CN-121976981-A - Double-pump bidirectional interchange energy recovery system of loader and movable arm oil cylinder of loader

CN121976981ACN 121976981 ACN121976981 ACN 121976981ACN-121976981-A

Abstract

A double-pump bidirectional exchange energy recovery system of a loader and a movable arm oil cylinder thereof relates to the technical field of hydraulic drive of the loader. The system comprises a two-position four-way electromagnetic directional valve, a three-position four-way electromagnetic directional valve, a hydraulic accumulator, a third two-position two-way electromagnetic directional valve connected with the hydraulic accumulator, a first pump motor and a second pump motor with oil inlets connected with a hydraulic oil tank, a first motor and a second motor respectively connected with the first pump motor and the second pump motor in a transmission mode, a hydraulic cylinder provided with a rodless cavity and a rod cavity, and a first two-position two-way electromagnetic directional valve and a second two-position two-way electromagnetic directional valve respectively connected with the rod cavity and the rodless cavity, wherein the two-position four-way electromagnetic directional valve is used for communicating oil outlets of the first pump motor and the second pump motor with the first two-position two-way electromagnetic directional valve and the second two-position two-way electromagnetic directional valve respectively. The three-position four-way electromagnetic directional valve is used for switching and communicating the third two-position two-way electromagnetic directional valve with the rodless cavity, the rod cavity and the oil inlet of the first pump motor.

Inventors

ZHOU FENGMING
Yao Zhaoyuan
CHEN QIHUAI
SUN ZIHAN
LIN TIANLIANG
MIAO CHENG
GUO LIZHONG
REN HAOLING
LAN KEWEI
ZHOU KAIYAN
HUANG TENGCHAO

Assignees

华侨大学

Dates

Publication Date: 20260505
Application Date: 20260402

Claims (10)

