Steering system, method for controlling the same and crane

Abstract

The application provides a steering system, a control method thereof and a crane, the steering system comprising a return pipe, a main steering subsystem, an auxiliary steering subsystem, a power steering device and a storage tank, the power steering device comprising an outlet and an inlet, the main steering subsystem comprising a first reversing valve and a main steering pump, the outlet and the inlet being in communication with the first reversing valve, one end of the return pipe being in communication with the storage tank, the other end of the return pipe being in communication with a communication pipe between the first reversing valve and the outlet, two ends of the main steering pump being in communication with the storage tank and the first reversing valve respectively, the auxiliary steering subsystem being in communication with the storage tank and the first reversing valve respectively, in a first working state, the main steering pump is in communication with the inlet, and the auxiliary steering subsystem is in communication with the return pipe, so that the hydraulic oil in the storage tank is delivered to the power steering device through the main steering pump, in a second working state, the auxiliary steering subsystem is in communication with the inlet, so that the hydraulic oil in the storage tank is delivered to the power steering device through the auxiliary steering subsystem.

Description

Steering systems and their control methods and cranes Technical Field

[0001] This invention relates to the field of crane steering system technology, specifically to a steering system and its control method, and a crane. Background Technology

[0002] Currently, power steering systems are generally used in engineering vehicles, such as truck cranes.

[0003] Under normal circumstances, only a small portion of the energy required to steer a vehicle is provided by the driver through mechanical steering, while the majority is provided by the engine through a hydraulic power steering system. During steering, the engine drives the power steering pump to operate, and the power steering pump provides pressure to assist in steering the tires.

[0004] If a vehicle encounters a sudden event while in normal driving condition, resulting in the loss of power to the entire vehicle and the engine stopping or stalling, the hydraulic power steering system will lose its power source. In this case, the driver will have to provide all the steering force through mechanical rotation, which will make it difficult for the driver to steer and can easily lead to an accident.

[0005] Therefore, it is necessary to provide a steering system, its control method, and a crane to solve the above-mentioned technical problems. Summary of the Invention

[0006] The main objective of this invention is to provide a steering system that addresses the technical problem that steering systems in the prior art fail when the engine is stopped or turned off.

[0007] According to one aspect of the present invention, a steering system is provided, comprising a return pipe, an active steering subsystem, an auxiliary steering subsystem, a power steering unit, and a storage tank. The power steering unit includes an outlet and an inlet. The active steering subsystem includes a first directional valve and a main steering pump. The outlet and the inlet are respectively connected to the first directional valve. One end of the return pipe is connected to the storage tank, and the other end of the return pipe is connected to a connecting pipe between the first directional valve and the outlet. Both ends of the main steering pump are respectively connected to the storage tank and the first directional valve. The auxiliary steering subsystem is connected to both the storage tank and the first directional valve.

[0008] The steering system has at least a first operating state and a second operating state.

[0009] When the steering system is in its first operating state, the main steering pump is connected to the inlet, and the main steering pump is started so that the hydraulic oil in the storage tank is delivered to the power steering unit through the main steering pump;

[0010] When the steering system is in the second operating state, the auxiliary steering subsystem is connected to the inlet, and the auxiliary steering subsystem is activated so that the hydraulic oil in the storage tank is delivered to the power steering unit through the auxiliary steering subsystem.

[0011] In one embodiment, the first reversing valve includes a first interface, a second interface, a third interface, and a fourth interface; the two ends of the main steering pump are respectively connected to the storage tank and the first interface; the third interface is connected to the inlet; and the fourth interface is connected to the outlet; the auxiliary steering subsystem is connected to the storage tank and the second interface.

[0012] When the steering system is in a first operating state, the first port of the first directional valve is connected to the third port, and the second port of the first directional valve is connected to the fourth port.

[0013] When the steering system is in the second operating state, the second port of the first directional valve is connected to the third port.

[0014] In one embodiment, the active steering subsystem further includes a first throttle valve, the two ends of which are respectively connected to the main steering pump and the first interface.

[0015] In one embodiment, the auxiliary steering subsystem includes a second reversing valve and an auxiliary steering pump. The second reversing valve includes a fifth port, a sixth port, and a seventh port. Both ends of the auxiliary steering pump, the fifth port, and the sixth port are all connected to the storage tank, and the seventh port is connected to the second port.

[0016] The second directional valve includes at least the following two states:

[0017] In the first operating state, the fifth interface is connected to the seventh interface so that one end of the auxiliary steering pump is connected to the second interface;

[0018] In the second operating state, the sixth interface is connected to the seventh interface so that the other end of the auxiliary steering pump is connected to the second interface.

[0019] In one embodiment, the active steering subsystem further includes a second throttle valve, the two ends of which are respectively connected to the seventh interface and the second interface.

[0020] In one embodiment, the first throttle valve is connected to a first overflow pipe, the second throttle valve is connected to a second overflow pipe, and both the first overflow pipe and the second overflow pipe are connected to the return pipe.

