Hydraulic control system, control method and operating machinery

Abstract

The present invention relates to the technical field of hydraulic systems, and provides a hydraulic control system, a control method, and an operating machine. In the hydraulic control system, a steering cylinder is connected to an oil source via a control valve. The control valve can switch between a steering position and a cut-off position. In the steering position, the oil source is connected to the steering cylinder; in the cut-off position, the oil source and the steering cylinder are cut off. The angle detection module is used to detect the actual angle deviation between the steering angle and the return angle of the wheel assembly. The timing module is connected to the angle detection module to detect the duration of each actual angle deviation. The control module is connected to the angle detection module, the timing module, and the control valve to control the working position of the control valve based on the detection results of the angle detection module and the timing module. In this way, the forward steering, reverse return, and centering locking actions of the wheel assembly are all controlled and realized by the same set of steering cylinders and control valves. Compared with the prior art, the hydraulic control system occupies less space and has lower costs.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic systems, and in particular to a hydraulic control system, a control method and an operating machine. Background Art

[0002] At present, the steering system of an operating machine mainly includes a main steering system and an auxiliary steering system. The main steering system is mostly a mechanical steering system. The auxiliary steering system is mostly a hydraulic steering control system. The existing hydraulic steering control system is equipped with a steering cylinder, a steering control valve, a centering cylinder and a centering control valve. Among them, the steering control valve is used to control the working state of the steering cylinder to drive the wheel to steer. The centering control valve is used to control the working state of the centering cylinder to lock the wheel in the centering state. In this hydraulic steering control system, two independent cylinders and control valves are used for steering and centering locking control respectively, which takes up a large space and is relatively expensive. Summary of the Invention

[0003] The present invention provides a hydraulic control system, a control method and an operating machine, which are used to solve the problem that the existing hydraulic steering control system uses two independent oil cylinders and control valves to perform steering and centering locking control respectively, which occupies a large space and is high in cost.

[0004] According to a first aspect of the present invention, there is provided a hydraulic control system comprising:

[0005] A steering cylinder, which is used to drive the wheel assembly to steer;

[0006] an oil source connected to the steering cylinder and used to drive the steering cylinder;

[0007] a control valve connected between the steering cylinder and the oil source, the control valve being switchable between a steering position and a cut-off position. In the steering position, the oil source is connected to the steering cylinder; in the cut-off position, the oil source and the steering cylinder are cut off.

[0008] An angle detection module, the angle detection module is used to detect an actual angle deviation between a steering angle and a return angle of the wheel assembly;

[0009] a timing module, connected to the angle detection module and configured to detect a duration of each actual angle deviation;

[0010] A control module is connected to the angle detection module, the timing module and the control valve, and is used to control the working position of the control valve based on the detection results of the angle detection module and the timing module.

[0011] According to a hydraulic control system provided by the present invention, the control module controls the control valve to switch to the cut-off position to lock the wheel assembly in alignment based on the angle detection module detecting that the actual angle deviation is less than or equal to the set angle deviation, and the timing module detecting that the actual angle deviation is less than or equal to the set angle deviation and the maintenance time is greater than or equal to the set time.

[0012] According to a hydraulic control system provided by the present invention, the steering cylinder includes a first cylinder and a second cylinder, wherein the first cylinder and the second cylinder are used to drive the coaxial opposite wheels in the wheel assembly to steer synchronously.

[0013] According to a hydraulic control system provided by the present invention, the oil source includes an oil pump and an oil tank, and the control valve includes a first working oil port, a second working oil port, a third working oil port, and a fourth working oil port. The first working oil port is connected to the oil pump. The second working oil port is connected to the oil tank. The third working oil port is connected to the rodless chamber of the first oil cylinder and the rod chamber of the second oil cylinder. The fourth working oil port is connected to the rod chamber of the first oil cylinder and the rodless chamber of the second oil cylinder.

[0014] According to a hydraulic control system provided by the present invention, the steering position includes a forward steering position and a reverse steering position.

