Hydraulic control valve for hydro-pneumatic suspension, hydraulic system for hydro-pneumatic suspension and working machine

Abstract

This application belongs to the field of work machinery technology and provides a hydropneumatic suspension hydraulic control valve, a hydropneumatic suspension hydraulic system, and work machinery. The hydropneumatic suspension hydraulic control valve has a first oil port, a second oil port, a third oil port, and a fourth oil port. The valve also includes a first oil passage and a second oil passage. The first oil passage connects the first oil port and the fourth oil port, and the second oil passage connects the second oil port and the third oil port. A first shut-off valve for controlling on / off is installed on the first oil passage, and a second shut-off valve for controlling on / off is installed on the second oil passage. The first and second shut-off valves are hydraulically controlled directional valves, and a connecting channel is provided between their hydraulically controlled directional ports. A pilot control valve for controlling on / off is installed between the connecting channel and the pilot oil source inlet. This valve has a simple control logic and produces minimal vehicle body posture oscillation when performing rigid-flexible support switching control.

Description

Technical Field

[0001] This application belongs to the field of operating machinery technology, specifically relating to a hydraulic control valve for an air-pneumatic suspension, an air-pneumatic suspension hydraulic system, and operating machinery. Background Technology

[0002] To achieve the switching between rigid and flexible support, existing hydropneumatic suspension systems employ a cross-circuit connection architecture between the left and right suspension cylinders. Specifically, the rodless chamber of the left suspension cylinder is connected to the rod chamber of the right cylinder, and vice versa. Two independent solenoid valves control the opening and closing of the left cross-circuit (left cylinder rod chamber - right cylinder rodless chamber) and the right cross-circuit (right cylinder rod chamber - left cylinder rodless chamber), thereby enabling the system to switch between rigid and flexible support.

[0003] In this system, when switching between flexible supports, the controller needs to send two separate control signals to control the two solenoid valves. Due to signal asynchrony and solenoid valve response delays, hydraulic coupling oscillations may sometimes occur during switching, causing fluctuations in the vehicle's attitude. Furthermore, the independent control of the two solenoid valves increases the complexity of the system control. Utility Model Content

[0004] In view of the above-mentioned defects or deficiencies, this application provides a hydraulic control valve for hydropneumatic suspension, a hydraulic system for hydropneumatic suspension, and a working machine, aiming to solve the technical problems of complex stiffness and flexibility support switching control of existing hydropneumatic suspension systems, which are prone to causing vehicle body posture fluctuations.

[0005] To achieve the above objectives, this application provides a hydraulic control valve for an air-pneumatic suspension system. The valve has a first port, a second port, a third port, and a fourth port. The first and second ports are connected to the rod-side and rodless-side chambers of the left suspension cylinder, respectively, and the third and fourth ports are connected to the rod-side and rodless-side chambers of the right suspension cylinder, respectively. The valve also includes a first oil passage and a second oil passage. The first oil passage connects to the first and fourth ports, and the second oil passage connects to the second and third ports. A first shut-off valve for controlling on / off switching is provided on the first oil passage, and a second shut-off valve for controlling on / off switching is provided on the second oil passage. The first and second shut-off valves are hydraulically controlled directional valves, and a connecting channel is provided between their hydraulically controlled directional ports. A pilot control valve for controlling on / off switching is provided between the connecting channel and the pilot oil source inlet.

[0006] In this embodiment, the hydraulic control valve of the air suspension is also provided with an oil inlet and an oil return port. The pilot control valve is connected to the oil inlet, the oil return port and the connecting channel respectively. The pilot control valve is used to control the connecting channel to selectively connect with the oil inlet or the oil return port.

[0007] In this embodiment, a pressure reducing valve is also provided between the pilot control valve and the oil inlet.

[0008] In this embodiment, the hydraulic control valve for the hydropneumatic suspension is further provided with an oil inlet and an oil return port. The first oil port and the third oil port are respectively connected to the oil inlet oil circuit, and the second oil port and the third oil port are respectively connected to the oil return port oil circuit. A first oil inlet control valve for controlling the on / off state is provided between the oil inlet and the first oil port, a second oil inlet control valve for controlling the on / off state is provided between the oil inlet and the third oil port, a first oil return control valve for controlling the on / off state is provided between the oil return port and the second oil port, and a second oil return control valve for controlling the on / off state is provided between the oil return port and the fourth oil port.

