Modeling Of Churn Drill Stranded Wire Helical Spring And Research On Winding Mechanism

Churn drills have been applied in engineering infrastructure widely because of their applicability.Their buffer spring are easy to be broken for their harsh working environment,which delays the progress of the project.Some manufacturers have adopted stranded wire helical spring(SWHS)as buffer spring for Churn drills,which has a significant contribute to Improving fatigue life and stiffness.Unfortunately,this way of manufacturing is tremendously difficult due to its complex structure as well as its numerous parameters.This paper utilizes certain stranded wire helical spring(SWHS)with parameters for a Churn drill provided by a spring manufacturer as the research object,Focusing on the problems in the winding process of the spring,researches on the winding process have been carried out.The winding device has been designed and the proving has been carried out thought the winding experiment and finite element analysis.A set of structure scheme has been provided for the manufacturing of the spring of a large churn drill.The main work of the thesis has been introduced in detail:(1)Based on the geometrical relationship of the spring,the centerline model of the spring with parallel circle is established.On the other hand,the geometrical shape of the winding process of the spring is analyzed.The space geometry model for its centerline of steel wire has been established.Based on the theoretical centerline model,the stranded wire helical spring model of a large churn drill is established,which proves the validity of the centerline model.It provides a theoretical basis for the design and debugging of the winding device.(2)The improvement analysis of the winding device has been analyzed based on the problems in the winding process of the spring,such as: low pass rate,low manufacturing efficiency,material waste and so on.The winding process without a mandrel has been adopted by comparing the schemes of winding device of the spring.And the mechanical structure of the winding device and its assisted device have been designed.(3)Based on the structure of the winding device,the Explicit Dynamics of the ANSYS is adopted to analyze the important parts(winding roller,mandrel of the roller,winding mandrel)of the winding device by simulating the winding process of the spring.The strength of the roller mandrels have been verified.The modal and fatigue of the winding mandrel have been analyzed.Totally,the check of the important parts of the winding device has been carried out.(4)Based on the winding device proposed in thesis,the feasibility of the winding device without a mandrel has been verified by winding the spring of a large churn drill.The results of winding experiment shows that the winding device not only can achieve the qualified products but also improves the efficiency of the winding process.