[0015] In the forward steering position, the first working oil port communicates with the third working oil port, and the second working oil port communicates with the fourth working oil port. In the reverse steering position, the first working oil port communicates with the fourth working oil port, and the second working oil port communicates with the third working oil port. In the blocked position, both the third and fourth working oil ports communicate with the second working oil port and are blocked from the first working oil port.

[0016] According to a hydraulic control system provided by the present invention, a hydraulic lock is provided between the steering cylinder and the control valve.

[0017] The hydraulic lock includes a first one-way valve and a second one-way valve. The oil inlet of the first one-way valve is connected to the third working oil port, and the oil outlet of the first one-way valve is connected to the rodless chamber of the first oil cylinder and the rod chamber of the second oil cylinder. The oil inlet of the second one-way valve is connected to the fourth working oil port, and the oil outlet of the second one-way valve is connected to the rod chamber of the first oil cylinder and the rodless chamber of the second oil cylinder. The control oil port of the first one-way valve is connected to the oil inlet of the second one-way valve. The control oil port of the second one-way valve is connected to the oil inlet of the first one-way valve.

[0018] According to a hydraulic control system provided by the present invention, a pressure compensation component is further provided at the control valve.

[0019] The pressure compensating assembly includes a pressure compensating valve and a shuttle valve. The oil inlet of the pressure compensating valve is connected to the oil pump. The oil outlet of the pressure compensating valve is connected to the first working oil port. The control oil port of the pressure compensating valve is connected to the oil outlet of the shuttle valve. The first oil inlet of the shuttle valve is connected to the third working oil port. The second oil inlet of the shuttle valve is connected to the fourth working oil port.

[0020] According to a hydraulic control system provided by the present invention, the angle detection module includes an angle sensor.

[0021] According to a second aspect of the present invention, there is provided a control method, comprising:

[0022] detecting an actual angle deviation between a steering angle and a return angle of the wheel assembly, comparing the actual angle deviation with a target angle deviation, and generating a primary comparison result;

[0023] When it is determined according to the first-level comparison result that the actual angle deviation is less than or equal to the target angle deviation, a duration comparison instruction is generated;

[0024] According to the duration comparison instruction, the duration for which the actual angle deviation is less than or equal to the target angle deviation is compared with the target duration to generate a secondary comparison result;

[0025] When it is determined according to the secondary comparison result that the holding time is greater than or equal to the target time, determining that the wheel assembly needs to be center-locked, and generating a control instruction;

[0026] The control valve is controlled to switch to the cut-off position according to the control instruction.

[0027] According to a control method provided by the present invention, the target angle deviation is 0.3 degrees, and the target duration is 3 seconds.

[0028] According to a third aspect of the present invention, there is provided a working machine comprising the hydraulic control system as described above, or employing the control method as described above when executing control of the hydraulic control system.

[0029] In the hydraulic control system provided by the present invention, the oil source is connected to the steering cylinder via a control valve. The control valve is capable of switching between a steering position and a cutoff position. When the control valve is in the steering position, the oil source is connected to the steering cylinder via the control valve, and the oil source supplies oil to the steering cylinder so that the steering cylinder drives the wheel assembly to steer forward or return to the center position. When the control valve is in the cutoff position, the oil source and the steering cylinder are cut off, and the steering cylinder is locked in its current state. The angle detection module, the timing module, and the control module cooperate with each other to achieve centering locking of the steering cylinder.

[0030] During operation, when the wheel assembly needs to steer forward or return to center, the control valve is switched to the steering position, and oil is supplied to the steering cylinder through the control valve, causing the steering cylinder to drive the wheel assembly to steer forward or return to center. For example, if the actual angular deviation between the wheel assembly's steering angle and the return angle is less than or equal to the set angular deviation, and the actual angular deviation remains less than or equal to the set angular deviation for a period of time greater than or equal to a set time, the wheel assembly is determined to be in a centered state and requires centering lock. At this point, the control module switches the control valve to the cutoff position, maintaining the steering cylinder in its current state, thereby completing the wheel assembly's centering lock.

[0031] This structural arrangement allows the wheel assembly's forward steering, reverse return, and centering locking actions to be controlled by the same steering cylinder and control valve. Compared to existing technologies, this hydraulic control system occupies less space and is less expensive.