[0009] In this embodiment, the first return oil control valve and the second return oil control valve have a bidirectional flow relief valve position and a one-way shut-off valve position, respectively. The one-way shut-off valve position is configured to open when hydraulic oil flows from the return oil port to the second oil port or the fourth oil port and to shut off in the reverse direction.

[0010] In this embodiment, flow control valves are respectively provided between the oil inlet and the first oil inlet control valve, and between the oil inlet and the second oil inlet control valve.

[0011] In this embodiment, the hydraulic control valve of the hydropneumatic suspension is further provided with a first buffer port and a second buffer port for connecting to the accumulator respectively. The first oil passage is also connected to the first buffer port, and the second oil passage is also connected to the second buffer port.

[0012] To achieve the above objectives, this application also provides an oil-pneumatic suspension hydraulic system, wherein the oil-pneumatic suspension hydraulic system includes the aforementioned oil-pneumatic suspension hydraulic control valve, a left suspension cylinder, and a right suspension cylinder, wherein the rod-side chamber and rodless chamber of the left suspension cylinder are respectively connected to the first oil port and the second oil port; and the rod-side chamber and rodless chamber of the right suspension cylinder are respectively connected to the third oil port and the fourth oil port.

[0013] In this embodiment, the hydraulic control valve of the hydropneumatic suspension is further provided with a first buffer port and a second buffer port. The first oil passage is also connected to the first buffer port, and the second oil passage is also connected to the second buffer port. The hydropneumatic suspension hydraulic system also includes a first hydropneumatic accumulator and a second hydropneumatic accumulator. The first hydropneumatic accumulator is connected to the first buffer port, and the second hydropneumatic accumulator is connected to the second buffer port.

[0014] To achieve the above objectives, this application also provides a working machine, wherein the working machine includes the above-described oil-gas suspension hydraulic system.

[0015] Through the above technical solution, the hydraulic control valve for the hydropneumatic suspension provided in this application embodiment has the following beneficial effects: In this embodiment, the hydraulic control valve for the air-pneumatic suspension integrates the first and second shut-off valves onto the same valve body. By directly creating a connecting channel within the valve body, the hydraulic control reversing ports of the first and second shut-off valves are physically connected. This not only optimizes the arrangement of hydraulic components but also facilitates the synchronous control of the first and second shut-off valves. When switching between rigid and flexible support in the vehicle suspension, this control valve only needs to control the pilot control valve to synchronously connect or disconnect the first and second oil passages. This completely avoids the problem of vehicle body posture oscillation caused by asynchronous operation of the first and second shut-off valves. Furthermore, the control logic is simple, requiring only a single signal to control the pilot control valve.

[0016] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to illustrate the present application and form part of the specification. They are used together with the following detailed description to explain the present application, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the hydraulic principle of the hydropneumatic suspension hydraulic system according to the embodiments of this application; Figure 2 This is a schematic diagram of the hydraulic principle of the hydraulic control valve for the air suspension according to the embodiments of this application.

[0018] Explanation of reference numerals in the attached figures A1, First oil port; B1, Second oil port; A2, Third oil port; B2, Fourth oil port; L1, First oil passage; L2, Second oil passage; L3, Connecting passage; P, Oil inlet; T, Oil return port; C1, First buffer oil port; C2, Second buffer oil port; 11, First shut-off valve; 12, Second shut-off valve; 13, Pilot control valve; 14, Pressure reducing valve; 15, First oil inlet control valve; 16, Second oil inlet control valve; 17, First oil return control valve; 18, Second oil return control valve; 19, Flow control valve; 21, Left suspension cylinder; 22, Right suspension cylinder; 31, First oil-gas accumulator; 32, Second oil-gas accumulator. Detailed Implementation

[0019] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this application.

[0020] The hydraulic control valve for the air suspension of this application is described below with reference to the accompanying drawings.

