CN108591144A - The distributed direct of the double accumulators of the double constant displacement pumps of motor driving drives excavator hydraulic system - Google Patents

Abstract

The present invention provides a distributed direct-drive excavator hydraulic system with motors driving double constant pumps and double accumulators. The controller inputs signals to the drivers, and then controls the drive in each hydraulic module through the drivers. The speed and direction of the motor are used to realize the control of the hydraulic cylinder, avoiding the throttling loss and overflow loss of the system, the system efficiency is high, the main circuit is short and there is no throttling element, so the pressure loss is less and the heat generation is less , no cooling device is required; two accumulators are used at the same time, wherein the second accumulator is used to replace the oil tank; When the effective area ratio of the chamber is inconsistent, it is used to balance the flow of the first chamber and the second chamber, and solve the problem that the displacement ratio of the two quantitative pumps cannot accurately match the effective area of the two chambers of the hydraulic cylinder than the problem.

Description

Distributed direct-drive excavator hydraulic system with motor-driven dual quantitative pumps and dual accumulators

technical field

The invention relates to the field of excavators, in particular to a hydraulic system of the excavator.

Background technique

As the most commonly used machinery in construction machinery, hydraulic excavators have the disadvantages of high fuel consumption, poor emissions, and low energy utilization. Under the situation of energy shortage and environmental pollution becoming more and more serious, how to realize the energy saving and emission reduction of excavators has attracted more and more attention, and has become a hot research topic at present.

The current excavator still uses the driving system of engine-variable pump-multi-way valve-actuator. Due to the requirements of energy saving and environmental protection, some studies have used ordinary motors to replace engines, but the system efficiency still needs to be improved. With the successive development of AC servo motors, servo motors-quantitative hydraulic pumps/motors-hydraulic valves-actuators have been used in engineering applications, such as injection molding machines. These hydraulic system energy saving methods play an important role in improving efficiency.

Invention patent CN201110453095 "An all-electric servo excavator" (disclosure date: 2013-07-03), adopts an electric-mechanical drive and servo system combining an AC servo motor and a ball screw, and its advantage is that electric energy is directly converted into Mechanical energy, simple system, less energy consumption, and small footprint. However, when low-speed, high-torque, and high-efficiency working conditions are required, this kind of motor-machine transmission and servo system needs to add a reducer to complete the transmission task, which makes the system complicated, and sometimes even adding a reducer still cannot meet the requirements.

Invention patent CN201610406357 "Full electric drive hydraulic excavator power system" (disclosure date: 2016-10-12), controls the speed and direction of each servo motor, so as to control the output flow of the bidirectional quantitative pump connected to it And direction, and finally complete the speed control of each hydraulic actuator. ①The system uses a servo motor to drive a two-way quantitative pump to control a symmetrical hydraulic cylinder. The effective area on the piston side of the hydraulic cylinder is reduced, so that the output force is greatly reduced when the piston is extended. ②When the system pressure is high, the torque required to drive the fixed displacement pump is relatively large, which requires high performance of the motor, for example, a wide range of torque and power. ③The system cannot recover the energy fed back by negative loads.

Contents of the invention

The technical problem to be solved by the present invention is to provide a distributed direct-drive excavator hydraulic system with dual quantitative pumps and double accumulators driven by a motor, which avoids the throttling loss and overflow loss of the system, has high system efficiency, and realizes energy saving, Emission reduction and noise reduction.

