柳工欧维姆助力“观天巨眼”主体工程顺利完工

正本刊讯7月3日,全球最大的单口径射电望远镜—500米口径球面射电望远镜(下简称FAST),在贵州平塘县完成了最后一块反射面单元的吊装,至此,这个"观天巨眼"的主体工程已完工。柳工欧维姆公司此次承接了FAST的反射面索网工程,反射面索网可谓是"巨眼"的骨架,因为,FAST正是依靠索网的柔性伸缩,帮助反射面实现对宇宙现象的对焦、定位、追踪。"观天巨眼"究竟强在哪?中国科学院国家天文台FAST工程总工艺师王启明接受采访时介绍,帮助反射面变位的2000多个液压促动器是通过伸     

FAST反射面单元铝合金背架加工方法研究

国家天文台FAST工程(500m口径球面射电望远镜)主动反射面基准面是一个口径500m、半径300m的球面,它由主体支承结构、促动器、反射面单元等组成.本文深入分析并研究了反射面单元铝合金背架结构网架节点与构件的加工技术.开创了铝合金网架杆件缩管连接模压成形新技术,为确保FAST工程项目的顺利实施打下了坚实基础.这些技术不仅成功解决了FAST工程反射面单元背架结构铝合金网架加工难题,也可为其他类似铝合金网架结构的加工提供参考.     

手持式液压碎石器

随着液压技术的迅速发展,工业发达国家一向以风动为主的建筑机械目前正被液压驱动机械所取代。七十年代初出现的液压碎石器经过十多年的发展日臻完善,其中派生出了一种微型机种——手持式液压冲击碎石器,它是一种多用途的通用设备,     

液压提升器连续升降的机理分析

从间歇式液压提升器出发,分析了准连续式液压提升器在构件升降过程中存在不连续的原因,从而对连续升降的运动机理进行了深入的研究,指出利用连续式液压提升器2个主液压缸的速度差和控制技术可实现连续作业,连续升降技术的关键是上、下主液压缸的负载能和谐地转移。     

液压提升器连续升降的机理分析

从间歇式液压提升器出发,分析了准连续式液压提升器在构件升降过程中存在不连续的原因,从而对连续升降的运动机理进行了深入的研究,指出利用连续式液压提升器2个主液压缸的速度差和控制技术可实现连续作业,连续升降技术的关键是上、下主液压缸的负载能和谐地转移.     

液压提升器连续升降的机理分析

从间歇式液压提升器出发，分析了准连续式液压提升器在构件升降过程中存在不连续的原因，从而对连续升降的运动机理进行了深入的研究，指出利用连续式液压提升器2个主液压缸的速度差和控制技术可实现连续作业，连续升降技术的关键是上、下主液压缸的负载能和谐地转移。     

YGD—2型手提式液压钢丝镦头器

先张法长线生产预应力混凝土构件时,目前大多采用圆管楔片夹具张拉钢丝。此种夹具加工比较复杂,楔片的退出比较费力,因此,我们试制了这种适于现场流动使用的镦头器。YGD-2型手提式液压钢丝镦头器,系采用液压构造,与油泵接通后,可冷镦直径     

石材液压劈裂器在荒料二次解体中的改进

劈裂器直接影响液压劈裂机的性能，因此高效率，长寿命，多功能成为研究者的主要目的，为此对二次解体用液压劈裂机的劈裂器进行了深入的研究提出了一种比较理想结构——带有二次解体功能的液压劈裂器。     

FAST反射面单元铝合金背架高精度拼装技术

国家天文台500m口径球面射电望远镜FAST主动反射面基准面是一个口径500m、半径300m的球面,由主体支承结构、促动器、反射面单元组成.本文从反射面单元工装定位、螺栓紧固控制、拼装精度控制、测量技术等重点着手,深入分析解决了铝合金背架拼装难点,总结研发了小拼单元面形数字化(智能化)摄影高精度拼装方法.本工程摄影测量自动化、智能化的高效应用成功解决了反射面单元高精度拼装快速测量的难题,确保了FAST项目能够顺利完成实施,也可为同类大型钢结构建筑的施工提供参考.     

