Balancing valve group and control method, controller and medium for hydraulic control circuit

Abstract

The application relates to the field of hydraulic control and discloses a balance valve group, a control method and a controller of a hydraulic control circuit and a medium. The balance valve group comprises a first oil port used for connecting an actuator, a second oil port used for connecting a main pump end, a balance valve main stage, a balance valve pilot stage and a first sensing piston. Two openings A1 and A2 of the balance valve main stage about a first cavity are connected with the first oil port and the second oil port respectively, an opening A3 of the balance valve main stage about a second cavity is connected with an opening of the balance valve pilot stage, the opening is also connected with the first oil port through a throttling opening of the first sensing piston, and another opening of the balance valve pilot stage is connected with the second oil port. The balance valve group can be matched with a flow control valve to realize integrated design of inlet and outlet oil ports before actual application, and the balance valve does not need to be additionally arranged at the actuator end during actual application, so that the hardware cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology, specifically to a control method, controller, and medium for a balance valve assembly and a hydraulic control circuit. Background Technology

[0002] Current hydraulic control circuits, especially load port independent control circuits, generally integrate independent inlet and outlet oil ports into the flow control valve. In actual applications, it is necessary to arrange a balance valve or hydraulic lock at the actuator end according to the load conditions to achieve functions such as load holding and return oil flow regulation under negative load conditions, which increases hardware costs.

[0003] Therefore, the present invention aims to design a novel balance valve assembly for hydraulic control circuits, in order to cooperate with flow control valves to achieve integrated control design of inlet and outlet oil ports. Summary of the Invention

[0004] The purpose of this invention is to provide a control method, controller, and medium for a balance valve assembly and a hydraulic control circuit. This is to achieve integrated control design of the inlet and outlet ports of the hydraulic control circuit by providing a novel balance valve assembly, thereby reducing the hardware cost of specially arranging balance valves in application.

[0005] To achieve the above objectives, the present invention provides a balancing valve assembly, comprising: a first port for connecting to an actuator; a second port for connecting to a main pump; and a balancing valve main stage, a balancing valve pilot stage, and a first sensing piston. The two openings A1 and A2 of the balancing valve main stage with respect to a first cavity are respectively connected to the first port and the second port, and the opening A3 of the balancing valve main stage with respect to a second cavity is connected to the opening of the balancing valve pilot stage. This opening is also connected to the first port through a throttling port of the first sensing piston, and another opening of the balancing valve pilot stage is connected to the second port.

[0006] Preferably, the main stage of the balance valve is configured to have a unidirectional conduction mode and a proportional regulation mode; in the unidirectional conduction mode, the main stage of the balance valve is unidirectionally conducted so that the first oil port and the second oil port are directly connected; in the proportional regulation mode, the main stage of the balance valve performs flow rate or back pressure regulation.

[0007] Preferably, the pilot stage of the balancing valve is a proportional throttle valve with controllable opening, used to change the pressure of the second chamber of the main stage of the balancing valve by adjusting the opening, so that the main stage of the balancing valve can regulate the flow rate or back pressure.

[0008] The present invention also provides a control method for a hydraulic control circuit, the hydraulic control circuit including an actuator and the aforementioned balance valve assembly adapted to the actuator. The control method includes: obtaining the load condition of the actuator when the second oil port is connected to a return oil circuit; and controlling the balance valve assembly to adjust the back pressure or the return oil flow rate according to the load condition.

[0009] Preferably, controlling the balance valve group to adjust the back pressure or the return oil flow according to the load condition includes: controlling the balance valve group to adjust the return oil flow when the load condition is a negative load condition; and controlling the balance valve group to adjust the back pressure when the load condition is a positive load condition.

[0010] Preferably, controlling the return oil flow rate of the balance valve assembly includes: obtaining the required flow rate of the main stage of the balance valve; calculating the desired second chamber pressure for the main stage of the balance valve based on the required flow rate and the first chamber pressure, wherein the desired second chamber pressure makes the output flow rate of the main stage of the balance valve consistent with the required flow rate; and executing a preset closed-loop control algorithm to output a control quantity for the opening of the pilot stage of the balance valve based on the deviation between the desired second chamber pressure and the current actual second chamber pressure, so as to adapt to the change of the actual second chamber pressure by changing the opening of the pilot stage of the balance valve.

[0011] Preferably, controlling the back pressure adjustment of the balancing valve assembly includes: acquiring the actual second chamber pressure and the desired second chamber pressure of the main stage of the balancing valve, wherein the desired second chamber pressure is the corresponding first chamber pressure; and, based on the deviation between the desired second chamber pressure and the current actual second chamber pressure, executing a preset closed-loop control algorithm to output a control quantity for the opening of the corresponding balancing valve pilot stage, so as to adapt to the change of the actual second chamber pressure by changing the opening of the balancing valve pilot stage, thereby achieving back pressure adjustment.

[0012] Preferably, the hydraulic control circuit further includes a first flow control valve group and a second flow control valve group disposed between the pump outlet and the second port, wherein the first flow control valve group is connected to the balance valve group through the second port, and the second flow control valve group is connected to the actuator through the second port. The control method further includes: when the second port is connected to the inlet oil circuit, controlling the first flow control valve group to adjust the inlet flow, the main stage of the balance valve is unidirectionally energized, the first flow control valve group is directly connected to the actuator, and controlling the second flow control valve group to perform oil circuit switching regarding the inlet oil circuit and the return oil circuit; and when the second port is connected to the return oil circuit, controlling the first flow control valve group to perform oil circuit switching regarding the inlet oil circuit and the return oil circuit, and controlling the second flow control valve group to adjust the inlet flow.

[0013] Preferably, the first flow control valve assembly includes a control valve main stage, a control valve pilot stage, and a second sensing piston. The two openings C1 and C2 of the control valve main stage are respectively connected to the second oil port and the pump outlet. The opening C3 of the control valve main stage is connected to the opening D1 of the control valve pilot stage, which is also connected to the pump outlet through the throttling orifice of the second sensing piston. The other opening D2 of the control valve pilot stage is connected to the second oil port. The pressure in the second chamber of the control valve main stage is controlled by adjusting the opening degree of the control valve pilot stage, thereby achieving the adjustment of the oil inlet quantity.