[0032] Furthermore, in the working machine provided by the present invention, since the working machine includes the hydraulic control system as described above, it also has the advantages as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 It is a schematic diagram of the hydraulic control system provided by the present invention;

[0035] Figure 2 is a flow chart of the control method provided by the present invention;

[0036] Reference numerals:

[0037] 101. First oil cylinder; 102. Second oil cylinder; 201. Oil pump; 202. Oil tank; 300. Control valve; 301. First working oil port; 302. Second working oil port; 303. Third working oil port; 304. Fourth working oil port; 305. Forward steering position; 306. Reverse steering position; 307. Cut-off position; 400. Angle detection module; 500. Wheel assembly; 601. First one-way valve; 602. Second one-way valve; 701. Pressure compensation valve; 702. Shuttle valve. DETAILED DESCRIPTION

[0038] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0039] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0040] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0041] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0042] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representation of the above terms does 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, in the absence of mutual 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 to make the purpose, technical solutions and advantages of the embodiment of the present invention clearer. The technical solutions in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0043] The following combination Figure 1 and Figure 2 A hydraulic control system, a control method, and a working machine provided by an embodiment of the present invention are described. It should be understood that the following description is merely an illustrative embodiment of the present invention and does not constitute any particular limitation to the present invention.

[0044] An embodiment of the first aspect of the present invention provides a hydraulic control system, such as Figure 1 As shown, the hydraulic control system includes:

[0045] A steering cylinder, which is used to drive the wheel assembly 500 to steer;

[0046] An oil source is connected to the steering cylinder and is used to drive the steering cylinder;

[0047] The control valve 300 is connected between the steering cylinder and the oil source. The control valve 300 can be switched between a steering position and a cut-off position 307. In the steering position, the oil source is connected to the steering cylinder; in the cut-off position 307, the oil source and the steering cylinder are cut off.

[0048] Angle detection module 400, the angle detection module 400 is used to detect the actual angle deviation between the steering angle and the return angle of the wheel assembly 500;

[0049] A timing module, which is connected to the angle detection module 400 and is used to detect the duration of each actual angle deviation;

[0050] The control module is connected to the angle detection module 400 , the timing module and the control valve 300 , and is used to control the working position of the control valve 300 based on the detection results of the angle detection module 400 and the timing module.

[0051] In the hydraulic control system provided by the present invention, the oil source is connected to the steering cylinder through the control valve 300. The control valve 300 can be switched between the steering position and the cut-off position 307. When the control valve 300 is in the steering position, the oil source is connected to the steering cylinder through the control valve 300, and the oil source supplies oil to the steering cylinder so that the steering cylinder drives the wheel assembly 500 to turn forward or return to the normal position. When the control valve 300 is in the cut-off position 307, the oil source and the steering cylinder are cut off, and the steering cylinder is locked in the current state. The angle detection module 400, the timing module and the control module cooperate with each other to achieve the centering locking of the steering cylinder.

[0052] In one embodiment of the present invention, the control module controls the control valve 300 to switch to the cut-off position 307 to center and lock the wheel assembly 500 based on the fact that the angle detection module detects that the actual angle deviation is less than or equal to the set angle deviation, and the timing module detects that the actual angle deviation is less than or equal to the set angle deviation and the duration of maintenance is greater than or equal to the set duration.

[0053] During operation, when the wheel assembly 500 needs to steer forward or return to the center position, the control valve 300 is switched to the steering position, and the oil source is supplied to the steering cylinder through the control valve 300, so that the steering cylinder drives the wheel assembly 500 to steer forward or return to the center position. When the actual angle deviation between the steering angle and the return angle of the wheel assembly 500 is less than or equal to the set angle deviation, and the actual angle deviation is less than or equal to the set angle deviation for a period of time greater than or equal to a certain set time, it is determined that the wheel assembly 500 is in the centering state and needs to be locked. At this time, the control module switches the control valve 300 to the cut-off position 307 to maintain the steering cylinder in the current state, thereby completing the centering lock of the wheel assembly 500.

