Servo feedback hydraulic steering system and engineering vehicle wheel type

Abstract

The utility model relates to vehicle steering system technical field provides a kind of servo feedback hydraulic steering system and engineering machinery wheeled vehicle, including steering device, transmission mechanism and steering module and auxiliary steering module, design is responsible for the main oil supply module of steering valve, pilot module, auxiliary oil supply module, one-way main oil supply module provides high-pressure oil source to steering valve, one-way auxiliary oil supply module provides pilot oil source to pilot module, and then guarantee stable pilot pressure and sufficient pilot flow by independent oil supply, realize the stable control to steering valve, improve steering stability, reduce steering delay, combine the control of steering servo mechanism, steering is not impact, without full hydraulic steering gear noise, driving comfort is also improved;While configuring auxiliary steering module, emergency oil supply is carried out, provides auxiliary steering function, when main road steering failure, emergency stop in safe position can be supported to car.

Description

Technical Field

[0001] This utility model relates to the field of vehicle steering system technology, and in particular to a servo feedback hydraulic steering system and a wheeled vehicle for engineering machinery. Background Technology

[0002] The steering systems of wheeled construction machinery vehicles are primarily fully hydraulic steering systems, with a smaller proportion using servo steering systems. In a fully hydraulic steering system, because there is no direct mechanical connection and the system relies entirely on the hydraulic circuit, the driver has difficulty perceiving the contact between the tires and the ground, resulting in a lack of road feel when steering and insufficient confidence in handling at high speeds. At the same time, the high-speed straight-line driving performance is poor, and the steering feels unstable. Furthermore, there is a large impact and noise (such as a squeaking sound) at the end of the steering process. Therefore, a mechanical limiter needs to be added when steering to the limit position.

[0003] Referring to Chinese Patent CN119283961A, "Servo Steering System and Dump Truck," the existing servo steering system consists of a steering device, a transmission mechanism, an actuator, a feedback mechanism, and an oil pump. When the actuator is in steering mode, the pilot valve supplies pilot oil to the steering valve, causing the steering valve to control the steering cylinder to drive the bogie to rotate. When the actuator is in a balanced state, the pilot valve stops supplying pilot oil to the steering valve, and the steering cylinder stops moving. The pilot valve of the actuator receives its oil source from a pressure reducing valve supplied by the steering pump, which then supplies the oil to the pilot valve to control the steering valve. Because the steering pressure is determined by the load, and the pressure fluctuates in real time, the instability of the pilot oil source pressure and flow rate leads to unstable pressure and flow rate in the steering valve controlled by the pilot valve of the actuator, resulting in poor steering smoothness. Furthermore, it lacks auxiliary steering functionality, failing to meet the requirements of GB / T 14781-2023 "Steering Requirements for Earthmoving Machinery (Tire-type Machines)," which states that "the steering system must have an auxiliary steering device to facilitate emergency stopping of the vehicle in a safe position in case of main steering failure." Summary of the Invention

[0004] This invention provides a servo feedback hydraulic steering system and a wheeled vehicle for engineering machinery, which solves the technical problems of poor steering stability, steering delay and lack of auxiliary steering function in existing vehicle steering systems.

[0005] To solve the above technical problems, this utility model provides a servo feedback hydraulic steering system, including a steering device, a transmission mechanism, a steering module, and an auxiliary steering module, wherein the transmission mechanism is mechanically connected to the steering device and the steering module; The steering module includes a main fuel supply module, an auxiliary fuel supply module, a steering valve, and a pilot module; The oil outlet of the oil supply module is connected to the oil inlet of the steering valve, and the auxiliary oil supply module is connected to the oil inlet of the pilot module. The oil outlet of the auxiliary steering module is connected to the oil inlet of the pilot module and the steering valve. The transmission mechanism is mechanically connected to the steering device and the control terminal of the pilot module, and the oil outlet of the pilot module is connected to the control terminal of the steering valve. When the steering pressure changes during steering, the main oil supply module and the auxiliary oil supply module respectively supply oil to the steering valve and the pilot module. Alternatively, the auxiliary steering module supplies oil to the pilot module and the steering valve in two separate paths to stably drive the steering valve to change direction.

