Steering control reversing device and hydraulic system

Abstract

The invention relates to the technical field of hydraulic systems of engineering machinery vehicles, and provides a steering control reversing device and a hydraulic system, a reversing valve core is used as a core, a first opening degree control module and a second opening degree control module are arranged on the two sides of the reversing valve core, and the first opening degree control module and the second opening degree control module are matched with each other. Valve element pressure difference control over the reversing valve element is achieved, and meanwhile pressure on an oil inlet P of the reversing valve element feeds back a load LS signal to the variable pump through a working oil port C; therefore, on the basis of one reversing valve element, direction switching, high-pressure pilot flow pressure difference control reversing of the reversing valve element and load LS signal feedback can be achieved, and the structural layout of a reversing system is further simplified; due to the unique design of one reversing valve element, gear synchronization in the vehicle reversing direction can be guaranteed, the opening degree of the main valve element is controlled by adjusting the pilot pressure proportion, stepless adjustment of the speed of an executing mechanism is achieved, reversing is faster and more stable, and the problem of switching delay caused by participation of other valve elements is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic systems for engineering machinery vehicles, and in particular to a steering control reversing device and a hydraulic system. Background Art

[0002] In construction machinery vehicles, the vehicle's steering method can be divided into deflection wheel steering, articulated steering and skid steering according to different operating conditions and the layout of the vehicle. Usually, deflection wheel steering, articulated steering and skid steering all use full steering hydraulic systems. The stability of the full steering hydraulic system is directly related to the safety of construction machinery vehicles.

[0003] In the existing technology, a pilot valve is usually used to control the reversing valve to perform reversing control. However, since high-pressure pilot control is implemented and the pilot flow participates in steering, in order to achieve this function, a main reversing valve core and a pilot valve core (or two pilot valve cores) are required. When the steering gear inputs the pilot flow, it is necessary to push the pilot valve core open first, and then push the reversing valve core open. The pilot oil passes through the reversing valve core and then enters the pilot valve core, and then acts on the other end of the reversing valve core to form a high-pressure pilot flow pressure difference control of the reversing valve core. During the switching process of the two valve cores, it is easy to cause slow steering response problems.

[0004] In the steering hydraulic system, the transmission function of the load LS signal is mainly realized by the LS opening control module network and the feedback oil circuit. The mechanical opening control module (steel ball or slide valve structure) requires a certain amount of time to switch, especially when multiple actuators act in combination, which may cause LS signal transmission lag and affect the dynamic response of the system. Summary of the Invention

[0005] The present invention provides a steering control reversing device and a hydraulic system, which solves the technical problem that the existing hydraulic reversing system uses a pilot valve to control the reversing valve to perform reversing control and uses an LS opening control module network to perform the load LS signal transmission function, resulting in slow system response.

[0006] To solve the above technical problems, the present invention provides a steering control reversing device and a hydraulic system, including a reversing valve core and an opening adjustment module, wherein the opening adjustment module includes a first opening control module and a second opening control module, wherein the first opening control module is connected to a spring end on one side of the reversing valve core and is also connected to a pilot oil outlet on the other side of the reversing valve core; the second opening control module is connected to the spring end on the other side of the reversing valve core and is also connected to a pilot oil outlet on one side of the reversing valve core;

[0007] When the pilot oil enters the reversing valve core through the first opening control module, it overcomes the spring force on the other side of the reversing valve core, driving the reversing valve core to open. The pilot oil enters the pilot oil inlet on one side of the reversing valve core and flows out through the pilot oil outlet on the same side. At this time, the oil pressure from the pilot oil outlet drives the second opening control module to act on the other side of the reversing valve core, realizing oil circuit opening control and steering control through the high-pressure pilot flow pressure difference.

[0008] When the pilot oil enters the reversing valve core through the second opening control module, it overcomes the spring force on one side of the reversing valve core, driving the reversing valve core to open. The pilot oil enters the pilot oil inlet on the other side of the reversing valve core and flows out through the pilot oil outlet on the same side. At this time, the oil pressure of the pilot oil outlet drives the first opening control module to act on one side of the reversing valve core, realizing oil circuit opening control and steering control through the high-pressure pilot flow pressure difference.

