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当前位置:J9九游会AG首页 J9九游会AG维修测试→工程机械_挖掘机的维修_液压控制系统的改进
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工程机械_挖掘机的维修_液压控制系统的改进

发布时间:2018-05-08 浏览次数:4120次

实现挖掘(jue)(jue)机的(de)电(dian)液比(bi)例控(kong)制、液压伺服控(kong)制及(ji)远(yuan)程无(wu)线控(kong)制,可(ke)大大减轻驾(jia)驶员(yuan)的(de)重复操作(zuo)劳(lao)动,把(ba)挖掘(jue)(jue)机驾(jia)驶员(yuan)从(cong)传(chuan)统(tong)(tong)的(de)杠(gang)杆(gan)操纵和恶劣的(de)工作(zuo)环境中(zhong)解放(fang)出来。基于以上思想,把(ba)一台WYI.5型液压挖掘(jue)(jue)机的(de)杠(gang)杆(gan)操作(zuo)系统(tong)(tong)改装设计成电(dian)液比(bi)例控(kong)制的(de)液压系统(tong)(tong),并基于E1型移动车(che)辆(liang)控(kong)制器来实现对整车(che)的(de)控(kong)制。

(1) WYI.5型挖掘(jue)机液压系统(tong)

WYI.5型挖掘机液(ye)(ye)(ye)(ye)压(ya)(ya)系统(tong)由油(you)(you)(you)箱、三联齿轮泵(beng)(一(yi)个(ge)3mL/r、两个(ge)8mL/r)、多路(lu)换向(xiang)阀(fa)(fa)、溢流阀(fa)(fa)、节流阀(fa)(fa)、动臂(bei)液(ye)(ye)(ye)(ye)压(ya)(ya)缸(gang)、斗杆液(ye)(ye)(ye)(ye)压(ya)(ya)缸(gang)、铲斗液(ye)(ye)(ye)(ye)压(ya)(ya)缸(gang)、工作装(zhuang)置(zhi)偏转(zhuan)液(ye)(ye)(ye)(ye)压(ya)(ya)缸(gang)、推(tui)土(tu)铲液(ye)(ye)(ye)(ye)压(ya)(ya)缸(gang)、左右行走马(ma)(ma)达、整(zheng)机回(hui)(hui)转(zhuan)马(ma)(ma)达、散热器和滤清器等组成(cheng)。推(tui)土(tu)铲供油(you)(you)(you)由一(yi)个(ge)3mL/r的齿轮泵(beng)单独完成(cheng),当推(tui)土(tu)铲不(bu)工作时,其(qi)高压(ya)(ya)油(you)(you)(you)直接返(fan)回(hui)(hui)油(you)(you)(you)箱。在整(zheng)机回(hui)(hui)转(zhuan)马(ma)(ma)达控制(zhi)阀(fa)(fa)后加(jia)装(zhuang)一(yi)换向(xiang)阀(fa)(fa),实现整(zheng)机回(hui)(hui)转(zhuan)马(ma)(ma)达和工作装(zhuang)置(zhi)偏转(zhuan)液(ye)(ye)(ye)(ye)压(ya)(ya)缸(gang)之(zhi)间的油(you)(you)(you)路(lu)切换控制(zhi)。其(qi)余(yu)液(ye)(ye)(ye)(ye)压(ya)(ya)系统(tong)为典型的双泵(beng)、双回(hui)(hui)路(lu)、中位回(hui)(hui)油(you)(you)(you)、可合流系统(tong)。