[0006] This basic design separates the main oil supply module and auxiliary oil supply module, which are responsible for the steering valve and pilot module, respectively. One route provides high-pressure oil to the steering valve through the main oil supply module, while the other route provides pilot oil to the pilot module through the auxiliary oil supply module. This independent oil supply ensures stable pilot pressure and sufficient pilot flow, achieving stable control of the steering valve, improving steering smoothness, reducing steering delay, and, combined with the control of the steering servo mechanism, resulting in shock-free steering, no noise from the full hydraulic steering system, and improved driving comfort. At the same time, an auxiliary steering module is configured to provide emergency oil supply and assist steering function, enabling the vehicle to be stopped in a safe position in case of steering failure on the main road.

[0007] In a further embodiment, the pilot module includes a pilot control valve and a pressure control valve; the inlet of the pilot control valve is connected to the outlet of the auxiliary steering module and the outlet of the auxiliary oil supply module, the control end is mechanically connected to the transmission mechanism, and the outlet is connected to the control end of the pressure control valve; the inlet of the pressure control valve is connected to the outlet of the auxiliary steering module and the outlet of the auxiliary oil supply module, and the outlet is connected to the control end of the steering valve.

[0008] The pressure control valve includes a left control valve and a right control valve; In a further embodiment, the oil inlet of the left control valve is connected to the oil outlet of the auxiliary steering module and the oil outlet of the auxiliary oil supply module, the oil outlet is connected to the left control end of the steering valve, and the control end is connected to the oil outlet L of the pilot control valve. The inlet of the right control valve is connected to the outlet of the auxiliary steering module and the outlet of the auxiliary oil supply module. The outlet is connected to the right control terminal of the steering valve, and the control terminal is connected to the outlet R of the pilot control valve.

[0009] This solution employs a pilot control valve and a pressure control valve for pilot control. The pilot control valve acquires the user's control force and converts it into corresponding pressure, which in turn controls the pressure control valve to achieve adjustable steering pressure. The pressure can be adjusted at any time according to steering requirements to meet the steering experience of different users. By precisely matching the pilot pressure and flow, steering smoothness and high-speed driving stability are effectively improved. At the same time, the left and right control valves enable dual-valve switching of the steering valve, allowing for more precise pressure level adjustment and smoother steering. The dual valves work together for faster dynamic response and more precise and sensitive steering control.

[0010] In a further embodiment, the auxiliary oil supply module includes an auxiliary oil supply pump, a flow priority valve, an overflow valve, and a first check valve; The inlet of the flow priority valve is connected to the outlet of the auxiliary oil supply pump, and the outlet is connected to the relief valve to stabilize the pilot pressure; the outlet of the flow priority valve is also connected to the pilot control valve and the pressure control valve respectively through the first check valve. The auxiliary oil supply pump provides oil to the flow priority valve, and the flow priority valve cooperates with the overflow valve to provide two outputs, respectively providing oil with constant pressure and constant flow to the pilot control valve and the pressure control valve.

[0011] This design uses a flow priority valve in conjunction with a relief valve to provide a constant pressure and flow rate of oil, ensuring priority supply and stable output of pilot flow and avoiding interference from pressure fluctuations during steering. The first check valve effectively prevents backflow in the pilot oil circuit.

[0012] In a further embodiment, the auxiliary steering module includes an emergency steering pump, a first priority valve, a first pressure reducing valve, and a second check valve. The inlet of the first priority valve is connected to the outlet of the emergency steering pump, and the outlet is connected to the inlet of the first pressure reducing valve and the inlet of the steering valve. The outlet of the first pressure reducing valve is connected to the pilot control valve and the pressure control valve respectively through the second check valve. In an emergency working environment, the emergency steering pump provides oil to the first priority valve, the first priority valve provides high-pressure oil to the steering valve, and in conjunction with the first pressure reducing valve, provides oil with constant pressure and constant flow to the pilot control valve and the pressure control valve through two separate paths.

