A method for optimizing a forging manipulator back beam structure

Abstract

The application discloses a kind of forging manipulator rear beam structure optimization method, it is related to the technical field of forging equipment, comprising the following steps: according to the load size and load distribution range of actual bearing of rear beam measured according to the conventional parameter of forging production;Establish the finite element simulation model of rear beam, in combination with load parameter, the load concentration stress point, stress distribution state, deformation and stress weak area under the working condition of rear beam are comprehensively analyzed by finite element;Adjust the local structure size of rear beam, transition structure, bearing support structure, eliminate local stress concentration defects;The equipment after transformation is put into actual forging production, through long-term operating condition monitoring, structure stress detection, deformation tracking, the application effect evaluation of transformation scheme is completed.The application has the advantages that: under the premise of controlling equipment transformation cost, without increasing the self weight of equipment, the structure strength, bearing stability and fatigue resistance of rear beam are greatly improved, and the service life of equipment is effectively prolonged.

Description

Technical Field

[0001] This invention relates to the field of forging equipment technology, and in particular to a method for optimizing the structure of the rear beam of a forging manipulator. Background Technology

[0002] Forging manipulators are core supporting equipment in forging production lines. They are mainly used for clamping, transferring, and aligning forgings, and work in conjunction with forging presses to complete workpiece forging. They are widely used in heavy machinery, nuclear power, heavy industry and other large-tonnage forging production scenarios.

[0003] When processing large-tonnage, large-size long strip forgings, conventional forging manipulators use the jaws as the core stress point. All impact and extrusion loads during the forging process are concentrated on the jaws. After the load is transmitted to the front structure through the jaws, it creates significant deformation resistance and reverse load forces in the rear beam, causing a localized area of ​​the rear beam to be under a complex stress state of high stress and high load for extended periods.

[0004] Traditional forging manipulators typically employ conventional integrated welded or cast structures for their rear beams. The structural design is not specifically optimized for the extreme stress conditions of forging large-tonnage, long-sized workpieces, resulting in defects such as uneven load distribution, localized stress concentration, and insufficient structural strength redundancy. During long-term continuous operation, high-stress areas of the rear beam will continuously experience fatigue damage, gradually initiating microcracks. As operating time increases, these cracks continue to propagate, easily leading to sudden localized fracture failure of the rear beam.

[0005] As the core load-bearing structure of the forging manipulator, excessive deformation, cracking, or fracture of the rear beam can directly lead to equipment downtime and workpiece scrapping. This not only severely impacts the continuous and stable operation of the forging production line and reduces production efficiency but also poses risks such as equipment damage and safety accidents, significantly increasing equipment maintenance costs and production losses. Currently, the industry lacks precise rear beam structural optimization solutions for this condition, and relying solely on periodic inspections and localized welding cannot fundamentally solve the problem of rear beam fatigue fracture. Therefore, a targeted method for optimizing the rear beam structure of forging manipulators is urgently needed to eliminate structural stress defects and improve equipment operational reliability and service life. Summary of the Invention

[0006] The purpose of this invention is to solve the technical problem that the rear beam of the existing forging manipulator is prone to fatigue cracks and sudden fractures under the forging conditions of large-tonnage and long-size workpieces, which affects the stability of production. The invention provides a method for optimizing the structure of the rear beam of the forging manipulator, which eliminates stress defects from the structural design level, improves the load-bearing capacity and service life of the rear beam, and ensures the safe and stable operation of the equipment.

[0007] Specifically, this invention provides a method for optimizing the rear beam structure of a forging manipulator, comprising the following steps:

[0008] S1. Load torque calculation: Based on the maximum tonnage and limit size parameters of conventional products in forging production, calculate the working torque borne by the entire equipment during the operation of the forging manipulator, and accurately determine the actual load size and load distribution range borne by the rear beam.

[0009] S2. Structural stress simulation analysis: Based on the original structural parameters, material parameters and assembly relationship of the rear beam of the existing forging manipulator, a finite element simulation model of the rear beam is established. Combined with the load parameters calculated in S1, a comprehensive finite element analysis is conducted on the load concentration points, stress distribution, deformation and weak stress areas of the rear beam under working conditions.

[0010] S3. Targeted Structural Optimization: Based on the finite element analysis results, structural optimization design is carried out for stress concentration points and weak stress areas of the rear beam. The local structural dimensions, transition structures, and load-bearing support structures of the rear beam are adjusted to optimize the load transfer path and eliminate local stress concentration defects.