[0021] This application provides a hydraulic control valve for an oil-pneumatic suspension, such as... Figure 1 and Figure 2As shown, the valve body of the hydropneumatic suspension hydraulic control valve is provided with a first oil port A1, a second oil port B1, a third oil port A2 and a fourth oil port B2. The first oil port A1 and the second oil port B1 are used to connect the rod chamber and the rodless chamber of the left suspension cylinder 21 respectively, and the third oil port A2 and the fourth oil port B2 are used to connect the rod chamber and the rodless chamber of the right suspension cylinder 22 respectively.

[0022] The valve body of the hydraulic control valve for the hydropneumatic suspension is also provided with a first oil passage L1 and a second oil passage L2. The first oil passage L1 is connected to the first oil port A1 and the fourth oil port B2, and the second oil passage L2 is connected to the second oil port B1 and the third oil port A2. The first oil passage L1 is provided with a first shut-off valve 11 for controlling the on and off, and the second oil passage L2 is provided with a second shut-off valve 12 for controlling the on and off.

[0023] The first shut-off valve 11 and the second shut-off valve 12 are hydraulically controlled directional valves, and a connecting channel L3 is provided between their hydraulically controlled directional ports. A pilot control valve 13 for controlling the on / off state is provided between the connecting channel L3 and the pilot oil source inlet.

[0024] In this embodiment, the hydraulic control valve for the air-pneumatic suspension integrates the first shut-off valve 11 and the second shut-off valve 12 onto the same valve body. By directly creating a connecting channel inside the valve body, the hydraulic control reversing ports of the first shut-off valve 11 and the second shut-off valve 12 can be physically connected. This not only optimizes the arrangement of hydraulic components but also facilitates the synchronous control of the first shut-off valve 11 and the second shut-off valve 12. When switching between rigid and flexible support of the vehicle suspension, this control valve only needs to control the pilot control valve 13 to synchronously connect or disconnect the first oil passage L1 and the second oil passage L2. This completely avoids the problem of vehicle body posture oscillation caused by asynchronous operation of the first shut-off valve 11 and the second shut-off valve 12. Furthermore, the control logic is simple, requiring only a single signal to control the pilot control valve.

[0025] like Figure 1 and Figure 2 As shown, in this embodiment, the hydraulic control valve of the air suspension is also provided with an oil inlet P and an oil return port T. The pilot control valve 13 is connected to the oil inlet P, the oil return port T, and the connecting channel L3 respectively. The pilot control valve 13 is used to control the connecting channel L3 to selectively connect with either the oil inlet P or the oil return port T.

[0026] The first shut-off valve 11 and the second shut-off valve 12 have spring ends at one end relative to the hydraulic control reversing port. The spring ends of the two valves are used to control the first shut-off valve 11 and the second shut-off valve 12 to remain in the open valve position under normal conditions. When pressure oil is input, the hydraulic control reversing ports of the two valves will control the first shut-off valve 11 and the second shut-off valve 12 to remain in the shut-off valve position.

[0027] The oil inlet P of the hydraulic control valve for the hydropneumatic suspension serves as the working oil inlet for the first oil inlet A1, the second oil inlet B1, the third oil inlet A2, and the fourth oil inlet B2, and also as the pilot oil inlet for the connecting channel L3.

[0028] When the controller controls the pilot control valve 13 to switch to the valve position where the oil inlet P and the connecting channel L3 are connected, the pressure oil in the oil inlet P will enter the hydraulic control reversing port of the first shut-off valve 11 and the second shut-off valve 12 through the connecting channel L3, driving the first shut-off valve 11 and the second shut-off valve 12 to move synchronously toward the shut-off valve position. The first shut-off valve 11 and the second shut-off valve 12 remain in the shut-off valve position, and the vehicle suspension will switch from flexible support to rigid support.

[0029] When the controller controls the pilot control valve 13 to switch to the valve position where the oil inlet P and the connecting channel L3 are closed, the first shut-off valve 11 and the second shut-off valve 12 will move toward the conducting valve position under the action of the spring. At this time, the vehicle suspension will return from rigid support to flexible support.