The present invention is achieved in this way: the hydraulic system of the distributed direct-drive excavator with the motor-driven dual quantitative pumps and dual accumulators includes a controller and at least one hydraulic module; each hydraulic module includes a hydraulic cylinder, a first two-way quantitative A pump, a second two-way quantitative pump, a first accumulator, a second accumulator, a three-position three-way control valve, a driver, and a drive motor;

The hydraulic cylinder includes a cylinder, a piston and a piston rod, one end of the piston rod is fixedly connected to the piston, the piston is airtightly slidably connected to the cylinder, and the piston connects the The inner part of the cylinder is divided into a first chamber and a second chamber;

The three-position three-way control valve includes a first oil connection port, a first hydraulic control control oil port, a second oil connection port, a second hydraulic control control oil port and a third oil connection port;

The first bidirectional quantitative pump includes a first drain port, a first port and a second port;

The second bidirectional quantitative pump includes a second oil drain port, a third port and a fourth port;

The second port and the fourth port are connected in parallel to the second accumulator; the first port, the first oil connection port and the first hydraulic control oil port are connected in parallel to communicate with the first chamber chamber; the third port, the second oil connection port and the second hydraulic control control oil port are connected in parallel to communicate with the second chamber; the third oil connection port is connected to the first accumulator; the The first oil drain port is connected between the second port and the fourth port, the second oil drain port is connected between the fourth port and the second accumulator,

The first bidirectional quantitative pump and the second bidirectional quantitative pump are respectively connected to the driving motor to realize synchronous movement; the driver is connected to the controller through communication.

Further, a power supply device is also included, and the driver and the controller are respectively electrically connected to the power supply device.

Further, each hydraulic module also includes a first control valve and a second control valve, and the first port, the first oil connection port and the first hydraulic control control oil port are connected in parallel to the first control valve in sequence , the first chamber; the third port, the second oil connection port and the second hydraulic control oil port are connected in parallel to the second control valve and the second chamber; the first The control valve and the second control valve are also communicatively connected to the controller.

Further, the first control valve and the second control valve are respectively two-position two-way solenoid valves.

Further, the first control valve and the second control valve are respectively two-position two-way cartridge valves.

Further, each hydraulic module further includes a first one-way valve, a second one-way valve, a first safety valve and a second safety valve;

The inlet of the first one-way valve and the outlet of the first safety valve are connected in parallel to the second port, and the outlet of the first one-way valve and the inlet of the first safety valve are connected in parallel and then connected to the second port. between the first control valve and the first chamber;

The inlet of the second one-way valve and the outlet of the second safety valve are connected in parallel to the second accumulator, and the outlet of the second one-way valve and the inlet of the second safety valve are connected in parallel connected between the second control valve and the second chamber.

Further, the three-position three-way control valve is a three-position three-way hydraulic control valve.

Further, the three-position three-way control valve is a three-position three-way cartridge valve.

Further, the driving motor is a servo motor, and the driver is a servo driver.

Further, the number of the hydraulic modules is three.

The present invention has the following advantages: the present invention controls the hydraulic cylinder by inputting a signal to the driver through the controller, and then controls the speed and direction of the drive motor in each hydraulic module through the driver, The throttling loss and overflow loss of the system are avoided, the system efficiency is high, the main circuit is very short and there is no throttling element, so the pressure loss is small, the calorific value is small, and no cooling device is used at the same time. Two accumulators are used, of which The second accumulator is used to replace the oil tank; the first accumulator is used when the displacement ratio of the first bidirectional quantitative pump and the second bidirectional quantitative pump is equal to the effective area of the first chamber and the second chamber When the ratio is inconsistent, it is used to balance the flow of the first chamber and the second chamber, and solve the problem that the displacement ratio of the first bidirectional quantitative pump and the second bidirectional quantitative pump cannot accurately match the first chamber and the second chamber. The problem of the effective area ratio of the second chamber.

Description of drawings

The present invention will be further described below in conjunction with the embodiments with reference to the accompanying drawings.

Fig. 1 is a schematic diagram of an embodiment of the hydraulic system of the present invention.

Fig. 2 is a schematic diagram of the oil operation of the hydraulic module in the first working condition according to the present invention.

Fig. 3 is a schematic diagram of the operation principle of the hydraulic module in the second working condition of the hydraulic module according to the present invention.

Fig. 4 is a schematic diagram of the operation principle of the oil in the hydraulic module according to the present invention in the third working condition.

