A hydraulic system for merging and splitting flow, agricultural machinery and control method

Abstract

This invention relates to a hydraulic system for merging and splitting flow, agricultural machinery, and a control method, relating to the field of hydraulics. The hydraulic system includes an oil tank, a multi-way valve system, a merging pump, a merging control valve, a lifting system, a lifting pump, and a controller. The outlet of the merging pump is connected to a first port, the third port is connected to the oil tank, the inlet of the lifting pump is connected to the oil tank, the outlet of the lifting pump is connected to the inlet of the lifting system, the outlet of the lifting system is connected to a fourth port, the fifth port is connected to a second port, and the sixth port is connected to the oil tank. The merging control valve can be switched to connect the fourth port to the fifth port or the sixth port. The controller is communicatively connected to the multi-way valve system, the merging control valve, and the lifting system. The agricultural machinery includes this hydraulic system. The control method is implemented using this hydraulic system. The lifting system and the multi-way valve system can operate independently and simultaneously. Switching the merging control valve allows switching between different oil supply modes of the multi-way valve system.

Description

Technical Field

[0001] This invention relates to the field of hydraulics, specifically to a hydraulic system for splitting and merging flow, agricultural machinery, and a control method. Background Technology

[0002] The hydraulic systems of most mainstream tractors in China are fixed-displacement systems, primarily due to their low cost and simple design. However, fixed-displacement systems suffer from significant power losses and higher operating costs; furthermore, their limited functionality fails to meet the demands of applications requiring high-flow hydraulic output. To provide a high flow rate of hydraulic oil, a common design approach is to incorporate a confluence pump. When the actuator requires a high flow rate, both the confluence pump and the booster pump simultaneously supply oil to the multi-way valve system. Increasing the booster pump's displacement can also achieve a high flow rate, but this significantly increases the power loss of the hydraulic system, hence this approach is rarely adopted.

[0003] Existing tractor hydraulic systems mainly consist of two fixed displacement pumps or one fixed displacement pump and a priority valve. Among them, a system with two fixed displacement pumps, such as... Figure 2 As shown, the lift pump supplies oil to the lift system and the multi-way valve system, while the steering pump supplies oil to the steering system. For example... Figure 3 As shown, in a system with a fixed displacement pump and a priority valve, all the oil supplied by the fixed displacement pump first reaches the priority valve, and then the priority valve gives priority to supplying oil to the steering system. The remaining oil is supplied to the lifting system and the multi-way valve system.

[0004] The disadvantages of existing technology are:

[0005] a. The flow rates of the booster system and the multi-way valve system can only be the same, which does not meet the actual needs, such as the multi-way valve system having a flow rate much greater than that of the booster system.

[0006] b. The lifting system and the multi-way valve system are connected in series and cannot work simultaneously. Summary of the Invention

[0007] The technical problem to be solved by this invention is how to flexibly adjust the required flow rate of the booster system and the multi-way valve system.

[0008] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A hydraulic system for splitting and merging flow includes an oil tank, a multi-way valve system, a merging pump, a merging control valve, a lifting system, a lifting pump, and a controller. The inlet of the merging pump is connected to the oil tank. The multi-way valve system has a first oil port, a second oil port, and a third oil port. The first oil port and the second oil port are respectively connected to the third oil port. The outlet of the merging pump is connected to the first oil port. The third oil port is connected to the oil tank. The inlet of the lifting pump is connected to the oil tank. The outlet of the lifting pump is connected to the inlet of the lifting system. The merging control valve has a fourth oil port, a fifth oil port, and a sixth oil port. The outlet of the lifting system is connected to the fourth oil port. The fifth oil port is connected to the second oil port. The sixth oil port is connected to the oil tank. The merging control valve can be switched to connect the fourth oil port to the fifth oil port or the sixth oil port. The controller is communicatively connected to the multi-way valve system, the merging control valve, and the lifting system.

[0009] The beneficial effects of this invention are: the lifting system and the multi-way valve system can work independently and simultaneously, the lifting pump supplies oil to the lifting system, and the confluence pump supplies oil to the multi-way valve system.

[0010] When the confluence control valve is switched to the first position, the fourth and fifth oil ports are connected, and the oil supplied by the booster pump is output to the multi-way valve system after passing through the booster system, realizing high-flow output of the multi-way valve system. When the confluence control valve is switched to the second position, the fourth and sixth oil ports are connected, and the oil supplied by the booster pump is directly returned to the oil tank after passing through the booster system, enabling the booster system to achieve high-power output.