[0030] In this embodiment, the pressure at the oil inlet P is generally high. If the shut-off valve is directly driven to switch, it may cause a large switching impact. In order to ensure the smooth switching of the first shut-off valve 11 and the second shut-off valve 12, a pressure reducing valve 14 can be set between the pilot control valve 13 and the oil inlet P to reduce the pressure flowing from the oil inlet P to the pilot control valve 13.

[0031] In this embodiment, the pressure reducing valve 14 can be a pressure reducing valve, a throttle valve, or other valve components.

[0032] like Figure 1 and Figure 2 As shown, in this embodiment, the first oil port A1 and the third oil port A2 are respectively connected to the oil inlet P, and the second oil port B1 and the third oil port A2 are respectively connected to the oil return port T. A first oil inlet control valve 15 for controlling the on / off state is provided between the oil inlet P and the first oil port A1, a second oil inlet control valve 16 for controlling the on / off state is provided between the oil inlet P and the third oil port A2, a first oil return control valve 17 for controlling the on / off state is provided between the oil return port T and the second oil port B1, and a second oil return control valve 18 for controlling the on / off state is provided between the oil return port T and the fourth oil port B2. Through the cooperation of the first oil inlet control valve 15, the second oil inlet control valve 16, the first oil return control valve 17, and the second oil return control valve 18, the overall lifting function of the vehicle suspension can be easily realized.

[0033] Specifically, such as Figure 1 and Figure 2As shown, in the flexible support state, when the entire vehicle needs to be lifted, the first oil inlet control valve 15 and the second oil inlet control valve 16 are switched to the open valve position, and the first oil return control valve 17 and the second oil return control valve 18 are kept in the shut-off valve position. At this time, the pressure oil at the oil inlet P will flow to the first oil port A1, the third oil port A2, and through the first oil passage and the second oil passage to the second oil port B1 and the fourth oil port B2, respectively. Since the oil at the first oil port A1 and the second oil port B1 both come from the oil inlet P, and the cross-sectional area of ​​the rodless chamber of the suspension cylinder is larger than the cross-sectional area of ​​the rod chamber, when the oil pressure in the two working chambers is the same, the piston of the cylinder will be pushed out under differential action.

[0034] Similarly, since the oil in the third oil port A2 and the fourth oil port B2 both come from the oil inlet P, the right suspension cylinder 22 will also extend under the action of differential. The extension of the two suspension cylinders achieves the lifting of the entire vehicle suspension.

[0035] When the left suspension cylinder 21 extends, oil flows from its rod-side chamber and sequentially through the first oil port A1, the first oil passage L1, and the fourth oil port B2 to the rodless chamber of the right suspension cylinder 22, thus replenishing the rodless chamber of the right suspension cylinder 22. When the right suspension cylinder 22 extends, the hydraulic oil in its rod-side chamber flows sequentially through the third oil port A2, the second oil passage L2, and the second oil port B1 to the rodless chamber of the left suspension cylinder 21, thus replenishing the rodless chamber of the left suspension cylinder 21. This cross-replenishment ensures the normal extension of both suspension cylinders even when the cross-oil circuits and oil source are disconnected.

[0036] like Figure 1 and Figure 2 As shown, in the flexible support state, when the vehicle suspension needs to be lowered, the first return oil control valve 17 and the second return oil control valve 18 are switched to the open valve position, while the first inlet oil control valve 15 and the second inlet oil control valve 16 are kept in the closed valve position. At this time, the working chambers of the left suspension cylinder 21 and the right suspension cylinder 22 are connected to the return oil port T. Driven by the weight of the vehicle, the left suspension cylinder 21 and the right suspension cylinder 22 retract, thereby lowering the vehicle.

[0037] like Figure 1 and Figure 2As shown, in this embodiment, the hydraulic control valve for the air-pneumatic suspension is further provided with a first buffer port C1 and a second buffer port C2 for connecting to the accumulator respectively. The first oil passage L1 is also connected to the first buffer port C1, and the second oil passage L2 is also connected to the second buffer port C2. Connecting the first buffer port C1 and the second buffer port C2 to the accumulator not only enables flexible support of the entire vehicle suspension, but also allows the accumulator to buffer the impact of vehicle chassis fluctuations on the hydraulic cylinder. In addition, through the cooperation of the accumulator with the first inlet control valve 15, the second inlet control valve 16, the first return control valve 17, and the second return control valve 18, the single-sided lifting function of the entire vehicle suspension can be easily realized.

