Hydraulic control system, control method and work machine

Abstract

The present invention relates to the field of hydraulic control, and provides a hydraulic control system, a control method and a working machine. The hydraulic control system includes: an electro-hydraulic proportional pump, a multi-way valve group, a flow priority valve and a detection device. The flow priority valve is arranged between the electro-hydraulic proportional pump and the multi-way valve group. The flow priority valve includes a priority port and a bypass port. The priority port is connected to the oil inlet of the multi-way valve group, and the bypass port is connected to the oil tank of the hydraulic control system. The detection device is arranged at the bypass port. To solve the defect that the overflow flow rate of the electro-hydraulic proportional pump in the prior art is large, resulting in a large amount of heat generation, the hydraulic control system provided by the present invention sets a flow priority valve on the main oil path between the electro-hydraulic proportional pump and the multi-way valve group, detects the overflow flow rate of the bypass port of the flow priority valve, and adjusts the flow rate output by the electro-hydraulic proportional pump based on the detection result of the detection device, effectively reducing the overflow flow rate of the electro-hydraulic proportional pump, thereby reducing the heat generation amount.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic control, and particularly to a hydraulic control system, a control method and a working machine. Background Art

[0002] In an electro-hydraulic proportional variable pump control system, the output flow of an electro-hydraulic pump depends on the opening degree of a multi-way valve. The main pump displacement of the electro-hydraulic pump is matched according to the opening degree value of the multi-way valve to meet the demand of the load flow. Due to the influence of external factors such as internal leakage and loss, rotational speed fluctuation, temperature, and deviation of the opening degree consistency of the multi-way valve in the electro-hydraulic proportional variable pump control system, the output flow error of the electro-hydraulic pump is relatively large.

[0003] When the output flow of the electro-hydraulic pump is large, in the existing control system, generally, the redundant oil is drained away through a three-way flow valve mechanism or the redundant oil is overflowed through an overflow valve. The redundant oil flows away from the three-way flow valve or the overflow valve, resulting in a relatively high heat generation of the system, a relatively large overflow sound, and a relatively high oil temperature. Summary of the Invention

[0004] The present invention provides a hydraulic control system, a control method and a working machine, which are used to solve the defect that the overflow amount of the electro-hydraulic pump in the related technology is large, resulting in a large amount of heat generation, and realize that the detection device detects the data of the bypass port of the flow priority valve as the basis for adjusting the electro-hydraulic pump, and then adjusts the output flow of the electro-hydraulic pump to reduce the heat generation.

[0005] The present invention provides a hydraulic control system, including:

[0006] An electro-hydraulic pump, which is connected to the fuel tank of the hydraulic control system;

[0007] A multi-way valve group, and a main oil path is formed between the multi-way valve group and the electro-hydraulic pump;

[0008] A flow priority valve, which is arranged between the main oil paths. The flow priority valve includes a priority port and a bypass port. The priority port is connected to the oil inlet of the multi-way valve group, and the bypass port is connected to the fuel tank;

[0009] A detection device, which is arranged at the bypass port and is used to detect the data of the bypass port and regulate the flow output of the electro-hydraulic pump based on the data.

[0010] According to the hydraulic control system provided by the present invention, it further includes a damper, and the detection device is arranged between the damper and the bypass port.

[0011] According to the hydraulic control system provided by the present invention, the flow priority valve includes a pilot control end, and the pilot control end is electrically controlled.

[0012] According to the hydraulic control system provided by the present invention, it further includes a controller, and the controller is electrically connected to the electro-hydraulic pump, the multi-way valve group, the detection device, and the pilot control end respectively.

[0013] According to the hydraulic control system provided by the present invention, the flow priority valve includes a pilot control end, and the pilot control end is hydraulically controlled.

[0014] According to the hydraulic control system provided by the present invention, it further includes a pilot pump and an electrically controlled pressure reducing valve, and the electrically controlled pressure reducing valve is arranged between the pilot pump and the pilot control end.

[0015] According to the hydraulic control system provided by the present invention, it further includes a unloading valve, and the unloading valve is arranged between the electrically controlled pressure reducing valve and the pilot pump.