[0014] Preferably, controlling the second chamber pressure of the main stage of the control valve by controlling the opening of the pilot stage of the control valve includes: obtaining the required flow rate of the main stage of the control valve; calculating the desired second chamber pressure for the main stage of the control valve based on the required flow rate and the pump outlet pressure, wherein the desired second chamber pressure makes the output flow rate of the main stage of the control valve consistent with the required flow rate; and executing a preset closed-loop control algorithm to output a control quantity for the opening of the pilot stage of the control valve based on the deviation between the desired second chamber pressure and the current actual second chamber pressure, so as to adapt to the change of the actual second chamber pressure by changing the opening of the pilot stage of the control valve.

[0015] Preferably, obtaining the required flow rate of the main stage of the control valve includes: querying the initial required flow rate of the main stage of the control valve based on the command signal and a preset Map table for showing the correlation between the command signal and the flow rate; obtaining the total required flow rate of the actuators; if the total required flow rate is greater than the maximum flow rate of the main pump, it is determined that the pump is in saturated flow rate condition, and the final required flow rate of each main stage of the control valve is weighted and allocated based on the maximum flow rate of the main pump according to the proportion of the initial required flow rate of each main stage of the control valve relative to the total required flow rate; and if the total required flow rate is less than or equal to the maximum flow rate of the main pump, the final required flow rate of each main stage of the control valve is determined to be its own initial required flow rate.

[0016] The present invention also provides a machine-readable storage medium storing instructions for causing a machine to perform the control method of any of the above-described hydraulic control loops.

[0017] The present invention also provides a controller, comprising: a memory storing a program executable on a processor; and the processor configured to implement a control method for any of the hydraulic control loops described above when executing the program.

[0018] Through the above technical solution, the present invention designs a novel balanced valve assembly, which includes a balanced valve main stage with a load pressure feedback mechanism, a balanced valve pilot stage for adjusting the oil flow of the balanced valve main stage, and a sensing piston. This allows it to cooperate with a flow control valve to achieve integrated control design of the inlet and outlet oil ports. In practical applications, the valve assembly with integrated control design can be directly assembled without the need to arrange a balanced valve or hydraulic lock at the actuator end to achieve functions such as load holding and backflow regulation under negative load conditions, thus reducing hardware costs.

[0019] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 This is a schematic diagram of the structure of the balance valve assembly according to Embodiment 1 of the present invention;

[0022] Figure 2 This is a flowchart illustrating the control method of Embodiment 2 of the present invention;

[0023] Figure 3 This is a schematic diagram of the process of controlling the balance valve group to regulate the return oil flow in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the process of controlling the balance valve group to regulate back pressure in an embodiment of the present invention;

[0025] Figure 5A This is a schematic diagram of the structure of a hydraulic control circuit adapted to an actuator in an embodiment of the present invention;

[0026] Figure 5B This is a schematic diagram of the hydraulic control circuit adapted to two actuators in an embodiment of the present invention;

[0027] Figure 6 This is an example of the overall control strategy block diagram of the control method in Embodiment 3 of the present invention.

[0028] Figure 7 This is a flowchart illustrating an example oil inlet flow control strategy in an embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram illustrating the principle of an example oil inlet flow control strategy in an embodiment of the present invention; and

[0030] Figure 9 This is a schematic diagram of the process for obtaining the required traffic at the corresponding primary level in an embodiment of the present invention.

[0031] Explanation of reference numerals in the attached figures

[0032] 100. Balance valve assembly; 200. Actuator; 300. Main pump; 400. First flow control valve assembly; 500. Second flow control valve assembly; 600. Pump outlet pressure sensor; 700. Return oil port pressure sensor;

[0033] 110, First oil port; 120, Second oil port; 130, Main stage of balance valve; 140, Pilot stage of balance valve; 150, First sensing piston; 160, Main relief valve;

[0034] 410, Control valve main stage; 420, Control valve pilot stage; 430, Second sensing piston. Detailed Implementation

[0035] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the directional terms such as "left" and "right" are exemplary and intended to facilitate the description of relative relationships. Those skilled in the art can understand the specific meaning of the above directional terms in this invention according to the specific circumstances.

[0037] It should also be noted that, for those skilled in the art, after understanding the hydraulic connection relationships shown in the accompanying drawings, simple replacements can be made to the oil circuit or valve body to achieve the function of the hydraulic control circuit of the present invention, which also falls within the protection scope of the present invention. The structure of related hydraulic components (e.g., proportional throttle valves, sensing pistons, conventional flow control valves, main pumps, etc.), the cavity design within the components (e.g., the valve core, second cavity, and first cavity of the corresponding main stage), and the connection relationships between some conventional components (e.g., the main pump and the corresponding valve body) are all well known to those skilled in the art. Therefore, the following description is only brief, while the focus is on the original balanced valve assembly and the corresponding original control method of the present invention.

[0038] Example 1

[0039] Figure 1 This is a schematic diagram of the balancing valve assembly according to Embodiment 1 of the present invention. Figure 1As shown, the balance valve assembly 100 includes: a first port 110 for connecting to an actuator; a second port 120 for connecting to the main pump (the connecting line is a dashed line, indicating that the second port can be indirectly connected to the main pump through other valve bodies); and a balance valve main stage 130, a balance valve pilot stage 140, and a first sensing piston 150. The two openings A1 and A2 of the balance valve main stage 130 with respect to the first chamber are respectively connected to the first port 110 and the second port 120. The opening A3 of the balance valve main stage 130 with respect to the second chamber is connected to the opening B1 of the balance valve pilot stage 140. The opening B1 is also connected to the first port 110 through the throttling port of the first sensing piston 150. The other opening B2 of the balance valve pilot stage 140 is connected to the second port 120.

