装裁机反铲节能的可行性分析

在装载机工作装置上加装一个由微机控制的反铲装置，使铲斗铲掘物料能依靠反铲的作用，沿着被铲物料的滑动面自上而下将物料装满铲斗，从而使铲掘阻力最小。这种装置改变了装载机传统作业方式，达到节能，并减轻了操作劳动强度。     

装截机工作装置性能分析

轮式装载机的功能主要表现在两个方面:一是完成铲掘、装载物料工作的能力。二是在场地转移、行驶方面的性能(速度、加速度、制动性等)。装载机的工作装置是实现铲掘、装卸物料的铲斗机构,其性能的好坏直接影响装载机的生产效率和作业质     

装载机铲斗铲掘过程受力分析

轮式装载机铲斗的铲掘受力是一个复杂的变化过程.以装载机铲斗为研究对象,对铲斗铲掘过程进行受力分析.针对不同铲掘过程的受力变化晴况,采用库伦土压力理论,对铲斗不同阶段的运动和受力大小进行分析,为装载机的铲掘作业提供了理论依据.     

72—71B装载机工作装置限位器

反铲工作装置采用动臂限位器笔铲斗限位器，实现了动臂在任一位置的自动限位，在铲斗在任一位置卸料后的自动放平。本文介绍了这种装载机工作装置限位器的构成、结构及工作原理。     

72—71重B装载机工作装置限位器

反铲工作装置采用动臂限位器和铲斗限位器,实现了动臂在任一位置的自动限位,和铲斗在任一位置卸料后的自动放平。本文介绍了这种装载机工作装置限位器的构成、结构及工作原理。     

轮式装载机工作装置强度计算中外载荷的确定

轮式装载机工作装置设计中,要对其各个部件的强度进行计算,方法很多,算出的结果也很精确,但如果外载荷选择不当,计算将是没有用的。本文对轮式装载机工作装置计算工况,计算载荷进行讨论,提出外载荷的求解方法。l计算位置和计算工况的确定装载机工作装置强度计算中,应选择工作装置受力最大的位置为计算位置。分析装载机铲掘、运输,提升及卸载等作业过程,以装载机在水平面上铲掘物料时,工作装置受力最大。因此对工作装置强度计算应取装载机在水平面上作业,铲斗斗底与地面水平时为计算位置。装载机工作装置计算工况,文献「l」、［…     

装载机铲斗设计新方法

铲斗是装载机工作装置的主要组成部件,装载机工作中既用铲斗直接切削、铲掘物料,又用它装载、运输和倾卸物料,所以铲斗的结构形状及尺寸参数对插入阻力、掘起力及生产率有着很大的影响。因此所设计的铲斗除应具有一定的容积外,还应具有合理的断面形状和较小的回转半径以保证较大的掘起力,较小的插入阻力及较大的满斗系数。装载机铲斗由前刃(有的装有斗齿)、侧刃、斗底、后壁、侧壁及后挡板焊合而成的斗形构件,它在车辆纵向断面的形状是不变的,所以铲斗的形状取决于断面的形状(如图1所示)。     

轮式装载机典型工况下铲斗铲装阻力实验获取方法

取原生土、大石方、松散土、小石方和半湿土5种作业物料,每种物料按一定比例的铲斗数进行实验。实验测试装载机动臂油缸压力,根据压力变化情况,把装载机的一个工作循环分为空载前进、铲掘、重载后退、重载前进及卸料、空载后退5个作业时段。实验测试各工作阻力消耗转矩曲线,折算后可以获得驱动力。根据装载机作业过程中力的平衡方程,获取典型工况铲掘作业时段铲斗工作阻力。与传统的根据经验公式计算获得的工作阻力相比,实验获取的铲斗工作阻力具有准确性和真实性的特点。工作阻力数字化后,可用于装载机动力性、燃油经济性虚拟仿真实验加载。     

轮式装载机铲斗铲掘与路径轨迹研究

以轮式装载机为研究对象,对铲斗铲掘过程及运行路径进行分析。通过研究影响铲斗在铲装过程中轨迹的相关参数,以及装载机在铲装点和卸载点之间形成的行车轨迹,为装载机轨迹研究提供一定的理论基础。     

轮式装载机铲斗铲掘与路径轨迹研究

以轮式装载机为研究对象,对铲斗铲掘过程及运行路径进行分析.通过研究影响铲斗在铲装过程中轨迹的相关参数,以及装载机在铲装点和卸载点之间形成的行车轨迹,为装载机轨迹研究提供一定的理论基础.     