[0011] When the multi-way valve system is operating at normal flow rate or the booster system is operating alone, the booster pump can supply oil, which can prevent the confluence pump from working and reduce energy consumption.

[0012] Based on the above technical solution, the present invention can be further improved as follows.

[0013] Furthermore, the hydraulic system for merging and splitting flow also includes a temperature control pipeline, a heat dissipation system, and a lubrication system. One end of the temperature control pipeline is connected to the third oil port, and the other end is connected to the inlet of the lubrication system. The outlet of the lubrication system is connected to the oil tank. The inlet of the heat dissipation system is connected to the third oil port, and the outlet of the heat dissipation system is connected to the inlet of the lubrication system.

[0014] The beneficial effects of adopting the above-mentioned further solution are as follows: most of the oil flowing out from the third oil port flows to the lubrication system through the temperature control pipeline, while a small portion of the oil flows through the cooling system and then reaches the inlet of the lubrication system. Since the viscosity of the oil increases as the temperature decreases, leading to increased flow resistance, the lower the oil temperature, the greater the resistance to the oil flowing through the cooling system, resulting in a smaller flow rate through the cooling system.

[0015] Furthermore, the hydraulic system for splitting and merging flow also includes a temperature control valve and a temperature sensor. Both the temperature control valve and the temperature sensor are communicatively connected to the controller. The temperature control valve is installed on the temperature control pipeline. The temperature control valve can be switched so that its inlet is connected to or disconnected from its outlet. The temperature sensor is located on the pipeline at the inlet of the temperature control valve.

[0016] The beneficial effects of adopting the above-mentioned further solution are as follows: the controller controls the opening size of the temperature control valve based on the measured value of the temperature sensor, thereby controlling the flow rate into the cooling system. When operating in areas with low temperatures, increasing the opening size of the temperature control valve and reducing the flow rate through the cooling system can quickly increase the oil temperature. When the confluence pump and the booster pump are operating at high power simultaneously, decreasing the opening size of the temperature control valve can increase the flow rate through the cooling system, ensuring that the oil temperature remains within the normal operating range.

[0017] Furthermore, the hydraulic system for splitting and merging flow also includes a back pressure valve, the inlet of which is connected to the temperature control pipeline at the outlet of the temperature control valve, and the outlet of which is connected to the oil tank.

[0018] The beneficial effect of adopting the above-mentioned further solution is that if the back pressure generated by the lubrication system is higher than the opening pressure of the back pressure valve, some of the oil at the lubrication system inlet will return to the oil tank after passing through the back pressure valve.

[0019] Furthermore, the hydraulic system for merging and splitting flow also includes a steering system and a steering pump, with the inlets of the oil tank, the steering pump, the steering system, and the cooling system connected in sequence.

[0020] The beneficial effect of adopting the above-mentioned further solution is that the steering pump supplies oil to the steering system.

[0021] Furthermore, the hydraulic system for merging and splitting flow also includes a clutch control system, and the inlets of the oil tank, the steering pump, the steering system, the clutch control system, and the cooling system are connected in sequence.

[0022] The beneficial effects of adopting the above-mentioned further solution are: the steering pump supplies oil to the steering system and the clutch control system, and after the oil flows out from the clutch control system, part of it enters the cooling system and part of it enters the lubrication system through the temperature control valve.

[0023] Furthermore, the hydraulic system for merging and splitting flow also includes a motor and a check valve. The motor is connected to the merging pump via a drive and is also connected to the controller via a communication connection. The check valve is provided on the pipeline between the outlet of the merging pump and the first oil port.

[0024] The beneficial effect of adopting the above-mentioned further solution is that the controller controls the speed of the confluence pump by controlling the speed of the motor, thereby controlling its flow rate. The oil flowing out of the confluence pump enters the multi-way valve system through a check valve, preventing oil backflow and thus protecting the multi-way valve system.

[0025] The present invention also provides an agricultural machine, including the aforementioned hydraulic system for splitting and merging flow.