[0013] This solution includes an emergency steering pump and its associated first priority valve, first pressure reducing valve, and second check valve. It can not only provide a high-pressure oil source to the steering valve, but also work with the first pressure reducing valve to provide a constant pressure and flow rate oil source to the pilot control valve and pressure control valve in two separate circuits. This provides multiple safety guarantees in the event of a main system failure and provides a stable and safe emergency pressure for the system. The second check valve effectively isolates the main oil circuit to prevent backflow of pressurized oil (backflow to the first pressure reducing valve should be avoided under normal operating conditions).

[0014] In a further embodiment, a third check valve is also included, the inlet of which is connected to the outlet of the first priority valve, and the outlet of which is connected to the inlet of the steering valve.

[0015] This solution incorporates a third check valve to isolate the main oil supply module and prevent oil backflow.

[0016] In a further embodiment, the main fuel supply module includes a steering pump and a fourth check valve. The inlet of the steering pump is connected to the fuel tank, and its outlet is connected to the inlet of the fourth check valve. The outlet of the fourth check valve is connected to the inlet of the steering valve.

[0017] This solution includes a fourth check valve to isolate the auxiliary steering module and prevent oil backflow.

[0018] In a further embodiment, the steering module further includes a steering cylinder, which is mechanically connected to the vehicle's bogie, and its inlet is connected to the outlet of the steering valve; the bogie is mechanically connected to the transmission mechanism.

[0019] In a further embodiment, a return oil filter connected to the oil tank is also included, the return oil filter being connected to the return port of the steering valve and the overflow valve.

[0020] This solution incorporates a return oil filter, which effectively removes wear particles and contaminants from the oil, controls oil cleanliness, reduces the risk of wear and failure of hydraulic components, and extends the service life of the hydraulic system.

[0021] This utility model also provides a wheeled engineering vehicle, including a servo feedback hydraulic steering system as described above. Attached Figure Description

[0022] Figure 1 This utility model provides a hydraulic circuit for a servo feedback hydraulic steering system. Figure 2 This is provided by the embodiment of the present utility model. Figure 1 Structural diagram of pilot control valve 2; Figure 3 This is provided by the embodiment of the present utility model. Figure 1Structural diagram of medium pressure control valve 3; Figure 4 This is provided by the embodiment of the present utility model. Figure 1 Enlarged view of the middle section of the hydraulic circuit; Figure 5 This is provided by the embodiment of the present utility model. Figure 1 Enlarged view of steering valve 1; Among them: Steering device A, transmission mechanism B, bogie C, oil tank D; Steering valve 1, pilot control valve 2, pressure control valve 3, left control valve 31, right control valve 32; auxiliary oil supply pump 4, flow priority valve 5, relief valve 6, first check valve 7; emergency steering pump 8, first priority valve 9, first pressure reducing valve 10, second check valve 11; third check valve 12, steering pump 13, fourth check valve 14, steering cylinder 15, return oil filter 16; Manually control valve stem a1, spring a2, four damping holes a3, valve body a4; Spring b1, spring b2. Detailed Implementation

[0023] The embodiments of this utility model are described in detail below with reference to the accompanying drawings. The embodiments are given for illustrative purposes only and should not be construed as limiting the utility model. The accompanying drawings are for reference and illustration only and do not constitute a limitation on the scope of patent protection of this utility model, because many changes can be made to this utility model without departing from the spirit and scope of this utility model.

[0024] Example 1 This utility model provides a servo feedback hydraulic steering system, such as Figures 1-5 As shown, in this embodiment, it includes a steering device A, a transmission mechanism B, a steering module, and an auxiliary steering module. The transmission mechanism B is mechanically connected to the steering device A and the steering module. The steering module includes a main fuel supply module, an auxiliary fuel supply module, a steering valve 1, and a pilot module; The oil outlet of the oil supply module is connected to the oil inlet of the steering valve 1, and the auxiliary oil supply module is connected to the oil inlet of the pilot module. The oil outlet of the auxiliary steering module is connected to the oil inlet of the pilot module and the steering valve 1; The transmission mechanism B is mechanically connected to the steering device A and the control terminal of the pilot module, and the oil outlet of the pilot module is connected to the control terminal of the steering valve 1. When the steering pressure changes during steering, the main oil supply module and the auxiliary oil supply module respectively supply oil to the steering valve 1 and the pilot module. Alternatively, the auxiliary steering module supplies oil to the pilot module and steering valve 1 in two separate paths to stably drive the steering valve 1 to change direction.