[0016] According to the hydraulic control system provided by the present invention, it further includes a controller, and the controller is electrically connected to the electro-hydraulic pump, the multi-way valve group, the detection device, and the electrically controlled pressure reducing valve respectively.

[0017] The present invention also provides a working machine, which includes the above-mentioned hydraulic control system.

[0018] A control method for the above-mentioned hydraulic control system includes:

[0019] Adjust the pressure value of the pilot end of the multi-way valve group. Based on the pressure value of the pilot end of the multi-way valve group, adjust the current value of the electro-hydraulic pump and the pressure value of the pilot control end of the flow priority valve. The pressure value of the pilot control end is used to control the opening degree of the bypass port of the flow priority valve; the detection device detects the bypass port of the flow priority valve;

[0020] Based on the data detected by the detection device, adjust the current value of the electro-hydraulic pump.

[0021] According to the control method provided by the present invention, the step of adjusting the pressure value of the pilot control end of the flow priority valve includes:

[0022] Based on the current value of the multi-way valve group, adjust the current value of the pilot control end of the flow priority valve again.

[0023] According to the control method provided by the present invention, the hydraulic control system includes a pilot pump and an electrically controlled pressure reducing valve arranged between the pilot pump and the flow priority valve. The step of adjusting the pressure value of the pilot control end of the flow priority valve includes:

[0024] Based on the current value of the multi-way valve group, adjust the current value of the electrically controlled pressure reducing valve.

[0025] According to the control method provided by the present invention, it further includes:

[0026] The pilot end of the multi-way valve group has no pressure and the electro-hydraulic proportional pump is de-energized.

[0027] The detection device detects the value at the bypass port of the flow priority valve, judges the value detected by the detection device, and if the detected value is greater than a preset value, controls the electro-hydraulic proportional pump to obtain a first input current so that the electro-hydraulic proportional pump is in a low-pressure standby working condition.

[0028] The hydraulic control system provided by the present invention sets a flow priority valve on the main oil path between the electro-hydraulic proportional pump and the multi-way valve group. The priority flow rate of the priority port of the flow priority valve is consistent with the opening flow rate of the multi-way valve group, and detects the overflow flow rate of the bypass port of the flow priority valve. Based on the detection result of the detection device, the flow rate output by the electro-hydraulic proportional pump is regulated, effectively reducing the overflow flow rate of the electro-hydraulic proportional pump, thereby reducing the heat generation; and compared with the related technology that uses the overflow flow rate at the detection three-way flow valve for feedback, the present invention has no fluctuations and no back-oil pipeline impact when the load changes.

[0029] Further, in the working machine provided by the present invention, since it has the above-mentioned hydraulic control system, it also has the above-mentioned various advantages; the control method provided by the present invention is implemented based on the above-mentioned hydraulic control system, and therefore, it also has the above-mentioned various advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0031] Figure 1 is one of the schematic diagrams of the hydraulic control system provided by the present invention;

[0032] Figure 2 is another schematic diagram of the hydraulic control system provided by the present invention;

[0033] Figure 3 is the block diagram of the controller connection relationship provided by the present invention;

[0034] Figure 4 is one of the flowcharts of the control method provided by the present invention;

[0035] Figure 5 is another flowchart of the control method provided by the present invention.

[0036] Reference Signs:

[0037] 100: Electric proportional pump; 200: Multi-way valve group; 201: Compensation valve; 202: Electric control main valve; 210: Actuator; 300: Flow priority valve; 301: Pilot pump; 302: Unloading valve; 303: Electric control pressure reducing valve; 310: Detection device; 311: Damper; 400: Controller. Detailed implementation mode

[0038] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the scope of protection of the present invention.

[0039] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the embodiments of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0040] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0041] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0042] The following will describe the embodiments of the present invention in conjunction with Figures 1 to 5 , it should be understood that the following description is only a schematic embodiment of the present invention and does not constitute a limitation on the present invention.