[0040] In the example, the pilot stage 140 of the balance valve is a proportional throttle valve with controllable opening, while the first sensing piston 150 is a component that changes the opening of the throttle port by being subjected to force at both ends. Furthermore, taking a hydraulic cylinder as the actuator, the first chamber can be understood as the hydraulic oil chamber between the cylinder and the balance valve assembly, and the second chamber can be understood as the hydraulic oil chamber between the main stage of the balance valve and the pilot stage of the balance valve. Additionally, a third chamber opposite to the second chamber may be included, connecting two openings A1 and A2. The pressure difference between the second and third chambers can be adjusted through the pilot stage of the balance valve, thereby achieving the opening adjustment of the main stage of the balance valve. Accordingly, combined with... Figure 1 It is readily understood that the main stage 130 of the balancing valve generates a valve core displacement under the influence of the second chamber pressure, which changes according to the opening change of the pilot stage 140 of the balancing valve, and the first chamber pressure, which is fed back from the actuator. This valve core displacement can then be used to change the oil flow rate. The first sensing piston 150 and the pilot stage 140 of the balancing valve together exert a pressure divider effect on the second chamber pressure of the main stage 130. That is, by controlling the opening of the pilot stage 140, the pressure divider relationship between it and the first sensing piston 150 on the main stage 130 can be changed, thereby altering the second chamber pressure of the main stage 130 and further changing its displacement. Combined with appropriate control strategies, this allows the main stage 130 to regulate either the flow rate or the back pressure.

[0041] Accordingly, Embodiment 1 of the present invention designs a novel balancing valve assembly, which includes a balancing valve main stage with a load pressure feedback mechanism (i.e., considering load feedback at the actuator end), a balancing valve pilot stage for adjusting the oil flow of the balancing valve main stage, and a sensing piston. This allows it to cooperate with a flow control valve to achieve integrated control design of the inlet and outlet ports. In practical applications, the balancing valve assembly with integrated control design can be directly assembled without the need to arrange a balancing valve or hydraulic lock at the actuator end to achieve functions such as load holding and backflow regulation under negative load conditions, thus reducing hardware costs.

[0042] In a preferred embodiment, the balancing valve assembly 100 may further include a main relief valve 160 disposed between the two oil ports, which serves as a safety unloading mechanism. For example, when the second oil port 120 is connected to the return oil circuit, the main relief valve 160 automatically opens to release pressure when the return oil port pressure reaches the set pressure, thereby ensuring stable back pressure.

[0043] In a preferred embodiment, the main stage 130 of the balancing valve is configured to have a unidirectional conduction mode and a proportional regulation mode. In the unidirectional conduction mode, the main stage 130 of the balancing valve is unidirectionally conducted, directly connecting the first port 110 and the second port 120. For example, if the second port 120 is connected to the inlet oil passage, the inlet oil passage is directly connected to the actuator via the unidirectional balancing valve main stage 130 to supply oil to the actuator. In the proportional regulation mode, the main stage 130 of the balancing valve regulates the flow rate or back pressure. For example, if the second port 120 is connected to the return oil passage, the main stage 130 of the balancing valve is subjected to opening control to regulate the return oil flow rate or back pressure. Further details regarding the specific application of the unidirectional conduction mode and the proportional regulation mode of the main stage 130 of the balancing valve, as well as the embodiments for regulating the return oil flow rate or back pressure, will be described in other embodiments and will not be repeated here.

[0044] The following will describe, through other embodiments, the multiple functions achieved by the balancing valve assembly of Embodiment 1 of the present invention.

[0045] Example 2

[0046] Embodiment 2 of the present invention provides a control method for a hydraulic control circuit, wherein the hydraulic control circuit includes an actuator 200 and a balance valve group 100 adapted to a first embodiment of each actuator.

[0047] Figure 2 This is a flowchart illustrating the control method of Embodiment 2 of the present invention. (In conjunction with...) Figure 1 and Figure 2 The control method includes the following steps S100 and S200:

[0048] Step S100: With the second oil port connected to the return oil circuit, obtain the load condition of the actuator.

[0049] Step S200: Control the balance valve group to adjust the back pressure or the return oil flow according to the load conditions.

[0050] In a preferred embodiment, step S200 includes: when the load condition is a negative load condition, controlling the balance valve group 100 to adjust the return oil flow rate; and when the load condition is a positive load condition, controlling the balance valve group 100 to adjust the back pressure.

[0051] In a more preferred embodiment, such as Figure 3 As shown, controlling the balance valve assembly 100 to adjust the return oil flow rate may include the following steps S211 to S213:

[0052] Step S211: Obtain the required flow rate of the main stage of the balancing valve.

[0053] The required flow rate can be set according to the speed requirements of the actuator. For example, for the hydraulic control of a crane cylinder, the return flow rate of the cylinder can be set according to the set speed of the hoisted object, which is the required flow rate.

[0054] Step S212: Calculate the desired second chamber pressure for the main stage of the balancing valve based on the required flow rate and the first chamber pressure.

[0055] The desired second chamber pressure ensures that the output flow rate of the main stage of the balancing valve matches the required flow rate.

[0056] In the example, the required flow rate and the first chamber pressure detected by the sensor can be input to a preset first master-level control model to output the desired second chamber pressure. The first master-level control model is a pre-constructed computational model based on the flow equation and force balance equation of the balancing valve master stage, used to illustrate the relationship between the required flow rate, the first chamber pressure, and the desired second chamber pressure. The following section will detail the scheme for constructing a corresponding second master-level control model for the control valve master stage; the first master-level control model is similar and will not be elaborated upon here.

[0057] Step S213: For the deviation between the desired second chamber pressure and the current actual second chamber pressure, execute a preset closed-loop control algorithm to output a control quantity for the opening of the pilot stage of the balance valve, so as to adapt to the change of the actual second chamber pressure by changing the opening of the pilot stage of the balance valve.

[0058] For step S213, the actual second chamber pressure needs to be obtained first. In a preferred embodiment, the first sensing piston 150 is a sensing element that is linearly related to the first chamber pressure; that is, when the sensing piston is configured in a non-limit position, the second chamber pressure of the main stage 130 of the balance valve is linearly related to the first chamber pressure. Therefore, the second chamber pressure of the main stage 130 of the balance valve can be obtained relatively easily through the first sensing piston 150. Secondly, after obtaining the actual second chamber pressure, a closed-loop control algorithm is needed to control this actual second chamber pressure. The closed-loop control algorithm can be a discrete PI algorithm, and its specific implementation can be found in the discrete PI algorithm described below in the strategy for adjusting the oil inlet measurement of the main stage of the control valve.

