Design And Key Components Research Design For Powder Quantitative Large Bag Automatic Packaging Machine

Automatic packaging machines for heavy-duty bags of powder material is to package the 50 Kg grade powder or granular materials by using heavy-duty bags, and have automatic functions of taking, sucking, weighing, filling and sealing bags, are widely used in food and chemicals packaging industry. At present, automatic packaging machines for heavy-duty bags are mostly dependent on import in China. Some of them developed by our country are not stable in the process of actual use, they are easy to fall bags and it will affect the production efficiency. Therefore, based on the projects cooperating with the enterprise, this thesis studies the mechanical structure, the reliability, the bag-absorbing capacity and the control system of automatic packaging machine for heavy-duty bags, and design a prototype with the functions of taking, transmitting, clamping, hugging and sealing bags.First, analyse the mechanical structural of automatic packaging machines for heavy-duty bags, and based on the packaging process, the whole system is divided into five subsystems of bags taking system, bags transmitting system, bag clamping system, bags hugging system and bags sealing system. This thesis uses Solidworks 3D software to design all the mechanical structure of the packaging machine with modularization.Second, this thesis analyzes the modules of the automatic packaging machines for heavy-duty bags. All the failure rates of the five subsystems are expected, and the reliability index of the packaging machine MTBFs has been computed. At the same time, this thesis has finished the failure mode effect analysis and built the failure tree according to the characteristics of the automatic packaging machines for heavy-duty bags. In order to carry out the accurate result of the importance analysis of the packaging machine, this thesis uses the analysis method based on triangular fuzzy tree.Third, the bag-absorbing capacity of different kinds of packaging bags by bag-absorbing devices of big wrapping machine is explored. Through analysis of the absorbing principle of the vacuum absorbing device, the vacuum absorbing model is built. The absorbing test is made on three wrapping bags, namely, lined woven bags, film-covered woven bags as well as paper-plastic compound bags, and the change of air pressure is recorded. Result shows that the change of air pressure differs according to different woven bags absorbed. The leakage coefficients of 0.192, 0.089 and 0.042 are introduced. According to the leakage coefficients and working efficiency, the vacuum air pressure of the three kinds of wrapping bags when being absorbed should be set as 59~64k Pa, 70~75k Pa, 66~71k Pa.Finally, in order to solve problems, such as the lines which easily go disorderly and broken in the process of operation and control, the control system based on Fieldbus of PROFIBUS-DP was designed. The hardware of the control system and the process of software is elaborately introduced, it has a very strong network communication ability, and it makes convenient the intellectualization of the automatic automatic packaging machine and long-distance monitoring.