Engineering vehicle and steering control system and method thereof

Abstract

The invention discloses an engineering vehicle and a steering control system and method.The system can be used for a new energy architecture and a fuel architecture, a steering control valve set of the system is arranged on an oil supply oil way, the oil supply oil way is divided into a steering oil way and a centering oil way through the steering control valve set, the steering oil way communicates with a steering execution element, and the centering oil way communicates with the steering execution element; the centering oil path is communicated with the centering execution element, and the steering control valve group has a first switching state and a second switching state for controlling an oil liquid flowing path; the centering control valve group is arranged on the centering oil path; in the first switching state, the steering oil way supplies oil to the steering execution element, and the centering control valve group controls the centering oil way to unload; and in the second switching state, the steering oil way is unloaded, and the centering control valve group controls the centering oil way to supply oil to the centering execution element. Interlocking of vehicle steering and centering can be achieved, namely the vehicle can only be in a steering or centering state, and the phenomenon that high-pressure oil exists in steering and centering at the same time due to component faults is avoided.

Description

Technical Field

[0001] The present application belongs to the technical field of engineering vehicles, and specifically relates to an engineering vehicle and a steering control system and method thereof. Background Art

[0002] According to the current development trend of engineering vehicles, new energy architecture has reached a certain scale. For hybrid engineering vehicles or general engineering vehicles, steering is usually divided into steering action and centering straight action. When one action is performed, the cylinder of the other action needs to enter a floating state. The two actions cannot be performed at the same time, otherwise they will cause failures due to interaction. Among them, the steering action requires controllable speed and smooth action; the centering action requires fast centering speed and good locking performance. At the same time, the steering and centering system involves driving safety, and has high requirements for system safety and reliability. However, in the prior art, when the vehicle is turning or centering, multiple solenoid valves must be energized or de-energized at the same time. If one side fails, it will cause abnormal action and affect steering safety. Summary of the invention

[0003] The purpose of the present application is to provide an engineering vehicle and a steering control system and method thereof, so as to enable the engineering vehicle to steer and center independently without affecting each other.

[0004] In order to achieve the above-mentioned object, the present application provides, on one hand, a steering centering control system for an engineering vehicle, the steering centering control system comprising:

[0005] Oil supply line;

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

[0007] The centering control valve group is arranged on the centering oil line;

[0008] Among them, 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 unloads, and the centering control valve group controls the centering oil circuit to supply oil to the centering actuator.

[0009] In some embodiments, the steering control valve assembly includes:

[0010] The electric proportional reversing valve is arranged on the steering oil circuit, the first side working oil port of the electric proportional reversing valve is connected with the oil tank, and the second side working oil port is connected with the steering actuator;

[0011] The electromagnetic reversing valve is arranged on the centering oil circuit, the first side working oil port of the electromagnetic reversing valve is connected to the oil tank, and the second side working oil port is connected to the centering actuator;

[0012] The unloading valve is arranged in the oil circuit between the electric proportional reversing valve and the steering actuator. The unloading valve includes a return oil port, a pilot oil port and a working oil port. The return oil port is connected to the oil tank, the pilot oil port is connected to the second side working oil port of the electromagnetic reversing valve, and the working oil port is connected to the steering actuator.

[0013] In some embodiments, the steering control valve group further includes a damping element, and the damping element is disposed on the connecting oil path between the unloading valve and the electromagnetic reversing valve.

[0014] In some embodiments, the steering control valve group further includes a one-way valve and a pressure reducing valve disposed on the centering oil circuit, and the pressure reducing valve is disposed on the oil circuit between the one-way valve and the electromagnetic reversing valve.

[0015] In some embodiments, the centering control valve group includes a hydraulically-controlled one-way valve having a forward flow passage and a reverse flow passage for hydraulic oil to flow.

[0016] In some embodiments, the steering centering control system further includes an emergency oil circuit for supplying oil to the steering oil circuit or the centering oil circuit in an emergency state.

