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

Abstract

The invention belongs to the technical field of vehicle engineering and provides a hydraulic power-assisted steering control unit, a hydraulic power-assisted steering system and a vehicle. The hydraulic power-assisted steering control unit comprises a power-assisted oil inlet path, a throttling oil path, a power-assisted working oil path and a fixed-difference pressure-reducing oil path, the power-assisted working oil path is connected with the power-assisted oil inlet path, the throttling oil path comprises a throttling input section and a throttling output section which are sequentially connected, the throttling input section is connected to the power-assisted oil inlet path, the throttling output section is connected to the power-assisted working oil path, and the fixed-difference pressure-reducing oil path is connected to the power-assisted working oil path. One end of the fixed-difference pressure reducing oil way is connected with the boosting oil inlet way, the other end of the fixed-difference pressure reducing oil way is connected with the oil return way, a fixed-difference pressure reducing valve is arranged on the fixed-difference pressure reducing oil way and provided with a pressure reducing control valve port, and the pressure reducing control valve port is connected to the throttling output section through a pipeline. The fixed differential pressure reducing valve and the throttling structure are connected in parallel to form the speed reducing valve, the flow of hydraulic oil supplied to the power-assisted working oil way from the power-assisted oil inlet way can be stabilized, and meanwhile the flow stabilizing mode is low in installation requirement and convenient to assemble.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle engineering, and in particular relates to a hydraulic power steering control unit, a hydraulic power steering system and a vehicle. Background Art

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

[0003] The hydraulic power steering system is mainly composed of a steering pump, a hydraulic power steering control unit, a power cylinder, a steering gear, etc. 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 cylinder. For the hydraulic power steering system, in order to ensure the safety and stability of the power steering, it is necessary to ensure that the flow entering the steering gear is stable, that is, the flow entering the steering gear is required to be: when the engine speed changes, the flow is not affected by factors such as load and flow pulsation, and try to maintain a stable output.

[0004] In order to ensure the flow stability, the existing hydraulic power steering system generally installs a flow stabilizing valve between the steering pump and the hydraulic power steering control unit. However, the existing flow stabilizing valve is generally expensive, and the installation and maintenance require specialized technicians, and the assembly and maintenance are difficult. Summary of the invention

[0005] In view of the above-mentioned defects or shortcomings, the present invention provides a hydraulic power steering control unit, a hydraulic power steering system and a vehicle, aiming to solve the technical problems that the components used in the existing hydraulic power steering system to achieve the flow stabilization function are high in price and difficult to assemble and maintain.

[0006] To achieve the above-mentioned purpose, the present invention provides a hydraulic power steering control unit, wherein the hydraulic power steering control unit includes a power-assisted oil inlet circuit, a throttling oil circuit, a power-assisted working oil circuit and a differential pressure-reducing oil circuit, one end of the power-assisted working oil circuit is connected to the power-assisted oil inlet circuit, and the other end is used to connect to the steering power-assisted execution unit, the throttling oil 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-assisted oil inlet circuit, and the outlet end of the throttling output section is connected to the power-assisted working oil circuit, one end of the differential pressure-reducing oil circuit is connected to the power-assisted oil inlet circuit, and the other end is connected to the return oil circuit, a differential pressure-reducing valve is provided on the differential pressure-reducing oil circuit, the differential pressure-reducing valve is provided with a pressure-reducing control valve port for adjusting the opening, 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 one-way valve is provided between the throttling output section and the power-assisting working oil circuit.

[0008] In an embodiment of the present invention, the hydraulic power steering control unit further comprises an accumulator, and a pipeline of the accumulator is connected to the power-assisted working oil circuit.

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

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

[0011] In an embodiment of the present invention, the opposite ends of the emergency switching valve are respectively a first pilot control end and a second pilot control end, 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 also provided with an indicator light control oil port, and the hydraulic power steering control unit also includes a light switch control element, which is a hydraulic control element and is connected to the indicator light control oil port; wherein, the first valve position is configured to connect the first oil inlet and the power-assisted working oil port, and to connect the second oil inlet and the indicator light control oil port, and the second valve position is configured to connect the second oil inlet and the power-assisted working oil port, and to cut off the first oil inlet and the indicator light control oil port respectively.

