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1故障现象某单位一台W4-60挖掘机在对液压系统进行检修(主要是更换换向阀、油缸以及油管各处密封圈)后,出现了如下故障:操纵动臂换向阀时,动臂油缸举升变慢,而且不能回落;而操纵铲斗和斗杆换向阀时,铲斗和斗杆油缸均工作正常。2故障分析该挖掘机动臂和铲斗均为双泵合流供油,由于铲斗工作正常,故障应位于动臂阀组至油缸间油路。可能原因有2个:一是油缸故障,如活塞在伸出后卡死在顶端位置,不能缩回,则动臂不能回落;二是换向阀故障。动臂换向阀内装有1个补油单向阀、2个防点头单向阀和1个油缸过载阀,如图1所示。乙泵压力油通过第一油道和第二油道进入 相似文献
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1故障现象及原因分析当挖掘机操作手柄搬到“动臂下降”的位置后,动臂不能平稳下降,而是出现一降一停的间断性下降,进而造成整机沿动臂方向前后剧烈摇晃,以至于无法正常工作。故障树分析示于图1。2可能原因的检测经压力表检测主油路系统压力为27.8MPa,符合规定,其它动作速度和力量均正常,可排除主油路压力与流量不足的原因。经压力表检测,先导控制系统油压为2.94MPa,符合规定,其它动作操纵正常,可排除先导控制油压不足的原因;经拆检右多路阀中的动臂阀杆,发现阀杆有些卡滞,但无异物,且阀杆表面无划伤;经拆… 相似文献
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为了满足刮平作业的要求,装载机液压多路阀的动臂控制联都设有浮动位置,此时动臂油缸的上下腔同时卸荷,动臂处于浮动状态。手动操纵液压多路阀的动臂联设有4个位置:提升、中位、下降、浮动(如图1),将操纵杆扳到浮动位置时,动臂油缸的上升、下降油路同时与回油接通。 相似文献
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1故障现象现场作业的一台CX360型挖掘机因故障检修,出现的故障是:动臂、斗杆均举升无力,挖掘作业无力,行走无力;动臂憋压容易造成发动机熄火,行走时也容易出现发动机熄火;熄火后偶尔显示故障代码,故障代码为0087。 相似文献
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1故障现象现场作业的一台CX360型挖掘机因故障检修,出现的故障是:动臂、斗杆均举升无力,挖掘作业无力,行走无力;动臂憋压容易造成发动机熄火,行走时也容易出现发动机熄火;熄火后偶尔显示故障代码,故障代码为0087. 相似文献
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挖掘机工作过程中出现动臂异响故障,原因可能是润滑不足、销轴卡滞和侧向挤压等,本文介绍动臂的工作原理,分析异响原因及故障排除方法。 相似文献
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全液压挖掘机的液压系统属于大流量高压力系统,流畅的油路是其高工作效率的保证.为了保证吸油效率首要素——主泵的吸油效率,挖掘机厂家都在油箱上加装预压式空气滤清器.预压式空气滤清器为液压系统油箱附件,也称呼吸阀,能对进入油箱的空气进行过滤,同时能够随油箱内液面的变化而使油箱内部保持一定的正气压.1传统呼吸阀目前大多数国产品牌挖掘机使用的都是传统的呼吸阀,主要包括两种结构形式. 相似文献
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Erno Keskinen Sirpa Launis Michel Cotsaftis & Yrjö Raunisto 《Computer-Aided Civil and Infrastructure Engineering》2001,16(4):229-238
Sheet-piling processes pose the problem of guiding the pile to follow a fixed trajectory in order to drive it correctly into the ground. Since the complete system consists of the supporting excavator boom with hydraulic actuators, the gripper, and the vibratory unit, the large number of system variables implies the use of servo control to allow a human operator to handle the operation. An exact inverse kinematic transformation from Cartesian workspace to boom joint space variables allows the pile penetration to be guided, keeping the valve input of the main boom actuator as the free parameter, while the remaining actuators are governed automatically by the control computer. The penetration record of the pile differs based on whether a constant valve input is used in semiautomatic steering mode or, alternatively, the desired penetration speed is governing the valve input in a feedback loop in full-automatic steering mode. A numerical model representing an actual industrial system has been developed. Variable results from computer simulations have led the manufacturer to realize the steering system. It has been verified in real piling tests that the steering system may be tuned to be stable and fast enough for practical working conditions. In particular, the performance of trajectory control in terms of tracking error is much better than in the conventional manual steering method, as expected. 相似文献
