Steering valve, steering system and engineering machinery

Abstract

The invention discloses a steering valve, a steering system and an engineering machine. The steering valve comprises a first working opening, a second working opening, a first valve body, a second valve body and a third valve body. The first working opening and the second working opening are used for being connected with a steering cylinder and a working opening of a coaxial flow amplification steering gear. The oil inlet is used for being connected with a steering oil supply port of the priority valve and an oil inlet of the coaxial flow amplification steering gear; a bidirectional cushion valve group is integrated between the first working port and the second working port of the conversion valve; an LS hole of the reversing valve is connected to a spring end of the LS decomposition valve, the first load feedback port and the second load feedback port are communicated with a first port and a second port of the LS decomposition valve, and the first load feedback port is connected to a non-spring end of the LS decomposition valve; the second load feedback port is communicated with the pilot end of the logic valve, and when the pressure of the second load feedback port is larger than the set pressure, the logic valve switches stations to cut off the communication state of the pilot oil port and the handle connecting port, so that the handle connecting port is communicated with the oil discharge port for unloading, and a pilot oil source is cut off; handle control and steering wheel control steering can be selected according to working conditions.

Description

Technical Field

[0001] This application belongs to the field of engineering machinery technology, and specifically relates to a steering valve, a steering system, and engineering machinery. Background Technology

[0002] The performance of the steering system in wheeled construction machinery directly affects the overall operating efficiency, reliability, and driver workload. Currently, the vast majority of wheeled construction machinery uses a fully hydraulic steering system centered around a steering gear. In existing technologies, the driver transmits mechanical torque to the steering gear by manipulating the steering wheel. The steering gear, acting as a mechanical-hydraulic conversion and amplification mechanism, proportionally controls the flow direction and volume of pressurized oil based on the steering wheel angle and speed, thereby driving the steering cylinder to extend and retract, achieving steering of the wheeled construction machinery.

[0003] However, the control method based on the steering gear has inherent defects: (1) High operator fatigue and poor ergonomics. The working conditions of wheeled construction machinery are complex, and frequent forward and backward cycles and small-radius turns are the norm. The driver needs to repeatedly and significantly turn the steering wheel, which consumes a lot of physical strength and easily leads to muscle fatigue. Especially in high-intensity and long-term continuous operation, operator fatigue will significantly reduce the driver's concentration and pose a safety hazard. (2) Complex control response and affect work efficiency: The operation of the steering wheel and the final steering wheel deflection need to be indirectly converted through the steering gear, and its response has a certain lag. When performing fine loading, alignment and other operations, the driver needs to accurately control the steering wheel angle and speed. The operation process is complex and requires high driver skills. This complex control chain prolongs the time of a single work cycle and reduces the overall efficiency of the machine. (3) Spatial layout: The steering wheel and steering column occupy a large amount of cab space, which limits the optimization of the cab layout. Summary of the Invention

[0004] Objective: In view of at least one of the above-mentioned technical problems, this application provides a steering valve, a steering system, and engineering machinery.

[0005] Technical solution: To solve the above-mentioned technical problems, the technical solution adopted in this application is as follows: In a first aspect, a steering valve is provided, including a reversing valve, a two-way buffer valve group, a logic valve and an LS decomposition valve installed in the valve body, and having a first working port, a second working port, an oil inlet port, an oil return port, an oil discharge port, a pilot oil port for connecting to the pilot pump oil supply port, a handle connection port, a second load feedback port for connecting to the load feedback port of the coaxial flow amplification steering gear, and a first load feedback port for connecting to the priority valve control port and the load-sensitive pump variable displacement control port; The first working port and the second working port are used to connect to the steering cylinder and the two working ports of the coaxial flow amplification steering gear; the oil inlet is used to connect to the priority valve steering oil supply port and the oil inlet of the coaxial flow amplification steering gear. The oil inlet of the reversing valve and the LS port of the reversing valve are connected to the oil inlet, the oil return port of the reversing valve is connected to the oil return port, the first working port of the reversing valve is connected to the first working port of the steering valve, and the second working port of the reversing valve is connected to the second working port of the steering valve; a bidirectional buffer valve group is integrated between the first working port and the second working port of the steering valve to realize the instantaneous connection function between the two chambers of the steering cylinder when the steering starts and stops. The LS port of the reversing valve is connected to the spring end of the LS decomposition valve. The first load feedback port is connected to the first port of the LS decomposition valve, and the second load feedback port is connected to the second port of the LS decomposition valve. The first load feedback port is connected to the non-spring end of the LS decomposition valve to enable the LS decomposition valve to reverse so that the first load feedback port is connected to the second load feedback port. The second load feedback port is connected to the pilot end of the logic valve. When the pressure at the second load feedback port is greater than the set pressure, the logic valve switches positions to cut off the connection between the pilot oil port and the handle connection port, so that the handle connection port is connected to the unloading port to unload, thereby cutting off the pilot oil source.

[0006] In some embodiments, the flow channel between the first load feedback port and the second load feedback port is integrated with LS damping so that the oil flow from the first load feedback port to the second load feedback port is in a throttling state.

[0007] In some embodiments, the LS decomposition valve has at least a first position and a second position; when the LS decomposition valve is in the first position, the first load feedback port and the second load feedback port are not connected; when the pressure at the first load feedback port is greater than the sum of the equivalent pressure of the steering load pressure and the spring force of the LS decomposition valve, the LS decomposition valve switches to the second position, and the first load feedback port and the second load feedback port are connected.

[0008] In some embodiments, the logic valve has at least a first position and a second position; when the pressure at the second load feedback port is less than the set pressure, the logic valve is in the first position and does not operate, the pilot oil port and the handle connection port are in a connected state, and the unloading port is always connected to the return oil port; when the pressure at the second load feedback port is greater than the set pressure, the logic valve switches to the second position, cuts off the connection between the pilot oil port and the handle connection port, and connects the handle connection port to the unloading port to unload, thereby cutting off the pilot oil source.

[0009] In some embodiments, the directional valve has at least a first position and a second position. When in the first position, the oil inlet of the directional valve is connected to the first working port of the directional valve, and the second working port of the directional valve is connected to the oil return port of the directional valve. When in the second position, the oil inlet of the directional valve is connected to the second working port of the directional valve, and the first working port of the directional valve is connected to the oil return port of the directional valve.

[0010] In some embodiments, the steering valve is further provided with a first steering pilot port and a second steering pilot port, the first control end of the directional valve is connected to the first steering pilot port, and the second control end of the directional valve is connected to the second steering pilot port.

[0011] In some embodiments, the bidirectional buffer valve assembly includes a first check valve, a second check valve, a shut-off valve, a first damper, a second damper, a first relief valve, and a second relief valve; the first working port is connected to the inlet of the shut-off valve through the first relief valve, the outlet of the shut-off valve is unidirectionally connected to the second working port through the second check valve, the second working port is connected to the inlet of the neutral oil passage of the shut-off valve through the second relief valve, the outlet of the shut-off valve is unidirectionally connected to the first working port through the first check valve, the first working port is connected to the first control terminal of the shut-off valve through the first damper, and the second working port is connected to the second control terminal of the shut-off valve through the second damper.

[0012] Furthermore, the first check valve, the second check valve, the shut-off valve, the first relief valve, the second relief valve, and the first working port are connected in parallel with the second working port. The first check valve and the second check valve are symmetrically arranged, the first relief valve and the second relief valve are symmetrically arranged, and the shut-off valve has a symmetrical valve core structure with a first position, a neutral position, and a second position. When it is in the neutral position, the inlet and outlet of the shut-off valve are connected; when it is in the first or second position, the inlet and outlet of the shut-off valve are not connected.

[0013] Secondly, this application also provides a steering valve, which further includes a first proportional solenoid valve and a second proportional solenoid valve. The oil inlet of the first proportional solenoid valve and the second proportional solenoid valve is connected to the handle connection port, and the oil return port of the first proportional solenoid valve and the second proportional solenoid valve is connected to the unloading port. The working port of the first proportional solenoid valve is connected to the first control end of the directional valve, and the working port of the second proportional solenoid valve is connected to the second control end of the directional valve. The valve is used to control the valve opening ratio of the directional valve through the steering control current of the first proportional solenoid valve and the second proportional solenoid valve, thereby controlling the steering pilot pressure and realizing the directional valve reversing.

