针刺机曲柄滑块机构动态特性研究

发布时间：2018-06-20 11:37

本文选题：振动 + 曲柄滑块机构　；参考：《西安工程大学》2012年硕士论文

【摘要】：针刺机是纺织行业中干法织布的重要设备，该机的核心部件为两个对称的曲柄滑块机构，当机器工作时滑块的纵向惯性力无法完全消除，导致针刺机有较大的振动与噪声现象出现，针刺机的寿命会大大减小，也会影响工人健康，而且故障出现频率也会大幅度提升，更重要的是产品质量也会有所降低。为进一步提高针刺机的针刺频率亟须对曲柄滑块机构的振动问题进行研究，本文以针刺机的曲柄滑块为研究对象对其进行研究。从针梁部件运动规律、构件受力、机构计算机模态分析与谐响应分析、主轴与针梁部件的振动波形分析（主要是时间波形图分析与频谱图分析）四大方面对其振动现象进行研究，找出可能造成振动的原因。首先，从曲柄滑块机构的运动特性着手，绘制出曲柄滑块机构主要部件的运动曲线图。其次，利用ANSYS的强大分析功能计算出曲柄滑块机构主要部件如连杆、曲轴的变形量，并验正其需用应力。再次，利用ANSYS软件对曲柄滑块机构的重要部件如：曲轴、连杆、针梁进行模态分析和谐响应分析，，找出重要部件的固有频率和振动模型与共振时的振动幅值和相位。最后，利用振动测试设备现场对曲柄滑块机构进行检测，绘制出主要位置的振动波形图和频谱图。综合分析理论运动曲线与计算机仿真的结果以及实际测出的振动信号，得出了引起振动的原因。通过运动曲线理论分析及ADAMS动力学仿真发现针刺机的曲柄滑块机构运动时存在比较大的冲击力，可能引起设备的振动从而影响产品质量和减少机器寿命。适当选择平衡块的质量和质心距就能最大限度地减少惯性力，但是曲柄滑块机构的惯性力不能完全消除，要减小该惯性力，需减小滑块和连杆的重量，以及偏心距和连杆的长度。连杆变形量在Z向即长度方向最大，连杆所受应力远小于其许用应力；在曲轴许可变形范围内计算出了曲轴端面的最大变形量，并得曲轴出扭转应力远小于其扭转许用应力。借助于ANSYS软件进行的模态分析和谐响应，得出连杆在频率为40HZ时会发生共振现象，曲轴在30HZ时会发生共振现象，针梁的前十阶固有频率最大为2.1561HZ，但是，在针刺机启动过程中会很快越过针梁共振区，所以，以后改进针刺机振动特性时完全可以把针梁的因素作为次要因素来考虑，本针刺机的最大工作频率为20HZ,不会引起曲柄滑块机构的共振现象。通过实地测试针刺机的曲柄滑块机构的振动，对其滤波后的振动信号的波形图和频谱图进行分析，得出引起曲柄滑块机构振动的主要原因是转子不平衡和碰磨。最后,提了三个出不同的优化方案，第一是通过绘制出滑块的理论加速度曲线图，改变加速度的相关参数从理论上使得加速度值得以大幅度减小。第二是通过变换不同的弹性模量、阻尼系数、磨擦系数即更换更优的材质后进行ADMAS仿真,使得加速曲线变得比较光滑，避免冲击力的产生。最后,通过在安装了飞轮和配重块并重新安装曲轴和摇臂装置,之后进行实地的振动测试，振动幅值减小为原来的三到五倍。
[Abstract]:The needle punching machine is an important equipment for dry weaving in the textile industry. The core components of the machine are two symmetrical crank slider mechanisms. When the machine works, the longitudinal inertia force of the slider can not be completely eliminated. The needle punching machine has a large vibration and noise phenomenon, the life of the needle punching machine will be greatly reduced, and the workers' health will also be affected. Moreover, it will also affect the health of the workers, and therefore, the health of the workers will also be affected. The frequency of obstacles will also greatly improve, and more importantly, the quality of products will also be reduced.
In order to further improve the frequency of the needle punching frequency of the needle machine, the vibration of the crank slider mechanism must be studied. In this paper, the crank slider of the needle machine is studied. The motion law of the part of the needle beam, the force of the component, the modal analysis of the mechanism and the harmonic response of the mechanism, and the analysis of the vibration wave of the spindle and the part of the needle and beam (main body) If the time waveform analysis and spectrum analysis), four aspects of the vibration phenomenon are studied to find out the possible causes of vibration.
First, starting from the motion characteristics of the crank slider mechanism, the motion graph of the main parts of the crank slider mechanism is drawn. Secondly, the deformation of the crank slider mechanism, such as the connecting rod, the crankshaft deformation, and the required stress are calculated by the powerful analysis function of the ANSYS. Then, the important part of the crank slider mechanism is used by the ANSYS software. Parts such as crankshaft, connecting rod and needle beam are analyzed by modal analysis and harmonic response analysis, and the vibration amplitude and phase of the natural frequency and vibration model and resonance of important parts are found. Finally, the vibration waveform and spectrum of the main position are drawn by the vibration testing equipment, and the theoretical motion is analyzed. The results of the curve and computer simulation and the measured vibration signals show the cause of the vibration.
Through the theoretical analysis of motion curve and ADAMS dynamic simulation, it is found that the crank slider mechanism of the needle punching machine has a relatively large impact force, which may cause the vibration of the equipment to affect the quality of the product and reduce the life of the machine. The proper selection of the mass and the center distance of the balance block can minimize the inertia force, but the crank slider The inertia force of the structure can not be completely eliminated. To reduce the inertia force, the weight of the slider and the connecting rod, the eccentricity and the length of the connecting rod are reduced. The deformation of the connecting rod is the largest in the direction of Z to the length, and the stress of the connecting rod is far less than the allowable stress. The maximum deformation of the crankshaft end is calculated and the crankshaft is calculated in the range of the crankshaft permissible deformation. The torsion stress is far less than its torsional allowable stress. With the modal analysis of the ANSYS software, the resonance phenomenon occurs when the frequency is 40HZ, and the resonance phenomenon occurs when the crankshaft is at 30HZ. The maximum natural frequency of the first ten steps of the needle beam is 2.1561HZ, but the needle beam will quickly cross the needle beam during the starting process of the needle punching machine. Therefore, the factor of the needle beam can be considered as a secondary factor in the future improvement of the vibration characteristics of the needle punching machine. The maximum working frequency of the needle punching machine is 20HZ, and the resonance phenomenon of the crank slider mechanism will not be caused. The vibration of the vibration signal after the filter is measured by the vibration of the crank slider mechanism of the needle punching machine and the wave pattern of the vibration signal after the filter. The analysis of the spectrum shows that the main cause of the vibration of the crank slider mechanism is rotor imbalance and rubbing.
Finally, three different optimization schemes are proposed. First, by drawing the theoretical acceleration curve of the slider, the acceleration is changed in theory by changing the relative parameters of the acceleration. The second is to simulate the ADMAS by changing the different modulus of elasticity, damping coefficient, and the friction coefficient, that is, to replace the better material. In the end, the vibration amplitude was reduced to three to five times that of the original, after installing the flywheel and the counterweight block and reinstalling the crankshaft and rocker device.
【学位授予单位】：西安工程大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH112

【参考文献】