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CN-121972754-A - Truss end seal automatic welding system

CN121972754ACN 121972754 ACN121972754 ACN 121972754ACN-121972754-A

Abstract

The application relates to the field of automatic welding, and discloses an automatic truss end sealing welding system which comprises a main frame, a four-axis module, a welding execution assembly, an automatic feeding and carrying mechanism, a bottom supporting mechanism and a control device. The control device is integrated with an air pressure closed loop adjusting module for continuously adjusting the output pressure of the pneumatic execution element. In the work piece positioning stage, the system controls the downward thrust of the vertical lifting cylinder and the upward jacking force of the bottom cylinder to achieve mechanical balance, a flexible constraint state allowing the work piece to follow-up displacement is formed, and in the welding stage, the pressure overflow characteristic of the electric proportion pressure regulating valve is utilized, so that the cylinder piston is allowed to generate trace yielding displacement when the work piece is heated and expanded, and thermal stress is released. In addition, the system utilizes the torque and current feedback of the servo motor to realize sensorless contact type position detection, corrects the welding path according to the coordinate transformation result of the measured data, and is matched with a physical correction mechanism based on the mechanical difference.

Inventors

  • ZHOU WEIDONG

Assignees

  • 固安县鑫盛达建筑钢制品有限公司

Dates

Publication Date
20260505
Application Date
20260317

Claims (10)