基于ADAMS的新型液压脱钩器系统仿真

采用基于ADAMS的虚拟样机技术,建立了新型液压脱钩器的仿真模型,对液压脱钩器在脱钩过程中动态特性进行仿真,通过试验验证模型正确可行,并对模型进行了不同通径二通插装阀下脱钩器系统的动态响应曲线的分析。     

提高工程机械液压系统清洁度

长期以来,工程机械液压系统的清洁度问题一直影响产品质量提高。据国内有关资料统计,工程机械由于液压系统不清洁出现的故障占整机故障率的40%,而由于液压油管内部不清洁造成的故障占液压系统故障率的60%。由此可见,提高液压系统的清洁度对于提高产品质量是何等的重要。 随着国际国内工程机械发展速度的加快,采用高新技术的液压控制元件、动力元件和执行元件越来越普及,相对的要求液压系统清洁度也就越来越严。 影响液压系统清洁度的因素很多,在液压系统中,液压动力元件（液压泵）、执行元件（液压缸）、控制调节元件（各种控制阀）、辅助装置（油箱、滤油器、油管及管接头）的清洁度,都会直接影响到装载机的性能和参数,直接影     

Improvement of boom control performance for hybrid hydraulic excavator with potential energy recovery

Potential energy recovery (ER) is an effective way to reduce energy consumption of hybrid hydraulic excavators; however, the ER system with a direct speed-control strategy is prone to oscillation of actuators due to the reduction of damping in comparison to the conventional throttle governing system. This paper aims to improve the boom control performance of a hybrid hydraulic excavator by properly designing the ER controller. Based on the dynamics of the system, mathematical modeling including hydraulic components and electrical components is carried out. A staged composite control strategy is proposed to achieve acceptable performance in the whole velocity range. Load torque observation is employed to increase the speed stiffness of the permanent magnet generator applied in the system as well as the stiffness of the boom motion. The leakage flow which affects the anti-disturbance capability and accuracy of the control system is compensated. Finally, the effectiveness of the proposed control scheme is verified by simulation and experimental results.     

Efficiency analysis and evaluation of energy-saving pressure-compensated circuit for hybrid hydraulic excavator

A hydraulic cylinder driven scheme combining a pressure compensator and an energy recovery device together has been proposed to achieve good control operation and energy-saving capability simultaneously. In this paper, its efficiency characteristics are further investigated in order to provide analytical and experimental references to practical applications. Since an excavator owns multiple actuators, a general schematic configuration including hydraulic cylinders with and without energy recovery is developed and analyzed. Based on the analysis of energy losses in every conversion, component selections and possible improvements are discussed, and then the design flowchart and criteria of key parameters are also presented. Finally, experiments under different load and velocity conditions are implemented on a test bench. Energy distributions, recovery efficiencies and component efficiencies are all evaluated.     

Development of a dual displacement controlled circuit for hydraulic shovel swing motion

Complexity of large structure of hydraulic shovel system drives the guideline development for designing a swing unit of the shovel. Some of the issues are how to achieve smooth swing motion, save energy, and easily adjust its swing velocity. In this paper, we proposed a dual-closed-hydraulic-circuit (DCHC) accordingly to meet the design requirement. In the DCHC system, instead of manual adjustment, the displacement of hydraulic axial piston pump is controlled by programmed software algorithm through electronic control device, which significantly simplifies the current circuit design. The DCHC system also enables controllable recuperation of kinetic energy of swing motion for use by other actuators. Accordingly, the new system will achieve smoother motion compared with existing system and more efficient operation. We demonstrate the advantages of our DCHC design through simulation and verify through developing a hydraulic shovel prototype with bucket capacity of 15 cubic meters and operational weight of 270 tons. Both simulation and experimental results indicate that the DCHC system is feasible and works as intended.     

