CN-122009978-A - Valve-controlled energy-saving hydraulic system of crane

Abstract

The invention relates to a valve-controlled energy-saving hydraulic system of a crane, wherein a first oil pump and an oil tank are respectively connected with a first working oil port through a first reversing valve, a second working oil port is connected with the oil tank, and a second oil pump is connected with the second working oil port. When the heavy object is required to be lowered, the flow of hydraulic oil is changed by using the first reversing valve, hydraulic oil is discharged from the first working oil port which is originally filled with oil, and meanwhile, the second working oil port is complemented by the second oil pump to avoid sucking air, so that the executing unit can work reversely in the lowering process, the friction force of the system is overcome by utilizing the heavy load, the acceleration required by lowering is provided, and the heavy object can be automatically lowered safely and reliably by means of self gravity, thereby being beneficial to improving the energy utilization efficiency and lowering the heating of the system.

Inventors

• YE JIANHUA
• YANG CHUNYU
• MA BANGGUO
• Sun Gujin
• XU WEI
• LI CHAOYANG
• HUANG HAORONG
• HUANG YANWEN

Assignees

• 中国海洋工程装备技术发展有限公司

Dates

Publication Date

20260512

Application Date

20260408

Claims (10)

1. 1. A valve controlled energy efficient hydraulic system for a crane, comprising: A power unit, a control unit, an execution unit (9) and an auxiliary unit; The power unit comprises a first oil pump (12) and a second oil pump (11), the control unit comprises a first reversing valve (62), the execution unit (9) comprises a first working oil port and a second working oil port, and the auxiliary unit comprises an oil tank; The first oil pump (12) and the oil tank are respectively connected with the first working oil port through the first reversing valve (62) and are used for feeding oil from the first working oil port when a weight rises and returning oil from the first working oil port when the weight falls, the second working oil port is connected with the oil tank and is used for returning oil from the second working oil port when the weight rises, and the second oil pump (11) is connected with the second working oil port and is used for supplementing oil from the second working oil port when the weight falls.
2. 2. The hydraulic system according to claim 1, wherein the auxiliary unit comprises a first oil path and a second oil path, the first reversing valve (62) is a three-way valve, the first oil path is respectively connected with the first working oil port and the working oil port of the first reversing valve (62), the second oil path is connected with the second working oil port and the oil tank, and the first oil pump (12) and the oil tank are respectively connected with the oil inlet and the oil return port of the first reversing valve (62).
3. 3. The hydraulic system according to claim 2, wherein the second oil passage is provided with a solenoid valve and a relief valve in this order in a direction extending from the second working oil port to the oil tank.
4. 4. The hydraulic system according to claim 1, characterized in that the auxiliary unit comprises a first oil supplementing branch, which connects the second oil pump (11) and the second working oil port, respectively.
5. 5. The hydraulic system according to claim 4, characterized in that the auxiliary unit comprises a second oil supplementing branch, which is connected to the second oil pump (11) and the first working oil port, respectively, for supplementing oil from the first working oil port when the weight is raised.
6. 6. The hydraulic system of claim 4, wherein the auxiliary unit includes an oil replenishment bypass connecting the oil tank and the second working port, the oil replenishment bypass being provided with a check valve for replenishing oil from the second working port when the weight falls under its own weight.
7. 7. The hydraulic system according to claim 1, further comprising a detection unit for acquiring lifting load data, wherein the control unit further comprises a processor and a second reversing valve (61), wherein the processor is respectively connected with the detection unit, the first reversing valve (62) and the second reversing valve (61) and is used for conducting the first reversing valve (62) or the second reversing valve (61) according to the comparison result of the lifting load data and a set value.
8. 8. The hydraulic system according to claim 7, wherein the second reversing valve (61) is a four-way valve, the first working port and the second working port are respectively connected to the working port of the second reversing valve (61), and the first oil pump (12) and the oil tank are respectively connected to the oil inlet and the oil return port of the second reversing valve (61).
9. 9. The hydraulic system according to claim 1, further comprising a detection unit for acquiring lifting load data, wherein the first oil pump (12) is a constant pressure variable pump, the execution unit (9) is a lifting variable motor, and the control unit further comprises a processor connected to the detection unit, the first oil pump (12) and the execution unit (9) respectively, for adjusting output flow and motor displacement according to the lifting load data.
10. 10. The hydraulic system according to claim 7, characterized in that the first reversing valve (62) and the second reversing valve (61) are electro-hydraulic proportional reversing valves.

