Automatic welding device for marine ladder
By introducing a multi-sensor system and dynamic parameter adjustment into the welding device, the problem that existing welding equipment cannot be adapted to rectangular crossbars has been solved, achieving high-precision and highly corrosion-resistant welding results, making it suitable for marine ladders in marine environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-02
- Publication Date
- 2026-03-24
AI Technical Summary
Existing welding equipment is not adapted to the right-angle cross-section characteristics of rectangular crossbars and cannot meet the special requirements of the marine environment, resulting in problems such as uneven weld reinforcement, lack of fusion, oxidation, and fluctuations in wire feeding resistance.
An automatic welding device for marine ladders was designed, which employs a welding module, tooling module, displacement component and multi-sensor system to detect data in real time during the welding process and dynamically adjust welding parameters to ensure the welding accuracy and corrosion resistance of rectangular crossbars and vertical bars.
It effectively suppressed the lack of fusion at the corners and the flow of molten pool on the plane, improved the corrosion resistance and consistency of the weld, and met the load-bearing strength requirements of marine ladders.
Smart Images
Figure CN121715652A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of welding of marine ladders, in particular to an automatic welding device for marine ladders. BACKGROUND
[0002] Marine ladders for sea operation ships are key structural components for ship navigation and operation, and need to meet high corrosion resistance, high structural strength and stable load bearing performance to adapt to the harsh use environment of high humidity and high salt spray in the ocean. The main structure of such ladders is mostly processed from stainless steel material, wherein the straight ladder is composed of flat steel on both sides and rectangular crossbars, the inclined ladder uses ball flat steel or angle steel as the ladder frame and rectangular crossbars as the steps, and the platform is composed of angle steel frame and rectangular crossbars. The rectangular crossbar, as the core load bearing component, directly determines the overall safety and service life of the ladder through the welding quality with the vertical rod.
[0003] At present, the welding of marine ladders mostly adopts MAG welding method, which is matched with a barrel-type wire feeding system, a welding robot and a positioner, and the workpiece is positioned by a pneumatic clamp before automatic welding. In the prior art, the parameters of the welding equipment are mostly fixed and preset, and only the conventional welding requirements can be met, without customized design for the structural characteristics of the rectangular crossbar and the special requirements of the marine environment. For example, the path planning of the welding robot is mostly a general straight line or circular arc trajectory, which is not adapted to the right angle cross-section characteristics of the rectangular crossbar; the angle adjustment of the positioner only relies on manual presetting, lacking real-time deviation compensation mechanism; the wire feeding system does not consider the resistance fluctuation caused by the interlayer pressure change of the barrel-type welding wire, making it difficult to dynamically adapt to the working condition changes in the welding process.
[0004] The right angle cross-section of the rectangular crossbar is easy to form a welding dead angle, and the molten pool is easy to accumulate at the corner and flow on the plane under the constraint of the right angle, resulting in uneven weld reinforcement and incomplete fusion; under the high humidity environment of the ocean, the welding torch nozzle is easy to leave splashes or adsorb water vapor, and if the cleanliness does not meet the standard, it will cause insufficient coverage of the protective gas, and the weld is easy to oxidize and produce pores; in addition, the interlayer pressure change of the barrel-type welding wire during consumption will cause the fluctuation of the wire feeding resistance, and then cause the instability of the current and voltage, resulting in uneven weld width.
[0005] Therefore, it is necessary for the inventor to design a new automatic welding device for marine ladders to overcome the above problems. SUMMARY
[0006] The main purpose of the present application is to provide an automatic welding device for marine ladders to solve the problems that the welding equipment on the market is not adapted to the right angle cross-section characteristics of the rectangular crossbar, is not adapted to the special treatment of marine ladders, and the wire feeding pressure is not adapted.
[0007] In order to achieve the above purpose, the present application provides an automatic welding device for marine ladders, comprising: The welding module, the tooling module for fixing the ladder of the sea operation ship, and the displacement assembly provided on the tooling module for driving the tooling module to adjust the angle; The welding module comprises a walking track arranged along the length direction of the tooling module, a welding robot for automatically welding the ladder of the sea operation ship fixed on the tooling module reciprocating through the walking track, and a wire feeding barrel provided on the walking track and synchronously operated with the welding robot; The tooling module comprises a tooling chassis, a support assembly and a fixing mechanism provided on the tooling chassis and used for fixing the ladder of the sea operation ship, and the cross bar in the middle of the ladder used for stepping is a rectangular cross bar; The displacement assembly comprises a displacement machine main body and a rotary support provided on the displacement machine main body and used for fixedly connecting with the tooling module, and the welding angle of the rectangular cross bar and the vertical bar of the ladder on the tooling module is adjusted through the rotary support, so that the full welding effect is achieved; The welding robot comprises a manipulator and a processor, the wire output end of the wire feeding barrel is provided with a wire feeding resistance sensor, and the bottom is provided with a weight sensor, the cleaning station on the walking track is provided with a micro vision sensor, a resistance type cleanliness sensor and a temperature sensor, the welding torch of the welding robot is provided with a laser vision sensor, and the rotary support of the displacement machine main body is provided with an angle encoder; The processor is configured to: receive real-time detection data of the wire feeding resistance sensor, the weight sensor, the micro vision sensor, the resistance type cleanliness sensor, the temperature sensor, the laser vision sensor and the angle encoder; call a preset welding parameter standard threshold value, including wire feeding resistance 3-5 N, nozzle residual splash area ≤0.5 mm², on-state resistance ≤10 Ω, nozzle temperature ≤60 ℃, rotary support angle deviation ≤0.2°; compare the real-time detection data with the standard threshold value, when the wire feeding resistance >5 N, increase the wire feeding motor torque and reduce the welding speed by 5%, when the wire feeding resistance <3 N, reduce the wire feeding motor torque and increase the welding voltage by 2-3 V; when the laser vision sensor detects the corner area of the rectangular cross bar, reduce the welding current by 10-15 A, increase the welding speed by 5%-8%, and control the welding torch to switch to a circular arc track; coordinate the action timing of the welding robot and the displacement assembly, according to the deviation data of the angle encoder, compensate the robot path or automatically correct the rotary support, ensure the welding precision of the rectangular cross bar and the vertical bar, and at the same time inhibit the defects such as weld oxidation and incomplete fusion, so as to adapt to the corrosion prevention requirements of the ladder of the sea operation ship.
