Multi-pump cooperative control electro-hydraulic system, control method and excavator

Abstract

The invention discloses a multi-pump cooperative control electro-hydraulic system, a control method and an excavator, belongs to the technical field of hydraulic pressure, and aims to solve the problem of load coupling of execution mechanisms of an existing double-pump oil supply system.The electro-hydraulic system comprises a power source module, a walking converging module, a movable arm module, a bucket rod module and a bucket module; the power source module comprises a motor driving mechanism, and a first plunger pump, a second two-quadrant pump, a third plunger pump and a fourth plunger pump which are respectively connected with the motor driving mechanism; the movable arm module, the bucket rod module and the bucket module are all connected with an outlet of the power source module through the walking confluence module and used for load complete decoupling when all the executing mechanisms act in a composite mode and confluence oil supply control when all the executing mechanisms act independently. The corresponding loops are completely decoupled, so that the oil source supplies oil independently, the waste of load coupling energy when the excavator executes the composite action is eliminated, and the single-action speed requirement of each executing mechanism is ensured.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic technology, and in particular relates to a multi-pump coordinated control electro-hydraulic system, control method and excavator. Background Technology

[0002] With the development of electrification in the construction machinery industry, in order to reduce the output power of a single pump and improve the overall working efficiency, various OEMs have launched their own electric construction machinery products, and the application scope of multi-pump hydraulic systems is also gradually expanding. Currently, reducing system energy consumption and improving system response have become the primary goals of the electrification of construction machinery.

[0003] To achieve this goal, the electric engineering machinery of related technologies mainly adopts a dual-pump oil supply system. The existing dual-pump oil supply system has the following problems: (1) The output power of a single pump is large, and multiple actuators cannot be decoupled, resulting in serious energy waste due to load differences; (2) The system using multi-pump oil supply requires multiple sets of motors to drive multiple piston pumps, which occupies a large space and the hydraulic pipeline is relatively complex; (3) There is a long hydraulic pipeline between the final control valve and the actuator, and the response speed of the actuator is relatively low, which is not conducive to the unmanned transformation of the excavator system.

[0004] Therefore, the dual-pump oil supply system of related technologies has many problems and cannot meet the requirements of high performance and intelligent control for dynamic response. Summary of the Invention

[0005] Purpose of the invention: In order to overcome the shortcomings of the prior art, the present invention provides a multi-pump collaborative control electro-hydraulic system, control method and excavator. Through the multi-pump collaborative control electro-hydraulic system, when each actuator performs compound actions, the corresponding circuits are completely decoupled so that their oil sources are supplied independently. This eliminates the energy waste and flow interference caused by load coupling when the various actuators of the excavator perform compound actions. Furthermore, the combined oil supply control is achieved through the travel merging module, which ensures the single action speed requirements of the actuators.

[0006] To achieve the above objectives, the present invention is implemented using the following technical solution: In a first aspect, the present invention provides a multi-pump coordinated control electro-hydraulic system, comprising: a power source module, a travel merging module, a boom module, a stick module, and a bucket module; The power source module includes a motor drive mechanism and a first plunger pump, a second two-quadrant pump, a third plunger pump and a fourth plunger pump respectively connected to the motor drive mechanism. The boom module, stick module, and bucket module are all connected to the power source module's outlet through the travel merging module. When the various actuators perform compound actions, each circuit is completely decoupled through the power source module to avoid mutual interference, ensuring that the compound actions do not affect each other. When the various actuators perform independent actions, each circuit achieves merging oil supply control through the travel merging module to ensure the single-action speed requirements of the actuators.

[0007] Optionally, the travel merging module includes a first travel control valve, a first travel priority valve, a boom merging valve, a second travel priority valve, and a second travel control valve; The oil inlets of the first travel control valve and the first travel priority valve are respectively connected to the oil outlet of the first plunger pump, for supplying oil to the left travel mechanism, boom module and bucket module by confluence. The first oil outlet of the first travel priority valve and the oil outlet of the boom confluence valve are connected to the boom module; The second oil outlet of the first travel priority valve is connected to the outlet of the second two-quadrant pump, and after merging, it is connected to the bucket module; The oil outlet of the second two-quadrant pump is connected to the boom module through the boom confluence valve, and the oil outlet of the second two-quadrant pump is connected to the bucket module for supplying oil to the boom and bucket confluence. The oil inlets of the second travel priority valve and the second travel control valve are respectively connected to the outlet of the third plunger pump; The oil outlet of the second travel priority valve is connected to the oil outlet of the fourth plunger pump and then connected to the boom module after merging.

[0008] Optionally, the motor drive mechanism includes a first motor and a second motor; The first plunger pump and the second quadrant pump are connected in series and then connected to the first motor; the third plunger pump and the fourth plunger pump are connected in series and then connected to the second motor.

[0009] Optionally, the boom module includes a boom large chamber oil inlet control valve, a boom large chamber oil return control valve, a boom small chamber oil inlet control valve, a boom small chamber oil return control valve, a boom flow regeneration valve, and a boom cylinder. The oil inlets of the boom large chamber oil inlet control valve and the boom small chamber oil inlet control valve are connected to the oil outlets of the first travel priority valve and the boom confluence valve. The inlet of the boom large chamber return oil control valve is connected to the outlet of the second two-quadrant pump. The inlet of the boom large chamber return oil control valve is connected to the outlet of the first plunger pump through the boom confluence valve. The outlet of the boom large chamber return oil control valve and the outlet of the boom large chamber inlet oil control valve are connected to the large chamber of the boom cylinder. The oil outlets of the boom chamber oil inlet control valve and the boom chamber oil return control valve are connected to the small chamber of the boom cylinder. The return ports of both the large-cavity return oil control valve and the small-cavity return oil control valve of the boom are connected to the main return oil circuit of the system. The inlet and outlet of the boom flow regeneration valve are connected to the large and small chambers of the boom cylinder, respectively.