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.     

WZ30-25型轮式挖掘装载机

WZ30-25型轮式挖掘装载机是在WZ25-20的基础上,吸收国内外新技术,并根据市场使用情况开发的一款系列化产品.该机外形美观、结构合理、性能先进、节能环保、操作轻便、可靠耐用,自投放市场后,得到国内外用户的普遍认可.介绍WZ30-25型轮式挖掘装载机的设计思想、主要参数、结构特点等.     

反铲斗挖掘土壤实验研究与挖掘阻力计算(上)

通过在实验室内对不同种类的土壤进行反铲斗挖掘试验研究,根据所观察到的土壤的破坏变形机理,对反铲斗的挖掘阻力作了定量分析,并建立了挖掘阻力计算的基本方程式,对基本方程式的正确性与实用性进行了分析.     

A database/spreadsheet application for equipment selection

A computerized system of selecting construction equipment is described. A database of technical criteria for a backhoe/loader machine is assembled and analysed with a spreadsheet technique. The process of selection uses the Kepner and Tregoe method to arrive at the best choice of excavator for a particular job.     

Teleoperation of construction machines with haptic information for underwater applications

Mechanization is necessary for safer and more efficient underwater construction work in port areas. Teleoperated underwater construction machines are under developing. The problem is that conventional TV camera system is useless in water because of turbidity. Haptic information is introduced as the aid to control construction machines substituting for visual information. Components of control technologies are visualization of haptic image, force feedback, and similar figure controller. Leveling experiment of gravel mound was carried out successfully on land with an experimental land model of underwater backhoe.     

小断面隧道施工关键技术

以救古坪隧道工程为例,结合工程地质情况和施工难点,介绍了小断面隧道爆破施工技术,对小断面隧道出碴运输方案进行了比选,并阐述了采用LWL-150型挖掘装载机的出碴工况和效果,从而取得良好的经济和社会效益。     

装载机工作装置操纵机构的改进

装载机的工作装置多数为双杆操纵,即操作人员通过操作两根操纵杆来完成工作装置的动作,操作过程复杂,劳动强度大。介绍了一种新型的优化改进机构——单杆操纵机构,该机构能大大简化操作,减轻操作人员的劳动强度,提高工作效率。     

Impedance control of a hydraulically actuated robotic excavator

In robotic excavation, hybrid position/force control has been proposed for bucket digging trajectory following. In hybrid position/force control, the control mode is required to switch between position- and force-control depending on whether the bucket is in free space or in contact with the soil during the process. Alternatively, impedance control can be applied such that one control mode is employed in both free and constrained motion. This paper presents a robust sliding controller that implements impedance control for a backhoe excavator. The control law consists of three components: an equivalent control, a switching control and a tuning control. Given an excavation task in world space, inverse kinematic and dynamic models are used to convert the task into a desired digging trajectory in joint space. The proposed controller is applied to provide good tracking performance with attenuated vibration at bucket–soil contact points. From the control signals and the joint angles of the excavator, the piston position and ram force of each hydraulic cylinder for the axis control of the boom, arm, and bucket can be determined. The problem is then how to find the control voltage applied to each servovalve to achieve force and position tracking of each electrohydraulic system for the axis motion of the boom, arm, and bucket. With an observer-based compensation for disturbance force including hydraulic friction, tracking of the piston ram force and position is guaranteed using robust sliding control. High performance and strong robustness can be obtained as demonstrated by simulation and experiments performed on a hydraulically actuated robotic excavator. The results obtained suggest that the proposed control technique can provide robust performance when employed in autonomous excavation with soil contact considerations.     

装载机木材夹钳装置设计

集材装置作为一种市场份额和利润都较高的装载机附属机具,倍受装载机制造企业的青睐.以LW350型装载机附属集材装置--木材夹钳装置为例,对两种不同类型的木材夹钳装置的设计思路及设计过程中所需注意问题进行简要论述.     

液压挖掘机反铲工作装置的优化设计

应用变换矩阵来建立数学模型，编制了挖掘机工作装置设计的软件系统。经实际运用证明，可有效地对挖掘机工作装置进行快速而有效的计算，为改善挖掘机工作性能提供了一条有效途径。