Fig. 5 is a schematic diagram of the operation principle of the oil in the hydraulic module according to the present invention in working condition four.

Fig. 6 is a schematic diagram of the operation principle of oil in the hydraulic module according to the present invention in working condition five.

Fig. 7 is a schematic diagram of the operation principle of the oil in the hydraulic module of the present invention under working condition six.

Fig. 8 is a schematic diagram of the operation principle of oil in the hydraulic module according to the present invention in working condition 7.

Fig. 9 is a schematic diagram of the operation principle of the hydraulic module of the present invention in working condition eight.

Fig. 10 is a schematic diagram of the effect of the present invention.

In the figure: 100, controller; 200, hydraulic module; 201, hydraulic cylinder; 2011, cylinder body; 2012, piston; 2013, piston rod; 202, first bidirectional quantitative pump; 2021, first port; 2022, second Port; 2023, the first oil drain port; 203, the second two-way quantitative pump; 2031, the third port; 2032, the fourth port; 2033, the second oil drain port; 204, the first accumulator; 205, the second Accumulator; 206, three-position three-way control valve; 2061, first oil connection port; 2062, first hydraulic control control oil port; 2063, second oil connection port; 2064, second hydraulic control control oil port; 2065 , the third oil connection port; 207, the driver; 208, the drive motor; 209, the first control valve; 210, the second control valve; 211, the first one-way valve; 212, the second one-way valve; 213, the first Safety valve; 214, second safety valve; 300, boom; 400, stick; 500, bucket; 600, power supply unit; 700, first chamber; 800, second chamber.

Detailed ways

Please refer to Figs. 1 to 10, the present invention provides a distributed direct-drive excavator hydraulic system with motor-driven double constant pumps and double accumulators, including a controller 100 and at least one hydraulic module 200; The module 200 includes a hydraulic cylinder 201, a first bidirectional quantitative pump 202, a second bidirectional quantitative pump 203, a first accumulator 204, a second accumulator 205, a three-position three-way control valve 206, a driver 207 and a drive motor 208;

The hydraulic cylinder 201 includes a cylinder body 2011, a piston 2012 and a piston rod 2013, one end of the piston rod 2013 is fixedly connected to the piston 2012, and the piston 2012 is airtightly slidably connected in the cylinder body 2011 , and the piston 2012 divides the interior of the cylinder 2011 into a first chamber 700 and a second chamber 800;

The three-position three-way control valve 206 includes a first oil connection port 2061, a first hydraulic control control port 2062, a second oil connection port 2063, a second hydraulic control control port 2064 and a third oil connection port 2065;

The first bidirectional quantitative pump 202 includes a first drain port 2023, a first port 2021 and a second port 2022;

The second bidirectional quantitative pump 203 includes a second oil drain port 2033, a third port 2031 and a fourth port 2032;

The second port 2022 and the fourth port 2032 are connected in parallel to the second accumulator 205; the first port 2021, the first oil connection port 2061 and the first hydraulic control oil port 2062 are connected in parallel communicate with the first chamber 700; the third port 2031, the second oil connection port 2063 and the second hydraulic control control oil port 2064 are connected in parallel and communicate with the second chamber 800; the third oil connection port 2065 Connected to the first accumulator 204; the first oil drain port 2023 is connected between the second port 2022 and the fourth port 2032, and the second oil drain port 2033 is connected to the fourth port 2032 and the second accumulator 205, can prevent the first two-way quantitative pump 202 or the second two-way quantitative pump 203 pressure from being too high and cause the casing to rupture, ensuring safety;

The first bidirectional quantitative pump 202 and the second bidirectional quantitative pump 203 are respectively connected to the drive motor 208 to realize synchronous movement; the driver 207 is connected to the controller 100 by communication.