[0008] Optionally, a bearing base for mounting the welding robot and the wire feeder is arranged on the walking track, and the cleaning station, the smoke extraction and dust removal purification assembly close to the welding robot, and the wire feeding pipe support above the wire feeder are arranged on the bearing base.
[0009] Optionally, the support assembly includes a plurality of support seats arranged on the tool base frame, which are used to increase the distance between the marine ladder and the tool base frame and adapt the welding accessibility of the rectangular cross bar.
[0010] Optionally, the fixing mechanism includes a side pushing mechanism, a pressing mechanism and a hard stop arranged on the tool base frame, which are used to position the vertical bar and the rectangular cross bar of the marine ladder to avoid displacement during welding.
[0011] Optionally, a driving motor for driving the rotary support to rotate is arranged in the body of the positioner, and a support base is arranged at the bottom of the body of the positioner. The driving motor can drive the rotary support to rotate by 180° to adapt to the welding of the front and back surfaces of the rectangular cross bar.
[0012] An automatic welding method of a marine ladder includes the following steps: S1: lifting the marine ladder for sea surface operation by the support assembly of the tool module, fixing the vertical bar and the rectangular cross bar of the ladder by the side pushing mechanism, the pressing mechanism and the hard stop, and driving the rotary support to rotate by the positioner assembly to adjust the ladder to an initial flat welding posture of the rectangular cross bar; S2: moving the bearing base to the welding starting position along the walking track, feeding the welding wire by the wire feeder through the wire feeding pipe support, starting the MAG welding mode of the welding robot, and adapting to the anti-corrosion requirement of the stainless steel material; S3: collecting the detection data of each sensor in real time by the processor according to the preset logic, dynamically adjusting the welding parameters and the position angle, synchronously coordinating the work of the cleaning station and the purification assembly, and processing the welding pain points of the rectangular cross bar; S4: after completing the welding of the weld on one side of the rectangular cross bar, driving the rotary support to rotate by 180° by the positioner assembly to switch to the welding of the weld on the other side, and repeating step S3; S5: monitoring the quality during the whole welding process, pausing and prompting when an abnormality occurs, and releasing the fixing mechanism after the normal completion, and manually hoisting the finished product to the buffer area.
[0013] Optionally, in step S3, when the wire feeding parameters are adaptively adjusted, a correlation model is established in combination with the detection value of the wire feeding resistance sensor and the remaining amount of the welding wire obtained by the weight sensor. When the wire feeding resistance is 5-8 N and the remaining amount of the welding wire is <30%, the torque of the wire feeding motor is additionally increased by 10% to ensure the stability of wire feeding.
[0014] Optionally, in step S3, during the closed-loop control of the cleaning station, if the residual spatter area detected by the miniature vision sensor is 0.5-1mm², increase the protective gas flow rate by 3-5L / min; if the on-resistance detected by the resistive cleanliness sensor is 10-20Ω, adjust the welding torch posture offset by 0.3-0.5mm to adapt to the high humidity environment of the sea surface.
[0015] Optionally, in step S3, when controlling the molten pool of the rectangular crossbar, if the laser vision sensor detects that the molten width of the planar area is >12mm, the welding current is reduced by 8-10A and the arc length is shortened by 1-2V to suppress the flow of the molten pool; when the molten width is <8mm, the welding current is increased by 5-8A to ensure the penetration depth.
[0016] Optionally, in step S3, when the displacement and robot work together, if the deviation detected by the angle encoder is 0.2°-0.5°, welding is paused and the slewing support is driven to automatically correct. After the correction is completed, the robot is re-detected and welding is resumed after the target is met. For every 1000mm welded by the robot, the displacement component is adjusted synchronously by 3° to adapt to the welding requirements of long-sized sea surface operation ladders.