[0021] In one embodiment, the steering system further includes a sideflow pipe, one end of which is connected to the power steering unit, and the other end of which is connected to the first interface.

[0022] According to another aspect of the present invention, the present invention also provides a steering system control method, the steering system control method being applied to the steering system as described above, the steering system control method comprising the following steps:

[0023] The main steering pump is controlled to draw hydraulic oil from the storage tank and deliver the hydraulic oil to the first directional valve;

[0024] If the delivery pressure of the main steering pump is greater than the threshold of the first reversing valve, the first reversing valve is controlled to operate so that the first interface is connected to the third interface and the second interface is connected to the fourth interface.

[0025] The hydraulic oil drawn by the main steering pump is controlled to enter the first directional valve from the first port and flow out from the third port to the power steering unit to drive the power steering unit; the auxiliary steering subsystem is controlled to draw hydraulic oil from the storage tank, deliver the hydraulic oil to the second port, and deliver the hydraulic oil flowing out from the fourth port into the return pipe and then to the storage tank; or,

[0026] If the delivery pressure of the main steering pump is less than the threshold of the first reversing valve, the first reversing valve is controlled to activate so that the second interface is connected to the third interface.

[0027] The auxiliary steering subsystem is controlled to draw hydraulic oil from the storage tank, deliver the hydraulic oil into the second interface, and deliver the hydraulic oil flowing out from the outlet to the power steering gear to drive the power steering gear.

[0028] In one embodiment, the steps of controlling the auxiliary steering subsystem to draw hydraulic oil from the storage tank and controlling the auxiliary steering subsystem to deliver the hydraulic oil into the second interface include:

[0029] Control the auxiliary steering pump to rotate forward or reverse to draw hydraulic oil from the storage tank, and control the auxiliary steering pump to deliver the hydraulic oil to the second directional valve;

[0030] If the auxiliary steering pump reverses, control the second reversing valve to connect the fifth port and the seventh port;

[0031] The auxiliary steering pump is controlled to rotate forward to draw hydraulic oil from the storage tank, and the auxiliary steering pump is controlled to deliver the hydraulic oil into the fifth port. The auxiliary steering pump is also controlled to deliver the hydraulic oil flowing out from the seventh port to the second port.

[0032] If the auxiliary steering pump reverses, control the second reversing valve to activate so that the sixth port is connected to the seventh port;

[0033] The auxiliary steering pump is controlled to reverse and draw hydraulic oil from the storage tank, the auxiliary steering pump is controlled to deliver the hydraulic oil into the sixth port, and the auxiliary steering pump is controlled to deliver the hydraulic oil flowing out from the seventh port to the second port.

[0034] According to another aspect of the present invention, the present invention also provides a crane, including a tire, an engine, a transmission device and the steering system described above, wherein the engine is driven to the main steering pump, the transmission device is driven to the auxiliary steering subsystem, and the power steering unit is driven to the tire.

[0035] In the above scheme, the steering system includes a return pipe, an active steering subsystem, an auxiliary steering subsystem, a power steering gear, and a storage tank. The power steering gear includes an outlet and an inlet. The active steering subsystem includes a first directional valve and a main steering pump. The outlet and inlet are respectively connected to the first directional valve. One end of the return pipe is connected to the storage tank, and the other end of the return pipe is connected to the connecting pipe between the first directional valve and the outlet. Both ends of the main steering pump are respectively connected to the storage tank and the first directional valve. The auxiliary steering subsystem is connected to the storage tank and the first directional valve. The steering system has at least a first operating state and a second operating state. When the steering system is in the first operating state, the main steering pump is connected to the inlet, and the main steering pump is started, so that the hydraulic oil in the storage tank flows through the main steering pump. The pump delivers hydraulic oil to the power steering gear. In the second operating state of the steering system, the auxiliary steering subsystem connects to the inlet and starts, allowing hydraulic oil from the storage tank to be delivered to the power steering gear. This steering system can be used in many scenarios, such as automobiles, large trains, or cranes. In these scenarios, when steering is required under normal operating conditions, the engine drives the main steering pump to draw hydraulic oil from the storage tank and deliver it to the first directional valve. Simultaneously, the driver operates the steering wheel to steer the tires. At this time, the transmission also drives the auxiliary steering subsystem to deliver hydraulic oil from the storage tank to the first directional valve. Since it is under normal operating conditions, the pressure generated by the main steering pump drawing hydraulic oil is greater than that of the first directional valve. When the valve threshold is reached, the internal channels of the first directional valve switch. The internal pipes of the first directional valve connect the main steering pump to the inlet of the power steering unit and the auxiliary steering subsystem to the outlet of the power steering unit. The main steering pump delivers hydraulic oil to the power steering unit, which provides power for steering and completes the steering process. The auxiliary steering subsystem is connected to the outlet of the power steering unit. Hydraulic oil discharged from the outlet prevents the auxiliary steering subsystem from delivering hydraulic oil to the outlet. Ultimately, the hydraulic oil delivered by the auxiliary steering subsystem and the hydraulic oil discharged from the outlet flow back to the storage tank through the return pipe on the connecting pipe between the outlet and the first directional valve for subsequent use. This completes the constant-flow hydraulic circuit. When the engine malfunctions, the... In situations such as engine shutdown, power reduction, or damage, when steering is required, the main steering pump cannot start due to engine failure. Therefore, it cannot deliver hydraulic oil from the reservoir to the power steering system. The pressure generated by the main steering pump drawing hydraulic oil is lower than the threshold of the first directional valve, preventing the valve's internal piping from switching. At this point, the auxiliary steering subsystem connects to the power steering system's inlet, drawing hydraulic oil from the reservoir and delivering it to the power steering system's inlet to provide power for steering. This structure provides the steering system with two power sources; even when the engine fails, the other power source can still drive the steering action, protecting the driver's safety. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0037] Figure 1 is a schematic diagram of the steering principle of the steering system of the present invention when the engine is normal in the forward state;

