CN-121976978-A - Excavator energy recovery system based on auxiliary oil supplementing of energy accumulator

CN121976978ACN 121976978 ACN121976978 ACN 121976978ACN-121976978-A

Abstract

An energy recovery system of an excavator based on auxiliary oil supplement of an energy accumulator relates to the technical field of excavator driving. The system comprises a hydraulic cylinder, a three-position four-way electromagnetic valve, a hydraulic pump, a motor connected with the hydraulic pump in a transmission way, a first two-position two-way electromagnetic valve connected with an oil return port T of the three-position four-way electromagnetic valve, a second two-position two-way electromagnetic valve connected between the first two-position two-way electromagnetic valve and the hydraulic oil tank, a hydraulic accumulator connected with the first two-position two-way electromagnetic valve, a third two-position two-way electromagnetic valve connected with the hydraulic accumulator and a fourth two-position two-way electromagnetic valve connected with the hydraulic accumulator. The oil inlet of the hydraulic pump is connected with the hydraulic oil tank and the fourth two-position two-way electromagnetic valve. The oil outlet A and the oil outlet B of the three-position four-way electromagnetic valve are respectively connected with a rod cavity and a rodless cavity of the hydraulic cylinder, and the oil inlet P is connected with the oil outlet of the hydraulic pump and the third two-position two-way electromagnetic valve. The oil cylinder stores energy through the hydraulic energy accumulator when retracting. When the oil cylinder stretches out, oil is replenished through the hydraulic accumulator.

Inventors

LIN YICHENG
FU XINRONG
CHEN CHENG
LIN TIANLIANG
CHEN QIHUAI
MIAO CHENG
HUANG TENGCHAO
HE PENG
QI JIA
WU YIFAN

Assignees

华侨大学

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (9)

