Hydraulic power steering control unit, hydraulic power steering system, and vehicle

Abstract

The present application belongs to the technical field of vehicle engineering and provides a hydraulic power steering control unit, a hydraulic power steering system and a vehicle. The hydraulic power steering control unit comprises a power assist inlet oil path, a throttle oil path, a power assist working oil path and a constant difference pressure reduction oil path. The power assist working oil path is connected to the power assist inlet oil path. The throttle oil path comprises a throttle input section and a throttle output section connected in sequence. The throttle input section is connected to the power assist inlet oil path, and the throttle output section is connected to the power assist working oil path. One end of the constant difference pressure reduction oil path is connected to the power assist inlet oil path, and the other end is connected to a return oil path. A constant difference pressure reduction valve is arranged on the constant difference pressure reduction oil path. The constant difference pressure reduction valve is provided with a pressure reduction control valve port, and a pipeline connected to the throttle output section. By connecting the constant difference pressure reduction valve and the throttle structure in parallel to form a speed reduction valve, the hydraulic oil flow rate supplied from the power assist inlet oil path to the power assist working oil path can be stabilized. Meanwhile, the installation requirement of this stabilization method is low, and the assembly is convenient.

Description

Technical Field

[0001] This invention belongs to the field of vehicle engineering technology, specifically relating to a hydraulic power steering control unit, a hydraulic power steering system, and a vehicle. Background Technology

[0002] For multi-axle vehicles, the axial load on the axles is relatively large when the vehicle is turning, so a hydraulic power steering system is needed to provide steering assistance to the axle wheels when the steering wheel is turned.

[0003] A hydraulic power steering system mainly consists of a steering pump, a hydraulic power steering control unit, a power steering cylinder, and a steering gear. The hydraulic power steering control unit is mainly used to guide the hydraulic oil output from the steering pump to the steering gear, and the steering gear is used to control the flow direction of the hydraulic oil in the power steering cylinder. For a hydraulic power steering system, in order to ensure the safety and stability of power steering, it is necessary to ensure a stable flow rate into the steering gear. That is, the flow rate entering the steering gear should be such that when the engine speed changes, the flow rate is not affected by factors such as load or flow pulsation, and the output should be kept as stable as possible.

[0004] To ensure stable flow, existing hydraulic power steering systems typically include a flow control valve between the steering pump and the hydraulic power steering control unit. However, these valves are generally expensive, and their installation and maintenance require specialized technicians, making assembly and repair difficult. Summary of the Invention

[0005] To address the aforementioned deficiencies or shortcomings, this invention provides a hydraulic power steering control unit, a hydraulic power steering system, and a vehicle, aiming to solve the technical problems of high component prices, assembly difficulties, and maintenance challenges in existing hydraulic power steering systems that require stable flow.

[0006] To achieve the above objectives, the present invention provides a hydraulic power steering control unit, wherein the hydraulic power steering control unit includes a power steering inlet circuit, a throttling circuit, a power steering working circuit, and a differential pressure reducing circuit. One end of the power steering working circuit is connected to the power steering inlet circuit, and the other end is used to connect to the power steering actuator. The throttling circuit includes a throttling input section and a throttling output section connected in sequence. The inlet end of the throttling input section is connected to the power steering inlet circuit, and the outlet end of the throttling output section is connected to the power steering working circuit. One end of the differential pressure reducing circuit is connected to the power steering inlet circuit, and the other end is connected to the return circuit. A differential pressure reducing valve is provided on the differential pressure reducing circuit. The differential pressure reducing valve has a pressure reducing control valve port for adjusting the opening degree, and the pressure reducing control valve port pipeline is connected to the throttling output section.

[0007] In an embodiment of the present invention, a first check valve is provided between the throttling output section and the power assist working oil circuit.

[0008] In an embodiment of the present invention, the hydraulic power steering control unit further includes an accumulator, the accumulator pipeline being connected to the power steering oil circuit.

[0009] In an embodiment of the present invention, a second check valve is provided between the power-assisted working oil circuit and the power-assisted inlet oil circuit, and the throttling output section and the accumulator are respectively connected to the power-assisted working oil circuit.

