阅读说明：本技术 分布式泵控系统及低压损控制方法 (Distributed pump control system and low-pressure-loss control method ) 是由 权龙� 王波 张晓刚 李运帷 乔舒斐 于 2021-02-19 设计创作，主要内容包括：一种分布式泵控系统,包括单出杆液压缸、分布式泵控系统,直流母线,分布式泵控系统包括,第Ⅰ电动/发电机、双向定量泵/马达、第Ⅰ逆变器、第Ⅰ补油单向阀、第Ⅱ补油单向阀、第Ⅰ溢流阀、第Ⅱ溢流阀；进一步增设有DC-DC变换器、超级电容组、流量分配补偿单元、压力补偿器、集中式补油泵、主电动机、第Ⅱ逆变器、控制器；本发明增设大功率的集中动力源和流量补偿分配单元,对所有分布式泵控子系统的不对称流量进行集中补偿和功率放大,用小功率的分布式泵控子系统实现大功率执行器的驱动牵引,同时采用高转速的电机和高效、小排量的定量泵,极大地减小了分布式泵控单元的容量、重量及成本,显著降低泵控多执行器系统总的装机功率。(A distributed pump control system comprises a single-rod hydraulic cylinder, a distributed pump control system and a direct-current bus, wherein the distributed pump control system comprises a first motor/generator, a bidirectional constant delivery pump/motor, a first inverter, a first oil supplementing one-way valve, a second oil supplementing one-way valve, a first overflow valve and a second overflow valve; a DC-DC converter, a super capacitor set, a flow distribution compensation unit, a pressure compensator, a centralized oil supplementing pump, a main motor, a second inverter and a controller are further added; the invention adds a high-power centralized power source and a flow compensation distribution unit, performs centralized compensation and power amplification on asymmetric flow of all distributed pump control subsystems, realizes driving traction of a high-power actuator by using a low-power distributed pump control subsystem, and greatly reduces the capacity, weight and cost of the distributed pump control unit and remarkably reduces the total installed power of the pump control multi-actuator system by adopting a high-speed motor and a high-efficiency and small-displacement constant delivery pump.)

1. The distributed pump control system comprises a single or a plurality of single-rod hydraulic cylinders (1), a single or a plurality of distributed pump control systems (2), a direct current bus (10) and a low-pressure accumulator (29), wherein each single-rod hydraulic cylinder is driven by one distributed pump control system, and the distributed pump control systems are connected to the low-pressure accumulator;

the distributed pump control system comprises a first motor/generator (3), a bidirectional constant displacement pump/motor (4), a first inverter (5), a first oil supplementing one-way valve (6), a second oil supplementing one-way valve (7), a first overflow valve (8) and a second overflow valve (9); the first motor/generator coaxially drives the bidirectional constant delivery pump/motor, two ends of the bidirectional constant delivery pump/motor are respectively communicated with two cavities of a single-outlet rod hydraulic cylinder, oil outlets of a first oil supplementing one-way valve and a second oil supplementing one-way valve are respectively communicated with two cavities of the bidirectional constant delivery pump/motor, oil inlets of the first oil supplementing one-way valve and the second oil supplementing one-way valve are communicated with a low-pressure energy accumulator, oil leakage is supplemented to the two cavities of the bidirectional constant delivery pump/motor through the low-pressure energy accumulator, oil inlets of a first overflow valve and a second overflow valve are communicated with the two cavities of the bidirectional constant delivery pump/motor, and oil outlets of the first overflow valve and the second overflow valve are communicated with an oil tank; the direct current bus is connected with a filter capacitor (11), a rectifier (14) and a power switch (15);

the method is characterized in that: a DC-DC converter (12), a super capacitor bank (13), a flow distribution compensation unit (16), a pressure compensator (20), a centralized oil supplementing pump (22), a main motor (23), a II inverter (25) and a controller (32) are further added;

the main motor is connected with a centralized oil supplementing pump, an oil outlet of the centralized oil supplementing pump is connected with an oil supply pipeline L, a main safety valve (24), a third pressure sensor (26) and a switch valve (27) are arranged on the oil supply pipeline L, and the main oil way L is communicated with the low-pressure accumulator through the switch valve;

each single-rod hydraulic cylinder is matched with a pressure compensator and a flow distribution compensation unit, and the pressure compensator and the flow distribution unit matched with each single-rod hydraulic cylinder are communicated with the oil supply pipeline L; the oil inlet of the pressure compensator is communicated with the oil supply pipeline L, the oil outlet of the pressure compensator is connected with the oil inlet of the flow compensation distribution unit, and the working oil port of the flow compensation distribution unit is communicated with two cavities of the single-rod hydraulic cylinder;

in the distributed pump control system, an I motor/generator is connected with the output end of an I inverter, the input end of the I inverter is connected with a direct current bus, a main motor is connected with the output end of an II inverter, the input end of the II inverter is connected with the direct current bus, one end of a DC-DC converter is connected with the direct current bus, and the other end of the DC-DC converter is connected with a super capacitor;

the controller comprises a signal receiver (33), an operation module (34) and a signal output device (35); the signal receiver continuously receives initial input signals, rotating speed and torque feedback signals fed back by the first motor/generator and the main motor, continuously receives pressure signals output by the first pressure sensor, the second pressure sensor, the third pressure sensor and the fourth pressure sensor, continuously receives displacement signals from the first displacement sensor, inputs the signals into the operation module for operation, and finally controls the rotating speed and torque of the first motor/generator and the main motor and the opening of the main control valve through the signal output device.