[0038] Taking the lifting of the right side of the entire vehicle as an example, such as Figure 1 and Figure 2 As shown, under the condition of flexible support (with the first shut-off valve 11 and the second shut-off valve 12 in operation), the first oil inlet control valve 15 is opened, and the second oil inlet control valve 16, the first oil return control valve 17, and the second oil return control valve 18 are closed. At this time, the hydraulic oil at the oil inlet P will enter the rod chamber of the left suspension cylinder 21 and the rodless chamber of the right suspension cylinder 22, causing the right suspension cylinder 22 to extend and the left suspension cylinder 21 to retract slightly. When the right suspension cylinder 22 extends and the left suspension cylinder 21 retracts slightly, the hydraulic oil flowing out of the rod chamber of the right suspension cylinder 22 and the rodless chamber of the left suspension cylinder 21 will enter the accumulator through the second buffer port C2 for temporary storage. The accumulator ensures that the vehicle suspension can normally lift one side.

[0039] Taking the right side of the vehicle as an example, under the condition of flexible support, the second return oil control valve 18 is turned on, and the first oil inlet control valve 15, the second oil inlet control valve 16, and the first return oil control valve 17 are turned off. At this time, the rod chamber of the left suspension cylinder 21 and the rodless chamber of the right suspension cylinder 22 are connected to the return oil port T. Since the rodless chamber of the suspension cylinder is the pressure-bearing side of the vehicle weight, under the action of the vehicle's own weight, the rodless chamber of the right suspension cylinder 22 leaks oil, and the right suspension cylinder 22 retracts. Although the retraction of the right suspension cylinder 22 will cause the rod chamber of the right suspension cylinder 22 to suck in oil, the accumulator will release the stored oil, so the left suspension cylinder 21 remains almost stationary.

[0040] In this embodiment, the principle of raising and lowering the left side of the vehicle is similar to that of the right side. The only difference is that when the left side of the vehicle is raised, the second oil inlet control valve 16 is turned on, and when the left side of the vehicle is lowered, the second oil return control valve 18 is turned on.

[0041] like Figure 1 and Figure 2As shown, in this embodiment, the connection between the first buffer port C1 and the first oil passage L1 can mean that when the first shut-off valve 11 is closed, the first buffer port C1 is located on the side near the first oil port A1 and is always connected to the first oil port A1, or it is located on the side near the fourth oil port B2 and is always connected to the fourth oil port B2. Similarly, the connection between the second buffer port C2 and the fourth oil port B2 can mean that when the second shut-off valve 12 is closed, the second buffer port C2 is located on the side near the second oil port B1 and is always connected to the second oil port B1, or it is located on the side near the third oil port A2 and is always connected to the third oil port A2.

[0042] like Figure 1 and Figure 2 As shown, in this embodiment, the hydraulic control valve of the air suspension can also realize the lifting function of each axle under the rigid support of the whole vehicle. Specifically, when the outriggers of the whole vehicle are deployed, and the outriggers lift the chassis and axles off the ground, the first cut-off valve 11 and the second cut-off valve 12 are controlled to be cut off, and the first oil inlet control valve 15, the second oil inlet control valve 16, the first oil return control valve 17, and the second oil return control valve 18 are all turned on. At this time, the left suspension cylinder 21 and the right suspension cylinder 22 will retract. Since the chassis is connected to the outriggers, and the axles are connected to the bottom of the chassis through the suspension cylinders, the axles will be lifted when the left suspension cylinder 21 and the right suspension cylinder 22 retract.

[0043] like Figure 1 and Figure 2 As shown, in this embodiment, the first return oil control valve 17 and the second return oil control valve 18 have a bidirectional flow discharge valve position and a one-way shut-off valve position, respectively. The one-way shut-off valve position is configured to conduct when hydraulic oil flows from the return oil port T to the second oil port B1 or the fourth oil port B2 and to shut off in the reverse direction.