[0014] Thirdly, this application also provides a steering system, including a steering cylinder, a hydraulic control handle, a coaxial flow amplification steering gear, a pilot pump, a load-sensitive pump, a priority valve, and the steering valve described in the second aspect; The pilot port of the steering valve is connected to the pilot pump supply port, and the return port and unloading port are connected to the return flow channel respectively. The hydraulic control handle's oil inlet is connected to the steering valve's handle connection port, the hydraulic control handle's oil return port is connected to the oil return channel, the hydraulic control handle's first working port is connected to the first control end of the reversing valve, and the hydraulic control handle's second working port is connected to the first control end of the reversing valve. The first load feedback port of the steering valve is connected to the control port of the priority valve and the variable displacement control port of the load-sensitive pump; the load feedback port of the coaxial flow amplifier steering gear is connected to the second load feedback port of the steering valve; the first working port of the coaxial flow amplifier steering gear is connected to the first working port of the steering valve; the first working port of the coaxial flow amplifier steering gear is connected to the second working port of the steering valve; the load feedback port of the coaxial flow amplifier steering gear is connected to the return oil port of the coaxial flow amplifier steering gear; the return oil port of the coaxial flow amplifier steering gear is connected to the return oil flow channel. The priority valve inlet is connected to the load-sensitive pump inlet, the steering valve inlet is connected to the priority valve steering inlet and the coaxial flow amplifier steering inlet, and the steering valve's first and second working ports are connected to the two working ports of the steering cylinder.

[0015] Furthermore, when the steering system is in the process of turning, the load-sensitive pump outputs the minimum standby flow rate that meets the system's operating requirements. The steering system LS oil circuit is unloaded to the coaxial flow amplification steering gear load feedback port through the first load feedback port of the steering valve, the LS decomposition valve, and the second load feedback port. It is then connected to the return oil channel through the coaxial flow amplification steering gear return oil port, thereby unloading the steering system LS pressure. When turning in the first direction: (1) Hydraulic control handle controls steering: By moving the hydraulic control handle, the angle of the hydraulic control handle is converted into the output pressure of the first working port of the hydraulic control handle, which controls the reversing valve of the steering valve to switch to the first position. The oil inlet of the steering valve is connected to the first working port and the second working port is connected to the return port, so that the first working port of the steering valve supplies oil and the second working port returns oil, thereby driving the steering cylinder to move; at the same time, the steering load pressure during steering is fed back to the priority valve control port and the variable displacement control port of the load sensitive pump through the LS decomposition valve and the first load feedback port, so as to realize priority steering and the load sensitive pump outputs steering flow as needed; (2) Steering wheel controls steering: By turning the steering wheel counterclockwise, the first working port of the coaxial flow amplification steering gear continuously supplies oil to the first working port, and the second working port returns oil through the second working port of the coaxial flow amplification steering gear. This controls the steering cylinder's movement. Simultaneously, the coaxial flow amplification steering gear load feedback port feeds back the steering load pressure to the second load feedback port of the steering valve. One path reaches the two working ports of the steering cylinder at the pilot end of the logic valve, cutting off the oil path from the pilot oil port to the handle connection port. This further cuts off the pilot oil source of the hydraulic handle pilot valve group, preventing the hydraulic handle from controlling the steering, thereby increasing the priority of steering wheel control. The steering load pressure from the second load feedback port of the steering valve is transmitted through the LS decomposition valve and the first load feedback port to the priority valve control port and the variable displacement control port of the load-sensitive pump, similarly achieving priority steering and the load-sensitive pump outputting steering flow as needed. When steering in the first direction, the steering start pressure from the first working port can be connected to the second working port through the first relief valve, the shut-off valve, and the second check valve, instantly unloading it onto the return oil passage. When turning in the second direction: (1) Hydraulic control handle controls steering: By moving the hydraulic control handle, the angle of the hydraulic control handle is converted into the output pressure of the second working port of the hydraulic control handle, which controls the reversing valve of the steering valve to switch to the second position. The oil inlet of the steering valve is connected to the second working port and the first working port is connected to the return port, so that the second working port of the steering valve supplies oil and the first working port returns oil, thereby driving the steering cylinder to move; at the same time, the steering load pressure during steering is fed back to the priority valve control port and the variable displacement control port of the load sensitive pump through the LS decomposition valve and the first load feedback port, so as to realize priority steering and the load sensitive pump outputs steering flow as needed; (2) Steering wheel controls steering: By turning the steering wheel counterclockwise, the second working port of the coaxial flow amplification steering gear continuously supplies oil to the second working port, and the first working port returns oil through the first working port of the coaxial flow amplification steering gear. This controls the steering cylinder's movement. Simultaneously, the coaxial flow amplification steering gear load feedback port feeds back the steering load pressure to the second load feedback port of the steering valve. One path reaches the two working ports of the steering cylinder at the pilot end of the logic valve, cutting off the oil path from the pilot oil port to the handle connection port. This further cuts off the pilot oil source of the hydraulic handle pilot valve group, preventing the hydraulic handle from controlling the steering, thereby increasing the priority of steering wheel control. The steering load pressure from the second load feedback port of the steering valve is transmitted through the LS decomposition valve and the first load feedback port to the priority valve control port and the variable displacement control port of the load-sensitive pump, similarly achieving priority steering and the load-sensitive pump outputting steering flow as needed. When steering in the second direction, the steering start pressure from the second working port can be connected to the first working port through the first relief valve, the shut-off valve, and the second check valve, instantly unloading it onto the return oil passage. When the steering stops, the inertial load of the wheeled construction machinery causes pressure fluctuations in the two chambers of the steering cylinder, causing the first and second working ports of the steering valve to alternately supply oil. When the first working port supplies oil, the pressure in the first working port opens the first relief valve, which, after passing through the middle oil passage of the shut-off valve, opens the second check valve, connecting the first and second working ports. At the same time, the pressure in the first working port reaches the first control end of the shut-off valve through the first damper, causing the shut-off valve to switch to the left position, thus disconnecting the first and second working ports, thereby achieving a short-term unloading from the first working port to the second working port. When the second working port supplies oil, the pressure in the second working port opens the second relief valve, which, after passing through the middle oil passage of the shut-off valve, opens the first check valve, connecting the second and first working ports. At the same time, the pressure in the second working port reaches the second control end of the shut-off valve through the second damper, causing the shut-off valve to switch to the right position, thus disconnecting the second and first working ports, thereby achieving a short-term unloading from the high-pressure oil in the second working port to the low-pressure oil in the first working port. This process repeats, reducing the impact of steering stop.

[0016] Fourthly, this application also provides a steering system, including a steering cylinder, a coaxial flow amplification steering gear, a pilot pump, a load-sensitive pump, a priority valve, an electric control lever, and the steering valve described in the third aspect; The pilot port of the steering valve is connected to the pilot pump supply port, and the return port and unloading port are connected to the return flow channel respectively; the first load feedback port of the steering valve is connected to the priority valve control port and the variable displacement control port of the load-sensitive pump. The load feedback port of the coaxial flow amplifier steering gear is connected to the second load feedback port of the steering valve; the first working port of the coaxial flow amplifier steering gear is connected to the first working port of the steering valve; the first working port of the coaxial flow amplifier steering gear is connected to the second working port of the steering valve; the load feedback port of the coaxial flow amplifier steering gear is connected to the return oil port of the coaxial flow amplifier steering gear; the return oil port of the coaxial flow amplifier steering gear is connected to the return oil flow channel. The oil inlet of the priority valve is connected to the oil supply port of the load-sensitive pump, the oil inlet of the steering valve is connected to the steering oil supply port of the priority valve and the oil inlet of the coaxial flow amplifier steering gear, and the first working port and the second working port of the steering valve are connected to the two working ports of the steering cylinder. The electric control handle includes a signal controller connected to the electromagnets of the first and second proportional solenoid valves. The controller converts the handle rotation angle signal of the electric control handle into a corresponding pilot control current for the electromagnets of the first and second proportional solenoid valves, thereby controlling the pilot control pressure output by the first and second proportional solenoid valves to achieve directional valve switching.