(2)电控液压系统的改进

①电(dian)(dian)(dian)(dian)液(ye)(ye)(ye)比例液(ye)(ye)(ye)压(ya)(ya)(ya)(ya)系(xi)(xi)统(tong)(tong)(tong)(tong)设(she)(she)计(ji) 为(wei)实现(xian)(xian)各机构的(de)(de)(de)(de)电(dian)(dian)(dian)(dian)液(ye)(ye)(ye)比例控(kong)(kong)制,在不(bu)(bu)(bu)改变原(yuan)(yuan)有杠(gang)(gang)(gang)杆(gan)操(cao)纵(zong)系(xi)(xi)统(tong)(tong)(tong)(tong)功能的(de)(de)(de)(de)基(ji)(ji)础上(shang)并联一(yi)套电(dian)(dian)(dian)(dian)控(kong)(kong)系(xi)(xi)统(tong)(tong)(tong)(tong)。为(wei)安全起见,两套系(xi)(xi)统(tong)(tong)(tong)(tong)设(she)(she)计(ji)成不(bu)(bu)(bu)能同时(shi)(shi)(shi)工(gong)作(zuo),在优(you)先级(ji)上(shang)电(dian)(dian)(dian)(dian)控(kong)(kong)系(xi)(xi)统(tong)(tong)(tong)(tong)工(gong)作(zuo)时(shi)(shi)(shi)杠(gang)(gang)(gang)杆(gan)操(cao)纵(zong)系(xi)(xi)统(tong)(tong)(tong)(tong)无法(fa)使用,而在电(dian)(dian)(dian)(dian)控(kong)(kong)系(xi)(xi)统(tong)(tong)(tong)(tong)停止工(gong)作(zuo)时(shi)(shi)(shi)杠(gang)(gang)(gang)杆(gan)操(cao)纵(zong)系(xi)(xi)统(tong)(tong)(tong)(tong)自动(dong)(dong)(dong)恢复正常工(gong)作(zuo)。如图K所示,为(wei)实现(xian)(xian)此功能,选取两位(wei)两通的(de)(de)(de)(de)电(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)换(huan)(huan)向(xiang)(xiang)阀(fa)(fa)1、2来实现(xian)(xian)高压(ya)(ya)(ya)(ya)油在电(dian)(dian)(dian)(dian)控(kong)(kong)系(xi)(xi)统(tong)(tong)(tong)(tong)和杠(gang)(gang)(gang)杆(gan)操(cao)纵(zong)系(xi)(xi)统(tong)(tong)(tong)(tong)中的(de)(de)(de)(de)切换(huan)(huan)。电(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)阀(fa)(fa)的(de)(de)(de)(de)控(kong)(kong)制基(ji)(ji)于软件编程实现(xian)(xian),其(qi)响(xiang)应时(shi)(shi)(shi)间(jian)、响(xiang)应速度(du)均与(yu)操(cao)作(zuo)者的(de)(de)(de)(de)熟练程度(du)没有关系(xi)(xi),因此选用电(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)换(huan)(huan)向(xiang)(xiang)阀(fa)(fa)3来实现(xian)(xian)整个(ge)系(xi)(xi)统(tong)(tong)(tong)(tong)不(bu)(bu)(bu)工(gong)作(zuo)时(shi)(shi)(shi)的(de)(de)(de)(de)卸荷(回流)。电(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)换(huan)(huan)向(xiang)(xiang)阀(fa)(fa)4用于系(xi)(xi)统(tong)(tong)(tong)(tong)的(de)(de)(de)(de)双(shuang)泵合流。原(yuan)(yuan)杠(gang)(gang)(gang)杆(gan)操(cao)纵(zong)系(xi)(xi)统(tong)(tong)(tong)(tong)在动(dong)(dong)(dong)臂(bei)(bei)提(ti)(ti)升(sheng)(sheng)(sheng)(sheng)时(shi)(shi)(shi),发(fa)现(xian)(xian)有短(duan)暂下(xia)降(jiang)然后(hou)才正常提(ti)(ti)升(sheng)(sheng)(sheng)(sheng)的(de)(de)(de)(de)现(xian)(xian)象。