[0059] In a more preferred embodiment, such as Figure 4 As shown, controlling the back pressure adjustment of the balance valve assembly 100 may include the following steps S221 to S222:

[0060] Step S221: Obtain the actual second chamber pressure and the desired second chamber pressure of the main stage of the balance valve.

[0061] Wherein, the desired second chamber pressure is the corresponding first chamber pressure. For example, the first sensing piston represents the second chamber pressure P. eid and return oil port pressure P d The linearly correlated sensing element, where the return port pressure equals the corresponding primary stage first chamber pressure, means the sensing piston can achieve P... d -P eid The sensing equation is then used to obtain the actual second chamber pressure P of the main stage of the balance valve. eid :

[0062]

[0063] In the formula, A i A is the working area of ​​the piston oil inlet chamber. d F0 is the working area of ​​the second chamber of the piston, and F0 is the piston spring preload.

[0064] Step S222: For the deviation between the desired second chamber pressure and the current actual second chamber pressure, a preset closed-loop control algorithm is executed to output a control quantity for the opening of the corresponding balance valve pilot stage, so as to adapt to the change of the actual second chamber pressure by changing the opening of the balance valve pilot stage, thereby realizing back pressure regulation.

[0065] For example, the closed-loop control algorithm employs the following discrete PI algorithm:

[0066] ΔI(k)=K p [e(k)-e(k-1)]+Ki e(k) (2)

[0067] e(k)=P ed (k)-P eid (k) (3)

[0068] Where ΔI(k) is the control quantity for the opening degree of the pilot stage of the balance valve, P ed (k) is the expected second chamber pressure at the k-th step size of the main stage of the balance valve, P eid (k) is the actual second chamber pressure at the k-th step of the main stage of the balancing valve, and e(k) is the deviation between the expected second chamber pressure and the current actual second chamber pressure at the k-th step of the main stage of the balancing valve. p It is the proportional gain coefficient, K i It is the integral gain coefficient.

[0069] Accordingly, taking the hydraulic cylinder as an example, the balance valve group 100 only conducts unidirectionally when oil enters the large chamber of the hydraulic cylinder, and selects between back pressure control and flow control when oil returns from the large chamber of the hydraulic cylinder. Thus, the balance valve group 100 can achieve throttling speed regulation under conditions such as negative load, and back pressure regulation under positive load conditions.

[0070] Example 3

[0071] Based on Example 2, Example 3 combines the balancing valve assembly 100 with the flow control valve assembly to perform an integrated inlet and outlet control design.

[0072] refer to Figure 5A For a single working link (i.e., the case with only one actuator), the hydraulic control circuit further includes a first flow control valve group 400 and a second flow control valve group 500 disposed between the pump outlet and the second port 120 corresponding to the main pump 300. The first flow control valve group 400 is connected to the balance valve group 100 via the second port 120, and the second flow control valve group 500 is connected to the actuator 200 via the second port 120. Further, the first flow control valve group 400 includes a control valve main stage 410, a control valve pilot stage 420, and a second sensing piston 430. The two openings C1 and C2 of the control valve main stage 410 are respectively connected to the second port 120 and the pump outlet. The opening C3 of the control valve main stage 410 is connected to the opening D1 of the control valve pilot stage 420, which is also connected to the pump outlet via the throttling port of the second sensing piston 430. The other opening D2 of the control valve pilot stage 420 is connected to the second port 120.

[0073] In addition, the hydraulic control circuit can also be equipped with a pump outlet pressure sensor 600 and a return port pressure sensor 700 to detect the pump outlet pressure corresponding to the main pump 300 and the return port pressure (or back pressure) corresponding to the actuator 200, respectively. The return port pressure is the same as the inlet pressure of the balance valve assembly and the first chamber pressure of the main stage of the balance valve; therefore, the return port pressure sensor 700 can also be understood as a pressure sensor for the first chamber of the main stage of the balance valve. Furthermore, similar to... Figure 1 The main relief valve 160 in the middle can also be set for the flow control valve group and the pump outlet for safety protection.

[0074] It should be noted that the structure of the second flow control valve assembly 500 is the same as that of the first flow control valve assembly 400, and therefore will not be described again here. It should also be noted that each actuator corresponds to a set of working couplers, and thus... Figure 5B As shown, it corresponds to two actuators and has two sets of working connections, but the loop structure of the other working connection is different from that of the others. Figure 5A The working connections shown are the same, so they will not be described again.

[0075] based on Figure 5A and Figure 5B The hydraulic control circuit shown has a flow control valve assembly and is connected to... Figure 2 The control method of Embodiment 3 of the present invention, as shown in the steps, may further include the following steps S300 and S400. Figure 2 (Not shown in the image). Additionally... Figure 6 This is an example of an overall control strategy block diagram of the control method according to Embodiment 3 of the present invention, which illustrates the specific implementation scheme of steps S100-S400 through examples. Accordingly, combined with Figure 6 Steps S300 and S400 (not shown in the figure) are as follows:

[0076] In step S300, with the second oil port 120 connected to the oil inlet circuit, the first flow control valve group 400 is controlled to adjust the oil inlet flow, the main stage 130 of the balance valve is unidirectionally turned on, the first flow control valve group 400 is directly connected to the actuator 200, and the second flow control valve group 500 is controlled to perform oil circuit switching between the oil inlet circuit and the oil return circuit.

[0077] In step S400, when the second oil port 120 is connected to the return oil circuit, the first flow control valve group 400 is controlled to perform oil circuit switching between the inlet oil circuit and the return oil circuit, and the second flow control valve group 500 is controlled to adjust the inlet oil flow.

