切屑形态对刀具振动特性影响规律研究

发布时间：2019-03-12 21:05

【摘要】：切削振动对表面质量和刀具磨损均有不利影响,切削加工过程中影响切削振动的因素包括工件材料,切削用量,机床结构,刀具,外部环境等,系统中各部分的振动最终会体现在刀具和工件的相对振动上,试验表明切屑形态对切削振动的影响明显,研究高速加工中的切屑形态变化对切削振动的影响,有助于丰富切削理论,并为优化切削加工参数提供依据。本文针对钛合金进行干式车削试验,通过单因素分析、正交分析等研究方法,研究了切削形态对切削振动的影响规律以及切削力与切削振动的关系,切削振动与表面粗糙度的关系,主要研究内容和结论如下:(1)研究了TC4、TA15和TA2在不同切削用量下的切削形态变化,研究结果表明切削速度,进给量,背吃刀量越大,切屑的锯齿化程度和步距越大,速度越大锯齿频率越大,进给量和背吃刀量越大,锯齿频率越小,相同切削用量下锯齿化程度顺序为TC4TA15TA2。(2)研究了切削用量对切削振动的影响以及切削力与切削振动的关系,研究结果表明进给量和背吃刀量越大,切削振动加速度越大,随着切削速度的上升,切削振动加速度的变化趋势为先上升再下降然后又上升,切削速度变化时切削力与切削振动加速度的变化规律不同,进给量与背吃刀量变化时切削力与切削振动加速度的变化规律相同。(3)研究了TA15和TC4切屑形态对切削振动频谱和小波能谱的影响,在切削速度低于77.4m/min时切屑形态近似带状,对切削振动全频域的加速度和小波能量影响都很小,大于等于77.4m/min时切屑形态为锯齿形切屑,对切削振动高频部分加速度和小波能量影响较大,对低频部分影响较小。
[Abstract]:Cutting vibration has an adverse effect on surface quality and tool wear. The factors affecting cutting vibration in cutting process include workpiece material, cutting quantity, machine tool structure, tool, external environment and so on. The vibration of each part of the system will finally be reflected in the relative vibration of the tool and the workpiece. The experiment shows that the chip shape has an obvious effect on the cutting vibration, and the influence of the chip shape change on the cutting vibration in the high-speed machining is studied. It is helpful to enrich the cutting theory and provide the basis for optimizing the cutting parameters. Through single factor analysis and orthogonal analysis, the influence of cutting shape on cutting vibration and the relationship between cutting force and cutting vibration are studied in this paper. In this paper, the dry turning test of titanium alloy is carried out, and by means of single factor analysis and orthogonal analysis, the influence of cutting shape on cutting vibration is studied. The relationship between cutting vibration and surface roughness is studied. The main contents and conclusions are as follows: (1) the change of cutting morphology of TC4,TA15 and TA2 under different cutting parameters is studied. The results show that the cutting speed, feed and feed amount increase. The greater the sawing degree and step of the chip, the greater the speed, the greater the sawtooth frequency, the greater the feed and the amount of the back feed, the smaller the sawtooth frequency, the greater the sawtooth frequency. The effect of cutting parameters on cutting vibration and the relationship between cutting force and cutting vibration are studied in the order of sawing degree TC4TA15TA2. (2) under the same cutting parameters. The results show that the higher the feed and the amount of back-feeding cutters, the greater the acceleration of cutting vibration. With the increase of cutting speed, the changing trend of cutting vibration acceleration is firstly rising and then decreasing and then rising. When the cutting speed changes, the law of cutting force and cutting vibration acceleration is different. The variation of cutting force and cutting vibration acceleration is the same as that of feed and feed. (3) the influence of chip morphology of TA15 and TC4 on the frequency spectrum and wavelet spectrum of cutting vibration is studied. When the cutting speed is lower than 77.4m/min, the chip shape is approximately banded and has little effect on the acceleration and wavelet energy of cutting vibration in all frequency domain. When the cutting speed is greater than or equal to 77.4m/min, the chip shape is sawtooth chip. It has a great influence on the acceleration and wavelet energy of the high frequency part of the cutting vibration, but less on the low frequency part of the cutting vibration.
【学位授予单位】：沈阳理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG501

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