[0009] When steering control is executed, the pressure on the reversing valve core oil inlet port P feeds back the load LS signal to the variable pump through the working oil port C.

[0010] This basic solution takes the reversing valve core as the core, and configures the first opening control module and the second opening control module on both sides thereof. Through the mutual cooperation of the first opening control module and the second opening control module, the valve core pressure difference control of the reversing valve core is realized, and at the same time, the pressure on the oil inlet P of the reversing valve core is fed back to the load LS signal to the variable pump through the working oil port C; thereby, direction switching, high-pressure pilot flow pressure difference control of the reversing valve core, and load LS signal feedback can be realized on the basis of one reversing valve core, further simplifying the structural layout of the reversing system; and the unique design of one reversing valve core can ensure the gear synchronization when the vehicle is reversing, and the main valve core opening is controlled by adjusting the pilot pressure ratio to realize stepless adjustment of the actuator speed, making the switching faster and more stable, and there is no switching delay problem caused by the participation of other valve cores.

[0011] In a further embodiment, the first opening control module includes a first shuttle valve and a first throttle hole; the first shuttle valve includes an oil inlet P1, an oil inlet P2, and an oil outlet A; the oil inlet P1 of the first shuttle valve is connected to the oil inlet end Pa of the pilot oil through the first throttle hole, the oil inlet P2 is connected to the pilot oil outlet on the other side of the reversing valve core, and the oil outlet A is connected to a spring end on one side of the reversing valve core;

[0012] The oil inlet end Pa is also connected to the pilot oil inlet on one side of the reversing valve core;

[0013] When the oil inlet end Pa is piloted to intake oil, since the reversing valve core is cut off in the middle position, the pressure transmitted from the oil inlet end Pa acts on the first shuttle valve through the first throttle hole, pushing the steel ball of the first shuttle valve to the upper position for cutoff, and the pressure acts on one side of the reversing valve core to promote reversing; after reversing, the reversing valve core is connected to the oil inlet end Pa and opens. After the oil at the oil inlet end Pa flows out through the reversing valve core, its pressure pushes open the second opening control module to act on the other side of the reversing valve core, and the oil circuit opening control and steering control are realized through the high-pressure pilot flow pressure difference.

[0014] In a further embodiment, the second opening control module includes a second shuttle valve and a second throttle hole; the second shuttle valve includes an oil inlet P1, an oil inlet P2, and an oil outlet A; the oil inlet P1 of the second shuttle valve is connected to the oil inlet end Pb of the pilot oil through the second throttle hole, the oil inlet P2 is connected to the pilot oil outlet on one side of the reversing valve core, and the oil outlet A is connected to the spring end on the other side of the reversing valve core;

[0015] The oil inlet end Pb is also connected to the pilot oil inlet on the other side of the reversing valve core.

[0016] This solution provides a first shuttle valve and a second shuttle valve on either side of the reversing valve. Based on the operating characteristics of the shuttle valves themselves, whether pilot oil is introduced at the oil inlet end Pa or the oil inlet end Pb, the pressure differential between the inlet and outlet of the reversing valve generated between the first and second shuttle valves can resist the pressure at the spring end, thereby achieving high-pressure pilot flow pressure differential and controlling the oil circuit opening. At the same time, the first and second shuttle valves open and close very quickly, enabling rapid response to steering control and improving the system's response rate.

[0017] In a further embodiment, the reversing valve core includes a three-position nine-way reversing valve, whose oil ports ① and ③ are respectively connected to the oil inlet ends Pa and Pb on both sides as pilot oil inlets, and oil ports ② and ④ are respectively connected to the first opening control module and the second opening control module as pilot oil outlets, and its oil port ⑤ is used as the oil inlet P, and oil ports ⑥ and ⑦ are respectively connected to the two ends of the steering cylinder as working oil ports A and working oil ports B; oil port ⑧ is connected to the variable pump as the working oil port C for feedback of the load LS signal; and oil port ⑨ is connected to the return oil port T;