[0017] In some embodiments, the steering centering control system further includes a control unit electrically connected to the steering control valve group, and the control unit is used to control the action of the steering control valve group according to the driving state of the engineering vehicle.

[0018] A second aspect of the present application provides a steering centering control method for an engineering vehicle, which is applied to the steering centering control system as described above. The steering centering control method comprises the following steps:

[0019] Get the driving status of the engineering vehicle;

[0020] When the engineering vehicle is in the steering state, the center oil circuit is controlled to unload, 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 controlled to unload, and the centering oil circuit supplies oil to the centering actuator.

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

[0023] Control the electric proportional reversing valve and the electromagnetic reversing valve to be energized, so that the hydraulic oil enters the steering actuator through the electric proportional reversing valve;

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

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

[0026] The control electric proportional reversing valve and the electromagnetic reversing valve are both de-energized, and the unloading valve opens to unload the hydraulic oil of the steering actuator;

[0027] The forward flow channel of the hydraulically controlled one-way valve is controlled to open, so that the hydraulic oil in the centering oil circuit enters the centering actuator through the electromagnetic reversing valve and the hydraulically controlled one-way valve.

[0028] In some embodiments, the steering centering control method further comprises the steps of:

[0029] Obtain the current oil pressure of the centering actuator in real time;

[0030] When the current oil pressure is lower than the preset oil pressure, the pressure reducing valve is controlled to open;

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

[0032] In some embodiments, the steering centering control method further comprises the steps of:

[0033] When the engineering vehicle is in an emergency state, the emergency oil circuit is controlled to start and supply oil.

[0034] A third aspect of the present application provides an engineering vehicle, comprising the steering centering control system as described above.

[0035] Through the above technical solution, the steering control valve group is arranged on the oil supply line, and the centering control valve group is arranged on the centering oil line. The steering control valve group divides the oil supply line into a steering oil line and a centering oil line. The steering oil line is connected to the steering actuator, and the centering oil line is connected to the centering actuator. The steering control valve group has a first switching state and a second switching state for controlling the oil flow path. In the first switching state, the steering oil line supplies oil to the steering actuator, and the centering control valve group controls the centering oil line to unload, and the vehicle realizes steering at this time; in the second switching state, the steering oil line is unloaded, and the centering control valve group controls the centering oil line to supply oil to the centering actuator, and the vehicle drives in a centering manner. The steering and centering control system of the present application can make the engineering vehicle only in the steering or centering state, avoid the phenomenon of steering and centering existing at the same time due to failure of hydraulic components, and improve reliability and safety.

[0036] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work. 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 flow chart of the steering centering control method of the present application.

[0040] Description of Reference Numerals

[0041] 10 Steering control valve group 30 Fuel tank

[0042] 11 Electric proportional directional valve 40 Centering actuator

[0043] 12 Solenoid reversing valve 50 Steering actuator

[0044] 13 Unloading valve 60 axle

[0045] 14 Damping valve L oil supply line

[0046] 15 Check valve L1 Steering oil circuit

[0047] 16 Pressure reducing valve L2 centering oil line

[0048] 20 Centering control valve group L3 Emergency oil circuit DETAILED DESCRIPTION

[0049] The specific implementation of the present application is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present application, and is not used to limit the present application.

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

[0051] like Figure 1As shown, the present application provides a steering centering control system for an engineering vehicle, the steering centering control system comprising an oil supply circuit L, a steering control valve group 10 and a centering control valve group 20; the steering control valve group 10 is arranged on the oil supply circuit L, the steering control valve group 10 divides the oil supply circuit L into a steering oil circuit L1 and a centering oil circuit L2, the steering oil circuit L1 is connected to a steering actuator 50, the centering oil circuit L2 is connected to a centering actuator 40, and the steering control valve group 10 has a first switching state and a second switching state for controlling the oil flow path state; the centering control valve group 20 is arranged on the centering oil circuit L2; wherein, in the first switching state, the centering control valve group 20 controls the centering oil circuit L2 to unload, the steering oil circuit L1 supplies oil to the steering actuator 50, the steering actuator 50 is actuated, and the vehicle can be driven to achieve steering; in the second switching state, the steering oil circuit L1 is unloaded, the centering control valve group 20 controls the centering oil circuit L2 to supply oil to the centering actuator 40, the centering actuator 40 is actuated under the action of hydraulic oil, thereby driving the vehicle to drive in a centering manner.