[0026] The present invention also provides a control method, implemented using the aforementioned flow splitting and merging hydraulic system, comprising the following steps:

[0027] The controller acquires the operating status of the lifting system and the multi-way valve system respectively, and the operating status includes working and not working;

[0028] If the lifting system is in the working state, the controller controls the confluence control valve to switch to the connection between the fourth oil port and the sixth oil port;

[0029] If the lifting system is in a non-operating state and the multi-way valve system is in an operating state, the controller controls the confluence control valve to switch to connect the fourth oil port and the fifth oil port.

[0030] The beneficial effects are: the controller switches the confluence control valve according to the working status of the multi-way valve system and the booster system, so as to realize the rational use of the confluence pump and reduce energy consumption.

[0031] Furthermore, the method specifically includes:

[0032] If the lifting system is in working state and the multi-way valve system is in working state, the controller controls the confluence control valve to switch to the connection between the fourth oil port and the sixth oil port, and the controller controls the confluence pump to stop.

[0033] If the lifting system is in working state and the multi-way valve system is in working state, the controller controls the confluence control valve to switch to the connection between the fourth oil port and the sixth oil port, and the controller controls the confluence pump to start at a speed of V2.

[0034] If the lifting system is inactive and the multi-way valve system is operational, and the multi-way valve system has a low required flow rate, the controller controls the confluence control valve to connect the fourth and fifth oil ports, and the controller controls the confluence pump to stop. If the multi-way valve system has a high required flow rate, the controller controls the confluence control valve to connect the fourth and fifth oil ports, and the controller controls the confluence pump to start at a speed of V1 or V2, where V1 is less than V2. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the hydraulic system for flow splitting and merging according to the present invention;

[0036] Figure 2 This is a schematic diagram of two existing metering pump systems;

[0037] Figure 3 This is a schematic diagram of a conventional metering pump and priority valve system.

[0038] The attached diagram lists the components represented by each number as follows:

[0039] 1. Multi-way valve system; 101. First oil port; 102. Second oil port; 103. Third oil port; 2. Lifting system; 3. Steering system; 4. Clutch control system; 5. Cooling system; 6. Lubrication system; 7. Controller; 8. Lifting pump; 9. Motor; 10. Merging pump; 11. Check valve; 12. Steering pump; 13. Temperature control valve; 14. Temperature sensor; 15. Back pressure valve; 16. Merging control valve; 161. Fourth oil port; 162. Fifth oil port; 163. Sixth oil port; 17. Temperature control pipeline. Detailed Implementation

[0040] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0041] like Figure 1As shown, this embodiment provides a hydraulic system for merging and splitting flow, including an oil tank, a multi-way valve system 1, a merging pump 10, a merging control valve 16, a lifting system 2, a lifting pump 8, and a controller 7. The inlet of the merging pump 10 is connected to the oil tank. The multi-way valve system 1 has a first oil port 101, a second oil port 102, and a third oil port 103. The first oil port 101 and the second oil port 102 are respectively connected to the third oil port 103. The outlet of the merging pump 10 is connected to the first oil port 101, and the third oil port 103 is connected to the oil tank. The inlet of the lifting pump 8 is connected to the oil tank. The outlet of the booster pump 8 is connected to the inlet of the booster system 2. The confluence control valve 16 has a fourth oil port 161, a fifth oil port 162, and a sixth oil port 163. The outlet of the booster system 2 is connected to the fourth oil port 161, the fifth oil port 162 is connected to the second oil port 102, and the sixth oil port 163 is connected to the oil tank. The confluence control valve 16 can be switched to connect the fourth oil port 161 to the fifth oil port 162 or the sixth oil port 163. The controller 7 is communicatively connected to the multi-way valve system 1, the confluence control valve 16, and the booster system 2.

[0042] The lifting system 2 and the multi-way valve system 1 can work independently and simultaneously. The lifting pump 8 supplies oil to the lifting system 2, and the confluence pump 10 supplies oil to the multi-way valve system 1.

[0043] When the confluence control valve 16 is switched to the first position, the fourth oil port 161 and the fifth oil port 162 are connected, and the oil supplied by the booster pump 8 is output to the multi-way valve system 1 after passing through the booster system 2, realizing a large flow output of the multi-way valve system 1. When the confluence control valve 16 is switched to the second position, the fourth oil port 161 and the sixth oil port 163 are connected, and the oil supplied by the booster pump 8 is directly returned to the oil tank after passing through the booster system 2, enabling the booster system 2 to achieve high power output.

