Hydraulic control system and excavator

Abstract

The invention discloses a hydraulic control system and an excavator. The hydraulic control system comprises a main valve; the main valve comprises a pressure oil inlet, an oil discharge part, a first work oil way used for supplying oil and returning oil for a first work cavity of a first executing element, and a second work oil way used for supplying oil and returning oil for a second work cavity of the first executing element. The hydraulic control system further comprises an oil returning control valve used for controlling oil return of the second work cavity; the oil returning control valve comprises a backpressure adjusting valve which is provided with a throttling device, a first oil port and a second oil port; the first oil port is connected with the second work oil way; the second oil port is connected with the second work cavity through a connection work oil way; the backpressure adjusting valve is provided with a first work position; and at the first work position of the backpressure adjusting valve, the first oil port and the second oil port of the backpressure adjusting valve are communicated through the throttling device. According to hydraulic control system, the oil returning backpressure of the second work cavity of the first executing element can be increased as required, and regeneration of the pressure oil of the second work oil cavity can be promoted.

Description

technical field [0001] The invention relates to the field of engineering machinery, in particular to a hydraulic control system and an excavator. Background technique [0002] The excavator mainly includes getting off the car, slewing device and working device. The working device of the excavator includes a boom, a stick, and a bucket. The excavator also includes a hydraulic control system for controlling each working device. The hydraulic control system realizes the control of the boom, stick, bucket and other working devices by controlling the actuators such as the boom cylinder, the stick cylinder and the bucket cylinder. In the hydraulic control system of the excavator, the pressure oil output by the main pump acts on each actuator through each working joint of the main valve to realize the compound action or individual action of each working device. [0003] Excavators have working conditions such as continuous excavation and leveling operations, and different workin...

AI Technical Summary

Problems solved by technology

[0007] 1. The stick regenerative back pressure valve 10' is only used to increase the regenerative back pressure of the stick, has no other function, and the utilization rate is low, which increases the complexity of the main valve structure;

[0008] 2. During the excavation operation of the excavator, when the pressure in the large cavity of the stick is greater than the pressure in the small cavity of the stick, the stick cannot be regenerated. At this time, the back pressure valve 10' does not have the regeneration function, but it will increase the oil return pressure loss of the stick;

[0009] 3. When the excavator is digging, the back pressure valve 10' increases the oil return back pressure of the stick, which reduces the digging force of the stick and affects the digging efficiency;

[0010] 4. Since the size of the damping hole 3' is fixed, it is necessary to select different sizes of damping holes for models of different tonnages, and the versatility is poor;

[0011] 5. The determination of the size of the damping hole 3' needs to be verified by replacing the damping hole 3' of a different size for the whole machine debugging and verification, which prolongs the research and development cycle of the whole machine and increases the research and development cost;

[0012] 6. When working on non-level ground, the damping hole 3' will increase the back pressure of the main pump oil circuit, resulting in the first main pump supplying oil to the first oil supply port P1 and the second main pump supplying oil to the second oil supply port P2. The outlet pressures of the two main pumps are inconsistent, resulting in an unbalanced power regulation of the two pumps and increasing the difficulty of system power regulation;

[0013] 7. When the excavator is working, the damping hole 3' will increase the pressure loss of the system circuit, increase the heat dissipation of the system, and cause power waste, especially when excavating, the power waste is the most serious

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