Manufacture And Application Of The High Accuracy Quick-change Follow Fixture Positioned By End-toothed Disc

With the development of society and the progress of science and technology,more and more "extreme" requirements are put forward to the manufacturing industry.In the field of ultra-precision machining,especially the ultra-precision machining process of complex and small structural parts,the repeated clamping error in the whole process of workpiece machining should be strictly controlled.With its standardized unified interface,the quick-change follow fixture can avoid the complex positioning adjustment steps,and realize high-precision repeated clamping and multi-station conversion conveniently,which is of great significance for improving the quality and efficiency of parts processing.However,the existing products and related research of quick-change follow fixture cannot fully meet the requirements of ultra-precision machining from the repeatability and applicability.Therefore,a kind of quick-change follow fixture with high precision and can adapt to the working condition of rotary,is designed and developed based on the end-toothed disc as the positioning element,and the related theoretical research,simulation analysis,structural design and experimental detection are carried out.It provides a possible technical way to solve the problem of high precision and fast repeated clamping and transposition in the field of ultra-precision machining.Firstly,the positioning principle of end-toothed disc is analyzed in this paper,and the influence of error average effect of multi tooth meshing and elastic compensation error effect on its matching accuracy is studied.The accurate tooth profile formula of end-toothed disc and the three tooth profile machining errors of end-toothed disc and their influence on meshing positioning error are analyzed and deduced.On this basis,a method to determine the tolerance of tooth profile machining error is proposed.A quick-change follow fixture based on the positioning of the end-toothed disc is designed and manufactured.The fixture adopts mechanical locking,pneumatic unlocking and rotary symmetrical design of the whole structure,and can adjust the dynamic balance,so that it can be installed on the rotating spindle in addition to static installation;The parameters of the end-toothed disc are designed and the tolerance of the tooth profile machining error is established;The mechanical locking mode is realized by slotted disc spring,and the parameters of disc spring are determined by calculation;Based on the three-dimensional modeling software,the three-dimensional modeling and two-dimensional engineering drawing of the fixture are completed,and the static and dynamic characteristics of the fixture are verified by the finite element simulation analysis method.Based on the four-axis linkage ultraprecision machining machine tool,the function and performance verification experiments of the designed quick-change follow fixture are carried out.Firstly,the usability of the fixture is proved by simple cutting experiments.Then,several groups of experiments are designed.Two high-precision sensors are used to detect the circular run out value and end face run out value after repeated clamping actions to verify the repeated positioning accuracy of the fixture,Finally,through the simulation of smalldiameter copper bar clamping and cylindrical surface cutting experiment,the influence of the use of quick-change follow fixture on workpiece processing is evaluated.