究其(qi)原(yuan)(yuan)因,液(ye)(ye)(ye)压(ya)(ya)(ya)(ya)系(xi)(xi)统(tong)(tong)(tong)(tong)不(bu)(bu)(bu)工(gong)作(zuo)时(shi)(shi)(shi)所有换(huan)(huan)向(xiang)(xiang)阀(fa)(fa)处(chu)于中位(wei)回油位(wei)置(zhi),泵出(chu)口处(chu)压(ya)(ya)(ya)(ya)力(li)(li)处(chu)于低压(ya)(ya)(ya)(ya)状态,当要(yao)提(ti)(ti)升(sheng)(sheng)(sheng)(sheng)动(dong)(dong)(dong)臂(bei)(bei)时(shi)(shi)(shi),换(huan)(huan)向(xiang)(xiang)阀(fa)(fa)切换(huan)(huan)到提(ti)(ti)升(sheng)(sheng)(sheng)(sheng)位(wei)置(zhi),这(zhei)时(shi)(shi)(shi)泵出(chu)口与(yu)杠(gang)(gang)(gang)杆(gan)操(cao)纵(zong)阀(fa)(fa)之间(jian)管路内的(de)(de)(de)(de)压(ya)(ya)(ya)(ya)力(li)(li)仍处(chu)于低压(ya)(ya)(ya)(ya)状态,而动(dong)(dong)(dong)臂(bei)(bei)液(ye)(ye)(ye)压(ya)(ya)(ya)(ya)缸下(xia)腔中的(de)(de)(de)(de)液(ye)(ye)(ye)压(ya)(ya)(ya)(ya)油要(yao)支撑整个(ge)动(dong)(dong)(dong)臂(bei)(bei)、斗杆(gan)、铲(chan)斗及其(qi)液(ye)(ye)(ye)压(ya)(ya)(ya)(ya)缸的(de)(de)(de)(de)重(zhong)力(li)(li),具有相(xiang)当的(de)(de)(de)(de)压(ya)(ya)(ya)(ya)力(li)(li),所以(yi)在换(huan)(huan)向(xiang)(xiang)阀(fa)(fa)刚(gang)刚(gang)切换(huan)(huan)到提(ti)(ti)升(sheng)(sheng)(sheng)(sheng)位(wei)置(zhi)时(shi)(shi)(shi),动(dong)(dong)(dong)臂(bei)(bei)液(ye)(ye)(ye)压(ya)(ya)(ya)(ya)缸下(xia)腔的(de)(de)(de)(de)液(ye)(ye)(ye)压(ya)(ya)(ya)(ya)油要(yao)流向(xiang)(xiang)压(ya)(ya)(ya)(ya)力(li)(li)低的(de)(de)(de)(de)管路系(xi)(xi)统(tong)(tong)(tong)(tong),表(biao)现(xian)(xian)为(wei)动(dong)(dong)(dong)臂(bei)(bei)早期下(xia)降(jiang);随着齿轮泵的(de)(de)(de)(de)工(gong)作(zuo),系(xi)(xi)统(tong)(tong)(tong)(tong)的(de)(de)(de)(de)压(ya)(ya)(ya)(ya)力(li)(li)不(bu)(bu)(bu)断升(sheng)(sheng)(sheng)(sheng)高,当与(yu)动(dong)(dong)(dong)臂(bei)(bei)液(ye)(ye)(ye)压(ya)(ya)(ya)(ya)缸下(xia)腔中的(de)(de)(de)(de)压(ya)(ya)(ya)(ya)力(li)(li)相(xiang)等时(shi)(shi)(shi),动(dong)(dong)(dong)臂(bei)(bei)停止下(xia)降(jiang);此后(hou),系(xi)(xi)统(tong)(tong)(tong)(tong)压(ya)(ya)(ya)(ya)力(li)(li)逐渐高于动(dong)(dong)(dong)臂(bei)(bei)液(ye)(ye)(ye)压(ya)(ya)(ya)(ya)缸下(xia)腔中的(de)(de)(de)(de)压(ya)(ya)(ya)(ya)力(li)(li),动(dong)(dong)(dong)臂(bei)(bei)开(kai)始提(ti)(ti)升(sheng)(sheng)(sheng)(sheng)。这(zhei)个(ge)过程存在的(de)(de)(de)(de)时(shi)(shi)(shi)间(jian)很短(duan),动(dong)(dong)(dong)臂(bei)(bei)下(xia)降(jiang)的(de)(de)(de)(de)幅度(du)也(ye)不(bu)(bu)(bu)大,但对挖(wa)掘机作(zuo)业是(shi)一(yi)个(ge)不(bu)(bu)(bu)可(ke)忽视的(de)(de)(de)(de)安全隐患(huan),所以(yi)在新(xin)的(de)(de)(de)(de)电(dian)(dian)(dian)(dian)控(kong)(kong)系(xi)(xi)统(tong)(tong)(tong)(tong)设(she)(she)计(ji)中加(jia)装(zhuang)了(le)液(ye)(ye)(ye)控(kong)(kong)单向(xiang)(xiang)阀(fa)(fa)5以(yi)保证(zheng)动(dong)(dong)(dong)臂(bei)(bei)提(ti)(ti)升(sheng)(sheng)(sheng)(sheng)的(de)(de)(de)(de)安全准确。其(qi)他(ta)控(kong)(kong)制系(xi)(xi)统(tong)(tong)(tong)(tong)的(de)(de)(de)(de)设(she)(she)计(ji)基(ji)(ji)本采用了(le)原(yuan)(yuan)杠(gang)(gang)(gang)杆(gan)操(cao)纵(zong)系(xi)(xi)统(tong)(tong)(tong)(tong)的(de)(de)(de)(de)方案。其(qi)工(gong)作(zuo)原(yuan)(yuan)理见图K。

