CN-121992843-A - Excavator bucket rod energy recovery system based on pump motor and control method thereof

CN121992843ACN 121992843 ACN121992843 ACN 121992843ACN-121992843-A

Abstract

An excavator bucket rod energy recovery system based on a pump motor and a control method thereof relate to the technical field of excavators. The system comprises a hydraulic oil cylinder, a reversible hydraulic pump motor, an electric power generation integrated machine, a three-position four-way electromagnetic valve provided with a first oil inlet, a first oil outlet, a second oil outlet and a first oil return port, a first hydraulic pump connected to the hydraulic oil tank, a first check valve communicated with the oil outlet of the hydraulic pump and the first oil inlet, a motor, a third check valve communicated with the first oil return port and a second pipeline interface of the reversible hydraulic pump motor, and a first two-position two-way electromagnetic valve communicated with a pipeline between the third check valve and the second pipeline interface to the first oil inlet. The first pipeline interface of the reversible hydraulic pump motor is respectively connected with the hydraulic oil tank through a fourth one-way valve and a third two-position two-way electromagnetic valve, and is connected with the first oil return port through a second two-position two-way electromagnetic valve pipeline. The first oil outlet pipeline is connected to the rodless cavity of the hydraulic oil cylinder, and the second oil outlet is connected to the rod cavity through a pipeline.

Inventors

CHEN CHENG
XU YINGYING
LIN TIANLIANG
HUANG TENGCHAO
MIAO CHENG
GUO LIZHONG
CHEN JUNYI
LIU JIEXIN
Yao Zhaoyuan

Assignees

华侨大学

Dates

Publication Date: 20260508
Application Date: 20260409

Claims (10)

