Engineering vehicles and their steering control systems and methods

Abstract

This application discloses an engineering vehicle and its steering control system and method. This system can be used in both new energy vehicle architectures and fuel vehicle architectures. The steering control valve assembly is located on the oil supply line, which splits the oil supply line into a steering line and a centering line. The steering line is connected to the steering actuator, and the centering line is connected to the centering actuator. The steering control valve assembly has a first switching state and a second switching state for controlling the oil flow path. The centering control valve assembly is located on the centering line. In the first switching state, the steering line supplies oil to the steering actuator, and the centering control valve assembly controls the centering line to unload. In the second switching state, the steering line unloads, and the centering control valve assembly controls the centering line to supply oil to the centering actuator. This application enables interlocking of vehicle steering and centering, meaning the vehicle can only be in either steering or centering state at a time, avoiding the phenomenon of high-pressure oil simultaneously present in steering and centering due to component failure.

Description

Technical Field

[0001] This application belongs to the field of engineering vehicle technology, and specifically relates to an engineering vehicle and its steering control system and method. Background Technology

[0002] Based on current development trends in engineering vehicles, new energy vehicle architectures have reached a certain scale. For hybrid or general engineering vehicles, steering typically involves two actions: steering and centering. During one action, the hydraulic cylinder for the other must be in a floating state; the two actions cannot occur simultaneously, otherwise, interaction can lead to malfunctions. Steering requires controllable speed and smooth movement; centering requires fast centering speed and good locking performance. Furthermore, the steering and centering system is crucial for driving safety, demanding high levels of system safety and reliability. However, in existing technologies, multiple solenoid valves must be simultaneously energized or de-energized during steering or centering. A malfunction in any one of these valves will result in abnormal movements, affecting steering safety. Summary of the Invention

[0003] The purpose of this application is to provide an engineering vehicle and its steering control system and method, so that the engineering vehicle can perform steering and centering independently without affecting each other.

[0004] To achieve the above objectives, this application provides a steering alignment control system for an engineering vehicle, the steering alignment control system comprising:

[0005] Oil supply circuit;

[0006] The steering control valve assembly is located on the oil supply line. The steering control valve assembly divides the oil supply line into a steering line and a centering line. The steering line is connected to the steering actuator, and the centering line is connected to the centering actuator. The steering control valve assembly has a first switching state and a second switching state for controlling the oil flow path.

[0007] The centering control valve assembly is located on the centering oil line;

[0008] In the first switching state, the steering oil circuit supplies oil to the steering actuator, and the centering control valve group controls the centering oil circuit to unload; in the second switching state, the steering oil circuit is unloaded, and the centering control valve group controls the centering oil circuit to supply oil to the centering actuator.

[0009] In some implementations, the steering control valve assembly includes an integrated unit:

[0010] An electro-proportional directional valve is installed on the steering oil circuit. The first working port of the electro-proportional directional valve is connected to the oil tank, and the second working port is connected to the steering actuator.

[0011] The electromagnetic directional valve is located on the centering oil line. The first working port of the electromagnetic directional valve is connected to the oil tank, and the second working port is connected to the centering actuator.

[0012] An unloading valve is located in the oil line between the electro-proportional directional valve and the steering actuator. The unloading valve includes a return port, a pilot port, and a working port. The return port is connected to the oil tank, the pilot port is connected to the second working port of the electromagnetic directional valve, and the working port is connected to the steering actuator.

[0013] In some embodiments, the steering control valve assembly further includes a damping element located in the connecting oil line between the unloading valve and the solenoid directional valve.

[0014] In some embodiments, the steering control valve assembly further includes a check valve and a pressure reducing valve located on the centering oil line, with the pressure reducing valve located on the oil line between the check valve and the solenoid directional valve.

[0015] In some embodiments, the centering control valve assembly includes a hydraulically controlled check valve having a forward flow passage and a reverse flow passage for hydraulic oil.