[0017] The automatic welding device for marine ladders provided by this invention has the following advantages compared with the prior art: By setting up a laser vision sensor next to the welding torch, the shape of the molten pool and the position of the corner of the crossbar are detected in real time. The processor calls the preset formula to adjust the welding parameters, reduce the welding current at the corner, increase the welding speed and switch the arc trajectory, effectively suppressing the lack of fusion at the corner and the flow of the planar molten pool, ensuring that the weld formation of the rectangular crossbar and vertical bar is uniform and meets the load-bearing strength requirements of the marine ladder.
[0018] By installing miniature vision sensors, resistive cleanliness sensors, and temperature sensors on the cleaning station, the area of residual spatter in the nozzle, conduction resistance, and temperature are quantitatively detected. The processor compares the detection data with standard thresholds and compensates for the impact of insufficient cleanliness by increasing the protective gas flow rate or adjusting the welding torch posture, thereby avoiding protective gas coverage failure, improving the corrosion resistance of the weld, and adapting to the harsh environment of marine operations.
[0019] By setting a wire feeding resistance sensor at the wire output end of the wire feed hopper and a weight sensor at the bottom, a correlation model is established. The processor dynamically adjusts the wire feeding motor torque, welding voltage, and speed based on real-time detection data to ensure stable wire feeding, avoid uneven weld width caused by current and voltage fluctuations, and improve the consistency of welding quality. Attached Figure Description
[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings: Figure 1 This is a three-dimensional schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the tooling module and displacement component of the present invention; Figure 3 This is a schematic diagram of the welding module of the present invention; Figure 4 This is a schematic diagram of the tooling module of the present invention; Figure 5 This is a schematic diagram of the main body of the positioner of the present invention.
[0021] The components include: 1. Welding module; 11. Walking track; 12. Welding robot; 13. Wire feed drum; 14. Cleaning station; 15. Wire feed tube support; 2. Tooling module; 21. Tooling base frame; 22. Side push mechanism; 23. Clamping mechanism; 24. Hard limit switch; 3. Positioning component; 31. Positioner body; 32. Rotary support; 33. Support base. Detailed Implementation
[0022] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.
[0023] It should be noted that the terms "first," "second," etc., used in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0024] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.
[0025] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.
[0026] In addition, the term "multiple" should mean two or more.
[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0028] Example 1 like Figures 1-5 As shown, an automatic welding device for marine ladders includes a welding module 1, a tooling module 2, and a positioning component 3. The traveling track 11 in the welding module 1 is made of high-strength aluminum alloy, with a length suitable for welding platforms up to 8000mm in length. Rollers are installed at the bottom of the support base to cooperate with the track, ensuring synchronization with the welding speed. The support components of the tooling module 2 are galvanized for rust prevention. The side-pushing mechanism 22 and the clamping mechanism 23 in the fixing mechanism both use standard cylinders, with air intake and exhaust controlled by solenoid valves, enabling rapid workpiece positioning and release. The positioner body 31 of the positioning component 3 adopts a welding frame structure, providing high rigidity. The slewing support 32 uses crossed roller bearings to ensure stability during welding of long workpieces.
[0029] The processor of welding robot 12 adopts a PLC controller, which integrates a multi-channel data acquisition interface, enabling it to receive signals from various sensors in real time and respond quickly. The wire feed hopper 13 is equipped with a wire feeding resistance sensor at the wire output end and a weight sensor at the bottom; the cleaning station 14 on the walking track 11 is equipped with a miniature vision sensor, a resistive cleanliness sensor, and a temperature sensor; a laser vision sensor is located next to the welding torch of welding robot 12; and an angle encoder is located at the slewing support 32 of the positioner body 31.
[0030] The processor is configured to: 1) receive real-time detection data from the wire feed resistance sensor, weight sensor, miniature vision sensor, resistive cleanliness sensor, temperature sensor, laser vision sensor and angle encoder; 2) Retrieve the preset welding parameter standard thresholds, including wire feed resistance 3-5N, nozzle residual spatter area ≤0.5mm², conduction resistance ≤10Ω, nozzle temperature ≤60℃, and slewing support 32-degree angle deviation ≤0.2°; 3) Compare the real-time detection data with the standard threshold. When the wire feeding resistance is >5N, increase the wire feeding motor torque and reduce the welding speed by 5%. When the wire feeding resistance is <3N, reduce the wire feeding motor torque and increase the welding voltage by 2-3V. 4) When the laser vision sensor detects the corner area of the rectangular crossbar, reduce the welding current by 10-15A, increase the welding speed by 5%-8%, and control the welding torch to switch to an arc trajectory. 5) Coordinate the action sequence of welding robot 12 and displacement component 3. Based on the deviation data of angle encoder, automatically correct through robot path compensation or slewing support 32 to ensure the welding accuracy of rectangular horizontal bar and vertical bar, while suppressing defects such as weld oxidation and lack of fusion, and adapting to the corrosion protection requirements of marine ladders.
[0031] The walking track 11 is equipped with a support base for mounting the welding robot 12 and the wire feeding drum 13. The cleaning station 14, the fume extraction and dust removal purification component near the welding robot 12, and the wire feeding tube bracket 15 located above the wire feeding drum 13 are all mounted on the support base.
