BULLDOZING HYDRAULIC SYSTEM WITH BULLDOZING BLADE FLOATING FUNCTION AND EXCAVATOR

A bulldozing hydraulic system with a bulldozing blade floating function and an excavator. The bulldozing hydraulic system comprises a load-sensitive pump (1), a bulldozing blade oil cylinder (3), a load-sensitive valve (2), and a station switching mechanism. The load-sensitive valve (2) comprises a four-position reversing valve (23). When the four-position reversing valve (23) is at a first station, oil enters a small-cavity A port of the bulldozing blade oil cylinder (3) and returns from a large-cavity B port, and a bulldozing blade is controlled to ascend; when the four-position reversing valve (23) is at a second station, oil enters the large-cavity B port of the bulldozing blade oil cylinder (3) and returns from the small-cavity A port, and the bulldozing blade is controlled to descend; and when the four-position reversing valve (23) is at a third station, the small-cavity A port and the large-cavity B port of the bulldozing blade oil cylinder (3) are communicated with an oil tank (7), such that the bulldozing blade floating function is realized. The excavator provided with the bulldozing hydraulic system solves the problem that an existing excavator bulldozing shovel does not have a floating function, and a reversing valve integration mode is adopted, a high-voltage electromagnetic reversing valve hydraulic element does not need to be externally connected between a reversing valve and a bulldozing blade oil cylinder, and due to an element integration mode, space is saved, and cost is reduced.