[0054] For example, if the angle deviation is set to 0.3 degrees and the time duration is set to 3 seconds, when the angle detection module 400 detects that the actual angle deviation is less than or equal to 0.3 degrees and the actual angle deviation is less than or equal to 0.3 degrees for 3 seconds or more, it is determined that the wheel assembly 500 needs to be locked in the center. The control module controls the control valve 300 to switch to the cut-off position 307 to lock the steering cylinder in the current state, thereby completing the center locking operation of the wheel assembly 500.

[0055] With this structural arrangement, the forward steering, reverse return and centering locking actions of the wheel assembly 500 are all controlled by the same set of steering cylinders and control valves 300. Compared with the prior art, the hydraulic control system occupies less space and has lower costs.

[0056] It should be noted that the present invention does not impose any limitation on the specific composition of the angle detection module 400. For example, in one embodiment of the present invention, the angle detection module 400 includes an angle sensor.

[0057] In one embodiment of the present invention, the steering cylinder includes a first cylinder 101 and a second cylinder 102. The first cylinder 101 and the second cylinder 102 are used to drive the coaxial opposite side wheels in the wheel assembly 500 to steer synchronously.

[0058] In one embodiment of the present invention, the oil source includes an oil pump 201 and an oil tank 202. The control valve 300 includes a first working oil port 301, a second working oil port 302, a third working oil port 303, and a fourth working oil port 304. The first working oil port 301 is connected to the oil pump 201. The second working oil port 302 is connected to the oil tank 202. The third working oil port 303 is connected to the rodless chamber of the first cylinder 101 and the rod chamber of the second cylinder 102. The fourth working oil port 304 is connected to the rod chamber of the first cylinder 101 and the rodless chamber of the second cylinder 102.

[0059] Furthermore, in one embodiment of the present invention, the steering position includes a forward steering position 305 and a reverse steering position 306 .

[0060] In the forward steering position 305, the first working oil port 301 is connected to the third working oil port 303, and the second working oil port 302 is connected to the fourth working oil port 304; in the reverse steering position 306, the first working oil port 301 is connected to the fourth working oil port 304, and the second working oil port 302 is connected to the third working oil port 303; in the cut-off position 307, the third working oil port 303 and the fourth working oil port 304 are both connected to the second working oil port 302 and cut off from the first working oil port 301.

[0061] For example, Figure 1As shown, the steering cylinder includes a first cylinder 101 and a second cylinder 102. The first cylinder 101 and the second cylinder 102 are respectively connected to the positions of the coaxial opposite wheels. The first cylinder 101 and the second cylinder 102 drive the coaxial opposite wheels to steer synchronously. In this embodiment, the rod cavity of the first cylinder 101 is connected to the rodless cavity of the second cylinder 102, and the rodless cavity of the first cylinder 101 is connected to the rod cavity of the second cylinder 102. That is, when the piston rod of the first cylinder 101 is extended, the piston rod of the second cylinder 102 is retracted. When the piston rod of the first cylinder 101 is retracted, the piston rod of the second cylinder 102 is extended.

[0062] The control valve 300 is a three-position, four-way solenoid directional control valve. The three-position, four-way solenoid directional control valve includes a first working oil port 301, a second working oil port 302, a third working oil port 303, and a fourth working oil port 304. The first working oil port 301 and the second working oil port 302 are connected to the oil pump 201 and the oil tank 202, respectively. The third working oil port 303 is connected to the rodless chamber of the first cylinder 101 and the rod chamber of the second cylinder 102. The fourth working oil port 304 is connected to the rod chamber of the first cylinder 101 and the rodless chamber of the second cylinder 102. The three-position, four-way solenoid directional control valve can switch between a forward steering position 305, a reverse steering position 306, and a cutoff position 307.