In a specific implementation, the hydraulic cylinder 201 is an asymmetric hydraulic cylinder 201, and the piston rod 2013 is connected to an applied load. In the present invention, the controller 100 inputs signals to the driver 207, and then controls the speed and direction of the drive motor 208 in each hydraulic module 200 through the driver 207, and then controls the first bidirectional quantitative pump 202 and The flow rate and flow direction of the second bidirectional quantitative pump 203 finally realize the control of the hydraulic cylinder 201 .

The first bidirectional quantitative pump 202 and the second bidirectional quantitative pump 203 are directly connected to the drive motor 208 to independently drive the hydraulic cylinder 201, not only to realize the flow rate of the first chamber 700 and the second chamber 800 The basic matching also avoids throttling loss and overflow loss, and the system efficiency is high.

The distributed intelligent control of power transmission by wires instead of hydraulic pipelines makes the main circuit of the invention very short and has no throttling elements, so the pressure loss is small, the calorific value is small, and no cooling device is needed.

Compared with the traditional hydraulic system, the present invention adopts a closed system that uses less oil, requires a small volume of the first accumulator 204 and the second accumulator 205, and can make each hydraulic module 200 into a hydraulic package form.

The drive motor 208 is used to replace the engine-driven variable pump in the traditional technology, the system efficiency is greatly improved, and energy saving, emission reduction and noise reduction are realized. After the traditional system starts to work, the actuator will not stop even if it is not working, and the motor and oil pump will run as usual, which consumes a lot of energy. In the present invention, when the hydraulic cylinder 201 needs to work, the driving motor 208 runs, and when the hydraulic cylinder 201 does not work, the driving motor 208 stops, so as to realize on-demand driving and save electric energy.

The present invention adopts two accumulators, wherein the second accumulator 205 is used to replace the oil tank, and since the hydraulic cylinder 201 is an asymmetrical hydraulic cylinder 201, the first chamber 700 and the second chamber The chamber 800 has an effective area difference, at this time, the second accumulator 205 also plays the role of balancing flow; When the displacement ratio of 203 is inconsistent with the effective area ratio of the first chamber 700 and the second chamber 800, it is used to balance the flow of the first chamber 700 and the second chamber 800, solving the problem of the first chamber 700 and the second chamber 800 The displacement ratio of the first bidirectional quantitative pump 202 and the second bidirectional quantitative pump 203 cannot precisely match the effective area ratio of the first chamber 700 and the second chamber 800 .

And in a specific implementation, the first bidirectional quantitative pump 202 and the second bidirectional quantitative pump 203 can be used as a pump and a motor respectively. At this time, the present invention also provides conditions for recycling the potential energy fed back by the load.

In specific implementation, a preferred embodiment further includes a power supply device 600, the driver 207 and the controller 100 are respectively electrically connected to the power supply device 600, and in the case of a negative load, the first bidirectional quantitative pump 202 and the second bidirectional quantitative pump 203 are used as motors, which can convert the potential energy fed back by the load at this time into electric energy and store it in the power supply device 600, so as to realize the recovery and utilization of energy at negative loads and save electric energy.

Each hydraulic module 200 also includes a first control valve 209 and a second control valve 210, the first port 2021, the first oil connection port 2061 and the first hydraulic control control port 2062 are connected in parallel and connected to the first control valve in sequence. A control valve 209, the first chamber 700; the third port 2031, the second oil connection port 2063 and the second hydraulic control control oil port 2064 are connected in parallel to the second control valve 210, the The second chamber 800; the first control valve 209 and the second control valve 210 are also respectively connected to the controller 100 in communication, and the controller 100 controls the first control valve 209 and the second control valve 210 on or off. The hydraulic cylinder 201 is locked by the first control valve 209 and the second control valve 210 to avoid sliding caused by the leakage of the first bidirectional quantitative pump 202 or the second bidirectional quantitative pump 203 .

The first control valve 209 and the second control valve 210 are respectively two-position two-way solenoid valves. When the flow rate is small, a two-position two-way solenoid valve is used, and it is mainly used in mini excavators in practical applications.

