Small Hydraulic Excavator Dipper Stick And Bucket Circuit Analysis And Controllability

Excavator is a machine which has multiple implementing parts with complicated working situation and high energy consumption. In the course of operations, in order to achieve the objective of high efficiency and energy saving, all executive parts need to have good control performance and be easily operated. As main executive parts of excavator, bucket and arm are very important in various working circle. However, in the actual course of operations, there are many bad phenomena such as the movement is too fast or too slow, dithering or standstill, which significantly affected the efficiency of work, and increased energy-consumption. So it is necessary to find a reasonable solution to solve these problems.Multi-control valve as one of the key components of the hydraulic system of excavator that determines the oil supply route and mode which hydraulic pump to the hydraulic components, the distribution of flow and how to achieve compound action in course of hydraulic components' movements, and directly affects parts' characteristic of action. The hydraulic system of mini-hydraulic excavator universally apply throttling three-potential six-way multi-control valve. The valve has various shapes and sizes of throttling orifice on valve spool. With the movement of valve spool, each throttling orifice forms different flow area, so as to achieve the goal of flow distribution to each implementing part, which controls the work speed. Therefore, the shapes and sizes of multi-control valve spool throttling orifice need to be designed rationally to form suitable flow area and improve the continuity of action. Accordingly complete work loop efficiently and economically.The article analyzed the characteristic of throttling speed control circuit, concluded how the throttling orifice match to obtain the perfect function and which kind of throttling speed control circuit can gained circuit's the best performance. Based on the analysis of features of working condition, hydraulic system and calculation of flow area of multi-control valve's throttling orifice, using system simulation software AMESim set up simulating model of the bucket and arm. Compared the simulating data with testing data, the accuracy of simulating model was verified. Then analyzed the actual problem of small hydraulic excavator and determined the amendment project. In the simulation model loaded parameters of flow area attained reasonable flow and pressure curves, then the flow area is determined. The flow area confirms the shape and size of throttling orifice. After the installation and testing, the result showed that amendment of throttling orifice is reasonable. Finally the issues are resolved.