2. The distributed pump control system of claim 1, wherein: the pressure compensator is additionally provided with an I displacement sensor (21); the flow compensation distribution unit includes: the hydraulic control system comprises an I pressure sensor (17), an II pressure sensor (18) and a main control valve (19), wherein an oil outlet of the pressure compensator is communicated with an oil inlet P of the main control valve, a spring end of the pressure compensator is connected with a load detection oil port LS of the main direction valve, the other end of the pressure compensator is connected with the oil inlet P of the main control valve, the oil outlet T of the main control valve is communicated with an oil tank, a working oil port A of the main control valve is communicated with a rodless cavity of a single-rod hydraulic cylinder, a working oil port B of the main control valve is communicated with a rod cavity of the single-rod hydraulic cylinder, and the I pressure sensor and the II pressure sensor are respectively communicated with a working oil port A, B of the main control valve.

3. A distributed pump control system according to claims 1-2, characterized by: the flow compensation distribution unit is further additionally provided with an I proportional valve (36), and an oil return port T of the main control valve is communicated with the oil tank through the I proportional valve.

4. A distributed pump control system according to claims 1-2, characterized by: a second proportional valve (37) and a third proportional valve (38) are additionally arranged on the flow compensation distribution unit, oil inlets of the second proportional valve and the third proportional valve are respectively communicated with a working oil port A, B of the main control valve, oil outlets of the second proportional valve and the third proportional valve are respectively communicated with an oil tank, and an oil return port T of the main control valve is blocked.

5. A distributed pump control system according to claims 1-2, characterized by: the flow compensation distribution unit is additionally provided with a proportional reversing valve (39), and a working oil port A of the proportional reversing valve₁、B₁Respectively communicated with the working oil port A, B of the main control valve and the oil inlet P of the proportional reversing valve₁Is plugged, and the oil return port T of the proportional reversing valve₁Is communicated with the oil tank.

6. A distributed pump control system according to claims 1-2, characterized by: the flow compensation distribution unit further comprises an IV proportional valve (40) and a V proportional valve (41), the IV proportional valve is arranged between the pressure compensator and an oil inlet P of the main control valve, the spring end of the pressure compensator is connected with an oil outlet of the IV proportional valve, the other end of the pressure compensator is connected with an oil inlet of the IV proportional valve, and an oil outlet T of the main control valve is communicated with the oil tank through the V proportional valve.

7. A distributed pump control system according to any one of claims 1 to 6, wherein: the oil supply pipeline L is also provided with a load detection proportional valve (42), the load detection proportional valve is a three-position three-way valve, and a third displacement sensor (44) and a proportional electromagnet (46) are further additionally arranged on the load detection proportional valve;

the second valve displacement sensor is integrated on the proportional electromagnet, and detects the displacement and the speed of the load detection proportional valve core by detecting the position of the iron core of the proportional electromagnet, or the through shaft is arranged on the load detection proportional valve core to directly detect the position and the speed of the load detection proportional valve core;

the oil inlet of the load detection proportional valve is connected with an oil supply pipeline L, and the oil outlet C, D of the load detection proportional valve is respectively connected with an oil tank and an oil supplement energy accumulator (43).

8. The distributed pump control system of claim 7, wherein: and a shuttle valve group (45) is further added, the maximum load pressure of the plurality of hydraulic actuators is screened and detected through the plurality of shuttle valves, the oil outlets of the shuttle valve group are connected to the spring end of the valve core of the load detection proportional valve through a hydraulic oil path, and the other end of the valve core of the load detection proportional valve is communicated with the oil supply pipeline L through a hydraulic pipeline and used for detecting the outlet pressure of the centralized oil replenishing pump.

9. The distributed pump control system of claim 1, wherein: the first oil-supplementing check valve and the second oil-supplementing check valve are common check valves or hydraulic control check valves; when the first oil-supplementing one-way valve/the second oil-supplementing one-way valve is a hydraulic control one-way valve, the oil outlet is respectively communicated with two cavities of the bidirectional constant delivery pump/motor, the oil inlet is communicated with the low-pressure energy accumulator, and the control oil port is communicated with a cavity in the bidirectional constant delivery pump/motor, which is communicated with the oil outlet of the other hydraulic control one-way valve.

10. The distributed pump control system of claim 1, wherein: a hydraulic motor (47), an auxiliary motor (48) and a third frequency converter (49) are further added, the hydraulic motor is coaxially and mechanically connected with the auxiliary motor and is matched with a pressure compensator and a flow distribution unit, an oil inlet of the pressure compensator is communicated with an oil supply pipeline L, an oil outlet of the pressure compensator is connected with an oil inlet of the flow compensation distribution unit, a working oil port of the flow compensation distribution unit is communicated with two cavities of the hydraulic motor, and the auxiliary motor is connected with a direct current bus through the third frequency converter.