[0078] The logic for determining the strategy of switching oil circuits and adjusting oil inlet flow should refer to... Figure 6Preferably, the method includes the following steps: acquiring the command signal from the operating handle; when the command signal instructs the actuator 200 to perform a first action, determining that the first flow control valve group 400 performs oil inlet flow regulation and determining that the second flow control valve group 500 performs the oil circuit switching; and when the command signal instructs the actuator 200 to perform a second action opposite to the first action, determining that the first flow control valve group 400 performs the oil circuit switching and determining that the second flow control valve group 500 performs oil inlet flow regulation.

[0079] Among them, the control strategy for adjusting the oil inlet flow rate is through Figure 7 , Figure 8 This is illustrated, and its purpose is to control the second chamber pressure of the main stage 410 of the control valve by controlling the opening degree of the pilot stage 420, so that the actual output flow rate of the corresponding main stage matches the required flow rate. Wherein, Figure 7 This is a flowchart illustrating the oil inlet flow control strategy. Figure 8 This is a schematic diagram illustrating the principle of the oil inlet flow control strategy. (For example...) Figure 7 As shown, and in combination Figure 8 Preferably, the following steps are included:

[0080] Step S701: Obtain the required flow rate of the main stage of the control valve.

[0081] Step S702: Calculate the desired spring chamber pressure for the main stage of the control valve based on the required flow rate and the pump outlet pressure. This desired spring chamber pressure ensures that the output flow rate of the main stage of the control valve matches the required flow rate.

[0082] Step S703: For the deviation between the desired spring chamber pressure and the current actual spring chamber pressure, execute a preset closed-loop control algorithm to output a control quantity for the opening of the pilot stage of the control valve, so as to adapt to the change of the actual spring chamber pressure by changing the opening of the pilot stage of the control valve.

[0083] Specifically, for step S701, such as Figure 9 As shown, the required flow rate of the main stage of the control valve is obtained through the following steps:

[0084] Step S801: Based on the command signal and a preset Map table used to show the correlation between the command signal and the flow rate, query the initial required flow rate of the main stage of the control valve.

[0085] Step S802: Obtain the total required flow of the actuator.

[0086] Step S803: If the total demand flow is greater than the maximum flow of the main pump, it is determined that the pump is in saturated flow condition. Based on the ratio of the initial demand flow of each control valve stage to the total demand flow, the final demand flow of each control valve stage is weighted and allocated according to the maximum flow of the main pump.

[0087] Step S804: If the total demand flow is less than or equal to the maximum flow of the main pump, then the final demand flow of each control valve stage is determined to be its initial demand flow.

[0088] For steps S801-S804, for example, firstly, the command signal of the operating handle is input to the set current-flow map table to query the required flow rate Q of the main stage of each valve group. i The required flow rate of valve group n is denoted as Q. in Secondly, as shown in equation (4) below, based on the demand flow Q in Sum the results and denot them as Q. j ; Again, Q j Maximum flow rate Q of the same main pump max Compare and determine whether the pump is in saturated flow condition. If it is in saturated flow condition, use the following formula (5) to weightedly allocate the required flow of each valve group.

[0089] Traffic Q j Calculation formula:

[0090]

[0091] Saturated flow distribution formula:

[0092]

[0093] Thus, Q en This refers to the final required flow rate of each valve group n's main stage. However, it should be noted that the following text mainly uses one main stage as an example. Therefore, for ease of description, the required flow rate used for calculation is directly denoted as Q. e .

[0094] The following is combined with Figure 5A , Figure 5B as well as Figure 6 The example illustrates the functions of flow regulation and back pressure regulation achieved by the combination of the balance valve group 100, the first flow control valve group 400, and the second flow control valve group 500.

[0095] In the example, the main stage of the control valve in the first flow control valve group 400 and the second flow control valve group 500 is a three-position four-way valve, while the main stage of the balance valve in the balance valve group 100 is a two-position two-way valve. The pilot stage of each valve group is a proportional throttle valve. For the second sensing piston 430, the pump outlet pressure and the spring chamber pressure of the control valve main stage are applied to both ends. The throttling opening of the sensing piston is adjusted under the interaction of the pressures at both ends, thereby ensuring the balance between the spring chamber pressure and the pump outlet pressure. Since the effective area ratio of the sensing piston is fixed, the pump outlet pressure and the spring chamber pressure have a linear relationship. Therefore, the second sensing piston 430 can act as a sensing element relating to the linear relationship between the pump outlet pressure and the corresponding main stage spring chamber pressure. Similarly, the first sensing piston 150 can act as a sensing element relating to the linear relationship between the back pressure and the corresponding main stage spring chamber pressure.

[0096] Furthermore, taking the first flow control valve assembly 400 as an example, its main control valve stage 410 is configured to generate valve core displacement under the action of the spring chamber pressure, which changes according to the opening degree of the pilot valve, and the load chamber pressure, which is fed back from the actuator end. This valve core displacement then alters the oil flow rate and oil path. The second sensing piston 430 and the pilot stage 420 of the control valve together act as a pressure divider on the spring chamber pressure. That is, by controlling the opening degree of the pilot stage 420, the pressure divider relationship can be changed, thereby changing the spring chamber pressure for flow regulation or oil path switching.

[0097] Furthermore, in the example, the main stage 410 of the control valve is a three-position four-way valve with an initial position of O-type function. When implementing the flow control function, the pilot stage opening is used to limit the spring chamber pressure of the main stage, so that the main stage works in the initial position and intermediate state. When it is necessary to switch to the return oil circuit, the pilot stage is fully opened, so that under the action of the load chamber pressure and the pump outlet pressure, the valve core of the main stage will be in the right position to realize the oil circuit switching. Thus, the main stage can simultaneously realize the functions of flow control and oil circuit switching, simplifying the system oil circuit.