[0010] Optionally, the boom module includes a boom large chamber oil inlet control valve, a boom large chamber oil return control valve, a boom small chamber oil inlet control valve, a boom small chamber oil return control valve, a boom flow regeneration valve, and a boom cylinder; The oil outlet of the second travel priority valve merges with the oil outlet of the fourth plunger pump and then connects to the oil inlet of the large chamber oil inlet control valve and the small chamber oil inlet control valve of the stick, supplying oil to the stick. The oil outlets of the boom cylinder's large chamber oil inlet control valve and the boom cylinder's large chamber oil return control valve are connected to the large chamber of the boom cylinder. The oil outlets of the boom cylinder small chamber oil inlet control valve and the boom cylinder small chamber oil return control valve are connected to the small chamber of the boom cylinder. The inlet and outlet of the boom flow regeneration valve are respectively connected to the large and small chambers of the boom cylinder. The return ports of the large-cavity return oil control valve and the small-cavity return oil control valve of the boom are connected to the main return oil circuit of the system.

[0011] Optionally, the bucket module includes a bucket control valve and a bucket cylinder; The oil inlet of the bucket control valve is connected to the second oil outlet of the first travel priority valve and the outlet of the second two-quadrant pump, respectively. The outlet of the second two-quadrant pump is also connected to the inlet of the boom confluence valve and the boom large chamber return oil control valve, and the outlet of the second two-quadrant pump is directly connected to the inlet of the bucket control valve. The large chamber of the bucket cylinder and the small chamber of the bucket cylinder are respectively connected to the first oil outlet and the second oil outlet of the bucket control valve, and the return oil outlet of the bucket control valve is connected to the main return oil circuit of the system.

[0012] In a second aspect, the present invention provides a multi-pump coordinated electro-hydraulic control method, based on the multi-pump coordinated control electro-hydraulic system described in the first aspect, wherein the multi-pump coordinated electro-hydraulic control method is executed by an excavator controller, and the method includes: Obtain the speed requirements of the boom cylinder, stick cylinder, bucket cylinder, and travel speed. Based on the speed requirements of the boom cylinder, a control signal is generated for the first motor, which controls the first plunger pump and the second quadrant pump to output corresponding flow and pressure oil, so that the power source module supplies oil to the boom module and stick module, driving the boom cylinder to extend, descend, or perform combined boom and stick actions. The control signal of the second motor is generated according to the speed requirement of the boom cylinder, which controls the third and fourth plunger pumps to output corresponding flow and pressure oil, so that the power source module supplies oil to the boom module and drives the boom to move. Based on the speed requirement of the bucket cylinder, a control signal is generated for the first motor, which controls the first plunger pump and the second quadrant pump to output corresponding flow and pressure oil, so that the power source module supplies oil to the bucket module and boom module, driving the bucket to move alone or the bucket and boom to move together. Based on the required walking speed, control signals are generated for the first and second motors, which control the first plunger pump, the second two-quadrant pump, the third plunger pump, and the fourth plunger pump to supply oil to the walking confluence module, thereby driving the vehicle to walk through the four pumps. Alternatively, control signals for the first and second motors can be generated based on the speed requirements of the boom cylinder, stick cylinder, bucket cylinder, and travel speed. These signals control the first and third plunger pumps to supply oil to the travel merging module; control the second two-quadrant pumps to supply oil to the boom module and bucket module; and control the fourth plunger pump to supply oil to the stick module. This achieves dual-pump travel while ensuring normal movement of the upper vehicle.

[0013] Optionally, the power source module supplies oil to the boom module and stick module to drive the boom cylinder to extend, lower, or perform combined boom and stick movements, including: Single-action lifting of the boom: The first plunger pump and the second quadrant pump both output corresponding flow pressure oil. The output pressure oil passes through the first travel priority valve, the boom confluence valve, and the boom large chamber oil inlet control valve to enter the large chamber of the boom cylinder, so as to drive the boom cylinder to extend in a single action. When the boom descends in a single motion: the first plunger pump is controlled to output pressure oil at a corresponding flow rate and the second two-quadrant pump is controlled to recover pressure oil; the output pressure oil enters the small chamber of the boom cylinder through the first travel priority valve and the boom small chamber oil inlet control valve. At this time, the oil in the large chamber of the boom cylinder is recovered through the second two-quadrant pump via the right position of the boom large chamber oil return control valve, and part of the oil is regenerated to the small chamber through the boom flow regeneration valve. The boom and bucket combined lifting action is as follows: the first plunger pump and the second quadrant pump both output corresponding flow pressure oil. The pressure oil output by the first plunger pump enters the large chamber of the boom cylinder through the first travel priority valve and the boom large chamber oil inlet control valve; the pressure oil output by the second quadrant pump is supplied to the bucket through the bucket control valve.

[0014] Optionally, the power source module supplies oil to the stick module to drive the stick movement, including: When the vehicle is not moving, the third and fourth plunger pumps are controlled to output corresponding flow rates of pressure oil. The pressure oil passes through the large chamber oil inlet control valve and the small chamber oil inlet control valve of the stick and supplies oil to the stick cylinder to control the stick cylinder's movement. When the vehicle is dismounted and traveling, the pressure oil output by the third plunger pump supplies oil to the second travel control valve, and the pressure oil output by the fourth plunger pump supplies oil to the boom cylinder to maintain the normal operation of the boom.