11. A low pressure loss control method of a distributed pump control multi-actuator system is characterized by comprising the following steps: comprises a plurality of single-rod hydraulic cylinders, and comprises the following specific steps,

the method comprises the following steps: giving a plurality of speed control signals of the single-rod hydraulic cylinder, taking the flow of the rod cavity of the single-rod hydraulic cylinder as a reference, and calculating the speed control signal according to a formula n_x＝vA_B/V_dCalculating the rotational speed of the first motor/generator of the distributed pump control system, wherein A_BThe area of a rod cavity of the single-rod hydraulic cylinder is V_dThe pump displacement is closed;

step two: the pressure of the driving cavities of the multiple single-rod hydraulic cylinders is detected in real time and compared, the difference value between the maximum load pressure and the other low load pressures is used as a control quantity, the control quantity is superposed on the rotation speed control of the first motor/generator, and the pressure of the driving cavities of the actuators is repeatedly adjusted to be equal, so that the equivalent loads of the multiple single-rod hydraulic cylinders are the same, and the throttling loss caused by the load difference on a pressure compensator is eliminated;

step three: respectively calculating the asymmetric flow Q of a plurality of single-rod hydraulic cylinders needing compensation₁、Q₂、Q₃… …, and summing to control the rotation speed of main motor and the opening of main control valve to make the highest load and low load actuators have the largest opening>80％；

Step four: and in the plurality of flow compensation distribution units, the valve core displacement of the pressure compensator is detected in real time, compared with the valve core displacement of the maximum set pressure compensator, the difference value of the valve core displacement is taken as a control quantity, the control quantity is superposed on the rotating speed control signal of the main motor, and the control quantity is repeatedly adjusted, so that the valve ports of the pressure compensator in the plurality of flow compensation distribution units are kept fully opened, the output flow of the oil supplementing pump can be considered to completely meet the asymmetric flow requirement of the plurality of single-rod hydraulic cylinders, and the flow matching is realized.

Technical Field

The invention belongs to a control system of multiple actuators in a hydraulic control technology, and particularly relates to an electro-hydraulic control system and method for volume direct-drive single-rod hydraulic cylinders, low-pressure-loss flow distribution and kinetic energy recovery of multiple actuators of a distributed pump of engineering equipment.

Background

In recent years, with the shortage of world energy and the continuous aggravation of the problem of environmental pollution, the research on energy conservation and emission reduction of a hydraulic system in various non-road mobile equipment such as engineering machinery, road building machinery, mining machinery, forestry machinery and agricultural machinery has become a hotspot. Although the energy-saving method of the hydraulic system such as the prior positive flow, negative flow and load sensitive technology plays an important role in improving the energy efficiency of the system, the energy-saving method can not overcome the defect that when the prior multi-actuator system generally adopts an internal combustion engine to drive a hydraulic pump as a power source, and distributes and transmits power through a multiway valve and a pipeline, the output pressure of the pump can only be matched with the highest load, the high-load actuator is used for controlling the flow, and the low-load actuator is used for compensating the great valve port throttling loss caused by load difference, and the loss is exactly the most main energy consumption source of the multi-actuator system and accounts for 35-39% of the output power of the engine.

By adopting a closed pump control technology, the throttling loss can be completely eliminated theoretically, but the existing research work mainly aims at a single-rod hydraulic cylinder, and is only used for simply superposing a multi-actuator system and a single-actuator loop, such as the scheme disclosed in the Chinese patent with the application number of 2016104063579. The problems with this solution are: the power sources of the actuators must be configured according to peak power, so that the total assembly power, the weight and the volume of the system are greatly increased, the system is limited by the assembly power and the cost of an electric drive unit, and the system is mainly used for low-power systems and machines at present. Secondly, in order to solve the problem that the area ratio of the hydraulic pump to the single-rod hydraulic cylinder is not matched, partial throttling loss still exists in the existing one-way valve compensation asymmetric flow scheme system. Therefore, in the solution disclosed in chinese patent application No. 2016104063579, the single-rod hydraulic cylinders for the boom, the arm, and the bucket of the excavator are replaced with the symmetrical single-rod hydraulic cylinders, which has new problems such as insufficient output force and excavating force compared to the asymmetrical single-rod hydraulic cylinders. In the overall scheme of the pump control system excavator disclosed in U.S. Pat. No. US6962050B2, in order to compensate for the area difference of the single-rod hydraulic cylinders, each single-rod hydraulic cylinder is driven by two hydraulic pumps, and the overall system needs at least 7 hydraulic pumps, so that the system structure is more complex and the cost is higher.

Disclosure of Invention

In view of the above problems, the present invention aims to provide a distributed pump control system with small installed power, small volume, high power-to-weight ratio, easy compensation of asymmetric flow of a single-rod hydraulic cylinder, capability of distributing the asymmetric flow of the system with extremely low pressure loss, and good control characteristics.