[0098] Continuing with the example of the main stage 410 control valve being a three-position four-way valve, let's take the pump outlet pressure P. p Load chamber pressure P c The pressure acting on the right side of the valve core of the main stage 410 of the control valve, after being divided between the pilot stage 420 and the second sensing piston 430, becomes the spring chamber pressure P of the main stage 410 of the control valve. e When the load is disturbed, the load chamber pressure P c Fluctuations will directly cause deviations in the oil flow rate of the main stage 410 of the control valve; simultaneously, the load chamber pressure P cBecause the force acts on the right side of the valve core of the main stage 410 of the control valve, the displacement of the valve core of the main stage 410 of the control valve changes synchronously. According to the formula for thin-bladed small-orifice valves, the effect of the change in the valve core displacement of the main stage 410 of the control valve on the oil flow rate is the same as that of the load chamber pressure P. c The resulting flow rate changes have opposite effects, thus compensating for the oil flow deviation and eventually reaching a certain equilibrium state under the pressure of the spring chamber. In this way, the main stage 410 of the control valve compensates for the flow error caused by the pressure difference across its throttling orifice due to the load through changes in valve core displacement, maintaining a balance. However, in this balanced state, the oil flow rate of the main stage 410 of the control valve is not the required flow rate, thus requiring subsequent flow control strategies to maintain the oil flow rate at the required level. It should be noted that the flow control and oil circuit switching scheme of the second flow control valve group 500 is similar to that of the first embodiment and will not be described again here.

[0099] Combination Figure 6 To further illustrate, the actuator is a hydraulic cylinder. A hydraulic control circuit according to this embodiment of the invention is set up for the large cavity of the hydraulic cylinder, and a corresponding control method is executed. The first action is, for example, the hydraulic cylinder extending, and the second action is, for example, the hydraulic cylinder retracting. Then, in conjunction with... Figure 5A and Figure 6 The selection of oil circuit switching, inlet flow control strategy, pressure control strategy, or return flow control strategy shown in steps S100-S400 can be described as follows:

[0100] 1) The operating handle responds to user input by issuing command signals instructing the hydraulic cylinders to extend or retract. Therefore, the number and actions of the controlled hydraulic cylinders can be determined by analyzing these command signals. For example, the command signal might be the handle current. After a set current is met, it can be counted and input into a pre-defined current-flow map to find the hydraulic circuits required to perform the specified actions of the cylinders, as well as the required flow rate supplied to the hydraulic control circuit in those circuits.

[0101] 2) When the actuator cylinder needs to extend and is under positive load, the pilot stage input current of the balance valve group 100 is 0mA. The balance valve group remains closed, and only the check valve is open. The first flow control valve group 400 regulates the oil flow to the actuator 200, while the second flow control valve group 500 is used to switch the oil circuit. This causes the pilot stage of the second flow control valve group 500 to fully open. Under the action of the load force and the pump outlet pressure, the valve core of the corresponding main stage will be in the right position to achieve oil circuit switching and realize the return flow of the actuator's small chamber. It should be noted that when the actuator cylinder extends, its large chamber is the oil inlet side and the small chamber is the oil return side, while when the actuator cylinder retracts, its large chamber is the oil return side and the small chamber is the oil inlet side.

[0102] 3) When the actuator cylinder needs to retract, the first flow control valve group 400 is used to switch the oil circuit, so that the pilot stage of the first flow control valve group 400 is fully open. Under the action of load force and pump outlet pressure, the main stage will be in the right position to realize the oil circuit switching. The second flow control valve 500 adjusts the oil inlet flow, and the balance valve group 100 adjusts the back pressure. When the load direction is determined based on the pump outlet pressure and the pressure of the first chamber of the balance valve group, and it is determined that the current working condition is negative load, the balance valve group 100 executes the return flow control strategy. At this time, the main pump 300 is connected to the balance valve group 100, and the balance valve group 100 adjusts the return flow.

[0103] It should be noted that, in combination Figure 6 The action judgment result of the command signal from the handle is simultaneously sent to the actuator. This result, combined with the actual action of the actuator, determines the load condition. For example, for a hydraulic cylinder, a negative load means the load direction is the same as the cylinder's movement direction; conversely, it is called a positive load. Alternatively, for a hydraulic cylinder, the load direction can also be determined using a pump outlet pressure sensor, as well as large-cavity and small-cavity pressure sensors configured for the cylinder, thus determining whether it is a negative load.

[0104] Similar to the balancing valve assembly 100, the flow control valve assembly outputs the corresponding desired spring chamber pressure based on a second master stage control model. This second master stage control model is a calculation model pre-constructed based on the flow equation and force balance equation of the corresponding master stage to show the relationship between the demand flow rate, pump outlet pressure and desired spring chamber pressure.

[0105] The following example illustrates the construction and application of the second-stage control model for flow control valve groups.

[0106] First, the flow equations for the corresponding primary stage are as follows:

[0107] Q e =K a x e -K b P c (6)

[0108] Among them, Q e It is demand traffic, K a This is the flow gain of the corresponding primary stage; K b This is the corresponding primary stage pressure gain, x e It is the valve core displacement of the corresponding main stage, P c It is the pressure in the load chamber.

[0109] Secondly, the force balance equation is:

[0110] P p A p -P e A e +Pc A c -F1=k e x e (7)

[0111] In the formula, A p This refers to the corresponding main stage oil inlet chamber's working area; A e This is the corresponding main stage spring cavity working area; A c It is the corresponding main stage load cavity area; k e F1 is the corresponding main spring stiffness; F1 is the corresponding main spring preload; P p It is the pump outlet pressure; P e This is the desired spring cavity pressure; x e It is the valve core displacement of the corresponding main stage, P c It is the pressure in the load chamber.

[0112] Furthermore, by setting the primary spring as a weak spring, the change in spring force caused by the change in spring displacement can be approximately ignored. P can be obtained through testing and fitting. c Regarding P e P p The linear equation is shown in equation (8):

[0113] P c =k1P e -k2P p +k3 (8)

[0114] In the formula, k1 is P e The proportionality constant, k2 is P p The proportionality coefficient, k3 is P c The offset.

[0115] Combining equations (6), (7), and (8), the second master-level control model is described as calculating the desired spring cavity pressure P using the following equation (9). e :

[0116]

[0117] The meanings of each parameter are as described above and will not be repeated here.