[0010] In an embodiment of the present invention, the power steering inlet circuit includes a main inlet circuit and an emergency inlet circuit, and the hydraulic power steering control unit includes a power steering working circuit and an emergency switching valve. The emergency switching valve is provided with a first inlet port, a second inlet port and a power steering working port. The first inlet port and the second inlet port are respectively used to connect the main inlet circuit and the emergency inlet circuit. The power steering working port is connected to the power steering working circuit. The emergency switching valve is provided with a first valve position and a second valve position. The first valve position is configured to open the first inlet port and the power steering working port, and the second valve position is configured to open the second inlet port and the power steering working port.

[0011] In an embodiment of the present invention, the two opposite ends of the emergency switching valve are a first pilot control end and a second pilot control end, respectively. The first pilot control end is used to control the emergency switching valve to remain in the first valve position under high pressure, and the second pilot control end is used to control the emergency switching valve to remain in the second valve position under high pressure. The first pilot control end is hydraulically connected to the throttling input section or the main oil inlet circuit, and the second pilot control end is hydraulically connected to the throttling output section.

[0012] In an embodiment of the present invention, the emergency switching valve is further provided with an indicator light control port, and the hydraulic power steering control unit further includes a light switch control element, which is a hydraulic control element and connected to the indicator light control port; wherein, the first valve position is configured to open the first oil inlet and the power steering working oil inlet, and open the second oil inlet and the indicator light control port, and the second valve position is configured to open the second oil inlet and the power steering working oil inlet, and close the first oil inlet and the indicator light control port respectively.

[0013] In an embodiment of the present invention, the lamp switch control element is a hydraulic directional valve. The hydraulic directional valve is provided with a directional control end and a spring reset end. The directional control end is connected to the indicator light control oil port and is also connected to the circuit switch of the emergency assist indicator light.

[0014] To achieve the above objectives, the present invention also provides a hydraulic power steering system, wherein the hydraulic power steering system includes a hydraulic power steering control unit, a power steering pump assembly, and a power steering execution unit as described above, the power steering pump assembly being connected to the power steering inlet circuit in the hydraulic power steering control unit, and the power steering execution unit being connected to the power steering inlet circuit via a power steering working circuit.

[0015] In an embodiment of the present invention, the power steering oil inlet circuit includes a main oil inlet circuit and an emergency oil inlet circuit, and the power steering pump assembly includes a main steering pump and an emergency steering pump, with the main steering pump and the emergency steering pump respectively connected to the main oil inlet circuit and the emergency oil inlet circuit.

[0016] To achieve the above objectives, the present invention also provides a vehicle, wherein the vehicle includes the hydraulic power steering system according to the above description.

[0017] Through the above technical solution, the hydraulic power steering control unit provided in the embodiments of the present invention has the following beneficial effects:

[0018] When the flow rate in the power steering inlet circuit exceeds the required flow rate in the power steering working circuit, the excess flow increases the pressure in the throttling output section, thereby increasing the opening of the differential pressure reducing valve and increasing the flow rate in the differential pressure reducing circuit. This achieves the goal of maintaining flow balance between the power steering inlet and power steering working circuits. When the flow rate in the power steering inlet circuit is less than the required flow rate in the power steering working circuit, the power steering working circuit actively draws in oil from the throttling output section, reducing the pressure in the throttling output section and decreasing the opening of the differential pressure reducing valve. By reducing the flow rate in the differential pressure reducing circuit and through auxiliary oil replenishment in the throttling circuit, the goal of maintaining flow balance between the power steering inlet and power steering working circuits is achieved. In summary, the hydraulic power steering control unit of this invention forms a deceleration valve by connecting the differential pressure reducing valve and the throttling structure in parallel. This allows for the stabilization of the hydraulic oil flow from the power steering inlet circuit to the power steering working circuit. Furthermore, the throttling structure and the differential pressure reducing valve are relatively common, resulting in low procurement costs and minimal installation requirements, facilitating assembly.

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

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

[0021] In the picture:

[0022] Figure 1 This is a schematic diagram of the hydraulic power steering control unit according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the hydraulic power steering system according to an embodiment of the present invention.

