A method for theoretical calculation of quasi-static deformation of turning workpiece and actual measurement of dynamic deformation

Abstract

The invention relates to a method for theoretically calculating quasi static deformation of a turned workpiece and actually testing dynamic deformation of the turned workpiece. A turned workpiece mechanical model under the restriction of an ejector pin is established; by using a singular function, a bending moment equation, an axial inertia moment equation and a deflection curve approximate differential equation are written; by using turning parameters and cutter parameters, a cutting force is calculated; by using an integral method, a deflection equation containing unknown integral variablesis obtained; and by using a boundary condition and the integral property of the singular function, an unknown quantity is calculated to obtain an equation of changes of the turning deformation along with the time. A workpiece dynamic deformation testing system is established; and the workpiece dynamic deformation testing system comprises an electric eddy-current displacement sensor, a voltage-stabilized source, a computer, a dynamic signal collection instrument and an assorted signal collection and analysis system, an assorted dial indicator magnetometer base and the like. The electric eddy-current displacement sensor measures the change of relative positions of the turned workpiece and the end surface of a probe; by using a proximitor, the changes of the relative positions are converted into the change of a voltage; the signal collection and analysis system collects a voltage signal and converts the voltage signal into an engineering signal so as to obtain dynamic deformation of the workpiece.

Description

technical field [0001] The invention relates to a theoretical simple calculation method for calculating the bending deformation of a turning workpiece and a system and method for actually measuring the dynamic bending deformation of a workpiece, especially a method for theoretical calculation of quasi-static deformation of a turning workpiece and an actual measurement method for dynamic deformation, belonging to the technical field of mechanical processing . Background technique [0002] It is understood that turning is a common and important machining method. During the turning process, due to the extrusion effect between the tool and the workpiece, the workpiece often produces bending deformation and vibration due to its insufficient rigidity. Deformation and vibration will affect the machining accuracy of the workpiece, increase tool wear and reduce tool life. Therefore, it is necessary to calculate the turning deformation of the workpiece and monitor and analyze the def...

AI Technical Summary

Problems solved by technology

[0004] In summary, there are few calculation results for turning deformation in the existing research, because the workpiece is a non-uniform cross-section bar during turning, and the magnitude of the turning force is not easy to determine directly. At the same time, the action point of the turning force is moving. or beam) bending deformation method——Integral method, due to the uncertainty of the force point, on the one hand, it is necessary to write the bending moment equation in segments, the more segments, the more unknown integral constants, resulting in difficulty in solving; on the other hand, segmenting The points are changing, so it is not convenient to directly write the segmental bending moment equation

In addition, there are few achievements in the actual measurement of turning deformation in the existing research, mainly because the workpiece is rotating during the turning process and cannot be measured by contact sensors; on the other hand, the deformation of the workpiece cannot be sensed by the displacement sensor with a large range. And the measurement also requires the cooperation of technical personnel who can turn and process to complete the test

Images