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Independent metering valve control system can overcome the shortcomings of the traditional four-side linkage valve controlled system, such as poor controllability and large energy consumption, especially under the overrunning load condition. Current researches mainly focus on the velocity, pressure and energy consumption characteristics of the hydraulic system. However, with the intelligent development of mobile machinery and the continuous improvement of work quality requirements, each actuator should not only meet the velocity and output force requirements, but also achieve high positioning accuracy. Therefore, according to the independent metering valve control system and pump-valve hybrid control principle, a velocity and position combined control strategy based on mode switching is proposed to control the boom and arm of hydraulic excavator. Then, a mechanical-hydraulic co-simulation model including the whole hydraulic excavator is established to verify the strategy, predict control characteristics and determine the controller parameters. Furthermore, a test prototype based on the above principle is established, and the boom and arm operating characteristics with the proposed strategy are tested and analyzed. The results show that the hydraulic cylinders can move smoothly along the expected trajectory under the premise of low energy consumption. The operate velocity fluctuation is small and the positioning error to the target position is about 1 mm. Due to the boom cylinder and arm cylinder in the research are separately typical two and four quadrants working actuators, the research work has universal significance to smooth, high-precision and low energy consumption automation operation of various types of mobile machineries. 相似文献
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挖掘装载机工作装置的"自动调平"是指装载机工作时,随着动臂的举升,可通过铲斗液压缸自动调整铲斗与动臂之间的夹角,防止在动臂举升过程中,铲斗向后倾撒物料,引发事故.论述托架连杆机构装载工作装置自动调平功能的实现方法,即动臂举升到一定位置时停止运动,铲斗正好处于临界撒料状态,然后调整铲斗与动臂之间的夹角,使铲斗前倾,再举升动臂,如此反复进行,直至铲斗达到卸料位置.介绍了实现铲斗自动调平功能的液压系统原理,以及为实现此功能而研制的用于控制铲斗液压缸的反馈机构.对有无调平功能的动臂举升时间进行对比,结果表明:实现自动调平后,动臂举升时间略有增加,但仍处于国家标准规定的7 s以内.研制的自动调平机构已在厦工集团生产的XG765型挖掘装载机上应用,用户反映良好. 相似文献
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塔式起重机吊臂的自重不但影响起重机的制造成本,而且影响起重特性,如何降低吊臂自重是塔式起重机设计中的关键问题之一。由于吊臂受力复杂,计算繁琐,要找到一种可行方案需花费很多时间,所以,怎祥才能找到自重最轻的设计方案是一个长期困扰设计者的问题。本文提出了一种离散优化设计方法并给出了一个吊臂设计通用程序,建立了塔式起重机常用型钢数据库,通过实际设计验证了该程序是一个简单可行的设计程序,比较圆满地解决了本文提出的问题。 相似文献
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基于ADAMS的飞机除冰车臂架调平机构仿真分析 总被引:1,自引:0,他引:1
为了寻求飞机除冰车臂架的最优调平机构,研究各液压缸动态受力情况,利用ADAMS软件建立飞机除冰车的臂架调平机构仿真模型,通过臂架举升仿真分析得到该臂架优化铰点后的动态调平角曲线,可以很好地满足调平使用要求。从臂架调平机构仿真分析得到的各液压缸动态受力曲线和速度曲线中,获得各液压缸受力的最大值及其对应的角度,并得出各液压缸准确可靠的行程。对飞机除冰车、臂架类高空作业装置的调平机构和液压缸设计,提供高效的设计方法和理论依据。 相似文献