[0032] The cleaning station 14 includes a wire brush cleaning mechanism and a high-pressure air knife, which can effectively remove spatter from the nozzle end face; the fume extraction and dust removal purification component adopts a cartridge dust collector, which can quickly extract welding fumes and dust, avoiding affecting sensor detection and weld quality. The wire feeding tube support 15 adopts an adjustable structure with a height adjustment range of 300-800mm, which can adapt to different wire feeding angles and reduce fluctuations in wire feeding resistance.
[0033] The support assembly includes several support seats mounted on the tooling base 2. The support seats are used to increase the distance between the marine ladder and the tooling base 2, adapt to the welding accessibility of the rectangular crossbar, and are equipped with rubber anti-slip pads on the top to prevent the workpiece from sliding. The fixing mechanism includes a side-pushing mechanism 22, a clamping mechanism 23, and a hard limit 24 mounted on the tooling base 2. It can limit the extreme position of the workpiece and, together with the side-pushing mechanism 22 and the clamping mechanism 23, achieve precise positioning and prevent displacement during welding.
[0034] The positioner body 31 is equipped with a drive motor for rotating the rotary support 32; the support base 33 at the bottom of the positioner body 31 is fixed with anchor bolts. The drive motor can drive the rotary support 32 to rotate 180° to fit the front and back welding of the rectangular crossbar. The rotation process is smooth and without impact.
[0035] Example 2 This embodiment is for a straight ladder used on a surface vessel. The straight ladder is composed of flat steel on both sides and rectangular crossbars.
[0036] The side-pushing mechanism 22 uses cylinders, symmetrically arranged on both sides of the tooling base 2, with push plates installed at the ends of the cylinder piston rods; the clamping mechanism 23 also uses cylinders, with pressure blocks installed at the bottom of the cylinders to effectively clamp the crossbars and prevent warping during welding. Hard limiters 24 are located at both ends of the tooling base 2, with their positioning surfaces fitting against the end faces of the ladder frame. In the displacement assembly 3, the slewing support 32 has a target rotation angle of 30°, adapting to the flat welding posture of the straight ladder, with a drive motor speed of 5° / s. During rotation, the angle encoder provides real-time position feedback, and the locking mechanism automatically locks after rotation to the desired position. Regarding sensor installation, the wire feeding resistance sensor is fixed to the wire guide tube outlet at the output end of the wire feeding drum 13 via a bracket, with a contact pressure of ≤0.5N with the welding wire to avoid affecting wire feeding; the weight sensor is installed on the shock-absorbing pad at the bottom of the wire feeding drum 13, which is made of rubber with a thickness of 10mm to reduce the impact of welding vibration on weight detection; the laser vision sensor is fixed to the side of the welding torch via a connecting rod, with a distance of 50mm from the welding torch nozzle, and the detection direction is at 45° to the welding direction to ensure clear capture of the molten pool shape and the position of the crossbar corner.
[0037] The adaptive control of wire feeding parameters adopts a linear formula: F=k×(M / M0)+F0, where F is the wire feeding resistance N, k is the proportional coefficient with a value of 3N, M is the remaining weight of the welding wire kg, M0 is the initial weight of the welding wire with a value of 40kg, and F0 is the basic resistance with a value of 2N. In the simulation parameters, when the initial state M=40kg, F=3×(40 / 40)+2=5N, which meets the standard of 3-5N. At this time, the wire feeding speed is maintained at 5.0m / min, the welding current is 170A, and the welding voltage is 24V. During the welding process, when M=20kg and 50% remains, F=3×(20 / 40)+2=3.5N, which is still within the standard range, and the above parameters remain unchanged. When M=10kg and 25% remains, F=3×(10 / 40)+2=2.75N<3N. The processor controls to reduce the torque of the wire feeding motor by 10% and at the same time increase the welding voltage to 26V to stabilize the arc and avoid arc interruption. When M=8kg and 20% remains, due to the change in interlayer pressure of the welding wire, F=6N>5N. The processor immediately increases the torque of the wire feeding motor by 15% and reduces the welding speed from 5.0m / min to 4.75m / min to ensure stable wire feeding. At this time, the welding current is maintained at 170A to avoid fluctuations in the penetration depth.
[0038] In the control of the molten pool of a rectangular crossbar, when the laser vision sensor detects the corner area of the crossbar, the distance from the corner to the detection point is 5mm. The welding parameters are adjusted using the formulas I=I0-ΔI×(L / L0) and v=v0+Δv×(L / L0), where I is the adjusted welding current (A), I0 is the standard current (170A), ΔI is the current adjustment amount (15A), L is the corner distance (mm), L0 is the set threshold (5mm), v is the adjusted welding speed (mm / min), v0 is the standard speed (480mm / min), and Δv is the speed adjustment amount (40mm / min). In the simulation parameters, when the laser vision sensor detects L=5mm and enters the corner area, I=170-15×(5 / 5)=155A, v=480+40×(5 / 5)=520mm / min, and at the same time, the welding torch is controlled to switch to an arc trajectory with a radius of 3mm, and the swing amplitude is reduced from 5mm to 3mm to avoid molten pool accumulation in the corner; when L=0mm is detected and the corner area is left, the standard parameters I=170A, v=480mm / min are restored, and the welding torch trajectory is switched to a straight trajectory.