  1. 1. An automated truss end closure welding system, comprising: The main frame (1), the said main frame (1) is divided into upper strata structure and lower floor structure; The four-axis module (2) is arranged on the upper layer of the main frame (1), and a welding gun (6) is arranged at the output end of the four-axis module (2); The welding execution assembly is arranged on the lower layer of the main frame (1) and comprises an electric welding machine (5) and a wire feeder (4), and the electric welding machine (5) is electrically connected with the welding gun (6); The automatic feeding and carrying mechanism is arranged on the lower layer of the main frame (1) and is used for carrying a workpiece to be processed from the feeding bin (3) to a position to be processed; the bottom supporting mechanism is arranged on the lower layer of the main frame (1) and positioned below the position to be processed and comprises an air cylinder (7) and a reinforcement cage supporting piece (15) driven by the air cylinder (7) to lift and fall, and The control device is configured in the control cabinet (10) and comprises a central control module (101), a motion driving module (102), an air pressure closed-loop adjusting module (103) and a pneumatic switching control module (104); the central control module (101) is respectively in communication connection with the motion driving module (102), the air pressure closed-loop adjusting module (103) and the pneumatic switching control module (104); the motion driving module (102) is electrically connected with the four-axis module (2) and is used for driving the welding gun (6) to execute space motion; the air pressure closed-loop adjusting module (103) is connected with the air path of the automatic feeding and carrying mechanism and is used for continuously adjusting the output air pressure; the pneumatic switching control module (104) is connected with the automatic feeding and carrying mechanism and the air path of the bottom supporting mechanism and is used for controlling the on-off of the pneumatic element.
  2. 2. The truss end closure automated welding system of claim 1, wherein the automated loading and handling mechanism comprises: the cylinder (9) with the guide bracket is arranged in front of the feeding bin (3), and the output end of the cylinder is provided with a steel bar conveying sliding table (8); the vertical lifting cylinder (17) is arranged on the steel bar conveying sliding table (8), and the tail end of an output shaft of the vertical lifting cylinder is connected with a connecting plate (18); the horizontal telescopic cylinder (14) is arranged on the connecting plate (18); A rotary cylinder (11) mounted at the output end of the horizontal telescopic cylinder (14), and The steel bar clamping hand (13) and the clamping hand cylinder (12) for driving the steel bar clamping hand to open and close are arranged at the output end of the rotary cylinder (11); the output gas circuit of the air pressure closed-loop adjusting module (103) is respectively communicated with the clamping cylinder (12) and the vertical lifting cylinder (17) so as to adjust the output force of the clamping cylinder; The output gas circuit of the pneumatic switching control module (104) is respectively communicated with the cylinder (9) with the guide bracket, the horizontal telescopic cylinder (14), the rotary cylinder (11) and the cylinder (7).
  3. 3. The truss end-sealing automatic welding system according to claim 2, wherein the air pressure closed-loop adjusting module (103) comprises an electric proportional pressure regulating valve connected in series in the air path and an analog pressure transmitter positioned at the output end of the air path; The control end of the electric proportional pressure regulating valve is connected to the analog output port of the central control module (101), and the signal end of the analog pressure transmitter is connected to the analog input port of the central control module (101); the central control module (101) is configured to adjust the voltage or current control signals sent to the electric proportional pressure regulating valve according to the actual pressure value fed back by the analog pressure transmitter based on a PID control algorithm, so as to control the output pressures of the clamping cylinder (12) and the vertical lifting cylinder (17).
  4. 4. A truss end seal automatic welding system according to claim 3, wherein said central control module (101) is configured to control the system into a flexible hold mode during a work piece positioning phase: The central control module (101) sets a pressure regulating coefficient as a flexible coefficient through the air pressure closed-loop regulating module (103) and controls the downward thrust of the vertical lifting cylinder (17) and the upward jacking force of the cylinder (7) to be in a balanced state; in this state, the vertical lift cylinder (17) forms a flexible constraint by means of the compressible nature of the gas, allowing a follow-up displacement of the workpiece when subjected to external thrust.
  5. 5. The truss end-seal automatic welding system according to claim 4, wherein said central control module (101) is further configured to perform a physical corrective sequence upon detecting that the workpiece position deviation exceeds a preset safety threshold: The central control module (101) adjusts a pressure adjustment coefficient to a relaxation coefficient, wherein the relaxation coefficient is less than the flexibility coefficient; The central control module (101) controls the air cylinder (7) to output an upward jacking force so that the jacking force is larger than the sum of the residual thrust of the vertical lifting air cylinder (17) under the relaxation coefficient, the gravity of the clamp assembly and the gravity of the workpiece, and therefore the workpiece is forced to be attached to the datum plane of the reinforcement cage support (15) upwards.
  6. 6. The truss end-seal automatic welding system according to claim 1, wherein said motion drive module (102) has integrated therein a current loop sampling circuit; the central control module (101) is configured to perform contact scanning based on torque current feedback, and is used for controlling the four-axis module (2) to drive a probe to approach to the surface of a workpiece and receiving real-time torque current data fed back by the motion driving module (102); And when the absolute value of the difference between the real-time torque current data and the no-load reference current is larger than the contact judgment current threshold value in a continuous preset sampling period, judging that the probe contacts the surface of the workpiece, and recording the current position coordinate.
  7. 7. The truss end-seal automatic welding system according to claim 6, wherein said central control module (101) is further configured to calculate actual center coordinates and actual normal vectors of the workpiece from the set of measurement points acquired by contact scanning, and to modify pre-stored theoretical waypoints to generate actual execution waypoints; The correction process comprises the steps of calculating a relative position vector of a theoretical path point relative to the center of a theoretical feature of a workpiece, carrying out rotary transformation on the relative position vector according to an attitude rotary matrix calculated by the actual normal vector and the theoretical normal vector, and finally superposing the transformed vector and the actual center coordinate to obtain an actual execution path point mapped to the actual spatial position of the workpiece.
  8. 8. A truss end seal automatic welding system according to claim 3, wherein said central control module (101) is configured to set the pressure adjustment coefficient to the locking coefficient during the welding phase; the system is configured to automatically open an exhaust port of the electric proportional pressure regulating valve to release pressure when welding heat input causes a workpiece to be heated and stretched and pushes the vertical lifting cylinder (17) to enable the pressure in the cylinder to rise above a set value, and allow a piston of the vertical lifting cylinder (17) to generate yielding displacement.
  9. 9. The truss end-seal automatic welding system of claim 1, further comprising a sensory feedback module (105); the sensing feedback module (105) comprises a steel reinforcement cage sensing system (16) arranged in the to-be-processed area, and the steel reinforcement cage sensing system (16) adopts a background suppression type photoelectric sensor and is used for detecting whether a workpiece reaches the to-be-processed position or not and sending a trigger signal to the central control module (101).
  10. 10. The truss end-seal automatic welding system of claim 1, further comprising a welding process control module (106); the welding process control module (106) is connected to the electric welding machine (5) and the wire feeder (4) through an isolated communication interface, and is used for receiving welding current, voltage and wire feeding speed instructions issued by the central control module (101) and feeding back an arcing success signal and a fault state code.