[0063] During operation, when forward steering is required, the control valve 300 is switched to the forward steering position 305, and the oil pump 201 supplies oil to the rodless chamber of the first cylinder 101 and the rod chamber of the second cylinder 102 through the first working oil port 301 and the third working oil port 303. The oil in the rod chamber of the first cylinder 101 and the rodless chamber of the second cylinder 102 then flows back to the oil tank 202 through the fourth working oil port 304 and the second working oil port 302. The piston rod of the first cylinder 101 extends, and the piston rod of the second cylinder 102 retracts. When reverse return is required, the control valve 300 is switched to the reverse steering position 306. The oil in the rodless cavity of the first cylinder 101 and the rod cavity of the second cylinder 102 flows back to the oil tank 202 through the third working oil port 303 and the second working oil port 302. The oil pump 201 supplies oil to the rod cavity of the first cylinder 101 and the rodless cavity of the second cylinder 102 through the first working oil port 301 and the fourth working oil port 304. The piston rod of the first cylinder 101 retracts, and the piston rod of the second cylinder 102 extends.

[0064] Similarly, when reverse steering is required, the control valve 300 is switched to the reverse steering position 306. The oil in the rodless cavity of the first cylinder 101 and the rod cavity of the second cylinder 102 flows back to the oil tank 202 through the third working oil port 303 and the second working oil port 302. The oil pump 201 supplies oil to the rod cavity of the first cylinder 101 and the rodless cavity of the second cylinder 102 through the first working oil port 301 and the fourth working oil port 304. The piston rod of the first cylinder 101 retracts, and the piston rod of the second cylinder 102 extends. When forward return is required, the control valve 300 is switched to the forward steering position 305. The oil pump 201 supplies oil to the rodless chamber of the first cylinder 101 and the rod chamber of the second cylinder 102 through the first working oil port 301 and the third working oil port 303. The oil in the rod chamber of the first cylinder 101 and the rodless chamber of the second cylinder 102 then flows back to the oil tank 202 through the fourth working oil port 304 and the second working oil port 302. The piston rod of the first cylinder 101 extends, and the piston rod of the second cylinder 102 retracts.

[0065] Furthermore, when the angle detection module 400 and the timing module cooperate to detect that the wheel assembly 500 needs to be locked in center, the control module switches the control valve 300 to the cutoff position 307. At this point, the rod chamber and the rodless chamber of the first oil cylinder 101 and the rod chamber and the rodless chamber of the second oil cylinder 102 are both cut off from the oil pump 201. The first oil cylinder 101 and the second oil cylinder 102 drive the wheel assembly 500 to maintain the centering state.

[0066] In one embodiment of the present invention, a hydraulic lock is provided between the steering cylinder and the control valve 300 .

[0067] The hydraulic lock includes a first one-way valve 601 and a second one-way valve 602. The oil inlet of the first one-way valve 601 is connected to the third working oil port 303. The oil outlet of the first one-way valve 601 is connected to the rodless chamber of the first oil cylinder 101 and the rod chamber of the second oil cylinder 102. The oil inlet of the second one-way valve 602 is connected to the fourth working oil port 304. The oil outlet of the second one-way valve 602 is connected to the rod chamber of the first oil cylinder 101 and the rodless chamber of the second oil cylinder 102. The control oil port of the first one-way valve 601 is connected to the oil inlet of the second one-way valve 602, and the control oil port of the second one-way valve 602 is connected to the oil inlet of the first one-way valve 601.

[0068] refer to Figure 1To describe, a first one-way valve 601 is provided on the oil inlet and return lines of the rodless chamber of the first oil cylinder 101 and the rod chamber of the second oil cylinder 102, and a second one-way valve 602 is provided on the oil inlet and return lines of the rod chamber of the first oil cylinder 101 and the rodless chamber of the second oil cylinder 102. When oil is output from the third working oil port 303, the first one-way valve 601 and the second one-way valve 602 open, and the oil is input into the rodless chamber of the first oil cylinder 101 and the rod chamber of the second oil cylinder 102 through the first one-way valve 601. The oil in the rod chamber of the first oil cylinder 101 and the rodless chamber of the second oil cylinder 102 flows back to the oil tank 202 through the second one-way valve 602 and the control valve 300.

[0069] Similarly, when oil is output from the fourth working oil port 304, the first one-way valve 601 and the second one-way valve 602 are opened, and the oil passes through the second one-way valve 602 into the rod chamber of the first cylinder 101 and the rodless chamber of the second cylinder 102. The oil in the rodless chamber of the first cylinder 101 and the rod chamber of the second cylinder 102 flows back to the oil tank 202 through the first one-way valve 601 and the control valve 300.