[0043] As Figure 1 shown, the present invention provides a hydraulic control system, including: an electro-hydraulic proportional pump 100, a multi-way valve group 200, a flow priority valve 300 and a detection device 310. The electro-hydraulic proportional pump 100 is connected to the fuel tank of the hydraulic control system; a main oil circuit is formed between the multi-way valve group 200 and the electro-hydraulic proportional pump 100; the flow priority valve 300 is arranged between the electro-hydraulic proportional pump 100 and the multi-way valve group 200, that is, the priority flow valve 300 is arranged on the main oil circuit. The flow priority valve 300 includes a priority port C and a bypass port D. The priority port C is connected to the inlet port of the multi-way valve group 200, and the bypass port D is used to be connected to the fuel tank; the detection device 310 is arranged at the bypass port D, and the detection device 310 is used to detect the data of the bypass port and regulate the flow output of the electro-hydraulic proportional pump 100 based on the data of the bypass port.

[0044] Specifically, the opening degree of the multi-way valve group 200 affects the flow rate of the electro-hydraulic proportional pump 100. The flow rate output by the electro-hydraulic proportional pump 100 is generally greater than the flow rate required by the opening degree of the multi-way valve group 200. The flow rate output by the electro-hydraulic proportional pump 100 flows into the multi-way valve group 200 through the priority port C of the flow priority valve 300, and the excess flow rate overflows back to the fuel tank through the bypass port D of the flow priority valve 300. The priority flow rate flowing out of the priority port C of the flow priority valve 300 is matched according to the opening degree of the multi-way valve group 200. That is to say, the priority port C allows the corresponding flow rate to pass through according to how much flow rate the multi-way valve group 200 needs.

[0045] When the flow rate output by the electro-hydraulic proportional pump 100 is less than the maximum flow rate allowed to pass through the priority port C, all the flow rate output by the electro-hydraulic proportional pump 100 passes through the priority port C and flows into the multi-way valve group 200. When the flow rate output by the electro-hydraulic proportional pump 100 is greater than the maximum flow rate allowed to pass through the priority port C, the flow rate output by the electro-hydraulic proportional pump 100 first flows into the multi-way valve group 200 at the maximum flow rate of the priority port C, and the excess flow rate flows back to the fuel tank from the bypass port D through the detection device 310. The detection device 310 detects the oil data flowing out at the bypass port D, for example, the flow rate or pressure, compares the detected oil data with a preset value, and controls the flow rate output of the electro-hydraulic proportional pump 100 based on the comparison result.

[0046] For example, if it is detected that the pressure at the bypass port D is greater than the preset value, the electro-hydraulic proportional pump 100 is controlled to reduce the output flow rate, thereby reducing the overflow flow rate at the bypass port D and lowering the overflow temperature. In the present invention, a flow priority valve 300 is provided on the main oil path to directly detect whether the output flow rate of the electro-hydraulic proportional pump 100 is excessive. In the related art, a three-way flow valve is provided on the return oil path, and the adjustment mechanism of the three-way flow valve is prone to fluctuations due to load changes. However, the flow priority valve 300 of the present invention will not cause fluctuations when the load changes, and the flow priority valve 300 can solve the jitter problem of the three-way flow valve caused by load changes. Moreover, the return oil path of the three-way flow valve is a low-pressure pipeline, which will cause an impact on the three-way flow valve pipeline when the load stops. The flow priority valve 300 of the present invention is provided on the main oil path, which can reduce the impact on the return oil pipeline after the load stops.

[0047] Among them, the multi-way valve group 200 can be electrically controlled or hydraulically controlled. When the multi-way valve group 200 is electrically controlled, the current value at the pilot end of the multi-way valve group 200 controls the opening degree of the multi-way valve group 200. The current value of the multi-way valve group 200 corresponds to the initial current value of the electro-hydraulic proportional pump 100, and then the current value of the electro-hydraulic proportional pump 100 is regulated through the pressure value of the flow priority valve 300 to change the output flow rate of the electro-hydraulic proportional pump 100.

[0048] When the multi-way valve group 200 is hydraulically controlled, a sensor is provided at the pilot end of the multi-way valve group 200 to detect the pressure value at the pilot end. The sensor is connected to the controller, and the controller converts the pressure value into an electrical signal and corresponds the electrical signal to the initial current value of the electro-hydraulic proportional pump 100, and then the current value of the electro-hydraulic proportional pump 100 is regulated through the pressure value of the flow priority valve 300 to change the output flow rate of the electro-hydraulic proportional pump 100.

