Unloading valve, hydraulic system, control method, device and apparatus for a hydraulic system

Abstract

The application relates to the technical field of engineering machinery, and discloses an unloading valve, a hydraulic system, a control method, device and equipment of the hydraulic system, wherein the unloading valve not only comprises an overflow valve and a first reversing valve, but also comprises an external oil circuit; a first end of the first reversing valve is in communication with an overflow port of the overflow valve; and a second end of the first reversing valve is in communication with the external oil circuit; thus, the first reversing valve can be controlled to reverse according to the overflow pressure of the overflow valve, and the first reversing valve can be controlled to reverse according to the oil inlet pressure when oil enters the external oil circuit; the first reversing valve can select a suitable reversing mode in different use scenarios; and the problem of power loss caused by the fact that whether the unloading valve is opened is determined by the P port pressure of a multi-way valve is solved.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, specifically to an unloading valve, a hydraulic system, a control method, device, and equipment for the hydraulic system. Background Technology

[0002] Dual-pump confluence hydraulic systems are widely used in wheel loaders. The steering pump supplies oil to the steering cylinder separately, while the excess flow is combined with the working pump to supply the working hydraulic cylinder in the working device, ensuring sufficient flow to keep the lifting time within a reasonable range.

[0003] When the entire machine operates under combined working conditions, both the hydraulic system's power demand and the machine's traction demand reach their maximum. If the engine's output power is insufficient, it can cause the engine to stall. To solve this problem, an unloading valve is typically added between the steering pump or work pump and the multi-way valve's inlet, depending on the system characteristics. In related technologies, the unloading valve uses a set unloading pressure value, which is generally about 2-3 MPa lower than the safety valve pressure of the multi-way valve. When the hydraulic system pressure is lower than the set unloading pressure value, both pumps in the hydraulic system—the steering pump and the work pump—supply oil to the working hydraulic system. When the system pressure is higher than the set unloading pressure value, the unloading valve opens, and one pump in the hydraulic system is directly connected to the oil tank. In this case, only one pump supplies oil to the working hydraulic system, thereby reducing the pump's power demand to meet the traction requirements under combined working conditions.

[0004] In related technologies, whether the unloading valve opens is determined by the pressure at the P port of the multi-way valve, and unloading cannot be performed according to demand. However, tests on wheel loaders show that, except during lifting, when dual pumps need to be combined, during bucket lowering, tipping, and lowering, dual pumps generally do not need to be combined. In these cases, if the pressure at the P port of the multi-way valve does not reach the set unloading pressure value, and both pumps still supply oil simultaneously, there will be a significant power loss. Summary of the Invention

[0005] In view of this, the present invention provides an unloading valve, a hydraulic system, a control method, a device, and equipment for the hydraulic system, in order to solve the problem of power loss caused by the fact that whether the unloading valve is open or not is determined solely by the pressure at the P port of the multi-way valve.

[0006] In a first aspect, the present invention provides an unloading valve, comprising a relief valve and a first directional valve, wherein the relief valve is provided with an oil inlet and an overflow port; a first end of the first directional valve is connected to the overflow port of the relief valve so that the first directional valve can switch according to the overflow pressure of the relief valve; a second end of the first directional valve is connected to an external oil circuit so that the first directional valve can switch according to the inlet pressure when oil enters the external oil circuit.

[0007] The unloading valve provided by this invention includes not only a relief valve and a first directional valve, but also an external oil circuit. The first end of the first directional valve is connected to the overflow port of the relief valve, and the second end of the first directional valve is connected to the external oil circuit. Thus, the first directional valve can be controlled to switch according to the overflow pressure of the relief valve, and also according to the inlet pressure when oil enters the external oil circuit. This allows the first directional valve to select the appropriate method for switching in different application scenarios, solving the problem of power loss caused by the fact that whether the unloading valve is open is determined solely by the P port pressure of the multi-way valve.

[0008] In one alternative embodiment, the unloading valve further includes a check valve disposed between the oil inlet of the relief valve and the first directional valve.

[0009] This ensures that the oil flows in one direction within the unloading valve.

[0010] Secondly, the present invention also provides a hydraulic system, including a first hydraulic pump, a second hydraulic pump, and an unloading valve, wherein both the first and second hydraulic pumps are used to supply oil to the working system, and the unloading valve is disposed between the first hydraulic pump and the working system, or between the second hydraulic pump and the working system.

[0011] In the hydraulic system provided by this invention, the unloading valve includes not only a relief valve and a first directional valve, but also an external oil circuit. The first end of the first directional valve is connected to the overflow port of the relief valve, and the second end of the first directional valve is connected to the external oil circuit. Thus, the first directional valve can be controlled to switch directions based on the overflow pressure of the relief valve, and also based on the inlet pressure when oil enters the external oil circuit. This allows the first directional valve to select an appropriate switching method in different application scenarios, solving the problem of power loss in hydraulic systems caused by the unloading valve's opening being determined solely by the P-port pressure of the multi-way valve.