[0017] Furthermore, when turning in the first direction: by moving the electric control handle, the signal controller converts the handle rotation angle signal of the electric control handle into a corresponding pilot control current and sends it to the electromagnet of the first proportional solenoid valve. The first proportional solenoid valve outputs pilot control pressure to the first control end of the reversing valve, controlling the reversing valve to switch to the first position, so that the first working port of the steering valve supplies oil and the second working port returns oil, thereby driving the steering cylinder to move. The steering load pressure during steering is fed back to the priority valve control port and the variable displacement control port of the load sensitive pump through the LS decomposition valve and the first load feedback port, so as to realize priority steering and the load sensitive pump outputs steering flow on demand. When turning in the second direction: by moving the electric control handle, the signal controller converts the handle rotation angle signal into a corresponding pilot control current and sends it to the electromagnet of the second proportional solenoid valve. The second proportional solenoid valve outputs pilot control pressure to the second control terminal of the directional valve, controlling the directional valve to switch to the second working position, so that the second working port of the steering valve supplies oil and the first working port returns oil, thereby driving the steering cylinder to move. The steering load pressure during steering is fed back to the priority valve control port and the variable displacement control port of the load sensitive pump through the LS decomposition valve and the first load feedback port, realizing priority steering and the load sensitive pump outputting steering flow as needed.

[0018] Fifthly, this application also provides an engineering machine equipped with the steering system described in the third or fourth aspect.

[0019] Beneficial Effects: This application provides a steering valve, steering system, and engineering machinery. By providing an integrated buffer steering valve and a redundant control steering system, this application first solves the problem of the single control architecture of the coaxial flow amplification steering system, allowing the driver to flexibly choose between lever control and steering wheel control according to working conditions; it solves the complexity of pipeline layout caused by the integrated buffer valve assembly in the steering system, optimizes the pipeline layout, and reduces the number of leakage failure points in the whole machine; it solves the technical upgrade problem of the coaxial flow amplification steering system being unable to be electro-hydraulic controlled or operated autonomously; it solves the problem of large steering impact in the coaxial flow amplification steering system by integrating the buffer valve assembly; it solves the problems of steering operation complexity and low efficiency by using lever control; and it realizes the function of coordinated steering control by the steering wheel and steering valve, with steering wheel control having the highest priority. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the first embodiment of the steering valve in this application; Figure 2 This is a schematic diagram of the first embodiment of the steering valve in this application; Figure 3 This is a schematic diagram of the first embodiment of the steering system of this application; Figure 4 This is a schematic diagram of the second embodiment of the steering system of this application; Figure 5 , Figure 6 , Figure 8 This is a schematic diagram of the structure of the first embodiment of the steering valve in this application; Figure 7 for Figure 6 Schematic diagram of the AA section; Figure 9 for Figure 8 Schematic diagram of the BB cross section; Figure 10 for Figure 7 Schematic diagram of the CC section; Figure 11 This is a schematic diagram of the structure of the second embodiment of the steering valve in this application; Figure 12 This is a cross-sectional schematic diagram AA of the second embodiment of the steering valve in this application.

[0021] Reference numerals: Valve body 1; Directional control valve 2; Directional control valve LS port 2.1; First check valve 3; Second check valve 4; Shut-off valve 5; First damping 5.1, Second damping 5.2; First relief valve 6, Second relief valve 7; Logic valve 8; LS decomposition valve 9; LS decomposition valve radial port 9.1; LS decomposition valve axial port 9.2; LS damping 9.3; First proportional solenoid valve 10; Second proportional solenoid valve 11; First hydraulic control end cap 12; Second hydraulic control end cap 13; First electronic control end cap 14; Second electronic control end cap 15; Hydraulic control steering valve 16; Electronic control steering valve 17; Steering cylinder 18; Hydraulic control handle 19; Pilot valve assembly 19.1; Coaxial flow amplification steering gear 20; Pilot pump 21; Load-sensitive pump 22; Priority valve 23; Electronic control handle 24; Signal controller 24.1; Steering valve inlet P; Steering valve return port T; First load pressure feedback port LS1 Second load pressure feedback port LS2; Steering valve unloading port Y; First steering pilot port L, second steering pilot port R; Handle connection port Pp; Pilot port Ps; First working port CL of steering valve, second working port CR of steering valve; Hydraulic handle inlet port P2; Hydraulic handle return port T2; First working port A1 of hydraulic handle, second working port B1 of hydraulic handle; Coaxial flow amplifier steering gear inlet port P3; Coaxial flow amplifier steering gear return port T3; Coaxial flow amplifier steering gear load feedback port LS3; First working port A2 of coaxial flow amplifier steering gear, second working port B2 of coaxial flow amplifier steering gear; Pilot pump supply port P1; Load sensitive pump 22; Load sensitive pump supply port P4; Variable displacement control port X; Priority valve inlet port HP; Priority valve control port LS4; Priority valve unloading port S3; Priority valve steering supply port CF; Priority valve confluence port EF. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may include different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0024] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0025] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0026] The technical terms used in this application are defined as follows: LS decomposition valve: enables the LS pressure of both the coaxial flow amplifier diverter and the diverter valve to be transmitted to the priority valve and the load-sensitive pump control port. Logic valve: When the coaxial flow amplifier steering gear is working, the steering load pressure cuts off the pilot oil, thereby increasing the steering priority of the steering wheel control. Buffer function: When steering starts or stops, it enables instantaneous connection between the two chambers of the steering cylinder, thereby eliminating steering shock.

[0027] In some related technologies, the coaxial flow amplification steering system directly controls the steering cylinder action through the coaxial flow amplification steering gear, resulting in a single steering control method. The control mode between the steering system control input and the steering actuator is fixed in the steering wheel operation. In other related technologies, the buffer valve used to mitigate hydraulic shock and protect system safety is usually an independent valve group, connected in parallel to the main oil circuit through external oil pipes and connecting blocks.

[0028] The relevant technologies have the following disadvantages: (1) The single control architecture makes the coaxial flow amplification steering system incompatible with more ergonomic electric or pilot control modes such as handle control. The driver cannot flexibly choose the optimal control mode according to the specific working conditions, which limits the further improvement of the overall machine's work friendliness and work efficiency; (2) The buffer valve is an independent valve group, which makes the system pipeline layout complex, increases the system connection points, leads to potential leakage risks, increases the failure rate, and also increases the system's space occupation; (3) Due to the single control mode and rigid system structure, the existing solution is difficult to use as a basic platform for smooth technical upgrades. For example, if it is desired to introduce electro-hydraulic control or realize the docking of the automatic driving system, a large number of additional devices must be added in addition to the existing mechanical-hydraulic main structure, which is difficult to modify, costly, and may introduce new uncertainties.

[0029] Therefore, this application provides a steering valve, a steering system and engineering machinery, (1) solving the single control architecture of the coaxial flow amplification steering system, allowing the driver to flexibly choose between handle control and steering wheel control according to the working conditions; (2) solving the complexity of pipeline layout caused by the integrated buffer valve group in the steering system, optimizing the pipeline layout and reducing the leakage failure points of the whole machine; (3) solving the technical upgrade problem of the coaxial flow amplification steering system being unable to be electro-hydraulic controlled or unmanned; (4) solving the problem of large steering impact in the coaxial flow amplification steering system.

