Research On The Dual-drive Variable-length Five-bar Mechanism And Its Application In The Grinding Machine

The research of planar linkage mechanism has been developed for thousands of years,but the research on planar linkage mechanism has never been interrupted by scholars all over the world.The research methods are constantly supplemented,and the application scope of the connecting rod mechanism is also expanding.At present,because the single degree linkage mechanism's trajectory curve is single that make the application to production is limited.In order to complete the relatively complex movement of the trajectory curve,the study of the multi-DOF linkage mechanism has become a hot research topic for many scholars.The five-bar mechanism,as a multi-DOF mechanism with the fewest number of rods and the least number of rings,is the basis for the further study of complex multi-DOF linkage mechanism.Now most of the processing of spherical pairs is completed by lathe,so the precision is low,the use in the industry that it is difficult to form a bearing oil film.If it is completed by artificial the form of grinding curve can't cover the surface uniform uniformly,and this is time-wasting.Aiming to solve this phenomenon,the application design,simulation analysis and optimization analysis of the double drive variable rod length five-bar mechanism in the grinder are completed.The main research contents of this paper are mainly composed by the following three parts.(1)The motion characteristics analysis of the sliding block five rod mechanism.Including the mechanism of the dynamic,singular point analysis,trajectory domain,motion unique determination conditions.The influence of the parameters of the mechanism on the motion performance of the mechanism,such as the matching of the driving crank length,the length of the rack,the matching of the input angular velocity,and the initial phase angle,are analyzed.These parameters are normalized and the trajectory map of the five-bar mechanism is obtained.It plays an important guiding role in industrial application.(2)Guiding by the concept design method,the double drive variable rod length five bar mechanism is applied to the grinding equipment,the prototype is made,and the simulation analysis is carried out.Analysis from mechanical structure side,compared with the planetary gear mechanism grinder,the structure is simple,the mechanism parameter adjustment is very flexibility,the economic performance is good,through the tooling replacement,it can not only complete plane grinding,but also can complete the spherical surface grinding work.The simulation of mechanism motion analysis turns out to be that the grinding trajectory curve has self-sealing.The trajectory curve is evenly distributed and the grinding effect is good.At the same time,the simulation results show that the change of mechanism motion parameters will have a great influence on the overall grinding quality,and it is necessary to determine the required mechanism parameters according to the process requirements in practical application,so as to ensure the overall machining quality.(3)The balance and optimization of the mechanism.The results of the prototype test show that the dynamic stability of the mechanism is poor at higher speed,and it is necessary to carry out the balance research and optimize the mechanism to complete the high-speed grinding.The setting of the initial posture of the mechanism will affect the inertial force of the axial forces of the mechanism and the inertial torque around the axes.By using MATLAB optimization toolbox to optimize the initial posture of the mechanism under the constraint,the optimized mechanism position parameters are obtained.The grinder based on the variable rod length five bar mechanism can be well accomplished plane and spherical grinding,not only expands the application of five bar mechanism,but also improves the precision of spherical machining process.This has great practical value.