Design and test of vacuum suction device for egg embryo activity sorting robot

Abstract: There are problems such as egg embryo falling and embryo aspiration in the sorting process of the 168-egg tray automatic sorting devices. In order to solve these problems, combined with the existing egg embryo sorting technology in China and abroad, we take the vacuum generator with negative pressure control as the core to design a vacuum chuck with independent negative control circuits. Based on the theoretical analysis of airflow fields during the process of holding egg embryo, the levitation force of the egg embryo and the suction cup is compared with the negative pressure suction at the time of contact, and the suction cup is optimized. At the time of holding, the sucker can be a good coupling with the egg embryo, so as to reduce the suction negative pressure. Meanwhile, the influencing factors of the vacuum sucker airflow field, such as the relationship between the length of the negative pressure trachea and the response time of the negative pressure, the performance of the vacuum generator, the shape of the sucker, the force of suction, the capacity of the accumulator and the amount of negative pressure, are analyzed theoretically and tested, thus allowing to optimize the control mode of the gas path. Through the analysis of the airflow field, the high pressure accumulator is used to drive the vacuum generator to provide negative pressure, and each sucker is controlled independently. The negative pressure balance of the vacuum sucker is achieved by using single point negative pressure generation and single point control. This method eliminates the negative pressure difference between the pipelines caused by the centralized negative pressure supply of the vacuum pumps, and it also prevents the egg embryo from falling and the leakage phenomenon caused by negative pressure unloading near the negative pressure pipeline when a pipe leaks. The vacuum generator's independent circuit for the control of negative pressure also limits the negative pressure, thus reducing the negative pressure circuit's negative pressure fluctuations, improving the reliability of the system support, and also solving the problem of embryo aspiration caused by an excessive negative partial pressure in the centralized negative pressure supply mode. Through the egg embryo holding kinetics, combined with the mobile control system requirements of the sucker device, the axial and radial forces required to suck the eggs are analyzed, and the pleated suction cup and the buffer rod of sucker are used, so the sucking disc and egg embryo can be well coupled before being sucked. It can also reduce the critical flow rate, so as to reduce the critical negative pressure of egg embryo. This solves the problem of germplasm aspiration during egg absorption, improves the dynamic response of the system, and reduces energy consumption. According to the analysis and design of the prototype, the egg sorting test and pressure supply performance verification of the negative pressure system are carried out. Each independent negative pressure circuit achieves a stable negative pressure supply, therefore reducing the amount of air consumption. The reliable embryo egg absorption rate is 99.89%, without any egg embryo falling nor embryo aspiration phenomenon.