Study On The Design Of Hydraulic Lifting Machine With Automatic Follow Mechanical Safety Device

Hydraulic lifting equipment is often used in engineering work,and when lifting heavy objects,hydraulic cylinders often need additional protection measures to prevent sudden collapse of lifting heavy objects after failure of hydraulic cylinders,so workers often use steel frames with different heights as safety support in actual lifting operations,which not only leads to low lifting efficiency,but also makes safety accidents easy for workers when operating cranes or forklifts to install steel frames.In view of the above disadvantages,this paper studies and designs a hydraulic jacking machine with automatic following mechanical safety device,which can automatically follow the lifting weight to carry on the safety support when the hydraulic cylinder works,which not only improves the efficiency of the lifting,but also ensures the safety of the lifting.This paper refers to a large number of literature on preventing and solving the failure of hydraulic equipment,and determines that four screw mechanisms with self-locking are used as safety support,and gear gears are used for transmission.The whole mechanical safety device is driven by DC motor,and the mechanical safety device in jacking machine is studied and designed from five aspects:structure design,finite element analysis,control system design,principle prototype making and experimental verification.For structural design,starting from the strength and stiffness of the parts,the dimensions of the screw,nut,load-bearing roof,fixed roof,load-bearing column and other parts are designed.On this basis,the three-dimensional modeling of the mechanical safety device is completed by Pro/E software.By means of ANSYS finite element analysis software,the stress simulation of the key parts in the mechanical safety device is carried out,and the maximum stress value and dangerous area of the parts are solved,and the strength and stiffness of the parts are further verified.Furthermore,taking the four-bar support frame in the mechanical safety device as the research object,the critical load of the four-bar support frame and the critical load of the single-bar in the support frame are calculated,and the numerical relationship between the two critical loads is analyzed and revealed by MATLAB software.With regard to the design of the control system,starting with the functions required by the mechanical safety device,the STM32 is used to design the control system of the device,complete the selection of electronic components such as main control board,DC motor driver,proximity switch and wireless remote control,and write the corresponding function program on the IAR software,so that the mechanical safety device can realize the functions of automatic following rise,automatic following drop,manual rise,manual drop,wireless communication and so on.Design and manufacture principle prototype and build experimental platform to carry out related experiments to ensure that the designed mechanical safety device can follow the lifting mechanism to rise and fall flexibly,and the control system can realize the functions of automatic follow,wireless remote control,motor speed regulation and so on.The experimental results show that the whole mechanical safety device can play the role of safety support when lifting the hydraulic cylinder.