The first control valve 209 and the second control valve 210 are respectively two-position two-way cartridge valves. Two-position two-way cartridge valves are used for large flows, and are mainly used in small, medium and large excavators in practical applications.

Each hydraulic module 200 also includes a first one-way valve 211, a second one-way valve 212, a first safety valve 213 and a second safety valve 214;

The inlet of the first one-way valve 211 and the outlet of the first safety valve 213 are connected in parallel to the second port 2022, and the outlet of the first one-way valve 211 and the outlet of the first safety valve 213 are connected in parallel. The inlet is connected in parallel between the first control valve 209 and the first chamber 700;

The inlet of the second one-way valve 212 and the outlet of the second safety valve 214 are connected in parallel to the second accumulator 205, and the outlet of the second one-way valve 212 and the second safety valve The inlet of 214 is connected in parallel between the second control valve 210 and the second chamber 800 . Through the combination of the first one-way valve 211 and the first safety valve 213, or the combination of the second one-way valve 212 and the second safety valve 214, it is possible to prevent the phenomenon of suction at low pressure, and to release the pressure at high pressure, and the excess The oil stored in the second accumulator 205, specifically, when the pressure of the first chamber 700 or the second chamber 800 is low, the corresponding first check valve 211 or the second The one-way valve 212 conducts, and the oil is added from the second accumulator 205 to the first chamber 700 or the second chamber 800; when the first chamber 700 or the second chamber 800 When the pressure is too high, the corresponding first safety valve 213 or second safety valve 214 is turned on to release the pressure, and the excess oil flows into the second accumulator 205 to ensure safety .

The three-position three-way control valve 206 is a three-position three-way hydraulic control valve.

The three-position three-way control valve 206 is a three-position three-way cartridge valve.

The driving motor 208 is a servo motor 208, and the driver 207 is a servo driver 207, which can make the control speed very accurate.

The number of the hydraulic modules 200 is three. Connect the respective piston rods 2013 of the three hydraulic modules 200 to the boom 300, stick 400, and bucket 500 of the excavator in one-to-one correspondence, so that the three can be driven independently, which is convenient for control and greatly shortens the In addition to the pipeline, the hydraulic module 200 can be made into a hydraulic package, which is directly installed near the boom 300, stick 400, and bucket 500, which is easy to install and small in size.

Specific control principle:

Due to the existence of the piston rod 2013, the first chamber 700 and the second chamber 800 have an asymmetric structure, so that the maximum volume of the first chamber 700 is greater than the maximum volume of the second chamber 800, The hydraulic cylinder 201 is an asymmetrical hydraulic cylinder 201. When the oil is delivered from the first chamber 700 to the second chamber 800, there is excess oil, and the excess oil needs to be stored in the second chamber 800. In the second accumulator 205, when the oil is delivered from the second chamber 800 to the first chamber 700, the oil in the second accumulator 205 needs to be added to the first chamber Room 700.

On the other hand, in Fig. 2 to Fig. 9, F is the external force exerted by the load on the piston rod 2013, and v is the running speed of the piston rod 2013; the direction of the hydraulic force is opposite to that of the external force F; the piston rod 2013 is connected Due to the load of the excavator, the load of the excavator will generate potential energy during the working process; the first bidirectional quantitative pump 202 and the second bidirectional quantitative pump 203 can be used as pumps or motors to generate electricity;

Positive load: the direction of the hydraulic pressure is the same as the direction of v, the piston rod 2013 extends or retracts, at this time the power supply device 600 outputs electric energy, and the controller 100 controls the driver 207 to drive the servo motor 208 Drive the first bidirectional quantitative pump 202 and the second bidirectional quantitative pump 203 to rotate according to the speed and direction set by the controller, and the piston rod 2013 outputs energy to the load;

Negative load: the direction of the hydraulic pressure is opposite to the direction of v, the piston rod 2013 extends or retracts, and the load feeds back energy to the piston rod 2013, and then the first bidirectional quantitative pump 202 and the second The two-way quantitative pump 203 is used as a motor to generate electricity, and energy is stored in the power supply device 600 for recycling;