1. The excavator bucket rod energy recovery system based on the pump motor is characterized by comprising a hydraulic oil cylinder, a reversible hydraulic pump motor, an electric power generation integrated machine which is in transmission connection with the reversible hydraulic pump motor, a three-position four-way electromagnetic valve which is provided with a first oil inlet, a first oil outlet, a second oil outlet and a first oil return port, a first hydraulic pump with a hydraulic pump oil inlet connected to the hydraulic oil tank, a first check valve which is communicated with the hydraulic pump oil outlet and the first oil inlet, a motor which is in transmission connection with the first hydraulic pump, a third check valve which is communicated with the first oil return port and a second pipeline interface of the reversible hydraulic pump motor, and a first two-position two-way electromagnetic valve which is used for communicating a pipeline between the third check valve and the second pipeline interface to the first oil inlet; The first pipeline interface of the reversible hydraulic pump motor is respectively connected with the hydraulic oil tank through a fourth one-way valve and a third two-position two-way electromagnetic valve, and is connected with the first oil return port through a second two-position two-way electromagnetic valve pipeline, the first oil outlet pipeline is connected with a rodless cavity of the hydraulic oil cylinder, and the second oil outlet is connected with the rod cavity through a pipeline.
2. The pump motor-based excavator stick energy recovery system of claim 1 further comprising a flow sensor in communication between the rodless chamber of the hydraulic ram and the first oil outlet.
3. The pump motor-based excavator stick energy recovery system of claim 1 further comprising a second one-way valve, a first overflow valve and a second overflow valve; The second one-way valve is communicated between the first two-position two-way electromagnetic valve and the first oil inlet; the first overflow valve is connected between the first oil inlet and the hydraulic oil tank; the second overflow valve is used for communicating a pipeline between the third one-way valve and the second pipeline interface to the hydraulic oil tank.
4. A control method of the pump-motor-based excavator stick energy recovery system, characterized by being used for controlling the pump-motor-based excavator stick energy recovery system according to any one of claims 1 to 3; The control method comprises the following steps: S1, acquiring a working voltage signal output by an operating handle, and comparing the working voltage signal with a preset neutral dead zone voltage range to acquire a current working state, wherein the working state comprises extension, retraction and stop; S2, when the working state is extension, acquiring a first required flow of the rodless cavity according to the extension required speed, and controlling a three-position four-way electromagnetic valve, a first two-position two-way electromagnetic valve, a second two-position two-way electromagnetic valve, a third two-position two-way electromagnetic valve, a motor and a motor-generator integrated machine according to the first required flow; when the first required flow exceeds the maximum flow threshold, the oil outlets of the first hydraulic pump and the reversible hydraulic pump motor are communicated with the rodless cavity, and the second two-position two-way electromagnetic valve is disconnected, so that the hydraulic cylinders form differential connection; S3, when the working state is retraction, obtaining second required flow of the rod cavity according to the retracted required speed, and controlling the three-position four-way electromagnetic valve, the first two-position two-way electromagnetic valve, the second two-position two-way electromagnetic valve, the third two-position two-way electromagnetic valve, the motor and the electric power generation integrated machine according to the second required flow; And S4, when the working state is stop, all the electromagnetic valves are closed, and the motor and motor power generation integrated machine is stopped or kept at idle speed.
5. The method of controlling a pump-motor-based excavator stick energy recovery system of claim 4 wherein the first demand flow rate Is provided with a first flow threshold Second flow threshold And a third flow rate threshold ; ; S2 specifically includes S21 to S25; S21, calculating the target extending speed of the excavator bucket rod according to the effective amplitude value of the working voltage signal deviated from the neutral dead zone voltage threshold value, and calculating the first required flow of the rodless cavity of the hydraulic oil cylinder according to the target extending speed ; S22, when The motor drives the first hydraulic pump to supply oil to the rodless cavity, hydraulic oil in the rod cavity drives the reversible hydraulic pump motor to drive the electric power generation integrated machine to generate electricity, and then the oil flows back to the oil tank through a third two-position two-way electromagnetic valve; S23, when When the reversible hydraulic pump motor is in a hydraulic pump state, the reversible hydraulic pump motor is used for conveying hydraulic oil with a rod cavity and a hydraulic oil tank to the rodless cavity; s24, when When the reversible hydraulic pump motor is in a hydraulic pump state, the reversible hydraulic pump motor is used for conveying hydraulic oil with a rod cavity and a hydraulic oil tank to the rodless cavity, and simultaneously, the first hydraulic pump supplies oil to the rodless cavity; s25, when The hydraulic oil pump is characterized in that the first hydraulic pump is connected with the hydraulic oil tank, the second two-position two-way electromagnetic valve and the third two-position two-way electromagnetic valve are disconnected, the first two-position two-way electromagnetic valve is communicated with the rod cavity of the hydraulic oil cylinder, the first hydraulic pump supplies oil to the rod cavity, and the reversible hydraulic pump motor is in a hydraulic pump state and is used for conveying hydraulic oil of the hydraulic oil tank to the rod cavity.