[0012] In one optional embodiment, the hydraulic system further includes a first multi-way valve, an electromagnetic proportional directional valve, a second directional valve, and a first controller, wherein the first multi-way valve is connected to a first hydraulic pump and / or a second hydraulic pump to meet various operational requirements; the electromagnetic proportional directional valve is disposed between a pilot oil source and the first multi-way valve; the second directional valve is disposed between a pilot oil source and an unloading valve; and the first controller is communicatively connected to the electromagnetic proportional directional valve and the second directional valve.

[0013] This invention, by setting up an electromagnetic proportional directional valve and a second directional valve, allows the inflow of oil into the external oil circuit to be controlled by the electromagnetic proportional directional valve and the second directional valve. Thus, not only can the first directional valve be controlled to switch based on the overflow pressure of the relief valve in the unloading valve, but also based on the inflow pressure when oil enters the external oil circuit. This solves the problem of power loss in hydraulic systems caused by the fact that the opening of the unloading valve is determined solely by the P-port pressure of the multi-way valve.

[0014] In one optional embodiment, the hydraulic system further includes a second multi-way valve, a third directional valve, a pilot valve, a shuttle valve, and a second controller, wherein the second multi-way valve is connected to the first hydraulic pump and / or the second hydraulic pump to meet various operational requirements; the third directional valve is disposed between the pilot oil source and the unloading valve; the pilot valve is disposed between the pilot oil source and the second multi-way valve; the shuttle valve is disposed between the pilot valve and the third directional valve; and the second controller is communicatively connected to the pilot valve and the third directional valve.

[0015] This invention, by setting up a third directional valve, a pilot valve, and a shuttle valve, allows the external oil circuit to be controlled by these three valves. This not only controls the first directional valve to switch based on the overflow pressure of the relief valve in the unloading valve, but also controls it based on the inlet pressure when oil enters the external oil circuit. This solves the problem of power loss in hydraulic systems caused by the unloading valve's opening being determined solely by the P-port pressure of the multi-way valve.

[0016] Thirdly, the present invention also provides a control method for a hydraulic system. The hydraulic system includes a first hydraulic pump, a second hydraulic pump, a first multi-way valve, an electromagnetic proportional directional valve, a second directional valve, and an unloading valve according to the first aspect or any corresponding embodiment thereof. Both the first and second hydraulic pumps are connected to the first multi-way valve to enable the first multi-way valve to meet various operational requirements. The unloading valve is disposed between the first hydraulic pump and the working system or between the second hydraulic pump and the working system. The electromagnetic proportional directional valve is disposed between the pilot oil source and the first multi-way valve. The second directional valve is disposed between the pilot oil source and the unloading valve. The control method for the hydraulic system includes the following steps: when dual pump confluence is required, a first signal is sent to the electromagnetic proportional directional valve to allow oil from the pilot oil source to enter the first multi-way valve through the electromagnetic proportional directional valve; when dual pump confluence is not required and unloading is required, a second signal is sent to the second directional valve to allow oil from the pilot oil source to enter the unloading valve through the second directional valve.

[0017] This invention utilizes an electromagnetic proportional directional valve and a second directional valve to control whether oil enters the external oil circuit. Specifically, when dual-pump confluence is required, a first signal is sent to the electromagnetic proportional directional valve to allow oil from the pilot oil source to enter the first multi-way valve. When dual-pump confluence is not required and unloading is needed, a second signal is sent to the second directional valve to allow oil from the pilot oil source to enter the unloading valve. This allows the first directional valve to be controlled not only by the overflow pressure of the relief valve in the unloading valve but also by the inlet pressure of the external oil circuit, thus solving the power loss problem in hydraulic systems where the opening of the unloading valve is determined solely by the P-port pressure of the multi-way valve.

[0018] Fourthly, the present invention also provides a control method for a hydraulic system, the hydraulic system comprising a first hydraulic pump, a second hydraulic pump, a second multi-way valve, a pilot valve, a shuttle valve, a third directional valve, and an unloading valve according to the first aspect or any corresponding embodiment thereof, wherein both the first and second hydraulic pumps are connected to the second multi-way valve to enable the second multi-way valve to meet various operational requirements; the unloading valve is disposed between the first hydraulic pump and the working system or between the second hydraulic pump and the working system; the third directional valve is disposed between the pilot oil source and the unloading valve; the pilot valve is disposed between the pilot oil source and the second multi-way valve; the shuttle valve is disposed between the pilot valve and the third directional valve; the control method for the hydraulic system comprises the following steps: when dual pump confluence is required, a third signal is sent to the pilot valve to allow oil in the pilot oil source to enter the second multi-way valve through the pilot valve; when dual pump confluence is not required and unloading is required, a fourth signal is sent to the pilot valve to allow oil in the pilot oil source to enter the unloading valve through the pilot valve and the shuttle valve.