The displacement of the first bidirectional quantitative pump 202 is marked as V _{p_a} , the displacement of the second bidirectional quantitative pump 203 is marked as V _{p_b} , the effective area of the first chamber 700 is marked as A ₁ , and the second chamber 800 The effective area is marked as A ₂ ; when V _{p_b} /V _{p_a} and A ₂ /A ₁ do not match, there are the following two situations:

Case 1, V _{p_b} /V _{p_a} is greater than A ₂ /A ₁ ; at this time, there are the following four working conditions:

Working condition 1, please refer to FIG. 2 . At this time, it is under negative load, the pressure of the first chamber 700 is greater than the pressure of the second chamber 800, and the oil flows from the second chamber 800 to the The first chamber 700, the first hydraulic control oil port 2062 connects the second oil port 2063 of the three-position three-way control valve 206 with the first accumulator 204, at this time the The oil in the first accumulator 204 is added to the oil flowing out of the second chamber 800 , and the oil in the second accumulator 205 flows out to be added to the first bidirectional quantitative pump 202 , delivered to the first chamber 700 by the first bidirectional quantitative pump 202, thereby realizing the flow balance of the first chamber 700 and the second chamber 800, while the first bidirectional quantitative pump 202 and The second bidirectional quantitative pump 203 converts the potential energy fed back by the load into electrical energy, and stores it in the power supply device 600 for recycling, which saves electrical energy.

Working condition 2, please refer to FIG. 3 , at this time it is under positive load, the pressure of the second chamber 800 is greater than the pressure of the first chamber 700, and the oil flows from the second chamber 800 to the The first chamber 700, the second hydraulic control oil port 2064 connects the first oil connection port 2061 of the three-position three-way control valve 206 with the first accumulator 204, at this time the The oil in the first accumulator 204 is directly added to the first chamber 700, and the oil in the second accumulator 205 flows out to be added to the first bidirectional quantitative pump 202. The first bidirectional quantitative pump 202 delivers energy to the first chamber 700, so as to achieve flow balance between the first chamber 700 and the second chamber 800, and at this time, the piston rod 2013 outputs energy to the load.

Working condition three, please refer to FIG. 4 , at this time it is under positive load, the pressure of the first chamber 700 is greater than the pressure of the second chamber 800, and the oil flows from the first chamber 700 to the The second chamber 800, the oil output by the first bidirectional quantitative pump 202 respectively flows into the second accumulator 205 and the second bidirectional quantitative pump 203, the first hydraulic control oil port 2062 Connect the second oil connection port 2063 of the three-position three-way control valve 206 with the first accumulator 204, at this time, part of the flow output by the second bidirectional quantitative pump 203 flows into the first accumulator In the device 204, another part of oil flows into the second chamber 800, so as to realize flow balance in the first chamber 700 and the second chamber 800, and at this time, the piston rod 2013 outputs energy to the load.

Working condition 4, please refer to FIG. 5 . At this time, it is under negative load, the pressure of the second chamber 800 is greater than the pressure of the first chamber 700, and oil flows from the first chamber 700 to all The second chamber 800, the second hydraulic control oil port 2064 connects the first oil connection port 201 of the three-position three-way control valve 206 with the first accumulator 204, and the first Part of the oil flowing out of the chamber 700 flows into the first accumulator 204 through the first oil connection port 2061 , and the other part is delivered to the second bidirectional quantitative pump 203 through the first bidirectional quantitative pump 202 and the second accumulator 205, thereby realizing the flow balance in the first chamber 700 and the second chamber 800, at this time, the first bidirectional quantitative pump 202 and the second bidirectional quantitative pump 203 feed back the load The potential energy is converted into electric energy and stored in the power supply device 600 for recycling, saving electric energy.

