Performance Simulation And Control Of Pneumatic Impact Hammer

Pneumatic impact hammer is a kind of power tool which is widely used and belongs to the category of mechanical impact.Domestic enterprises mainly import and imitate foreign technology in the research and development of electric hammer,or rely only on experience,resulting in low product quality,long research and development cycle and high cost.This study takes an electric hammer product as the research object,carries on the performance simulation analysis,the optimization design systematically,and applies the PID control system,which has certain theoretical and practical guiding significance for the research and development of electric hammer.This paper is divided into six chapters:In the first chapter,the current situation of electric hammer products,pneumatic transmission of electric hammer and percussive drilling at home and abroad is studied.On the basis of summarizing and drawing lessons from previous research results,this paper puts forward feasible and innovative research programs to determine the research content of the paper.In the second chapter,the mathematical models of electric hammer driving,transmission,pneumatic impact and rock drilling are established systematically and comprehensively.The model includes crank-connecting rod motion,hammer impact motion,air block motion,O-ring friction and leakage,and the interaction between drill bit and working medium.It provides a theoretical basis for subsequent numerical simulation of electric hammer.In the third chapter,the simulation model of pneumatic impact system of the electric hammer is established.The performance of the electric hammer is analyzed by simulation,focusing on the changing rule of each state parameter in the stable operation state and the influence characteristics of each structure parameter on the output performance of the electric hammer.The validity and accuracy of the simulation model are verified,and the optimal design of the structure parameters is finally realized.In the fourth chapter,the finite element model of percussion drilling system of the electric hammer is established.Through finite element analysis,the basic dynamic characteristics of concrete failure,deformation and dynamic response of the system during impact drilling are studied and analyzed.The process of hammer percussion drilling under different structural parameters is simulated,and the validity and rationality of the model are verified by comparing with the test results.In the fifth chapter,the rationality and effectiveness of the air pressure design of the chamber air block is verified by Latin square test.Then,the PID control is designed and implemented in the electric hammer from two aspects of software and hardware.In the aspect of hardware,the original piston structure was improved,and the installation structure of air pressure sensor was designed.The sixth chapter summarizes the work and prospects of this paper.