[0016] In some implementations, the steering alignment control system also includes an emergency oil circuit for supplying oil to the steering oil circuit or the alignment oil circuit in an emergency.

[0017] In some implementations, the steering alignment control system further includes a control unit electrically connected to the steering control valve assembly, which controls the operation of the steering control valve assembly according to the driving status of the engineering vehicle.

[0018] A second aspect of this application provides a steering alignment control method for an engineering vehicle, applied in the steering alignment control system described above. The steering alignment control method includes the following steps:

[0019] Obtain the driving status of engineering vehicles;

[0020] When the engineering vehicle is in a turning state, the control center oil circuit is unloaded, and the steering oil circuit supplies oil to the steering actuator.

[0021] When the engineering vehicle is in the centering state, the steering oil circuit is unloaded, and the centering oil circuit supplies oil to the centering actuator.

[0022] In some embodiments, the step of controlling the steering hydraulic circuit to supply oil to the steering actuator and unloading the intermediate hydraulic circuit when the engineering vehicle is in a steering state includes:

[0023] Both the electro-proportional directional valve and the solenoid directional valve are energized so that hydraulic oil enters the steering actuator through the electro-proportional directional valve.

[0024] The reverse flow channel of the control hydraulic check valve is opened to unload the hydraulic oil in the centering oil circuit.

[0025] In some embodiments, the step of controlling the steering hydraulic circuit to unload and the centering hydraulic circuit to supply oil to the centering actuator when the engineering vehicle is in the centering state includes:

[0026] The control electro-proportional directional valve and the solenoid directional valve are both de-energized, and the unloading valve opens to unload the hydraulic oil in the steering actuator.

[0027] The positive flow channel of the control hydraulic check valve is opened so that the hydraulic oil in the centering oil circuit enters the centering actuator through the solenoid directional valve and the control hydraulic check valve.

[0028] In some implementations, the steering centering control method further includes the step of:

[0029] Real-time acquisition of the current oil pressure of the centering actuator;

[0030] When the current oil pressure is lower than the preset oil pressure, the pressure reducing valve is opened.

[0031] When the current oil pressure is greater than or equal to the preset oil pressure, the pressure reducing valve is closed.

[0032] In some implementations, the steering centering control method further includes the step of:

[0033] When the engineering vehicle is in an emergency, the emergency fuel line is activated and fuel is supplied.

[0034] A third aspect of this application provides an engineering vehicle including a steering centering control system as described above.

[0035] The above technical solution places the steering control valve assembly on the oil supply line and the centering control valve assembly on the centering oil line. The steering control valve assembly splits the oil supply line into a steering line and a centering line. The steering line is connected to the steering actuator, and the centering line is connected to the centering actuator. The steering control valve assembly has a first switching state and a second switching state for controlling the oil flow path. In the first switching state, the steering line supplies oil to the steering actuator, and the centering control valve assembly controls the centering line to unload, at which point the vehicle steers. In the second switching state, the steering line is unloaded, and the centering control valve assembly controls the centering line to supply oil to the centering actuator, at which point the vehicle aligns. The steering and centering control system of this application enables engineering vehicles to be in either steering or centering state only, avoiding the simultaneous occurrence of steering and centering due to hydraulic component failure, thus improving reliability and safety.

[0036] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0037] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without any inventive effort. In the drawings:

[0038] Figure 1 This is a schematic diagram of the hydraulic principle of the steering centering control system of this application;

[0039] Figure 2 This is a flowchart illustrating the steering centering control method of this application.

[0040] Explanation of reference numerals in the attached figures

[0041] 10 Steering control valve assembly 30 Oil tank

[0042] 11 Electro-proportional directional valve 40 centering actuator

[0043] 12 Solenoid directional valve 50 Steering actuator

[0044] 13 Unloading valve 60 axle

[0045] 14 Damping valve L Oil supply circuit

[0046] 15. One-way valve L1: Steering oil circuit

[0047] 16. Pressure reducing valve L2, centering oil circuit

[0048] 20 Centering control valve group L3 emergency oil circuit Detailed Implementation

[0049] The specific embodiments of this application 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 this application.