[0019] This invention, by incorporating a third directional valve, a pilot valve, and a shuttle valve, allows for the control of whether oil enters the external oil circuit. Specifically, when dual-pump confluence is required, a third signal is sent to the pilot valve, causing oil from the pilot oil source to enter the second multi-way valve through the pilot valve. When dual-pump confluence is not required and unloading is necessary, a fourth signal is sent to the pilot valve, causing oil from the pilot oil source to enter the unloading valve through the pilot valve and the shuttle valve. This not only controls the first directional valve to switch based on the overflow pressure of the relief valve in the unloading valve, but also controls it based on the inlet pressure when oil enters the external oil circuit, thus solving the power loss problem in hydraulic systems where the opening of the unloading valve is determined solely by the P-port pressure of the multi-way valve.

[0020] Fifthly, the present invention provides a control device for a hydraulic system, the hydraulic system including a first hydraulic pump, a second hydraulic pump, a first multi-way valve, an electromagnetic proportional directional valve, a second directional valve, and an unloading valve according to the first aspect or any corresponding embodiment thereof, wherein both the first and second hydraulic pumps are connected to the first multi-way valve to enable the first multi-way valve to meet various operational requirements; the unloading valve is disposed between the first hydraulic pump and the working system or between the second hydraulic pump and the working system; the electromagnetic proportional directional valve is disposed between the pilot oil source and the first multi-way valve; the second directional valve is disposed between the pilot oil source and the unloading valve; the control method of the hydraulic system includes a first control module and a second control module, wherein the first control module is used to send a first signal to the electromagnetic proportional directional valve when dual pump confluence is required, so that oil in the pilot oil source enters the first multi-way valve through the electromagnetic proportional directional valve; the second control module is used to send a second signal to the second directional valve when dual pump confluence is not required and unloading is required, so that oil in the pilot oil source enters the unloading valve through the second directional valve.

[0021] In a sixth aspect, the present invention also provides a control device for a hydraulic system, the hydraulic system comprising a first hydraulic pump, a second hydraulic pump, a second multi-way valve, a pilot valve, a shuttle valve, a third directional valve, and an unloading valve according to the first aspect or any corresponding embodiment thereof, wherein both the first hydraulic pump and the second hydraulic pump are connected to the second multi-way valve to enable the second multi-way valve to meet various operational requirements; the unloading valve is disposed between the first hydraulic pump and the working system or between the second hydraulic pump and the working system; the third directional valve is disposed between the pilot oil source and the unloading valve; the pilot valve is disposed between the pilot oil source and the second multi-way valve; the shuttle valve is disposed between the pilot valve and the third directional valve; the control method of the hydraulic system comprises a third control module and a fourth control module; wherein the third control module is used to send a third signal to the pilot valve when dual pump confluence is required, so that oil in the pilot oil source enters the second multi-way valve through the pilot valve; the fourth control module is used to send a fourth signal to the pilot valve when dual pump confluence is not required and unloading is required, so that oil in the pilot oil source enters the unloading valve through the pilot valve and the shuttle valve.

[0022] In a seventh aspect, the present invention also provides a computer device, including a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the control method of the hydraulic system of the third or fourth aspect.

[0023] Eighthly, the present invention also provides a computer-readable storage medium storing computer instructions for causing a computer to execute the control method of the hydraulic system of the third or fourth aspect.

[0024] In a ninth aspect, the present invention also provides a computer program product, including computer instructions for causing a computer to execute the control method of the hydraulic system of the third or fourth aspect.

[0025] The unloading valve, hydraulic system, control method, device, and equipment provided by this invention have the following beneficial effects: The unloading valve includes not only a relief valve and a first directional valve, but also an external oil circuit. The first end of the first directional valve is connected to the overflow port of the relief valve, and the second end of the first directional valve is connected to the external oil circuit. Thus, the first directional valve can be controlled to switch according to the overflow pressure of the relief valve, and also according to the inlet pressure when oil enters the external oil circuit. This allows the first directional valve to select an appropriate method for switching in different application scenarios, solving the problem of power loss caused by the fact that whether the unloading valve is open is determined solely by the P port pressure of the multi-way valve. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of the unloading valve according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of a hydraulic system according to an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of an example hydraulic system according to an embodiment of the present invention;

[0030] Figure 4 This is a flowchart illustrating an example of a hydraulic system control method according to an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of another example of a hydraulic system according to an embodiment of the present invention;

[0032] Figure 6 This is a flowchart of another example of a hydraulic system control method according to an embodiment of the present invention;

[0033] Figure 7 This is a structural block diagram of an example of a hydraulic system control device according to an embodiment of the present invention;

[0034] Figure 8This is a structural block diagram of another example of a hydraulic system control device according to an embodiment of the present invention;

[0035] Figure 9 This is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention;

