the tail end of the welding gun (the end close to the welding gun nozzle) will not change due to shaking during the welding process, thereby not causing a decrease in welding accuracy.

[0071] The driving mechanism 6 is also used to drive the flexible bending arm 2 to extend or extend or to drive the flexible bending arm 2 to bend to any side, and the bending angle range is 0 to 60 degrees, for example, 0 to 45 degrees. When the axis of the flexible bending arm 2 coincides with the axis of the tail end of the rigid bending arm 3 (i.e., the connection end with the flexible bending arm 2), the bending angle of the flexible bending arm 2 is 0 degrees. During the welding process, the flexible bending arm 2 can be extended or extended to adjust the axis position, or the flexible bending arm 2 can be bent to adjust the angle. At this time, the extension and extension amount of the flexible bending arm 2 and the bending angle adjustment amount will enable the welding gun nozzle 1 to be fine-tuned to adapt to the slight deviation of the weld position from the original welding route, thereby improving the weld tracking accuracy, improving the accuracy of the welding gun end posture control, and reducing the difficulty of tracking complex welds.

[0072] As a further solution of the above embodiment, for the flexible bending arm 2, as Figure 3 As shown, the structure includes an elastic member 201, and the two ends of the elastic member 201 are respectively connected to the rigid bending arm 3 and the welding gun nozzle 1. The elastic member 201 has a resilience. In addition, the elastic member 201 needs to be able to stretch and contract, and can be bent to any side. After the elastic member 201 is stretched or bent, it can be reset by its resilience, that is, in this solution, the driving mechanism 6 can drive the elastic member 201 to contract or bend to any side, and the elastic member 201 is reset by its resilience.

[0073] like Figure 8 As shown, the welding gun is connected to the industrial robot arm 10, and the bending amounts of the industrial robot arm 10 and the rigid bending arm 3 at different welding positions can be planned before welding.

[0074] Fig.10 As shown in the target part structure, the inner wall of the pipe 8 needs to be welded with multiple reinforcement rings 9 at intervals.

[0075] like Fig. 9As shown, when the reinforcement ring 9 is welded inside the pipe 8 ( Fig. 9 , which is an axial cross section of the pipe 8 and the reinforcing ring 9), since the position of the reinforcing ring 9 will be offset before welding, and usually, such offset will not be too large, however, even if the offset is not large, the impact on the welding quality is relatively serious, so it is necessary for the end of the welding gun to be able to adjust a small angle and a small displacement. In this solution, since the elastic member 201 is elastic, and the elasticity can meet the requirements of smaller displacement and smaller angle, the position and angle of the welding gun nozzle 1 installed at the end of the welding gun can be slightly adjusted by the expansion or bending of the elastic member 201, thereby improving the accuracy of the posture control of the end of the welding gun and improving the weld tracking accuracy.

[0076] Specifically, the elastic member 201 can be a coil spring, which has resilience, can be extended and retracted, and can be bent at a small angle to any side. At the same time, the driving force required to drive the coil spring to deform is also small. Since the welding gun needs to enter a small space, its radial size should not be too large. When the driving force required to drive the coil spring to deform is small, it is easier to achieve with a smaller radial size.

[0077] In this solution, a connecting ring 202 is installed at one end of the coil spring away from the rigid bending arm 3 , and the coil spring is connected to the welding gun nozzle 1 via the connecting ring 202 .

[0078] At least three ropes 4 are evenly distributed along the circumferential direction on the connecting ring 202. When there are three ropes 4, the angle between adjacent ropes 4 is 120 degrees. More ropes 4 are connected to the connecting ring 202, and the angle between the ropes 4 arranged circumferentially will be smaller. At this time, the elastic member 201 has more bending directions, and the accuracy of adjusting the end of the welding gun is higher.

[0079] The rope 4 is connected to the driving mechanism 6, and the driving mechanism 6 is used to drive the rope 4 to pull the connecting ring 202 to drive the spiral spring to contract or bend. When the driving mechanism 6 drives all the ropes 4 connected to the connecting ring 202 to reel together, the spiral spring contracts; when the driving mechanism 6 drives all the ropes 4 connected to the connecting ring 202 to unwind together, the spiral spring extends; when the driving mechanism 6 drives a part of the rope 4 connected to the connecting ring 202 to rewind (the rewinding length can be different), and the remaining part of the rope 4 is unwound, the spiral spring bends to one side. By controlling the rewinding length and unwinding length of the rope 4, the spiral spring can be bent at a small angle.