[0011] S4. Implementation and Effect Evaluation: Based on the optimized design results, a complete implementation plan for the rear beam modification was formulated. After the rear beam was processed and manufactured, and the equipment was assembled and modified, the modified equipment was put into actual forging production. Through long-term operation monitoring, structural stress detection, and deformation tracking, the application effect of the modification plan was evaluated.

[0012] Furthermore, in step S1, the tonnage of the conventional product size includes the maximum workpiece weight, maximum workpiece length, and maximum workpiece forging load. The real-time torque and ultimate load value of the force transmitted from the manipulator jaws to the rear beam are calculated using the torque balance formula.

[0013] Furthermore, in step S2, the finite element analysis includes static stress analysis and dynamic load fatigue analysis, simulating the impact load and continuous load action state of the entire forging process of large-tonnage, long-size workpieces, and accurately identifying the high stress concentration area, low structural strength weak area and easily deformable and fractured parts of the rear beam.

[0014] Furthermore, in step S3, the structural optimization includes adding an arc transition structure to the stress concentration area of ​​the rear beam, thickening the plate in the weak part, adding auxiliary support ribs, optimizing the connection and assembly structure between the rear beam and the fuselage, evenly dispersing the local concentrated load, and optimizing the force flow transmission trajectory.

[0015] Furthermore, in step S4, the application evaluation indicators include the deformation of the rear beam during operation, the peak working stress, the degree of fatigue damage, and the probability of crack formation. By comparing the operating status of the equipment before and after the modification, the effectiveness and reliability of the structural optimization are verified.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. This invention solves the core problems of local stress concentration and excessive load in the rear beam from the root by first accurately calculating the working load, then simulating and locating defects, and finally optimizing the structure in a targeted closed-loop design process, thus completely avoiding the risk of crack initiation and sudden fracture of the rear beam during long-term operation.

[0018] 2. This invention uses finite element simulation to accurately locate structural weak points and stress concentration areas, achieving precise and targeted structural optimization. It eliminates the need to blindly thicken the overall structure, significantly improving the strength, load-bearing stability, and fatigue resistance of the rear beam structure without increasing the equipment's weight, thus effectively extending the equipment's service life.

[0019] 3. This invention can be adapted to optimize and modify the rear beam of forging manipulators of different tonnages and models. It has strong versatility and high applicability. After modification, the equipment failure rate is greatly reduced, effectively ensuring continuous and stable production of the forging production line, reducing equipment downtime losses and maintenance costs, and resulting in significant economic benefits. Detailed Implementation

[0020] The present invention will be further described below with reference to specific embodiments, so that those skilled in the art can better understand and implement the present invention, but the embodiments are not intended to limit the present invention.

[0021] To achieve the above objectives, the present invention provides a method for optimizing the rear beam structure of a forging manipulator, comprising the following core steps:

[0022] Step 1: Load Torque Calculation: Based on the statistical analysis of parameters for conventional forging products in the workshop, the maximum forged workpiece weight is determined to be 50t, and the maximum workpiece length to be 8m. Combining the lever arm parameters of the clamping center of the forging manipulator and the load-bearing point of the rear beam, the ultimate working condition torque calculation is performed. In this embodiment, the eccentric loading of the workpiece under forging conditions is the main source of force on the rear beam. The calculation is based on the core formula for static torque balance, M=F×L. The parameter values ​​are: ultimate forging eccentric load F=600kN, which is the maximum eccentric impact load generated during the forging of a 50t large-size long workpiece, suitable for eccentric loading conditions of ultra-long workpieces; effective eccentric lever arm L=2.0m, which is the maximum eccentric distance between the clamping center of the clamp and the load-bearing point of the rear beam, and is a fixed parameter of the equipment structure. Substituting the parameters for precise calculation: M=600kN×2.0m=1200kN·m, the maximum torque borne by the rear beam under extreme forging conditions is accurately calculated to be 1200kN·m, thus clarifying the normal operating load range and peak impact load of the equipment.