[0030] Example 1: This example provides a steering valve, such as... Figure 1 , Figure 3 As shown, it can be used as a hydraulic steering valve 16, including a valve body 1 and a reversing valve 2, a two-way buffer valve group, a logic valve 8, and an LS decomposition valve 9 installed in the valve body 1, and has a first working port CL, a second working port CR, an oil inlet port P, an oil return port T, an oil discharge port Y, a pilot oil port Ps for connecting to the oil supply port P1 of the pilot pump 21, a handle connection port Pp, a second load feedback port LS2 for connecting to the load feedback port LS3 of the coaxial flow amplification steering gear 20, and a first load feedback port LS1 for connecting to the control port LS4 of the priority valve 23 and the variable displacement control port X of the load sensitive pump 22; Among them, the first working port CL and the second working port CR are used to connect to the two working ports of the steering cylinder 18 and the coaxial flow amplification steering gear 20; the return oil port T and the unloading oil port Y are respectively connected to the return oil flow channel; the inlet oil port P is used to connect to the steering oil supply port CF of the priority valve 23 and the inlet oil port P3 of the coaxial flow amplification steering gear 20. The oil inlet of the reversing valve 2 and the LS port 2.1 of the reversing valve are connected to the oil inlet P, the oil return port of the reversing valve 2 is connected to the oil return port T, the first working port of the reversing valve 2 is connected to the first working port CL of the steering valve, and the second working port of the reversing valve 2 is connected to the second working port CR of the steering valve. A bidirectional buffer valve assembly is integrated between the first working port CL and the second working port CR to achieve instantaneous connection between the two chambers of the steering cylinder when the steering starts and stops. The directional load pressure of the reversing valve 2 is connected to the spring end of the LS decomposition valve 9 through the LS port 2.1 of the reversing valve. The first load feedback port LS1 is connected to the first port of the LS decomposition valve 9, and the second load feedback port LS2 is connected to the second port of the LS decomposition valve 9. The first load feedback port LS1 is connected to the non-spring end of the LS decomposition valve 9 to make the LS decomposition valve 9 reverse so that the first load feedback port LS1 is connected to the second load feedback port LS2. The second load feedback port LS2 is connected to the pilot end of the logic valve 8. When the pressure of the second load feedback port LS2 is greater than the set pressure, the logic valve 8 switches positions to cut off the connection between the pilot oil port Ps and the handle connection port Pp, so that the handle connection port Pp is connected to the unloading port Y to unload, thereby cutting off the pilot oil source.

[0031] In some embodiments, the steering valve is further provided with a first steering pilot port L and a second steering pilot port R, the first control end of the reversing valve 2 is connected to the first steering pilot port L, and the second control end of the reversing valve 2 is connected to the second steering pilot port R.

[0032] In some embodiments, the flow channel between the first load feedback port LS1 and the second load feedback port LS2 is integrated with an LS damper 9.3 to throttle the oil flow from the first load feedback port LS1 to the second load feedback port LS2. Further, in this embodiment, the LS damper 9.3 is integrated within the first load feedback port LS1.

[0033] In some embodiments, the LS decomposition valve includes an LS decomposition valve radial hole 9.1 and an LS decomposition valve axial hole 9.2, and the pressure of the first load feedback port LS1 is connected to the non-spring end of the LS decomposition valve 9 through the LS decomposition valve radial hole 9.1 and the LS decomposition valve axial hole 9.2.

[0034] During steering, the steering load pressure is transmitted to the spring end of the LS decomposition valve 9, further increasing the pressure at the first load feedback port LS1. At this time, the pressure at the first load feedback port LS1 is equal to the sum of the steering load pressure and the equivalent pressure of the LS decomposition valve spring force. In this embodiment, the steering load pressure of the reversing valve 2 acts on the spring end of the LS decomposition valve 9 through the reversing valve LS port 2.1. The first load feedback port LS1 is connected to the first port of the LS decomposition valve 9 through the LS damper 9.3, and the second load feedback port LS2 is connected to the second port of the LS decomposition valve 9. The pressure at the first load feedback port LS1 is connected to the non-spring end of the LS decomposition valve 9 through the radial port 9.1 and the axial port 9.2 of the LS decomposition valve, which is used to reverse the LS decomposition valve 9.

[0035] In some embodiments, the LS decomposition valve 9 has at least a first position (right position) and a second position (left position). When it is in the first position, the first load feedback port LS1 and the second load feedback port LS2 are not connected. When the pressure of the first load feedback port LS1 is greater than the sum of the equivalent pressure of the steering load pressure and the spring force of the LS decomposition valve, and it is switched to the second position (left position), the first load feedback port LS1 and the second load feedback port LS2 are connected, and the LS damping 9.3 makes the oil flow from the first load feedback port LS1 to the second load feedback port LS2 throttled.

[0036] In this application, the LS decomposition valve enables the LS pressure of both the handle-controlled steering valve and the coaxial flow amplification steering gear to be fed back to the priority valve 23 control port LS4 and the load-sensitive pump variable displacement control port X, thereby achieving priority steering and on-demand oil supply.

[0037] In some embodiments, the logic valve 8 has at least a first position and a second position. When the second load feedback port LS2 is low-pressure oil and the pressure is less than the set pressure (equivalent pressure of the spring force of the logic valve 8), the logic valve 8 is in the first position (left position) and does not operate. The pilot oil port Ps and the handle connection port Pp are in a connected state, and the unloading port Y is always connected to the return oil port T. When the second load feedback port LS2 is high-pressure oil and the pressure is greater than the set pressure (equivalent pressure of the spring force of the logic valve 8), the logic valve 8 switches to the second position (right position), cuts off the connection between the pilot oil port Ps and the handle connection port Pp, and connects the handle connection port Pp to the unloading port Y to unload, thereby cutting off the pilot oil source.

[0038] In this application, the valve body integrates a logic valve 8, which allows the driver to flexibly choose between lever control and steering wheel control according to the working conditions. When lever control fails, steering wheel control takes priority, or in case of emergency, steering wheel also has the highest steering control authority.

[0039] In some embodiments, such as Figure 1 , Figure 2As shown, the bidirectional buffer valve assembly includes a first check valve 3, a second check valve 4, a shut-off valve 5, a first damper 5.1, a second damper 5.2, a first relief valve 6, and a second relief valve 7. The first working port CL is connected to the inlet of the shut-off valve 5 via the first relief valve 6. The outlet of the shut-off valve 5 is unidirectionally connected to the second working port CR via the second check valve 4. The second working port CR is connected to the inlet of the shut-off valve 5 via the second relief valve 7. The outlet of the shut-off valve 5 is unidirectionally connected to the first working port CL via the first check valve 3. The first working port CL is connected to the first control terminal of the shut-off valve 5 via the first damper 5.1. The second working port CR is connected to the second control terminal of the shut-off valve 5 via the second damper 5.2. The specifications of the first damper 5.1 and the second damper 5.2 can be adjusted to meet different steering impact requirements of the entire machine, adapting to different engineering vehicles or market customers.

[0040] Furthermore, in some embodiments, such as Figure 1 , Figure 2 As shown, the first check valve 3, the second check valve 4, the shut-off valve 5, the first relief valve 6, the second relief valve 7 are connected in parallel with the first working port CL and the second working port CR. The first check valve 3 and the second check valve 4 are arranged symmetrically, the first relief valve 6 and the second relief valve 7 are arranged symmetrically, and the shut-off valve 5 has a symmetrical valve core structure with a first position, a middle position and a second position. When it is in the middle position, the inlet and outlet of the shut-off valve 5 are connected; when it is in the first or second position, the inlet and outlet of the shut-off valve 5 are not connected. When turning in the first direction, the first working port CL is the high-pressure chamber, and the second working port CR is the low-pressure chamber. At the moment of steering initiation impact, the first relief valve 6 opens, and the steering impact is unloaded into the through-pass oil passage (the intermediate oil passage of the shut-off valve 5). It then passes through the second check valve 4 and enters the low-pressure chamber (the second working port CR). Simultaneously, the high-pressure chamber of the first working port CL enters the first control end of the shut-off valve 5 through the first damper 5.1, causing the shut-off valve 5 to further block the through-pass oil passage (the intermediate oil passage of the shut-off valve 5). The first damper 5.1 delays the closing time of the through-pass oil passage (the intermediate oil passage of the shut-off valve 5), and this time period is the release time of the steering impact. The first damper 5.1 and the second damper 5.2 have the same specifications; changing their size adjusts the closing time of the shut-off valve 5. The principle is the same when turning in the second direction. When steering stops, the first working port CL and the second working port CR of the steering valve alternately switch between high and low pressure. Through the first damping 5.1 and the second damping 5.2, the closing process of the shut-off valve 5 is delayed, ensuring that the first working port CL and the second working port CR of the steering valve are momentarily connected, thereby eliminating the steering stop impact. In this application, the valve body integrates a buffer valve assembly, optimizing the piping layout of the steering system and reducing leakage points.