[0024] Explanation of reference numerals in the accompanying drawings of the embodiments of the present invention

[0025] 1. Power steering inlet circuit; 11. Main inlet circuit; 12. Emergency inlet circuit; 2. Throttling circuit; 21. Throttling input section; 22. Throttling output section; 3. Differential pressure reducing circuit; 31. Differential pressure reducing valve; 31a. Pressure reducing control valve port; 41. Power steering working circuit; 42. Emergency switching valve; P1. First inlet; P2. Second inlet; a. Power steering working port; b. Indicator light control port; 43. Light switch control element; 44. Circuit switch; 51. First check valve; 52. Second check valve; 6. Accumulator; 71. Main steering pump; 72. Emergency steering pump; T. Return circuit. Detailed Implementation

[0026] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0027] The hydraulic power steering control unit of the present invention is described below with reference to the accompanying drawings.

[0028] like Figure 1 and Figure 2 As shown, the hydraulic power steering control unit provided by the present invention includes a power steering inlet circuit 1, a throttling circuit 2, a power steering working circuit 41, and a differential pressure reducing circuit 3.

[0029] The power steering inlet circuit 1 is mainly used to supply the hydraulic oil output by the power steering pump to the power steering working circuit 41.

[0030] One end of the power steering oil circuit 41 is connected to the power steering oil inlet circuit 1, and the other end is used to connect to the power steering actuator.

[0031] The throttling oil circuit 2 includes a throttling input section 21 and a throttling output section 22 connected in sequence. A throttling structure, such as a throttling orifice or a throttling valve, is provided between the throttling input section 21 and the throttling output section 22. The end of the throttling input section 21 away from the throttling output section 22 (the inlet end) is connected to the power assist oil inlet circuit 1 through a pipeline, and the outlet end of the throttling output section 22 away from the throttling input section 21 is connected to the power assist working oil circuit 41.

[0032] One end of the differential pressure reducing oil circuit 3 is connected to the power assist oil inlet circuit 1, and the other end is connected to the return oil circuit T. The differential pressure reducing oil circuit 3 is equipped with a differential pressure reducing valve 31. The differential pressure reducing valve 31 is equipped with a pressure reducing control valve port 31a for adjusting the opening. The pressure reducing control valve port 31a is connected to the throttling output section 22.

[0033] The hydraulic oil in the power-assisted inlet circuit 1 can enter the throttling input section 21 and, after passing through the throttling structure, enter the throttling output section 22. When the flow rates between the power-assisted inlet circuit 1 and the power-assisted working circuit 41 are balanced, the oil pressure in the power-assisted inlet circuit 1 will be equal to the oil pressure in the power-assisted working circuit 41. At this time, because the hydraulic oil in the throttling output section 22 is throttled by the throttling structure, the oil pressure in the throttling output section 22 will not enter the power-assisted working circuit 41. The pressure in the throttling output section 22 remains stable at a certain value, and the opening of the differential pressure reducing valve 31 also remains fixed.

[0034] When the flow rate of the power assist inlet circuit 1 is greater than the required flow rate of the power assist working circuit 41, the excess flow rate will increase the pressure of the throttling output section 22, thereby increasing the opening of the differential pressure reducing valve 31 and increasing the flow rate of the differential pressure reducing circuit 3, thus achieving the purpose of maintaining the flow balance between the power assist inlet circuit 1 and the power assist working circuit 41.

[0035] When the flow rate of the power assist inlet oil circuit 1 is less than the required flow rate of the power assist working oil circuit 41, the power assist working oil circuit 41 will actively draw in oil from the throttling output section 22. The pressure of the throttling output section 22 will decrease, and the opening of the constant differential pressure reducing valve 31 will decrease. By reducing the flow rate of the constant differential pressure reducing oil circuit 3 and by supplementing oil through the throttling oil circuit 2, the flow balance between the power assist inlet oil circuit 1 and the power assist working oil circuit 41 can be maintained.

[0036] In summary, the hydraulic power steering control unit of this invention forms a deceleration valve by connecting the differential pressure reducing valve 31 in parallel with the throttling structure, which can stabilize the flow of hydraulic oil supplied from the power steering inlet circuit to the power steering working circuit. At the same time, the throttling structure and the differential pressure reducing valve 31 are relatively common, with low procurement costs and low installation requirements, making them easy to assemble.

[0037] In an embodiment of the present invention, the differential pressure relief oil circuit 3 can be integrated inside the hydraulic power steering control unit.

