Multi-pump combined flow electro-hydraulic system and excavator

Abstract

This invention provides a multi-pump confluence electro-hydraulic system and an excavator. The multi-pump confluence electro-hydraulic system increases the maximum system flow rate and improves the actuator operating speed by using multiple pumps to increase the flow rate under complex operating conditions. It also matches the characteristics of the operating terminal signal with the flow requirements of the controlled actuator to solve the impact of sudden load changes on the speed regulation performance of the open-center system. Furthermore, it matches the return oil pressure value in the multi-way valve with the load pressure and hydraulic components to reduce the output of the hydraulic components under low flow conditions and increase the output of the hydraulic components under high flow conditions, thus achieving better energy-saving effects.

Description

Technical Field

[0001] This invention relates to the field of hydraulic system control technology, and more specifically, to a multi-pump confluence electro-hydraulic system and an excavator. Background Technology

[0002] With the continuous advancement of hydraulic technology, and its advantages of flexible layout, easy automation, stable operation, and high power per unit volume, hydraulic systems are widely used in various construction machinery. As an essential power source within the hydraulic system, the hydraulic pump station directly determines the performance of the actuators. Currently, construction machinery products often have multiple actuators and various complex action requirements. The system flow and pressure requirements vary significantly under different actions, and single-pump systems often struggle to meet all these requirements. Under a given system power and low-load conditions, the system flow is constant, resulting in slow actuator operation. While some construction machinery uses multi-pump systems to provide hydraulic pressure, increase system flow, and improve actuator speed, this often simply involves merging the pressure from multiple pumps to increase the flow rate of the actuator requiring high load. Therefore, during multi-pump hydraulic system merging operations for complex actions, the speed regulation performance of the actuator on the low-load side is affected by the actuator on the high-load side, causing the low-load actuator to operate poorly or its execution speed to lag behind, severely impacting the operator's experience. Summary of the Invention

[0003] This invention discloses a multi-pump confluence electro-hydraulic system and an excavator to solve the above-mentioned problems.

[0004] The present invention adopts the following solution:

[0005] This application provides a multi-pump confluence electro-hydraulic system, including a control component, a first hydraulic component, a second hydraulic component, a third hydraulic component electrically connected to the control component, a first three-position six-way proportional valve, a second three-position six-way proportional valve, a third three-position six-way proportional valve, a fourth three-position six-way proportional valve, a fifth three-position six-way proportional valve, a sixth three-position six-way proportional valve, and a first two-position three-way proportional valve, as well as a first actuator, a second actuator, a third actuator, and a fourth actuator;

[0006] The first hydraulic component is connected to the first three-position six-way proportional valve and acts on the first actuator.

[0007] The first hydraulic component, the first three-position six-way proportional valve, and the second three-position six-way proportional valve are sequentially connected and act on the second actuator; the second hydraulic component, the three-position six-way proportional valve, and the fourth three-position six-way proportional valve are sequentially connected and act on the second actuator.

[0008] The first hydraulic assembly, the first three-position six-way proportional valve, the second three-position six-way proportional valve, and the fifth three-position six-way proportional valve are connected in sequence and act on the third actuator; the second hydraulic assembly and the third three-position six-way proportional valve are connected and act on the third actuator; the third hydraulic assembly, the sixth three-position six-way proportional valve, and the two-position three-way proportional valve are connected in sequence and act on the third actuator.

[0009] The third hydraulic component is connected to the sixth three-position six-way proportional valve and acts on the fourth actuator.

[0010] Furthermore, it also includes eight electromagnetic proportional pressure reducing valves electrically connected to the control component, with each pair of electromagnetic proportional pressure reducing valves used to control the oil flow direction of a proportional valve.

[0011] Furthermore, the first actuator, the second actuator, and the third actuator are used to perform reciprocating movements of extending and retracting; the fourth actuator is used to perform rotational movements.

[0012] Furthermore, the first actuator, the second actuator, and the third actuator are hydraulic cylinders; the fourth actuator is a rotary motor.

[0013] Furthermore, pressure sensors are installed on the oil inlet pipes at both ends of the first actuator, the second actuator, the third actuator, and the fourth actuator; the pressure sensors are electrically connected to the control component.

[0014] Furthermore, it also includes a battery management system electrically connected to the control component, a battery module and a high-voltage management unit electrically connected to the battery management system, and a first controller, a second controller, and a third controller electrically connected to the high-voltage management unit; the first controller, the second controller, and the third controller are respectively used to control the first hydraulic component, the second hydraulic component, and the third hydraulic component.