[0044] When the multi-way valve system 1 is operating normally with its own flow output or the booster system 2 is operating alone, the booster pump 8 supplies oil, which can prevent the confluence pump 10 from working and reduce energy consumption.

[0045] Optionally, the confluence control valve 16 can be a solenoid valve or a mechanical valve.

[0046] Optional, such as Figure 1 As shown, in the de-energized state, the fourth port 161 and the fifth port 162 are connected, and in the energized state, the fourth port 161 and the sixth port 163 are connected; or, in the de-energized state, the fourth port 161 and the sixth port 163 are connected, and in the energized state, the fourth port 161 and the fifth port 162 are connected.

[0047] Based on any of the above schemes, the hydraulic system for splitting and merging also includes a temperature control pipeline 17, a heat dissipation system 5, and a lubrication system 6. One end of the temperature control pipeline 17 is connected to the third oil port 103, and the other end is connected to the inlet of the lubrication system 6. The outlet of the lubrication system 6 is connected to the oil tank. The inlet of the heat dissipation system 5 is connected to the third oil port 103, and the outlet of the heat dissipation system 5 is connected to the inlet of the lubrication system 6.

[0048] Most of the oil flowing out from the third oil port 103 flows to the lubrication system 6 through the temperature control line 17, while a small portion of the oil flows through the cooling system 5 and then reaches the inlet of the lubrication system 6. Since the viscosity of the oil increases as the temperature decreases, the flow resistance increases. Therefore, the lower the oil temperature, the greater the resistance to the oil flowing through the cooling system 5, resulting in a smaller flow rate through the cooling system 5.

[0049] Based on any of the above schemes, the hydraulic system for splitting and merging flow also includes a temperature control valve 13 and a temperature sensor 14. Both the temperature control valve 13 and the temperature sensor 14 are communicatively connected to the controller 7. The temperature control valve 13 is installed on the temperature control pipeline 17. The temperature control valve 13 can be switched to connect or disconnect its inlet from its outlet. The temperature sensor 14 is located on the pipeline at the inlet of the temperature control valve 13.

[0050] The controller 7 controls the opening size of the temperature control valve 13 based on the measured oil temperature value from the temperature sensor 14, thereby controlling the flow rate into the cooling system 5. When operating in areas with low temperatures, increasing the opening size of the temperature control valve 13 reduces the flow rate through the cooling system 5, allowing for a rapid increase in oil temperature. When the confluence pump 10 and the booster pump 8 are operating at high power simultaneously, decreasing the opening size of the temperature control valve 13 increases the flow rate through the cooling system 5, ensuring the oil temperature remains within the normal operating range.

[0051] Optionally, the temperature control valve 13 can be a solenoid valve or a mechanical valve.

[0052] Specifically, the temperature control valve 13 is a two-position two-way solenoid valve, and the controller 7 controls the opening size of the temperature control valve 13, thereby regulating the flow rate through it.

[0053] Based on any of the above schemes, the hydraulic system for splitting and merging flow also includes a back pressure valve 15, the inlet of which is connected to the temperature control pipeline 17 at the outlet of the temperature control valve 13, and the outlet of which is connected to the oil tank.

[0054] If the back pressure generated by the lubrication system 6 is higher than the opening pressure of the back pressure valve 15, some of the oil at the inlet of the lubrication system 6 will return to the oil tank after passing through the back pressure valve 15.

[0055] Based on any of the above schemes, the hydraulic system for splitting and merging also includes a steering system 3 and a steering pump 12, with the inlets of the oil tank, the steering pump 12, the steering system 3, and the cooling system 5 connected in sequence.

[0056] Steering pump 12 supplies oil to steering system 3.

[0057] Based on any of the above schemes, the hydraulic system for merging and splitting flow also includes a clutch control system 4, and the inlets of the oil tank, the steering pump 12, the steering system 3, the clutch control system 4 and the cooling system 5 are connected in sequence.

[0058] The steering pump 12 supplies oil to the steering system 3 and the clutch control system 4. After the oil flows out of the clutch control system 4, part of it enters the cooling system 5 and part of it enters the lubrication system 6 through the temperature control valve 13.

[0059] Based on any of the above schemes, the hydraulic system for splitting and merging flow also includes a motor 9 and a check valve 11. The motor 9 is connected to the merging pump 10 for transmission and to the controller 7 for communication. The check valve 11 is provided on the pipeline between the outlet of the merging pump 10 and the first oil port 101.