[0049] Furthermore, in an embodiment of the present invention, the hydraulic control system further includes a damper 311, and the detection device 310 is arranged between the damper 311 and the bypass port D. That is to say, the damper 311 is arranged between the bypass port D and the fuel tank. The detection device 310 is used to detect the pressure value between the bypass port D and the damper 311, and make a judgment by comparing the pressure value with the preset value, and then control the flow rate output of the electro-hydraulic proportional pump 100, that is, control the current magnitude of the electro-hydraulic proportional pump 100. For example, when the detection device 310 detects that the pressure value at the bypass port D is greater than the preset value, therefore, the electro-hydraulic proportional pump 100 is controlled to reduce the current value, thereby reducing the output flow rate of the electro-hydraulic proportional pump 100 and lowering the overflow flow rate; achieving precise regulation of the electro-hydraulic proportional pump 100. Among them, the detection device 310 can be a pressure sensor.

[0050] In addition, the damper 311 can be connected in parallel with an overflow valve for overflow protection.

[0051] In addition, in an alternative embodiment of the present invention, the flow priority valve 300 includes a pilot control end B, and the pilot control end B is electrically controlled. That is to say, the flow priority valve 300 is an electrically controlled flow priority valve 300, and the priority flow rate of the priority port C is adjusted by adjusting the current of the pilot control end B. For example, when the opening of the multi-way valve group 200 increases, the priority flow rate of the priority port C of the corresponding flow priority valve 300 needs to increase. By increasing the current of the pilot control end B of the flow priority valve 300, the priority flow rate is further increased to meet the opening requirement of the electro-hydraulic multi-way valve.

[0052] Furthermore, in a specific embodiment of the present invention, the hydraulic control system further includes a controller 400, and the controller 400 is electrically connected to the electro-proportional pump 100, the multi-way valve group 200, the detection device 310, and the pilot control end B respectively.

[0053] Specifically, based on the working condition of the actuator 210, the controller 400 inputs the electrical signal corresponding to the actuator 210 into the multi-way valve group 200 to control the opening of the multi-way valve group 200. Based on the electrical signal of the multi-way valve group 200, the controller 400 inputs the corresponding electrical signal to the electro-proportional pump 100, and then controls the output flow rate of the electro-proportional pump 100. At the same time, based on the electrical signal of the multi-way valve group 200, the controller 400 inputs the corresponding electrical signal to the pilot control end B of the flow priority valve 300 to adjust the priority flow rate of the priority port C to adapt to the opening requirement of the multi-way valve group 200.

[0054] The detection device 310 obtains the oil fluid data of the bypass port D in real time and sends the oil fluid data to the controller 400. The controller 400 compares the obtained oil fluid data with a preset value and controls the electrical signal of the electro-proportional pump 100 based on the comparison result. For example, the detection device 310 obtains the pressure value of the bypass port D in real time and sends the pressure value to the controller 400. The controller 400 compares the pressure value with the preset value. If the pressure value is greater than the preset value, the controller 400 reduces the current value of the electro-proportional pump 100 to reduce the output flow rate of the electro-proportional pump 100, and further reduces the overflow flow rate of the bypass port D of the flow priority valve 300.

[0055] As Figure 1 and Figure 2 shown, in another alternative embodiment of the present invention, the flow priority valve 300 includes a pilot control end B, and the pilot control end B is hydraulically controlled. That is to say, the flow priority valve 300 is a hydraulically controlled flow priority valve 300. The priority flow rate of the priority port C is adjusted by adjusting the oil pressure of the pilot control end B. For example, when the opening of the electro-hydraulic multi-way valve increases, the priority flow rate of the priority port C of the corresponding flow priority valve 300 needs to increase correspondingly. By increasing the oil pressure of the pilot control end B, the priority flow rate is further increased to meet the opening requirement of the multi-way valve group 200.

[0056] Specifically, as Figure 2As shown, in a specific embodiment of the present invention, the hydraulic control system further includes a pilot pump 301 and an electronically controlled pressure reducing valve 303, and the electronically controlled pressure reducing valve 303 is arranged between the pilot pump 301 and the pilot control end B.

