外文文獻(xiàn)翻譯--基于80t起重機(jī)回轉(zhuǎn)系統(tǒng)的動(dòng)態(tài)模擬實(shí)驗(yàn)研究【中文2250字】 【PDF+中文WORD】,中文2250字,PDF+中文WORD,外文文獻(xiàn)翻譯,基于80t起重機(jī)回轉(zhuǎn)系統(tǒng)的動(dòng)態(tài)模擬實(shí)驗(yàn)研究【中文2250字】,【PDF+中文WORD】,外文,文獻(xiàn),翻譯,基于,80,起重機(jī),回轉(zhuǎn),系統(tǒng),動(dòng)態(tài),模擬 Dynamic Simulation and Experimental Study of Slewing System on 80T Crane CHEN Jinshi1,LIU Xinhui1,2,Zhang Cui1,DONG Quan3,ZHAO Feng1(1.College of Mechanical Science and Engineering,Jilin University,Changchun,130025 2.State Key Laboratory of Automobile Dynamics Simulation,Jilin University,Changchun,130025,China 3.Xuzhou Heavy Machinery Co.,Ltd.Xuzhou,221002,China)C AbstractThis paper models and studies the dynamic characteristics of slewing system of 80T truck crane.Analyzing the composition and working principle of the hydraulic system,and building the model of slewing system based on AMESim,then testing the model.And the simulation analysis results indicate the factors which affect the dynamic characteristics of the system and propose the measures to improve them.The results show that adopting the bypass circuit makes the shock pressure reduced 18 percent when the system operates;besides,changing the system s control strategy and installing one-way throttle enhance the stability of braking obviously.Keywords:truck crane slewing system dynamic simulation pressure shock I.INTRODUCTION Recently,as the country investment of ports,subway,highways and so on expanding rapidly,and power station,smelting equipment,bridge engineering and high-rise building increasing year by year,the crane industry has entered a rapid development period.Slewing system is an important part of truck crane.However,the slewing mechanism s moment of inertia and frictional resisting torque between mechanisms is large,which result in great impact on hydraulic system when the slewing system starts or stops and make the rotary stability badly.Therefore,analyzing the dynamic performance of slewing system is very important.Analyzing and designing the dynamic characteristics of hydraulic systems,the traditional methods of relying on experience and analogy haven t satisfied the requirements of high-performance systems.This paper builds the simulation model of slewing system based on AMESim,and studies the dynamic stability through simulation analysis and experimental testing.II.COMPOSITION AND PRINCIPLE OF SLEWING SYSTEM The slewing system of 80T truck crane belongs to open loop of pump-controlled motor.Fig.1 shows the system is composed of the main circuit and control circuit.The combination using of the pressure compensation valve 4 and the direction control valve 5 of the primary circuit eliminates the impact of external load on the system,so that the flow into the motor 10 is directly proportional to the opening of the valve 5.The valve 9 has buffer and filling oil functions.Pump 18 provides a stable control pressure 3Mpa to the control loop and the whole control loop is electronic priority valve control circuit.The accumulator 12 can eliminate pressure pulsation and fill oil transiently 1-2.1.pump 2.safety valve 3.shuttle valve 4.pressure compensation valve 5.direction control valve 6.reversing control valve 7.oil return control valve 8.oil return valve 9.oil fill valve 10.rotary motor 11.brake 12.accumulator 13.rotary main control valve 14.priority relief valve 15.brake control valve pression release valve 17.relief valve 18.pilot control pump 19.tank Figure 1.Hydraulic slewing system of truck crane Slewing system works as follows:1)When the rotary main-control valve 13 does not power up,the slewing mechanism is locked,and the rotary motor 10 does not work.2)When the valve 13 is electrified,the system control circuit connects to pressure oil.First,the oil through the brake control valve 15 and open the brake 11,the slewing brake is relieved.Then,if the oil return control valve Y5,Y6 was electrified simultaneously and the reversing control valve 6 did not power up,the slewing system is in a self-regulating state.If the reversing control valve Y3 was electrified and the valve 5 connected to the left,while the 2011 Third International Conference on Measuring Technology and Mechatronics Automation978-0-7695-4296-6/11$26.00 2011 IEEEDOI 10.1109/ICMTMA.2011.2821129valve Y6 was electrified and connected to the oil return valve 8,the main loop of the motor 10 is connected,and then realizing the rotary platform turning.If the valve Y4 and Y5 had power simultaneously,the rotary platform will turn reversed.3)When the operating device needs to stop turning,the valve 5 is in the middle state and the valve 8 is closed,and the power of the motor 10 is cut off.Meanwhile the brake control valve 15 loses of power and the brake starts to work.The inertia force of the slewing mechanism is absorbed by the buffer-fill valve and the brake,and the device stops finally.III.THE ESTABLISH OF SLEWING SYSTEM AMESIM MODEL According to the composition and working principle of 80T truck crane slewing system,establish the simulation model based on AMESim shown in Fig.2.The model consists of Hydraulic,Signal,Control,Mechanical and Powertrain.In the modeling process,some hydraulic components were equivalent,and the model was simplified necessarily.Such as replace the hydraulic control valves and the brake by electricity control model,neglect the control oil circuit and replace the direction control valve by a combination solenoid valve.The main parameters of the model are shown in table 1.Figure 2.AMESim model of truck crane slewing system TABLE I.MAIN PARAMETERS OF THE SLEWING SYSTEM MODEL pump capacity/(mlr-1)motor