[0018] When in the normal position, the reversing valve core is cut off in the middle position, and the oil ports ② and ④ are connected, so that the pressure at both ends of the valve core is always equal in the middle position state, and the oil port ⑧ is connected with the oil port ⑨;

[0019] When oil is introduced into the oil inlet end Pa / the oil inlet end Pb, the pressure is transmitted to one side / the other side of the reversing valve core through the first opening control module / the second opening control module, overcoming the spring force on the other side / one side of the reversing valve core, and the reversing valve core opens. The oil port ⑤ is connected with the oil port ⑤ through the throttle port; at this time, the pressure of the oil port ⑤ pushes open the second opening control module / the first opening control module and acts on the other side / one side of the reversing valve core, realizing oil circuit opening control and steering control through the high-pressure pilot flow pressure difference; at the same time, the oil port ⑤ is connected with the oil port ⑧, and the load LS signal is fed back to the variable pump.

[0020] This solution uses a three-position, nine-way directional valve as the sole spool in the steering control mechanism. This valve, in conjunction with the first and second shuttle valves, enables steering direction switching, resulting in a simple structure, high response rate, and low cost. Furthermore, in the normal position, port ⑧ is connected to the oil return port via port ⑨, maintaining a neutral shutoff. When steering is in effect, port ⑤ is connected to port 8, feeding the load LS signal to the variable displacement pump. The directional valve spool itself provides real-time feedback on load pressure, enabling precise flow control.

[0021] In a further embodiment, a first one-way valve is further included, wherein the oil inlet of the first one-way valve is connected to the pilot oil outlet on one side of the reversing valve core, and the oil outlet is connected to the steering cylinder.

[0022] In a further embodiment, a second one-way valve is further included, wherein the oil inlet of the second one-way valve is connected to the pilot oil outlet on the other side of the reversing valve core, and the oil outlet is connected to the steering cylinder.

[0023] In this solution, the first one-way valve and the second one-way valve are respectively connected to the pilot oil outlets on both sides of the reversing valve core, so that the pilot control flow participates in the steering, which can effectively avoid flow waste.

[0024] In a further embodiment, a first protection module is further included, which includes a third one-way valve and a first oil replenishing valve; the oil outlet A of the reversing valve core is connected to one end of the first oil replenishing valve and the oil outlet of the third one-way valve, and the other end of the first oil replenishing valve, the oil inlet of the third one-way valve and the oil return port are connected.

[0025] In a further embodiment, a second protection module is further included, which includes a fourth one-way valve and a second oil replenishing valve; the oil outlet B of the reversing valve core is connected to one end of the second oil replenishing valve and the oil outlet of the fourth one-way valve, and the other end of the second oil replenishing valve, the oil inlet of the fourth one-way valve and the oil return port are connected.

[0026] This solution sets up a first protection module and a second protection module consisting of a one-way valve + an oil replenishing valve for the oil outlets A and B of the reversing valve core respectively. The one-way valve prevents backflow, making the system more stable; the oil replenishing valve eliminates vacuum and protects the hydraulic components.

[0027] In a further embodiment, a priority valve and a relief valve are further included; the oil inlet P of the priority valve is connected to the variable pump, the CF port is connected to the oil inlet P of the reversing valve core, the EF port is connected to the oil inlet of the distribution valve of the working system, and the LS port is connected to the working oil port C of the reversing valve core; the oil inlet of the relief valve is connected to the valve stem of the priority valve, and the oil outlet is connected to the oil return port T.

[0028] This solution sets a priority valve connected to the working oil port C of the reversing valve core to provide steering priority control function through intelligent flow distribution; a relief valve is set to provide overpressure protection, significantly improving the safety, energy efficiency and control accuracy of the hydraulic system, while reducing failure rate and maintenance costs.