[0038] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, a first check valve 51 is provided between the throttling output section 22 and the power-assisted working oil circuit 41. By providing the first check valve 51, the hydraulic oil in the power-assisted working oil circuit 41 can be prevented from affecting the throttling output section 22.

[0039] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the hydraulic power steering control unit further includes an accumulator 6, which is connected to the power steering oil circuit 41. By setting the accumulator 6, two-stage pressure stabilization is achieved. At the same time, when the power steering oil circuit 41 is in emergency oil inlet mode, the accumulator 6 can perform flow and pressure compensation.

[0040] In an embodiment of the present invention, an on / off control element, such as a shut-off valve or a directional valve for controlling on / off, may be provided between the accumulator 6 and the power assist oil circuit 41.

[0041] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, a second check valve 52 is provided between the power-assisted working oil circuit 41 and the power-assisted inlet oil circuit 1, and the throttling output section 22 and the accumulator 6 are respectively connected to the power-assisted working oil circuit 41. By providing the second check valve 52, backflow of hydraulic oil in the power-assisted working oil circuit 41 can be prevented when the flow rate of the power-assisted inlet oil circuit 1 is less than the required flow rate of the power-assisted working oil circuit 41.

[0042] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the power steering inlet circuit 1 includes a main inlet circuit 11 and an emergency inlet circuit 12. The hydraulic power steering control unit includes a power steering working circuit 41 and an emergency switching valve 42. The emergency switching valve 42 is provided with a first inlet port P1, a second inlet port P2 and a power steering working port a. The first inlet port P1 and the second inlet port P2 are respectively used to connect the main inlet circuit 11 and the emergency inlet circuit 12. The power steering working port a is connected to the power steering working circuit 41. The emergency switching valve 42 is provided with a first valve position and a second valve position. The first valve position is configured to connect the first inlet port P1 and the power steering working port a, and the second valve position is configured to connect the second inlet port P2 and the power steering working port a.

[0043] The main oil inlet circuit 11 is used to connect to the main steering pump 71, and the emergency oil inlet circuit 12 is used to connect to the emergency steering pump 72. During normal operation, the emergency switching valve 42 is in the first position, at which time the first oil inlet P1 and the power steering working oil port a are connected, and the hydraulic oil from the main steering pump 71 flows to the power steering actuator through the power steering working oil circuit 41. When the main steering pump 71 fails, the emergency switching valve 42 switches to the second position, at which time the emergency steering pump 72 supplies oil to the power steering working oil circuit 41. Since the existing emergency steering pump 72 cannot output large displacement for extended periods, an accumulator 6 is installed to compensate for the flow and pressure of the power steering working oil circuit 41 during emergency power steering.

[0044] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the two opposite ends of the emergency switching valve 42 are a first pilot control end and a second pilot control end, respectively. The first pilot control end is used to control the emergency switching valve 42 to remain in a first valve position under high pressure, and the second pilot control end is used to control the emergency switching valve 42 to remain in a second valve position under high pressure. The first pilot control end is hydraulically connected to the throttling input section 21 or the main oil inlet circuit 11, and the second pilot control end is hydraulically connected to the throttling output section 22. A reset spring is disposed at the second pilot control end.

[0045] When the main inlet oil circuit 11 or the throttle input section 21 is under high pressure, it indicates that the main steering pump 71 is in operation. Due to the throttle structure, the pressure in the throttle input section 21 is greater than the pressure in the throttle output section 22. At this time, the emergency switching valve 42 will automatically remain in the first valve position. When the main inlet oil circuit 11 or the throttle input section 21 is under low pressure, it indicates that the main steering pump 71 is malfunctioning. At this time, the emergency switching valve 42 will automatically reset to the second valve position under the action of the return spring, so that the emergency steering pump 72 can supply oil to the power steering working oil circuit 41. By hydraulically connecting the first pilot control end to the throttle input section 21 or the main inlet oil circuit 11, hydraulically connecting the second pilot control end to the throttle output section 22, and optimizing the position of the return spring, the valve position of the emergency switching valve 42 can correspond to the working state of the two pumps.

[0046] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the emergency switching valve 42 is further provided with an indicator light control port b, and the hydraulic power steering control unit further includes a light switch control element 43, which is a hydraulic control element and is connected to the indicator light control port b; wherein, the first valve position is configured to open the first oil inlet P1 and the power steering working oil inlet a, and open the second oil inlet P2 and the indicator light control port b, and the second valve position is configured to open the second oil inlet P2 and the power steering working oil inlet a, and close the first oil inlet P1 and the indicator light control port b respectively.

