The Research Of Force For Folded Hydraulic Shovel

This paper takes up on intensive study about the folded hydraulic shovel's manipulator's structure, motion and digging force in four work conditions, at the mean time some improved methods are put forward.In motion analysis, for the components can be intuitively expressed by plural, and the dot's motion expression is related with the position expression, the plural is widely used in this part. Later the manipulator's motion in the four work conditions is full-scale analyzed and the algebraic expression is established completely. Especially as for the folded mechanism, the bulk motion gets difficult.In digging force calculating, a novel method based on the theorem of kinetic energy is presented. By this method the digging process is described by energy flow, and the digging resistance is regarded as absorbing the system's energy. By this way, the maximum dynamic digging force's mathematical model is presented. In this model every force's power appears independently, so various kinds of digging force from these forces can be calculated.The digging force is calculated by both uni-directional and global calculating flow. The theorem of kinetic energy method and moment equilibrium is both calculated by the uni-directional flow. In the condition of hydro-cylinder floating, the manipulator is not in a static equilibrium, so the latter method is not meet, however the former method is in point in this condition. The calculating results show that former method's result is larger than that of the latter one, and more identical with the data provided by abroad. So the theorem of kinetic energy method is a method of universal significance.The global calculating flow is similar with digging chart, by altering the fluid cylinders'length recurrently, so the digging force can be calculated at all posture.In order to show the digging performance in a stereoscopic way, the dot matrix chart is prompt on the base of the idea of hydro- cylinder coordinate, the cylinder space, and the digging space. By the chart not only the global digging force can be showed, but also how the work is restrained in the digging space appears obviously. So the chart is helpful in grasping the overall situation in the digging space.