[0057] In other words, the pilot pump 301 delivers the pilot oil to the pilot control end B of the flow priority valve 300 through the electronically controlled pressure reducing valve 303 to adjust the priority flow rate of the priority port C of the flow priority valve 300. By adjusting the current of the electronically controlled pressure reducing valve 303, the oil pressure entering the pilot control end B is adjusted, thereby adjusting the priority flow rate.

[0058] Wherein, the controller 400 can be electrically connected to the multi-way valve group 200, the electro-hydraulic proportional pump 100, the electronically controlled pressure reducing valve 303 and the detection device 310 respectively. The controller 400 controls the current value of the multi-way valve group 200, and then controls the opening degree of the multi-way valve group 200. Based on the opening degree of the multi-way valve group 200, the controller 400 controls the current value of the electro-hydraulic proportional pump 100 to adjust the output flow rate of the electro-hydraulic proportional pump 100 to meet the requirement of adapting to the opening degree of the multi-way valve group 200. At the same time, based on the opening degree of the multi-way valve group 200, the controller 400 controls the current value of the electronically controlled pressure reducing valve 303 to realize the matching of the priority flow rate of the flow priority valve 300 to the requirement of the opening degree of the multi-way valve group 200.

[0059] The detection device 310 detects the oil data of the bypass port D of the flow priority valve 300, sends the oil data to the controller 400, and the controller 400 compares the oil data with a preset value and adjusts the current value of the electro-hydraulic proportional pump 100 based on the comparison result to adjust the output flow rate of the electro-hydraulic proportional pump 100. The specific comparison process is the same as that of the above-mentioned electronically controlled flow priority valve 300 and will not be elaborated here.

[0060] Continue to refer to Figure 2 , in other optional embodiments of the present invention, the hydraulic control system further includes a unloading valve 302, and the unloading valve 302 is arranged between the electronically controlled pressure reducing valve 303 and the pilot pump 301.

[0061] Wherein, the unloading valve 302 includes a first working position and a second working position. In the low-speed standby state of the pilot pump 301, the unloading valve 302 is in the first working position, and the pilot pump 301 is connected to the fuel tank, and the pilot oil output by the pilot pump 301 directly flows back to the fuel tank. In the state where the pilot pump 301 starts to work normally, the unloading valve 302 is in the second working position, and the pilot oil of the pilot pump 301 enters the electronically controlled pressure reducing valve 303 through the unloading valve 302, and after being decompressed by the electronically controlled pressure reducing valve 303, it enters the pilot control end B of the flow priority valve 300.

[0062] For example, the pilot pump 301 is connected in series with the electro-hydraulic proportional pump 100, that is, both the pilot pump 301 and the electro-hydraulic proportional pump 100 are driven by the same motor. When the electro-hydraulic proportional pump 100 is in the idle state, the pilot pump 301 is also in the idle state.

[0063] Among them, in some embodiments of the present invention, the hydraulic control system further includes a controller 400, and the controller 400 is electrically connected to the electro-hydraulic proportional pump 100, the multi-way valve group 200, the detection device 310, and the electro-controlled pressure reducing valve 303 respectively.

[0064] Specifically, taking the electro-controlled multi-way valve group 200 as an example, based on the flow requirement of the actuator 210, the controller 400 controls the current value of the multi-way valve group 200, and then controls the opening degree of the multi-way valve group 200. The controller 400 determines the current value of the electro-hydraulic proportional pump 100 based on the opening degree of the multi-way valve group 200, and then controls the output flow of the electro-hydraulic proportional pump 100 to adapt to the opening degree requirement of the multi-way valve group 200. At the same time, after the controller 400 controls the multi-way valve group 200 to be powered on, it controls the unloading valve 302 to be powered on and commutated. And the controller 400 controls the current value of the electro-controlled pressure reducing valve 303 based on the opening degree of the multi-way valve group 200, and then adjusts the priority flow of the flow priority valve 300 to make the priority flow adapt to the opening degree requirement of the multi-way valve group 200.