[0015] Optionally, the stick action includes stick retraction and stick swing; wherein, when the stick retracts, the oil in the small chamber of the stick cylinder returns to the main return oil circuit of the system through the small chamber return oil control valve; When the boom swings outward, the oil in the large chamber of the boom cylinder is returned to the oil tank separately through the boom large chamber return oil control valve to reduce the back pressure in the large chamber of the boom cylinder.

[0016] Optionally, the power source module supplies oil to the bucket module and boom module to drive the bucket to move individually or in combination with the boom, including: When the bucket is in single action, the first plunger pump and the second quadrant pump both output corresponding flow pressure oil. The pressure oil output by the first plunger pump is combined with the pressure oil of the second quadrant pump through the first travel priority valve, and then supplied to the bucket cylinder through the bucket control valve. When the bucket and boom are in combined motion, the pressure oil output by the first plunger pump is supplied to the boom module through the first travel priority valve; the pressure oil output by the second two-quadrant pump is directly supplied to the bucket module.

[0017] In a third aspect, the present invention provides an excavator, wherein the excavator is equipped with the multi-pump coordinated control electro-hydraulic system described in the first aspect, and the excavator vehicle controller executes the control method described in the second aspect.

[0018] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: (1) By controlling the electro-hydraulic system in a multi-pump coordinated manner, each actuator can be completely decoupled from its corresponding circuit during compound actions, so that its oil source can be supplied independently. This eliminates the energy waste and flow interference caused by load coupling during compound actions of each actuator of the excavator. Furthermore, the combined oil supply control is achieved through the travel merging module, ensuring the single action speed requirements of the actuator.

[0019] (2) The multi-pump coordinated control electro-hydraulic system designed by the present invention can realize multi-layer energy recovery of boom potential energy. It can be directly regenerated through the flow in the valve or recovered through the two-quadrant pump. During excavation and reset, it can also be regenerated to the bucket through the cross-loop.

[0020] (3) When the boom, stick, and bucket actuators operate independently, a dual-pump combined oil supply is used to meet the single-action speed requirements, while reducing the maximum displacement of a single pump, thereby reducing the rated power of a single pump, which is more conducive to the selection of motor pumps. (4) The upper boom, stick and bucket adopt a split electro-hydraulic cylinder design, which eliminates the pipeline connection between the valve and the cylinder in the traditional system, improves the system response speed, and facilitates unmanned and intelligent control.

[0021] (5) Dual pumps supply walking speed to ensure walking speed requirements, dual pumps supply the upper vehicle to ensure that all upper vehicle actions can be performed normally during walking, and if necessary, four pumps can be used to supply walking speed to increase walking speed and improve walking efficiency. Attached Figure Description

[0022] Figure 1 This is a system structure diagram of the electro-hydraulic system of the present invention.

[0023] Figure 2 This is a schematic diagram of the dual-pump oil supply principle for boom lifting in this invention.

[0024] Figure 3 This is a schematic diagram illustrating the energy recovery principle of boom descent in this invention.

[0025] Figure 4 This is a schematic diagram of the boom lowering support vehicle or the combined principle of the present invention and the bucket.

[0026] Figure 5 This is a schematic diagram illustrating the principle of the flat-ground movement of this invention.

[0027] Figure 6 This is a schematic diagram illustrating the principle of the three-component excavation action of the present invention.

[0028] Figure 7 This is a flowchart of the multi-pump coordinated electro-hydraulic control method of the present invention.

[0029] In the diagram: 1. First motor; 2. First plunger pump; 3. Second two-quadrant pump; 4. Second motor; 5. Third plunger pump; 6. Fourth plunger pump; 7. First travel control valve; 8. First travel priority valve; 9. Boom confluence valve; 10. Second travel priority valve; 11. Second travel control valve; 12. Boom large chamber oil inlet control valve; 13. Boom large chamber oil return control valve; 14. Boom small chamber oil inlet control valve; 15. Boom small chamber oil return control valve; 16. Boom flow regeneration valve; 23. Boom cylinder; 17. Bucket control valve; 24. Bucket cylinder; 18. Stick large chamber oil inlet control valve; 19. Stick large chamber oil return control valve; 20. Stick small chamber oil inlet control valve; 21. Stick flow regeneration valve; 22. Stick cylinder; 25. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention. Example

[0031] This embodiment provides a multi-pump coordinated control electro-hydraulic system, including: a power source module, a travel merging module, a boom module, a stick module, and a bucket module; The power source module includes a motor drive mechanism and a first plunger pump 2, a second two-quadrant pump 3, a third plunger pump 5, and a fourth plunger pump 6, which are respectively connected to the motor drive mechanism. The motor drive mechanism includes a first motor 1 and a second motor 4. The motor drive mechanism is not limited to the limitations of this embodiment. In other embodiments, the number of motors can be increased to change it to four motors driving four pumps or three motors driving four pumps, including two single pumps and a double-tandem pump, to meet the power requirements of each actuator. The first plunger pump 2 and the second two-quadrant pump 3 are connected in series to the first motor 1. The third plunger pump 5 and the fourth plunger pump 6 are connected in series to the second motor 4.

[0032] The boom module, stick module, and bucket module are all connected to the power source module's outlet through the travel merging module. When the various actuators perform compound actions, each circuit is completely decoupled through the power source module to avoid mutual flow interference, ensuring that the compound actions do not affect each other. When the various actuators perform independent actions, each circuit achieves merging oil supply control through the travel merging module, realizing flow doubling and ensuring the single-action speed requirements of the actuators.

