A hydraulic system of an excavator and its stick

Abstract

The invention provides an excavator and a hydraulic system for the bucket arm of the excavator. The hydraulic system comprises a bucket arm cylinder, which comprises an armless chamber and an arm chamber; a first oil way, which is communicated with the armless chamber; a second oil way, which is communicated with the arm chamber; a third oil way, which is connected with the second oil way; and a bucket arm control valve, which is used for enabling an oil supply way to be communicated with the first oil way when a soil excavation signal is received and enabling the oil supply way to be communicated with the third oil way and an oil return way to be communicated with the first oil way when a soil dumping signal is received. A reversing valve is arranged between the third oil way and the second oil way. The second oil way is connected with a hydraulic control valve. When the soil excavation signal is received, the hydraulic control valve is arranged at a conducted position to conduct the reversing valve and therefore the second oil way is communicated with the oil return way; and when the oil dumping signal is received, the hydraulic control valve is arranged at a shut-off position to shut off the reversing valve and therefore hydraulic oil can flow in one way only from the third oil way to the second oil way. The excavator and the hydraulic system have the advantages that the position of the bucket arm can be kept reliably during soil dumping operation and the dangers caused by accidental sinking of the bucket arm can be avoided simply and effectively.

Description

technical field [0001] The invention relates to construction machinery, in particular to an excavator and a hydraulic system of a stick thereof. Background technique [0002] Excavator is a kind of construction machinery, which is widely used in construction, road, mine and other engineering fields, and its main function is to carry out excavation operations. [0003] figure 1 It is an outline structure diagram of an excavator in the prior art, as shown in the figure, the working part of the excavator mainly includes a bucket (bucket) 110, a stick (arm) 120 and a boom (boom) 130, and these working parts , are driven by hydraulic cylinders. Wherein, the stick 120 is driven by a stick cylinder 121 . [0004] figure 2 Schematic diagram of dumping operation for an existing excavator; e.g. figure 2 As shown, in the soil dumping process when the bucket 110 is overturned, in order to prevent the excavator from touching the earth moving truck, the position of the stick 120 ne...

AI Technical Summary

Problems solved by technology

At this time, the arm 120 is stretched out to the maximum, and the load combination composed of the weight of the bucket, the weight of the load on the bucket, and the weight of the arm itself has the greatest effect on the arm cylinder 121. The high-pressure oil stops entering the rod cavity, and under the action of this load combination, there will be a dangerous situation where the stick 120 will sink uncontrollably

Images