金属平面塑性精加工机及其控制系统的研究和制造/

2019-04-05 20:56:15

machine processing plastic precise 滚压



金属件平面的精密加工目前主要是采用磨削加工技术,该技术已是成熟的加工方法,并被普遍用于机械制造行业中。但在磨削加工中,砂轮的消耗是不可避免的,为了避免工件的磨削烧伤,还必须冷却液的连续供给。此外,有色金属磨削时由于砂轮粘附堵塞致使磨削难以进行也是迄今尚未解决的难题。
金属平面塑性精密加工技术是金属塑性加工技术和精密加工技术在金属平面加工中的综合应用,根据金属在一定的条件下产生塑性变形的原理,使金属在滚动压力的作用下,产生连续局部塑性变形,从而改善和提高机械零件的最终表面质量和性能。
本论文是我的导师宋玉泉教授连续局部塑性精成形和精密加工总体研究的一个重要组成部分。论文首先是根据宋玉泉教授的实用新型专利“金属滚压平面塑性精成型装置”中所拟定的基于机械式牛头刨床的金属平面塑性精加工机的设计方案,即以机械式牛头刨床的滑枕运动作为X方向的动力机构,工作台的进给运动作为金属平面塑性精加工机的Y方向的运动,Z方向的进给运动装置及其控制系统自行设计制造,确立了金属平面塑性精加工机的基本方案和设计思路。该专利虽然有创新思路,但是要成为造价低、自动控制、运行稳定、使用性能好的生产样机,尚需进行大量的改进、补充和完善工作。
本论文在对所属研究领域的资料搜集和评述的前提下进行了如下的工作:通过对滚压加工工艺和刨削加工工艺特点的比较、机械式牛头刨床与液压牛头刨床的对比,确定了金属平面塑性精加工机的整机机械方案用液压牛头刨床代替机械牛头刨床并增设了保证和适合于滚压加工工艺过程特点的轴进给装置及控制系统、滚压力及滚压速度的测量和采集装置,并进行了机械零件的加工、机械装置的装配与调试、控制系统的布线、控制装置的安装与调试、传感器的标定,研制了金属平面塑性精加工机。金属平面塑性精加工机综合应用了机械技术、液压技术、电子技术和计算机技术,X方向主运动具有较宽的调速范围并且能够在急回时实现滚压装置的自动抬刀,光栅线位移传感器和计算机的应用能够精确测量和记录主运动速度,从而为滚压工艺实验过程中寻求滚压速度和滚压加工质量之间的关系提供了实验手段;Y方向运动能够调节进给量的大小,为滚压加工工艺实验过程中寻求滚压进给量与滚压件表面质量之间的关系创造了条件;Z向微量进给装置及控制系统用以实现滚压加工时调整Z向的精确进给量,控制精度可达0.01mm,在滚压加工过程中通过力传感器测定滚压力的大小,并且可以调节滚压进给量和滚压力的大小。准确记录滚压加工过程中滚压速度、滚压力及所需时间,自动生成力—时间曲线、速度—时间曲线等。扭矩支承装置消除了滚压加工过程中滑枕与燕尾槽之间的间隙,保证了滚压加工过程中Z向的精确进给量;感应加热及控制装置保证了金属平面塑性精加工机具有较宽的加工范围,可以加工从有色金属到钛合金范围内的金属,因此适应了实际加工中零件材料多样性的特点。
金属平面塑性精加工机根据金属平面塑性精加工工艺的特点和要求,结合液压牛头刨床的工作特点改造而成,它只是金属平面塑性精加工机的起步阶级,还存在以下难点有待于在以后的工作中进行研究和改进:(1)由于牛头刨床滑枕重量较大,已经安装在液压牛头刨床上并且对抗扭矩装置而言没有可以利用的现成对接面,因此,抗扭矩装置与刨床滑枕之间的对接存在困难;(2)感应加热装置是通过电磁感应原理及利用涡流对工件进行加热,一般用于棒形件的加热,如果用来对平面表层进行瞬间加热,使金属工件表面瞬间软化,还需设计专用感应加热圈;(3)Z向进给装置采用的是半闭环控制系统,如果需要更高的精度及制造专用设备,还有待于根据工艺要求改为闭环控制系统。虽然说目前还存在这些难点,但它为以后进行金属平面塑性精加工专用设备的设计提供了设计思想和设计原理模型。




