Energy-saving Research Of Hydraulic System On Hosting Mechanism Of Crane Truck

The crane is one of the important part in the engineering machinery field,and crane truck which has high walking speed, good maneuverability and othercharacters is widely used by the transportation, buildings, roads, mines and otheroccasions in the crane industry. Crane truck works under different environmentalconditions, and this will encounter different load weights during the craneworking process. However, the rated lifting weight of the crane is fixed, whenthe affair of the large tonnage crane is used to hoist lighter weight, this situationmay result in a larger energy loss for the system. Namely, as the crane truck’srated lifting weight lifting has been confirmed, when lifting load is smaller, thehydraulic system’s pump need to provide the higher pressure. Thus the greaterenergy loss will generate, and this will reduce the efficiency significantly for thecrane truck’s hydraulic system.In order to solve this kind of problem of small load with the high pressure,by analyzing the current situations of the crane truck, the existing crane truckhydraulic system’s shortcomings are summarized, and the reason of large energyconsumption for the crane truck is analyzed when the crane truck is used to lift the smaller tonnage weight under the rated lifting weight. And at the same time,in order to achieve the energy－saving purpose for the hydraulic system of thecrane truck, an idea of applying a new load－sensing counterbalance valve tothe hydraulic system of the crane truck is proposed.Taking the20tons crane truck’s hoisting hydraulic system as an example,this paper discusses the effect of the system’s energy loss after the new load－sensing counterbalance valve had been used in the hydraulic system. Bycomparing the pump’s output power of the ordinary balance valve and the newload－sensing counterbalance valve’s lifting hydraulic system, the gap of thepump’s output power for the two lifting hydraulic system is obtained. Thenusing this difference, the saving－energy effect of the new load sensingcounterbalance valve’s lifting hydraulic system is distinguished, and finally thecorresponding conclusion is drawn.This paper mainly applies simulation software AMEsim to analyze andcompare the two hydraulic systems. The ordinary balance valve lifting hydraulicsystem and the new load－sensing counterbalance valve lifting hydraulic systemare simulated under the three kinds of special working situations(no load, lightload and heavy load). And the pump’s output power curve of the two hydraulicsystems is drawn, especially under the three kinds of special conditions. Thenthe data from the curves are calculated and compared, the result of the twohydraulic system’s energy consumption is obtained. By calculating andanalyzing, this paper obtains a conclusion: when the load decreases, the energy saving rate of the new load－sensing counterbalance valve lifting hydraulicsystem reaches more than90%.After the application of AMESim, the two hydraulic systems of the cranetruck are analyzed and simulated, and the lifting load spectrum of the liftinghydraulic system for the crane truck is studied. And two load spectrums of thecrane truck are determined: standard load spectrum and the assumptive normaldistribution. When the load distributes as the standard load spectrum, this paperpartly calculates the pump’s output pressure of the ordinary balance valve liftinghydraulic system and the new load－sensing counterbalance valve liftinghydraulic system under the load going down. Then the paper compares, analyzesand calculates the output pressure of the two hydraulic systems. By the sametime, when the load distributes as the assumptive normal distribution, afterdrawing out the pump’s output pressure, the data is compared, analyzed andcalculated. With the two load spectrums, quantitatively, the energy consumptionof the two hydraulic systems is analyzed. And the conclusion is consistent withthe analysis and simulation of the AMESim. The final calculative resultsconfirms the fact: applying the new load－sensing counterbalance valve in thelifting hydraulic system of the crane truck can reduce the system’s energy lossand achieve the system’s energy saving.