內(nèi)容提要
挖掘機(jī)作為我國(guó)工程機(jī)械的主力機(jī)種，被廣泛應(yīng)用于各種各樣的施工作業(yè)中。挖掘機(jī)產(chǎn)品的核心技術(shù)就是液壓系統(tǒng)設(shè)計(jì)，由于挖掘機(jī)的工作條件惡劣，要求實(shí)現(xiàn)的動(dòng)作復(fù)雜，于是它對(duì)液壓系統(tǒng)的設(shè)計(jì)提出了很高的要求，其液壓系統(tǒng)也是工程機(jī)械液壓系統(tǒng)中最為復(fù)雜的。因此，對(duì)挖掘機(jī)液壓系統(tǒng)的分析設(shè)計(jì)對(duì)推動(dòng)我國(guó)挖掘機(jī)發(fā)展具有十分重要的意義。
在搜集了國(guó)內(nèi)外挖掘機(jī)液壓系統(tǒng)相關(guān)資料的基礎(chǔ)上，了解了挖掘機(jī)液壓系統(tǒng)的發(fā)展歷史，并對(duì)挖掘機(jī)液壓系統(tǒng)的技術(shù)發(fā)展動(dòng)態(tài)進(jìn)行了分析總結(jié)。論文對(duì)挖掘機(jī)的各種工況進(jìn)行了分析，系統(tǒng)總結(jié)了挖掘機(jī)液壓系統(tǒng)的設(shè)計(jì)要求。根據(jù)挖掘機(jī)液壓系統(tǒng)的設(shè)計(jì)要求，論文中采用通用多路閥，配以專用控制閥和簡(jiǎn)單的電子控制系統(tǒng)，設(shè)計(jì)了一套適合我國(guó)生產(chǎn)制造的LS恒功率控制單斗挖掘機(jī)液壓系統(tǒng)。
本次畢業(yè)設(shè)計(jì)課題是ＳＷＥ７０Ｈ型液壓挖掘機(jī)。課題以企業(yè)為依托。小型挖掘機(jī)由多個(gè)系統(tǒng)組成，包括液壓系統(tǒng)，傳動(dòng)系統(tǒng)，操縱系統(tǒng)，工作裝置，底架，轉(zhuǎn)臺(tái)，油箱，發(fā)動(dòng)機(jī)安裝等。本人的設(shè)計(jì)主要致力于分析和設(shè)計(jì)小型液壓挖掘機(jī)工作裝置中斗桿機(jī)構(gòu)液壓系統(tǒng)。本課題選擇了國(guó)內(nèi)的質(zhì)量和技術(shù)性能都接近設(shè)計(jì)要求的７０t挖掘機(jī)作為基型，并在此基礎(chǔ)上研究了國(guó)外的先進(jìn)機(jī)型，設(shè)計(jì)出我們挖掘機(jī)的液壓系統(tǒng)方按圖，總體裝配圖以及相應(yīng)的部件圖和零件圖。圖紙基本采用Auto CAD二維軟件繪圖。本液壓挖掘機(jī)的優(yōu)點(diǎn)是采用伺服先導(dǎo)操縱系統(tǒng)，造型美觀，具備挖掘，抓物，鉆孔，推土，清溝和破碎等功能。平臺(tái)可360°旋轉(zhuǎn)，性能可靠，操作舒適，可廣泛應(yīng)用于建筑，市政，供水，供氣，供電農(nóng)林建設(shè)








Summary
The excavator is a main consrtuctional machine，which is now widely used in various construction sites.The core technique of excavator is hydrau1ic technique. Becauseofthe bad working condition and conmplicated working movements of the excavatot，it has high requitements for its hydraulic system.Since the excavator’s hydraulic system is the most complicated one in all constructional machines ,the analysis and research of its hydrau1ic system make very important sens.
On the basis of comprehensive co11ection of re1ated information about the excavator’s hydraulic system at home and abroad，the main working conditions of the excavator are studied and the design requitments of its hydraulic system are systematically summarized. According to the design pressure compensated hydraulic system is creatively designed using general multiple until value equipped with special contol valve and electronic contor systems,which has useful reference value for the future research and development of the excavator’s hydraulic system in our country.
The name of this graduated task is “SWE70H” medium type hydraulic excavator”.This task is requested by company. My task is to analyze and design the hydraulic system of the medium type hydraulic excavator. This task choose the domestic excavator whose quality and character is most similar to our request as the basic type, further study the overseas advanced type. Then I designed projects of hydraulic system of our excavator,collectivity assemblage drawing and interrelated parts drawing, accessory drawing. All the blueprints drawn by the soft of AutoCAD. The strongpoint of this hydraulic excavator is used servo forerunner control system. It has beautiful sculpt. Beijing provided with the fuction of excavating, grappling, drilling, pushing, cleaning channel and crashing etc. 360°swwing plat roof,good quality, controlling comfortable, be widely used in construction,supply and city planning.






目 錄

內(nèi)容提要 I
Summary II
一 前言 1
（一）挖掘機(jī)簡(jiǎn)介 1
（二）國(guó)內(nèi)外研究現(xiàn)狀及發(fā)展動(dòng)態(tài) 2
（三）本設(shè)計(jì)的研究?jī)?nèi)容 5
二 液壓挖掘機(jī)結(jié)構(gòu)與工作原理 5
（一）液壓挖掘機(jī)整機(jī)性能 6
（二）液壓挖掘機(jī)結(jié)構(gòu) 7
（三）液壓挖掘機(jī)傳動(dòng)原理 9
三 液壓挖掘機(jī)工況分析及液壓系統(tǒng)設(shè)計(jì)方案的確定 10
（一）液壓挖掘機(jī)的工況 10
（二）挖掘機(jī)液壓系統(tǒng)的設(shè)計(jì)要求 14
（三）挖掘機(jī)液壓系統(tǒng)的分析 15
（四）液壓系統(tǒng)方案擬訂 16
四 液壓系統(tǒng)的設(shè)計(jì) 17
（一）液壓系統(tǒng)方案及參數(shù)確定 17
（二）執(zhí)行元件液壓缸及系統(tǒng)壓力的初選 18
（三) 計(jì)算工作裝置鏟斗液壓缸的主要尺寸 19
（四）液壓系統(tǒng)原理圖的制定 21
五 液壓元件的選擇與專用件的設(shè)計(jì) 25
（一）液壓泵的選擇和泵的參數(shù)的計(jì)算 26
（二）柴油發(fā)動(dòng)機(jī)的選擇 28
（三）液壓閥的選擇 28
（四）其他液壓元件的選擇 31
（五）油箱容量的確定 33
六 液壓系統(tǒng)性能驗(yàn)算 34
（一）液壓系統(tǒng)壓力損失 34
（二）液壓系統(tǒng)的發(fā)熱溫升計(jì)算 36
總 結(jié) 41
參考文獻(xiàn) 42
致 謝 44