[0047] In an embodiment of the present invention, the lamp switch control element 43 can be a hydraulic directional valve. The hydraulic directional valve has a directional control end and a spring reset end. The directional control end is connected to the indicator light control port b and is also connected to the circuit switch 44 of the emergency assist indicator light. When the emergency switching valve 42 is in the first valve position, the emergency steering pump 72 supplies oil to the indicator light control port b to drive the valve core of the hydraulic directional valve to move, thereby pushing the circuit switch 44 of the indicator light to open. When the emergency switching valve 42 is in the second valve position, the directional control end is under low pressure, the hydraulic directional valve resets, and the circuit switch 44 of the indicator light closes.

[0048] To achieve the above objectives, the present invention also provides a hydraulic power steering system, wherein the hydraulic power steering system includes a hydraulic power steering control unit, a power steering pump assembly, and a power steering actuator as described above. The power steering pump assembly is connected to the power steering inlet circuit 1 in the hydraulic power steering control unit, and the power steering actuator is connected to the power steering inlet circuit 1 via a power steering working circuit 41. The power steering actuator generally includes a steering gear and a steering cylinder.

[0049] When the power steering pump unit is working, hydraulic oil flows sequentially through the power steering inlet circuit 1 and the power steering working circuit 41 to the steering gear. If the vehicle needs to turn, the steering gear will control the flow of hydraulic oil to the steering cylinder. Due to the influence of the steering resistance of the axle, the load on the steering cylinder will change, causing a mismatch between the required flow rate of the power steering working circuit 41 and the flow rate of the power steering inlet circuit 1.

[0050] When the flow rate of the power assist inlet circuit 1 is greater than the required flow rate of the power assist working circuit 41, the excess flow rate will increase the pressure of the throttling output section 22, thereby increasing the opening of the differential pressure reducing valve 31 and increasing the flow rate of the differential pressure reducing circuit 3, thus achieving the purpose of maintaining the flow balance between the power assist inlet circuit 1 and the power assist working circuit 41.

[0051] When the flow rate of the power assist inlet oil circuit 1 is less than the required flow rate of the power assist working oil circuit 41, the power assist working oil circuit 41 will actively draw in oil from the throttling output section 22. The pressure of the throttling output section 22 will decrease, and the opening of the constant differential pressure reducing valve 31 will decrease. By reducing the flow rate of the constant differential pressure reducing oil circuit 3 and by supplementing oil through the throttling oil circuit 2, the flow balance between the power assist inlet oil circuit 1 and the power assist working oil circuit 41 can be maintained.

[0052] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the power steering inlet circuit 1 includes a main inlet circuit 11 and an emergency inlet circuit 12, and the power steering pump assembly includes a main steering pump 71 and an emergency steering pump 72, which are respectively connected to the main inlet circuit 11 and the emergency inlet circuit 12. By setting the emergency inlet circuit 12 and the emergency steering pump 72, an emergency steering assist function can be realized when the main steering pump 71 fails. Through the accumulator 6, the flow and pressure of the power steering working circuit 41 can be compensated during emergency steering assist, and the flow of the power steering working circuit 41 can be stabilized in two stages when the main steering pump 71 is working.

[0053] To achieve the above objectives, the present invention also provides a vehicle comprising the hydraulic power steering system described above. Since the vehicle employs all the technical solutions described in the above embodiments, it possesses at least the beneficial effects brought about by the above embodiments, which will not be repeated here.

[0054] In the description of this invention, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0055] In this invention, unless otherwise explicitly 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 them; 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 explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. 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.