Case 2, V _{p_b} /V _{p_a} is less than A ₂ /A ₁ ; at this time, there are the following four working conditions:

Working condition five, please refer to FIG. 6 , at this time it is under negative load, the pressure of the first chamber 700 is greater than the pressure of the second chamber 800, and the oil flows from the second chamber 800 to the The first chamber 700, the first hydraulic control oil port 2062 connects the second oil port 2063 of the three-position three-way control valve 206 with the first accumulator 204, at this time the Part of the oil flowing out of the second chamber 800 flows into the first accumulator 204, and the other part flows to the second bidirectional quantitative pump 203 and is delivered to the first bidirectional quantitative pump 202, and the second accumulator The oil in the energy device 205 flows out, replenishes in the first two-way quantitative pump 202, and is delivered to the first chamber 700 by the first two-way quantitative pump 202, thereby realizing the first chamber 700 and The flow in the second chamber 800 is balanced, while the first bidirectional quantitative pump 202 and the second bidirectional quantitative pump 203 convert the potential energy fed back by the load into electrical energy, and store it in the power supply device 600 for recycling, saving electrical energy.

Operating condition 6, please refer to FIG. 7 , at this time, it is under positive load, the pressure of the second chamber 800 is greater than the pressure of the first chamber 700, and the second hydraulic control oil port 2064 will The first oil connection port 2061 of the three-position three-way control valve 206 is connected to the first accumulator 204, the oil flows from the second chamber 800 to the first chamber 700, and the second The oil in the accumulator 205 is added to the first two-way quantitative pump 202, and part of the oil output by the first two-way quantitative pump 202 flows into the first chamber 700, and the other part passes through the first interface. The oil port 2061 flows into the first accumulator 204, so as to realize flow balance in the first chamber 700 and the second chamber 800, and at this time, the piston rod 2013 outputs energy to the load.

Working condition 7, please refer to FIG. 8 , at this time, it is under positive load, the pressure of the first chamber 700 is greater than the pressure of the second chamber 800, and the first hydraulic control oil port 2062 connects the The second oil connection port 2063 of the three-position three-way control valve 206 is connected to the first accumulator 204, the oil flows from the first chamber 700 to the second chamber 800, and the first Part of the oil output from the bidirectional quantitative pump 202 flows into the second accumulator 205, and the other part flows into the second bidirectional quantitative pump 203, and then flows into the second chamber 800, while the first accumulator The oil in the device 204 flows into the second chamber 800 through the second oil connection port 2063, so as to realize the flow balance between the first chamber 700 and the second chamber 800, at this time, the piston Rod 2013 outputs energy to the load.

Working condition 8, please refer to FIG. 9 . At this time, it is under negative load, the pressure of the second chamber 800 is greater than the pressure of the first chamber 700, and the oil flows from the first chamber 700 to all The second chamber 800, the second hydraulic control oil port 2064 connects the first oil connection port 2061 of the three-position three-way control valve 206 with the first accumulator 204, at this time the The oil flowing out of the first chamber 700 flows into the first bidirectional quantitative pump 202 , and the oil in the first accumulator 204 flows into the first bidirectional quantitative pump 202 from the first oil connection port 2061 In the pump 202, part of the oil output by the first bidirectional quantitative pump 202 flows into the second chamber 800 through the second bidirectional quantitative pump 203, and another part flows into the second accumulator 205, thereby realizing The flow in the first chamber 700 and the second chamber 800 is balanced, while the first bidirectional quantitative pump 202 and the second bidirectional quantitative pump 203 convert the potential energy fed back by the load into electrical energy and store it in the power supply device 600 for recycling, saving electricity.

Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments we have described are only illustrative, rather than used to limit the scope of the present invention. Equivalent modifications and changes made by skilled personnel in accordance with the spirit of the present invention shall fall within the protection scope of the claims of the present invention.