[0038] Figure 2 is a schematic diagram of the steering principle of the steering system in the forward state when the engine malfunctions in an embodiment of the present invention.

[0039] Figure 3 is a schematic diagram of the steering principle of the steering system of the present invention when the engine is normal in the reverse state;

[0040] Figure 4 is a schematic diagram of the steering principle of the steering system in the reverse state when the engine malfunctions in an embodiment of the present invention.

[0041] Figure 5 is a schematic diagram of the active steering subsystem according to an embodiment of the present invention;

[0042] Figure 6 is a schematic diagram of the auxiliary steering subsystem according to an embodiment of the present invention;

[0043] Figure 7 is a flowchart illustrating the steering system control method of the first embodiment of the present invention;

[0044] Figure 8 is a flowchart illustrating the steering system control method according to the second embodiment of the present invention.

[0045] Explanation of icon numbers:

[0046]

[0047] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0049] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0050] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. 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.

[0051] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean 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.

[0052] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0053] According to one aspect of the present invention, referring to Figures 1-6, the present invention provides a steering system 100, including a return pipe 1, an active steering subsystem 2, an auxiliary steering subsystem 3, a power steering unit 4, and a storage tank 5. The power steering unit 4 includes an outlet 41 and an inlet 42. The active steering subsystem 2 includes a first directional valve 21 and a main steering pump 22. The outlet 41 and the inlet 42 are respectively connected to the first directional valve 21. One end of the return pipe 1 is connected to the storage tank 5, and the other end of the return pipe 1 is connected to a connecting pipe between the first directional valve 21 and the outlet 41. Both ends of the main steering pump 22 are respectively connected to the storage tank 5 and the first directional valve 21. The auxiliary steering subsystem 3 is respectively connected to the storage tank 5 and the first directional valve 21. The steering system 100 has at least a first operating state and a second operating state.

[0054] When the steering system 100 is in the first working state, the main steering pump 22 is connected to the inlet 42, and the main steering pump 22 is started so that the hydraulic oil in the storage tank 5 is delivered to the power steering gear 4 through the main steering pump 22.

[0055] When the steering system 100 is in its second operating state, the auxiliary steering subsystem 3 is connected to the inlet 42, and the auxiliary steering subsystem 3 is activated to allow the hydraulic oil in the storage tank 5 to be delivered to the power steering gear 4. The steering system 100 can be used in many scenarios, such as automobiles, large trains, or cranes. In these scenarios, when steering is required under normal operating conditions, the engine 101 drives the main steering pump 22 to start and draw hydraulic oil from the storage tank 5 to the first directional valve 21. At the same time, the driver will operate the steering wheel to steer the tires. At this time, the transmission device 102 will also drive the auxiliary steering subsystem 3 to deliver hydraulic oil from the storage tank 5 to the first directional valve 21. Then, due to normal operating conditions, the pressure generated by the hydraulic oil drawn by the main steering pump 22 exceeds the threshold of the first directional valve 21. At this time, the internal channels of the first directional valve 21 are switched, and the internal pipes of the first directional valve 21 connect the main steering pump 22 to the inlet 42 of the power steering unit 4, and the auxiliary steering subsystem 3 to the outlet 41 of the power steering unit 4. The main steering pump 22 delivers hydraulic oil to the power steering unit 4, which provides power for steering and drives the steering to complete the steering. The auxiliary steering subsystem 3 is connected to the outlet 41 of the power steering unit 4. The hydraulic oil discharged from the outlet 41 will prevent the auxiliary steering subsystem 3 from delivering hydraulic oil to the outlet 41. Finally, the auxiliary steering subsystem... The hydraulic oil supplied by the auxiliary steering subsystem 3 and discharged from outlet 41 flows back to the storage tank 5 through the return pipe 1 on the connecting pipe between outlet 41 and the first directional valve 21 for subsequent use, thus completing the constant flow hydraulic circuit. When the engine 101 malfunctions, such as stopping, power reduction, or damage, and steering is required, the main steering pump 22 cannot start due to the engine 101 failure. Therefore, it cannot supply hydraulic oil from the delivery tank to the power steering gear 4. At this time, the pressure generated by the main steering pump 22 drawing hydraulic oil is less than the threshold of the first directional valve 21, preventing the internal pipes of the first directional valve 21 from switching. Thus, the auxiliary steering subsystem 3 and the power steering gear 4 are not connected. The hydraulic oil is connected to port 42, which allows the auxiliary steering subsystem 3 to draw hydraulic oil from the storage tank 5 and deliver it to the inlet 42 of the power steering unit 4. This provides power to the power steering unit 4 for steering, driving it to complete the steering operation. Then, the hydraulic oil in the power steering unit 4 is discharged through outlet 41. At this time, since the first directional valve 21 is in its normal state, the hydraulic oil discharged from the power steering unit 4 will not flow out through the first directional valve 21, but will flow back to the storage tank 5 through the return pipe 1 on the connecting pipe between outlet 41 and the first directional valve 21. This structure allows the steering system 100 to have two power sources. When the engine 101 is damaged, the other power source can also drive the steering to complete the steering action, protecting the driver's safety.