[0060] The controller 7 controls the speed of the confluence pump 10 by controlling the speed of the motor 9, thereby controlling its flow rate. The oil flowing out of the confluence pump 10 enters the multi-way valve system 1 through the check valve 11 to prevent backflow of oil and thus protect the multi-way valve system 1.

[0061] The present invention also provides an agricultural machine, including the aforementioned hydraulic system for splitting and merging flow.

[0062] The present invention also provides a control method, implemented using the aforementioned flow splitting and merging hydraulic system, comprising the following steps:

[0063] The controller 7 acquires the operating status of the lifting system 2 and the multi-way valve system 1 respectively, and the operating status includes working and not working;

[0064] If the working state of the lifting system 2 is working, the controller 7 controls the confluence control valve 16 to switch to connect the fourth oil port 161 and the sixth oil port 163;

[0065] If the lifting system 2 is in a non-operating state and the multi-way valve system 1 is in an operating state, the controller 7 controls the confluence control valve 16 to switch to connect the fourth oil port 161 and the fifth oil port 162.

[0066] In this way, the controller 7 switches the confluence control valve 16 according to the working status of the multi-way valve system 1 and the lifting system 2, so as to realize the rational use of the confluence pump 10 and reduce energy consumption.

[0067] Based on the above scheme, the method is specifically as follows:

[0068] If the working state of the lifting system 2 is working and the working state of the multi-way valve system 1 is not working, the controller 7 controls the confluence control valve 16 to switch to connect the fourth oil port 161 and the sixth oil port 163, and the controller 7 controls the confluence pump 10 to stop.

[0069] If the working state of the lifting system 2 is working, and the working state of the multi-way valve system 1 is working, the controller 7 controls the confluence control valve 16 to switch to the connection between the fourth oil port 161 and the sixth oil port 163, and the controller 7 controls the confluence pump 10 to start, with a speed of V2.

[0070] If the lifting system 2 is inactive and the multi-way valve system 1 is operational; if the multi-way valve system 1 requires a small flow rate, the controller 7 controls the confluence control valve 16 to connect the fourth port 161 and the fifth port 162, and the controller 7 controls the confluence pump 10 to stop; if the multi-way valve system 1 requires a large flow rate, the controller 7 controls the confluence control valve 16 to connect the fourth port 161 and the fifth port 162, and the controller 7 controls the confluence pump 10 to start, with a speed of V1 or V2, where V1 is less than V2.

[0071] The statement that the multi-way valve system 1 requires a small flow rate means that the oil supplied by the booster pump 8 is sufficient to drive the operating components of the multi-way valve system 1. The statement that the multi-way valve system 1 requires a large flow rate means that the oil supplied by the booster pump 8 alone (or the oil supplied by the booster pump 8 and the oil supplied by the combined pump 10 at speed V1) is insufficient to drive the operating components of the multi-way valve system 1.

[0072] If, without considering oil temperature, both the lifting system 2 and the multi-way valve system 1 are inactive, the confluence control valve 16 can be in any position. Optionally, the confluence control valve 16 can remain in its previous state without switching.

[0073] In one more specific embodiment, the control method includes:

[0074] The controller 7 acquires the operating status of the lifting system 2 and the multi-way valve system 1, the operating status including working and not working;

[0075] The specific solutions for handling the different operating states of lifting system 2 and multi-way valve system 1 are as follows:

[0076] A. If the working state of the multi-way valve system 1 is not working, and the working state of the lifting system 2 is working (i.e. only the lifting system 2 is working), the controller 7 controls the motor 9 to rotate at 0, and the controller 7 controls the confluence control valve 16 to switch to connect the fourth oil port 161 and the sixth oil port 163. The oil supplied by the lifting pump 8 flows through the lifting system 2 and the confluence control valve 16 and then flows back to the oil tank.

[0077] B. If the working state of the multi-way valve system 1 is working, and the working state of the lifting system 2 is not working (i.e., only the multi-way valve system 1 is working);

[0078] B1. If the required flow rate of the multi-way valve system 1 is small, the controller 7 controls the motor 9 to rotate at 0 speed, and the controller 7 controls the confluence control valve 16 to switch to connect the fourth oil port 161 and the fifth oil port 162. The oil supplied by the lift pump 8 flows through the lift system 2 and the confluence control valve 16 and then enters the multi-way valve system 1.