[0033] In this embodiment, the boom, stick, and bucket of the upper vehicle adopt a split electro-hydraulic cylinder design, which eliminates the pipeline connection between the valve and the cylinder in the traditional system, improves the system response speed, and facilitates unmanned and intelligent control.

[0034] like Figure 1 The travel merging module shown in this embodiment mainly includes a first travel control valve 7, a first travel priority valve 8, a boom merging valve 9, a second travel priority valve 10, and a second travel control valve 11; the boom module includes a boom large chamber oil inlet control valve 12, a boom large chamber oil return control valve 13, a boom small chamber oil inlet control valve 14, a boom small chamber oil return control valve 15, a boom flow regeneration valve 16, and a boom cylinder 23; the bucket module includes a bucket control valve 17 and a bucket cylinder 24; the stick module includes a stick large chamber oil inlet control valve 18, a stick large chamber oil return control valve 19, a stick small chamber oil inlet control valve 20, a stick small chamber oil return control valve 21, a stick flow regeneration valve 22, and a stick cylinder 25.

[0035] In some possible implementations, the inlets of the first travel control valve 7 and the first travel priority valve 8 in the travel merging module are respectively connected to the outlet of the first plunger pump 2 for merging oil supply to the left travel mechanism, boom module, and bucket module; the first outlet of the first travel priority valve 8 and the outlet of the boom merging valve 9 are connected to the boom module for merging oil supply to the boom module after merging through the travel merging module; the second outlet of the first travel priority valve 8 is connected to the outlet of the second two-quadrant pump 3 and is connected to the bucket module after merging for merging oil supply to the bucket; the outlet of the second two-quadrant pump 3 is connected to the boom merging module. The oil inlet of valve 9 is connected to the boom module, and the oil outlet of the second two-quadrant pump 3 is connected to the bucket module, for supplying oil to the boom and bucket in a combined flow. The oil inlets of the second travel priority valve 10 and the second travel control valve 11 are respectively connected to the outlet of the third plunger pump 5, for mainly supplying oil to the right travel and stick in a combined flow. The oil outlet of the second travel priority valve 10 is connected to the oil outlet of the fourth plunger pump 6 and then connected to the stick module after the combined flow, for supplying oil to the stick in a combined flow. In addition, the first travel control valve 7 and the second travel control valve 11 are respectively connected to the left and right travel motors, thereby controlling the start, stop and speed of the left and right travel motors of the vehicle.

[0036] In some possible implementations, the oil inlets of the boom large chamber oil inlet control valve 12 and the boom small chamber oil inlet control valve 14 in the boom module are connected to the oil outlets of the first travel priority valve 8 and the boom confluence valve 9. The inlet of the boom large chamber return oil control valve 13 is connected to the outlet of the second two-quadrant pump 3 and also to the bucket module. The inlet of the boom large chamber return oil control valve 13 is connected to the outlet of the first plunger pump 2 through the boom confluence valve 9. The travel confluence module realizes the combined oil supply of the bucket and boom, and the boom potential energy is recovered when the boom descends. The outlet of the boom large chamber return oil control valve 13 and the outlet of the boom large chamber inlet oil control valve 12 are connected to the large chamber of the boom cylinder 23; the outlets of the boom small chamber inlet oil control valve 14 and the boom small chamber return oil control valve 15 are connected to the small chamber of the boom cylinder 23; the return ports of the boom large chamber return oil control valve 13 and the boom small chamber return oil control valve 15 are both connected to the main return oil circuit of the system; the inlet and return ports of the boom flow regeneration valve 16 are connected to the large chamber and small chamber of the boom cylinder 23, respectively. In this embodiment, the boom potential energy can be recovered in multiple layers through the boom large chamber oil inlet control valve 12, boom large chamber oil return control valve 13, boom small chamber oil inlet control valve 14, boom small chamber oil return control valve 15, and boom flow regeneration valve 16. At the same time, it can be recovered directly through the flow regeneration in the valve or through the two-quadrant pump. During excavation and reset, it can also be regenerated to the bucket through the cross-circuit.

[0037] In some possible implementations, the oil outlet of the second travel priority valve 10 in the boom module merges with the oil outlet of the fourth plunger pump 6 and is then connected to the oil inlet of the boom large chamber oil inlet control valve 18 and the boom small chamber oil inlet control valve 20 to supply oil to the boom; the oil outlets of the boom large chamber oil inlet control valve 18 and the boom large chamber return oil control valve 19 are connected to the large chamber of the boom cylinder 25; the oil outlets of the boom small chamber oil inlet control valve 20 and the boom small chamber return oil control valve 21 are connected to the small chamber of the boom cylinder 25; the oil inlet and return port of the boom flow regeneration valve 22 are connected to the large chamber and the small chamber of the boom cylinder 25, respectively; and the return ports of the boom large chamber return oil control valve 19 and the boom small chamber return oil control valve 21 are connected to the main return oil circuit of the system.

[0038] In some possible implementations, the bucket module includes a bucket control valve 17 and a bucket cylinder 24; The oil inlet of the bucket control valve 17 is connected to the second oil outlet of the first travel priority valve 8 and the outlet of the second two-quadrant pump 3, respectively; it can supply oil to the bucket after the travel merging module merges with the second two-quadrant pump 3.