[0039] In the displacement angle compensation, the angle encoder detects that the actual angle of the rotary support 32 is 29.8°, which is 0.2° different from the target angle of 30°. The processor adjusts the welding gun position through the robot path compensation formula Δx=Δθ×π / 180×L, where Δx is the path compensation amount in mm and L is the distance from the welding gun to the workpiece, which is taken as 200mm. The calculated value is Δx=0.2×π / 180×200≈0.698mm. The robot compensates 0.7mm along the positive X-axis to ensure that the welding gun is aligned with the center line of the weld.
[0040] In the welding process, the ladder components are first manually hoisted onto the support base of the tooling frame 2 using a crane. The flat steel is aligned with the positioning surface of the hard limit 24. The side push cylinder is activated, and the piston rod extends to clamp and position the flat steel. Then, the clamping cylinder is activated, and the piston rod extends downward, pressing the rectangular crossbar to fix the workpiece. Next, the support base moves along the travel track 11 to the welding start position. The wire feed hopper 13 feeds the welding wire through the wire feed tube bracket 15. The welding robot 12 starts the MAG welding mode, and the shielding gas flow rate is set to 22L / min. Afterward, the processor collects data from various sensors in real time and dynamically adjusts the welding parameters and welding torch trajectory according to the above control logic. Simultaneously, the fume extraction and dust removal purification component is activated, and the air intake is aimed at the welding area to extract the fumes. After the welding of one side of the ladder is completed, the displacement component 3 drives the rotary support 32 to rotate 180° to switch to welding the other side, and the above parameter adjustment and welding process is repeated. The welding process is monitored for quality. When a sudden change in wire feeding resistance >2N / s is detected, welding is paused and an audible and visual warning is issued. The wire feeding tube is then manually checked for blockage. Once the process is completed normally, the side push cylinder and the clamping cylinder are reset, and the finished product is manually hoisted to the buffer area by a crane.
[0041] Example 3 This embodiment is for a sloping ladder used on a sea surface operation vessel. The ladder frames on both sides are made of bulb flat steel, and the rectangular crossbars are made of 22×22 square steel. The ends of the crossbars are rounded. The total length of the sloping ladder is 7325mm, and the spacing between the crossbars is 640mm.
[0042] In tooling module 2, six support bases are provided, with the top tilt angle matching the tilt angle of the inclined ladder frame at 45° to ensure stable placement of the inclined ladder. The side-pushing mechanism 22 uses two SC32×60 cylinders, with a stroke extended to accommodate the straight ladder. The piston rod end push plate adopts a wedge-shaped structure, tightly fitting the bulb flat steel. The clamping mechanism 23 uses eight SC40×30 cylinders, one cylinder corresponding to each crossbar to ensure uniform clamping force. Hard limiters 24 are located at both ends of the ladder frame, with anti-slip textured surfaces to prevent the inclined ladder from sliding. In the displacement assembly 3, the front welding target tilt angle is 45°, and the back welding target angle is 35°. The drive motor speed is 3° / s to avoid excessive rotation causing workpiece vibration. The rotary support 32 locking mechanism uses a double-cylinder locking mechanism with a locking force ≥4000N to ensure no workpiece displacement during welding on both sides. Regarding sensor installation, the angle encoder is installed on the gear end of the slewing support 32, meshing with the gear for transmission and real-time detection of the rotation angle; the laser vision sensor is adjusted to be perpendicular to the welding surface of the inclined ladder to ensure accurate detection of the molten pool; the wire feeding resistance sensor and the weight sensor are installed in the same way as in Example 1, adapting to the welding posture of the inclined ladder.
[0043] The displacement angle deviation compensation uses the formulas Δx=Δθ×π / 180×L and Δy=Δθ×π / 180×H, where Δx is the X-axis compensation amount in mm, Δy is the Y-axis compensation amount in mm, Δθ is the angle deviation in °, L is the horizontal distance from the welding torch to the workpiece, which is taken as 200 mm, and H is the vertical distance from the welding torch to the workpiece, which is taken as 150 mm. In the simulation parameters, the target angle during front welding is 45°, the angle encoder detects an actual angle of 44.7°, Δθ=0.3°, and the calculated Δx=0.3×π / 180×200≈1.047mm, Δy=0.3×π / 180×150≈0.785mm. The robot compensates 1.0mm along the positive X-axis and 0.8mm along the positive Y-axis to ensure weld alignment. When Δθ=0.6°>0.5°, the processor pauses welding, and the drive motor drives the rotary support 32 to automatically correct the angle at a speed of 1° / s. After correction, the angle is re-detected, and welding resumes after the angle meets the standard.