[0036] Among them, 1. First hydraulic pump; 2. Electromagnetic proportional directional valve; 3. Second directional valve; 4. Unloading valve; 4-1. Relief valve; 4-2. First directional valve; 4-3. External oil circuit; 5. Second hydraulic pump; 6. First multi-way valve; 7. Hydraulic oil tank; 8. First controller; 9. Second multi-way valve; 10. Third directional valve; 11. Pilot valve; 12. Shuttle valve; 12-1. First shuttle valve; 12-2. Second shuttle valve; 13. Steering system; 14. Pilot oil source; 15. Boom cylinder; 16. Bucket cylinder. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] like Figure 1 As shown, according to an embodiment of the present invention, an unloading valve 4 is provided, including an overflow valve 4-1 and a first directional valve 4-2, wherein the overflow valve 4-1 is provided with an oil inlet and an overflow outlet; the first end of the first directional valve 4-2 is connected to the overflow outlet of the overflow valve 4-1 so that the first directional valve 4-2 switches according to the overflow pressure of the overflow valve 4-1; the second end of the first directional valve 4-2 is connected to an external oil circuit 4-3 so that the first directional valve 4-2 switches according to the inlet pressure when oil enters the external oil circuit 4-3.

[0039] The unloading valve provided by this invention includes not only an overflow valve 4-1 and a first directional valve 4-2, but also an external oil circuit 4-3. The first end of the first directional valve 4-2 is connected to the overflow port of the overflow valve 4-1, and the second end of the first directional valve 4-2 is connected to the external oil circuit 4-3. Thus, the first directional valve 4-2 can be controlled to switch according to the overflow pressure of the overflow valve 4-1, and also according to the inlet pressure when oil enters the external oil circuit 4-3. This allows the first directional valve 4-2 to select an appropriate switching method in different application scenarios, solving the problem of power loss caused by the fact that whether the unloading valve is open is determined solely by the P port pressure of the multi-way valve.

[0040] Furthermore, for loaders, power and torque figures vary at different speeds, with lower torque at idle. If the working hydraulic system and the overall transmission hydraulic system operate in conjunction at idle, excessive torque consumption in the working hydraulic system can lead to poor acceleration performance. Therefore, torque control of the hydraulic system, independent of pressure, is also necessary. This highlights the crucial importance of readily controllable unloading valves.

[0041] In one optional embodiment, the unloading valve 4 further includes a one-way valve disposed between the oil inlet of the overflow valve 4-1 and the first directional valve 4-2. This ensures that the oil flows in one direction within the unloading valve.

[0042] like Figure 2 As shown, according to an embodiment of the present invention, a hydraulic system is provided, including a first hydraulic pump 1, a second hydraulic pump 5, and a first-aspect unloading valve 4, wherein both the first hydraulic pump 1 and the second hydraulic pump 5 are used to supply oil to the working system, and the unloading valve 4 is disposed between the first hydraulic pump 1 and the working system, or between the second hydraulic pump 5 and the working system.

[0043] In the hydraulic system provided by this invention, the unloading valve includes not only a relief valve 4-1 and a first directional valve 4-2, but also an external oil circuit 4-3. The first end of the first directional valve 4-2 is connected to the overflow port of the relief valve 4-1, and the second end of the first directional valve 4-2 is connected to the external oil circuit 4-3. Thus, the first directional valve 4-2 can be controlled to switch directions based on the overflow pressure of the relief valve 4-1, and also based on the inlet pressure when oil enters the external oil circuit 4-3. This allows the first directional valve 4-2 to select an appropriate switching method in different application scenarios, solving the problem of power loss caused by the fact that whether the unloading valve is open is determined solely by the P port pressure of the multi-way valve.

[0044] In one optional embodiment, the hydraulic system further includes a first multi-way valve 6, an electromagnetic proportional directional valve 2, a second directional valve 3, and a first controller 8, wherein the first multi-way valve 6 is connected to the first hydraulic pump 1 and / or the second hydraulic pump 5 to meet various operational requirements; the electromagnetic proportional directional valve 2 is disposed between the pilot oil source 14 and the first multi-way valve 6; the second directional valve 3 is disposed between the pilot oil source 14 and the unloading valve 4; and the first controller 8 is communicatively connected to the electromagnetic proportional directional valve 2 and the second directional valve 3.

[0045] In other words, such as Figure 3As shown, the hydraulic control system comprises a first hydraulic pump 1, a second hydraulic pump 5, an unloading valve 4, a first multi-way valve 6, an electromagnetic proportional directional valve 2, a second directional valve 3, a first controller 8, a steering system 13, a pilot oil source 14, a boom cylinder 15, and a bucket cylinder 16. Specifically, the unloading valve 4 consists of a relief valve 4-1 and a first directional valve 4-2. An external oil circuit 4-3 is added to the unloading valve 4, allowing the first directional valve 4-2 to be controlled not only by the overflow pressure of the relief valve 4-1 but also by the external oil circuit 4-3. When dual-pump confluence is required, the pressure of the relief valve 4-1 is used for control. When dual-pump confluence is not required, the external oil circuit 4-3 connects the first directional valve 4-2 to the right position, causing the second hydraulic pump 5 to unload and stop confluence, thus reducing power loss. Whether the external oil circuit 4-3 is connected to the unloading valve 4 is determined by the first controller 8 and the second directional valve 3. The second directional valve 3 can be controlled by an electrical signal and can also be manually controlled.