[0039] The outlet of the second two-quadrant pump 3 is also connected to the inlet of the boom confluence valve 9 and the boom large chamber return oil control valve 13, and the outlet of the second two-quadrant pump 3 is directly connected to the inlet of the bucket control valve 17; the large chamber and small chamber of the bucket cylinder 24 are respectively connected to the first outlet and the second outlet of the bucket control valve 17, and the return oil port of the bucket control valve 17 is connected to the main return oil circuit of the system.

[0040] In some possible implementations, a control valve for controlling the hydraulically driven rotary device can be added. Its inlet is connected to the outlet of one of the four pumps: the first plunger pump 2, the second two-quadrant pump 3, the third plunger pump 5, and the fourth plunger pump. Its outlet is connected to the rotary device, and its return port is connected to the system return oil.

[0041] In addition, built-in or external displacement sensors and other measuring devices can be installed on the boom cylinder 23, bucket cylinder 24, and stick cylinder 25 to measure the displacement of the cylinders and realize closed-loop control of the movement speed or cylinder position. Example

[0042] This embodiment provides a multi-pump coordinated electro-hydraulic control method based on the multi-pump coordinated control electro-hydraulic system of Embodiment 1. The multi-pump coordinated electro-hydraulic control method is executed by the excavator controller, and the method includes: like Figure 7 The controller shown acquires the speed requirements of boom cylinder 23, stick cylinder 25, bucket cylinder 24, and travel speed respectively. Based on the speed requirement of the boom cylinder 23, a control signal is generated for the first motor 1, which controls the first plunger pump 2 and the second two-quadrant pump 3 to output corresponding flow and pressure oil, so that the power source module supplies oil to the boom module and the stick module, driving the boom cylinder 23 to extend, descend, or perform a combined boom and stick action. Based on the speed requirement of the boom cylinder 25, a control signal is generated for the second motor 4, which controls the third plunger pump 5 and the fourth plunger pump 6 to output corresponding flow and pressure oil, so that the power source module supplies oil to the boom module and drives the boom to move. Based on the speed requirement of the bucket cylinder 24, a control signal is generated for the first motor 1, which controls the first plunger pump 2 and the second two-quadrant pump 3 to output corresponding flow and pressure oil, so that the power source module supplies oil to the bucket module and the boom module, driving the bucket to move alone or the bucket and boom to move together. Based on the required walking speed, control signals are generated for the first motor 1 and the second motor 4, which control the first plunger pump 2, the second two-quadrant pump 3, the third plunger pump 5 and the fourth plunger pump 6 to supply oil to the walking confluence module, thereby driving the vehicle to walk through the four pumps. Alternatively, control signals for the first motor 1 and the second motor 4 can be generated based on the speed requirements of the boom cylinder 23, the stick cylinder 25, the bucket cylinder 24, and the travel speed requirements. This controls the first plunger pump 2 and the third plunger pump 5 to supply oil to the travel merging module; controls the second two-quadrant pump 3 to supply oil to the boom module and the bucket module; and controls the fourth plunger pump 6 to supply oil to the stick module, so as to achieve dual-pump travel while ensuring normal movement of the upper vehicle.

[0043] In this embodiment, the controller acts as the execution entity, and is electrically connected to various input devices and sensors. It can receive analog / digital signals generated by devices such as handles and foot pedals, real-time signals detected by sensors, and control data input from other systems. It analyzes these data to obtain the speed requirements of the boom cylinder 23, the stick cylinder 25, the bucket cylinder 24, and the travel speed requirements, as well as detect changes in the excavator load.

[0044] In some possible implementations, the power source module supplies oil to the boom module and stick module, driving the boom cylinder 23 to extend, lower, or perform a combined boom and stick movement, including: like Figure 2 When the boom is lifted in a single action, the first plunger pump 2 and the second quadrant pump 3 are controlled to output corresponding flow pressure oil. The output pressure oil passes through the first travel priority valve 8, the boom confluence valve 9, and the boom large chamber oil inlet control valve 12 to enter the large chamber of the boom cylinder 23, so as to drive the boom cylinder 23 to extend in a single action. like Figure 3When the boom descends in a single motion, the first plunger pump 2 is controlled to output pressure oil at a corresponding flow rate, and the second two-quadrant pump 3 is controlled to recover the pressure oil. The output pressure oil passes through the first travel priority valve 8 and the boom small chamber oil inlet control valve 14 to enter the small chamber of the boom cylinder 23. At this time, the oil in the large chamber of the boom cylinder 23 passes through the right position of the boom large chamber return oil control valve 13 and is recovered by the second two-quadrant pump 3. Part of the oil is regenerated to the small chamber through the boom flow regeneration valve 16. This achieves multi-layer energy recovery of boom potential energy. It can also be directly regenerated through the valve flow and recovered through the two-quadrant pump. In addition, the boom potential energy can also be regenerated to the bucket through the cross-loop.

[0045] The boom and bucket combined lifting action controls the first plunger pump 2 and the second quadrant pump 3 to output corresponding flow and pressure oil, such as... Figure 4 The pressure oil output from the first plunger pump 2 enters the large chamber of the boom cylinder 23 through the first travel priority valve 8 and the boom large chamber oil inlet control valve 12; the pressure oil output from the second two-quadrant pump 3 supplies oil to the bucket through the bucket control valve 17 (not shown).