[0050] The following description, with reference to the accompanying drawings, describes the engineering vehicle and its steering control system and method according to this application. The engineering vehicle can be a fuel-powered vehicle or a new energy vehicle. New energy vehicles generally include: pure electric, range-extended electric, hybrid, fuel cell electric, hydrogen engine, etc.

[0051] like Figure 1As shown, this application provides a steering alignment control system for an engineering vehicle. The steering alignment control system includes an oil supply line L, a steering control valve assembly 10, and an alignment control valve assembly 20. The steering control valve assembly 10 is located on the oil supply line L and divides the oil supply line L into a steering oil line L1 and an alignment oil line L2. The steering oil line L1 is connected to a steering actuator 50, and the alignment oil line L2 is connected to an alignment actuator 40. The steering control valve assembly 10 has a first switching state and a second switching state for controlling the oil flow path. In the first switching state, the centering control valve group 20 is installed on the centering oil circuit L2. In the second switching state, the steering oil circuit L1 is unloaded, and the steering oil circuit L1 supplies oil to the steering actuator 50. The steering actuator 50 actuates and drives the vehicle to steer. In the third switching state, the steering oil circuit L1 is unloaded, and the centering control valve group 20 controls the centering oil circuit L2 to supply oil to the centering actuator 40. The centering actuator 40 actuates under the action of hydraulic oil, thereby driving the vehicle to center.

[0052] The steering actuator 50 can be a steering cylinder, which steers the vehicle through its movement; the centering actuator 40 can be a centering cylinder, which aligns the vehicle's tires for proper driving. In engineering vehicles, both the centering cylinder and the steering cylinder are mounted on the steering knuckle of the axle 60. Figure 1 As shown, the present application has two steering cylinders, which control the steering action of the left and right tires respectively. The rod chamber and rodless chamber of the two steering cylinders are connected and connected to the same oil circuit.

[0053] In this embodiment, the hydraulic oil supply line L is split into two independent oil lines by the steering control valve group 10: the steering oil line L1 and the centering oil line L2. The switching function of the steering control valve group 10 can switch the flow path of the hydraulic oil. When centering is required, the centering oil line L2 supplies oil to the centering actuator 40, while the steering actuator 50 unloads oil. When turning is required, the steering oil line L1 supplies oil to the steering actuator 50, while the centering actuator 40 unloads oil. This allows the vehicle's steering and centering to be interlocked, meaning the vehicle can only be in a steering or centering state. Steering and centering are performed independently and do not affect each other, avoiding the phenomenon of high-pressure oil existing during steering and centering due to solenoid valve failure in the prior art, thus improving safety.

[0054] In some embodiments, the steering control valve assembly 10 includes an integrated electro-proportional directional valve 11, a solenoid directional valve 12, and an unloading valve 13. The electro-proportional directional valve 11 is located on the steering oil circuit L1 and is a three-position four-way solenoid valve. The first working port of the electro-proportional directional valve 11 is connected to the oil tank 30, and the second working port is connected to the steering actuator 50. The solenoid directional valve 12 is located on the centering oil circuit L2 and is a two-position four-way solenoid valve. The first working port is connected to the oil tank 30, and the second working port is connected to the centering actuator 40. The unloading valve 13 is located on the oil line between the electro-proportional directional valve 11 and the steering actuator 50. There are two unloading valves 13, which are respectively connected to the rod chamber and rodless chamber of the two steering cylinders. The unloading valve 13 includes a return port, a pilot port and a working port. The return port is connected to the oil tank 30, the pilot port is connected to the second working port of the solenoid directional valve 12, and the working port is connected to the steering actuator 50.