[0080] It should be noted that the elastic member 201 is not limited to a whole coil spring, and any other structure in the prior art that can be driven by the driving mechanism 6 to extend and bend is acceptable, which will not be described in detail here.

[0081] As a further solution of the above embodiment, for the rigid bending arm 3, as Figure 2 As shown, the rigid bending arm 3 includes a plurality of spaced joints 301, and adjacent joints 301 are connected by spring hinges 302. The driving mechanism 6 can drive each joint 301 to bend toward the same side, and each joint 301 is reset to a vertical state by the resilience of the spring hinge 302.

[0082] Due to the limitation of the spring hinge 302, each joint 301 of the rigid bending arm 3 can only bend in one direction, but not in other directions, so that the rigid bending arm 3 can be limited from shaking in other directions. In addition, the direction of the driving force of the driving mechanism 6 is opposite to the direction of the rebound force of the spring hinge 302, so that the two forces are balanced, thereby preventing the rigid bending arm 3 from shaking in the bending direction or the rebound direction. Since the rigid bending arm 3 as a whole will not shake in any direction, the rigid bending arm 3 has little adverse effect on the accuracy of the tail end of the welding gun (the end close to the welding gun nozzle).

[0083] In this solution, there are three joints 301, and one of the joints 301 can be bent individually, or multiple joints 301 can be bent simultaneously, so that the rigid bending arm 3 can be bent to any angle within the bending angle range.

[0084] In this solution, each joint 301 is connected to at least one rope 4, for example, one rope, and the rope 4 is connected to the driving mechanism 6. The driving mechanism 6 drives the rope 4 to reel in, thereby pulling the joint 301 to bend. When the driving mechanism 6 drives the rope 4 to unwind, the joint 301 can be reset to a vertical state under the action of the resilience of the spring hinge 302.

[0085] Since the joint 301 needs to bear the weight of the flexible bending arm 2 and the welding gun nozzle 1, its structural strength has high requirements, and its resilience also has high requirements. The use of the spring hinge 302 can improve the strength of the rigid bending arm 3 and is also conducive to providing a larger resilience. In addition, increasing the weight of the rigid bending arm 3 to make it heavier than the flexible bending arm 2 is also conducive to keeping the center of gravity away from the end of the welding gun, thereby improving the stability of the welding gun and preventing the end from shaking.

[0086] It should be noted that the rope 4 is flexible and can be bent and deformed. Such ropes 4 are relatively mature in the prior art and will not be described in detail here.

[0087] As a further solution of the above embodiment, arc flanges 3012 are provided on adjacent end surfaces of adjacent joints 301, and the arc flanges 3012 are arranged correspondingly and at intervals. The arc flanges 3012 and the spring hinge 302 are located on the opposite side of the bending direction of the joint 301.

[0088] By providing the arc-shaped flange 3012 , when the adjacent joints 301 are bent until the adjacent arc-shaped flanges 3012 abut against each other, the adjacent joints 301 cannot continue to bend, and the arc-shaped flange 3012 can limit the bending angle.

[0089] like Figure 4 As shown, the driving mechanism 6 includes a first housing. The head end joints of the plurality of joints 301 are connected to the first housing via a spring hinge 302 , and the tail end joints of the plurality of joints 301 are fixedly connected to the end of the elastic member 201 .

[0090] A plurality of winding wheels 601 are installed in the first housing. Specifically, each winding wheel 601 is arranged corresponding to each rope 4. In the present embodiment, there are six winding wheels 601.

[0091] The rope 4 is wound on the winding wheel 601. When the control component 5 drives the winding wheel 601 to rotate forward or reverse, the rope 4 is wound or released.

[0092] like Figure 5 As shown, the control component 5 includes a second shell connected to the first shell, and multiple motors 501 are installed in the second shell. Each motor 501 is arranged corresponding to each winding wheel 601. The motor 501 is transmission-connected to the winding wheel 601, and the winding wheel 601 can be driven to rotate forward or reverse by the motor 501.