[0056] Referring to Figures 1 and 2, in one embodiment, the first directional valve 21 includes a first port 211, a second port 212, a third port 213, and a fourth port 214. The two ends of the main steering pump 22 are connected to the storage tank 5 and the first port 211, respectively. The third port (213) is connected to the inlet (42), and the fourth port (214) is connected to the outlet (41). The auxiliary steering subsystem 3 is connected to the storage tank 5 and the second port 212, respectively. The first directional valve 21 includes at least the following two states:

[0057] When the steering system 100 is in the first working state, the first port 211 of the first reversing valve 21 is connected to the third port 213, and the second port 212 of the first reversing valve 21 is connected to the fourth port 214.

[0058] When the steering system 100 is in its first operating state, the second port 212 of the first directional valve 21 is connected to the third port 213. The normal operating state of the first directional valve 21 is emergency mode, with the second port 212 connected to the third port 213. When the main steering pump 22 can draw hydraulic oil from the storage tank 5, and the pressure generated by the main steering pump 22 exceeds the threshold of the first directional valve 21, it can open the valve of the first directional valve 21, causing the internal piping of the first directional valve 21 to switch. This connects the first port 211 to the third port 213, and the second port 212 to the fourth port 214. In this way, the main steering pump 22 can connect to the inlet 42 of the power steering gear 4 through the first port 211 and the third port 213. The auxiliary steering subsystem 3 is connected to the outlet 41 of the power steering unit 4 via the second interface 212 and the fourth interface 214. The main steering pump 22 sequentially delivers hydraulic oil to the power steering unit 4 in the order of first interface 211, third interface 213, and inlet 42. The power steering unit 4 provides power for steering and drives the steering process. The auxiliary steering subsystem 3 is connected to the outlet 41 of the power steering unit 4. The hydraulic oil discharged from the outlet 41 will prevent the auxiliary steering subsystem 3 from delivering hydraulic oil to the outlet 41. Finally, the hydraulic oil delivered by the auxiliary steering subsystem 3 and the hydraulic oil discharged from the outlet 41 will flow back to the storage tank 5 through the return pipe 1 on the connecting pipe between the outlet 41 and the first reversing valve 21, for use in power steering. In subsequent use, this completes the constant-flow hydraulic circuit. When the engine 101 malfunctions, such as stopping, power reduction, or damage, and steering is required, the main steering pump 22 cannot start due to the engine 101 failure. Therefore, it cannot deliver hydraulic oil from the delivery tank to the power steering gear 4. At this time, the pressure generated by the main steering pump 22 drawing hydraulic oil is less than the threshold of the first directional valve 21, preventing the internal piping of the first directional valve 21 from switching. Thus, it remains in its normal state, with the second interface 212 and the third interface 213 connected. The auxiliary steering subsystem 3 then connects to the inlet 42 of the power steering gear 4 through the second and third interfaces 212 and 213, allowing the auxiliary steering subsystem 3 to draw hydraulic oil from the storage tank 5. Hydraulic oil is supplied to the power steering unit 4 through the second port 212, the third port 213, and the inlet 42, providing power for steering and driving the unit to complete the steering. The hydraulic oil in the power steering unit 4 is then discharged through the outlet 41. At this time, since the first directional valve 21 is in its normal state (i.e., the second port 212 and the third port 213 are connected, and the other ports are not connected), the hydraulic oil discharged from the power steering unit 4 will not flow out through the first directional valve 21, but will flow back to the storage tank 5 through the return pipe 1 on the connecting pipe between the outlet 41 and the fourth port 214. The switching of multiple power sources can be achieved through a simple hydraulic directional valve, and this structure can significantly reduce the production cost of the steering system 100.