[0044] The wire feeding parameters are controlled using the same wire feeding resistance formula as in Example 1. In the simulation parameters, when the initial state M=40kg, F=3×(40 / 40)+2=5N, the wire feeding speed is 5.0m / min, the welding current is 180A, and the welding voltage is 25V. During the welding process, when M=12kg and 30% remains, F=3×(12 / 40)+2=2.9N<3N, so the welding voltage is increased to 27V and the wire feeding motor torque is reduced by 8%. When M=6kg and 15% remains, F=7N>5N, so the wire feeding motor torque is increased by 20%, the welding speed is reduced from 450mm / min to 427.5mm / min, and the shielding gas flow rate is increased to 25L / min to avoid weld oxidation.
[0045] The closed-loop control of cleaning station 14 adopts the formulas S=S0-k3×t and R=R0+k4×t, where S is the area of residual splashes in the nozzle (mm²), S0 is the initial residual area (0 mm²), k3 is the cleaning efficiency coefficient (0.1 mm² / s), t is the cleaning time (s), R is the conduction resistance (Ω), R0 is the initial resistance (5 Ω), and k4 is the resistance change coefficient (-0.5 Ω / s). In the simulation parameters, after welding 5 inclined ladder workpieces, approximately 30 minutes later, the welding robot 12 moves to the cleaning station 14. The cleaning time is set to 5 seconds. The calculated values are S = 0 - 0.1 × 5 = 0 mm² (actual detection shows 0.1 mm² ≤ 0.5 mm²), R = 5 - 0.5 × 5 = 2.5 Ω ≤ 10 Ω, and the nozzle temperature is detected as 55℃ ≤ 60℃. The cleaning meets the standards, and welding resumes. When S = 0.8 mm² > 0.5 mm² is detected, the processor controls the increase of the shielding gas flow rate by 3 L / min (from 25 L / min to 28 L / min), while simultaneously adjusting the welding torch posture offset by 0.3 mm to prevent arc blow.
[0046] During the welding process, the inclined ladder components are manually hoisted onto the support base of the tooling frame 2. A side-push cylinder pushes the flat steel to fit against the hard limit 24, and a clamping cylinder clamps the crossbar, completing the positioning. The displacement component 3 drives the rotary support 32 to rotate to 45°, adjusting it to the front welding posture and locking it. The bearing base moves along the walking track 11 to the welding start position, the wire feeder 13 feeds the welding wire, and the welding robot 12 starts the MAG welding mode with a protective gas flow rate of 25L / min. The processor collects sensor data in real time, dynamically adjusting welding parameters, welding torch trajectory, and displacement angle. The cleaning station 14 cleans the welding torch nozzle according to a set cycle, and the fume extraction and dust removal components operate continuously. After completing the front weld, the displacement component 3 drives the rotary support 32 to rotate 180°, adjusting it to a 35° back weld posture. After locking, the robot begins back weld welding, repeating the above parameter adjustment and welding process. After welding is completed, the displacement component 3 returns to 0°, the fixing mechanism is released, and the finished product is manually hoisted to the buffer area.
[0047] Example 4 This embodiment is for a marine operation platform. The platform frame is made of angle steel L75×75×10, the platform surface is made of rectangular crossbars, square steel 22×22, material SUS316L, crossbar spacing is 70mm, platform width is 1000mm, length is 8000mm, and automatic welding only considers the welding of the frame and square steel.
[0048] In tooling module 2, eight support seats are evenly distributed along the length of tooling base 2 with a spacing of 1000mm and a height of 100mm, ensuring an 80mm distance between the platform frame and tooling base 2, facilitating welding of the bottom weld seam of the frame by the welding torch. Hard limiters 24 are located at the four corners of the platform frame. In positioning component 3, the positioner adjusts synchronously with the robot's welding position during welding, tilting 3° for every 1000mm of welding, with a maximum tilt angle of 15°, and a drive motor speed of 2° / s, ensuring accessibility for long-dimension welding. Regarding sensor installation, a laser vision sensor is installed directly in front of the welding torch, 60mm from the nozzle, to detect weld width and weld pool morphology; temperature sensors are installed at the midpoint and end point of the platform frame to monitor workpiece temperature changes in real time; other sensors are installed in the same way as in the previous two embodiments.
[0049] The adaptive control of the weld pool width is set based on empirical formulas and combined with actual welding data. When I=180A and v=480mm / min, the weld pool width W=10mm (standard value); when I=190A and v=500mm / min, W=11mm; when I=200A and v=520mm / min, W=12mm. When W=13mm>12mm is detected, the processor controls to reduce the welding current by 8A (to 192A) and increase the welding speed by 20mm / min (to 520mm / min), adjusting W=11.5mm, returning to the standard range. When W=7mm<8mm is detected, the welding current is increased by 5A (to 185A) and the welding speed is reduced by 30mm / min (to 450mm / min), adjusting W=9mm, which meets the requirements.