[0052] The steering actuator 50 may be a steering cylinder, and the steering of the vehicle is achieved through the action of the steering cylinder; the centering actuator 40 may be a centering cylinder, and the centering of the vehicle tires can be achieved through the action of the centering cylinder. In the engineering vehicle, the centering cylinder and the steering cylinder are both installed on the steering knuckle of the axle 60. Figure 1 As shown, the number of the steering cylinders of the present application is two and they respectively control the steering action of the left and right tires, and the rod chambers and rodless chambers of the two steering cylinders are communicated and connected to the same oil circuit.

[0053] In this embodiment, the oil supply circuit L is divided into two independent oil circuits: the steering oil circuit L1 and the centering oil circuit L2 by the steering control valve group 10. The flow path of the hydraulic oil can be switched by the switching function of the steering control valve group 10. When centering driving is required, the centering oil circuit L2 supplies oil to the centering actuator 40, and the steering actuator 50 unloads oil. When steering is required, the steering oil circuit L1 supplies oil to the steering actuator 50, and the centering actuator 40 unloads oil. This allows the steering and centering of the vehicle to be interlocked, that is, the vehicle can only be in the steering or centering state. Steering and centering are performed independently and do not affect each other, thereby avoiding the phenomenon of high-pressure oil existing in steering and centering at the same time due to the failure of the solenoid valve in the prior art, thereby improving safety.

[0054] In some embodiments, the steering control valve group 10 includes an electric proportional reversing valve 11, an electromagnetic reversing valve 12 and an unloading valve 13 which are integrated into one body; the electric proportional reversing valve 11 is arranged on the steering oil circuit L1, the electric proportional reversing valve 11 is a three-position four-way electromagnetic valve, the first side working oil port of the electric proportional reversing valve 11 is connected to the oil tank 30, and the second side working oil port is connected to the steering actuator 50; the electromagnetic reversing valve 12 is arranged on the centering oil circuit L2, the electromagnetic reversing valve 12 is a two-position four-way electromagnetic valve, and the electromagnetic reversing valve 12 The first side working oil port is connected to the oil tank 30, and the second side working oil port is connected to the centering actuator 40; the unloading valve 13 is arranged on the oil circuit between the electric proportional reversing valve 11 and the steering actuator 50, and there are two unloading valves 13, which are respectively connected to the rod chamber and the rodless chamber of the two steering cylinders. The unloading valve 13 includes a return oil port, a pilot oil port and a working oil port. The return oil port is connected to the oil tank 30, the pilot oil port is connected to the second side working oil port of the electromagnetic reversing valve 12, and the working oil port is connected to the steering actuator 50.

[0055] Among them, the unloading valve 13 functions as a safety valve when working normally. When the pressure in the steering cylinder is higher than the set pressure of the unloading valve 13, the unloading valve 13 opens to overflow, so that the pressure in the steering cylinder is maintained at about the set value of the unloading valve 13; when there is high-pressure oil at the pilot port of the unloading valve 13, the unloading valve 13 is fully opened, and the oil in the steering cylinder can flow directly to the oil tank 30 to complete the unloading. In addition, the present application replaces the combination of the overflow valve and the hydraulically controlled one-way valve in the prior art with the unloading valve 13, and realizes two functions with one valve, which can reduce the number of components, save the internal layout space of the valve body, and reduce the failure rate.

[0056] In this embodiment, the functions of components such as the electric proportional reversing valve 11, the electromagnetic reversing valve 12 and the unloading valve 13 are integrated and simplified to reduce the number of components, cost and failure.