[0059] Referring to Figures 1-5, in one embodiment, the active steering subsystem 2 further includes a first throttle valve 24, the two ends of which are connected to the main steering pump 22 and the first interface 211, respectively. The main function of the first throttle valve 24 is to regulate the flow rate and pressure. By setting the first throttle valve 24, the flow rate and pressure of the hydraulic oil delivered by the main steering pump 22 can be regulated. In this way, even if the engine 101 experiences a slight power reduction, the pressure can still reach the threshold of the first directional valve 21, ensuring the normal operation of the equipment. At the same time, it also prevents excessive flow from causing excessive pipeline pressure and rupture.

[0060] Referring to Figures 3 and 4, in one embodiment, the auxiliary steering subsystem 3 includes a second reversing valve 31 and an auxiliary steering pump 32. The second reversing valve 31 includes a fifth port 311, a sixth port 312, and a seventh port 313. Both ends of the auxiliary steering pump 32, the fifth port 311, and the sixth port 312 are all connected to the storage tank 5, and the seventh port 313 is connected to the second port 212. The second reversing valve 31 includes at least the following two states:

[0061] In the first working state, the fifth interface 311 is connected to the seventh interface 313 so that one end of the auxiliary steering pump 32 is connected to the second interface (212);

[0062] In the second operating state, the sixth interface 312 is connected to the seventh interface 313 so that the other end of the auxiliary steering pump 32 is connected to the second interface (212). When the steering system 100 is applied to equipment with forward and reverse working states, when forward movement is required, the front end of the auxiliary steering pump 32 draws hydraulic oil, at which time the fifth port 311 and the seventh port 313 are connected, and the hydraulic oil flows in the order of storage tank 5, fifth port 311, seventh port 313 and first directional valve 21. At this time, steering can be performed in the forward state. When reverse movement is required, the second directional valve 31 switches, at which time the sixth port 312 and the seventh port 313 are connected, and the rear end of the auxiliary steering pump 32 draws hydraulic oil, and the hydraulic oil flows in the order of storage tank 5, sixth port 312, seventh port 313 and first directional valve 21. At this time, steering can be performed in the reverse state. By setting the second directional valve 31, the steering system 100 can be steered in both forward and reverse states, avoiding the limitations of the steering system 100. Therefore, this setting allows the steering system 100 to have a wider range of applications.

[0063] Referring to Figures 3 and 4, in one embodiment, the active steering subsystem 2 further includes a second throttle valve 23, the two ends of which are connected to the seventh interface 313 and the second interface 212, respectively. The main function of the second throttle valve is to regulate the flow rate and pressure. By setting the second throttle valve, the flow rate and pressure of the hydraulic oil delivered by the auxiliary steering pump 32 can be regulated to ensure the normal operation of the equipment, while also preventing excessive flow rate from causing excessive pipeline pressure and rupture.

[0064] Referring to Figures 3 and 4, in one embodiment, the first throttle valve 24 is connected to a first overflow pipe 241, and the second throttle valve 23 is connected to a second overflow pipe 231. Both the first overflow pipe 241 and the second overflow pipe 231 are connected to the return pipe 1. By providing the first overflow pipe 241 and the second overflow pipe 231, when the flow rate is adjusted by the first throttle valve 24 and the second throttle valve 23, all excess hydraulic oil can be returned to the storage tank 5, allowing the hydraulic oil to be reused and reducing the cost of use.

[0065] Referring to Figures 1, 2, and 5, in one embodiment, the steering system 100 further includes a side flow pipe 6. One end of the side flow pipe 6 is connected to the power steering gear 4, and the other end of the side flow pipe 6 is connected to the first interface 211. When the engine 101 has insufficient power, the engine 101 can still drive the main steering pump 22 to draw hydraulic oil from the storage tank 5. However, due to the insufficient power of the engine 101, the pressure that the main steering pump 22 can output will decrease, and the pressure will not reach the threshold of the first reversing valve 21. At this time, the hydraulic oil drawn by the main steering pump 22 will flow into the power steering gear 4 from the side flow pipe 6, providing a portion of the hydraulic oil to the power steering gear 4, thereby increasing the output power of the power steering gear 4. This structure can assist the auxiliary steering pump 32 in driving the power steering gear 4 and reduce the driving pressure of the auxiliary steering pump 32.

[0066] Furthermore, all of the above pipelines are equipped with one-way valves 7 to prevent backflow and thus prevent the steering system 100 from failing.

[0067] Referring to Figure 7, which is a flowchart illustrating the intelligent deceleration method of the first embodiment of the present invention; according to another aspect of the present invention, the present invention also provides a steering system 100 control method, which is applied to the steering system 100 as described above, and includes the following steps:

[0068] S10. Control the main steering pump 22 to draw hydraulic oil from the storage tank 5 and deliver the hydraulic oil to the first directional valve 21;

[0069] The engine 101 drives and controls the main steering pump 22 to draw hydraulic oil from the storage tank 5, and controls the main steering pump 22 to deliver the drawn hydraulic oil to the first directional valve 21.