[0041] In this embodiment, Figure 5 , Figure 6 , Figure 8This is a schematic diagram of the structure of the first embodiment of the steering valve in this application; Figure 7 for Figure 6 Schematic diagram of the AA section; Figure 9 for Figure 8 Schematic diagram of the BB cross section; Figure 10 for Figure 7 A cross-sectional view of the CC section; the reversing valve 2, the first check valve 3, the second check valve 4, the shut-off valve 5, the logic valve 8, and the LS decomposition valve 9 are spool valves; the second relief valve 7 and the first relief valve 6 are connected to the valve body 1 by insert thread; the steering valve in this embodiment also includes a first hydraulic control end cap 12 and a second hydraulic control end cap 13, which are fixedly connected to the valve body 1 by screws. Figure 9 As shown, logic valve 8, LS decomposition valve 9, shut-off valve 5, first relief valve 6, and second relief valve 7 are arranged in parallel within valve body 1, forming a structure with the same cross-section of the valve body. First damping 5.1 is arranged vertically between first relief valve 6 and shut-off valve 5, and second damping 5.2 is arranged vertically between second relief valve 7 and shut-off valve 5. A through oil passage (the middle position oil passage of shut-off valve 5) is arranged between first relief valve 6 and second relief valve 7, passing through the valve hole of shut-off valve 5 and arranged vertically thereto. When shut-off valve 5 is activated, it can cut off the through oil passage (the middle position oil passage of shut-off valve 5). First check valve 3 and second check valve 4 are arranged vertically on both sides of the through oil passage (the middle position oil passage of shut-off valve 5).

[0042] In some embodiments, the directional control valve 2 has at least a first position (left position) and a second position (right position). When in the first position (left position), the oil inlet of the directional control valve 2 is connected to the first working port of the directional control valve 2, and the second working port of the directional control valve 2 is connected to the oil return port of the directional control valve 2. When in the second position (right position), the oil inlet of the directional control valve 2 is connected to the second working port of the directional control valve 2, and the first working port of the directional control valve 2 is connected to the oil return port of the directional control valve 2. In this embodiment, the directional control valve 2 is a three-position four-way valve.

[0043] In this embodiment, the reversing valve 2 and the LS decomposition valve 9 are arranged parallel to each other within the valve body 1; as Figure 7 As shown, the reversing valve 2 is located in another section of the valve body 1. When the reversing valve 2 is reversed to the first working position (left position), the oil inlet P is connected to the first working port CL, and the second working port CR is connected to the return port T. When the reversing valve 2 is reversed to the second working position (right position), the oil inlet P is connected to the second working port CR, and the first working port CL is connected to the return port T.

[0044] Example 2: Based on Example 1, this example provides a steering valve, such as... Figure 2 , Figure 4As shown, the hydraulic steering valve 17 also includes a first proportional solenoid valve 10 and a second proportional solenoid valve 11. The oil inlet of the first proportional solenoid valve 10 and the second proportional solenoid valve 11 is connected to the handle connection port Pp, and the oil return port of the first proportional solenoid valve 10 and the second proportional solenoid valve 11 is connected to the unloading port Y. The working port of the first proportional solenoid valve 10 is connected to the first control end (first steering pilot port L) of the directional valve 2, and the working port of the second proportional solenoid valve 11 is connected to the second control end (second steering pilot port R) of the directional valve 2. The valves are used to control the valve opening ratio of the directional valve 2 through the steering control current of the first proportional solenoid valve 10 and the second proportional solenoid valve 11, thereby controlling the steering pilot pressure and realizing the directional valve 2 switching.

[0045] In some embodiments, Figure 11 This is a schematic diagram of the structure of the second embodiment of the steering valve in this application; Figure 12 This is a cross-sectional view (AA) of the second embodiment of the steering valve in this application. Unlike embodiment 1, the steering valve in this embodiment also includes a first electrically controlled end cap 14 and a second electrically controlled end cap 15, wherein the first electrically controlled end cap 14 and the second electrically controlled end cap 15 are fixedly connected to the valve body 1 by screws; the first proportional solenoid valve 10 and the first electrically controlled end cap 14, and the second proportional solenoid valve 11 and the second electrically controlled end cap 15 are all connected by a plug-in structure and screws.

[0046] It should be noted that the integrated buffer function steering valve designed in this application can also reduce or add new functions to the steering valve, such as integrating the LS overflow valve, buffer suction valve, priority valve, etc. into the steering valve, or integrating the emergency manual mechanism into the electronic control end cover to realize emergency steering.

[0047] In this application embodiment, the hydraulic control handle-controlled steering valve and the electric control handle-controlled steering valve are valves on the same platform. The hydraulic control steering valve can be switched to or upgraded to an electric control steering valve by replacing the electric control end cap and the electric control valve body.

[0048] Example 3: Based on Example 1, this example provides a steering system (a coaxial flow amplification steering system for wheeled engineering machinery compatible with hydraulic control handles), including a steering cylinder 18, a hydraulic control handle 19, a coaxial flow amplification steering gear 20, a pilot pump 21, a load-sensitive pump 22, a priority valve 23, and the hydraulic control steering valve 16 described in Example 1; The pilot port Ps of the steering valve is connected to the oil supply port P1 of the pilot pump 21, and the return port T and the unloading port Y are respectively connected to the return flow channel. The hydraulic control handle 19 includes a pilot valve assembly 19.1, which has an oil inlet P2, an oil return port T2, a first working port A1, and a second working port B1. The oil inlet P2 of the hydraulic control handle 19 is connected to the handle connection port Pp of the steering valve, the oil return port T2 of the hydraulic control handle 19 is connected to the oil return channel, the first working port A1 of the hydraulic control handle 19 is connected to the first steering pilot port L of the steering valve, and the second working port B1 of the hydraulic control handle 19 is connected to the second steering pilot port R of the steering valve. The first load feedback port LS1 of the steering valve is connected to the control port LS4 of the priority valve 23 and the variable displacement control port X of the load-sensitive pump 22; the load feedback port LS3 of the coaxial flow amplifier steering gear 20 is connected to the second load feedback port LS2 of the steering valve; the first working port A2 of the coaxial flow amplifier steering gear 20 is connected to the first working port CL of the steering valve; the first working port B2 of the coaxial flow amplifier steering gear 20 is connected to the second working port CR of the steering valve; the load feedback port LS3 of the coaxial flow amplifier steering gear 20 is connected to the return port T3 of the coaxial flow amplifier steering gear 20; the return port T3 of the coaxial flow amplifier steering gear 20 is connected to the return flow channel. The oil inlet HP of the priority valve 23 is connected to the oil supply port P4 of the load-sensitive pump 22. The oil inlet P of the steering valve is connected to the steering oil supply port CF of the priority valve 23 and the oil inlet P3 of the coaxial flow amplification steering gear 20. The first working port CL and the second working port CR of the steering valve are connected to the oil inlet and return port of the steering cylinder 18.

[0049] It should be noted that the priority valve unloading port S3 is connected to the return oil flow channel; when the priority valve 23 is in the first working state (right position), oil is supplied to the steering valve through the steering oil supply port CF of the priority valve 23; when the priority valve 23 is in the second working state (left position), while supplying oil to the steering valve through the steering oil supply port CF of the priority valve 23, it can also supply oil to the main valve of other actuators through the priority valve confluence port EF.

[0050] The steering system described in this embodiment operates as follows: When the steering system is about to turn, the load-sensitive pump 22 outputs the minimum standby flow rate that meets the system's operating requirements. The steering system LS oil circuit is unloaded through the first load feedback port LS1 of the steering valve, LS damping 9.3, LS decomposition valve 9, and the second load feedback port LS2 to the load feedback port LS3 of the coaxial flow amplification steering gear 20. It is then connected to the return oil channel through the return oil port T3 of the coaxial flow amplification steering gear 20, thereby unloading the steering system LS pressure.

