The Research Of Hydraulic Crane Secondary Lifting Characteristics Based On Differential Pressure Method

With the expanding of the hydraulic crane application field and range, therequirements of hydraulic crane performance is increasing highly. Lifting mechanism isthe key to the crane used to implement the weight lifting and falling actuator, the standor fall of its performance is directly related to the production efficiency and personnelsafety. Secondary decline phenomenon refers to the phenomenon of reverse movementof the crane load in the secondary upgrading process, is a common problem of the crane.It has seriously affected the crane lifting, but also makes it difficult to accuratelyinstalling.The paper is based on hydraulic crane secondary lifting slipping problem, the mainresearch contents include:(1) The hydraulic hoisting mechanism of crane and lifting hydraulic system wasanalyzed. With QU8models of truck crane as research object, analyses its hoistingworking principle of the hydraulic system.(2) According to hoisting working principle of hydraulic system, analyses thecauses of the secondary hoisting falling. The working principle of the current four waysto solve the two hydraulic crane lifting and sliding of the problem is analysed detail (i.e.adjusting parameter method, electric control method, memory pressure method andpressure differential controlling method).(3) According to the theory of power bond graph, set up each element keys orhydraulic system graph model and establish the power bond graph model of thehydraulic lifting loop by differential pressure controlling.(4) According to the differential pressure control loop of hydraulic lift bond graphmodel, establish the simulation model of AMESim, and do some research of the thehydraulic lifting loop by differential pressure controlling. An analysis is made for thepressure differential controlling method is able to solve hydraulic crane secondarylifting slipping problem or not.(5) In view of the working condition of hydraulic crane weight falling, analysis thedeficiency of the balancing valve over-compensation damping, F type π-bridgeresistance network is applied to the balancing valve pilot liquid resistance network, andthe pressure characteristics is derived.