[0046] like Figure 3 As shown, the specific implementation method is as follows:

[0047] (1) Depending on the working conditions of the loader, the boom generally needs to be lifted by the confluence of two pumps. The second hydraulic pump 5 and the unloading valve 4 are connected to the P port and together with the first hydraulic pump 1 supply oil to the multi-way valve. When lifting is required, the controller sends an electrical signal to the electromagnetic proportional directional valve 2. The oil inlet of the electromagnetic proportional directional valve 2-1 is connected and enters the first multi-way valve 6 to control the valve stem to move to the left. The oil supplied by the two pumps enters the large chamber of the boom cylinder 15 to realize the lifting of the boom.

[0048] When the pressure at port P of the multi-way valve reaches the set pressure of the relief valve 4-1, the relief valve 4-1 opens, and the overflowing oil pushes open the right-hand position of the first directional valve 4-2, thus unloading the second hydraulic pump 5. When not lifting, the dual pumps do not need to combine. Therefore, in the control logic, as long as the first controller 8 does not send a signal to the electromagnetic proportional directional valve 2-1, the first controller 8 can continuously send a power signal to the second directional valve 3, which is then closed to the right. The oil from the pilot oil source 14 enters port A of the unloading valve 4, the first directional valve 4-2 is connected to the right, and the second hydraulic pump 5 is unloaded. The oil output from the second hydraulic pump 5 is connected to the hydraulic oil tank 7, thereby reducing power loss. Furthermore, the noise of the second hydraulic pump 5 is reduced after unloading, and its lifespan is significantly extended.

[0049] (2) If, based on actual working conditions, it is necessary to merge the two pumps during the bucket-collecting process, then when the first controller 8 sends an electrical signal to the electromagnetic proportional directional valve 2-3, it simultaneously shuts off the electrical signal to the second directional valve 3, causing the second directional valve 3 to move to the left position, thus merging the two pumps. This logic can be used to control the unloading valve 4 to determine whether the second hydraulic pump 5 needs to merge.

[0050] (3) If you want the second hydraulic pump 5 to be in the unloaded state under a certain working condition, you can manually operate the first directional valve 4-2 to the right position and the unloading valve 4 to the right position, so that the second hydraulic pump 5 is unloaded.

[0051] This invention, by setting up an electromagnetic proportional directional valve 2 and a second directional valve 3, allows the electromagnetic proportional directional valve 2 and the second directional valve 3 to control whether oil enters the external oil circuit 4-3. This not only controls the first directional valve 4-2 to switch based on the overflow pressure of the relief valve 4-1 in the unloading valve, but also controls the first directional valve 4-2 to switch based on the inlet pressure when oil enters the external oil circuit 4-3. This solves the problem of power loss in hydraulic systems caused by the fact that the opening of the unloading valve is determined solely by the P-port pressure of the multi-way valve.

[0052] Based on this, according to an embodiment of the present invention, a control method embodiment for a hydraulic system is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0053] This embodiment provides a control method for a hydraulic system, which can be used in computer equipment. Figure 4 This is a flowchart illustrating an example of a hydraulic system control method according to an embodiment of the present invention, such as... Figure 4 As shown, the process includes the following steps:

[0054] Step S401: When dual pumps need to merge, a first signal is sent to the electromagnetic proportional directional valve 2 so that the oil in the pilot oil source 14 enters the first multi-way valve 6 through the electromagnetic proportional directional valve 2.

[0055] Step S402: When dual pump confluence is not required and unloading is required, a second signal is sent to the second directional valve 3 so that the oil from the pilot oil source 14 enters the unloading valve 4 through the second directional valve 3.

[0056] In one optional embodiment, the hydraulic system further includes a second multi-way valve 9, a third directional valve 10, a pilot valve 11, a shuttle valve 12, and a second controller. The second multi-way valve 9 is connected to the first hydraulic pump 1 and / or the second hydraulic pump 5 to meet various operational requirements. The third directional valve 10 is disposed between the pilot oil source 14 and the unloading valve 4. The pilot valve 11 is disposed between the pilot oil source 14 and the second multi-way valve 9. The shuttle valve 12 is disposed between the pilot valve 11 and the third directional valve 10. The second controller is communicatively connected to the pilot valve 11 and the third directional valve 10.