[0023] Step 2, Finite Element Simulation Modeling and Stress Analysis: In this embodiment, the ANSYS Workbench simulation software is used to complete the finite element modeling and mechanical analysis of the rear beam. The specific model establishment and simulation process are as follows: (1) Import and simplification of the three-dimensional model: Based on the original design drawings of the rear beam of the forging manipulator, all structural dimensions are collected, and the core bearing structures such as the main bearing beam, connecting support, assembly installation surface, and load-bearing end face of the rear beam are retained; the small round holes, chamfers, process grooves, and assembly fine step structures that do not affect the overall stress and stiffness are reasonably simplified to eliminate redundant simulation features, improve the mesh generation quality and calculation efficiency, and import the established three-dimensional model into the ANSYS simulation module. (2) Definition of material properties: The parent material of the rear beam is Q355 low alloy high strength structural steel. The corresponding mechanical parameters are entered in the material library: elastic modulus E=206GPa, Poisson's ratio μ=0.3, material density ρ=7850kg / m³, yield strength 355MPa, fatigue allowable stress 235MPa, and the material values ​​are assigned and the material properties are assigned to the overall model of the rear beam. (3) Assembly constraint application: Define constraint conditions according to the actual assembly conditions of the equipment. The rear end of the rear beam is rigidly fixed to the frame. Apply constraints to the assembly contact surface of the rear end of the rear beam. Fully fixed support , restricting displacement and rotation in all directions of the end face; the middle and front ends of the rear beam are free bearing load ends without additional constraints, which are completely consistent with the actual installation load state of the equipment. (4) Load boundary conditions: Based on the limit working condition parameters calculated in step 1, an equivalent eccentric load is applied to the bearing surface of the corresponding jaw of the rear beam. The maximum eccentric load is applied as F=600kN, and the loading arm is strictly set according to the eccentricity of 2.0m. At the same time, the small dynamic impact load coefficient of the forging working condition is superimposed to simulate the continuous static load and instantaneous impact composite load of the forging process of large tonnage and long size forgings. (5) Mesh division: The intelligent mesh division strategy is adopted to refine the mesh of key load areas such as the right angle transition area, load action area, and support connection area of ​​the rear beam. The mesh unit size is controlled to be 2mm. The main beam body that is not in the core load is divided into 8mm conventional meshes. The overall mesh quality is greater than 0.85, with no deformed units, to ensure the accuracy of simulation calculation. (6) Solution calculation and result analysis: Submit the static structure solution, and solve the overall stress cloud diagram, deformation cloud diagram and strain distribution of the beam.

[0024] The solution formula is as follows:

[0025]

[0026] In the formula: This is the equivalent stress according to the fourth strength theory; These are the first, second, and third principal stresses of the element obtained after simulation. Geometric stress concentration exists at the right-angle transition position of the original rear beam structure. During load transfer, the force flow undergoes a sharp bending, causing a surge in the local principal stress gradient. Under the ultimate static load of 600kN + forging dynamic impact coupling condition, ANSYS solves for the principal stresses of this critical element as follows: , , Substitute into the formula to calculate:

[0027]

[0028] Simulation results show that the peak stress in the right-angle transition area of ​​the original rear beam reaches 385MPa, exceeding the allowable fatigue stress of Q355 material. The deformation in the middle load-bearing area is as large as 0.8mm. This area is a weak area of ​​the structure. Long-term exposure to alternating forging loads can easily generate fatigue microcracks and continue to propagate, eventually leading to structural fracture.

[0029] Step 3: Targeted Optimization Design of Rear Beam Structure: Based on the stress concentration distribution and weak area distribution results obtained from finite element simulation analysis, optimization is carried out to address simulation defects. Specifically, for local stress concentration points, the structural transition form is optimized by adding arc transition structures, and all right-angle transition parts of the rear beam are optimized to R30 arc transitions to eliminate stress abrupt changes caused by right-angle structures. For weak areas, the local structural strength is improved by thickening the load-bearing plates, adding reinforcing ribs, and optimizing the support layout. Two 20mm thick longitudinal reinforcing ribs are added in the high-load area in the middle of the rear beam, and the plate thickness in weak areas is increased by 5mm. The bolt layout connecting the rear beam and the fuselage is optimized to balance assembly stress, optimize load transfer paths, disperse local concentrated loads, balance the overall stress distribution of the rear beam, reduce local deformation resistance and fatigue damage, and fundamentally avoid the risk of cracks and fractures.