[0118] Furthermore, the second sensing piston 430 is a sensing element that is linearly related to the spring chamber pressure and the pump outlet pressure; that is, when the sensing piston is configured to be in a non-limit position, the spring chamber pressure P... ei With pump outlet pressure P p It exhibits a linear correlation, meaning it can achieve P. p -P ei Sensing equation. Based on this, the current actual spring cavity pressure P of the corresponding main stage can be calculated using the following equation (10). ei :

[0119]

[0120] In the formula, A i A is the working area of ​​the piston oil inlet chamber. d P is the effective area of ​​the piston spring cavity, F0 is the piston spring preload, and P is the piston spring preload. p This is the pump outlet pressure. Therefore, the spring chamber pressure can be easily obtained through the sensing piston, which simplifies the calculation process and allows for flow control with fewer components.

[0121] For flow control valve assemblies, the closed-loop control algorithm used can be described as the discrete PI algorithm shown in the following equation:

[0122] ΔI(k)=K p [e(k)-e(k-1)]+K i e(k) (11)

[0123] e(k)=P e (k)-P ei (k) (12)

[0124] Where Δu(k) is the control quantity for the opening degree of the proportional throttle valve, P e (k) is the expected spring cavity pressure P at the k-th step size. e P ei (k) is the actual spring cavity pressure P at the k-th step size. ei K p It is the proportional gain coefficient, K i ΔI(k) is the integral gain coefficient, and e(k) is the deviation between the desired spring chamber pressure and the current actual spring chamber pressure at the k-th step. ΔI(k) is the control variable, which is the control current for the proportional throttle valve (pilot valve). It controls the opening of the proportional throttle valve to ensure that the main stage has sufficient spring chamber pressure. Therefore, even when the main stage adapts to the differential pressure shift due to the load chamber pressure, the spring chamber pressure can still ensure that the main stage has a suitable opening so that the output flow rate matches the demand flow rate.

[0125] It should be noted that, in addition to the discrete PI method mentioned above, the conventional PID algorithm can also be used.

[0126] In summary, the control method of the hydraulic control circuit in the embodiments of the present invention has at least the following advantages:

[0127] 1) A hydraulic control loop with flow-displacement-hydraulic feedback configuration was designed, and strategies for oil circuit switching, flow control and back pressure control were configured. In the way of "strategy + loop configuration", the independent oil circuit of conventional load port is simplified, while multiple control functions are used to ensure the accuracy of flow distribution in the loop.

[0128] 2) The flow-displacement-hydraulic feedback configuration of this invention uses load pressure feedback to adaptively adjust the opening of the main stage, and achieves flow deviation compensation under load disturbance through the designed flow control strategy, so that there is no large flow change under load fluctuation, and can ensure high flow control accuracy under multiple load compound and drastic load conditions.

[0129] 3) The flow control strategy of this invention considers both differential pressure and flow rate, so the flow control (or throttling opening control) and differential pressure control of the main metering port are not decoupled, the influence of hydraulic force is low, the flow controllable range is large, the flow control characteristics are programmable and not limited by structure.

[0130] 4) The embodiments of the present invention simplify the control strategy through a sensing piston model, and the entire control strategy does not require the application of displacement sensors, tilt sensors, etc., which makes it easy to achieve high flow distribution accuracy of compound actions with fewer components.

[0131] 5) The present invention designs a balance valve group and integrates the return oil throttling port into the balance valve group in a distributed manner. The balance valve group is configured to have the functions of return oil flow control and back pressure control, so as to realize positive load back pressure regulation and negative load throttling speed regulation functions by means of flow control and back pressure control.

[0132] Example 4

[0133] Embodiment 4 of the present invention provides a controller, comprising: a memory storing a program capable of running on a processor; and the processor configured to implement the control method described in Embodiment 2 or Embodiment 3 when executing the program.

[0134] The controller can be implemented using a conventional controller with computing and data transmission capabilities, such as the controller that comes with engineering machinery (such as fire trucks, cranes, etc.) that uses the control methods of Embodiments 2 and 3.

[0135] The processor contains a kernel, which retrieves the corresponding program units from memory. One or more kernels can be configured, and the control methods described in this embodiment of the invention can be implemented by adjusting the kernel parameters.

[0136] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Additionally, the memory may include at least one memory chip.

[0137] For more details on the implementation and effects of the controller in Embodiment 3, please refer to Embodiments 1 to 3, which will not be repeated here.

[0138] Another embodiment of the present invention provides a machine-readable storage medium storing instructions for causing a machine to execute the control method described in any of the above embodiments. The machine may be, for example, a separately configured controller or a controller integrated into engineering machinery. Furthermore, the machine-readable storage medium includes, but is not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, and various other media capable of storing program code.

[0139] For further implementation details and effects of the machine-readable storage medium in this embodiment, please refer to the embodiments of the corresponding methods described above, which will not be repeated here.

[0140] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0141] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0142] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0143] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0144] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0145] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0146] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0147] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0148] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0149] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner, without contradiction, such as by exchanging the execution order of some steps. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0150] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A balancing valve assembly (100), characterized in that, include: The first oil port (110) is used to connect the actuator; The second oil port (120) is used to connect to the main pump end; as well as Balance valve main stage (130), balance valve pilot stage (140) and first sensing piston (150). The main stage (130) of the balance valve has two openings (A1, A2) about the first chamber that are connected to the first oil port (110) and the second oil port (120) respectively. The opening (A3) of the main stage (130) about the second chamber is connected to the opening (B1) of the pilot stage (140) of the balance valve. The opening (B1) is also connected to the first oil port (110) through the throttle port of the first sensing piston (150). The other opening (B2) of the pilot stage (140) of the balance valve is connected to the second oil port (120). The first cavity is a hydraulic oil cavity between the actuator and the balance valve assembly (100), the second cavity is a hydraulic oil cavity between the main stage (130) of the balance valve and the pilot stage (140) of the balance valve, and the main stage (130) of the balance valve also includes a third cavity opposite to the second cavity, the third cavity being connected to the two openings (A1, A2) of the first cavity. The first sensing piston (150) and the pilot stage (140) of the balance valve together exert a pressure-dividing effect on the pressure in the second chamber of the main stage (130) of the balance valve.