[0057] In other words, such as Figure 5As shown, the hydraulic system includes a first hydraulic pump 1, a second hydraulic pump 5, an unloading valve 4, a second multi-way valve 9, a third directional valve 10, a pilot valve 11, a shuttle valve 12, a second controller, a hydraulic oil tank 7, a steering system 13, a pilot oil source 14, a boom cylinder 15, and a bucket cylinder 16. The unloading valve 4 consists of a relief valve 4-1 and a first directional valve 4-2. An external oil circuit 4-3 is also added to the unloading valve 4, allowing the first directional valve 4-2 to be controlled not only by the overflow pressure of the relief valve 4-1 but also by the external oil circuit 4-3. When dual-pump confluence is required, the pressure of the relief valve 4-1 is used for control. When dual-pump confluence is not required, the external oil circuit 4-3 activates the right-hand position of the first directional valve 4-2, causing the second hydraulic pump 5 to unload and stop confluence, thus reducing power loss. Whether the external oil circuit 4-3 is connected to the unloading valve 4 is determined by the pilot control oil from the pilot valve 11 to the second multi-way valve 9. The function of the shuttle valve 12 is to prevent the control oil circuits of the pilot valve 11 from being interconnected and affecting each other, and to provide stable and clear control oil to the third directional valve 10 to ensure that clear commands are issued. The third directional valve 10 can be hydraulically controlled and can also be manually controlled. For example, if the oil from port A2 of the pilot valve 11 enters the first shuttle valve 12 and moves to the right, it prevents the oil from entering port xB2 of the second multi-way valve 9 through port 1' and causing an erroneous action. At the same time, the second shuttle valve 12 will also move to the right to prevent the oil from entering port xB1 of the second multi-way valve 9 through port 3' of the shuttle valve 12. Then the pilot control oil enters the directional valve through port 2' of the shuttle valve 12 to control the unloading valve 4.

[0058] like Figure 5 As shown, the specific implementation is as follows:

[0059] (1) According to the working conditions of the loader, the boom generally needs to be lifted by two pumps. The second hydraulic pump 5 and the unloading valve 4 are connected to the P port, and together with the first hydraulic pump 1, they supply oil to the multi-way valve. When lifting is required, the pilot valve 11 connects to the A1 port, enters the second multi-way valve 9xA1, the valve stem moves to the left, and the right position is connected to achieve lifting. At this time, there is no pressure oil connected to the third directional valve 10. The third directional valve 10 is in the left position, and the relief valve 4-1 is in the left position. Whether the unloading valve 4 overflows and unloads is determined by the pressure of the P port of the second multi-way valve 9. When the pressure of the P port reaches the set pressure of the relief valve 4-1, the second hydraulic pump 5 unloads; otherwise, it is always in the state of dual pump confluence.

[0060] When not lifting, the dual pumps do not need to combine. When the boom lowers, the P port of pilot valve 11 connects to the B1 port, and the B1 port of pilot valve 11 connects to the 3 port of shuttle valve 12. The oil enters the xB1 port of the second multi-way valve 9 through the 3' port of shuttle valve 12. The valve stem moves to the right, closing the left position, thus achieving descent. At the same time, the oil enters the third directional valve 10 from the X port of shuttle valve 12, closing the right position of the third directional valve 10. This controls the oil to enter the unloading valve 4, closing the right position of the first directional valve 4-2, and unloading the second hydraulic pump 5. This achieves the goal of not combining the two pumps during descent, thereby reducing power loss. Furthermore, the noise of the second hydraulic pump 5 is reduced after unloading, and its lifespan is significantly extended. Similarly, when the bucket closing and tipping do not require combining, the pilot oil of the second multi-way valve 9 is controlled, which also connects to the third directional valve 10. Then, the first directional valve 4-2 of the unloading valve 4 moves to the right position, and the second hydraulic pump 5 is unloaded.

[0061] (2) If, according to the actual working conditions, it is also necessary to perform dual pump merging during the bucket collection process, then the A2 control oil of the pilot valve 11 can be connected to the shuttle valve 12, and the 8-1 inside the shuttle valve 12 can be removed, leaving only the pilot control signal selection for descent and bucket tipping.

[0062] (3) If you want the second hydraulic pump 5 to be in the unloaded state under a certain working condition, you can manually operate the third directional valve 10 to the right position, and the first directional valve 4-2 of the unloading valve 4 to the right position, so that the second hydraulic pump 5 is unloaded.

[0063] This invention, by setting a third directional valve 10, a pilot valve 11, and a shuttle valve 12, allows the external oil circuit 4-3 to be controlled by the pilot valve 11, the shuttle valve 12, and the third directional valve 10. This not only controls the first directional valve 4-2 to switch based on the overflow pressure of the relief valve 4-1 in the unloading valve, but also controls the first directional valve 4-2 to switch based on the inlet pressure when oil enters the external oil circuit 4-3. This solves the problem of power loss in hydraulic systems caused by the unloading valve's opening being determined solely by the P-port pressure of the multi-way valve.

[0064] Based on this, according to an embodiment of the present invention, a control method embodiment for a hydraulic system is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0065] This embodiment provides a control method for a hydraulic system, which can be used in computer equipment. Figure 6 This is a flowchart of another example of a hydraulic system control method according to an embodiment of the present invention, such as... Figure 6 As shown, the process includes the following steps:

[0066] Step S601: When dual pumps need to merge, a third signal is sent to the pilot valve 11 so that the oil in the pilot oil source 14 enters the second multi-way valve 9 through the pilot valve 11.

[0067] Step S602: When dual pump confluence is not required and unloading is required, a fourth signal is sent to pilot valve 11 so that the oil from pilot oil source 14 enters unloading valve 4 through pilot valve 11 and shuttle valve 12.