In order to achieve the purpose, the invention adopts the following technical scheme:

a distributed pump control system comprises a single or a plurality of single-rod hydraulic cylinders, a single or a plurality of distributed pump control systems, a direct-current bus and a low-pressure energy accumulator, wherein each single-rod hydraulic cylinder is driven by one distributed pump control system, and the plurality of distributed pump control systems are uniformly connected with the low-pressure energy accumulator;

the distributed pump control system comprises a first motor/generator, a bidirectional constant delivery pump/motor, a first inverter, a first oil supplementing one-way valve, a second oil supplementing one-way valve, a first overflow valve and a second overflow valve; the first motor/generator coaxially drives the bidirectional constant delivery pump/motor, two ends of the bidirectional constant delivery pump/motor are respectively communicated with two cavities of a single-outlet rod hydraulic cylinder, oil outlets of a first oil supplementing one-way valve and a second oil supplementing one-way valve are respectively communicated with two cavities of the bidirectional constant delivery pump/motor, oil inlets of the first oil supplementing one-way valve and the second oil supplementing one-way valve are communicated with a low-pressure energy accumulator, oil leakage is supplemented to the two cavities of the bidirectional constant delivery pump/motor through the low-pressure energy accumulator, oil inlets of a first overflow valve and a second overflow valve are communicated with the two cavities of the bidirectional constant delivery pump/motor, and oil outlets of the first overflow valve and the second overflow valve are communicated with an oil tank; the direct current bus is connected with a filter capacitor, a rectifier and a power switch;

the method is characterized in that: a DC-DC converter, a super capacitor set, a flow distribution compensation unit, a pressure compensator, a centralized oil supplementing pump, a main motor, a second inverter and a controller are further added;

the main motor is connected with a centralized oil supplementing pump, an oil outlet of the centralized oil supplementing pump is connected with an oil supply pipeline L, a main safety valve, a third pressure sensor and a switch valve are arranged on the oil supply pipeline L, and the main oil way L is communicated with the low-pressure accumulator through the switch valve;

each single-rod hydraulic cylinder is matched with a pressure compensator and a flow distribution compensation unit, and the pressure compensator and the flow distribution unit matched with each single-rod hydraulic cylinder share the same oil supply pipeline L; the oil inlet of the pressure compensator is communicated with the oil supply pipeline L, the oil outlet of the pressure compensator is connected with the oil inlet of the flow compensation distribution unit, and the working oil port of the flow compensation distribution unit is communicated with two cavities of the single-rod hydraulic cylinder;

in the distributed pump control system, an I motor/generator is connected with the output end of an I inverter, the input end of the I inverter is connected with a direct current bus, a main motor is connected with the output end of an II inverter, the input end of the II inverter is connected with the direct current bus, one end of a DC-DC converter is connected with the direct current bus, and the other end of the DC-DC converter is connected with a super capacitor;

the controller comprises a signal receiver, an operation module and a signal output device; the signal receiver continuously receives initial input signals, rotating speed and torque feedback signals fed back by the first motor/generator and the main motor, continuously receives pressure signals output by the first pressure sensor, the second pressure sensor, the third pressure sensor and the fourth pressure sensor, continuously receives displacement signals from the first displacement sensor, inputs the signals into the operation module for operation, and finally controls the rotating speed and torque of the first motor/generator and the main motor and the opening of the main control valve through the signal output device;

the first displacement sensor is additionally arranged on the pressure compensator; the flow compensation distribution unit includes: the hydraulic control system comprises a first pressure sensor, a second pressure sensor and a main control valve, wherein a working oil port A of the main control valve is respectively connected with the first pressure sensor and a rodless cavity of a single-rod hydraulic cylinder; the oil outlet of the pressure compensator is communicated with the oil inlet P of the main control valve, the oil outlet T of the main control valve is communicated with the oil tank, the spring end of the pressure compensator is connected with the load detection oil port LS of the main directional valve, and the other end of the pressure compensator is connected with the oil inlet P of the main control valve.

The flow compensation distribution unit is further additionally provided with an I proportional valve, and an oil return port T of the main control valve is communicated with the oil tank through the I proportional valve.

The flow compensation distribution unit is further additionally provided with a second proportional valve and a third proportional valve, oil inlets of the second proportional valve and the third proportional valve are respectively communicated with a working oil port A, B of the main control valve, oil outlets of the second proportional valve and the third proportional valve are respectively communicated with an oil tank, and an oil return port T of the main control valve is blocked.

The flow compensation distribution unit is additionally provided with a proportional reversing valve, and a working oil port A of the proportional reversing valve₁、B₁Respectively communicated with the working oil port A, B of the main control valve and the oil inlet P of the proportional reversing valve₁Is plugged, and the oil return port T of the proportional reversing valve₁Is communicated with the oil tank.

The flow compensation distribution unit further comprises an IV proportional valve and a V proportional valve, the IV proportional valve is arranged between the pressure compensator and an oil inlet P of the main control valve, the spring end of the pressure compensator is connected with an oil outlet of the IV proportional valve, the other end of the pressure compensator is connected with an oil inlet of the IV proportional valve, and an oil outlet T of the main control valve is communicated with the oil tank through the V proportional valve.