6. The control method of the pump motor-based excavator stick energy recovery system of claim 5, wherein S25 comprises: when (when) The hydraulic cylinder is characterized in that a first oil inlet of a three-position four-way electromagnetic valve is communicated with a first oil outlet, a second oil outlet is communicated with a first oil return port, a first two-position two-way electromagnetic valve is conducted, a second two-position two-way electromagnetic valve and a third two-position two-way electromagnetic valve are not conducted, a motor drives a first hydraulic pump to supply oil to a rodless cavity of the hydraulic cylinder, and simultaneously, an electric power generation integrated machine drives a reversible hydraulic pump motor to supply oil to the rodless cavity of the hydraulic cylinder through the first two-position two-way electromagnetic valve.
7. The control method of the pump motor-based excavator stick energy recovery system of claim 5, S22 comprising: when (when) The motor drives the first hydraulic pump to supply oil to a rodless cavity of the hydraulic cylinder, so that hydraulic oil with a rod cavity flows back to the reversible hydraulic pump motor, and then flows into the oil tank through the third two-position two-way electromagnetic valve, and at the moment, the reversible hydraulic pump motor is in a motor working condition, the electric power generation integrated machine is driven to be in a power generation working condition, and generated electric energy is fed back to the energy storage device; s23 specifically comprises when The electric power generation integrated machine drives the reversible hydraulic pump motor to supply oil to a rodless cavity of the hydraulic cylinder, so that hydraulic oil in the rod cavity flows back to an oil inlet of the reversible hydraulic pump motor through the second two-position two-way electromagnetic valve to supplement the oil; S24 specifically comprises when The electric power generation integrated machine drives the reversible hydraulic pump motor to supply oil to the rodless cavity of the hydraulic cylinder through the first two-position two-way electromagnetic valve, and meanwhile, hydraulic oil in the rod cavity flows back to the oil inlet of the reversible hydraulic pump motor through the second two-position two-way electromagnetic valve to supplement oil.
8. The method of claim 4, wherein the second demand flow rate is a second demand flow rate Is provided with a fourth flow threshold And a fifth flow threshold ; S3 specifically comprises: s31, calculating the target retraction speed of the excavator bucket rod according to the effective amplitude value of the working voltage signal deviated from the neutral dead zone voltage threshold value, and calculating the second required flow of the rod cavity of the hydraulic oil cylinder according to the target retraction speed ; S32, when The motor drives the first hydraulic pump to supply oil to the rod cavity, and hydraulic oil in the rodless cavity drives the reversible hydraulic pump motor to drive the electric power generation integrated machine to generate electricity, and then the oil flows back to the oil tank through the third two-position two-way electromagnetic valve; S33, when When the reversible hydraulic pump motor is in a hydraulic pump state, oil is supplied to the rod cavity, and hydraulic oil in the rod-free cavity flows back to the hydraulic oil tank; S34, when When the hydraulic pump is in a hydraulic pump state, oil is supplied to the rod cavity, meanwhile, the first hydraulic pump supplies oil to the rod cavity, and hydraulic oil in the rodless cavity flows back to the hydraulic oil tank.
9. The control method of the pump motor-based excavator stick energy recovery system of claim 8, wherein S32 comprises: when (when) The motor drives the first hydraulic pump to supply oil to a rod cavity of the hydraulic cylinder, so that hydraulic oil in a rodless cavity flows back to the reversible hydraulic pump motor and then flows into the oil tank through the third two-position two-way electromagnetic valve; S33 specifically comprises when The electric power generation integrated machine drives the reversible hydraulic pump motor to supply oil to a rod cavity of the hydraulic oil cylinder, and the hydraulic oil part of the rod-free cavity supplements oil to a first pipeline interface of the reversible hydraulic pump motor and partially flows back to the hydraulic oil tank; S34 specifically includes when The motor drives the first hydraulic pump to supply oil to the rod cavity of the hydraulic oil cylinder, and the electric power generation integrated machine drives the reversible hydraulic pump motor to supply oil to the rod cavity of the hydraulic oil cylinder through the first two-position two-way electromagnetic valve at the same time, so that hydraulic oil without the rod cavity flows back to the hydraulic oil tank.
10. The control method of the pump motor-based excavator bucket rod energy recovery system according to any one of claims 4 to 9, wherein the first hydraulic pump is a fixed displacement pump; when the excavator bucket energy recovery system based on the pump motor is provided with a flow sensor: step S2 further includes S26; S26, according to the first demand flow Acquiring a first target rotating speed of the motor and the electric power generation integrated machine, driving the motor and the electric power generation integrated machine, acquiring an actual flow signal of a flow sensor and a first required flow Comparing, and adjusting the first target rotating speed by adopting a PID proportion-integral-derivative closed-loop control method according to the comparison result to realize flow closed-loop control; step S3 further includes S35; S35, according to the second demand flow Acquiring the working state and the second target rotating speed of the motor and the motor-generator integrated machine, driving the motor and the motor-generator integrated machine, acquiring the actual flow signal of the flow sensor and the second required flow And (3) comparing, and adjusting the second target rotating speed by adopting a PID proportion-integral-derivative closed-loop control method according to the comparison result to realize flow closed-loop control.

