Vibration Analysis And Reduction Research Of High Speed Needle-punched Machine

The needle punching machine is a kind of large-scale machine that drives the needle beam and needle plate to repeatedly puncture the fiber net through the crank connecting rod mechanism to form the nonwovens.With the application of nonwovens more and more widely,the development of the needle punching machine is very rapid,but the vibration problem has been the key factor to restrict the working efficiency and quality improvement of the needle punching machine.Based on this,the vibration problem of the acupuncture machine is analyzed and the corresponding vibration reduction measures are put forward.First of all,the dynamic analysis of the needle punching machine is carried out.The dynamic static analysis method is used to decompose the components,calculate the force conditions of each component,establish the force equations,and then solve the equations in a joint way.The forces between the moving pairs are calculated in detail,and the forces at 1200 r/ min,1500r/ min and 1800r/ min are compared and analyzed.It is found that with the increase of rotating speed,the interaction force between the moving pairs increases significantly,which has a serious impact on the imbalance and vibration of the whole machine.Secondly,the power spectrum analysis of the vibration of the whole machine is carried out.It is found that the main frequency components of the vibration signal are fundamental frequency and 25 Hz in the range of the highest working frequency of the acupuncture machine.Among them,the frequency component of 25 Hz does not change with the increase of rotating speed,which is the natural vibration of the structure caused by the impact of reciprocating motion.Using the method of combining finite element software and experiment,the modal analysis of the main parts of the needle machine is carried out.It is found that the first-order natural frequency of the needle beam part is 24.13 Hz,which is near 25 Hz,and it is the component that contributes a lot to the vibration of the whole machine.When the needle punching machine works at the rated speed,it will produce resonance.Finally,according to the results of the above analysis,using the simulation analysis method,the vibration reduction research and simulation analysis of the needle machine are carried out from two aspects: balancing the rotating system and improving the needle beam material to increase its natural frequency,reduce the mass and then reduce the impact.The first is to establish a parameterized model of the whole machine of the needle punching machine,and to optimize the trimming chord length of the balance wheel with the help of the COMSOL finite element software.From the stress and deformation of the optimized bearing seat,it is found that when the trimming chord length is 75 mm,the deformation of the bearing seat is the smallest,and the force between the moving pairs is obviously reduced,which is conducive to the vibration reduction of the needle punching machine;the second is to rebuild the material of the needle beam Through the finite element modal analysis,it is found that the first-order natural frequencies of needle beams made of magnesium aluminum alloy and carbon fiber composite materials are far higher than 25 Hz,far away from the working frequency of the needle machine,and the density of new materials is lower,the mass of needle beams of the same size and shape is smaller,so the inertial force and moment are smaller,which can significantly reduce the vibration of the needle machine.