[0046] In some possible implementations, the power source module supplies oil to the stick module to drive the stick movement, including: like Figure 5 As shown, when the boom and stick are in two combined movements and there is no travel when dismounting: the boom control process is the same as described above. The first plunger pump 2 and the second quadrant pump 3 both output corresponding flow pressure oil. The output pressure oil enters the boom module through the first travel priority valve 8 and the boom confluence valve 9 to drive the boom movement. At the same time, the third plunger pump 5 and the fourth plunger pump 6 are controlled to output corresponding flow pressure oil. The pressure oil output by the third plunger pump 5 is combined with the pressure oil output by the fourth plunger pump 6 through the second travel priority valve 10. Then, it is supplied to the stick cylinder 25 through the stick large chamber oil inlet control valve 18 and the stick small chamber oil inlet control valve 20 to control the movement of the stick cylinder 25. When the dismount travel and stick movement are combined: the pressure oil output by the third plunger pump 5 supplies oil to the second travel control valve 11 to achieve right travel oil supply, and the pressure oil output by the fourth plunger pump 6 supplies oil to the stick cylinder 25 to maintain the normal operation of the stick.

[0047] Optionally, the stick action includes stick retraction and stick swing; wherein, when the stick retracts, the oil in the small chamber of the stick cylinder 25 returns to the main return oil circuit of the system through the stick small chamber return oil control valve 21; When the boom swings outward, the oil in the large chamber of the boom cylinder 25 returns to the oil tank separately through the boom large chamber return oil control valve 19, which is used to reduce the back pressure of the large chamber of the boom cylinder 25.

[0048] In some possible implementations, the power source module supplies oil to the bucket module and the boom module to drive the bucket to move individually or in combination with the boom, including: When the bucket is in single motion, the first plunger pump 2 and the second quadrant pump 3 both output corresponding flow pressure oil. The pressure oil output by the first plunger pump 2 merges with the pressure oil of the second quadrant pump 3 after passing through the right position of the first travel priority valve 8, and then supplies oil to the bucket cylinder 24 through the bucket control valve 17 to ensure the bucket movement speed.

[0049] When the bucket and boom are in combined motion, the pressure oil output by the first plunger pump 2 is supplied to the boom module through the left position of the first travel priority valve 8; the pressure oil output by the second two-quadrant pump 3 is directly supplied to the bucket module, so that the oil supply sources of the boom and bucket are unloaded and avoid interference with the combined motion of the boom and bucket.

[0050] In some possible implementations, this also includes the combined action of the boom, bucket, and stick, such as... Figure 6 The control system outputs corresponding flow rates of pressure oil from the first plunger pump 2, the second two-quadrant pump 3, the third plunger pump 5, and the fourth plunger pump 6. The pressure oil output from the first plunger pump 2 passes through the first travel priority valve 8 and enters the boom large chamber oil inlet control valve 12 and the boom small chamber oil inlet control valve 14 to the boom cylinder 23 to drive the boom movement. The pressure oil output from the second two-quadrant pump 3 directly enters the bucket control valve 17 and then the bucket cylinder 24 to drive the bucket movement. The pressure oil output from the third plunger pump 5 merges with the pressure oil output from the fourth plunger pump 6 through the second travel priority valve 10 and then passes through the stick large chamber oil inlet control valve 18 and the stick small chamber oil inlet control valve 20 to the stick cylinder 25 to drive the stick cylinder 25 to move.

[0051] In some possible implementations, control signals for the first motor 1 and the second motor 4 are generated based on the speed requirements of the boom cylinder 23, the stick cylinder 25, the bucket cylinder 24, and the travel speed requirements. These signals control the first plunger pump 2 and the third plunger pump 5 to supply oil to the travel merging module; control the second two-quadrant pump 3 to supply oil to the boom module and the bucket module; and control the fourth plunger pump 6 to supply oil to the stick module, so as to achieve dual-pump travel while ensuring normal movement of the upper vehicle.

[0052] In this embodiment, when only the vehicle is dismounted and moving, the first motor 1 drives the first plunger pump 2 to work, and supplies oil to the left travel motor through the first travel control valve 7. The second motor 4 drives the third plunger pump 5 to work, and supplies oil to the right travel motor through the second travel control valve 11. The second two-quadrant pump 3 and the fourth plunger pump 6 are in standby mode, and are used to supply oil to the vehicle when the vehicle is dismounted and moving.

[0053] When long-distance travel is required, the second quadrant pump 3 can merge with the first plunger pump 2 through the right position of the first travel priority valve 8 and then travel to the left to supply oil. Similarly, the fourth plunger pump 6 can merge with the third plunger pump 5 through the second travel priority valve 10 and then travel to the right to supply oil, thereby realizing four pumps to supply oil for travel and improving travel efficiency.

[0054] When the loading and unloading operations are combined, the first plunger pump 2 and the third plunger pump 5 supply oil to the left and right motors respectively, the second two-quadrant pump 3 supplies oil to the boom and bucket simultaneously through the left position of the boom confluence valve 9, and the fourth plunger pump 6 supplies oil to the stick module, realizing dual pump supply for travel and dual pump supply for loading, ensuring the normal operation of loading and unloading operations.

[0055] This embodiment uses dual pumps to supply the walking mechanism, ensuring the required walking speed. Dual pumps also supply the upper vehicle, guaranteeing the normal operation of all upper vehicle functions during walking. If necessary, four pumps can be used to supply the walking mechanism, increasing walking speed and efficiency. Example 3 This embodiment provides an excavator equipped with a multi-pump coordinated control electro-hydraulic system as described in Embodiment 1, and the excavator vehicle controller executes the control method of Embodiment 2.

[0056] In summary, this invention utilizes a multi-pump collaborative control electro-hydraulic system to ensure that all actuators receive independent oil supply during compound actions, with complete decoupling of each circuit. This eliminates energy waste caused by load coupling during compound actions of multiple actuators in an excavator and achieves combined oil supply control through a travel merging module, guaranteeing the single-action speed requirements of the actuators. The multi-pump collaborative control electro-hydraulic system designed in this invention enables multi-layer energy recovery of the boom's potential energy. This can be achieved directly through in-valve flow regeneration or through a two-quadrant pump. During excavation and resetting, energy can also be regenerated to the bucket through a cross-circuit regeneration.