[0051] When turning in the first direction: (1) Hydraulic control handle controls steering: By moving the hydraulic control handle 19, the angle of the hydraulic control handle 19 is converted into the output pressure of the first working port A1 of the hydraulic control handle 19, which controls the reversing valve 2 of the steering valve to switch to the first position. The oil inlet P of the steering valve is connected to the first working port CL, and the second working port CR is connected to the return port T, so that the first working port CL of the steering valve supplies oil and the second working port CR returns oil, thereby driving the steering cylinder 18 to move. At the same time, the steering load pressure during steering is fed back to the priority valve 23 control port LS4 and the variable displacement control port X of the load sensitive pump 22 through the LS decomposition valve 9 and the first load feedback port LS1, so as to realize priority steering and the load sensitive pump 22 outputs steering flow as needed; (2) Steering wheel controls steering: By turning the steering wheel counterclockwise, the first working port A2 of the coaxial flow amplification steering gear 20 continuously supplies oil to the first working port CL, and the second working port CR returns oil through the second working port B2 of the coaxial flow amplification steering gear 20. This controls the steering cylinder 18 to move, while the coaxial flow amplification steering gear 20 load feedback port LS3 feeds back the steering load pressure to the second load feedback port LS2 of the steering valve. One path reaches the pilot end (non-spring end) of the logic valve 8, cutting off the oil path from the pilot oil port Ps to the handle connection port Pp, further cutting off the pilot oil source of the pilot valve group of the hydraulic control handle 19, making the hydraulic control handle unable to control steering, thereby increasing the priority of steering wheel control. The steering load pressure of the second load feedback port LS2 of the steering valve is transmitted to the control port LS4 of the priority valve 23 and the variable displacement control port X of the load sensitive pump 22 through the LS decomposition valve 9 and the first load feedback port LS1, thus achieving priority steering and the load sensitive pump 22 outputting steering flow as needed. When steering in the first direction, the steering start pressure of the first working port CL can be connected to the second working port CR through the first relief valve 6, the shut-off valve 5, and the second check valve 4, instantly unloading to the return oil channel, further improving steering stability.

[0052] When turning in the second direction: (1) Hydraulic control handle controls steering: By moving the hydraulic control handle 19, the angle of the hydraulic control handle 19 is converted into the output pressure of the second working port B1 of the hydraulic control handle 19, which controls the reversing valve 2 of the steering valve to switch to the second position. The oil inlet P of the steering valve is connected to the second working port CR, and the first working port CL is connected to the return port T, so that the second working port CR of the steering valve supplies oil and the first working port CL returns oil, thereby driving the steering cylinder 18 to move; at the same time, the steering load pressure during steering is fed back to the priority valve 23 control port LS4 and the variable displacement control port X of the load sensitive pump 22 through the LS decomposition valve 9 and the first load feedback port LS1, so as to realize priority steering and the load sensitive pump 22 outputs steering flow as needed; (2) Steering wheel controls steering: By turning the steering wheel counterclockwise, the second working port B2 of the coaxial flow amplification steering gear 20 continuously supplies oil to the second working port CR, and the first working port CL returns oil through the first working port A2 of the coaxial flow amplification steering gear 20. This controls the steering cylinder 18 to move, while the coaxial flow amplification steering gear 20 load feedback port LS3 feeds back the steering load pressure to the second load feedback port LS2 of the steering valve. One path reaches the pilot end (non-spring end) of the logic valve 8, cutting off the oil path from the pilot oil port Ps to the handle connection port Pp, further cutting off the pilot oil source of the pilot valve group of the hydraulic control handle 19, making the hydraulic control handle unable to control steering, thereby increasing the priority of steering wheel control. The steering load pressure of the second load feedback port LS2 of the steering valve is transmitted to the control port LS4 of the priority valve 23 and the variable displacement control port X of the load sensitive pump 22 through the LS decomposition valve 9 and the first load feedback port LS1, thus achieving priority steering and the load sensitive pump 22 outputting steering flow as needed. When steering in the second direction, the steering start pressure of the second working port CR can be connected to the first working port CL through the first relief valve 6, the shut-off valve 5, and the second check valve 4, instantly unloading to the return oil channel, further improving steering stability.

[0053] When the steering stops, the inertial load of the wheeled construction machinery causes pressure fluctuations in the two chambers of the steering cylinder 18, causing the first working port CL and the second working port CR of the steering valve to alternately supply oil. Since the steering valve integrates a two-way buffer valve assembly, when the first working port CL supplies oil, the pressure at the first working port CL opens the first relief valve 6, and after passing through the through-oil passage (the middle oil passage of the shut-off valve 5), it opens the second check valve 4, connecting the first working port CL and the second working port CR. Simultaneously, the pressure at the first working port CL reaches the first control end of the shut-off valve 5 through the first damper 5.1, causing the shut-off valve 5 to reverse to the left, thereby disconnecting the first working port CL from the second working port CR, thus achieving... The high-pressure oil at the first working port CL is temporarily unloaded to the low-pressure oil at the second working port CR. When the second working port CR supplies oil, the pressure at the second working port CR opens the second relief valve 7, and after passing through the through oil passage (the middle oil passage of the shut-off valve 5), it opens the first check valve 3, connecting the second working port CR with the first working port CL. At the same time, the pressure at the second working port CR reaches the second control end of the shut-off valve 5 through the second damper 5.2, causing the shut-off valve 5 to switch to the right position, thereby disconnecting the second working port CR from the first working port CL. This achieves the temporary unloading of the high-pressure oil at the second working port CR to the low-pressure oil at the first working port CL. This process is repeated to reduce the impact of steering stop.

[0054] Example 4: Based on Example 2, this example provides a steering system (a coaxial flow amplification steering system for wheeled construction machinery compatible with electric control handle control), including a steering cylinder 18, a coaxial flow amplification steering gear 20, a pilot pump 21, a load-sensitive pump 22, a priority valve 23, an electric control handle 24, and the electric control steering valve 17 described in Example 2; The pilot port Ps of the steering valve is connected to the supply port P1 of the pilot pump 21; the first load feedback port LS1 of the steering valve is connected to the control port LS4 of the priority valve 23 and the variable displacement control port X of the load-sensitive pump 22; the load feedback port LS3 of the coaxial flow amplification steering gear 20 is connected to the second load feedback port LS2 of the steering valve; the first working port A2 of the coaxial flow amplification steering gear 20 is connected to the first working port CL of the steering valve; the first working port B2 of the coaxial flow amplification steering gear 20 is connected to the second working port CR of the steering valve; the load feedback port LS3 of the coaxial flow amplification steering gear 20 is connected to the return port T3 of the coaxial flow amplification steering gear 20; and the return port T3 of the coaxial flow amplification steering gear 20 is connected to the return flow channel. The oil inlet HP of the priority valve 23 is connected to the oil supply port P4 of the load-sensitive pump 22. The oil inlet P of the steering valve is connected to the steering oil supply port CF of the priority valve 23 and the oil inlet P3 of the coaxial flow amplification steering gear 20. The first working port CL and the second working port CR of the steering valve are connected to the oil inlet and return port of the steering cylinder 18. The electric control handle 24 includes a signal controller 24.1, which is connected to the electromagnets of the first proportional solenoid valve 10 and the second proportional solenoid valve 11. The controller converts the handle rotation angle signal of the electric control handle 24 into a corresponding pilot control current and supplies it to the electromagnets of the first proportional solenoid valve 10 and the second proportional solenoid valve 11, thereby controlling the pilot control pressure output by the first proportional solenoid valve 10 and the second proportional solenoid valve 11 to realize the switching of the directional valve 2.

[0055] The steering system in this embodiment operates in essentially the same way as the steering system described in Embodiment 3, with the system working states being to be steered, the coaxial flow amplification steering gear controlling the steering, and the steering stopping. Only the differences are described here: When the wheeled construction machinery needs to turn, the electric control handle 24 is pulled, and the electric control handle 24 transmits the handle rotation angle signal to the signal controller 24.1. The signal controller 24.1 will output different pilot control currents to the electromagnets of the first proportional solenoid valve 10 and the second proportional solenoid valve 11 according to different handle rotation angles according to the pre-programmed program, thereby controlling the first proportional solenoid valve 10 and the second proportional solenoid valve 11 to output different pilot control pressures, and further realize the reversing valve 2 reversing.

[0056] When turning in the first direction (left): by moving the electric control handle 24, the signal controller 24.1 converts the handle rotation angle signal of the electric control handle 24 into a corresponding pilot control current and sends it to the electromagnet of the first proportional solenoid valve 10. The first proportional solenoid valve 10 outputs pilot control pressure to the first control terminal of the reversing valve 2, controlling the reversing valve 2 to switch to the first position, so that the first working port CL of the steering valve supplies oil and the second working port CR returns oil, thereby driving the steering cylinder 18 to move. The steering load pressure during steering is fed back to the control port LS4 of the priority valve 23 and the variable displacement control port X of the load sensitive pump 22 through the LS decomposition valve 9 and the first load feedback port LS1, so as to realize priority steering and the load sensitive pump 22 outputs steering flow as needed.