[0055] In this design, the unloading valve 13 functions as a safety valve during normal operation. When the pressure inside the steering cylinder exceeds the set pressure of the unloading valve 13, the unloading valve 13 opens to overflow, maintaining the pressure inside the steering cylinder at approximately the set value. When there is high-pressure oil at the pilot port of the unloading valve 13, the unloading valve 13 fully opens, allowing the oil in the steering cylinder to flow directly to the oil tank 30 to complete the unloading. Furthermore, this application replaces the existing combination of an overflow valve and a hydraulic check valve with the unloading valve 13, achieving two functions with a single valve. This reduces the number of components, saves internal space within the valve body, and decreases the failure rate.

[0056] In this embodiment, by integrating and simplifying the functions of components such as the electro-proportional directional valve 11, the solenoid directional valve 12, and the unloading valve 13, the number of components is reduced, thereby lowering costs and reducing the likelihood of malfunctions.

[0057] In addition, the steering centering control system also includes a constant pressure variable pump for pumping hydraulic oil in the oil tank 30 at constant pressure, so as to achieve the stability of the oil supply pressure of the entire hydraulic control system.

[0058] In some embodiments, the steering control valve assembly 10 further includes a damping element located in the oil connection between the unloading valve 13 and the solenoid directional valve 12. The damping element can be a damping valve 14, which is capable of absorbing pressure shocks and fluctuations in the pilot control oil of the unloading valve 13, thus preventing the unloading valve 13 from opening and closing intermittently.

[0059] In some embodiments, the steering control valve assembly 10 further includes a check valve 15 and a pressure reducing valve 16 disposed on the centering oil circuit L2, wherein the pressure reducing valve 16 is disposed on the oil circuit between the check valve 15 and the solenoid directional valve 12.

[0060] The one-way valve 15 isolates the steering oil circuit L1 from the centering oil circuit L2, preventing the pressure in the centering oil circuit L2 from affecting the steering oil circuit L1. The pressure reducing valve 16 controls the pressure inside the centering cylinder. When the pressure inside the centering cylinder does not reach the set pressure of the pressure reducing valve 16, the valve remains open, allowing high-pressure oil to flow into the centering cylinder. When the pressure inside the centering cylinder reaches the set pressure of the pressure reducing valve 16, the valve closes, maintaining the pressure inside the cylinder at approximately the set value. In this embodiment, by setting the pressure reducing valve 16, the pressure inside the centering cylinder can be controlled, preventing excessive force from damaging the axle 60 components.

[0061] In some embodiments, the centering control valve assembly 20 includes a hydraulically controlled check valve, which has a forward flow channel and a reverse flow channel for hydraulic oil. The hydraulically controlled check valve is an integrated valve body structure, and a pressure testing interface for detecting oil pressure is also provided on the oil circuit connecting the hydraulically controlled check valve and the centering cylinder. The centering cylinder includes two working chambers and an intermediate non-working chamber located between the two working chambers. The centering control valve group 20 includes a second oil inlet P2, a first oil return port T1, and a second pressure feedback port X2. When the hydraulic oil flows in the forward direction, it enters the working chamber of the centering cylinder from the second oil inlet P2 along the forward flow channel. The hydraulic oil in the intermediate non-working chamber of the centering cylinder flows back to the oil tank 30 from the first oil return port T1. When there is high-pressure oil at the second pressure feedback port X2, the hydraulic oil flows in the reverse direction. The hydraulic oil flowing out of the working chamber of the centering cylinder flows back to the oil tank 30 through the second oil inlet P2. The hydraulic oil in the intermediate non-working chamber of the centering cylinder flows back to the oil tank 30 from the first oil return port T1, thereby realizing the pressure relief of the centering cylinder.

[0062] In this embodiment, the pressure in the centering cylinder can be locked and unloaded by a hydraulically controlled check valve. The locking performance is better than that of the directional valve in the prior art, which can avoid centering failure caused by pipeline leakage or damage.