[0029] The present invention also provides a hydraulic system comprising a steering cylinder, a steering gear, a variable displacement pump and an oil tank, and also comprising the steering control reversing device as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a structural diagram of a steering control reversing device provided in Example 1 of the present invention;

[0031] Figure 2 The embodiment 1 of the present invention provides Figure 1 Structural diagram of the middle reversing valve core;

[0032] Figure 3 This is a schematic diagram of the steering operation when the oil inlet end Pa is piloted to supply oil, as provided in Example 1 of the present invention;

[0033] Figure 4 is a structural diagram of a hydraulic system provided by Example 2 of the present invention;

[0034] Among them: reversing valve core 1, first shuttle valve 2, first throttle hole 3, second shuttle valve 4, second throttle hole 5, first one-way valve 6, second one-way valve 7, third one-way valve 8, first oil supply valve 9, fourth one-way valve 10, second oil supply valve 11, priority valve 12, overflow valve 13, steering cylinder 14, steering gear 15, variable pump 16, oil tank 17, throttle port 18. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings. The embodiments are provided for illustrative purposes only and are not to be construed as limiting the present invention. The accompanying drawings are provided for reference and illustration only and do not constitute a limitation on the scope of protection of the present invention. Many changes may be made to the present invention without departing from the spirit and scope of the present invention.

[0036] Example 1

[0037] An embodiment of the present invention provides a steering control reversing device, such as Figures 1 to 3 As shown, in this embodiment, it includes a reversing valve core 1 and an opening adjustment module, the opening adjustment module includes a first opening control module and a second opening control module, the first opening control module is connected to the spring end on one side of the reversing valve core 1, and is also connected to the pilot oil outlet on the other side of the reversing valve core 1; the second opening control module is connected to the spring end on the other side of the reversing valve core 1, and is also connected to the pilot oil outlet on one side of the reversing valve core 1;

[0038] When the pilot oil enters the reversing valve core 1 through the first opening control module, it overcomes the spring force on the other side of the reversing valve core 1, driving the reversing valve core 1 to open. The pilot oil enters the pilot oil inlet on one side of the reversing valve core 1 and flows out through the pilot oil outlet on the same side. At this time, the oil pressure of the pilot oil outlet drives the second opening control module to act on the other side of the reversing valve core 1, realizing oil circuit opening control and steering control through the high-pressure pilot flow pressure difference.

[0039] When the pilot oil enters the reversing valve core 1 through the second opening control module, it overcomes the spring force on one side of the reversing valve core 1, driving the reversing valve core 1 to open. The pilot oil enters the pilot oil inlet on the other side of the reversing valve core 1 and flows out through the pilot oil outlet on the same side. At this time, the oil pressure of the pilot oil outlet drives the first opening control module to act on one side of the reversing valve core 1, realizing oil circuit opening control and steering control through the high-pressure pilot flow pressure difference.

[0040] When performing steering control, the pressure on the oil inlet P of the reversing valve core 1 feeds back the load LS signal to the variable pump 16 through the working oil port C.

[0041] In this embodiment, the first opening control module includes a first shuttle valve 2 and a first throttle hole 3; the first shuttle valve 2 includes an oil inlet P1, an oil inlet P2, and an oil outlet A. The oil inlet P1 of the first shuttle valve 2 is connected to the oil inlet end Pa of the pilot oil through the first throttle hole 3, the oil inlet P2 is connected to the pilot oil outlet on the other side of the reversing valve core 1, and the oil outlet A is connected to the spring end on one side of the reversing valve core 1.

[0042] The oil inlet end Pa is also connected to the pilot oil inlet on one side of the reversing valve core 1;

[0043] See also Figure 3 When the oil inlet Pa is piloted to flow in, the reversing valve core 1 is closed in the middle position. The pressure transmitted from the oil inlet Pa acts on the first shuttle valve 2 through the first throttle orifice 3, pushing the steel ball of the first shuttle valve 2 to the upper closed position. The pressure acts on one side of the reversing valve core 1 (the left side in this embodiment) to promote reversal. After reversing, the reversing valve core 1 is connected to the oil inlet Pa and opens. The oil at the oil inlet Pa flows out through the reversing valve core 1. The pressure from this pressure pushes open the second opening control module (i.e., pushes open the second shuttle valve 4, closing it to the lower closed position) and acts on the other side of the reversing valve core 1 (the right side in this embodiment). The high-pressure pilot flow pressure differential controls the oil circuit opening and steering. At this time, the reversing displacement is equal to the pressure differential generated by the oil inlet Pa flow through the reversing valve core 1 overcoming the spring force of the reversing valve core 1. The greater the oil inlet Pa flow (not related to pressure, but only affecting the opening), the greater the pressure differential generated, and the longer the displacement stroke of the reversing valve core 1.