[0057] When the boom, stick, and bucket actuators operate independently, a dual-pump combined oil supply is used to meet the single-action speed requirements, while reducing the maximum displacement of a single pump, thereby reducing the rated power of a single pump and making it easier to select a motor pump. The upper boom, stick, and bucket adopt a split electro-hydraulic cylinder design, eliminating the pipeline connection between the valve and the cylinder in the traditional system, improving the system response speed, and facilitating unmanned and intelligent control.

[0058] Finally, dual pumps supply the walking mechanism to ensure the required walking speed, and dual pumps supply the upper vehicle to ensure that all actions of the upper vehicle can be performed normally during walking. If necessary, four pumps can be used to supply the walking mechanism to increase the walking speed and improve walking efficiency.

[0059] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0060] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A multi-pump coordinated control electro-hydraulic system, characterized in that it comprises: Power source module, travel merging module, boom module, stick module, and bucket module; The power source module includes a motor drive mechanism and a first plunger pump, a second two-quadrant pump, a third plunger pump and a fourth plunger pump respectively connected to the motor drive mechanism. The boom module, stick module, and bucket module are all connected to the outlet of the power source module through the travel merging module, which is used for complete load decoupling when the various actuators perform compound actions and for merging oil supply control when the various actuators perform independent actions.

2. The multi-pump coordinated control electro-hydraulic system according to claim 1, characterized in that, The walking and merging module includes a first walking control valve, a first walking priority valve, a boom merging valve, a second walking priority valve, and a second walking control valve. The oil inlets of the first travel control valve and the first travel priority valve are respectively connected to the oil outlet of the first plunger pump, for supplying oil to the left travel mechanism, boom module and bucket module by confluence. The first oil outlet of the first travel priority valve and the oil outlet of the boom confluence valve are connected to the boom module; The second oil outlet of the first travel priority valve is connected to the outlet of the second two-quadrant pump, and after merging, it is connected to the bucket module; The oil outlet of the second two-quadrant pump is connected to the boom module through the boom confluence valve, and the oil outlet of the second two-quadrant pump is connected to the bucket module for supplying oil to the boom and bucket confluence. The oil inlets of the second travel priority valve and the second travel control valve are respectively connected to the outlet of the third plunger pump; The oil outlet of the second travel priority valve is connected to the oil outlet of the fourth plunger pump and then connected to the boom module after merging.

3. The multi-pump coordinated control electro-hydraulic system according to claim 1, characterized in that, The motor drive mechanism includes a first motor and a second motor; The first plunger pump and the second quadrant pump are connected in series and then connected to the first motor; the third plunger pump and the fourth plunger pump are connected in series and then connected to the second motor.

4. The multi-pump coordinated control electro-hydraulic system according to claim 2, characterized in that, The boom module includes a boom large chamber oil inlet control valve, a boom large chamber oil return control valve, a boom small chamber oil inlet control valve, a boom small chamber oil return control valve, a boom flow regeneration valve, and a boom cylinder. The oil inlets of the boom large chamber oil inlet control valve and the boom small chamber oil inlet control valve are connected to the oil outlets of the first travel priority valve and the boom confluence valve. The inlet of the boom large chamber return oil control valve is connected to the outlet of the second two-quadrant pump. The inlet of the boom large chamber return oil control valve is connected to the outlet of the first plunger pump through the boom confluence valve. The outlet of the boom large chamber return oil control valve and the outlet of the boom large chamber inlet oil control valve are connected to the large chamber of the boom cylinder. The oil outlets of the boom chamber oil inlet control valve and the boom chamber oil return control valve are connected to the small chamber of the boom cylinder. The return ports of both the large-cavity return oil control valve and the small-cavity return oil control valve of the boom are connected to the main return oil circuit of the system. The inlet and outlet of the boom flow regeneration valve are connected to the large and small chambers of the boom cylinder, respectively.

5. The multi-pump coordinated control electro-hydraulic system according to claim 1, characterized in that, The boom module includes a boom large chamber oil inlet control valve, a boom large chamber oil return control valve, a boom small chamber oil inlet control valve, a boom small chamber oil return control valve, a boom flow regeneration valve, and a boom cylinder; The oil outlet of the second travel priority valve merges with the oil outlet of the fourth plunger pump and then connects to the oil inlet of the large chamber oil inlet control valve and the small chamber oil inlet control valve of the stick, supplying oil to the stick. The oil outlets of the boom cylinder's large chamber oil inlet control valve and the boom cylinder's large chamber oil return control valve are connected to the large chamber of the boom cylinder. The oil outlets of the boom cylinder small chamber oil inlet control valve and the boom cylinder small chamber oil return control valve are connected to the small chamber of the boom cylinder. The inlet and outlet of the boom flow regeneration valve are respectively connected to the large and small chambers of the boom cylinder. The return ports of the large-cavity return oil control valve and the small-cavity return oil control valve of the boom are connected to the main return oil circuit of the system.

