Design Of Apple Cover Net Device Based On PLC

China ranks first in the word for apple production.Apple's rapid commercialization makes it a common phenomenon that a lot of apple sales in different places in the country and conduct international trade. Because of its crisp texture, apple is affected by mechanical damage in the processes of picking, packing, transportation, storage and all aspects of deep processing. Mechanical damage is one of the main reasons of the heavy losses in the process of apple transportation. At present, It is an important way to protect the apple from mechanical damage by using the net immediately after harvest,but the process is done by hand, With the increase in production and labor costs as well as the purposes of improving the degree of automation of apple packaging requirements, it is imperative to design a automatic apple cover net device.Apple cover net device is a mechanical, electrical, gas, light integrated equipment,which uses PLC as the core to control the machine.Apple into the positioning plate of the positioning and conveying mechanism,and can quickly realize the positioning of the fruit stem perpendicular to the horizontal plane, to ensure the foaming nets to trap the compressive strength of the smallest apple dine parts; According to the measured photoelectric signal and position signal, PLC set the agency network after apple's positioning to control all parts of Network mechanism of the action instead of manual operation for the apple set of foam screen process automation, which effectively improve the efficiency of the set of network.In this paper, the mechanical system design of the device is carried out,mainly including the design of the positioning transport mechanism, the composition of each work unit and the assembly of the whole machine.I designed the Pneumatic system for Apple network equipment.we use PLC technology to control various solenoid valve coil in the pneumatic system diagram.I completed many mission including pneumatic components selection and the design of gas dynamic circuit, pneumatic circuit simulation of dynamic characteristics and so on.The device uses the FX2 N series PLC as the control core and detectes apple whether in place or not using photoelectric sensor. I use the solid state relay SSR to control the separation and engagement of the electromagnetic clutch and then control the operation status of the positioning and conveying mechanism.The operation process and working principle of the apple net device were determined.The software and hardware design of the electric control system is carried out, the operation panel is designed, and the wiring diagram of the system is drawn. I listed the control system I/O table.According to the control logic of the apple network device, the ladder diagram program is compiled and the simulation program is compiled.