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

[0058] In some embodiments, the steering control valve group 10 further includes a damping element, which is disposed in the connecting oil path between the unloading valve 13 and the electromagnetic reversing valve 12. The damping element may be a damping valve 14, which can absorb the pressure shock and fluctuation of the pilot control oil of the unloading valve 13 to prevent the unloading valve 13 from opening and closing.

[0059] In some embodiments, the steering control valve group 10 further includes a one-way valve 15 and a pressure reducing valve 16 disposed on the centering oil circuit L2 , and the pressure reducing valve 16 is disposed on the oil circuit between the one-way valve 15 and the electromagnetic reversing valve 12 .

[0060] Among them, the function of the one-way valve 15 is to isolate the steering oil circuit L1 from the centering oil circuit L2, so as to prevent the pressure of the centering oil circuit L2 from affecting the steering oil circuit L1. The pressure reducing valve 16 can control the pressure in the centering oil cylinder. When the pressure in the centering oil cylinder does not reach the set pressure of the pressure reducing valve 16, the pressure reducing valve 16 is normally open, so that the high-pressure oil can flow to the centering oil cylinder. When the pressure in the centering oil cylinder reaches the set pressure of the pressure reducing valve 16, the pressure reducing valve 16 is closed, so that the pressure in the oil cylinder can be maintained at about the set value. In this embodiment, by setting the pressure reducing valve 16, the pressure in the centering oil cylinder can be controlled to prevent excessive force from damaging the parts of the axle 60.

[0061] In some embodiments, the centering control valve group 20 includes a hydraulically controlled one-way valve having a forward flow channel and a reverse flow channel for hydraulic oil to flow. The hydraulically controlled one-way valve is an integrated valve body structure, and a pressure measuring interface for detecting the oil circuit pressure is also provided on the connecting oil circuit of the hydraulically controlled one-way valve and the centering oil 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, and 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 in the second pressure feedback port X2, the hydraulic oil flows in the reverse direction, and 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, and 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 pressure unloading of the centering cylinder.

[0062] In this embodiment, the pressure in the centering cylinder can be locked and unloaded by the hydraulically controlled one-way valve, and the locking performance is better than that of the reversing valve in the prior art, which can avoid centering failure caused by oil leakage or damage to the pipeline.

[0063] The steering control valve group 10 has a first working oil port A1 and a second working oil port B2. The first working oil port A1 is communicated with a rod chamber of the steering cylinder, and the second working oil port B2 is communicated with a rodless chamber of the steering cylinder.

[0064] When the vehicle is turning, the electric proportional reversing valve 11 and the electromagnetic reversing valve 12 are both energized, the steering oil circuit L1 is connected, and the high-pressure oil enters from the oil inlet P of the steering control valve group 10 and is divided into the center oil circuit L2 and the steering oil circuit L1; the hydraulic oil of the center oil circuit L2 flows through the one-way valve 15, the pressure reducing valve 16, and the left position of the electromagnetic reversing valve 12, and enters the centering control valve group 20 from the X1 port of the steering control valve group 10, and opens the hydraulic control one-way valve. The hydraulic oil of 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 of the steering oil circuit L1 flows through the electric proportional reversing 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 to drive the axle 60 to achieve steering.

[0065] When the vehicle is driving in the center, the electric proportional reversing valve 11 and the electromagnetic reversing valve 12 are both de-energized, the electric proportional reversing valve 11 is in the middle position, and the steering oil circuit L1 is disconnected. The hydraulic oil enters from the oil inlet P of the steering control valve group 10 and is divided into the center oil circuit L2 and the steering oil circuit L1; the hydraulic oil in the steering oil circuit L1 flows through the check valve 15, the pressure reducing valve 16, and the right position of the electromagnetic reversing valve 12. At this time, the hydraulic oil enters the pilot oil port of the unloading valve 13 through the damping valve 14. Under the pressure of the hydraulic oil, the unloading valve 13 is driven to open, 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 oil circuit L2 flows from the C port of the steering control valve group 10 to the second oil inlet P2 of the centering control valve group 20, and enters the centering oil cylinder through the forward flow channel of the hydraulic control check valve, so that the piston rod of the centering oil cylinder moves to drive the tire to be in a neutral locking state.