6. The multi-pump coordinated control electro-hydraulic system according to claim 4, characterized in that, The bucket module includes a bucket control valve and a bucket cylinder; The oil inlet of the bucket control valve is connected to the second oil outlet of the first travel priority valve and the outlet of the second two-quadrant pump, respectively. The outlet of the second two-quadrant pump is also connected to the inlet of the boom confluence valve and the boom large chamber return oil control valve, and the outlet of the second two-quadrant pump is directly connected to the inlet of the bucket control valve. The large chamber of the bucket cylinder and the small chamber of the bucket cylinder are respectively connected to the first oil outlet and the second oil outlet of the bucket control valve, and the return oil outlet of the bucket control valve is connected to the main return oil circuit of the system.

7. A multi-pump coordinated electro-hydraulic control method, characterized in that, Based on the multi-pump coordinated control electro-hydraulic system according to any one of claims 1 to 6, the multi-pump coordinated electro-hydraulic control method is executed by the excavator controller, and the method includes: Obtain the speed requirements of the boom cylinder, stick cylinder, bucket cylinder, and travel speed. Based on the speed requirements of the boom cylinder, a control signal is generated for the first motor, which controls the first plunger pump and the second quadrant pump to output corresponding flow and pressure oil, so that the power source module supplies oil to the boom module and stick module, driving the boom cylinder to extend, descend, or perform combined boom and stick actions. The control signal of the second motor is generated according to the speed requirement of the boom cylinder, which controls the third and fourth plunger pumps to output corresponding flow and pressure oil, so that the power source module supplies oil to the boom module and drives the boom to move. Based on the speed requirement of the bucket cylinder, a control signal is generated for the first motor, which controls the first plunger pump and the second quadrant pump to output corresponding flow and pressure oil, so that the power source module supplies oil to the bucket module and boom module, driving the bucket to move alone or the bucket and boom to move together. Based on the required walking speed, control signals are generated for the first and second motors, which control the first plunger pump, the second two-quadrant pump, the third plunger pump, and the fourth plunger pump to supply oil to the walking confluence module, thereby driving the vehicle to walk through the four pumps. Alternatively, control signals for the first and second motors can be generated based on the speed requirements of the boom cylinder, stick cylinder, bucket cylinder, and travel speed. These signals control the first and third plunger pumps to supply oil to the travel merging module; control the second two-quadrant pump to supply oil to the boom module and bucket module; and control the fourth plunger pump to supply oil to the stick module. This allows for simultaneous travel with dual pumps supplying oil to the boom, bucket, and stick for normal movement of the vehicle.

8. The multi-pump coordinated electro-hydraulic control method according to claim 7, characterized in that, The power source module supplies oil to the boom module and stick module, driving the boom cylinder to extend, lower, or perform combined boom and stick movements, including: When the boom lifts in a single motion, the first plunger pump and the second quadrant pump both output corresponding flow pressure oil. The output pressure oil passes through the first travel priority valve, the boom confluence valve, and the boom large chamber oil inlet control valve to enter the large chamber of the boom cylinder, thereby driving the boom cylinder to extend in a single motion. When the boom descends in a single motion, the first plunger pump is controlled to output pressure oil at a corresponding flow rate, and the second two-quadrant pump is controlled to recover the pressure oil. The output pressure oil enters the small chamber of the boom cylinder through the first travel priority valve and the boom small chamber oil inlet control valve. At this time, the oil in the large chamber of the boom cylinder is recovered through the second two-quadrant pump via the right position of the boom large chamber oil return control valve. Part of the oil is regenerated to the small chamber through the boom flow regeneration valve. When the boom and bucket are lifted in a combined action, the first plunger pump and the second quadrant pump both output corresponding flow pressure oil. The pressure oil output by the first plunger pump enters the large chamber of the boom cylinder through the first travel priority valve and the boom large chamber oil inlet control valve; the pressure oil output by the second quadrant pump is supplied to the bucket through the bucket control valve.

9. The multi-pump coordinated electro-hydraulic control method according to claim 7, characterized in that, The power source module supplies oil to the stick module, driving the stick to move, including: When the vehicle is not moving, the third and fourth plunger pumps are controlled to output corresponding flow rates of pressure oil. The pressure oil passes through the large chamber oil inlet control valve and the small chamber oil inlet control valve of the stick and supplies oil to the stick cylinder to control the stick cylinder's movement. When the vehicle is dismounted and traveling, the pressure oil output by the third plunger pump supplies oil to the second travel control valve, and the pressure oil output by the fourth plunger pump supplies oil to the boom cylinder to maintain the normal operation of the boom.

10. The multi-pump coordinated electro-hydraulic control method according to claim 7, characterized in that, The stick actions include stick retraction and stick swing; wherein, when the stick retracts, the oil in the small chamber of the stick cylinder returns to the main return oil circuit of the system through the small chamber return oil control valve; When the boom swings outward, the oil in the large chamber of the boom cylinder is returned to the oil tank separately through the boom large chamber return oil control valve to reduce the back pressure in the large chamber of the boom cylinder.

11. The multi-pump coordinated electro-hydraulic control method according to claim 7, characterized in that, The power source module supplies oil to the bucket module and boom module, driving the bucket to move individually or in combination with the boom, including: When the bucket is in single action, the first plunger pump and the second quadrant pump both output corresponding flow pressure oil. The pressure oil output by the first plunger pump is combined with the pressure oil of the second quadrant pump through the first travel priority valve, and then supplied to the bucket cylinder through the bucket control valve. When the bucket and boom are in combined motion, the pressure oil output by the first plunger pump is supplied to the boom module through the first travel priority valve; the pressure oil output by the second two-quadrant pump is directly supplied to the bucket module.

12. An excavator, characterized in that, The excavator's vehicle controller executes the control method according to any one of claims 7 to 11, and the excavator is equipped with a multi-pump coordinated control electro-hydraulic system according to any one of claims 1 to 6.

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