本文選題：液壓挖掘機 + 挖掘力��； 參考：《重慶大學(xué)》2014年博士論文

【摘要】：作為典型的機電液一體化產(chǎn)品，挖掘性能是挖掘機的核心性能指標，對挖掘性能的研究是實現(xiàn)機械、液壓和控制系統(tǒng)性能匹配的前提，更是實現(xiàn)液壓挖掘機節(jié)能、高效和智能化的基礎(chǔ)。國內(nèi)外眾多學(xué)者針對挖掘性能的研究取得了很多成果，也存在一些不足。這些不足主要體現(xiàn)在以下方面：①現(xiàn)有方法并不能解決實際挖掘過程中挖掘阻力的準確求解問題；②強度分析結(jié)果與實際失效形式不符，缺乏對工作裝置動靜態(tài)強度分析的有效方法；③現(xiàn)有理論挖掘力模型無法得到挖掘機在極限挖掘工況下所能發(fā)揮的最大挖掘力，也不能針對復(fù)合挖掘工況的挖掘能力進行有效評估；④現(xiàn)有圖譜分析法不能對挖掘性能作出準確的評價。為解決這些問題，本文主要針對實際挖掘過程中挖掘阻力模型、應(yīng)力和挖掘阻力測試平臺、動靜強度分析和驗證方法、理論挖掘力建模和挖掘性能分析方法等方面進行了理論與實驗研究。本文的具體工作和研究成果主要包括以下內(nèi)容： 1)基于平面力系原理，提出一種將挖掘阻力系向切削刃合成為切向阻力、法向阻力和阻力矩的方法，使挖掘阻力的準確求解成為可能。建立液壓挖掘機運動學(xué)和動力學(xué)模型，結(jié)合挖掘阻力系合成結(jié)果，提出實際作業(yè)過程中挖掘阻力準確求解的測試計算方法，突破了利用經(jīng)驗公式和模擬方法預(yù)測挖掘阻力大小的現(xiàn)狀，使斗形裝置實際作業(yè)中挖掘阻力特性分析成為可能，為挖掘性能相關(guān)研究奠定理論基礎(chǔ)。 2)建立液壓挖掘機工作裝置姿態(tài)、應(yīng)變和油壓的同步采集測試平臺，并完成多次挖掘過程中多種數(shù)據(jù)的采集、轉(zhuǎn)換和擬合。利用測試數(shù)據(jù)和挖掘阻力模型，計算各種挖掘工況對應(yīng)的挖掘阻力，根據(jù)應(yīng)力應(yīng)變關(guān)系計算所有測點在挖掘過程中的當量應(yīng)力，為挖掘阻力特性研究和應(yīng)力結(jié)果對比提供實驗依據(jù)。 3)對比實際挖掘過程的動應(yīng)力峰值與相同挖掘姿態(tài)下的靜應(yīng)力仿真值，分析靜強度計算結(jié)果與真實動應(yīng)力之間的關(guān)系，研究液壓挖掘機工作裝置廣義動載系數(shù)的范圍，提供一種利用靜強度分析手段解決動載荷問題的方法。 4)利用實驗測試數(shù)據(jù)，基于達朗貝爾形式的挖掘阻力模型，計算出動臂和斗桿各個鉸點在實際挖掘過程中的載荷譜。將其作為外載，，利用瞬態(tài)分析方法仿真動臂和斗桿整體動應(yīng)力分布規(guī)律。對比動應(yīng)力的測試與仿真結(jié)果，不但驗證了瞬態(tài)分析過程的正確性，找到一種動強度分析的可行方法，也驗證了挖掘阻力模型的正確性。 5)利用實際挖掘過程中挖掘阻力的測試計算結(jié)果，從總體特性、力值大小和方向特性3個方面分析挖掘阻力各個部分的變化規(guī)律，基于統(tǒng)計學(xué)原理研究阻力系數(shù)、阻力矩系數(shù)、阻力角、差值角的主值區(qū)間和概率密度。研究斗形裝置在真實作業(yè)過程中的挖掘特性和挖掘阻力變化規(guī)律，為工作裝置的設(shè)計、優(yōu)化和理論挖掘力模型的建立提供實驗依據(jù)。 6)基于挖掘阻力的總體特性和力值大小特性提出極限挖掘力的概念和計算模型，解決了現(xiàn)有理論挖掘力模型無法計算出挖掘機本身在單獨挖掘工況下所能發(fā)揮的極限挖掘力問題；基于復(fù)合挖掘過程中挖掘阻力的方向特性，提出并建立了復(fù)合挖掘力的概念和模型，為復(fù)合挖掘過程挖掘能力的評價提供一種方法，突破現(xiàn)有理論，奠定了液壓挖掘機挖掘性能準確評價的理論基礎(chǔ)。 7)突破以挖掘姿態(tài)為研究對象的傳統(tǒng)方法限制，提出基于工作域的圖譜分析法。該方法從根本上避免了因一個挖掘點對應(yīng)多種挖掘姿態(tài)而帶來的問題。以挖掘阻力的測試計算結(jié)果為基準，對比基于工作域的圖譜分析法與傳統(tǒng)方法，結(jié)果表明：基于工作域的圖譜分析法能夠更為準確的反映所在挖掘點的挖掘能力，基于此得到的挖掘力圖和挖掘限制圖揭示了挖掘力及其限制因素的區(qū)域性分布規(guī)律，能夠準確展現(xiàn)液壓挖掘機的挖掘性能。利用基于工作域的圖譜分析法研究了4種噸位相近的中型反鏟液壓挖掘機的挖掘性能，分析過程顯示該方法不僅可以提供較為直觀的理論挖掘力及其限制因素分布圖，還可以提供挖掘力和限制因素比例的統(tǒng)計結(jié)果，為液壓挖掘機挖掘性能的分析和評價提供了理論依據(jù)，為實際的工程應(yīng)用提供了可靠的方法。
[Abstract]:As a typical integrated product of electro - mechanical fluids , the mining performance is the core performance index of the excavator , and the research on the excavation performance is the premise of realizing the performance matching of the mechanical , hydraulic and control systems , and it is the foundation of energy saving , high efficiency and intelligence of the hydraulic excavator .
( 2 ) The results of strength analysis do not accord with the actual failure modes , and there is a lack of effective methods to analyze the dynamic static strength of the working device ;
( 3 ) the existing theory mining force model can not obtain the maximum digging force which can be exerted by the excavator under the limit digging condition , and can not effectively evaluate the digging capacity of the composite excavation working condition ;
In order to solve these problems , this paper mainly focuses on the theory and experimental research on excavating resistance model , stress and excavation resistance test platform , dynamic and static strength analysis and verification method , theoretical digging force modeling and mining performance analysis method in actual excavation process . The concrete work and research results of this paper mainly include the following :

