Optimal Design And Experimental Study Of Three Dimensional Elliptical Vibration Cutting Device With Multi-expected Performance

In the processing of hard and brittle optical crystals,titanium alloys,ferrous metals and other difficult-to-machine materials,there are problems such as severe tool wear,large cutting forces,and high cutting heat,which seriously affect the surface quality of parts.Three-dimensional elliptical vibration cutting is one of the effective methods to solve the above problems.However,the existing three-dimensional elliptical vibration cutting device mostly uses a compliant mechanism in the form of a flexible hinge as a carrier to realize three-dimensional vibration.Performance indicators such as natural frequency and accompanying displacement ratio have a limited range of optimization.This paper takes advantage of the large adjustment range of the space curved beam performance index.A three-dimensional elliptical vibration cutting device with desired performance is designed by combining degrees of freedom with constrained topological configuration and isogeometric theory.By changing the shape of the curved beam,its geometric parameters can be optimized in a larger range,and then the performance index can be optimized to increase the range.So as to meet higher processing performance requirements.(1)The principle of three-dimensional elliptical vibration cutting is elaborated in detail.It deduces the ellipse trajectory equation of the tool tip under three-dimensional driving.It obtains the variation rule of space ellipse trajectory with phase difference and amplitude of driving signal.It provides a theoretical basis for the design and experiment of a three-dimensional elliptical vibration cutting device.(2)It combines the degrees of freedom with constrained topological configuration method and isogeometric analysis to design a spatial curved beam compliance mechanism.The static analysis,modal analysis and transient dynamic analysis are carried out.With the aim of improving the first-order natural frequency of the space curved beam compliance mechanism and accompanying displacement ratio.Collaborative optimization of the spatial curved beam compliance mechanism with the coordinates of the middle control point of the curved beam as variables.After multi-disciplinary collaborative optimization,the relative displacement ratio of x-y increased by 22.77%,the displacement ratio of x-z increased by 14.59%,and the first-order natural frequency increased by 6.47%.A non-resonant three-dimensional elliptical vibration cutting device is designed based on the optimized spatial curved beam compliance mechanism.(3)The three-dimensional elliptical vibration cutting device was tested experimentally,and the testing platform was built.Sinusoidal signal response and maximum stroke were tested.The output trajectory of the tool tip of the three-dimensional elliptical vibration cutting device is tested,and the fitting results show that the input space ellipse meets the design requirements.The designed device was used to carry out turning experiments.And compared with ordinary turning,it is concluded that the surface flatness of the aluminum rod with added vibration is better.The roughness of three-dimensional elliptic vibration turning and ordinary turning was measured.It is concluded that the roughness measured by three-dimensional elliptic vibration cutting Ra is equal to 0.833?m,while the roughness obtained by ordinary turning is Ra equal to 1.324?m,which increases by 58.94%.It is proved that the surface roughness is significantly improved.The feasibility of a three-dimensional elliptical vibration cutting device designed with a spatial curved beam compliance mechanism as a carrier was verified.