The new electronic packaging weighing machine design for agricultural fertilizers

There are many links in the industrial production process that involve quantitative weighing, such as the packaging process of food, the ingredient process of medicine and chemical industry, the ingredient packaging process of feed and so on. The traditional mode is to use static weighing and bagging machine first, and then manual packaging or ingredients. This often leads to extremely low efficiency, extremely labor intensity of workers, and low precision. The emergence of electronic packaging scales has improved the accuracy of static mechanical weighing, but in the rapid production process, dynamic weighing accuracy is a problem. So how to solve the problem of dynamic accuracy in the process of high-speed weighing has become a hot topic of current research.

Based on the current research results of dynamic weighing at home and abroad, combined with the specific requirements of agricultural fertilizer production for quantitative weighing and packing machine, an electronic quantitative packaging dynamic weighing system suitable for agricultural fertilizer production is designed.

Mechanical structure design of dynamic weighing system of electronic quantitative packaging scale

The dynamic weighing system of the electronic packing scale is mainly composed of a feeding system, a quantitative weighing system, and a packaging system. Since there is little difference between weighing packing machine at home and abroad, the focus of research is on the feeding part and the quantitative weighing part.

The feed system of automatic weight packing machine can be divided into auger conveyor feeding, belt conveyor feeding, direct current feeding, plunger feeding, screw feeding, vibration feeding, etc. from the structural form. Various methods have their advantages and disadvantages. Since agricultural fertilizer packaging is a packaging of heavier materials, in order to take into account efficiency and accuracy, our feeding system adopts a direct-flow feeding method. At the same time, in order to achieve the actual needs of rapid weighing on the production line, a double-scale structure is adopted in the weighing structure (A, B scale). The entire dynamic weighing system of the electronic weight packing machine is first fed to the storage hopper of the DC feeding device through the belt conveying feeding device, and then fed by the DC feeding device.

During the dynamic weighing process of small scale packaging machine, the material flow rate directly determines the impact force of the material weighing system. When the material discharge flow is large, the weighing speed is fast, but the weighing accuracy will be difficult to guarantee. Conversely, if the material flow rate is small, the weighing accuracy can be improved, but the weighing efficiency is very low. In order to meet the weighing accuracy of the system and take into account the weighing speed, we adopt a multi-level flow control method on the feeding rate. The experimental results show that the use of three-level feeding control mode can better solve the contradiction between speed and accuracy.

Judging from the operating conditions on site, this packing weight machine can basically meet the design requirements. However, there is still room for improvement in terms of control accuracy. If the feeding system can be improved so that the feeding speed can be strictly controlled, the requirements for the control part of the automatic weighing packing machine will be greatly reduced, and some traditional and very effective control methods can be adopted.