1 ) Based on the principle of plane force system , a method of combining excavation resistance to cutting edge into tangential resistance , normal resistance and resistance moment is proposed to make the accurate solution of excavation resistance possible .

2 ) establishing a synchronous acquisition test platform of the attitude , the strain and the oil pressure of the working device of the hydraulic excavator , and completing the collection , conversion and fitting of various data during the plurality of excavation processes .

3 ) comparing the dynamic stress peak value of the actual excavation process with the static stress simulation value under the same excavation posture , analyzing the relation between the static strength calculation result and the real dynamic stress , researching the range of the generalized dynamic load coefficient of the working device of the hydraulic excavator , and providing a method for solving the dynamic load problem by using the static strength analysis means .

4 ) Using the experimental test data , the load spectrum of each hinge point of the boom and bucket rod is calculated on the basis of the excavation resistance model in the form of the Dalang Bell . As an external load , the dynamic stress distribution law of the movable arm and the bucket rod is simulated by the transient analysis method . The test and simulation results of the contrast dynamic stress are verified , and the correctness of the transient analysis process is verified , and the feasible method for analyzing the dynamic strength is found , and the correctness of the excavation resistance model is also verified .

5 ) Based on the statistical principle , the rule of resistance coefficient , drag torque coefficient , drag angle , main value interval and probability density of resistance coefficient , drag coefficient , drag angle and difference angle are analyzed from three aspects of overall characteristic , force value size and directional characteristic .

6 ) the concept and the calculation model of the limit digging force are put forward based on the overall characteristic and the force value size characteristic of the excavation resistance , and the problem that an excavator can not be calculated can be calculated by the existing theory digging force model can not be calculated ;
Based on the directional characteristic of excavation resistance in the process of compound excavation , the concept and model of compound digging force are proposed and established , which provides a method for the evaluation of the excavation capacity of the composite excavation process .

In this paper , the mining performance of the hydraulic excavator can be accurately reflected by using the map analysis method based on the working domain . The results show that the method not only can provide more visual theoretical digging force and its limiting factor distribution map , but also can provide the statistical results of the mining force and the limiting factor ratio , and provide theoretical basis for the analysis and evaluation of the excavation performance of the hydraulic excavator .

【學(xué)位授予單位】：重慶大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：TU621

【參考文獻】

相關(guān)期刊論文 前3條

1 曹善華,徐志新;液壓挖掘機工作裝置運動軌跡的微機控制[J];同濟大學(xué)學(xué)報;1988年01期

2 何清華;張大慶;黃志雄;張新海;;液壓挖掘機工作裝置的自適應(yīng)控制[J];同濟大學(xué)學(xué)報(自然科學(xué)版);2007年09期

3 史青錄;連晉毅;林慕義;;挖掘機最大理論挖掘力的確定[J];太原科技大學(xué)學(xué)報;2007年01期

相關(guān)博士學(xué)位論文 前7條

1 林瀟;液壓挖掘機并聯(lián)式混合動力系統(tǒng)控制策略研究[D];浙江大學(xué);2010年

2 張樹忠;基于液壓式能量回收的挖掘機動臂節(jié)能研究[D];西南交通大學(xué);2011年

3 林添良;混合動力液壓挖掘機勢能回收系統(tǒng)的基礎(chǔ)研究[D];浙江大學(xué);2011年

4 肖清;液壓挖掘機混合動力系統(tǒng)的控制策略與參數(shù)匹配研究[D];浙江大學(xué);2008年

5 郝鵬;液壓挖掘機動力系統(tǒng)匹配及節(jié)能控制研究[D];中南大學(xué);2008年

6 王冬云;混合動力挖掘機動力總成及參數(shù)匹配方法研究[D];浙江大學(xué);2009年

7 陳明東;液壓挖掘機動臂下降勢能回收技術(shù)研究[D];吉林大學(xué);2013年

本文編號：1769423