[0025] The steering device A includes a steering wheel.

[0026] In this embodiment, the pilot module includes a pilot control valve 2 and a pressure control valve 3; the oil inlet of the pilot control valve 2 is connected to the oil outlet of the auxiliary steering module and the oil outlet of the auxiliary oil supply module, the control end is mechanically connected to the transmission mechanism B, and the oil outlet is connected to the control end of the pressure control valve 3; the oil inlet of the pressure control valve 3 is connected to the oil outlet of the auxiliary steering module and the oil outlet of the auxiliary oil supply module, and the oil outlet is connected to the control end of the steering valve 1.

[0027] In this embodiment, the pressure control valve 3 includes a left control valve 31 and a right control valve 32; The oil inlet of the left control valve 31 is connected to the oil outlet of the auxiliary steering module and the oil outlet of the auxiliary oil supply module. The oil outlet is connected to the left control end of the steering valve 1, and the control end is connected to the oil outlet L of the pilot control valve 2. The oil inlet of the right control valve 32 is connected to the oil outlet of the auxiliary steering module and the oil outlet of the auxiliary oil supply module. The oil outlet is connected to the right control end of the steering valve 1, and the control end is connected to the oil outlet R of the pilot control valve 2.

[0028] in: (1) See Figure 2 The pilot control valve 2 is preferably a three-position six-way valve, which is equipped with an oil inlet P, an oil return port T, a left-turn pilot oil port L, a right-turn pilot oil port R, a manual control valve stem a1, a spring a2, four damping holes a3, and a valve body a4.

[0029] The output pressure of pilot control valve 2 is determined by the area gradient change of the four damping orifices a3. Specifically, the steering wheel controls the manual control valve stem a1, producing a certain stroke. This stroke causes an area change in the four damping orifices a3 within the valve body a4, achieving the required control pressure. Spring a2 serves to reset and center the valve stem.

[0030] The hydraulic half-bridge, composed of four damping holes a3, allows for manual control of the valve stem a1 at different positions, matching the corresponding pressure to precisely control the steering valve 1.

[0031] (2) See Figure 3 The pressure control valve 3 is preferably composed of two sets of two-position three-way valves.

[0032] The left control valve 31 is a two-position three-way valve with an oil inlet P, an oil return port T, a left-turn pilot port L1 / L2, and a spring b1; correspondingly, the right control valve 32 is with an oil inlet P, an oil return port T, a right-turn pilot port R1 / R2, and a spring b2.

[0033] The working principle is as follows: oil from port R (or port L) of pilot control valve 2 acts on end R1 (or end L1), causing the left control valve 31 (or right control valve 32) to switch internally. Oil from inlet P flows out through internal oil passage from R2 (or L2) to control port R (or L) of steering valve 1. The spring force f of springs b1 and b2 is adjustable according to design requirements. The output pressure of R2 is equal to R1-f, and the output pressure of L2 is equal to L1-f. Through pressure control valve 3, the steering pressure is adjustable and can be adjusted at any time according to steering requirements.

[0034] The independent oil circuit of pressure control valve 3 ensures sufficient pilot flow to control steering valve 1, avoiding steering delay. Meanwhile, the adjustable spring force f increases the system's pressure control range, improving its adaptability.