[0066] The present application changes the control method for steering centering from conventional electronic control to electronic control + hydraulic control, thereby achieving interlocking of steering and centering, reducing the number of solenoid valves, improving vehicle steering reliability, and reducing components prone to failure.

[0067] In some embodiments, the steering centering control system also includes an emergency oil circuit L3 for supplying oil to the steering oil circuit L1 or the centering oil circuit L2 in an emergency state. Among them, the emergency oil circuit L3 can use an emergency oil pump or an accumulator for emergency oil supply. When the constant pressure variable pump or the engine of the engineering vehicle fails to provide high-pressure oil due to a fault during driving, the electric proportional reversing valve 11 and the electromagnetic reversing valve 12 are both de-energized, the oil supply of the steering oil circuit L1 is disconnected, and the emergency oil source provides high-pressure oil to the centering oil circuit L2 through the third oil inlet P1. The high-pressure oil passes through the pressure reducing valve 16 and the right position of the electromagnetic reversing valve 12, and the hydraulic oil of the steering cylinder flows to the unloading valve 13. Under the action of the hydraulic oil, the unloading valve 13 is driven to open to unload the steering cylinder; the hydraulic oil of the centering oil circuit L2 enters the centering cylinder to put the tire in a neutral locking state, which can make the engineering vehicle drive smoothly until it stops, and prevent the vehicle tire from swinging left and right when the constant pressure variable pump or engine fails, causing a safety accident.

[0068] In some embodiments, the steering centering control system further includes a control unit electrically connected to the steering control valve group 10, and the control unit is used to control the action of the steering control valve group 10 according to the driving state of the engineering vehicle. By setting the control unit to control the action of the steering control valve group 10 according to the driving state of the vehicle, the entire control process is automated and the failure rate is reduced.

[0069] A second aspect of the present application provides a steering centering control method for an engineering vehicle, which is applied to the steering centering control system as described above. Figure 2 As shown, the steering centering control method includes the steps of:

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

[0071] S20: When the engineering vehicle is in a steering state, the central oil circuit L2 is controlled to unload, 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 controlled to unload, and the centering oil circuit L2 supplies oil to the centering actuator 40 .

[0073] During the steering centering control process, the oil flow conditions of the centering oil circuit L2 and the steering oil circuit L1 are controlled according to the different driving states of the vehicle, namely, steering or centering. When one of the oil circuits 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 at the same time and affect each other.

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

[0075] Control the electric proportional reversing valve 11 and the electromagnetic reversing valve 12 to be energized, so that the hydraulic oil enters the steering actuator 50 through the electric proportional reversing valve 11;

[0076] The reverse flow channel of the hydraulically controlled one-way valve is controlled to open to unload the hydraulic oil in the centering oil circuit L2.

[0077] When the vehicle is in a steering state, the control electric proportional reversing valve 11 and the electromagnetic reversing valve 12 are both energized. At this time, the electric proportional reversing valve 11 is in the left position or the right position (can be selected according to the action form of the steering cylinder), and the electromagnetic reversing valve 12 is in the left position. The hydraulic oil of the centering oil circuit L2 passes through the left position of the electromagnetic reversing valve 12 from the X port of the steering control valve group 10 into the centering control valve group 20. At this time, the reverse flow channel is controlled to be opened, so that the hydraulic oil of the centering cylinder is unloaded, so that the centering cylinder is in a floating state.

[0078] The hydraulic oil in the steering oil circuit L1 enters the steering oil cylinder from the electric proportional reversing valve 11 , so that the piston rod of the steering oil cylinder is extended or retracted, thereby realizing the steering of the axle 60 .