[0093] The control assembly 5 also includes a main control board 504 and a controller 503. The controller 503 and the motor 501 are both electrically connected to the main control board 504. The motor 501 can be controlled to drive the winding wheel 601 to rotate forward or reversely, and can also be controlled to drive the winding wheel 601 to rotate at a rotation speed and a rotation time. This is relatively mature in the prior art and will not be repeated here.

[0094] The first housing includes a first platform 602 and a second platform 603 which are spaced apart from each other. A first annular side plate 604 is installed between the first platform 602 and the second platform 603. The first platform 602, the first annular side plate 604 and the second platform 603 form an installation space. In the formed installation space, an L-shaped angle piece 605 is installed on the second platform 603, and a gear fixing plate 606 and a pulley frame 610 are installed on the L-shaped angle piece 605. A gear shaft 607 is installed on the gear fixing plate 606, and the winding wheel 601 is installed on one end of the gear shaft 607. The gear shaft 607 is connected to the output shaft of the motor 501 through a bevel gear set 608. A pulley 611 is installed on the pulley frame 610, and the rope 4 unwound from the winding wheel 601 passes around the pulley 611, thereby entering the wire feeding tube 401.

[0095] A cable fixing plate 609 is also installed on the L-shaped angle piece 605, and a plurality of wire feeding tubes 401 are fixed by the cable fixing plate 609, and the plurality of wire feeding tubes 401 are arranged in a ring. In this solution, the number of the wire feeding tubes 401 is also 6.

[0096] The first end joint of the plurality of joints 301 is connected to the first platform 602 via a connecting plate 303 .

[0097] The second housing includes a second annular side plate 502 connected to the second platform 603, the motor 501 is mounted on the second platform 603, the second annular side plate 502 covers the motor 501, and an end cover 506 is mounted on the end of the second annular side plate 502 away from the second platform 603. A circular cable hole 5061 is centrally provided on the end cover 506, and a flange hole 5062 is further provided on the end cover 506 outside the circular cable hole 5061, so that the second housing can be connected to other mechanisms.

[0098] The main control board 504 and the controller 503 are both arranged in the second annular side plate 502, and the second annular side plate 502 can protect them. A motor power supply 505 can also be arranged in the second annular side plate 502 to realize power supply to the motor 501.

[0099] The joint 301 is provided with a through hole for allowing the rope 4 to pass through, and an avoidance groove 3013 is formed between adjacent joints 301. For the rope 4 located in the avoidance groove 3013:

[0100] The rope 4 connected to the connecting ring 202 is inserted into the wire feeding tube 401;

[0101] The rope 4 connected to the joint 301 is exposed in the avoidance groove 3013 adjacent to the connected joint 301 , and is inserted into the wire feeding tube 401 in other avoidance grooves 3013 .

[0102] The rope 4 connected to the joint 301 is connected to the joint 301 via a fixing point 3011 provided on the joint 301 .

[0103] The through hole and the wire feeding tube 401 can limit the ropes 4 to prevent other ropes from becoming loose when some ropes 4 are wound up, which helps to improve the accuracy of control.

[0104] Regarding the arrangement of the welding cable 7, in one scheme, the joint 301 is cylindrical, and the first platform 602, the second platform 603, and the connecting plate 303 are all centrally provided with a through hole for accommodating the welding cable 7 to pass through, and the end cover 506 is centrally provided with a circular cable hole 5061 for accommodating the welding cable 7 to pass through. At this time, the spiral spring, the joint 301, the first shell, and the second shell form a coaxial accommodating cavity, and this accommodating cavity allows the welding cable 7 to pass through, and the welding cable 7 is then connected to the welding gun nozzle 1.

[0105] By arranging the welding cable 7 in the center, the elastic member 201 can be bent toward any side without being interfered by the welding cable 7. If the welding cable 7 is arranged outside the elastic member 201 and the joint 301, that is, arranged in parallel with the elastic member 201 and the joint 301, when the elastic member 201 or the joint 301 is bent toward the installation side of the welding cable 7, the welding cable 7 will interfere, resulting in a limited bending angle.

[0106] In addition, the central arrangement of the welding cable 7 will also center the center of gravity of the welding gun end, so that the welding gun end is more stable and less likely to shake or produce additional small displacements, thereby not affecting the welding accuracy.

