| Hard and brittle materials,especially non-metallic non-conductive materials and semiconductor materials,because of its excellent characteristics,are widely used in the electronics,machinery and other fields.Owing to low plasticity,high hardness and high brittleness of hard and brittle material,making it difficult to process.It has the advantages of good flexibility,good incision,low cutting force and small supplies with fixed abrasive diamond wire saw cutting hard and brittle materials.However,due to the dynamic change of the cutting force during the cutting process,the surface quality of the slices is affected.Therefore,the cutting force of the diamond wire saw cutting hard and brittle material is studied.In this paper,the cutting force in the cutting process of diamond wire saw is analyzed,and the cutting force control system is established.The controller keeps the normal force constant in the cutting process by adjusting the wire saw velocity to improve the processing efficiency and the slice surface quality.Aiming at the reciprocating fixed abrasive diamond wire sawing system,the cutting force in the process of diamond wire saw cutting hard and brittle material is studied.The influence of wire saw velocity,part feed rate and wire saw tension on cutting force is analyzed experimentally.In particular,the impact of different wire saw velocity on cutting force is researched.The response model of cutting force is established by using surface response method,and the variance analysis is carried out to obtain the influence rule of different cutting process parameters on cutting force and the optimum process parameters.The wire saw velocity with large influence factors on the cutting force is selected as the input,and the normal cutting force as the output is controlled.Using the system identification method to establish the mathematical model of the cutting force control system.The inverse M sequence is input to the cutting force control system by the determinant order method,and the system output normal cutting force of the corresponding is collected.The input and output data is used to calculate the determinant ratio to identify system order.The forgetting factor recursive least squares method is used to identify the parameters of the system,and the selected parameter identification method is simulated.Finally,the minimum variance self-tuning controller is designed.The MATLAB simulation analysis of the controller is carried out with different expected output.The results show that the controller has good control performance and can control the cutting force.The fixed abrasive diamond wire saw cutting force control system is built.The expected normal cutting force value is determined by comparing the conventional experimental normal cutting forces under different process parameters,and the constant cutting force control experiment is carried out.The results show that the cutting force control system can realize the constant force control well.The results of cutting force control experiment and conventional experimental results are compared between cutting force and slice surface quality.The comparison results show that cutting force control system can achieve constant control of the cutting force and improve the processing efficiency and the surface quality of the slices. |