capacity/(mlr-1)equivalent moment of inertia of motor shaft/(kgm2)pressure of relief valve/MPa pressure of buffer fill valve/MPa rotational speed of engine/?r?min-1?rated flow of direction control valve/(L/min)rated flow of oil return valve/(L/min)torque of brake/Nm reducer transmission ratio teeth number of gear/module of gear/mm teeth number of tooth ring/module of tooth ring/mm 48 28 0.0012 23 18 850?2200 120 120 250 105.7 14/12 149/12 IV.SIMULATION AND EXPERIMENT RESULTS ANALYSIS During the crane slewing process,moment of inertia and frictional resistance torque of the slewing mechanism change along with the weight configuration,lifting weights,boom angle and boom length,meanwhile,transforming between static and dynamic and the speed changing when turning will also bring about significant effect to them 3-4.According to the actual conditions,simulate the model under the conditions of the weight 4.75t,no load,rotation radius of 5m and rotary controlling handle pushed quickly,and analyze the inlet pressure of the direction control valve.The simulation result is shown in Fig.3 and the experiment result is shown in Fig.4.Comparing Fig.3 and Fig.4 find that the simulation and the experimental trends are consistent.During the two rotating duty circle,the stable system pressure are 6.2Mpa and starting pressure shock are 10.8Mpa.Therefore,the model establish is correct.?Figure 3.Simulation result of inlet pressure of direction control valve Figure 4.Experimental result of inlet pressure of direction control valve 1130Through analysis,increasing the damping ratio of hydraulic system can reduce the starting pressure impact of the slewing mechanism which has large inertia 5.Comparison of various speed control loop,bypass loop has particular effect on increasing system damping ratio 6.When the original system rotates,the direction control valve and the corresponding oil return valve electrified constitutes a return oil circuit,which forms the bypass loop if another oil return valve is open.Under the same parameter settings of the system,the original system loop and the bypass loop have different simulation result.Fig.5 shows the results of motor inlet pressure of both loops.And the Fig.represents that input the same signal to direction control valve,comparing with the original system loop,the system pressure of the bypass loop reduces 2.5Mpa and has 0.46s hysteresis at the beginning.Figure 5.Simulation results of system pressure of the original and bypass loop When the slewing mechanism stops turning,the experimental results are shown in Fig.6.The figure presents that the crane shakes fiercely and needs 10s to tend stably and the whole system s stability is very poor.This is because the direction control valve is in the unloading position at this time and the brake shuts down prematurely,then both ends of the motor have not pressure fluctuation and the hydraulic system can t consume the platform s kinetic energy.Figure 6.Experimental results of brake control pressure and both ports of motor s pressure Figure 7.Improvements of the system Based on the above analysis results,optimize the parameters of the slewing system under the simulation model and put forward the improvements as shown in Fig.7,which modifies the original system s control strategy,adds the bypass loop and delays the control signal of the brake,besides,installs one-way throttle valve to the oil return port of the brake.Test the improved system,and the results are shown in Fig.8.As shown in the figure,the shock pressure of improved system is 2Mpa lower than the original system and the brake shuts down delay when rotation stops.The hydraulic system absorbs the kinetic energy of the platform,so the whole system motion stably.Figure 8.Experimental results of the improved system V.CONCLUSION (1)Establish the simulation model of the 80T truck crane slewing system based on AMESim,and test the model through experiments.Then,simulate and analyze the dynamic characteristics of the slewing system under the starting and stopping conditions.(2)Bypass loop can reduce the starting pressure impact of the slewing system which has large moment of inertia and frictional resistance torque.It can improve the starting stability of the slewing system effectively.1131(3)Increasing the time control signal and install the one-way throttle valve to the hydraulic brake loop can ensure braking delay when rotation stops.Therefore,the kinetic energy of the slewing mechanism can be absorbed by hydraulic system sufficiently,and the brake stability of the slewing system can be improved.According to the simulation and analysis results,improve the real vehicle slewing system and test the system.And the results show that the working stability of the slewing system is enhanced evidently.ACKNOWLEDGE This work is partly supported by the National 863 Project(2007AA04Z208).REFERENCES 1 IMAGINE SA:Hydraulic Component Design Library version 8.0A S,June 2008.2 IMAGINE SA:AMESim version 8.0A S,June 2008.3 GAO Shunde,ZHANG Minghui,WANG Xin,LI Xihong.Simulation research of slewing hydraulic system on large crawler cranes J.Construction Machinery,2007(7):47-51.4 ZHANG Minghui.Simulation research of slewing hydraulic system on large crawler crane D.Dalin University of Technology,2006.5 YUE Liming.Dynamic analysis and design of hydraulic circuit for rotating mechanism in hydraulic crane J.Construction Machinery and Equipment,1991(10):27-30.6 HUANG Xiaojiang,BI Long.Dynamic Characteristics Simulation of Throttling Speed Control Circuit on Hydraulic System J.Machine Tool&Hydraulics,2006(12):214-218.1132