[0107] In one embodiment, the present invention also provides a motion control method for a rigid-flexible coupled deformable welding gun, such as Figure 6 As shown, it includes welding path planning stage and welding process control stage;

[0108] The welding path planning stage is used to generate the welding gun motion control program, which includes the following steps:

[0109] Obtain the spatial position of the target weld;

[0110] The position of the sampling point at the end of the welding gun is calculated by combining the end position of the welding gun and the spatial position of the weld;

[0111] Calculate the bending angle of each joint 301 of the welding gun rigid bending arm 3 based on the position of each sampling point of the welding gun;

[0112] The release length of each rope 4 connected to the joint 301 is calculated through the welding gun rigid bending arm section; the release length of the rope 4 corresponding to the position of each welding path sampling point is saved to the controller 503, and a welding gun motion control program is generated;

[0113] The welding process control stage is used to adjust the end position of the welding gun to achieve weld tracking, including the following steps:

[0114] Execute the welding gun motion control program to make the end of the welding gun reproduce the weld trajectory position;

[0115] During welding, the center position of the welding gun end and the center position of the weld are detected in real time, and the spatial position deviation is calculated;

[0116] During welding, the release length of each rope 4 connected to the connecting ring 202 is adjusted according to the spatial position deviation, and the extension and bending angle of the flexible bending arm 2 are adjusted to make the center position of the end of the welding gun correspond to the center position of the weld;

[0117] After adjusting the center position of the welding gun end, adjust the welding parameters.

[0118] When calculating the bending angle of each joint 301 of the rigid bending arm 3 of the welding gun based on the position of each sampling point of the welding gun, first, the ropes 4 connected to the connecting ring 202 are contracted to the same length at the same time to contract the elastic member 201 and make the bending angle of the flexible bending arm 2 0; then, the release length of each rope 4 connected to the joint 301 is adjusted to make each joint 301 bend.

[0119] like Figure 7 As shown in the figure, in the planning stage, the three driving ropes of the flexible bending arm are simultaneously contracted to a certain length, so that the actual length of the flexible bending arm section becomes L s , the bending angle of the flexible bending arm section is 0. Assume that the lengths of the joints of the rigid bending arm section are L1, L2, L3, and the length of the welding gun nozzle is L e By changing the length of the driving rope, the bending angles of the joints of the rigid bending arm section are θ1, θ2, and θ3, and the end position of the welding gun is at {Z B O B X B The position in the coordinate system can be expressed as:

[0120]

[0121] The attitude angle of the welding gun end can be expressed as:

[0122] +θ2+θ3

[0123] Since the flexible bending arm section is pre-contracted to a certain length, it can achieve extension movement.

[0124] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A method for controlling a rigid-flexible coupled deformable welding gun, characterized in that: The rigid-flexibly coupled deformable welding gun comprises a driving mechanism (6) and a rigid bending arm (3), a flexible bending arm (2), and a welding gun nozzle (1) which are connected in sequence; The driving mechanism (6) is used to drive the rigid bending arm (3) to bend toward at least one side, and the bending angle range is 0 to 180 degrees; The driving mechanism (6) is also used to drive the flexible bending arm (2) to extend and retract, or to drive the flexible bending arm (2) to bend toward any side, with the bending angle ranging from 0 to 60 degrees; The flexible bending arm (2) comprises an elastic member (201), and two ends of the elastic member (201) are respectively connected to the rigid bending arm (3) and the welding gun nozzle (1); a connecting ring (202) is installed at one end of the elastic member (201) away from the rigid bending arm (3), and the elastic member (201) is connected to the welding gun nozzle (1) via the connecting ring (202); at least three ropes (4) are evenly distributed along the circumference of the connecting ring (202), and the ropes (4) are connected to a driving mechanism (6), and the driving mechanism (6) is used to drive the ropes (4) to pull the connecting ring (202) to drive the elastic member (201) to contract or bend; The rigid bending arm (3) comprises a plurality of joints (301) arranged at intervals; each joint (301) is connected to at least one rope (4), the rope (4) is connected to a driving mechanism (6), and the driving mechanism (6) is used to drive the rope (4) to pull the joint (301) to bend; The control method includes a welding path planning stage and a welding process control stage; The welding path planning stage is used to generate the welding gun motion control program, which includes the following steps: Obtain the spatial position of the target weld; The position of the sampling point at the end of the welding gun is calculated by combining the end position of the welding gun and the spatial position of the weld; Calculating the bending angle of each joint (301) of the welding gun rigid bending arm (3) based on the position of each sampling point of the welding gun; Calculating the release length of each rope (4) connected to the joint (301) through the welding gun rigid bending arm section; saving the release length of the rope (4) corresponding to the position of each welding path sampling point to the controller (503), and generating a welding gun motion control program; The welding process control stage is used to adjust the end position of the welding gun to achieve weld tracking, including the following steps: Execute the welding gun motion control program to make the end of the welding gun reproduce the weld trajectory position; During welding, the center position of the welding gun end and the center position of the weld are detected in real time, and the spatial position deviation is calculated; During welding, the release length of each rope (4) connected to the connection ring (202) is adjusted according to the spatial position deviation, and the extension amount and bending angle of the flexible bending arm (2) are adjusted so that the center position of the end of the welding gun corresponds to the center position of the weld; After adjusting the center position of the welding gun end, adjust the welding parameters.