[0065] When the output flow of the electro-hydraulic proportional pump 100 enters the multi-way valve group 200 through the priority port C of the flow priority valve 300, the excess flow of the electro-hydraulic proportional pump 100 flows out from the bypass port D of the flow priority valve 300. The detection device 310 detects the oil data of the bypass port D and sends the oil data to the controller 400. The controller 400 judges the oil data and adjusts the current value of the electro-hydraulic proportional pump 100 based on the judgment result. For example, if the oil data detected by the detection device 310 is greater than the preset value, the controller 400 reduces the current value of the electro-hydraulic proportional pump 100, thereby reducing the output flow of the electro-hydraulic proportional pump 100, reducing the overflow flow of the bypass port D, and then reducing the overflow temperature. Among them, the actuator 210 can be a hydraulic cylinder, a hydraulic motor, etc.

[0066] Furthermore, as Figure 2 shown, in the embodiment of the present invention, for the electro-hydraulic proportional pump 100, the electro-hydraulic proportional pump 100 includes a main pump and a booster pump, and the oil outlet of the booster pump is connected to the oil inlet of the main pump. The booster pump and the main pump are both driven by the same motor, and the electro-hydraulic proportional pump 100 has a constant power and pressure cut-off function.

[0067] For the multi-way valve group 200, the multi-way valve group 200 includes an electro-controlled main valve 202 and a flow compensation valve 201.

[0068] The present invention also provides a working machine, including the above hydraulic control system. The working machine can be a construction machine such as a crane, an excavator, a pile driver, etc., or an engineering vehicle such as an aerial work platform, a fire truck, a mixer truck, etc.

[0069] As Figure 4 and Figure 5 shown, the present invention also provides a control method for the hydraulic control system according to the above embodiments, including:

[0070] S10: Adjust the pressure value at the pilot end of the multi-way valve group 200. Based on the pressure value at the pilot end of the multi-way valve group 200, adjust the current value of the electro-hydraulic pump 100 and the pressure value at the pilot control end B of the flow priority valve 300. The pressure value at the pilot control end is used to control the opening degree of the bypass port D of the flow priority valve 300. That is to say, when the multi-way valve group 200 is electrically controlled, the multi-way valve group 200 is energized, the electro-hydraulic pump 100 is energized, and the priority flow of the flow priority valve 300 is regulated, so as to achieve that the current value of the electro-hydraulic pump 100 controls the output flow of the electro-hydraulic pump 100, and the output flow matches the opening degree of the multi-way valve group 200 corresponding to the current value. At the same time, the priority flow at the priority port C of the flow priority valve 300 matches the opening degree of the multi-way valve group 200. Among them, the priority flow at the priority port C depends on the pressure value at the pilot control end B. The greater the pressure value, the greater the priority flow at the priority port C.

[0071] S11: The detection device 310 detects the bypass port D of the flow priority valve 300;

[0072] S12: Based on the data detected by the detection device 310, adjust the current value of the electro-hydraulic pump 100 again. After the priority flow at the priority port C of the flow priority valve 300 matches the opening degree of the multi-way valve group 200, the flow overflowing from the bypass port D of the flow priority valve 300 is the excess flow provided by the electro-hydraulic pump 100, and the excess flow of the electro-hydraulic pump 100 is detected. Then compare the detected data with the preset value and make a judgment. Based on the result of the comparison and judgment, adjust the current value of the electro-hydraulic pump 100 to adjust the output flow of the electro-hydraulic pump 100. For example, when the data detected by the detection device 310 is greater than the preset value, lower the current value of the electro-hydraulic pump 100, thereby lowering the output flow of the electro-hydraulic pump 100, reducing the overflow flow at the bypass port D, and reducing the overflow temperature.

[0073] Further, in an embodiment of the present invention, the step of adjusting the pressure value at the pilot control end B of the flow priority valve 300 includes: adjusting the current value at the pilot control end B of the flow priority valve 300 based on the current value of the multi-way valve group 200.

[0074] That is to say, when the multi-way valve group 200 is powered on, the electro-hydraulic proportional pump 100 is powered on, and the flow priority valve 300 is powered on. The current values of the flow priority valve 300 and the electro-hydraulic proportional pump 100 are both determined based on the current value of the multi-way valve group 200 to achieve matching of the opening degree of the multi-way valve group 200. Among them, the larger the current value of the multi-way valve group 200, the larger the opening degree, the corresponding larger the current value of the electro-hydraulic proportional pump 100, and the larger the output flow of the electro-hydraulic proportional pump 100; the corresponding larger the current value of the flow priority valve 300, and the larger the priority flow of the priority port C.