Claims (10)

1. The distributed direct-drive excavator hydraulic system of motor-driven dual quantitative pumps and dual accumulators, including a controller, is characterized in that: it also includes at least one hydraulic module; each hydraulic module includes a hydraulic cylinder, a first two-way quantitative pump , the second two-way quantitative pump, the first accumulator, the second accumulator, the three-position three-way control valve, the driver and the driving motor; The hydraulic cylinder includes a cylinder, a piston and a piston rod, one end of the piston rod is fixedly connected to the piston, the piston is airtightly slidably connected to the cylinder, and the piston connects the The inner part of the cylinder is divided into a first chamber and a second chamber; The three-position three-way control valve includes a first oil connection port, a first hydraulic control control oil port, a second oil connection port, a second hydraulic control control oil port and a third oil connection port; The first bidirectional quantitative pump includes a first drain port, a first port and a second port; The second bidirectional quantitative pump includes a second oil drain port, a third port and a fourth port; The second port and the fourth port are connected in parallel to the second accumulator; the first port, the first oil connection port and the first hydraulic control oil port are connected in parallel to communicate with the first chamber chamber; the third port, the second oil connection port and the second hydraulic control control oil port are connected in parallel to communicate with the second chamber; the third oil connection port is connected to the first accumulator; the The first oil drain port is connected between the second port and the fourth port, the second oil drain port is connected between the fourth port and the second accumulator, The first bidirectional quantitative pump and the second bidirectional quantitative pump are respectively connected to the driving motor to realize synchronous movement; the driver is connected to the controller through communication. 2. The distributed direct-drive excavator hydraulic system of motor-driven double constant pumps and double accumulators according to claim 1 is characterized in that: it also includes a power supply device, and the driver and the controller are respectively electrically connected to the power supply device. 3. According to claim 1 or 2, the distributed direct-drive excavator hydraulic system with double constant pumps and double accumulators driven by a motor is characterized in that: each hydraulic module also includes a first control valve and a second control valve , the first port, the first oil connection port and the first hydraulic control control oil port are connected in parallel to the first control valve and the first chamber in turn; the third port, the second oil connection port And the second hydraulic control oil port is connected in parallel to the second control valve and the second chamber in sequence; the first control valve and the second control valve are also respectively connected to the controller through communication. 4. The distributed direct-drive excavator hydraulic system with motor-driven double constant pumps and double accumulators according to claim 3, characterized in that: the first control valve and the second control valve are respectively two-position two-way electromagnetic valve. 5. The distributed direct-drive excavator hydraulic system with motor-driven dual quantitative pumps and dual accumulators according to claim 3, characterized in that: the first control valve and the second control valve are respectively two-position two-way plug-in Install the valve. 6. The distributed direct-drive excavator hydraulic system of motor-driven double constant pumps and double accumulators according to claim 3, characterized in that: each hydraulic module also includes a first one-way valve and a second one-way valve , the first safety valve and the second safety valve; The inlet of the first one-way valve and the outlet of the first safety valve are connected in parallel to the second port, and the outlet of the first one-way valve and the inlet of the first safety valve are connected in parallel and then connected to the second port. between the first control valve and the first chamber; The inlet of the second one-way valve and the outlet of the second safety valve are connected in parallel to the second accumulator, and the outlet of the second one-way valve and the inlet of the second safety valve are connected in parallel connected between the second control valve and the second chamber. 7. According to claim 1 or 2, the distributed direct-drive excavator hydraulic system with motor-driven dual quantitative pumps and dual accumulators is characterized in that: the three-position three-way control valve is a three-position three-way hydraulic control valve . 8. According to claim 1 or 2, the distributed direct-drive excavator hydraulic system with motor-driven dual quantitative pumps and dual accumulators is characterized in that: the three-position three-way control valve is a three-position three-way cartridge valve . 9. The distributed direct-drive excavator hydraulic system with motor-driven double constant pumps and double accumulators according to claim 1 or 2, characterized in that: the drive motor is a servo motor, and the driver is a servo driver. 10. The distributed direct-drive excavator hydraulic system with motor-driven double constant pumps and double accumulators according to claim 1 or 2, characterized in that: the number of said hydraulic modules is three.