Large-tonnage Truck Cranes From The Dynamic Simulation Analysis And Optimization Of The Hydraulic System Of The Lifting Mechanism

Crane is indispensable as one of engineering machineries in the engineering construction.It plays a pivotal role in China’s economic construction. Truck crane (which is wheeled crane)has its particularly prominent position among many types of cranes. With its advantages ofgood mobility and rapid transferring, it has been widely used in the engineering construction.Now with the increase of load weight and size, better performances including better handlingof the machine, higher lifting security and stronger stability are requested.Lifting hydraulicsystem is one important means for power and control of the lifting mechanism. The dynamicperformance of the secondary lifting of the hydraulic system has a direct impact on the wholemachine’s lifting performance. Early study of hoisting mechanism is limited by small andmedium tonnage,"passive oil filing" idea which is generally used to solve secondary declinehas been not adapted to the crane with large tonnage. Therefore it is quite necessary todevelop a new control scheme or to improve the original design. There is one " initiative oilfilling " design solution in Engineering applications, such as: auxiliary fuel tank of diesellocomotive uses initiative oil filling system to ensure reliability and reduce costs; oil-filledequipment in substation implements electrified initiative oil filling strategy to reduceequipment downtime frequency and outage time, further to improve power supply reliability,and simplify the oil filling process of oil-filled equipment in application. Taking an existingproduct of a company as an object of study, based on the principle of passive oil fillinghydraulic lifting system, with theory study of the hydraulic control system, the strategy of "initiative oil filling is proposed to improve the hydraulic system technology. With regard tothe problem of secondary decline in load lifting, a good hydraulic control strategy is designed.Below are the main contents of this paper:1. AMESim is used in the simulation study of hydraulic control system for large-tonnagetruck crane hoisting mechanism. Dynamic characteristics of the hydraulic system areresearched. Mathematical modeling is built to study the control system for load,hoisting mechanism and the proportion of Hydraulic Motor servo;2. Using AMESim simulation to load two key operations of"static-Lifting and static-down", further identify the goals and direction for improvement, and propose theimprovement solution.3. Take” initiative oil filling "strategy to eliminate the problem of secondary decline. Ahydraulic schematic diagram is designed and simulation model is built.4. After comparing the hydraulic lifting effects of typical simulation analysis,"passive oilfilling" and " initiative oil filling “, the results approves that" initiative oil filling " solution basically can eliminate the problem of secondary decline of large-tonnagecranes in lifting process.A simulation model of large-tonnage hydraulic hoisting system is establishedsuccessfully, a simulation study is done. The research achievement provides theoretical basisfor large-tonnage cranes lifting system improvements, optimization and design, Thesimulation technology brought into the crane hydranlic system design has a certain theoreticalsignificance and application value.