小型液压挖掘机电控系统现状与发展

电控系统作为挖掘机的关键配套部件,更是小型液压挖掘机功能改善和发展的设计核心,其性能和功能对小型液压挖掘机有着重大的影响。本文介绍了小型液压挖掘机电控系统的发展历程、应用情况,并针对现状分析了小型液压挖掘机电控系统的发展趋势。     

Development of an intuitive user interface for a hydraulic backhoe

This paper describes the development of an intuitive user interface for controlling a hydraulic backhoe, a piece of excavating equipment with a digging bucket on the end of a two-part articulated arm typically mounted on the back of a tractor or front-end loader. Controlling a backhoe requires a highly trained operator to control several hydraulic actuators simultaneously with fine inverse kinematic mapping. With this work, we propose a novel joystick configuration with hybrid cylindrical coordinate and independent bucket control, in which each joystick can execute horizontal and vertical movements of the backhoe. For this, a robotic controller scheme with a joystick rate control has been developed. The proposed method allows an operator to control the hydraulic backhoe intuitively and operate complex motions smoothly with no constraints. The suggested joystick scheme has several advantages compared to Cartesian coordinated control methods as follows; 1) independent horizontal and vertical motion control 2) more natural and intuitive for excavator works 3) less complicated and expensive 4) closer to conventional joystick operation mode and 5) easy return to standard mode by software. A virtual simulator and an actual backhoe test bed were developed to demonstrate the effectiveness of the proposed interface scheme. Preliminary user studies were performed for flattening and digging tasks using the virtual backhoe simulator interfaced to real joysticks. The results showed that the proposed intuitive interface facilitated faster and more precise operation than the conventional actuator control scheme. The controller was designed hierarchically to achieve the suggested joystick configuration control of the hydraulic backhoe system with electric joysticks. This included high-level control for rate control of the joystick, mid-level control for end-effector disturbance compensation, and low-level control for robust control of the hydraulic cylinders. The prototype backhoe with hydraulic control system had maximum position errors of 3 cm for vertical, horizontal, and slope movements with intuitive coordinate operations, making it more functional for performing various excavating tasks in natural and effective ways.     

BG15液压多功能旋挖钻机及应用

结合BG15液压多功能旋挖钻机的结构和工作原理，就其测量定位、钻机对中及不同地质条件下的施工工艺作了介绍，通过经济技术比较分析，阐明了BG15型钻机的技术和经济优点。     

Performance analysis of hydraulic excavator powertrain hybridization

Traditional methods have played an important role in energy saving of hydraulic excavators. However the excavators are still working with low fuel efficiency and bad exhaust. So, new technologies are urgently needed to further reduce fuel consumption and pollutant emissions. Researchers have begun to focus on hybrid technology of hydraulic excavators. This paper systematically analyzed the performance of the powertrain hybridization of hydraulic excavator and compared the main performance among the parallel, the series and the conventional configurations based on a 5-ton excavator. The data of the conventional excavator used for analysis were gathered from the real working process, while that of the hybrid configurations were got from the model simulation. The data used as the load input of the model were also gathered from the real working process. The model of the hybrid powertrains were built with the reliable lookup-table approach, which provides deep insight into the energy conversion phenomena. The presented results indicate that the parallel hybrid powertrain features better fuel economy than the other two configurations in heavy mode and light mode, whereas both the series and parallel hybrid powertrains feature better fuel economy in medium mode. Considering the performance and cost synthetically, the parallel powertrain is the best configuration for hybrid excavators at present.     

液压提升设备在桥梁钢桁梁高速提升中的应用

本文以上海闵浦大桥钢桁梁高速提升为例,阐述液压提升设备的设计计算、安装、钢桁梁提升施工工艺等情况,介绍了提升设备实现高速提升的几点关键技术。     

500 m口径球面射电望远镜索网结构形态和受力分析

500m口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)是国家重大科技基础设施项目。口径500m、半径300.4m的球冠形索网是FAST反射面的主体支承结构。通过促动器的主动控制,索网可以在标准球面和不同抛物面之间转换,即索网为可主动变位的结构。针对FAST索网结构设计中由主动变位引起的形态分析和轻量化需求等问题开展研究,提出了目标位形应变补偿法,统一了球面基准态和抛物面态的形态分析方法,解决了多目标位形索网结构的形态分析问题;提出预应力优化方法,将球面基准态最大索力降低了29%;研究了索网球面基准态和抛物面态的受力性能,并与实测结果进行对比,索力吻合较好,50%以上钢索索力相对误差在5%以内。