Design And Analysis Of The Holding Manipulator For The Pipe Racking System Of The Core Drill

With the development of automation technology,pipe laying machine is widely used in oil drilling industry and Continental Scientific Drilling.In core drilling field,traditional manual operation is still used.The pipe racking system is rarely used in core drilling,which is related to the manipulator used.The pipe row machine is less used in core drilling,which is related to the use of the manipulator.The diameter of core drill rod is small and the clamping diameter of the manipulator is large,which is difficult to hold effectively.The large size of the manipulator's shape makes the pipe racking system occupy a large space,while the core drilling derrick is relatively small and the space is limited.Therefore,the premise of wide application of core pipe racking system is to design a mechanical hand with a suitable holding range and small size.Firstly,the design parameters of the manipulator are determined according to the common pipe specifications in geological core drilling.According to the requirements of the parameters,a design scheme for the clamping mechanism was determined,and detailed design and optimization were performed.At the same time,the hydraulic circuit of the manipulator and the tooth plate of the mechanical hand that increases friction are also designed.Next,the stress calculation of the mechanical hand that clamps the different specification pipes was carried out in detail,and the dangerous stress condition was found out.The finite element analysis of the important parts of manipulator holding mechanism is carried out,and the results show that the strength of the manipulator is sufficient.Under the condition of the manipulator clamping the drill pipe the stress on the surface of the drill pipe and the deformation of the pipe body are also analyzed by the finite element analysis,and the results are also met the requirements.Then,through the simulation,the kinematics and dynamics characteristics of the manipulator in the execution of the clamping action are analyzed.The manipulator's clamping mechanism model is introduced into Adams,and a virtual prototype is established.Through setting driving parameters,the kinematics and dynamics simulation of multi rigid body is carried out.The change of the position,speed and acceleration of the important parts of the manipulator in the process of clamping drill rod are obtained.Considering the deformation of the splint when the clamping drill pipe is clamped,the dynamic simulation of rigid flexible coupling is carried out,and the dynamic characteristics of the mechanism are obtained.In addition,the hydraulic circuit of the manipulator is simulated and analyzed,and the pressure and flow parameters in the hydraulic circuit are obtained.The mechanical and hydraulic co-simulation of the manipulator was also carried out,and the dynamic characteristics of the manipulator under the hydraulic system were obtained.Finally,the equivalent friction coefficient of the tooth plate is tested by the experiment.In the force analysis of the manipulator,0.24 as the equivalent friction coefficient of the tooth plate was taken according to the relevant literature.According to the experimental results,the minimum equivalent friction coefficient of the hobbing plate is at least 0.24 under different conditions.It is proved that the value of the equivalent friction coefficient of the tooth plate is safe enough,and the result of the mechanical hand's stress analysis is accurate and reliable.