Selection of Mechanisms for Supplying Bag Parts to rotary packing machine
The cam mechanism can realize the complex motion law of the follower through the design of the cam profile track curve, so as to realize the motion coordination of the multi-motion mechanism; however, the mechanism manufacturing and adjustment requirements are high, and the accuracy of the motion law will be affected after wear. The link mechanism is simple in structure, easy to manufacture, has a large bearing capacity, and can realize long-distance transmission, but it cannot realize the precise pause and arbitrary trajectory movement of the follower for a long time. Due to its inherent limitations, a single mechanism cannot meet various requirements. Therefore, automatic machinery mostly adopts a compound mechanism based on cams and connecting rods to realize complex motion of multiple actuators.
The bag-feeding action of the bag-feeding part of the rotary packing machine includes two parts: one is the friction drive of the bag-sweeping belt and the bag-feeding belt of the bag-feeding platform, which are driven by their respective motors; the other is the cam group on the distribution shaft and the connecting The rod mechanism drives the primary bag loading mechanism, the secondary bag loading mechanism, the bag clamping lifting mechanism, the vacuum suction cup and the gripper to perform coordinated actions to realize automatic bag supply to the rotary packing machine.
Considering the factors of centralized drive, structure size, control, etc., a composite mechanism of cam and connecting rod is used for the bag supply parts of the bag packaging machine to realize the automatic bag supply action of prefabricated packaging bags. The mechanism model is shown in the figure. Taking the design packaging speed of the rotary packing machine as an example of 50 bags/min, the bag feeding mechanism is designed. The automatic bag loading time of each bag is 1.2 s, that is, the working cycle time of the bag feeding mechanism with the distribution axis O1 as the reference axis tk=1.2 s. According to the production capacity requirements of the packaging machine, combined with the automatic bag feeding process of the bag feeding mechanism of the bag packaging machine, the motion coordination, time synchronization and space non-interference of each actuator, as well as the error of the mechanism motion law, the clearance of the motion pair, the mechanism of the mechanism, are comprehensively considered. Factors such as component processing and assembly errors, movement deformation of mechanism components, etc., can allocate the ratio of the time required for each bag feeding action to the movement cycle time, and design the working cycle diagram of the bag feeding mechanism, as shown in the figure. According to the working cycle diagram, the size optimization and structural design of the bag feeding mechanism of the bag packaging machine can be completed by using the relevant mechanism synthesis, cam design theory and simulation technology.