Study On Profile Following Laser Cladding And Trajectory Planning Of Complex Surface Of Oil Bit

Laser cladding is a new high-tech technology,which has been developed rapidly recently.Laser cladding uses laser beam to melt the powder into the molten pool and rapidly solidifies to form an alloy deposition layer.At the same time,according to the 3D layered data of each section of the part model,the material is piled up line by line and layer by layer until the 3D metal parts or repair parts are formed.The reason why laser cladding is more and more popular in additive remanufacturing is its advantages of energy saving,high yield and small matrix deformation.To make the cladding layer more rational,the path of laser cladding must be reasonable.In this paper,the path planning of laser cladding is studied with the oil bit blade as the research object,and the model is reconstructed with NURBS method.In this paper,an interpolation point search algorithm based on the bow height is proposed,which reduces the calculation amount of interpolation point search and significantly improves the working efficiency,and thus the running trajectory of the laser gun is obtained.Simulation software was used to simulate the running path,and the running path of laser head was imported into the simulation software to monitor the running situation of the robot in the process of simulation in real time,thus verifying the correctness of the planned cladding path.Finally,the cladding experiment was carried out on the bit blade,and the results show that the cladding layer has smooth surface,compact structure,wear resistance,hardness and other properties,which are better than the bit body.The main research contents and conclusions of this paper are as follows:(1)The main failure modes of oil bit and the repair characteristics of laser cladding are analyzed,and the blade of oil bit is determined as the research object.Firstly,the 3D scanner is used to get the point cloud data on the bit surface,and the data is processed,so that the deviation value of the point cloud data is small and the contour is clear.Then,the NURBS method is used to reverse the cutter wing model.(2)The planning method of laser cladding path and the search method of interpolation points are studied.The method of point cloud slicing is adopted to determine the cladding processing path.At the same time,the manual interaction method is introduced to determine the cladding processing direction based on the characteristics of the blade surface.The distance between slices is influenced by multi-channel lap joints in the laser cladding process.An interpolation point search algorithm based on bow height is proposed to determine the machining points,which reduces the computation amount required in the process of interpolation point search,improves the working efficiency,and finally obtains the trajectory of the laser gun head.(3)The application of robot off-line simulation technology in robot cladding path simulation is studied.Before the actual cladding,the simulation software was used to simulate and analyze the cladding path.The correctness of the planned path was verified by analyzing the Angle changes of six axes in the robot cladding simulation process.Finally,the actual cladding experiment of the bit blade was carried out.The results of the cladding experiment showed that the cladding layer was relatively smooth and compact in structure.After testing the wear resistance and hardness of the cladding layer,the conclusion was drawn that the performance of the cladding layer was greatly improved relative to the bit body.