[0015] Furthermore, it also includes a second two-position three-way proportional valve electrically connected to the control component, serving as a pilot safety valve.

[0016] Furthermore, flow sensing components are provided on the return oil lines of the second actuator, the third actuator, and the fourth actuator.

[0017] This application also provides an excavator, including a traveling mechanism, an upper turntable, and a working device, characterized in that it further includes the aforementioned multi-pump confluence electro-hydraulic system; a first actuator is used to drive the bucket in the working device to perform operations; a second actuator is used to drive the stick in the working device to perform operations; a third actuator is used to drive the boom in the working device to perform operations; and a fourth actuator is used to drive the upper turntable in the working device to rotate.

[0018] By adopting the above technical solution, the present invention can achieve the following technical effects:

[0019] 1. A multi-pump system is adopted to increase the maximum flow rate of the system and improve the operating speed of the actuator by merging the flow under complex operating conditions;

[0020] 2. Match the control terminal signal with the flow demand of the controlled actuator to address the impact of sudden load changes on the speed regulation performance of the open-center system.

[0021] 3. By matching the return oil pressure value of the multi-way valve with the load pressure and the characteristics of the hydraulic components, the output of the hydraulic components is reduced under low flow conditions and increased under high flow conditions, thus achieving a better energy-saving effect. Attached Figure Description

[0022] Figure 1 A schematic diagram of a multi-pump confluence electro-hydraulic system according to an embodiment of the present invention;

[0023] Figure 2 This is a typical combined working condition operation cycle diagram of the excavator according to an embodiment of the present invention;

[0024] Icons: First hydraulic component 1, Second hydraulic component 2, Third hydraulic component 3, First three-position six-way proportional valve 4, Second three-position six-way proportional valve 5, Third three-position six-way proportional valve 6, Fourth three-position six-way proportional valve 7, Fifth three-position six-way proportional valve 8, Sixth three-position six-way proportional valve 9, First two-position three-way proportional valve 10, First actuator 11, Second actuator 12, Third actuator 13, Fourth actuator 14, Pressure sensor 15, Flow sensing component 16, Electromagnetic proportional pressure reducing valve 17, Second two-position three-way proportional valve 18, Main relief valve 19. Detailed Implementation

[0025] Combination Figure 1 and Figure 2As shown, this embodiment provides a multi-pump confluence electro-hydraulic system, including a control component, a first hydraulic component 1, a second hydraulic component 2, a third hydraulic component 3 electrically connected to the control component, a first three-position six-way proportional valve 4, a second three-position six-way proportional valve 5, a third three-position six-way proportional valve 6, a fourth three-position six-way proportional valve 7, a fifth three-position six-way proportional valve 8, a sixth three-position six-way proportional valve 9 and a first two-position three-way proportional valve 10, as well as a first actuator 11, a second actuator 12, a third actuator 13 and a fourth actuator 14;

[0026] The first hydraulic component 1 is connected to the first three-position six-way proportional valve 4 and acts on the first actuator 11;

[0027] The first hydraulic component 1, the first three-position six-way proportional valve 4, and the second three-position six-way proportional valve 5 are sequentially connected and act on the second actuator 12; the second hydraulic component 2, the three-position six-way proportional valve, and the fourth three-position six-way proportional valve 7 are sequentially connected and act on the second actuator 12.

[0028] The first hydraulic component 1, the first three-position six-way proportional valve 4, the second three-position six-way proportional valve 5, and the fifth three-position six-way proportional valve 8 are connected in sequence and act on the third actuator 13; the second hydraulic component 2 and the third three-position six-way proportional valve 6 are connected and act on the third actuator 13; the third hydraulic component 3, the sixth three-position six-way proportional valve 9, and the two-position three-way proportional valve are connected in sequence and act on the third actuator 13.

[0029] The third hydraulic component 3 is connected to the sixth three-position six-way proportional valve 9 and acts on the fourth actuator 14.