  

电液比例控制系统设计图

电(dian)磁(ci)换(huan)(huan)向(xiang)阀(fa)的(de)(de)(de)滑阀(fa)机(ji)能如图K所(suo)示,为(wei)A型(xing)(xing)换(huan)(huan)向(xiang)阀(fa)。而控(kong)制各执(zhi)行(xing)机(ji)构动作(zuo)的(de)(de)(de)直动式电(dian)磁(ci)比例阀(fa)只有通(tong)径(jing)为(wei)6与10两种型(xing)(xing)号可选(xuan)择。为(wei)减少液压阀(fa)板的(de)(de)(de)设(she)计难度和(he)加(jia)工费用(yong),换(huan)(huan)向(xiang)阀(fa)也在(zai)通(tong)径(jing)6与10中选(xuan)取。为(wei)减少因误(wu)操作(zuo)引起线(xian)(xian)(xian)圈(quan)烧毁的(de)(de)(de)损失(shi),选(xuan)用(yong)湿式可更(geng)换(huan)(huan)线(xian)(xian)(xian)圈(quan)电(dian)磁(ci)铁。与图7-11中的(de)(de)(de)液压泵(beng)匹配的(de)(de)(de)L375柴油(you)机(ji)的(de)(de)(de)最低稳(wen)定转(zhuan)速为(wei)小于650r/s,最高(gao)转(zhuan)速为(wei)2650r/s,外特性(xing)曲线(xian)(xian)(xian)中的(de)(de)(de)最低油(you)耗(hao)点在(zai)1950r/s。单(dan)个齿轮泵(beng)的(de)(de)(de)排量(liang)(liang)(liang)为(wei)8mL/r,可计算(suan)出换(huan)(huan)向(xiang)阀(fa)1、2、3的(de)(de)(de)流量(liang)(liang)(liang)都应为(wei)5.2~21.2L/min,经济油(you)耗(hao)流量(liang)(liang)(liang)为(wei)15.6L/min。换(huan)(huan)向(xiang)阀(fa)4的(de)(de)(de)流量(liang)(liang)(liang)是(shi)换(huan)(huan)向(xiang)阀(fa)1、2、3的(de)(de)(de)两倍。根(gen)据通(tong)径(jing)6、10的(de)(de)(de)A型(xing)(xing)湿式可更(geng)换(huan)(huan)线(xian)(xian)(xian)圈(quan)电(dian)磁(ci)铁换(huan)(huan)向(xiang)阀(fa)的(de)(de)(de)特性(xing)曲线(xian)(xian)(xian),可以看出流动方向(xiang)P-A、P-B,通(tong)径(jing)6与10的(de)(de)(de)换(huan)(huan)向(xiang)阀(fa)在(zai)流量(liang)(liang)(liang)小于20L/min时,其压降差别不大(da),均在(zai)0.1~0.2MPa之间;而在(zai)流量(liang)(liang)(liang)大(da)于20L/tnin后(hou),6通(tong)径(jing)换(huan)(huan)向(xiang)阀(fa)压降随流量(liang)(liang)(liang)的(de)(de)(de)增加(jia)升高(gao)很快。故此换(huan)(huan)向(xiang)阀(fa)1、2、3选(xuan)用(yong)6通(tong)径(jing),即(ji)3WE6A-61B/CG24N9ZSL型(xing)(xing);而换(huan)(huan)向(xiang)阀(fa)4选(xuan)用(yong)10通(tong)径(jing),即(ji)3WE10A-31B/CG24N925L型(xing)(xing)。

该(gai)挖掘机(ji)(ji)(ji)中的(de)(de)(de)六个执行(xing)(xing)(xing)机(ji)(ji)(ji)构(gou).(左行(xing)(xing)(xing)走(zou)、右行(xing)(xing)(xing)走(zou)、整(zheng)机(ji)(ji)(ji)回转马达;动臂、斗(dou)杆(gan)(gan)、铲(chan)斗(dou)液压缸)的(de)(de)(de)控(kong)制(zhi)均采(cai)用(yong)比例(li)换(huan)向(xiang)阀,比例(li)换(huan)向(xiang)阀的(de)(de)(de)机(ji)(ji)(ji)能为如图K所示的(de)(de)(de)E型(xing)。由于电(dian)控(kong)挖掘机(ji)(ji)(ji)的(de)(de)(de)铲(chan)斗(dou)运动轨迹要做(zuo)精确控(kong)制(zhi),所以动臂、斗(dou)杆(gan)(gan)、铲(chan)斗(dou)液压缸的(de)(de)(de)控(kong)制(zhi)选取带阀芯位(wei)置(zhi)电(dian)气反馈的(de)(de)(de)4WRE型(xing)比例(li)换(huan)向(xiang)阀。左行(xing)(xing)(xing)走(zou)、右行(xing)(xing)(xing)走(zou)、整(zheng)机(ji)(ji)(ji)回转马达采(cai)用(yong)普通型(xing)的(de)(de)(de)4WRA型(xing)比例(li)换(huan)向(xiang)阀。