[0013] In an embodiment of the present invention, the light switch control element is a hydraulically controlled reversing valve, which is provided with a reversing control end and a spring return end. The reversing control end is connected to the indicator light control oil port, and the reversing control end is transmission-connected to the circuit switch of the emergency power-assisting indicator light.

[0014] To achieve the above-mentioned purpose, 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 group and a steering power execution unit as described above, the power steering pump group is connected to the power-assist oil inlet circuit in the hydraulic power steering control unit, and the steering power execution unit is connected to the power-assist oil inlet circuit through a power-assist working oil circuit.

[0015] In an embodiment of the present invention, the power-assisted oil inlet circuit includes a main oil inlet circuit and an emergency oil inlet circuit, and the power-assisted steering pump group includes a main steering pump and an emergency steering pump, which are respectively connected to the main oil inlet circuit and the emergency oil inlet circuit.

[0016] To achieve the above object, the present invention also provides a vehicle, wherein the vehicle comprises the hydraulic power steering system described above.

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

[0018] When the flow rate of the power-assisting oil inlet circuit is greater than the required flow rate of the power-assisting working oil circuit, the excess flow rate will increase the pressure of the throttling output section, thereby increasing the opening of the differential pressure-reducing valve and increasing the diversion flow of the differential pressure-reducing oil circuit, thereby achieving the purpose of maintaining the flow balance between the power-assisting oil inlet circuit and the power-assisting working oil circuit. When the flow rate of the power-assisting oil inlet circuit is less than the required flow rate of the power-assisting working oil circuit, the power-assisting working oil circuit will actively inhale the oil of the throttling output section, the pressure of the throttling output section will decrease, the opening of the differential pressure-reducing valve will decrease, and the diversion flow of the differential pressure-reducing oil circuit will be reduced, and the purpose of maintaining the flow balance between the power-assisting oil inlet circuit and the power-assisting working oil circuit will be achieved by reducing the diversion flow of the differential pressure-reducing oil circuit and supplementing the oil through the auxiliary throttling oil circuit. In summary, the hydraulic power steering control unit in the present invention can stabilize the flow of hydraulic oil supplied from the power-assisting oil inlet circuit to the power-assisting working oil circuit by connecting the differential pressure-reducing valve in parallel with the throttling structure. At the same time, the throttling structure and the differential pressure-reducing valve are relatively common, with low procurement costs, and low installation requirements, which are convenient for assembly.

[0019] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide an understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention.

[0021] In the figure:

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

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

[0024] DESCRIPTION OF NUMBERS FOR THE EMBODIMENTS OF THE PRESENT INVENTION

[0025] 1. Power-assisted oil inlet; 11. Main oil inlet; 12. Emergency oil inlet; 2. Throttle oil circuit; 21. Throttle input section; 22. Throttle output section; 3. Differential pressure-reducing oil circuit; 31. Differential pressure-reducing valve; 31a. Pressure-reducing control valve port; 41. Power-assisted working oil circuit; 42. Emergency switching valve; P1. First oil inlet; P2. Second oil inlet; a. Power-assisted working oil port; b. Indicator light control oil port; 43. Light switch control element; 44. Circuit switch; 51. First non-return valve; 52. Second non-return valve; 6. Accumulator; 71. Main steering pump; 72. Emergency steering pump; T. Oil return circuit. DETAILED DESCRIPTION

[0026] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0027] The hydraulic power steering control unit of the present invention will be 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-assisted oil inlet circuit 1, a throttling oil circuit 2, a power-assisted working oil circuit 41 and a differential pressure-reducing oil circuit 3.

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

[0030] One end of the power-assisting working oil circuit 41 is connected to the power-assisting oil inlet circuit 1 , and the other end is used to be connected to the power-assisting steering execution unit.