[0030] Specifically, in this embodiment, taking an excavator as an example, it includes a traveling mechanism, an upper turntable, and a working device, as well as the aforementioned multi-pump confluence electro-hydraulic system; the first actuator 11 is used to drive the bucket in the working device to perform operations; the second actuator 12 is used to drive the stick in the working device to perform operations; the third actuator 13 is used to drive the boom in the working device to perform operations; and the fourth actuator 14 is used to drive the upper turntable in the working device to rotate. The first actuator 11 is a first hydraulic cylinder, the front end of which is connected to the bucket, and is used to drive the bucket's working action; the second actuator 12 is a second hydraulic cylinder, the front end of which is connected to the stick, and is used to drive the stick to swing; the third actuator 13 is a third hydraulic cylinder, the front end of which is connected to the boom, and is used to drive the boom to swing; and the fourth actuator 14 is a hydraulic rotary motor, which enables the upper turntable to perform a rotary action. All of the above hydraulic components include a motor and a hydraulic pump, which output hydraulic oil from the oil tank to drive the piston rod of the hydraulic cylinder to extend and retract, and to make the rotary motor rotate.

[0031] When controlling the extension and retraction of the first hydraulic cylinder, pressure oil is output through the first hydraulic component 1, and the operation of the first hydraulic cylinder is controlled through the first three-position six-way proportional valve 4.

[0032] When controlling the extension and retraction of the second hydraulic cylinder, the first hydraulic component 1 outputs pressurized oil, which enters the second hydraulic cylinder through the first three-position six-way proportional valve 4 and the second three-position six-way proportional valve 5; the second hydraulic component 2 outputs pressurized oil, which enters the second hydraulic cylinder through the third three-position six-way proportional valve 6 and the fourth three-position six-way proportional valve 7; the extension and retraction of the second hydraulic cylinder are controlled by the combined flow of the two pressurized oils.

[0033] When controlling the extension and retraction of the third hydraulic cylinder, the first hydraulic component 1 outputs pressurized oil, which enters the third hydraulic cylinder through the first three-position six-way proportional valve 4, the second three-position six-way proportional valve 5, and the fifth three-position six-way proportional valve 8; the second hydraulic component 2 outputs pressurized oil, which enters the third hydraulic cylinder through the third three-position six-way proportional valve 6; and the third hydraulic component 3 outputs pressurized oil, which enters the third hydraulic cylinder through the sixth three-position six-way proportional valve 9 and the first two-position three-way proportional valve 10. The extension and retraction of the third hydraulic cylinder are controlled by the convergence of the three pressurized oil flows.

[0034] When the hydraulic rotary motor is controlled to rotate, the combined flow of the pressure oil output by the third hydraulic component 3 to the third hydraulic cylinder will be cut off, and the hydraulic rotary motor will be supplied with oil separately through the sixth three-position six-way proportional valve 9 to ensure the independence of the hydraulic rotary motor's operation.

[0035] Because excavators often require multiple actuators to work simultaneously, such as Figure 2 The diagram shown is a typical combined working cycle diagram of an excavator, which will be explained in detail below:

[0036] In the first stage, the first hydraulic cylinder and the third hydraulic cylinder operate under combined motion conditions. Since the bucket's movement is relatively small, it requires less hydraulic oil flow and is supplied solely by the first hydraulic assembly 1. However, due to the boom's larger movement, a greater hydraulic oil flow is needed to ensure its operating efficiency. At this time, the hydraulic oil supplied by the first hydraulic assembly 1, after passing through the first three-position six-way proportional valve 4, supplies the first hydraulic cylinder with sufficient hydraulic oil while simultaneously supplying the excess hydraulic oil to the third hydraulic cylinder through the second three-position six-way proportional valve 5. The hydraulic oil output from the second hydraulic assembly 2 is supplied to the third hydraulic cylinder through the third three-position six-way proportional valve 6. The hydraulic oil output from the third hydraulic assembly 3 enters the third hydraulic cylinder through the sixth three-position six-way proportional valve 9 and the first two-position three-way proportional valve 10. The first hydraulic assembly 1, the second hydraulic assembly 2, and the third hydraulic assembly 3 jointly supply oil to the third hydraulic cylinder, ensuring the boom's operating efficiency.

[0037] In the second stage, the second and third hydraulic cylinders extend, and the hydraulic rotary motor performs a combined action. To ensure the independent operation of the hydraulic rotary motor, the third hydraulic component 3 supplies oil to the hydraulic rotary motor independently through the sixth three-position six-way proportional valve 9. The first hydraulic component 1 and the second hydraulic component 2 combine to control the operation of the stick and the boom, and control the distribution of hydraulic oil through the three-position six-way proportional valve. That is, when only the stick is operating in the early stage, a large amount of hydraulic oil is supplied to the second hydraulic cylinder; while when the boom also starts to operate in the later stage, the control component sends a signal to control the three-position six-way proportional valve to distribute the flow to the third hydraulic cylinder.