1. The double-pump bidirectional exchange energy recovery system of the movable arm oil cylinder of the loader is characterized by comprising a two-position four-way electromagnetic directional valve, a three-position four-way electromagnetic directional valve, a hydraulic accumulator, a third two-position two-way electromagnetic directional valve connected with the hydraulic accumulator, a first pump motor and a second pump motor of which oil inlets are connected with a hydraulic oil tank, a first motor and a second motor which are respectively connected with the first pump motor and the second pump motor in a transmission manner, a hydraulic oil cylinder provided with a rodless cavity and a rod cavity, and a first two-position two-way electromagnetic directional valve and a second two-position two-way electromagnetic directional valve which are respectively connected with the rod cavity and the rodless cavity; The three-position four-way electromagnetic directional valve is used for switching and communicating the third two-position two-way electromagnetic directional valve with a rodless cavity, a rod cavity and an oil inlet of the first pump motor; When the loader is lifted, if the starting time of the first pump motor exceeds a first preset value and the pressure of the hydraulic accumulator exceeds a second preset value, the hydraulic accumulator supplements oil for the first pump motor; when lifting, if the speed of the hydraulic oil cylinder exceeds a third preset value and the pressure of the hydraulic energy accumulator is smaller than a fourth preset value, communicating the rod cavity with the hydraulic energy accumulator, otherwise, communicating the rod cavity with the second pump motor; when the loader is lowered, if the pressure of the hydraulic accumulator is smaller than a fifth preset value, the rodless cavity is communicated with the hydraulic accumulator; When the hydraulic cylinder is lowered, if the speed of the hydraulic cylinder exceeds a sixth preset value and the pressure of the hydraulic accumulator is smaller than a seventh preset value, the rodless cavity is communicated with the hydraulic accumulator, and otherwise, the rodless cavity is communicated with the first pump motor.
2. The dual pump bi-directional interchangeable energy recovery system of a boom cylinder of a loader of claim 1, wherein if a first pump motor start time exceeds a first preset value and a hydraulic accumulator pressure exceeds a second preset value, the hydraulic accumulator supplements the first pump motor with oil, comprising: Judging whether the starting time of the first pump motor exceeds a first preset value; when judging that the starting time of the first pump motor exceeds a first preset value, further judging whether the pressure at the valve port of the hydraulic accumulator exceeds a second preset value; When the pressure at the valve port of the hydraulic accumulator exceeds a second preset value, the third two-position two-way electromagnetic directional valve is in a communication state, and the three-position four-way electromagnetic directional valve is in a state of being communicated with the liquid inlet of the first pump motor, so that the hydraulic accumulator is communicated with the liquid inlet of the first pump motor to carry out auxiliary oil supplementing; The two-position four-way electromagnetic directional valve is in a communication state, the first two-position two-way electromagnetic directional valve is in a communication state, and hydraulic oil enters a rodless cavity of the hydraulic oil cylinder through the first hydraulic pump, the two-position four-way electromagnetic directional valve and the first two-position two-way electromagnetic directional valve so as to drive the movable arm to lift.
3. The dual pump bi-directional interchangeable energy recovery system of a boom cylinder of a loader of claim 1, wherein if the hydraulic cylinder speed exceeds a third preset value and the hydraulic accumulator pressure is less than a fourth preset value during lifting, a rod chamber and a hydraulic accumulator are in communication, and otherwise, the rod chamber and a second pump motor are in communication, comprising: judging whether the instantaneous movement speed of the hydraulic cylinder exceeds a third preset value; when the instantaneous movement speed of the hydraulic oil cylinder exceeds a third preset value, further judging whether the pressure at the valve port of the hydraulic accumulator exceeds a fourth preset value; When the pressure at the valve port of the hydraulic accumulator is judged to be smaller than a fourth preset value, the third two-position two-way electromagnetic directional valve is in a communication state, the three-position four-way electromagnetic directional valve is in a state of being communicated with a rod cavity of the hydraulic oil cylinder, and the second two-position two-way electromagnetic directional valve is in a disconnection state, so that the hydraulic accumulator is communicated with the rod cavity of the hydraulic oil cylinder to conduct instantaneous impact energy recovery; When the pressure at the valve port of the hydraulic accumulator is judged to be not smaller than a fourth preset value, the second two-position two-way electromagnetic directional valve is in a communication state, the third two-position two-way electromagnetic directional valve is in a disconnection state, so that hydraulic oil enters the second pump motor through the second two-position two-way electromagnetic directional valve and the two-position four-way electromagnetic directional valve, and a rotating shaft of the second pump motor is in transmission connection with the second motor to drive the motor to reversely rotate to generate electric energy to charge the storage battery.
4. The dual pump bi-directional interchangeable energy recovery system of a boom cylinder of a loader of claim 1, wherein if the hydraulic accumulator pressure is less than a fifth preset value, the rodless cavity is in communication with the hydraulic accumulator, comprising: judging whether the pressure at the valve port of the hydraulic accumulator exceeds a fifth preset value; When the pressure at the valve port of the hydraulic accumulator is judged to be smaller than a fifth preset value, the three-position four-way electromagnetic directional valve is in a state of being communicated with a rodless cavity of the hydraulic cylinder, the third two-position two-way electromagnetic directional valve is in a communicated state, and the first two-position two-way electromagnetic directional valve is in a disconnected state, so that the hydraulic accumulator is communicated with the rodless cavity of the hydraulic cylinder to recover instantaneous impact potential energy; The two-position four-way electromagnetic directional valve is in a communication state, and the second two-position two-way electromagnetic directional valve is in a communication state, so that hydraulic oil enters a rod cavity of the hydraulic oil cylinder through the second hydraulic pump, the two-position four-way electromagnetic directional valve and the second two-position two-way electromagnetic directional valve to drive the movable arm to be released.
5. The dual pump bi-directional interchangeable energy recovery system of a boom cylinder of a loader of claim 1, wherein the rodless chamber and the hydraulic accumulator are connected when the hydraulic cylinder is lowered if the hydraulic cylinder speed exceeds a sixth preset value and the hydraulic accumulator pressure is less than a seventh preset value, and wherein the rodless chamber and the first pump motor are connected otherwise, specifically comprising: judging whether the instantaneous movement speed of the hydraulic cylinder exceeds a sixth preset value; when judging that the instantaneous movement speed of the hydraulic oil cylinder exceeds a sixth preset value, further judging whether the pressure at the valve port of the hydraulic accumulator exceeds a seventh preset value; When the pressure at the valve port of the hydraulic accumulator is judged to be smaller than a seventh preset value, the three-position four-way electromagnetic directional valve is in a state of being communicated with a rodless cavity of the hydraulic cylinder, the third two-position two-way electromagnetic directional valve is in a communicating state, and the first two-position two-way electromagnetic directional valve is in a disconnecting state, so that the hydraulic accumulator is communicated with the rodless cavity of the hydraulic cylinder to perform instantaneous impact energy recovery; When the pressure at the valve port of the hydraulic accumulator is judged to be not smaller than a seventh preset value, the first two-position two-way electromagnetic directional valve is in a communicating state, the third two-position two-way electromagnetic directional valve is in a disconnecting state, so that hydraulic oil enters the first pump motor through the first two-position two-way electromagnetic directional valve and the two-position four-way electromagnetic directional valve, and a rotating shaft of the first pump motor is in transmission connection with the first motor to drive the motor to reversely rotate to generate electric energy to charge the storage battery.
6. The system for recovering energy of double-pump bidirectional interchange of a boom cylinder of a loader according to any one of claims 1 to 5, further comprising an electric storage device connected to a first motor and a second motor, wherein the first motor and the second motor are all electric power generation integrated machines, can drive the pump motor to supply oil in an electric state, and can generate electricity under the drive of the pump motor in a power generation state; The second preset value > the fourth preset value; fourth preset value = fifth preset value; Fifth preset value > seventh preset value.
7. The dual pump bi-directional interchangeable energy recovery system of a boom cylinder of a loader of any of claims 1 to 5, further comprising a check valve and a throttle valve; The liquid inlet of the one-way valve is connected with the three-position four-way electromagnetic reversing valve, and the liquid outlet of the one-way valve is connected between the first pump motor and the hydraulic oil tank; the throttle valve is connected between the liquid outlet of the first pump motor and the two-position four-way electromagnetic reversing valve.
8. The dual pump bi-directional interchangeable energy recovery system of a boom cylinder of a loader of any of claims 1 to 5, further comprising a first relief valve, a second relief valve, and a third relief valve; The liquid inlet of the first overflow valve is connected with the liquid outlet of the first pump motor; the liquid inlet of the second overflow valve is connected with the liquid outlet of the second pump motor; the liquid inlet of the third overflow valve is connected with the hydraulic port of the hydraulic accumulator; the liquid outlets of the first overflow valve, the second overflow valve and the third overflow valve are connected with the hydraulic oil tank.
9. The dual pump bi-directional interchangeable energy recovery system of a boom cylinder of a loader according to any one of claims 1 to 5, wherein a default state of the first two-position two-way electromagnetic directional valve and the second two-position two-way electromagnetic directional valve is a connected state; the default state of the third two-position two-way electromagnetic reversing valve is an off state; The default state of the two-position four-way electromagnetic reversing valve is the disconnection state.
10. A loader characterized by a double pump bi-directional interchangeable energy recovery system comprising a boom cylinder of a loader according to any of claims 1 to 9.

