| The assembly spot welding of the fan-shaped component is one of the important processes in the compressor manufacturing process.The quality of the assembly spot welding has an important impact on the overall reliability,life span and aerodynamic performance of the compressor.At present,the entire assembly process has obvious empirical and experimental characteristics,mainly relying on operators to complete it manually,and it is difficult to ensure high-quality,high-precision and high-reproducible manufacturing.In order to solve this problem,this paper studies several key technologies involved in the automatic assembly spot welding of fan-shaped components of compressor.The main contents of this thesis are as follows:(1)The structural design of assembly fixture for fan-shaped components.First,the positioning and clamping schemes were determined according to the production technical requirements of the fan-shaped components,the design of the components of the assembly fixture was completed,and the preliminary structure of the assembly fixture was determined.Then verify the structure of the assembly fixture,use SolidWorks to verify that the designed assembly fixture has no interference,and complete the assembly fixture model manufacturing through 3D printing technology,further demonstrating the functionality and operability of the assembly fixture.Finally,the static analysis of the assembly fixture is carried out,and the clamping force of the assembly fixture is estimated,The clamping force of the screw is derived according to the working principle of the wedge.The deformation analysis of the assembly fixture are carried out in SolidWorks Simulation,The result meets the assembly requirements of the fan-shaped components.The assembly fixture can ensure that the blade will not slip out from the outer ring blade hole,leaving enough operating space for the spot welding position of the fan-shaped component,which provides conditions for the realization of automatic spot welding.(2)The model of spot welding robot is determined and the kinematics analysis and calculation are completed.First,a D-H model without joint angle offset of 6-axis articulated robot is established according to the size of the selected robot structure.Then,the forward and reverse kinematics analysis and calculation of the spot welding robot are completed,which prepares for the robot's trajectory planning.Finally,the simulation model of the spot welding robot is established in MATLAB,and the forward and reverse kinematics simulation of the robot is completed.The simulation results are consistent with the kinematic analysis calculation results.The Monte Carlo method was used to solve the motion space of the spot welding robot in MATLAB,which proved the correctness of the simulation model.(3)The design of spot welding equipment for fan-shaped assembly and planning of spot welding trajectory.First,the structural scheme and control scheme of the assembly spot welding equipment are designed.the assembly fixture completes the assembly of the fan-shaped component,the transfer platform is responsible for the round-trip transmission of the assembly fixture at the loading station and the spot welding station,and the spot welding robot performs the automatic spot-pointing of the fan-shaped component.The control of the equipment adopts the control mode of host computer-main controller.Then combined with the results of the finite element analysis of the fixture,the structure of the assembly fixture was optimized,the final structure of the assembly fixture was determined,and the design of the transmission platform was completed,the overall structure of the spot welding equipment is assembled in SolidWorks.Finally,the fifth-order polynomial interpolation function is used to complete the planning of the spot welding position trajectory in the joint space,and the trajectory planning is simulated.The simulation results show that the planned robot trajectory is continuous and stable,which meets the needs of the sector-shaped spot welding. |
PDF Full Text Request