[0079] B2. If the multi-way valve system 1 requires a large flow rate, the controller 7 controls the confluence control valve 16 to switch to connect the fourth oil port 161 and the fifth oil port 162, and the controller 7 controls the motor 9 to rotate at a speed of V1. The oil output from the confluence pump 10 flows through the check valve 11 and enters the multi-way valve system 1, where it, together with the oil supplied by the booster pump 8, provides pressurized oil to the actuator of the multi-way valve system 1. When the oil supplied by the booster pump 8 is abnormal (such as the booster pump 8 is damaged, or the confluence control valve 16 is stuck) or the actuator of the multi-way valve system 1 requires a larger flow rate, and the current operating conditions cannot meet the flow rate requirement, the acceleration button connected to the controller 7 can be operated. The controller 7 controls the motor 9 to rotate at a speed of V2, ensuring that the confluence pump 10 outputs a large flow rate, wherein V1 is less than V2.

[0080] C. When the working state of the multi-way valve system 1 is working and the working state of the lifting system 2 is working (when the multi-way valve system 1 and the lifting system 2 are working simultaneously), the controller 7 controls the confluence control valve 16 to switch to connect the fourth oil port 161 and the sixth oil port 163, the lifting pump 8 supplies oil to the lifting system 2, and the controller 7 controls the rotation speed of the confluence pump 10 to V2, the confluence pump 10 supplies oil to the multi-way valve system 1. At this time, the multi-way valve system 1 cannot output a large flow rate.

[0081] D. If the working state of the multi-way valve system 1 is not working, and the working state of the lifting system 2 is not working (i.e., in standby state), the controller 7 controls the speed of the motor 9 to 0, the confluence pump 10 does not work, and the lifting pump 8 and the diverting pump 12 work normally.

[0082] When the temperature measured by temperature sensor 14 is lower than T1 (within this temperature range, steering system 3 cannot function properly and requires a rapid increase in oil temperature), the confluence control valve 16 and temperature control valve 13 are de-energized. The oil supplied by lift pump 8 flows through multi-way valve system 1 and merges with the oil supplied by steering pump 12. Most of the oil flows to lubrication system 6 through temperature control valve 13, while a small portion flows through cooling system 5 before reaching the inlet of lubrication system 6. The lower the temperature, the greater the resistance to oil flow through cooling system 5, resulting in a smaller flow rate. If the back pressure generated by lubrication system 6 is higher than the opening pressure of back pressure valve 15, some of the oil at the inlet of lubrication system 6 returns to the oil tank after passing through back pressure valve 15.

[0083] When the temperature measured by the oil temperature sensor is higher than T1 and lower than T2 (within this temperature range, the steering system 3 can work normally, but the oil temperature is low, the kinematic viscosity is high, the system operating loss is large, and the oil temperature needs to be increased), the flow control valve 16 is energized, and the oil supplied by the lift pump 8 flows back to the oil tank after passing through the flow control valve 16; the temperature control valve 13 is de-energized, and most of the oil flows to the inlet of the lubrication system 6 through the temperature control valve 13.

[0084] When the temperature measured by the oil temperature sensor is higher than T2 (the oil temperature within this range needs to be automatically adjusted according to the system's power consumption), the confluence control valve 16 is energized, and the oil supplied by the booster pump 8 flows back to the oil tank after passing through the confluence control valve 16; the opening size of the temperature control valve 13 is automatically adjusted by the controller 7 according to the measured oil temperature value; the higher the oil temperature, the smaller the opening size of the temperature control valve 13. Where T1 is less than T2.