[0044] In this embodiment, flow control valves 19 are respectively provided between the oil inlet P and the first oil inlet control valve 15, and between the oil inlet P and the second oil inlet control valve 16. By providing flow control valves 19, the extension and retraction rate of the suspension cylinder can be easily controlled.

[0045] like Figure 1 As shown, to achieve the above objectives, this application also provides an oil-pneumatic suspension hydraulic system, wherein the oil-pneumatic suspension hydraulic system includes the aforementioned oil-pneumatic suspension hydraulic control valve, a left suspension cylinder 21 and a right suspension cylinder 22, wherein the rod-side chamber and the rodless chamber of the left suspension cylinder 21 are respectively connected to the first oil port A1 and the second oil port B1; and the rod-side chamber and the rodless chamber of the right suspension cylinder 22 are respectively connected to the third oil port A2 and the fourth oil port B2.

[0046] By controlling the first shut-off valve 11 and the second shut-off valve 12 to conduct, the rodless chamber of the left suspension cylinder 21 can be connected to the rod chamber of the right suspension cylinder 22, and the rod chamber of the left suspension cylinder 21 can be connected to the rodless chamber of the right suspension cylinder 22. When the vehicle is driving on uneven ground, the hydraulic oil in the working chambers of the left suspension cylinder 21 and the right suspension cylinder 22 will flow adaptively between the cross-connected working chambers through the first oil passage L1 and the second oil passage L2, so that the stroke of the left suspension cylinder 21 and the right suspension cylinder 22 can match the undulation of the road surface. In this way, the flexible support function of the hydropneumatic suspension hydraulic system is realized.

[0047] By controlling the first shut-off valve 11 and the second shut-off valve 12 to cut off, the left suspension cylinder 21 and the right suspension cylinder 22 can be isolated. When the road surface is uneven, the stroke of the suspension cylinder remains fixed. At this time, the hydraulic system of the air suspension is in a rigid locked state.

[0048] In the rigid-flexible switching, this system only needs to send a single control signal to the pilot control valve 13 to realize the rigid-flexible support switching of the system, which greatly simplifies the control logic. At the same time, when the rigid-flexible support switching is performed, the first shut-off valve 11 and the second shut-off valve 12 can act synchronously, which effectively avoids the problem of vehicle body posture oscillation caused by asynchronous control.

[0049] like Figure 1 As shown, in this embodiment, the hydraulic control valve of the hydropneumatic suspension also has a first buffer port C1 and a second buffer port C2. The first oil passage L1 is also connected to the first buffer port C1, and the second oil passage L2 is also connected to the second buffer port C2. The hydropneumatic suspension hydraulic system also includes a first hydropneumatic accumulator 31 and a second hydropneumatic accumulator 32. The first hydropneumatic accumulator 31 is connected to the first buffer port C1, and the second hydropneumatic accumulator 32 is connected to the second buffer port C2. By setting the accumulator, when the system is performing flexible support, the accumulator can buffer the impact of the external environment on the cylinder, allowing the cylinder to float to a certain extent. At the same time, the accumulator can also store oil and act as a replenishment oil source when the suspension is raised or lowered on one side.

[0050] To achieve the above objectives, this application also provides a work machinery, which includes the aforementioned oil-pneumatic suspension hydraulic system. The work machinery generally includes a chassis with multiple axles and a superstructure working mechanism mounted on the chassis. Since the work machinery adopts all the technical solutions of the above embodiments, it at least possesses the beneficial effects brought by the above embodiments, and will not be repeated here.

[0051] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0052] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0053] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0054] Although embodiments of this application have been described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A hydro-pneumatic suspension control valve, characterized in that The hydraulic control valve for the air suspension is provided with a first oil port (A1), a second oil port (B1), a third oil port (A2), and a fourth oil port (B2). The first oil port (A1) and the second oil port (B1) are used to connect the rod chamber and the rodless chamber of the left suspension cylinder (21) respectively, and the third oil port (A2) and the fourth oil port (B2) are used to connect the rod chamber and the rodless chamber of the right suspension cylinder (22) respectively. The hydraulic control valve for the hydropneumatic suspension is further provided with a first oil passage (L1) and a second oil passage (L2). The first oil passage (L1) is connected to the first oil port (A1) and the fourth oil port (B2). The second oil passage (L2) is connected to the second oil port (B1) and the third oil port (A2). The first oil passage (L1) is provided with a first shut-off valve (11) for controlling the on / off state. The second oil passage (L2) is provided with a second shut-off valve (12) for controlling the on / off state. Among them, the first shut-off valve (11) and the second shut-off valve (12) are hydraulic control directional valves and a connecting channel (L3) is provided between their hydraulic control directional ports. A pilot control valve (13) for controlling the on and off is provided between the connecting channel (L3) and the pilot oil source inlet.