The oil supply pipeline L is also provided with a load detection proportional valve which is a three-position three-way valve, and the load detection proportional valve is further additionally provided with a third displacement sensor and a proportional electromagnet;

the second valve displacement sensor is integrated on the proportional electromagnet, and detects the displacement and the speed of the load detection proportional valve core by detecting the position of the iron core of the proportional electromagnet, or the through shaft is arranged on the load detection proportional valve core to directly detect the position and the speed of the load detection proportional valve core;

an oil inlet of the load detection proportional valve is connected with an oil supply pipeline L, and an oil outlet C, D of the load detection proportional valve is respectively connected with an oil tank and an oil supplement energy accumulator;

the system is further additionally provided with a shuttle valve group, the maximum load pressure of the plurality of hydraulic actuators is screened and detected through the plurality of shuttle valves, the oil outlets of the shuttle valve group are connected to the spring end of the valve core of the load detection proportional valve through a hydraulic oil circuit, and the other end of the valve core of the load detection proportional valve is communicated with the oil supply pipeline L through a hydraulic pipeline and used for detecting the outlet pressure of the centralized oil replenishing pump.

The first oil supplementing check valve and the second oil supplementing check valve are common check valves or hydraulic control check valves; when the first oil-supplementing one-way valve/the second oil-supplementing one-way valve is a hydraulic control one-way valve, the oil outlet is respectively communicated with two cavities of the bidirectional constant delivery pump/motor, the oil inlet is communicated with the low-pressure energy accumulator, and the control oil port is communicated with a cavity in the bidirectional constant delivery pump/motor, which is communicated with the oil outlet of the other hydraulic control one-way valve.

The system is further additionally provided with a hydraulic motor, an auxiliary motor and a third frequency converter, the hydraulic motor is coaxially and mechanically connected with the auxiliary motor and is matched with a pressure compensator and a flow distribution unit, an oil inlet of the pressure compensator is communicated with an oil supply pipeline L, an oil outlet of the pressure compensator is connected with an oil inlet of the flow compensation distribution unit, a working oil port of the flow compensation distribution unit is communicated with two cavities of the hydraulic motor, and the auxiliary motor is connected with a direct-current bus through the third frequency converter.

A low pressure loss control method of a distributed pump control multi-actuator system is characterized by comprising the following steps: comprises a plurality of single-rod hydraulic cylinders, and comprises the following specific steps,

the method comprises the following steps: giving a plurality of speed control signals of the single-rod hydraulic cylinder, taking the flow of the rod cavity of the single-rod hydraulic cylinder as a reference, and calculating the speed control signal according to a formula n_x＝vA_B/V_dCalculating the rotational speed of the first motor/generator of the distributed pump control system, wherein A_BThe area of a rod cavity of the single-rod hydraulic cylinder is V_dThe pump displacement is closed;

step two: the pressure of the driving cavities of the multiple single-rod hydraulic cylinders is detected in real time and compared, the difference value between the maximum load pressure and the other low load pressures is used as a control quantity, the control quantity is superposed on the rotation speed control of the first motor/generator, and the pressure of the driving cavities of the actuators is repeatedly adjusted to be equal, so that the equivalent loads of the multiple single-rod hydraulic cylinders are the same, and the throttling loss caused by the load difference on a pressure compensator is eliminated;

step three: respectively calculating the asymmetric flow Q of a plurality of single-rod hydraulic cylinders needing compensation₁、Q₂、Q₃… …, and summing to control the rotation speed of main motor and the opening of main control valve to make the highest load and low load actuators have the largest opening>80％；

Step four: and in the plurality of flow compensation distribution units, the valve core displacement of the pressure compensator is detected in real time, compared with the valve core displacement of the maximum set pressure compensator, the difference value of the valve core displacement is taken as a control quantity, the control quantity is superposed on the rotating speed control signal of the main motor, and the control quantity is repeatedly adjusted, so that the valve ports of the pressure compensator in the plurality of flow compensation distribution units are kept fully opened, the output flow of the oil supplementing pump can be considered to completely meet the asymmetric flow requirement of the plurality of single-rod hydraulic cylinders, and the flow matching is realized.

Compared with the prior art, the invention has the following technical advantages:

the invention adds a high-power centralized power source and a flow compensation distribution unit, performs centralized compensation and power amplification on asymmetric flow of all distributed pump control subsystems, realizes the driving traction of a high-power actuator by using a low-power distributed pump control subsystem, and greatly reduces the capacity, weight and cost of the distributed pump control unit and the total installed power of the pump control multi-actuator system by adopting a high-speed motor and a high-efficiency and small-displacement constant delivery pump;

the flow compensation distribution unit with a new structure is adopted, the distributed pump control subsystem is driven and pre-compacted in a two-way mode through the main control valve, the driving power of the pump control subsystem is improved, and the flow of a centralized power source is accurately distributed in real time through the pressure compensator for inhibiting dynamic pressure fluctuation, overlarge load difference and pipeline loss of the system;

according to the extremely-low pressure loss control method provided by the invention, the pressure of the non-driving cavity of each actuator is regulated and controlled by the distributed pump control unit, so that the pressure of the driving cavity of the low-load actuator is consistent with the highest load, the throttling loss generated by load difference is eliminated, and the flow matching control is adopted, so that the control valve is positioned at a larger opening, the throttling loss of the valve port of the flow compensation distribution unit is greatly reduced, the system achieves the energy efficiency equivalent to that of a closed pump control single-rod hydraulic cylinder, and meanwhile, the system has high dynamic response;

the distributed pump control system is a driving unit and an actuator kinetic potential energy recycling unit, can directly utilize the kinetic potential energy generated by each actuator through a direct current bus, can convert the generated kinetic potential energy into electric energy to be stored in a super capacitor, and is particularly suitable for electric engineering equipment.