[0085] In the description of this invention, the terms "first" and "second" 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 as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0086] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0087] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hydraulic system for merging and splitting flow, characterized in that, The system includes an oil tank, a multi-way valve system (1), a confluence pump (10), a confluence control valve (16), a lifting system (2), a lift pump (8), a controller (7), a temperature control pipeline (17), a heat dissipation system (5), a lubrication system (6), a steering system (3), and a steering pump (12). The inlet of the confluence pump (10) is connected to the oil tank. The multi-way valve system (1) has a first oil port (101), a second oil port (102), and a third oil port (103). The first oil port (101) and the second oil port (102) are respectively connected to the third oil port (103). The outlet of the confluence pump (10) is connected to the first oil port (101). The inlet of the lift pump (8) is connected to the oil tank. The outlet of the booster pump (8) is connected to the inlet of the booster system (2). The confluence control valve (16) has a fourth oil port (161), a fifth oil port (162) and a sixth oil port (163). The outlet of the booster system (2) is connected to the fourth oil port (161). The fifth oil port (162) is connected to the second oil port (102). The sixth oil port (163) is connected to the oil tank. The confluence control valve (16) can be switched to connect the fourth oil port (161) to the fifth oil port (162) or the sixth oil port (163). The controller (7) is connected to the multi-way valve system (1), the confluence control valve (16) and the booster system (2) respectively. One end of the temperature control pipeline (17) is connected to the third oil port (103), and the other end is connected to the inlet of the lubrication system (6). The outlet of the lubrication system (6) is connected to the oil tank. The inlet of the heat dissipation system (5) is connected to the third oil port (103), and the outlet of the heat dissipation system (5) is connected to the inlet of the lubrication system (6). The temperature control valve (13) is installed on the temperature control pipeline (17). The oil tank, the steering pump (12), the steering system (3), and the inlet of the heat dissipation system (5) are connected in sequence.

2. The hydraulic system for splitting and merging flow according to claim 1, characterized in that, It also includes a temperature sensor (14). The temperature control valve (13) and the temperature sensor (14) are both connected to the controller (7). The temperature control valve (13) can be switched to connect or disconnect its inlet from its outlet. The temperature sensor (14) is located on the pipeline at the inlet of the temperature control valve (13).

3. The hydraulic system for splitting and merging flow according to claim 2, characterized in that, It also includes a back pressure valve (15), the inlet of which is connected to the temperature control pipeline (17) at the outlet of the temperature control valve (13), and the outlet of which is connected to the oil tank.

4. The hydraulic system for splitting and merging flow according to claim 1, characterized in that, It also includes a clutch control system (4), and the inlets of the oil tank, the steering pump (12), the steering system (3), the clutch control system (4) and the cooling system (5) are connected in sequence.

5. A hydraulic system for splitting and merging flow according to any one of claims 1-4, characterized in that, It also includes a motor (9) and a check valve (11). The motor (9) is connected to the confluence pump (10) and communicates with the controller (7). The check valve (11) is provided on the pipeline between the outlet of the confluence pump (10) and the first oil port (101).

6. An agricultural machine, characterized in that, Includes the hydraulic system for splitting and merging flow as described in any one of claims 1-5.

7. A control method, characterized in that, The method employs the flow splitting and merging hydraulic system as described in any one of claims 1-5, comprising the following steps: The controller (7) acquires the working status of the lifting system (2) and the multi-way valve system (1), respectively, and the working status includes working and not working; If the working state of the lifting system (2) is working, the controller (7) controls the confluence control valve (16) to switch to the connection between the fourth oil port (161) and the sixth oil port (163); If the working state of the lifting system (2) is not working and the working state of the multi-way valve system (1) is working, the controller (7) controls the confluence control valve (16) to switch to the connection between the fourth oil port (161) and the fifth oil port (162).

8. The control method according to claim 7, characterized in that, The method is specifically as follows: If the working state of the lifting system (2) is working and the working state of the multi-way valve system (1) is not working, the controller (7) controls the confluence control valve (16) to switch to the connection between the fourth oil port (161) and the sixth oil port (163), and the controller (7) controls the confluence pump (10) to stop. If the working state of the lifting system (2) is working, and the working state of the multi-way valve system (1) is working, the controller (7) controls the confluence control valve (16) to switch to the connection between the fourth oil port (161) and the sixth oil port (163), and the controller (7) controls the confluence pump (10) to start, with a speed of V2; If the working state of the lifting system (2) is not working and the working state of the multi-way valve system (1) is working, if the required flow of the multi-way valve system (1) is small, the controller (7) controls the confluence control valve (16) to switch to the connection between the fourth oil port (161) and the fifth oil port (162), and the controller (7) controls the confluence pump (10) to stop; if the required flow of the multi-way valve system (1) is large, the controller (7) controls the confluence control valve (16) to switch to the connection between the fourth oil port (161) and the fifth oil port (162), and the controller (7) controls the confluence pump (10) to start, with a speed of V1 or V2, where V1 is less than V2.

Images