[0070] By providing a hydraulic lock between the steering cylinder and the control valve 300 , when the control valve 300 leaks, the steering cylinder and the oil source can still be completely cut off, thereby improving the cut-off reliability between the steering cylinder and the oil source.

[0071] In one embodiment of the present invention, a pressure compensation component is further provided at the control valve 300 .

[0072] The pressure compensation assembly includes a pressure compensation valve 701 and a shuttle valve 702. The oil inlet of the pressure compensation valve 701 is connected to the oil pump 201. The oil outlet of the pressure compensation valve 701 is connected to the first working oil port 301, and the control oil port of the pressure compensation valve 701 is connected to the oil outlet of the shuttle valve 702. The first oil inlet of the shuttle valve 702 is connected to the third working oil port 303, and the second oil inlet of the shuttle valve 702 is connected to the fourth working oil port 304.

[0073] According to the embodiments described above, by providing a pressure compensation valve 701 and a shuttle valve 702 on both sides of the control valve 300, the pressure difference between the inlet and outlet ports of the control valve 300 can be kept constant, thereby improving the working stability of the control valve 300.

[0074] In a second aspect of the present invention, an embodiment provides a control method, such as Figure 2 As shown, including:

[0075] Detecting an actual angle deviation between the steering angle and the return angle of the wheel assembly 500, comparing the actual angle deviation with the target angle deviation, and generating a primary comparison result;

[0076] When the actual angle deviation is determined to be less than or equal to the target angle deviation according to the first-level comparison result, a duration comparison instruction is generated;

[0077] According to the duration comparison instruction, the duration during which the actual angle deviation is less than or equal to the target angle deviation is compared with the target duration to generate a secondary comparison result;

[0078] When it is determined based on the secondary comparison result that the holding time is greater than or equal to the target time, it is determined that the wheel assembly 500 needs to be locked in centering, and a control instruction is generated;

[0079] The control valve 300 is controlled to switch to the cut-off position 307 according to the control instruction.

[0080] For example, in one embodiment of the present invention, the target angle deviation is 0.3 degrees, and the target duration is 3 seconds.

[0081] Specifically, the angle detection module 400 detects the actual angular deviation between the steering angle and the return angle of the wheel assembly 500. The actual angular deviation is compared with a preset target angular deviation. For example, the target angular deviation is 0.3 degrees. When the actual angular deviation is less than or equal to 0.3 degrees, a duration comparison instruction is generated. Specifically, the duration during which the actual angular deviation is less than or equal to 0.3 degrees is compared with the target duration. For example, the target duration is 3 seconds. When the duration during which the actual angular deviation is less than or equal to 0.3 degrees is greater than or equal to 3 seconds, it is determined that the wheel assembly 500 requires a centering lock operation and a control instruction is generated. Specifically, the control instruction switches the control valve 300 to the cutoff position 307, locking the steering cylinder in the center position. In other words, the wheel assembly 500 is determined to require a centering lock operation only when both the actual angular deviation and the duration meet the target conditions. If it is determined that a centering lock operation is required, a control instruction is generated to switch the control valve 300 to the cutoff position 307, completing the centering lock operation.

[0082] Thus, the steering, centering and center locking operations of the wheel assembly 500 can be performed using the same set of steering cylinders and control valves 300 .

[0083] An embodiment of the third aspect of the present invention provides a working machine, comprising the hydraulic control system as described above, or employing the control method as described above when executing control of the hydraulic control system.

[0084] For example, the above-mentioned working machine includes a wheeled crane.

[0085] It should be noted that the above embodiment is only an illustrative embodiment of the present invention and does not constitute any limitation to the present invention. For example, in other embodiments of the present invention, the above working machine may also include an excavator, etc.

[0086] Furthermore, since the working machine includes the hydraulic control system as described above, or adopts the control method as described above when executing the hydraulic control system control, it also has the advantages as described above.

