Quality Of Hose Assembly Of Bulldozer Hydraulic System

Bulldozer is one of the most widely used products in construction machinery.With the rapid development of construction machinery in recent years,the amount of bulldozers has increased exponentially.In order to better meet customer service requirements,in recent years,bulldozers manufacturers put forward the concept of"one year no time limit" service concept,which requires higher quality of bulldozers,especially for hose assemblies as vulnerable parts.By analyzing the cause of the failure of the rubber assembly of the bulldozer working device,this paper proposes the improvement plan,which is of great practical significance for improving the reliability of the bulldozer hose assembly.According to the fault data of the hydraulic system of bulldozer hose assembly for bulldozer hydraulic system assembly statistics of three key factors:pressing fault leakage,cracking and burst out glue,accounted for 60%of total failure rate,analysis of three kinds of hose assembly fault factors,provide the basis for fault analysis.The factors affecting the quality of the hose assembly are expounded from four aspects of human,machine,material and method,and the corresponding technological requirements,measures and means are put forward.The cracking of the rubber tube caused by the replacement of raw materials was tested by the low temperature resistance test.For hose burst,the pressure of hose assembly during bending and twisting is tested.The results show that the burst pressure is reduced by 20%when the twist value of hose assembly is 5 degrees.The reason that the material can not meet the use requirement is analyzed by the method of exclusion.By using ABAQUS finite element analysis method,the simulation of 4SP-12 and 2SN two kinds of hose assembly,and the withholding amount of fastening pressure showed that determined in the same amount of withhold,4SP hose buckle pressure is greater than the same 2SN hose,pressure rating,4SP tube can withstand greater impact pressure.The results of finite element simulation 4SP hose assembly based on pulse swaging assembly test and engine test respectively.The results showed that:in 1.33 times the working pressure of the 4SP pulse tube up to 674000 times the number of 2SN reached more than 3 times the number of pulse tube test machine;average life is above 3500h,the failure rate is reduced to 0.1 ‰.