[0068] and Figure 4 As shown, this embodiment also provides a control device for a hydraulic system, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0069] This embodiment provides a control device for a hydraulic system, such as... Figure 7 As shown, it includes:

[0070] The first control module 701 is used to send a first signal to the electromagnetic proportional directional valve 2 when dual pumps need to be combined, so that the oil in the pilot oil source 14 enters the first multi-way valve 6 through the electromagnetic proportional directional valve 2.

[0071] The second control module 702 is used to send a second signal to the second directional valve 3 when the dual pumps do not need to merge and unloading is required, so that the oil from the pilot oil source 14 enters the unloading valve 4 through the second directional valve 3.

[0072] and Figure 6 Correspondingly, this embodiment also provides a control device for a hydraulic system, which is used to implement the above embodiments and preferred embodiments, and will not be repeated as already described. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0073] This embodiment provides a control device for a hydraulic system, such as... Figure 8 As shown, it includes:

[0074] The third control module 801 is used to send a third signal to the pilot valve 11 when dual pumps need to be combined, so that the oil in the pilot oil source 14 enters the second multi-way valve 9 through the pilot valve 11.

[0075] The fourth control module 802 is used to send a fourth signal to the pilot valve 11 when the dual pumps do not need to merge and unloading is required, so that the oil from the pilot oil source 14 enters the unloading valve 4 through the pilot valve 11 and the shuttle valve 12.

[0076] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0077] In this embodiment, the control device of the hydraulic system is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0078] This invention also provides a computer device having the above-described features. Figure 7 or Figure 8 The control device for the hydraulic system shown.

[0079] Please see Figure 9 , Figure 9 This is a schematic diagram of the structure of a computer device provided in an optional embodiment of the present invention, such as... Figure 9 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 9 Take a processor 10 as an example.

[0080] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GPA), or any combination thereof.

[0081] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0082] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0083] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0084] The computer device also includes an input device 30 and an output device 40. The processor 10, memory 20, input device 30, and output device 40 can be connected via a bus or other means. Figure 9 Taking the example of a connection between China and Israel via a bus.

[0085] Input device 30 can receive input numerical or character information, and generate key signal inputs related to user settings and function control of the computer device, such as a touchscreen, keypad, mouse, trackpad, touchpad, joystick, one or more mouse buttons, trackball, joystick, etc. Output device 40 may include display devices, auxiliary lighting devices (e.g., LEDs), and haptic feedback devices (e.g., vibration motors). The aforementioned display devices include, but are not limited to, liquid crystal displays, light-emitting diodes, displays, and plasma displays. In some alternative embodiments, the display device may be a touchscreen.

[0086] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0087] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0088] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A hydraulic system, characterized in that, include: The first hydraulic pump (1) is used to supply oil to the working system; The second hydraulic pump (5) is used to supply oil to the working system; An unloading valve (4) is disposed between the first hydraulic pump (1) and the working system, or between the second hydraulic pump (5) and the working system; The first multi-way valve (6) is connected to the first hydraulic pump (1) and / or the second hydraulic pump (5) to meet various operational requirements; An electromagnetic proportional directional valve (2) is disposed between the pilot oil source (14) and the first multi-way valve (6); The second directional valve (3) is disposed between the pilot oil source (14) and the unloading valve (4); The first controller (8) is communicatively connected to the electromagnetic proportional directional valve (2) and the second directional valve (3); The unloading valve includes: The overflow valve (4-1) is equipped with an oil inlet and an overflow outlet; The first directional valve (4-2) has its first end connected to the overflow port of the relief valve (4-1) so that the first directional valve (4-2) switches according to the overflow pressure of the relief valve (4-1); the second end of the first directional valve (4-2) is connected to the external oil circuit (4-3) so that the first directional valve (4-2) switches according to the inlet pressure when oil enters the external oil circuit (4-3); Whether the external oil circuit is connected to the unloading valve is determined by the first controller and the second directional valve.

2. The hydraulic system according to claim 1, characterized in that, Also includes: A one-way valve is disposed between the oil inlet of the overflow valve (4-1) and the first reversing valve (4-2).

3. The hydraulic system according to claim 1, characterized in that, Also includes: The second multi-way valve (9) is connected to the first hydraulic pump (1) and / or the second hydraulic pump (5) to meet various operational requirements; The third directional valve (10) is disposed between the pilot oil source (14) and the unloading valve (4); A pilot valve (11) is located between the pilot oil source (14) and the second multi-way valve (9); A shuttle valve (12) is disposed between the pilot valve (11) and the third directional valve (10); The second controller is communicatively connected to the pilot valve (11) and the third directional valve (10).