[0063] The steering control valve assembly 10 has a first working port A1 and a second working port B2. The first working port A1 is connected to the rod chamber of the steering cylinder, and the second working port B2 is connected to the rodless chamber of the steering cylinder.

[0064] When the vehicle is turning, both the electro-proportional directional valve 11 and the solenoid directional valve 12 are energized, and the steering oil circuit L1 is connected. High-pressure oil enters from the oil inlet P of the steering control valve group 10 and is divided into the centering oil circuit L2 and the steering oil circuit L1. The hydraulic oil in the centering oil circuit L2 flows through the check valve 15, the pressure reducing valve 16, and the left position of the solenoid directional valve 12, and enters the centering control valve group 20 from the X1 port of the steering control valve group 10. The hydraulic control check valve is opened, and the hydraulic oil in the centering cylinder flows along the reverse flow channel to the oil tank 30 to complete the unloading, so that the centering cylinder is in a floating state. The hydraulic oil in the steering oil circuit L1 flows through the electro-proportional directional valve 11 and enters the steering cylinder from the first working oil port A1 or the second working oil port B2. The piston rod of the steering cylinder moves, thereby driving the axle 60 to achieve steering.

[0065] When the vehicle is centered, both the electro-proportional directional valve 11 and the solenoid directional valve 12 are de-energized. The electro-proportional directional valve 11 is in the neutral position, and the steering circuit L1 is disconnected. Hydraulic oil enters from the inlet P of the steering control valve assembly 10 and is divided into the centering circuit L2 and the steering circuit L1. The hydraulic oil in the steering circuit L1 flows through the check valve 15, the pressure reducing valve 16, and the right position of the solenoid directional valve 12. At this time, the hydraulic oil enters the pilot port of the unloading valve 13 through the damping valve 14. Under the pressure of the hydraulic oil, the unloading valve 13 is opened, the high-pressure oil in the steering cylinder is unloaded, and the steering cylinder is in a floating state. The hydraulic oil in the centering circuit L2 flows from the C port of the steering control valve assembly 10 to the second inlet P2 of the centering control valve assembly 20, and enters the centering cylinder through the positive flow channel of the hydraulic check valve, so that the piston rod of the centering cylinder moves and drives the tire to be in the center-locked state.

[0066] This application changes the steering centering control method from conventional electronic control to electronic control + hydraulic control, realizing steering and centering interlock, reducing the number of solenoid valves, improving vehicle steering reliability, and reducing faulty components.

[0067] In some embodiments, the steering alignment control system also includes an emergency oil circuit L3 that supplies oil to the steering oil circuit L1 or the alignment oil circuit L2 in an emergency. The emergency oil circuit L3 can be supplied with oil using an emergency oil pump or an accumulator. When the constant pressure variable pump or engine fails to provide high-pressure oil during vehicle operation, both the electro-proportional directional valve 11 and the solenoid directional valve 12 lose power, disconnecting the oil supply to the steering oil circuit L1. The emergency oil source supplies high-pressure oil to the alignment oil circuit L2 through the third inlet P1. The high-pressure oil flows through the pressure reducing valve 16 and the right position of the solenoid directional valve 12, and the hydraulic oil in the steering cylinder flows to the unloading valve 13. Under the action of the hydraulic oil, the unloading valve 13 is opened to unload the steering cylinder. The hydraulic oil in the alignment oil circuit L2 enters the alignment cylinder, locking the tires in a neutral position, allowing the vehicle to drive smoothly to a stop and preventing tire swaying that could cause a safety accident in the event of a constant pressure variable pump or engine failure.

[0068] In some embodiments, the steering alignment control system also includes a control unit electrically connected to the steering control valve assembly 10. This control unit controls the operation of the steering control valve assembly 10 according to the driving conditions of the engineering vehicle. By configuring the control unit to control the operation of the steering control valve assembly 10 according to the vehicle's driving conditions, the entire control process is automated, reducing the failure rate.