2. The control method of the rigid-flexible coupled deformable welding gun according to claim 1, characterized in that: The elastic member (201) is a coil spring.

3. The control method of the rigid-flexible coupling deformable welding gun according to claim 2, characterized in that: Adjacent joints (301) are connected via spring hinges (302); The driving mechanism (6) is used to drive each joint (301) to bend towards the same side; each joint (301) is reset to a vertical state through the resilience of the spring hinge (302).

4. The control method of the rigid-flexible coupling deformable welding gun according to claim 3, characterized in that: Adjacent end surfaces of adjacent joints (301) are each provided with an arc-shaped flange (3012), and the arc-shaped flanges (3012) are arranged correspondingly and at intervals; The arc-shaped flange (3012) and the spring hinge (302) are located on the side opposite to the bending direction of the joint (301).

5. The control method of the rigid-flexible coupled deformable welding gun according to claim 3, characterized in that: The driving mechanism (6) comprises a first housing; the head end joints of the plurality of joints (301) are connected to the first housing via a spring hinge (302), and the tail end joints of the plurality of joints (301) are fixedly connected to the end of the elastic member (201); A plurality of winding wheels (601) are installed in the first housing, each winding wheel (601) being arranged corresponding to each rope (4), and the rope (4) is wound on the winding wheel (601); It also includes a control component (5), which is used to drive the winding wheel (601) to rotate forward or reverse, thereby winding or releasing the rope (4).

6. The control method of the rigid-flexible coupling deformable welding gun according to claim 5, characterized in that: The control assembly (5) comprises a second housing connected to the first housing, a plurality of motors (501) are installed in the second housing, and each motor (501) is arranged corresponding to each winding wheel (601); The motor (501) is drivingly connected to the winding wheel (601) and is used to drive the winding wheel (601) to rotate forward or reverse.

7. The control method of the rigid-flexible coupling deformable welding gun according to claim 6, characterized in that: The control component (5) further includes a main control panel (504); The controller (503) and the motor (501) are both electrically connected to the main control board (504).

8. The control method of the rigid-flexible coupling deformable welding gun according to claim 5, characterized in that: The coil spring, the joint (301), and the first housing are all provided with a coaxial central through hole, wherein the central through hole is used to allow a welding cable (7) to pass through; The welding cable (7) is connected to the welding gun nozzle (1).

9. The method for controlling a rigid-flexible coupled deformable welding gun according to claim 5, characterized in that: The joint (301) is provided with a through hole for allowing the rope (4) to pass through; An avoidance groove (3013) is formed between adjacent joints (301). For the rope (4) located in the avoidance groove (3013): The rope (4) connected to the connecting ring (202) is inserted into the wire feeding tube (401); The rope (4) connected to the joint (301) is in an exposed state in the avoidance groove (3013) adjacent to the connected joint (301), and is inserted into the wire feeding tube (401) in the other avoidance grooves (3013).

10. The control method of the rigid-flexible coupling deformable welding gun according to claim 1, characterized in that: When calculating the bending angles of the joints (301) of the rigid bending arm (3) of the welding gun based on the positions of the sampling points of the welding gun, firstly, the ropes (4) connected to the connecting ring (202) are simultaneously contracted to the same length, so that the elastic member (201) contracts and the bending angle of the flexible bending arm (2) is 0; then, the release lengths of the ropes (4) connected to the joints (301) are adjusted to allow the joints (301) to bend.

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