[0035] This embodiment uses a pilot control valve 2 and a pressure control valve 3 for pilot control. The pilot control valve 2 obtains the user's control force and converts it into corresponding pressure, which in turn controls the pressure control valve 3 to achieve adjustable steering pressure. The pressure can be adjusted at any time according to steering requirements to meet the steering experience of different users. By accurately matching the pilot pressure and flow, steering smoothness and high-speed driving stability are effectively improved. At the same time, the left control valve 31 and the right control valve 32 are set to perform dual-valve switching of the steering valve 1, which can achieve more precise pressure level adjustment and smooth switching. The dual valves work together, resulting in faster dynamic response and more precise and sensitive steering control.

[0036] In this embodiment, the auxiliary oil supply module includes an auxiliary oil supply pump 4, a flow priority valve 5, an overflow valve 6, and a first check valve 7; The inlet of the flow priority valve 5 is connected to the outlet of the auxiliary oil supply pump 4, and the outlet is connected to the overflow valve 6 to stabilize the pilot pressure; the outlet of the flow priority valve is also connected to the pilot control valve 2 and the pressure control valve 3 respectively through the first check valve 7. The auxiliary oil supply pump 4 provides oil to the flow priority valve 5. The flow priority valve 5, together with the overflow valve 6, provides two outputs, respectively providing oil with constant pressure and constant flow to the pilot control valve 2 and the pressure control valve 3.

[0037] The port T of the flow priority valve can also be connected to other systems or the return oil tank D as needed.

[0038] In this embodiment, a flow priority valve 5 is set in conjunction with a relief valve 6 to provide a constant pressure and flow rate of oil source, so as to ensure the priority supply and stable output of pilot flow and avoid the interference of pressure fluctuations on pilot pressure during steering; the first check valve 7 can effectively prevent backflow in the pilot oil circuit.

[0039] In this embodiment, the auxiliary steering module includes an emergency steering pump 8, a first priority valve 9, a first pressure reducing valve 10, and a second check valve 11. The oil inlet of the first priority valve 9 is connected to the oil outlet of the emergency steering pump 8, and the oil outlet is connected to the oil inlet of the first pressure reducing valve 10 and the oil inlet of the steering valve 1. The oil outlet of the first pressure reducing valve 10 is connected to the pilot control valve 2 and the pressure control valve 3 respectively through the second check valve 11. In an emergency working environment, the emergency steering pump 8 provides oil to the first priority valve 9, the first priority valve 9 provides high-pressure oil to the steering valve 1, and also works with the first pressure reducing valve 10 to provide a constant pressure and constant flow rate oil to the pilot control valve 2 and the pressure control valve 3 in two separate circuits.

[0040] This embodiment is equipped with an emergency steering pump 8 and its matching first priority valve 9, first pressure reducing valve 10 and second check valve 11. It can not only provide a high-pressure oil source to the steering valve 1, but also work with the first pressure reducing valve 10 to provide a constant pressure and constant flow oil source to the pilot control valve 2 and pressure control valve 3 in two separate circuits. It provides multiple safety guarantees in the event of failure of the main system and provides a stable and safe emergency pressure for the system. The second check valve 11 effectively isolates the main oil circuit and prevents backflow of pressurized oil (backflow to the first pressure reducing valve 10 should be avoided under normal working conditions).

[0041] In this embodiment, a third check valve 12 is also included. The oil inlet of the third check valve 12 is connected to the oil outlet of the first priority valve 9, and the oil outlet is connected to the oil inlet of the steering valve 1.

[0042] In this embodiment, a third check valve 12 is provided to isolate the main oil supply module and prevent oil backflow.

[0043] In this embodiment, the main oil supply module includes a steering pump 13 and a fourth check valve 14. The oil inlet of the steering pump 13 is connected to the oil tank D, and its oil outlet is connected to the oil inlet of the fourth check valve 14. The oil outlet of the fourth check valve 14 is connected to the oil inlet of the steering valve 1.

[0044] The steering pump 13 adopts a conventional design in the art, which will not be described in detail in this embodiment.

[0045] In this embodiment, a fourth one-way valve 14 is provided to isolate the auxiliary steering module and prevent oil backflow.

[0046] In this embodiment, the steering module further includes a steering cylinder 15, which is mechanically connected to the vehicle's bogie C, and its oil inlet is connected to the oil outlet of the steering valve 1; the bogie C is mechanically connected to the transmission mechanism B.