[0044] In this embodiment, the second opening control module includes a second shuttle valve 4 and a second throttle hole 5. The second shuttle valve 4 includes an oil inlet P1, an oil inlet P2, and an oil outlet A. The oil inlet P1 of the second shuttle valve 4 is connected to the oil inlet end Pb of the pilot oil through the second throttle hole 5. The oil inlet P2 is connected to the pilot oil outlet on one side of the reversing valve core 1. The oil outlet A is connected to the spring end on the other side of the reversing valve core 1.

[0045] The oil inlet end Pb is also connected to the pilot oil inlet on the other side of the reversing valve core 1 .

[0046] Similarly, when the oil inlet end Pb pilots the oil inlet, since the reversing valve core 1 is cut off in the middle position, the pressure transmitted from the oil inlet end Pb acts on the second shuttle valve 4 through the second throttle hole 5, pushing the steel ball of the second shuttle valve 4 to the upper position to be cut off, and the pressure acts on the other side of the reversing valve core 1 to promote reversing; after reversing, the reversing valve core 1 is connected to the oil inlet end Pb and opened. After the oil in the oil inlet end Pb flows out through the reversing valve core 1, its pressure pushes open the first opening control module (that is, pushes open the first shuttle valve 2 to make it cut off in the lower position) and acts on one side of the reversing valve core 1, and realizes oil circuit opening control and steering control through the high-pressure pilot flow pressure difference.

[0047] In this embodiment, a first shuttle valve 2 and a second shuttle valve 4 are respectively provided on both sides of the reversing valve. Based on the working characteristics of the shuttle valves themselves, whether the pilot oil is introduced at the oil inlet end Pa or the oil inlet end Pb, the pressure difference between the oil inlet and the oil outlet of the reversing valve generated between the first shuttle valve 2 and the second shuttle valve 4 can resist the pressure at the spring end, thereby realizing a high-pressure pilot flow pressure difference and controlling the oil circuit opening. At the same time, the opening and closing processes of the first shuttle valve 2 and the second shuttle valve 4 are very rapid, which can achieve a fast response of the steering control and improve the response rate of the system.

[0048] In this embodiment, see Figure 2 The reversing valve core 1 includes a three-position, nine-way reversing valve. Its oil ports ① and ③ serve as pilot oil inlets and are connected to the oil inlet ends Pa and Pb on both sides respectively. Oil ports ② and ④ serve as pilot oil outlets and are connected to the first opening control module and the second opening control module respectively. Its oil port ⑤ serves as the oil inlet P, and oil ports ⑥ and ⑦ serve as working oil ports A and B, which are connected to the two ends of the steering cylinder 14 respectively; oil port ⑧ serves as the working oil port C and is connected to the variable pump 16 for feedback of the load LS signal; and oil port 9 is connected to the oil return port T.

[0049] When in the normal position, the pressure in the spring chamber LS of the priority valve core 12 is unloaded through the neutral position of the reversing valve core 1. The flow pumped out passes through the priority valve 12, overcomes the spring force of the priority valve 12 and enters the EF port. The reversing valve core 1 is cut off in the neutral position, and oil ports ② and ④ are connected, always ensuring that the pressure at both ends of the valve core is equal in the neutral state. Oil port ⑧ is connected to oil port ⑨;

[0050] When oil enters the oil inlet end Pa / the oil inlet end Pb, the pressure is transmitted to one side / the other side of the reversing valve core 1 through the first opening control module / the second opening control module, overcoming the spring force on the other side / one side of the reversing valve core 1, and the reversing valve core 1 opens. The oil port ⑤ is connected to the oil port ⑤ through the throttle port 18; at this time, the pressure of the oil port ⑤ pushes the second opening control module / the first opening control module to act on the other side / one side of the reversing valve core 1, and the oil circuit opening control and steering control are realized through the high-pressure pilot flow pressure difference; at the same time, the oil port ⑤ is connected to the oil port ⑧, and the load LS signal is fed back to the variable pump 16.