[0031] The throttling oil circuit 2 includes a throttling input section 21 and a throttling output section 22 connected in sequence, and a throttling structure such as a throttling hole, a throttling valve, etc. is provided between the throttling input section 21 and the throttling output section 22. One end (inlet end) of the throttling input section 21 away from the throttling output section 22 is connected to the booster 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 booster 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. A differential pressure reducing valve 31 is provided on the differential pressure reducing oil circuit 3. The differential pressure reducing valve 31 is provided with a pressure reducing control valve port 31a for adjusting the opening, and the pressure reducing control valve port 31a pipeline is connected to the throttling output section 22.

[0033] The hydraulic oil in the booster oil inlet circuit 1 can enter the throttling input section 21, and enter the throttling output section 22 after passing through the throttling structure. When the flow between the booster oil inlet circuit 1 and the booster working oil circuit 41 is balanced, the oil pressure in the booster oil inlet circuit 1 will be equal to the oil pressure in the booster working oil circuit 41. At this time, since 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 booster working oil circuit 41. The pressure in the throttling output section 22 is stabilized at a certain value, and the opening of the differential pressure reducing valve 31 is also kept fixed.

[0034] When the flow rate of the power-assisted oil inlet circuit 1 is greater than the required flow rate of the power-assisted working oil 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 diversion flow of the differential pressure-reducing oil circuit 3, thereby achieving the purpose of maintaining the flow balance between the power-assisted oil inlet circuit 1 and the power-assisted working oil circuit 41.

[0035] When the flow rate of the power-assisted oil inlet circuit 1 is less than the required flow rate of the power-assisted working oil circuit 41, the power-assisted working oil circuit 41 will actively inhale the oil of the throttling output section 22, the pressure of the throttling output section 22 will decrease, and the opening of the differential pressure-reducing valve 31 will decrease. By reducing the diversion flow of the differential pressure-reducing oil circuit 3 and supplementing the oil through the throttling oil circuit 2, the purpose of maintaining the flow balance between the power-assisted oil inlet circuit 1 and the power-assisted working oil circuit 41 will be achieved.

[0036] In summary, the hydraulic power steering control unit in the present 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-assisted oil inlet circuit to the power-assisted working oil 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 the embodiment of the present invention, the differential pressure reducing oil circuit 3 may be integrated inside the hydraulic power steering control unit.

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

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

[0040] In the embodiment of the present invention, an on-off control element, such as a stop valve, a reversing valve for controlling on-off, etc., may be provided between the accumulator 6 and the power-assisting working oil circuit 41 .

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

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

[0043] The main oil inlet 11 is used to connect to the main steering pump 71, and the emergency oil inlet 12 is used to connect to the emergency steering pump 72. During normal operation, the emergency switching valve 42 is in the first valve position, at which time the first oil inlet P1 is connected to the power-assisting working oil port a, and the hydraulic oil of the main steering pump 71 will flow to the steering assist actuator through the power-assisting working oil circuit 41. When the main steering pump 71 is damaged, the emergency switching valve 42 will switch to the second valve position, at which time the emergency steering pump 72 supplies oil to the power-assisting working oil circuit 41. Since the existing emergency steering pump 72 cannot output a large displacement for a long time, by setting an accumulator 6, the flow and pressure of the power-assisting working oil circuit 41 can be compensated during emergency steering assistance.

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

[0045] When the main oil inlet 11 or the throttle input section 21 is at high pressure, it means that the main steering pump 71 is in working condition. Due to the existence of the throttling structure, the pressure of the throttle input section 21 is greater than the pressure of the throttle output section 22. At this time, the emergency switching valve 42 will automatically maintain the first valve position. When the main oil inlet 11 or the throttle input section 21 is at low pressure, it means that the main steering pump 71 is faulty. At this time, the emergency switching valve 42 will automatically reset to the second valve position under the action of the reset spring, so that the emergency steering pump 72 supplies oil to the power-assisted working oil circuit 41. By hydraulically connecting the first pilot control end to the throttle input section 21 or the main oil inlet 11, hydraulically connecting the second pilot control end to the throttle output section 22, and optimizing the position of the reset 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 also provided with an indicator light control oil 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 oil port b; wherein, the first valve position is configured to connect the first oil inlet P1 and the power-assisted working oil port a, and connect the second oil inlet P2 and the indicator light control oil port b, and the second valve position is configured to connect the second oil inlet P2 and the power-assisted working oil port a, and respectively cut off the first oil inlet P1 and the indicator light control oil port b.