[0038] In the third stage, the first hydraulic cylinder, the third hydraulic cylinder, and the rotary motor perform a combined action. Before the rotary motor operates, the first hydraulic component 1 outputs hydraulic oil to control the piston rod of the first hydraulic cylinder to retract. At the same time, the excess hydraulic oil from the first hydraulic component 1 and the hydraulic oil output from the second hydraulic component 2 and the third hydraulic component 3 merge to jointly control the piston rod of the third hydraulic cylinder to retract, thereby controlling the boom's rotation. When the rotary motor starts operating, the hydraulic oil output from the third hydraulic component 3 no longer merges, and independently controls the operation of the rotary motor.

[0039] In the fourth stage, the second hydraulic cylinder and the rotary motor perform a combined action. The first hydraulic component 1 and the second hydraulic component 2 merge to output hydraulic oil to control the retraction of the piston rod of the second hydraulic cylinder, while the hydraulic oil output by the third hydraulic component 3 independently controls the operation of the hydraulic rotary motor.

[0040] In this embodiment, eight electromagnetic proportional pressure reducing valves 17 electrically connected to the control component are also included. Each pair of electromagnetic proportional pressure reducing valves 17 is used to control the oil flow direction of a proportional valve. It should be noted that the excavator is equipped with two electric control handles electrically connected to the control component. Each electric control handle includes displacement in four directions: forward, backward, left, and right. The left and right directions of the first electric control handle control one electromagnetic proportional pressure reducing valve 17 to output hydraulic oil to push the valve core of the first three-position six-way proportional valve 4 to move, correspondingly controlling the piston rod extension and retraction of the first hydraulic cylinder. The forward and backward directions of the first electric control handle control four electromagnetic proportional pressure reducing valves 17, thereby controlling the displacement of the valve cores of the second three-position six-way proportional valve 5, the third three-position six-way proportional valve 6, the sixth three-position six-way proportional valve 9, and the first two-position three-way proportional valve 10 to correspondingly control the piston rod extension and retraction of the third hydraulic cylinder.

[0041] The second electric control handle controls the two electromagnetic proportional pressure reducing valves 17 in the left and right directions, thereby controlling the valve core displacement of the sixth three-position six-way proportional valve 9, which in turn controls the operation of the hydraulic rotary motor; the second electric control handle controls the two electromagnetic proportional pressure reducing valves 17 in the forward and backward directions, thereby controlling the valve core displacement of the first three-position six-way proportional valve 4 and the fourth three-position six-way proportional valve 7, which in turn controls the piston rod extension and retraction of the second hydraulic cylinder.

[0042] Furthermore, pressure sensors 15 are installed on the oil inlet pipes at both ends of the first actuator 11, the second actuator 12, the third actuator 13, and the fourth actuator 14; the pressure sensors 15 are electrically connected to the control component; and flow sensing components 16 are installed on the return oil lines of the second actuator 12, the third actuator 13, and the fourth actuator 14. The real-time return oil pressure and flow rate sensed by the flow sensing components 16 and the pressure sensors 15 are fed back to the control component. The target flow rate required by the current actuator is estimated by the opening degree of the electric control handle, and the valve core opening degree of the electromagnetic proportional pressure reducing valve 17 under the current load pressure and flow rate requirements is calculated. The opening degree of the electric control handle corresponds to the target flow rate required by the actuator in a direct proportional relationship. After receiving the output signal from the electric control handle, the control component outputs a control signal to the corresponding electromagnetic proportional pressure reducing valve 17. After receiving the control signal, the electromagnetic proportional pressure reducing valve 17 outputs pressure oil to drive the three-position six-way proportional valve to actuate, thereby controlling the operating speed of the actuator.

[0043] During the return oil flow, the control algorithm stored within the control component performs closed-loop control on the return oil pressure detected by the flow sensing component 16. A relatively small return oil pressure is set, which corresponds to changing the speed of the drive motor of the corresponding hydraulic circuit, thus maintaining the return oil pressure within the set value range. The return oil pressure is directly proportional to the return oil flow rate; the lower the return oil pressure, the higher the system energy utilization rate, improving the system's energy efficiency.