2. The hydrocarbon suspension hydraulic control valve according to claim 1, wherein, The hydraulic control valve for the air suspension is also provided with an oil inlet (P) and an oil return port (T). The pilot control valve (13) is connected to the oil inlet (P), the oil return port (T), and the connecting channel (L3) respectively. The pilot control valve (13) is used to control the connecting channel (L3) to selectively connect with either the oil inlet (P) or the oil return port (T).

3. The hydrocarbon suspension hydraulic control valve according to claim 2, wherein, A pressure reducing valve (14) is also provided between the pilot control valve (13) and the oil inlet (P).

4. The hydrocarbon suspension hydraulic control valve of claim 1, wherein, The hydraulic control valve for the air suspension is also provided with an oil inlet (P) and an oil return port (T). The first oil port (A1) and the third oil port (A2) are respectively connected to the oil inlet (P) oil circuit, and the second oil port (B1) and the third oil port (A2) are respectively connected to the oil return port (T) oil circuit. A first oil inlet control valve (15) for controlling the on / off state is provided between the oil inlet (P) and the first oil port (A1), a second oil inlet control valve (16) for controlling the on / off state is provided between the oil inlet (P) and the third oil port (A2), a first oil return control valve (17) for controlling the on / off state is provided between the oil return port (T) and the second oil port (B1), and a second oil return control valve (18) for controlling the on / off state is provided between the oil return port (T) and the fourth oil port (B2).

5. The hydrocarbon suspension hydraulic control valve of claim 4, wherein, The first return oil control valve (17) and the second return oil control valve (18) have a bidirectional drain valve position and a one-way shut-off valve position, respectively. The one-way shut-off valve position is configured to open when hydraulic oil flows from the return oil port (T) to the second oil port (B1) or the fourth oil port (B2) and to shut off in the reverse direction.

6. The hydrocarbon suspension hydraulic control valve of claim 4, wherein, A flow control valve (19) is provided between the oil inlet (P) and the first oil inlet control valve (15), and between the oil inlet (P) and the second oil inlet control valve (16).

7. The hydraulic control valve for an air suspension according to any one of claims 1 to 6, characterized in that, The hydraulic control valve for the hydropneumatic suspension is also provided with a first buffer port (C1) and a second buffer port (C2) for connecting to the accumulator respectively. The first oil passage (L1) is also connected to the first buffer port (C1), and the second oil passage (L2) is also connected to the second buffer port (C2).

8. A hydrocarbon suspension hydraulic system characterized by, The hydropneumatic suspension hydraulic system includes: The hydraulic control valve for the hydropneumatic suspension according to any one of claims 1 to 7; Left suspension cylinder (21), the rod chamber and rodless chamber of the left suspension cylinder (21) are respectively connected to the first oil port (A1) and the second oil port (B1); The right suspension cylinder (22) has its rod chamber and rodless chamber connected to the third oil port (A2) and the fourth oil port (B2), respectively.

9. The hydro-pneumatic suspension system of claim 8, wherein, The hydraulic control valve of the hydropneumatic suspension is also provided with a first buffer port (C1) and a second buffer port (C2). The first oil passage (L1) is also connected to the first buffer port (C1), and the second oil passage (L2) is also connected to the second buffer port (C2). The hydropneumatic suspension hydraulic system also includes a first hydropneumatic accumulator (31) and a second hydropneumatic accumulator (32). The first hydropneumatic accumulator (31) is connected to the first buffer port (C1), and the second hydropneumatic accumulator (32) is connected to the second buffer port (C2).

10. A work machine characterized by, Includes the hydropneumatic suspension hydraulic system as described in any one of claims 8 to 9.

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