[0047] In this embodiment, a return oil filter 16 connected to the oil tank D is also included. The return oil filter 16 is connected to the return oil port of the steering valve 1 and the overflow valve 6.

[0048] In this embodiment, the return oil filter 16 can effectively filter out wear particles and contaminants generated in the oil, control the cleanliness of the oil, reduce the risk of wear failure of hydraulic components, and extend the service life of the hydraulic system.

[0049] Example 2 This utility model embodiment also provides an engineering machinery wheeled vehicle, including a servo feedback hydraulic steering system as described in Embodiment 1 above.

[0050] In this embodiment, the specific steering control principle is as follows: (1) Normal work The steering pump 13 provides a high-pressure oil source to the steering valve 1, which is ready at the valve oil port.

[0051] The auxiliary oil supply pump 4 provides oil to the flow priority valve 5. The flow priority valve 5, in conjunction with the relief valve 6, provides oil with a constant pressure and a constant flow rate to the pilot control valve 2 and the pressure control valve 3 in two separate paths, according to the set requirements.

[0052] When the steering wheel (steering device A) is turned, the pilot control valve 2 is pulled through the transmission mechanism B. At this time, the pilot pressure acts on the control end of the pressure control valve 3, pushing the pressure control valve 3 to switch internally. In this way, the pressure oil from the flow priority valve 5 enters the control end of the steering valve 1 through the internal passage of the pressure control valve 3, pushing the steering valve 1 to switch internally. The steering pump 13 provides a high-pressure oil source to drive the steering cylinder 15 to move through the internal passage of the steering valve 1, so as to realize the steering of the whole machine.

[0053] (2) Emergency assisted steering Emergency steering pump 8 provides oil to first priority valve 9. First priority valve 9 automatically switches to steering priority position. One oil output is connected to the main steering pipeline (i.e., output to the oil inlet of steering valve 1), and the other oil output is connected to first pressure reducing valve 10. First pressure reducing valve 10 provides appropriate pressure oil to merge with pilot oil circuit to ensure normal operation of pilot control valve 2 and pressure control valve 3.

[0054] This causes the pressure control valve 3 to switch internally, so that the pressure oil from the first pressure reducing valve 10 enters the control end of the steering valve 1 through the internal passage of the pressure control valve 3, pushing the steering valve 1 to switch internally. The emergency steering pump 8 provides a high-pressure oil source to drive the steering cylinder 15 through the first priority valve 9 and the internal passage of the steering valve 1, thereby realizing the steering of the whole machine.

[0055] This utility model embodiment is designed with a main oil supply module and an auxiliary oil supply module responsible for the steering valve 1 and the pilot module, respectively. One route provides high-pressure oil to the steering valve 1 through the main oil supply module, and the other route provides pilot oil to the pilot module through the auxiliary oil supply module. This independent oil supply ensures stable pilot pressure and sufficient pilot flow, thereby achieving stable control of the steering valve 1, improving steering smoothness, reducing steering delay, and combined with the control of the steering servo mechanism, resulting in shock-free steering, no noise from the full hydraulic steering gear, and improved driving comfort. At the same time, an auxiliary steering module is configured to provide emergency oil supply and assist steering function, enabling the vehicle to be stopped in a safe position in case of steering failure on the main road.

[0056] The above embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A servo feedback hydraulic steering system, characterized in that: It includes a steering device, a transmission mechanism, a steering module, and an auxiliary steering module, wherein the transmission mechanism is mechanically connected to the steering device and the steering module; The steering module includes a main fuel supply module, an auxiliary fuel supply module, a steering valve, and a pilot module; The oil outlet of the oil supply module is connected to the oil inlet of the steering valve, and the auxiliary oil supply module is connected to the oil inlet of the pilot module. The oil outlet of the auxiliary steering module is connected to the oil inlet of the pilot module and the steering valve. The transmission mechanism is mechanically connected to the steering device and the control terminal of the pilot module, and the oil outlet of the pilot module is connected to the control terminal of the steering valve. When the steering pressure changes during steering, the main oil supply module and the auxiliary oil supply module respectively supply oil to the steering valve and the pilot module. Alternatively, the auxiliary steering module supplies oil to the pilot module and the steering valve in two separate paths to stably drive the steering valve to change direction.