[0070] S20. If the delivery pressure of the main steering pump 22 is greater than the threshold of the first reversing valve 21, control the first reversing valve 21 to activate so that the first interface 211 is connected to the third interface 213 and the second interface 212 is connected to the fourth interface 214.

[0071] The hydraulic oil drawn by the main steering pump 22 enters the first directional valve 21 from the first port 211 and flows out from the third port 213 to the power steering unit 4 to drive the power steering unit 4; the auxiliary steering subsystem 3 draws hydraulic oil from the storage tank 5, delivers the hydraulic oil to the second port 212, and delivers the hydraulic oil flowing out from the fourth port 214 into the return pipe 1 and then to the storage tank 5.

[0072] The first directional valve 21 is normally in emergency mode, with the second port 212 connected to the third port 213. When the main steering pump 22 can draw hydraulic oil from the storage tank 5, and the pressure generated by the main steering pump 22 is greater than the threshold of the first directional valve 21, it can open the valve of the first directional valve 21, causing the internal pipeline of the first directional valve 21 to switch, thereby connecting the first port 211 to the third port 213 and the second port 212 to the fourth port 214. In this way, the main steering pump 22 can be connected to the inlet 42 of the power steering gear 4 through the first port 211 and the third port 213, and the auxiliary steering subsystem 3 can be connected to the power steering gear 4 through the second port 212 and the fourth port 214. The outlet 41 of the power steering unit 4 is connected, and the main steering pump 22 delivers hydraulic oil to the power steering unit 4 in sequence according to the flow direction of the first interface 211, the third interface 213 and the inlet 42. The power steering unit 4 provides power for steering and drives the steering to complete the steering. The auxiliary steering subsystem 3 is connected to the outlet 41 of the power steering unit 4. The hydraulic oil discharged from the outlet 41 will prevent the auxiliary steering subsystem 3 from delivering hydraulic oil to the outlet 41. Finally, the hydraulic oil delivered by the auxiliary steering subsystem 3 and the hydraulic oil discharged from the outlet 41 will flow back to the storage tank 5 from the return pipe 1 on the connecting pipe between the outlet 41 and the first reversing valve 21 for subsequent use. This completes the constant flow hydraulic circuit.

[0073] S30. If the delivery pressure of the main steering pump 22 is less than the threshold of the first reversing valve 21, control the first reversing valve 21 to activate so that the second interface 212 is connected to the third interface 213.

[0074] The auxiliary steering subsystem 3 draws hydraulic oil from the storage tank 5, delivers the hydraulic oil into the second interface 212, and delivers the hydraulic oil flowing out of the outlet 41 to the power steering unit 4 to drive the power steering unit 4.

[0075] When engine 101 malfunctions, such as stopping, power reduction, or damage, and steering is required, the main steering pump 22 cannot start due to the engine 101 failure. Therefore, it cannot deliver hydraulic oil from the delivery tank to the power steering gear 4. At this time, the pressure generated by the main steering pump 22 drawing hydraulic oil is lower than the threshold of the first directional valve 21, preventing the internal piping of the first directional valve 21 from switching. Thus, it remains in its normal state, with the second interface 212 and the third interface 213 connected. The auxiliary steering subsystem 3 then connects to the inlet 42 of the power steering gear 4 through the second interface 212 and the third interface 213, assisting... The steering subsystem 3 draws hydraulic oil from the storage tank 5 and delivers it to the power steering unit 4 according to the flow direction of the second port 212, the third port 213 and the inlet 42. This provides power to the power steering unit 4 for steering and drives it to complete the steering. Then, the hydraulic oil in the power steering unit 4 is discharged through the outlet 41. At this time, since the first reversing valve 21 is in normal condition, that is, the second port 212 and the third port 213 are connected and the other ports are connected, the hydraulic oil discharged from the power steering unit 4 will not flow out through the first reversing valve 21, but will flow back to the storage tank 5 through the return pipe 1 on the connecting pipe between the outlet 41 and the fourth port 214.

[0076] In the above embodiments of the present invention, by setting two power sources, when the engine 101 is damaged, the other power source can also drive the steering to complete the steering action, thus protecting the driver's safety; and the switching of multiple power sources can be realized through a simple hydraulic reversing valve. Such a structure can significantly reduce the production cost of the steering system 100.

[0077] Referring to Figure 8, which is a flowchart illustrating the intelligent deceleration method of the first embodiment of the present invention; in one embodiment, the steps of controlling the auxiliary steering subsystem 3 to extract hydraulic oil from the storage tank 5 and controlling the auxiliary steering subsystem 3 to deliver the hydraulic oil into the second interface 212 include:

[0078] S21, Control the auxiliary steering pump 32 to rotate forward or reverse to draw hydraulic oil from the storage tank 5, and control the auxiliary steering pump 32 to deliver the hydraulic oil to the second directional valve 31;

[0079] The auxiliary steering pump 32 is connected to the transmission system, such as the gearbox, drive axle and transfer case. The transmission system drives and controls the auxiliary steering pump 32 to draw hydraulic oil from the storage tank 5 and to deliver the drawn hydraulic oil to the second interface 212.