Description

Valve-controlled energy-saving hydraulic system of crane Technical Field The invention relates to the technical field of lifting equipment, in particular to a valve control energy-saving hydraulic system of a crane. Background The crane for offshore operation is a special crane device designed for marine environment, and is usually installed on a ship or a floating platform for carrying out the tasks of cargo transportation between ships, offshore replenishment, underwater equipment throwing and recovery, and the like. Unlike land cranes, it is necessary to cope with complex environmental loads such as wind, waves, currents, etc., and the great challenges of hull sway. The problem of low energy utilization rate is very prominent in the hydraulic crane system in the related art, especially in heavy load operation. The core reason is that the system generally adopts a mode of 'throttling and speed regulating' to control the descending speed of the heavy objects. The process needs to throttle the hydraulic oil through a valve, and converts huge gravitational potential energy generated when a heavy object descends into heat energy and dissipates the heat energy. This not only results in valuable energy being wasted but also results in a steep increase in the oil temperature of the overall hydraulic system. Too high an oil temperature accelerates the aging of the hydraulic oil and the seals, increasing the risk of system leakage and thus reducing the service life of the hydraulic components. Accordingly, there is a need to develop a novel valve-controlled energy-saving hydraulic system for a crane to improve the above-mentioned problems in the related art. Disclosure of Invention The invention aims to provide a valve-control energy-saving hydraulic system of a crane, which can effectively utilize gravitational potential energy of heavy objects falling under heavy load, improve energy utilization efficiency and reduce system heating. The aim of the invention can be achieved by the following technical scheme: The invention provides a valve control energy-saving hydraulic system of a crane, which comprises: the device comprises a power unit, a control unit, an execution unit and an auxiliary unit; The power unit comprises a first oil pump and a second oil pump, the control unit comprises a first reversing valve, the execution unit comprises a first working oil port and a second working oil port, and the auxiliary unit comprises an oil tank. The first oil pump and the oil tank are respectively connected with the first working oil port through the first reversing valve and used for feeding oil from the first working oil port when the weight rises and returning oil from the first working oil port when the weight falls, the second working oil port is connected with the oil tank and used for returning oil from the second working oil port when the weight rises, and the second oil pump is connected with the second working oil port and used for supplementing oil from the second working oil port when the weight falls. The auxiliary unit further comprises a first oil way and a second oil way, the first reversing valve is a three-way valve, the first oil way is connected with the first working oil port and the working oil port of the first reversing valve respectively, the second oil way is connected with the second working oil port and the oil tank, and the first oil pump and the oil tank are connected with the oil inlet and the oil return port of the first reversing valve respectively. Further, the second oil path is provided with an electromagnetic valve and an overflow valve in sequence in the direction from the second working oil port to the extending direction of the oil tank. Further, the auxiliary unit comprises a first oil supplementing branch, and the first oil supplementing branch is respectively connected with the second oil pump and the second working oil port. Further, the auxiliary unit comprises a second oil supplementing branch, and the second oil supplementing branch is respectively connected with the second oil pump and the first working oil port and is used for supplementing oil from the first working oil port when the weight rises. Further, the auxiliary unit comprises an oil supplementing bypass, the oil supplementing bypass is connected with the oil tank and the second working oil port, and a one-way valve is arranged on the oil supplementing bypass and used for supplementing oil from the second working oil port when the dead weight of the heavy object descends. The control unit further comprises a processor and a second reversing valve, wherein the processor is respectively connected with the detection unit, the first reversing valve and the second reversing valve and is used for conducting the first reversing valve or the second reversing valve according to the comparison result of the lifting load data and the set value. Further, the second reversing valve is a four-way valve, the first working oil p