[0047] In the embodiment of the present invention, the light switch control element 43 can be a hydraulically controlled reversing valve, which is provided with a reversing control end and a spring reset end, the reversing control end is connected to the indicator light control oil port b, and the reversing control end is in transmission connection with the circuit switch 44 of the emergency power-assisted indicator light. When the emergency switching valve 42 is in the first valve position, the emergency steering pump 72 will supply oil to the indicator light control oil port b to drive the valve core of the hydraulically controlled reversing valve to move, thereby pushing the circuit switch 44 of the indicator light to disconnect. When the emergency switching valve 42 is in the second valve position, the reversing control end is low pressure, the hydraulically controlled reversing valve is reset, and the circuit switch 44 of the indicator light is closed.

[0048] To achieve the above object, the present invention further provides a hydraulic power steering system, wherein the hydraulic power steering system comprises the hydraulic power steering control unit, the power steering pump group and the steering power actuator unit according to the above, the power steering pump group is connected to the power oil inlet 1 in the hydraulic power steering control unit, and the steering power actuator unit is connected to the power oil inlet 1 through the power working oil circuit 41. The steering power actuator unit generally includes a steering gear and a steering cylinder.

[0049] When the power steering pump group is working, the hydraulic oil will flow to the steering gear through the power-assisted oil inlet circuit 1 and the power-assisted working oil circuit 41 in sequence. At this time, if the vehicle needs to turn, the steering gear will control the hydraulic oil to flow to the steering cylinder. Affected by the steering resistance of the axle, the load of the steering cylinder will change, resulting in a mismatch between the required flow of the power-assisted working oil circuit 41 and the flow of the power-assisted oil inlet circuit 1.

[0050] When the flow rate of the power-assisted oil inlet circuit 1 is greater than the required flow rate of the power-assisted working oil 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 diversion flow of the differential pressure-reducing oil circuit 3, thereby achieving the purpose of maintaining the flow balance between the power-assisted oil inlet circuit 1 and the power-assisted working oil circuit 41.

[0051] When the flow rate of the power-assisted oil inlet circuit 1 is less than the required flow rate of the power-assisted working oil circuit 41, the power-assisted working oil circuit 41 will actively inhale the oil of the throttling output section 22, the pressure of the throttling output section 22 will decrease, and the opening of the differential pressure-reducing valve 31 will decrease. By reducing the diversion flow of the differential pressure-reducing oil circuit 3 and supplementing the oil through the throttling oil circuit 2, the purpose of maintaining the flow balance between the power-assisted oil inlet circuit 1 and the power-assisted working oil circuit 41 will be achieved.

[0052] like Figure 1 and Figure 2 As shown, in the embodiment of the present invention, the power-assisted oil inlet circuit 1 includes a main oil inlet circuit 11 and an emergency oil inlet circuit 12, and the power-assisted steering pump group includes a main steering pump 71 and an emergency steering pump 72, and the main steering pump 71 and the emergency steering pump 72 are respectively connected to the main oil inlet circuit 11 and the emergency oil inlet circuit 12. By providing the emergency oil inlet circuit 12 and the emergency steering pump 72, the emergency steering assist function can be realized when the main steering pump 71 fails, and the accumulator 6 can be used to compensate the flow and pressure of the power-assisted working oil circuit 41 during emergency steering assist, and the flow of the power-assisted working oil circuit 41 can be stabilized at the second level when the main steering pump 71 is working.

[0053] To achieve the above object, the present invention further provides a vehicle, wherein the vehicle includes the hydraulic power steering system described above. Since the vehicle adopts all the technical solutions of the above embodiments, it at least has the beneficial effects brought by the above embodiments, which will not be repeated here.