Drawings

FIG. 1 is a schematic diagram of a distributed pump-controlled single actuator system of the present invention;

FIG. 2 is a schematic diagram of a first structure of the flow compensation distribution unit of the present invention;

FIG. 3 is a schematic diagram of a second structure of the flow compensation distribution unit of the present invention;

FIG. 4 is a schematic diagram of a third structure of the flow compensation distribution unit of the present invention;

FIG. 5 is a schematic diagram of a fourth configuration of the flow compensated distribution unit of the present invention;

FIG. 6 is a schematic diagram of a fifth structure of the flow compensation distribution unit of the present invention;

FIG. 7 is a schematic diagram of a distributed pump controlled multiple actuator system of the present invention;

FIG. 8 is a schematic diagram of the construction of the controller of the present invention;

fig. 9 is a flow chart of a control method of the present invention.

In the figure: 1-single-rod hydraulic cylinder, 2-distributed pump control system, 2-1-I distributed pump control system, 2-2-II distributed pump control system, 3-I motor/generator, 4-bidirectional constant displacement pump/motor, 5-I inverter, 6-I oil-supplementing one-way valve, 7-II oil-supplementing one-way valve, 8-I overflow valve, 9-II overflow valve, 10-DC bus, 11-filter capacitor, 12-DC-DC converter, 13-super capacitor group, 14-rectifier, 15-power switch, 16-flow compensation distribution unit, 16-1-I flow compensation distribution unit, 16-2-II flow compensation distribution unit, 16-3-III flow compensation distribution unit, 17-the pressure sensor I, 18-the pressure sensor II, 19-the main control valve, 20-the pressure compensator, 20-1-the pressure compensator I, 20-2-the pressure compensator II, 20-3-the pressure compensator III, 21-the displacement sensor I, 22-the centralized oil supply pump, 23-the main motor, 24-the main safety valve, 25-the inverter II, 26-the pressure sensor III, 27-the switch valve, 28-the overflow valve III, 29-the low pressure accumulator, 30-the pressure sensor IV, 31-the displacement sensor II, 32-the controller, 33-the signal receiver, 34-the operation module, 35-the signal output device, 36-the proportional valve I, 37-the proportional valve II, 38-a third proportional valve, 39-a proportional reversing valve, 40-a fourth proportional valve, 41-a fifth proportional valve, 42-a load detection proportional valve, 43-an oil supplement accumulator, 44-a third displacement sensor, 45-a shuttle valve, 46-a proportional electromagnet, 47-a hydraulic motor, 48-an auxiliary motor and 49-a third frequency converter.

Detailed Description

The first embodiment is as follows:

as shown in fig. 1, the distributed pump control single actuator system includes a single-rod hydraulic cylinder 1, a distributed pump control system 2, a flow compensation distribution unit 16, a pressure compensator 20, a centralized oil replenishment pump 22, a main motor 23, a ii-th inverter 25, a load detection proportional valve 42, an oil replenishment accumulator 43, a dc bus 10, and a controller 32.

The single-outlet-rod hydraulic cylinder 1 is provided with a second displacement sensor 31 for detecting the position of a piston rod, the single-outlet-rod hydraulic cylinder 1 is controlled by a distributed pump control system 2, and the distributed pump control system 2 comprises a first motor/generator 3, a bidirectional constant delivery pump/motor 4, a first inverter 5, a first oil supplementing one-way valve 6, a second oil supplementing one-way valve 7, a first overflow valve 8 and a second overflow valve 9; the I motor/generator 3 coaxially drives the two-way constant delivery pump/motor 4, two ends of the two-way constant delivery pump/motor 4 are respectively communicated with two cavities of the single-rod hydraulic cylinder 1, oil outlets of the I oil supplementing check valve 6 and the II oil supplementing check valve 7 are respectively communicated with two cavities of the two-way constant delivery pump/motor 4, oil inlets of the I oil supplementing check valve 6 and the II oil supplementing check valve 7 are communicated with the low-pressure energy accumulator 29, oil is supplemented to the two cavities of the two-way constant delivery pump/motor 4 through the low-pressure energy accumulator 29 for compression, leakage and the like, oil inlets of the I overflow valve 8 and the II overflow valve 9 are communicated with the two cavities of the two-way constant delivery pump/motor 4, and oil outlets of the I overflow valve 8 and the II overflow valve 9 are communicated with an oil tank.