[0079] In some embodiments, when the engineering vehicle is in the centering state, 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 includes:

[0080] The electric proportional reversing valve 11 and the electromagnetic reversing valve 12 are both de-energized, and the unloading valve 13 is opened to unload the hydraulic oil of the steering actuator 50;

[0081] The forward flow channel of the hydraulically controlled one-way valve is controlled to open, so that the hydraulic oil in the centering oil circuit L2 enters the centering actuator 40 through the electromagnetic reversing valve 12 and the hydraulically controlled one-way valve.

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

[0083] Since the solenoid reversing valve 12 is in the right position after losing power, the hydraulic oil flowing in from the centering oil circuit L2 enters the second oil inlet P2 of the centering control valve group 20 through the right position and C port of the solenoid reversing valve 12, and enters the upper and lower working chambers of the centering cylinder along the forward flow channel, and the middle non-working chamber of the centering cylinder realizes oil return, thereby causing the centering cylinder to operate to realize the centering driving of the vehicle.

[0084] In some embodiments, the steering centering control method further comprises the steps of:

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

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

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

[0088] Since a pressure measuring interface for detecting oil pressure is provided on the connecting oil circuit between the centering oil cylinder and the hydraulically controlled one-way valve, the opening or closing of the valve port 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, so that the hydraulic oil in the centering oil circuit L2 can be maintained within a suitable range, and the axle 60 is prevented from being damaged due to excessive hydraulic oil pressure. Among them, the preset oil pressure of this embodiment is equal to the spring force set by the pressure reducing valve 16 itself, which can be set in the system in advance according to actual conditions and is not limited here.

[0089] In some embodiments, the steering centering control method further comprises the steps of:

[0090] When the engineering vehicle is in an emergency state, the emergency oil circuit L3 is controlled to start and supply oil.

[0091] In this embodiment, by starting the emergency oil circuit L3 to supply oil to the centering oil circuit L2 in an emergency state, the steering cylinder can be unloaded, and the centering cylinder is activated to put the tire in a neutral locked state, thereby preventing the vehicle from having a safety accident in an emergency state.

[0092] The third aspect of the present application provides an engineering vehicle, including the steering centering control system as described above. The engineering vehicle may be a hybrid new energy engineering vehicle or a general engineering vehicle. Since the engineering vehicle adopts all the embodiments of the steering centering control system as described above, it has all the beneficial effects brought by the steering control system as described above, which are not listed one by one here.

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

[0094] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0095] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. 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 present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0096] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A steering centering control system for an engineering vehicle, characterized in that: include: Oil supply line (L); A steering control valve group (10) is arranged on the oil supply oil circuit (L), the steering control valve group (10) divides the oil supply oil circuit (L) into a steering oil circuit (L1) and a centering oil circuit (L2), the steering oil circuit (L1) is connected to a steering actuator (50), the centering oil circuit (L2) is connected to a centering actuator (40), and the steering control valve group (10) has a first switching state and a second switching state for controlling an oil flow path; A centering control valve group (20) is arranged on the centering oil circuit (L2); Wherein, in the first switching state, the steering oil circuit (L1) supplies oil to the steering actuator (50), and the centering control valve group (20) controls the centering oil circuit (L2) to unload; in the second switching state, the steering oil circuit (L1) unloads, and the centering control valve group (20) controls the centering oil circuit (L2) to supply oil to the centering actuator (40).

2. The steering centering control system according to claim 1, characterized in that: The steering control valve group (10) comprises: An electric proportional reversing valve (11) is arranged on the steering oil circuit (L1), wherein a first side working oil port of the electric proportional reversing valve (11) is in communication with an oil tank (30), and a second side working oil port is in communication with the steering actuator (50); An electromagnetic reversing valve (12) is arranged on the centering oil circuit (L2), a first side working oil port of the electromagnetic reversing valve (12) is in communication with the oil tank (30), and a second side working oil port is in communication with the centering actuator (40); The unloading valve (13) is arranged on the oil circuit between the electric proportional reversing valve (11) and the steering actuator (50), and the unloading valve (13) comprises an oil return port, a pilot oil port and a working oil port. The oil return port is connected to the oil tank (30), the pilot oil port is connected to the second side working oil port of the electromagnetic reversing valve (12), and the working oil port is connected to the steering actuator (50).