[0044] Furthermore, this embodiment also includes a second two-position three-way proportional valve 18 electrically connected to the control component as a pilot safety valve, and a main relief valve 19; the main relief valve 19 protects the main oil circuit to prevent excessive system pressure, and the pilot safety valve protects the pilot oil circuit to prevent excessive pilot oil circuit pressure.

[0045] It should be noted that this embodiment also includes a battery management system electrically connected to the control component, a battery component and a high-voltage management unit electrically connected to the battery management system, and a first controller, a second controller, and a third controller electrically connected to the high-voltage management unit; the first controller, the second controller, and the third controller are respectively used to control the first hydraulic component 1, the second hydraulic component 2, and the third hydraulic component 3. The above belongs to the prior art and will not be described in detail here.

[0046] This invention employs a multi-pump system to increase the maximum system flow rate and improve actuator operating speed under complex operating conditions by merging flows. It also matches the characteristics of the operating terminal signal with the flow requirements of the controlled actuator to resolve the impact of sudden load changes on the speed regulation performance of the open-center system. Furthermore, it matches the return oil pressure value in the multi-way valve with the load pressure and hydraulic components to reduce the output of the hydraulic components under low flow conditions and increase the output of the hydraulic components under high flow conditions, thus achieving better energy-saving effects.

[0047] It should be understood that the above are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of the present invention are within the scope of protection of the present invention.

[0048] The accompanying drawings used in the above description of the embodiments only illustrate certain embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

Claims

1. A multiple pump combined flow electro-hydraulic system, characterized in that, It includes a control component, a first hydraulic component, a second hydraulic component, a third hydraulic component electrically connected to the control component, a first three-position six-way proportional valve, a second three-position six-way proportional valve, a third three-position six-way proportional valve, a fourth three-position six-way proportional valve, a fifth three-position six-way proportional valve, a sixth three-position six-way proportional valve, and a first two-position three-way proportional valve, as well as a first actuator, a second actuator, a third actuator, and a fourth actuator. The first hydraulic component is connected to the first three-position six-way proportional valve and acts on the first actuator. The first hydraulic component, the first three-position six-way proportional valve, and the second three-position six-way proportional valve are sequentially connected and act on the second actuator; the second hydraulic component, the third three-position six-way proportional valve, and the fourth three-position six-way proportional valve are sequentially connected and act on the second actuator. The first hydraulic assembly, the first three-position six-way proportional valve, the second three-position six-way proportional valve, and the fifth three-position six-way proportional valve are connected in sequence and act on the third actuator; the second hydraulic assembly and the third three-position six-way proportional valve are connected and act on the third actuator; the third hydraulic assembly, the sixth three-position six-way proportional valve, and the first two-position three-way proportional valve are connected in sequence and act on the third actuator. The third hydraulic component is connected to the sixth three-position six-way proportional valve and acts on the fourth actuator; The first actuator, the second actuator, and the third actuator are used to perform reciprocating movements of extending and retracting; the fourth actuator is used to perform rotational movements. The first actuator, the second actuator, and the third actuator are hydraulic cylinders; the fourth actuator is a rotary motor.

2. The multiple pump combined flow electro-hydraulic system of claim 1, wherein, Pressure sensors are installed on the oil inlet pipes at both ends of the first actuator, the second actuator, the third actuator, and the fourth actuator; the pressure sensors are electrically connected to the control component.

3. The multi-pump confluence electro-hydraulic system according to claim 1, characterized in that, It also includes a battery management system electrically connected to the control component, a battery component and a high-voltage management unit electrically connected to the battery management system, and a first controller, a second controller, and a third controller electrically connected to the high-voltage management unit; the first controller, the second controller, and the third controller are respectively used to control the first hydraulic component, the second hydraulic component, and the third hydraulic component.

4. The multi-pump confluence electro-hydraulic system according to claim 1, characterized in that, It also includes a second two-position three-way proportional valve that is electrically connected to the control component and serves as a pilot safety valve.

5. The multi-pump confluence electro-hydraulic system according to claim 1, characterized in that, A flow sensing component is provided on the return oil line of the second actuator, the third actuator, and the fourth actuator.

6. An excavator, comprising a traveling mechanism, an upper turntable, and a working device, characterized in that, It also includes a multi-pump confluence electro-hydraulic system as described in any one of claims 1-5; the first actuator is used to drive the bucket in the working device to perform operations; the second actuator is used to drive the boom in the working device to perform operations; The third actuator is used to drive the boom in the working device to perform operations; the fourth actuator is used to drive the upper turntable in the working device to rotate.

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