[0050] The thermal accumulation compensation control adopts the formulas I=I0-k5×T and v=v0+k6×T, where T is the workpiece temperature in °C, k5 is the current compensation coefficient with a value of 0.05A / °C, k6 is the speed compensation coefficient with a value of 2mm / (min・°C), I0 is the initial current with a value of 190A, and v0 is the initial speed with a value of 500mm / min. In the simulation parameters, the workpiece temperature at the start of welding is 25℃, I=190-0.05×25=188.75A≈189A, v=500+2×25=550mm / min; when welding reaches the midpoint of 4000mm, the temperature sensor detects T=80℃, I=190-0.05×80=186A, v=500+2×80=660mm / min; when welding reaches the end point (8000mm), the temperature sensor detects T=140℃, I=190-0.05×140=183A, v=500+2×140=780mm / min. At the same time, the temperature is paused for 20s every 1000mm of welding to cool down and avoid burn-through caused by heat accumulation.
[0051] The displacement and robot collaborative control adopts the formula v_robot=v_weld+k7×Δθ, where v_robot is the robot walking speed (mm / min), v_weld is the welding speed (mm / min), k7 is the collaboration coefficient with a value of 100mm / (min・°), and Δθ is the displacement angle increment (°). In the simulation parameters, the robot welding speed is 500mm / min. For every 3° increase in displacement angle, the robot walking speed increases by 300mm / min (500+100×3=800mm / min) to ensure synchronous adaptation and avoid weld misalignment. When a fluctuation of >10% in the robot walking speed is detected, such as a decrease from 800mm / min to 700mm / min, the processor controls the reduction of the welding current by 5A to stabilize the molten pool.
[0052] During the welding process, a worker uses a crane to hoist the spot-welded platform frame onto the support seat of the tooling base 2. A side-push cylinder pushes the frame to fit against the hard limit 24, and a clamping cylinder clamps the rectangular crossbar, completing the positioning. The displacement component 3 adjusts to the initial welding posture of 0°. The support base moves along the walking track 11 to the welding start position, the wire feeder 13 feeds the welding wire, and the welding robot 12 starts the MAG welding mode with a protective gas flow rate of 28L / min. The processor collects sensor data in real time and dynamically adjusts the welding parameters, robot walking speed, and displacement angle according to the formula. A 20-second pause is taken every 1000mm of welding to allow for cooling, and the cleaning station 14 periodically cleans the welding torch. After welding one side of the frame and crossbar, the displacement component 3 drives the rotary support 32 to rotate 180°, and the robot begins welding the other side, repeating the above parameter adjustment and welding process. After welding is completed, the displacement component 3 resets, the fixing mechanism is released, and the finished product is manually hoisted to the buffer area. Welding data is automatically stored for easy traceability.
[0053] This invention, through three embodiments, adapts to the welding requirements of straight ladders, inclined ladders, and platforms. Through precise mechanical structure design, multi-sensor data acquisition, and closed-loop control logic, it effectively solves pain points such as incomplete fusion at the corners, molten pool flow, and weld oxidation in rectangular crossbar welding. It is suitable for the corrosion resistance and structural strength requirements of marine products used in offshore operations, improving welding efficiency and quality stability. It has strong practicality and industrial application value. In addition, the tooling module 2 can be located on both sides of the welding module 1. After welding on one side is completed, the operator can hoist it, while the welding module 1 performs welding work on the other side of the ladder, further improving efficiency.
[0054] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. An automatic welding device for marine ladders, characterized in that: include: Welding module (1), tooling module (2) for fixing ladders on marine work vessels, and displacement component (3) provided on the tooling module (2) for driving the tooling module (2) to adjust the angle. The welding module (1) includes a walking track (11) arranged along the length of the tooling module (2); a welding robot (12) that reciprocates along the walking track (11) and is used for automatic welding of a marine ladder fixed on the tooling module (2); and a wire feeder (13) arranged on the walking track (11) and running synchronously with the welding robot (12). The tooling module (2) includes a tooling base frame (21); a support assembly and a fixing mechanism for fixing the marine ladder are provided on the tooling base frame (21), and the crossbar in the middle of the marine ladder for stepping is a rectangular crossbar; The displacement assembly (3) includes a displacement machine body (31); a rotary support (32) provided on the displacement machine body (31), the rotary support (32) is used to be fixedly connected to the tooling module (2), and the welding angle between the rectangular crossbar and the ladder vertical bar on the tooling module (2) is adjusted by rotating the rotary support (32) to achieve a full welding effect; The welding robot (12) includes a manipulator and a processor; the wire feeder (13) is equipped with a wire feed resistance sensor at the wire output end and a weight sensor at the bottom; the cleaning station (14) on the walking track (11) is equipped with a miniature vision sensor, a resistive cleanliness sensor and a temperature sensor; a laser vision sensor is provided next to the welding torch of the welding robot (12); an angle encoder is provided at the slewing support (32) of the positioner body (31); The processor is configured to: It receives real-time detection data from wire feeding resistance sensors, weight sensors, miniature vision sensors, resistive cleanliness sensors, temperature sensors, laser vision sensors, and angle encoders. Retrieve preset welding parameter standard thresholds, including wire feeding resistance 3-5N, nozzle residual spatter area ≤0.5mm2, conduction resistance ≤10Ω, nozzle temperature ≤60℃, and slewing support (32) angle deviation ≤0.2°; Compare real-time detection data with standard thresholds. When the wire feeding resistance is >5N, increase the wire feeding motor torque and reduce the welding speed by 5%. When the wire feeding resistance is <3N, reduce the wire feeding motor torque and increase the welding voltage by 2-3V. When the laser vision sensor detects the corner area of the rectangular crossbar, the welding current is reduced by 10-15A, the welding speed is increased by 5%-8%, and the welding torch is switched to an arc trajectory. The timing of the coordinated action of the welding robot (12) and the displacement component (3) is automatically corrected by the robot path compensation or the slewing support (32) based on the deviation data of the angle encoder, so as to ensure the welding accuracy of the rectangular crossbar and the vertical bar, while suppressing defects such as weld oxidation and lack of fusion, and adapting to the corrosion protection requirements of the ladder for marine operations.