1. The excavator energy recovery system based on auxiliary oil supplement of the energy accumulator is characterized by comprising a hydraulic oil cylinder, a three-position four-way electromagnetic valve, a hydraulic pump, a motor connected with the hydraulic pump in a transmission way, a first two-position two-way electromagnetic valve connected with an oil return port T of the three-position four-way electromagnetic valve through a pipeline, a second two-position two-way electromagnetic valve connected between the first two-position two-way electromagnetic valve and the hydraulic oil tank through a pipeline, a hydraulic energy accumulator connected with the first two-position two-way electromagnetic valve through a pipeline, and a third two-position two-way electromagnetic valve and a fourth two-position two-way electromagnetic valve connected with the hydraulic energy accumulator through a pipeline, wherein an oil inlet pipeline of the hydraulic pump is connected with the hydraulic oil tank and the fourth two-position two-way electromagnetic valve through an oil outlet A and an oil outlet B of the three-position four-way electromagnetic valve are respectively connected with a rod cavity and a rodless cavity of the hydraulic oil cylinder through pipelines, and an oil inlet P pipeline is connected with the oil outlet of the hydraulic pump and the third two-position two-way electromagnetic valve; When the hydraulic cylinder stretches out, the motor drives the hydraulic pump to supply oil to the rodless cavity, and if the starting time of the hydraulic pump does not exceed the first preset time, the first two-position two-way electromagnetic valve and the third two-position two-way electromagnetic valve are conducted; When the hydraulic cylinder is retracted, the motor drives the hydraulic pump to supply oil to the rod cavity, if Zyr is larger than Z, the first two-position two-way electromagnetic valve is conducted, if Zyr is smaller than Z, the first two-position two-way electromagnetic valve and the second two-position two-way electromagnetic valve are conducted, wherein Zyr is the pressure of the rodless cavity of the hydraulic cylinder, and the pressure in the Z hydraulic accumulator is higher than that of the hydraulic cylinder.
2. The energy recovery system for an excavator based on accumulator assisted refill of claim 1 wherein the step of extending the hydraulic ram comprises: The motor drives the hydraulic pump to pump oil and enables the control end a of the three-position four-way electromagnetic valve to be electrified, the oil inlet P is communicated with the oil outlet A, and the oil outlet B is communicated with the oil return port T, so that the hydraulic pump can feed oil to the rodless cavity of the hydraulic oil cylinder and realize oil return of the rod-containing cavity of the hydraulic oil cylinder; Judging whether the starting operation time of the hydraulic pump exceeds a first preset time; When the starting time of the hydraulic pump is judged not to exceed the first preset time, the first two-position two-way electromagnetic valve and the third two-position two-way electromagnetic valve are conducted, so that hydraulic oil of the hydraulic energy accumulator is fed to a rodless cavity of the hydraulic oil cylinder through the third two-position two-way electromagnetic valve, return oil of a rod cavity of the hydraulic oil cylinder enters the third two-position two-way electromagnetic valve through the three-position four-way electromagnetic valve and the first two-position two-way electromagnetic valve, and the frequency response time of a hydraulic system is reduced; When the starting time of the hydraulic pump exceeds the first preset time, the first two-position two-way electromagnetic valve, the second two-position two-way electromagnetic valve and the fourth two-position two-way electromagnetic valve are conducted, so that hydraulic oil of the hydraulic accumulator can be fed to an oil inlet of the hydraulic pump through the fourth two-position two-way electromagnetic valve, and auxiliary oil supplementing is achieved.
3. The energy recovery system for an excavator based on accumulator assisted refill of claim 2 wherein the step of retracting the hydraulic ram comprises: The motor drives the hydraulic pump to pump oil and enables the control end B of the three-position four-way electromagnetic valve to be electrified, the oil inlet P is communicated with the oil outlet B, and the oil outlet A is communicated with the oil return port T, so that the hydraulic pump can feed oil to the rod cavity of the hydraulic oil cylinder and realize the rodless cavity oil return of the hydraulic oil cylinder; Acquiring the pressure Zyr of a rodless cavity of the hydraulic cylinder and comparing the pressure Z in the hydraulic accumulator; When Zyr > Z is judged, judging whether the pressure Z of the hydraulic accumulator is smaller than a pressure threshold value, if yes, switching on a first two-position two-way electromagnetic valve so that hydraulic oil without a rod cavity of the hydraulic oil cylinder can flow to the hydraulic accumulator for energy storage through the first two-position two-way electromagnetic valve and a third one-way valve; When Zyr is not less than Z or when Z is not less than the pressure threshold value, the first two-position two-way electromagnetic valve and the second two-position two-way electromagnetic valve are conducted, so that hydraulic oil in the rodless cavity of the hydraulic oil cylinder flows to the hydraulic oil tank through the first two-position two-way electromagnetic valve and the second two-position two-way electromagnetic valve.
4. The energy recovery system of the excavator based on auxiliary oil supplement of the energy accumulator according to claim 1, wherein the three-position four-way solenoid valve comprises an oil inlet P, an oil outlet A, an oil outlet B and an oil return port T; the three-position four-way electromagnetic valve is structured in such a way that when the control end a is powered on, the oil inlet P is communicated with the oil outlet A, the oil return port T is communicated with the oil outlet B, and when the control end B is powered on, the oil inlet P is communicated with the oil outlet B, the oil return port T is communicated with the oil outlet A, and when the three-position four-way electromagnetic valve is positioned at the middle position, all the oil ports are not communicated with each other; The output shaft of the motor is connected with the hydraulic pump in a transmission way and is used for driving the hydraulic pump to work; The oil return port T of the three-position four-way electromagnetic valve is connected with the inlet of the first two-position two-way electromagnetic valve, the outlet of the first two-position two-way electromagnetic valve is connected with the hydraulic port of the hydraulic accumulator and the inlet of the second two-position two-way electromagnetic valve, and the outlet of the second two-position two-way electromagnetic valve is connected with the hydraulic oil tank; The hydraulic port of the hydraulic accumulator is connected with the inlets of the third two-position two-way electromagnetic valve and the fourth two-position two-way electromagnetic valve, the outlet of the third two-position two-way electromagnetic valve is connected with the oil outlet of the hydraulic pump, and the outlet of the fourth two-position two-way electromagnetic valve is connected with the oil inlet of the hydraulic pump.
5. The energy recovery system of an excavator based on accumulator assisted recharge of any one of claims 1 to 4 further comprising a first check valve and a second check valve; The oil outlet of the first one-way valve is connected with the oil inlet of the hydraulic pump; the oil inlet of the second one-way valve is connected with the oil outlet of the hydraulic pump, and the oil outlet of the second one-way valve is connected with the oil inlet P of the three-position four-way electromagnetic valve.
6. The energy recovery system of an excavator based on accumulator assisted recharge of claim 5 further comprising a first relief valve and a second relief valve; the oil inlet pipeline of the first overflow valve is connected with the oil outlet of the second one-way valve; the oil inlet of the second overflow valve is connected with the hydraulic port of the hydraulic accumulator, and the oil outlet pipeline of the second overflow valve is connected with the hydraulic oil tank.
7. The energy recovery system of an excavator based on auxiliary oil replenishment of any one of claims 1 to 4 further comprising a third one way valve having an oil inlet coupled to the outlet of the first two-way solenoid valve and to the inlet of the second two-way solenoid valve and an oil outlet coupled to the inlet of the third two-way solenoid valve, to the inlet of the fourth two-way solenoid valve and to the hydraulic accumulator hydraulic port.
8. The energy recovery system of an excavator based on accumulator assisted recharge of any one of claims 1 to 4 further comprising a fourth check valve and a fifth check valve; an oil inlet of the fourth one-way valve is connected with an outlet of the third two-position two-way electromagnetic valve, and an oil outlet of the fourth one-way valve is connected with an oil inlet P of the three-position four-way electromagnetic valve; an oil inlet of the fifth one-way valve is connected with an outlet of the fourth two-position two-way electromagnetic valve, and an oil outlet of the fifth one-way valve is connected with an oil inlet of the hydraulic pump.
9. The energy recovery system of an excavator based on auxiliary oil replenishment of any one of claims 1 to 4 wherein the first two-position two-way solenoid valve, the second two-position two-way solenoid valve, the third two-position two-way solenoid valve and the fourth two-position two-way solenoid valve are each of a vent-less construction; When the hydraulic oil cylinder stretches out, closing all electromagnetic valves after the hydraulic oil cylinder stretches out to the proper position; The step of retracting the hydraulic cylinder includes closing all solenoid valves after the cylinder is retracted into position.

