试验机电动力夹持技术研究与夹持装置开发

发布时间：2018-04-20 00:13

本文选题：试验机夹具 + 楔形夹紧　；参考：《吉林大学》2015年硕士论文

【摘要】：在试验机夹具技术领域当中，手动、气动、液压驱动夹紧的发展日益成熟，而电力驱动的夹紧装置到目前为止还是一个崭新的领域。作为一种新的夹紧方式，它具有动力提供方便、便于自动控制、无污染、噪声小等独有的优点，这是各类科学技术产品最需要的特性。因此，适应发展需要的电力驱动将是试验机夹具行业一个必然的发展趋势。本文从试验机上最常见的楔形拉伸夹具入手，分析了夹具结构及夹紧力施加特点，探索电力驱动的可行性，提出了电力夹持的理论方法，研发出一套可以实用的电动夹紧装置，并通过实验加以验证。首先，建立楔形夹紧装置的力学模型，分析夹紧时夹块的受力情况，讨论斜楔角度对夹紧的影响，选择15°这一具有代表性的楔形角为研究角度。提出了一种计算初始夹紧推力的方法。其次，研究夹具的夹持特性，发现在整个夹持过程中，大部分时间所需夹紧力矩不大，只有很小的一段时间需要很大力矩来完成夹紧。在这段时间中，夹块位移基本为零。联系电动机的运行特点，考虑利用其堵转特性，即电机在堵转状态下可以提供额定值几倍的转矩。如此，利用很小的电机就可以为夹紧装置提供很大的驱动力，节省成本。采用力矩电机，在堵转时电机仍能正常工作，不会烧坏。再次，建立电动夹具的结构系统，设计出两套电动夹紧结构方案。选择其中大载荷的夹紧装置进行详细设计。采用链传动传递电机输出扭矩，利用丝杠螺母机构完成电机轴回转运动向直线运动的转换，利用偏心机构保证螺母不产生旋转，带动夹块作直线运动。计算每个零部件尺寸，校核分析、确认可用后投入生产加工，完成试验产品的制造安装。设计电动机传统控制电路及电子半导体控制电路，确保电动机能够正常运行。最后，在试验机上使用所设计制造的电动夹具进行金属拉伸试验，整套设备能够完成最大设计载荷的夹紧试验，试验结束试样能顺利退出夹具，且试样表面压痕平整，无拖动痕迹，说明夹紧过程中不存在打滑、剥皮现象。试验成功，证明设计的电动夹具合乎标准，所提出的电动夹紧理论可行。本课题创新性地提出了一种新的试验机夹具驱动方式，并通过实际生产制造，，证明了电力驱动的可行性、可靠性，为试验机夹具驱动提供了新的思路、做出了新的探索。
[Abstract]:In the field of fixture technology, manual, pneumatic and hydraulic clamps are becoming more and more mature, and the electric clamping device is still a new field up to now. As a new clamping method, it has the advantages of convenient power supply, easy automatic control, no pollution, low noise and so on, which is the most needed characteristic of all kinds of scientific and technological products. Therefore, the electric drive which adapts to the development needs will be an inevitable development trend of the testing machine fixture industry. This paper begins with the most common wedge drawing fixture on the testing machine, analyzes the structure of the fixture and the characteristics of the clamping force, explores the feasibility of the electric drive, puts forward the theoretical method of the electric clamping, and develops a set of practical electric clamping device. It is verified by experiment. Firstly, the mechanical model of the wedge clamping device is established, and the stress of the clamping block is analyzed, and the influence of the angle of the oblique wedge on the clamping is discussed. The representative wedge angle of 15 掳is chosen as the research angle. A method for calculating the initial clamping thrust is presented. Secondly, the clamping characteristics of the clamping fixture are studied. It is found that the clamping torque required for most of the time is not large, and only a very large moment is needed for a very small period of time to complete the clamping in the whole clamping process. During this period, the block displacement is basically zero. Considering the running characteristics of the motor, it is considered that the motor can provide torque with a rating of several times under the condition of clogging. In this way, the use of a very small motor can provide a great driving force for the clamping device, saving cost. Using torque motor, the motor can still work normally and won't burn out. Thirdly, the structure system of electric fixture is established, and two sets of electric clamping structure are designed. The clamping device with large load is selected for detailed design. The output torque of motor is transmitted by chain drive, the rotating motion of motor shaft is transformed to linear motion by using the screw nut mechanism, and the eccentric mechanism is used to ensure that the nut does not produce rotation and drive the clamp into linear motion. Calculate the dimensions of each component, check and analyze, confirm the availability and put into production and processing, complete the manufacturing and installation of the test products. The traditional control circuit and electronic semiconductor control circuit are designed to ensure the normal operation of the motor. Finally, the metal tensile test is carried out by using the electric fixture designed and manufactured on the testing machine. The whole set of equipment can complete the clamping test of the maximum design load, and the specimen can be successfully withdrawn from the fixture at the end of the test, and the surface indentation of the sample is flat. No drag trace, indicating that the clamping process there is no slip, peeling phenomenon. The experimental results show that the designed electric clamp conforms to the standard and the theory of electric clamping is feasible. In this paper, a new jig driving mode of testing machine is put forward innovatively, and the feasibility and reliability of electric drive are proved through actual manufacture, which provides a new way of thinking and new exploration for jig driving of testing machine.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG75

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