单个泵的(de)(de)流(liu)(liu)量在(zai)5.2~21.2L/min之间(jian),经济油耗(hao)流(liu)(liu)量为15.6L/min。结合(he)液压挖掘机(ji)的(de)(de)实际(ji)工作情(qing)况,行(xing)(xing)走(zou)时每(mei)个马达基本由一个泵供油;整(zheng)车(che)回(hui)转(zhuan)(zhuan)过(guo)程中(zhong)具有较大(da)的(de)(de)转(zhuan)(zhuan)动惯量,在(zai)停(ting)止回(hui)转(zhuan)(zhuan)时所产生的(de)(de)冲(chong)击(ji)振动会(hui)对车(che)辆(liang)回(hui)转(zhuan)(zhuan)部件的(de)(de)使用(yong)寿命产生较大(da)影响(xiang),故(gu)(gu)回(hui)转(zhuan)(zhuan)速度不(bu)宜过(guo)大(da),即(ji)不(bu)宜采用(yong)双泵合(he)流(liu)(liu)。结合(he)6通径(jing)(jing)、10通径(jing)(jing)4WRA型(xing)比(bi)(bi)例(li)换(huan)(huan)向(xiang)阀的(de)(de)流(liu)(liu)量、输(shu)入值和阀压降的(de)(de)特性曲(qu)线可知(zhi),在(zai)控制精度要(yao)求不(bu)高的(de)(de)情(qing)况下,6通径(jing)(jing)、名义流(liu)(liu)量为17L/min的(de)(de)比(bi)(bi)例(li)换(huan)(huan)向(xiang)阀可满足左行(xing)(xing)走(zou)、右行(xing)(xing)走(zou)及整(zheng)机(ji)回(hui)转(zhuan)(zhuan)马达的(de)(de)要(yao)求,故(gu)(gu)选用(yong)4WRE6E20-10B/24N24/M型(xing)比(bi)(bi)例(li)换(huan)(huan)向(xiang)阀。

由(you)液(ye)压(ya)(ya)挖(wa)(wa)掘机(ji)的实际工作情况知,动臂、斗杆、铲斗液(ye)压(ya)(ya)缸的供油均(jun)存在(zai)(zai)双(shuang)泵(beng)合(he)流(liu)(liu)工况,单泵(beng)供油时其控(kong)制阀的流(liu)(liu)量(liang)为5.2~21.4L/min,双(shuang)泵(beng)供油时为10.2~42.4L/min,对应(ying)的经(jing)济油耗(hao)流(liu)(liu)量(liang)为15.6L/min或(huo)31.2L/min。结合(he)分析6通径与(yu)10通径4WRE型比例换(huan)(huan)向阀的流(liu)(liu)量(liang)、输入值和阀压(ya)(ya)降的特性曲线,可以看到所有曲线都在(zai)(zai)其输入值的30%~80%之(zhi)间最为平直,线性程度好,易于实现精(jing)确控(kong)制,加之(zhi)在(zai)(zai)实现挖(wa)(wa)掘机(ji)电液(ye)比例控(kong)制时希望(wang)在(zai)(zai)液(ye)压(ya)(ya)阀进出口的台肩总压(ya)(ya)降最小。结合(he)以上数据(ju)与(yu)原则选取了10通径、名义流(liu)(liu)量(liang)为64L/min的比例换(huan)(huan)向阀,即4WRE10E64-10B/24ZA/M型比例换(huan)(huan)向阀。

其他溢流(liu)(liu)阀(fa)、节流(liu)(liu)阀(fa)、单(dan)向节流(liu)(liu)阀(fa)、液(ye)控单(dan)向阀(fa)的(de)(de)选取均根据与其连接、的(de)(de)换(huan)向阀(fa)和原(yuan)机(ji)设计的(de)(de)工作压力、流(liu)(liu)量而定(ding)。

(3)总(zong)结

挖(wa)掘机电液比例(li)控制液压(ya)系统(tong)改造后,系统(tong)控制采用德国INTER CONTROL公司的(de)E1型移动(dong)车辆控制器,开发软件并调(diao)试成(cheng)(cheng)功(gong),可近程(cheng)(cheng)有线遥(yao)(yao)控操作,也可按程(cheng)(cheng)序(xu)自(zi)动(dong)完(wan)成(cheng)(cheng)事(shi)先预(yu)定的(de)动(dong)作,实现了原机杠杆操纵系统(tong)所能完(wan)成(cheng)(cheng)的(de)全(quan)部(bu)功(gong)能,为下一步实现挖(wa)掘机的(de)远程(cheng)(cheng)遥(yao)(yao)控操作奠定了坚(jian)实的(de)基础。


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