The Dynamic Analysis And Fatigue Life Assessment Of DTH Drill Working Device

The DTH drill has been developing vigorously in the mining industry as a typical large punch application equipment.As the core part of DTH drill,the structure design,dynamic characteristics and fatigue life of the key components in the working device have a great influence on the performance and life of the machine.Therefore,the dynamic characteristics,strength and fatigue life of the key components of the DTH drilling rig are studied.The research results provide the basis for the structure design and structure improvement of the working device.The specific research work in this paper is as follows:By analyzing the working principle and structural characteristics of DTH drill,the relevant size parameters can be determined according to different working conditions.The three-dimentional model of DTH drill is established by using Pro/E software,which provides a virtual prototype model for the dynamic analysis of the working device of DTH drill.ADAMS software is used to analyze the dynamic analysis of the working device of DTH drill,getting the force variation curves of the lifting oil cylinder of the drill arm,the deflecting oil cylinder of the drill arm,the lifting oil cylinder of the drill frame,the reverse oil cylinder of the drill frame and the propelling compensation oil cylinder;Combined with the one dimension 16 stage axis pressure spectrum and the rotary torque spectrum of DTH drill,the maximum hinges force in the horizontal and vertical direction of the joint of the drill arm lifting oil cylinder and drill arm,the joint of drill arm and gooseneck is obtained.Through the drill arm's maximum hinges force of the dynamic analysis of the working device and obtained the drill arm's stress and strain cloud chart by the ANSYS statics analysis,determine the dangerous position and ?-F transmission coefficient,calculate the stress spectrum of the dangerous position of the drill arm.According to the S-N curve of the part and the Miner linear fatigue damage theory,the fatigue life of the drill arm is calculated.The analysis results show that the minimum life appears at the joint area of the drill frame lifting oil cylinder and drill arm,which provides a basis for subsequent structural design and optimal design of the working device.