[0075] In addition, in another embodiment of the present invention, the hydraulic control system includes a pilot pump 301 and an electronically controlled pressure reducing valve 303 provided between the pilot pump 301 and the flow priority valve 300. The pressure value adjustment step of the pilot control end B of the flow priority valve 300 includes: adjusting the current value of the electronically controlled pressure reducing valve 303 based on the current value of the multi-way valve group 200.

[0076] Specifically, when the multi-way valve group 200 is powered on, the electro-hydraulic proportional pump 100 is powered on, and the electronically controlled pressure reducing valve 303 is powered on. The current values of the electro-hydraulic proportional pump 100 and the electronically controlled pressure reducing valve 303 are both determined based on the current value of the multi-way valve group 200 to achieve matching of the opening degree of the multi-way valve group 200. Among them, the larger the current value of the multi-way valve group 200, the larger the opening degree, the corresponding larger the current value of the electro-hydraulic proportional pump 100, and the larger the output flow of the electro-hydraulic proportional pump 100; the corresponding larger the current value of the electronically controlled pressure reducing valve 303, the larger the pressure of the pilot control port of the flow priority valve 300, and the larger the priority flow of the priority port C.

[0077] In addition, in other embodiments of the present invention, the control method further includes:

[0078] S20: There is no pressure at the pilot end of the multi-way valve group 200. For example, when the multi-way valve group 200 loses power, the electro-hydraulic proportional pump 100 loses power; at this time, the electro-hydraulic proportional pump 100 is in the low-pressure standby working condition, there is no current input to the electro-hydraulic proportional pump 100, and the electro-hydraulic proportional pump 100 outputs at the maximum displacement. Among them, there is only spring pre-tightening force at the pilot control end B of the flow priority valve 300. For example, when the flow priority valve 300 is electronically controlled, the flow priority valve 300 loses power; when the flow priority valve 300 is hydraulically controlled, the electronically controlled pressure reducing valve 303 loses power, the unloading valve 302 loses power, and the pilot oil of the pilot pump 301 is unloaded from the overflow valve.

[0079] S21: The detection device 310 detects the data of the bypass port D of the flow priority valve 300, judges the value detected by the detection device 310. If the detected value is greater than the preset value; control the electro-hydraulic proportional pump 100 to obtain the first input current to make the electro-hydraulic proportional pump 100 in the low-pressure standby working condition.

[0080] With the continuous output of the electro-hydraulic proportional pump 100, the inlet pressure of the flow priority valve 300 continuously increases. When the inlet pressure of the flow priority valve 300 is greater than the spring pre-tightening force of the flow priority valve 300, the flow rate entering the inlet of the flow priority valve 300 completely flows out from the bypass port D. The data detected by the detection device 310 is compared with the preset value, and the next step is carried out when the detected data is greater than the preset value.

[0081] When the detected data is greater than the preset value, the electro-hydraulic proportional pump 100 obtains the first input current, that is, the minimum input current of the electro-hydraulic proportional pump 100, thereby reducing the flow rate output of the electro-hydraulic proportional pump 100, and the electro-hydraulic proportional pump 100 is in the low-pressure standby working condition.

[0082] Among them, the preset value set for the low-pressure standby working condition can be different from the preset value when the electro-hydraulic proportional pump 100 is working normally. For example, the preset value set for the low-pressure standby working condition is greater than the preset value when the electro-hydraulic proportional pump 100 is working normally.

[0083] The hydraulic control system provided by the present invention sets a flow priority valve 300 on the main oil path between the electro-hydraulic proportional pump 100 and the multi-way valve group 200. The priority flow rate of the priority port C of the flow priority valve 300 is consistent with the opening flow rate of the multi-way valve group 200, and the overflow flow rate of the bypass port D of the flow priority valve 300 is detected. Based on the detection result of the detection device 310, the flow rate output by the electro-hydraulic proportional pump 100 is regulated, effectively reducing the overflow flow rate of the electro-hydraulic proportional pump 100, thereby reducing the heat generation; and compared with the related art that uses the overflow flow rate at the detection three-way flow valve for feedback, the present invention has no fluctuation and no impact on the oil return pipeline when the load changes.

