| Hydraulic excavator is a versatile production of construction machinery, including the conventional digging job, firmed up ground, crushed rock, lifting heavy item, crushing, piling, drilling and many other functions by replaced the device. It’s widely used in the construction of water conservancy facilities, road construction, building construction, port construction, defense, engineering, earth and stone construction and earthquake rescue, known as’The king of construction machinery’Working device is one of the main devices of the hydraulic excavator, whether the design of structural is reasonable or not will directly affect the overall performance and service life of the machine, the design of work equipment has always been attacked much attention of many manufacturers. Because of the relatively poor working environment operating conditions and variations working attitude and the working device boring more dynamic loads, structure of the excavator will be ruptured in local or even the entire after a certain time in the service. But the working device is a type of box structure which is made of the steel plates of different thickness and shapes. Traditional manual calculation method for this complex structure can only simplify the calculation, and any of the stress state of the machine can not be got. In view of this, the following research were made by45t hydraulic excavators of a company in this article.(1) According to the structure and principle of the hydraulic system of hydraulic excavator, the test scheme of the structure stress and pressure and displacement of hydraulic cylinder were made, key position’s stress data of the structure and the date of hydraulic pressure and displacement were obtained.(2) The finite element model of excavator for structural finite element analysis were made with the finite element analysis software ANSYS, and the simulated results were compared with the test results of corresponding working conditions and verified, the stress level of structural in the dangerous attitude was calculated at last.(3) The local stiffness of the components of structural whose stress distribution is unreasonable was researched (including stress concentration, uneven distribution of local structural stress), and the structural was improved to relax the stress distribution.(4) The weld which influences the fatigue life and structural strength in different length height ratio, different width ratio and different structure type was researched. Finally a more ideal structure was obtained. |
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