[0080] S22. If the auxiliary steering pump 32 rotates forward, control the second reversing valve 31 to connect the fifth port 311 and the seventh port 313.

[0081] The auxiliary steering pump 32 is controlled to rotate forward to draw hydraulic oil from the storage tank 5, and the auxiliary steering pump 32 is controlled to deliver the hydraulic oil into the fifth port 311. The auxiliary steering pump 32 is also controlled to deliver the hydraulic oil flowing out from the seventh port 313 to the second delivery port 212.

[0082] When forward movement is required, the auxiliary steering pump 32 rotates forward and draws hydraulic oil from its front end. At this time, the fifth port 311 and the seventh port 313 are connected, and the hydraulic oil flows in the order of storage tank 5, fifth port 311, seventh port 313 and first directional valve 21. At this time, steering can be performed in the forward movement state.

[0083] S23. If the auxiliary steering pump 32 reverses, control the second reversing valve 31 to connect the sixth port 312 and the seventh port 313.

[0084] The auxiliary steering pump 32 is controlled to reverse and extract hydraulic oil from the storage tank 5. The auxiliary steering pump 32 is controlled to deliver the hydraulic oil into the sixth port 312. The auxiliary steering pump 32 is also controlled to deliver the hydraulic oil flowing out from the seventh port 313 to the second delivery port 212.

[0085] When it is necessary to reverse, the auxiliary steering pump 32 reverses and the second reversing valve 31 switches. At this time, the sixth port 312 and the seventh port 313 are connected. The rear end of the auxiliary steering pump 32 draws hydraulic oil. The hydraulic oil flows in the order of storage tank 5, sixth port 312, seventh port 313 and first reversing valve 21. At this time, it can perform steering function in the reverse state.

[0086] In the above embodiments of the present invention, by setting the second reversing valve 31, the steering system 100 can be steered in both forward and reverse states, avoiding the limitations of the steering system 100, and thus enabling the steering system 100 to have a wider range of applications.

[0087] According to another aspect of the present invention, a crane is also provided, comprising tires, an engine 101, a transmission device 102, and the aforementioned steering system 100. The engine 101 is drivenly connected to the main steering pump 22, the transmission device 102 is drivenly connected to the auxiliary steering subsystem 3, and the power steering unit 4 is drivenly connected to the tires. Since the crane includes all embodiments of the aforementioned steering system 100, it possesses at least all the beneficial effects of all the aforementioned embodiments, which will not be elaborated upon here.

[0088] The above are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A steering system, characterized in that, The system includes a return pipe (1), an active steering subsystem (2), an auxiliary steering subsystem (3), a power steering unit (4), and a storage tank (5). The power steering unit (4) includes an outlet (41) and an inlet (42). The active steering subsystem (2) includes a first directional valve (21) and a main steering pump (22). The outlet (41) and the inlet (42) are respectively connected to the first directional valve (21). One end of the return pipe (1) is connected to the storage tank (5), and the other end of the return pipe (1) is connected to the connecting pipe between the first directional valve (21) and the outlet (41). Both ends of the main steering pump (22) are respectively connected to the storage tank (5) and the first directional valve (21). The auxiliary steering subsystem (3) includes a return pipe (1), an active steering subsystem (2), an auxiliary steering subsystem (3), a power steering unit (4), and a storage tank (5). The auxiliary steering subsystem (3) is connected to the storage tank (5) and the first directional valve (21) respectively; the steering system (100) has at least a first working state and a second working state. When the steering system (100) is in the first working state, the main steering pump (22) is connected to the inlet (42), and the main steering pump (22) is started so that the hydraulic oil in the storage tank (5) is delivered to the power steering unit (4) through the main steering pump (22); when the steering system (100) is in the second working state, the auxiliary steering subsystem (3) is connected to the inlet (42), and the auxiliary steering subsystem (3) is started so that the hydraulic oil in the storage tank (5) is delivered to the power steering unit (4) through the auxiliary steering subsystem (3). The power steering system (4) is supplied with power; the first directional valve (21) includes a first port (211), a second port (212), a third port (213), and a fourth port (214). The two ends of the main steering pump (22) are connected to the storage tank (5) and the first port (211), respectively. The third port (213) is connected to the inlet (42), and the fourth port (214) is connected to the outlet (41). The auxiliary steering subsystem (3) is connected to the storage tank (5) and the second port (212), respectively. When the steering system (100) is in the first working state, the first port (211) of the first directional valve (21) is connected to the third port (213). The second port (212) of the first reversing valve (21) is connected to the fourth port (214); when the steering system (100) is in the second working state, the second port (212) of the first reversing valve (21) is connected to the third port (213); the auxiliary steering subsystem (3) includes a second reversing valve (31) and an auxiliary steering pump (32), the second reversing valve (31) includes a fifth port (311), a sixth port (312) and a seventh port (313), both ends of the auxiliary steering pump (32), the fifth port (311) and the sixth port (312) are all connected to the storage tank (5), and the seventh port (313) is connected to the second port (212);The second directional control valve (31) includes at least the following two states: In a first operating state, the fifth port (311) is connected to the seventh port (313) so that one end of the auxiliary steering pump (32) is connected to the second port (212); In a second operating state, the sixth port (312) is connected to the seventh port (313) so that the other end of the auxiliary steering pump (32) is connected to the second port (212).

