Numerical Simulation And Design Optimization Of Friction Separation Mechanism Of Franking Machine

Franking machine is a widely used automated stamping equipment. It improves the efficiency of the postal sectors greatly. But current domestic self-developed franking machine has several problems such as low separation efficiency, high rates of jam and missing, while the foreign price are very expensive. Therefore, a new type of friction separation mechanism was designed in this dissertation. A unique three-dimensional dynamic simulation modal was established basing on the LS-DYNA software. The main factors of franking machine's performance were analyzed and the corresponding improving measures were put forward. And then, through the vibration experiments and modal analysis, the separation mechanism was further improved and optimized. The main contents and achievements were as follows:1. Combined with related academic achievements, a new friction separation mechanism with the combination of a rubber sheet and rubber toothed cylinder belt was designed, and its key dynamic parameters were analyzed by the theoretical mechanics.2. Four gears of the friction separation mechanism were set up through the dynamic simulation analysis to the key impact factors, there were roller angle 37°(0.2mm~2.5mm),26°(2.5mm~5mm),18°(5mm~8mm),5°(8mm~10mm) respectively to make ensure that the different thickness of envelopes can be effectively separated.3. The envelope getting in and out of the separation channel was the main source of vibration and its intensity increased as the thickness of the envelope increased, but when separated mixed thickness of envelopes, the vibration intensity was the lowest. 4. The leaf spring would get resonance with the working frequency of the high-speed franking machine, and swing from side to side. It affected the moving posture of the envelope, and increasing the thickness of the leaf spring was proposed to get improvement.For the problems such as low separation efficiency, high rates of jam and missing, this dissertation designed a new friction separation mechanism, and combined with the dynamic simulation, the key parameters were determined. Further improvement was achieved by experimental testing and modal analyzing method, and it made good effects.