[0087] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A hydraulic control system, characterized in that: include: A steering cylinder, which is used to drive the wheel assembly to steer; an oil source connected to the steering cylinder and used to drive the steering cylinder, the oil source comprising an oil pump and an oil tank; a control valve connected between the steering cylinder and the oil source, the control valve being switchable between a steering position and a cut-off position. In the steering position, the oil source is connected to the steering cylinder; in the cut-off position, the oil source and the steering cylinder are cut off. An angle detection module, the angle detection module is used to detect an actual angle deviation between a steering angle and a return angle of the wheel assembly; a timing module, connected to the angle detection module and configured to detect a duration of each actual angle deviation; a control module connected to the angle detection module, the timing module, and the control valve, and configured to control a working position of the control valve based on detection results of the angle detection module and the timing module; The control module controls the control valve to switch to the cut-off position to lock the wheel assembly in alignment based on the fact that the angle detection module detects that the actual angle deviation is less than or equal to the set angle deviation, and the timing module detects that the actual angle deviation is less than or equal to the set angle deviation for a period of time greater than or equal to the set time. The steering cylinder includes a first cylinder and a second cylinder, and the first cylinder and the second cylinder are used to drive the coaxial opposite side wheels in the wheel assembly to steer synchronously; The control valve includes a first working oil port, a second working oil port, a third working oil port and a fourth working oil port, the first working oil port is connected to the oil pump, the second working oil port is connected to the oil tank, the third working oil port is connected to the rodless chamber of the first oil cylinder and the rod chamber of the second oil cylinder, and the fourth working oil port is connected to the rod chamber of the first oil cylinder and the rodless chamber of the second oil cylinder; The steering position includes a forward steering position and a reverse steering position. In the forward steering position, the first working oil port is connected to the third working oil port, and the second working oil port is connected to the fourth working oil port; in the reverse steering position, the first working oil port is connected to the fourth working oil port, and the second working oil port is connected to the third working oil port; in the blocked position, the third working oil port and the fourth working oil port are both connected to the second working oil port and blocked from the first working oil port; A hydraulic lock is provided between the steering cylinder and the control valve. The hydraulic lock includes a first one-way valve and a second one-way valve, the oil inlet of the first one-way valve is connected to the third working oil port, the oil outlet of the first one-way valve is connected to the rodless chamber of the first oil cylinder and the rod chamber of the second oil cylinder, the oil inlet of the second one-way valve is connected to the fourth working oil port, the oil outlet of the second one-way valve is connected to the rod chamber of the first oil cylinder and the rodless chamber of the second oil cylinder, the control oil port of the first one-way valve is connected to the oil inlet of the second one-way valve, and the control oil port of the second one-way valve is connected to the oil inlet of the first one-way valve.

2. The hydraulic control system according to claim 1, characterized in that: The control valve is also provided with a pressure compensation component. The pressure compensating assembly includes a pressure compensating valve and a shuttle valve, the oil inlet of the pressure compensating valve is connected to the oil pump, the oil outlet of the pressure compensating valve is connected to the first working oil port, the control oil port of the pressure compensating valve is connected to the oil outlet of the shuttle valve, the first oil inlet of the shuttle valve is connected to the third working oil port, and the second oil inlet of the shuttle valve is connected to the fourth working oil port.

3. The hydraulic control system according to claim 2, characterized in that: The angle detection module includes an angle sensor.

4. A control method, characterized in that: The control method is performed based on the hydraulic control system according to any one of claims 1 to 3, and includes: detecting an actual angle deviation between a steering angle and a return angle of the wheel assembly, comparing the actual angle deviation with a target angle deviation, and generating a primary comparison result; When it is determined according to the first-level comparison result that the actual angle deviation is less than or equal to the target angle deviation, a duration comparison instruction is generated; According to the duration comparison instruction, the duration for which the actual angle deviation is less than or equal to the target angle deviation is compared with the target duration to generate a secondary comparison result; When it is determined according to the secondary comparison result that the holding time is greater than or equal to the target time, determining that the wheel assembly needs to be center-locked, and generating a control instruction; The control valve is controlled to switch to the cut-off position according to the control instruction.

5. A working machine, characterized in that: The method comprises the hydraulic control system according to any one of claims 1 to 3, or adopts the control method according to claim 4 when executing the control of the hydraulic control system.

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