[0051] This embodiment uses a three-position, nine-way directional valve as the sole directional control valve core 1 in the steering control mechanism. This valve, in conjunction with the first shuttle valve 2 and the second shuttle valve 4, achieves steering direction switching, resulting in a simple structure, high response rate, and low cost. Furthermore, in the normal position, oil port ⑧ is connected to the oil return port via oil port 9, maintaining a neutral shutoff. During steering control, oil port ⑤ is connected to oil port 8, feeding the load LS signal to the variable pump 16. This precise flow control is achieved through the directional control valve core 1's own real-time feedback of load pressure.

[0052] In this embodiment, a first one-way valve 6 is further included. The oil inlet of the first one-way valve 6 is connected to the pilot oil outlet on one side of the reversing valve core 1 , and the oil outlet is connected to the steering cylinder 14 .

[0053] In this embodiment, a second one-way valve 7 is further included. The oil inlet of the second one-way valve 7 is connected to the pilot oil outlet on the other side of the reversing valve core 1 , and the oil outlet is connected to the steering cylinder 14 .

[0054] In this embodiment, the first check valve 6 and the second check valve 7 are respectively connected to the pilot oil outlets on both sides of the reversing valve core 1. That is, the pilot control flow of the pilot oil outlet pushes open the check valve and enters the A / B port. The pressure pushes open the first shuttle valve 2 / the second shuttle valve 4 to act on the right end of the reversing valve core 1, so that the pilot control flow participates in the steering, which can effectively avoid flow waste.

[0055] In this embodiment, a first protection module is also included, which includes a third one-way valve 8 and a first oil replenishing valve 9; the oil outlet A of the reversing valve core 1 is connected to one end of the first oil replenishing valve 9 and the oil outlet of the third one-way valve 8, and the other end of the first oil replenishing valve 9 and the oil inlet of the third one-way valve 8 are connected to the oil return port.

[0056] In this embodiment, a second protection module is also included, which includes a fourth one-way valve 10 and a second oil replenishing valve 11; the oil outlet B of the reversing valve core 1 is connected to one end of the second oil replenishing valve 11 and the oil outlet of the fourth one-way valve 10, and the other end of the second oil replenishing valve 11, the oil inlet of the fourth one-way valve 10 and the oil return port are connected.

[0057] In this embodiment, a first protection module and a second protection module consisting of a one-way valve + an oil replenishing valve are respectively provided for the oil outlets A and B of the reversing valve core 1. The one-way valve is used to prevent backflow, making the system more stable; the oil replenishing valve is used to eliminate vacuum and protect the hydraulic components.

[0058] In this embodiment, a priority valve 12 and a relief valve 13 are also included; the oil inlet P of the priority valve 12 is connected to the variable pump 16, the CF port is connected to the oil inlet P of the reversing valve core 1, the EF port is connected to the oil inlet of the distribution valve of the working system, and the LS port is connected to the working oil port C of the reversing valve core 1; the oil inlet of the relief valve 13 is connected to the valve stem of the priority valve 12, and the oil outlet is connected to the oil return port T.

[0059] During steering, because port ⑤ of reversing valve spool 1 is connected to port ⑧, the pressure at port A is transmitted through port ⑧ to the spring port and LS port of priority valve 12. At this point, a pressure difference exists between the LS port and port P of priority valve 12. The pressure on the left side of priority valve 12 compares with the pressure on the right side (spring end), causing the valve to open toward the steering valve. Priority valve 12 prioritizes flow during steering. When not steering, priority valve 12 switches flow to the distribution valve.

[0060] In this embodiment, a priority valve 12 connected to the working oil port C of the reversing valve core 1 is provided to provide a steering priority control function through intelligent flow distribution; a relief valve 13 is provided to provide overpressure protection, which significantly improves the safety, energy efficiency and control accuracy of the hydraulic system, while reducing the failure rate and maintenance cost.