2. The balancing valve assembly according to claim 1, characterized in that, The main stage of the balance valve is configured to have a unidirectional conduction mode and a proportional adjustment mode. In the unidirectional conduction mode, the main stage of the balance valve is unidirectionally conducted, so that the first oil port and the second oil port are directly connected. In the proportional regulation mode, the main stage of the balance valve regulates the flow rate or back pressure.

3. The balancing valve assembly according to claim 1, characterized in that, The pilot stage (140) of the balance valve is a proportional throttle valve with controllable opening, used to change the pressure of the second chamber of the main stage (130) of the balance valve by adjusting the opening, so that the main stage (130) of the balance valve can regulate the flow rate or back pressure.

4. A control method for a hydraulic control circuit, characterized in that, The hydraulic control circuit includes an actuator and a balance valve assembly (100) adapted to the actuator as described in any one of claims 1-3, and the control method includes: With the return oil circuit connected to the second oil port (120), the load condition of the actuator is obtained; and The back pressure or return oil flow rate is adjusted by controlling the balance valve group (100) according to the load conditions.

5. The control method according to claim 4, characterized in that, The step of controlling the balance valve group to adjust the back pressure or the return oil flow rate according to the load condition includes: When the load condition is a negative load condition, the balance valve assembly is controlled to adjust the return oil flow; and When the load condition is a positive load condition, the balance valve group is controlled to adjust the back pressure.

6. The control method according to claim 4, characterized in that, Controlling the return oil flow rate of the balance valve assembly includes: Obtain the required flow rate of the main stage (130) of the balancing valve; Based on the required flow rate and the first chamber pressure, calculate the desired second chamber pressure for the main stage (130) of the balancing valve, such that the output flow rate of the main stage (130) of the balancing valve matches the required flow rate; and For the deviation between the desired second chamber pressure and the current actual second chamber pressure, a preset closed-loop control algorithm is executed to output a control quantity for the opening of the pilot stage (140) of the balance valve, so as to adapt to the change of the actual second chamber pressure by changing the opening of the pilot stage (140) of the balance valve.

7. The control method according to claim 4, characterized in that, Controlling the back pressure adjustment of the balance valve assembly includes: Obtain the actual second chamber pressure and the desired second chamber pressure of the main stage of the balance valve, wherein the desired second chamber pressure is the corresponding first chamber pressure; and For the deviation between the desired second chamber pressure and the current actual second chamber pressure, a preset closed-loop control algorithm is executed to output a control quantity for the opening of the corresponding balance valve pilot stage (140), so as to adapt to the change of the actual second chamber pressure by changing the opening of the balance valve pilot stage (140) and realize back pressure regulation.

8. The control method according to claim 4, characterized in that, The hydraulic control circuit also includes a first flow control valve group (400) and a second flow control valve group (500) disposed between the pump outlet and the second oil port (120), wherein the first flow control valve group (400) is connected to the balance valve group (100) through the second oil port (120), and the second flow control valve group (500) is connected to the actuator (200) through the second oil port (120). The control method further includes: With the second port (120) connected to the inlet oil circuit, the first flow control valve group (400) is controlled to regulate the inlet oil flow, the main stage (130) of the balance valve is unidirectionally energized, the first flow control valve group (400) is directly connected to the actuator (200), and the second flow control valve group (500) is controlled to perform oil circuit switching regarding the inlet oil circuit and the return oil circuit; and When the second oil port (120) is connected to the return oil circuit, the first flow control valve group (400) is controlled to perform oil circuit switching between the inlet oil circuit and the return oil circuit, and the second flow control valve group (500) is controlled to adjust the inlet oil flow.

9. The control method according to claim 8, characterized in that, The first flow control valve assembly (400) includes a control valve main stage (410), a control valve pilot stage (420), and a second sensing piston (430). The two openings (C1, C2) of the control valve main stage (410) are respectively connected to the second oil port (120) and the pump outlet. The opening (C3) of the control valve main stage with respect to the second cavity is connected to the opening (D1) of the control valve pilot stage (420). The opening (D1) is also connected to the pump outlet through the throttling port of the second sensing piston (430). The other opening (D2) of the control valve pilot stage (420) is connected to the second oil port (120). The pressure in the second chamber of the main stage of the control valve is controlled by controlling the opening degree of the pilot stage (420) of the control valve, so as to achieve the adjustment of the oil inlet quantity.

10. The control method according to claim 9, characterized in that, The method of controlling the pressure in the second chamber of the main stage of the control valve by controlling the opening of the pilot stage of the control valve includes: Obtain the required flow rate of the main stage of the control valve; Based on the required flow rate and pump outlet pressure, calculate the desired second chamber pressure for the main stage of the control valve, such that the output flow rate of the main stage of the control valve matches the required flow rate; and For the deviation between the desired second chamber pressure and the current actual second chamber pressure, a preset closed-loop control algorithm is executed to output a control quantity for the opening of the pilot stage of the control valve, so as to adapt to the change of the actual second chamber pressure by changing the opening of the pilot stage of the control valve.

11. The control method according to claim 10, characterized in that, The process of obtaining the required flow rate of the main stage of the control valve includes: Based on the command signal and a preset Map table showing the correlation between the command signal and the flow rate, query the initial required flow rate of the main stage of the control valve; Obtain the total demand flow of the actuator; If the total demand flow rate is greater than the maximum flow rate of the main pump, then the pump is determined to be in saturation flow condition. Based on the ratio of the initial demand flow rate of each control valve stage to the total demand flow rate, the final demand flow rate of each control valve stage is weighted and allocated according to the maximum flow rate of the main pump. If the total demand flow is less than or equal to the maximum flow of the main pump, then the final demand flow of each control valve stage is determined to be its respective initial demand flow.

12. A machine-readable storage medium storing instructions for causing a machine to perform a control method of the hydraulic control circuit according to any one of claims 4 to 11.

13. A controller, characterized in that, include: Memory, which stores programs that can run on a processor; as well as The processor is configured to implement the control method of the hydraulic control circuit according to any one of claims 4 to 11 when executing the program.

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