The main motor 23 is connected with the centralized oil replenishing pump 22, the oil outlet of the centralized oil replenishing pump 22 is connected with an oil supply pipeline L, the oil supply pipeline L is provided with a pressure compensator 20, a main safety valve 24, a III pressure sensor 26, a switch valve 27 and a load detection proportional valve 42, the oil outlet of the centralized oil replenishing pump 22 is respectively communicated with the oil inlet of the pressure compensator 20, the oil inlet of the main safety valve 24, the oil inlet of the III pressure sensor 26, the oil inlet of the switch valve 27 and the oil inlet of the load detection proportional valve 42 through the oil supply pipeline L, the oil outlet of the pressure compensator 20 is connected with a flow compensation distribution unit 16, the pressure compensator 20 is provided with an I displacement sensor 21, the flow compensation distribution unit 16 is communicated with a working oil port of the single-rod hydraulic cylinder 1 to compensate asymmetric flow caused by the area difference of the single-rod hydraulic cylinder 1, the oil outlet of the main safety valve 24 is communicated with an oil tank, the oil outlet of the switch valve 27 is communicated with a low-pressure accumulator 29, the centralized oil replenishing pump 22 is controlled by the switch valve 27 to replenish oil to the low-pressure accumulator 29. The load detection proportional valve 42 is communicated with an oil tank at a working oil port C, is connected with an oil supplementing energy accumulator 43 at a working oil port D, is connected with a spring end of the pressure compensator 20 at a spring end, detects the load pressure of the actuator, is communicated with the main oil line L at an end 46 of the proportional electromagnet, detects the oil outlet pressure of the centralized oil supplementing pump 22, and ensures that the outlet pressure of the centralized oil supplementing pump 22 is always higher than the load pressure of the actuator by a fixed value through the spring force of the load detection proportional valve 42. The main motor 23 and the distributed pump control system 2 are respectively connected with the direct current bus 10 through a IIth inverter 25 and an I th inverter 5, and the super capacitor bank 13 is connected with the direct current bus 10 through the DC-DC converter 12.

As shown in fig. 2, the flow compensation distribution unit 16 includes: a first pressure sensor 17, a second pressure sensor 18 and a main control valve 19; the oil outlet of the pressure compensator 20 is communicated with the oil inlet P of the main control valve 19, the oil outlet T of the main control valve 19 is communicated with an oil tank, the working oil port A of the main control valve 19 is respectively connected with the first pressure sensor 17 and the rodless cavity of the single-rod hydraulic cylinder 1, and the working oil port B of the main control valve 19 is respectively connected with the second pressure sensor 18 and the rod cavity of the single-rod hydraulic cylinder 1. The spring end of the pressure compensator 20 is connected with the load detection oil port LS of the main directional valve 20, and the other end of the pressure compensator 20 is connected with the oil inlet P of the main control valve 19.

Fig. 3 shows a second schematic diagram of the flow compensation distribution unit, which differs from fig. 2 in that the flow compensation distribution unit 16 is further provided with an i-th proportional valve 36, and the main control valve 19 has an oil return port T communicated with the oil tank through the i-th proportional valve 36.

Fig. 4 shows a third structural schematic diagram of the flow compensation distribution unit, which is different from fig. 2 in that a second proportional valve 37 and a third proportional valve 38 are additionally arranged in the flow compensation distribution unit 16, oil inlets of the second proportional valve 37 and the third proportional valve 38 are respectively communicated with a working oil port A, B of the main control valve 19, oil outlets of the second proportional valve 37 and the third proportional valve 38 are respectively communicated with an oil tank, and an oil return port T of the main control valve 19 is blocked.

FIG. 5 is a schematic diagram of a fourth structure of the flow compensation distribution unit, which is different from FIG. 2 in that the flow compensation distribution unit 16 is additionally provided with a proportional reversing valve 39, and a working oil port A of the proportional reversing valve 39₁、B₁Respectively communicated with a working oil port A, B of the main control valve 19 and an oil inlet P of the proportional reversing valve 39₁Is blocked, and the oil return port T of the proportional reversing valve 39₁Is communicated with the oil tank.

Fig. 6 shows a fifth schematic diagram of the flow compensation distribution unit, which is different from fig. 2 in that the flow compensation distribution unit 16 further includes an iv proportional valve 40 and a v proportional valve 41, the iv proportional valve 40 is disposed between the pressure compensator 20 and the oil inlet P of the main control valve 19, the spring end of the pressure compensator 20 is connected to the oil outlet of the iv proportional valve 40, the other end is connected to the oil inlet of the iv proportional valve 40, and the oil outlet T of the main control valve 19 is communicated with the oil tank through the v proportional valve 41.

Example two:

as shown in fig. 7, the distributed pump-controlled multi-actuator system includes a first single-rod hydraulic cylinder 1-1, an ith distributed pump-controlled system 2-1, an ith flow compensation distribution unit 16-1, an ith pressure compensator 20-1, a centralized oil supplementing pump 22, a main motor 23, an ith inverter 25, a load detection proportional valve 42, an oil supplementing accumulator 43, a dc bus 10, and a controller 32, which have the same structure and connection mode as those of the first embodiment.

