Research On Automatic Assembling System Of Screw Sleeves

In recent years,as a kind of fastener with internal thread,screw sleeve has high strength and good wear resistance.It is mainly used to make up for the deficiency of aluminum alloy internal thread and repair thread defects.It is widely used in electronic products,auto parts,communication equipment,home appliances and other fields.However,the existing internal expansion fixture can only clamp the screw sleeve,which does not have the tightening function,or has a large restriction on the tightening Agle.Tightening function still needs to be completed manually,and the automation degree is low,so it is difficult to ensure assembly quality and efficiency.In order to improve the shortcomings of the existing device and realize the automatic assembly of the screw sleeve.In this paper,screw sleeve automatic assembly technology as the research object,and an automatic assembly device of screw sleeve is designed by integrating the function of clamping and tightening.At the same time,the automatic assembly system of screw sleeve was built by combining the cross slide module and visual inspection device.The functional modules composition,visual detection technology and the development of system control software of automatic assembly system are discussed in detail.(1)In this paper,through the analysis of the functional requirements of the automatic assembly system of screw sleeve,the design scheme of the overall system architecture is put forward.The system consists of a control system,a motion matrix,a positioning device and an end-effector.Among them,the control system is composed of motion controller and upper computer,the screw sliding platform module is used as motion matrix,the monocular vision system is used as visual positioning device,and an automatic mounting tool of screw sleeve is used as end-effector.The design scheme of the system is analyzed from mechanical system,motion control system and visual inspection system,and the assembly process of the automatic assembly system of screw sleeve is determined.(2)Aiming at the problem of limiting the rotation angle of the existing internal expansion clamp,a conductive slip ring is embedded in the tightening mechanism,and an automatic installation tool for screw sleeve is proposed.Using 3D printing technology to process the main mechanical structures that perform the clamping and tightening functions.At the same time,the rationality and applicability of the structure design are verified by experiments.In order to achieve accurate positioning of the screw sleeve,servo motor was used to control the screw sliding platform module,and the motion accuracy was controlled within ±0.05 mm.(3)The precise feedback of the screw sleeve position was realized by machine vision,and the calibration of industrial camera was completed by Zhang Zhengyou calibration method.Image preprocessing technology and least square method were used to extract the edge,and the positioning coordinates of the screw sleeve were obtained.It provides accurate feedback for the automatic positioning of the automatic assembly system.(4)Developed and assembled the screw sleeve automatic assembly system prototype,built the system assembly experiment platform.Completed the system debugging,including electrical debugging,system parameter setting and system function joint adjustment.The rationality and feasibility of the design of the automatic assembly system of the screw sleeve are further verified by experiments on the clamping process and tightening process of the screw sleeve respectively.