Description

Truss end seal automatic welding system Technical Field The invention relates to the technical field of automatic welding, in particular to an automatic welding system for truss end seals. Background The steel bar truss is used as an important structural component in the industrial production of the building, and the welding quality of the end sealing plate directly influences the stress performance of the integral component. With the development of intelligent manufacturing technology, automatic welding equipment gradually replaces manual welding, and becomes mainstream equipment on a production line. However, in the practical application process, the existing automatic welding technology still has technical problems to be solved in the aspects of tool clamping, positioning sensing, track adaptability and the like. The existing truss end welding equipment adopts a fixed-stroke cylinder or a mechanical clamp to fix the workpiece. Such clamping mechanisms typically have only a single locked state, with the mechanical stiffness remaining unchanged throughout the welding process. During welding operations, the work pieces are subject to high heat input and have a significant tendency to thermally expand. Because the traditional rigid clamp cannot generate adaptive yielding along with expansion of the workpiece, the workpiece is subjected to strong mechanical constraint when being heated and stretched, and the thermal stress cannot be effectively released. The over-constraint state is extremely easy to cause buckling deformation of the workpiece or crack of the weld joint root, and the size precision and the structural strength of the final finished product are seriously affected. In addition, in order to ensure accurate coincidence of the welding track and the workpiece weld, the prior art generally relies on a machine vision system or an external force sensor mounted at the end of the welding gun to position the workpiece. However, the welding field environment is extremely harsh, and there are continuous strong light interference, smoke diffusion and high temperature spatter. The precise optical vision equipment is extremely easy to lose efficacy due to lens pollution or illumination change in long-term operation, and the external force sensor not only increases the load and structural complexity of the tail end of the welding gun, but also is easy to generate signal drift or hardware damage under high-temperature radiation and electromagnetic interference environments, so that the equipment is high in maintenance cost and insufficient in operation stability. Meanwhile, truss end workpieces to be processed are subjected to a pre-procedure blanking process, a certain dimensional tolerance or micro-warpage often exists, and random errors exist in the placing positions of the workpieces in the feeding and conveying processes. Conventional automated welding equipment lacks an efficient physical correction and path compensation coordination mechanism. If the fixed path is only used for teaching programming, the fixed path cannot adapt to the actual position change of the workpiece, and if the workpiece with the body warping lacks compaction correction of a physical layer and is directly welded, even if software compensation is applied, the problems of welding quality defect, welding deviation, unfused or poor appearance molding and the like easily occur due to the fact that the workpiece is not tightly attached are difficult to be eliminated. Disclosure of Invention Aiming at the defects of the prior art, the invention provides an automatic welding system for truss end sealing, which solves the problems that the positioning accuracy of a workpiece is low, the over-constraint deformation is easily caused by a rigid clamp, and an expensive external sensor is relied on in the existing welding process of the end of a reinforcement cage. The automatic welding system for the truss end seal comprises the following technical scheme. The system mainly comprises a main frame, a four-axis module, a welding execution assembly, an automatic feeding and carrying mechanism, a bottom supporting mechanism and a control device. The main frame is divided into an upper layer structure and a lower layer structure, and provides rigid support for the system. The four-axis module is arranged on the upper layer of the main frame, and the output end of the four-axis module is provided with a welding gun for executing the welding path movement with multiple degrees of freedom. The welding execution assembly is positioned at the lower layer of the main frame and comprises an electric welding machine and a wire feeder, and provides electric arc energy and filling materials for the welding process. The automatic feeding and carrying mechanism is arranged on the lower layer of the main frame and is responsible for transferring the workpiece to be processed from the feeding bin to the position to be processed. The bottom supporting mechanism is