【摘要】：高速切削加工技術(shù)具有加工效率高,切削力小,表面質(zhì)量好的優(yōu)點,被公認為是面向二十一世紀的先進加工技術(shù)。而卡盤是現(xiàn)代機床加工回轉(zhuǎn)型的零件的關(guān)鍵夾具,被廣泛應(yīng)用。液壓動力卡盤由于其具有高轉(zhuǎn)速、夾緊力大、結(jié)構(gòu)緊湊等優(yōu)點,而被廣泛應(yīng)用于中速及高速數(shù)控車床、數(shù)控車銑中心和數(shù)控磨床等加工技術(shù)中。但是卡盤在高速運轉(zhuǎn)下由于卡爪的質(zhì)量大導(dǎo)致卡盤的離心力作用使動態(tài)夾緊力損失,限制了液壓動力卡盤高轉(zhuǎn)速的提升。另外,動力卡盤的夾持精度也是制約數(shù)控機床精度提高的關(guān)鍵因素之一。本文主要對卡盤的定心精度和夾緊力進行了研究。首先,在清華大學(xué)夾持精度已有研究的基礎(chǔ)上,針對卡盤盤體和楔心套在裝配過程中存在的裝配間隙過大或過小,裝配精度差的問題,根據(jù)分組互換法原理提出了分組互換裝配法,并通過實驗進行了驗證。對比實驗結(jié)果和已有理論分析,證明提出的分組互換裝配法對卡盤的定心精度有著很大的提高。其次,對卡盤夾緊力進行研究。在實驗的基礎(chǔ)上以良好的楔式動力卡盤為研究對象,在內(nèi)蒙古眾環(huán)油缸綜合試驗機上對卡盤進行摩擦磨損實驗,研究了卡盤夾緊力隨重復(fù)夾緊次數(shù)的變化規(guī)律。并利用掃描電鏡(SEM)和能譜分析儀(EDS)等現(xiàn)代儀器對卡盤主要摩擦表面的表面形貌進行了觀察分析,探究了卡盤摩擦副的磨損機理,得出卡盤摩擦磨損主要以氧化磨損和磨粒磨損為主,黏著磨損為輔的情況。并對卡盤的設(shè)計和使用提出指導(dǎo)意見。采用有限元分析的方法對影響卡盤夾緊力的因素進行了分析,并進行了仿真,獲得了卡盤摩擦系數(shù)、使用參數(shù)和卡爪材料等對卡盤夾緊力的影響規(guī)律。文章詳細的描述了有限元仿真的過程。最后通過實驗的方法對卡盤動態(tài)夾緊力與轉(zhuǎn)速的關(guān)系進行研究。并利用ANSYS的二次開發(fā)功能,初步開發(fā)了卡盤參數(shù)有限元仿真系統(tǒng)。本文以KT55-200楔式卡盤為例,說明參數(shù)化模塊開發(fā)的過程。
[Abstract]:High speed cutting technology has the advantages of high machining efficiency, low cutting force and good surface quality. It is recognized as an advanced machining technology facing the 21 century. Chuck is the key fixture of modern machine tool. Hydraulic power chuck has been widely used in machining technology such as medium speed and high speed CNC lathe, CNC turn-milling center and CNC grinder because of its advantages of high speed, high clamping force and compact structure. However, the centrifugal force of the chuck can lose the dynamic clamping force due to the high quality of the chuck at high speed, which limits the increase of the high speed of the hydraulic power chuck. In addition, the clamping accuracy of power chuck is also one of the key factors restricting the improvement of NC machine accuracy. In this paper, the centering accuracy and clamping force of chuck are studied. First of all, on the basis of the existing research on the clamping accuracy of Tsinghua University, the problems of too large or too small assembly clearance and poor assembly accuracy exist in the assembly process of the chuck disk body and the wedge core sleeve. According to the principle of grouping exchange, a grouping exchange assembly method is proposed and verified by experiments. Compared with the experimental results and theoretical analysis, it is proved that the proposed grouping exchange assembly method can greatly improve the accuracy of chuck centering. Secondly, the chuck clamping force is studied. On the basis of the experiment, the friction and wear experiments of the chuck were carried out on the inner Mongolia multi-ring oil cylinder comprehensive testing machine with a good wedge power chuck, and the variation law of the chuck clamping force with the repeated clamping times was studied. The surface morphology of the main friction surface of the chuck was observed and analyzed by using modern instruments such as scanning electron microscope (SEM) and energy dispersive analyzer (EDS), and the wear mechanism of the chuck friction pair was explored. The results show that the friction and wear of chuck are mainly oxidation wear and abrasive wear, and adhesion wear is secondary. And to the chuck design and use of the guidance. The factors affecting the chuck clamping force are analyzed by finite element analysis. The friction coefficient of the chuck, the parameters of the chuck and the clawing material, etc., are obtained by simulation, and the law of influence on the chuck clamping force is obtained. This paper describes the process of finite element simulation in detail. Finally, the relationship between dynamic clamping force and rotational speed of chuck is studied by experimental method. The finite element simulation system of chuck parameters is developed by using the secondary development function of ANSYS. Taking KT 55-200 wedge chuck as an example, this paper explains the development process of parameterized module.
【學(xué)位授予單位】：煙臺大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TG75
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本文編號：2129685