[0057] Although embodiments of the present invention have been described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A hydraulic power steering control unit, characterized in that, The hydraulic power steering control unit includes: Assisted oil inlet circuit (1); The power steering oil circuit (41) is connected at one end to the power steering oil inlet circuit (1) and at the other end to the power steering actuator. The throttling oil circuit (2) includes a throttling input section (21) and a throttling output section (22) connected in sequence. The inlet end of the throttling input section (21) is connected to the power-assisted oil inlet circuit (1), and the outlet end of the throttling output section (22) is connected to the power-assisted working oil circuit (41). A first check valve (51) is provided between the throttling output section (22) and the power-assisted working oil circuit (41). The differential pressure reducing oil circuit (3) is connected at one end to the power assist oil inlet circuit (1) and at the other end to the return oil circuit (T). The differential pressure reducing oil circuit (3) is equipped with a differential pressure reducing valve (31). The differential pressure reducing valve (31) is equipped with a pressure reducing control valve port (31a) for adjusting the opening degree. The pressure reducing control valve port (31a) is connected to the throttling output section (22). The differential pressure reducing valve (31) is configured such that the greater the pressure at the pressure reducing control valve port (31a), the greater the opening degree of the differential pressure reducing valve (31).

2. The hydraulic power steering control unit according to claim 1, characterized in that, The hydraulic power steering control unit also includes an accumulator (6), the accumulator (6) being connected to the power steering oil circuit (41).

3. The hydraulic power steering control unit according to claim 2, characterized in that, A second check valve (52) is provided between the power-assisted working oil circuit (41) and the power-assisted inlet oil circuit (1), and the throttling output section (22) and the accumulator (6) are respectively connected to the power-assisted working oil circuit (41).

4. The hydraulic power steering control unit according to any one of claims 1 to 3, characterized in that, The power steering inlet circuit (1) includes a main inlet circuit (11) and an emergency inlet circuit (12). The hydraulic power steering control unit includes a power steering working circuit (41) and an emergency switching valve (42). The emergency switching valve (42) is provided with a first inlet (P1), a second inlet (P2) and a power steering working port (a). The first inlet (P1) and the second inlet (P2) are respectively used to connect the main inlet circuit (11) and the emergency inlet circuit (12). The power steering working port (a) is connected to the power steering working circuit (41). The emergency switching valve (42) is provided with a first valve position and a second valve position. The first valve position is configured to connect the first inlet (P1) and the power steering working port (a). The second valve position is configured to connect the second inlet (P2) and the power steering working port (a).

5. The hydraulic power steering control unit according to claim 4, characterized in that, The emergency switching valve (42) has a first pilot control terminal and a second pilot control terminal at opposite ends. The first pilot control terminal is used to control the emergency switching valve (42) to remain in the first valve position when under high pressure. The second pilot control terminal is used to control the emergency switching valve (42) to remain in the second valve position when under high pressure. The first pilot control terminal is hydraulically connected to the throttling input section (21) or the main oil inlet circuit (11). The second pilot control terminal is hydraulically connected to the throttling output section (22). The second pilot control terminal is provided with a reset spring.

6. The hydraulic power steering control unit according to claim 5, characterized in that, The emergency switching valve (42) is also provided with an indicator light control port (b), and the hydraulic power steering control unit also includes a light switch control element (43), which is a hydraulic control element and is connected to the indicator light control port (b). The first valve position is configured to open the first oil inlet (P1) and the power assist working oil port (a), and to open the second oil inlet (P2) and the indicator light control oil port (b). The second valve position is configured to open the second oil inlet (P2) and the power assist working oil port (a), and to close the first oil inlet (P1) and the indicator light control oil port (b) respectively.

7. The hydraulic power steering control unit according to claim 6, characterized in that, The lamp switch control element (43) is a hydraulic directional valve. The hydraulic directional valve is provided with a directional control end and a spring reset end. The directional control end is connected to the indicator light control port (b) and is also connected to the circuit switch (44) of the emergency assist indicator light.

8. A hydraulic power steering system, characterized in that, The hydraulic power steering system includes: The hydraulic power steering control unit according to any one of claims 1 to 7; The power steering pump assembly is connected to the power steering inlet circuit (1) in the hydraulic power steering control unit; The power steering actuator is connected to the power steering inlet circuit (1) via the power steering working oil circuit (41).

9. The hydraulic power steering system according to claim 8, characterized in that, The power steering inlet circuit (1) includes a main inlet circuit (11) and an emergency inlet circuit (12). The power steering pump assembly includes a main steering pump (71) and an emergency steering pump (72). The main steering pump (71) and the emergency steering pump (72) are respectively connected to the main inlet circuit (11) and the emergency inlet circuit (12).

10. A vehicle, characterized in that, Includes the hydraulic power steering system according to claim 8 or 9.

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