3. The steering centering control system according to claim 2, characterized in that: The steering control valve group (10) further comprises a damping element, wherein the damping element is arranged on the connecting oil path between the unloading valve (13) and the electromagnetic reversing valve (12).

4. The steering centering control system according to claim 2, characterized in that: The steering control valve group (10) further comprises a one-way valve (15) and a pressure reducing valve (16) arranged on the centering oil circuit (L2); the pressure reducing valve (16) is arranged on the oil circuit between the one-way valve (15) and the electromagnetic reversing valve (12).

5. The steering centering control system according to claim 1, characterized in that: The centering control valve group (20) comprises a hydraulically controlled one-way valve having a forward flow channel and a reverse flow channel for hydraulic oil to flow.

6. The steering centering control system according to claim 1, characterized in that: The steering centering control system further comprises an emergency oil circuit (L3) for supplying oil to the steering oil circuit (L1) or the centering oil circuit (L2) in an emergency state.

7. The steering centering control system according to claim 1, characterized in that: The steering centering control system further comprises a control unit electrically connected to the steering control valve group (10), the control unit being used to control the action of the steering control valve group (10) according to the driving state of the engineering vehicle.

8. A steering centering control method for an engineering vehicle, characterized in that: Applied to the steering centering control system according to any one of claims 1 to 7, the steering centering control method comprises the steps of: Acquiring the driving status of the engineering vehicle; When the engineering vehicle is in a steering state, the centering oil circuit (L2) is controlled to unload, and the steering oil circuit (L1) supplies oil to the steering actuator (50); When the engineering vehicle is in a centering state, the steering oil circuit (L1) is controlled to unload, and the centering oil circuit (L2) supplies oil to the centering actuator (40).

9. The steering centering control method according to claim 8, characterized in that: When the engineering vehicle is in a steering state, the step of controlling the steering oil circuit (L1) to supply oil to the steering actuator (50) and unloading the centering oil circuit (L2) comprises: Controlling the electric proportional reversing valve (11) and the electromagnetic reversing valve (12) to be energized so that the hydraulic oil enters the steering actuator (50) via the electric proportional reversing valve (11); The reverse flow passage of the hydraulically controlled one-way valve is controlled to open so as to unload the hydraulic oil in the centering oil circuit (L2).

10. The steering centering control method according to claim 8, characterized in that: The step of controlling the steering oil circuit (L1) to unload the load and the centering oil circuit (L2) to supply oil to the centering actuator (40) when the engineering vehicle is in the centering state comprises: The electric proportional reversing valve (11) and the electromagnetic reversing valve (12) are both controlled to lose power, and the unloading valve (13) is opened to unload the hydraulic oil of the steering actuator (50); The forward flow channel of the hydraulically controlled one-way valve is controlled to open, so that the hydraulic oil in the centering oil circuit (L2) enters the centering actuator (40) through the electromagnetic reversing valve (12) and the hydraulically controlled one-way valve.

11. The steering centering control method according to claim 8, characterized in that: The steering centering control method further comprises the steps of: acquiring the current oil pressure of the centering actuator (40) in real time; When the current oil pressure is less than the preset oil pressure, controlling the pressure reducing valve (16) to open; When the current oil pressure is greater than or equal to the preset oil pressure, the pressure reducing valve (16) is controlled to be closed.

12. The steering centering control method according to claim 8, characterized in that: The steering centering control method further comprises the steps of: When the engineering vehicle is in an emergency state, the emergency oil circuit (L3) is controlled to start and supply oil.

13. An engineering vehicle, characterized in that: Comprising a steering centering control system according to any one of claims 1 to 7.

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