2. The steering system according to claim 1, characterized in that, The active steering subsystem (2) further includes a first throttle valve (24), the two ends of which are connected to the main steering pump (22) and the first interface (211), respectively.

3. The steering system according to claim 2, characterized in that, The active steering subsystem (2) also includes a second throttle valve (23), the two ends of which are connected to the seventh interface (313) and the second interface (212), respectively.

4. The steering system according to claim 3, characterized in that, The first throttle valve (24) is connected to the first overflow pipe (241), and the second throttle valve (23) is connected to the second overflow pipe (231). Both the first overflow pipe (241) and the second overflow pipe (231) are connected to the return pipe (1).

5. The steering system according to any one of claims 2 to 4, characterized in that, The steering system (100) also includes a side flow pipe (6), one end of which is connected to the power steering unit (4), and the other end of which is connected to the first interface (211).

6. A steering system control method, said steering system control method being applied to a steering system (100) as described in any one of claims 1 to 5, characterized in that, The steering system control method includes the following steps: controlling the main steering pump (22) to draw hydraulic oil from the storage tank (5) and deliver the hydraulic oil to the first directional valve (21); if the delivery pressure of the main steering pump (22) is greater than the threshold of the first directional valve (21), controlling the first directional valve (21) to operate so that the first interface (211) is connected to the third interface (213) and the second interface (212) is connected to the fourth interface (214); controlling the hydraulic oil drawn by the main steering pump (22) to enter the first directional valve (21) from the first interface (211) and flow out from the third interface (213) to the power steering gear (4) to drive the power steering gear (4) to operate; controlling the auxiliary steering subsystem (3) to draw hydraulic oil from the storage tank (5) and controlling the auxiliary steering subsystem to operate. The system (3) delivers the hydraulic oil into the second interface (212) and controls the auxiliary steering subsystem (3) to deliver the hydraulic oil flowing out from the fourth interface (214) into the return pipe (1) and deliver it to the storage tank (5); if the delivery pressure of the main steering pump (22) is less than the threshold of the first reversing valve (21), the system controls the first reversing valve (21) to operate so that the second interface (212) and the third interface (213) are connected; the system controls the auxiliary steering subsystem (3) to draw hydraulic oil from the storage tank (5), controls the auxiliary steering subsystem (3) to deliver the hydraulic oil into the second interface (212), and controls the auxiliary steering subsystem (3) to deliver the hydraulic oil flowing out from the outlet (41) to the power steering gear (4) to drive the power steering gear (4) to operate.

7. The steering system control method according to claim 6, characterized in that, The steps of controlling the auxiliary steering subsystem (3) to draw hydraulic oil from the storage tank (5) and controlling the auxiliary steering subsystem (3) to deliver the hydraulic oil into the second interface (212) include: controlling the auxiliary steering pump (32) to rotate forward or reverse to draw hydraulic oil from the storage tank (5), and controlling the auxiliary steering pump (32) to deliver the hydraulic oil to the second reversing valve (31); if the auxiliary steering pump (32) rotates forward, controlling the second reversing valve (31) to activate so that the fifth interface (311) and the seventh interface (313) are connected; controlling the auxiliary steering pump (32) to rotate forward to draw hydraulic oil from the storage tank (5), and controlling the auxiliary steering pump (32) to deliver the hydraulic oil to the second reversing valve (212) The hydraulic oil is fed into the fifth port (311), and the auxiliary steering pump (32) is controlled to deliver the hydraulic oil flowing out of the seventh port (313) to the second port (212). If the auxiliary steering pump (32) reverses, the second reversing valve (31) is controlled to activate so that the sixth port (312) is connected to the seventh port (313). The auxiliary steering pump (32) is controlled to reverse to extract the hydraulic oil in the storage tank (5), and the auxiliary steering pump (32) delivers the hydraulic oil into the sixth port (312), and the auxiliary steering pump (32) delivers the hydraulic oil flowing out of the seventh port (313) to the second port (212) of the conveyor.

8. A crane, characterized in that, The system includes tires, an engine (101), a transmission (102), and a steering system (100) according to any one of claims 1 to 5, wherein the engine (101) is driven to the main steering pump (22), the transmission (102) is driven to the auxiliary steering subsystem (3), and the power steering unit (4) is driven to the tires.

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