[0057] When turning in the second direction (right): by moving the electric control handle 24, the signal controller 24.1 converts the handle rotation angle signal of the electric control handle 24 into a corresponding pilot control current and sends it to the electromagnet of the second proportional solenoid valve 11. The second proportional solenoid valve 11 outputs pilot control pressure to the second control terminal of the reversing valve 2, controlling the reversing valve 2 to switch to the second position, so that the second working port CR of the steering valve supplies oil and the first working port CL returns oil, thereby driving the steering cylinder 18 to move. The steering load pressure during steering is fed back to the control port LS4 of the priority valve 23 and the variable displacement control port X of the load sensitive pump 22 through the LS decomposition valve 9 and the first load feedback port LS1, realizing priority steering and the load sensitive pump 22 outputting steering flow as needed.

[0058] Example 5: This example provides an engineering machine equipped with the steering system described in Example 3 or Example 4.

[0059] This application embodiment, by providing an integrated buffer function steering valve and a redundant control steering system, firstly solves the problem of the single control architecture of the coaxial flow amplification steering system, allowing the driver to flexibly choose between lever control and steering wheel control according to operating conditions; it also solves the complexity of the pipeline layout caused by the integrated buffer valve assembly in the steering system, optimizes the pipeline layout, and reduces the number of leakage failure points; it solves the technical upgrade problem of the coaxial flow amplification steering system being unable to be electro-hydraulic controlled or autonomously driven; it solves the problem of large steering impact in the coaxial flow amplification steering system by integrating the buffer valve assembly; it solves the problems of steering operation complexity and low efficiency by using lever control; and it realizes the function of coordinated steering control by the steering wheel and steering valve, with steering wheel control having the highest priority.

[0060] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this application. The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A steering valve, characterized in that, It includes a reversing valve, a two-way buffer valve group, a logic valve and an LS decomposition valve installed in the valve body, and is provided with a first working port, a second working port, an oil inlet port, an oil return port, an oil discharge port, a pilot oil port for connecting to the pilot pump oil supply port, a handle connection port, a second load feedback port for connecting to the load feedback port of the coaxial flow amplifier steering gear, and a first load feedback port for connecting to the priority valve control port and the load sensitive pump variable displacement control port; The first working port and the second working port are used to connect to the steering cylinder and the two working ports of the coaxial flow amplification steering gear; the oil inlet is used to connect to the priority valve steering oil supply port and the oil inlet of the coaxial flow amplification steering gear. The oil inlet of the reversing valve and the LS port of the reversing valve are connected to the oil inlet, the oil return port of the reversing valve is connected to the oil return port, the first working port of the reversing valve is connected to the first working port of the steering valve, and the second working port of the reversing valve is connected to the second working port of the steering valve; a bidirectional buffer valve group is integrated between the first working port and the second working port of the steering valve to realize the instantaneous connection function between the two chambers of the steering cylinder when the steering starts and stops. The LS port of the reversing valve is connected to the spring end of the LS decomposition valve. The first load feedback port is connected to the first port of the LS decomposition valve, and the second load feedback port is connected to the second port of the LS decomposition valve. The first load feedback port is connected to the non-spring end of the LS decomposition valve to enable the LS decomposition valve to reverse so that the first load feedback port is connected to the second load feedback port. The second load feedback port is connected to the pilot end of the logic valve. When the pressure at the second load feedback port is greater than the set pressure, the logic valve switches positions to cut off the connection between the pilot oil port and the handle connection port, so that the handle connection port is connected to the unloading port to unload, thereby cutting off the pilot oil source.

2. The steering valve according to claim 1, characterized in that, The flow channel between the first load feedback port and the second load feedback port is integrated with LS damping so that the oil flow from the first load feedback port to the second load feedback port is in a throttling state.

3. The steering valve according to claim 1, characterized in that, The LS decomposition valve has at least a first position and a second position; when the LS decomposition valve is in the first position, the first load feedback port and the second load feedback port are not connected; when the pressure of the first load feedback port is greater than the sum of the equivalent pressure of the turning load pressure and the spring force of the LS decomposition valve, the LS decomposition valve switches to the second position, and the first load feedback port and the second load feedback port are connected.

4. The steering valve according to claim 1, characterized in that, The logic valve has at least a first position and a second position. When the pressure at the second load feedback port is less than the set pressure, the logic valve is in the first position and does not operate. The pilot oil port and the handle connection port are in a connected state, and the unloading port is always connected to the return oil port. When the pressure at the second load feedback port is greater than the set pressure, the logic valve switches to the second position, cuts off the connection between the pilot oil port and the handle connection port, and connects the handle connection port to the unloading port to unload, thereby cutting off the pilot oil source.

5. The steering valve according to claim 1, characterized in that, The directional valve has at least a first position and a second position. When it is in the first position, the oil inlet of the directional valve is connected to the first working port of the directional valve, and the second working port of the directional valve is connected to the oil return port of the directional valve. When it is in the second position, the oil inlet of the directional valve is connected to the second working port of the directional valve, and the first working port of the directional valve is connected to the oil return port of the directional valve.

6. The steering valve according to claim 1, characterized in that, The steering valve is further provided with a first steering pilot port and a second steering pilot port. The first control end of the reversing valve is connected to the first steering pilot port, and the second control end of the reversing valve is connected to the second steering pilot port.

7. The steering valve according to claim 1, characterized in that, The bidirectional buffer valve assembly includes a first check valve, a second check valve, a shut-off valve, a first damper, a second damper, a first relief valve, and a second relief valve. The first working port is connected to the inlet of the shut-off valve through the first relief valve. The outlet of the shut-off valve is unidirectionally connected to the second working port through the second check valve. The second working port is connected to the inlet of the neutral oil passage of the shut-off valve through the second relief valve. The outlet of the shut-off valve is unidirectionally connected to the first working port through the first check valve. The first working port is connected to the first control terminal of the shut-off valve through the first damper. The second working port is connected to the second control terminal of the shut-off valve through the second damper.

8. The steering valve according to claim 7, characterized in that, The first check valve, the second check valve, the shut-off valve, the first relief valve, the second relief valve, the first working port, and the second working port are connected in parallel. The first check valve and the second check valve are arranged symmetrically, the first relief valve and the second relief valve are arranged symmetrically, and the shut-off valve has a symmetrical valve core structure with a first position, a neutral position, and a second position. When it is in the neutral position, the inlet and outlet of the shut-off valve are connected; when it is in the first or second position, the inlet and outlet of the shut-off valve are not connected.

9. The steering valve according to any one of claims 1-8, characterized in that, It also includes a first proportional solenoid valve and a second proportional solenoid valve. The oil inlet of the first proportional solenoid valve and the second proportional solenoid valve are connected to the handle connection port, and the oil return port of the first proportional solenoid valve and the second proportional solenoid valve are connected to the unloading port. The working port of the first proportional solenoid valve is connected to the first control end of the directional valve, and the working port of the second proportional solenoid valve is connected to the second control end of the directional valve. It is used to control the valve opening ratio of the directional valve through the steering control current of the first proportional solenoid valve and the second proportional solenoid valve, thereby controlling the steering pilot pressure and realizing the directional valve switching.

10. A steering system, characterized in that, Includes a steering cylinder, a hydraulic control handle, a coaxial flow amplification steering gear, a pilot pump, a load-sensitive pump, a priority valve, and a steering valve as described in any one of claims 1 to 8; The pilot port of the steering valve is connected to the pilot pump supply port, and the return port and unloading port are connected to the return flow channel respectively. The hydraulic control handle's oil inlet is connected to the steering valve's handle connection port, the hydraulic control handle's oil return port is connected to the oil return channel, the hydraulic control handle's first working port is connected to the first control end of the reversing valve, and the hydraulic control handle's second working port is connected to the first control end of the reversing valve. The first load feedback port of the steering valve is connected to the control port of the priority valve and the variable displacement control port of the load-sensitive pump; the load feedback port of the coaxial flow amplifier steering gear is connected to the second load feedback port of the steering valve; the first working port of the coaxial flow amplifier steering gear is connected to the first working port of the steering valve; the first working port of the coaxial flow amplifier steering gear is connected to the second working port of the steering valve; the load feedback port of the coaxial flow amplifier steering gear is connected to the return oil port of the coaxial flow amplifier steering gear; the return oil port of the coaxial flow amplifier steering gear is connected to the return oil flow channel. The priority valve inlet is connected to the load-sensitive pump inlet, the steering valve inlet is connected to the priority valve steering inlet and the coaxial flow amplifier steering inlet, and the steering valve's first and second working ports are connected to the two working ports of the steering cylinder.

