Research On Automatic Assembly Technology Of Servo Valve Armature Components

With the rapid development of aerospace technology,micro precision components are widely used because of its small size and reliable performance.The armature component in this paper is the core components of the electro-hydraulic servo valve,has the characteristic of small size,high precision assembly,the assembly quality directly affect the control precision and the service life of the electro-hydraulic servo valve.At present,the assembly operation of this component is still finished by manual work,which not only requires the workers to have higher assembly experience,but also the high labor costs and the poor consistency of the products and low pass rate.Therefore,it is of great significance to apply the automation equipment to the precision assembly of micro components.In order to solve the problems of manual assembly,according to the structural characteristics of the parts and assembly requirements,combined with sensors,machine vision,micro assembly technology,the precision press-fit equipment has been developed.Through the design of the overall framework,the upper and lower fixtures,the adjusting device of part's posture,the measuring device of force and displacement and vision alignment device,the clamping,alignment and precision press-fit of armature component has achieved by choosing the general parts reasonably and connecting the circuitry and gas circuit correctly.The press-fit equipment has the advantages of high automation degree,high assembly precision and high product consistency.In this paper,the structure characteristic and the assembly requirements of armature assembly has been studied.And the reasonable assembly process and control strategy has also been formulated.Based on Lab VIEW graphical programming software,The modular design ideas is used to write the control program of the press-fit equipment.The whole control program is divided into communication control module,logic control module,parameter input module,motion control module,image acquisition and processing module and data acquisition and storage module.According to the actual operation process,the man-machine interaction interface is divided into system initialization module,parameter setting module,reaction force bar pressing module,connecting rod pressing module,armature pressing module and manual remove assembly module.The control program uses the informer in the Lab VIEW software to realize the communication between the functions.Using the IMAQ Vision module in Lab VIEW software,the position acquisition and image processing of the parts are realized,and the precision of the assembly is ensured by the high precision alignment between the components.The main factors influencing the assembly precision of the armature assembly are studied by analyzing each module of the automatic press-fit equipment of the armature assembly.After the calibration of the precision of each module,the visual alignment device of the press fitting equipment is analyzed.By setting up different spatial coordinate system,the assembly error caused by the inclination of the three guide rails is deduced,and the error influence equation is deduced.And the error compensation is added to the alignment algorithm.It is proved that the press-fit equipment meet the assembly requirements of the armature components by using the equipment to carry on the press-fit experiment.