Description

Excavator energy recovery system based on auxiliary oil supplementing of energy accumulator Technical Field The invention relates to the technical field of excavator driving, in particular to an excavator energy recovery system based on auxiliary oil supplementing of an energy accumulator. Background In the field of construction machinery, particularly in the fields of earthwork, mines, road construction and the like, an excavator is a vital device. When fine operations such as land leveling and slope trimming are performed, extremely high requirements are placed on the response speed and control accuracy of the hydraulic system. However, when the hydraulic pump is started, the pressure of the outlet needs to be re-established, and the dead zone exists in the response of the output flow of the pump to the input rotation speed due to the internal leakage of the hydraulic pump and the compressibility of the oil, so that the steady state error of the system is increased, obvious response delay is caused, and the accuracy and the efficiency of the operation are seriously affected. In addition, the hydraulic pump of the core power element of the excavator is easy to generate negative pressure at the oil suction port under the working condition of high speed operation, and causes 'suction and cavitation'. The problem not only can lead to hydraulic oil atomization, reduce the transmission performance and stability of the system, but also can cause abnormal wear and even damage of equipment due to air suction when serious, and directly threaten the reliability and service life of the equipment. The problem is that the traditional excavator hydraulic system has the inherent defects of high energy consumption and low energy utilization rate for a long time. In conditions such as boom down, a large amount of hydraulic energy is dissipated in the form of a throttle or overflow, and is not effectively recovered and reused. This energy waste not only increases the running cost of the equipment, but also is contrary to the current trend of the engineering machinery for green, energy saving and sustainable development. Therefore, how to realize high frequency response of the system, avoid damage to key elements and efficiently recycle energy has become a technical problem to be solved. Disclosure of Invention The invention provides an energy recovery system of an excavator based on auxiliary oil supplement of an energy accumulator, and aims to improve at least one of the technical problems. In order to solve the technical problems, the invention provides an energy recovery system of an excavator based on auxiliary oil supplement of an energy accumulator, which comprises a hydraulic cylinder, a three-position four-way electromagnetic valve, a hydraulic pump, a motor connected with the hydraulic pump in a transmission way, a first two-position two-way electromagnetic valve connected with an oil return port T of the three-position four-way electromagnetic valve through a pipeline, a second two-position two-way electromagnetic valve connected between the first two-position two-way electromagnetic valve and a hydraulic oil tank through a pipeline, a hydraulic energy accumulator connected with the first two-position two-way electromagnetic valve through a pipeline, a third two-position two-way electromagnetic valve connected with the hydraulic energy accumulator through a pipeline and a fourth two-position two-way electromagnetic valve. The oil inlet pipeline of the hydraulic pump is connected with the hydraulic oil tank and the fourth two-position two-way electromagnetic valve. The oil outlet A and the oil outlet B of the three-position four-way electromagnetic valve are respectively connected with a rod cavity and a rodless cavity of the hydraulic cylinder in a pipeline way, and the oil inlet P is connected with the oil outlet of the hydraulic pump and the third two-position two-way electromagnetic valve in a pipeline way. When the hydraulic cylinder extends out, the motor drives the hydraulic pump to supply oil to the rodless cavity. If the starting time of the hydraulic pump does not exceed the first preset time, the first two-position two-way electromagnetic valve and the third two-position two-way electromagnetic valve are conducted. If the starting time of the hydraulic pump exceeds the first preset time, the first two-position two-way electromagnetic valve, the second two-position two-way electromagnetic valve and the fourth two-position two-way electromagnetic valve are conducted. When the hydraulic cylinder retracts, the motor drives the hydraulic pump to supply oil to the rod cavity. If Zyr > Z, the first two-position two-way solenoid valve is turned on. If Zyr is less than or equal to Z, the first two-position two-way electromagnetic valve and the second two-position two-way electromagnetic valve are conducted. Wherein Zyr is the pressure of the rodless cavity of the hydraulic cylinder. Z is the pressure in the hydra