11. The steering system according to claim 10, characterized in that, When the steering system is about to turn, the load-sensitive pump outputs the minimum standby flow rate to meet the system's operating requirements. The steering system LS oil circuit is unloaded to the coaxial flow amplifier steering gear load feedback port through the first load feedback port of the steering valve, the LS decomposition valve, and the second load feedback port. It is then connected to the return oil channel through the coaxial flow amplifier steering gear return oil port, thus unloading the steering system LS pressure. When turning in the first direction: (1) The hydraulic control handle controls the steering: by moving the hydraulic control handle, the angle of the hydraulic control handle is converted into the output pressure of the first working port of the hydraulic control handle, which controls the reversing valve of the steering valve to switch to the first working position. The oil inlet of the steering valve is connected to the first working port and the second working port is connected to the return port, so that the first working port of the steering valve supplies oil and the second working port returns oil, thereby driving the steering cylinder to move; at the same time, the steering load pressure during steering is fed back to the priority valve control port and the variable displacement control port of the load sensitive pump through the LS decomposition valve and the first load feedback port, so as to realize priority steering and the load sensitive pump outputs steering flow as needed; (2) Steering wheel control: By turning the steering wheel counterclockwise, the first working port of the coaxial flow amplification steering gear continuously supplies oil to the first working port, and the second working port returns oil through the second working port of the coaxial flow amplification steering gear, thereby controlling the steering cylinder to move. At the same time, the load feedback port of the coaxial flow amplification steering gear feeds back the steering load pressure to the second load feedback port of the steering valve, and one path reaches the two working ports of the steering cylinder at the pilot end of the logic valve, cutting off the oil path from the pilot oil port to the handle connection port, and further cutting off the pilot oil source of the hydraulic control handle pilot valve group, so that the hydraulic control handle cannot control the steering, thereby increasing the priority of steering wheel control; the steering load pressure of the second load feedback port of the steering valve is transmitted to the priority valve control port and the variable displacement control port of the load sensitive pump through the LS decomposition valve and the first load feedback port, which also realizes priority steering and the load sensitive pump outputs steering flow as needed; when turning in the first direction, the steering start pressure of the first working port can be connected to the second working port through the first overflow valve, the shut-off valve, and the second check valve, and is instantly unloaded to the return oil channel; When turning in the second direction: (1) Hydraulic control handle controls the steering: by moving the hydraulic control handle, the angle of the hydraulic control handle is converted into the output pressure of the second working port of the hydraulic control handle, which controls the reversing valve of the steering valve to switch to the second position. The oil inlet of the steering valve is connected to the second working port and the first working port is connected to the return port, so that the second working port of the steering valve supplies oil and the first working port returns oil, thereby driving the steering cylinder to move; at the same time, the steering load pressure during steering is fed back to the priority valve control port and the variable displacement control port of the load sensitive pump through the LS decomposition valve and the first load feedback port, so as to realize priority steering and the load sensitive pump outputs steering flow as needed; (2) Steering wheel control: By turning the steering wheel counterclockwise, the second working port of the coaxial flow amplification steering gear continuously supplies oil to the second working port, and the first working port returns oil through the first working port of the coaxial flow amplification steering gear, thereby controlling the steering cylinder to move. At the same time, the load feedback port of the coaxial flow amplification steering gear feeds back the steering load pressure to the second load feedback port of the steering valve, and one path reaches the two working ports of the steering cylinder at the pilot end of the logic valve, cutting off the oil path from the pilot oil port to the handle connection port, and further cutting off the pilot oil source of the hydraulic control handle pilot valve group, so that the hydraulic control handle cannot control the steering, thereby increasing the priority of steering wheel control; the steering load pressure of the second load feedback port of the steering valve is transmitted to the priority valve control port and the variable displacement control port of the load sensitive pump through the LS decomposition valve and the first load feedback port, which also realizes priority steering and the load sensitive pump outputs steering flow as needed; when turning to the second direction, the steering start pressure of the second working port can be connected to the first working port through the first overflow valve, the shut-off valve, and the second check valve, and is instantly unloaded to the return oil channel; When the steering stops, the inertial load of the wheeled construction machinery causes pressure fluctuations in the two chambers of the steering cylinder, causing the first and second working ports of the steering valve to alternately supply oil. When the first working port supplies oil, the pressure in the first working port opens the first relief valve, which, after passing through the middle oil passage of the shut-off valve, opens the second check valve, connecting the first and second working ports. At the same time, the pressure in the first working port reaches the first control end of the shut-off valve through the first damper, causing the shut-off valve to switch to the left position, thus disconnecting the first and second working ports, thereby achieving a short-term unloading from the first working port to the second working port. When the second working port supplies oil, the pressure in the second working port opens the second relief valve, which, after passing through the middle oil passage of the shut-off valve, opens the first check valve, connecting the second and first working ports. At the same time, the pressure in the second working port reaches the second control end of the shut-off valve through the second damper, causing the shut-off valve to switch to the right position, thus disconnecting the second and first working ports, thereby achieving a short-term unloading from the high-pressure oil in the second working port to the low-pressure oil in the first working port. This process repeats, reducing the impact of steering stop.

12. A steering system, characterized in that, It includes a steering cylinder, a coaxial flow amplification steering gear, a pilot pump, a load-sensitive pump, a priority valve, an electric control handle, and the steering valve as described in claim 9; The pilot port of the steering valve is connected to the pilot pump supply port, and the return port and unloading port are connected to the return flow channel respectively; the first load feedback port of the steering valve is connected to the priority valve control port and the variable displacement control port of the load-sensitive pump. The load feedback port of the coaxial flow amplifier steering gear is connected to the second load feedback port of the steering valve; the first working port of the coaxial flow amplifier steering gear is connected to the first working port of the steering valve; the first working port of the coaxial flow amplifier steering gear is connected to the second working port of the steering valve; the load feedback port of the coaxial flow amplifier steering gear is connected to the return oil port of the coaxial flow amplifier steering gear; the return oil port of the coaxial flow amplifier steering gear is connected to the return oil flow channel. The oil inlet of the priority valve is connected to the oil supply port of the load-sensitive pump, the oil inlet of the steering valve is connected to the steering oil supply port of the priority valve and the oil inlet of the coaxial flow amplifier steering gear, and the first working port and the second working port of the steering valve are connected to the two working ports of the steering cylinder. The electric control handle includes a signal controller connected to the electromagnets of the first and second proportional solenoid valves. The controller converts the handle rotation angle signal of the electric control handle into a corresponding pilot control current for the electromagnets of the first and second proportional solenoid valves, thereby controlling the pilot control pressure output by the first and second proportional solenoid valves to achieve directional valve switching.

13. The steering system according to claim 12, characterized in that, When turning in the first direction: by moving the electric control handle, the signal controller will convert the handle rotation angle signal of the electric control handle into a corresponding pilot control current and send it to the electromagnet of the first proportional solenoid valve. The first proportional solenoid valve outputs pilot control pressure to the first control end of the reversing valve, controlling the reversing valve to switch to the first position, so that the first working port of the steering valve supplies oil and the second working port returns oil, thereby driving the steering cylinder to move. The steering load pressure during steering is fed back to the priority valve control port and the variable displacement control port of the load sensitive pump through the LS decomposition valve and the first load feedback port, so as to realize priority steering and the load sensitive pump outputs steering flow on demand; When turning in the second direction: by moving the electric control handle, the signal controller converts the handle rotation angle signal into a corresponding pilot control current and sends it to the electromagnet of the second proportional solenoid valve. The second proportional solenoid valve outputs pilot control pressure to the second control terminal of the directional valve, controlling the directional valve to switch to the second working position, so that the second working port of the steering valve supplies oil and the first working port returns oil, thereby driving the steering cylinder to move. The steering load pressure during steering is fed back to the priority valve control port and the variable displacement control port of the load sensitive pump through the LS decomposition valve and the first load feedback port, realizing priority steering and the load sensitive pump outputting steering flow as needed.

14. An engineering machinery, characterized in that, It is equipped with the steering system according to any one of claims 10 to 13.

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