[0061] Example 2

[0062] The embodiment of the present invention also provides a hydraulic system, see Figure 4 , including a steering cylinder 14, a steering gear 15, a variable pump 16 and an oil tank 17, and also includes a steering control reversing device as described in Example 1 above.

[0063] The hydraulic system disclosed in this embodiment can be assembled on wheel steering equipment such as loaders, graders, and mining trucks as needed.

[0064] The embodiment of the present invention takes the reversing valve core 1 as the core, and configures the first opening control module and the second opening control module on both sides thereof. Through the mutual cooperation of the first opening control module and the second opening control module, the valve core pressure difference control of the reversing valve core 1 is realized, and at the same time, the pressure on the oil inlet P of the reversing valve core 1 is fed back to the load LS signal to the variable pump 16 through the working oil port C; thereby, direction switching, high-pressure pilot flow pressure difference control of the reversing valve core 1, and load LS signal feedback can be realized on the basis of one reversing valve core 1, further simplifying the structural layout of the reversing system; and the unique design of one reversing valve core 1 can ensure the gear synchronization of the vehicle in reversing, and the main valve core opening is controlled by adjusting the pilot pressure ratio to realize stepless adjustment of the actuator speed, and the switching is faster and more stable, and there is no switching delay problem caused by the participation of other valve cores.

[0065] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A steering control reversing device, characterized in that: The valve core comprises a reversing valve and an opening adjustment module, wherein the opening adjustment module comprises a first opening control module and a second opening control module, wherein the first opening control module is connected to a spring end on one side of the reversing valve core and is also connected to a pilot oil outlet on the other side of the reversing valve core; the second opening control module is connected to the spring end on the other side of the reversing valve core and is also connected to a pilot oil outlet on one side of the reversing valve core; When the pilot oil enters the reversing valve core through the first opening control module, it overcomes the spring force on the other side of the reversing valve core, driving the reversing valve core to open. The pilot oil enters the pilot oil inlet on one side of the reversing valve core and flows out through the pilot oil outlet on the same side. At this time, the oil pressure from the pilot oil outlet drives the second opening control module to act on the other side of the reversing valve core, realizing oil circuit opening control and steering control through the high-pressure pilot flow pressure difference. When the pilot oil enters the reversing valve core through the second opening control module, it overcomes the spring force on one side of the reversing valve core, driving the reversing valve core to open. The pilot oil enters the pilot oil inlet on the other side of the reversing valve core and flows out through the pilot oil outlet on the same side. At this time, the oil pressure of the pilot oil outlet drives the first opening control module to act on one side of the reversing valve core, realizing oil circuit opening control and steering control through the high-pressure pilot flow pressure difference. When steering control is executed, the pressure on the reversing valve core oil inlet port P feeds back the load LS signal to the variable pump through the working oil port C.

2. A steering control reversing device according to claim 1, characterized in that: The first opening control module includes a first shuttle valve and a first throttle hole; the first shuttle valve includes an oil inlet P1, an oil inlet P2, and an oil outlet A. The oil inlet P1 of the first shuttle valve is connected to the oil inlet end Pa of the pilot oil through the first throttle hole, the oil inlet P2 is connected to the pilot oil outlet on the other side of the reversing valve core, and the oil outlet A is connected to the spring end on one side of the reversing valve core; The oil inlet end Pa is also connected to the pilot oil inlet on one side of the reversing valve core; When the oil inlet end Pa is piloted to intake oil, since the reversing valve core is cut off in the middle position, the pressure transmitted from the oil inlet end Pa acts on the first shuttle valve through the first throttle hole, pushing the steel ball of the first shuttle valve to the upper position for cutoff, and the pressure acts on one side of the reversing valve core to promote reversing; after reversing, the reversing valve core is connected to the oil inlet end Pa and opens. After the oil at the oil inlet end Pa flows out through the reversing valve core, its pressure pushes open the second opening control module to act on the other side of the reversing valve core, and the oil circuit opening control and steering control are realized through the high-pressure pilot flow pressure difference.

