Design And Experiment Of Automatic Weighing And Dropping Device For Barreled Premix

In the process of feed processing,premix such as feed additives play an important role although they account for a small proportion in feed raw materials.At present,after weighing and preparing feed additives and other premix,most feed production enterprises mainly manually put the prepared premix into the main mixer,and need to record relevant information such as dropping and weighting review of premix.In order to reduce the labor intensity of premix dropping workers and improve work efficiency,an automatic weighing and dropping device for barreled premix is designed,an automatic control system based on STM32 single chip microcomputer is developed,and the human-computer interaction interface is developed by QT to realize the automatic recording the information of barreled premix’s automatic dropping and weight review.The main research contents and results are as follows:(1)Design of automatic weighing and dropping device for barreled premix.The device is mainly composed of weighing mechanism,lifting mechanism,clamping mechanism and turnover mechanism to realize the weighing,lifting,clamping and dropping of barreled premix.The weighing mechanism is composed of three strain sensors in parallel to improve the weighing accuracy;The lifting mechanism uses electric cylinders to control the lifting of the barrel;The clamping mechanism uses the cylinder to provide power,and uses the self-locking function of the connecting rod mechanism to clamp the material barrel;The turnover mechanism takes the electric cylinder as the power source and adopts the connecting rod mechanism to realize the turnover of the barrel about 140° to ensure that all the premix in the barrel are discharged.In the design process,the motion and dimensional parameters of the key mechanism are analyzed,at the same time,the lifting and turnover process of the device is simulated by Solid Works,and the stress of the dropping process of the dropping device is analyzed by ANSYS.(2)Control system design.On the basis of determining the automatic weighing and dropping program of barreled premix,the control system of the device is designed.The control system mainly includes weighing module,dropping process control module,alarm module and information recording module.The weighing module uses HX711 chip to convert the analog signal of the weighing sensor into digital signal for STM32 single chip microcomputer processing to realize the function of weighing and rechecking premix;The dropping process control module mainly adopts relay and solenoid valve to control the lifting mechanism,clamping mechanism and turnover mechanism respectively,so as to realize the lifting,clamping and dropping functions of the dropping device;The alarm module uses the active buzzer as the alarm device to realize the alarm function when the premix weight is unreasonable;The information recording module uses QT to design the human-computer interaction interface,sets the premix weight range in the single chip microcomputer through the serial port,and records the name of premix,weight information,dropping time,dropping batch and dropping person.(3)Device performance test.The prototype of the device is manufactured,and the device is debugged and tested.In this test,the stainless steel barrel with a volume of 45 L is used,and its maximum loading capacity is 36kg(the volume weight of premix is0.8t/m3).Firstly,the trial operation test is carried out on the device.The trial operation shows that the device operates well,and the functions of weighing,lifting,clamping,dropping,emergency braking,alarm and reset are well realized.At the same time,the functions of setting and recording dropping information are fully realized by the man-machine interface software.During the performance test,5-35kg(with an interval of5kg)of 7 batches of premix shall be filled in the barrel respectively,and each batch of premix shall be measured for 3 times,and the average value shall be taken as the final result.According to the test statistics,the maximum error of weighing is 15 g and the minimum is 3g;The maximum and minimum cycle of repeated verification and delivery of each batch is 49.62 s and 49.34 s respectively;The residue rate was 0.06% at the maximum and 0.01% at the minimum.The test results show that the basic function,weighing accuracy,dropping cycle and residual rate of the device meet the design requirements and basically meet the actual production needs.