The accurate processing of metal work piece plane mostly adopts abrasive machining technology in present, this technology has been mature processing method, and is widely used in mechanical industry. But in the abrasive machining technology, the consumption of emery wheel is unavoidable; in order to avoid the abrasive burning, the continuous supply of coolant is necessary. In the process of grinding nonferrous metal, the paste and block of emery wheel makes it difficult to continue, which is the difficulty that has not been solved until now.
The plastic precise-processing technology to metal plane is the comprehensive application of the metal plastic process technology and precision process technology in the metal plane. According to the plastic deforming principle of metal under certain conditions, metal would produce continuous and partial plastic deformation under rolling pressure, so that change and improve the final surface quality and property.
This paper is an important component of overall research about continuous partial plastic-precise deformation and precision process which is researched by my tutor-professor Song YuQuan. The article is about the design plan of metal plane plastic precise-processing machine based on mechanical shaping machine specified in professor Song YuQuan’s practical new-type patent “the plastic precise-forming device” ,i.e. taking the ram-motion of mechanical shaping machine as X direction dynamic mechanism, the feeding motion of working platform as Y direction movement of the plastic precise-processing machine to metal plane, the feeding-movement device and its control system in Z direction are designed and produced by ourselves, so that the basic plan and design idea of the plastic precise-processing machine to metal plane are specified. Although there are some creative ideas in the patent, there still need quantity of improving, supplement and perfecting works to make the model machine low cost, automatic control, working steadily and excellent quality.
The following works have been done in the premise of data-collection and commenting on the research area in the article: by contrasting the arts between rolling processing technology and shaping processing technology, and comparing the features between mechanical shaping machine and hydraulic shaping machine, the overall mechanical plan of the plastic precise-processing machine is specified, the mechanical shaping machine is replaced by hydraulic shaping machine and added ensuring and fitting the rolling processing craft axis feeding device and its control system、the data-measurement and collection device、mechanical workpieces machined、the installation and test of the mechanical device、the circuit arrangement of control system、the installation and test of control device and the sensor’s demarcate, so that the plastic precise- processing machine to metal plane is researched. The plastic precise- processing machine to metal plane comprehensively uses mechanical technology、hydraulic technology、electric technology and computer technology, the primate movement in X direction has widely adjusting velocity range and can realize the automatic raise the knife rest device in quickly coming back, the applying of light-grind line movement sensor and the computer can measure and save the date of velocity in the prime movement precisely, so that the experiment method of seeking the relationship between rolling velocity and the processing quality of rolling is supplied in the course of rolling craft experiment; The feeding quantity in Y direction can be modified, the condition was created for seeking the relationship between the feeding quantity in rolling and the surface quality of rolling workpieces in the course of rolling craft experiment; In the course of rolling , the adjustment of precise feeding quantity in Z direction can be realized, the control precision can be reached to 0.01mm, the quantity of rolling power can be measured by power-sensor, the feeding quantity and rolling power can be adjusted. Record rolling velocity、rolling power and time precisely, automatically produce the strength-time curved line、distance-time curved line etc. The bending moment supporting device eliminate the space between the ram and devotail slot and ensure the precise feeding quantity in Z direction while rolling; the deduction heating device and its control system ensure the plastic precise-processing machine has wide processing range, which can process the metal in the range from nonferrous metal to titanium alloy and fit the characteristic of multiple kinds of worpieces’ material in real processing.
The plastic precise-processing machine to metal plane is based on the draft characteristic and demand of the plastic and precise processing, compound with the working characteristic of hydraulic shaping machine. it is only the beginning of researching the plastic precise-processing machine to metal plane, and there still exist some difficulties to be solved in the following works: (1) The ram fixed on the shaping machine weighs high and has no jointed surface available, which makes the joint between shaping machine and the bending moment supporting device difficult;(2) The induction heating device heating workpiece by electromagnetic induction principle is used to heating clavate workpiece; the specialized induction heating device circle need to be designed if the deduction heating device was applied to fulfill instant heating to the plane layer and make the surface soft instantly;(3) The half close circuit control system is adopted in the feeding device in Z direction, which need to be changed to close circuit control system according to draft experiment demand if more precision and specialized device are needed. Although there exists these difficulties at present,It provides the design idea and design principle model supplied for the design of the plastic precise- processing specialized machine in the future.