[0069] The second aspect of this application provides a steering alignment control method for an engineering vehicle, applied in the steering alignment control system described above, such as... Figure 2 As shown, the steering centering control method includes the following steps:

[0070] S10: Obtain the driving status of the engineering vehicle;

[0071] S20: When the engineering vehicle is in a turning state, control the unloading of the center oil circuit L2, and the steering oil circuit L1 supplies oil to the steering actuator 50.

[0072] S30: When the engineering vehicle is in the centering state, the steering oil circuit L1 is unloaded and the centering oil circuit L2 supplies oil to the centering actuator 40.

[0073] During the steering and centering control process, the oil flow of the centering oil circuit L2 and the steering oil circuit L1 is controlled according to the different driving states of the vehicle, namely steering or centering. When one oil circuit is in the oil supply state, the other oil circuit unloads the corresponding cylinder, thereby enabling the steering and centering to be interlocked, so that the vehicle can only be in the steering or centering state, avoiding the situation where centering and steering exist simultaneously and affect each other.

[0074] In some embodiments, the step of controlling the steering hydraulic circuit L1 to supply oil to the steering actuator 50 and unloading the intermediate hydraulic circuit L2 when the engineering vehicle is in a steering state includes:

[0075] Both the electro-proportional directional valve 11 and the solenoid directional valve 12 are energized so that hydraulic oil enters the steering actuator 50 through the electro-proportional directional valve 11.

[0076] The reverse flow channel of the control hydraulic check valve is opened to unload the hydraulic oil in the centering oil circuit L2.

[0077] When the vehicle is in a steering state, both the electro-proportional directional valve 11 and the solenoid directional valve 12 are energized. At this time, the electro-proportional directional valve 11 is in the left or right position (which can be selected according to the action mode of the steering cylinder), and the solenoid directional valve 12 is in the left position. The hydraulic oil of the centering oil circuit L2 enters the centering control valve group 20 from the X port of the steering control valve group 10 through the left position of the solenoid directional valve 12. At this time, the reverse flow channel is opened, which unloads the hydraulic oil of the centering cylinder and makes the centering cylinder float.

[0078] The hydraulic oil in the steering circuit L1 enters the steering cylinder from the electro-proportional directional valve 11, so that the piston rod of the steering cylinder extends or retracts, thereby realizing the steering of the axle 60.

[0079] In some embodiments, the step of controlling the steering oil circuit L1 to unload and the centering oil circuit L2 to supply oil to the centering actuator 40 when the engineering vehicle is in the centering state includes:

[0080] The control proportional directional valve 11 and the solenoid directional valve 12 are both de-energized, and the unloading valve 13 opens to unload the hydraulic oil in the steering actuator 50.

[0081] The positive flow channel of the control hydraulic check valve is opened so that the hydraulic oil in the centering oil circuit L2 enters the centering actuator 40 through the solenoid directional valve 12 and the control hydraulic check valve.

[0082] When the vehicle is in a centered driving state, both the control electro-proportional directional valve 11 and the solenoid directional valve 12 are de-energized. At this time, the electro-proportional directional valve 11 is in the neutral position, so the hydraulic oil in the steering oil circuit L1 cannot flow to the steering cylinder through the electro-proportional directional valve 11. Instead, the high-pressure oil at the second working port of the electro-proportional directional valve 11 enters the pilot port of the unloading valve 13 through the damping valve 14. The pressure relief valve opens, so the hydraulic oil in the steering cylinder is unloaded, and the steering cylinder is in a floating state.

[0083] Since the solenoid directional valve 12 is in the right position after being de-energized, the hydraulic oil flowing in from the centering oil circuit L2 passes through the right position and port C of the solenoid directional valve 12 and enters the second oil inlet P2 of the centering control valve group 20. It then enters the upper and lower working chambers of the centering cylinder along the forward flow channel. The middle non-working chamber of the centering cylinder returns oil, thereby causing the centering cylinder to move and realize the centering of the vehicle.

