Papers by Keyword: Tool Vibration

Abstract: When processing materials using the milling technology, regenerative fluctuations of vibrations are the decisive factors, which limit productivity. In some case the size of the vibrations can cause shortened lifespan of the tool, decrease reliability and operational condition of the device, and subsequently case poor quality of the processed surface. Predicting the size of the vibrations between the milling machine and the work-piece is important as a lead for the users of the tool to select optimum depth of the cut and turning of the spindle, which leads to maximum rate of splinter removal. The extent of the research is focused especially on the process of monitoring, with the goal to analyze the size of the vibration at three places determined in advance - spindle head, work-piece and support, where rotation speed of the spindle change during the processing, as well as rate of splinter removal. By evaluating the results of experimental research, it is possible to determine adequate rotation speed of the spindle and depth of the cut, to achieve longest lifespan of the machine.

Abstract: Existing research on machined surface topography, only consider its response to vibration or wear certain factors, both vibration and wear impact on machined surface topography exist ambiguity and uncertainty, it cannot solve the design conflicts of machined surface topography. For this, this paper analyzes blade installation error, tool wear, vibration and deformation to reveal effects of tip space trajectory, build a three-dimensional model of machined surface topography in simulation, extract its characteristic parameters, by simulation of different amplitudes and wear, found that axis amplitude is a key factor affecting surface residual height, flank wear affects contour distribution distance significantly, by specimen milling experiments, use vibration measuring instrument and ultra-depth microscopy to obtain vibration, wear characteristics and machined surface topography parameters under different cutting parameters, then use the gray system theory to get correlation analysis of the test data, results showed that the influence of tool wear on machined surface topography is prominent than tool vibration.

Abstract: This paper presents the effect of high speed micro end milling parameters on tool vibration during machining of poly (methyl methacrylate) (PMMA). The main focus is to achieve minimum tool vibration by controlling the cutting parameters; spindle speed, feed rate and depth of cut. An empirical model for tool vibration has been developed using Taguchi method. The orthogonal array, signal-to-noise ratio and analysis of variance revealed that high spindle speed is the most influential parameter to increase the level of tool vibration.

Abstract: titanium alloy cutting force testing experiment of end-surface turning is made, and spectrum character is analyzed by obtained data of cutting force experiment, and ten the influencing rule of cutting parameter on cutting force character is discovered; using the similarity between tools vibration character and cutting force spectrum character, and based on obtained data of machined surface roughness testing experiment, the two characteristic parameters of vibration frequency and amplitude value relative to work piece is calculated, and the relationship curve between cutting parameters and tools vibration character parameter is established is this paper.

Abstract: This study focuses on the nonlinear dynamic characteristics of tool vibration in ultra precision diamond turning. Considering the first mode vibration of a tool, the tool is modelled as a one degree of freedom spring-mass-damper system with a developed cutting force model. Numerical simulations were carried out to anlyze the nonlinear dynamics of the system, using bifurcation diagrams, Poincaré maps, phase protraits, time histories and power spectral densities. The results indicated that the dynamic response of the tool is dominantly periodic and harmonic at its natural frequency with a little negligible chaos and its natural frequency, more than its fundamental frequency, is slightly shifted by depth of cut and cutting force.

Abstract: Vibration-assisted machining (VAM) combines small-amplitude vibration with different machining process to improve the process fabrication quality. It has been applied to a number of machining processes, such as turning, drilling, grinding and polishing. The emphasis on this literature is the vibration-assisted abrasive machining (VAAM), which involves with finishing and grinding processes where VAAM have been applied to hard metal, brittle material and complex geometries products like optical molds. This paper presents different vibrating units in VAAM from tool vibration to workpiece vibration, which also includes different vibrating paths from linear to ellipse. Typical hardware systems used to achieve these vibratory motions are described too.

Abstract: According to the problems of low efficiency and high cost in blisk manufacturing, based on large margin slotting and rough machining, a kind of compound and efficient powerful milling process was proposed, that is, disc milling-plunge milling-flank milling. In order to compare the effect of this new process and the traditional plunge milling or flank milling, experiment on disc milling and plunge milling processing performance was carried out. Compared with plunge milling, the cutting force and tool vibration of disc milling are larger, but its processing efficiency was improved significantly. The experiment proved that the compound and efficient powerful milling process is feasible and effective for the large margin slotting and rough machining of blisk.