Research On Line Thrower For Unmanned Rescue Boat

With the vigorous development of China's marine industry,the number of ships continues to increase,and offshore platforms such as oil platforms are gradually established,then marine disasters happen.In order to meet the rescue needs under various sea conditions,unmanned rescue boats were developed and utilized.The line thrower is a device for throwing line at a long distance,which is widely used in the fields of marine rescue,fire rescue and so on.If the existing line thrower can be improved,redesigned and installed on the unmanned rescue boat,the rescue capability of the unmanned rescue boat will be greatly enhanced.This work is devoted to study and design a kind of line thrower,which is small,light-weight and has a fast-response valve.By electronic launching mode,installed on the unmanned rescue boat,it can launch the projectile body with life buoy,and pull back the line with the recovery device,realizing the rescue of people overboard.The main contents of this paper are as follows:(1)According to the rescue needs of the unmanned rescue boat,the design indexes for the miniature line thrower of unmanned rescue boat are put forward.And the project design is proposed around the using condition and the design indexes,which mainly includes the material selection,the calculation of the center of gravity position,the force analysis of main parts in the cavity,the strength analysis of concentrated stressed part,etc.Moreover,we used SolidWorks and AutoCAD software to carry out 3D and 2D modeling.In order to reduce the space occupied by the gas supply equipment,this article uses a miniature carbon dioxide gas cylinder as the gas source,at the same time,a rechargeable air inlet interface is designed.(2)The force analysis of the main spool and the piston in cavity of the line thrower is carried out,and the conditions for the main spool and the piston in cavity to start moving are obtained.The Simulation module in SolidWorks is used to analysis the core parts of the line thrower and the concentrated force parts to ensure that the line thrower can work normally,by finite element analysis.In order to study the response speed of the main spool and the movement characteristics of the piston in cavity during launch,we analyze the 3D model and working principle of the main spool and the piston in cavity,after that the thermal aerodynamic models of the main spool and the piston in cavity are established,using AMESim simulation software.Next enter the actual data for simulation.The motion simulation curves of the main spool and the piston in cavity are obtained.Afterwards analyze the values and trends of the curves,and the results show that the main spool and the piston in cavity respond quickly.(3)The initial velocity of projectile launch is theoretically analyzed from two perspectives of using energy to work and object moving under force.Obtain the relationship between the initial velocity of the projectile and the structure of the line thrower as well as the pressure of the launch.In order to verify the reliability of the results,the AMESim simulation software is used to model the line thrower as a whole.And,the actual parameters are used to accomplish simulation,obtaining the simulation curve of the initial velocity of the projectile under different pressure.The simulation results are compared with the theoretical results,showing that the initial velocity calculated from the point of using energy to work is closer to the simulation results.