【正文】
對(duì)AutoCAD的熟練運(yùn)用有了巨大的提高。銷軸支座的擠壓應(yīng)力: (439)銷軸套的擠壓應(yīng)力: (4—40)式中——軸套的支承長(zhǎng)度。(a)水平偏載(Pxa=295KN,PZa=0) 如圖4—4a所示,取鏟斗為脫離體,根據(jù)平衡原理,分析鏟斗的受力:由 (4—10) (4—11) 由 (4—12) 所以 (4—13) 由 (4—14) 則 (4—15) 如圖3—24b所示,取連桿為脫離體,根據(jù)平衡原理,作用于連桿兩端的力大小相等,方向相反,即: (4—16)由圖示受力分析可知,連桿此時(shí)受拉。 工作裝置的受力分析在確定了計(jì)算位置及外載荷的大小后,便可進(jìn)行工作裝置的受力分橋。綜合上述分機(jī)可以得到如下六種工作裝置的典型工況(圖4—2):1. 對(duì)稱水平力的作用工況(圖4—2a)水平力(即插入阻力PC)的大小由裝載機(jī)的牽引力決定,其水平力的最大值為: (4—1)此處根據(jù)相關(guān)資料取 (4—2)——裝載機(jī)空載時(shí)的最大牽引力, ——插入力。3)對(duì)工作裝置進(jìn)行受力分析。此外,在采用動(dòng)臂油缸下端擺動(dòng)的連接方式時(shí),要注意油缸下端在擺動(dòng)過(guò)程中不與機(jī)體發(fā)生于涉。 為了得到較好的舉升工作力臂變化特性曲線,以適應(yīng)舉升過(guò)程中阻力矩的變化和合理地選定舉升油缸的功率,采用中間鉸接式油缸是比較理想的,如圖所示。綜合考慮這些因素,一般舉升油缸都布置在前橋與前后車架的鉸接點(diǎn)之間的狹窄空間里。完成上述構(gòu)件尺寸選擇后,就可用下述作圖方法來(lái)確定連桿CD的長(zhǎng)度、轉(zhuǎn)斗油缸與車架的鉸點(diǎn)G及行程。為此,建議按下述方法進(jìn)行設(shè)計(jì):按單搖桿條件設(shè)計(jì)六桿機(jī)構(gòu),連桿與鏟斗鉸點(diǎn)C的位置影響連桿的受力和轉(zhuǎn)斗油缸的行程,選擇時(shí)主要考慮當(dāng)鏟斗處于地面挖掘位置情況下,轉(zhuǎn)斗油缸作用在連桿CD的有效分力較大,以發(fā)揮比較大的掘起力。一般,A點(diǎn)取在前輪右上方,與前軸心水平距離為軸距的處。(2)把已選定的輪胎外廓畫在坐標(biāo)圖上。 圖解法比較直觀,易于掌握,是目前工程設(shè)計(jì)時(shí)常用的一種方法。由于現(xiàn)今國(guó)內(nèi)、外購(gòu)輪胎式裝載機(jī)廣泛地采用反轉(zhuǎn)六桿工作機(jī)構(gòu),并且它的設(shè)計(jì)難度較大,又有一定的代表性,所以以其為例,闡述工作機(jī)構(gòu)連桿系統(tǒng)的尺寸參數(shù)設(shè)計(jì),以求舉一反三。對(duì)于裝有擋板的鏟斗: (2—10) 根據(jù)有關(guān)計(jì)算有: (2—11) A——鏟斗橫斷面面積,如圖2—5中所示陰影面積 ——鏟斗內(nèi)壁寬(m), a——擋板高度(m); b——斗刃刃口與擋板最上部之間的距離(m)。因此鏟斗的其它參數(shù)依據(jù)它來(lái)決定。對(duì)主要用于土方工程的裝載機(jī),在設(shè)計(jì)鏟斗時(shí)要考慮斗體內(nèi)的流動(dòng)性,減少物料在斗內(nèi)的移動(dòng)或滾動(dòng)阻力,同時(shí)要有利于在鏟裝粘性物料時(shí)有良好的卸凈性。 鏟斗的斗齒 鏟斗斗齒分為尖齒和鈍齒。 鏟斗是在惡劣的條件下工作,承受很大的沖擊載荷和劇烈的磨削,所以要求鏟斗具有足夠的強(qiáng)度和剛度,同時(shí)要耐磨。關(guān)鍵詞 工程機(jī)械,裝載機(jī),鏟斗ZL50 loader reverse six connecting rod working device design of bucketAbstract Loaders is one of the main machine the engineering machinery, widely used in construction, mine, water and electricity, Bridges, railways, highways, ports, docks and national economic sectors. In this article refer to a large number of earthwork the design of mechanical reference books, most of which is about the loader, have a plenty of a single ponent design work device, some is the whole work device design, and there are many relevant work device optimization design, the reference involved loader although different model, the method also has difference, but prehensive up basically is reviewed the current design method. Foreign loader development is rapid, and our country loader in the design has a lot of problems, which mainly focus on reliability, structural design intensity, etc. And work device is also the most for loader, so the design of the device has a direct influence on the service life of the loader and work efficiency, etc. Although now in the market of the loader has increasingly mature, but for the design improvement there are still very important sense, especially of the loader working device. The bucket is an important part of the work unit, directly used to cutting, shovel dug, transportation and discharged materials. The bucket structure shape, size parameters on the resistance, resistance to dig up into the working efficiency and impact, so the bucket loader design according to the main application and operation conditions from reduce resistance, and insert the rise and improve the efficiency of resistance and rational