4. A control method for a hydraulic system, characterized in that, The hydraulic system includes a first hydraulic pump (1), a second hydraulic pump (5), a first multi-way valve (6), an electromagnetic proportional directional valve (2), a second directional valve (3), and an unloading valve (4) in the hydraulic system according to any one of claims 1 to 3, wherein the first hydraulic pump (1) and the second hydraulic pump (5) are both connected to the first multi-way valve (6) so that the first multi-way valve (6) can meet various operational requirements; the unloading valve (4) is disposed between the first hydraulic pump (1) and the working system or between the second hydraulic pump (5) and the working system; the electromagnetic proportional directional valve (2) is disposed between the pilot oil source (14) and the first multi-way valve (6); the second directional valve (3) is disposed between the pilot oil source (14) and the unloading valve (4); the control method of the hydraulic system includes: When dual pumps need to be combined, a first signal is sent to the electromagnetic proportional directional valve (2) so that the oil in the pilot oil source (14) enters the first multi-way valve (6) through the electromagnetic proportional directional valve (2). When dual pump confluence is not required and unloading is required, a second signal is sent to the second directional valve (3) so that the oil from the pilot oil source (14) enters the unloading valve (4) through the second directional valve (3).

5. A control method for a hydraulic system, characterized in that, The hydraulic system includes a first hydraulic pump (1), a second hydraulic pump (5), a second multi-way valve (9), a pilot valve (11), a shuttle valve (12), a third directional valve (10), and an unloading valve (4) in the hydraulic system according to any one of claims 1 to 3, wherein the first hydraulic pump (1) and the second hydraulic pump (5) are both connected to the second multi-way valve (9) so that the second multi-way valve (9) can meet various operational requirements; the unloading valve (4) is disposed between the first hydraulic pump (1) and the working system or between the second hydraulic pump (5) and the working system; the third directional valve (10) is disposed between the pilot oil source (14) and the unloading valve (4); the pilot valve (11) is disposed between the pilot oil source (14) and the second multi-way valve (9); the shuttle valve (12) is disposed between the pilot valve (11) and the third directional valve (10); the control method of the hydraulic system includes: When dual pumps need to be combined, a third signal is sent to the pilot valve (11) so that the oil in the pilot oil source (14) enters the second multi-way valve (9) through the pilot valve (11). When dual pump confluence is not required and unloading is required, a fourth signal is sent to the pilot valve (11) so that the oil from the pilot oil source (14) enters the unloading valve (4) through the pilot valve (11) and the shuttle valve (12).

6. A control device for a hydraulic system, characterized in that, The hydraulic system includes a first hydraulic pump (1), a second hydraulic pump (5), a first multi-way valve (6), an electromagnetic proportional directional valve (2), a second directional valve (3), and an unloading valve (4) in the hydraulic system according to any one of claims 1 to 3, wherein the first hydraulic pump (1) and the second hydraulic pump (5) are both connected to the first multi-way valve (6) so that the first multi-way valve (6) can meet various operational requirements; the unloading valve (4) is disposed between the first hydraulic pump (1) and the working system or between the second hydraulic pump (5) and the working system; the electromagnetic proportional directional valve (2) is disposed between the pilot oil source (14) and the first multi-way valve (6); the second directional valve (3) is disposed between the pilot oil source (14) and the unloading valve (4); the control method of the hydraulic system includes: The first control module is used to send a first signal to the electromagnetic proportional directional valve (2) when dual pumps need to be combined, so that the oil in the pilot oil source (14) enters the first multi-way valve (6) through the electromagnetic proportional directional valve (2). The second control module is used to send a second signal to the second directional valve (3) when the dual pumps do not need to merge and unloading is required, so that the oil from the pilot oil source (14) enters the unloading valve (4) through the second directional valve (3).

7. A control device for a hydraulic system, characterized in that, The hydraulic system includes a first hydraulic pump (1), a second hydraulic pump (5), a second multi-way valve (9), a pilot valve (11), a shuttle valve (12), a third directional valve (10), and an unloading valve (4) in the hydraulic system according to any one of claims 1 to 3, wherein the first hydraulic pump (1) and the second hydraulic pump (5) are both connected to the second multi-way valve (9) so that the second multi-way valve (9) can meet various operational requirements; the unloading valve (4) is disposed between the first hydraulic pump (1) and the working system or between the second hydraulic pump (5) and the working system; the third directional valve (10) is disposed between the pilot oil source (14) and the unloading valve (4); the pilot valve (11) is disposed between the pilot oil source (14) and the second multi-way valve (9); the shuttle valve (12) is disposed between the pilot valve (11) and the third directional valve (10); the control method of the hydraulic system includes: The third control module is used to send a third signal to the pilot valve (11) when dual pumps need to be combined, so that the oil in the pilot oil source (14) enters the second multi-way valve (9) through the pilot valve (11). The fourth control module is used to send a fourth signal to the pilot valve (11) when the dual pumps do not need to merge and unloading is required, so that the oil from the pilot oil source (14) enters the unloading valve (4) through the pilot valve (11) and the shuttle valve (12).

8. A computer device, characterized in that, include: A memory and a processor are interconnected, the memory storing computer instructions, and the processor executing the computer instructions to perform the control method of the hydraulic system as described in any one of claims 4 or 5.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the control method of the hydraulic system according to any one of claims 4 or 5.

10. A computer program product, characterized in that, Includes computer instructions for causing a computer to perform the control method of the hydraulic system according to any one of claims 4 or 5.

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