装载机动臂疲劳试验方法研究

发布时间：2018-02-23 23:35

本文关键词： 装载机动臂销轴传感器当量外载荷疲劳试验　出处：《长安大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着国内经济发展速度的放缓,基础设施建设的减少,装载机的需求增长速度也出现了下滑,装载机生产企业的关注点从过去的产销量转变到质量上来,以提升自身的竞争力。从使用经验来看,国内装载机存在的主要问题是可靠性不高。工作装置作为装载机的核心组成部分之一,在长期随机工作载荷作用下,容易发生疲劳破坏,而其中又以动臂的断裂最常见,严重影响整机的性能和使用寿命。因此,研究一种装载机动臂载荷谱的测试方法,并利用测得的载荷谱对动臂进行台架疲劳试验是很有必要的。本文以ZL90装载机为对象,主要研究了装载机动臂载荷谱的测试方法和当量外载荷的计算方法两个方面。动臂载荷谱测试方面:提出了测试动臂载荷谱的两种方法——销轴传感器法和动臂贴片法。在销轴传感器法中,对装载机铲斗进行了受力分析,详细论述了销轴传感器、连杆传感器和侧向力传感器的工作原理,设计方法,自行设计了销轴传感器标定工装和标定方法,对铲斗有关部位进行了技术改造,并对改造后的铲斗进行了强度校核。在动臂贴片法中,阐述了该方法的测量原理,设计制作了动臂验证模型进行试验,以检验其可行性,最后制定了动臂装机标定方案。当量外载荷的计算方面:根据装载机工作装置各部件的参数,利用几何法求取各铰点坐标。以传感器测得的力为基础,计算动臂各铰点在大地坐标系下的受力,并将其转换到动臂坐标系中。在动臂坐标系中,作出动臂中性面弯矩时间历程,求出动臂的当量弯矩图;在工作装置的铲掘姿态下,根据动臂的当量弯矩图求取动臂的当量载荷,并反推得到疲劳试验时应当施加于铲斗的当量外载荷,根据当量外载荷设计动臂疲劳试验方案。
[Abstract]:In recent years, with the slowdown of domestic economic development and the decrease in infrastructure construction, the demand for loaders has also declined. The focus of loader manufacturing enterprises has shifted from past production and sales to quality. In order to improve their own competitiveness, the main problem of domestic loaders is that the reliability is not high. As one of the core components of loaders, the working device is under the action of long-term random working load. Fatigue failure is easy to occur, and the fracture of the arm is the most common, which seriously affects the performance and service life of the whole machine. It is necessary to make use of the measured load spectrum to carry out the bench fatigue test of the arm. This paper takes the ZL90 loader as an object. This paper mainly studies the measuring method of load spectrum of loader arm and the calculation method of equivalent external load. In the aspect of measuring load spectrum of moving arm, two methods of measuring load spectrum of moving arm, pin shaft sensor method and arm mount method, are put forward. Sheet method. In the pin shaft sensor method, The mechanical analysis of the loader bucket is carried out, the working principle and design method of pin shaft sensor, connecting rod sensor and lateral force sensor are discussed in detail, and the calibration tool and calibration method of pin shaft sensor are designed by ourselves. The relevant parts of the bucket were reformed, and the strength of the improved bucket was checked. The measuring principle of the method was expounded, and the verification model of the movable arm was designed and made to test the feasibility of the method. Finally, the calibration scheme of the moving arm loader is worked out. The calculation of the equivalent external load: according to the parameters of the components of the loader's working device, the coordinate of the hinge points is obtained by using the geometric method, and based on the force measured by the sensor, The force on each hinge point of the arm is calculated in geodetic coordinate system, and it is converted to the moving arm coordinate system. In the moving arm coordinate system, the time history of bending moment on neutral plane of the arm is made, and the equivalent moment diagram of the moving arm is obtained. According to the equivalent bending moment diagram of the arm, the equivalent load of the arm is calculated, and the equivalent external load which should be applied to the bucket during the fatigue test is deduced back, and the fatigue test scheme of the arm is designed according to the equivalent external load.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH243

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