2. The automatic welding device for marine ladders according to claim 1, characterized in that: The walking track (11) is provided with a support base for installing the welding robot (12) and the wire feeding drum (13). The cleaning station (14), the fume extraction and dust removal purification component near the welding robot (12) and the wire feeding tube support (15) located above the wire feeding drum (13) are all provided on the support base.
3. The automatic welding device for marine ladders according to claim 1, characterized in that: The support assembly includes several support seats disposed on the tooling base (21), which are used to increase the distance between the marine ladder and the tooling base (21) and to adapt to the welding accessibility of the rectangular crossbar.
4. The automatic welding device for marine ladders according to claim 1, characterized in that: The fixing mechanism includes a side-pushing mechanism (22), a pressing mechanism (23), and a hard limit (24) mounted on the tooling base frame (21) to position the vertical bar and rectangular horizontal bar of the marine ladder and prevent displacement during welding.
5. The automatic welding device for marine ladders according to claim 1, characterized in that: The positioner body (31) is provided with a drive motor for driving the slewing support (32) to rotate, and a support base (33) located at the bottom of the positioner body (31). The drive motor can drive the slewing support (32) to rotate 180° to adapt to the welding of the front and back sides of the rectangular crossbar.
6. An automatic welding method for marine ladders, characterized in that: An automatic welding apparatus for marine ladders according to any one of claims 1-5 includes the following steps: S1: The ladder for sea operation is raised by the support components of the tooling module (2). The ladder vertical bar and rectangular horizontal bar are fixed by the side push mechanism (22), the clamping mechanism (23) and the hard limit (24). The displacement component (3) drives the slewing support (32) to rotate, so that the ladder is adjusted to the initial flat welding posture of the rectangular horizontal bar. S2: The support base moves along the walking track (11) to the welding start position, the wire feeding drum (13) feeds the welding wire through the wire feeding tube support (15), and the welding robot (12) starts the MAG welding mode to meet the corrosion resistance requirements of stainless steel. S3: The processor collects the detection data of each sensor in real time according to the preset logic, dynamically adjusts the welding parameters and displacement angle, and coordinates the work of the cleaning station (14) and the purification components in a synchronous manner to address the pain points of rectangular crossbar welding. S4: After completing the welding of one side of the rectangular crossbar, the displacement component (3) drives the rotary support (32) to rotate 180°, switch to welding the other side, and repeat step S3; S5: The welding process is monitored throughout. If any abnormality occurs, the process is paused and a notification is given. Once the process is completed normally, the fixing mechanism is released, and the finished product is manually hoisted to the buffer area.
7. The automatic welding method for marine ladders according to claim 6, characterized in that: In step S3, when the wire feeding parameters are adaptively adjusted, a correlation model is established by combining the detection value of the wire feeding resistance sensor and the remaining amount of welding wire obtained by the weight sensor. When the wire feeding resistance is 5-8N and the remaining amount of welding wire is <30%, the torque of the wire feeding motor is increased by 10% to ensure the stability of wire feeding.
8. The automatic welding method for marine ladders according to claim 6, characterized in that: In step S3, when the cleaning station (14) is under closed-loop control, if the area of residual spatter detected by the micro vision sensor is 0.5-1mm2, increase the flow rate of the protective gas by 3-5L / min; if the on-resistance detected by the resistive cleanliness sensor is 10-20Ω, adjust the welding torch posture offset by 0.3-0.5mm to adapt to the high humidity environment of the sea surface.
9. The automatic welding method for marine ladders according to claim 6, characterized in that: In step S3, when controlling the molten pool of the rectangular crossbar, if the laser vision sensor detects that the molten width of the planar area is >12mm, the welding current is reduced by 8-10A and the arc length is shortened by 1-2V to suppress the flow of the molten pool; when the molten width is <8mm, the welding current is increased by 5-8A to ensure the penetration depth.
10. The automatic welding method for marine ladders according to claim 6, characterized in that: In step S3, when the displacement and robot work together, when the deviation detected by the angle encoder is 0.2°-0.5°, welding is paused and the slewing support (32) is driven to automatically correct. After the correction is completed, the robot is re-detected and welding is resumed after the target is met. For every 1000mm welded by the robot, the displacement component (3) is adjusted by 3° to adapt to the welding requirements of long-size sea surface operation ladders.