Description

Double-pump bidirectional interchange energy recovery system of loader and movable arm oil cylinder of loader Technical Field The invention relates to the technical field of hydraulic drive of loaders, in particular to a double-pump bidirectional exchange energy recovery system of a loader and a movable arm oil cylinder of the loader. Background In the field of engineering construction and material transfer, a loader is used as a key earth and stone working machine, and the working efficiency and the energy consumption performance of the loader directly influence the engineering economy and the environmental influence. The hydraulic system of the loader, in particular to a movable arm lifting and descending loop, consumes a great amount of energy in frequent operation, and how to effectively recycle and reuse gravitational potential energy generated when the movable arm descends becomes the technical problem to be solved currently. In the existing loader hydraulic system, during the process of descending a movable arm, a throttle valve or an overflow valve is generally adopted to throttle and control hydraulic oil, so that gravitational potential energy is dissipated to a hydraulic oil tank in a heat energy mode. The treatment mode not only causes a great deal of energy waste, but also causes excessive temperature rise of hydraulic oil, influences the sealing performance of the system and the service life of elements, and increases the burden of a cooling system. Some improvement schemes attempt to introduce a single pump motor or an energy accumulator for energy recovery, but are limited by a single energy recovery path and a fixed working mode, so that the energy recovery system is difficult to adapt to the requirements of various working conditions such as heavy load, light load, rapid operation and the like, and has a large improvement space for recovery efficiency and system stability. Although the prior art attempts to realize partial energy recovery through a hydraulic accumulator or an electric energy storage unit, the prior art scheme generally has the problems of single energy recovery mode and poor working condition adaptability. The energy recovery capability is insufficient under the heavy load working condition, the high-efficiency energy-saving operation is difficult to realize during light load or quick operation, and the energy recovery and the recycling process are often mutually interfered, so that the response speed and the operation stability of the system are affected. The defects cause low energy utilization rate and large throttling loss of the existing hydraulic system, and restrict the further improvement of the whole energy of the loader. Disclosure of Invention The invention provides a double-pump bidirectional exchange energy recovery system of a loader and a movable arm oil cylinder thereof, and aims to improve at least one of the technical problems. In order to solve the technical problems, the invention provides a double-pump bidirectional exchange energy recovery system of a movable arm oil cylinder of a loader, which comprises a two-position four-way electromagnetic directional valve, a three-position four-way electromagnetic directional valve, a hydraulic accumulator, a third two-position two-way electromagnetic directional valve connected with the hydraulic accumulator, a first pump motor and a second pump motor of which oil inlets are connected with a hydraulic oil tank, a first motor and a second motor which are respectively connected with the first pump motor and the second pump motor in a transmission way, a hydraulic oil cylinder provided with a rodless cavity and a rod cavity, and a first two-position two-way electromagnetic directional valve and a second two-position two-way electromagnetic directional valve which are respectively connected with the rod cavity and the rodless cavity. The two-position four-way electromagnetic directional valve is used for respectively communicating oil outlets of the first pump motor and the second pump motor with the first two-position two-way electromagnetic directional valve and the second two-position two-way electromagnetic directional valve. The three-position four-way electromagnetic directional valve is used for switching the third two-position two-way electromagnetic directional valve to be communicated with a rod cavity of the hydraulic oil cylinder, the rod cavity and an oil inlet of the first pump motor. When the loader is lifted, if the starting time of the first pump motor exceeds a first preset value and the pressure of the hydraulic accumulator exceeds a second preset value, the hydraulic accumulator supplements oil for the first pump motor. When the hydraulic cylinder is lifted, if the speed of the hydraulic cylinder exceeds a third preset value and the pressure of the hydraulic accumulator is smaller than a fourth preset value, the rod cavity and the hydraulic accumulator are communicated. Otherwise, the rod cavity