Design And Research Of Crab Cage Automatic Decoupling Machine

Portunus trituberculatus is a kind of important economic crab in coastal areas of China.It is also the main target of crab cage fishing vessels in China.In crab cage fishing,the unloading process of crab cage lifting mainly depends on manual work.When the crab cage is pulled out,3000 crab cages need to be unloaded.The number of unloaded crab cages is 26 per minute.The self-weight of the crab cage is 2Kg.In the process of pulling out the crab cage,four professional unloaders need to work alternately to complete the work.Crab cage boats need to start and release cages four times a day,and each person needs 12,000 hooks and decouples,so the labor intensity is very high.Designing a device which can automatically unload the crab cage in the process of lifting and pulling the crab cage out of the main rope is of great and practical significance for reducing the worker’s work intensity and improving the work efficiency.In this paper,the decoupling technology of crab cage in the process of lifting crab cage during fishing operation of crab cage fishing boat is studied.The process of crab cage operation,the hooks connected with the main rope,the mechanical device and its control system of pressing the hooks are studied,and an automatic decoupling equipment of crab cage with impact type is designed.The main contents of this paper are as follows:1)The whole process of crab cage fishing boat operation was investigated.Mainly includes: cage release,cage lifting,cage unloading,stern rope arrangement,rear deck cabin arrangement cage and manual crab binding on the front deck,etc.2)The structure and decoupling principle of the traditional hand-held hook are studied,and a new type of hook is proposed,which is decoupled by mechanical impact.By measuring the geometric and mechanical parameters of the traditional hand-held hook,as an important reference in the design of the new hook,the structure of the new hook is determined.According to the lifting speed of the main rope and the unloading process,the mechanical characteristics of the hook under impact are studied,and the relevant structure design and material selection of the components of the new hook are completed through three-dimensional software modeling and analysis.3)An automatic decoupling machine for crab cage matched with a new type of hook is designed.The water resistance caused by the movement of main rope,branch rope ring and crab cage connection rope,crab cage and catches,gravel and so on in the process of lifting crab cage is calculated,and the structure design and three-dimensional modeling of the front-end separation device are carried out.4)Finite element structural analysis of the key parts of the crab cage hook is carried out,and structural improvement is made according to the analysis results.In addition,ANSYS is used to display the dynamic analysis of the impact separation process of the hook.The results show that the designed structure is safe and reliable.5)Design the electro-hydraulic control system of crab cage automatic decoupling machine,including hydraulic control and electrical control.The main parts are drawing up of hydraulic system diagram,selection and determination of hydraulic components,software and hardware design of PLC control system,etc.