颗粒状物料集装袋自动定量充填系统的研究

发布时间：2018-04-04 13:39

本文选题：集装袋　切入点：给料　出处：《天津科技大学》2015年硕士论文

【摘要】：颗粒状物料集装袋自动定量充填系统是用于将颗粒状物料按要求自动定量充填到集装袋的一种包装设备,在食品、化工等行业有着广泛应用。本文通过对系统的工作过程进行分析,结合已有系统的性能特点,提出了设计系统应该具备的功能。最后设计了安全性高、结构简单、自动化程度高的称重下置式的颗粒状物料集装袋定量充填系统,并利用Pro/Engineer创建了系统结构的三维模型。系统的给料机构采用料门式给料,结构简单可靠、调整容易,可以实现颗粒物料的粗、精两级自动给料从而保证充填精度。下置的称重机构用来支撑集装袋的底面从而称量袋内颗粒物料的质量,同时配有升降机构,能够在充填时自动向上运动支撑集装袋,在充填完毕后能够自动下降脱离与袋的接触,以方便袋的运离。自动压袋机构可以受控制自动将集装袋进料口的紧压在导料筒上,以防止进料口脱离,并在完成充填后自动松开压袋。采用挂钩可以向外90度自动翻转的挂袋机构来挂集装袋的吊耳,防止充填过程中集装袋叠在一起,并在充填完毕后可以自动脱钩。整个挂袋和压袋机构及导料筒都通过内支架由称重机构的称重托盘支撑与给料机构不直接接触,从而减少了干扰因素对称重精度的影响。利用离散元法借助PFC3D软件仿真计算了称重托盘受到颗粒物料的冲击力,利用ANSYS/WORKBENC H软件对称重托盘进行了动力学和静力学分析,得到了其模态特征以及在额定载荷作用下的应力与应变等,同时分析了在冲击力作用下的瞬态动力学动态响应等,分析结果显示结构设计可靠。对称重机构中的升降机构进行了受力分析,确定了工作时所需的驱动力,同时利用ANSYS进行了结构有限元分析。利用离散元法借助PFC3D软件仿真计算给料机构中料门受颗粒物料的作用力,对得到的结果进行了分析,确定了料门打开所需的作用力,确定选择的驱动气缸能够满足需求。研究了影响系统包装精度和速度的因素,提出了提高包装精度的有效措施,详细阐述对系统延时和空中料柱的预测补偿与选择最优两级给料切换点这两种提高包装精度的措施。设计了系统基于PLC的控制系统,控制系统可以根据得到的重量信号按照系统设定自动控制各执行机构动作。
[Abstract]:The automatic quantitative filling system of granular material packing bag is a kind of packing equipment which is used to automatically fill granular material into container bag according to requirement. It is widely used in food, chemical industry and so on.Based on the analysis of the working process of the system and the performance characteristics of the existing system, the functions of the design system are put forward in this paper.Finally, a quantitative filling system with high safety, simple structure and high degree of automation is designed, and the three-dimensional model of the system structure is created by using Pro/Engineer.The feeding mechanism of the system adopts the feedstock gate type feed, the structure is simple and reliable, the adjustment is easy, can realize the coarse and fine two-stage automatic feeding of the granular material to ensure the filling accuracy.The lower weighing mechanism is used to support the bottom surface of the container bag so as to weigh the quality of the granular material in the bag, and is equipped with a lifting mechanism, which can automatically move upward during filling to support the container bag,After filling the bag can automatically drop off contact with the bag to facilitate the bag removal.The automatic bag pressing mechanism can be controlled to automatically press the inlet of the container on the guide tube to prevent the inlet from leaving, and to release the bag automatically after the filling is completed.The hooks can be used to hang the hooks of the container bags, which can be turned out 90 degrees automatically, so as to prevent the stacks from stacking together in the filling process, and can be automatically decoupled after filling.The whole bag and bag pressing mechanism and the guide tube are supported by the weighing pallet of the weighing mechanism without direct contact with the feeding mechanism through the inner support thereby reducing the influence of the interference factors on the symmetrical weight accuracy.By using discrete element method and PFC3D software, the impact force of the weighing pallet is calculated, and the dynamics and statics of the symmetrical weight tray are analyzed by using the ANSYS/WORKBENC H software.The modal characteristics, stress and strain under rated load are obtained, and the transient dynamic response under impact force is analyzed. The results show that the structure design is reliable.The lifting mechanism in the symmetrical weight mechanism is analyzed, and the driving force is determined. At the same time, the finite element analysis of the structure is carried out by using ANSYS.The discrete element method is used to simulate and calculate the force of the grain material acting on the door of the feed mechanism with the help of PFC3D software. The results obtained are analyzed, the force required for the opening of the material door is determined, and the selected driving cylinder can meet the demand.This paper studies the factors affecting the system packaging accuracy and speed, puts forward effective measures to improve the packaging accuracy, and expounds in detail the two measures to improve the packaging accuracy, namely, system delay, prediction and compensation of the air feeding column and selection of the optimal two-stage feed switching point.The control system based on PLC is designed. The control system can automatically control the actions of each executing mechanism according to the system setting according to the weight signal.
【学位授予单位】：天津科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB486

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