In this embodiment, three sets of actuators are arranged in parallel on the oil supply pipeline L, and in addition to the first single-rod hydraulic cylinder 1-1, a second single-rod hydraulic cylinder 1-2 and a hydraulic motor 47 are further added;

the second single-rod hydraulic cylinder 1-2 is matched with a second distributed pump control system 2-2, a second flow compensation distribution unit 16-2 and a second pressure compensator 20-2, the third single-rod hydraulic cylinder 1-3 is matched with a third distributed pump control system 2-3, a third flow compensation distribution unit 16-3 and a third pressure compensator 20-3. Each pressure compensator is provided with an I displacement sensor 21, and each single-rod hydraulic cylinder is provided with an II displacement sensor 31 for detecting the position of a piston rod;

the difference between the second distributed pump control system 2-2 and the first distributed pump control system 2-1 is that one of the two check valves in the system is a hydraulic control check valve, oil outlets of the check valve and the hydraulic control check valve in the system are respectively communicated with two cavities of the bidirectional constant delivery pump/motor 4, an oil inlet is communicated with the low-pressure energy accumulator 29, and an oil control port of the hydraulic control check valve in the system is communicated with a cavity in the constant delivery pump/motor 4, which is communicated with the oil outlet of the check valve;

the hydraulic motor 47 is coaxially and mechanically connected with the auxiliary motor 48, and is matched with a III pressure compensator 20-3 and a III flow compensation distribution unit 16-3, an oil inlet of the III pressure compensator 20-3 is communicated with an oil supply pipeline L, an oil outlet of the III pressure compensator 20-3 is connected with an oil inlet of the III flow compensation distribution unit 16-3, a working oil port of the III flow compensation distribution unit 16-3 is communicated with two cavities of the hydraulic motor 47, and the auxiliary motor 48 is connected with the direct current bus 10 through a III frequency converter 49.

As shown in fig. 7, the system is further provided with a shuttle valve group 45, one end of an oil inlet of the shuttle valve 45 is communicated with an LS oil port of the main control valve 19 in the flow compensation distribution unit 16, the other end of the shuttle valve 45 is communicated with an oil outlet of the shuttle valve in the next flow compensation distribution unit 16, an oil outlet of the first shuttle valve 45 is connected with an oil port of a spring end of the load detection proportional valve 42, so that the spring end of the load detection proportional valve 42 detects the highest load pressure of each actuator, and the other end of the last shuttle valve 45 is communicated with an oil tank.

As shown in fig. 8, the controller 32 includes a signal receiver 33, an operation module 34, and a signal output device 35; the signal receiver 33 continuously receives the initial input signal, the rotation speed and torque feedback signals fed back by the i-th motor/generator 3 and the main motor 23, continuously receives the pressure signals output by the i-th pressure sensor 17, the ii-th pressure sensor 18, the iii-th pressure sensor 26 and the iv-th pressure sensor 30, continuously receives the displacement signal from the i-th displacement sensor 21, inputs the signals into the operation module 34 for operation, and finally controls the rotation speed and torque of the i-th motor/generator 3 and the main motor 23 and the opening of the main control valve 19 through the signal output device 35.

As shown in fig. 9, the specific operation module includes the following steps:

the method comprises the following steps: giving a plurality of speed control signals of the single-rod hydraulic cylinder 1, taking the flow of the rod cavity of the single-rod hydraulic cylinder as a reference, and calculating according to a formula n_x＝vA_B/V_dCalculating the rotational speed of the first motor/generator 3 of the distributed pump control system 2, wherein A_BThe area of a rod cavity of the single-rod hydraulic cylinder is V_dIs a closed pump displacement.

Step two: the pressure of the driving cavities of a plurality of single-rod hydraulic cylinders 1 is detected in real time by the pressure sensor I17 or the pressure sensor II 18 and compared in the controller 32, and the difference value between the maximum driving cavity pressure and the driving cavity pressure of each actuator is used as a control quantity, namelyThe rotation speed control of the first motor/generator 3 is superposed, and the pressure of the driving cavities of the actuators is equal through repeated adjustment, so that the equivalent loads of the single-rod hydraulic cylinders 1 are the same, and the throttling loss caused by the load difference on the pressure compensator 20 is eliminated.

Step three: respectively calculating the asymmetric flow Q of a plurality of single-rod hydraulic cylinders 1 to be compensated₁、Q₂、Q₃… …, and summing to control the rotation speed of the main motor 23 and the opening of the main control valve 19, so that the highest load main control valve 19 has the largest opening and the low load actuator main control valve has the largest opening>80% and above, the 80% control amount can be set according to specific conditions in practice.

Step four: in the multiple flow compensation distribution units 16, the first displacement sensor 21 is adopted to detect the valve core displacement of the pressure compensator 20 in real time, the valve core displacement is compared with the valve core displacement of the maximum set pressure compensator 20, the difference value is taken as a control quantity and is superposed on a rotating speed control signal of the main motor 23, and the control quantity is repeatedly adjusted, so that the valve ports of the pressure compensator 20 in the multiple flow compensation distribution units 16 are kept fully opened, the output flow of the oil supplementing pump 23 can be considered to completely meet the asymmetric flow requirement of the multiple single-rod hydraulic cylinders 1, and the flow matching is realized.

The foregoing merely illustrates several embodiments of the invention, which are described in greater detail and detail, and not to limit the scope of the invention. The distributed pump control unit in the inventive concept adopts a transformer to drive a fixed displacement pump to realize flow control, and for those skilled in the art, the distributed pump control unit can also adopt a diesel engine to drive a variable displacement pump to realize flow control without departing from the inventive concept, which also belongs to the protection scope of the invention. Accordingly, it is intended that all equivalent alterations and modifications be made without departing from the spirit and scope of the invention.