[0030] Step 4: Implementation and Effect Evaluation: Integrate all structural optimization parameters, develop a standardized and feasible implementation plan for the rear beam structural modification, complete the processing and fabrication of the optimized rear beam, equipment disassembly and assembly, and modification and debugging, and put the modified forging manipulator into actual production conditions for trial operation. Continuously run for 6 months to monitor the working stress, structural deformation, and operating vibration parameters of the rear beam online, track the fatigue operation status of the equipment, and compare the equipment's operational stability, failure rate, and structural damage before and after the modification. Monitoring data shows that the maximum stress peak of the optimized rear beam is reduced to below 220MPa, the maximum deformation is reduced to below 0.3mm, and there are no micro-cracks or deformation exceeding the standard. The equipment's operational stability is greatly improved.

[0031] The beneficial effects of this invention are:

[0032] 1. This invention adopts a closed-loop design process that first accurately calculates the working load, then simulates and locates defects, and finally optimizes the structure in a targeted manner. This process eliminates the drawbacks of traditional experience-based modification and optimizes the scheme to accurately match the forging conditions of large-tonnage and long-size forgings. It solves the core problems of local stress concentration and excessive load in the rear beam from the root and completely avoids the risk of crack initiation and sudden fracture of the rear beam during long-term operation.

[0033] 2. By accurately locating structural weak points and stress concentration areas through finite element simulation, precise and targeted structural optimization can be achieved. Without blindly thickening the overall structure, the strength, load-bearing stability and fatigue resistance of the rear beam structure can be significantly improved without controlling equipment modification costs or increasing equipment weight, thus effectively extending the service life of the equipment.

[0034] 3. This invention can be adapted to optimize and modify the rear beam of forging manipulators of different tonnages and models. It has strong versatility and high applicability. After modification, the equipment failure rate is greatly reduced, effectively ensuring continuous and stable production of the forging production line, reducing equipment downtime losses and maintenance costs, and resulting in significant economic benefits.

[0035] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for optimizing the rear beam structure of a forging manipulator, characterized in that, Includes the following steps: S1. Load torque calculation: Based on the maximum tonnage and limit size parameters of conventional products in forging production, calculate the working torque borne by the entire equipment during the operation of the forging manipulator, and accurately determine the actual load size and load distribution range borne by the rear beam. S2. Structural stress simulation analysis: Based on the original structural parameters, material parameters and assembly relationship of the rear beam of the existing forging manipulator, a finite element simulation model of the rear beam is established. Combined with the load parameters calculated in S1, a comprehensive finite element analysis is conducted on the load concentration points, stress distribution, deformation and weak stress areas of the rear beam under working conditions. S3. Targeted Structural Optimization: Based on the finite element analysis results, structural optimization design is carried out for stress concentration points and weak stress areas of the rear beam. The local structural dimensions, transition structures, and load-bearing support structures of the rear beam are adjusted to optimize the load transfer path and eliminate local stress concentration defects. S4. Implementation and Effect Evaluation: Based on the optimized design results, a complete implementation plan for the rear beam modification was formulated. After the rear beam was processed and manufactured, and the equipment was assembled and modified, the modified equipment was put into actual forging production. Through long-term operation monitoring, structural stress detection, and deformation tracking, the application effect of the modification plan was evaluated.

2. The method for optimizing the rear beam structure of a forging manipulator according to claim 1, characterized in that, In step S1, the conventional product size tonnage includes the maximum workpiece weight, maximum workpiece length, and maximum workpiece forging load. The real-time torque and ultimate load value transmitted from the manipulator jaws to the rear beam are calculated using the torque balance formula.

3. The method for optimizing the rear beam structure of a forging manipulator according to claim 1, characterized in that, In step S2, the finite element analysis covers static stress analysis and dynamic load fatigue analysis, simulating the impact load and continuous load action state of the entire forging process of large-tonnage, long-size workpieces, and accurately identifying the high stress concentration area, low structural strength weak area and easily deformable and fractured parts of the rear beam.

4. The method for optimizing the rear beam structure of a forging manipulator according to claim 1, characterized in that, In step S3, the structural optimization includes adding an arc transition structure to the stress concentration area of ​​the rear beam, thickening the plate in the weak part, adding auxiliary support ribs, optimizing the connection and assembly structure between the rear beam and the fuselage, evenly dispersing the local concentrated load, and optimizing the force flow transmission trajectory.

5. The method for optimizing the rear beam structure of a forging manipulator according to claim 1, characterized in that, In step S4, the application evaluation indicators include the deformation of the rear beam during operation, the peak working stress, the degree of fatigue damage, and the probability of crack formation. By comparing the operating status of the equipment before and after the modification, the effectiveness and reliability of the structural optimization are verified.

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