Design And Analysis Of A Spring Disassembly System Of Railway Freight Car Bogie

China is a major transportation country,and railway freight transportation is the main artery of China’s cargo transportation.In 2020,my country’s railway freight volume will reach 3.58 billion tons.There are nearly 400,000 railway freight cars installed with K2/K6 type bogies,a large number of bogies need to enter the maintenance section for maintenance,But in the maintenance process found that spring fracture fault accounted for 38.0% of all failures.Because the bogie structure is relatively complex,the spring disassembly is still manual operation,there are low efficiency,high risk factor,poor working environment and other problems,it is urgent to improve the automation rate of maintenance process,improve maintenance efficiency and maintenance quality.In view of the actual needs of the project,this paper innovatively proposes a spring disassembly system composed of six-degree-of-freedom manipulator and spring grips in the bogie overhaul process,and designs a complete spring disassembly workstation combining with the actual production of machinery and equipment in the factory.And the joint structure and scheme of the spring disassembly device are designed and analyzed.It can complete the disassembly and assembly tasks of bogie springs.First,give an overall solution plan for the actual problems in the project,and perform three-dimensional modeling of the mechanical equipment that has been used in the factory,divide the overall plan into modular processing,and analyze and design the devices of each module according to the technical route.A six-degree-of-freedom manipulator is selected as the main body of the project.The overhaul of the bogie is divided into several modules: bogie transportation device,hoisting device,spring disassembly and assembly device,and spring transportation device.Thereby forming a complete overhaul system.The D-H theoretical model of 6-DOF manipulator is established based on the theory of joint postposition coordinate system.The forward kinematics solution of the manipulator was obtained by using the ontology mechanism parameters and coordinate transformation matrix of the manipulator,and the forward kinematics solution was verified in the ADAMS simulation model.The analytical solution of the inverse motion of the 6-DOF manipulator was obtained by using algebraic method,and eight groups of inverse solutions were verified,and the results of the inverse solution were obtained which met the kinematics requirements of the manipulator.Secondly,according to the bogie side frame structure and the site operation of the design of the appropriate spring grip.According to different characteristic requirements,three kinds of spring grippers were designed respectively for simulation test,and the performance of spring gripper was improved step by step through the characteristic analysis of each gripper.By comparing the three kinds of grippers,the spring gripper which can not only actively grasp and stabilize the gripper,but also meet the requirements of the working space of the side connection structure is obtained.The grasping force is calculated and the selection of the driving motor of the gripper is determined according to the calculation.Finally,the forward and inverse solutions of the manipulator are used to plan the joint space and workspace of the manipulator.The robot arm was combined with the spring grip,and the task planning was carried out through the method of combining joint space and workspace trajectory planning,and the simulation experiment of grasping spring was completed.It is proved that the gripper design meets the requirements and the trajectory planning can complete the established tasks.