[0084] In some implementations, the steering centering control method further includes the step of:

[0085] Real-time acquisition of the current oil pressure of the centering actuator 40;

[0086] When the current oil pressure is lower than the preset oil pressure, control the pressure reducing valve 16 to open;

[0087] When the current oil pressure is greater than or equal to the preset oil pressure, control the pressure reducing valve 16 to close.

[0088] Because a pressure testing interface for detecting oil pressure is provided on the connecting oil line between the centering cylinder and the hydraulic check valve, the opening or closing of the pressure reducing valve 16 is controlled by comparing the current oil pressure with the spring force set by the pressure reducing valve 16 itself. This ensures that the hydraulic oil in the centering oil circuit L2 is maintained within a suitable range, preventing damage to the axle 60 due to excessive hydraulic oil pressure. In this embodiment, the preset oil pressure is equal to the spring force set by the pressure reducing valve 16 itself. This can be preset in the system according to actual conditions and is not limited here.

[0089] In some implementations, the steering centering control method further includes the step of:

[0090] When the engineering vehicle is in an emergency, the emergency fuel line L3 is activated and fuel is supplied.

[0091] In this embodiment, by activating the emergency oil circuit L3 to supply oil to the centering oil circuit L2 in an emergency, the steering cylinder can be unloaded, the centering cylinder can be activated, and the tires can be locked in the center position, thereby preventing vehicle accidents in an emergency.

[0092] A third aspect of this application provides an engineering vehicle including the steering alignment control system described above. The engineering vehicle can be a hybrid new energy engineering vehicle or a general engineering vehicle. Since this engineering vehicle employs all embodiments of the aforementioned steering alignment control system, it possesses all the beneficial effects brought by the aforementioned steering control system, which will not be listed individually here.

[0093] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0094] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0095] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0096] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A steering alignment control system of a work vehicle characterized by, The steering and centering control system comprises: an oil supply oil path (L); a steering control valve group (10) provided on the oil supply oil path (L), the steering control valve group (10) divides the oil supply oil path (L) into a steering oil path (L1) and a centering oil path (L2), the steering oil path (L1) is communicated with a steering actuating element (50), the centering oil path (L2) is communicated with a centering actuating element (40), the steering control valve group (10) has a first switching state and a second switching state of a control oil flow path; a centering control valve group (20) provided on the centering oil path (L2); wherein, in the first switching state, the steering oil path (L1) supplies oil to the steering actuating element (50), and the centering control valve group (20) controls the centering oil path (L2) to be unloaded; in the second switching state, the steering oil path (L1) is unloaded, and the centering control valve group (20) controls the centering oil path (L2) to supply oil to the centering actuating element (40); the steering control valve group (10) comprises an integrated: an electric proportional directional valve (11) provided on the steering oil path (L1), a first side working oil port of the electric proportional directional valve (11) is communicated with an oil tank (30), and a second side working oil port is communicated with the steering actuating element (50); an electromagnetic directional valve (12) provided on the centering oil path (L2), a first side working oil port of the electromagnetic directional valve (12) is communicated with the oil tank (30), and a second side working oil port is communicated with the centering actuating element (40); an unloading valve (13) provided on an oil path between the electric proportional directional valve (11) and the steering actuating element (50), the unloading valve (13) comprises a return port, a pilot port and a working port, the return port is communicated with the oil tank (30), the pilot port is communicated with the second side working oil port of the electromagnetic directional valve (12), and the working port is communicated with the steering actuating element (50).

2. The turn centering control system of claim 1, wherein The steering control valve group (10) further comprises a damping element provided on a connecting oil path between the unloading valve (13) and the electromagnetic directional valve (12).