[0054] In the description of the present invention, 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 invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0055] In the present invention, 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 one; 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 the present invention can be understood according to specific circumstances.

[0056] 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 invention. 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.

[0057] Although the embodiments of the present invention have been described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary 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 comprises: Power assist oil inlet line (1); A power-assisting working oil circuit (41), one end of which is connected to the power-assisting oil inlet circuit (1), and the other end of which is used to be connected to a power-assisting steering execution unit; The throttling oil circuit (2) comprises a throttling input section (21) and a throttling output section (22) which are connected in sequence, wherein the inlet end of the throttling input section (21) is connected to the boosting oil inlet circuit (1), and the outlet end of the throttling output section (22) is connected to the boosting working oil circuit (41), and a first non-return valve (51) is provided between the throttling output section (22) and the boosting working oil circuit (41); A differential pressure reducing oil circuit (3) is connected at one end to the booster oil inlet circuit (1) and at the other end to the oil return circuit (T). A differential pressure reducing valve (31) is provided on the differential pressure reducing oil circuit (3). The differential pressure reducing valve (31) is provided 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) through a pipeline.

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), and a pipeline of the accumulator (6) is connected to the power-assisted working oil circuit (41).

3. The hydraulic power steering control unit according to claim 2, characterized in that: A second one-way valve (52) is provided between the boost working oil circuit (41) and the boost oil inlet circuit (1), and the throttling output section (22) and the accumulator (6) are respectively connected to the boost 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-assisted oil inlet circuit (1) comprises a main oil inlet circuit (11) and an emergency oil inlet circuit (12); the hydraulic power-assisted steering control unit comprises a power-assisted working oil circuit (41) and an emergency switching valve (42); the emergency switching valve (42) is provided with a first oil inlet port (P1), a second oil inlet port (P2) and a power-assisted working oil port (a); the first oil inlet port (P1) and the second oil inlet port (P2) are respectively used to connect the main oil inlet circuit (11) and the emergency oil inlet circuit (12); the power-assisted working oil port (a) is connected to the power-assisted working oil 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 conduct the first oil inlet port (P1) and the power-assisted working oil port (a); the second valve position is configured to conduct the second oil inlet port (P2) and the power-assisted working oil port (a).

5. The hydraulic power steering control unit according to claim 4, characterized in that: The emergency switching valve (42) has two opposite ends, namely a first pilot control end and a second pilot control end. The first pilot control end is used to control the emergency switching valve (42) to remain in the first valve position when high pressure is applied, and the second pilot control end is used to control the emergency switching valve (42) to remain in the second valve position when high pressure is applied. 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). The second pilot control end is provided with a return 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 oil port (b), and the hydraulic power steering control unit further comprises a light switch control element (43), wherein the light switch control element (43) is a hydraulic control element and is connected to the indicator light control oil port (b); The first valve position is configured to connect the first oil inlet (P1) and the power-assisted working oil port (a), and connect the second oil inlet (P2) and the indicator light control oil port (b); the second valve position is configured to connect the second oil inlet (P2) and the power-assisted working oil port (a), and respectively cut off the first oil inlet (P1) and the indicator light control oil port (b).

7. The hydraulic power steering control unit according to claim 6, characterized in that: The light switch control element (43) is a hydraulically controlled reversing valve, which is provided with a reversing control end and a spring return end, the reversing control end is connected to the indicator light control oil port (b), and the reversing control end is transmission-connected to the circuit switch (44) of the emergency power-assisting indicator light.

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

9. The hydraulic power steering system according to claim 8, characterized in that: The power-assisted oil inlet circuit (1) comprises a main oil inlet circuit (11) and an emergency oil inlet circuit (12); the power-assisted steering pump assembly comprises 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 oil inlet circuit (11) and the emergency oil inlet circuit (12).

10. A vehicle, characterized in that: Comprising a hydraulic power steering system according to claim 8 or 9.

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