2. The servo feedback hydraulic steering system as described in claim 1, characterized in that: The pilot module includes a pilot control valve and a pressure control valve; the inlet of the pilot control valve is connected to the outlet of the auxiliary steering module and the outlet of the auxiliary oil supply module, and its control end is mechanically connected to the transmission mechanism, and its outlet is connected to the control end of the pressure control valve; the inlet of the pressure control valve is connected to the outlet of the auxiliary steering module and the outlet of the auxiliary oil supply module, and its outlet is connected to the control end of the steering valve.

3. The servo feedback hydraulic steering system as described in claim 2, characterized in that: The pressure control valve includes a left control valve and a right control valve; The oil inlet of the left control valve is connected to the oil outlet of the auxiliary steering module and the oil outlet of the auxiliary oil supply module. The oil outlet is connected to the left control end of the steering valve, and the control end is connected to the oil outlet L of the pilot control valve. The inlet of the right control valve is connected to the outlet of the auxiliary steering module and the outlet of the auxiliary oil supply module. The outlet is connected to the right control terminal of the steering valve, and the control terminal is connected to the outlet R of the pilot control valve.

4. The servo feedback hydraulic steering system as described in claim 2, characterized in that: The auxiliary oil supply module includes an auxiliary oil supply pump, a flow priority valve, an overflow valve, and a first check valve; The inlet of the flow priority valve is connected to the outlet of the auxiliary oil supply pump, and the outlet is connected to the relief valve to stabilize the pilot pressure; the outlet of the flow priority valve is also connected to the pilot control valve and the pressure control valve respectively through the first check valve. The auxiliary oil supply pump provides oil to the flow priority valve, and the flow priority valve cooperates with the overflow valve to provide two outputs, respectively providing oil with constant pressure and constant flow to the pilot control valve and the pressure control valve.

5. A servo feedback hydraulic steering system as described in claim 2, characterized in that: The auxiliary steering module includes an emergency steering pump, a first priority valve, a first pressure reducing valve, and a second check valve. The inlet of the first priority valve is connected to the outlet of the emergency steering pump, and the outlet is connected to the inlet of the first pressure reducing valve and the inlet of the steering valve. The outlet of the first pressure reducing valve is connected to the pilot control valve and the pressure control valve respectively through the second check valve. In an emergency working environment, the emergency steering pump provides oil to the first priority valve, the first priority valve provides high-pressure oil to the steering valve, and in conjunction with the first pressure reducing valve, provides oil with constant pressure and constant flow to the pilot control valve and the pressure control valve through two separate paths.

6. The servo feedback hydraulic steering system as described in claim 5, characterized in that: It also includes a third check valve, the inlet of which is connected to the outlet of the first priority valve, and the outlet of which is connected to the inlet of the steering valve.

7. The servo feedback hydraulic steering system as described in claim 1, characterized in that: The main fuel supply module includes a steering pump and a fourth check valve. The inlet of the steering pump is connected to the fuel tank, and its outlet is connected to the inlet of the fourth check valve. The outlet of the fourth check valve is connected to the inlet of the steering valve.

8. A servo feedback hydraulic steering system as described in claim 4, characterized in that: The steering module also includes a steering cylinder, which is mechanically connected to the vehicle's bogie, and its inlet is connected to the outlet of the steering valve; the bogie is mechanically connected to the transmission mechanism.

9. A servo feedback hydraulic steering system as described in claim 4, characterized in that: It also includes a return oil filter connected to the oil tank, the return oil filter being connected to the return oil port of the steering valve and the overflow valve.

10. A wheeled engineering vehicle, characterized in that: Includes a servo feedback hydraulic steering system as described in any one of claims 1 to 9.

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