3. The turn centering control system of claim 1, wherein The steering control valve group (10) further comprises a check valve (15) and a pressure reducing valve (16) provided on the centering oil path (L2), the pressure reducing valve (16) is provided on an oil path between the check valve (15) and the electromagnetic directional valve (12).

4. The turn centering control system of claim 1, wherein The centering control valve group (20) comprises a hydraulic control check valve, the hydraulic control check valve has a forward flow channel and a reverse flow channel for hydraulic oil flow.

5. The turn centering control system of claim 1, wherein, The steering and centering control system further comprises an emergency oil path (L3) for supplying oil to the steering oil path (L1) or the centering oil path (L2) in an emergency state.

6. The turn centering control system of claim 1, wherein The steering and centering control system further comprises a control unit electrically connected with the steering control valve group (10), the control unit is used for controlling the action of the steering control valve group (10) according to the driving state of the engineering vehicle.

7. A method of steering alignment control of a work vehicle, characterized by, The steering alignment control method applied to the steering alignment control system according to any one of claims 1 to 6 comprises steps of: acquiring a running state of the engineering vehicle; controlling the alignment oil circuit (L2) to be unloaded and the steering oil circuit (L1) to supply oil to the steering actuator (50) when the engineering vehicle is in a steering state; controlling the steering oil circuit (L1) to be unloaded and the alignment oil circuit (L2) to supply oil to the alignment actuator (40) when the engineering vehicle is in an alignment state.

8. The turn centering control method according to claim 7, characterized by, The alignment control valve group (20) comprises a hydraulic control check valve having a forward flow passage and a reverse flow passage for hydraulic oil flow, and the step of controlling the alignment oil circuit (L2) to be unloaded and the steering oil circuit (L1) to supply oil to the steering actuator (50) when the engineering vehicle is in a steering state comprises: controlling the electric proportional directional valve (11) and the electromagnetic directional valve (12) to be powered to make the hydraulic oil enter the steering actuator (50) through the electric proportional directional valve (11); controlling the reverse flow passage of the hydraulic control check valve to be opened to unload the hydraulic oil of the alignment oil circuit (L2).

9. The turn centering control method according to claim 7, characterized by, The alignment control valve group (20) comprises a hydraulic control check valve having a forward flow passage and a reverse flow passage for hydraulic oil flow, and the step of controlling the alignment oil circuit (L2) to be unloaded and the steering oil circuit (L1) to supply oil to the steering actuator (50) when the engineering vehicle is in a steering state comprises: controlling the electric proportional directional valve (11) and the electromagnetic directional valve (12) to be powered to make the hydraulic oil enter the steering actuator (50) through the electric proportional directional valve (11); controlling the reverse flow passage of the hydraulic control check valve to be opened to unload the hydraulic oil of the alignment oil circuit (L2).

10. The turn centering control method according to claim 7, characterized by, The steering control valve group (10) further comprises a check valve (15) and a pressure reducing valve (16) arranged on the alignment oil circuit (L2), the pressure reducing valve (16) is arranged on an oil circuit between the check valve (15) and the electromagnetic directional valve (12), and the steering alignment control method further comprises steps of: acquiring a current oil pressure of the alignment actuator (40) in real time; controlling the pressure reducing valve (16) to be opened when the current oil pressure is less than a preset oil pressure; controlling the pressure reducing valve (16) to be closed when the current oil pressure is greater than or equal to the preset oil pressure.

11. The turn centering control method according to claim 7, characterized by, The steering alignment control system further comprises an emergency oil circuit (L3) for supplying oil to the steering oil circuit (L1) or the alignment oil circuit (L2) in an emergency state, and the steering alignment control method further comprises a step of: controlling the emergency oil circuit (L3) to be started and supply oil when the engineering vehicle is in an emergency state.

12. An engineering vehicle characterized by, The steering alignment control system according to any one of claims 1 to 6.

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