Description

Excavator bucket rod energy recovery system based on pump motor and control method thereof Technical Field The invention relates to the technical field of excavators, in particular to an excavator bucket rod energy recovery system based on a pump motor and a control method thereof. Background The excavator is used as core equipment in the field of engineering machinery and is widely applied to complex operation scenes such as earth excavation, mining, material loading and unloading and the like. In the daily work cycle of the excavator, the extending and retracting actions of the bucket rod are very frequent, and the motion control precision and the energy efficiency of the bucket rod directly influence the performance of the whole excavator. At present, a bucket rod hydraulic system commonly adopts a valve control mode to realize speed adjustment, namely, the flow entering a hydraulic cylinder is controlled through the throttling action of a multi-way valve, so that the speed requirements under different working conditions are matched. However, this conventional valve control approach has significant inherent drawbacks. In the process of extending or retracting the bucket rod, when the output flow of the first hydraulic pump is larger than the required flow of the oil cylinder, redundant high-pressure oil flows back to the oil tank through the overflow valve, and the hydraulic energy is directly converted into heat energy. Even in the flow matching phase, the throttling action of the valve port generates a large pressure loss, and also causes energy to be dissipated in the form of heat energy. This heat is carried away by the hydraulic oil, resulting in a sharp increase in oil temperature. Too high oil temperature can greatly reduce the viscosity of hydraulic oil, further cause the increase of system internal leakage and the action retardation of an executive component, and accompany abnormal vibration, and long-term operation can also accelerate the abrasion and aging of the hydraulic component, thereby seriously threatening the working stability and reliability of the excavator. Therefore, the existing excavator bucket rod driving system has obvious defects in the aspect of energy utilization rate, and the problem that the energy consumption of the whole excavator is high is not fundamentally solved for a long time. In particular, potential energy contained in the bucket rod under a specific working condition (such as a deceleration or gravity descending stage), the existing system cannot be effectively recovered, and unnecessary energy waste is further aggravated. How to realize accurate flow matching and efficient recovery and dissipation of energy from the system architecture and energy management level has become a technical bottleneck to be broken through in the art. Disclosure of Invention The invention provides an excavator bucket rod energy recovery system based on a pump motor and a control method thereof, and aims to improve at least one of the technical problems. In order to solve the technical problems, the invention provides an excavator bucket rod energy recovery system based on a pump motor, which comprises a hydraulic cylinder, a reversible hydraulic pump motor, an electric power generation integrated machine connected to the reversible hydraulic pump motor in a transmission way, a first oil inlet, a first oil outlet, a three-position four-way electromagnetic valve with a second oil outlet and a first oil return port, a first hydraulic pump with a hydraulic pump oil inlet connected to the hydraulic tank, a first one-way valve communicating the hydraulic pump oil outlet and the first oil inlet, a motor connected to the first hydraulic pump in a transmission way, a third one-way valve communicating the first oil return port and a second pipeline interface of the reversible hydraulic pump motor, and a first two-position two-way electromagnetic valve for communicating a pipeline between the third one-way valve and the second pipeline interface to the first oil inlet. The first pipeline interface of the reversible hydraulic pump motor is respectively connected with the hydraulic oil tank through a fourth one-way valve and a third two-position two-way electromagnetic valve, and is connected with the first oil return port through a second two-position two-way electromagnetic valve pipeline. The first oil outlet pipeline is connected to the rodless cavity of the hydraulic oil cylinder, and the second oil outlet is connected to the rod cavity through a pipeline. As a further refinement, the pump motor-based excavator stick energy recovery system further comprises a flow sensor in communication between the rodless chamber of the hydraulic ram and the first oil outlet. As a further optimization, the pump motor-based excavator boom energy recovery system further comprises a second one-way valve, a first overflow valve and a second overflow valve. The second one-way valve is communicated between the f