3. A steering control reversing device according to claim 2, characterized in that: The second opening control module includes a second shuttle valve and a second throttle hole; the second shuttle valve includes an oil inlet P1, an oil inlet P2, and an oil outlet A. The oil inlet P1 of the second shuttle valve is connected to the oil inlet end Pb of the pilot oil through the second throttle hole, the oil inlet P2 is connected to the pilot oil outlet on one side of the reversing valve core, and the oil outlet A is connected to the spring end on the other side of the reversing valve core; The oil inlet end Pb is also connected to the pilot oil inlet on the other side of the reversing valve core.

4. A steering control reversing device according to claim 3, characterized in that: The reversing valve core includes a three-position, nine-way reversing valve, whose oil ports ① and ③ serve as pilot oil inlets and are connected to the oil inlet ends Pa and Pb on both sides respectively; oil ports ② and ④ serve as pilot oil outlets and are connected to the first opening control module and the second opening control module respectively; its oil port ⑤ serves as the oil inlet P; oil ports ⑥ and ⑦ serve as working oil ports A and B, respectively, and are connected to the two ends of the steering cylinder; oil port ⑧ serves as working oil port C and is connected to the variable pump for feedback of the load LS signal; and oil port 9 is connected to the oil return port T; When in the normal position, the reversing valve core is cut off in the middle position, and the oil ports ② and ④ are connected, so that the pressure at both ends of the valve core is always equal in the middle position state, and the oil port ⑧ is connected with the oil port ⑨; When oil is introduced into the oil inlet end Pa / the oil inlet end Pb, the pressure is transmitted to one side / the other side of the reversing valve core through the first opening control module / the second opening control module, overcoming the spring force on the other side / one side of the reversing valve core, and the reversing valve core opens. The oil port ⑤ is connected with the oil port ⑤ through the throttle port; at this time, the pressure of the oil port ⑤ pushes open the second opening control module / the first opening control module and acts on the other side / one side of the reversing valve core, realizing oil circuit opening control and steering control through the high-pressure pilot flow pressure difference; at the same time, the oil port ⑤ is connected with the oil port ⑧, and the load LS signal is fed back to the variable pump.

5. The steering control reversing device according to claim 1, characterized in that: It also includes a first one-way valve, the oil inlet of the first one-way valve is connected to the pilot oil outlet on one side of the reversing valve core, and the oil outlet is connected to the steering cylinder.

6. The steering control reversing device according to claim 1, characterized in that: It also includes a second one-way valve, the oil inlet of the second one-way valve is connected to the pilot oil outlet on the other side of the reversing valve core, and the oil outlet is connected to the steering cylinder.

7. The steering control reversing device according to claim 1, characterized in that: It also includes a first protection module, which includes a third one-way valve and a first oil replenishing valve; the oil outlet A of the reversing valve core is connected to one end of the first oil replenishing valve and the oil outlet of the third one-way valve, and the other end of the first oil replenishing valve, the oil inlet of the third one-way valve and the oil return port are connected.

8. The steering control reversing device according to claim 1, characterized in that: It also includes a second protection module, which includes a fourth one-way valve and a second oil replenishing valve; the oil outlet B of the reversing valve core is connected to one end of the second oil replenishing valve and the oil outlet of the fourth one-way valve, and the other end of the second oil replenishing valve, the oil inlet of the fourth one-way valve and the oil return port are connected.

9. The steering control reversing device according to claim 1, characterized in that: It also includes a priority valve and a relief valve; the oil inlet P of the priority valve is connected to the variable pump, the CF port is connected to the oil inlet P of the reversing valve core, the EF port is connected to the oil inlet of the distribution valve of the working system, and the LS port is connected to the working oil port C of the reversing valve core; the oil inlet of the relief valve is connected to the valve stem of the priority valve, and the oil outlet is connected to the oil return port T.

10. A hydraulic system comprising a steering cylinder, a steering gear, a variable displacement pump and an oil tank, characterized in that: It also includes a steering control reversing device according to any one of claims 1 to 9.

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