[0084] Furthermore, in the working machine provided by the present invention, due to having the above-mentioned hydraulic control system, it also has the above-mentioned various advantages; the control method provided by the present invention is realized based on the above-mentioned hydraulic control system, and therefore, it also has the above-mentioned various advantages.

[0085] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydraulic control system, characterized in that, Comprising: An electro-proportional pump (100), which is connected to the fuel tank of the hydraulic control system; A multi-way valve group (200), a main oil path being formed between the multi-way valve group (200) and the electro-proportional pump (100); A flow priority valve (300), which is arranged between the main oil paths. The flow priority valve (300) includes a priority port and a bypass port. The priority port is connected to the oil inlet of the multi-way valve group (200), and the bypass port is connected to the fuel tank; A detection device (310), which is arranged at the bypass port for detecting the data of the bypass port and regulating the flow output of the electro-proportional pump (100) based on the data.

2. The hydraulic control system according to claim 1, characterized in that, It further includes a damper (311), and the detection device (310) is arranged between the damper (311) and the bypass port.

3. The hydraulic control system according to claim 1, characterized in that, The flow priority valve (300) includes a pilot control end, and the pilot control end is electrically controlled.

4. The hydraulic control system according to claim 3, characterized in that, It further includes a controller, and the controller is electrically connected to the electro-proportional pump (100), the multi-way valve group (200), the detection device (310), and the pilot control end respectively.

5. The hydraulic control system according to claim 1, characterized in that, The flow priority valve (300) includes a pilot control end, and the pilot control end is hydraulically controlled.

6. The hydraulic control system according to claim 5, characterized in that, It further includes a pilot pump (301) and an electro-controlled pressure reducing valve (303), and the electro-controlled pressure reducing valve (303) is arranged between the pilot pump (301) and the pilot control end.

7. The hydraulic control system according to claim 6, characterized in that, It further includes a unloading valve (302), and the unloading valve (302) is arranged between the electro-controlled pressure reducing valve (303) and the pilot pump (301).

8. The hydraulic control system according to claim 6, characterized in that, It further includes a controller, and the controller is electrically connected to the electro-proportional pump (100), the multi-way valve group (200), the detection device (310), and the electro-controlled pressure reducing valve (303) respectively.

9. A working machine, characterized in that, Comprising the hydraulic control system according to any one of claims 1 to 8.

10. A control method for the hydraulic control system according to any one of claims 1 to 8, characterized in that, Comprising: Adjusting the pressure value of the pilot end of the multi-way valve group (200), and based on the pressure value of the pilot end of the multi-way valve group (200), adjusting the current value of the electro-proportional pump (100) and the pressure value of the pilot control end of the flow priority valve (300), and the pressure value of the pilot control end is used to control the opening degree of the bypass port of the flow priority valve (300); The detection device (310) detects the bypass port; Based on the data detected by the detection device (310), adjusting the current value of the electro-proportional pump (100) again.

11. The control method according to claim 10, characterized in that, The step of adjusting the pressure value of the pilot control end of the flow priority valve (300) includes: Based on the current value of the multi-way valve group (200), adjusting the current value of the pilot control end of the flow priority valve (300).

12. The control method according to claim 10, characterized in that, The hydraulic control system includes a pilot pump (301) and an electro-controlled pressure reducing valve (303) arranged between the pilot pump (301) and the flow priority valve (300). The step of adjusting the pressure value of the pilot control end of the flow priority valve (300) includes: Based on the current value of the multi-way valve group (200), adjusting the current value of the electro-controlled pressure reducing valve (303).

13. The control method according to any one of claims 10 to 12, characterized in that, It further includes: The pilot end of the multi-way valve group (200) has no pressure, and the electro-hydraulic proportional pump (100) loses power. The detection device (310) detects the value at the bypass port of the flow priority valve (300), judges the value detected by the detection device (310), and if the detected value is greater than the preset value, controls the electro-hydraulic proportional pump (100) to obtain a first input current so that the electro-hydraulic proportional pump (100) is in the low-pressure standby condition.

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